JP5409410B2 - Ophthalmic imaging equipment - Google Patents

Description

  The present invention relates to an ophthalmologic photographing apparatus, and more particularly to an ophthalmic photographing apparatus such as a fundus camera capable of photographing the fundus of a subject's eye in different photographing modes such as monocular photographing and stereo photographing.

  In the fundus camera, after observing the fundus of the subject eye and performing alignment with the subject eye, the photographing light source emits light, and the subject fundus is photographed. As the fundus photographing light source, for example, a U-shaped strobe tube is used (Patent Document 1).

  Further, a ring slit for blocking harmful reflection light of illumination light from the photographing light source and reducing the amount of illumination light is disposed in the illumination optical system. Usually, the ring slit is composed of a plurality of light shielding plates arranged at a position conjugate with several portions of the anterior eye portion of the eye to be examined, such as a crystalline lens and a cornea, and the light shielding plate arranged at a position conjugate with the crystalline lens is a crystalline lens. The light shielding plate arranged at a position conjugate with the cornea shields the harmful reflected light from the cornea. These light shielding plates have different sizes and shapes depending on whether the photographing mode is monocular photographing or stereo photographing, and the light shielding plates are switched according to the photographing mode.

  However, since the light shielding plates constituting the ring slit are arranged at positions very close to each other, it is difficult to provide a light shielding plate replacement mechanism. Therefore, as disclosed in Patent Document 2 below, a configuration is adopted in which the light shielding plate of the ring slit is divided and a part thereof is arranged at different positions.

  Also, since the illumination light incident on the eye to be examined is reflected by the objective lens and becomes a bright spot with a bright center, a black spot plate having a black spot at the center is placed in the optical path of the illumination optical system. The quality of the fundus image is improved by blocking harmful reflected light. The position, shape, size, number, and the like of the black spots on the black spot plate differ depending on whether they are monocular photography or stereo photography (Patent Document 3).

Japanese Utility Model Publication No. 5-27794 JP-A-6-78882 JP 2009-165613 A

  The configuration described in Patent Document 2 employs a structure in which a part of the light shielding plate constituting the ring slit is provided between the perforated mirror and the black spot plate. In this case, the light shielding plate provided between the perforated mirror and the black spot plate serves as a secondary light source due to the slight reflected light of the light shield plate itself, and is a source of the central spot that is to be taken at the black spot. It is desirable to configure so that light is not irradiated.

  In addition, if the light shielding plate disposed between the perforated mirror and the black spot plate has a structure in which a light shielding portion is attached to a transparent glass plate, the reflection of the glass plate becomes a secondary light source, which is not preferable for the same reason as described above.

  Therefore, according to the present invention, even when the fundus of the subject's eye is photographed in various photographing modes, it is possible to acquire a high-quality fundus image with little harmful reflection light from the anterior eye portion (the crystalline lens, cornea) of the subject's eye. It is an object to provide a simple ophthalmologic photographing apparatus.

The present invention
An ophthalmologic photographing apparatus capable of photographing the fundus of the eye to be examined in different photographing modes,
A light source for photographing that emits illumination light for illuminating the fundus during fundus photographing;
A black spot plate that shields harmful reflected light from the objective lens of the illumination light;
A first light-shielding member whose size or position is variable according to an imaging mode disposed at a position conjugate with the eye lens between the imaging light source and the black spot plate;
A perforated mirror for directing illumination light from the imaging light source toward the fundus of the eye to be examined;
A second light-shielding member that is variable in size or position in accordance with an imaging mode disposed at a position conjugate with the eye cornea to be examined between the perforated mirror and the black spot plate,
The second light shielding member and the photographic light source are disposed at an optically conjugate position.

