JPS5854820B2 - Menu - Google Patents

Description

[Detailed description of the invention] The present invention relates to an optometrist that measures the refractive power of the eye.

Conventionally, the Bausch O optometry machine was used to measure the refractive power of the eye.
Safil and Offsalmo Metron (trade names) manufactured by Co., Ltd. are well-known, but the eye examination time is long at 3 to 4 seconds, and the examinee must keep their eyes open to look at the optotype. Ta.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and to provide an eye examination machine that shortens the time required for eye examination so as not to burden the subject.

The present invention will be explained below based on illustrated embodiments.

FIG. 1 shows an embodiment for examining both eyes at once, and the upper and lower parts are symmetrical, so for the sake of simplicity, corresponding parts will be given the same reference numerals and the upper half will be explained.

In FIG. 1, an index 2 illuminated by an optotype light source 1 is used to fix the subject's eyes in a state where they are looking at the farthest point.

The light emitted from the optotype 2 passes through the first optometry lens 3, is reflected by the dichroic square 4, and enters the eye 6 of the subject via the eyepiece 5.

The dichroic mirror 4 transmits infrared light, but
Visible light is reflected.

Therefore, the optometrist can see indicator 2.

Reference numeral 1a denotes a filter that can be switched to allow only visible light in a specific wavelength range to enter the eye 6 of the subject.

The optotype 2 is set so that it appears slightly further away than the farthest distance that the subject can see by adjusting the extension of the first optometry lens 3.

Reference numeral 1 denotes a light source for optometry, which emits light in a specific wavelength range such as infrared light through a slit or pinhole 8.

For example, by using a light emitting diode, infrared light in a specific wavelength range can be obtained.

The infrared light passes through the second optometry lens 9, is reflected by an edge mirror 10 installed so that its edge is in contact with the optical axis, is further transmitted through the dichroic mirror 4 via the image rotor 11, and then passes through the eyepiece lens 5. and enters the eye 6 of the subject.

The second optometry lens 9 is adjusted in conjunction with the adjustment of the first optometry lens, and the slit or pinhole 8 is set at a position optically equivalent to the optotype 2 with respect to the crystalline lens 6b of the eye. .

The above-mentioned infrared light is further reflected off the retina 6a and returned to the eyepiece 5, the dichroic mirror 4, and the image low cheater 1.
The light passes through the first and third optometry lenses 12 and the refractive prism 13, and enters the light receiving section 14, which is divided into two parts in a direction parallel to the edge of the edge mirror 10.

According to the principle described later, when the subject's retina 6a and the light receiving section 14 are in an optically conjugate position with respect to the crystalline lens 6b of the eye, the light receiving section 1
A signal enters the discrimination circuit 15 from 4.

The image rotator 11 rotates at high speed around the optical axis of the detection optical system, and relatively rotates the direction of the subject's eye 6 and the edge mirror 10 around the optical axis for the purpose of astigmatism detection.

A rotary encoder 16 is integrally attached to the image low cheater 11, and information on the rotational angular position of the image low cheater is stored by inputting the scale 16a to the angular position determination circuit 18 via the reading section 1γ. input to the circuit 19.

The optometry block 20 is movable in one direction along the optical axis of the detection optical system, and in this embodiment is integrally constructed with the refraction prism 13, the light receiving section 14, and the scale reading section 21. There is.

In addition, as an alternative to this, the prism 13 and the light receiving section 14 are fixed, and the scale reading section 21 is attached to the optometry lens 12.
The same effect can be achieved even if the optometry block is configured to move in one direction along the optical axis.

22 is a diopter scale, and the scale reading section 21
The information on the position of the optometry block 20 is transmitted to the counting circuit 23 by
is input.

The information on the position of the optometry block 20 inputted to the counting circuit 23 is inputted to the storage circuit 19. The arrow 24 indicates the range in which the optometry block 20 moves in one direction. , for example, it is possible to detect from -15 day opters to 20 day opters.

When the measurement is completed, a mechanism (not shown) closes the optometry block 20.
is constructed so that it can return in the direction opposite to the arrow 24.

