JP2000070222A - Eye examination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify constitution and to perform cornea periphery measurement in cornea shape measurement. SOLUTION: At the time of the cornea shape measurement, a light source 6 and a light source 7 or only the light source 6 is lighted. A luminous flux form the light source 6 made incident on a joined surface 5 enters the inside of a bottom part 1 and a short cylinder part 3, repeats total reflection, is diffused at a ring-like light diffusion part 8 to be a secondary light source and is emitted form a ring-like light transmission part to the cornea C as ring light. Also, the light source 7 is used both for illumination at the time of front eye part observation and for cornea center part curvature radius measurement and illuminates a front eye part including the cornea C through an optical member 4. Plural cornea ring images reflected at the cornea C of an eye E to be tested are picked up in an image pickup means 35 through lenses 27 and 32 and a telecentric diaphragm 33 and observed on a television monitor 40 and positioning is performed. Then, the video images of the ring images are fetched to the memory of a signal processing means 39 at an appropriate timing, the ring images are analyzed, a cornea shape is obtained and the light source 7 is put out at the time of fetch.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optometric apparatus used for measuring a corneal shape in an ophthalmic hospital or the like.

[0002]

2. Description of the Related Art Conventionally, an ophthalmologic apparatus of this type projects a plurality of ring light sources on a cornea and analyzes a reflected image of the cornea to determine a shape of the cornea.

[0003]

However, the above-described conventional apparatus has the following problems. (1) The ring light source member can be simplified if it is formed in a flat plate shape. However, since the size cannot be increased, it is impossible to measure the peripheral portion of the cornea.

(2) In a conventional optometry apparatus capable of measuring a corneal shape, a radius of curvature of a central portion of the cornea, and a refraction measurement, a light source for measurement of a corneal shape and a radius of curvature of a central portion of the cornea are shared. Since the corneal curvature measurement is performed simultaneously with the refraction measurement, infrared light is used so as not to hinder the measurement. However, since infrared light has strong reflection from the iris, the contrast of the ring image applied to the iris is low, and it is difficult to measure the corneal shape with high accuracy. Also, when measuring the corneal center curvature, it is not easy to perform positioning because a ring image appears around the cornea.

(3) In a corneal shape measuring device that illuminates a plurality of rings with white light, the pupil is not clear because the reflection of the iris is weak, and it is not easy to determine the relationship between the corneal shape and the pupil.

(4) In an optometry apparatus for analyzing a corneal shape by a corneal reflection image using white light, a fluorescent lamp or a strobe is used as a light source, but it is not easy to recognize a pupil.

SUMMARY OF THE INVENTION An object of the present invention is to solve the problem of the prior art (1), to make it possible to measure the periphery of the cornea with a simple structure, and to provide a multifunction machine which does not take up space in the optical axis direction. To provide an optometric apparatus that performs

An object of the present invention is to solve the problem of the prior art (1) and to provide an optometric apparatus which can simplify the configuration and perform a corneal peripheral measurement in corneal shape measurement.

An object of the present invention is to solve the problem of the prior art (2), and to perform corneal shape measurement, corneal curvature measurement, and refraction measurement.
It is an object of the present invention to provide an optometry apparatus that facilitates continuous measurement of corneal curvature and corneal refraction.

An object of the present invention is to solve the problem of the prior art (3) and to provide an optometric apparatus which has a simple configuration in a corneal curvature measuring apparatus provided with an anterior segment observation means.

An object of the present invention is to solve the problem of the prior art of (4) and to improve the contrast of the corneal reflection image and to easily recognize the pupil in an optometry apparatus for analyzing the corneal reflection image and measuring the corneal shape. To provide an optometric apparatus.

[0012]

According to the present invention, there is provided an optometry apparatus for projecting a light beam onto a cornea of an eye to be examined and analyzing a reflected image thereof to obtain a shape of the cornea. An optical member consisting of a short cylindrical part with a bottom is arranged in front of the optometry so that the inside faces the eye to be inspected, and the optical member forms a plurality of ring-shaped light reflecting portions around the optical axis inside, Light is introduced from an illumination light source into the optical member, and reflected light from the light reflecting portion is emitted in a ring shape toward the subject's eye.

Further, the optometry apparatus according to the present invention comprises a light source member for measuring a corneal shape, wherein the light source member has a plurality of ring-shaped secondary light sources provided at the center of the optical axis, which is visible light, provided opposite to the eye to be examined. It has a light source for measuring a radius of curvature of a central portion of the cornea that illuminates the cornea with infrared light through a member, and an eye refraction measuring unit that projects a light beam onto the fundus and photoelectrically detects reflected light to obtain an eye refraction value. And

An optometric apparatus according to the present invention has a plurality of ring-shaped secondary light sources around the optical axis provided facing the subject's eye inward, and includes an optical member comprising a short cylindrical part having a bottom. A plurality of primary light sources provided on an optical axis circumference for illuminating the ring-shaped secondary light source unit, and corneal shape measuring means for measuring a corneal shape by a corneal reflection image by the ring-shaped secondary light source. Features.

