JPH11299735A - Ophthalmoscopic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a ring beam by a high luminance source of light with a simple structure. SOLUTION: A light source 55 for measurement of refractive power projects a beam in an oblique direction to a cylindrical light guide 53 through a lens 54. This beam is emitted from the light guide 53 as a conical beam and collects light to the position of a converging point F through a lens 51, a ring diaphragm 50, a perforated mirror 42, a dichroic mirror 41, and a light dividing member 40, and projects a ring-shaped beam from the periphery of a pupil P to the eyeground. The reflected light returns through the same optical path, is received by a two-dimensional array sensor 46 as a ring beam through the perforated mirror 42, a central small aperture diaphragm 43, a lens 44 and a diaphragm 45. This image is analyzed by an operation means to obtain a refraction value. Thus, the beam in the direction where the intensity of radiation of the light source 55 for measurement of refractive power is the strongest is led to the light guide 53 and can be utilized effectively, and further, by an action of the diaphragm 45, unnecessary light entering a photometry system through the periphery of an object lens 2 can be shut off.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optometry apparatus such as a fundus camera and an auto-refractometer.

[0002]

2. Description of the Related Art Conventionally, there has been known an apparatus for performing optometric measurement by irradiating a subject with a ring light beam formed by combining a plurality of light sources and a light diffusing member or using a conical prism.

[0003] Japanese Patent Application Laid-Open No. 3-4833 proposes an apparatus that shields unnecessary light by providing a light-shielding member at a position substantially conjugate with an eye to be examined. Japanese Patent Application Laid-Open No. 7-59734 proposes an apparatus for projecting a light beam from a ring light source to a cornea via an objective lens and a field lens, and photoelectrically detecting the reflected light to measure the shape of the cornea.

Further, an apparatus for projecting a ring-shaped light beam onto the fundus and photoelectrically detecting the reflected light to measure the refraction value of the eye. A technique for removing light is disclosed in JP-A-3-4833.

[0005]

However, in the above-mentioned prior art, it is difficult to form a ring light beam because the light source of high brightness has a small divergence angle, and it is necessary to use a separate light source for the ring light beam. Therefore, there is a problem that the configuration of the optical system becomes complicated.

An object of the present invention is to solve the above-mentioned problems,
An object of the present invention is to provide an optometry apparatus that forms a ring light beam with a high-luminance light source with a simple configuration.

Another object of the present invention is to provide an optometric apparatus in which unnecessary light is effectively restricted from entering the measuring optical system.

It is still another object of the present invention to provide an optometric apparatus which can measure even when eyeglasses are worn.

[0009]

An optometry apparatus according to the present invention for achieving the above object is to provide a light guide having a circular cross section from a diagonal direction, and project an emitted light beam as a ring light beam to an eye to be examined. Then, eye measurement is performed by photoelectrically detecting the reflected light.

The optometry apparatus according to the present invention projects a light beam onto the fundus of an eye to be examined via an objective lens and a light splitting member.
In an optometry apparatus that photoelectrically detects the reflected light to measure an eye refractive power, an aperture is provided at a conjugate position in the light receiving optical system at a position distant from the anterior eye part, to limit a light beam transmitted through the periphery of the objective lens. It is characterized by.

An optometry apparatus according to the present invention projects a light beam from a ring light source to a cornea through a field lens provided at a conjugate position with an anterior eye image of an eye to be inspected by an objective lens, and photoelectrically detects reflected light thereof. An optometric apparatus for measuring a corneal shape is characterized in that it has a measurement light receiving aperture provided in the ring light source and a ring-shaped aperture provided between the ring light source and the field lens.

