JPH11345084A - Pointing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pointing device improving the S/N of the output signals of an encoder and improving reliability relating to the pointing device provided with a mechanical rotary encoder and inputting coordinate information or the like to an information processor. SOLUTION: A photointerrupter 4 is provided with a light emitting element 25 and a light receiving element 26 facing each other through a slit 24 and a holder 41 for holding the light emitting element 25 and the light receiving element 26 at a prescribed position. The holder 41 is provided with a light emitting element housing part 32 provided with an opening part 35, a light receiving element housing part 33 provided with the opening part 36 and a connection part 34 for integrating the light emitting element housing part 32 and the light receiving element housing part 33. The light emitting element housing part 32 is provided with a light shielding part 42 projected to a disk on a wall surface facing a peripheral edge part 20 outer than at least the slit 24 of a disk 22 and the output light of the light emitting element 25 made to enter between the outer peripheral side face of the disk 22 and a connection part 34 is interrupted by the light shielding part 42 in this pointing device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pointing device provided with an optical mechanical rotary encoder (hereinafter abbreviated as "encoder") for inputting coordinate information and the like to an information processing apparatus, and more particularly to improving the SN ratio of the encoder. Related to a pointing device.

A pointing device such as a mouse for inputting coordinate information to an information processing apparatus generally includes an encoder for generating coordinate information. A signal output from the encoder as the pointing device moves is input to the information processing apparatus as coordinate information. Is done.

However, if the signal-to-noise ratio of the signal output from the encoder is low, completely different coordinate information is input, which causes a malfunction. Therefore, the SN of the output signal of the encoder
There is a demand for the development of a pointing device with an improved ratio and improved reliability.

[0004]

2. Description of the Related Art FIG. 5 is a perspective view showing a main part of a mouse, and FIG. 6 is a perspective view showing a conventional photo interrupter.

A normal mouse incorporates a ball 1 and two encoders 2 respectively corresponding to the X-axis direction and the Y-axis direction as shown in FIG. 5, and the ball 1 can roll in an arbitrary direction as the mouse moves. In this state, it is supported by a mouse cover (not shown).

The encoder 2 has a shaft 21 rotatably supported by a mouth cover and a disk 22 fixed to one end of the shaft 21, and the ball 1 is pressed against a roller portion 23 formed in the middle of the shaft 21. The shaft 21 rotates as the ball 1 rolls.

The disk 22 driven by the ball 1 and rotated together with the shaft 21 has a plurality of slits 24 arranged at equal intervals in the circumferential direction, and has a gap between the disk 22 and the slit 24. Light-emitting element 25 and light-receiving element 26 facing each other are discs
22 are located on both sides.

When the slit 24 is interposed in the middle, the output light of the light emitting element 25 is incident through the slit 24 to increase the output voltage of the light receiving element 26. When the slit 24 passes through the middle, the output light of the light emitting element 25 is reduced. The output voltage of the light receiving element 26 is reduced by being blocked by the disk 22.

That is, the number of slits 24 corresponding to the rotation angle of the disk 22 with the rolling of the ball 1 is equal to the number of the light emitting element 25 and the light receiving element.
26, and each time the slit 24 passes, the output voltage of the light receiving element 26 increases, and a signal indicating the moving direction and the moving amount of the mouse is output.

When an independent light emitting element and light receiving element are incorporated in such an encoder, it is difficult to align the optical axes of the two elements. Therefore, a photointerrupter in which a light emitting element and a light receiving element are incorporated in the same holder and the optical axis is adjusted in advance is used.

In the conventional photointerrupter, the light emitting element 25 shown in FIG. 6B is provided in the light emitting element housing 32 of the holder 31 shown in FIG. 6C, and the light receiving element shown in FIG. Element 26
However, the lens 27 and the light receiving unit 28 are assembled so as to face each other, and the optical axes of both are aligned.

The holder 31 has a light-emitting element accommodating portion 32 and a light-receiving element accommodating portion 33 integrated by a connecting portion 34. The light-emitting element accommodating portion 32 has an opening 35 at a position facing the lens 27 of the light-emitting element 25.
The light receiving element housing part 33 has an opening 36 at a position facing the light receiving part 28 of the light receiving element 26.

[0013]

FIG. 7 is a perspective view showing a problem in the conventional mouse, and FIG. 8 is a diagram showing a decrease in the SN ratio in the conventional mouse.

