JPH06181888A - Ophthalmoscope - Google Patents

Abstract

PURPOSE:To provide a simplified and compact ophthalmoscope capable of easily confirming the position of an eye to be inspected and preventing a measuring error due to the deviation of the eye to be inspected from occurring favorably. CONSTITUTION:The ophthalmoscope equipped with an observation window 24 on which a lens 26 for inspection is loaded and formed so as to visualize a barometer 28 from the rear side of the observation window 24 via the lens 26 is provided with (a): a projector means 30 (32) which projects light on one point on the optical axis of the observation window 24 where the cornea apex of the eye 22 to be inspected is located, and (b): a light receiving means 34 (36) which outputs a light reception signal by receiving reflected light by the cornea apex of the eye 22 to be inspected emitted from the projector means 30 (32).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a subjective eye examination apparatus used for measuring the refractive power of an eye, and in particular, it is possible to advantageously prevent or correct a measurement error due to a distance difference caused by a positional deviation of an eye to be examined. The present invention relates to an optometry device.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 2, as a kind of device for measuring the refractive power of the eye for the examination of the refractive error of the eyeball, etc., an observation in which a predetermined lens 2 is replaceably mounted There is a known subjective optometry apparatus that includes a window 4 and allows an eye 6 to be inspected to visually recognize an index 12 from behind the observation window 4 through the lens 2.

By the way, in such a subjective optometry apparatus, the distance (aiming distance) L between the rear surface of the lens (reference position) and the apex of the cornea of the eye to be inspected: L is a constant value (for example, 1).
The eye refraction diopter is designed to be measured under the precondition that it is 2 mm). Therefore, at the time of examination, it is necessary to confirm whether or not the eye 6 to be inspected is in a position satisfying such a value.

Therefore, in the conventional subjective eye examination apparatus, generally, as shown in the figure, a corneal sighting window 10 is provided in the eye examination unit 8 and the position of the apex of the cornea of the eye 6 for visually recognizing the index 12 is determined by the examiner 14. Can be confirmed through the reflecting mirror 16 and the sighting scale 18.

However, in such a conventional subjective eye examination apparatus, as shown by a virtual line in the drawing, when there is an angular error in the observation direction (corneal aiming direction) by the examiner 14, the eye to be examined. Since the position of 6 cannot be accurately confirmed on the aiming scale 18, there is a problem that it is difficult to obtain sufficient measurement accuracy.

Moreover, with the conventional subjective optometry apparatus, it is practically impossible to simultaneously check both eyes 6 and 6 of the examinee, and after one eye 6 is aligned,
If the other eye 6 to be inspected is aligned, the position of the eye to be inspected earlier may be displaced.

Further, in such a conventional subjective optometry apparatus, the examiner 14 must frequently confirm the position of the eye 6 to be examined in order to prevent a change in the aiming distance during the examination period. There was also a problem that the operation was troublesome and the burden on the examiner was heavy.

Incidentally, Japanese Patent Laid-Open No. 2-52631 discloses that
By optically detecting the position of the apex of the cornea of the eye to be inspected (aiming distance) by a detector such as a CCD, outputting it as an electric signal, and automatically detecting the position of the eye to be inspected,
There has been proposed a subjective optometry apparatus that prevents the measurement accuracy from deteriorating due to the angle error in the observation direction as described above and improves operability.

However, in such an optometric apparatus, in the subjective optometric apparatus having the conventional structure as shown in FIG. 2, a detector such as CCD is simply arranged instead of the examiner and the aiming distance is set. Since it is intended to be taken out as an electric signal, it is unavoidable that a large, complicated and expensive device such as a CCD camera or a television monitor is required as its detector, and its practical application has been extremely difficult.

In addition, since the optometry apparatus becomes large, there is a problem that the subject feels nervousness during the examination and it becomes difficult to measure the eye refraction power accurately.

[0011]

The present invention has been made in view of the circumstances as described above. The problem to be solved by the present invention is that the position of an eye to be inspected can be easily confirmed and the structure is An object is to provide a simple and compact subjective optometry device.

