JPH0226492B2 - - Google Patents

Description

[Detailed description of the invention] The present invention is used in eye hospitals, optical stores, etc.
The present invention relates to a multipurpose optometry device that performs objective refractive power measurements, visual acuity tests, and so-called over-refraction measurements in which refractive measurements are performed through refractive lenses such as glasses.

Conventionally, various types of optometry devices have been known, such as those that perform subjective refraction tests, objective refraction tests, or visual acuity tests, but recently, due to the diversification of occupations, Multipurpose optometry is becoming more important due to factors such as an increase in the amount of information received from people and an aging population. In other words, it has become necessary to collect data necessary for self-management, such as the setting of eyeglass power according to each occupation and the difference in refractive power depending on the fixation direction with progressive multifocal lenses. There is.

In order to meet such demands, it is an object of the present invention to enable over-refraction in visual acuity tests by changing the fixation direction after setting an appropriate spectacle lens, and to enable over-refraction by changing the fixation direction, depending on the examinee's occupation, age, Another purpose is to provide a multi-purpose optometry device that can accurately perform comprehensive examinations that are adapted to the conditions of the eye to be examined. a refraction measuring means for measuring the refractive power of the eye by inputting a luminous flux and receiving the luminous flux introduced into the subject's eye; an exchangeable lens group disposed between the refracting measuring means and the subject's eye; The apparatus is characterized by comprising means for rotating the optotype and the refraction measuring means integrally about a rotation point of the subject's eye.

EMBODIMENT OF THE INVENTION Below, this invention is demonstrated in detail based on the Example of illustration.

FIG. 1 is an optical arrangement diagram according to this embodiment, and E
indicates the eye to be examined, F indicates the fundus, C indicates the cornea, and P indicates the iris. The projection optical system that inputs the luminous flux into the eye E includes, following the illumination light source 1, a measurement mask 2, a projection lens 3, a mask 4 for regulating the luminous flux, a movable relay lens 5, a fixed relay lens 6, and a hole. A clear mirror 7 and an objective lens 8 are arranged. on the other hand,
An image receiving optical system that receives the light beam entering the eye E is provided on the reflection side of the perforated mirror 7, and includes a fixed relay lens 9, a reflecting mirror 10, a movable relay lens 11, a mask 12 for regulating the light beam, and an image receiving system. A lens 13 and a detection mask 14 are arranged in sequence, and three light receiving elements 15a, 15b, and 15c are provided on a plane.

Here, it is preferable that the illumination light source 1 uses an infrared light emitting diode. In addition, as shown in FIG. 2, the measurement mask 2 has three measurement slits 2 equidistant from the optical axis and perpendicular to the three meridians.
It has a, 2b, and 2c. However, in order to further improve measurement accuracy, the number of meridians to be measured may be increased. As shown in FIG. 3, the light flux regulating mask 4 is provided with a circular aperture 4a on the optical axis. The projection lens 3 and the movable relay lens 5 are fixed to the lens barrel A1 so that their focal planes coincide, and the mask 4 is located on the focal plane.
This lens barrel A1 is supported so as to be movable in the optical axis direction. As shown in FIG. 4, the perforated mirror 7 has a circular aperture 7a on the optical axis, and the focal plane of the fixed relay lens 6 and the position of the aperture 7a coincide. Regarding the objective lens 8, the cornea C or pupil P is conjugate with the aperture 7a of the perforated mirror 7. The focal plane of the fixed relay lens 9 coincides with the aperture 7a of the perforated mirror 7, and the mask 12 for regulating the light flux
As shown in FIG. 5, the lens has a concentric slit opening 12a centered on the optical axis. The movable relay lens 11 and the image receiving lens 13 are fixed to a lens barrel A2 so that their focal planes coincide, and the mask 12 is located on the focal plane, and this lens barrel A2 is movable in the optical axis direction. is supported by

