JPH035810B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an eye position detecting device for an ophthalmological instrument.

A fundus camera for observing and photographing the fundus of the subject's eye;
In an ophthalmological instrument such as a refractometer that measures the refractive power of an eye to be examined, before photographing or measuring, it is necessary to perform so-called alignment adjustment to set the ophthalmological instrument at an appropriate position relative to the eye to be examined. This alignment adjustment consists of adjusting the optical axis of the eye to be examined and the optical axis of the ophthalmological equipment (hereinafter referred to as optical axis misalignment adjustment), and adjusting the distance between the eye to be examined and the ophthalmological equipment to an appropriate distance (hereinafter referred to as operation). (referred to as distance adjustment). As for refractometers, since both of the above-mentioned adjustment errors appear as errors in the refractive power measurement value, alignment adjustment before measurement is an important element in terms of measurement accuracy. In order to perform this alignment adjustment, it is necessary to detect the position of the eye to be examined relative to the ophthalmological instrument, and various eye position detection devices have been proposed for the ophthalmological instrument. For example, the optical axis misalignment between the eye to be examined and an ophthalmological instrument is detected by projecting the image of the eye to be examined onto a reference index installed in the observation optical system of the ophthalmological instrument, and determining the amount of deviation between the anterior segment image of the eye to be examined and the reference index. A device configured to do this has been proposed. In this case, the optical axis misalignment adjustment is performed by moving the entire ophthalmological instrument horizontally and vertically so that the anterior segment image of the eye to be examined matches the center of the reference index, and the working distance adjustment is performed by moving the entire ophthalmological instrument in the horizontal and vertical directions. This is done by moving the ophthalmic instruments back and forth so that the anterior segment image of the eye to be examined is focused. This type of device directly observes the image of the eye being examined, so even if the optical axis of the eye to be examined and the optical axis of the ophthalmological instrument are significantly misaligned, the amount of misalignment can be immediately known and rough alignment adjustments can be made. It can be said that it is suitable for Furthermore, by being able to directly observe the condition of the subject's eye, it is possible to know the subject's blinking during measurement even after alignment adjustment, and in particular, with a refractometer, it is possible to eliminate measurement disturbances due to blinking, etc. This has the effect of making it possible. On the other hand, in this device, whether the working distance is appropriate must be determined based on the focus state of the anterior segment image, and it is difficult to obtain the accuracy required for working distance adjustment. Furthermore, it is not possible to know in which direction the adjustment position has deviated from the proper position, which is a drawback in terms of adjustment operations. Furthermore, since the misalignment between the optical axis of the eye to be examined and the optical axis of the ophthalmological instruments is directly visually determined, it is not possible to accurately know the range of the proper position of the eye to be examined, and it takes a lot of time to make adjustments. but also
This method has the disadvantage that the adjustment results include individual differences among examiners.

An object of the present invention is to provide an eye detection device for an ophthalmological instrument that eliminates the above-mentioned conventional drawbacks, and its structural features are as follows:
an eye observation system for observing an anterior segment image of the eye to be examined superimposed on a reference index, an eye position detection unit for electrically detecting the amount of deviation of the eye to be examined from a proper position, and the eye position to be examined. and a display section that displays that the deviation amount is within a predetermined tolerance based on an electrical signal from the detection section, and the observation image of the eye observation system and the display on the display section can be observed within the same field of view. This is how it was configured.

Hereinafter, an example in which an embodiment of the present invention is applied to an autorefractometer will be described based on the drawings.

As shown in FIG. 1, the measurement system of the autorefractometer includes a target projection optical system 100 that projects a measurement target onto the fundus of the eye to be examined, and a light receiving optical system 2 that forms a target image on the fundus of the eye.
It consists of 00.

