JPH0337066Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a displacement detection mechanism of a coordinate input device that detects the coordinates of a rolling ball rolling on a plane.

BACKGROUND ART Conventionally, a displacement detection mechanism of a coordinate input device includes a shaft rotatably held in a ball housing housing a rolling ball, and a roller that rotates in contact with the rolling ball and synchronized with this roller. The rotating slit disk is fixed. Moreover, a light-shielding plate having two slits formed therein, each of which corresponds to a suitable two of a plurality of slits arranged circumferentially on the peripheral edge of the slit disk, is fixed to the shaft in close proximity to the slit disk. Ta. In addition,
Since the alignment control of each slit in the slit disk and the light shielding plate affects the accuracy of detecting the coordinates of the rolling ball, strict dimensional control has conventionally been applied to the assembly of the slit disk and the light shielding plate.

Problems to be Solved by the Invention However, it is necessary to use a relatively expensive resin with excellent sliding resistance for the bearing part that receives the shaft of the ball housing. It was not possible to use a superior resin, and in the end, the entire ball housing was made of the expensive resin with excellent sliding resistance. Furthermore, since each component of the displacement detection mechanism must be attached to the ball housing one by one, and precision is required for alignment between the slit disk and the light shielding plate, the efficiency of the assembly work is reduced. was forced to decline.

Therefore, an object of this invention is to provide a displacement detection mechanism for a coordinate input device that can reduce the cost of parts receiving a shaft and improve the efficiency of assembly work.

Means for Solving the Problems In order to achieve the above object, this invention makes the components into a unit so that they can be attached to the ball housing. Moreover, the shaft to which the roller and slit disk are fixed is not supported by the ball housing.

In other words, the displacement detection mechanism includes a roller that rotates by contacting an arbitrary point of a rolling ball, a slit disk that rotates in synchronization with the roller, and has a slit that is circumferentially arranged on the peripheral edge side. The shaft guide includes a shaft to which the roller and the slit disk are fixed, and a shaft guide that rotatably holds the shaft, and the shaft guide includes a guide portion that holds the shaft, and a shaft that supports the slit disk. It is characterized in that it is integrally equipped with a light shielding plate having slits that match the slits in the plate.

Function: Only the shaft guide, which receives the shaft that transmits the movement of the roller due to the rolling of the rolling ball to the slit disk, is made of resin with excellent sliding resistance. moreover,
Other components can be attached to the shaft guide. This unit can be attached to a ball housing that accommodates rolling balls.

Embodiment FIG. 1 is a perspective view showing an embodiment of this invention.

In the figure, reference numeral 60 denotes a displacement detection mechanism for detecting the coordinates of the rolling ball 40, and two displacement detection mechanisms 60 are attached to the coordinate input device as shown in FIGS. 3 and 4. That is, one is used for the X-axis and the other is used for the Y-axis.

Specifically, the displacement detection mechanism 60 includes a slit disk 6 in which a plurality of slits are arranged along the circumference in the circumferential direction.
1 and a roller 6 pressed against the rolling ball 40
2, a shaft 63 to which a slit disk 61 and a roller 62 are fixed, and a shaft guide 64 that rotatably holds the shaft 63.
The shaft guide 64 includes a rectangular cylindrical guide portion 64a with an open upper surface, and a rectangular light shielding plate 64 integrally formed on one end side of the guide portion 64a.
It has b. Furthermore, two slits that match two appropriate slits of the slit disk 61 are formed in the light shielding plate 64b.

Next, the coordinate input device will be explained with reference to FIG.

Reference numeral 10 denotes a ball pressing mechanism, which includes a torsion coil spring 11 and this torsion coil spring 1.
The roller 12 is rotatably attached to a straight portion of one of the leading ends 11b of the roller 1. The torsion portion 11a of the torsion coil spring 11 is fitted onto the cylindrical portion 21 of the box body 20. The box body 20 is a rectangular box with an open top, and has a circular opening 22 smaller than the diameter of the rolling ball 40 near the cylindrical portion 21 .

Reference numeral 30 is formed in the shape of a rectangular plate, and components to be described later are assembled on the upper surface, and printed wiring is formed on the lower surface. This circuit board 30 has an opening 31 through which the cylindrical portion 21 of the box 20 passes, and an opening 32 that overlaps coaxially with the opening 22 of the box 20. Above the opening 32 of the circuit board 30, the lower side of the rolling ball 40 protrudes from the opening 22 of the box body 20.

