JPS5990547A - Eyebottom camera - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ophthalmological photographing device, and more particularly to a device for taking photographs for stereoscopic viewing.

Traditionally, stereoscopic viewing has been performed using negative film photographed from the fundus of the eye, and its range of applications is wide, including the ability to determine glaucoma based on the degree of indentation of the papilla.

This type of stereoscopic imaging can be achieved by, for example, installing an Allen prism in front of the objective lens of a fundus camera and rotating it.
How to take photos from two directions Each photo is 35mm
Since it corresponds to a full screen of film, it is advantageous in terms of magnification, but since the optical axis of the eyeball and the optical axis of the fundus camera are misaligned, image performance is poor and switching operations are troublesome.

On the other hand, the pupil is divided into two parts at a position conjugate to the pupil of the subject, and the pupil is divided into three parts.
A simultaneous stereoscopic photography method in which two images are taken in one frame of a 5m+n film is also known, but this method is disadvantageous in that the photographing magnification and field of view are small.

An object of the present invention is to realize photographs that are comparable in image performance to those taken with an ordinary fundus camera and that have a sufficiently wide field of view.

FIG. 1 depicts an embodiment of the invention. In the figure, E is the eye to be examined, Ep is the pupil, and EC is the cornea. 1 is an objective lens, 2 is an oblique perforated bell, and 6 is a two-hole diaphragm. The two-hole diaphragm 3 has two openings 3a and 3 in the horizontal direction as shown in FIG.
b and is placed conjugately with the pupil Ffp or the cornea Eic to bisect the IA foramen. The center distance l of the aperture is a length that can sufficiently realize stereoscopic vision. Reference numeral 20 denotes an aperture selection shutter plate, which is placed close to the two-hole aperture O and is movable in the horizontal direction. 6 and 4 show a drive device for the aperture selection shutter plate, and 21 is a guide member that guides the shutter plate 20 to move in the horizontal direction. 2'5 is a protrusion provided at the end of the shutter plate, which engages with the elongated hole of the drive lever 24. 25 is a rotary solenoid, and the drive lever 24
is fixed to the rotating shaft of the rotary solenoid. A spring 26 always urges the shutter plate 20 to the right. Although not shown in the drawings, a stopper is provided so that when the shutter plate moves from side to side, the opening 20a comes to rest exactly at the position where it overlaps the aperture opening 6a or 6b.

In FIG. 3, the solenoid 25 is not energized, and the shutter plate 20 is moved to the right by the force of the spring 26. However, when the solenoid 25 is energized, the shaft of the solenoid moves as shown in FIG. Due to the rotation, the lever 24 tilts to the left, and the shutter plate 20 moves to the left against the spring force. Now, either the aperture 6a or 3b is selected.

Returning to FIG. 1, reference numeral 4 denotes a focusing lens, which is movable in the optical axis direction.

Reference numeral 5 denotes an imaging lens, which has the function of re-forming the fundus image formed by the objective lens 1 together with the focusing lens 4 (!l).

Objective lens 1. The focusing lens 4 and the imaging lens 5 are arranged on the same original axis. 6 is a quick return mirror, which moves out of the υ optical path in response to a release signal. 7
7 is a film feeding mechanism, and 7' is a film. S is a shutter opening/closing mechanism. The above members constitute the iF1 bottom photographing system.

Further, 8 is a condenser lens, 9 is an optical path bending prism, and 10 is an eyepiece lens, which constitute a finder and are useful for observing the fundus image through the quick return mirror 6.

Next, 10 is a relay lens, 12 is a ring slit plate,
The ring slit plate 12 is arranged conjugately with the pupil Ep of the eye test. In addition, Bc and Bl are respectively axial light-shielding points, and Bc
is placed conjugate with the cornea EC, and Bl is placed conjugate with the fundus side of the crystalline lens, so that the fundus illumination light causes harmful reflections and scattering on the cornea or crystalline lens and mixes into the photographing light (light flux from the fundus to the film). prevent

16 is an optical path bending mirror, 14 and 15 are condenser lenses, 16 is a xenon discharge tube for photographing, and 17 is an incandescent bulb. The luminous flux emitted from the incandescent bulb 17 converges on the condenser lenses 15 and 14 and on the ring slit plate 12, and the luminous flux emitted from the xenon discharge tube 16 converges on the condenser lens 14 and on the ring slit plate 12. After the light beam emitted from the annular slit of the ring slit plate forms an image on the perforated mirror 2 by the action of the relay lens 110,
An objective lens 1 forms an open ring on the pupil plane to uniformly illuminate the fundus of the eye. Above, the members numbered 11 to 17 and the objective lens 1. The perforated mirror 2 constitutes a fundus illumination system.

Furthermore, R is a release synchronization device, and when the release operation is performed, the quick return mirror 6 is moved away and the shutter is opened, just like in a normal camera.
6 is emitted to illuminate the fundus of the eye, and the device is set to the first mode (then, the rotary solenoid 25 is energized and activated, and the shutter plate 20 moves to replace the diaphragm 3a. The diaphragm 3b is opened, the quick return mirror 6 is moved away again, the shutter is opened, the xenon discharge tube 16 emits light, the fundus reflected light is exposed to the film 7', the film 7' is wound, and the rotary On the other hand, when the MR device is set to the second mode, the first release operation executes the process up to film winding, and then the second release process starts. During the process, the rotary solenoid 25 is activated and the aperture (aperture) 6 is switched.Continued (after exposure and film winding, the power supply to the rotary solenoid 25 is cut off and the shutter plate 2° returns. It is also possible to operate only the solenoids independently.

Since the configuration is as described above, photography is performed with the shutter plate 20 positioned on the right side and the diaphragm 93a opened, and the photograph looking into the fundus from the left half of the subject's pupil is 55 mrn. Formed on the full screen of the film. Thereafter, the shutter plate 20 moves to the left to open the diaphragm 3b, and a photograph looking into the fundus from the right half of the pupil is formed on the next full screen of the film. Therefore, stereoscopic viewing can be achieved by viewing two consecutive photographs at the same time.

According to the present invention described above, the Mf2 has a wide angle of view and guarantees image quality.Furthermore, the combination of the two-hole aperture and the shutter plate described in the embodiment makes it possible to quickly and easily change the viewing direction. The switchability provides a much more effective device than conventional prism rotation or camera movement.

[Brief explanation of the drawing]

Claims (2)

[Claims] (1) In an apparatus comprising a fundus imaging system and a fundus illumination system, a means for dividing the 1lCii hole into at least two parts at a position approximately conjugate with the pupil of the eye to be examined in the optical path of the fundus imaging system; A fundus camera, characterized in that it comprises means for selecting one of the pupils. (2) The fundus camera is used to switch the selection method.