The optometry apparatus according to the present invention condenses a light beam in front of the eye and projects a ring-shaped light beam from the periphery of the pupil to the fundus.
In an optometry apparatus for measuring an eye refractive power by photoelectrically detecting the reflected light, a center light shielding member is provided substantially conjugate with a light beam condensing position of an objective lens.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the illustrated embodiment. FIG. 1 shows a configuration diagram of the first embodiment,
This is a composite device having the functions of a non-mydriatic retinal camera, an auto-refractometer, and an auto-keratometer. Infrared light source 1
A lens 3, a strobe light source 4, a ring stop 5, a lens 6, a perforated mirror 7, and a visible light transmission switching mirror 8 are sequentially arranged on an optical path O1 from the optical path O1 to the objective lens 2. On an optical path O2 on the right side of the perforated mirror 7, a focus lens 9, a photographing lens 10, a switching mirror 11, and a fundus image capturing means 12 are arranged. On an optical path O3 in the incident direction of the switching mirror 11, a field is provided. A lens 13, a dichroic mirror 14, a lens 15, and a half mirror 16 are arranged, and the half mirror 16 separates an optical path of a fixation light source 17 from a refractive power and a cornea measurement target 18.

A dichroic mirror 19 is disposed in the reflection direction of the switching mirror 8, and the field lens 2 is disposed on an optical path O 4 in the reflection direction of the dichroic mirror 19.
0, a ring stop 21, a ring light source 22, a lens 23, a field lens 24, a dichroic mirror 14, a lens 25, and a video camera 26 as an image pickup means are arranged in order. The field lens 20 sets the rear focal position of the objective lens 2 to a lens 23 that functions as a diaphragm.
And a conjugate relationship with the aperture. Also, the ring light source 22
Consists of a light source that is actually formed in a continuous ring shape, or a light source in which a plurality of LEDs and the like are arranged at intervals on the circumference, and in each case, the focus position is known so that alignment can be easily performed. And a divergent light source. The ring diaphragm 21 allows the light beam to strike only the center of the field lens 20 and only to the periphery of the objective lens 2,
The reflected light is prevented from entering the measuring optical system.

On the optical path O5 in the incident direction of the dichroic mirror 19, a perforated mirror 27 conjugate to the anterior segment and a pupil P
A central aperture stop 28, a lens 29, and a light source 30 for measuring a refractive power of an infrared LED are sequentially arranged.
1. A relay lens 32 having an opening, a field lens 33, and a light beam around the pupil P that is substantially conjugate to the pupil P and transmitted 6
An aperture stop 34, a light beam splitting prism 35 composed of six wedge prisms, and an area array sensor 36 of a two-dimensional CCD are arranged.

The opening of the relay lens 32 is
Has a diaphragm function of transmitting only a light beam passing through the center portion of the lens, and by this diaphragm function, unnecessary light entering the measurement optical system when the objective lens 2 is large is shielded.
The aperture may be provided separately from the relay lens 32. The position of this stop on the optical path O6 is conjugated to a position at a certain distance from the anterior segment of the eye E to be inspected, that is, a position between the vicinity of the objective lens 2 and the rear focal position of the objective lens 2. At least one is arranged before 35.

First, in the case of fundus oculi observation photographing, the anterior eye portion is photographed by the video camera 26, and is observed on a television monitor (not shown) to perform approximate alignment. The switching mirrors 8 and 11 are kept at the positions indicated by the solid lines, and the fixation light source 17 is turned on. The luminous flux is reflected by a half mirror 16 and a dichroic mirror 14.
Is reflected by the switching mirror 11, passes through the switching mirror 8, and is projected to the eye E to be examined. The anterior segment is illuminated by an infrared light source (not shown), and the reflected light beam is reflected by the switching mirror 8 and the dichroic mirror 19, is captured by the video camera 26 through the optical path O4, and the anterior segment image is displayed on the television monitor. To be observed.

When the position of the anterior segment image matches to a certain extent, the fundus is observed, and the switching mirror 8 is lowered to the position indicated by the dotted line. The light flux from the infrared light source 1 illuminates the fundus through the optical path O1, and the reflected light travels along the optical path O2, is reflected by the switching mirror 11, forms an image on the field lens 13, and is further reflected by the dichroic mirror 14. Then, the image is captured by the video camera 26 as a fundus image by the lens 25 and observed on a television monitor.
The focus adjustment is performed by moving the focus lens 9 while watching this image, the switching mirror 11 is raised to the position indicated by the dotted line at the time of shooting, the strobe light source 4 emits light, and the fundus image is picked up by the image pickup means 12.