The target projection optical system 100 includes a pair of infrared light sources 101a and 101 arranged around the optical axis.
b, condensing lenses 102a and 102b that condense the light from the infrared light sources 101a and 101b, respectively;
A collimator lens 103 that produces parallel light, a measurement target 105 having a circular aperture diaphragm 104, an imaging lens 106, a projection imaging lens 107, a half mirror 108 for infrared light, and a mirror that reflects infrared light in the long wavelength region and in the visible region. and a dichroic mirror 10 having a characteristic of transmitting infrared light in the vicinity thereof.
It consists of 9. The above pair of infrared rays 10
The sources 1a and 101b are turned on alternately at high speed, and both sources 101a and 101b are configured to be rotatable together about the optical axis.

In the above configuration, a pair of infrared light sources 101
The light from a and 101b is transmitted through the condenser lens 1, respectively.
02a and 102b, the collimator lens 103 converts the light into parallel light, and the light enters the circular aperture stop 104 obliquely. circular aperture 1
The light that has passed through the lens 04 is focused by the imaging lens 106.
After forming the image at position P ₁ , the projection imaging lens 10
7. The light enters the eye E through the half mirror 108 and the dichroic mirror 109. Here, the images of the infrared light sources 101a and 101b are formed on the pupil position of the eye E to be examined, and the image of the circular aperture stop 104 of the measurement target 105 is formed on the fundus _P2 of the eye to be examined. Then, the measurement target 105 and the eye to be examined E
When the fundus of the eye P ₂ is in a conjugate positional relationship,
An image of the circular aperture stop 104 illuminated by light from the infrared light source 101a and an infrared light source 101b
a circular aperture stop 104 illuminated by light from
are formed at the same position on the fundus _P2 . On the other hand, the measurement target 105 and the fundus P ₂ of the eye E to be examined
When they are not in a conjugate positional relationship, the images of the circular aperture stop 104 illuminated by the light from the infrared light sources 101a and 101b are respectively formed at two separate locations on the fundus _P2 .

The target light receiving optical system 200 includes a dichroic mirror 109, a half mirror 108, a light receiving objective lens 210, a mirror 211, a corneal reflected light blocking diaphragm 212 and a relay arranged in a position conjugate with the cornea of the eye to be examined regarding the light receiving objective lens 210. It is composed of a lens 213. The corneal reflected light blocking diaphragm 212 is configured to rotate in conjunction with this rotational movement when the infrared light sources 101a, 101b rotate around the optical axis. Furthermore, the corneal reflected light blocking diaphragm 212 is placed at the front focal position of the relay lens 213, and the light receiving optical system using the relay lens 213 becomes similar to a telecentric optical system.

In the above configuration, the measurement target image of the eye to be examined P ₂ is projected onto the two-dimensional detector 214 by the dichroic mirror 109, the half mirror 108, the light receiving objective lens 210, the mirror 211, and the relay lens 213. Ru. At this time, harmful reflected light from the cornea of the eye to be examined is removed by a protruding light shielding portion provided in the reflected light blocking diaphragm 212. The two-dimensional detector 214 detects that the image of the circular aperture diaphragm 104 on the fundus P ₂ of the examined eye is detected by the infrared light sources 101a and 1
It is determined whether they match or are separated by alternate lighting of 01b, and when they are separated, the separation distance is measured. From this measured value, the refractive power of the subject's eye in the radial direction of the infrared light sources 101a and 101b is calculated by a calculation circuit to be described later.

Next, as shown in FIG. 1, the subject eye position detection device according to the present invention includes a aiming optical system 300 configured to observe an anterior segment image of the subject's eye, and an electrically detecting subject's eye position. It consists of a detection system 400 for

The aiming optical system 300 includes a half mirror 109, a projection lens 302, a half mirror 304, and an image pickup tube 306 arranged on the same optical axis, and a light source 307 and a condenser lens 3 arranged on the reaction optical axis of the half mirror 304.
08, a collimating plate 310, a mirror 312, and a projection lens 314 are arranged. Photograph tube 306 is connected to television monitor 316. Sighting plate 3
10, as shown in FIG. 2, has a collimation scale 311 with a circle in the center and rays around the circle.

