JP4551727B2 - Ophthalmic imaging equipment - Google Patents

Description

  The present invention relates to an ophthalmologic photographing apparatus used in an ophthalmic clinic or the like.

  In fundus photography in a group medical examination, the subject's line of sight is adjusted so that a position just between the optic disc and the macula is at the center of the screen. Therefore, it is necessary to guide the macular to a position eccentric from the optical axis and take a picture. However, since the structure of the fundus is symmetrical between the left and right eyes, the fixation target position must be changed between when the right eye is photographed and when the left eye is photographed.

  Therefore, in the fundus camera, as disclosed in Patent Documents 1 to 3, conventionally, an optical path branched from the imaging optical system is provided, and a plurality of light sources are used as fixation targets at conjugate positions with the imaging surface in the optical path. The fixation target according to the left and right eyes is presented to the subject by selectively turning on the light source. Since both the imaging light and the fixation target are visible light, a flip-up mirror or a half mirror that branches the optical path is used.

Japanese Patent Laid-Open No. 60-60831 JP-A-6-217941 JP-A-9-271464

  Further, a method of Patent Document 4 in which a light source is arranged in an illumination optical system so as to be freely inserted and removed and a fixation target is presented is also known.

JP 51-137413 A

  In the conventional method described above, the optical system is enlarged to provide a branching optical path, and the mechanism is complicated when a flip-up mirror is used, or the use efficiency of the light amount is reduced when a half mirror is used. There is a problem that a light source having a larger capacity is required and the glare of the subject increases.

  In addition, the method of arranging the light source as a fixation target in the illumination optical system is that the fundus illumination light is obstructed by the components for supporting the light source, the light source itself, and the cable, etc., causing uneven illumination, and the fundus observation image There is a problem that the image quality of the image is degraded.

  An object of the present invention is to provide an ophthalmologic photographing apparatus that solves the above-described problems, selectively turns on light sources corresponding to the left and right eyes, and obtains a good-quality fundus image without uneven illumination with a small structure. There is.

The technical feature of the ophthalmologic photographing apparatus according to the present invention for achieving the above object is that the first and second relay lenses having a focus at a position substantially conjugate with the anterior eye portion of the eye to be examined, and the second relay A fundus illuminating unit having a plurality of visible light sources arranged circumferentially on a substantially focal plane of the lens and the first and second relay lenses, and the fundus of the subject's eye according to the selection of the visible light source Projecting means for projecting the fixation target at different positions .

  According to the ophthalmologic photographing apparatus according to the present invention, it is possible to present a fixation target corresponding to the left and right eyes only by selectively turning on the light source in the illumination optical system fixedly arranged. The optical system can be downsized.

  Moreover, since the light source used for photographing can also be used for fixation target illumination, the number of parts can be reduced and the structure can be simplified.

  The present invention will be described in detail based on the embodiments shown in the drawings.

  FIG. 1 is a configuration diagram of a fundus camera embodying the present invention. In front of the eye E, the objective lens 1, the perforated mirror 2, the photographing aperture 3, the focusing lens 4, the photographing lens 5, the color separation prism 6, the image sensors 7r and 7g, arranged in the hole of the perforated mirror 2, An imaging mechanism consisting of 7b is arranged to constitute a fundus observation imaging means.

  In the fundus illumination system in the incident direction of the perforated mirror 2, the corneal diaphragm 8 having a ring-shaped opening projected from the perforated mirror 2 side to the vicinity of the cornea, the first relay lens 9, and the reflection by the objective lens 1 are removed. A fixation target unit 11 that moves in the direction of the optical axis in conjunction with the black spot plate 10 and the focus lens 4 formed with black spots near the optical axis, and retracts out of the optical path during still image shooting, a second relay lens 12, An optical path branching mirror 13 that reflects visible light and transmits infrared light, a lens diaphragm 14 having a ring-shaped opening that projects near the rear surface of the crystalline lens of the eye E, and a ring-shaped opening 15a that projects near the pupil Ep of the eye E As shown in FIG. 2, LED light sources 16a to 16f for observation that emit infrared light are arranged along a ring aperture 15 having a ring shape and a ring-shaped opening 15a.

  In the reflection direction of the optical path branching mirror 13, a lens diaphragm 17 having a ring-shaped opening that projects near the rear surface of the lens of the eye E, a ring diaphragm 18 having a ring-shaped opening 18a that projects near the pupil Ep of the eye E, As shown in FIG. 3, visible light sources 19 a to 19 f such as white LEDs are arranged along the opening 18 a.

