JPH07250814A - Eye measuring apparatus - Google Patents

Abstract

PURPOSE:To obtain eye information based on the measurement of refracting power of eyes and a reflected image of a cornea using the same two-dimensional position sensor. CONSTITUTION:Light flux from a retinal illumination light source 21 reaches the eye ground Er of an eye to be inspected after reflected with a light splitting member 24 passing through a bored mirror 23. The luminous flux reflected on the eye ground is reflected on the light splitting member 24, further, with a bored mirror 23 and then, passes through a wedge prism 32 to be reflected with a deflection mirror 33 and an optically coupling member 28, reaching an area sensor array 29 to measure the refracting power of the eye from the imaging position of the laminous flux. On the other hand, the luminous flux emitted from a spot-like cornea illumination light source 26 forms a false image of the light source on a cornea Ec and an image is formed on the area sensor array 29 with an objective lens 25 to measure cornea information from the imaging position obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a function of an autorefractometer for measuring diopter, astigmatism, etc. of an eye to be inspected, and further, such an autorefractometer and an autokeratometer for measuring corneal curvature. The present invention relates to an eye measuring device that has both functions of different eye measuring means.

[0002]

2. Description of the Related Art Conventionally, there have been 1 eye refractive power measurement using fundus reflected light and 1 eye measurement using a corneal reflection image such as corneal shape measurement.
When performing with one device, the configuration was complicated because a plurality of sensors were required.

[0003]

An object of the present invention is to perform eye refractive power measurement using fundus reflected light and eye measurement using a corneal reflection image with the same two-dimensional optical position sensor with a simple configuration. Another object of the present invention is to provide an eye measuring device that can perform both measurements well even if the eye moves.

[0004]

An eye measuring apparatus according to the present invention for achieving the above object comprises a projection optical system for projecting a light beam on a fundus of an eye to be examined and a two-dimensional fundus reflected light of the projected light beam. A detection optical system for projecting on an optical position sensor, an eye refractive power measurement system for performing eye refractive power measurement based on the fundus reflection light position on the two-dimensional optical position sensor, and for irradiating the cornea of the eye to be examined with light. A light source means composed of a point light source, a measurement optical system for projecting a corneal reflection image of the light source means onto the two-dimensional optical position sensor, and a corneal reflection image position on the two-dimensional optical position sensor for the eye to be inspected. And an eye measurement system for obtaining eye measurement information.

[0005]

The eye measuring device having the above-mentioned configuration uses the same two-dimensional optical position sensor to obtain the eye refractive power measurement based on the fundus reflection image and the eye measurement information using the corneal reflection image.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail based on the illustrated embodiments. FIG. 1 shows an embodiment of the present invention, which is a fundus illumination light source 21.
A lens 22 is provided along the optical axis O5 of the light flux emitted from the optical axis, a perforated mirror 23 having a single aperture in the center and provided substantially conjugate to the pupil of the eye to be inspected, and a similarly provided light splitting member 24 are arranged. Then, the eye E to be inspected is placed on the optical axis O6 on the reflection side of the light dividing member 24.
The objective lens 25 that faces is arranged. As shown in FIG. 2A, four point light sources 26a, 26b, 26c and 26d are arranged around the objective lens 25 at equal angles with respect to the optical axis O6. On the optical axis O6 behind the objective lens 25 and the light splitting member 24, a diaphragm 27, an obliquely provided optical coupling member 28, and an area sensor array 29 are sequentially arranged.

Of the light emitted from the eye E to be examined, the light beam reflected by the light splitting member 24 in the direction of the optical axis O5 on the optical axis O7 on the side reflected by the perforated mirror 23 is shown in FIG. The three openings 30a, 30b, 3 arranged radially as shown in FIG.
0c, a diaphragm 30 provided substantially conjugate to the eye to be inspected,
Lens 31, three small wedge prisms 32 shown in FIG. 2 (c)
A wedge prism 32 having a, 32b, and 32c and a deflecting mirror 33 that is obliquely arranged are arranged, and the light beam deflected by the deflecting mirror 33 passes through an optical axis O8 and an optical axis O6 by an optical coupling member 28.
It is deflected in the direction and enters the area sensor array 29. Here, the fundus illumination light source 21 and the area sensor array 29 are substantially conjugate with the fundus Er of the eye E to be inspected.