  In such a configuration, since the second light-shielding member and the light source for photographing are arranged at optically almost conjugate positions, the support portion that supports the light-shielding portion of the second light-shielding member is substantially the same as the non-light-emitting portion of the photographing light source. By forming an image at the same corneal position, it is possible to prevent the edge of the support portion from becoming a secondary light source and shining brightly even when the imaging light source emits light. Therefore, the harmful central image due to the reflection from the objective lens by the secondary light source is an image of the light source for light photography and the image of the light shielding part as a whole, there is no locally bright part, and the quality of the fundus image to be photographed is improved. Can be increased.

1 is an optical diagram showing an overall configuration of an ophthalmologic photographing apparatus. It is a front view of the light source for imaging | photography. (A) is a front view of the light-shielding member arranged at a position conjugate with the crystalline lens of the eye to be examined, and (b) is a front view of a diaphragm arranged at a position conjugate with the pupil of the eye to be examined. It is explanatory drawing which shows the image of the light shielding member in the to-be-examined eye part. It is a front view of a black spot plate. It is a front view of the light shielding member arrange | positioned in the position conjugate with the cornea of a to-be-tested eye. It is explanatory drawing which shows the image in the cornea surface of the light shielding member of FIG. 6, and the light source for imaging | photography. FIG. 2 is an optical diagram showing a basic optical configuration when performing stereo shooting with the optical arrangement of FIG. 1. (A) is a front view of a two-hole aperture, and (b) is a front view of a single-hole aperture. (A) is a front view of a photographing mask for stereo photography and monocular photography shown separately, and (b) is a front view of a photography mask for stereo photography and monocular photography arranged in an overlapping manner.

  Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. In the following embodiments, description will be made by taking a fundus camera as an example of an ophthalmologic photographing apparatus.

  FIG. 1 shows a fundus camera 10 capable of performing stereo photography (stereo photography) and monocular photography (monaural photography). FIG. 1 is drawn centering on stereo photography, and can switch to corresponding optical elements in monocular photography.

  The fundus camera 10 is provided with an illumination optical system for illuminating the fundus and a photographing optical system for photographing the illuminated fundus. In the illumination optical system, the light emitted from the light source 11 such as a halogen lamp and the light reflected by the concave mirror 12 become infrared light through a visible cut infrared transmission filter 13 that can be inserted into and removed from the optical path, and become a light source 14 for photographing. Is incident on the diffusion plate 15 and diffused, illuminates a ring slit (light shielding member) 16 disposed at a position conjugate with the crystalline lens, and disposed at a position conjugate with the anterior pupil 1b of the eye 1 to be examined. Pass through the fixed aperture 72.

  As shown in FIG. 2, the photographing light source 14 is a light source in which xenon is sealed in, for example, a ring-shaped or U-shaped discharge tube 14a, and instantaneous discharge is generated in the tube by applying a high voltage to the electrode 14b. It emits light close to natural daylight. Since the discharge tube 14a of the imaging light source 14 is ring-shaped or U-shaped, a circular or elliptical cavity portion 14c is formed at the center, and a horizontally long non-light emitting portion 14d is formed near the electrode 14b. Is done. The imaging light source 14 is arranged at a position conjugate with the cornea of the anterior ocular segment to be examined with the center of the cavity 14c aligned with the illumination optical axis 70 of the illumination optical system.

  3A, the ring slit 16 is a metal black light shielding member composed of a ring-shaped opening 16c in which a light shielding part 16a located at the center is supported by a support part 16b. The center of the part 16a is aligned with the illumination optical axis 70 of the illumination optical system and is arranged at a position conjugate with the rear surface of the eye lens to be examined.

  The ring slit 16 is for stereo photography, and is switched to the ring slit 16 ′ shown on the right side of FIG. 3A during monocular photography (or during fundus observation). The ring slit 16 ′ is also a metal black light shielding member made of a ring-shaped opening 16c ′ in which the light shielding portion 16a ′ located at the center is supported by the support portion 16b ′. When the ring slit 16 ′ is inserted into the optical path, the light shielding portion The center of 16a ′ is aligned with the illumination optical axis 70 of the illumination optical system and is arranged at a position conjugate with the rear surface of the eye lens to be examined.

