JPS624127B2 - - 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 once, and then the intermediate lens 11
The image is then enlarged and imaged by a television camera 13 via a semi-transparent mirror 12. The captured infrared image is
The image is visually projected on the screen 15 of the sensor receiver 14.

A fixation target 16 is illuminated by a light source 17, 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 18, and a semitransparent mirror 19. The eyeball 1 is made to directly face the device by making the user look at the device in this order. In addition, 20 is a background light source that emits weak visible light of suitable brightness to the semi-transparent mirror 1.
9, the imaging lens group 18, 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, although there are some differences in the optical path arrangement. The conventional fundus perimetry projects a light spot on the fundus 2 by introducing a visible light beam from the outside into the above optical path, and the background light source 2
While adjusting the brightness of 0, the position, brightness, size, etc. of the light spot are changed and the subject is asked to answer whether or not they can see the light spot, thereby measuring the photosensitivity of each part of the fundus. That's what I was doing. Therefore, the position of the light spot does not clearly appear on the screen 15 of the monitor receiver 14, making it difficult to accurately match the infrared image with the position of the light spot.

In this invention, as means for projecting a light spot onto the fundus of the eye, an infrared filter 22 having a narrow hole 21 is provided on the imaging plane in the imaging optical path of the television camera 13, and a visible light source 23 is used to filter the infrared filter 22 onto the semi-transparent mirror 12. It was illuminated through the The above-mentioned imaging plane is the imaging position of the fundus image by the objective lens 8 and the imaging lens group 9.

In the above-described apparatus, since the infrared filter 22 transmits infrared rays without any problem, a monitor image of the fundus of the eye similar to that in the conventional apparatus is displayed on the screen 15 of the monitor receiver 14. When the light source 23 is turned off, the narrow hole 21 of the infrared filter 22 is displayed as a bright light spot 24 superimposed on the above-mentioned monitor image, but this is because the infrared filter itself This is because it absorbs infrared rays.

Therefore, the infrared filter 22 is placed so that the light spot 24 overlaps the desired position of the fundus image on the screen 15.
By moving and adjusting the position within the imaging plane and turning on the light source 23, a desired position of the fundus 2 can be irradiated with a visible light beam. Therefore, by changing the brightness of the light source 23 or replacing the infrared filter 22 with one with a different pore diameter, it is possible to perform the same examination as with a conventional fundus perimetry more easily and more accurately. can.

Adjustment of the movement of the infrared filter 22 can be made easier by the following method. That is, a light pen 25 having a light-receiving element at its tip is prepared, and the received light output obtained by contacting the light pen 25 with the screen 15 of the monitor receiver 14 is converted into the horizontal polarization sawtooth wave of the television camera 13 and the horizontal polarization sawtooth wave of the television camera 13 in the signal conversion circuit 26 By contrasting with the vertically polarized sawtooth wave, it is converted into a position signal in both the X and Y directions, and this position signal is used to operate the driving device 27 of the infrared filter 22, thereby bringing the light pen 25 into contact with the monitor image of the fundus. The narrow hole 21 can be moved to a different position. In addition, a transparent plate 29 with indicators 28, 28 drawn thereon is provided on the front surface of the screen 15, and a position transmitter 3 attached thereto is provided.
By operating the drive device 27 in response to the position signals in both the X and Y directions in which 0 is generated, the thin hole 21 of the infrared filter 22 can be moved to the position indicated by the indicators 28 and 28. When used as an eye movement tester, the light source 17 and the fixation target 16 are not used, the visible light beam is moved while the user is looking at it, and the movement of the retina following the visible light beam is observed.

As is clear from the above description, in the present invention, the position where the small through-hole of the infrared filter is placed is on the imaging plane itself that is being imaged by the television camera. Therefore, some deviations in the optical system,
It becomes possible to accurately irradiate a light beam to a specified position on a monitor image of the fundus, regardless of fluctuations in the operation of a television camera or monitor receiver due to fluctuations in power supply voltage. Therefore, it is possible to quickly and accurately measure the photosensitivity at a specified position on the monitor image of the fundus, the movement of the fundus following the beam, and the like.

[Brief explanation of the drawing]

The figures are an optical path diagram and an electric circuit diagram of an embodiment of the present invention. 2... Fundus, 3 and 4... Infrared source, 8-11
...Main optical system, 13...TV camera, 14...
Monitor receiver, 21...Small hole, 22...Infrared filter, 23...Visible light source.

Claims (1)

[Claims] 1. A television camera, a main optical system that guides an image of the fundus to the television camera, an infrared source that retrogradely irradiates infrared rays toward the fundus from the middle of the main optical system, and a monitor receiver that displays images from the television camera. an infrared filter that is installed at a variable position on the fundus image forming plane in the main optical system and has a thin hole through which visible light passes; and the infrared filter is placed on the side of the television camera. An eye examination device having a visible light source emitted from the ophthalmoscope.