JPH06189913A - Eyeground camera - Google Patents

Abstract

PURPOSE:To reduce ghost and flare caused by scattering reflected light generated at the time of illuminating the eyeground and to ease the pain of a tested person. CONSTITUTION:A field stop 8 having a diaphragm blade provided on the optical path of a photographing system is disposed at a conjugate position with the eyeground Ef while being interlocked with a lens 12 provided separately. A sliding plate is driven by a field stop driving device to which a command signal from a control device 24 is input to open and close the diaphragm blade. Thus, the aperture of the light flux entering an examined eye E is changed to a value according to photographing, observation and the diopter of a tested person so as to prevent the generation of scattering reflected light and the pain applied to a tested person.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fundus camera used in an ophthalmology clinic or the like.

[0002]

[Prior art]

(A) Conventionally, since the field angle of the fundus illumination system of the fundus camera is constant, a constant range is always illuminated, and when variable magnification is possible, it is set to the wide-angle side. For this reason, on the narrow-angle side, the illumination is wider than the actual shooting range. This is not only a pain for the subject, but in an object having a concave surface such as the fundus, scattered reflected light generated in the peripheral portion is likely to cause ghost or flare.

Therefore, conventionally, in order to remove harmful light, as described in Japanese Patent Publication No. 62-4008, a field diaphragm for limiting the illumination area on the fundus of the eye to be examined is used.
A field-magnification projection system that projects on the fundus of the eye to be examined and a focusing system that focuses on a predetermined observation surface or a shooting surface, or a zooming system that enables variable-magnification observation or variable-magnification shooting with the shooting system. It is known that harmful light is removed by linking and.

(B) Further, in photographing with a fundus camera, the subject needs to fix the anterior eye portion or to fix the anterior segment in order to determine an appropriate photographing position.

[0005]

[Problems to be Solved by the Invention]

(1) However, in (a) of the conventional example, only the field stop projection system is moved to a position conjugate with the fundus of the eye, and the aperture system of the field stop does not change depending on the diopter of the eye to be examined. There is such a problem. That is, since the aperture system of the field stop is set to a size necessary for a hypermetropic subject under the set angle of view, an aperture system smaller than the set aperture system of emmetropia, myopia, etc. However, for a subject having no trouble, scattered light is generated around the fundus of the fundus, or an unnecessarily large amount of light is irradiated, which causes pain to the subject.

(2) In (b) of the conventional example, a means for transmitting the will of the examinee to the examiner without largely changing the proper position after the photographing position is decided by the examiner's instruction is proposed. Not not. In addition, no method has been proposed in which the subject's will is taken into consideration in imaging control. For example, the subject has no choice but to convey the response by mouth, and when the subject responds to the question of the examiner after completing the alignment, the alignment may be misaligned.

It is a first object of the present invention to provide a fundus camera which reduces ghosts and flares due to scattered reflected light generated during fundus illumination and alleviates the pain on the subject.

A second object of the present invention is to provide a fundus camera capable of transmitting the intention of the subject to the examiner without significantly changing the proper position.

[0009]

A fundus camera according to a first aspect of the invention for achieving the above object is an illumination system having a field diaphragm capable of opening and closing an aperture system for limiting an illumination area of a fundus of an eye to be examined. , A focusing system capable of observing or photographing by focusing the fundus image of the eye to be examined on a predetermined observation surface or photographing surface without depending on the diopter of the eye to be examined, and depending on the focusing operation of the focusing system. And a means for opening and closing the aperture system of the field stop.

Further, the fundus camera according to the first aspect of the present invention comprises an input means that the subject can input, a display means that displays the output of the input means at a position where the examiner can visually recognize, and an output of the input means. And a photographing control means for discriminating whether the photographing is permitted or not.

[0011]

According to the fundus camera of the first aspect of the present invention, when the fundus image of the eye to be inspected is focused on the photographing surface, the aperture system of the field stop is arranged conjugate with the fundus image of the eye to be observed. Harmful light is removed by opening and closing the aperture system according to the angle of view and the diopter of the subject.

