JP2020000472A - Fundus image spherical face projection system - Google Patents

Abstract

To provide a fundus image spherical face projection system for making it possible to grasp, in a three-dimensional manner, a two-dimensional fundus image output from a super wide-angle fundus camera.SOLUTION: A fundus image spherical face projection system includes: fundus image projection means 2 for projecting a two-dimensional fundus image on a fundus photographed using a super wide-angle fundus camera; and a spherical face-like fundus-shaped spherical face screen 3 simulating the fundus on which the two-dimensional fundus image is projected. The fundus-shaped spherical face screen 3 includes a projection face 32 that largely extends from a hemisphere face 33 to the side of an aperture 31 along a spherical face.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fundus image spherical projection system that projects a two-dimensional fundus image captured by a super-wide-angle fundus camera.

  An ophthalmologist makes a diagnosis based on a fundus image obtained by capturing a fundus image with a fundus camera. The fundus image is also used for explaining symptoms to a patient, medical treatment to be performed, and the like.

  Conventionally, several inventions relating to a fundus camera for photographing a fundus have been proposed. For example, Japanese Patent Application Laid-Open No. 3-162823 proposes a laser scanning fundus camera that scans and projects a laser beam onto a fundus of a subject to capture an image of the fundus (Patent Document 1).

  In addition, as shown in FIG. 7, the conventional fundus camera has a prospective angle of view Ω (hereinafter, “prospect image”) of a fundus image captured when it is assumed that the camera lens is disposed at the center position of the eyeball 5. A wide-angle retinal camera having an angle of about 50 to 60 degrees has been the mainstream, but in recent years, an ultra-wide-angle retinal camera capable of capturing an ultra-wide angle such that the expected angle of view exceeds 60 degrees has been developed. .

JP-A-3-162823

  However, in the conventional fundus camera including the invention described in Patent Literature 1, although the actual shape of the fundus is three-dimensional, the captured fundus image is displayed as a two-dimensional image on a display or the like. There is a problem that it is difficult to convey information. Moreover, the photographed three-dimensional fundus image is deformed by being enlarged or reduced at each position in one image in order to convert it into a predetermined two-dimensional image such as a circle. In particular, with the recent increase in the expected angle of view, the deformation ratio of the image at the outer peripheral position has increased, making it difficult for an ophthalmologist who grasps the stereoscopic image of the retina to accurately grasp the position and size of the affected part. Has become. Furthermore, it is impossible for a patient who does not understand the structure of the fundus to understand correctly even if the explanation is given based on the two-dimensional image.

  The present invention has been made in order to solve the above-described problems, and has a fundus image spherical projection system capable of three-dimensionally grasping a two-dimensional fundus image output from an ultra-wide-angle fundus camera. It is intended to provide.

  SUMMARY OF THE INVENTION A fundus image spherical projection system according to the present invention provides a two-dimensional fundus of a fundus photographed by an ultra-wide-angle fundus camera in order to solve the problem of three-dimensionally grasping a two-dimensional fundus image output from the super-wide-angle fundus camera. A fundus image projection unit for projecting an image; and a spherical fundus spherical screen simulating the fundus for projecting the two-dimensional fundus image.

  Further, as one aspect of the present invention, in order to solve the problem of projecting a two-dimensional fundus image having an estimated angle of view exceeding 180 degrees on a spherical projection surface, the projection surface of the fundus-shaped spherical screen has a hemispherical surface. It may be greatly extended toward the opening side along the spherical surface.

  Further, as one aspect of the present invention, in order to solve the problem that the two-dimensional fundus image projected on the spherical projection surface becomes difficult to see depending on the viewing angle, the projection surface of the fundus-type spherical screen is formed by Lambertian reflection. May be configured as a diffuse reflection surface similar to

  Further, as one aspect of the present invention, in order to solve the problem that the contrast of a two-dimensional fundus image projected on a spherical projection surface is reduced, the projection surface of the fundus-shaped spherical screen has a retroreflective property. It may be configured as a surface having.

  Further, as one aspect of the present invention, it is possible to solve the problem that the luminance of an overlapped image edge portion when projecting a two-dimensional fundus image by a plurality of fundus image projection means is higher than that at a non-overlapping portion. A plurality of divided image projection units that project the divided images obtained by dividing the two-dimensional fundus image from multiple directions according to the number of divisions, and overlap each of the divided images when projecting the divided images. An edge brightness correction unit that corrects the brightness of the image edge to be performed so as to match the brightness of the non-overlapping image.