Here, the outer diameter of the slit opening 12a of the mask 12 is set to be smaller than the diameter of the pupil image, assuming that the pupil image is projected onto the mask 12 by the lenses 8, 9, and 11. shall
The pupil diameter at this time is assumed to be the size of the pupil constricted by the indoor light in the measurement room. Further, the inner diameter of the slit opening 12a is such that the opening 7a of the perforated mirror 7 is the same as that of the lenses 9, 11.
The diameter of the aperture 7a of the perforated mirror 7 is set to be slightly larger than the aperture image of the aperture 7a.
The aperture 4a of the mask 4 for regulating light flux is the lens 5, 6.
When it is assumed that the image is projected onto the perforated mirror 7, the aperture image is set to be equal to or slightly larger than the aperture image of the aperture 4a. Furthermore, assuming that the light flux emitted from the aperture 7a of the perforated mirror 7 where the pupil image is formed is:
Since lenses 5 and 6 and lenses 9 and 11 are afocal, movable relay lenses 5 and 11
Regardless of the movement of the pupil, the size and position of the pupil remain the same. On the other hand, the projection lens 3 and the image receiving lens 13,
Movable relay lenses 5 and 11, fixed relay lens 6
If the focal lengths of and 9 are made the same, the projection side lens groups 3 and 5, that is, the lens barrel A1, and the light receiving side lens groups 11 and 13, that is, the lens barrel A.
Since the amount of movement of lens barrels A1 and A2 can be matched,
can be coupled by arm D and driven together in the direction of the arrow.

As shown in FIG. 6, the detection mask 14 has three rectangular detection slits 14a, 14b, and 14c equidistant from the optical axis and perpendicular to the three meridians, respectively. The light beams that have passed through the light receiving elements 15a and 15 are respectively
b, 15c to receive light. In addition,
A position detector B such as a linear encoder is connected to the lens barrel A1 or A2 to detect the position on the optical axis of the lens group related to the refractive power.

Now, between the objective lens 8 and the eye E to be examined, there is a beam splitter 16, and one eyeglass lens 17a out of a large number of eyeglass lens groups arranged on the eyeglass lens board 17.
are separated by a predetermined working distance. Further, in front of the eye E to be examined, a visual target 18 is arranged with a variable distance and can be observed through the beam splitter 16 and the above-mentioned spectacle lens 17a. In some cases, the beam splitter 16 may be a dichroic mirror that reflects infrared light and transmits visible light. As illustrated in FIG. 7, the spectacle lens disk 17 includes spectacle lenses 17a, 17 that include only empty frames around the center O.
A group of b, 17c... is arranged, and each center O
Openings 19a, 19 having a small diameter in the direction of the symmetry axis
b, 19c... are perforated, and these openings 19
A detection light source 20 that emits light to a, . . . , and a detector 21 opposite thereto are arranged as shown in FIG. The center O of the eyeglass lens disc 17 coincides with the rotation center axis 22, and the eyeglass lens disc 17 is rotatable around this rotation center axis 22.

In the above configuration, if the arm D moves once from the far point direction to the near point direction or vice versa with a constant flux, at a certain point during the movement, the measurement mask 2, the fundus F, and the fundus F and detection mask 14 are conjugate, that is, measurement mask 2 and detection mask 1
4 are conjugate to each other. However, if the subject's eye E and the spectacle lens 17a have astigmatism, each meridian will not become conjugate at the same time, so the conjugate point will be detected individually.

When the illumination light source 1 is turned on, each measurement slit 2a, 2b, 2c of the measurement mask 2 is illuminated, and each measurement slit 2 having a conjugate relationship shown by the solid line optical path is illuminated.
The beams emitted from the beams a, 2b, and 2c are once imaged by the projection lens 3 and the movable relay lens 5, and then reimaged by the fixed relay lens 6 after the perforated mirror 7, and further transferred to the objective lens 8 and the beam beam. Pritsuta 1
6. Projected onto the fundus F through the spectacle lens 17a. At that time, the opening 4a of the mask 4 for regulating the light flux is
Although all the projected light beams are regulated, the image of the aperture 4a having the conjugate relationship shown by the optical path of the broken line is formed on the aperture 7a of the perforated mirror 7 by the action of the movable relay lens 5 and the fixed relay lens 6. . Next, since the aperture image is formed near the pupil of the eye E by the action of the objective lens 8, the area through which the projected light flux passes on the cornea C or pupil is regulated.

