JPH05337085A - Ophthalmologic refraction measuring device - Google Patents

Abstract

PURPOSE:To make precise measurement even when the reflection factor on a fundus is low by conjugatively arranging a light source, the fundus, and a light position sensor, reflecting the light flux from the light source on a test eye, then forming a bright image on the light position sensor. CONSTITUTION:A composite lens 2 constituted, of six small lens sections 2a-2f, integrally molded of a synthetic resin, and arranged with one face on the side of a point light source 1 as a curved face centering on the optical axis and the other on a concentric circle, a six-hole aperture 3 having six openings 3a-3f provided to match the optical axis of the small lens sections of the composite lens 2, a perforated mirror 4 having a hole section at the center section, and an objective lens 5 are provided in sequence on the optical path 01 from the point light source 1 to a test eye E. An aperture 6 having a center opening, a lens 7, and a light position sensor 8 are provided behind the perforated mirror 4, the point light source 1 is made conjugate to the focal plane F of the objective lens 5 with respect to the composite lens 2, and the light of six spots is projected on a fundus.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ophthalmic refraction measuring device used in an ophthalmological clinic, an eyeglass store, or the like.

[0002]

2. Description of the Related Art As a conventional measuring method in an ophthalmic refraction measuring apparatus, Japanese Patent Laid-Open No. 1-148235 and Japanese Patent Laid-Open No.
As disclosed in JP-A-270847 and the like, a light beam that has passed through a ring slit disposed substantially conjugate with the eye to be inspected is projected from the peripheral portion of the pupil, and reflected light passing through the center of the pupil is referred to as a ring slit. The refractive power of the eye to be inspected is calculated from the shape of the ring-shaped light beam received and received by the conjugated CCD element or the like.

In other types of ophthalmic refraction measuring devices,
JP-A-56-161031 and JP-A-57-743
As disclosed in Japanese Patent Publication No. 1 etc., a light source, an emmetropic fundus, and a sensor are arranged in a conjugate manner, and a wedge prism is further arranged between the fundus and the sensor to magnify and separate a light source image on a sensor surface, and a refraction value Is calculated.

[0004]

However, the above-mentioned conventional example has a problem that it is difficult to collect a light beam on the fundus of the eye, so that strong reflected light cannot be obtained.

Further, the wedge prism may cause chromatic aberration, or the image on the sensor surface may be blurred so that an accurate position may not be detected.

An object of the present invention is to eliminate the above-mentioned drawbacks and provide a more accurate ophthalmic refraction measuring device.

[0007]

A first ophthalmic refraction measuring apparatus for achieving the above object comprises a projection optical system for separately projecting a light beam onto a fundus from a plurality of locations around a pupil of an eye to be examined.
A light receiving optical system for receiving reflected light from the center of the pupil by an optical position sensor provided at the rear of the conjugate point of the pupil, and calculating eye refractive power from the positional relationship of the light flux on the optical position sensor. To do.

A second ophthalmic refraction measuring apparatus for achieving the above object is to detect an object from an image forming position where a plurality of light beams generated by passing through a plurality of openings are incident on an optical position sensor surface. In an ophthalmic refraction measuring device for calculating a refraction value of an optical system, the same number of lens groups corresponding to the plurality of openings are arranged at predetermined positions in the vicinity of the plurality of openings. ..

[0009]

In the first ophthalmic refraction measuring device having the above-mentioned configuration, the light source, the fundus and the optical position sensor are arranged in a conjugate manner, and the luminous flux from the light source is reflected by the eye to be examined and then a bright image is formed on the optical position sensor. Image.

In the second ophthalmic refraction measuring apparatus, a plurality of light beams generated by passing through the plurality of openings are
Each is refracted by the lens group, and a light source image with little blur is formed on the optical position sensor or a position conjugate with the optical position sensor.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail based on the illustrated embodiments. FIG. 1 is a block diagram of an ophthalmic refraction measuring apparatus in the first embodiment. On the optical path O1 from the point light source 1 to the eye E, integrally molded with synthetic resin as shown in FIG. 2, the surface on the side of the point light source 1 is a curved surface centered on the optical axis, and the other surfaces are concentric circles. A composite lens 2 composed of six small lens portions 2a to 2f arranged above, and six apertures 3a to 3 shown in FIG. 3 provided so as to match the optical axes of the small lens portions of the composite lens 2.
A 6-hole diaphragm 3 having 3f, a perforated mirror 4 having a hole in the center, and an objective lens 5 are sequentially provided. A diaphragm 6 having a central aperture, a lens 7, and an optical position sensor 8 are provided behind the perforated mirror 4, and the point light source 1 is conjugated with respect to the focal plane F of the objective lens 5 with respect to the compound lens 2. , 6 spot lights are projected on the fundus Er.