  In addition, as one aspect of the present invention, in order to solve the problem of making the spherical projection surface easily visible from the opening side, the fundus-shaped spherical screen transmits an image projected from the outer peripheral surface side to the inner peripheral surface side. The fundus image projecting means may project the two-dimensional fundus image on the outer peripheral surface.

  Further, as one aspect of the present invention, in order to solve the problem of grasping a two-dimensional fundus image output from an ultra-wide-angle fundus camera as a virtual stereoscopic image, the fundus-type dome screen is provided with a head-mounted display. May be constituted by a virtual screen composed of:

  According to the present invention, a two-dimensional fundus image output from a super-wide-angle fundus camera can be grasped three-dimensionally.

1 is a perspective view illustrating a first embodiment of a fundus image spherical projection system according to the present invention. FIG. 3 is a schematic vertical cross-sectional view showing an arrangement of a fundus-shaped spherical screen and an enlarged projection lens of a fundus image projecting means in the fundus image spherical projection system of the first embodiment. FIG. 7 is a schematic vertical cross-sectional view showing an arrangement of a fundus-shaped spherical screen and a plurality of divided image projection units in a second embodiment of the fundus image spherical projection system according to the present invention. It is a block diagram showing composition of a fundus image projection means in a second embodiment. FIG. 11 is a schematic vertical cross-sectional view showing a fundus-shaped spherical screen and a plurality of divided image projectors arranged on the outer surface side in a third embodiment of the fundus image spherical projection system according to the present invention. It is a 4th embodiment of the fundus image spherical projection system concerning the present invention, and is a mimetic diagram showing the example realized by the head mount display. It is a longitudinal cross-sectional view which shows the eyeball image | photographed by the conventional wide-angle fundus camera, and an estimated angle of view.

  Hereinafter, a first embodiment of a fundus image spherical projection system according to the present invention will be described with reference to the drawings.

  As shown in FIG. 1, a fundus image spherical projection system 1A according to the first embodiment includes a fundus image projection unit 2 that projects a two-dimensional fundus image, and a fundus-shaped spherical screen 3 that projects the two-dimensional fundus image. Have. Hereinafter, each configuration will be described in detail.

  The fundus image projection means 2 projects a two-dimensional fundus image of the fundus taken by a super-wide-angle fundus camera (not shown), and is a so-called projector. The fundus image projection means 2 in the first embodiment includes an enlargement projection lens 21 that enlarges and projects a two-dimensional fundus image to a predetermined projection angle of view. Note that the projection angle of view is an angle representing a range of an image projected through the magnifying projection lens 21 and is an angle represented by 2θ in FIG.

  Note that the super-wide-angle fundus camera is a fundus camera that can shoot at a prospective angle of view exceeding that of a normal fundus camera or a wide-angle fundus camera, which is about 60 degrees. Examples of the ultra-wide-angle retinal camera include a laser scanning retinal camera and an LED confocal scanner retinal camera, but the photographing method is not particularly limited, and may be selected from existing photographing methods and methods developed in the future. It may be selected appropriately. As the expected angle of view Ω of the super wide-angle fundus camera, Ω> 60 degrees, 70 degrees, 80 degrees, 90 degrees, 100 degrees, 110 degrees, 120 degrees, 130 degrees, 140 degrees, 150 degrees, 160 degrees, 170 degrees, Although 180 degrees, 190 degrees, 200 degrees, 210 degrees, and 220 degrees can be cited, in the first embodiment, it is considered that a super-wide-angle retinal camera having an estimated angle of view Ω exceeding 180 degrees is more preferable. Will be described. Further, the two-dimensional fundus image captured and output by the super-wide-angle fundus camera according to the first embodiment has a larger deformation ratio as it is located closer to the outer periphery than the center.

  The fundus image projection means 2 is connected so as to be able to receive image data output to the super-wide-angle fundus camera, and a two-dimensional fundus image of the fundus taken by the super-wide-angle fundus camera, the first embodiment In this example, a two-dimensional fundus image having an estimated angle of view of about 200 degrees is received, and the two-dimensional fundus image is projected onto the fundus-shaped spherical screen 3 via the magnifying projection lens 21.

