JPS61276533A - Eye self-positioning apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a self-eye alignment device that is installed in various ophthalmological equipment and allows the patient to align the eye to be examined to the proper position of the ophthalmological equipment. It is.

[Prior Art] In recent years, it has been desired that ophthalmological equipment that can be operated by the examiner himself/herself will become more widespread so that both the examiner and the examinee can save labor. For example, intraocular pressure is similar to blood pressure. It is desirable to be able to measure intraocular pressure easily and accurately at home, such as with a home sphygmomanometer, by regularly measuring the intraocular pressure.

By the way, when the patient himself/herself operates the ophthalmological equipment,
The subject must align their own silver precisely in place with respect to the device. This alignment is based on the distance between the device and the eye to be examined, that is, the working distance.
It consists of a predetermined distance, and an alignment mechanism that aligns the optical axis of the device with the eye axis of the eye to be examined, and requires accuracy of about 1 mm or less.

Conventional positioning devices of this type have only been contact-type devices that press terminals against the cornea, and these contact-type devices require anesthesia and disinfection, and cannot be easily operated by the patient. This difficulty in self-aligning the eyes is one of the reasons that prevents the spread of ophthalmological equipment that can be used at home.

[Object of the Invention] An object of the present invention is to provide a self-eye positioning device in various ophthalmological apparatuses that allows the subject to easily and accurately align his or her own eye to a predetermined working distance of the ophthalmological equipment. It is in.

[Summary of the Invention] The gist of the present invention for achieving the above-mentioned object is that when the eye to be examined is located at a predetermined working distance of an ophthalmological device, the light emitted from the anterior segment of the eye to be examined is transformed into a substantially parallel beam of light. This self-eye positioning device is characterized in that a reflective optical system is arranged in front of the eye to be examined, aligned with the optical axis of the ophthalmological equipment so as to return to the eye to be examined.

[Embodiments of the invention] The present invention will be explained in detail based on illustrated embodiments.

FIG. 1 is a configuration diagram of the main parts of a device in which the first embodiment is applied to a non-contact tonometer. A concave mirror l whose focal length is the working distance of the ophthalmological device is arranged on the optical axis 01 of the device. In order to apply it to a tonometer, an opening is provided at the center of the concave mirror 1, and a nozzle 1a passes through the opening. Then, air is blown onto the eye E located on the optical axis 01 through a nozzle 1a by an air compressor (not shown), and the cornea of the eye E is deformed in response to the pressure of the blown air. It is possible to measure pressure.

In order to apply a constant pressure to the eye E during intraocular pressure measurement, the eye axis of the eye E must match the axis of the nozzle 1a, and the eye E must be located at a predetermined working distance from the nozzle 1a. Note that the axis of nozzle 1a is optical axis 01.
Therefore, the alignment of the eye E to be examined can be made by aligning the eye axis with the optical axis 01.

By the way, in an emmetropic eye with rested accommodation, an object at infinity forms an image on the retina. Therefore, when the eye E to be examined is located at the focal position f1 of the concave mirror 1, any light beam emitted from any position on the eye E will be reflected as a parallel beam by the concave mirror 1, and the examinee will be able to see his or her own eye E. The image E' will be clearly visible within the concave mirror l. Therefore,
If the operating pressure own of the intraocular pressure measuring device is fl, then the concave mirror 1 whose focal length is fl, that is, the radius of curvature rl = 2 fl
A concave mirror 1 is placed on the optical axis 01, and the subject positions his or her own eye E at a position where the image E' of the eye E is clearly visible. , the working distance fl of the device can be determined immediately. In addition, alignment to match the eye axis of the eye E to be examined with the optical axis O1 is as follows:
This can be achieved by positioning the eye E to be examined at the center of the concave mirror 1.

That is, a concave mirror l having a radius of curvature twice the operating pressure 11jlWD of the intraocular pressure measuring device is arranged on the optical axis 01, and the subject can clearly see an image E' of his or her own eye E at the center of this concave mirror 1. By positioning the subject's eye E so that the subject's eye E is seen, the patient can easily align the subject's eye E by oneself.

In this way, accurate positioning is possible for subjects with emmetropia, but let's consider what happens to subjects with myopic eyes and hyperopic eyes.

In the case of a myopic subject, when the subject's eye E is positioned at the focal position f1 of the concave mirror 1, an image E° that appears to be at infinity will be focused in front of the retina of the subject's eye E. become. Therefore, in order to view the image E' in focus, the subject must position his or her own eye at the focus position f1 of the concave mirror 1, that is, at a distance slightly closer to the concave mirror 1 than the operating pressure #. .