[0012]

In order to solve such a problem, the present invention is provided with an observation window in which a predetermined lens is replaceably attached, and allows an eye to be inspected to visually recognize an index from behind the observation window through the lens. In the subjective optometry device,
(A) A light projecting means for projecting light onto one point on the optical axis of the observation window where the apex of the cornea of the eye to be inspected is located;
Light receiving means for receiving a light reflected by the corneal apex of the eye to be inspected of the light projected by the light projecting means and outputting a light receiving signal is provided.

Further, the present invention is also characterized by a subjective eye examination apparatus in which at least a part of the light projecting path in the light projecting means and / or the light receiving path in the light receiving means is constituted by an optical fiber. .

Furthermore, the present invention corresponds to a plurality of light projecting means for projecting light to different points on the optical axis of the observation window by the light projecting means and the light receiving means, and the respective light projecting means. The subjective optometry apparatus including a plurality of pairs of light receiving means is provided as a feature.

Further, the present invention is an subjective optometry apparatus comprising a plurality of pairs of light projecting means and light receiving means as described above, wherein the object is detected based on the light receiving signals output by the plurality of light receiving means. It is also characterized in that it is provided with arithmetic means for detecting the aiming distance between the corneal apex of the optometry and the reference position of the lens, and correcting the measurement value of the eye refractive power according to the detected value. It is a thing.

Furthermore, the present invention is a subjective eye examination apparatus having various structures as described above, wherein the light receiving state of the reflected light can be recognized from the outside based on the light receiving signal output by the light receiving means. The one having a display device for displaying is also a feature thereof.

[0017]

In other words, in the subjective optometry apparatus having the structure according to the present invention, the cornea apex of the eye to be inspected is projected by the light projecting means only when it is positioned at a predetermined position. The position of the eye to be inspected can be easily confirmed by the received light signal output from the light receiving means from the point where the reflected light of the light from the eye to be inspected enters the light receiving means.

Moreover, in such a subjective eye examination apparatus, since the position of the eye to be examined is judged by the presence or absence of light incident on the light receiving means, it is possible to employ a simple light receiving sensor as the light receiving means. Since it is not necessary to use a complicated one such as a CCD camera, it is possible to effectively achieve simplification, compactness and cost reduction of the device structure.

Further, in such a subjective optometry apparatus,
Since it is not necessary for the examiner to visually check the position of the eye to be inspected directly, the labor of the examiner can be reduced, and the occurrence of measurement error caused by the negligence in the operation of the examiner is prevented. Thus, excellent measurement accuracy can be stably obtained.

Further, at least a part of an optical path of the light projecting means and the light receiving means is constituted by an optical fiber.
In the subjective optometry apparatus described in (1), it is not always necessary to set the optical path linearly, and the degree of freedom in designing the apparatus structure can be advantageously ensured, thereby making the apparatus even more compact and manufacturable. It can be improved.

Further, in the subjective optometry apparatus according to claim 3, wherein a plurality of pairs of light projecting means and light receiving means are provided.
It is possible to position the eye to be examined with high accuracy even when it is difficult to position the eye to the intended position due to the facial features of the subject or the depth of the eye, etc. Can be advantageously performed.

Further, there is provided arithmetic means for correcting the measured value according to the position of the eye to be inspected on the basis of the aiming distances detected by the plurality of pairs of light projecting means and light receiving means. In the subjective optometry apparatus according to, it is possible to easily obtain the correct eye refractive power regardless of the position of the eye to be inspected, and it is possible to prevent the occurrence of an error due to an error at the time of correction, and to simplify the measurement work. Can be very advantageously achieved.

Further, in the subjective optometry apparatus according to claim 5, further comprising a display device for displaying the light receiving state by the light receiving means, the examiner can easily detect the position of the eye to be inspected or the position shift during the examination. From what can be known, the measurement workability can be improved more advantageously.

[0024]

The embodiments of the present invention will now be described in detail with reference to the drawings in order to clarify the present invention more specifically.

First, FIG. 1 schematically shows the structure of a subjective eye examination apparatus as an embodiment of the present invention. In the figure, reference numerals 20 and 20 denote device cases that are divided for the left and right eyes, and are supported by a support member (not shown) so that the relative distance can be changed. It is supposed to be available.

