JPH04150828A - Target projection type view measuring apparatus - Google Patents

Abstract

PURPOSE:To enable more accurate projection of a target from a specified position of an internal surface of a dome by using a rotary encoder to detect an angle of rotation of a reflection mirror for target projection directly. CONSTITUTION:A motor 25 of a projection mechanism 4 rotates a reflection mirror 5 for target projection about a vertical shaft 26 and with a cylinder section 30 as rotating shaft, a cylinder section 31 supports a hemispherical rotary member 35 rotatable. The cylinder section 30 has a reference scale plate 67 at a part of a rotary encoder 68 and a light emitting element 69 is mounted on one side thereof while a slit array 71 and a detector array 72 on the other surface side thereof. An angle of rotation of the reflection mirror 5 for target projection is detected based on rotation. A reference scale plate 74 is provided at a part of an optical type rotary encoder 73 on a rotating shaft 41 of the rotary member 35 and a light emitting element 76 and a photo detector 77 are provided on a mounting plate 75 to detect an angle of horizontal rotation of the reflection mirror 5 for target projection.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an improvement in an optotype projection type visual field measuring device that measures a visual field by projecting an optotype spot onto the inner surface of a hemispherical dome that is a projection surface.

(Prior Art) Conventionally, an optotype projection type visual field measuring device is known that measures a visual field by projecting an optotype spot onto the inner surface of a hemispherical dome.

In this conventional optotype projection type visual field measurement device, a rotating member is rotatably supported by a support member, and the rotating member is provided with an optotype projection reflection mirror that reflects the optotype spot light toward the inner surface of the dome. It is being The rotating member is connected to a motor via a wire and a pulley, and is rotated about a horizontal axis by the motor. A potentiometer for detecting the rotation angle of the optotype projection reflection mirror around the horizontal axis is directly connected to the motor. Further, the support member is rotated about the vertical axis by another motor, and a potentiometer for detecting the rotation angle of the target projection reflection mirror about the vertical axis is directly connected to the other motor.

(Problem to be Solved by the Invention) However, in this conventional optotype projection type visual field measuring device, the rotation angle of the optotype projection reflecting mirror is indirectly detected by measuring the rotation angle of the motor using a potentiometer. This configuration does not directly detect the rotation angle of the optotype projection reflective mirror, so errors in the pulley wire component dimensions and installation errors may be mixed into the detection error of the rotation angle of the optotype projection reflective mirror. There is a drawback that the optotype cannot be accurately projected at a desired designated position on the inner surface of the dome.

In addition, since the potentiometer is directly connected to the output shaft of the motor, the motor must be selected taking into account the rotational resistance of the potentiometer, and a large melon motor must be used accordingly. .

The present invention has been made in view of the above circumstances, and is an optotype projection type visual field measurement method that allows the use of a small motor and allows the optotype to be more accurately projected at a specified position on the inner surface of the dome. The purpose is to provide equipment.

(Means for Solving the Problems) In order to solve the above-mentioned problems, an optotype projection type visual field measuring device according to the present invention is provided with an optotype projection reflective mirror for reflecting and projecting an optotype spot on a projection surface. A reference scale plate, which constitutes a part of a rotary encoder that detects the rotation angle of the reflection mirror for visual target projection, is provided on the rotation axis of the target, and a take-out part, which constitutes a part of the rotary encoder, is provided facing the reference scale plate. and a detection section.

(Function) According to the visual target projection type visual field measuring device according to the present invention, since the rotation angle of the reflective mirror for visual target projection is directly detected using the rotary encoder, the visual target can be designated on the inner surface of the dome. Projection can be made more accurately depending on the position.

In addition, since the rotation angle of the optotype projection reflection mirror is detected in a non-contact manner using a rotary encoder, the load on the motor can be reduced accordingly, allowing the use of a smaller motor. Become.

(Example) Hereinafter, an example of the visual target projection type visual field measuring device according to the present invention will be described with reference to the drawings.

In FIG. 6, reference numeral 1 indicates the main body of the visual field measurement device, 2 indicates a housing, and 3 indicates a hemispherical dome. Inside Dome 3,
71st! ! A projection mechanism 4 is provided as shown in II. A reflection mirror 5 for projecting an optotype is rotatably supported on the projection mechanism 4 . The details of the configuration of this projection mechanism 4 will be described later.

On the back side of the dome 3 and inside the housing 2, an optotype spot light emitting means 6 is provided. The optotype spot light emitting means 6 includes a light source 7, an aperture 8, and a liquid crystal filter 8.
, and a projection lens 10. The liquid crystal filter 9 plays the role of setting the brightness of the optotype spot light to a predetermined value, and is controlled by a liquid crystal filter driving means 11. The liquid crystal filter driving means 11 is 1111
It is connected to the fIJ means 12. This control means 12 stores in advance a sequence for a perimetry test, for example a procedure for a dynamic test or a static test. The control means 12 controls the liquid crystal filter driving means 11 and the projection mechanism 4 according to this sequence.
is controlled via servo means 13. LCD filter 8
The optotype spot light that passes through and is given a predetermined brightness is
The light is guided to the projection mechanism 4 through the projection lens 10 and the guide hole 7, and is reflected by the reflection mirror 5 to form an optotype spot S at a designated position on the inner surface 8 of the dome 3.

