JPH04226622A - Ophthalmorefractometer - Google Patents

Abstract

PURPOSE:To enable a person to be examined to make exact and easy alignment and to make self-measurement. CONSTITUTION:The visible luminous flux from a visual index 11 arrives at an eye E to be examined through a lens 10, a light splitting member 5 and an aperture 6a of a bored concave mirror 6. On the other hand, the image of the eye to be examined is projected on the concave mirror 6 and, therefore, the eye E to be examined is focused and observed by the person to be examined. The person aligns the eye E to be examined by moving the eye in such a manner that the aperture 6a comes to the center of the pupil. The IR luminous flux from a light source 1 for refractive value measurement provided off the axis of the eye is reflected by the light splitting member 5 and is made incident on the eye E to be examined via the aperture 6a at the time of ophthalmorefractive value measurement. The eyeground reflected luminous flux returns in the same optical path and is received by a photoelectric sensor 9, by which the ophthalmorefractive value is measured.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eye refractometer used, for example, in eye clinics and eyeglass stores.

0002

2. Description of the Related Art Various types of recent eye refractometers have been proposed for self-measurement, in which the subject himself/herself operates the eye refractometer to measure the eye refraction value.

0003

However, conventional ocular refractometers require an examiner to perform alignment. An object of the present invention is to provide an eye refractometer that allows the subject to perform accurate and easy positioning himself/herself and perform accurate self-measurement.

0004

[Means for Solving the Problems] An eye refractometer according to the present invention for achieving the above-mentioned object transmits near-infrared light and at least a part of visible light near the optical axis, and faces the eye to be examined. a concave mirror, a light splitting member provided behind the concave mirror to split a visible light beam and a near-infrared light beam, and a light splitting member for splitting a light beam from a near-infrared light source into the vicinity of the optical axis of the concave mirror through the light splitting member. and an ocular refraction value measuring means for measuring an ocular refraction value by receiving the reflected light flux of the fundus through a photoelectric sensor near the optical axis of the concave mirror and via the light splitting member. It is characterized by:

[0005]

[Operation] In the eye refractometer having the above configuration, the subject observes and aligns the image of the subject's eye reflected on the concave mirror and the visible light flux that has passed through the light splitting member and the vicinity of the optical axis of the concave mirror. After that, measure the eye refraction value.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail based on the illustrated embodiments. FIG. 1 shows a configuration diagram of an embodiment, in which a lens 2, a small mirror 3, A lens 4, a light splitting member 5 that reflects an infrared beam and transmits a visible beam, and a perforated concave mirror 6 having an opening 6a and having a concave mirror surface facing the eye E side to be examined are arranged. On the optical path O2 behind the small mirror 3, there is a light beam 6 integrated with the small mirror 3 as shown in the cross-sectional view of FIG. 2, and as shown in the front view of FIG.
The separation prism 7 is composed of wedge prisms 7a to 7f, on which a mask having openings 7A to 7F is formed, a lens 8, and a photoelectric sensor 9 are arranged. On the other hand, on the optical path O3 behind the light splitting member 5, a lens 10,
A visual target 11 that is movable in the optical axis direction is provided. The refraction value measurement light source 1 and the photoelectric sensor 9 are conjugated with the fundus Er of the emmetropic eye E through the light splitting member 5, and the separation prism 7 is conjugated with the pupil Ep.

The visible light flux from the optotype 11 travels on the optical path O3, passes through the lens 10, the light splitting member 5, and the aperture 6a of the perforated concave mirror 6, and reaches the eye E to be examined, as shown in FIG. The examiner sees the eye image E0 to be examined projected on the concave mirror 6 and the optotype 11 through the aperture 6a. Therefore, the subject's eye E is moved and aligned in a plane perpendicular to the optical axis so that the aperture 6a is at the center of the pupil, so that the subject's eye image E0 reflected on the concave mirror 6 can be clearly seen. After alignment in the optical axis direction, a measurement switch (not shown) or the like is pressed to start diopter guidance and eye refraction value measurement. The near-infrared light flux from the light source 1 for refractive value measurement travels on the optical path O1, passes through the lens 2, is reflected by the small mirror 3, passes through the lens 4, is reflected by the light splitting member 5, and is reflected by the opening 6a of the perforated concave mirror 6. The eye E is reached through the eye E. The reflected light flux from the fundus Er returns along the same optical path to the aperture 7 of the separation prism 7.
Images Ma to Mf are separated from the optical axis by wedge prisms 7a to 7f via A to 7F, and as shown in FIG. 5, images Ma to Mf are formed on a photoelectric sensor 9 by a lens 8. An eye refraction value is calculated.

The focal length of the perforated concave mirror 6 is 10 to 2
Approximately 0 mm is appropriate, and positioning and measurement will be easier if a forehead support member or the like is provided to fix the face. In addition, by moving the optotype 11 in the optical axis direction, the eye to be examined E
However, the optotype 11 may be omitted so that the user can view the distant external world. Further, the method for measuring the eye refraction value is not limited to this embodiment, and other well-known methods may be used without any problem. Furthermore, the concave mirror 6 may be a half mirror, and the opening 6a may not actually be a hole, but may be made of transparent glass, for example.

[0009]

As explained above, the eye refractometer according to the present invention is provided with a concave mirror facing the subject's eye, and the image of the subject's eye reflected on the concave mirror and the light splitting member and concave mirror are separated. By observing the visible light beam passing near the optical axis, the subject can accurately and easily align the position himself/herself, so it can be used for self-measurement.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram.

FIG. 2 is a cross-sectional view of a separation prism.

FIG. 3 is a front view of a separation prism.

FIG. 4 is an explanatory diagram of an image of the subject's eye reflected on a perforated concave mirror.

FIG. 5 is an explanatory diagram of a projected image on a photoelectric sensor.

[Explanation of symbols]

1. Light source for refraction value measurement 3 Small mirror 6 Hole concave mirror 7 Separation prism 9 Photoelectric sensor 11 Visual target

Claims (1)

[Claims] 1. A concave mirror that transmits near-infrared light and at least part of visible light near the optical axis and faces the eye to be examined;
A light splitting member is provided behind the concave mirror and splits visible light and near-infrared light, and the light from the near-infrared light source is passed through the light splitting member near the optical axis of the concave mirror to produce an image of the subject's eye. an eye refractive value measuring means for measuring an eye refractive value by receiving the reflected light flux near the optical axis of the concave mirror and through the light splitting member by a photoelectric sensor. Refractometer.