Note that the two optometry blocks 20 corresponding to both eyes shown in the upper and lower portions of FIG. 1 move integrally.

In the above configuration, when the optometry block 20 is moving in one direction along the optical axis of the detection optical system, information that the retina 6a and the light receiving section 14 are in an optically conjugate position is transmitted from the light receiving section to the discriminating circuit. 15, the discrimination circuit 15 instructs the storage circuit 19 to write the information of the counting circuit 23 to the position corresponding to the angle discriminated by the angular position discrimination circuit 18.

The image rotator 11 is rotating at a high speed as described above, and the optometry block 20 is moving relatively slowly along the arrow 24.
Since the image rotator 11 moves in the direction, the information of the counting circuit 23 is written in the position corresponding to each angle (for example, 32 equal parts of the circumference) of the image rotator 11 as described above, and the information is transmitted to the retina 6a and the light receiving part 14. is the position information of the optometry block 20 when it is in an optically conjugate position, so if the cheater written in the memory circuit 19 is input to the display system, the refractive power of the subject's eye corresponding to each angle can be obtained. It becomes possible to display.

FIG. 2 explains the principle of detecting that the subject's retina 6a and the light receiving unit 14 are in optically conjugate positions with respect to the crystalline lens 6b of the eye in the above embodiment. 5, 4, 11, 12, and 13 are omitted from the illustration.

The infrared light from the optometric light source emitted from the slit 8 is reflected by the edge mirror 10 and reaches the retina 6a via the crystalline lens 6b.

As explained with reference to FIG. 1, since the eye is looking at the optotype 2, the image of the slit 8, which is located at an optically equivalent position, is also approximately formed on the retina.

After the reflected light from the retina 6a exits the crystalline lens 6b, its lower half is cut by an edge mirror 10 and enters the light receiving section 14.

As described above, the light receiving section 14 is divided into two parts.

That is, the light receiving section 14 is composed of light receiving elements 14a and 14b, the light receiving element 14a.

14b, there is a gap 14c parallel to the edge of the edge mirror 10, and the gap 14c has approximately the same width as the slit 8.

The light receiving unit 14 is located at a position optically conjugate with the subject's retina 6a (
If the position indicated by b in Fig. 2) is present, the light receiving element 1
4a.

The reflected light from the retina 6a does not enter the retina 14b, and the electrical outputs of the light receiving elements 14a and 14b are approximately equal.

(Situation shown in Figure 3) However, if the light receiving section 14 is located at a position that is not optically conjugate with the subject's retina 6a (the position indicated by a or C in Figure 2), there is a large Light enters the light receiving element 14a.

The electric signal of one of the light receiving elements 14b becomes larger.

(Situation in Figure 3 a or C) Therefore, if the optical system in Figure 3 is used to find a position where the electric outputs of the light receiving elements 14a and 14b are equal, the position where the light receiving part 14 is optically conjugate with the retina 6a of the subject is found. This position naturally corresponds to the refractive power of the eye.

As is clear from the above configuration, the output of the light receiving element 14 is affected only by the refractive power of the eye in the direction perpendicular to the edge direction of the edge mirror 10, that is, in the vertical direction of the paper.

Therefore, by inserting an image rotor between the edge mirror 10 and the eye as shown in Figure 1 and changing the angular relationship between the two, information on the refractive power of the crystalline lens in all directions around the optical axis of the eye can be obtained. This makes it possible to measure astigmatism.

Next, the above circuit for writing optometry data into the memory circuit 19 will be explained in more detail in FIG.
5 is composed of a differential amplifier 25, an analog comparator 26, a digital comparator 21, and an M word/1 bit register 28, and the signals of the divided light receiving elements 14 are divided into signals A and B, which are multiplied by Lδ by the amount of light received by each. dynamic amplifier 2
Send to 5.

Differential amplifier 25 amplifies the difference between signals A and B and sends it to analog comparator 26 .