Reference numeral 50 denotes a ball housing consisting of a substantially square box with an open bottom, which is fixed to the top surface of the circuit board 30, and together with the circuit board 30, the rolling ball 40
It is designed to store. A circular opening 51 smaller than the diameter of the rolling ball 40 is formed on the upper surface of the ball housing 50. One corner of the ball housing 50 is chamfered, and a rectangular opening 52 is formed therein. The roller 12 of the ball pressing mechanism 10 described above is positioned in this opening 52, and the torsion coil of the ball pressing mechanism 10 is attached to a locking piece 53 having a substantially U-shaped longitudinal section and arranged on the upper surface of the ball housing 50. The other lead-out end 11c of the spring 11 is adapted to be hooked. This ball pressing mechanism 10 causes the rolling ball 40 to be displaced by the displacement detection mechanism 6.
0 and 60 rollers 62 and 62 at all times (see FIG. 5). In this state, the roller 62 of one displacement detection mechanism 60
contacts an arbitrary point on the rolling ball 40, and the roller 62 of the other displacement detection mechanism 60 comes into contact at a position shifted by 90 degrees from the contact position of the roller 62 of the one displacement detection mechanism 60. (See Figure 5). Note that the pressing force for pressing the roller 12 of the ball pressing mechanism 10 against the rolling ball 40 is as follows:
The other lead-out end 11 of the torsion coil spring 11
The position where c is hooked, that is, the ball housing 50
It can be adjusted as appropriate by changing the mounting position of the locking piece 53 provided in the.

Reference numeral 70 denotes a holding stand having a substantially U-shaped cross section, and two sets of a light receiving element 80 and a light emitting element 90 are mounted facing each other at a constant interval. This holding stand 70 is attached to the ball housing 50
The displacement detection mechanism 60 is attached in relation to the attachment position of the displacement detection mechanism 60. In the assembled state, the slit disk 61 is interposed between the light receiving element 80 and the light emitting element 90. Note that instead of the light receiving element 80 and the light emitting element 90 disposed on the holding base 70 in this way, it is also possible to use, for example, a photointerrupter.

Next, the operation of the coordinate input device will be briefly explained.

When the coordinate input device shown in FIGS. 3 and 4 is placed on a flat surface, such as on a desk, and moved appropriately, the rolling ball 40 housed in the ball housing 50 rolls. As the rolling ball 40 rolls, the rollers 62, 62 rotate individually to rotate the slit disks 61, 61. As the slit discs 61, 61 rotate, the light that is incident on the light receiving element 80 from the light emitting element 90 is passed through and blocked by the slits in the slit disc 61 and the light shielding plate 64b of the shaft guide 64. Based on this, the light receiving element 80 is turned on and off. From this on/off, it is detected in which direction and how many times the slit disks 61, 61 have rotated. Based on this detected value, the coordinates of the rolling ball 40 are detected, and the CRT cursor is moved accordingly.

Effects of the invention As explained above, according to this invention, the component parts can be assembled into a unit and attached to the ball housing, making assembly work easier and contributing to improved productivity. Moreover, since the shaft guide is integrally equipped with a guide part and a light shielding plate, the positioning of the slit disk and the light shielding plate for passing and blocking the light incident from the light emitting element to the light receiving element can be performed with high precision. Moreover, the effect of being easy to perform can be obtained. In addition, since only the shaft guide, which is the bearing part of the shaft, is made of a resin with excellent sliding resistance, the cost is lower than the conventional case where the entire ball housing is made of the relatively expensive resin. play.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one embodiment of this invention, Fig. 2 is an exploded perspective view showing the main parts of the coordinate input device applied in this embodiment, and Figs. 3 and 4 are after assembly. FIG. 5 is a perspective view showing the coordinate input device, and is an explanatory view showing the state of contact between the rolling ball 40 and the rollers 12 and 62. 40...Rolling ball, 60...Displacement detection mechanism,
61...Slit disk, 62...Roller, 63...
...Shaft, 64...Shaft guide, 64a...
...Guide part, 64b... Light shielding plate.

Claims (1)

[Claims for Utility Model Registration] A displacement detection mechanism for a coordinate input device that detects the coordinates of a rolling ball by rolling the ball, the roller rotating by contacting any point on the rolling ball. a slit disk that is rotated in synchronization with the roller and has slits circumferentially arranged on the peripheral edge side; a shaft to which the roller and the slit disk are fixed; and a shaft that is rotatable. a shaft guide for holding the shaft, and the shaft guide integrally includes a guide portion for holding the shaft and a light shielding plate having a slit that matches the slit of the slit disk. A displacement detection mechanism for a coordinate input device characterized by: