JPH10337276A - Optometry device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable alignment to be achieved easily and accurately at a position away from a subject. SOLUTION: Measurements are taken with the subject watching a fixation target provided far outside, and rectangular beams 15R, 15L provided by two projection optical systems are projected onto the upper and lower parts of the anterior eye part. An image of the anterior eye part and an alignment mark A are displayed on a display means 17, and an examinant adjusts the operating distance by making the beams 15R, 15L coincident in horizontal direction and adjusts the optical axis by aligning the pupil P with the alignment mark A. Signals of scanning lines S from an image pickup means are taken one by one into a computing means, which in turn computes the degree of coincidence of the beams 15R, 15L and the position of the pupil P.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optometric apparatus such as an auto-refractometer belonging to the optical optics technique or the optometric machine technique.

[0002]

[Prior art]

(1) Conventionally, the auto-refractometer has a short working distance,
The measurement must be performed with the face fixed on the face cradle. For example, JP-A-49-78391 discloses a technique of projecting a semi-circular light beam from both sides of a measurement optical axis.

(2) Further, in order to eliminate the influence of disturbance light on the measurement, a conventional auto-refractometer is provided with a filter that transmits only the measurement light wavelength in the measurement light path, or a shutter in another light path to the measurement sensor. Or is provided.
In addition, measurements are taken by covering the device around or turning off the light.

(3) In addition, a device based on the principle of photofraction is used for measuring the refraction of the eye of a baby, and the measurement is performed by showing a target provided on a device about 1 m away.
Further, when a refraction measurement is performed with a fixation target placed at a distant outside, a target that does not change is used.

[0005]

[Problems to be solved by the invention]

(B) However, in the above-mentioned conventional example (1), the face cradle cannot be used when refraction measurement of infants is performed, and JP-A-49-78391 does not have a detection optical system. There is a point.

(B) In the above conventional example (2),
There is a problem that the structure of the device becomes complicated to block the disturbance light, and it is particularly difficult to cut off the reflected light from the anterior segment of the subject's eye.

(C) In the above-mentioned conventional example (3), there is a problem that the fixation of the infant cannot be reliably performed even if the invariant optotype placed far away from the outside is used.

A first object of the present invention is to solve the above-mentioned problem (a).
It is an object of the present invention to provide an optometric apparatus that can easily and accurately perform positioning at a position away from a subject.

A second object of the present invention is to solve the above problem (b).
It is an object of the present invention to provide an optometry apparatus in which disturbance light reflected on the anterior segment of the eye to be examined does not mix with the photoelectric array sensor.

A third object of the present invention is to solve the above problem (c).
It is therefore an object of the present invention to provide an optometry apparatus which can reliably fixate when a refraction measurement is performed with a fixation target placed outside at a distance.

[0011]

According to the present invention, there is provided an optometry apparatus for projecting a light beam onto an eye to be inspected to measure an optometry, and an optometry apparatus tilted with respect to an optical axis of the optometry apparatus. Projection means for projecting an infrared light beam to the anterior segment of the eye to be examined from the set direction, illumination means for illuminating the pupil of the eye with the infrared light beam, imaging means and display means for imaging the anterior segment of the eye to be examined Wherein the position of the infrared light beam and the position of the pupil are detected by a signal from the imaging means.

In an optometry apparatus according to the present invention, an optometry apparatus which projects a light beam from a light source to an eye to be inspected, receives reflected light from the eye to be inspected by an array sensor, and measures the optometry. The signal of the array sensor is fetched into a memory without turning on the light source, and a difference from when the light source is turned on is calculated to perform optometry.

An optometry apparatus according to the present invention includes a fixation target that temporarily emits light or sound by a remote control;
An optometric measurement means for projecting a light beam to the eye to be inspected, detecting reflected light, and measuring the optometry.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the illustrated embodiment. FIG. 1 shows a side view of the hand-held eye refractometer of the embodiment, and the distance from the eye E to the apparatus housing 1 is about 5 mm.
Since the measurement is possible at 0 cm without fixing the face, it can be used for infants. A dichroic mirror 2, a lens 3, a dichroic mirror 4, and an imaging unit 5 having an area array sensor as an imaging element are sequentially arranged on the horizontal optical path O1 of the eye E in the apparatus housing 1.
A lens 6, a mirror 7, a light splitting member 8 conjugate to the pupil P, and a mirror 9 are arranged on an optical path O2 in the reflection direction of the dichroic mirror 2, and the optical path in the reflection direction of the mirror 9 reaches the dichroic mirror 4. The light splitting member 8 includes a central mirror portion 8a and a peripheral portion 8b having a six-hole opening, and a lens 1 is disposed on an optical path O3 in the reflection direction of the central mirror portion 8a.
0, a stop 11 conjugate to the fundus of the standard eye, and a refraction measurement light source 12 composed of an infrared LED are arranged.

