JPS6195434A - Input device of positional information - Google Patents

Abstract

PURPOSE:To detect the rotational speed of a sphere by extracting the moving speed of reflected light having different patterns as to optical reflection factors on the surface of the sphere through filters. CONSTITUTION:The sphere 20 is irradiated by a light source 21 and the reflected light reflected from the surface of the sphere 20 is formed as images on optical filter reticules 23, 24 having stripe-like patterns consisting of transparent and opaque parts through an optical system 22a, 22b. The transmitted light through the reticules 23, 24 are converted into electric signals by photoelectric converters 25a, 25b, 26a, 26b. Since the out put signals of the converters 25a, 25b correspond to the transmitted light through respective reticules 23 which are shifted by 1/4 pitch, a speed component can be found out from the phase difference between the output signals. Similarly, the other speed component can be also found out as to the reticules 24 and the photoelectric converters 26a, 26b. Since the reticules 23, 24 have the stripe-like patterns which are rectangularly intersected with each other, the two-dimensional speed components of the rotational speed of the sphere 20 can be found out respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a position information input device that is effective for inputting two-dimensional position information into information equipment such as a computer.

Configuration of conventional examples and their problems In recent years, in the field of information processing centered on computers, inexpensive and easy-to-use position information input devices are used to indicate the position of displayed information or to move a cursor on a display device. demand is increasing.

Hereinafter, a conventional position information input device will be described with reference to the drawings. FIG. 1 is a schematic diagram of a conventional position information input device, where 1 indicates a rotating ball 2a.

2b is a rotary encoder, 3a and sb are rotary encoders.
rollers attached to the rotary shafts 4a and 4b of the encoder;
5 is an exterior case, and 6 is a signal extraction cable.

The operation of the conventional position information input device configured as described above will be described below. When the exterior case 5 is moved on a flat plate, the rotating pole 1 rotates due to friction with the flat plate, and the rollers 3a and 3b in contact with the rotating ball surface are rotated.
The rotary encoder 2a rotates due to friction with the rotating pole surface.

2b. Since the rollers 3a and 3b are mounted perpendicular to each other, the rotary encoder 2a
, 2b rotate at a speed corresponding to the speed component in the X direction and the speed component in the Y direction of the rotational speed of the rotary pole 1. At this time, the output signals of the rotary encoders 2a and 2b are shown in FIG. 2(-) and FIG. 2(b), respectively. In FIG. 2, φ0, φ1 are two-phase output signals, φ0. By measuring the phase difference between the rising edges of both pulses φ1, the rotation speed component and rotation direction of each axis can be determined.

However, in the above configuration, the roller 3a
, 3b and the rotating pole 1, and especially when the rotating direction of the rotating pole 1 is at an angle close to the axial direction of the roller, the slipping between the two is large and the accuracy of detecting the rotational speed is reduced. It had some problems.

OBJECTS OF THE INVENTION An object of the present invention is to provide a position information input device that can always stably detect position information with high precision, without the detection accuracy depending on the rotation direction.

Structure of the Invention The position information input device of the present invention includes a sphere that is rotatably held and has patterns of different optical reflectances on its surface, illumination means for illuminating the surface of the sphere, and the sphere illuminated by the illumination means. an optical imaging means for forming an image of the reflected light from the surface, an image forming surface of the reflected light by the imaging means has a striped pattern consisting of a transparent part and an opaque part; Optical filters are installed perpendicularly to the optical axis of the imaging plane, such that the pitches of the striped patterns are shifted from each other by a predetermined distance on both sides of an axis perpendicular to the striped pattern at the center of the pattern, A pair of photoelectric converters for detecting light transmitted through the optical filter and converting it into an electrical signal are installed at the rear of each of the optical filters, and the optical imaging means, the optical filter, and the photoelectric converter are connected to each other. The pair of optical filters are installed so that the directions of their striped patterns are orthogonal to each other, and the frequency and phase of each output signal of the pair of photoelectric converters are determined by the frequency and phase of each output signal of the pair of photoelectric converters. It is configured to detect the dimensional velocity component, and since there is no transmission part due to mechanical friction between the sphere rotating from K and the velocity component detector, the decrease in detection accuracy due to this is This makes it possible to detect stable position information at all times.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 3 is a schematic diagram showing the principle of detecting velocity components of a position information input device according to an embodiment of the present invention.

In Fig. 3, 1o is a point light source, 11 is a convex lens, and 12 is a point light source.
An optical filter (hereinafter referred to as a reticle) having a striped pattern consisting of a transparent part and an opaque part (hereinafter referred to as a reticle) 13 is a photoelectric converter. For ease of understanding, it is assumed that the distances between the convex lens 11, the point light source 1o, and the reticle 12 are equal, and the image of the point light source 1o is formed on the reticle 12. First, consider a case where the point light source 10 moves at a speed V in a direction perpendicular to the direction of the striped pattern of the reticle 12. Assuming that each width of the transparent portion and the opaque portion of the striped pattern of the reticle 12 is a, the output signal of the photoelectric converter becomes a square wave with a period of 2 a/V, as shown in FIG. Therefore, the moving speed of the point light source 1o can be detected from the period or frequency of this square wave.

