JPH07194554A - Stereoscopic fundus camera - Google Patents

Abstract

PURPOSE:To facilitate alignment of an eye to be examined with a device by providing at least one pair of alignment light sources in or near a pupil conjugate position which are symmetrical with respect to the optical axis of an objective lens. CONSTITUTION:A holed mirror 2 and a diaphragm plate 3 are disposed on the optical path 01 of an objective lens 1. A prism 4L, a focusing lens 5L, an image-focusing lens 6L, a switching mirror 7L, and a prism 8L are provided on the optical path OL of an opening on the left side of the diaprhagm plate 3, and a prism 4R, a focusing lens 5R, an image focusing lens 6R, a switching mirror 7R and a prism 8R are arranged on the optical path OR of an opening on the right side of the plate 3. A common field lens 9 is placed behind the prisms 8L, 8R and a relay lens 10 and a TV camera 11 are disposed on the optical path 02 of the lens 9 and connected to a TV monitor 12. An alignment light source 14 is placed between the holed mirror 2 and the diaphragm plate 3 via an optical fiber 13 having a bifurcated end, and the two end faces of the fiber 13 are installed in the hole in the mirror.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art In a conventional stereoscopic fundus camera, alignment is performed by observing a fundus image from the left and right optical paths.

[0003]

However, with this conventional apparatus, it is difficult to perform accurate alignment, and an image on one side may be blurred or partially darkened. In addition, in a non-mydriasis fundus camera that observes a fundus image using an infrared television, it is difficult to perform alignment because flare does not appear.

The object of the present invention is to solve the above-mentioned problems,
An object of the present invention is to provide a stereoscopic fundus camera that facilitates the alignment between the eye to be inspected and the device.

[0005]

A stereoscopic fundus camera according to the present invention for achieving the above object divides the reflected light from the fundus of the eye to be examined into two light fluxes by a two-hole diaphragm and opens the fundus of the eye to be examined. In the stereoscopic fundus camera for photographing, at least a pair of alignment light sources symmetrical to the optical axis of the objective lens is provided at or near the pupil conjugate position.

[0006]

In the stereoscopic fundus camera having the above-mentioned structure, since the corneal reflected light from the positioning light source can be observed in a state of overlapping with the fundus image, the positioning can be performed easily and accurately.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail based on the illustrated embodiments. FIG. 1 is a configuration view of a non-mydriatic stereoscopic fundus camera capable of stereoscopic imaging according to the first embodiment as viewed from above. On the optical path O1 behind the objective lens 1 having the focal plane for the eye E to be inspected, a perforated mirror 2 arranged at a conjugate position with the pupil and a diaphragm plate 3 having two left and right openings are arranged. A prism 4L and a focus lens 5 are provided on the optical path OL at the left opening of the diaphragm plate 3.
L, imaging lens 6L, switching mirror 7L, prism 8L
Is provided, and the prism 4R, the focus lens 5R, the imaging lens 6L, and the switching mirror 7 are provided on the optical path OR of the right opening.
R and the prism 8R are arranged. Prism 8L, 8
A shared field lens 9 is placed behind R, a relay lens 10 and a TV camera 11 are arranged on the optical path O2 thereof, and the output of the TV camera 11 is connected to a TV monitor 12.

A positioning light source 14 is placed between the perforated mirror 2 and the diaphragm plate 3 via an optical fiber 13 having a bifurcated tip, and when the perforated mirror 2 is viewed from the optical axis direction, As shown in FIG. 2, two holes of the optical fiber 13 are placed in the hole 2a.
Two end surfaces 13L and 13R are installed, and the openings 3L and 3R of the diaphragm plate 3 are located behind the hole 2a. As shown in FIG. 3, a lens 15, a field stop 16, a collimator lens 17, and a fundus illuminating light source 18 are arranged on the optical path O3 in the reflection direction of the perforated mirror 2, and the field stop 16 includes focus lenses 5L and 5R. It is designed to work together. Further, the fixation light sources 19L and 19R are arranged behind the objective lens 1 on both sides of the optical path O1 at positions where the emitted light beams cross the optical axis at an angle of about 15 ° after passing through the objective lens 1. ing.

This stereoscopic fundus camera is mainly used for analysis of the nipple En, and photographs with the nipple En at the center of the screen. FIG. 1 shows an example in which the right eye is photographed, and the nipple En reaches the optical axis of the objective lens 1 when the subject gazes at the light flux emitted from the fixation light source 19L with the right eye. When photographing the left eye, the fixation light source 19R may be fixed to the left eye. The luminous fluxes emitted from the fixation light sources 19L and 19R and incident on the eye E to be inspected have only to have an angle of about 15 ° with respect to the optical axis. Therefore, the fixation light sources 19L and 19R are located on the field stop 16. Can also be provided.

A luminous flux from a fundus illuminating light source 18 including an infrared light source for observing the fundus and a strobe for photographing passes through a collimating lens 17, a field stop 16 and a lens 15, and is reflected by a perforated mirror 2 to pass through the objective lens 1. Through the fundus of the eye E to be examined
Illuminate Er. The fundus reflected light passes through the objective lens 1 and the perforated mirror 2, and is split into two left and right light beams by the openings 3L and 3R of the diaphragm plate 3. The left light flux is a prism 4L, a focus lens 5L, an imaging lens 6L, a switching mirror 7
L, the right light flux passes through the path of the prism 8L
R, focus lens 5R, imaging lens 6R, switching mirror 7R, prism 8R, field lens 9, relay lens 10, and television camera 11 respectively.
Is imaged. At this time, the field stop 16 is interlocked with the focus lenses 5L and 5R to clearly form the fundus image E ′ on the image pickup surface of the television camera 11.