A lens 13, an aperture plate 14 having a rectangular opening, and a wavelength different from that of the light source 12 for refraction measurement are emitted on two right and left optical paths O 4 inclined at 7 to 8 degrees to the horizontal optical path O 1 for measurement and imaging. The projection optical system illumination light sources 15 each composed of an infrared LED are arranged to form a projection optical system.

As shown in FIG. 2, an optical path O1
An opening 21 for the measurement optical system is provided in the direction, and two openings 22L and 22R for the projection optical system are provided in the direction of the optical path O4. A measurement switch 16 for emitting a measurement start signal is provided on the lower part of the front surface of the housing 1, a display means 17 such as a liquid crystal monitor is provided on the back surface, and a fixation target arranged about 5 m outside the housing 1 is activated. The light source 18 for generating an optical signal is disposed.

The outputs of the imaging means 5 and the measuring switch 16 are connected to a calculating means 19, and the outputs of the calculating means 19 are connected to a display means 17, a light signal generating light source 18 and a memory 20, respectively. The output of the imaging means 5 is stored in the memory 20.
The output of the memory 20 is connected to the display means 17.

The measurement is performed in a state in which the subject is looking at a fixation target provided far away from the outside from the side of the housing 1. In the two left and right projection optical systems, the light beam from the illumination light source 15 is incident on the aperture plate 14, and the rectangular aperture images are projected by the lens 13 as rectangular light beams 15L and 15R above and below the anterior segment of the eye E to be examined. As shown in FIG. 3, this rectangular light flux 15L,
15R coincides laterally at a predetermined working distance.

The projection optical system also serves as an anterior segment illuminating device for imaging the anterior segment image on the imaging unit 5, and the anterior segment image passes through dichroic mirrors 2 and 4 and passes through the lens 3 to the imaging unit 5. And the display means 17 as shown in FIG.
Will be displayed. The alignment mark A generated by the character is also displayed at the center of the position corresponding to the optical axis of the display means 17, and the examiner looks at the image on the display means 17 and matches the lateral directions of the light beams 15L and 15R by the projection optical system. Then, the working distance is adjusted, and the pupil P is aligned with the alignment mark A to adjust the optical axis. Then, the signal of the scanning line S of the image pickup means 5 is sequentially taken into the calculation means 19, and the light flux 1
The degree of matching between 5L and 15R and the position of the pupil P are calculated.

The selected two scanning lines S of the image pickup means 5 are symmetrical with respect to the optical path O1, and when the alignment is made, the four intersections of the scanning line S and the pupil P are located symmetrically with respect to the optical path O1. come. At this time, since the reflected light from the fundus due to the light flux of the projection optical system does not enter the optical path O1, the inside of the pupil P appears dark. On the other hand, the iris is bright because it is illuminated by infrared light. At this time, the position of the pupil P is recognized by calculating the difference in level between the pupil and the iris from the signal of the scanning line S. A measurement start signal is issued when alignment with a predetermined distance is achieved,
Start refraction measurement automatically.

The light beam from the refraction measuring light source 12 is
By 0, an image is formed on the central mirror portion 8a of the light dividing member 8, and is projected from the center of the pupil P of the eye E as a spot light beam onto the fundus via the lens 6 and the dichroic mirror 2. The light reflected from the fundus returns along the same optical path, and the light splitting member 8
The light is separated into six light beams through the six-hole opening in the peripheral portion 8b of the light source, reflected by the dichroic mirror 4, and received by the imaging means 5 as six light beams B as shown in FIG. The signal of the image pickup means 5 is taken into the memory 20, and the position of each light beam B is recognized by the calculation of the calculation means 19 to calculate the refraction value. It should be noted that when the measurement switch 16 is pressed, a measurement start signal is also issued and refraction measurement can be performed.

The projection optical system may be provided on one side without being provided on both the left and right sides. In this case, the light beam 15L or 15R is projected from one side. Then, the horizontal position is detected at the position of the intersection of the scanning lines S, and if the position is a predetermined position, it is assumed that the distance is matched. In the case of visual observation by the display means 17, the distance is adjusted so that the light flux is symmetrical in the lateral direction with respect to the pupil P or the iris. The pupil illumination optical system and the distance matching light beam projection optical system may be different.