An observation window 24 is provided in each of the device cases 20, and an inspection lens 26 is arranged in the observation window 24. Although not explicitly shown in the drawing, a plurality of types of the inspection lens 26 having different refractive powers are prepared inside or outside the device case 20, and any one of the lenses is selected and replaced. Is able to.

Then, like the conventional subjective optometry apparatus, the apparatus cases 20 and 20 are arranged in front of the eyes 22 and 22,
The index 28 is visually recognized through the inspection lens 26 set in the observation windows 24, 24 to the eyes 22 and 22, and the eye refractive index of the eyes 22 and 22 is determined by knowing the inspection lens that gives the best visual acuity. It is designed to measure.

Further, in the subjective optometry apparatus, the optical axes of the observation window 24 in which the inspection lens 26 is arranged, that is, the collimation axis m of the index 28 of the eye 22 to be inspected, are symmetrically positioned. On both sides, a first light projecting device 30 and a second light projecting device 32 as light projecting means, and a first light receiving device 34 and a second light receiving device 36 as light receiving means are arranged, respectively. . In FIG. 1, the first light projecting device 30, the second light projecting device 32, and the first light receiving device 34 and the second light receiving device 36 are shown close to each other, but in reality, The arrangement structure of the device can be simplified by arranging the respective pairs so as to be displaced by a predetermined amount in the circumferential direction around the optical axis: m of the observation window 24.

The first and second light projecting devices 30, 32
Are light sources 38, 38 'such as LEDs and optical fibers 40, 40' for guiding the light from the light sources 38, 38 ', respectively.
And the condenser lenses 42 and 42 'through which the light guided by the optical fibers 40 and 40' is transmitted. The light transmitted through the condenser lenses 42 and 42 'is
The light is projected to a point on the optical axis of the observation window 24 through the light projecting windows 44 and 44 'provided in the device case 20.

Further, here, the first light projecting device 30
The light projected through the light projecting window 44 and the light projected through the light projecting window 44 ′ by the second light projecting device 32 are
The light is projected on different points on the optical axis of the observation window 24, which are separated by a predetermined distance. In particular, in the present embodiment, the light projected by the first light projecting device 30 causes the inspection lens 26 to be on the optical axis of the observation window 24.
Standard distance from the reference position (back of the inspection lens 26):
The light projected by the second light projecting device 32 is projected on a point separated by L = 12 mm (hereinafter, referred to as “standard point”), and on the optical axis of the observation window 24, further behind it. Is projected onto a point separated by a predetermined distance: L '.

On the other hand, the first and second light receiving devices 34,
36 are the first and second light projecting devices 30, respectively.
Condensing lenses 46 and 46 ′ through which the light projected by 32 and reflected by the eye 22 to be inspected are transmitted;
Optical fibers 48, 48 'for guiding the light transmitted through 46'
And a light receiving element 50, 50 'such as a photodiode to which the light guided by the optical fiber 48, 48' is irradiated.

Then, the light projected by the first light projecting device 30 when the eye 22 to be inspected is positioned at the standard point,
The device case 20 is reflected by the apex of the cornea of the eye 22 to be examined.
Through the light receiving window 52 provided in the first light receiving device 34
When the eye 22 is positioned a predetermined distance L ′ from the standard point, the second projection is performed while the light receiving element 50 outputs an electric signal indicating the state of incidence. The light projected by the optical device 32 is the subject's eye 2
The light is reflected at the apex of the cornea 2 and is made incident on the second light receiving device 36 through the light receiving window 52 'provided in the device case, whereby the light receiving element 50' outputs an electric signal indicating the incident state. It has become so.

Therefore, the eye 22 to be inspected is caused by the electric signal output from the light receiving element 50 constituting the first light receiving device 34.
It is possible to determine whether or not the eye 22 is located at the standard point by the electric signal output from the light receiving element 50 'constituting the second light receiving device 36. It is possible to judge whether or not the vehicle is located at a point behind by a predetermined distance: L '.

