WO2022231429A1

WO2022231429A1 - Head mounted video recording assembly on a user

Info

Publication number: WO2022231429A1
Application number: PCT/NL2022/050231
Authority: WO
Inventors: Samy Ralph Andary; Tessa Sabina MELLEMA
Original assignee: Crescent Technologies B.V.; Crescent Medical
Priority date: 2021-04-28
Filing date: 2022-04-28
Publication date: 2022-11-03

Abstract

The invention relates to a video recording assembly (100) for recording an object area (184) of an object (180) defining an object plane (185), comprising: a carrier frame (110) configured for fitting on a user (10); a video recording device (120) mounted on the carrier frame, and comprising video optics (121) defining a field of view (160) and a focus plane (171) and within the focus plane a target area (172), wherein at least a part of the object is in the field of view and at an object distance (186) from the video optics, and wherein the object plane is substantially parallel to the focus plane; a first light projector (130) mounted on the carrier frame and arranged for projecting first markings on an adjacent area arranged adjacent to the target area and on the object; and a second light projector (140) mounted on the carrier frame and arranged for projecting second markings on the adjacent area and on the object; wherein the first light projector and the second light projector are adapted such that one or more of the first markings and the second markings indicate if the object area is within the target area; and wherein the first light projector and the second light projector are adapted such that one or more of the first markings and the second markings indicate if the object plane and the focus plane match.

Description

HEAD MOUNTED VIDEO RECORDING ASSEMBLY ON A USER

FIELD OF THE INVENTION

The invention relates to a video recording assembly mountable on a user. The invention more specifically relates to a recording assembly for high quality recording instruction videos specifically in the medical area.

BACKGROUND OF THE INVENTION

US2020192089 (A1) discloses a head-worn adaptive display. This disclosure concerns an interactive head- mounted eyepiece with an integrated processor for handling content for display and an integrated image source for introducing the content to an optical assembly through which the user views a surrounding environment and the displayed content. The optical assembly includes absorptive polarizers or anti-reflective coatings to reduce stray light.

US2013278631 (A1) discloses a 3D positioning of augmented reality information. Disclosed is a system and method for providing informational labels with perceived depth in the field of view of a user of a head mounted display device. In one embodiment, the method includes determining a physical location of the user and the head mounted display device, and identifying and determining a distance from the user to one or more objects of interest in the user's field of view. Using the distance from the user for each object, one can calculate a disparity value for viewing each object. The processor of the head mounted device may gather information concerning each of the objects in which the user is interested. The head mounted display device then provides a label for each of the objects and for each eye of the user, and, using the disparity values, places the labels within the field of view of the user.

Although the head-worn adaptive display of US2020192089 (A1) as well as the system for 3D positioning of augmented reality information of US2013278631 (A1) may be used to record the looked at area, no feedback is given to the user wearing the display or system what is in view and what is in focus. Furthermore, the display and system are highly complex devices using considerable amounts of energy. Furthermore, the system and display are relatively heavy while being worn as a typical glass on the nose and ears causing irritation and sore spots. Further, the system or display resting on nose and eras and may shift relative to the head and thus eyes causing misalignment between system and display versus eyes.

SUMMARY OF THE INVENTION

An object of the invention is to overcome one or more of the disadvantages mentioned above.

According to a first aspect of the invention, a video recording assembly for recording an object area of an object defining an object plane, comprising:

- a carrier frame configured for fitting on a user;

- a video recording device mounted on the carrier frame, and comprising video optics defining a field of view and a focus plane and within the focus plane a target area, wherein at least a part of the object is in the field of view and at an object distance from the video optics, and wherein the object plane is substantially parallel to the focus plane;

- a first light projector mounted on the carrier frame and arranged for projecting first markings on an adjacent area arranged adjacent to the target area and on the object; and

- a second light projector mounted on the carrier frame and arranged for projecting second markings on the adjacent area and on the object; wherein the first light projector and the second light projector are adapted such that one or more of the first markings and the second markings indicate if the object area is within the target area; and wherein the first light projector and the second light projector are adapted such that one or more of the first markings and the second markings indicate if the object plane and the focus plane match.

A video recording assembly mountable on a user may be used to record training or instruction videos for medical procedures. Although the video recording may be done from any viewpoint, it is preferred to take the viewpoint of the medical person performing the procedure, such as the surgeon, for providing the most realistic viewpoint for the instruction video. The same arguments may validly be applied to other fields outside the medical profession. A video recording assembly mountable on a user may be a video recording assembly mountable on a user for recording an instruction video, such as a medical instruction video. A video recording assembly mountable on a user may be a video recording assembly mountable on a user for recording the viewpoint of an actor, such as a medical actor or surgeon, performing some specific duty subject of the instruction video.

The video recording assembly records an object. The object may be anything. Typically, not the whole object is recorded, but only an object area, which is a part of the object. As an example, the object may be a person and the object area may be an area operated on. The object area operated on may be an opening in the skin on a patient, wherein the object area is below the skin. The object area may be an organ or part of an organ of the patient. The object area or object surface is typically a flat or substantially flat area or surface defining an object plane. In case of a curved object area, the object plane is arranged such that the object plane averages/flattens the object area or is an equalized object area. The object plane may for example be the skin around the object area.

The carrier frame configured for mounting on the user is typically mounted close to the eyes of the user for specifically capturing the viewpoint of the user. Close to the eyes may be considered the body, chest, shoulders, neck or head. Specifically, if the carrier frame is mounted on the head, such as fixated or fitted on the head, the carrier frame typically turns together with the head. And as the eyes are typically looking at a specific downward angle, specifically when performing a strenuous task such as an operation, the assembly typically records the object area viewed by the eyes of the user.