  The light shielding part 16a of the ring slit 16 for stereo photography has an oval shape with a vertical width d1 and a horizontal width d2, and the light shielding part 16a 'of the ring slit 16' for monocular photography is circular and has a diameter d1 '. Is larger than d1 and smaller than d2.

  As shown in FIG. 3B, the fixed diaphragm 72 is a circular aperture diaphragm having an opening 72a smaller than the diameters of the openings 16c and 16c ′ of the ring slits 16 and 16 ′, and the center of the opening 72a. It is arranged at a position conjugate with the pupil of the anterior ocular segment to be examined so as to coincide with the illumination optical axis 70 of the illumination optical system.

  As shown in FIG. 4, the image of the fixed aperture 72 is formed at the position of the pupil 1b of the eye to be examined, and the images of the ring slits 16 and 16 'are formed on the rear surface of the crystalline lens 1d of the eye 1 to be examined. The fundus 1a to be examined is uniformly illuminated by the illumination light that has passed through. In FIG. 4 (also in FIG. 7), for convenience of explanation, the reference numerals of the images are shown with the same reference numerals as the actual members, and the images at the time of monocular photography are shown with parentheses.

  The ring slits 16 and 16 ′ are arranged between the photographing light source 14 and a black spot plate described later, and have different sizes or positions depending on whether they are stereo photography or monocular photography, and the size or position varies depending on the photography mode. A light shielding member is formed. Further, since the ring slits 16 and 16 'are disposed at a position conjugate with the eye lens (rear surface) to be examined, it is possible to block harmful reflection light at the center of the lens of the illumination light.

  Returning to FIG. 1, the illumination light that has passed through the ring slit 16 and the fixed aperture 72 is a black dot plate 18, a half mirror 19, and a relay lens 20 for blocking harmful reflection light of illumination light from the lens 17 and the objective lens 22. Then, the light passes through the light blocking member 71 and is totally reflected by the perforated mirror 21 having a hole in the center. Illumination light reflected by the perforated mirror 21 passes through the objective lens 22, enters the fundus 1a from the pupil 1b of the eye 1 to be examined, and illuminates the fundus 1a with infrared light.

  As shown in FIG. 5, the black spot plate 18 is a black spot plate for stereo photography in which an elliptical black spot 18 a having a length of 0.3 mm and a width of 0.5 mm is formed in the center of a circular transparent glass plate. The center of 18a is arranged in the illumination optical system so as to coincide with the illumination optical axis 70 of the illumination optical system. The black spot plate 18 is switched to the black spot plate 18 'during monocular photography. The black spot plate 18 ′ is obtained by superimposing two glass plates on which a circular black spot 18a ′ having a diameter of 0.3 mm is formed at the center of a circular transparent glass plate, and the center of each black spot is the illumination optical system. Are arranged in the illumination optical system so as to coincide with the illumination optical axis 70.

  At the time of stereo photography, the black spot plate 18 is inserted into the optical path of the illumination optical system, and the lens surface reflection image of the black spot 18a by the objective lens 22 covers a two-hole aperture to be described later, so that it is reflected by the central surface of the objective lens 22 This prevents the illumination light (photographing light) from passing through the two-hole aperture. Further, at the time of monocular photography, a black spot plate 18 'is inserted into the optical path, and the image of the black spot 18a' covers a single-hole stop, which will be described later, so that the illumination light reflected by the surface of the objective lens 22 passes through the single-hole stop. To prevent it. As described above, the black spot plates 18 and 18 ′ can block the harmful reflection light generated at the center of the surface of the objective lens of the illumination light, and can improve the quality of the photographed fundus image.

  As shown on the left side of FIG. 6, the light-shielding member 71 for stereo photography disposed between the perforated mirror 21 of the illumination optical system and the black spot plate 18 has an oblong shape with a vertical width of d3 and a horizontal width of d4. This is a metallic black light-shielding member having a ring-shaped opening 71c in which the part 71a is supported by the support part 71b. The center of the light-shielding part 71a is aligned with the illumination optical axis 70 of the illumination optical system, and It is placed at a position conjugate with the cornea.