  Note that the connection between the fundus image projecting means 2 and the super-wide-angle fundus camera is not limited to the case of direct connection, and as shown in the second to fourth embodiments, the image processing means 23 It may be possible to receive the data through a device such as a computer used as a computer.

  The fundus-shaped spherical screen 3 is a screen formed in a spherical shape simulating the fundus. As shown in FIG. 1, the fundus-shaped spherical screen 3 in the first embodiment takes in the two-dimensional fundus image projected by the fundus image projection means 2 from the opening 31 side and forms a concave and spherical shape inside the fundus image. The two-dimensional fundus image is projected onto the projected projection surface 32.

  The projection surface 32 of the fundus-shaped spherical screen 3 according to the first embodiment is larger than the hemisphere 33 toward the opening 31 along the spherical surface so as to project the entire two-dimensional fundus image having an estimated angle of view of about 200 degrees. Has been extended. That is, as shown in FIG. 2, the fundus-shaped spherical screen 3 is such that, when cut along a plane passing through the spherical center O, the central angle の of the circular arc appearing in the cross section is about 200 degrees or more. Is formed.

  In the first embodiment, two hemispheres each having a spherical concave surface having a radius of about 200 mm (diameter of about 400 mm) are used, and one of the hemispheres is used as the extending portion (the central angle of the arc of a cross section passing through the spherical center O). Cut the other part (the part where the central angle of the arc of the cross section passing through the spherical center O is about 160 degrees) so as to leave the part where θ becomes about 10 degrees (approximately 20 degrees in total), It is formed by combining the remaining ring shape after cutting with the other uncut hemisphere.

  Note that the center angle θ of the arc of the portion to be extended is not limited to about 10 degrees, and may be appropriately selected according to the expected angle of view that can be photographed by the ultra-wide-angle fundus camera. Further, the projection surface 32 in the first embodiment is formed in a true spherical shape, but the eyeball of the actual subject is not a true spherical shape. Therefore, the projection surface 32 is formed in accordance with the shape of an actual patient's eyeball, or when it is difficult to form the projection surface 32 for each patient, a shape approximated to the actual eyeball using the statistical values of the dimensions of a plurality of patients. May be formed.

  Further, since the projection surface 32 of the fundus-shaped spherical screen 3 is spherical, visibility may be reduced depending on the viewing angle. That is, as shown in FIG. 2, the two-dimensional fundus image is incident on the edge 32 a of the projection surface 32 on the opening 31 side at a very low incident angle substantially parallel to the edge 32 a of the projection surface 32. On the other hand, in order to observe the edge 32 a of the projection surface 32 on the side of the opening 31, it is necessary to look through the opening 31. If the projection plane 32 reflects in a state close to specular reflection, the two-dimensional fundus image is reflected toward the back side and cannot be observed from the opening 31 side.

  Therefore, the projection surface 32 of the first embodiment is configured by a diffuse reflection surface approximated to Lambert reflection, which diffuses and reflects uniformly in all directions regardless of the incident angle of the image. Specifically, a matte white paint is applied to the entire projection surface 32 of the fundus-shaped spherical screen 3 to form a diffuse reflection surface similar to Lambertian reflection.

  Note that the color of the projection surface 32 is not limited to white, and a color such as gray may be appropriately selected within a range in which the function of diffuse reflection is exhibited. Further, as shown in the second embodiment, the projection surface 32 may be configured as a surface having a retroreflective characteristic in order to suppress a decrease in luminance and a decrease in contrast due to scattered reflection.

  Next, an example of the arrangement of the fundus image projection means 2 and the fundus-shaped spherical screen 3 in the fundus image spherical projection system 1A of the first embodiment will be described.

  As shown in FIG. 2, the fundus image projecting means 2 is disposed on the opening 31 side of the fundus-shaped spherical screen 3 on a line passing through the spherical center O of the fundus-shaped spherical screen 3 and the center o of the opening surface. That is, the fundus image projection means 2 and the fundus-shaped spherical screen 3 are arranged so as to match the positional relationship between the fundus and the super-wide-angle fundus camera when capturing a two-dimensional fundus image of the fundus.

  At this time, the central angle extending from the hemispherical surface 33 of the fundus-shaped spherical screen 3 toward the opening 31 along the spherical surface is θ, the radius of the projection surface 32 of the fundus-shaped spherical screen 3 is r, and the fundus-shaped spherical surface is When the distance from the spherical center O of the projection surface 32 of the screen 3 to the magnifying projection lens 21 is l, if the projection angle of view of the magnifying projection lens 21 is 2θ or more, the projection light is projected onto the entire projection surface 32. be able to.