An optometric apparatus according to the present invention is provided with an anterior ocular segment observing means for analyzing a corneal reflection image of a light source to measure a corneal curvature. A light source is provided, and the light diverging light source is also used for the anterior ocular segment observation means and the corneal curvature measurement.

An optometry apparatus according to the present invention is an optometry apparatus for projecting a light beam onto a cornea and analyzing a reflected image thereof to measure a corneal shape, wherein the light beam is red wavelength light.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the illustrated embodiment. FIG. 1 is a schematic diagram of an ophthalmologic apparatus capable of measuring a corneal shape, a corneal central curvature radius, and a refraction measurement. In front of the eye to be examined E, an optical member 4 having a hole 2 in the center of a flat bottom 1, a short cylindrical portion 3 around it, and a predetermined thickness and having transparency is covered on the inside. Optometry E
It is arranged toward. The oblique joining surface 5 between the bottom portion 1 and the short cylindrical portion 3 has a light splitting characteristic, and a plurality of light sources 6 for projecting a visible light beam from behind toward the joining surface 5 are provided. . Note that a red LED is used as the light source 6.
The use of is preferable because the iris reflex is also appropriate and the pupil edge is clear, so that the pupil can be easily recognized. Behind the bottom 1 of the optical member 4, LEs are equally spaced on the circumference of the optical axis.
Eight light sources 7 made of D or the like and emitting infrared light are provided.

FIG. 2 is a partially enlarged view of the optical member 4. A plurality of light diffusing portions 8 formed in a ring shape centering on the hole portion 2 are formed on the outer surface of the bottom portion 1 and the short cylindrical portion 3, and a reflecting film 9 for reflecting red light excluding these light diffusing portions 8. Are applied uniformly. In addition, the light diffusing part 8 which becomes a secondary light source by making the whole surface a mirror surface may be formed by applying a white paint in a ring shape.
On the inner surface of the optical member 4, except for the ring-shaped translucent portion 10 in which the light flux L diffused by the light diffusing portion 8 is directed toward the cornea of the eye E, other portions are similarly reflective films. 11 is given. The inner peripheral surface of the hole 2 of the optical member 4 and the front end 12 of the short cylindrical portion 3 are also provided with a reflection film.

The short cylindrical portion 3 may be illuminated by another light source instead of the light source 6. In that case, it is necessary to provide the bonding surface 5 as a reflecting surface and provide another light source for illuminating the inside of the short cylindrical portion 3.

On the optical path O1 passing through the hole 2 of the optical member 4,
From the eye E side, a light splitting member 21, an objective lens 22, a perforated mirror 23, an aperture 24 conjugate with the pupil, a lens 25, and a refraction measurement light source 26 are arranged. Further, the lens 27 and the light splitting member 2
8, a mirror 29, a diopter variable lens 30, and an index 31 are provided, and a lens 32, a telecentric diaphragm 33, and a light splitting member 3 are provided on an optical path O3 in a reflection direction of the light splitting member 28.
4. The imaging means 35 is arranged. Further, between the perforated mirror 23 and the light splitting member 34, a six-hole stop 20, a lens 37, and a splitting prism 38 are arranged from the perforated mirror 23 side. The output of the imaging means 35 is output from the signal processing means 3.
9. Connected to the TV monitor 40.

An eye refraction measuring light beam emitted from the refraction measuring light source 26 at the time of measuring the refracting power includes a lens 25, a pupil conjugate aperture 24,
Perforated mirror 23, objective lens 22, light splitting member 21,
The light is projected on the fundus of the eye E through the hole 2. The reflected light from the fundus returns to the original optical path, is reflected by the perforated mirror 23, and is transmitted to the imaging means 35 via the six-hole stop 20, the lens 37, the separation prism 38, and the light splitting member 34 conjugated to the pupil.
It is received as a light beam. Then, the video signal obtained by the imaging means 28 is arithmetically analyzed by the signal processing means 39, and the refraction value is calculated by a known method.

When measuring the corneal shape, the light source 6 and the light source 7 or only the light source 6 are turned on. The luminous flux from the light source 6 that has entered the bonding surface 5 enters the inside of the bottom portion 1 and the short cylindrical portion 3 and is repeatedly reflected and diffused by the ring-shaped light diffusion portion 8 serving as a secondary light source. The light is emitted from 10 toward the cornea C as ring light. The light source 7 is also used for illumination during observation of the anterior segment and for measuring the radius of curvature of the central cornea, and illuminates the anterior segment including the cornea C through the optical member 4.

A plurality of corneal ring images reflected by the cornea C of the eye E to be examined are imaged by the imaging means 35 through the lenses 27 and 32 and the telecentric diaphragm 33, and the television monitor 40
Observe and align with. At the time of positioning, the diopter variable lens 30 is adjusted by performing rough refraction measurement, and the target 29 is adjusted.
Is visible to the eye E. Then, the image of the ring image is taken into the memory of the signal processing means 39 at an appropriate timing, the ring image is analyzed to determine the corneal shape, and the light source 7 is turned off when the image is taken.

