JPS588245B2 - Objective eye refraction measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical refraction measuring device that does not require a subjective response from a subject.

Currently, other types of ocular refraction measurement devices have insufficient functions to eliminate accommodation of the subject's eye during measurement (so-called mechanical myopia), are expensive, and are difficult to measure due to the fact that the device is expensive. There are disadvantages such as the inconvenience of having to rotate the eyepiece twice in the direction, the inconvenience that the eyepiece moves according to the refractive power of the eye to be examined, and the time required to calculate and record the measurement results.

Therefore, the present invention prevents mechanical myopia, which is particularly severe in young people, and
It reduces the subject's photophobia (feeling of dazzle), shortens measurement time, and is equipped with electrical calculation, display, and printing functions to quickly obtain measurement results.

Moreover, it is an object of the present invention to provide an inexpensive non-party type ocular refraction measuring device.

Next, the illustrated embodiments of the present invention will be described in detail.

FIGS. 1-A and 1-B are schematic illustrations of the present ocular refraction measuring apparatus in use, with the eyes 1, 1' to be examined looking far above the optical assembly 2 of the apparatus.

That is, the angle between the optical axis of the objective lens 3 of the assembly and the plane including the line of sight of both eyes to be examined is set to be 6 or more, and the examiner's eye 5 is configured to perform measurement through the eyepiece 4.

Then, if the subject is myopic, a natural binocular fog state can be obtained in the condition shown in Figure 1, and if the subject is farsighted, by placing the plus lens 3 in the subject's line of sight, it is possible to obtain a natural binocular fog condition, especially for young people. Significant mechanical myopia is eliminated, measurement accuracy is improved, and the feeling of photophobia in the eye to be examined can be reduced.

In order to fix the line of sight of the subject, it is sufficient to place a gaze target 6 such as a penlight at the installation position (3r to 5m) of the visual acuity chart during normal subjective measurement.

FIG. 2 shows an embodiment of the optical assembly 2 described above, in which the light rays emitted from the light source 7 are condensed by a condensing lens 8 and illuminate a visual target 9. As shown in FIG.

The light rays emitted from this optotype are reflected by the orthogonal reflector 10, the reflector 11,
12, relay lens 13, reflector 14, perforated reflector 1
5. Eye to be examined 1 passes through reflector 16, 17 and objective lens 3.
Or reach the retina of 1/.

In addition, the light rays reflected by the retina are passed through the objective lens 3 and the reflecting mirror 17.
, 16 in reverse, pass through the small hole of the perforated reflector 15, and pass through the relay lens 13/, the reflectors 12', 11, and the orthogonal reflector 1.
0', it passes through the eyepiece 4 and reaches the examiner's eye 5, but it is connected to the orthogonal reflector 10 and 10' by a connecting body 21, and is held by a sliding guide mechanism (not shown) to move it along the optical axis. Allows movement in the direction of the arrow.

The movement of the orthogonal reflective bell 10 causes a shift in the optical mirror image position of the optotype 9 with respect to the position of the relay lens 13, so that even if the optotype is fixed at one point on its optical axis, Since the distance of the visual target to be presented can be changed, the electrical drive device for the visual target shown in FIG. 4, which will be described later, can be simplified, and the eyepiece lens 4 can be made immovable.

And relay lenses 13, 13', reflectors 11, 12
, 11', 12', the focal lengths of the orthogonal reflectors 10, 10' and the spacing between these optical elements are made the same, so that an image is formed on the retina of the subject's eye 1 or 1' by the movement of the orthogonal reflector 10. The image of the optotype 9 obtained by using the retina as a secondary light source is
The image is formed on the conjugate point 20 of , and is immobile in the optical axis direction.

FIG. 3A shows an embodiment of the left and right detection device for the eyes 1, 1' to be examined, in which a shielding plate 22 attached to the lower part of the optical assembly 2 of FIG. Depending on whether or not to block the light beams of the attached photocouplers 24 and 25, the signal shown in FIG.
Although the left and right sides of 1' are determined, a means such as a microswitch may be used instead of a photocoupler.

Furthermore, FIG. 4 shows an embodiment of the electric drive device for the visual target 9, in which the outer cylinders 26 and 27 are connected with screws (not shown), are rotatably held in the machine frame 46 by bearings 2B and 29, and are rotated by gears. The operation of the knob 32 engaged by 30.31 rotates around the optical axis X, and the angle detector 34 engaged by gear 30.33 also rotates. It is held by mounted bearings 36 and 37, and is fixed to the outer cylinder 26, and the gear head 39 of the drive motor 40 and the gear 38 are engaged, so that the inner cylinder 35 can rotate independently of the rotation of the outer cylinder 26 and 27. .