The video recording device comprises video optics defining a focus plane and a field of view. The focus plane comprises a target area. The target area is typically in the field of view. The target area is typically centred to the field of view. The target area is typically centred in the focus plane. The field of view is typically expressed in an angle. The focus plane and target area are typically expressed in square metre, centimetre, or millimetre. The target area is arranged as part of the focus plane. The video recording device may be a relatively simple video camera. The device is directed to the target area for recording of the target area. The target area typically at least partly coincides with the viewing area of the user. The focus plane may alternatively be seen as having a particular thickness, wherein everything within the focus plane having a particular thickness is considered in focus. The thickness may be defined as the depth of field. The thickness varies with the optics and/or the required sharpness of the details in the recording. The thickness of the focus plane may vary in a range of 0 cm to 30 cm, preferably 0 cm to 10 cm, more preferably 0 cm to 4 cm, most preferably 0 cm to 2 cm. In a particular case, when operating on tiny structures in for example a patient, such as during brain surgery, wherein the surgeon is aided by a microscope, the range of the focus plane thickness may well be in the sub-centimetre range, wherein the thickness of the focus plane is based on the optics of the video recording device and/or the microscope. The focus plane may alternatively be named a focus cuboid. The distance between the focus plane and the video optics may be defined as the focal distance. The focal distance may be a range, which range may define a depth of field.

The first and second light projectors are arranged for projecting markings. The markings may be visual indicators or visual markings. The projected markings are projected on an adjacent area. The adjacent area is adjacent to the target area. The adjacent area is typically positioned as a border bordering, encircling or around the target area. The adjacent area may be within, outside or partly inside the field of view. The markings may be visualised by the markings lighting up compared to the immediate surrounding area, or by the markings causing a shade compared to the immediate surrounding area. Further, light used for providing a contrast for visually identifying the position and shape of the markings may be plane white light or coloured light, such as a primary colour or a combination, such as one of the colours blue, red, green, yellow, cyan or magenta or a combination.

The video recording device, the first light projector and the second light projector are all arranged to the carrier frame. As the carrier frame is mountable on the user, the device and two projectors are advantageously easily turned toward the area viewed by the user by the user moving himself or herself. Further, by mounting the device and two projectors on the carrier frame, the assembly is easily placed on and/or removed from the body or the head.

One or more, preferably all, of the first markings and the second markings are adapted for bordering the target area for indicating the target area. That one or more of the markings are adapted for may be interpreted as that one or more of the markings are positioned and/or shaped to indicated the target area. Indicating the target area may be locating the position and/or the shape of the target area based on one or more of the markings. The one or more markings used for indicating the target area typically have a shape mirroring the shape of the edge of the target area. As an example, if the target area has a section with a straight edge, a marking may comprise a straight edge arranged adjacent or adjoint to this straight edge of the target area. As another example, if the target area has a section with a curved edge, a marking may comprise a mirrored similar curved edge arranged adjacent or adjoint to this curved edge of the target area for following this curved edge. The indication of the target area allows the user to bring the object area in the target area by moving the video recording assembly.

One or more, possibly all, of the first markings and the second markings are adapted for indicating a match between the focus plane and the object plane. Typically, if the focus plane and the object plane match, the object is in focus of the video recording device. Typically, if the focus plane and the object plane match, the object area is in focus. Typically, if the focus plane and the object plane match, the adjacent area on the object is in focus. As the focus plane may have a predefined or particular thickness and/or the object plane may be based on a flattened object area, tilting of the focus plane relative to the object plane may be accommodated for within the field of view. That one or more of the markings are adapted for, may be interpreted as that one or more of the markings are positioned and/or shaped to indicated the match between the focus plane and the object plane. Indicating the match between the focus plane and the object plane may be based on one or more of the markings. Typically, the match is indicated by a marking from the first light projector cooperating with a marking from the second light projector. As the first light projector and the second light projector are physical objects which are placed alongside each other or spaced at a distance, the markings from the respective projectors are thus projected on the adjacent area under different angles, such as under converging or diverging angles. It is an insight of the inventor that when the assembly is moved closer to or away from the target area, the relative position, such as the distance, between the cooperating markings will change. The cooperating markings are typically shaped and positioned in the adjacent area such that when the focus plane and the object plane match or the object area is in focus, the cooperating markings touch, are adjoint or make contact with each other. And typically, the cooperating markings are shaped and positioned in the adjacent area such that, when the focus plane and the object plane have a mismatch or the object area is out of focus, the cooperating markings are spaced apart and/or overlap at least partly. In another example, the cooperating markings are typically shaped and positioned in the adjacent area such that when the focus plane and the object plane match or the object area is in focus, the cooperating markings overlap at least partly, preferably completely with each other.

The first light projector and the second light projector projecting respectively the first and the second markings provide a straightforward and intuitive instruction to the user for what is in view and in focus. In view may be also be named in frame, such as in frame of the video recording device, more specific the video optics. Further, as the video recording device may have limited zoom options or even lack zoom options, such as automatic zoom options, the video optics may be reduced in weight, and thus the video recording device may be reduced in weight. Typically, the video recording device is suitable for recording the target area in relatively high quality. Further, the carrier frame carrying the device and the two projectors is typically shaped for intuitive use. Hence, combining markings used for indicating the target area and for indicating if the object area is in view and focus has the technical effect of enhancing intuitiveness of the use of the assembly and/or reducing the information presented to the user. A further technical effect may be that the assembly may be light weight due to the absence of zoom options making that the assembly can be worn over longer periods of time, such as during long surgical procedures, for recording the whole procedure which may be lengthy. A further technical effect may be that due to reusing the markings for two functions, being in view and in focus, the assembly uses less energy and thus may be more suitable to be battery powered. A further technical effect may be that by combining the use of the markings and reducing the amount of information presented to the user, the information becomes simpler for the user and/or more intuitive to the user. A further technical effect is that the markings ensure that the use of the assembly doesn’t distract the user from his primary interest, doesn’t interfere with his primary interest, prevents the attention to be drawn away from his primary interest, such as performing an operation. A further technical effect is that the video recording assembly may be operated handsfree, more specific no manual or hand operation is required to get the target area in view and in focus. A further technical effect is that the video recording assembly may not need any additional setting and/or pre-use calibration before use and/or recording. The assembly may therefore be typed as plug-and-play.

In an embodiment of the video recording assembly, the first markings and the second markings define a set of border markings indicating a border of the target area and a set of focus markings indicating a focus of the object plane. One subset of the first and the second markings are used for indicating the border of the target area. Another subset of the first and the second markings are used for indicating the focus of the object plane and/or the object area. This provides the advantage of clearly identifying the function of a marking allowing to select a more appropriate shape for the marking.

