JP2665511B2 - Interpupillary distance detecting apparatus and ophthalmic apparatus using the same - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eye width detecting device incorporated in various types of ophthalmic machines such as an auto-refractometer and an ophthalmic device using the same.

[Prior Art] Conventionally, a device using a potentiometer has been widely put into practical use as an interpupillary distance detecting device incorporated in an auto-refractometer or the like.

FIG. 8 shows a main part of a conventional example using this potentiometer, and shows a cross section along a sliding shaft 3 for sliding a machine main body 2 on a base 1 in the interpupillary direction of an eye to be examined. Sliding shaft 3
At both ends of the toothed wheel 4 that rotates in the direction of approaching and leaving the eye to be examined
a and 4b are attached, and a block 6 is slidably fitted to a guide shaft 5 provided on the machine main body 2.
The pin 6a projecting downward is movable in the front-rear direction along the guide groove 1a provided in the base 1. A wire 8 is wound between the pulley 7a attached to the block 6 and the pulleys 7b and 7c attached to the machine main body 2 side. The pulley 7c of the potentiometer 9 is rotated by the wire 8 The movement in the direction is detected as a change in the output of a resistor connected to the potentiometer 9.

[Problems to be Solved by the Invention] However, the conventional example having such a configuration has the following disadvantages.

(1) The block 6 needs many separate members such as the guide shaft 5 to detect only the amount of movement in the left-right direction corresponding to the interpupillary distance from the sliding of the machine body 2 in the front-rear direction and the left-right direction. Complexity and cost increase.

(2) Since the wire 8 easily slides on the pulleys 7a, 7b, 7c, the reference value of the potentiometer 9 may be shifted.

(3) Since the mechanical connection is used for the detection, there is a concern that abrasion, friction noise, generation of unnecessary contact feeling, and the like may occur.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks of the conventional example, and to provide an eye width detecting apparatus using an optical detection system without using any mechanical mechanism and an ophthalmologic apparatus using the same.

[Means for Solving the Problems] In an interpupillary distance detecting apparatus according to the present invention for achieving the above object, a mechanism for moving a machine main body in the left-right eye direction, and the apparatus main body includes a left-right eye of a subject And a detecting means for optically detecting the movement between the opposing faces, and measuring the interpupillary distance based on the detection result of the detecting means.

Further, in the ophthalmologic apparatus according to the present invention, in the ophthalmologic apparatus for moving the apparatus main body in the left-right direction of the subject and measuring the subject's eye, the main body faces the left and right eyes of the subject, respectively. And a calculating means for obtaining the interpupillary distance of the subject based on the detection result obtained by the detecting means.

[Operation] The interpupillary distance detecting device having the above-described configuration and the ophthalmologic apparatus using the same can detect the interpupillary distance between the left and right eyes of the subject without requiring an extra mechanical mechanism. It is structurally easier and eliminates problems caused by mechanical mechanisms.

Embodiment The present invention will be described in detail based on an embodiment shown in FIGS.

FIG. 1 shows a schematic view of, for example, an eye refractometer incorporating an interpupillary distance detecting device according to the present invention, in which a sliding guide portion 12 slidable back and forth and left and right within a certain range on a base 11 is provided. A movable base 13 slidable left and right within a certain range is provided on the sliding guide part 12, and a sliding base 14 is configured by these. A machine main body 15 is mounted on the slide base 14, an objective lens barrel 16 is provided at a front portion of the machine main body 15, a television monitor 17 is provided at a rear portion, and an arithmetic processing means 18 is built therein. Also, movable table
An operation rod 19 is attached to 13, an upper and lower ring 20 is provided rotatably at the base of the operation rod 19, and a measurement switch is provided at the upper end.
21 are provided respectively. Then, the machine main body 15 on the slide table 14 can be slid in a desired direction by tilting the operation rod 19 in an arbitrary direction, and the height of the machine main body 15 can be freely adjusted by turning the upper and lower rings 20. I can do it. Further, on the subject P side of the base 11, a face fixing base 22 to which a chin rest 22 a and a forehead rest 22 b are attached in order to support the face of the subject P is provided.

The examiner observes the television monitor 17 so that the optical axis of the objective lens barrel 16 of the machine body 15 is correctly aligned with the eye E fixed at a fixed position by the face fixing base 22 and has an appropriate working distance. The alignment is adjusted by operating the operating rod 19 and the upper and lower rings 20 while doing so. When the measurement switch 21 is pressed after the alignment is adjusted, the refraction value of the eye to be inspected is automatically calculated by the arithmetic processing means 18, and the result is displayed on the television monitor 17 or printed by a printer.