The light flux from the fundus illuminating light source 21 is reflected by the lens 2
2. The light passes through the perforated mirror 23, is reflected by the light splitting member 24, and then passes through the objective lens 25 to reach the fundus Er of the eye E to be examined. The fundus reflected from the fundus Er is reflected by the objective lens 25.
After being reflected by the light splitting member 24, the mirror 2 with holes is further reflected.
After being reflected by 3, the light passes through the diaphragm 30, the lens 31, the wedge prism 32, and is further reflected by the deflection mirror 33 and the optical coupling member 28 to reach the area sensor array 29.

If the eye E to be inspected is an emmetropic eye, 3 of the diaphragms 30
The light flux emitted from the individual openings 30a, 30b, 30c is
Since they match on the area sensor array 29, they are separated and the wedge prism 32 for measuring their positions is used.
Will be required. For example, the light beam emitted from the aperture 30a of the diaphragm 30 is deflected by the small wedge prism 32a and reaches the position 21A shown in FIG. 3A on the area sensor array 29. Similarly, the luminous flux emitted from the openings 30b and 30c is 2
From the positions of 1B and 21C, the refraction values in the directions of the three radial lines can be known by measuring the positions of these light fluxes, and the refraction values of the spherical power, the astigmatism and the astigmatism angle can be calculated therefrom. The measuring principle is described in JP-A-59-6.
No. 4022 gazette. Also, 21A, 21
Since the light beam position information of B and 21C can be obtained not only in the radial direction but also in the radial direction, the information for obtaining the refraction value increases.

On the other hand, the luminous flux emitted from the corneal illumination light source 26 which is a point light source for measuring corneal curvature forms a virtual image of the light source by the cornea Ec, which is formed on the area sensor array 29 by the objective lens 25 as shown in FIG. It is imaged as shown. In FIG. 3B, the images of the four point light sources 26a, 26b, 26c, and 26d formed on the area sensor array 29 are shown as 26
It is represented by A, 26B, 26C and 26D.

Since the size of the image shown in FIG. 3 (b) and the corneal curvature are in a proportional relationship, the respective images are dispersed when the corneal curvature is increased, and conversely, the images are concentrated when the corneal curvature is decreased. , The corneal curvature can be obtained by measuring the positions of these images. If the cornea Ec of the eye E to be examined has astigmatism and the corneal curvatures are different in the vertical direction and the horizontal direction, the distances between the images 26A and 26C and the distances 26B and 26D in FIG. 3B are different. .

If the astigmatic angle is slanted, the image 2
Since the direction connecting 6A and 26B deviates from that of the light source, the astigmatic degree and the astigmatic angle can be obtained from these amounts. In principle, there are three unknowns with respect to the corneal refraction value: spherical power, astigmatic power, and astigmatic angle, and when the central coordinates (x, y) are included, there are five unknowns. If the position is known, these values can be calculated.

In the above embodiment, the light splitting member may move the mirror to split the optical path,
It goes without saying that the shutter and the half mirror may be combined.

[0014]

As described above, the eye measuring apparatus according to the present invention uses the single two-dimensional optical position sensor for the eye refractive power measurement using the fundus reflected light and the eye measurement using the corneal reflection image. By using a point light source to obtain the corneal reflection image, the shape analysis of the corneal reflection image is not required, and the eye measurement can be performed easily and quickly. The measurement of the movement-sensitive corneal reflection image is less likely to be affected by the movement of the eye. Thereby, even if the measurement is performed by a single two-dimensional position sensor, both of the measurements can be favorably performed.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment.

FIG. 2 is a front view of a member used in Examples.

FIG. 3 is an explanatory diagram of a bottom reflected light flux and a cornea reflected light flux on the area sensor array.

[Explanation of symbols]

 21 fundus illumination light source 27, 30 diaphragm 23 perforated mirror 24 light splitting member 25 objective lens 26 corneal illumination light source 32 wedge prism 28 light coupling member 29 area sensor array

Claims (1)

[Claims] 1. A projection optical system for projecting a light flux onto a fundus of an eye to be examined, a detection optical system for projecting fundus reflected light of the projected light flux onto a two-dimensional optical position sensor, and a fundus on the two-dimensional optical position sensor. An eye-refractive-power measuring system that measures the eye-refractive-power based on the position of the reflected light, a light source means that includes a point light source for irradiating the cornea of the eye to be examined with light, and a corneal reflection image of the light-source means is two-dimensional An eye measuring device comprising: a measuring optical system for projecting onto an optical position sensor; and an eye measuring system for obtaining eye measuring information of an eye to be examined based on a corneal reflection image position on the two-dimensional optical position sensor.