The light beam of the light projector 41, which is a series of reference elements, is transmitted through the small hole 43 of the outer cylinder 26, the l hole 44 of the inner cylinder 35, and the outer cylinder 2.
The reference point for rotation is when the light passes through the small hole 45 of No. 7 and is received by the light receiving device 42, and the motor 40 is stopped by the electric circuit shown in FIG. The rotation angle of the detected outer cylinders 26 and 27 and the rotation angle of the optotype 9 match.

The motor 40 is rotated by the signal from the astigmatism switch 52 shown in FIG. 5 at the time of transition from spherical power measurement to astigmatic power measurement of the eye to be examined, and the optotype 9 is aligned with the second principal meridian direction of the eye to be examined.
The inner cylinder 35 holding the rotates and stops.

With this device, the time required for measurement can be shortened.

FIG. 5 shows the electric circuit of the device of the present invention, showing the signals of the movement amount detector 47 (FIG. 2) of the orthogonal reflecting mirror 10, 10' and the rotation angle detector 34 (FIG. 4) of the optotype 9. is input to the central processing unit 60 via the signal conversion circuit 4B, and the signals from the left/right detector 51 and the astigmatism switch 52 are input to the central processing unit 60 via the input/output control circuit 59.

These signals are processed by the central processing unit 60, and the spherical power, astigmatic power, and astigmatic axis of the right or left side of the eye 1, 1' to be examined are digitally displayed on the display 61.

Further, a motor 40 for rotating the optotype 9 receives a signal from an astigmatism switch 52, a signal from a reference point detector 50 including a light projecting device 41 and a light receiving device 42, a shielding plate 22, and a photocoupler 2.
The input/output control circuit 59 inputs signals from the left and right detectors 51 including
degree, and by switching the signals from the left and right detectors 51, the optotype 9 is rotated back until a signal from the reference point detector 50 is obtained.

The central processing unit 60 includes a memory circuit for storing the measurement results of the eyes 1 and 1', receives the signal from the call switch 54, receives the signal from the left and right detectors 51, and receives the signal from the left and right detectors 51. 1' measurement results are displayed.

Further, when the signal from the print switch 55 is input to the central processing unit 60 following the signal from the call switch 54, the measurement results of the eye to be examined are driven by the printer drive circuit 58 on both the right and left sides in a predetermined order. Printer 51
This eliminates the need for recording during measurement and prevents transfer errors.

Furthermore, by switching the output signals of the left and right detectors 51, the central processing unit 60 resets the signal of the astigmatism switch 52,
To shorten the time required for operation when changing from one eye to the other eye by restoring the spherical power measurement device to a state capable of measuring spherical power.

Note that 53 is a switch for arbitrarily changing the distance between the corneal vertices and displaying the diopter of the corrective lens that will be worn at that distance when displaying the eye refractive power.

This function eliminates the need for complicated calculations associated with changes in the corneal vertex distance.

Next, describe the operation of the Hon et al ocular refraction measuring device.

First, when the main switch of the power source 49 (Figure 5) is turned on, the light source 7 (Figure 2) turns on, the reference point detector 50 in Figure 5 operates, and the motor 40 rotates in Figure 4. , the inner cylinder 35 rotates, and its small hole 44 opens into the outer cylinder 26,
When it coincides with the small holes 43 and 45 of 27, the light from the light projecting device 41 hits the light receiving device 42, the motor is stopped by that signal, and the position of the visual indicator (for example, an arrow) 9 at that time becomes the reference point. .

Next, in the optical assembly 2 of FIG.
When the eye 1 was moved back and forth, the image of the optotype 9 was formed on the optical axis of the eye 1 or 1' by the lenses 13 and 3, and the retinal reflection image was best seen by the examiner's eye 5 through the lens 4. When,
The spherical power of the eye to be examined is obtained.

Well, if you turn the knob 32 in Fig. 4 to see the target 9 more clearly, move the connecting body 21 slightly so that the target can be seen more clearly. The spherical power is obtained and detected as a signal by the movement amount detector 47 in FIG. is detected and digitally displayed or (
and) are printed, and these values are stored in the circuit.