From the embodiment in the detailed description it becomes clear that these subsets may overlap. Typically, when overlapping, for the markings in both subsets, one part, such as a side, of the marking is used for indicating the focus and another part, such as another side, of the marking is used for indicating the border or the edge of the target area. The overlap in subsets provides the advantage of using one marking for two functions further enhancing the selection of an appropriate shape of the marking.

In a further embodiment of the video recording assembly, at least two focus markings are adjoint when the object area is in focus; and the at least two focus markings are not adjoint when the object area is out of focus. This advantageously allows a simple and straightforward indication. Either the object area is in focus or out of focus, thus simple to interpreted binary information is conveyed to the user.

In an even further embodiment of the video recording assembly, the focus markings are shaped to indicate the match between the focus plane and the object plane. This provides the advantage of an intuitive operation of the video recording assembly to the user. In an embodiment of the video recording assembly, at least two focus markings merge to form the shape of a border marking when the focus plane and the object plane match. This allows the markers to have an identical shape or form an identical shape for further increasing the intuitive operation of the video recording assembly by providing symmetry to the view when in focus. It is directly clear to the user that the focus markings should merge when the object plane is almost in focus.

In an embodiment of the video recording assembly, the video optics define that the target area has a substantially rectangular shape; and wherein the first light projector and the second light projector are adapted such that respectively the first markings and the second markings are substantially arranged to a side, preferably halfway the side, of the rectangular shape. The region of interest is typically in the middle of the target area or in the middle of the field of view. The markings on the side may be used as a sort of crosshair for simplifying arranging the region of interest in the middle. In general, the markings may advantageously be seen as augmented reality. The target area is advantageously selected rectangular to match the form of the playback device. Preferably, the rectangular shape advantageously has the ratio of regular television HD television, or computer screen. The minimum number of markings for a rectangular shape may be five markings, wherein 3 markers are border markers each on a side of the rectangle, and 2 markers are focus markers arranged to the fourth side, wherein preferably the focus markers together form the shape of a border when in focus.

In an embodiment of the video recording assembly, the first markings and the second markings total to a number of at least four markings, preferably at least six markings. In a configuration with four markings and a rectangular target area, the four markings may stretch out each along a side of the rectangle, wherein when the markings contact each other in a corner of the rectangle, the object plane is in focus. An example of a configuration with six markings is detailed in the detailed description.

In an embodiment of the video recording assembly, the number of markings is evenly spread over the first light projector and the second light projector. This advantageously requires both light projectors to radiate the same amount of light for projecting the markings. In a preferred embodiment, the projections of the first markings have a mirrored configuration of or rotationally symmetric with the second markings advantageously simplifying production.

In a further embodiment of the video recording assembly, the number of border markings and the number of focus markings are both evenly spread over the first light projector and the second light projector further enhancing one or more of the advantages mentioned in the preceding paragraph.

In a further embodiment of the video recording assembly, a border marking is projected respectively adjacent to the left side and the right side of the rectangular shape; and wherein the focus markings are projected respectively adjacent to the top and the bottom side of the rectangular shape. This advantageously allows the six markings to form a crosshair or crosshair like shape when in focus for advantageously drawing more attention of the user to the centre part of the target area or centring the object plane to the target area. This centring may advantageously increase the usability of the recording for e g. instruction videos, such as instruction videos for educating medical personal, such as surgeons.

In an embodiment of the video recording assembly, the first markings and/or the second markings advantageously comprise a marking part adjoint or substantially adjoint to the target area.

In an embodiment of the video recording assembly, the video recording assembly advantageously comprises a video camera.

In an embodiment of the video recording assembly, the video recording assembly comprises a first video camera and a second video camera mutually aligned and having overlapping target areas. In a further embodiment the first and the second video camera are identical or almost identical for stereoscopic recording of the target area for providing a 3D recording. In a further embodiment the first and the second video camera provide a different field of view or angular aperture. This may be accomplished using different video optics for the different video cameras. The video camera with the wide field of view may provide an overview to the viewer of the recording. The video camera with the narrow field of view may provide details to the viewer of the recording. This may advantageously be used when the viewer of the recording needs to have an overview of the target area as well as a detailed view ofthe target area. Typically, the field of views of the video cameras are centred or substantially centred to each other at the focus plane advantageously allowing quick zooming in and out. Depending on the use of the recording, the viewer may be presented with both recorded stream at the same time or the viewer is presented with one recorded stream at the time and a producer has compiled a mix of the recorded stream. This mix is typically based on if there are larger and/or a lot of movement in the target area. This mix may also be used to compile a video stream with gradually or stepped zooming. In another further embodiment of the first and the second video camera are identical or almost identical wherein only the focal distances ofthe video cameras are different. The focal distances of the camera each define a range of distances wherein the object is in focus for the respective camera. The range of focal distances considered in focus may be typed as a depth of fields or a depth of field is derivable from this range of focal distance. The focal distance may comprise a point of optimum focus. The focal distance and/or the depth of field is typically depending on an aperture arranged to the lens of the camera. The focal distances of the two video cameras are typically selected such that the focal distances are adjacent or partly overlapping for extending the range wherein an object is considered as in focus. This provides the advantage that the focal distance becomes less critical. Furthermore, when the user must move his head closer or further away from the object, the object may advantageously remain or at least be longer in focus. The video camera or video cameras may be a wireless camera or cameras for increasing the freedom of movement of the user.

In an embodiment of the video recording assembly, the video recording device, the first light projector and the second light projector are advantageously arranged on one line, preferably a horizontal line, on the carrier frame. In a further embodiment of the video recording assembly, both light projectors are arranged on opposite sides of the video recording device advantageously providing symmetry or balance. Further, the speed of relative change of a focus marking relative to another cooperating focus marking is based on the distance between the first and the second light projector. If the distance between the light projectors is increased, the speed of change of the distance between the focus markings relative to each other will increase when the distance between the video optics and the object is changed and vice versa. Further, if the distance between the light projectors is increased, the parallax effect of the markings relative to each other as well as relative to the video optics may increase. Also, if the distance between the video recording device, such as the video camera, relative to the eyes of the user increases, the parallax effect may cause the user to be able to observe and work, such as operate, on a target area while this target area is not in view of the viewer watching the video recording of the video recording assembly. The video recording device, such as the video camera, is advantageously placed close to the eyes of the user. Further, the distance between the light projector is advantageously tuned to the thickness of the focus plane or the range of focal distances designated as in focus.