  In addition, since the fundus-shaped spherical screen 3 in the first embodiment extends from the hemisphere 33 to the opening side like an eaves, if the distance between the fundus image projecting means 2 and the fundus-shaped spherical screen 3 is too long. Then, the back side of the extended portion becomes shaded, and the two-dimensional fundus image cannot be projected on the projection plane 32. For example, when the distance l from the spherical center O to the magnifying projection lens 21 is infinite, the incident angle is parallel to a line passing through the spherical center O and the center o of the opening surface, and the extended back side is shaded. Become.

Therefore, the distance l from the spherical center O of the fundus-shaped spherical screen 3 capable of projecting the entire two-dimensional fundus image to the projection plane 32 to the magnifying projection lens 21 is the radius r of the projection plane 32 and the central angle of the extended arc. If θ is used, it is expressed by the following equation (1).
l = r / sin θ (1)

  Here, the radius of the projection surface 32 is 200 mm (diameter 400 mm), and the central angle θ of the arc extending toward the opening 31 is 10 degrees (= (the central angle of the projection surface 32 ２００: 200 degrees−the center of the hemisphere 33). (Angle: 180 degrees) ÷ 2), and when substituted into equation (1), the distance 1 from the spherical center O to the magnifying projection lens 21 is about 1152 mm. That is, by using the magnifying projection lens 21 having an angle of view of 2θ or more in the fundus image projection means 2 and disposing it at a distance of about 1152 mm or less with respect to the fundus-shaped spherical screen 3, the entire two-dimensional fundus image can be projected on the projection surface 32. Can be projected to

  Next, the operation of each component in the fundus image spherical projection system 1A of the first embodiment will be described.

  The fundus image projection means 2 receives a two-dimensional fundus image having an estimated angle of view of about 200 degrees captured by a super-wide-angle fundus camera. The fundus image projection means 2 projects the received two-dimensional fundus image toward the projection surface 32 of the fundus-shaped spherical screen 3.

  At this time, in the first embodiment, the two-dimensional fundus image received from the ultra-wide-angle fundus camera has a larger deformation ratio as it is located closer to the outer periphery than the center of the image. On the other hand, since the projection surface 32 of the fundus-shaped spherical screen 3 is formed in a concave and spherical shape, the incident angle becomes larger as it is located closer to the outer periphery than the center of the projection surface 32. The area of one degree angle of view projected on the outer peripheral side is larger than the area of one degree angle of view projected near the center of 32. That is, although the outer peripheral side is reduced by the ultra-wide-angle fundus camera, the projection area on which the two-dimensional fundus image is projected is enlarged. Note that the incident angle is an angle between an incident ray and a normal to the boundary surface at the incident point when light is incident on the boundary surface of the medium.

  Therefore, in the first embodiment, the two-dimensional fundus image projected on the projection plane 32 is projected so as to have the same three-dimensional shape as the fundus and coincide with the position of the corresponding fundus. At this time, when the deformation ratio at which the two-dimensional fundus image is reduced and the ratio at which the two-dimensional fundus image is enlarged by being projected on the spherical projection surface 32 relatively match, the two-dimensional fundus image to be projected is There is no need to correct the deformation ratio.

  In order to observe the fundus image projected on the projection surface 32 of the fundus-shaped spherical screen 3, since the fundus image projecting means 2 is arranged at the front position on the opening 31 side of the fundus-shaped spherical screen 3, the fundus image projecting means is required. Observe as if you are looking in from a position avoiding 2. At this time, in the first embodiment, since the projection surface 32 is formed of a diffuse reflection surface that approximates Lambertian reflection, the projected fundus image can be observed from any angle. In particular, it is possible to sufficiently secure the visibility of a portion extending toward the opening 31 from the hemispherical surface 33 where the projected incident angle is low.

According to the fundus image spherical projection system 1A of the first embodiment as described above, the following effects can be obtained.
1. The two-dimensional fundus image output from the ultra-wide-angle fundus camera can be projected in the same three-dimensional shape as the fundus and so as to match the position of the corresponding fundus.
2. By extending the projection surface 32 more largely toward the opening 31 along the spherical surface than the hemispherical surface 33, it is possible to project the entire two-dimensional fundus image having an expected angle of view exceeding 180 degrees.
3. Since the projection surface 32 is formed of a diffuse reflection surface similar to Lambertian reflection, the projected fundus image can be observed from any angle on the opening 31 side.