In the aiming optical system 300 configured as described above, an image of the anterior segment of the subject's eye E by the projection lens 302 and an image of the collimation index 311 by the projection lens 314 are projected onto the image pickup tube 306 in a superimposed manner, and displayed on monitor 316. This aiming optical system 3
00 can not only make general adjustments but also observe the anterior segment of the subject's eye, so it is possible to detect the blinking of the subject's eyes during measurement.

The eye position detection system 400 includes a light emitting element 402,
pin-pole aperture 404, projection lens 400, first
Half mirror 408 and second half mirror 410
is placed on the reflection optical axis of the second half mirror 410. Further, on the reflection optical axis of the first half mirror 408, an imaging lens 412, a chopper 414,
A two-dimensional light receiving element 416 is arranged. Further, on one side of the chopper 414 is a reference signal light emitting element 418, and on the other side is a reference signal light receiving element 4.
20 are placed. As shown in FIG. 3, the movement bar 414 is constituted by a disk having a plurality of fan-shaped slits 422, and rotates around a center 424 of the disk. The optical axis 425 is a fan-shaped slit 42
Pass through the center of 2. Further, the diaphragm 428 is used to make the amount of light incident on the light receiving element 416 constant, and has an aperture twice as large as that of the fan-shaped slit 422. Luminous flux 4 in fan-shaped slit 422
30 is a circumcircle of the aperture of the diaphragm 428.

In the above configuration, when the working distance is appropriate, the image of the pinhole diaphragm 404 is projected by the projection lens 406, via the first half mirror 408, the second half mirror 410, and the dichroic mirror 109.
An image is formed on the anterior segment of the eye E to be examined, and is reflected by the corneal surface of the eye E to be examined. This reflected light beam is imaged on a two-dimensional light receiving element 416 via a dichroic mirror 109, a second half mirror 410, a first half mirror 408, an imaging lens 412, and a chopper 414.

The detection principle of the eye position detection system 400 having the above configuration is as follows. Imaging lens 412
and imaging point 4 of the pinhole aperture image due to corneal reflection.
26 is behind the light receiving element 416 (imaging lens 41
2), if the
14 rotates, the fan-shaped slit 422 gradually closes the imaging lens 41 as shown in FIGS. 4A, B, and C.
2, the light receiving element 41
6, light beams as shown in FIG. 5A, B, and C are incident. In FIG. 5, X indicates the passing position of the optical axis, and 0 indicates the center of gravity of the cross section of the incident light beam. The detection signal of the light receiving element 416 at this time is as shown by the solid line in FIG. In FIG. 6, the horizontal axis shows the position of the chopper, and the vertical axis shows the coordinate value in the Y-axis direction. Note that the diaphragm 426 is omitted in FIGS. 4 and 5.

Further, when the imaging point 428 by the imaging lens 412 is located in front of the light receiving element 416 (on the imaging lens 412 side), when the chopper 414 rotates, the image becomes as shown in FIGS. 7 and 8. Figure 7,
FIG. 8 corresponds to FIGS. 4 and 5, respectively. The detection signal of the light receiving element 416 at this time is as shown by the dotted line in FIG.

Furthermore, when the imaging point by the imaging lens 412 is on the light receiving element 416, the light receiving element 41
The detection signal No. 6 is a straight line parallel to the horizontal axis, as shown by the dashed line in FIG.

That is, the detection signal of the light receiving element 416 determines where the image forming point is in the front-back direction of the light-receiving element, or in other words, the position of the corneal apex of the eye to be examined is deviated from a predetermined position in the front-back direction and by how much. Can be detected. At the same time, by detecting the coordinates of the average incident position on the light receiving element 416, it is possible to detect in which direction and by how much the corneal apex position of the eye to be examined deviates from a predetermined appropriate position in the vertical and horizontal directions. .
In this example, when the eye to be examined E is in a proper position, the pinhole diaphragm 404 is arranged so as to have a conjugate positional relationship with the corneal apex of the eye to be examined. It may be placed at a midpoint with the center or at a position conjugate with the center of corneal curvature.