Furthermore, in the eye examination apparatus of this embodiment,
Each device case 20 is provided with a first display lamp 53 and a second display lamp 54. Then, when the incident signal is output from the light receiving element 50 that constitutes the first light receiving device 34, the first display lamp 53 lights up, and the eye 22 to be inspected
Indicates that it is located at the standard point while the light receiving element 50 'constituting the second light receiving device 36 outputs an incident signal, the second display lamp 54 lights up and the eye to be inspected. It is displayed that 22 is located behind the standard point by a predetermined distance: L '.

By the way, in order to measure the eye refracting power of the eye 22 to be inspected by the subjective eye examination apparatus having such a structure,
First, similar to the conventional device, the device cases 20 and 20 are moved so that the eye 22 to be inspected is positioned through the inspection lens 26 provided in the observation window 24 so that the index 28 disposed in front can be visually recognized. Excuse me.

Then, a forehead rest (not shown) is adjusted to position the eye 22 to be inspected with respect to the device cases 20 and 20 in the front-rear direction, and the eye 22 is moved back to the standard point or a predetermined distance L'from the standard point. It is located at the point of. That is, the fact that the eye 22 to be inspected is positioned at any one of these points means that the first or second display lamps 53, 54.
The light can be easily checked by the examiner.

In order to improve the operability when the eye 22 to be inspected is positioned at those standard points or at a point behind the standard points by a predetermined distance: L ', the device case 2 is used.
It is effective to provide a corneal aiming window (see FIG. 2) conventionally used for 0 and 20.

The first or second display lamp 53,
Under the lighting state of 54, the eye 22 to be inspected
In addition, the inspection lens 26 that gives the best visual acuity by visually recognizing the index 28 through the various inspection lenses 26
The refractive power of the eye is measured from the lens power of.

When the measurement is performed while the first display lamp 53 is lit, that is, when the eye 22 to be inspected is positioned at the standard point, the inspection lens 2 is used.
From the lens power of 6, it is possible to immediately know the refractive power of the eye, and no correction is necessary.

On the other hand, when the eye 22 to be inspected cannot be positioned at the standard point because of the facial feature of the person to be inspected and the measurement is performed while the second display lamp 54 is lit, that is, the eye 22 to be inspected. When the measurement is performed under the condition of being positioned at a point rearward by a predetermined distance L'from the standard point, it is necessary to correct the eye refraction power obtained from the lens power of the inspection lens 26. That is, as is known, when the eye refractive power obtained from the lens power of the inspection lens 26 is D _S , the eye refractive power: D _g of the eye to be inspected is expressed by the following (Equation 1) in units of diopter. It

[0041] _{D g = 1000 × D S /} (1000-D S × L ') ··· ( Equation 1)

Incidentally, such correction processing is performed by the distance: L '
It is also possible to calculate a correction value according to the value of the eye refractive power: D _S in advance to create a table and the like, and the examiner corrects the obtained value of the eye refractive power: D _S. Although possible, it is also possible to have the arithmetic unit automatically perform such correction processing.

More specifically, for example, the eye 22 to be inspected is positioned behind the standard point by a predetermined distance: L ', and an incident signal is output from the light receiving element 50' constituting the second light receiving device 36. If the measurement is performed under the condition, after the measurement,
An arithmetic device that performs correction calculation based on the above (Equation 1) on the obtained eye refractive power: D _S , and an output device such as a printer that outputs the eye refractive power: D _g calculated by the arithmetic device. By providing the arithmetic processing means provided,
Can be realized.

Therefore, in the above-described subjective optometry apparatus, the examiner does not directly visually recognize the position of the eye 22 by the light receiving signals output from the first and second light receiving apparatuses 34 and 36. Since the position of the eye 22 to be inspected can be easily confirmed, therefore, the measurement operation is easy and the burden on the examiner can be reduced, and the measurement error caused by the negligence in the operation of the examiner can be reduced. This can be prevented from occurring, and excellent measurement accuracy can be stably obtained.

Moreover, in such a subjective optometry apparatus, simple light receiving elements 50 and 50 'can be adopted as the light receiving means, and it is not necessary to use a complicated one such as a CCD camera. It can be advantageously realized with a simple and compact device structure.