Next, if fundus F and measurement mask 2 are conjugate,
A clear image of each measurement slit 2a, 2b, 2c is formed on the fundus F, and the light beams scattered and reflected there exit the eye E, pass through the eyeglass lens 17a and the beam splitter 16, and enter the objective lens 8. Once formed into an image, it is reflected by the mirror surface of the perforated mirror 7,
Furthermore, the image is re-imaged by a fixed relay lens 9. This reflected light flux from the fundus F changes direction at the reflection mirror 10,
A slit image is formed on the detection mask 14 by the movable relay lens 11 and the image receiving lens 13, and each detection slit 14a, 14b, 14c of the detection mask 14
The light beams that have passed through the respective light receiving elements 15a to 1
The light is received at 5c. At this time, the light flux that can pass through the slit aperture 12a of the light flux regulating mask 12 is limited to the light flux that passes through the area where the slit aperture image is formed, assuming that the mask 12 is projected onto the pupil. Therefore, as mentioned above, the size of the image of the inner diameter of the slit aperture 12a on the pupil is slightly larger than the size of the image of the aperture 7a, and a part of the projected light flux reflected by the cornea C is added to the reflected light flux from the fundus F. There will be no contamination.

In the above embodiment, the moment when the fundus F and the measurement mask 2 become conjugate was explained, but such a moment only occurs once during the scanning of the lens group, and at other times there are differences in degree. However, the slit image on the fundus F and on the detection mask 14 is blurred. 8 and 9 show the relationship between the blurred obliquely shaded slit image on the detection mask 14 and the rectangular detection slits 14a to 14c shown by solid lines. If the eye E to be examined does not have astigmatism, the eighth
If there is astigmatism, it will be deformed as shown in Figure 9. Note that AX indicates the astigmatism axis.

If the measurement slit image is blurred in this way, the amount of light passing through each detection slit 14a to 14c is naturally reduced compared to when the measurement slit image is clear.
If the amount of light passing through a to 14c is measured, the fundus E
It is possible to detect the point in time when each of the measurement slits 2a to 2c of the measurement mask 2 becomes conjugate.

Generally, based on Euler's formula for toric surfaces, the refractive power Pθ on a meridian inclined by an angle θ from the strong principal meridian is calculated using the refractive power Ph in the strong principal meridian direction and the refractive power Pe in the weak principal meridian direction. , Pθ=Ph・sin ² θ+Pe・cos ² θ, and the movement in the direction of the measurement meridian determines the refractive power in that direction. From this, the light passing through each of the detection slits 14a to 14c is received by each of the light receiving elements 15a to 15c, the output peak is detected as an electrical signal, and the spherical diopter and astigmatism are determined from the position of the lens barrel A1 at that point. Being able to calculate degrees and astigmatism axis is
For example, it is disclosed in Japanese Patent Application Laid-Open No. 54-77495.

In the above embodiment, the measurement slits 2a, 2b, 2c of the measurement mask 2 and the detection slits 14a, 14b, 14c of the detection mask 14 were in a conjugate relationship with respect to the fundus E, respectively. As shown, the image blur extends not only along the measurement meridian but also in the direction perpendicular to it, especially in the case of astigmatism.
As shown in the figure, each slit image undergoes various deformations as a result of the combination of the meridian direction and the astigmatic axis AX direction due to the astigmatism of the eye.

Therefore, this effect can be suppressed by avoiding measurements near both ends of the slit image where the most deformation occurs, and the detection mask 1 on the light receiving side
It is effective to make the lengths of the four detection slits 14a, 14b, 14c in the direction perpendicular to the meridian shorter than the clear fundus reflection images of the measurement slits 2a, 2b, 2c of the measurement mask 2 in advance.

In addition, in the above embodiment, the lens groups on the projection side and the light receiving side were moved, but the units of the measurement mask 2 and the light source 1 for sharpness, the detection mask 14 and the light receiving element 1 were moved.
The units 5a to 15c can be moved under a certain correlation, and the movable lens group can have various configurations other than those in the embodiment.

Further, the light receiving elements 15a to 15c are arranged behind the measurement mask 2 of the embodiment, the illumination light source 1 is provided behind the detection mask 14, the projection side and the light reception side are reversed, and the projection is performed from the axial band-shaped part. It is also possible to project the luminous flux onto the fundus F and extract the reflected luminous flux from the central portion thereof.

Next, regarding how the power part of the measurement results differs between the eye E and the spectacle lens,
If the power of the inserted spectacle lens is input, the power of the eye E to be examined can be determined by subtracting the power of the inserted spectacle lens from the measurement result. For this purpose, the light from the detection light source 20 is received by the detector 21 using the openings 19a, 19b, 19c... corresponding to the respective glasses lenses 17a, 17b, 17c... on the glasses lens plate 17. Shine.
By counting this with a counter (not shown), it is possible to derive the value input in advance as the power of each inserted spectacle lens.

The series of operations from measurement to display are as shown in FIG. In other words, the power of the eye to be examined including the power of the eyeglass lens is determined as the value of "refraction measurement", and the value is calculated along the solid line flow when the eyeglass lens is worn, and when the eyeglass lens is not worn. Along the flow of the dashed line,
The power of only the eye to be examined can be obtained as a "display".

In the above explanation, only one eye was shown regarding the insertion of the spectacle lens, but in order to maintain binocular vision, as shown in FIG. Needless to say, the spectacle lens disc 17L can be used at the same time.

Figures 12 and 13 show examples of overrefraction performed by changing the fixation direction.
In FIG. 12, a predetermined eyeglass lens on the eyeglass lens board 17, the visual axis of the eye E to be examined, and the optotype 19 are aligned with the optical axis V1−
V2, and a refraction measuring optical system is provided in the direction of V1-O-U2 via a beam splitter 16.

On the other hand, in FIG. 13, the spectacle lens on the spectacle lens disc 17 is on the optical axis V1-V2, but the visual axis of the eye E and the optotype 19 are on the optical axis W1-W2, and the refraction measurement optical system is W1-O via beam splitter 16
−Exists on U2. That is, this case is a comparative example of measurement when changing the line of sight, and the optical axis V1−
V2 and the optical axis W1-W2 intersect at the rotation point of the eye E to be examined.

When performing refraction measurement in the above example, a method is adopted in which an index is projected into the eye E to be examined and its reflected image is detected. Of course, this can be done using a method using .

As explained above, in the optometry device according to the present invention, it is possible to perform overrefraction after setting an appropriate spectacle lens during a visual acuity test.
It is possible to obtain a device that is fully equipped with multi-purpose functions, departing from the conventional optometry function, and has the effect that a comprehensive examination adapted to the occupation of the examinee and the situation of the eye to be examined can be performed with high accuracy.

[Brief explanation of drawings]

The drawings show an embodiment of the optometry apparatus according to the present invention, and FIG. 1 is an optical layout diagram of the first embodiment, FIG. 2 is a front view of a measurement mask, and FIG. 3 is a diagram of a mask for regulating light flux. Figure 4 is a front view of the perforated mirror, Figure 5 is a front view of the mask for limiting luminous flux, and Figure 6 is a front view of the mirror with a hole.
The figure is a front view of the detection mask, FIG. 7 is a front view of the spectacle lens disc, FIGS. 8 and 9 are illustrations of blurred slit images on the detection mask, and FIG. 10 is an illustration of the operation.
Figure 11 is a layout diagram of another embodiment; Figure 12;
FIG. 3 is a layout diagram of an example of overrefraction in which the fixation direction is changed. 1 is a light source for illumination, 2 is a measurement mask, 3 is a projection lens, 4 is a mask for regulating light flux, 5, 6,
9 and 11 are movable relay lenses, 7 is a perforated mirror, 8 is an objective lens, 10 is a reflective mirror, 12 is a mask for regulating light flux, 13 is an image receiving lens, 14 is a detection mask, 15a to 15c are light receiving elements, 16 is a beam splitter, 17, 17R, 17L are spectacle lens discs, 17a is a spectacle lens, 19 is an optotype, 1
9a, 19b, 19c... are openings, 20 is a detection light source, 21 is a detector, A1, A2 are lens barrels, D is an arm, and B is a position detector.

Claims (1)

[Scope of Claims] 1. An optotype presented to the eye to be examined; a refraction measuring means for measuring the refractive power of the eye by injecting a light beam into the eye to be examined and receiving the light beam introduced into the eye to be examined;
It is characterized by comprising an exchangeable lens group disposed between the refraction measuring means and the eye to be examined, and means for rotating the optotype and the refraction measuring means together approximately around the rotation point of the eye to be examined. optometry equipment. 2. The optometry apparatus according to claim 1, wherein a beam splitter is provided between the eye to be examined and the refraction measuring means, and the optotype is observed through the beam splitter. 3 The replaceable lens group is configured with a combination that selectively includes an empty frame and a lens, and means for detecting the refractive power of the lens group at a predetermined position, and feedback of the detected refractive power to a measured value of eye refractive power. The optometry apparatus according to claim 1, further comprising a calculation means. 4. The optometry device according to claim 1, wherein the presentation distance of the optotype is variable.