Next, the two-dimensional light receiving element 4 of the eye detection system 400
16, an electric circuit for detecting the relative positional relationship between the eye E and the autofractometer is connected to the ninth
This will be explained based on the diagram. As shown in FIG. 10, when the light beam 450 is incident on the light receiving element 416,
Distances x ₁ , x ₂ , y ₁ , y ₂ related to the coordinates of the incident position and voltages X ₁ , X ₂ , Y ₁ , Y ₂ corresponding to the amount of incident light are output. When the light beam 450 enters the center of the light receiving element 426, X ₁ =X ₂ and Y ₁ =Y ₂ . In this embodiment, the light beam is scanned in the Y direction by the rotation of the chopper 414.

First, a circuit for detecting a horizontal deviation of the optical axis of the eye to be examined with respect to the X direction, that is, the optical axis of the autorefractometer will be described.

Since the chopper 414 scans in the Y direction, the signal X ₁ , which indicates the average position of the light beam 450, regardless of the amount of deviation of the eye
X ₂ is output at a constant level unless the amount of light incident on the light receiving element 416 changes. Light receiving element 41
The output signals X ₁ and X ₂ of 6 are each sent to an amplifier circuit 45.
2,454, and each operation (X ₁ -X ₂ ) is amplified by a subtraction circuit 456 and an addition circuit 458.
and (X ₁ +X ₂ ) are performed. The outputs of the subtraction circuit 456 and the addition circuit 458 are sent to the first division circuit 460.
(X _{1 -} X ₂ )/(X _{1 +} This is so that you can obtain the following. This is the output of the first division circuit 460 (X ₁ −
X ₂ )/(X ₁ +X ₂ )=The absolute value of the X value is the X of the eye to be examined.
It shows the amount of deviation in the direction, and its sign indicates the direction of the deviation. The output of this first division circuit 460 is input to a first comparator 462 and a second comparator 464. The first + reference setter 466 generates a reference allowable setting signal +ε, and the output signal of the first divider circuit 460 and the reference signal +ε
A comparison is made with The first comparator 462
+ “1” if the output of the first divider circuit 460 is smaller than the allowable setting signal +ε from the reference setter 466
A signal is generated, and if the signal is large, a “0” signal is generated. Similarly, the second comparator 464 generates a "1" signal when the output of the first divider circuit 460 is greater than the allowable setting signal -ε from the first reference setter 468; , a “0” signal is generated. Here, the output signals +ε and -ε of the first + reference setter 466 and the first − reference setter 468 indicate the allowable range of setting error when setting the ophthalmological instrument for the eye E to be examined. Further, if the output signal of the first comparator 462 is a, and the output signal of the second comparator 464 is b,
When the optical axis of the eye E to be examined is shifted to the right from the optical axis of the autorefractometer by more than a predetermined allowable range, the signal a becomes a signal "0" and the signal b becomes a signal "1". Similarly, when there is a shift to the left, the signal a becomes a signal "1" and the signal b becomes a signal "0". Further, if the signal is within the predetermined tolerance range, both the signal a and the signal b become "1". The output signals a and b of the first comparator 462 and the second comparator 464 are transmitted to the display control circuit 4.
70 is input.

