JPH0767833A - Visual field meter - Google Patents

Abstract

PURPOSE:To inspect a visual field with constitution capable of reducing the size of the visual field meter. CONSTITUTION:The reflected luminous fluxes of the anterior part of the eye E to be examined by the luminous fluxes from light sources 6, 7 for illumination of the anterior parts are reflected by the reflection surface 4a of a beam splitting member 4 and are subjected to image pickup by a television camera 10. An anterior part image Pf in which the light source images P1, P2 are picked up is projected together with an alignment mark AM on a television monitor 12. An inspector makes alignment while observing this television monitor 12. The luminous flux from a light source 2 illuminates an electronic display panel 3 on which a visual target is displayed according to the program of a display control means 13 from behind this panel. The luminous flux from the electronic display panel 3 passes an objective lens 5 and is projected to the fundus oculi of the eye E to be examined, by which the visual target is displayed on the eye E to be examined. The inspector changes the sight of the displayed visual target by moving the electronic display panel 3 or the objective lens 5, thereby letting a testee view the visual target and respond the visual recognition by a responding means 14. The visual field inspection is thus carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a perimeter used in an ophthalmic clinic or the like.

[0002]

2. Description of the Related Art In a conventional perimeter, a subject's head is fixed to a face pedestal provided in front of a dome-shaped screen, and a visual target displayed on the screen is visually responded to. Performing visual field inspection.

[0003]

However, in the above-mentioned conventional example, since a screen having a certain size is required, there is a drawback that the apparatus becomes large in size. Further, since the visual field inspection generally takes a long time, fixing the head causes extra pain to the subject.

The object of the present invention is to solve the above-mentioned problems,
An object of the present invention is to provide a perimeter capable of performing a visual field inspection without fixing the head by downsizing the device.

[0005]

A perimeter according to the present invention for achieving the above object comprises an objective lens arranged so that a pupil of an eye to be examined is located in a front focal plane, and a rear side of the objective lens. A light beam splitting member, an imaging lens provided on the optical path in the reflection direction of the light beam splitting member, an imaging means for picking up an image of an eye to be inspected, and an electron provided on the optical path in the transmission direction of the light beam splitting member. Display means, adjusting means for adjusting the distance between the objective lens and the electronic display means, and display control means for controlling the electronic display means to display a visual target for visual field inspection.

[0006]

The perimeter having the above-mentioned structure takes an image of the eye to be inspected from the reflection direction of the light beam splitting member and performs alignment. Then, the visual target is displayed on the electronic display means, and the visual target is presented by presenting the visual target to the subject through the light beam splitting member and the objective lens to make the visual response. The diopter of this optotype is changed by adjusting the distance between the objective lens and the electronic display means.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail based on the illustrated embodiments. FIG. 1 is a configuration diagram of the first embodiment, and an electronic display panel 3 made of a liquid crystal display plate or the like for displaying an optotype on an optical path O1 from the light source 2 inside the measurement unit 1 to the eye E to be inspected, A light beam splitting member 4 having a reflecting surface 4a that reflects infrared light in the central portion and an objective lens 5 are arranged. The objective lens 5 faces the eye E to be inspected and emits infrared light to the periphery thereof. Light sources 6 and 7 for illuminating the anterior segment, which are composed of LEDs or the like, are arranged. Further, a diaphragm 8, an imaging lens 9, and a television camera 10 are arranged on the optical path O2 in the reflection direction of the reflection surface 4a of the internal light beam splitting member 4 of the measuring section 1.

The output of the television camera 10 is connected to the camera control unit 11 and the television monitor 12 outside the measuring section 1, and the electronic display panel 3 is connected to the display control means 13 outside the measuring section 1 for further display control. A response means 14 having a response button 14a is connected to the means 13.

Light fluxes from the anterior ocular segment illumination light sources 6 and 7 illuminate the anterior ocular segment of the eye E to be imaged as light source images P1 and P2 on the cornea. The reflected light flux here passes through the objective lens 5, becomes a parallel light flux, is reflected by the reflecting surface 4a of the light flux splitting member 4, passes through the imaging lens 9, and is imaged by the television camera 10 as the anterior segment image Pf. The signal from the television camera 10 is output to the television monitor 12 via the camera control unit 11, and together with the alignment mark AM generated by the camera control unit 1, the anterior segment image Pf obtained by capturing the light source images P1 and P2 is displayed. Will be issued.

The examiner performs alignment while observing the television monitor 12. In order to focus the anterior segment image Pf, the measuring unit 1 is moved along the optical path O1 to move the eye E to be inspected.
The pupil Ep is positioned on the front focal plane of the objective lens 5. Then, the measurement unit 1 is finely adjusted in a plane perpendicular to the optical path O1 so that the pupil Ep of the eye E to be examined becomes concentric with the alignment mark AM.