In an embodiment of the video recording assembly, the carrier frame is adapted for fitting on the head of the user. This advantageously allows to arrange the video recording device close to the eyes of the user minimizing the parallax effect between the eyes of the user and the video recording device. This advantageously allows a platform for the video recording assembly that typically allows to align the target area with the field of view of the eyes of the user, as the user is typically looking straight forward. In a further embodiment of the video recording assembly, wherein preferably the carrier frame comprises a headband configure for wearing the carrier frame on the head of the user. This headband advantageously allows the carrier frame to be more adaptable to different hairstyles of the user. In a further embodiment of the video recording assembly, the headband comprises an overhead band for advantageously balancing the video recording assembly on the head of the user. Even further, enhancing the adaptability of the headband to different hairstyles of the user.

In an embodiment of the video recording assembly, recording the object area comprises generating a video stream; and the video recording assembly comprises a controller arranged for:

- receiving the video stream comprising images;

- determining a focus area in an image of the video stream;

- determining a focus value of the focus area, wherein the focus value is based on matching of the focus plane and the object plane; and

- providing the focus value, preferably to the user and/or an operator. This allows for automated feedback to the user of the operator. This may typically be used to align video camera and light projectors, such as during production or during setting an offset before a recording. This offset may be used to pre-align/align in advance the video camera to another focal distance compared to the light projector. This offset may be useful for example when the area operated on being the object area is in an elevated position or a recessed position compared to the adjacent area, such as surrounding skin whereupon the markings are projected. This advantageously allows the object area, typically centred to the target area, to be placed in focus by the user with the help of the markings, more specific the focus markings.

In an embodiment of the video recording assembly, the first light projector and/or the second light projector comprise:

- a light source; and

- a mask arranged to the light source and having openings for projecting the markings. This is a simple to produce solution for projecting markings.

In a further embodiment of the video recording assembly, the first light projector and/or the second light projector further comprise adaptation means arranged to the light source and/or the mask for adapting the position of the markings in the adjacent area. More specific, the adjustment means allow to adapt the focal distance, such as introducing an offset. In an embodiment of the video recording assembly the mask is an adaptive mask; and the step of providing comprises adapting the first markings and/or the second markings from respectively the first light projector and/or the second light projector. More specific, the adaptive mask allows to adapt the focal distance, such as introducing an offset.

- a laser; and

- a lens arranged to the laser for projecting the markings. This is a simple to produce solution for projecting markings. A lens can be a simple lens, compound lens, multifocal diffractive lens, diffractive beam splitter, diffractive lens, or diffractive optical element.

In a further embodiment of the video recording assembly, the first light projector and/or the second light projector further comprise adaptation means arranged to the laser and/or the lens for adapting the position of the markings in the adjacent area. This allows to advantageously adapt the target area and/or the focal distance.

In a further embodiment of the video recording assembly, the lens is an adaptive lens; and wherein the step of providing comprises adapting the first markings and/or the second markings from respectively the first light projector and/or the second light projector. This allows to advantageously adapt the target area and/or the focal distance. The adaptive lens may be a repositionable lens and/or a shapeable lens.

In an embodiment of the video recording assembly, the video optics comprise an adaptive lens for adapting the focus plane of the video recording device; and the providing step comprises adapting the adaptive lens.

According to another aspect of the invention, a video recording assembly for recording an object area of an object defining an object plane, comprising: a carrier frame configured for fitting on a user; a first video recording device mounted on the carrier frame, and comprising first video optics defining a first field of view and a first focus plane and within the first focus plane a first target area, wherein at least a part of the object is in the first field of view and at a first object distance from the first video optics, and wherein the object plane is substantially parallel to the first focus plane; a second video recording device mounted on the carrier frame, and comprising second video optics defining a second field of view and a second focus plane and within the second focus plane a second target area, wherein at least a part of the object is in the second field of view and at a second object distance from the second video optics, and wherein the object plane is substantially parallel to the second focus plane; and a light projector mounted on the carrier frame and arranged for projecting light, preferably markings on an adjacent area arranged adjacent to the first and/or second target area and on the object. It is understood that the video recording device is the first video recording device, the first video optics is the video optics, the first field of view is the field of view, the first focus plane is the focus plane, the first target area is the target area, the first object distance is the object distance, the first light projector is the light projector, and the first markings are the markings.

In an embodiment, the first field of view and the second field of view are different and the second target area encompasses the first target area, preferably for allowing zooming on the recorded video streams. The video recording assembly may have the first video camera and the second video camera mutually aligned and typically having overlapping target areas. The first and the second video camera may provide a different field of view or angular aperture. This may be accomplished using different video optics for the different video cameras. The video camera with the wide field of view may provide an overview to the viewer of the recording. The video camera with the narrow field of view may provide details to the viewer of the recording. This may advantageously be used when the viewer of the recording needs to have an overview of the target area as well as a detailed view of the target area. Typically, the field of views of the video cameras are centred or substantially centred to each other at the focus plane advantageously allowing quick zooming in and out. Depending on the use of the recording, the viewer may be presented with both recorded stream at the same time or the viewer is presented with one recorded stream at the time and a producer has compiled a mix of the recorded stream. This mix is typically based on if there are larger and/or a lot of movement in the target area. This mix may also be used to compile a video stream with gradually or stepped zooming. In another embodiment, the first and the second video camera are identical or almost identical wherein only the focal distances of the video cameras are different. The focal distances of the camera each define a range of distances wherein the object is in focus for the respective camera. The range of focal distances considered in focus may be typed as a depth of fields or a depth of field is derivable from this range of focal distance. The focal distance may comprise a point of optimum focus. The focal distance and/or the depth of field is typically depending on an aperture arranged to the lens of the camera. The focal distances of the two video cameras are typically selected such that the focal distances are adjacent or partly overlapping for extending the range wherein an object is considered as in focus. This provides the advantage that the focal distance becomes less critical. Furthermore, when the user must move his head closer or further away from the object, the object may advantageously remain or at least be longer in focus. The video camera or video cameras may be a wireless camera or cameras for increasing the freedom of movement of the user.