A panel 14 is provided in the front part of the dome 3, and the panel 14
A face receiving hole 15 is formed in which the face of the subject P is received. The face receiving hole 15 is provided with an original support member 16 for fixing the surgical part. The face rest is member 16
has a forehead rest part 17 and a chin rest part 18. During the examination, the subject P places his forehead and chin on the forehead rest part 17 and the chin rest part 18, puts his face into the face receiving hole 15, and looks at the fixation target K projected on the inner surface 8 of the dome 3. Patients are now being tested while keeping a close eye on the situation.

The examiner operates various operation switches provided on the operation unit 19 shown in FIG. Perform visual field measurement.

The projection mechanism 4 includes a frame 2 as shown in FIGS.
has 0. The frame 20 is attached to the dome 3 at a predetermined position so as not to interfere with the projection of the visual target. The frame 20 has a bracket 21.22°, and the bearing has a member 23.
is installed. Motor 2 is attached to bracket 21.
4 is fixed. A motor 25 is fixed to the bracket 22. The motor 25 is a reflective mirror 5 for visual target projection.
The motor 2
4 serves to rotate the optotype projection reflecting mirror 5 around the horizontal axis 27 .

A support member 29 is rotatably supported on the bearing member 23 via a ball bearing 28 . The bearing member 29 has a cylindrical portion 30, which is generally composed of a cylindrical portion 30 and 31.
is fitted into the inner ring of the ball bearing 28. The cylindrical portion 30, to which a pulley 32 is fixed at the end thereof, serves as a rotation axis about the vertical axis 26 of the optotype projection reflecting mirror 5.

Support brackets 83, 33 are attached to the cylindrical portion 31 so as to face each other. Each support bracket 33 is provided with a ball bearing 34,34.

The support bracket 33.33 has a hemispherical pivot member 3.
A mounting recess 37 is formed in the end face 36 of the zero rotation member 35 on which the rotation member 5 is rotatably supported.

A mounting plate 38 is fixed to the mounting recess 37. For mounting, the plate 38 is U-shaped and consists of a pair of arm plate parts 39, 39 and a fixing plate part 40. A rotation axis 41 is fixed to the pair of arm plate parts 39.39, and the rotation axis 41.41 is connected to a ball bearing 34.3.
4 is fitted. The reflective mirror 5 for visual target projection has a pair of rotation axes fixed to the end surface 36 of the rotating member 35, and 41 serves as a rotation axis around the horizontal axis 27 of the reflective mirror 5 for visual target projection. A pulley support plate 42 is attached to one of the support bracket wings 33 using a screw member 43. 44 is a color. Pulleys 45, 47 are rotatably supported on the pulley support plate 42 at intervals in the vertical direction.

A pulley 49 is fixed to the output shaft 48 of the motor 25. One end 53 of the wire 52 is attached to the pulley 49.
is fixed, and the wire 52 is pulled out toward the pulley 32 and returned to the pulley 49 via the pulley 32, and the other end 54 of the wire 52 is fixed to the pulley 49. When the motor 25 rotates, the rotation is transmitted to the pulley 32 via the wire 52,
The cylindrical portion 31 is rotated about the vertical axis 26. Note that a coil spring similar to a tension coil spring 57 provided between a first wire and a second wire, which will be described later, is attached to the wire 52.

A pulley 55 is fixed to the output shaft (not shown) of the motor 24. A wire 56 is wound around the pulley 55 multiple times. The wire 56 is connected to the first wire 58 with the tension coil spring 57 as the boundary.
and a second wire 59. The first wire 58 has one end 60 pulled by the coil spring 5
It is locked at one end of 7.

The other end of the first wire 58 passes through the cylindrical portion 30 and extends toward the pulley 46, and the first wire 58 is brought into contact with the pulley 46 to change direction. The first wire 58 is extended toward the rotating member 35 via the pulley 46, and the first wire 58 is extended toward the rotating member 35 via the pulley 46.
The other end 61 of the rotating member 35 is fixed to the lower circumferential surface 62 using screws along the circumferential surface of the rotating member 35. The second wire 58 has one end 63 pulled by the coil spring 5
7 is fixed to the other end.

The other end of the second wire 56 passes through the pulley 55, passes through the cylinder l[30, extends toward the pulley 45, and comes into contact with the pulley 45 to change direction. The second wire 56 is pulled out toward the pulley 47 via the pulley 45, and its direction is changed by the pulley 47 so that the other end 61 of the first wire 58 extends along the circumferential surface of the rotating member 35. The second wire 59 extends in the opposite direction, and the other end 64 of the second wire 59 is fixed to the upper circumferential surface 65 of the co-moving member 35 using screws. Here, the pulley 46 serves to position the first wire 58 and the second wire 56 in a plane that includes the vertical axis 26, so that even if the support member 31 rotates around the vertical axis 26, the wire 56 is twisted. is prevented.