FIG. 6 shows a schematic configuration diagram of a position information input device according to an embodiment of the present invention. In FIG. 5, 20 is a sphere having a turn on its surface with different optical reflectance;
1 is a light source that illuminates the surface of the sphere 20; 22a and 22b are optical systems; 23.24 is a reticle with a striped pattern; the striped pattern is shifted by 1/4 of the pitch of the striped pattern in the center; The reticles 23 and 24 are configured such that their striped patterns are orthogonal to each other. 26a.

b and 26a are photoelectric converters that detect the transmitted light of the reticles 23 and 24.

The operation of the position information input device of this embodiment configured as described above will be described below. First, the sphere 2o is illuminated by the light source 21, and the reflected light from the surface of the sphere 2Q is transmitted to the reticles 23, 23 and 22 by the optical systems 22a and 22blC.
The transmitted light of the reticle 23, 24 is focused on the photoelectric converter 25 &, 25b.

26a and 2ebK are converted into electrical signals.

The output signals of the photoelectric converters 2esa and 2sb are shown in FIGS. 6a and 6b, respectively.

The output signals of the photoelectric converters 25a and 25b are signals corresponding to the transmitted light of the respective reticles shifted by 1/4 pitch, so as is clear from the explanation of the principle, the pitch of the reticle is set to 2a, and the movement of the image on the reticle is If the speed is V, the phase difference between the two output signals is a/4V or 3a
/4 V, and the velocity component can be determined from this phase difference. Reticle 24, photoelectric converter 26&, 2
8bK, the velocity component can be found in the same way, but since the striped patterns of the reticle 23 and the reticle 24 are orthogonal, it is possible to find the two-dimensional velocity component of the rotational speed of the sphere 2o. According to this embodiment, the rotational speed of the sphere can be detected by extracting the moving speed of reflected light of patterns with different optical reflectances on the sphere's surface using an optical filter.

Effects of the Invention As is clear from the above description, the present invention uses an optical system to convert light reflected from the surface of a rotatable sphere having patterns of different optical reflectances from striped patterns of transparent and opaque parts. The image is formed on an optical filter, and the light transmitted through the optical filter is converted into an electrical signal by a photoelectric converter, so that the speed of movement of the pattern on the surface of the sphere can be detected. Since this is done optically, there is no reduction in detection accuracy due to mechanical friction between the sphere and the speed detector, resulting in the excellent effect of stably detecting position information. In addition, since detection accuracy depends on the pitch of the striped pattern of the optical filter used, even if the pattern on the spherical surface becomes dirty or scratched due to long-term use, detection accuracy is hardly affected. You can also get

[Brief Description of the Drawings] Fig. 1 is a schematic diagram of a conventional position information input device, Fig. 2 is a graph showing an output signal waveform of the conventional position information input device, and Fig. 3 is an embodiment of the present invention. A schematic diagram showing the principle of detecting velocity components of such a position information input device, FIG. 4 is a graph showing the output signal waveform of the photoelectric converter in FIG. 3, and FIG. 6 is a diagram showing the position information input device according to an embodiment of the present invention. FIG. 6, which is a schematic configuration diagram of the apparatus, is a graph showing the output signal of the photoelectric converter in FIG. 1... Rotating ball, 2a, 2b... Rotary contest encoder! , 3a, 3b...roller,
1o...point light source, 11...convex lens,
12...Optical filter (reticle), 13
・・・Photoelectric converter, 2o・・・Sphere, 21
......Light source, 22a, 22b...Optical system, 23.24...Reticle with striped pattern,
25a, 26b, 26a, 26b--Photoelectric converter. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 3 O Figure 4 Outside 2

Claims (1)

[Claims] a sphere held rotatably and having patterns of different optical reflectances on its surface; an illumination means for illuminating the surface of the sphere; and an optical system for forming an image of the reflected light from the surface of the sphere irradiated by the illumination means. comprising an imaging means, having a striped pattern consisting of transparent parts and opaque parts on an imaging surface of the reflected light by the imaging means, and perpendicular to the striped pattern at the center of the striped pattern; On both sides of the axis, optical filters are installed perpendicular to the optical axis of the image plane, such that the pitches of the striped patterns are shifted from each other by a predetermined distance;
A pair of photoelectric converters for detecting the transmitted light of the optical filter and converting it into an electric signal are installed at the rear of each of the optical filters, and the optical imaging means, the optical filter, and the photoelectric converter are connected to each other. The pair of optical filters are installed so that the directions of their striped patterns are perpendicular to each other, and the two-dimensional shape of the sphere is determined from the frequency and phase of each output signal of the pair of photoelectric converters. A position information input device characterized by being configured to detect a velocity component.