The light signal generating light source 18 emits a light signal toward the fixation target in response to the measurement start signal. The fixation target is, for example, a stuffed cat or the like, and if the fixation target is provided with a light receiving portion for an optical signal and a sound generating portion for emitting the cat's singing for about 10 seconds, the sound is output so that even infants can be sure. The fixation target can be seen at the same time. The time of 10 seconds is enough time to perform the measurement without distracting the infant. It should be noted that light may be used instead of sound, or the light may be moved.

The light source 18 for generating an optical signal may be provided separately from the housing 1 and operated by a foot switch. Since the space between the apparatus housing 1 and the subject's eye E is vacant, there is a possibility that room illumination light hits the anterior eye, and the illumination light is reflected on the cornea and enters the imaging unit 5. In order to eliminate this effect, an image when the light source 12 is not turned on is stored in the memory 20 immediately before or immediately after the light source 12 is turned on.
To calculate the difference from the image at the time of lighting.

That is, FIG. 5 shows an image captured by turning on the light source 12 for refraction measurement and captured by the image pickup means 5. The spot image of the six light beams B and the disturbance light F are reflected. difficult. FIG. 6 is an image captured without turning on the light source 12 for refraction measurement, in which only disturbance light F is shown.
By taking the difference between the two, the disturbance light F is removed as shown in FIG. Therefore, even if the disturbance light F is reflected from the anterior segment, the position of the light flux B of the refraction measurement light source 12 can be recognized with high accuracy, and the measurement accuracy is improved.

Although the above description has been made taking an auto-refractometer as an example, the present invention can be similarly applied to other optometers such as an auto-keratometer.

[0027]

The optometry apparatus according to the first aspect of the present invention performs the alignment using the infrared light flux of the imaging means and the signal of the position of the pupil, so that the optometry apparatus can be easily and accurately positioned away from the subject. Positioning can be performed.

An optometric apparatus according to a fourth aspect of the present invention calculates a difference between a signal when the light source is turned on and a signal when the light source is turned off, so that even if there is reflection of disturbance light from the anterior ocular segment, The position of the image can be accurately recognized, and the measurement accuracy is improved.

In the optometry apparatus according to the fifth aspect of the present invention, by arranging a fixation target which temporarily emits light or sound, the distant fixation target can be reliably visually recognized by the subject, and the accuracy is high. Refraction measurements can be made.

[Brief description of the drawings]

FIG. 1 is a side view of an optometry apparatus according to an embodiment.

FIG. 2 is a front view of the optometry apparatus.

FIG. 3 is a front view of the display means.

FIG. 4 is an explanatory diagram of a light beam on an imaging unit.

FIG. 5 is an explanatory diagram of a light beam on an imaging unit.

FIG. 6 is an explanatory diagram of a light beam on an imaging unit.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 housing 2, 4 dichroic mirror 5 imaging means 8 light splitting member 12 light source for refraction measurement 14 aperture plate 15 light source for projection optical system 16 display means 17 light signal generation light source 18 measurement switch 19 arithmetic means 20 memory

Claims (6)

[Claims] 1. An optometry unit that projects a light beam onto an eye to be examined and measures the optometry, and a projection unit that projects an infrared light beam onto an anterior eye of the eye from a direction inclined with respect to the optical axis of the optometry unit. Illuminating means for illuminating the pupil of the eye to be inspected with an infrared light beam; imaging means and display means for imaging the anterior segment of the eye to be inspected; wherein the position of the infrared light beam and the position of the pupil are determined by a signal from the imaging means. An optometry apparatus for performing alignment detection. 2. The optometry apparatus according to claim 1, wherein the projection unit also serves as the illumination unit. 3. The optometric apparatus according to claim 1, wherein the optometric measurement is automatically started by the alignment detection. 4. An optometry apparatus for projecting a light beam from a light source to an eye to be examined and receiving reflected light from the eye to an array sensor to measure an optometry, without turning on the light source before or after a measurement start signal. An optometric apparatus, wherein a signal from the array sensor is fetched into a memory, and a difference from when the light source is turned on is calculated to perform optometric measurement. 5. An optometry comprising: a fixation target that temporarily emits light or sound by a remote control; and an optometry measurement unit that projects a light beam to the subject's eye, detects reflected light, and measures the optometry. apparatus. 6. The optometry apparatus according to claim 5, wherein the fixation target emits light or sound in accordance with a measurement start signal.