When the point light source 1 is turned on, the light flux passes through the solid line path of FIG. 1 and enters the eye E to be examined through the focal point Q of the anterior segment of the eye, and six spot lights are projected on the fundus Er. .. The fundus reflected light returns through the path indicated by the broken line, passes through the hole of the perforated mirror 4, passes through the diaphragm 6 and the lens 7, and is received by the optical position sensor 8.

FIG. 4 is a front view of the optical position sensor 8.
Individual light source images 1a 'to 1f' are formed. Light source image 1
Since the distance from the center of each of a ′ to 1f ′ to the center of the optical position sensor 8 is proportional to the refractive power of the eye E to be examined, the eye refractive power can be obtained by analyzing the positions of the light source images 1a ′ to 1f ′. .. Furthermore, by analyzing the six light source images 1a 'to 1f' in the directions of the three-diameter line, astigmatism can be calculated.

FIG. 5 is a configuration diagram of the second embodiment, showing an eye E to be inspected and an objective lens 5. As shown in FIG. 5, the focal point Q of the projected light flux on the eye E has changed from the anterior segment shown in FIG. 1 to the inside of the eye shown in FIG. Even in this case, the same effect as that of the first embodiment can be obtained.

FIG. 6 is a block diagram of the third embodiment, in which an ophthalmic refraction measuring device and a keratometer are combined. On the optical path O2 from the point light source 11 for the ophthalmic refraction measuring device to the eye E, a compound lens 12 similar to the compound lens 2 of the first embodiment, a 6-hole diaphragm 13, and a mirror surface projecting and inclined in the center. 14a, a mirror plate 14, a mirror 15, and a lens 1, which are parallel plates having a mirror surface 14a at the tip and a transparent periphery.
6. The dichroic mirror 17 is sequentially arranged. Optical path O3 in the reflection direction of the mirror surface 14a of the mirror plate 14
A diaphragm 18, a lens 19, a dichroic mirror 20, and a lens 21 are sequentially arranged on the upper side to reach a two-dimensional optical position sensor 22. Also, dichroic mirror 1
A lens 23 and a diaphragm 24 are provided between 7 and 20, and four measuring light sources 25 are symmetrically arranged between the dichroic mirror 17 and the eye E to surround the optical axis.

At the time of eye refraction measurement, the light beam emitted from the point light source 11 passes around the compound lens 12, the 6-hole diaphragm 13 and the mirror plate 14 and is reflected by the dichroic mirror 17 through the mirror 15 and the lens 16 to be examined. Six spot lights are projected on E. The reflected light of the fundus Er returns through the same path,
Reflected by the mirror surface 14a of the mirror plate 14, the diaphragm 18,
The light passes through the lens 19, passes through the dichroic mirror 20 and the lens 21, enters the optical position sensor 22, and the eye refraction value is calculated from the six reflected images on the optical position sensor 22 as in the previous embodiment.

When measuring corneal curvature, four measuring light sources 2 are used.
5 emits light and forms four pieces of corneal reflected light 25 'on the cornea Ec. The reflected light flux is dichroic mirror 17, lens 2
3, mirror 15, dichroic mirror 20, lens 2
The incident light enters the optical position sensor 22 via 1 and the four reflected lights 2
The corneal shape is analyzed from the 5'coordinate relationship.

FIG. 7 is a block diagram of the fourth embodiment, in which a lens 32, an optical path O4 from the point light source 31 to the eye E are examined.
As shown in FIG. 8, an aperture 33a is formed in the center, a diaphragm 33 conjugated to the pupil Ep, a perforated mirror 34 having a hole in the center, and an objective lens 35 are sequentially arranged. Is a 6-hole diaphragm 36 of the same type as the 6-hole diaphragm 3 shown in FIG. 3 and conjugate with the pupil Ep, and has optical axes that match the centers of the respective apertures. As shown in FIG.
A lens plate 37 having 37f and an optical position sensor 38 such as a two-dimensional CCD conjugate with the point light source 31 are arranged.