The luminous flux from the light source 2 illuminates from behind the electronic display panel 3 on which the visual target is displayed according to the program of the display control means 13. The light flux from the electronic display panel 3 passes through the light flux splitting member 4 and the objective lens 5 and the fundus of the eye E to be examined.
The image is projected onto Er and the target is presented on the eye E to be examined.

The examiner moves the electronic display panel 3 or the objective lens 5 along the optical path O1, changes the diopter of the optotype displayed on the electronic display panel 3, and the eye E to be examined reveals the optotype. The visual field is inspected by allowing the subject to visually recognize and respond to the visual target. Even if the distance between the electronic display panel 3 and the objective lens 5 is changed, the reflected light beam from the anterior ocular segment illumination light sources 6 and 7 at the anterior ocular segment is made parallel by the objective lens 5, so that the television camera 10 The focus position of the anterior ocular segment image Pf does not change.

As a method of presenting the optotype, a method suitable for the purpose of inspection may be adopted. For example, as shown in FIG. 2, the test target S and the fixation target T are displayed on the electronic display panel 3 and presented to the eye E to be examined. The examiner causes the examinee to hold the response means 14 and instructs the subject to fixate on the fixation target T, and the television monitor 12
By observing the light source images P1 and P2 of 1., it is confirmed that the line of sight of the eye E is fixed.

The test optotype S is moved according to the program stored in the display control means 13, and when the examiner can visually recognize the test optotype S, the response button 14a of the response means 14 is displayed. Instruct to press. The response signal from the response unit 14 is sequentially captured by the display control unit 13 and the visual field of the eye E to be examined is analyzed.

As a second example of the method, the inspection target S
Only the image is displayed on the electronic display panel 3, and the eye E to be examined is fixed. The test optotype S moves according to a program stored in the display control means 13, and the visual field is analyzed based on the amount of movement of the line of sight of the eye E to follow the movement. In this case,
Although it is not necessary to use the response means 14, the head of the subject is fixed to the measurement unit 1, and the relative position between the pupil Ep of the eye E and the light source images P1 and P2 is monitored using a computer. ,
It is necessary to confirm whether the line of sight follows the moving direction of the inspection target S.

In order to satisfy the former condition, for example, the measurement unit 1 is installed in a goggle-type frame so as to be movable left and right, and the goggle frame is fixed to the head of the subject for inspection. In this case, the luminous flux from the electronic display panel 3 has a spread of about 60 degrees in front of the eye E to be inspected, the focal length of the objective lens 5 is set to about 20 mm, and the measuring unit 1 is downsized.
Further, the camera control unit 11, the television monitor 12, the display control means 13, and the response means 14 are separately arranged.

In this embodiment, the light beam splitting member 4 is formed of a prism, and the reflecting surface 4a for reflecting the light beam reflected by the anterior ocular segment by the anterior ocular segment illumination light sources 6 and 7 is provided only in the central portion. In addition, since the light beam splitting member 4 can be made thin, the movable range of the objective lens 5 becomes long, and the diopter adjustment range of the presented optotype can be widened. Also, the objective lens 5
If the lens is composed of an aspherical lens, the distance to the rear focal point can be increased, so that the diopter adjustment range can be widened and the structure can be simplified.

Alternatively, in order to correct the curvature of the objective lens 5, it is preferable to insert a field flattener 21 immediately before the electronic display panel 3 as shown in FIG. The light flux from the electronic display panel 3 is collimated with the optical path O1 by the field flattener 21. Therefore, even if the distance between the electronic display panel 3 and the objective lens 5 is changed to adjust the diopter, the eye E Does not change the viewing angle.

[0019]

As described above, the perimeter according to the present invention can be downsized by using the electronic display means instead of the screen. If the device is fixed to the head of the subject, the examination can be performed without fixing the movement of the head.

[Brief description of drawings]

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

FIG. 2 is a front view of an electronic display panel.

FIG. 3 is a configuration diagram when a field flattener is inserted.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Measurement part 2 Light source 3 Electronic display panel 4 Light flux dividing member 5 Objective lens 6, 7 Light source for anterior ocular segment illumination 10 TV camera 11 Camera control unit 12 TV monitor 13 Display control means 14 Response means 21 Field flatner

Claims (1)

[Claims] 1. An objective lens arranged so that a pupil of an eye to be examined is positioned on a front focal plane, a light beam splitting member provided on the rear side of the objective lens, and provided on an optical path in a reflection direction of the light beam splitting member. An image forming lens, an image pickup means for picking up an image of an eye to be inspected, an electronic display means provided on an optical path in the transmission direction of the light beam splitting member, and an adjusting means for adjusting a distance between the objective lens and the electronic display means. And a display control unit that controls the electronic display unit to display a visual target for visual field inspection.