The analog comparator 26 compares the difference signal with the O potential, and sends a logic level corresponding to the magnitude relationship (for example, 1 for A≧B, 0 for A<B) to the digital comparator 27, and also outputs the M word/ It is stored in the 1-bit register 28.

On the other hand, the rotary encoder 16 rotates at high speed in the direction of arrow 29 together with the image rotary cheetah shown in FIG.
It has a mark 16b indicating.

A scale reading unit 1γa included in the reading unit 11 inputs an angle pulse for each θ0 to the timing circuit 30.

(In the figure, the unit θ0 = 180°/M) Also, reset reading section 1
γb sends a reset pulse to the timing circuit every time the rotary encoder 16 returns to 0°.

As mentioned above, the angular position determination circuit 18 in FIG. 1 is comprised of the timing circuit 30.

Therefore, the timing circuit 30 receives information about the angular position of the rotary encoder 16 every time the rotary encoder 16 rotates once due to the angle pulse and the reset pulse, and the timing circuit 30 is designed to shift one word for each angle pulse. The M word/1 bit register 28 and the M word/1 bit register 28 and the M word/1 bit register 28 forming the memory circuit in FIG.
An address shift command is sent to the 1-bit register 19.

Note that the switch 33 is connected to the a terminal during eye examination.

Upon receiving the address shift command, the M word/1 bit register 28 sends the previously stored information from the analog comparator 26 to the digital comparator 27.

This information corresponds to the information before one revolution of the rotary encoder 16 at that address.

The digital comparator 2γ compares the output of the same address sent from the M word/1 bit register one revolution before with the current output sent from the analog comparator, and stores a write command only when they are not equal. /N bit register 19.

As will be described later, this write command controls whether or not the position information of the optometry block is written into the M word/N bit register.

The optometry flock 20 is moved in one direction of the arrow 24 by a servo motor 32 controlled by a motor control circuit 31, and by this movement, it is possible to detect, for example, from -15 dayopters to 20 dayopters.

The scale reading section is composed of a light source 21a and a reading section 21b, and each time the diopter scale 22 passes one division, it sends a pulse to the N-bit up/down counter 23 comprising the counting circuit tJ in FIG.

Also, the N-bit up/down counter is in the scale reading section 2.
The pulses from 1b are added or subtracted according to the designation from the motor control circuit 31 (the designation changes depending on whether it is going or returning).

Information of the N-bit up/down counter during counting is sent to the M-word/N-bit register 19.

When receiving a write command from the digital comparator 21, the M word/N bit register 19 writes the information of the N bit up/down counter 23 to the address corresponding to the angle designated by the timing circuit 30.

In the manner described above, the diopters at each angle around the optical axis of the eye are written into the memory circuit.

Note that when reading information, the switch 33 is connected to the b terminal, and the output clock 3 with a frequency suitable for the display system is connected.
The address of the word is shifted by the address shift command No. 4 and input to the display system 35.

FIG. 5 illustrates another embodiment of the invention.

In FIG. 5, differences from the embodiment in FIG. 1 will be explained. The eyepiece lens 5 can be switched between an eyepiece lens 5a for nearsightedness and an eyepiece lens 5b for farsightedness.

The mirror 36 is a dichroic mirror consisting of two parts above and below the optical axis: a part 36a that reflects both visible light and infrared light, and a part 36b that reflects visible light but passes infrared light.

The filter 31 is a switchable filter that allows only visible light in a specific wavelength range to pass through, similar to 1a in FIG. have

As is clear from the above, in this embodiment, the light source 1 serves as a light source for optotypes and for optometry.

That is, the filter 37 as a whole illuminates the optotype 2 with light in a specific wavelength range, and the light is reflected by the dichroic mirror 36 and enters the eye, so that the subject can see it.

On the other hand, the infrared light emitted from the light source 1 and allowed to pass through the slit or pinhole 37a is reflected by the dichroic mirror portion 36a and forms an image on the retina 6a of the eye, and is further reflected and exits the eye. The lower half of the light beam is cut off at the portion 36a and enters the light receiving section 14.

