JPH0473040A - Ophthalmologic measuring apparatus - Google Patents

Abstract

PURPOSE:To obtain both functions of a keratometer and a lensmeter with a simple construction by introducing a cornea reflected luminous flux which is obtained by projecting a luminous flux to a cornea of an eye to be inspected and to a lens to be inspected and a luminous flux passing through the lens to measure a radius of curvature of the cornea and a refraction value of the lens to be inspected. CONSTITUTION:A solenoid 36 is driven to insert a stop 35 onto an optical path and when light sources 20a-20d are turned ON, four cornea reflected images are generated on a cornea Ec by these luminous fluxes and after reflected with a mirror 23, the images are reflected on a mirror 30 via a lens 29 to be projected onto an image sensor 19 via a lens 33, a mirror 34 and a stop 35 to measure a radius of curvature of the cornea Ec from a positional relationship thereamong. On the other hands, a lens G to be inspected is set on the side of a light source 16 near a stop 14 and when the light 16 is turned ON, a luminous flux thereof is reflected with a mirror 27 through a lens 15, the lens G to be inspected and the stop 14 and then, with a mirror 34 via a lens 13, a lens 28 and a mirror 25. Thus. four luminous flux images are projected onto the image sensor 19 corresponding to an opening of the stop 14 thereby measuring a refraction value of the lens G to be inspected from a positional relationship among the images.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ophthalmological measuring device having functions as a keratometer and a lens meter used, for example, in eye clinics.

[Prior Art] Conventionally, a keratometer has been used to measure the radius of curvature of the cornea, a refractometer has been used to measure the ocular refraction of the eye to be examined, and a refractometer has been used to measure the refraction of glasses or contact lenses worn by the eye to be examined. A lens meter is used, and an integrated refractometer and lens meter has also been proposed.

[Problem to be Solved by the Invention 1] However, in the conventional example described above, there is no apparatus that can measure the radius of corneal curvature and determine the lens refraction value -11 using one instrument. Therefore, separate devices must be used for each of these measurements, but preparing these separately increases costs and requires a long time to compare the measured values from each device. This causes inconvenience when prescribing glasses.

SUMMARY OF THE INVENTION An object of the present invention is to provide an ophthalmological measuring device having a simple structure and having both functions as a keratometer and a lens meter.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the ophthalmological measuring device according to the present invention projects a light beam onto the cornea of the eye to be examined and measures the radius of curvature of the cornea using the corneal reflected light beam. a lens refraction value measurement optical system that measures a refraction value using a lens-transmitted light beam obtained by projecting a light beam onto a test lens disposed non-conjugately with respect to the cornea; It is characterized by having a light guide optical system that guides the light flux and the lens-transmitted light flux to the same photoelectric element via an optical path coupling member.

[Function] The ophthalmological measurement device having the above-described configuration projects a light beam onto the cornea of the eye to be examined and the lens to be examined, and guides the obtained corneal reflected light beam and lens transmitted light beam to the same photoelectric element to measure the eye. Measures the radius of curvature and refractive value of the lens to be examined.

[Example] The present invention will be explained in detail based on illustrated embodiments.

FIG. 1 shows a configuration diagram of the first embodiment. On the optical axis 01 extending from the light source 1 provided for measuring the eye refraction value to the eye E to be examined, there are a lens 2, an aperture 3, a perforated mirror 4, A mirror 5, a lens 6, and a dichroic mirror 7 and a dichroic mirror 8 are arranged as optical path coupling members, and in the reflection direction of the perforated mirror 4, an aperture 9 having a plurality of apertures, a lens 10,
A separation prism 11 constituted by a wedge prism corresponding to the aperture, and a non-life insurance element 12 such as a two-dimensional CCD are arranged. Optical axis 0 of the reflection direction of the dichroic mirror 8
2, a lens 13, an aperture 14 having four apertures 14a to 14d as shown in FIG. Behind the dichroic mirror 8.7 on the optical axis 03 that coincides with the eye axis of E, there is a lens 17, an aperture 18, and a two-dimensional C
Image carrier elements 19 such as CDs are arranged. In addition, for measuring the radius of curvature of the eye E to be examined, the optical axis 0 is placed opposite the eye E to be examined.
Four light sources 20a to 20d are arranged at symmetrical positions around 3. Note that the diaphragm 14 and the diaphragm 18 are made conjugate via a dichroic mirror 8, and the dichroic mirror 7 reflects the light beam from the light source 1 to the light source 16.20.
The dichroic mirror 8 transmits the light beams from the light sources 1.20a to 20d, and reflects the light beams from the light sources 16 to the light sources 1.20a to 20d.
It has a wavelength division characteristic that transmits the light beam from 20d.