  During monocular photography, the light shielding member 71 is switched to the light shielding member 71 '. As shown on the right side of FIG. 6, the light shielding member 71 ′ is a metal having a ring-shaped opening 71c ′ in which a circular light shielding portion 71a ′ having a diameter d3 ′ larger than d3 and smaller than d4 is supported by a supporting portion 71b ′. The black light-shielding member made of black is arranged at a position conjugate with the cornea of the anterior ocular segment to be examined so that the center of the light-shielding portion 71a ′ coincides with the illumination optical axis 70 of the illumination optical system.

  As shown in FIG. 4, the image of the light shielding member 71 (71 ′) is formed on the surface of the cornea 1c of the eye to be examined, and the image of the light shielding part 71a (71a ′) viewed on the cornea surface through the objective lens. Is shown in FIGS. 7 (a) and 7 (b). The imaging light source 14 is also in a conjugate position with the cornea, and its image is indicated by a dotted line in FIG. Note that the image of the light shielding member 71 (71 ′) is reversed in the actual left-right relationship with respect to the image of the imaging light source 14 by the lens, and therefore, as shown in FIG. 71b ′) and the image orientation of the non-light emitting portion 14d of the photographic light source 14 coincide.

  As shown in FIGS. 7A and 7B, the image on the cornea surface of the light shielding portion 71a (71a ′) of the light shielding member 71 (71 ′) is the outer diameter of the image of the discharge tube of the imaging light source 14. The size and shape of the light-shielding portion 71a (71a ′) are determined so as to be smaller and to cover the cornea image of the cavity portion 14c. Further, the size and position of the support portion 71b (71b ′) of the light shielding member 71 (71 ′) are determined so that the image on the cornea surface substantially matches the image of the non-light emitting portion 14d of the imaging light source 14. It is done.

  Since the support portion 71b (71b ′) of the light shielding member 71 (71 ′) forms an image at substantially the same corneal position as the non-light emitting portion 14d of the imaging light source 14, it is non-reflective even when the imaging light source 14 emits light. The edge of the support portion 71b (71b ′) does not shine brightly as a secondary light source. Therefore, the harmful central image due to the reflection from the objective lens by the secondary light source is an image of the light source 14 for light photography and the image of the light shielding portion 71a (71a ') as a whole, and there is no locally bright part and is photographed. The quality of the fundus image can be improved.

  The light shielding members 71 and 71 'differ in size or position depending on whether they are stereo photography or monocular photography, and constitute a second light shielding member whose size or position is variable depending on the photography mode. Further, since the light shielding members 71 and 71 ′ are arranged at a position conjugate with the eye cornea to be examined, it is possible to shield harmful reflection light from the cornea of illumination light.

  Returning to FIG. 1, the reflected light from the fundus 1a is received through the objective lens 22, passes through the hole of the perforated mirror 21, and has two circular holes 31a as shown in FIG. And a two-hole aperture 31 as an imaging aperture having 31b. The two-hole aperture 31 is arranged at a position substantially conjugate with the pupil 1b of the eye 1 with its center 31c aligned with the imaging optical axis 48, and the reflected light from the fundus is reflected by the two holes 31a and 31b of the two-hole aperture 31. The optical path is divided into left and right. A pair of left and right light beams from the fundus la with the optical path divided are incident on the focus lens 32. The focus lens 32 is movable along the photographing optical axis 48 and has a fundus imaging position due to individual differences in the eye diopter. Correct the deviation. In monocular photography, instead of the two-hole aperture 31, a single-hole aperture 31 'as shown in FIG. 9B is inserted in the optical path at the conjugate position with the anterior eye pupil.