The first optometry lens 3 can be extended along the arrow 38 in order to adjust the visible position of the optotype as in the first embodiment.

Here, what is characteristic of this embodiment is that the third optometry lens 12 is extended along the arrow 40 by the interlocking mechanism 39 in conjunction with the extension of the first optometry lens 3.

Furthermore, by drawing out the third optometric lens, the cylinder 42 is rotated via the interlocking member 41.

A diopter scale 42c is diagonally carved on the side surface 42a of the cylinder 42, as shown in the lower exploded view 42b.

Therefore, the diopter scale 42c located directly below the movement locus of the scale reading section moves left and right as the cylinder 42 rotates.

As is clear from the above configuration, in this example, when adjusting the first optometry lens according to the visual acuity of the subject, the third optometry lens is adjusted accordingly, and the third optometry lens is adjusted according to the amount of adjustment. This movement of the diopter scale is naturally inputted into the storage circuit via the scale reading section.

Therefore, as a result of this operation, the diopter scale as positional information that approximately corresponds to the refractive power of the eye of the subject is already located directly below the scale reading section, and the optometry block 20 can be roughly adjusted as described above. In order to measure the obtained diopter more precisely, it is only necessary to slightly move the vicinity of the scale already directly below it, enough to cover the variation in diopter in subjects with severe astigmatism.

As described above, in this embodiment, the eye examination block 20 does not need to move over the entire range from -15 to 20 dayopters as in the first embodiment, and the eye examination time can be further shortened.

Since the present invention is configured as described above, astigmatism is measured by moving the optometric flock back and forth at each angle around the optical axis of the eye as in the past, but by measuring the astigmatism based on the moving speed of the optometric flock. By rotating the image incident on the eye sufficiently quickly, we obtain angle information from the image locheater, diopter information and the conjugate information explained above from the optometry block, process these and write them into the memory circuit. It is something.

Therefore, the measurement of astigmatism is completed by simply moving the optometry block once in one direction, so the eye exam time is shortened and the burden on the subject is reduced, providing significant advantages during optometry.

Furthermore, the existence of the memory circuit makes it possible to move the two eye examination flocks for both eyes in one direction at the same time and memorize information for both eyes at once, which also contributes to shortening the eye examination time. It is something.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an embodiment of the present invention, Fig. 2 is a diagram explaining the principle of the same embodiment, Fig. 3 is a graph showing the output of Fig. 2, and Fig. 4 is a graph showing the output of Fig. 2.
The figure is a block diagram showing an example of an information processing circuit in the same embodiment, and FIG. 5 is a sectional view of another embodiment of the present invention. 1... Light source, 2... Visual target, 3...
・・1st optometric lens, 6・・Eye, 1・・・・
- Optometric light source, 8... Pinhole or slit, 9... Second optometry lens, 10... Edge mirror, 11... Image Lochita, 1
2...Third optometry lens, 14...Light receiving unit, 15...Discrimination circuit, 16...Rotary encoder, 1γ...Reading Department, 18・
... Angular position discrimination circuit, 19 ... Memory circuit, 20 ... Optometry block, 21 ...
Scale reading section, 22...Diopter scale, 23
...Counting circuit, 36...Dichroic mirror, 37...Filter, 31a...
...Slit or pinhole, 42...Cylinder,
42b... Surface development view of cylinder 42, 42c...
- Diopter scale.

Claims (1)

[Claims] 1. A detection optical system including an optotype for the subject to gaze at, a light receiving section whose output changes when the crystalline lens of the subject's eye becomes optically conjugate with the retina, and the light receiving section. a movable member movable in the optical axis direction of the eye in order to change the optical positional relationship between the eye and the retina; a position detection means for detecting the position of the movable member as information on the refractive power of the eye; and the detection optical system. a rotating member that rotates at high speed around the optical axis of the eye in order to change the detection angle by the eye; angle detecting means that detects the rotation angle of the rotating member; output information of the light receiving section and information from the position detecting means; and a means for processing and storing information from the angle detecting means, and measuring the astigmatism of the subject by one movement of the movable member in one direction. Device.