Further, in the fundus camera according to the second aspect of the invention, when the fundus is photographed, the photographing control means determines from the output of the subject input means whether the photographing is permitted or not.
Communicate the will of the examinee to the examiner.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the embodiments shown in FIGS. FIG. 1 is a configuration diagram of the first embodiment, in which a first condenser lens 2, a photographing light source 3, a second condenser lens 4, a ring slit 5, and a reflection mirror 6 are provided on the optical path of the observation light source 1. The relay lens 7, the field stop 8, the relay lens 9, and the perforated mirror 10 are sequentially arranged in the reflection direction of the reflection mirror 6. An objective lens 11 for the eye E to be inspected is provided in the reflection direction of the perforated mirror 10, and a focusing lens 12, a variable power lens 13, a taking lens 14, a flip-up mirror 15, a film are provided behind the perforated mirror 10. 16 are arranged in order. Further, a field lens 17 and a reflection mirror 18 are provided in the reflection direction of the flip-up mirror 15 so that they can be observed through an eyepiece lens 19.

The field stop 8 is fixedly mounted on a moving plate 21 attached to the focus shaft 20, and the focusing lens 12 is also attached to the focus shaft 20 via a focus lever 22 so as to interlock with the focusing lens 12. The field stop 8 can be moved in the optical axis direction. Also,
The focus shaft 20 is provided with a diopter detector 23 for detecting its rotation angle, and the output of the diopter detector 23 is a control device 24.
It is connected to the.

Further, the variable power lens 13 is provided with a cam ring 25 via a pin, and a large variable gear 26 is coupled to the cam ring 25. This variable large gear 26 is used for the zooming shaft 2
The zooming shaft 2 is meshed with a variable power small gear 28 having
The output of the variable power detector 29 for detecting the angle 7 is the control device 2
4 is connected. The field diaphragm 8 is opened and closed by the field diaphragm driving device 30.

FIG. 2 is a plan view of the field diaphragm 8 and FIG. 3 is a front view thereof. The movable plate 21 is provided with a field diaphragm driving device 30 to which an output from the control device 24 is connected, and the field diaphragm driving device 30. Is provided with a pinion 31. The pinion 31 meshes with a rack 33 fixedly mounted on a sliding plate 32, and the sliding plate 32 has elongated holes 32a, 32b and a hole 32c. Guide screws 34 and 35 fixed to the field stop 8 are loosely fitted in the long holes 32a and 32b, and an opening / closing pin 36 for controlling opening / closing of the diaphragm blade 8a of the field stop 8 is fitted in the hole 32c. .

At the time of observation, the luminous flux emitted from the observation light source 1 passes through the first condenser lens 2, the second condenser lens 4 and the ring slit 5, and is reflected by the reflection mirror 6.
Is reflected by the relay lens 7, the field stop 8 and the relay lens 9 and is incident on the perforated mirror 10. The light flux reflected by the perforated mirror 10 uniformly illuminates the fundus Ef of the eye E to be examined over a wide range by the objective lens 11. The fundus passes through the objective lens 11, the aperture of the perforated mirror 10, the focusing lens 12, the variable magnification lens 13, and the taking lens 14, and reaches the flip-up mirror 15. The fundus image reflected by the flip-up mirror 15 includes a field lens 17, a reflection mirror 18,
It is observed by the examiner via the eyepiece lens 19.

At the time of photographing, the photographing light source 3 emits light, the photographing light passes through substantially the same optical path, and the flip-up mirror 15 moves out of the optical path, so that the fundus image is photographed on the film 16.

Further, the examiner looks into the eyepiece lens 19 and looks at the fundus.
Observing Ef, driving a focus knob (not shown) provided on the focus shaft 20 to rotate the focus shaft 20,
Focus the focus system to the fundus Ef. Next, the examiner stops the focus operation when the subject is in focus, and brings the focusing lens 12 to a stationary position. At that time, the movable plate 21 is interlocked with the rotation of the focus lever 22, and the field stop 8 is arranged at a position conjugate with the fundus oculi Ef. At the same time, diopter detector 2
3, the diopter information of the subject is input to the control device 24. Further, the examiner performs a zooming operation to rotate the zooming shaft 27, which causes the variable power small gear 28 to rotate,
The variable large gear 26 also rotates to drive the cam ring 25. At this time, the variable power lens 13 moves in a predetermined relationship to change the angle of view to a desired size.

At the same time, the variable power detector 29 sends the angle of view information to the control device 24. The control device 24, to which these two pieces of information are input, calculates the aperture opening amount that optimizes the diopter and the angle of view, and outputs a command signal to the field aperture drive device 30. The field stop driving device 30 drives the sliding plate 32 in a direction perpendicular to the optical axis via the pinion 31 and the rack 33. At this time, the guide screws 34 and 35 are attached to the long hole 32.
Since it moves along a and 32b, the field stop 8 is not displaced in the optical axis direction, and the focused state is not damaged. Further, as the sliding plate 32 moves, the opening / closing pin 36 of the diaphragm blade 8a is driven, thereby opening / closing the diaphragm blade 8a of the field diaphragm 8.

