JP2541974B2 - Fundus camera - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fundus camera, and more particularly to a fundus camera having an index projection system for focusing.

(Prior Art) As a fundus camera, there is known a fundus camera provided with an index projection system for focusing in order to facilitate focusing on the fundus. In this type of fundus camera, the focus state of the focus index image projected on the fundus is observed, and the focus adjustment to the fundus is performed based on this focus state.

In addition, in the fundus camera, in addition to general color photography, an exciter filter is inserted in the illumination system and a barrier filter is inserted in the observation and photography system so that fluorescence fundus image photography is possible. In this technique, a subject is injected with a fluorescent agent, and a plurality of changes in the fundus image after the injection of the fluorescent agent are photographed.

By the way, at the time of this fluorescence imaging, a fluorescent blood vessel image is observed thinly in the initial stage of the injection of the fluorescent agent,
Like a conventional fundus camera, with the same brightness of the index image for focusing as in general color imaging, there is a drawback that the focus index image interferes and a fine blood vessel image cannot be observed. Is.

(Object of the Invention) The present invention is intended to solve the problem of this conventional fundus camera, and during general photography such as color photography, the focus index image is clearly observed. An object of the invention is to provide a fundus camera capable of projecting a focusing index that does not hinder observation of a fine blood vessel image during fluorescence imaging.

(Structure of the Invention) In order to achieve the above object, the present invention provides an illumination system for illuminating a fundus of a subject's eye, an observation and photographing system for observing and photographing the fundus of the subject's eye, and for focusing on the fundus of the subject's eye. With a target projection system for projecting a target image, in a fundus camera configured to perform focusing of the observation and photographing system by observing the in-focus state of the focus index image, in the fundus of the eye to be examined. When the fluorescent image is observed and photographed, the fundus camera is configured to reduce the brightness of the focus index image.

(Example) Hereinafter, the Example of this invention is described based on drawing.

1 and 2 are views showing an embodiment of the present invention.

First, the configuration will be described. FIG. 1 shows an optical system of a fundus camera, which projects an illumination system 1, an observation and photographing system 2 which is orthogonal to the illumination system 1 and faces the eye E to be inspected, and a focusing index. And an index projection system 3 for

In this illumination system 1, a photographing light source 6, a condenser lens 8, a ring slit plate 10, a relay lens 11 and the like are sequentially arranged on an illumination optical axis 4. Further, a semi-transparent mirror 12 is obliquely provided between the condenser lens 8 and the ring slit plate 10, and an observation light source 16 and a condenser lens 18 are arranged on the incident optical axis of the semi-transparent mirror 12. Further, an exciter filter 9 for fluorescence photography is disposed between the relay lens 11 and the ring slit plate 10 so as to be freely inserted and removed. The exciter filter 9 is inserted by the exciter filter driving device 7 into the optical path of the illumination system 1 only during fluorescence photography.

In the illumination system 1 having the above structure, the illumination light emitted from the observation light source 16 or the photographing light source 6 is transmitted through the ring slit plate 10 and then reflected by the perforated oblique mirror 22 to pass through the objective lens 20. It leads to the eye E to be inspected and illuminates the fundus F.

On the other hand, the observation / photographing system 2 is for observing and photographing the image of the fundus F illuminated by the illumination system 1, and includes an objective lens 20, a perforated oblique mirror 22, along the observation / photographing optical axis 19. The focusing lens 24 and the imaging lens 26 are provided, and the fundus image is film 28.
Form on top. At the time of observation, the reversing mirror 30 is obliquely provided on the observation and photographing optical axis 19 as shown by the solid line in the figure, and the fundus image formed on the field lens 32 is observed by the examiner by the reflection mirror 34 and the eyepiece lens 36. . In addition, focusing lens 24
And a small mirror 52, 52 ', which will be described later, are provided with a barrier filter 60 which is removably arranged.
The barrier filter driving device 66 inserts 60 into the optical path of the observation and photographing system 2 only during fluorescence photographing.

In addition, the index projection system 3 uses the index image for focusing on the fundus F.
62 for projecting a light source 40 arranged on the index projection optical axis 38, a condenser lens 42, an index mask plate 46 having a slit-shaped opening to which a deflection prism 44 is adhered, a focusing lens 48, a reflection An index mask plate 4 having a mirror 50
The light beam that has passed through 6 is separated into two light beams of different directions by the deflection prism 44, and then small mirrors arranged on both sides of the observation and photographing optical axis 19 (arranged in the direction perpendicular to the paper surface in the figure). A target index image 62 for focusing is formed on the fundus F through the objective lens 20 by being reflected by 52 and 52 '. The focusing lens 48 is movable along the index projection optical axis 38 in conjunction with the movement of the focusing lens 24 of the observation and photographing system 2.