Next, a circuit for detecting a vertical deviation of the optical axis of the eye E to be examined with respect to the Y direction, that is, the optical axis of the autorefractometer will be described. Chiyotsupa 41
4 is performed in the Y direction, the voltage signals Y ₁ , Y ₂ output from the light receiving element 416
becomes a modulation signal corresponding to the scanning. here,
The voltage signals Y ₁ and Y ₂ are supplied to the eye position detection system 40
As shown in the explanation of the principle of 0, since it also includes information on the position in the Z direction, that is, the longitudinal direction (optical axis direction) of the refractometer, from now on, the signal Y ₁ (Z ₁ ),
It shall be denoted by Y ₂ (Z ₂ ). Y ₁ of light receiving element 416
(Z ₁ ), Y ₂ (Z ₂ ) outputs are output from amplifier circuits 472, 47
4, a subtraction circuit 476 and an addition circuit 47
8 is input. The output of the subtraction circuit 476 passes through a low-pass filter circuit 480 to the second division circuit 48.
2 is input. The output of adder circuit 478 is directly input to second divider circuit 482 . The low-pass filter circuit 480 is for removing the influence of the modulation portion, that is, the signals Z ₁ and Z ₂ from the output signal of the subtracting circuit 476, to obtain a voltage signal of a constant level. The second division circuit 482 calculates the Y value = (Y ₁ - _{Y 2} )/
Perform the calculation (Y ₁ + Y ₂ ). The absolute value of the output Y of the division circuit 482 indicates the amount of deviation of the eye E in the Y direction,
Its sign indicates the direction of deviation. Second division circuit 48
The output of 2 is the third comparator 484 and the fourth comparator 4
86, a comparison is made with the output signals of the second + reference setter 488 and the second - reference setter 490.
If the output signals of the third comparator 484 and the fourth comparator 486 are signal c and signal d, respectively, then the optical axis of the eye E to be examined is shifted upward from the predetermined allowable width with respect to the optical axis of the autorefractometer. If so, the signal c becomes a signal "0" and the signal d becomes a signal "1". On the other hand, when there is a downward shift, the signal c becomes a signal "1" and the signal d becomes a signal "0". If both the vertical direction is within the predetermined allowable width, the signal c
and signal d both become signal "1". The output signals of the third comparator 484 and the fourth comparator 486 are input to the display control circuit 470.

Next, a circuit for detecting the deviation in the Z direction, that is, the amount of deviation from the ideal distance between the autorefractometer main body and the eye to be examined, will be described. The subtraction circuit 476 and addition circuit 478 in the circuit related to the Y direction are directly connected to the third division circuit 492. The third divider circuit 492 is connected to a low pass filter circuit 498 via a bandpass filter circuit 494 and a synchronous rectifier circuit 496. Further, the reference signal light receiving element 420 is connected to a synchronous rectification circuit 496 via an amplifier circuit 502. In the above circuit, the third division circuit 492 outputs the signal Y _Z =Y ₁
(Z ₁ )−Y ₂ (Z ₂ )/Y ₁ (Z ₁ )+Y ₂ (Z ₂ ) is calculated and input to the bandpass filter circuit 494. The bandpass filter circuit 494 outputs a modulated wave having an amplitude proportional to the amount of shift in the Z direction. This modulated wave is shown in Fig. 11A and B.
As shown in the figure, the signal has a different phase depending on the direction of the shift. On the other hand, the output of the reference signal light receiving element 420 is amplified by the amplifier circuit 502 and
It is input to the synchronous rectifier circuit 496 as a rectangular wave reference signal shown in FIG. Synchronous rectifier circuit 496
uses this reference signal to synchronously rectify the output from the bandpass filter circuit 494, and outputs the signal shown in FIG. 11D or E depending on the direction of shift. The output from the synchronous rectifier circuit 496 is converted into a signal F or G in FIG. 11 by a low pass filter circuit 498. That is, the absolute value of the output of the low-pass filter circuit 498 indicates the amount of shift in the Z direction, and its sign indicates the direction of the shift.
Input to comparator 506. a fifth comparator 504;
The sixth comparator 506, the third + reference setter 508, and the third - reference setter 510 have the same functions as the comparators and reference setters described in the X-direction and Y-direction detection. That is, the fifth comparator 50
The output signals of the fourth and sixth comparators 506 are
and signal f. If the distance between the autorefractometer and the eye E to be examined is smaller than a predetermined tolerance, the signal e will be "0" and the signal f will be "1"; if it is larger than the predetermined tolerance, signal e
is the signal “1”, and the signal f is the signal “0”. When the distance amount is within a predetermined tolerance, the signals e and f become "1". Signals e and f are input to display circuit 470. Further, a seventh comparator 512 connected to the light amount setter 510 and the addition circuit 478 detects whether or not a projected image by corneal reflection of a light beam for detecting the position of the eye to be examined is projected onto the light receiving element 416. When the level of light level incident on the light receiving element 416 is equal to or higher than the set value of the light level setting level 510, a signal “1” is generated, and when it is below the set value of the light level standard 510, a signal “0” is generated. This output is called signal g. The signals a to g mentioned above are
It is input to AND circuit 514. AND circuit 514
The signal “1” is generated only when the signals a to f are “1”, that is, when the eye E to be examined is within the specified tolerance range with respect to the autorefractometer body (when the alignment adjustment is completed). It is. The output signal of this AND circuit 514 is transmitted to the light source 307 of the reference index displayed on the television monitor 316.
is input to the control circuit 516 of the AND circuit 514
When the output signal becomes "1", the reference index light source 307 is configured to be in a blinking state.
With this configuration, alignment adjustment is performed according to the display on the television monitor 316 as described later, and when the adjustment is completed, the reference index image displayed overlapping with the image of the eye E to be examined blinks. This makes it extremely easy to know when the adjustment is complete.