When light source 1 is turned on when measuring the eye refraction value, the luminous flux is directed to the optical axis O.
1, passes through the lens 2, the aperture 3, and the aperture of the perforated mirror 4, is reflected by the mirror 5, passes through the lens 6, is reflected by the dichroic mirror 7, and then passes through the dichroic mirror 8 to the eye E to be examined. reach. The light flux reflected by the fundus Er returns along the same optical path and is reflected by the perforated mirror 4, passes through the diaphragm 9, the lens 10, and the separation prism 11, and then passes through the image sensor 1.
Four fundus reflection images corresponding to the aperture of the aperture 9 are projected onto the diaphragm 2, and an ocular refraction value is calculated from these projected coordinate positions.

When the light sources 20a to 20d are turned on when measuring the radius of curvature of the eye E, these light beams produce a third light on the cornea Ec.
As shown in the figure, corneal reflection images Ma-Md are generated at positions corresponding to the light sources 20a to 20d, and these reflection images advance on the optical axis 03, and four corneal reflection images are projected onto the image carrier 19. The refractive value including astigmatism, that is, the radius of curvature is measured from these positional relationships. In addition, four corneal reflection images Ma
- The eccentricity of Md can be detected and used for alignment.

When measuring the refractive value of the test lens G worn by the test eye E, as shown in FIG. When the light source 16 is turned on while being fixed at a position non-conjugate with the cornea Ec, the light flux passes through the lens 15, the test lens G, the diaphragm 14, and the lens 13, and is reflected by the dichroic mirror 8, and then the dichroic mirror 7 and the lens 17. , the aperture 14a of the aperture 14 as shown in FIG.
Four luminous fluxes Pa to Pd corresponding to ~14d are projected,
Refraction value measurement is performed based on the positional relationship of these light beams. Note that by arranging the lens G to be examined non-conjugately with the cornea Ec, it can be separated into four light beams on the image sensor 19.

Here, since the aperture 14 and the aperture 18 are arranged conjugately, even if the test lens G is decentered from the optical axis 02, all of the four light beams Pa=Pd are transmitted to the image sensor 19.
The eccentricity of these light beams Pa to Pd can be detected and used for alignment of the lens G to be tested. Further, the aperture 18 is disposed between the rear focal point of the lens 17 and the image sensor 19 to prevent measurement errors from occurring due to errors in the working distance.

The projected image on the image sensor 12.19 may be converted into a video signal by a video camera and then subjected to signal processing.
It is preferable to make the positional relationship of .about.20d with respect to the optical axis correspond as in the above-described embodiment, and to also provide four apertures of the diaphragm 9 to correspond, since the signal processing process of the projected image can be shared. For measurement, it is sufficient to calculate the refractive power in the three radial directions using the positions of three or more projected images, so there is no problem even if the number of apertures is increased to six, or an annular aperture or an annular light source is used. Even in that case, it is desirable that the signal processing process be common.

FIG. 5 shows a configuration diagram of the second embodiment, in which the same reference numerals as in the first embodiment represent the same members.

A lens 2, a small mirror 21a of an optical member 21, a lens 22, and a dichroic mirror 23 are arranged on an optical axis 01 extending from a light source 1 for measuring an eye refraction value to an eye E to be examined.

A small mirror 21a on the optical axis 04 that coincides with the eye axis of the eye E to be examined.
As shown in FIG. 6, four masked peripheral openings 21b to 21e, an optical member 21 having four wedge prisms corresponding to these, a lens 24, and a dichroic mirror 25 are arranged behind the lens. There is. From the light source 16 for measuring the refractive value of the test lens G to the dichroic mirror 25
A lens 15, a diaphragm 14, a mirror 27, and lenses 13 and 28 are arranged on the optical axis 05 leading to . On the optical axis 06 in the direction of reflection of the dichroic mirror 23, there is a lens 2.
9, dichroic mirror 30, lens 31, mirror 3
2 are arranged, and on the optical axis 07 in the reflection direction of the dichroic mirror 30, a lens 33, a dichroic mirror 34 whose other reflection direction matches the reflection direction of the dichroic mirror 25, an aperture 35 which can be inserted into and removed from the optical path, Image sensor 1
A solenoid 36 is connected to the diaphragm 35 to drive the diaphragm 35. Also,
On the optical axis 08 in the reflection direction of the mirror 32, a lens 37 and an optotype 38, which are movable in the direction along the optical axis 08, are arranged. Further, light sources 20a to 20d for measuring the radius of curvature are provided facing the eye E to be examined, and a plurality of light sources 39 are arranged for illuminating the anterior ocular segment. Note that the optical member 21
is approximately conjugate to the pupil of the eye E to be examined, and the image sensor 19 is conjugate to the emmetropic fundus on the optical axis for measuring the eye refraction value, and is conjugate to the anterior segment on the optical axis for measuring the radius of curvature of the angle 1iEc. The dichroic mirror 23 uses visible light and light sources 20a to 20d, 3
The dichroic mirror 25 reflects the light beam from the light source 1, and the dichroic mirror 25 reflects the light beam from the light source 1.
The light beam from the light source 16 passes through the dichroic mirror 30.
reflects the luminous flux from the light sources 20a to 20d, 39 and transmits visible light, and the dichroic mirror 34 is connected to the light source 1.16.
It has a wavelength division characteristic of reflecting the light flux from the light sources 20a to 20d and transmitting the light flux from the light sources 20a to 20d and 39.

