JPS6141569B2 - - Google Patents

Description

Detailed Description of the Invention This invention examines the photosensitivity of each part of the fundus and the movement of the fundus following the beam by irradiating each part of the fundus with a visible light beam while observing the fundus under magnification using an infrared television. related to a device for

Such devices have been known as fundus perimetry and eye movement testers, but it has been difficult to correctly match the enlarged infrared image to the area irradiated with the visible light beam. For example, if a small abnormality is found in an enlarged infrared image, a visible light beam may be irradiated to this abnormality, or conversely, if an abnormality in photosensitivity is discovered by irradiation with a visible light beam. Furthermore, it was difficult to determine which part of the enlarged infrared image this irradiated area corresponded to.

This invention realizes a fundus perimetry, an eye movement tester, etc. that can quickly and accurately irradiate a light beam to a desired part of the fundus by specifying an arbitrary part in an enlarged infrared image. The purpose is to

Next, the present invention will be explained based on illustrated embodiments.

1 indicates the eyeball, and 2 indicates the fundus. 3 is the light source,
Only infrared rays are extracted from the light by an infrared filter 4, and the light passes through a condenser lens group 5, a reflecting mirror 7 having a through hole 6 in the center, and a microscope objective lens 8 in order, and is irradiated to the entire area of the fundus 2. An infrared image of the fundus is created by an objective lens 8, a through hole 6, an imaging lens group 9, and a semi-transparent mirror 1.
0 in order, the image is formed on a plane 11, further passes through an intermediate lens 12 and a semi-transparent mirror 13, and is then enlarged and imaged by a television camera 14. The captured infrared image passes through the central control device 15 of the computer 26,
The image is visually displayed on the screen 17 of the monitor receiver 16.

A fixation target 18 is illuminated by a light source 19, and is connected to an objective lens 8, a through hole 6, an imaging lens group 9, a semitransparent mirror 10, an imaging lens group 20, and a semitransparent mirror 21. The eyeball 1 is made to directly face the device by making the user look at the device in this order. In addition, 22 is a background light source that emits weak visible light of suitable brightness to the semi-transparent mirror 2.
1, the imaging lens group 20, the semitransparent mirror 10, the imaging lens group 9, the through hole 6, and the objective lens 8, and the entire area of the fundus 2 is irradiated.

The above configuration is common to the conventional fundus perimetry, except for the fact that the computer 26 is involved, although there are some differences in the optical path arrangement. The conventional fundus perimetry introduces a visible light beam into the optical path to project a light spot onto the fundus 2, and adjusts the brightness of the background light source 22 while adjusting the position, brightness, size, etc. of the light spot. Instead, the examinee was asked to answer whether or not they saw a light spot, and based on this, the photosensitivity of each part of the fundus was measured. Therefore, the screen 1 of the monitor receiver 16
Since the position of the light spot does not clearly appear in 7, it was difficult to accurately correlate the infrared image with the position of the light spot.

In this invention, a light pen and a cathode ray tube are used as means for projecting a light spot onto the fundus of the eye. The light pen 23 has a built-in light receiving element with a narrow field of view at its tip, and detects light emission from the screen 17 by bringing the tip into contact with the screen 17 of the monitor receiver 16. This detection signal is written into the frame memory 24 of the computer 26, but since the frame memory 24 is scanned synchronously with the television camera 14 and monitor receiver 16, the writing position is determined by touching the light pen 23. corresponds to the position. and,
Signals read out by the same synchronous scanning are projected as light spots on the screen 28 of the cathode ray tube 27 which is also performing the same synchronous scanning. The light spot on the screen 28 passes through a reflecting mirror 29, an imaging lens group 30, a semi-transparent mirror 13, and an intermediate lens 12, and forms an image on the plane 11, and then passes through a semi-transparent mirror 10, an imaging lens 9, and a transparent mirror. The light passes through the hole 6 and the objective lens 8 in this order and is projected onto the fundus 2. Here, by adjusting the control register 25, the frame memory 24
The diameter of the light spot projected on the cathode ray tube screen 28 can be freely adjusted around the writing position, and by further adjusting the brightness modulation circuit (not shown) of the cathode ray tube 27, the diameter of the light spot projected on the screen 28 can be The brightness of the emitted light spot can be adjusted freely. In addition, when used as an eye movement testing device, the light source 19 and fixation target 18 are not used, and the visible light beam is moved while staring at the beam.
Observe the movement of the retina that follows this.

Therefore, according to the present invention, it is possible to specify the part in which the photosensitivity of the fundus is desired to be measured and the direction in which the eyeball is desired to be moved in the displayed image of the monitor receiver 15. The position can be made to correspond accurately to the monitor image.

[Brief explanation of the drawing]

The figures are an optical path diagram and an electric circuit diagram showing an embodiment of the present invention. 2...fundus, 8-13...main optical system, 14...
Television camera, 16...Monitor receiver, 23...
Light pen, 27... CRT, 29-30...
…Optical system.

Claims (1)

[Claims] 1. A main optical system that guides an image of the fundus, a television camera that captures an image by this main optical system, an infrared source that sends infrared rays toward the fundus into the main optical system, and an infrared image of the fundus by the television camera. a monitor receiver that projects an image, a light pen equipped with a light receiving element with a narrow field of view at the tip, and synchronizing the light reception output of the light pen with the television camera when the light pen is brought into contact with the monitor receiver screen. An eye examination device comprising: a cathode ray tube that displays an image by scanning; and an optical system that introduces an image displayed by the cathode ray tube into the main optical system and projects it onto the fundus of the eye.