A predetermined tension is applied to the wire 56 by a tension coil spring 57. When the motor 24 is rotated in the direction of arrow A, the first wire 58 is pulled in the direction of arrow B, so that the rotating member 35 rotates in the direction of arrow C around the horizontal axis 27. On the other hand, since the other end 64 of the second wire 59 is fixed to the rotating member 35, it is pulled in the direction of the arrow.

Since a tension coil spring 57 is interposed between the first wire 58 and the second wire 58, when the wire 56 tries to become excessively tense or relaxed, the tension coil spring 57 will release the excessive tension or relaxation. The load applied to the motor 24 is kept constant because the motor 24 is stretched in a direction that relieves the stress. The same applies to the reverse rotation of the motor 24.

The cylindrical portion 30 is provided with a disc-shaped reference scale plate 67 that constitutes a part of an optical rotary encoder 68. Additionally, a reference scale plate 67 is provided on the frame 20.
An encoder unit 68 is provided facing the rotation range. As shown in FIG. 3, the encoder unit 68 has a light emitting element 69 and a collimator lens 70 attached to one side of a reference scale plate 67 as an extraction section.

The encoder unit 68 also includes a reference scale plate 6.
A slit array 71 having a grating having a 90° phase difference as a detection section and a detector array 72 as a light receiving element are attached at a position facing the collimator lens 70 on the other side of the detector 7 . The output of the detector array 72 is input to the servo mechanism 13. The optical rotary encoder 68 serves to directly detect the rotation angle of the target projection reflecting mirror 5 about the vertical axis 26 based on the rotation of the reference scale plate 67.

A disc-shaped reference scale plate 74 that constitutes a part of the optical rotary encoder 73 is provided on the rotation shaft 41 of the rotation member 35 . As shown in FIGS. 4 and 5, one side of the support bracket 33 is provided with a mounting plate 75 that constitutes a part of the optical rotary encoder 73, and a reference scale plate 74 is mounted on the plate 75. A light emitting element 76 and a light receiving element 77 facing each other facing the rotation range of
and is provided. The output of the light receiving element 77 is similarly input to the servo mechanism 13. The optical rotary encoder 73 plays the role of directly detecting the rotation angle of the target projection reflecting mirror 5 around the horizontal axis 27 based on the rotation of the reference scale plate 74.

Note that 78 is a light shielding plate, which is identified on the frame 20.

In the embodiment, a case has been described in which an optical rotary encoder is used, but the present invention is not limited to this, and both a magnetic type and an electrostatic type can be used.

(Effects) As explained above, the visual target projection type visual field measuring device according to the present invention directly detects the rotation angle of the reflective mirror for visual target projection using the rotary encoder, so that the visual target can be easily detected. By specifying the position on the inner surface of the dome, it is possible to project the image even more clearly.

Furthermore, since the rotary encoder is used to detect the rotation angle of the optotype projection reflection mirror in a non-contact manner, the load on the motor can be reduced accordingly, and a smaller motor can be used.

[Brief explanation of drawings]

FIG. 1 is a front view showing the main parts of the visual target projection type visual field measuring device according to the present invention, FIG. 2 is a side view showing the main parts of the visual target projection type visual field measuring device according to the present invention, and 31! [ is an enlarged view showing the detailed configuration of the optical rotary encoder unit that detects the rotation angle around the vertical axis, j114 is a front view showing the installation state of the optical rotary encoder unit that detects the rotation angle around the horizontal axis, Fig. 5 is a side view showing the installation state of the rotary encoder shown in Fig. 4, Fig. 6 is a perspective view showing the overall configuration of the optotype projection type visual field measuring device according to the present invention, and Fig. 7 is a side view showing the installation state of the rotary encoder shown in Fig. 4. 1 is a schematic diagram showing a schematic configuration of an optotype projection type visual field measuring device. 3...Dome, 5...Reflection mirror for visual target projection 24.
... Motor 35 ... Rotating member 41 ... Rotating shaft,
68.73...Rotary encoder 67.74.
・Reference scale plate, 69.76 ・Light emitting element 72・
...Detector array (light receiving element) 77... Light receiving element S... Visual target Figure 1 Figure 2 Figure 3 Figure 4m

Claims (1)

[Claims] (1) A reference forming part of a rotary encoder that detects the rotation angle of the optotype projection reflecting mirror, which is attached to the rotation axis of the optotype projection reflecting mirror for reflecting and projecting the optotype spot on the projection surface. 1. An optotype projection type visual field measuring device, characterized in that a scale plate is provided, and an extraction section and a detection section that constitute a part of an optical rotary encoder are provided facing the reference scale plate.