JPH0351165B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ocular refractometer such as an autorefractometer used in an eye clinic or an eyeglass store.

[Conventional technology] Conventionally, when measuring the refractive power of the eye to be examined,
If you are wearing glasses, it is often impossible to take measurements because the reflections from the glasses lenses interfere.

[Object of the Invention] An object of the present invention is to provide an ocular refractometer that makes it possible to measure the refractive power of an eye to be examined while wearing glasses.

[Summary of the invention] The gist of the present invention for achieving the above object is as follows:
It has a light projection optical system that projects light onto the fundus of the eye to be examined, and a light reception optical system that takes out the reflected light from the fundus, and the light projection optical system projects a luminous flux from a first region on the pupil of the eye to be examined. The light-receiving optical system is arranged so that the first light receiving optical system
In an eye refractometer that extracts light reflected from the fundus from a second region different from the second region, the light-receiving optical system includes a shielding portion at a position substantially conjugate with a light projection region to a reflecting portion located near the front side of the cornea of the eye to be examined. This eye refractometer is characterized by:

[Embodiments of the Invention] The present invention will be described in detail based on illustrated embodiments.

FIG. 1 shows an embodiment of the present invention, in which an incident light flux L1 from a refractometer (not shown) enters from one side of the center line of the pupil Ep of the eye E and is reflected by the fundus Er, and this reflected light flux L2 is reflected from the pupil Ep. The light is received by the refractometer through the other side of the When the eyeglass user wears the eyeglass lens 1 normally, the eyeglass lens 1 is 15mm from the cornea Ec.
It will be in a certain position. The light receiving optical system of the refractometer has an aperture so that the aperture image P' is formed at this position, that is, the aperture image P', that is, the shielding part image is formed in the light projection area of the spectacle lens 1 in FIG. If a light shielding object P is placed which is decentered from the optical axis, the aperture of the aperture image P' will be
Only the reflected light flux L2 from Er is allowed to pass through.

As a result, the light reflected from the spectacle lens 1 surface due to the incident light beam L1 is removed by the aperture P. By adopting a method in which the incident light beam L1 enters from one side of the center line of the pupil Ep and the reflected light beam L2 is taken out from the other side, it is possible to separate only the necessary light beam on one surface of the eyeglass lens, eliminating unnecessary reflections. Light is removed.

FIG. 2 is a configuration diagram of this embodiment, and the projection optical system includes a light source 2, a relay lens 3, an aperture 4 having an aperture eccentric from the optical axis in order to enter the incident light beam L1 from one side of the center line of the pupil, Consists of objective lens 5,
The light receiving optical system includes an objective lens 5, a mirror 6 that reflects only the reflected light beam on one side of the center line of the pupil, an aperture 7 having an eccentric aperture, a relay lens 8, and a spectacle lens 1.
A light shielding object P having an eccentric aperture conjugate to , a light source 2
It consists of an observation plane 9 conjugate to . Normally, the light source 2 and the observation surface 9 are conjugate to the fundus Er of the emmetropic eye,
The apertures 5 and 8 are conjugate to the pupil Ep, and the aperture 4 is conjugate to the light shielding object P. The reflected light from the spectacle lens 1 is removed by the light shield P, and by measuring the position of the light source image on the observation surface 9, the refraction value of the eye E to be examined can be determined.

Note that by inserting and rotating an image rotator in the optical path, refraction values in meridian directions other than the plane of the paper can be determined, and astigmatism angles can be measured. Furthermore, if three beams of light with different meridians are incident on one side of the pupil and the reflected beam is received from the other side, the angle of astigmatism can be similarly determined by calculation.

In the embodiment described above, the mirror 6 that divides the light emitting optical system and the light receiving optical system is located near the pupil position, but it may be a half mirror provided between the eye E and the objective lens 5, for example.

In addition, in the above embodiment, the light beam is emitted from one side of the pupil and the reflected light is taken out from the side, but even if the light is emitted from the center of the pupil and taken out from the periphery, the glasses of the light receiving optical system If a light shield is provided at the center of the optical axis at a position conjugate with the lens, the effect of removing reflected light can be obtained.

Further, the present invention is not limited to spectacle lenses, but can be similarly applied to lenses for measuring subjective refraction in a horopter, eyelids, and eyelashes of an eye to be examined.

[Effects of the Invention] As explained above, the ocular refractometer according to the present invention has the following effects:
It becomes possible to measure refraction values while wearing glasses, so-called overrefraction.

[Brief explanation of drawings]

The drawings show an embodiment of the eye refractometer according to the present invention, with FIG. 1 being a principle explanatory diagram and FIG. 2 being a configuration diagram. 1 is a spectacle lens, 2 is a light source, 4 and 7 are apertures, 5 is an objective lens, 6 is a mirror, 9 is an observation surface,
P is a light shield.

Claims (1)

[Claims] 1. A light projection optical system that projects light onto the fundus of the eye to be examined;
a light receiving optical system that extracts reflected light from the fundus, the light projecting optical system projects a light beam from a first region on the pupil of the eye to be examined, and the light receiving optical system projects light from the first region on the pupil of the eye to be examined. In the ocular refractometer that extracts light reflected from the fundus from a second region different from the second region, the light-receiving optical system includes a shielding portion at a position substantially conjugate with a light projection region to a reflecting portion located near the front side of the cornea of the eye to be examined. An eye refractometer featuring: 2. The light projecting optical system projects a light beam from the first region on one side of the center line of the pupil of the eye to be examined, and the light receiving optical system extracts reflected light from the second region on the other side of the center line of the pupil. An eye refractometer according to claim 1, which is configured as follows.