JP2001327469A - Eye refractometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform measurement with high accuracy and even in case of a small pupil without being affected by an unrequired reflected light. SOLUTION: When a measurement is carried out, an optical axis O1 is centered to the center of the pupil P of an eye E to be examined, a projected luminous flux L generated by an infrared light from a light source 10 is reflected with a small mirror 9, and the flux is projected on a fundus oculi as a spot flux from the lower part of the pupil P. In this way, the pupil P is protected from the flux. A cornea reflected light L of the luminous flux L is out of an objective lens 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eye refractometer such as an auto-refractometer used in ophthalmic hospitals and optician stores.

[0002]

2. Description of the Related Art In a conventional objective auto-refractometer, measurement is performed by projecting measurement light from an inspection apparatus to an eye to be inspected.

[0003]

However, in the above-mentioned prior art, when the measurement projection light beam hits the eyelashes, the reflected light beam may cause a measurement error. Further, when the measurement is performed while wearing spectacles, the measurement may not be possible due to the reflection depending on the angle of the spectacle lens. Furthermore, when measuring through an optometry lens, measurement cannot be performed due to reflection of the lens. The light polarizing member is provided near the perforated mirror.

An object of the present invention is to solve the above-mentioned problems,
It is an object of the present invention to provide an eye refractometer capable of objectively performing refraction measurement even when the eyelashes are hung on the pupil of the examinee's eye, while wearing eyeglasses, or through an optometry lens.

It is another object of the present invention to provide an eye refractometer which can accurately measure even a small pupil.

[0006]

According to the present invention, there is provided an ophthalmic refractometer for projecting a light beam from a part of a pupil to a fundus and transmitting reflected light from other parts of the pupil in different directions. In an eye refraction optical system that deflects light to a sensor and receives light by a sensor, an objective lens that forms a light beam on the pupil of the eye to be inspected, a relay lens that re-images the pupil image, A light shielding member provided at a conjugate position and a light deflecting member provided near a pupil imaging position of the relay lens are provided.

The eye refractometer according to the present invention comprises a perforated mirror conjugated to the anterior segment of the eye to be examined, a projection optical system for projecting a light beam from the center of the pupil to the fundus through the perforated mirror, and a relay lens. A diaphragm for extracting fundus reflected light from the periphery of the pupil provided conjugately with the perforated mirror through the aperture mirror, and an area sensor for receiving a light beam passing through the diaphragm. It is characterized by measuring.

Further, the eye refractometer according to the present invention projects the light flux from a part of the pupil to the fundus, deflects the reflected light from each part of the other pupil in different directions, and receives the light by a sensor. The system is characterized in that a light-blocking member is detachably provided at a conjugate position of the light receiving optical system before the eye to be examined.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail based on the illustrated embodiment. FIG. 1 shows a configuration diagram of an optical system of the auto-refractometer according to the first embodiment. On the optical axis O1 in front of the subject's eye E, a spectacle lens X, an objective lens 1,
A 5-hole aperture stop 2, a field lens 3 provided at a position substantially conjugate to the pupil P of the eye E to be inspected with respect to the objective lens 1, and a conjugate position at a position where the projection light beam strikes the spectacle lens X and provided on one side of the optical path. The light-shielding member 4, the relay lens 5, the imaging lens 6, the light deflecting member 7 placed at a position substantially conjugate with the aperture stop 2, and the area sensor 8 such as a CCD conjugated to the fundus of the eye are provided. I have.

FIG. 2 is a front view of the pupil conjugate position of the objective lens 1 viewed from the direction of the optical axis O1. In the 5-hole aperture stop 2,
Five openings 2a, 2b, 2c, 2d, and 2e are provided symmetrically with respect to the optical axis, and a small mirror 9 that reflects a projection light beam is attached between the openings 2a and 2e. This small mirror 9
A light beam L from the light source 10 which is an infrared LED conjugated to the fundus of the normal eye by the optical axis O2.
A lens 11, a central aperture stop 12 conjugate to the pupil P, and a lens 13 for imaging the aperture stop 12 on the small mirror 9 are arranged on the optical axis O2 from the light source 10 side.