In an embodiment, the first focus plane defines a first field of depth, and the second focus plane defines a second field of depth; and the field of depth and the second field of depth are different, preferably partly overlap or are adjacent, more preferably wherein the combination of the field of depth and the second field of depth provides an extended and/or enlarged field of depth such that switching between the video stream from the video recording device and the second video recording device allows to keep the object in focus when the distance between the carrier frame and the object varies.

The video recording assembly typically has the first video camera and the second video camera mutually aligned and typically having overlapping target areas. The first and the second video camera may provide a different field of view or angular aperture. This may be accomplished using different video optics for the different video cameras. The video camera with the wide field of view may provide an overview to the viewer of the recording. The video camera with the narrow field of view may provide details to the viewer of the recording. This may advantageously be used when the viewer of the recording needs to have an overview ofthe target area as well as a detailed view ofthe target area. Typically, the field of views of the video cameras are centred or substantially centred to each other at the focus plane advantageously allowing quick zooming in and out. Depending on the use ofthe recording, the viewer may be presented with both recorded stream at the same time or the viewer is presented with one recorded stream at the time and a producer has compiled a mix ofthe recorded stream. This mix is typically based on if there are larger and/or a lot of movement in the target area. This mix may also be used to compile a video stream with gradually or stepped zooming.

In an embodiment, the target area and the second target area overlap or substantially overlap for providing a 3D recording. The video recording assembly typically has the first video camera and the second video camera mutually aligned and typically having overlapping target areas. The first and the second video camera are identical or almost identical for stereoscopic recording of the target area for providing a 3D recording.

In an embodiment, a second light projector mounted on the carrier frame and arranged for projecting second markings on the adjacent area and on the object; wherein the light projector and the second light projector are adapted such that one or more ofthe markings and the second markings indicate if the object area is within the first target area and/or second target area; and wherein the light projector and the second light projector are adapted such that one or more of the markings and the second markings indicate if the object plane and the focus plane match.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be apparent from and elucidated further with reference to the embodiments described by way of example in the following description and with reference to the accompanying drawings, in which:

Figure 1 schematically shows a perspective view of an embodiment of a video recording assembly;

Figure 2 schematically shows a first perspective view of the projections;

Figure 3 schematically shows a second perspective view ofthe projections;

Figure 4 schematically shows a third perspective view ofthe projections;

Figure 5 schematically shows a view perpendicular to the projection ofthe markings;

Figure 6a, 6b, and 6c show a top view of a first embodiment ofthe projected markings;

Figure 7a, 7b, and 7c show a top view of a second embodiment of the projected markings;

Figure 8a, 8b, and 8c show a top view of a third embodiment ofthe projected markings;

Figure 9a, 9b, and 9c show a top view of a fourth embodiment of the projected markings;

Figure 10a, 10b, and 10c show a top view of a fifth embodiment ofthe projected markings; and

Figure 11 schematically shows an isometric view of an embodiment of a video recording assembly.

The figures are purely diagrammatic and not drawn to scale. In the figures, elements which correspond to elements already described may have the same reference numerals.

LIST OF REFERENCE NUMERALS

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The following figures may detail different embodiments. Embodiments can be combined to reach an enhanced or improved technical effect. These combined embodiments may be mentioned explicitly throughout the text, may be hint upon in the text or may be implicit.

Figure 1 schematically shows a perspective view of an embodiment of a video recording assembly 100. The video recording assembly is or at least a part of the video recording assembly arranged on a user 10, such as arranged on the head 11 of the user.

The video assembly comprises a carrier frame 110, a video recording device 120, a first light projector 130, and a second light projector 140. The video recording device comprises video optics 121. The video assembly may further comprise a light 150, typically a high-power light for providing enough light to an object area for performing a particular task, such as operating on an item or object, e g. tissue, in the object area. The video assembly may comprise an overhead band preventing the carrier frame to slip down over the head. The overhead band may comprise a ring-shaped part 111 . The overhead band may also prevent that the ring-shaped part has to clamp on the head or at least clamp firmly on the head. This prevents the carrier frame to become uncomfortable for the user after several hours of continuous use. The video assembly may comprise an adjustment wheel 112.

The adjustment wheel may rotate the video optics, the first light projector, the second light projector, and the optional light simultaneous. The rotation is typically such that the angle downward can be adjusted to be in alignment with the typical downward viewing angle of the user for optimizing comfort.

Figure 2 schematically shows a first perspective view of the projections. Figure 2 schematically shows the video recording assembly 100. The video assembly comprises a video recording device 120 comprising video optics 121 . The video recording device at least based on the video optics defines a field of view 160. The field of view is typically diverging. When the field of view has a rectangular shape, the corners of the field of view 161 , 162, 163, 164 are indicated as diverging lines in Figure 2. The shape may be pyramid shaped with the top of the pyramid at the video recording device. When the field of view has a circular shape, the field of view may have a cone shape with the tip of the cone at the video recording device. Other shapes of the field of view are clear for the skilled person. Further, the video recording device at least based on the video optics defines a focal distance 170. The focal distance is the distance at which an item is recorded with a particular maximum contrast or sharpness. The focal distance is typically a range, wherein when the item is within this range from the video recording device, the recording is considered sharp enough or having enough contrast. All these distances together form a focus plane 171. Alternatively, the focus plane may be typed as a truncated pyramid, a cuboid, a parallelepiped, a rectangular prism, or a quadrangular prism due to the 2D field of view and the focal distance being a range of values or distances providing a thickness to the focus plane. Alternatively, depending on the shape of the field of view, the focus plane may be typed as a cylinder, or a truncated cone due to the 2D field of view and the focal distance being a range of values or distances. The focus plane comprises a target area 172. The target area may stretch out over the complete field of view. Alternatively, the target area may be a selection of the field of view, such as a smaller size than the field of view.