The conventional mouse has a slit 24 as shown in FIG.
As a means for suppressing light that enters the light receiving element 26 from another path without passing through the light receiving element 26, the light receiving element housing part 33 is positioned so as to come as close as possible to the disk 22 when the photo interrupter 3 is combined with the disk 22. .

As a result, the gap interposed between the light emitting element accommodating portion 32 and the disk 22 is enlarged, and the scattered light output from the light emitting element 25 is reflected by, for example, the connecting portion 34, and There is a problem that the light enters the light receiving element 26 via a gap interposed between the light receiving element 34 and the light receiving element 26.

The output voltage of the light receiving element 26 when there is no light incident on the light receiving element 26 from another path has a large difference between the voltage at the high level and the voltage at the low level as shown by the solid line in FIG. Although the SN ratio is obtained, the output voltage of the light receiving element 26 is increased as the light incident on the light receiving element 26 from another path increases.
As shown by the broken line in FIG. 8, the voltage at the low level rises, the difference from the voltage at the high level is compressed, and the SN ratio decreases.

It is an object of the present invention to provide an encoder output signal S
It is an object of the present invention to provide a pointing device with an improved N ratio and improved reliability.

[0018]

FIG. 1 is a perspective view showing a main part of a pointing device according to the present invention. The same object is denoted by the same symbol throughout the drawings.

The above problem has a disk 22 provided with a plurality of slits 24 arranged in a circumferential direction and rotating together with a shaft 21, and a photo interrupter 4 arranged on an outer peripheral portion of the disk 22. The photo interrupter 4 has a light emitting element 25 and a light receiving element 26 opposed to each other through a slit 24, and a holder 41 for holding the light emitting element 25 and the light receiving element 26 at predetermined positions. A light-emitting element housing 32 having an opening 35 at a position facing the light-receiving element 27;
Light receiving element housing part 33 having an opening 36 at a position facing 28
And a connecting portion 34 for integrating the light emitting element housing portion 32 and the light receiving element housing portion 33, and the light emitting element housing portion 32 is at least a wall surface facing the peripheral edge portion 20 outside the slit 24 of the disk 22. The light-emitting element 25 has a light-shielding portion 42 protruding toward the disk, and the output light of the light-emitting element 25 incident between the outer peripheral side surface of the disk 22 and the connecting portion 34 is blocked by the light-shielding portion 42. Is achieved by the pointing device of the present invention.

As described above, the light emitting element accommodating portion has the light shielding portion protruding toward the disk at least on the wall surface facing the peripheral portion outside the slit of the disk, and has the outer peripheral side surface of the disk and the connecting portion. By intercepting the output light of the light emitting element that enters between them by the light shielding part, the light that enters the light receiving element from other paths without passing through the slit is suppressed, and the output voltage of the light receiving element becomes the high level voltage and the low level. The difference of voltage at the time of level is enlarged and SN
The ratio improves.

That is, it is possible to realize a pointing device in which the SN ratio of the output signal of the encoder is improved and the reliability is improved.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 2 is a perspective view showing a first embodiment of the present invention, FIG. 3 is a perspective view showing a second embodiment of the present invention, and FIG. 4 is a perspective view showing a third embodiment of the present invention.

In the first embodiment of the present invention, as shown in FIG. 2, the holder 41 is connected to the light emitting element housing 32, the light receiving element housing 33 and the connecting portion.
34, and the light emitting element accommodating section 32 has an opening 35 for allowing output light to pass therethrough at a position facing the lens 27 of the light emitting element 25 accommodated therein.

Unlike the conventional holder, the light emitting element accommodating portion 32 has a light shielding portion 42 protruding toward the disk on the wall surface between the opening 35 and the connecting portion 34, and a part of the light shielding portion 42 is A light-emitting element that extends to 35 and covers part of the lens 27 and heads for the connection
25 output light is blocked.

In the second embodiment of the present invention, as shown in FIG. 3, the holder 41 includes a light-emitting element accommodating section 32, a light-receiving element accommodating section 33, and a connecting section 34, and the light-emitting element accommodating section 32 is accommodated therein. The light emitting element 25 includes an opening 35 at a position facing the lens 27 to allow the output light to pass therethrough.

Unlike the holder 41, the light-emitting element accommodating portion 32 has light-shielding portions 43 protruding toward the disk on both side walls of the opening 35, and a part of the light-shielding portion 43 is formed in the opening 35. A light-emitting element that extends to cover the part of the lens 27
25 output light is blocked.