  The optical system portion of the fixation target unit 11 disposed between the first and second relay lenses 9 and 12 includes an infrared filter 11a that transmits infrared light but blocks visible light. As shown in FIG. 4, minute openings 11b and 11c are perforated at positions that are symmetrically decentered in the center of the filter 11a. As shown in FIG. 5, the minute openings 11b and 11c are inclined in different directions and penetrate the filter 11a.

  The aperture of the perforated mirror 2 is substantially conjugate with the anterior segment of the eye E with respect to the objective lens 1, and the focal positions of the first relay lens 9 and the second relay lens 12 are also the same as the anterior segment of the eye E. It is almost conjugate. Therefore, the diaphragm 15 and the diaphragm 18 are disposed at substantially the focal position of the second relay lens 12.

  The outputs of the image sensors 7r, 7g, and 7b are connected to the image board 22 via the amplifier circuits 21r, 21g, and 21b. The image board 22 includes an A / D converter 23 and a memory 24. The control means 25, the television monitor 26 and the system bus 27 are connected. Further, the system bus 27 selects the fixation target presentation position according to the fixation target unit 11, CPU 28, photographing switch 29, recording means 30, focus adjustment switch 31, observation light amount dimming knob 32, and right and left of the eye E to be examined. A selection switch 33 and a lamp driving circuit 34 for driving the visible light sources 19a to 19f are connected.

  When photographing the fundus Er of the eye E using this fundus camera, the photographer seats the subject in front of the fundus camera, observes the fundus Er of the subject by moving images, and examines the eye E and the fundus. Align and focus with the camera.

  Light emitted from the LED light sources 16a to 16f passes through the ring-shaped opening 15a of the diaphragm 15 and the ring-shaped opening of the diaphragm 14, passes through the optical path branching mirror 13, and passes through the second relay lens 12, the fixation target unit 11, and the black spot. It passes through the aperture of the plate 10, the first relay lens 9, and the diaphragm 8, is reflected leftward by the perforated mirror 2, passes through the objective lens 1, and illuminates the fundus Er through the pupil Ep of the eye E to be examined.

  The reflected image of the fundus Er illuminated in this way again passes through the objective lens 1, the photographing aperture 3, the focus lens 4, and the photographing lens 5, and passes through the color separation prism 6 to the image sensor 7 r that receives red and infrared light. Led. This signal is converted into a video signal by the amplifier circuit 21r, input to the image board 22, and displayed on the television monitor 26 via the image control means 25.

  The photographer observes the fundus image reflected on the television monitor 26 and confirms the imaged region. When the brightness of the fundus image is not appropriate, the photographer operates the observation light amount dimming knob 32. In accordance with the operation of the knob 32, the amount of current flowing through the LED light sources 16a to 16f is adjusted, the intensity of the emitted light changes, and the photographer can observe the fundus image with appropriate brightness.

  As shown in FIG. 3, only the light source 19b among the visible light sources 19a to 19f for fixation target presentation arranged circumferentially along the opening 18a of the diaphragm 18 is steady light with a luminance lower than that at the time of photographing. Lights on. Visible light emitted from the light source 19 b passes through the opening 18 a of the diaphragm 18, is reflected upward by the optical path branch mirror 13, and passes through the second relay lens 12 to illuminate the fixation target unit 11.

Since the light source 19b is disposed substantially in the focal plane of the second relay lens 12, the light emitted from the light source 19b becomes parallel light toward the filter 11a by the second relay lens 12 as shown in FIG. The light travels with the same inclination. The opening 11b of the filter 11a has an inclination equal to the angle of the light beam, and the other opening 11c has an inclination that matches the angle of the light beam emitted from the light source 19e.

  Accordingly, of the light emitted from the light source 19b, the light that has entered the opening 11b is transmitted through the opening 11b, passes through the openings of the black spot plate 10, the first relay lens 9, and the diaphragm 8, and is a mirror around the perforated mirror 2. Is reflected to the left by the projection and projected onto the fundus Er via the objective lens 1 and the pupil Ep. On the other hand, since the light entering the opening 11c is blocked by the inclined hole, only the image of the opening 11b is presented to the subject E as the fixation target.

  Similarly, when the light source 19e is turned on, the light emitted from the light source 19e becomes parallel light inclined in the opposite direction to the light emitted from the light source 19b by the second relay lens 12, and illuminates the filter 11a. . Accordingly, the light beam incident on the aperture 11c passes through the aperture 11c, passes through the apertures of the black spot plate 10, the first relay lens 9, and the diaphragm 8, and reaches the fundus Er of the eye E to be examined, but the light beam incident on the aperture 11b. Is blocked by the inclined hole of the opening 11b.

  Accordingly, the subject can visually recognize only the image of the opening 11c as a fixation target. That is, the position of the fixation target can be switched by switching the light source 19 to be lit.