An object 180 may be held at several distances. The object may comprise a feature 183. The object feature or the object comprises an object area 184. The object area is the area that should be recorded while it is in focus and in the field of view. When the object 180 is held at an object distance 186’ from the video optics as shown, which is too close, the object area 184 is out of focus. It is further noted that the object at the edges of the target area may have a different distance from the video optics compared to the object area. It is to be understood that the object area is of interest and thus should lie in the focus plane for obtaining a sharp recording and/or record with high contrast. The object area 184 or object surface may define an object plane 185. The object plane is preferably substantially parallel to the focus plane. Or if under an angle, at least the part of the object plane that is of interest for recording, such as the object area, should fit inside the focus plane, thus fit inside the focal distance range.

Adjacent to the target area 172 is an adjacent area 173. The adjacent area is impinging or projected on the object 180. The adjacent area 173 comprises first markings 190, 191 and second markings 194, 195. The markings may have a triangle shape, but any other shape may be used.

For the adjacent area 173, the first marking 190 contacts the second marking 194, and the first marking 191 contacts the second marking 195 for indicating that the object area and/or the object plane is in focus. For the first and second markings to cooperate or contact each other, the markings should have a mirrored side, typically with a high contrast around the side contacting or cooperating with the other marking. A typical example is to select a side shape in the form of a line, such as a triangle. A further advantage of the triangle is that the shape indicates also if the object area is too close to or too far away from the video optics to be in focus. Other shapes for achieving the same effect are envisioned. Typically, the shape of the marking an opposite side from the side contacting another marking should be different to enable distinguishing too far or too close from each other. Further, for the adjacent area 173, the first markings 190, 191 , 192 and the second markings 194, 195, 196 indicate the target area and therefore which part of the object is in the target area. The edge of the markings marking the edge between the adjacent area and the target area is typically straight or substantially straight. In alternative embodiments of the target area, the target area may have circular or oval edges. The edge between the adjacent area and the target area is typically indicated by a sharp and/or with high contrast side of the marking. The side of the marking typically follows the edge for a substantial part.

For the adjacent area 173’, the first marking 190’ is spaced apart from the second marking 194’, and the first marking 191 ’ is spaced apart from the second marking 195’ for indicating that the object area and/or the object plane is out of focus. This indicates that the object or more specific the object area and/or object plane is too close to the video optics.

For the adjacent area 173”, the first marking 190” is spaced apart from the second marking 194”, and the first marking 191 ” is spaced apart from the second marking 195” for indicating that the object area and/or the object plane is out of focus. This indicates that the object or more specific the object area and/or object plane is too far away from the video optics.

Figure 3 schematically shows a second perspective view of the projections. With reference to Figure 2, similar numbers have a similar meaning. Further, when the object 180 is held at an object distance 186 from the video optics as shown, which is at the optimum distance, the object area 184 is in focus.

Figure 4 schematically shows a third perspective view of the projections. With reference to Figure 2, similar numbers have a similar meaning. Further, when the object 180 is held at an object distance 186” from the video optics as shown, which is too far away, the object area 184 is out of focus.

Figure 5 schematically shows a view perpendicular to the projection of the markings. Further, the distances of the adjacent areas 173, 173’, 173” are selected similar to Figure 2. The first light projector 130 and the second light projector 140 project the first and second markings, respectively. On the right side of Figure 3 the markings are shown as seen by the user. In an embodiment of the invention, at least the adjacent area comprising the markings used for determining the focus is in the field of view of the video optics. This provides the advantage that when reviewing the recording afterwards it might easily be determined if the object area is in focus.

As the markings, or at least a subset of the markings, cooperate for indicating if the object area is in focus, the markings may also be typed as proximity indicators. Further, as the markings are projected on the object in the adjacent area and the adjacent area may have a different distance from the video optics compared to the object area and/or object plane, the markings may be set at an offset for compensating the difference between these distances such that while the markings are project in the adjacent area the markings correctly indicate when the object area is in focus.

Further, as the markings, or at least a subset of the markings, cooperate for indicating if the object area is in focus, the markings may comprise an indicator for indicating how far the object area and/or the object plane is out of focus. This indication may be qualitative or quantitative. The quantitative indication is typically an analogue indication.

Figure 6a, 6b, and 6c show a top view of a first embodiment of the projected markings. Each of the figures shows the target area 172 at different object distances. Further, each of the figures shows the first markings and the second markings.

Figure 6a shows the first markings 190’, 191 ', 192’, and the second markings 194’, 195’, 196’. For Figure 6a the object distance 186’ is too small, which translates in a misalignment of the focus plane and the object plane. That the object distance is too small is indicated by the misalignment of the first and second markings. More specific the first markings 191 ’, 190’, and the second markings 195’, 194’ do not form a circle, respectively.

Figure 6b shows the first markings 190, 191, 192, and the second markings 194, 195, 196. For Figure 6b the object distance 186 is optimal or almost optimal or within a range considered in focus, which translates in an alignment of the focus plane and the object plane. That the object distance is optimal or almost optimal or within a range considered in focus is indicated by the alignment of the first and second markings. More specific the first markings 191 , 190, and the second markings 195, 194 form a circle, respectively. When the subset of first markings and the second markings align, these markings may form a shape that is symmetrical for more intuitive recognizing the alignment, and/or these markings may form a shape similar to the individual first and second markings for more intuitive recognizing the alignment.

Figure 6c shows the first markings 190”, 191”, 192”, and the second markings 194”, 195”, 196”. For Figure 6c the object distance 186” is too large, which translates in a misalignment of the focus plane and the object plane. That the object distance is too large is indicated by the misalignment of a subset of the first and second markings. More specific the first markings 191”, 190”, and the second markings 195”, 194” do not form a circle, respectively. It should further be noted that the target area and markings scale relative to the object distance.

Figure 7a, 7b, and 7c show a top view of a second embodiment of the projected markings. Figure 7a, 7b, and 7c are similar to Figure 6a, 6b, and 6c, respectively. When a subset of the first markings and the second markings aligns, these aligned markings form almost a semi-circle. Further, the almost straight side of the semi-circle is in fact curved to follow curved side of the target area, which is circular in this embodiment.