  The fundus image that has passed through the focus lens 32 subsequently passes through the imaging lens 33, is reflected by the half mirror 34, and is disposed at a position conjugate with the fundus 1a to pass through the imaging masks 42 and 43 that define the imaging range of the fundus. Then, it is incident on an infrared transmission visible reflection mirror (optical path dividing means) 36. The focus lens 32 and the imaging lens 33 form a first imaging optical system (imaging optics) that forms a pair of left and right fundus images with parallax via the two-hole aperture 31 as intermediate images at the position of the imaging mask 43. System).

  As shown in FIG. 10A, the imaging mask 42 is a monocular imaging mask including a circular opening 42a and a light-shielding portion 42b that does not transmit all wavelengths. The shooting mask 43 is a shooting mask for stereo shooting and includes a rectangular opening 43a and a region 43b having a circular outer periphery that transmits only infrared light. The photographing mask 42 is fixedly disposed in the optical path of the photographing optical system with its center aligned with the photographing optical axis 48. At the time of stereo photographing, the photographing mask 43 is photographed at its center as shown in FIG. It is inserted into the optical path so as to coincide with the optical axis 48. At the time of monocular imaging, as shown in FIG. 10A, the imaging mask 43 is released from the optical path, and the imaging mask 42 becomes effective. In the case of the photographing mask 42 for monocular photography, the photographing light is transmitted through the opening 42a, and in the case of the photographing mask 43 for stereo photography, the photographing light is transmitted through the opening 43a having a smaller area than the opening 42a. By changing the mode, the transmission range of the imaging light passing through the imaging mask changes.

  Returning to FIG. 1, the infrared light transmitted through the infrared transmission visible reflection mirror 36 is reflected by the mirror 38, passes through the lens 37, and is configured by an infrared CCD having sensitivity to the infrared light. (Imaging means) is incident on 40 and the signal is input to the monitor 41.

  A relay lens 47 is disposed to connect the exit pupil image of the first imaging optical system to a second imaging optical system described later. Visible light reflected by the mirror 36 is incident on the two-hole aperture 50 disposed at a conjugate position with the anterior eye pupil 1 b through the relay lens 47. The two-hole diaphragm 50 is a diaphragm similar to the two-hole diaphragm 31 shown in FIG. 9A, and a pair of optical path divisions in the vicinity of the two-hole diaphragm 50 (that is, at a position almost conjugate with the two-hole diaphragm 31). Lenses 51 and 52 are arranged. As will be described later, the pair of optical path dividing lenses divides the optical path from the photographing mask 43 and separates the left and right fundus images formed as intermediate images at the position of the photographing mask 43 so as not to overlap each other. Thus, a second imaging optical system for re-imaging is configured. Here, the optical path splitting lenses 51 and 52 are optimally arranged at equal intervals with respect to the photographing optical axis 48, that is, axially symmetrical with respect to the photographing optical axis 48.

  An imaging surface 53a of an imaging device (imaging means) 53 composed of a visible CCD having sensitivity to visible light is disposed on the imaging surface by the second imaging optical system, and the optical path splitting lenses 51 and 52 and the imaging are taken. A return mirror 60 is disposed between the elements 53. When the visible cut infrared transmission filter 13 is removed from the optical path and the return mirror 60 is inserted into the optical path, the pair of left and right fundus images separated by the eyepiece (binocular observation means) 62 through the mirror 61 is visually observed. Can be observed.

  The fundus image picked up by the image pickup device 53 can be stored in the memory 54, and is taken into an external personal computer (not shown), displayed on the monitor 41, or outputted to a printer (not shown). .

  The pair of optical path dividing lenses 51 and 52 having the same magnification can be switched to another pair of optical path dividing lenses 51 'and 52' having different magnifications, and a pair of fundus images can be taken at different magnifications. When the pair of optical path splitting lenses 51 ′ and 52 ′ having different magnifications is switched, the photographing mask 43 for stereo photographing is also switched to the photographing mask 43 ′ having a different opening.

  At the time of monocular photography, an imaging lens 55 for monocular photography is inserted into the optical path instead of the optical path dividing lenses 51 and 52, and the two-hole aperture 50 is detached from the optical path.