Next, in the case of measuring the refractive power, the switching mirrors 8 and 11 are set at the positions indicated by the solid lines. The optotype 18 reflects the half mirror 16 and the switching mirror 11, and the switching mirror 8
And is presented to the eye E to be examined. The anterior ocular segment observation at the time of positioning is performed by the video camera 26 via the optical path O4, as in the case of fundus imaging. The light beam from the refractive power measuring light source 30 is transmitted through a lens 29, a small central aperture stop 28, and a perforated mirror 2.
7. The light passes through the dichroic mirror 19 that transmits this wavelength light, and is projected from the center of the pupil P to the fundus as a spot light flux.

The light reflected by the fundus returns to the same optical path, is reflected by the perforated mirror 27, forms an image of the position of the objective lens 2 on the relay lens 32 by the field lens 31, and further forms an image of the anterior eye on the field lens 31 by the relay lens 32. The partial image is formed at the position of the field lens 33, and is received by the array sensor 36 as six light beams via the six-hole stop 34 and the light beam separating prism 35 by the field lens 33. The positions of the six light beams received by the array sensor 36 are calculated by a calculation means (not shown) to calculate an eye refraction value.

In the case of corneal measurement as well, the switching mirrors 8 and 11 are positioned at solid lines, and the target 18 is projected onto the eye E through the half mirror 16 and the switching mirror 11. The focus lens 9 is moved and set to the position measured by the refractive power measuring optical system, and the ring light source 22 is turned on. The corneal reflection image is formed on the field lens 20 by the objective lens 2 together with the anterior segment image, and the field lens 24 is formed by the lens 23.
The image is re-formed on the imaging surface of the video camera 26 by the lens 25 and observed. Then, at the time of measurement, the corneal reflection image is taken into the arithmetic means and analyzed, and the corneal curvature radius is calculated.

FIG. 2 shows a configuration diagram of the second embodiment, and FIG.
This is an apparatus having a composite function as in the embodiment of the present invention, and members having the same function are represented by the same numbers. In this embodiment, the illumination optical system for measuring the cornea and the optical system for measuring the refraction are different from those in FIG. 1, and the ring stop 21 and the ring light source 22 on the optical path O4 are not used.

The light splitting member 4 is moved in the incident direction of the switching mirror 8.
And a dichroic mirror 41, a perforated mirror 42, a small central aperture stop 43 conjugate to the pupil P, a lens 44, and an objective lens conjugate to the objective lens 2 on the optical path O 5 in the transmission direction of the light splitting member 40. A stop 45 for restricting a light beam from the peripheral portion of the lens 2, a two-dimensional array sensor 4 conjugate to the ocular fundus
6 are sequentially arranged. Further, the light guide 47 and the lens 4 having a circular
8, a cornea measurement light source 49 of an infrared LED is arranged, and in the incident direction of the perforated mirror 42, a ring diaphragm 50 conjugate to the pupil P, a lens 51, a mirror 52, a cylindrical light guide 53, a lens 54, The refractive power measurement light sources 55 are sequentially arranged.

The light beam from the corneal measuring light source 49 is
The light is condensed by 8 and enters the end surface of the light guide 47 from an oblique direction. This light beam repeats total reflection inside the light guide 47, and is emitted from the light guide 47 as a conical light beam having the same angle. This corneal measurement light source 49
Is reflected by the light splitting member 41 and the light splitting member 40
, A conical light beam is projected onto the cornea C of the eye E through the switching mirror 8 and the peripheral portion of the objective lens 2 to generate a ring-shaped corneal reflection image.

The reflected light from the cornea C is reflected by the light dividing member 40, and is imaged by the video camera 26 as parallel corneal reflected light by the aperture function of the lens 23 as in the first embodiment.
Observed and measured. When the luminous flux from the corneal measurement light source 49 enters the light guide 47, it converges so as to form an image at the rear focal point of the objective lens 2, and exits from the light guide 47. Since the light beam becomes a parallel light beam in the meridian direction, it is not affected by the working distance.