Next, the display control circuit 470 to which the signals a to g are input will be described. Display control circuit 470
The position information of the eye E to be examined is displayed on the screen of the television monitor 316 on which the image of the eye to be examined is displayed via the image pickup tube 306 using signals a to g. The display on the television monitor 316 will be described below in accordance with the autorefractometer alignment adjustment procedure. First, the subject is fixed to the subject fixing device of the autorefractometer. At this time, the position of the eye E to be examined often deviates from the proper position with respect to the autorefractometer body, and is displayed on the television monitor as shown in FIG. 12A. In FIG. 12A, 530 is an image of the eye to be examined, 532 is an image of the reference index 311, and 534 is an eye position detection information index to be described later. In this case, since the light beam projected onto the cornea of the eye to be examined for detecting the position of the eye to be examined is not projected onto the cornea, no reflected projection image is projected onto the light receiving element 416. Further, the signal g is a signal "0", and this signal "0" causes the display control circuit 470 to display the subject's eye position detection information index 534 at the lower part of the television monitor. The electric circuit of the optometry position detection system 400 is not operating. The examiner roughly moves the autorefractometer main body to the right and upward using a known movement adjustment mechanism (not shown) so that the eye image 530 to be examined matches the reference index 532. Regarding the working distance adjustment, the autorefractometer body is adjusted by moving back and forth until the eye image 530 to be examined is approximately in focus. When this rough adjustment is completed, the light beam for detecting the position of the eye to be examined is reflected by the cornea of the eye E to be examined, and the reflected light beam enters the light receiving element 416. As a result, the output signal of the seventh comparator 512 becomes "1", and the display control circuit 470 controls the display of the eye position detection information index 534 based on the input signals a to f. When the above-mentioned general adjustment is completed, the projection light source for detecting the position of the eye to be examined is projected onto the cornea of the eye to be examined, and the image of the pinhole diaphragm 404 can be observed on the cornea of the eye to be examined on the television monitor 316. .