  Next, a second embodiment of the fundus image spherical projection system according to the present invention will be described with reference to the drawings. The same or corresponding components as those described in the first embodiment are denoted by the same reference numerals, and the description thereof will not be repeated.

  As shown in FIG. 3, the fundus image spherical projection system 1 </ b> B according to the second embodiment arranges the fundus image projection means 2 at a position shifted from the front position on the opening 31 side of the fundus-shaped spherical screen 3. It is easy to observe the obtained fundus image from the front on the opening 31 side.

  As shown in FIG. 4, the fundus image projection unit 2 according to the second embodiment includes a plurality of divided image projection units 22 that project the divided images obtained by dividing the two-dimensional fundus image from multiple directions according to the number of divisions. An image dividing unit 251 that divides the three-dimensional fundus image, a deformation ratio correcting unit 252 that corrects the deformation ratio of the image with respect to the position of the projection plane 32, and corrects the luminance of an image edge v that overlaps when each of the divided images is projected. And an image processing unit 23 functioning as an edge luminance correction unit 253.

  The divided image projection unit 22 is a projector that projects a divided image obtained by dividing the two-dimensional fundus image. In the second embodiment, as shown in FIG. 3, the two divided image projection units 22 are arranged at positions shifted upward and downward from the front position on the opening 31 side of the fundus-shaped spherical screen 3. I have. The upper divided image projection unit 22 projects the fundus image of the lower half of the projection plane 32, and the lower divided image projection unit 22 projects the fundus image of the upper half of the projection plane 32. In addition, the projection is performed so that the image edges v of adjacent divided images overlap each other so that no blank space occurs between the projected divided images.

  The image processing means 23 corresponds to a computer for executing the fundus image stereoscopic projection program 1a, as shown in FIG. 4, and mainly includes various data such as a two-dimensional fundus image received from an ultra-wide-angle fundus camera. And an arithmetic processing unit 25 that executes arithmetic processing for functioning as an image dividing unit 251, a deformation ratio correcting unit 252, and an edge luminance correcting unit 253.

  The storage unit 24 includes a ROM, a RAM, a hard disk, a flash memory, and the like, stores various data, and functions as a working area when the arithmetic processing unit 25 executes an arithmetic operation. The storage unit 24 in the second embodiment includes a program storage unit 241 that stores a fundus image stereoscopic projection program 1a, a two-dimensional fundus image storage unit 242 that stores a two-dimensional fundus image received from an ultra-wide-angle fundus camera, and image segmentation. A division image storage unit 243 for storing divided images before and after processing by the unit 251, the deformation ratio correction unit 252, and the edge luminance correction unit 253.

  In the program storage unit 241, a fundus image stereoscopic projection program 1a is installed. Then, the arithmetic processing means 25 executes the fundus image stereoscopic projection program 1a, and causes a computer to function as each component described later.

  The usage form of the fundus image stereoscopic projection program 1a is not limited to the above configuration. For example, the fundus image stereoscopic projection program 1a may be stored in a non-transitory computer-readable recording medium such as a CD-ROM or a USB memory, and may be directly read from the recording medium and executed.

  The arithmetic processing means 25 is constituted by a CPU (Central Processing Unit) and the like, and executes the fundus image stereoscopic projection program 1a installed in the storage means 24, thereby causing the computer to execute the image dividing section 251 and the deformation ratio correcting section. 252 and the edge brightness correction unit 253.

  The image dividing unit 251 appropriately divides the two-dimensional fundus image in order to project the two-dimensional fundus image from multiple directions by the plurality of divided image projecting units 22. In the second embodiment, the two-dimensional fundus image is divided into two images, an upper half and an upper half, so that the two upper and lower divided image projectors 22 project the two images.