Furthermore, in the eye examination apparatus of this embodiment,
Since part of the optical paths in the light projecting devices 30, 32 and the light receiving devices 34, 36 are composed of the optical fibers 48, 48 ', it is not necessary to set the optical paths linearly, and the degree of freedom in designing the device structure is reduced. It can be secured in an advantageous manner.

Further, in the eye examination apparatus of this embodiment, since two pairs of the light projecting device and the light receiving device are provided, even when it is difficult to position the eye to be the standard point, the eye to be inspected It is possible to position with high accuracy, and it is possible to advantageously measure the eye refractive power.

Furthermore, in the eye examination apparatus of this embodiment, the light receiving states of the first and second light receiving devices 34 and 36 are displayed by the first and second display lamps 53 and 54, and the eye 22 to be inspected. Since it is possible to easily visually recognize whether or not the eye is located at the standard point or a predetermined position behind the standard point, it is possible to detect the position of the eye 22 to be inspected or the position deviation during the examination. It is possible for a person to easily know, and more excellent measurement workability can be exhibited.

The embodiments of the present invention have been described in detail above, but these are literal examples and the present invention should not be construed as being limited to such specific examples.

For example, in the above embodiment, two pairs of the light projecting device and the light receiving device are provided, and whether or not the eye 22 to be inspected is located at the two points of the standard point and a predetermined position behind the standard point. However, it is of course possible to provide a pair of the light projecting device and the light receiving device which form such a pair, or three or more pairs.

Further, the first and second display lamps 53,
It is also possible to adopt a buzzer or the like instead of 54,
Further, for example, in the case where the arithmetic device is operated by the output signals from the first and second light receiving devices 34 and 36 to automatically perform the correction process, such an external display device is not always necessary. is not.

Further, in the above embodiment, a part of the optical path in the light projecting device and the light receiving device is constituted by the optical fiber, but it is not always necessary to use the optical fiber.

Although not listed one by one, the present invention is
Based on the knowledge of those skilled in the art, it can be implemented in various modified, modified, and improved modes, and
It goes without saying that all such embodiments are included in the scope of the present invention without departing from the spirit of the present invention.

[Brief description of drawings]

FIG. 1 is an explanatory diagram schematically showing the configuration of a subjective eye examination apparatus as one embodiment of the present invention.

FIG. 2 is an explanatory view schematically showing a specific example of a subjective eye examination apparatus having a conventional structure.

[Explanation of symbols]

 20 device case 22 eye to be inspected 24 observation window 26 inspection lens 28 index 30 first light projecting device 32 second light projecting device 34 first light receiving device 36 second light receiving device 38, 38 'light source 40, 40' Optical fiber 48, 48 'Optical fiber 50, 50' Light receiving element 53 First display lamp 54 Second display lamp

Claims (5)

[Claims] 1. A subjective eye examination apparatus comprising an observation window in which a predetermined lens is replaceably mounted, and an index is made visible to the eye to be examined through the lens from the rear of the observation window. A light projecting unit that projects light onto a point on the optical axis of the observation window where the corneal apex is located, and receives light reflected by the corneal apex of the eye to be inspected by receiving the light projected by the light projecting unit. A subjective optometry apparatus, comprising: a light receiving unit that outputs a signal. 2. The subjective optometry apparatus according to claim 1, wherein at least a part of a light projecting path of the light projecting unit and / or a light receiving path of the light receiving unit is configured by an optical fiber. 3. A plurality of light projecting means, wherein the light projecting means and the light receiving means project light at different points on the optical axis of the observation window, and a plurality of light receiving means corresponding to the respective light projecting means. The subjective optometry apparatus according to claim 1 or 2, wherein a plurality of pairs are provided. 4. The aiming distance between the corneal apex of the eye to be inspected and the reference position of the lens is detected based on the light receiving signals output by the plurality of light receiving means, and the eye refraction power is detected according to the detected value. The subjective optometry apparatus according to claim 3, further comprising arithmetic means for correcting the measurement value of. 5. The display device according to claim 1, further comprising a display device that displays a light receiving state of the reflected light from the outside based on a light receiving signal output from the light receiving means. Self-conscious optometry device.