JPH0332637A - Handy eye refractometer - Google Patents

Abstract

PURPOSE:To make the constitution simple and light in weight and to instantaneously perform the alignment and the measurement of a refraction value by executing roughly the alignment through a split member, and subsequently, executing exactly the alignment, while looking at a display means. CONSTITUTION:On an optical path P1 extending from a measuring light source 3 to an eye E to be examined, a hole opening mirror 6 and a dichroic mirror 9 are provided together with other lens, etc. On an optical axis P2 in which a reflected light for the eye to be examined is reflected by an optical split mirror 7, a photoelectric sensor 10 is provided, and on an optical axis P3 reflected by the hole opening mirror, a photoelectric sensor 15 is placed. Also, on the extension of the optical path of the eye to be examined and the dichroic mirror, a fixed target 16 is provided. In this regard, the dichroic mirror reflects a near infrared ray for the alignment and the measurement, and allows a visible light to transmit through. Also, outputs of both the photoelectric sensors are connected to a control part 17, and an output of the control part is connected to the measuring light source. In such a way, when a relative position to a device for the eye to be examined is detected through the dichroic mirror and the alignment is executed, while looking at a position display, the sensor detects it and a refraction value can be measured instantaneously.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a hand-held eye refractometer used, for example, in eye clinics.

[Prior Art] Conventional autorefractometers are known to have a fixation target inside, for example, or to have a fixation target located far outside. The refraction value is measured after automatic alignment is performed with the subject fixating on the fixation target, and even if the subject's eye moves during adjustment guidance for automatic alignment, it is followed and positioned. It has a complicated mechanism for matching.

[Problems to be Solved by the Invention] However, a typical autorefractometer has a complicated structure and is heavy, as in the conventional example described above, and therefore cannot be hand-held and cannot be easily used.

The object of the present invention is to provide a hand-held eye refractometer that eliminates the drawbacks of the conventional example described above, that can perform instantaneous alignment and refraction value measurement, has a simple and lightweight configuration, and can be held and used easily. Our goal is to provide the following.

[Means for Solving the Problems] In order to achieve the above object, one feature of the hand-held eye refractometer according to the present invention is to perform measurements with the subject fixating on a fixation target located far away. In a hand-held eye refractometer, the optical member is placed in front of the eye to be examined and separates visible light and infrared light, a position detection means for detecting the relative position of the eye to be examined with respect to the main body of the device, and the position detection means and a refraction value measuring means that automatically starts measuring a refraction value in response to a matching signal from the position detection means.

[Operation 1] The hand-held eye refractometer with the above configuration detects the relative position of the eye to be examined with respect to the main body of the device, and when the examiner moves the eye while observing the position display to perform alignment, this alignment is performed. The refraction value is measured by detecting that this has been done.

[Example] The present invention will be explained in detail based on illustrated embodiments.

FIG. 1 shows a configuration diagram in which a hand-held eye refractometer according to the first embodiment is brought into contact with the face of a subject S. On the optical path Pi from the measurement light source 3 to the eye E to be examined inside the apparatus main body l for zero position alignment and refraction value measurement, in which the alignment part 2 is provided, there are lenses 4, 4, As shown in FIG. 2, a central aperture diaphragm 5. has a central aperture 5a. A perforated mirror 6, a light splitting mirror 7, a lens 8, and a dichroic mirror 9 are provided. On the optical axis P2 in the direction in which the reflected light from the eye E is reflected by the light splitting mirror 7, there are five sensor elements 10a to 10e as shown in FIG. sensor elements 10b-10e
A photoelectric sensor 10 is provided. Also,
As shown in FIG.
It is attached to the outside of the device main body 1 so that the examiner can observe it. On the optical axis P3 in the direction in which the reflected light from the eye E is reflected by the perforated mirror 6, there is a six-hole diaphragm 12 having openings 12a to 12f as shown in FIG. lens 1
3. As shown in FIG. 6, six wedge prisms 14a~
Separating prism 14.14 consisting of 14f. Photoelectric sensor 1
5 is placed. In addition, the dichroic mirror 9 is placed on the extension of the optical path connecting the eye E to be examined and the dichroic mirror 9.
A fixation target 16 is provided behind the. Note that the dichroic mirror 9 has a property of reflecting near-infrared light used for alignment and measurement, and transmitting visible light irradiated onto the fixation target 16. Further, 17 is a control unit, and the output of the photoelectric sensor 1O115 is connected to the control unit 17.
The output of the control section 17 is connected to the measurement light source 3.

When measuring the refraction value, the examiner holds the main body of the device L in his hand and points the protrusion 2 on the face of the patient S below the eye to be examined so that the optical axis P4 coincides with the optical axis of one eye of the eye E. While looking at the subject's eye E through the dichroic mirror 9, the subject S
to fixate the fixation target 16 via the dichroic mirror 9.

The light beam from the measurement light source 3 passes through the lens 4, the central aperture 5, the perforated mirror 6, the light splitting mirror 7, and the lens 8, and is reflected by the optical mirror 9 in the direction of the eye E to be examined, reaching the eye E. The light beam from the corneal reflected image returns along the same optical path, and the light beam reflected by the light splitting mirror 7 is projected onto the photoelectric sensor 10. In addition, the fundus reflected light reflected by the fundus Er passes through a light splitting mirror 7 and a perforated mirror 6.
After passing through the aperture 12 and the lens 13, the separation prism 14
After being deflected in a direction separating from the optical axis P3, six fundus reflected lights are projected onto the photoelectric sensor 15 as shown in FIG.