When the photointerrupter 4 having such a holder 41 is mounted on a disk 22 which rotates together with the shaft 21 as shown in FIG. 1, the output of the light emitting element which enters between the outer peripheral side surface of the disk and the connecting portion. The light is blocked by the light-shielding portion, so that the SN ratio can be improved.

In the third embodiment of the present invention, as shown in FIG. 4, the holder 41 is connected to the light emitting element housing 32, the light receiving element housing 33 and the connecting portion.
34, and the light receiving element accommodating portion 33 has an opening 36 for passing incident light at a position facing the light receiving portion 28 of the light receiving element 26 accommodated therein.

Unlike the holder 41, the light receiving element housing 33
Has a mask portion 44 on both side walls of the opening portion 36 for reducing the width of the opening portion 36. When the light receiving element 26 is accommodated in the light receiving element housing portion 33, the outside of the light receiving portion chip 29 included in the light receiving portion 28 is masked. Covered by part 44.

When the photo-interrupter 4 having such a holder 41 is mounted on a disk 22 which rotates together with the shaft 21 as shown in FIG. 1, light incident on the light receiving element from another path without passing through the slit is transmitted by the mask portion. Suppressed and the SN ratio can be improved.

Although not described in the embodiment, FIG.
As shown in the figure, a light-shielding part 42 protruding toward the disk is provided on the wall surface of the light-emitting element housing part 32, and a mask part 44 for reducing the width of the opening part 35 is formed in the light-receiving element housing part 33 to further improve the SN ratio. Can be improved.

That is, it is possible to realize a pointing device in which the SN ratio of the output signal of the encoder is improved and the reliability is improved.

[0033]

As described above, according to the present invention, it is possible to provide a pointing device in which the SN ratio of the output signal of the encoder is improved and the reliability is improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a main part of a pointing device of the present invention.

FIG. 2 is a perspective view showing a first embodiment of the present invention.

FIG. 3 is a perspective view showing a second embodiment of the present invention.

FIG. 4 is a perspective view showing a third embodiment of the present invention.

FIG. 5 is a perspective view showing a main part of the mouse.

FIG. 6 is a perspective view showing a conventional photo interrupter.

FIG. 7 is a perspective view showing a problem in a conventional mouse.

FIG. 8 is a diagram showing a decrease in the SN ratio in a conventional mouse.

[Explanation of symbols]

 4 Photo interrupter 20 Peripheral edge 21 Shaft 22 Disk 24 Slit 25 Light emitting element 26 Light receiving element 27 Lens 28 Light receiving section 29 Light receiving section chip 32 Light emitting element accommodating section 33 Light receiving element accommodating section 34 Connecting section 35, 36 Opening 41 Holder 42, 43 Shield 44 Mask

Claims (2)

[Claims] 1. A disk having a plurality of slits disposed in a circumferential direction and rotating together with a shaft, and a photo interrupter disposed on an outer peripheral portion of the disk, wherein the photo interrupter includes: A light-emitting element and a light-receiving element that face each other through the slit, and a holder that holds the light-emitting element and the light-receiving element at a predetermined position; and the holder has an opening at a position facing the lens of the light-emitting element. A light-emitting element accommodating section, a light-receiving element accommodating section having an opening at a position facing the light-receiving section of the light-receiving element, and a connecting section for integrating the light-emitting element accommodating section and the light-receiving element accommodating section. The light-emitting element accommodating portion has a light-shielding portion protruding toward the disk at least on a wall surface facing a peripheral edge portion outside the slit of the disk, and an outer peripheral side surface of the disk and the light-shielding portion. The output light of the light emitting element incident between the light emitting element and the connection portion is A pointing device, wherein the pointing device is blocked by a light shielding unit. 2. A disk having a plurality of slits arranged in a circumferential direction and rotating together with a shaft, and a photo interrupter opposed to an outer peripheral portion of the disk, wherein the photo interrupter is A light-emitting element and a light-receiving element opposed to each other via a slit; and a holder for holding the light-emitting element and the light-receiving element at predetermined positions, the holder including an opening at a position facing the lens of the light-emitting element. A light-emitting element housing, a light-receiving element housing having an opening at a position facing the light-receiving element of the light-receiving element, and a connecting part for integrating the light-emitting element housing with the light-receiving element housing. The pointing device is characterized in that the light receiving element accommodating portion is provided with mask portions covering the outside of the light receiving portion chip of the light receiving element on both sides of the opening.