Figure 8a, 8b, and 8c show a top view of a third embodiment of the projected markings. Figure 8a, 8b, and 8c are similar to Figure 6a, 6b, and 6c, respectively. When a subset of the first markings and the second markings aligns, these aligned markings form a square equal in size, thus completely or almost completely overlap. When almost in focus, the relation between width and height of the overlapping markings indicates the alignment of the focus plane with the object plane. And if the height and width are equal or almost equal, the focus plane aligns with the object plane.

Figure 9a, 9b, and 9c show a top view of a fourth embodiment of the projected markings. Figure 9a, 9b, and 9c are similar to Figure 6a, 6b, and 6c, respectively.

Figure 10a, 10b, and 10c show a top view of a fifth embodiment of the projected markings. Figure 10a, 10b, and 10c are similar to Figure 6a, 6b, and 6c, respectively. The first and second markings in this embodiment align with the corners of the target area for indicating the target area. Further, the first and second markings or a subset of the first and second markings align with each other to indicate the alignment of the object plane with the focus plane.

Figure 11 schematically shows an isometric view of an embodiment of a video recording assembly 100. The video recording assembly is or at least a part of the video recording assembly may be arranged on a user, such as arranged on the head of the user. The video assembly comprises a carrier frame 110, a first video recording device 120, a light projector 130, and a second video recording device 123. The first video recording device comprises first video optics 121. The second video recording device comprises second video optics 122. The light projector may be a high-power light for providing enough light to an object area for performing a particular task, such as operating on an item or object, e g. tissue, in the object area. The video assembly may comprise an overhead band preventing the carrier frame to slip down over the head. The overhead band may comprise a ring-shaped part 111. The overhead band may also prevent that the ring-shaped part has to clamp on the head or at least clamp firmly on the head. Alternatively, the overhead band may comprise a flexible strap 111 as shown in Figure 11 . This prevents the carrier frame to become uncomfortable for the user after several hours of continuous use.

Examples, embodiments or optional features, whether indicated as non-limiting or not, are not to be understood as limiting the invention as claimed. It should be noted that the figures are purely diagrammatic and not drawn to scale. In the figures, elements which correspond to elements already described may have the same reference numerals.

It will be appreciated that the invention also applies to computer programs, particularly computer programs on or in a carrier, adapted to put the invention into practice. The program may be in the form of a source code, a code intermediate source and an object code such as in a partially compiled form, or in any other form suitable for use in the implementation of the method according to the invention. It will also be appreciated that such a program may have many different architectural designs. For example, a program code implementing the functionality of the method or system according to the invention may be sub-divided into one or more sub-routines. Many different ways of distributing the functionality among these sub-routines will be apparent to the skilled person. The sub-routines may be stored together in one executable file to form a self-contained program. Such an executable file may comprise computer-executable instructions, for example, processor instructions and/or interpreter instructions (e g. Java interpreter instructions). Alternatively, one or more or all of the sub-routines may be stored in at least one external library file and linked with a main program either statically or dynamically, e g. at run-time. The main program contains at least one call to at least one of the sub-routines. The sub-routines may also comprise function calls to each other. An embodiment relating to a computer program product comprises computer-executable instructions corresponding to each processing stage of at least one of the methods set forth herein. These instructions may be sub-divided into sub-routines and/or stored in one or more files that may be linked statically or dynamically. Another embodiment relating to a computer program product comprises computer- executable instructions corresponding to each means of at least one of the systems and/or products set forth herein. These instructions may be sub-divided into sub-routines and/or stored in one or more files that may be linked statically or dynamically.

The carrier of a computer program may be any entity or device capable of carrying the program. For example, the carrier may include a data storage, such as a ROM, for example, a CD ROM or a semiconductor ROM, or a magnetic recording medium, for example, a hard disk. Furthermore, the carrier may be a transmissible carrier such as an electric or optical signal, which may be conveyed via electric or optical cable or by radio or other means. When the program is embodied in such a signal, the carrier may be constituted by such a cable or other device or means. Alternatively, the carrier may be an integrated circuit in which the program is embedded, the integrated circuit being adapted to perform, or used in the performance of, the relevant method.

The term “substantially” herein, such as in “substantially all emission" or in “substantially consists", will be understood by the person skilled in the art. The term “substantially" may also include embodiments with “entirely", “completely", “all", etc. Hence, in embodiments the adjective substantially may also be removed. Where applicable, the term “substantially" may also relate to 90% or higher, such as 95% or higher, especially 99% or higher, even more especially 99.5% or higher, including 100%. The term “comprise" includes also embodiments wherein the term “comprises" means “consists of’.

The term "functionally" will be understood by, and be clear to, a person skilled in the art. The term “substantially" as well as “functionally" may also include embodiments with “entirely", “completely", “all", etc. Hence, in embodiments the adjective functionally may also be removed. When used, for instance in “functionally parallel", a skilled person will understand that the adjective “functionally" includes the term substantially as explained above. Functionally in particular is to be understood to include a configuration of features that allows these features to function as if the adjective “functionally" was not present. The term “functionally" is intended to cover variations in the feature to which it refers, and which variations are such that in the functional use of the feature, possibly in combination with other features it relates to in the invention, that combination of features is able to operate or function. For instance, if an antenna is functionally coupled or functionally connected to a communication device, received electromagnetic signals that are receives by the antenna can be used by the communication device. The word “functionally" as for instance used in “functionally parallel" is used to cover exactly parallel, but also the embodiments that are covered by the word “substantially" explained above. For instance, “functionally parallel" relates to embodiments that in operation function as if the parts are for instance parallel. This covers embodiments for which it is clear to a skilled person that it operates within its intended field of use as if it were parallel.

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein. The devices or apparatus herein are amongst others described during operation. As will be clear to the person skilled in the art, the invention is not limited to methods of operation or devices in operation.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb "to comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the device or apparatus claims enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

The invention further applies to an apparatus or device comprising one or more of the characterising features described in the description and/or shown in the attached drawings. The invention further pertains to a method or process comprising one or more of the characterising features described in the description and/or shown in the attached drawings. The various aspects discussed in this patent can be combined in order to provide additional advantages.

