JPH0515498A - Fundus oculi camera - Google Patents

Abstract

PURPOSE:To provide a fundus oculi camera which can change a photographing position with no eye turned by moving a part of a photographing lens to the direction perpendicularly instersected with the optical axis of a photographing optical system. CONSTITUTION:A part of a photographing lens 31 is designed to be moved to the direction normal to the optical axis '0' of a photographing optical system 2. When the photographing lens 31 is displaced, an image forming point 35 at the center of a film surface as an image forming surface is displaced vertically, a photographing position to be photographed on a film 32 is thereby changed. By reason of the fact, relative relation between the quantity of the vertical movement of the photographing lens 31 and the photographing position is computed in advance, so that the relation is stored in a frame memory 36. The photographing position over a film can be made sure by means of a monitor television provided that the observation position by the monitor television is to be changed based on the quantity of the vertical movement of the photographing lens.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fundus camera capable of changing a photographing part of a fundus without turning an eyeball.

[0002]

2. Description of the Related Art Conventionally, in fundus photography, as shown in FIG. 1, at the time of low-magnification photography (angle of view 45 °), the fovea central fovea 50
The optic disc and the optic disc 51 are positioned substantially evenly with respect to the center 52 of the screen, and a photograph is taken by determining the imaging site. In high-magnification photography (angle of view 30 °), the optic disc is shown in Fig. 2. A photographed portion is taken so that the photographed portion is positioned so that 51 is substantially located at the center 52 of the screen.

In order to obtain a photograph as shown in FIG. 1, as shown in FIG. 3, the central axis of the macula 50 is aligned with the optical axis 53 of the photographing optical system.
The eyeball 55 must be turned so that the midpoint 54 connecting the line between the optic disc and the optic disc 51 coincides. In order to obtain a photograph as shown in FIG. 2, the optical axis 53 of the photographing optical system of the fundus camera is required. The eyeball 55 must be turned so that the optic disc 51 is aligned with the eyeball. In the case shown in FIG. 1, the turning angle of the eyeball 55 is approximately 3 ° with respect to the optical axis 53 of the photographing optical system, and in the case shown in FIG.
The rotation angle of is about 11 ° with respect to the optical axis 53 of the photographing optical system.

For this reason, in the conventional fundus camera, the fixation target of the fixation target projection optical system is configured to be movable, and the eyeball 55 is rotated so that a desired photographing region can be obtained. Further, in another conventional fundus camera, a plurality of fixation targets are provided and one of them is turned on so that a desired imaging site can be obtained, and the eyeball 55 is turned.
In this type of fundus camera, one fixation target is required for each of the left and right eyes for low magnification and high magnification, so that at least four fixation targets are required.

[0005]

However, the eyeball 55
The turning is painful to the subject, and it is desirable to be able to change the imaging site with the eyeball 55 fixed as much as possible.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a fundus camera capable of changing a region to be photographed without turning the eyeball.

[0007]

A fundus camera according to the present invention comprises at least a part of a photographing lens provided in a photographing optical system for changing a photographing region of a fundus of an eye to be examined. It is characterized in that movable means for moving in a direction orthogonal to the axis is provided.

[0008]

[Operation] According to the present invention, the movable means moves a part of the taking lens in a direction perpendicular to the optical axis. When a part of the photographing lens is displaced in the direction perpendicular to the optical axis, the central image forming point on the image forming plane moves in the direction perpendicular to the optical axis, and the photographing region is changed.

[0009]

FIG. 4 shows a first embodiment of the fundus camera according to the present invention. In FIG. 4, 1 is a fundus illumination system,
2 is a fundus imaging system. The fundus illumination system 1 includes a halogen lamp 3 as an observation light source, a condenser lens 4, a xenon tube 5 as a photographing light source, a condenser lens 6, a ring diaphragm 7, a reflecting mirror 8, a relay lens 9, and a perforated mirror 10.
The fundus imaging system 2 has an objective lens 12, a focusing lens 13, and a quick return mirror 14 which face the eye 11 to be examined. The quick return mirror 14 constitutes a part of an image receiving optical system 15 as an observation device. The image receiving optical system 15 is a field lens 16,
It has a reflection mirror 17, a TV relay lens 18, and a CCD camera 19.

The illumination light of the halogen lamp 3 is once focused by the condenser lens 4 at the position of the xenon tube 5, re-focused by the condenser lens 6 and guided to the ring diaphragm 7. The illumination light passes through the ring-shaped diaphragm 7, becomes a ring-shaped light flux, is reflected by the reflecting mirror 8 and is guided to the relay lens 9, and passes through this relay lens 9 and is guided to the perforated mirror 10. The annular light flux is reflected by the perforated mirror 10 and guided to the objective lens 12, passes through the objective lens 12, and illuminates the fundus 20 of the eye 11 to be inspected.

The reflected light beam from the fundus 20 is guided to the quick return mirror 14 via the objective lens 12, the hole portion 21 of the perforated mirror 10 and the focusing lens 13, and is reflected by the quick return mirror 14 to be reflected by the field lens 16. First, a fundus image is formed. The light flux forming this fundus image is reflected by the reflection mirror 17,
The image is guided to the CCD camera 19 via the TV relay lens 18, and a fundus image is formed on the image receiving surface of the CCD camera 19.

Near the hole 21 of the perforated mirror 10, two optical fibers 23 and 24 for guiding the light beam from the light source 22 are provided. The tip 23 of this optical fiber 23, 24
The light beams emitted from a and 24a are guided to the cornea 25 via the objective lens 12 as a light beam for eye position adjustment, and a light spot image is formed on the cornea 25. The luminous flux that forms the light spot image is the fundus 20
Similarly to the reflected light flux from, the light is guided to a CCD camera 19 having an image receiving surface as a conjugate surface of the fundus of the eye to be inspected, and the CCD camera
A light spot image is formed at 19.