In addition, in the case of a hyperopic subject, when the subject's eye E is positioned at the focal position f1 of the concave mirror 1, an image E' that appears to be at infinity is focused behind the retina of the subject's eye E. Therefore, in order to view the image E' in focus, the subject needs to position his/her own eye at a location slightly further away from the concave mirror 1 than the focal length f1 of the concave mirror 1, that is, the operating pressure fiWD. .

In this way, the working distance differs to some extent depending on the subject's diopter, but this has little effect on the intraocular pressure measurement.
In an apparatus equipped with a concave mirror 1 of 0 mm, the following conditions apply to the eye to be examined, which is in the range of 14 to +4 diopters, which is the range of general myopic and hyperopic eyes. In other words, for the -4 dayopter myopic eye E, the image E' is clearly visible as the image E''! '(Eye to be examined E #) et al. 25
``° separation F'''' position 1 formation 54. In this case, the working distance WD is approximately 0.4 mm shorter for an emmetropic subject. Conversely, in the case of a hyperopic eye E with +4 day optics, the working distance WD becomes 0.4 ma+ longer. By the way, since the accuracy of the intraocular pressure measuring device and normal ophthalmological equipment is about 1 mm or less, an error in the working distance WD of about 0.4 mm has little effect on the intraocular pressure measuring device, and the reflection from the concave mirror 1 Light can be regarded as approximately a parallel beam of light.

In this way, the first embodiment allows for sufficiently accurate positioning of the own eye, but in addition, the concave mirror 1
When a light source (not shown) is placed at an appropriate position on the optical axis 01 on the opposite side of the eye E, a corneal reflection image is created through the nozzle 1a, and alignment is performed without looking at the sufficiently small corneal reflection image. By doing so, alignment can be easily achieved. Furthermore, if the light source is viewed through the pipe-shaped nozzle 1a before viewing the corneal reflection image of the light source reflected on the concave mirror 1, the ocular axis of the eye E to be examined will approximately coincide with the optical axis 01, so alignment will be necessary. It can be done even more quickly.

FIG. 2 shows a second embodiment used in an infrared refractometer, in which a concave mirror 2 is placed in front of the subject's eye E as in the previous embodiment, and an objective lens 3 is placed behind it with the same optical axis 02. is placed above. The concave mirror 2 is a guichroic mirror that reflects visible light and transmits infrared light. In this embodiment, infrared light for measurement is projected onto the subject's eye E from behind the objective lens 3 and acts in the same way as a normal infrared refractometer. Using light, it can be confirmed that the eye E to be examined is at a predetermined working distance, as in the previous embodiment.

FIG. 3 is a block diagram of the third embodiment, which is applied to a non-contact tonometer like the first embodiment. The self-eye alignment device consists of a condenser lens 4, for example, a concave mirror 5 made of a half mirror, and a pair of light sources 6, which are part of the intraocular pressure measuring device arranged sequentially on the optical axis o3. 6 is arranged so that the center thereof is located on the optical axis 03.

Here, the concave mirror 5 is placed at the focal point f2 of the condenser lens 4, and the light source 6 is placed at a position with a radius of curvature r2 of the concave mirror 5.

A cylinder 7 constituting the intraocular pressure measuring device is arranged obliquely to the optical axis 03, and the condenser lens 4 is fitted into a part of the cylinder 7. A nozzle 4a passes through the center of the condensing lens 4, and a piston 8 is installed inside the cylinder 7. The optical path portion 9 inserted into the alignment optical path of the cylinder 7 is formed of a transparent material so as not to interfere with the alignment light beam. When measuring the intraocular pressure, the piston 8 moves, and the air in the cylinder 7 is blown onto the eye E through the nozzle 4a of the condensing lens 4, so that the intraocular pressure can be measured.

When positioning is performed, the light beam emitted from the light source 6 passes through the concave mirror 5 and further passes through the optical path section 9 of the cylinder 7, and then is refracted by the condenser lens 4 and reaches the cornea of the eye E to be examined. The light is then reflected by the cornea, refracted by the condensing lens 4, reflected by the concave mirror 5, and further converted into a parallel beam by the condensing lens 4.

At this time, if the emmetropic eye without accommodation sees the corneal reflection image opposed by the concave mirror 5 of the light fIA6, then the light source 6
Since the light beam from the eye should have reached the retina, a parallel light beam is incident on the cornea of the eye E. Therefore, the concave mirror 5 is arranged at the focal position f2 of the condenser lens 4. Therefore, the corneal reflected image that enters the condenser lens 4 of the light source 6 as a parallel light beam is reflected by the concave mirror 5 located at the focal position f2 of the condenser lens 4, and becomes a parallel light beam again after entering the condenser lens 4. It will enter the cornea.