  Further, the illumination optical system is provided with a focus dot light source 30, and a light beam from the light source 30 is incident on the fundus 1 a via the half mirror 19, and the focus dot position changes according to the movement of the focus lens 32. The examiner can focus on the fundus of the eye to be examined by observing the focus dot.

  Further, since the anterior eye lens 44 is inserted in the initial stage of alignment, the examiner can confirm the image of the anterior eye part of the eye 1 on the monitor 41. Further, during alignment or focusing operation, one of the internal fixation lamps 45 composed of a plurality of LED light sources 45a is turned on, and the examiner performs alignment by causing the subject to gaze at the fixation lamps. And focusing operation can be ensured.

  FIG. 8 shows a main part of an optical system that forms a fundus image when performing stereo photography. The same elements as those in FIG. 1 are denoted by the same reference numerals.

  1 and 8, the position conjugate with the fundus 1a of the eye 1 to be examined is indicated by R, and the position conjugate with the anterior eye pupil is indicated by P.

  1 and 8, the two-hole apertures 31, 50 and the optical path splitting lenses 51, 52 are shown so as to split the optical path vertically in the drawing. In the direction perpendicular to). However, since it is difficult to illustrate the state in which the light beam is split in the left-right direction in the drawings, in FIGS. 1 and 8, the two-hole apertures 31, 50 and the optical path splitting lenses 51, 52 are perpendicular to the paper surface for convenience. The figure when viewed from the direction of is shown.

  In the fundus camera configured as described above, since the visible cut infrared transmission filter 13 is inserted in the illumination optical path, when the halogen lamp 11 is turned on, the fundus is illuminated with infrared light.

  At the time of fundus observation (monocular imaging), a ring slit 16 ′, a black spot plate 18 ′, a light shielding member 71 ′, a single aperture stop 31 ′, and an imaging lens 55 for monocular imaging are inserted into the optical path, and the imaging mask 43, The two-hole aperture 50 is removed from the optical path.

  The fundus image illuminated with the infrared light is imaged at the position of the photographing mask 42 by the objective lens 22, the focus lens 32, and the imaging lens 33, passes through the infrared transmission visible reflection mirror 36, and is formed by the imaging lens 37. Since the image is re-imaged on the imaging surface of the image sensor 40 as a moving image, the fundus image is displayed on the monitor 41 as a monochrome image, and the examiner can observe the fundus image with a non-mydriatic pupil via the monitor 41. At this time, if the imaging magnification on the image sensor 40 is set lower than the imaging magnification by the second imaging optical system, a wide-angle fundus image can be observed, and alignment at the time of non-mydriatic pupil Can be easily. In addition, by observing the focus dot from the light source 30, it is possible to focus on the fundus of the eye to be examined.

  In the initial stage of alignment, since the anterior ocular lens 44 is inserted, the examiner performs alignment by observing the image of the anterior ocular segment of the eye 1 to be examined with the monitor 41.

  When the alignment is completed, the shutter switch 46 is operated, the shutter operation signal is input to the image sensor 53 and the memory 54, the image sensor 53 is activated, and the fundus still image capturing operation is started. Since a signal for instructing light emission is transmitted from the image sensor 53 to the photographing light source 14 in synchronization with the operation signal, the photographing light source 14 emits light. The fundus illuminated by the light emission of the imaging light source 14 is imaged as a still image by the imaging element 53.

  At the time of acquiring this fundus image, the non-reflective support portion 71b ′ of the light shielding member 71 ′ is formed at substantially the same corneal position as the non-light emitting portion 14d of the imaging light source 14, as shown in FIG. 7B. Therefore, even if the imaging light source 14 emits light, the edge of the support portion 71b ′ does not shine brightly as a secondary light source, and there are few harmful images due to reflection of the objective lens. Therefore, it is possible to improve the quality of the fundus image captured with a single eye.