  Further, the fixation target unit 11 moves in the optical axis direction in conjunction with the focus lens 4 so that the imaging position of the opening 11b or the opening 11c, which is the fixation target, always coincides with the imaging surface. Accordingly, the fixation target always having a good contrast can be projected onto the eye E by viewing the fundus image displayed on the TV monitor 26 by operating the focus adjustment switch 31 and focusing on the fundus Er. it can.

  The photographer observes the fundus image displayed on the TV monitor 26, and after the subject gazes at the fixation target and confirms that the photographing range is appropriate, the photographing switch 29 is operated. The CPU 28 detecting the input to the photographing switch 29 turns off the light sources 16a to 16f, temporarily turns off the light source 19b, retracts the fixation target unit 11 to the outside of the optical path, and stops the amplification factors of the amplification circuits 21b, 21g, and 21r. The image capturing light source 19a to 19f is emitted for a short time with the image capturing luminance.

  Light emitted from the imaging light sources 19a to 19f passes through the aperture 18a of the diaphragm 18 and the aperture of the diaphragm 17, is reflected upward by the optical path branching mirror 13, and is reflected by the second relay lens 12, the black spot plate 10, and the first relay. The lens 9 passes through the aperture of the diaphragm 8 and is reflected to the left by the mirror portion of the perforated mirror 2 to illuminate the fundus Er through the objective lens 1 and the pupil Ep.

  The fundus image illuminated in this way again passes through the pupil Ep, the objective lens 1, the photographing aperture 3, the focus lens 4, and the photographing lens 5, and is blue (B), green (G), red (R) by the color separation prism 6. ), Are imaged on the image sensors 7b, 7g, and 7r, converted into electric signals, amplified by the amplifier circuits 21b, 21g, and 21r so that an appropriate color balance is obtained, and an A / D conversion unit 23 is converted into digital data, displayed on the television monitor 26, and recorded on the recording medium D by the recording means 30. Then, the fixation target unit 11 is inserted again into the optical path, the light sources 16a to 16f and the light source 19b are turned on, and a series of photographing operations is completed.

  Next, when photographing the other eye, when the left and right eye selection switch 33 is operated, the CPU 28 detecting the input of the switch 33 turns on the light source 19b or 19e corresponding to the direction selected through the lamp driving circuit 34. Light.

  Similarly to the above, when the light source 19b is turned on, the light emitted from the light source 19b can pass only through the opening 11b, so that the image of the opening 11b can be presented to the subject as a fixation target. it can.

  In the above-described embodiment, the fixation target presentation position corresponding to the left and right eyes is switched by the selection switch 33. However, the right and left of the eye E is detected using known detection means, and based on the detected information. The fixation target may be switched.

  Further, in the fixation target unit 11 of the first embodiment, the example in which the openings 11b and 11c which are inclined and perforated in the infrared filter 11a are used as the fixation target is shown, but in the vicinity of the opening used as the fixation target. A prism that deflects the optical path may be arranged. 7 to 9 show Embodiment 2 in that case.

  FIG. 7 is a configuration diagram of the fixation target unit 11 using a prism, and an infrared filter 41 that transmits infrared light and blocks visible light is interposed between the transparent plates 40a and 40b. In the second embodiment, since an inclined opening is not provided, a sheet-like low-cost infrared filter 41 is used. Further, openings 41a and 41b are provided near the center of the infrared filter 41 as fixation targets as shown in FIG. 8, and a portion of the transparent plate 40a corresponding to these openings 41a and 41b has a prism. 42a and 42b are formed.

  As a result, as shown in FIG. 9, the light emitted from the light source 19b becomes parallel light by the second relay lens 12 as in the first embodiment, and the openings 41a and 41b of the infrared filter 41 are passed through the transparent plate 40b. Illuminate. The light beam incident on the opening 41a is deflected by the prism 42a at an angle opposite to the optical axis. This light beam passes through the black spot plate 10 and passes through the apertures of the first relay lens 9 and the diaphragm 8, travels to the mirror portion around the perforated mirror 2, reaches the fundus Er of the eye E, and the subject opens the aperture. The image 41a can be visually recognized as a fixation target.

  On the other hand, the light incident on the opening 41b is deflected by the prism 42b in a direction having a larger angle with respect to the optical axis. Therefore, this light does not enter the first relay lens 9 after passing through the black spot plate 10. Alternatively, even if the light enters the first relay lens 9, it is blocked by the diaphragm 8, so that it does not reach the fundus Er of the subject.