At the time of measurement, the optical axis O1 is aligned with the center of the pupil of the eye E, and the projection light beam L from the light source 10 is reflected by the small mirror 9 and projected from below the pupil P as a spot light beam onto the fundus. By projecting downward in this manner, no luminous flux is applied to the eyelashes. Note that a stop having an opening similar in shape to the stop 12 may be provided at a conjugate position of the spectacle lens X on the light source 10 side of the lens 11 on the projection optical axis O2.

FIG. 3 is a sectional view of the light path at the position of the light shielding member 4. The light-shielding member 4 is conjugately provided at a position where the projection light beam L passes through a spectacle lens X about 15 mm in front of the subject's eye E, and the reflected light La passes through five openings 2a, 2b, 2c, 2d, and 2e. , Lb, Lc, Ld, Le. The reflected light L 'of the measurement light beam at the cornea C exits outside the objective lens 1, but the reflected light of the spectacle lens X may return to the optical path O1 depending on the angle. 8 will not be reached.

FIG. 4 shows five wedge prisms 7 of the light deflecting member 7.
FIG. 7 is a view of a, 7b, 7c, 7d, and 7e as viewed from the optical axis O1 direction.
Deflection away from 1.

FIG. 5 shows the diaphragm 2 received by the area sensor 8.
Light beam L corresponding to the light beam passing through each of the holes 2a to 2e
a, Lb, Lc, Ld, Le, and the distance from the center of the optical axis O1 indicates the refractive power in that direction. Each light beam La
Since the positions of Le are determined by the position of the light beam of the projection optical system, the signals of these area sensors 8 are taken into a not-shown calculating means to calculate the refraction value. The method of calculating the refraction value may be a known method as described in JP-A-6-121774.

FIG. 6 shows a second embodiment, in which measurement is performed using an optometry lens 21. On the measurement optical axis O3 passing through the center of the pupil P, the optometry lens 21, the objective lens 22, the perforated mirror 23 provided near the conjugate position of the pupil P, and the small An aperture 24 having a circular aperture, a lens 25, an aperture 26 having a small circular aperture on the optical axis at a position conjugate to the optometry lens 21, and a light source 27 composed of an infrared LED conjugated to the fundus of a predetermined diopter are arranged. I have.

On the light receiving optical axis O4 in the reflection direction of the perforated mirror 23, a lens 28, a light shielding member 29, a light shielding member 30 provided conjugate with the optometry lens 21, a relay lens 31, and a vicinity of the perforated mirror 23 Aperture stop 32 conjugated with the pupil P of FIG.
3, a lens 34, and an area sensor 35 conjugated to the fundus of a predetermined diopter are arranged. The light shielding member 30 shields the projection light beam on the optical axis O4 passing through the optometry lens 21 and is configured to be freely inserted into and removed from the optical axis O4 by the actuator 36.

FIG. 7 shows a light shielding member 29 for shielding the lens 28 and the optical axis O4 conjugate with the projection light beam.
Is provided conjugately to the tip of the eyelash which is about 10 mm from the cornea C, and shields the reflected light of the projection light flux from the eyelash. Even when the eyelashes hang on the center of the pupil P, its reflection is shielded and does not disturb the measurement.

The measurement light beam from the light source 27 passes through the center of the pupil P of the subject's eye E and is projected onto the fundus. The reflected light from the periphery of the pupil P is converted into a ring light beam and received by the area sensor 35. You. The signal of the area sensor 35 is taken into the calculating means, the ring light beam is recognized as an ellipse, and the refraction value of the eye E is obtained by calculation from the size and the principal meridian direction.

When measuring with the optometry lens 21,
The light shielding member 30 is inserted into the optical axis O4 using the actuator 36 as shown in FIG. When the optometry lens 21 is attached, it becomes closer to emmetropia, so that the reflected light beam becomes parallel light and is not obstructed by the light blocking member 30. If you have strong myopia,
The light reflected by the fundus converges in front of the eye, and the light blocking member 30 interferes with the measurement. Since the reflected light from the optometry lens 21 is shielded by the light blocking member 29, the optometry lens 2
The eye refraction measurement can be performed objectively through one. If the projection light beam is a sufficiently thin light beam, the aperture 26 can be omitted.

FIG. 8 is a sectional view of a measurement light beam on the pupil P plane in the optical system of FIG. Since the ring aperture stop 32 is conjugated to the perforated mirror 22 by the relay lens 31, the distance between the projected light beam A and the received light beam B can be reduced. In other words, measurement can be performed using a wider portion of the pupil P, and accurate measurement can be performed by approaching the case of subjective refraction measurement. Further, even the eye E having the small pupil P ′ can measure the fundus reflected light by extracting the fundus reflected light.