The CCD camera 19 has a character composition processing circuit 26.
The character synthesis processing circuit 26 is connected to a monitor television 27 as a display means. On the monitor TV 27, light spot images 29 and 30 are displayed together with the fundus image 28. The examiner determines the relative positions of the fundus camera and the eye 11 to be examined depending on whether or not the light spot images 29 and 30 are reflected at the regular positions.

When the photographing switch is operated, the xenon tube 5 emits light. The illumination light from the xenon tube 5 illuminates the fundus 20 in the same manner as the illumination light from the halogen lamp 3. The light flux reflected by the fundus 20 is guided to the quick return mirror 14 via the objective lens 12, the hole portion 21 of the perforated mirror 10, and the focusing lens 13. Behind the quick return mirror 14, a taking lens 31 as a magnification varying means is provided. A film 32 as a recording means is provided behind the taking lens 31.

The quick return mirror 14 is adapted to retract from the optical path of the photographing optical system 2 in association with the operation of the photographing switch. The light flux reflected from the fundus 20 is guided to the photographing lens 31 by retracting the quick return mirror 14 from the photographing optical system 2. The taking lens 31 is for low magnification here. The taking lens 33 for high magnification is retracted from the optical path of the taking optical system 2.

The taking lens 31 forms a fundus image on the film 32. The photographing range of the fundus image is substantially the same as the observation range displayed on the monitor television 27.

At least a part of the photographing lens 31 is movable by a movable means 34 in a direction perpendicular to the optical axis O of the photographing optical system 2 (direction of arrow Z). When the taking lens 31 is displaced as shown by the broken line, the image forming point 35 at the center of the film surface as the image forming plane is displaced in the vertical direction, so that the image taking part to be taken on the film 32 is changed. The correlation between the vertical movement amount of the photographing lens 31 and the photographing region is calculated in advance, the correlation is stored in the frame memory 36, and the monitor is performed based on the vertical movement amount of the photographing lens 31. By changing the observation portion of the television 27, the photographed portion on the film 32 can be confirmed by the monitor television 27. Further, the photographing lens 31 may be moved in the vertical direction when the photographing field mark on the monitor TV 27 is moved.

The same applies when the taking lens 33 for high magnification is inserted in the optical path of the taking optical system 2.

The character synthesizing processing device is used in the monitor television 27 by replacing the photographing lens 31 and the photographing lens 33.
The shooting angle of view and shooting field mark are displayed on.

In the case of the first embodiment, the image receiving optical system 15 as the observing means and the magnification varying means for photographing are independent, and when the photographing lens 33 is inserted in the optical path of the photographing optical system 2, The shooting range is smaller than the observation range.

FIGS. 5 and 6 show a second embodiment of the fundus camera according to the present invention, in which taking lenses 31 and 33 are provided between the focusing lens 13 and the quick return mirror 14, respectively. According to the configuration, when a part of the taking lenses 31, 33 is moved in the direction perpendicular to the optical axis O of the taking optical system 2 (direction of arrow Z), the observation range of the fundus image 28 displayed on the monitor TV 27 is changed. It is changed according to the change of the shooting range to be reflected on the film 32.

As shown in FIG. 6, the monitor television 27 has a photographing field mark 37 for low magnification and a photographing field mark 38 for high magnification when the photographing lens 31 for low magnification is inserted. When the photographing visual field mark 38 is displayed and is moved, the amount of movement of the photographing lens 33 for high magnification in the vertical direction with respect to the optical axis O is determined correspondingly to the selection of the photographing visual field mark 38 for high magnification. The taking lens 33 is used to take an optical system 2
When it is inserted into the optical path of, the shooting field of view switches to high magnification first, and the moving means 34 moves the shooting lens 33 according to the selection.
Is moved.

Although the embodiment has been described above, the present invention is not limited to this, and includes the following.

In the first embodiment, the focusing lens 13 has a relay lens function for forming a real image, and the taking lenses 31, 33
It is also possible to give a relay lens function to the and to change the magnification by removing and replacing the relay lens system.

It is also possible to automatically change the photographing light amount according to the magnification change of the magnification changing means of the photographing optical system 2.

It is also possible to change the magnification by exchanging a part of the photographing lenses 31 and 33, and to change the magnification with the zoom lens.

[0027]

According to the fundus camera of the present invention, it is possible to change the imaging region without turning the eyeball.

[Brief description of drawings]

FIG. 1 is a diagram showing a photographing state of a fundus image for low magnification.

FIG. 2 is a diagram showing a photographing state of a fundus image for high magnification.

FIG. 3 is a diagram for explaining a turning angle of an eyeball.

FIG. 4 is a diagram showing an optical system of a first embodiment of the fundus camera according to the present invention.

FIG. 5 is a diagram showing an optical system of a second embodiment of the fundus camera according to the present invention.

6 is a diagram for explaining an observation range of a fundus image shown in FIG.

[Explanation of symbols]

2 Shooting optical system 11 Eye to be examined 20 fundus 27 monitor tv 31, 33 Shooting lens 32 films 34 Movable means O optical axis

Claims (3)

[Claims] 1. A fundus camera characterized by further comprising movable means for moving at least a part of a taking lens provided in the taking optical system in a direction orthogonal to an optical axis of the taking optical system. 2. The fundus camera according to claim 1, wherein the photographing optical system has an observing unit and a magnification varying unit for photographing independent of the observing unit. 3. The mark indicating the fundus photographing range by the magnification varying unit is displayed on the display unit of the observing unit, and the mark and the photographing range are interlocked with each other. Fundus camera.