The light beam emitted from the alignment light source 14 is guided by the optical fiber 13, and its end face serves as a secondary light source.
The cornea Ec of the eye E to be examined is irradiated through the hole of the perforated mirror 2 and the objective lens 1. As shown in FIG. 1, in the case of photographing the right eye to be inspected, the corneal reflected light generated by irradiation of the left end face 13L of the optical fiber 13 is the objective lens 1 and the perforated mirror 2.
Through the left side opening 3L of the diaphragm plate 3, and the prism 4
L, the focus lens 5L, the imaging lens 6L, the switching mirror 7L, the field lens 9, and the relay lens 10, and the television camera 11 overlaps with the fundus image by the left optical path.
Is imaged. Therefore, the examiner performs alignment so that the corneal reflection image 13 'clearly appears in the right center of the screen of the television monitor 12 as shown in FIG.

As shown in FIG. 2, when the tip surfaces 13L and 13R of the optical fiber 13 are arranged on the left and right on the center lines of the two openings of the diaphragm plate 3, when the distance between the end surfaces 13L and 13R becomes too short, As shown in FIG. 4, the end faces 13L, 13
The R may be arranged so as to be shifted above or below the center line.
In that case, as shown in FIG. 5, the corneal reflection image 13 ′ is aligned when it comes to a vertically eccentric position on the screen of the television monitor 12, but the precise position is difficult to understand, so it was generated by the mark generator. The reference mark M is displayed on the TV monitor 12
Precise alignment can be performed by outputting the image on the screen of No. 2 and matching the reference mark M with the corneal reflection image 13 '. The reference mark M is output to the upper part of the left or right screen of the television monitor 12 together with the switching of the fixation light sources 19L and 19R between right and left.

As shown in FIG. 5, the optical fiber 1 is aligned so that the image 13 'is located at the vertical center line of the single-sided screen.
It is preferable to determine the distance between the three end faces 13L and 13R. The end faces 13L and 13R in FIGS. 2 and 4 are arranged on both the left and right sides of the objective lens 1, but if a pair of optical fiber end faces is further provided on the outer side, a reflected image can be projected on both side screens. .

FIG. 6 is a layout view of the fixation light sources when the angle of view is rather narrow. The fixation light sources 21L and 21R are arranged on both the left and right sides of the objective lens 1. In addition, the light source for fixation 21
Immediately before L and 21R, small openings 22L and 22R, respectively
Is provided. The light beams emitted from the small openings 22L and 22R are narrowed down, and are less visible to the eyes other than the eye to be examined, and blurring is reduced.

FIG. 7 is a block diagram of the second embodiment, which is an example of a mydriasis type fundus camera. The prism 8L in FIG.
8R, the field lens 9, the relay lens 10, the television camera 11, and the television monitor 12 are removed, and a mirror 24 is provided on the optical path behind the switching mirrors 7L and 7R, respectively.
L and 24R are placed, and mirrors 25L and 2L are provided in the reflecting direction.
5R is placed. Further, eyepiece lenses 26L and 26R are arranged in the reflection directions of the mirrors 25L and 25R, respectively.

As in the first embodiment, the fundus images that have passed through the left and right optical paths are switched mirrors 7L and 7R and the mirror 2 respectively.
4L, 24R, mirrors 25L, 25R, eyepiece lens 26
After passing L and 26R, it is observed by left and right eye examinations eL and eR. On either the left or right eye, the corneal reflection image is visually recognized together with the fundus image. The reference mark is the eyepiece lens 26L and the eyepiece lens 26.
By providing it on the focal plane of R, the examiner can visually recognize the reference mark together with the corneal reflection image, and the alignment can be performed by aligning both.

In the second embodiment, since the fundus is illuminated with visible light, the subject feels glare, but since the fixation light sources 21L and 21R are outside the fundus illumination visual field. You can stare.

[0018]

As described above, since the stereoscopic fundus camera according to the present invention is provided with the light source for alignment, the alignment of the eye to be inspected can be performed easily and accurately.

[Brief description of drawings]

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

FIG. 2 is a configuration diagram of the vicinity of a perforated mirror viewed from the optical axis direction.

FIG. 3 is a configuration diagram of a perforated mirror reflection direction.

FIG. 4 is a configuration diagram of the vicinity of a perforated mirror viewed from the optical axis direction.

FIG. 5 is a front view of a television monitor.

FIG. 6 is a layout view of a light source for fixation when the angle of view is narrow.

FIG. 7 is a configuration diagram of an optical finder portion of a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Objective lens 2 Perforated mirror 3 Two-hole diaphragm plate 12 Television monitor 13 Optical fiber 14 Light source for alignment 18 Light source for fundus illumination 19L, 19R, 21L, 21R Light source for fixation

Claims (1)

[Claims] 1. A stereoscopic fundus camera for photographing a fundus of an eye to be examined by dividing a reflected light from a fundus of the eye to be examined into two light fluxes by a two-hole diaphragm plate, and at the optical axis of an objective lens at or near a pupil conjugate position. A stereoscopic fundus camera provided with at least a pair of symmetrical light sources for alignment.