  Thus, the subject can visually recognize only the opening 41a as a fixation target. When the light source 19e is turned on, the light incident on the opening 41a is blocked by the action of the prism 42a and is deflected by deflecting the light beam out of the optical path, and the light incident on the opening 41b is lighted by the action of the prism 42b. The light is deflected in a symmetric direction with respect to the axis, and is projected onto the eye E through the black spot plate 10, the first relay lens 9, and the aperture 8.

  Therefore, when the light source 19e is turned on, the subject can visually recognize only the opening 41b as a fixation target. Thus, by switching the lighting of the light sources 19b and 19e, the subject can respond to the left and right of the eye E. It is possible to present a fixation target.

  Further, the fixation target illumination light source can be provided near the fundus illumination light source, and FIGS. FIG. 10 shows a circumferential arrangement of the imaging light sources 19g to 19l with respect to the aperture 18a of the stop 18. The two fixation target illumination light sources 45a and 45b are flush with the imaging light sources 19g to 19l and the light sources 19g to 19l. It is arranged closer to the optical axis than.

  FIG. 11 is a configuration diagram of the fixation target unit 11 according to the third embodiment, in which minute openings 41a and 41b are formed between the transparent plates 46a and 46b at symmetrical positions closer to the center as in the previous embodiment. Infrared filter 41 is sandwiched.

  As shown in FIG. 12, the light beam emitted from the light source 45 a passes through the opening 15 a of the ring diaphragm 15, further passes through the opening of the crystalline lens diaphragm 14, and becomes parallel light by the second relay lens 12, and thus the fixation target unit 11. The light passing through the opening 41a is projected onto the fundus Er of the eye E through the transparent plate 43, the black spot plate 10, the first lens 9, and the aperture 8 of the diaphragm 8. The

  However, since the light source 45a is disposed closer to the optical axis than the light sources 19g to 19e, the light to illuminate the opening 41b is blocked by the light shielding portion around the optical axis of the stop 18 as shown by the broken line in FIG. Therefore, the opening 41b is not illuminated. Therefore, the subject can visually recognize only the image of the opening 41a as a fixation target.

  Similarly, since the light emitted from the light source 45b is blocked by the light shielding portion of the diaphragm 18, the opening 41b can be illuminated, but the opening 41a is not illuminated. In this way, by switching the lighting of the light sources 45a and 45b, a fixation target corresponding to the right and left of the eye E can be presented.

1 is a configuration diagram of a fundus camera of Example 1. FIG. It is an arrangement view of the aperture of the ring diaphragm and the LED light source. It is an arrangement view of the aperture of the ring diaphragm and the visible light source. It is a top view of the minute opening of an infrared filter. It is sectional drawing of the minute opening of an infrared filter. It is explanatory drawing of the light beam which passes through micro opening. FIG. 6 is a configuration diagram of a fixation target unit according to a second embodiment. It is a top view of the minute opening of an infrared filter. It is explanatory drawing of the light beam which passes through micro opening. FIG. 6 is a layout diagram of an aperture of a ring diaphragm and a light source in Example 3. It is a block diagram of a fixation target unit. It is explanatory drawing of the light beam which passes through micro opening.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Objective lens 2 Perforated mirror 6 Color separation prism 7 Imaging element 8, 14, 15, 17, 18 Aperture 9 First relay lens 11 Fixation target unit 11a, 41 Infrared filter 11b, 11c Aperture 12 Second relay Lens 13 Optical path branching mirror 16 Observation light source 19 Imaging light source 21 Amplifying circuit 22 Image board 25 Image control means 26 TV monitor 27 System bus 28 CPU
29 photographing switch 30 recording means 40a, 40b, 46a, 46b transparent plate 41a, 41b opening 42a, 42b prism 45a, 45b light source for fixation target illumination

Claims (5)

First and second relay lenses having a focal point at a position substantially conjugate with the anterior segment of the eye to be examined;
Fundus illuminating means having a plurality of visible light sources arranged circumferentially on a substantially focal plane of the second relay lens;
Ophthalmic photography characterized by comprising: a projecting unit disposed between the first and second relay lenses and projecting a fixation target to a different position of the fundus of the eye to be examined according to the selection of the visible light source apparatus. The fundus illumination means has a light source for emitting infrared light to illuminate the fundus, the projection means ophthalmologic photographing apparatus according to claim 1, characterized by being configured to transmit the infrared light . The ophthalmologic photographing apparatus according to claim 2, wherein the projection unit sets a plurality of openings perforated in different directions with respect to the optical axis as a fixation target. The ophthalmologic photographing apparatus according to claim 2, wherein the projection unit includes an opening that transmits visible light and a prism that is arranged corresponding to the opening and deflects in different directions. The ophthalmologic photographing apparatus according to claim 1, wherein the visible light source is a light source using a white LED.

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