During alignment, the sensor element 10a of the photoelectric sensor 10
When an amount of light equal to or greater than a preset threshold value is received in ~10e, the corresponding LEDlla-1ie connected to each of the sensor elements 10a-10e that received the light lights up. The LEDs 11a to 11e are set to light up when the amount of incident light is large. Then, when the corneal reflected light beam is received by the sensor element 10a at the center of the photoelectric sensor 10, it is detected that the alignment is completed.

Once the alignment is completed, the measurement light source 3 is turned on in response to a command from the control unit 17, and the process is completed in several tens of milliseconds until the fundus reflected light beam for measuring the refraction value is received on the photoelectric sensor 15. Since the subject S is fixating on the distant fixation target 16,
There is no need to guide accommodation of the eye E when alignment is completed and refractive value measurement is started.

Note that methods for measuring refraction values may be considered other than the above-mentioned embodiments, but in the above-mentioned embodiments, information on each meridian is taken in at the same time, and since it is not affected by the movement of the eye E to be examined, highly accurate measurement can be performed. Further, the protrusion 2 is brought into contact with the face of the subject S below the eye E to be examined, but this is because the difference between races and the like is smaller below the eye E to be examined than above it.

FIG. 8 shows a configuration diagram of the second embodiment, and the optical path p in FIG.
Gicroic mirror 1 instead of light splitting mirror 7 on t
8 is provided, and the optical axis P2L in the direction reflected by the gicroic mirror 18 is the lens 1 made of a concave lens.
9. separation prism 20 consisting of two wedge prisms;
The mirror 21 is offset by jQ, and a dichroic mirror 22 is provided on the optical axis P3 to guide the light beam reflected by the mirror 21 to the photoelectric sensor 15. In addition, a positioning light source 23 for positioning is provided on an optical path P near the lens 8.
This positioning light source 23 is provided apart from I.
The wavelength of the light beam from the measuring light source 3 is different from the wavelength of the light beam from the measurement light source 3, and the gicroic mirror 18 and the dichroic mirror 22 are designed to be able to distinguish these wavelengths.

The light beam from the positioning light source 23 is reflected by the guichroic mirror 9 and reaches the eye E, and the corneal reflected light beam returns along the same optical path and passes through the lens 8 to the guichroic mirror 1.
8, is separated from the optical axis Pl by the separation prism 20 through the lens 19, is further reflected by the mirror 21 and the dichroic mirror 22, and is detected on the photoelectric sensor 15 as shown in FIG. Reflection image Eo and corneal reflection image E
c” is received.

The light beam from the measurement light source 3 when measuring the refraction value is transmitted through the lens 4,
Center aperture 5. Hole mirror 6, Guicroic mirror 18. Lens 8, Guikroi.

The light beam reflected from the fundus reaches the fundus of the subject's eye E via the mirror 9, returns along the same optical path Pl, is reflected by the perforated mirror 6, and is reflected by the perforated mirror 6.
The light passes through the aperture 12, the lens 13, the separation prism 14, the guichroic mirror 22, and is received by the photoelectric sensor 15.

Note that when the 1-separation prism 20 is not used, the anterior segment reflection image Eo is received on the photoelectric sensor 15, so this may be displayed on a liquid crystal display element or the like for positioning. Since fi'Ec' has a particularly large amount of light, the position of this corneal reflected image Ec' can be detected by setting a threshold value. The misalignment in the optical axis direction is detected from the interval between these two corneal reflection images Ec', and the corneal reflection image E
Positioning is performed by detecting misalignment in a plane perpendicular to the optical axis from position c''. Once this positioning is achieved, refraction value measurement is performed in the same manner as in the previous embodiment.

[Effects of the Invention] As explained above, the hand-held eye refractometer according to the present invention can perform approximate positioning through the one-piece member, and more precisely, can perform positioning while moving the display means q. Measurement starts instantly when the values match, making it easy to carry it by hand.

[Brief explanation of drawings]

The drawings show an embodiment of the hand-held eye refractometer according to the present invention, and the first
The figure shows the configuration of the first embodiment, Figure 2 is a front view of the central aperture diaphragm, Figure 3 is a front view of the photoelectric sensor, Figure 4 is a front view of the monitor, and Figure 5 is the front view of the 6-hole diaphragm. Figure 6 is a front view of the separation prism, Figure 7 is an explanatory diagram of the fundus reflected image on the photoelectric sensor, Figure 8 is a configuration diagram of the second embodiment, and Figure 9 is the reflected image of the photoelectric sensor F. FIG. Symbol l is the main body of the device, 3 is the measurement light source, 6 is the perforated mirror,
Reference numerals 9, 18, and 22 designate a guichroic mirror, 10.15 a photoelectric sensor, 11 an LED, 16 a fixation target, 17 a control unit, and 23 a positioning light source.

Claims (1)

[Claims] 1. In a hand-held eye refractometer that performs measurements with the subject fixating on a fixation target set far away, a dividing member is placed in front of the subject's eye to separate visible light and infrared light. , a position detection means for detecting the relative position of the eye to be examined with respect to the main body of the device;
A hand-held eye refractor comprising: a display means for displaying a position detected by the position detecting means; and a refractive value measuring means for automatically starting measurement of a refractive value in response to a matching signal from the position detecting means. Total.