  During stereo shooting, the ring slit 16, the black spot plate 18, and the light blocking member 71 are inserted into the optical path instead of the ring slit 16 ′, the black spot plate 18 ′, and the light blocking member 71 ′. Further, in place of the single-hole stop 31 'and the imaging lens 55, the two-hole stop 31 and the optical path dividing lenses 51 and 52 are inserted into the optical path, and the two-hole stop 50 is inserted into the optical path.

  The light beam from the fundus 1a is divided into right and left by the two-hole aperture 31, and is imaged at the position of the photographing mask 43 as a pair of left and right intermediate images with parallax by the focus lens 32 and the imaging lens 33. An image is observed by the monitor 41.

  The region 43b of the imaging mask 43 is a region that transmits only infrared light, and the rectangular opening 43a transmits the light flux in all bands, so that the image captured by the image sensor 40 is displayed on the monitor 41. As shown by A in the upper right of FIG. 1, a rectangular outline 43c corresponding to the rectangular opening 43a is displayed, and the examiner can confirm how much the photographing range at the time of stereo photographing is. it can.

  In this way, during fundus observation, light (infrared light) is transmitted through the regions 43a and 43b of the photographing mask, and during fundus photographing in which the photographing light source 14 emits light, the region of the photographing mask region 43b is defined. Light (visible light) is transmitted, and the transmission range of light that passes through the imaging mask changes between observation and imaging.

  A pair of left and right fundus images with parallax imaged at the position of the photographing mask 43 pass through the relay lens 47 and the two-hole aperture 50 and enter the optical path dividing lenses 51 and 52.

  The relay lens 47 is disposed so as to connect the exit pupil image of the first imaging lens 33 to the optical path splitting lenses 51 and 52. That is, the optical path splitting lenses 51 and 52 are arranged at a position almost conjugate with the pupil 1b of the eye to be examined via the relay lens 47, and the image of one hole 31a of the two-hole aperture 31 is the optical path splitting lens 52. The image of the other hole 31 b is formed in the vicinity of the optical path splitting lens 51. Therefore, as shown in FIG. 8, the centers 31c and 31d of the apertures 31a and 31b of the two-hole aperture and the lens centers 52a and 51a of the optical path splitting lenses 52 and 51 are in an imaging relationship (conjugate relationship).

  Light rays 51b and 52b passing through the lens centers 51a and 52a of the optical path splitting lenses 51 and 52 through the center of the imaging mask 43 reach the points 51c and 52c on the imaging surface 53a. The distance between the arrival points 51c and 52c is set to a length equal to a distance approximately half of the entire length L of the imaging surface 53a along the direction orthogonal to the imaging optical axis 48 (vertical direction in FIG. 8). The fundus image formed by the optical path dividing lens 51 with the fundus image of FIG. 5 is not superimposed on the upper half of the imaging surface 53a, and the fundus image formed by the optical path dividing lens 52 is not superimposed on the lower half of the imaging surface 53a. Therefore, it is possible to acquire a fundus image for stereoscopic viewing that is separated and imaged and effectively uses the entire imaging surface 53a.

  In FIG. 8, as can be seen from the path of the light beam filled with a thin point, the left image with parallax (lower side in FIG. 8) is connected to the left side (lower side) of the imaging surface, and the right image is connected to the right side (upper side). A parallax image in which the left-right relationship is matched can be acquired without the need for a prism for switching the left and right as in the prior art.

  When the visible cut infrared transmission filter 13 is detached from the optical path and the return mirror 60 is inserted into the optical path, as shown in FIG. 1, the fundus image with a pair of left and right parallax separated by the optical path splitting lenses 51 and 52 is obtained. The eyepiece 62 can be observed through the mirror 61. At this time, the observed fundus images are the separated fundus images 1c and 1d having a pair of left and right parallaxes, as indicated by B in the upper right of FIG.