Next, when the astigmatism switch 52 shown in FIG. 5 is turned on, the motor 40 rotates as shown in FIG. The astigmatic power is obtained by determining the best point of the optotype, which is also detected as a signal by the movement amount detector 47 as described above, and the difference from the previously obtained spherical power is determined to obtain the astigmatic power. Digital display, etc.

What has been described above is the measurement of the refractive power of one of the eyes 1 and 1', and in order to measure the other eye, the optical assembly 2 and the shielding plate 22 must be moved to the left in FIG. 3, 1A. At this time, the light between the photocouplers 24 and 25 is interrupted, and the voltage of one eye shown in FIG. To enable the refractive power of optometry to be measured as described above.

The device of the present invention has such a configuration. The optical assembly that approaches the subject's eye can capture light from one retina of the subject's eye without obstructing the subject's visual field, thereby eliminating the problem of the subject's eye's own retina, which is a major hindrance in multi-part eye refraction measurements. Accommodation, that is, mechanical myopia, does not occur, so accurate refractive power measurement is possible, and the optotype remains stationary on the optical axis and the power is measured by moving the optical element, making this measurement easy and accurate. In addition, the reference point and required rotation angle of the optotype are detected by rotating the rotating body to which the optotype is fixed and the rotating body equipped with a knob and an angle detector. , the inner cylinder on which the optotype is fixed is flattened by a motor, the motor is fixed to the outer cylinder equipped with a knob and an angle detector, and both cylinders are made coaxial, making the mechanism extremely compact and making it possible to The assembly can be made compact, the reference point of the optotype and the required rotation angle can be easily detected, and the left or right eye can be immediately measured by switching between the right and left eyes of the subject's eye. It is possible to measure the refractive power of the eye, and the measured value of the refractive power can be displayed digitally and/or
Since it can be printed, it has excellent effects such as accurately knowing the refractive power of both eyes and being able to immediately compare the two.

[Brief explanation of drawings]

FIG. 1 is a schematic elevational view of a measurement state using an optical assembly according to an embodiment of the present invention, FIG. 1B is a schematic plan view of the same, FIG. 2 is a schematic diagram showing the configuration of the optical assembly, and FIG. FIG. 3 is a schematic diagram of the slope of the switching mechanism for the left and right sides of the eye to be examined, FIG. FIG. 3 is an electrical circuit diagram of this embodiment. 1.1'... Eye to be examined, 2... Optical assembly, 5.
... Examiner's eye, 6... Gaze target, 7... Light source, 9...
- Visual target, 10, 10'... Orthogonal reflecting mirror, 21... Connector, 22... Shielding plate, 24.25... Photocoupler, 26, 27... Outer cylinder, 32... Picking, 34.
...Angle detector, 35...Inner cylinder, 40...Motor, 41...Light emitter, 42...Light receiver, 43,4
4,45...small hole.

Claims (1)

[Scope of Claims] 1. An optical assembly capable of capturing light from one retina of an eye to be examined without interfering with the visual field of the examinee, and an image of an optical target that is fixed on the optical axis in the assembly. A means for detecting the moving distance of an optical element that allows the human eye to see clearly, and a rotation of a rotating body to which the optotype is fixed and a rotating body equipped with a knob and an angle detector, the reference of the optotype is determined. A means for detecting the point and the required rotation angle, a means for detecting the right and left sides of the eye to be examined so that the left or right can be measured immediately, and signals from these means are used to detect the spherical power, astigmatism, and axis of the eye to be examined. 1. An optical refraction measuring device equipped with an electric circuit capable of digitally displaying and/or printing the astigmatic power. 2. An optical assembly capable of capturing light from one retina of the subject's eye without obstructing the subject's field of vision, and an optical assembly that allows the examiner's eye to clearly see the image of an optotype that is fixed on the optical axis in the assembly. an inner cylinder rotated by a motor, and an outer cylinder provided with a series of reference elements, knobs, and angle detectors and to which the motor is fixed, coaxially provided; A reference point of the optotype, the motor is stopped when the reference elements match, and the motor is rotated by an astigmatism switch to rotate the optotype by 90 degrees from the reference point; means for detecting the required rotation angle;
A means for detecting the left and right sides of the eye to be examined so that the left or right side can be measured immediately, and digital display and/or printing of the spherical power, astigmatic axis degree, and astigmatic power of the eye to be examined based on the signals from these means. An optical refraction measuring device equipped with an electric circuit capable of