The light beam emitted from the point light source 31 at the time of measurement passes through the lens 32, the diaphragm 33, the hole portion of the perforated mirror 34, and the objective lens 35, and enters the eye E to be inspected. Fundus of eye E to be examined
The reflected light in Er passes through the objective lens 35, is reflected by the perforated mirror 34, and is divided into six light beams by the six-hole diaphragm 36. The divided luminous flux is used for the lens portion 37 of the lens plate 37.
Six light source images are formed on the optical position sensor 38 through the light beams a to 37f. The eye refraction value of the eye E to be inspected in the case of including astigmatism is calculated from the positional relationship of these light source images by a computer (not shown). Since the light beams incident on the optical position sensor 38 are condensed by the lens portions 37a to 37f, the light source image on the optical position sensor 38 is well converged, and the measurement accuracy of the light receiving position is improved. It should be noted that it is convenient to integrally mold the lens plate 37 with synthetic resin or the like, and the 6-hole diaphragm 36 and the lens plate 37 may be integrated.

FIG. 10 is a block diagram of the essential portions of the fifth embodiment, which is an improvement of the light receiving system portion of FIG. In this embodiment, a lens 39 having the same size as the lens plate 37 is arranged near the lens plate 37 between the lens plate 37 and the optical position sensor 38, and the lens portions 37a to 37f and the lens 39 are refracted. By appropriately selecting the force, the light receiving position in the optical position sensor 38 can be freely adjusted, and the most suitable optical position sensor in terms of practicality and cost can be selected.

FIG. 11 is a block diagram of the sixth embodiment, which is used for a lens meter. On the optical path from the point light source 41 to the optical position sensor 42, a collimator lens 43, a lens 44 to be inspected, and four openings 45a to 4a as shown in FIG.
A four-hole diaphragm 45 having 5d and a lens plate 46 having four small lens portions are arranged.

The light beam emitted from the light source 41 is collimated by the collimator lens 43, passes through the lens 44 to be inspected,
The light is received by the optical position sensor 42 via the aperture stop 45 and the lens plate 46. As for the refractive power of the lens 44 to be inspected, as in the case of the fourth embodiment, the refraction value is measured from the positions of the four images obtained by the optical position sensor 42.

[0023]

As described above, in the first ophthalmic refraction measuring apparatus according to the present invention, since the light source image is formed on the optical sensor, the S / S ratio is high even when the reflectance at the fundus is low.
It is possible to obtain the N ratio, and it is possible to perform accurate measurement.

Further, in the second ophthalmic refraction measuring apparatus, since a plurality of spot lights for measurement are bent by a plurality of lens groups corresponding to each of them, the degree of focusing on the measuring sensor is high and the position measuring accuracy is high. Is improved. Further, since no prism is used, chromatic aberration is not added to the measurement light.

[Brief description of drawings]

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

FIG. 2 is a front view of a compound lens.

FIG. 3 is a front view of a 6-hole diaphragm.

FIG. 4 is a front view of an optical position sensor.

FIG. 5 is a configuration diagram of main parts of a second embodiment.

FIG. 6 is a configuration diagram of a third embodiment.

FIG. 7 is a configuration diagram of a fourth embodiment.

FIG. 8 is a front view of a diaphragm.

FIG. 9 is a front view of a lens plate.

FIG. 10 is a configuration diagram of a fifth embodiment.

FIG. 11 is a configuration diagram of a sixth embodiment.

FIG. 12 is a front view of a 4-hole diaphragm.

[Explanation of symbols]

 1, 11, 31, 41 Point light source 2, 12 Composite lens 4, 34 Hole mirror 6, 13, 36 6-hole diaphragm 8, 22, 38, 42 Optical position sensor 14 Mirror plate 25 Measurement light source 37, 46 Lens plate 45 4-hole aperture

Claims (2)

[Claims] 1. A projection optical system for separating and projecting a light flux onto a fundus from a plurality of places around a pupil of an eye to be examined, and a light receiving device for receiving reflected light from the center of the pupil by an optical position sensor provided at a rear portion of a conjugate point of the pupil. An ophthalmic refraction measuring apparatus comprising: an optical system; and calculating an eye refracting power from a positional relationship of light fluxes on the optical position sensor. 2. An ophthalmic refraction measuring apparatus for calculating a refraction value of an optical system to be inspected from an image forming position where a plurality of light fluxes generated by passing through a plurality of openings enter an optical position sensor surface. An ophthalmic refraction measuring apparatus, wherein the same number of lens groups corresponding to the plurality of openings are arranged at predetermined positions in the vicinity of the plurality of openings.