When the above-mentioned general adjustment is completed, the eye position detection system to be examined functions. The signals a and b input to the display control circuit 470 indicate the amount of optical axis deviation in the left and right direction of the eye to be examined with respect to the optical axis of the autorefractometer. When b is "0", an arrow 534a is displayed on the TV monitor 316, and when signal a is "0",
When the signal b is "1", an arrow 534b is displayed on the television monitor 316. That is, the direction in which the autorefractometer body should be moved and adjusted is displayed on the television monitor 316, and the examiner can adjust the autorefractometer body to the left or right in accordance with this display. When the eye E to be examined comes within the predetermined range by this horizontal adjustment, both the signal a and the signal b become "1", and in this case, the display control circuit 470 makes the arrows 534a and 534b on the television monitor 316 disappear.

Similarly, the display control circuit 470 controls the television monitor 31 using signals c and d indicating the amount of optical axis deviation in the vertical direction.
Arrows 534c and 534d are displayed at 6 to indicate the adjustment direction.

Note that in this embodiment, arrows 534a, 534b,
Although 534c and 534d are configured with arrows of a constant length, they may be configured so that the value of the amount of deviation from the allowable amount is converted into the length in the longitudinal direction of the arrow and displayed. In this case, the amount of deviation from the allowable amount can be immediately determined based on the length of the arrow. Furthermore, in this embodiment, if the rough adjustment is not completed and the reflected projection image is not projected on the light receiving element 416, the eye position detection information 534 is not displayed at the bottom of the television monitor 316; It may be configured to display special indicators different from information.

Further, the display control circuit 470 is configured to display the letter B or F at the center of the display device of the arrows 534a to 534d on the television monitor 316 based on the signals e and f indicating the amount of shift in the working distance in the front-rear direction. In other words, if the distance between the autorefractometer and the eye to be examined (working distance) is smaller than the predetermined allowable range and the signal e is "0" and the signal f is "1", the autorefractometer is moved backward with respect to the eye E to be examined. The letter “B” indicating that movement adjustment is required is displayed on the screen. Conversely, if the working distance is greater than the predetermined allowable range, the letter "F" is displayed. If the working distance falls within the predetermined tolerance range, the letter “B”,
“F” is not displayed either. FIG. 12B shows an example of the display on the television monitor 316 when the rough adjustment has been completed and the optical axis of the autorefractometer is slightly shifted leftward and downward relative to the eye E to be examined, and the working distance is too small. This shows that. The examiner follows the display on the television monitor 316 and
Adjust the autorefractometer by moving it left and right, up and down, and back and forth. Then, when all three directions fall within the allowable range, that is, when signals a to f all become "1" and g becomes "1", arrows 534a to 534d and letters B and F all disappear. At the same time, the reference index image 532, which is displayed overlapping with the eye image to be examined, starts blinking as described above. In other words, by blinking the reference index image 532, it is extremely easy to recognize that the alignment adjustment in all directions, that is, the optical axis shift adjustment and the working distance adjustment have been completed.

After the above alignment adjustment is completed, measurement with the autorefractometer is started, but during the measurement, it is necessary to observe the blinking of the eye to be examined and at the same time recognize whether or not the eye to be examined E has shifted from its proper position. Can be done. Note that the autoref calculation section 540
is a calculation unit for calculating the refractive power of the eye to be examined from the measurement signal from the two-dimensional detector 214. The electrical signal corresponding to the refractive power of the eye to be examined calculated by the auto-ref calculation unit 540 is input to the display control circuit 470. After completing the alignment adjustment described above,
The refractive power of the eye to be examined is measured using the measurement system of an autorefractometer, and the measurement result can be displayed on the lower part of the television monitor 316 using an electric signal from the autorefractometer 540. That is, the subject image, the subject's eye position information, and the refractive power measurement results of the subject's eye are all displayed on the television monitor.

In this example, when the eye to be examined falls within the appropriate tolerance range for the autorefractometer, the reference index 5
32 is configured to be in a blinking state, instead of blinking the reference index 532, the light source 402 of the light beam projected onto the subject's eye may be in a blinking state. That is,
When the rough adjustment is completed, a bright pinhole diaphragm 404 image can be observed on the corneal surface of the subject's eye on the television monitor 316 due to the light beam from the light source 402;
Pinhole aperture 404 by blinking 2
If the image is configured so that it blinks, it can be recognized very easily that the alignment adjustment has been completed, as described above.