The light source 55 for measuring refractive power is a lens 54.
The light flux is projected from the diagonal direction to the light guide 53 through the light guide 53, and this light flux is emitted from the light guide 53 as a conical light flux, condensed by the lens 51, passes through the ring stop 50,
This wavelength light is reflected by the perforated mirror 42, passes through the dichroic mirror 41, passes through the light splitting member 40, and is condensed at the position of the condensing point F of 15 to 20 mm corresponding to the spectacle lens surface in front of the cornea C. Then, a ring-shaped light beam is projected on the fundus of the eye E passing through the periphery of the pupil P. The reflected light returns along the same optical path, passes through a perforated mirror 42, a center small aperture stop 43, a lens 44, and a stop 45, and is received by a two-dimensional array sensor 46 as a ring light beam. The refraction value is obtained by analyzing this image by the calculation means.

As described above, the light beam in the direction in which the light intensity of the refracting power measuring light source 55 is the strongest can be guided to the light guide 53 for effective use. Unnecessary light that passes through and enters the measurement optical system can be shielded. If a light-shielding member that shields a light beam on the optical axis is provided in the vicinity of the central small-aperture stop 43 that is substantially conjugate to the converging point F, the reflected light of the measurement projection light from the spectacle surface can be shielded. It is possible to measure refractive power while wearing spectacles.

[0028]

As described above, in the optometry apparatus according to the present invention, a light beam is incident on a light guide having a circular cross section from an oblique direction, and the emitted light beam, which has become a ring light beam, is projected onto the eye to be examined to perform eye measurement. Thereby, the luminous flux of the light source can be used effectively.

Further, the optometry apparatus according to the present invention uses a large objective lens by providing an aperture at a conjugate position in the light receiving optical system at a position distant from the anterior eye part to limit a light beam transmitted through the periphery of the objective lens. In such a case, it is possible to effectively restrict light flux unnecessary for measurement from being mixed into the measurement optical system.

According to the optometry apparatus of the present invention, the measurement light receiving aperture provided in the ring light source and the ring-shaped aperture provided between the ring light source and the field lens are provided.
The reflected light of the field lens and the objective lens can be prevented from entering the measuring optical system.

In the optometry apparatus according to the present invention, the center light-blocking member is provided substantially conjugately at the light beam condensing position of the objective lens, so that the eye to be examined wearing glasses can be measured.

[Brief description of the drawings]

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

FIG. 2 is a configuration diagram of a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Infrared light source 4 Strobe light source 7, 27 Perforated mirror 8, 11 Switching mirror 12 Imaging means 14, 19, 41 Dichroic mirror 16 Half mirror 17 Fixation light source 18 Optotype 22 Ring light source 26 Video camera 30, 55 Refractive power Light source for measurement 35 Beam splitting prism 36, 46 Array sensor 40 Light splitting member 47, 53 Light guide 49 Light source for corneal measurement

Claims (5)

[Claims] 1. A light beam is incident on a light guide having a circular cross section from an oblique direction, an emitted light beam that has become a ring light beam is projected onto an eye to be examined, and the reflected light is photoelectrically detected to perform eye measurement. Optometrist. 2. The light guide according to claim 1, wherein an end surface of the light guide is provided in the vicinity of a conjugate position with respect to the objective lens with respect to the anterior segment of the subject's eye.
The optometry apparatus according to item 1. 3. An optometric apparatus for projecting a light beam onto the fundus of an eye to be inspected via an objective lens and a light splitting member, and photoelectrically detecting the reflected light to measure the refractive power of the eye. An optometry apparatus provided with a stop at a conjugate position in a light receiving optical system for limiting a light beam transmitted around the objective lens. 4. An optometry in which a luminous flux is projected from a ring light source to a cornea through a field lens provided at a conjugate position with an anterior ocular segment image of an eye to be inspected by an objective lens, and reflected light is photoelectrically detected to measure a corneal shape. An optometric apparatus, comprising: a measurement light receiving aperture provided in the ring light source; and a ring-shaped diaphragm provided between the ring light source and the field lens. 5. An optometry apparatus for converging a light beam in front of the eye, projecting a ring-shaped light beam from the periphery of the pupil to the fundus, and photoelectrically detecting the reflected light to measure an eye refractive power. An optometric apparatus, wherein a central light-blocking member is provided substantially conjugate with a light position.