JPH0554779B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a fundus camera for stereoscopic photography that can obtain a stereoscopic photograph of a fundus image.

(Prior art) In addition to regular imaging, there has been a demand for fundus cameras to take three-dimensional images of the surface and irregularities of the fundus in order to actively analyze lesions and their progress. In response to this demand, various fundus cameras for stereoscopic photography have been proposed that can obtain stereoscopic photographs of fundus images.

For example, an optical path splitting prism that divides the light beam reflected from the fundus into two is placed behind and near the perforated mirror for fundus illumination provided in the imaging system for photographing the fundus image. In this system, two images of the fundus are formed simultaneously on a film by moving the fundus camera itself by a small amount in parallel to the subject's eye, capturing images of the fundus at each position of movement, and printing the images onto a single film. There is a method that forms a fundus image that is shifted and obtains a stereoscopic photograph of the fundus image.

(Problem to be solved by the invention) However, the conventional fundus camera for stereoscopic photography, which divides the optical path into two to obtain a stereoscopic picture, is only for stereoscopic photography and cannot take pictures of normal fundus images. There is a problem. In addition, the fundus camera for stereoscopic photography, which obtains a stereoscopic photograph of the fundus image by moving the fundus camera itself by a small amount in parallel with the conventional eye to be examined, can also take regular fundus photographs in addition to stereoscopic photography. However, it has the disadvantage that the fundus camera itself must be moved relative to the subject's eye and a fundus image must be taken at each moving position, and two fundus images cannot be obtained at the same time. However, there is a problem that the shooting operation is troublesome.

(Object of the Invention) Therefore, an object of the present invention is to provide a 3D system that is capable of not only 3D imaging but also normal imaging, and that allows two fundus images to be taken at the same time with good operability during 3D imaging. An object of the present invention is to provide a fundus camera for photography.

(Means for Solving the Problems) A fundus camera for stereoscopic photography of the present invention for achieving the above object includes: an illumination system for illuminating the fundus of the eye to be examined; and a first photographing of the fundus image of the eye to be examined. The first guide to the means
an imaging optical system having an optical path; an optical path splitting and reflecting member disposed in the first optical path and forming a second optical path that guides the fundus image of the eye to be examined to a second photographing means; and the first optical path or the second optical path. a light beam splitting member that is provided in one of the optical paths at a position substantially conjugate with the pupil of the eye to be examined and that divides the light beam from the fundus image formed by the imaging optical system into two; Accordingly, one of the first and second photographing means has a relay lens for forming two fundus images.

(Function) According to the present invention, normal fundus photography and stereoscopic photography can be performed by selectively switching the optical path depending on the photography, so desired photography can be performed with a simple photography operation. be able to.

(Example) Hereinafter, an example of the fundus camera according to the present invention will be described with reference to the drawings.

In FIG. 1, 1 is an illumination system, 2 is an imaging optical system, 3 is a finder system, 4 is an eye to be examined, and 5 is the fundus of the eye 4 to be examined. The illumination system 1 includes an observation light source 6
, a first condenser lens 7, a photographing light source 8,
It is roughly composed of a second condenser lens 9, a ring-shaped slit aperture stop 10, a total reflection mirror 11, and a relay lens 12, and _l1 is the optical axis of the illumination system 1. The imaging optical system 2 includes an objective lens 13
, a perforated mirror 14 , a focusing lens 15 , and an imaging lens 16 , and l ₂ is the optical axis of the imaging optical system 2 . Imaging lens 16 of this imaging optical system 2
A switching mirror 17, a quick return mirror 18, and a film 19 are provided behind the mirror. Here, the film 19 constitutes a part of a first photographing means for photographing a normal fundus image. The finder system 3 is composed of a quick return mirror 18, a field lens 20, a prism 21, and an eyepiece lens 22. The quick return mirror 18 is inserted into the optical path of the imaging optical system 2 during observation, and is inserted into the optical path of the imaging optical system 2 during photography. It is evacuated out of the optical path.

The observation light source 6 is turned on during observation, the photographing light source 8 is turned on during photographing, the first condenser lens 7 has a function of condensing illumination light during observation, and the second condenser lens 9 has the function of condensing illumination light during photographing. It has the function of concentrating light. During observation and photographing, each illumination light passes through a ring-shaped slit aperture diaphragm 10 arranged at a position substantially conjugate with the pupil of the eye to be examined, is guided as ring-shaped slit light to a total reflection mirror 11, and then passes through a relay lens 12 and an aperture. The image is projected onto the fundus 5 of the eye 4 to be examined via the open mirror 14 and the objective lens 13 .

The switching mirror 17 is used when taking stereoscopic photographs.
It is inserted into the first optical path constituted by the imaging optical system 2, and is withdrawn from the first optical path during normal photography. This switching mirror 17 functions as an optical path splitting and reflecting member that forms a second optical path that guides the fundus image to the second photographing means 23 . Second photographing means 2
3 is a lens 24, an aperture plate 25, and an aperture plate 25;
It is composed of a prism 26 for deflecting the two light beams divided inwardly with respect to the optical axis, relay lenses 27 and 28 for forming fundus images from the two light beams, and a film 29, It can be attached to and detached from a lens barrel (not shown) that constitutes the imaging optical system 2. Here, the second
The photographing means 23 is for taking a stereoscopic photograph, and the aperture plate 25 is provided on the second optical path at a position substantially conjugate with the pupil of the eye to be examined. This aperture plate 25 has small holes 30, 3 as shown in FIG.
1 is formed. This aperture plate 25 functions as a light beam splitting member that divides the fundus image formed by the imaging optical system 2 into two.

3 and 4 show second and third embodiments of the fundus camera for stereoscopic photography according to the present invention, and the prism 26 in FIG. The prism 26 in FIG. 4 is configured to reflect two beams in opposite directions and guide them to separate films 32 and 33 while increasing the distance and reflecting them in the same direction. This is what I did.

(Effects of the Invention) As explained above, the fundus camera according to the present invention selectively switches the imaging optical path depending on the imaging, so it is possible to perform not only stereoscopic imaging but also normal imaging, and , when taking stereoscopic shots,
This has the effect of improving operability and allowing two fundus images to be taken at the same time.

[Brief explanation of the drawing]

FIG. 1 is an optical system path diagram showing the main part configuration of a fundus camera for stereoscopic photography according to the present invention, and FIG.
The enlarged plan view of the diaphragm plate shown in the figure, FIGS.
FIG. 7 is a path diagram of a principal optical system showing a third embodiment. 1...Lighting system, 2...Photographing system, 4...Eye to be examined,
5... fundus, 10... ring-shaped slit aperture diaphragm, 15... focusing lens, 17... switching mirror, 19... film, 23... second photographing means,
25...Aperture plate, 27...Relay lens.

Claims (1)

[Scope of Claims] 1. An illumination system that illuminates the fundus of the eye to be examined;
an imaging optical system having an optical path; an optical path splitting and reflecting member disposed in the first optical path and forming a second optical path that guides the fundus image of the eye to be examined to a second photographing means; and the first optical path or the second optical path. a light beam splitting member that is provided in one of the optical paths at a position substantially conjugate with the pupil of the eye to be examined and that divides the light beam from the fundus image formed by the imaging optical system into two; A fundus camera for stereoscopic photography, characterized in that it comprises a relay lens for forming two fundus images on one of the first and second photographing means.