Furthermore, some of the features can form the basis for one or more divisional applications.

Claims

1. Video recording assembly (100) for recording an object area (184) of an object (180) defining an object plane (185), comprising:

- a carrier frame (110) configured for fitting on a user (10);

- a video recording device (120) mounted on the carrier frame, and comprising video optics (121) defining a field of view (160) and a focus plane (171) and within the focus plane a target area (172), wherein at least a part ofthe object is in the field of view and at an object distance (186) from the video optics, and wherein the object plane is substantially parallel to the focus plane;

- a first light projector (130) mounted on the carrier frame and arranged for projecting first markings on an adjacent area arranged adjacent to the target area and on the object; and

- a second light projector (140) mounted on the carrier frame and arranged for projecting second markings on the adjacent area and on the object; wherein the first light projector and the second light projector are adapted such that one or more of the first markings and the second markings indicate if the object area is within the target area; and wherein the first light projector and the second light projector are adapted such that one or more of the first markings and the second markings indicate if the object plane and the focus plane match.

2. Video recording assembly according to the preceding claim, comprising a second video recording device mounted on the carrier frame, and comprising second video optics defining a second field of view and a second focus plane and within the second focus plane a second target area, wherein at least a part of the object is in the second field of view and at a second object distance from the second video optics, and wherein the object plane is substantially parallel to the second focus plane.

3. Video recording assembly according to the preceding claim, wherein the field of view and the second field of view are different and the second target area encompasses the target area, preferably for allowing zooming on the recorded video streams.

4. Video recording assembly according to claim 2, wherein the focus plane defines a field of depth, and the second focus plane defines a second field of depth; and wherein the field of depth and the second field of depth are different, preferably partly overlap or are adjacent, more preferably wherein the combination of the field of depth and the second field of depth provides an extended and/or enlarged field of depth such that switching between the video stream from the video recording device and the second video recording device allows to keep the object in focus when the distance between the carrier frame and the object varies.

5. Video recording assembly according to claim 2, wherein the target area and the second target area overlap or substantially overlap for providing a 3D recording.

6. Video recording assembly according to any ofthe preceding claims, wherein the first markings and the second markings define a set of border markings indicating a border of the target area and a set of focus markings indicating a focus of the object plane.

7. Video recording assembly according to the preceding claim, wherein at least two focus markings are adjoint when the object area is in focus; and wherein the at least two focus markings are not adjoint when the object area is out of focus.

8. Video recording assembly according to the preceding claim, wherein the focus markings are shaped to indicate the match between the focus plane and the object plane.

9. Video recording assembly according to any ofthe preceding claims 6-8, wherein at least two focus markings merge to form the shape of a border marking when the focus plane and the object plane match.

10. Video recording assembly according to any of the preceding claims, wherein the video optics define that the target area has a substantially rectangular shape; and wherein the first light projector and the second light projector are adapted such that respectively the first markings and the second markings are substantially arranged to a side, preferably halfway the side, of the rectangular shape.

11. Video recording assembly according to any of the preceding claims, wherein the first markings and the second markings total to a number of at least four markings, preferably at least six markings.

12. Video recording assembly according to the preceding claim, wherein the number of markings is evenly spread over the first light projector and the second light projector; and wherein preferably, when depending on claim 6, the number of border markings and the number of focus markings are both evenly spread over the first light projector and the second light projector.

13. Video recording assembly according to any of the preceding claims 11-12 also depending on claim 10, wherein a border marking is projected respectively adjacent to the left side and the right side of the rectangular shape; and wherein the focus markings are projected respectively adjacent to the top and the bottom side of the rectangular shape.

14. Video recording assembly according to any of the preceding claims, wherein the first markings and/or the second markings comprise a marking part adjoint or substantially adjoint to the target area.

15. Video recording assembly according to any of the preceding claims, wherein the video recording assembly comprises a video camera; or wherein the video recording assembly comprises a first video camera and a second video camera mutually aligned and having overlapping target areas.

16. Video recording assembly according to any of the preceding claims, wherein the video recording device, the first light projector and the second light projector are arranged on one line, preferably a horizontal line, on the carrier frame; and wherein preferably both light projectors are arranged on opposite sides of the video recording device.

17. Video recording assembly according to any of the preceding claims, wherein the carrier frame is adapted for fitting on the head of the user; and wherein preferably the carrier frame comprises a headband configure for wearing the carrier frame on the head of the user.

18. Video recording assembly according to any of the preceding claims; wherein recording the object area comprises generating a video stream; and wherein the video recording assembly comprises a controller arranged for:

- receiving the video stream comprising images;

- determining a focus area in an image of the video stream;

- determining a focus value of the focus area, wherein the focus value is based on matching ofthe focus plane and the object plane; and

- providing the focus value, preferably to the user and/or an operator.

19. Video recording assembly according to any ofthe preceding claims, wherein the first light projector and/or the second light projector comprise:

- a light source; and

- a mask arranged to the light source and having openings for projecting the markings.

20. Video recording assembly according to any of the preceding claims, when also depending on claim 19, wherein the first light projector and/or the second light projector further comprise adaptation means arranged to the light source and/or the mask for adapting the position of the markings in the adjacent area; or wherein the mask is an adaptive mask; and wherein the step of providing comprises adapting the first markings and/or the second markings from respectively the first light projector and/or the second light projector.

21. Video recording assembly according to any of the preceding claims, wherein the first light projector and/or the second light projector comprise:

- a laser; and

- a lens arranged to the laser for projecting the markings.

22. Video recording assembly according to any of the preceding claims, when also depending on claim 21, wherein the first light projector and/or the second light projector further comprise adaptation means arranged to the laser and/or the lens for adapting the position of the markings in the adjacent area; or wherein the lens is an adaptive lens; and wherein the step of providing comprises adapting the first markings and/or the second markings from respectively the first light projector and/or the second light projector.

23. Video recording assembly according to any of the preceding claims 18-22, wherein the video optics comprise an adaptive lens for adapting the focus plane of the video recording device; and wherein the providing step comprises adapting the adaptive lens.