At the time of alignment, the solenoid 36 is operated and the aperture 35 is
When the light source 39 is turned on with the light beam removed from the optical path, this light beam is reflected at the anterior segment of the eye and then passes through the dichroic mirror 2.
3 , is reflected by the dichroic mirror 30 via the lens 29 , and an anterior segment image is formed on the image sensor 19 via the lens 33 and the dichroic mirror 34 . The examiner outputs this to, for example, a television monitor (not shown), observes it, and performs alignment.

When the light source 1 is turned on during eye refraction measurement, the light beam from the light source L travels on the optical axis O1, is reflected by the small mirror 21a, passes through the lens 22 and the dichroic mirror 23, and reaches the eye E to be examined, and the light beam reflected by the fundus Er is Returning along the same optical path,
The fundus reflection images corresponding to the four peripheral apertures 21b to 21d of the optical member 21 are reflected by the dichroic mirror 25 and the dichroic mirror 34 via the peripheral apertures 21b to 21e of the optical member 21, the wedge prism, and the lens 24, and are displayed on the image sensor 19. is projected, and the eye refraction value is measured based on these positional relationships.

In this case, the optotype 38 is used to guide the diopter of the eye E to be examined, and the visible light beam reflected by the optotype 38 passes through the lens 37, is reflected by the mirror 32, passes through the lens 31, the dichroic mirror 30, and then passes through the dichroic mirror 30. The light is reflected by the mirror 23 and reaches the subject's eye E, and by moving the lens 37 in the direction along the optical axis 08, the apparent diopter of the optotype 38 is adjusted.

When measuring the radius of curvature of the cornea, the light sources 20a to 20 are operated while the solenoid 36 is driven and the aperture 35 is inserted on the optical path.
When d is turned on, four corneal reflection images are generated on the cornea Ec by these light beams, and these corneal reflection images are reflected by the dichroic mirror 23 and then reflected by the lens 29.
is reflected by the dichroic mirror 30, and is reflected by the lens 3.
3. Four corneal reflection images are projected onto the image sensor 19 via the dichroic mirror 34 and the aperture 35, and the radius of curvature of the cornea Ec is measured based on their positional relationship.

On the other hand, when measuring the refractive value of the test lens G, when the light source 16 is turned on with the test lens G placed near the aperture 14 on the light source 16 side, this luminous flux is transmitted to the lens 15, the test lens G, It is reflected by the mirror 27 through the aperture 14, and the lens 1
3. After passing through the lens 28 and the dichroic mirror 25, it is reflected by the dichroic mirror 34, and the image sensor 19
Four beam images corresponding to the aperture of the diaphragm 14 are projected above, and the refractive value of the lens G to be tested is measured based on the positional relationship between these images. Note that the eccentricity of the four beam images can also be detected and used for alignment of the lens G to be tested.

The aperture of the diaphragm 14 and the peripheral apertures 21b to 21 of the optical member 21
e. Similarly to the above-described embodiment, there are no restrictions on the arrangement positions, shapes, etc. of the light sources 20a to 20d. In addition, although a two-dimensional image sensor 19 is used in the embodiment, -
Alternatively, a plurality of dimensional CCDs may be arranged.

[Effects of the Invention] As explained above, the ophthalmological measuring device according to the present invention uses the same photoelectric element to project the cornea reflected light flux and the lens transmitted light flux obtained by projecting the light flux onto the cornea of the eye to be examined and the lens to be examined, respectively. The keratometer has a simple configuration and can be used to measure the radius of curvature of the cornea and the refractive value of the lens to be tested.
It has the function of a lens meter. Furthermore, since these results can be easily compared, they can be useful for prescription of eyeglass lenses.

[Brief explanation of drawings]

The drawings show an embodiment of the ophthalmological measuring device according to the present invention, and the first
2 is a front view of the aperture, FIG. 3 is an illustration of a corneal reflection image on the cornea, FIG. 4 is an illustration of a projected light beam on the image sensor, and FIG. The figure is a configuration diagram of the second embodiment, and FIG. 6 is an explanatory diagram of a mask of an optical member. Symbols 1.16.20a to 20d, 39 are light sources, 3.9.
14.18.35 is the aperture, 5.7.8.23.25.3
0.34 is a dichroic mirror, 12.19 is an image sensor, 21 is an optical member, and G is a lens to be tested.

Claims (1)

[Claims] 1. A radius of curvature measuring optical system that projects a light beam onto the cornea of the eye to be examined and measures the radius of curvature of the cornea using the reflected light beam; It has a lens refraction value measuring optical system that measures a refraction value using the obtained lens transmitted light flux, and a light guiding optical system that guides the corneal reflected light flux and the lens transmitted light flux to the same photoelectric element via an optical path coupling member. An ophthalmological measurement device characterized by: