JPH0348806B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a subjective eye refractive power measurement device, that is, an aperture diaphragm having a plurality of apertures in which a light beam from a focus detection chart is arranged at a position conjugate with the pupil of the eye to be examined. The present invention relates to a subjective eye refractive power measuring device configured to project images onto the fundus of an eye to be examined.

Prior Art Examples of conventional subjective eye refractive power measuring devices include:
Project the eye refractive power measurement chart onto the fundus of the subject's eye using a projection lens system, and project the chart to a position where the chart image is focused on the fundus of the subject's eye, that is, a position where the subject can clearly see the chart. Move it on the optical axis of the lens system. For this adjustment, there is a method that measures the eye refractive power by detecting in which direction and how much the chart has moved from a reference position corresponding to a diopter of 0.

Another example of the conventional subjective eye refractive power measurement device is that in the above conventional example, instead of moving the chart on the optical axis, lenses with different refractive powers are selectively inserted on the optical axis. Some devices are configured to measure the eye refractive power from the refractive power of the lens.

However, with the above-mentioned conventional apparatus, it is necessary to judge whether or not the chart image is focused on the fundus of the examinee's eye based on the degree of blur in the chart image, but this judgment is difficult for the examinee. Therefore, high precision measurements could not be expected.

In yet another example of a conventional subjective eye refractive power measuring device, in order to solve the problems of the conventional device described above, the light beam from the chart is passed through a two-hole diaphragm placed at a position conjugate with the pupil of the patient's eye. There is one that is configured to project onto the fundus of the eye. This means that when the light beam from the chart is focused on the fundus of the examinee's eye,
When the two chart images are aligned and formed on the fundus of the subject's eye, but are not in focus, the two chart images are formed separately, so the in-focus state of the chart images can be easily and accurately determined. This is a so-called matching type subjective refractive power measuring device.

However, in the above-mentioned matching type subjective refractive power measuring device, in order for the measurement light flux that has passed through the two-hole diaphragm to pass through the pupil of the subject's eye, so-called alignment adjustment is performed to match the optical axis of the measuring device and the optical axis of the subject's eye. This posed the problem of difficult measurement operations.

Purpose of the Invention The present invention was made in view of the above-mentioned conventional problems, and enables easy and highly accurate refractive power measurement.
Another object of the present invention is to provide a subjective refractive power measuring device that does not substantially require so-called alignment adjustment.

Structure of the Invention According to the present invention, a chart for measuring eye refractive power;
a diaphragm having a plurality of apertures disposed on the optical path of the projected light flux from the chart at a position substantially conjugate with the pupil of the subject's eye; and a diaphragm having a plurality of apertures that is arranged on the optical path of the projected light flux from the chart, and projecting a chart image onto the fundus of the subject's eye by the light flux transmitted through the aperture of the diaphragm. It comprises a projection lens system for creating a substantially conjugate relationship between the diaphragm and the pupil of the eye to be examined, and the aperture of the diaphragm is arranged in an area wider than the size corresponding to the pupil of the eye to be examined in the diaphragm, and corresponds to the pupil of the eye to be examined. The eye refractive power of the eye to be examined is determined from the composite state of a chart image for measuring the refractive power of each eye formed on the fundus of the eye to be examined by each light beam passing through the aperture such that the size always includes two or more diaphragm apertures. A subjective eye refractive power measuring device is provided.

Embodiment The first embodiment has a configuration in which a circular aperture image is formed over a much wider area than the pupil on a plane containing the pupil of the eye to be examined. FIG. 1 is a perspective view of the optical system of the first embodiment, which consists of an optical system R for the right eye to be examined and an optical system L for the left eye to be examined. Both optical systems R and L have the same configuration, and are provided with a light source 10 and a cross mark 12 illuminated by the light source 10 and arranged near a position conjugate with the fundus 19 of the eye to be examined, on the respective optical axes RO and LO. a chart plate 14 , a multi-hole aperture plate 18 having a plurality of circular holes 16 , a relay lens 20 that forms an image of the cross mark 12 near a position 21 that is conjugate with the fundus 19 of the eye to be examined, and a relay lens 20 that focuses the image of the cross mark 12 on the fundus 19 of the eye to be examined.
A projection lens 24 projects an image of the circular hole 16 onto the pupil 22 of the eye to be examined. The projection magnification of the projection lens 24 is as shown in FIG.
It is determined that, for example, four are included in the pupil 22 of the eye to be examined.

In the above configuration, when the cross mark 12 of the chart board 14 is focused and projected onto the fundus 19 of the eye to be examined, an image of only one cross mark 12 is formed. On the other hand, when the image is projected out of focus, as many images of the cross mark 12 as there are images 16' of the circular hole in the pupil 22 of the subject's eye are formed at different positions. By the way, the pupil of the eye to be examined 22
As shown in Fig. 2, the image 16' of the circular hole is formed over an area approximately 10 times that area, so the position of the pupil 22 of the eye to be examined is quite different from the optical axes LO and RO. Even if there is a deviation, the light beam passing through the circular hole 16 can form an image on the fundus 19 of the eye to be examined.

In the apparatus of the above embodiment, the chart plate 14 is moved on the optical axes RO and LO according to the test subject's response,
Alternatively, the subject himself moves the chart board 14 to focus the image of the cross mark 12 on the fundus 19 of the subject's eye. At this time, the refractive power of the eye to be examined can be measured from the amount of movement of the chart plate 14 from the position of the refractive power O. At this time, if the focal point of the lens 20 on the subject's eye side is placed at a position conjugate with the pupil formed by the lens 40, the moving distance of the chart becomes linear with the principal point refractive power of the subject's eye, while at a position conjugate with the glasses wearing position. For example, the refractive power and movement distance of the eye to be examined are linear.
This measuring method is the same in the second to sixth embodiments below.

The second embodiment is constructed by replacing the aperture plate of the first embodiment with an aperture plate having a plurality of parallel slits. The projection magnification of the aperture plate onto the pupil of the subject's eye is as shown in FIG.
At least two slit images 52 of 0' are determined to be on the pupil 22 of the eye to be examined.

In the above configuration, when the cross mark image 12 is focused and projected onto the fundus 19 of the subject's eye, an image of only one cross mark 12 is formed, as in the first embodiment.
On the other hand, when the cross index 12 is projected onto the fundus 19 of the subject's eye without focusing, the image 5 of the slit in the pupil 22 of the subject's eye
Two images of the cross marks 12 are formed while being shifted from each other in a direction perpendicular to the slit length direction.

The third embodiment is constructed by replacing the aperture plate of the first embodiment with an aperture device that rotates an aperture disk having a plurality of circular holes. As shown in FIG. 4, the aperture disk 100 has a plurality of circular holes in a circular hole zone 102, and the optical axis LO (RO) passes through the middle of the circular hole zone.

In the above configuration, the refractive power is measured using the aperture disk 1.
00 is rotated around the rotation center O. When the cross mark 12 of the chart board 14 is focused and projected onto the fundus 19 of the eye to be examined, a single fixed cross mark image is formed. On the other hand, when projected in an out-of-focus state, the plurality of cross-shaped index images are separated and simultaneously moved in the vertical direction.

The fourth embodiment is constructed by replacing the aperture plate of the first embodiment with an aperture device that rotates an aperture disk having a plurality of slits in the radial direction. Aperture disk 150
As shown in FIG. 5, the slit zone 152 has a plurality of slits 154 in the radial direction, and the optical axis LO (RO) passes through the middle of the slit zone 152.

In the above configuration, the refractive power is measured using the aperture disk 1.
50 is rotated around the rotation center O. When the cross mark 12 of the chart board 14 is focused and projected onto the fundus 19 of the eye to be examined, a single fixed cross mark image is formed. On the other hand, when projected out of focus, the multiple crosshair images move on a single vertical line, compared to the case where the crosshair index 12 is fixed.
Furthermore, the in-focus state can be detected more easily.

The fifth embodiment is configured by arranging a pair of indicators and a diaphragm on different optical axes. FIG. 6 showing the fifth embodiment shows an optical system for measuring the refractive power of either the left or right eye to be examined. That is, the optical system of the fifth embodiment is a first light source 200 disposed on the first optical axis _O1 , and is illuminated by the first light source 200 and movably disposed near a conjugate position with the fundus 202 of the eye to be examined. First chart board 204, first chart board 20
A first relay lens 206 that forms an image of 4 at a position conjugate with the fundus 202 of the eye to be examined, a first multi-hole diaphragm plate 210 arranged conjugate to the pupil 208 of the eye to be examined, and a first optical axis.
The second optical axis has the same configuration as O ₁ and is located on the second optical axis O ₂ .
It includes a light source 212, a second chart plate 214, a second relay lens 216, and a second porous aperture plate 218. The optical system of the fifth embodiment further has a second optical axis.
A mirror 220 is disposed on O ₂ and bends the second optical axis O ₂ in the direction of the first optical axis O ₁ , and a mirror 220 is arranged on the optical axis O 2 to transmit the light beam along the first optical axis O ₁ and bend the second optical axis O ₂ in the direction of the first optical axis O 1 . A half mirror 222 that reflects the rays of light, and a first chart board 2
04 and the second chart plate 214 are projected onto the fundus 202 of the eye to be examined, and the images of the first porous aperture plate 210 and the second
It includes a projection lens 224 that projects the multi-hole diaphragm plate 218 onto the pupil 208 of the eye to be examined.

First chart board 204 and second chart board 21
4 has two arcuate slits 230, 232, and 2, respectively, as shown in FIGS. 7A and 7B.
34, 236, and when the four arcuate slits 230, 232, 234, 236 are combined, they form one ring. The first multi-hole aperture plate 210 and the second multi-hole aperture plate 218 each have a plurality of circular holes 21
0A, 218A, and the circular hole 210
When projected onto the pupil 208 of the subject's eye, the position of A, 218A is the same as that of the foramen image 210, as shown in FIG.
The rows of A' and the rows of hole images 218A' are arranged alternately in the vertical direction. In addition, the circular hole 210
The size and spacing of A and 218A are determined so that two hole images 210A' and 218A' each enter the pupil 208 of the eye to be examined, as shown in FIG. Furthermore, the first chart board 204 and the second chart board 214 are configured to move together on their respective optical axes.

In the above configuration, when the first chart plate 204 and the second chart board 214 are focused and projected onto the fundus 202 of the eye to be examined, one toric chart image is formed and projected out of focus. Then, a double or more circular chart image is formed.

The sixth embodiment has polarization axes in two directions perpendicular to one optical axis, whereas in the fifth embodiment the chart projection light flux is composed of two light fluxes along two optical axes. A chart projection light beam is constructed by arranging polarizing plates. That is, in the sixth embodiment, as shown in FIG. 9, a light source 250 is placed on the optical axis O, a ring slit plate 252 illuminated by the light source 250, and an image of the ring slit plate 252 is conjugated with the fundus 254 of the subject's eye. A relay lens 256 that forms an image at a certain position, a porous diaphragm plate 260 arranged conjugately with the pupil 258 of the eye to be examined, and a ring slit plate 252.
The image is projected onto the fundus 254 of the eye to be examined, and
60 onto the pupil 258 of the eye to be examined.
Consisting of 2. The ring slit plate 252 is divided into four equal parts by a line passing through the center of the ring slit 264, as shown in FIG. A polarizing plate with an axis is attached. On the other hand, a polarizing plate having a polarization axis in the direction indicated by the arrow in FIG. 11 is attached to each of the plurality of circular holes 266 of the multi-hole aperture plate 260. In addition, the plurality of circular holes 2
The size and interval of 66 are such that when the multi-hole diaphragm plate 260 is projected onto the pupil 258 of the eye to be examined,
It is determined that the images of approximately four circular holes 266 fit into the area 8.

In the above configuration, the ring slit plate 252
is focused and projected onto the fundus 202 of the eye to be examined,
When one toroidal chart image is formed and projected out of focus, two or more toric chart images are formed.

In the above-mentioned embodiment, polarization was used as a means for dividing, but it is also possible to divide by wavelength. That is, instead of the polarizing plate shown in FIG. 10, two or three types of filters with different transmission wavelengths are attached to the ring slit plate, and the porous aperture plate 2 is attached.
By alternately arranging wavelength selection filters that transmit only light beams of one wavelength out of a plurality of different wavelengths in the plurality of circular holes 266 of 60, the same effect as in the above embodiment can be obtained.

In the seventh embodiment, as shown in FIG. 12, instead of moving the chart plate 14 of the first embodiment, lenses 300 with various refractive powers are placed in a turret type arrangement before and after the diaphragm plate 18 on the eye side to be examined. It is inserted selectively. At this time, if the lens 24 is placed in a position that is conjugate with the position of the eyeglasses, the refractive power of the lens 300 becomes the corrective refractive power of the eye to be examined. In FIG. 12, the same members as those in the first embodiment are given the same reference numerals, and the explanation thereof will be omitted.

In the eighth embodiment, as shown in FIG. 13, instead of operating the chart plate 14 of the first embodiment, a turret 400 with various refractive powers is placed between the pupil 22 of the eye to be examined and the projection lens 24. It is inserted selectively into the expression. At this time, as in the seventh embodiment, if the lens 400 is placed in the spectacle wearing position, the refractive power of the lens 400 becomes the corrective refractive power of the eye to be examined. 1st
In FIG. 3 as well, the same members as those in the first embodiment are designated by the same reference numerals, and the explanation thereof will be omitted.

The image formation state of the cross mark 12 on the fundus 19 of the subject's eye in the seventh and eighth embodiments is also the same as in the first embodiment. and the inserted lens 300 or 400
The desired refractive power can be determined from the difference between the reference refractive power of the eye and the refractive power of the lens that was inserted when focusing on a certain eye.

Effects of the Invention Since the present invention is configured as described above, the in-focus state of the target image in the fundus of the subject's eye can be easily and reliably detected by detecting the coincidence of the target images, and the refractive power can be measured. can be performed efficiently and with high precision. Further, alignment adjustment to align the optical axis of the eye to be examined with the optical axis of the measuring device is substantially unnecessary. In other words, according to experiments conducted by the present inventor, alignment adjustment that conventionally required alignment within a range of ±0.5 mm can be measured within a range of ±10.0 mm using the device of the present invention. Generally, measurements can be made by looking normally through the eyepiece of the measuring device. The large tolerance range for alignment adjustment has the advantage that interpupillary distance adjustment can be made unnecessary, especially in an apparatus that simultaneously measures the refractive power of both eyes as in the first embodiment.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the optical system of the first embodiment of the present invention, FIG. 2 is an explanatory diagram of the diaphragm plate image of FIG. 1, and FIG. 3 is an explanatory diagram of the diaphragm plate image of the second embodiment. Figure 4 is the third
FIG. 5 is a plan view of the aperture disk of the fourth embodiment, FIG. 6 is an optical diagram of the fifth embodiment, and FIGS. 7A and 7B are charts of the fifth embodiment. A plan view of the plate, FIG. 8 is an explanatory diagram of the multi-hole aperture plate of the fifth embodiment, FIG. 9 is an optical diagram of the sixth embodiment, and FIG. 10 is a plan view of the ring slit plate of the sixth embodiment. FIG. 11 is a plan view of a multi-hole aperture plate according to the sixth embodiment, FIG. 12 is an optical diagram of the seventh embodiment, and FIG. 13 is an optical diagram of the eighth embodiment. 14... Chart board, 16... Circular hole, 18...
...Porous aperture plate, 19... Fundus of the eye to be examined, 22... Pupil of the eye to be examined, 24... Projection lens, 100... Aperture disk, 204... First chart plate, 214... Second
Chart board.

Claims (1)

[Scope of Claims] 1. A chart for measuring eye refractive power, a diaphragm having a plurality of apertures arranged at positions substantially conjugate with the pupil of the eye to be examined on the optical path of the projection light flux from the chart, and an aperture of the diaphragm. The system includes a projection lens system for projecting a chart image onto the fundus of the eye to be examined using the transmitted light flux and for creating a substantially conjugate relationship between the aperture and the pupil of the eye to be examined, and the aperture of the aperture corresponds to the pupil of the eye to be examined at the aperture. It is arranged in an area wider than the pupil of the subject's eye, and is configured to always include two or more diaphragm apertures within the size corresponding to the pupil of the subject's eye, and is formed on the fundus of the subject's eye by each light flux passing through the aperture. A subjective eye refractive power measuring device characterized in that the eye refractive power of the eye to be examined is measured based on the matching state of chart images for measuring the refractive power of each eye. 2. The subjective eye refractive power measuring device according to claim 1, wherein the aperture of the diaphragm is circular. 3. The subjective eye refractive power measuring device according to claim 1, wherein the aperture of the diaphragm has a slit shape. 4. The subjective eye refractive power measuring device according to any one of claims 1 to 3, wherein the diaphragm is configured to be movable in a direction perpendicular to the optical axis of the projection lens system. 5. The subjective eye refractive power measuring device according to any one of claims 1 to 4, wherein the chart for measuring eye refractive power is configured to be movable in a direction perpendicular to the optical axis of the projection lens system. .