  The deformation ratio correction unit 252 corrects the deformation ratio of the divided image according to the deformation ratio that is enlarged or reduced by being projected onto the spherical projection surface 32. In the second embodiment, the positional relationship between the fundus and the super-wide-angle fundus camera when capturing a two-dimensional fundus image of the fundus does not match the arrangement of the divided image projection unit 22 and the fundus-shaped spherical screen 3. A difference in the deformation ratio occurs. Therefore, for example, the deformation ratio correction unit 252 adjusts, for each pixel of the divided image divided by the image division unit 251, the deformation ratio to be enlarged or reduced in the two-dimensional fundus image that changes from the center position toward the outer periphery. And the deformation ratio is appropriately corrected so as to match the projected area of the position where each pixel is projected. The method for correcting the deformation ratio is not particularly limited, and a correction method for projecting a two-dimensional image onto a spherical surface can be appropriately applied.

  The edge luminance correction unit 253 corrects the luminance of the overlapping image edge v when projecting each divided image so as to match the luminance of the non-overlapping image. The edge luminance correction unit 253 in the second embodiment corrects the luminance of the overlapping image edge v so that the luminance of the image before overlapping is reduced to １ ／ of the luminance of the image before overlapping. By projecting from the divided image projection units 22, 22, the luminance of the overlapped image edge v is made to match the luminance of the non-overlapping image.

  Then, the divided images processed by the image division unit 251, the deformation ratio correction unit 252, and the edge luminance correction unit 253 are stored in the divided image storage unit 243 and output to the divided image projection units 22, 22, respectively.

  Next, the fundus-shaped spherical screen 3 in the second embodiment will be described. The projection surface 32 of the fundus-shaped spherical screen 3 is configured as a surface having retroreflective characteristics in order to suppress a decrease in contrast due to scattered reflection. Specifically, a retroreflective paint containing glass beads in the paint is applied to the entire projection surface 32 of the fundus-shaped spherical screen 3. In addition, the method of forming the surface having the retroreflective property is not limited to the method of applying the retroreflective paint, and the retroreflective material made of glass beads or the like is fixed to the projection surface 32 with an adhesive. Alternatively, a thin film retroreflective sheet having a retroreflective material attached to its surface may be laid on the projection surface 32.

  In addition, the projection surface 32 in the second embodiment is not limited to the surface having the retroreflection characteristics, and is configured as a diffuse reflection surface similar to Lambertian reflection, similarly to the projection surface 32 in the first embodiment. It may be.

  According to the fundus image spherical projection system 1B of the second embodiment as described above, since the fundus image projection means 2 is not disposed at the front position on the opening 31 side of the fundus-shaped spherical screen 3, the observer can view the projection surface from the front. It is easy to observe because you can look into 32. In addition, by appropriately correcting the deformation ratio corresponding to the position of the projection plane 32 and the luminance of the overlapped image edge v, the two-dimensional fundus image output from the super-wide-angle fundus camera can be obtained, as in the first embodiment. It can be projected so as to have the same three-dimensional shape as the fundus and to match the position of the corresponding fundus. Further, since the surface of the projection surface 32 has a retroreflective characteristic, the two-dimensional fundus image incident from the opening 31 side is reflected in the incident direction and is projected so as to look into the opening 31 side. Even when the fundus image is observed, the contrast is maintained, and the visibility can be improved.

  Next, a third embodiment of the fundus image spherical projection system according to the present invention will be described with reference to the drawings. The same or corresponding components as those described in the first embodiment and the second embodiment are denoted by the same reference numerals and the description thereof will not be repeated.

  As shown in FIG. 5, the fundus image spherical projection system 1C according to the third embodiment is configured by a transmission screen in which the fundus-shaped spherical screen 3 transmits an image projected from the outer peripheral surface 34 side to the inner peripheral surface 35 side. In addition, the two-dimensional fundus image is projected on the outer peripheral surface 34 of the fundus-shaped spherical screen 3.

  The fundus image projection unit 2 has a plurality of divided image projection units 22 and an image processing unit 23 that functions as an image division unit 251, a deformation ratio correction unit 252, and an edge luminance correction unit 253. In the third embodiment, as shown in FIG. 5, the two divided image projection units 22, 22 are positioned at the upper and lower positions on the outer peripheral surface 34 side of the fundus-shaped spherical screen 3 toward the outer peripheral surface 34. Are located. Then, each of the divided image projecting units 22, 22 divides the divided images appropriately divided by the deformation ratio correcting unit 252 and the edge luminance correcting unit 253 by the image dividing unit 251 and outputs the divided images to the outer peripheral surface of the fundus-shaped spherical screen 3. 34 is projected.