  When an image is picked up by the image pickup device 53, the shutter switch 46 is operated. In synchronization with this operation, the return mirror 60 is detached from the optical path, and the photographing light source 14 emits light. The fundus images 1c and 1d having a pair of left and right parallax separated without overlapping as shown by B in FIG.

  At the time of acquiring this fundus image, the non-reflective support portion 71b of the light shielding member 71 is imaged at substantially the same corneal position as the non-light emitting portion 14d of the imaging light source 14 as shown in FIG. Even when the photographing light source 14 emits light, the edge of the support portion 71b does not shine brightly as a secondary light source, and there are few harmful images, so that the quality of the fundus image taken in stereo can be improved as in monocular photography. Can be increased.

  The pair of fundus images captured in this way are stored in the memory 54 and can be read later and stereoscopically viewed by the stereoscopic device.

  As shown in FIG. 1, the pair of optical path splitting lenses 51 and 52 can be switched to another pair of optical path splitting lenses 51 'and 52' having different magnifications. In this case, a pair of fundus images with reduced or enlarged parallax are captured. At this time, in conjunction with the switching, the photographic mask 43 is switched to the photographic mask 43 ′ having an opening enlarged or reduced according to the magnification.

  Further, the two-hole aperture 50 arranged close to the optical path splitting lenses 51 and 52 is not necessarily required because the lens barrel of each lens 51 and 52 can be used.

DESCRIPTION OF SYMBOLS 1 Eye to be examined 1a Fundus 1b Anterior eye part 16, 16 'Ring slit (1st light shielding member)
18, 18 'Black spot plate 21 Perforated total reflection mirror 22 Objective lens 31 Two-hole aperture 31' Single-hole aperture 32 Focus lens 33 Imaging lens 40 Image sensor 42, 43 Imaging mask 46 Shutter switch 47 Relay lens 50 Two-hole aperture 51 , 52 Optical path dividing lens 53 Imaging element 55 Imaging lens for monocular photography 62 Eyepiece 71, 71 ′ Light shielding member (second light shielding member)

Claims (6)

An ophthalmologic photographing apparatus capable of photographing the fundus of the eye to be examined in different photographing modes,
A light source for photographing that emits illumination light for illuminating the fundus during fundus photographing;
A black spot plate that shields harmful reflected light from the objective lens of the illumination light;
A first light-shielding member whose size or position is variable according to an imaging mode disposed at a position conjugate with the eye lens between the imaging light source and the black spot plate;
A perforated mirror for directing illumination light from the imaging light source toward the fundus of the eye to be examined;
A second light-shielding member that is variable in size or position in accordance with an imaging mode disposed at a position conjugate with the eye cornea to be examined between the perforated mirror and the black spot plate,
The ophthalmologic photographing apparatus, wherein the second light shielding member and the photographing light source are disposed at an optically conjugate position.   The second light shielding member has a light shielding part and a non-reflective support part for supporting the light shielding plate, and the photographing light source has a ring-shaped or U-shaped light emitting part with a non-light emitting part in part. The ophthalmic imaging apparatus according to claim 1, wherein the support portion of the second light-shielding member and the non-light-emitting portion of the imaging light source are in a position conjugate with the eye cornea to be examined.   The size and position of the support portion are determined so that the image on the cornea surface of the support portion of the second light-shielding member substantially matches the image on the cornea surface of the non-light-emitting portion of the imaging light source. The ophthalmologic imaging apparatus according to claim 2.   The ophthalmologic photographing apparatus according to any one of claims 1 to 3, wherein the photographing mode includes a stereo photographing mode.   5. The ophthalmologic photographing according to claim 1, wherein a transmission range of photographing light passing through a photographing mask disposed at a fundus conjugate position of the photographing optical system is changed by changing the photographing mode. apparatus.   2. The transmission range of light that passes through an imaging mask arranged at a fundus conjugate position of an imaging optical system changes between observation of the fundus before imaging and imaging of the fundus that emits light from the imaging light source. The ophthalmologic imaging apparatus according to any one of 1 to 5.

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