In this way, the aperture diameter of the optical axis that is incident on the eye E to be examined at the time of photographing becomes the aperture opening diameter corresponding to the photographing, the angle of view for observation, and the diopter of the subject, and at the periphery of the fundus Ef. It is possible to prevent the generation of harmful scattered and reflected light that is generated, and to prevent the subject from being irradiated with an unnecessary light beam and causing pain.

FIG. 4 is a block diagram of the second embodiment. The fundus camera 41 has a display device 42 and a photographing switch 4 on the examiner side.
3 is provided, and an input switch 44 and a chin rest 45 are provided on the subject side. FIG. 5 is a circuit diagram of the inside of the fundus camera 41, in which the state signal S1 of the subject of the input switch 44 is input.
Is connected to the display device 42 and the photographing control system 46, and the photographing start signal S2 from the photographing switch 43 is also connected to the photographing control system 46. Further, the photographing control system 46 outputs a photographing operation start signal S3 to the photographing system.

The subject is fixed to the chin rest 45, and the examiner performs an alignment operation. The subject presses the input switch 44 when it is determined that the photographing is impossible. The examiner confirms by the display device 42 whether or not the subject is pressing the input switch 44, and the photographing switch 43 is used when photographing is performed.
push.

The shooting control system 46 determines whether to output the shooting operation start signal S3 from the status signal S1 and the shooting start signal S2. When the status signal S1 outputs a shooting enable signal, the shooting operation start signal S3 is output in response to the shooting start signal S2, and when the status signal S1 outputs a shooting disable signal, The shooting control system 46 does not output the shooting operation start signal S3 regardless of the shooting start signal S2.

In this way, when the subject himself / herself determines that the photographing is impossible, the photographing can be interrupted, and the subject can inspect and the imaging system without largely changing the proper position. Status can be transmitted to.

FIG. 6 is a circuit diagram of the third embodiment, and the same symbols as those in FIGS. 4 and 5 indicate the same members. The status signal S1 of the input switch 44 is the photographing mode switch 47.
Shooting control system 4 via a switch 48 controlled by
Connected to 6.

When the examiner turns on the photographing mode switch 47, the switch 48 is turned on, and the same effect as the second embodiment can be obtained. Further, when the examiner turns off the photographing mode switch 47, the switch 48 is also turned off, and the input switch 44 can be set to the invalid state as in the conventional example. In this way, when the examiner determines that the examinee's will is not necessary, conventional imaging can be performed.

[0028]

As described above, in the fundus camera according to the first aspect of the present invention, the field diaphragm is set to have an aperture diameter according to the diopter, photographing, and observation angle of view of the subject, thereby causing harmful scattering around the fundus. There is an effect of preventing the generation of reflected light and irradiating the subject with an unnecessary light beam to cause pain.

Further, in the fundus camera according to the second aspect of the present invention, when the subject is fixed or close to a proper position for photographing, the subject does not change the proper position significantly and The status can be transmitted to the shooting system. Moreover, since the examinee's will is reflected in the device, it is possible to reduce the number of imaging failures.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment.

FIG. 2 is a plan view of a field stop.

FIG. 3 is a front view of a field stop.

FIG. 4 is a configuration diagram of a second embodiment.

FIG. 5 is a circuit diagram of a second embodiment.

FIG. 6 is a circuit diagram of a third embodiment.

[Explanation of symbols]

 12 Focusing lens 15 Jumping mirror 18 Film 20 Focus axis 21 Moving plate 22 Focus lever 23 Diopter detector 24 Control device 29 Variable magnification detector 30 Field stop driving device 31 Pinion 32 Sliding plate 33 Rack 36 Opening pin 41 Eye fundus Camera 42 Display device 43 Shooting switch 44 Input switch 46 Shooting control system

Claims (3)

[Claims] 1. An illumination system having a field stop capable of opening and closing an aperture system for limiting an illumination area of a fundus of an eye to be inspected, and a fundus image of the eye to be inspected to a predetermined observation surface without depending on the diopter of the eye to be inspected. Or a focusing system that allows observation or shooting by focusing on the shooting surface,
And a means for opening and closing the aperture system of the field stop according to the focusing operation of the focusing system. 2. An input unit which a subject can input, a display unit which displays an output of the input unit at a position where the examiner can visually recognize, and an output of the input unit determines permission / non-permission of photographing. A fundus camera, comprising: 3. The fundus camera according to claim 2, wherein the photographing control means has a switching means for enabling or disabling the input means by an examiner.