  The fundus-shaped spherical screen 3 is configured as a transmission screen that transmits an image projected from the outer peripheral surface 34 side to the inner peripheral surface 35 side. The transmission screen is made of, for example, Japanese paper, polished glass, a transparent resin material processed into a polished glass shape, a milky white resin material, or the like.

  According to the fundus image spherical projection system 1C of the third embodiment as described above, the fundus image projection means 2 is not arranged at all on the opening 31 side of the fundus-shaped spherical screen 3, and the projected fundus image is opened. It can be observed from the front on the 31 side.

  Next, a fourth embodiment of the fundus image spherical projection system according to the present invention will be described with reference to the drawings. The same or corresponding components as those described in the first to third embodiments are denoted by the same reference numerals, and the description thereof will not be repeated.

  The fundus image spherical projection system 1D of the fourth embodiment includes a head-mounted display 4, as shown in FIG. The fundus image projection means 2 is the head cap display 4, and the fundus-shaped spherical screen 3 is a virtual screen 36 constituted by the head cap display 4.

  According to the fundus image spherical projection system 1D of the fourth embodiment, a virtual screen 36 is formed by the head-mounted display 4, and a fundus image captured by an ultra-wide-angle fundus camera is virtually projected on the virtual screen 36. Therefore, the entire projection plane 32 can be observed without placing the realistic fundus image projection unit 2 in the field of view of the observer 6.

  Note that the fundus image spherical projection system according to the present invention is not limited to the above-described embodiment, and can be appropriately changed. For example, the formation of the diffuse reflection surface and the application of the retroreflective paint are not limited to the entire projection surface 32, and may be configured only on a particularly affected portion such as the edge 32 a of the projection surface 32. It may be. Further, the fundus-shaped spherical screen 3 may be configured by a transmission screen, and the two-dimensional fundus image may be projected from the inner peripheral surface 35 having the opening 31 and observed from the outer peripheral surface 34 side.

1A, 1B, 1C, 1D Fundus image spherical projection system
1a fundus image stereoscopic projection program 2 fundus image projection means 3 fundus spherical screen 4 head cloak display 5 eyeball 6 observer 21 magnifying projection lens 22 divided image projection unit 23 image processing means 24 storage means 25 arithmetic processing means 31 aperture 32 projection Surface 32a Edge of projection plane 33 Hemisphere 34 Outer peripheral surface 35 Inner peripheral surface 36 Virtual screen 241 Program storage unit 242 Two-dimensional fundus image storage unit 243 Divided image storage unit 251 Image division unit 252 Deformation ratio correction unit 253 Edge luminance correction Part Ω Estimated angle of view O Ball center o Center of aperture plane 中心 Center angle of projection plane θ Center angle of extended arc r Radius of projection plane l Distance from ball center to magnifying projection lens v Image edge

Claims (7)

Fundus image projection means for projecting a two-dimensional fundus image of the fundus taken by a super-wide-angle fundus camera;
And a spherical fundus-shaped spherical screen simulating the fundus for projecting the two-dimensional fundus image.   The fundus image spherical projection system according to claim 1, wherein a projection surface of the fundus-shaped spherical screen extends to the opening side along a spherical surface more than a hemispherical surface.   The fundus image spherical projection system according to claim 1 or 2, wherein the projection surface of the fundus-shaped spherical screen is configured as a diffuse reflection surface that approximates Lambertian reflection.   The fundus image spherical projection system according to any one of claims 1 to 3, wherein the projection surface of the fundus-shaped spherical screen is configured as a surface having retroreflective characteristics.   The fundus image projection unit includes: a plurality of divided image projection units that project the divided images obtained by dividing the two-dimensional fundus image from multiple directions according to the number of divisions; and an image edge that overlaps when each of the divided images is projected. 5. The fundus image spherical projection system according to claim 1, further comprising: an edge luminance correction unit configured to correct the luminance of the unit to match the luminance of the non-overlapping image.   The fundus-shaped spherical screen is configured by a transmission screen that transmits an image projected from the outer peripheral surface side to the inner peripheral surface side, and the fundus image projection unit projects the two-dimensional fundus image on the outer peripheral surface, A fundus image spherical projection system according to claim 1.   The fundus image spherical projection system according to claim 1 or 2, wherein the fundus-shaped spherical screen is a virtual screen constituted by a head-mounted display.

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