Further, a filter unit 54 for changing the color tone and brightness of the index projection light is provided between the index mask plate 46 and the condenser lens 42. The filter section 54 is provided with a green filter 56 and a neutral density filter 58 so that it can be selectively inserted into the optical path, and the green filter 56 is inserted into the optical path during observation in general color photography. Also, in the case of fluorescence photography, a neutral density filter 58
Is inserted into the optical path.

This selection is automatically made by driving the exciter filter 9 and the barrier filter 60.

That is, the filter unit 54 is driven by the filter unit driving device 61, and the filter unit driving device 61 is electrically connected to the control unit 64. The control unit 64 is also connected to the barrier filter driving device 66 and the exciter filter driving unit 7, and the operation switch
The signal from 68 drives each filter. When the fluorescence photographing mode is set by the operation switch 68, the control unit 64 causes the exciter filter 9 to enter the optical path of the illumination system 1 and the barrier filter.
60 is automatically inserted in the optical path of the observation and imaging system 2,
The neutral density filter 58 of the filter unit 54 is configured to be inserted into the optical path of the index projection system 3. Also, when the color shooting mode is set by the operation switch 68,
The control unit 64 is configured so that the exciter filter 9 and the barrier filter 60 are separated from each optical path, and the green filter 56 of the filter unit 54 is inserted into the optical path of the index projection system 3.

With such a configuration, at the time of color photographing, the green filter 56 is inserted into the optical path of the index projection system 3, so that the green focus index image 62 is projected on the fundus F and is superimposed on the fundus image. Are observed as shown in FIG. In this case, the fundus image has a red color tone, and the green focus index image 62 is clearly identified.

Further, in the case of fluorescence photography, a dimming filter 58 is inserted in the optical path of the index projection system 3 instead of the green filter 56, white light is present on the fundus F, and depending on the brightness at the time of color imaging. A dark focus index image 62 is projected.
At the time of this fluorescence imaging, the fundus blood vessel image has a green color tone, the white light focusing image 62 can be clearly identified, and the brightness is darker than in color imaging, so a thin dark blood vessel image is obtained. It does not hinder the observation.

As a result, the connection lens is used for both color imaging and fluorescence imaging.
At 36, as shown in FIG. 2, the fundus images are superimposed and the focusing index image 62 is clearly observed. The focusing lens 2 is aligned so that the focusing index image 62 is aligned.
It is possible to adjust the focus on the fundus by moving the lenses 4 and 48, and when this adjustment is completed, the photographing light source 6 is caused to emit light, and the reflection mirror 30 is removed from the optical path to cause the fundus image on the film 28. Is to shoot.

(Effects of the Invention) According to the present invention described above, when the fluorescent image of the fundus of the eye to be inspected is observed and photographed, the brightness of the focusing index image is reduced, so that it is used for focusing during general color photographing. It is possible to set the brightness of the index image so that it can be clearly identified, and it is possible to reduce the brightness of the index image for focusing during fluorescence photography, especially when the fundus blood vessel image is dark at the initial stage of injection of the fluorescent agent. A fine fluorescent blood vessel image can be easily observed without disturbing the index image.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a fundus camera of the present invention, FIG. 1 is a diagram showing an optical system of the fundus camera, and FIG. 2 is a diagram showing a fundus image. 1 …… Illumination system 2 …… Observation and photography system 3 …… Index projection system 9 …… Exciter filter 54 …… Filter section, 56 …… Green filter 58 …… Dimming filter, 60 …… Barrier filter 62 …… Focus Index image for alignment E ... Eye to be examined, F ... Fundus

Claims (2)

(57) [Claims] 1. An illumination system for illuminating a fundus of a subject's eye, an observation projection system for observing and photographing the fundus of the subject's eye, and an index projection system for projecting an index image for focusing on the fundus of the subject's eye. In a fundus camera configured to observe the in-focus state of the focusing index image to perform focusing of the observation and photographing system, when observing and photographing the fluorescence image of the fundus of the eye to be examined, the focusing is performed. A fundus camera characterized by being configured to reduce the brightness of the index image. 2. An exciter filter in the illumination optical path,
A barrier filter is arranged in the optical path of the observation / photographing system so that it can be freely inserted and removed, and at least one of the filters is inserted in the optical path to reduce the brightness of the focus index image. The fundus camera according to claim 1, which is characterized.