FIG. 9 shows the configuration of the third embodiment, in which an optometry lens 21, an objective lens 31, a central aperture stop 32 conjugate to the pupil P, an eye to be inspected, on an optical axis O5 in front of the eye E to be examined. A splitting member 34 composed of a conical prism provided with a small mirror 33 on the E side, a lens 35, a light-shielding member 36 on the optical axis substantially conjugate to the tip of the eyelashes, a light-shielding member 37 substantially conjugate to the optometry lens 21,
An area sensor 38 conjugate to the fundus of a predetermined diopter is provided. A light source 39, a pupil-conjugated small stop 40, a fundus conjugated small stop 41, and a lens 42 are provided on the illumination optical axis O6 incident on the small mirror 33. The small aperture 40 forms an image on the small mirror 33 conjugate to the pupil P by the lens 42 so that the light beam does not hit the edge of the small mirror 33.

The light-shielding members 36 and 37 are made larger than the projection light beam by an amount corresponding to the spread of the light beam by the split member 34, and the light-shielding member 37 can be inserted into and removed from the optical axis O5 by the actuator 43 as shown in FIG. It is inserted into the optical axis O5 when measuring through the optometry lens 21. Light shielding member 36
Is conjugate with eyelashes about 10 mm away from cornea C,
Irrespective of the diopter of the eye E, it does not interfere with the received light beam, so that it may be fixed.

A spot light is projected from the center of the pupil P onto the fundus, reflected light is extracted from a ring-shaped portion around the pupil P, and a ring-shaped light beam is received by the area sensor 38.
The refraction value is calculated by calculating the shape. Even in the subject's eye E in which the eyelashes are hung on the central part of the pupil P by the light shielding member 36,
Then, even through the optometry lens 21 by the light shielding member 37, the measurement can be performed without being hindered by the reflected light.

[0024]

As described above, the eye refractometer according to the present invention can perform measurement without being hindered by reflection of eyelashes, eyeglasses, and an optometry lens.

Further, when the projection light and the fundus reflection light are divided by the perforated mirror, the measurement can be performed accurately and even with a small pupil.

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram viewed from an optical axis direction at a pupil conjugate position.

FIG. 3 is an explanatory diagram of a reflected light beam.

FIG. 4 is a front view of a light deflecting member.

FIG. 5 is an explanatory diagram of a light beam on an area sensor.

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

FIG. 7 is a front view of a pupil light shielding member.

FIG. 8 is an explanatory diagram of a light beam at a pupil.

FIG. 9 is a configuration diagram of a third embodiment.

FIG. 10 is a front view of a light-shielding member that can be inserted and removed.

[Explanation of symbols]

 1, 22, 31 Objective lens 2, 8, 24, 32, 40, 41 Aperture 4, 29, 36, 37 Light shielding member 8, 35, 38 Area sensor 10, 27, 39 Light source 21 Lens to be inspected

Claims (3)

[Claims] 1. An eye refraction optical system that projects a light beam from a part of a pupil to the fundus, deflects reflected light from other parts of the pupil in directions different from each other, and receives the light with a sensor. An objective lens for imaging a pupil image, a relay lens for re-imaging a pupil image, a light-shielding member provided at a conjugate position before an eye to be examined in an optical path of the relay lens, and provided near a pupil imaging position of the relay lens. An eye refractometer, comprising: a light deflecting member. 2. A perforated mirror conjugated to the anterior segment of the eye to be examined, a projection optical system for projecting a light beam from the center of the pupil to the fundus through the perforated mirror, and a conjugate with the perforated mirror via a relay lens. An eye for retrieving light reflected by the fundus from the periphery of the pupil, and an area sensor for receiving a light beam passing through the aperture, and performing eye refraction measurement based on a signal from the area sensor. Refractometer. 3. An eye refraction optical system which projects a light beam from a part of a pupil onto the fundus, deflects reflected light from other parts of the pupil in directions different from each other, and receives light by a sensor. An ophthalmic refractometer, wherein a light shielding member is provided at a conjugate position in front of the eye so as to be freely inserted and removed.