Note that the alignment completion signal is transmitted from the light source of the reference index or the light source 4 of the pinhole aperture 404.
02 is also used, but it goes without saying that the display is not limited to this and may be configured to display a special index.

As explained in detail above, the present invention allows optical axis alignment adjustment and working distance adjustment to be performed while directly observing the anterior segment of the subject's eye, and furthermore, it is possible to complete the adjustment with all of these positional relationships within the appropriate range. Since it can be identified very easily, it has an extremely significant effect on the work efficiency and adjustment accuracy of proper position adjustment. In addition, since whether or not it falls within the appropriate range is electrically detected and displayed, it has the advantage that there is no variation in the adjustment results depending on the examiner.

[Brief explanation of the drawing]

The drawings show an embodiment in which the present invention is applied to a refractometer. Fig. 1 is an optical diagram, Fig. 2 is a front view of the collimating plate of the aiming optical system, and Fig. 3 is an explanation of the relationship between the tipper and the luminous flux. Figure 4 is an explanatory diagram of the light flux passing through the chopper when the distance between the eye to be examined and the refractometer is smaller than the appropriate value, and Figure 5 is an explanatory diagram of the relationship between the luminous flux and the light receiving element in the state shown in Figure 4. , Fig. 6 is a detection signal diagram of the light receiving element, Fig. 7 is an explanatory diagram of the light flux passing through the chopper when the distance between the eye to be examined and the refractometer is larger than the appropriate value, and Fig. 8 is a diagram of the light flux passing through the chopper in the state shown in Fig. 7. An explanatory diagram of the relationship between the light flux and the light receiving element, FIG. 9 is a flowchart of the electric circuit, FIG. 10 is an explanatory diagram of the function of the light receiving element, FIG. 11 is a waveform diagram in the flowchart of FIG. 9, and FIG. It is a display explanatory diagram of a television monitor. 100...Target projection optical system, 101...
Infrared light source, 105...Measurement target, 200
...Target light receiving optical system, 212... Corneal reflected light blocking diaphragm, 214... Two-dimensional detector, 300...
...Aiming optical system, 302...Projection lens, 314...
...TV monitor, 400...Test eye position detection system,
404...Pinhole diaphragm, 414...Chopper, 420...Reference signal light receiving element.

Claims (1)

[Scope of Claims] 1. An eye observation system for observing the anterior segment image of the eye to be examined superimposed on a reference index, and an eye position detection system for electrically detecting the amount of deviation of the eye to be examined from the proper position. and a display section that displays that the deviation amount is within a predetermined tolerance based on an electric signal from the eye position detection section, and the observation image of the eye observation system and the display on the display section 1. A device for detecting the position of an eye to be examined in an ophthalmological machine, characterized in that the device is configured such that the eyes can be observed within the same field of view. 2 The eye position observation section is composed of an optical system for forming an image of the eye to be examined and a television monitor for displaying the image of the eye as a visible image, and the display section is configured to display an image on the television monitor screen. An eye position detecting device for an ophthalmological machine according to claim 1, which is configured to detect the position of an eye to be examined in an ophthalmological machine. 3. The subject eye position detection unit has an index projection system that projects an aperture image for proper position detection onto the subject eye, and displays the aperture image on the display unit by blinking or non-blinking. Eye position detection device for ophthalmology equipment. 4. The eye position detecting device for an ophthalmological machine according to claim 2, wherein the display on the display section is performed according to the lighting state of the reference indicator. 5. The eye position detecting device for an ophthalmological machine according to claim 2, wherein the television monitor also displays the direction of deviation of the ophthalmological machine from the proper position based on an electric signal from the eye position detecting section.