In order to obtain such a corneal reflected light flux, the corneal incident light flux must enter the focal position of the cornea, that is, in the direction toward the retina.
Considering the relationship between this and the light source image 4°, which does not actually form an image but can be considered to exist when considering the traveling state of the light beam, the concave mirror 5 is at the focal point of the condenser lens 4. Since the light source 6 is conjugate with the focal position of the cornea with respect to the condenser lens 4, the light beam passing through the concave mirror 5 will not be reflected or refracted and will proceed straight. Therefore, when the subject clearly sees the reflected image of his or her own cornea, the working distance WD also matches the predetermined distance.

FIG. 4 shows the field of view seen by the eye E in the third embodiment, and since the light sources 6 are arranged in pairs around the optical axis 03, the alignment and operating pressure gIWD are appropriate. If there is, the subject's eye will clearly see light source images 6' on the left and right sides of the nozzle 4a, as shown in FIG. 4(a). However, even if the working distance WD is appropriate, if the alignment is incomplete, two clear light source images of 4° will be seen at positions eccentric from the nozzle 4a, as shown in FIG. 4(b). .

In addition, when the alignment is appropriate but the working distance WD is incomplete, the light source image 4 is
° appears blurred to the left and right of the nozzle 4a. Furthermore, if both the alignment and the working distance WD are imperfect, it goes without saying that the blurred light source image 4° will appear at an eccentric position. Accurate alignment can be performed by moving the self-eye until it appears as shown.

Note that also in the third embodiment, f is added to the formula of the working distance WD.
As can be seen from the inclusion of e, the working distance differs slightly depending on the subject's diopter, as in the first and second embodiments, but this also has little effect on the measured value. Regarding the position of the reflective optical system in this third embodiment, if it is a convex mirror, its position may be between the position of the concave mirror 5 shown in the figure and the condensing lens 4. If a concave mirror is used, it may be placed between the illustrated concave mirror 5 and the light source 6. However, in that case, it is necessary to use a curved mirror with a curvature adapted to the spread angle of the reflected light beam at that position. Become. Furthermore, when a reflective optical system is disposed between the eye E and the condensing lens 4, a plane mirror can be used.

Although the above-mentioned embodiment has been described in the case where it is applied to a non-contact tonometer and a refractometer, similarly accurate positioning can be achieved in other ophthalmic instruments by simply incorporating the positioning device of the above-mentioned embodiment. be able to. When matching the alignment optical path at this time with the measurement optical path of other ophthalmological equipment, use reflective optical systems depending on the wavelength.
It is also conceivable to adopt means such as branching and separating the measurement light and the alignment light.

[Effects of the Invention] As explained above, the self-eye positioning device according to the present invention has a reflective optical system on the optical axis of the device that is aligned with the axis of the ophthalmological equipment, and the self-eye alignment device according to the present invention has a reflective optical system on the optical axis of the device that is aligned with the axis of the ophthalmological equipment, and the self-eye alignment device according to the present invention has a reflective optical system on the optical axis of the device that is aligned with the axis of the ophthalmological equipment. By adjusting the focus and position of the corneal reflection image, etc.,
Since the examinee himself/herself can easily and highly accurately align his/her own eyes, the present invention can be usefully applied to ophthalmological equipment operated by the examinee himself/herself.

[Brief explanation of drawings]

The drawings show an embodiment of the self-eye alignment device according to the present invention, and FIGS.
, a configuration diagram of the second and third embodiments, and FIG. 4 is an explanatory diagram of the state of the subject's visual field in the third embodiment, where (a) is when the alignment is appropriate, (b) is (C) is a case where only the working distance is appropriate, and (C) is a case where only the alignment is appropriate. 1.2 is a concave mirror, 3 is an objective lens, 4 is a condensing lens, 5 is a concave mirror, 6 is a light source, 7 is a cylinder, and 8 is a piston. Patent applicant Canon Co., Ltd. Figure 1

Claims (1)

[Claims] 1. A reflective optical system is provided so that when the eye to be examined is located at a predetermined working distance of the ophthalmological equipment, the light emitted from the anterior segment of the eye to be examined returns to the eye as a substantially parallel beam. A self-eye positioning device characterized in that the self-eye positioning device is arranged in front of the eye to be examined so as to be aligned with the optical axis of the ophthalmological equipment. 2. The self-eye alignment device according to claim 1, wherein the reflective optical system is a half mirror. 3. The self-eye positioning device according to claim 1, wherein the reflective optical system is a concave mirror, and the eye image reflected by the reflective optical system is visually recognized by the eye to be examined. 4. The self-eye positioning device according to claim 1, wherein the reflective optical system is a convex mirror, and a target light source for forming a corneal reflection image of the eye to be examined is arranged behind the convex mirror. . 5. The self-eye alignment device according to claim 4, wherein the optotype light sources are a pair, the center of which is located on the optical axis.