When measuring the radius of curvature of the central portion of the cornea, the light source 7
The image of the reflected image 7 ′ is captured by the imaging means 35 via the optical system of the optical path O 3, taken into the arithmetic means of the signal processing means 39, and the position of the reflected image 7 ′ is analyzed and calculated. In this case, since there is no ring image around the cornea, the positioning is easy. Further, since infrared light is projected from the light source 7, the subject is not dazzling and does not hinder refraction measurement. The refraction measurement and the corneal curvature measurement can be performed simultaneously and continuously.

FIG. 3 shows a second embodiment of the optical member 4.
Since the optical member 4 is configured symmetrically with respect to the optical path O1, only the upper half is shown. A short cylindrical portion 3 outside the edge of the bottom 1
Are joined, and these joining surfaces 41 are cut obliquely. Further, several other light sources 6 are arranged on the circumference toward the joint surface 41.

The light beam from the light source 6 enters the short cylindrical portion 3 once, enters the bottom portion 1 again, repeats total reflection, and is diffused by the light diffusing portion 8 as in the first embodiment to form a ring-shaped light transmitting portion. A ring-shaped light source emitted from 10 is obtained.

In the third embodiment shown in FIG. 4, in addition to the second embodiment, the reflecting members 42 having a triangular cross section are attached to the front end portion 12 of the short cylindrical portion 3 by the number of the light sources 6. It enters from one end of the reflection member 42 and is reflected by the reflection member 42,
As in the second embodiment, the light enters the short cylindrical portion 3 and the bottom portion 1.

In the case of an optometry apparatus having no refraction measurement function, the hole 2 on the optical path O1 of the optical member 4 is unnecessary, so that the optical member 4 having no opening can be used. Also, the reflection films 9 and 11 on the front and back mirror surfaces of the optical member 4 are not necessarily required because many light beams are totally reflected.

[0029]

As described above, the optometry apparatus according to the present invention can measure the peripheral portion of the cornea with the ring light beam emitted from the optical member composed of the short cylindrical portion having the bottom.

The optometry apparatus according to the present invention can perform corneal shape measurement, corneal curvature measurement, and refraction measurement using a visible ring secondary light source and infrared light, and can perform refraction measurement simultaneously with corneal curvature measurement. it can.

The optometry apparatus according to the present invention can accurately measure a corneal shape from a corneal reflection image from a ring-shaped secondary light source.

In the optometry apparatus according to the present invention, the light diverging light source is also used for measuring the corneal curvature of the anterior ocular segment, and has a simple configuration.

In the optometry apparatus according to the present invention, by measuring the corneal shape using red wavelength light, the contrast of the ring image is high and the pupil can be easily recognized.

[Brief description of the drawings]

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

FIG. 2 is an enlarged view of a light source unit.

FIG. 3 is a configuration diagram of a second embodiment.

FIG. 4 is a configuration diagram of a third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bottom part 2 Hole part 3 Short cylindrical part 4 Optical member 5, 41, 42 Joining surface 6, 7, 26 Light source 8 Light diffusion part 9, 11 Reflection pupil 10 Ring-shaped light transmission part 22 Objective lens 35 Imaging means 39 Signal processing means 40 TV monitor 42 Reflector

Claims (5)

[Claims] In an optometry apparatus for projecting a light beam onto a cornea of an eye to be examined and analyzing a reflected image thereof to obtain a shape of the cornea, an optical member comprising a bottomed short cylindrical portion is provided in front of the eye to be examined. Arranged so as to face the optometry, the optical member forms a plurality of ring-shaped light reflecting portions around the optical axis inside, introduces light from an illumination light source into the optical member, and receives light from the light reflecting portion. An optometry apparatus wherein reflected light is emitted in a ring shape toward an eye to be examined. 2. A corneal shape measurement light source member having a plurality of ring-shaped secondary light source portions centered on an optical axis, which is visible light, provided to face an eye to be examined. An optometry apparatus comprising: a light source for measuring a radius of curvature of a central portion of a cornea illuminated by light; and an eye refraction measuring means for projecting a light beam to the fundus and photoelectrically detecting reflected light to obtain an eye refraction value. 3. An optical member comprising a plurality of ring-shaped secondary light source sections provided at the center of an optical axis and provided in a manner facing the subject's eye inward, comprising a short cylindrical section having a bottom, and the ring-shaped secondary section. An optometric apparatus comprising: a plurality of primary light sources provided on the circumference of an optical axis for illuminating a light source unit; and a corneal shape measuring unit for measuring a corneal shape based on a corneal reflection image from the ring-shaped secondary light source. 4. An optometric apparatus comprising an anterior segment observation means for analyzing a corneal reflection image of a light source and measuring a corneal curvature, wherein a plurality of spot-shaped light diverging light sources are provided on the circumference of the optical axis. An optometry apparatus, wherein a divergent light source is used for both the anterior segment observation means and the corneal curvature measurement. 5. An optometry apparatus for projecting a light beam onto a cornea and analyzing a reflected image thereof to measure a corneal shape, wherein the light beam is red wavelength light.