FIG. 2 shows an embodiment of the interpupillary distance detecting means incorporated in the slide table 14, and the left-right direction is the left-right sliding direction of the slide table 14,
The vertical direction is the front-back sliding direction. A small light source body 31 composed of a light emitting diode or the like is attached to the sliding guide portion 12, and a pinhole plate 32 provided with a pinhole 32a and a CCD (Charge C)
oupled Device (PSD) element or PSD (Position Sensitive D)
evice) The light position detecting element 33 including an element
, The small light source 31 and the pinhole 32a
Are separated by an interval L in the front-rear direction and by W in the left-right direction.
The light from the small light source 31 passes through the pinhole 32a and is projected from the pinhole plate 32 onto the light position detecting element 33 on the right by the interval D. When the slide 14 slides left and right, the distance between the small light source body 31 and the pinhole 32a changes, and this change is caused by the position of the projected image on the light position detecting element 33 as shown in the enlarged view of the main part in FIG. 1 is detected as a change. As shown in the principle diagram of FIG. 4, the projected image position l of the small light source 31 on the light position detecting element 33
And the amount of lateral sliding W of the machine body 15 with respect to the base 11 has the following proportional relationship.

l: L = D: W From this proportional relationship, the lateral sliding amount W can be obtained as follows.

W = D · L / l In the above configuration, the slide base 14 is slid so as to face the left and right eyes of the eye E to be inspected, and the projected image of the small light source 31 on the light position detecting element 33 for each eye. The position l is detected, the actual left / right sliding amount W corresponding to each eye is obtained by the arithmetic processing means 18, and the absolute value of the difference is used as the interpupillary distance.

In the embodiment shown in FIG. 5, the small light source body 31 is a pinhole plate.
Provided on the movable base 13 side similarly to 32 and the optical position detection element 33,
A light shielding plate 41 for preventing light from the small light source body 31 from being directly detected by the light position detection element 33 is provided, and a reflector 42 having a reflection surface 42a is attached to the sliding guide portion 12. As shown in the principle diagram of FIG.
The distance a is a distance L 'in the front-rear direction and the distance W is a distance W in the left-right direction from the reflection surface 42a, and has the same proportional relationship as in the previous embodiment.

l: L '/ 2 = D: W From this proportional relationship, the lateral sliding amount W can be obtained as follows.

W = D · L ′ / 2l Further, the electrical connection between the small light source body 31 and the light position detecting element 33 can be integrated on the movable base 13 side, which is effective in improving workability and durability. In addition, the reflection surface 42a may be a convex curved surface or a cylindrical surface having an axis in the front-rear direction, in addition to the flat surface,
In these cases, the resolution of the light position detecting element 33 is not required as compared with the case where the reflection surface 42a is a flat surface.

The embodiment shown in FIG. 7 is a modification of the embodiment shown in FIG. 5, in which a projection lens 43 is provided between a small light source 31 and a reflector 42, and a pinhole plate having a pinhole 32a is provided. An imaging lens 44 is provided instead of 32. Each lens
If the reflection surface 42a and the light position detecting element 33 are provided at the focal positions of 43 and 44, blurring of the image of the small light source body 31 on the light position detecting element 33 can be prevented, and more precise measurement can be performed. In this embodiment, the members attached to the sliding guide portion 12 and the movable base 13 may be exchanged, and when the reflection surface 42a is a plane in the front-rear direction, the reflector 42 is attached to the base 11. You may.

[Effects of the Invention] As described above, according to the interpupillary distance detecting apparatus and the ophthalmologic apparatus using the same, the interpupillary distance measurement can be performed without adding an extra mechanical mechanism. The cost can be reduced, and detection can be performed without problems such as abrasion due to friction, friction noise, unnecessary contact, and the like, and there is an advantage in durability of the detection element.

[Brief description of the drawings]

1 to 7 show an embodiment of an interpupillary distance detecting device according to the present invention and an ophthalmologic apparatus using the same. FIG. 1 is a schematic diagram of an eye refractometer incorporating the interpupillary distance detecting device. 2 is a configuration diagram, FIG. 3 is an enlarged view of a main part, FIG. 4 is a principle diagram, FIG. 5 is a configuration diagram according to another embodiment, FIG. 6 is a principle diagram, and FIG. 7 is still another embodiment. FIG. 8 is a block diagram of a conventional example. Reference numeral 11 is a base, 12 is a sliding guide, 13 is a movable table, 14 is a sliding table, 15 is a machine body, 16 is an objective lens barrel, 17 is a television monitor,
31 is a small light source, 32 is a pinhole plate, 32a is a pinhole, 3
3 is an optical position detecting element, 41 is a light shielding plate, 42 is a reflector, 42a is a reflecting surface, 43 is a projection lens, and 44 is an imaging lens.

Claims (2)

(57) [Claims] 1. A mechanism for moving a machine body in the left and right eye directions, and a detecting means for optically detecting movement of the apparatus body in opposition to the left and right eyes of a subject. An interpupillary distance detecting device that performs interpupillary distance measurement based on a detection result. 2. The apparatus body is moved in the left and right eye directions of the subject,
In an ophthalmologic apparatus for measuring a subject's eye, detection means for optically detecting movement of the apparatus body while facing the left and right eyes of the subject, and a detection result obtained by the detection means. An ophthalmologic apparatus, comprising: a calculating unit for calculating the eye width of the subject based on the calculation result.