JPH025957Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly detects the position of printed characters arranged on a printing wheel of a printer using a detection plate and a brush. The present invention relates to a so-called mechanical contact type detection mechanism.

Here, we will explain how this detection mechanism is used. A detection plate is fixed to a type wheel shaft that rotatably supports a type wheel. On the surface of this detection plate, conductive patterns corresponding to the number of characters arranged on the type wheel are arranged, and a detection brush is arranged in contact with the conductive patterns. When the type wheel shaft is rotated by a motor, the type wheel and the detection plate rotate in synchronization. Therefore, there is a correspondence between the characters on the type wheel and the signals obtained by the detection plate and detection brush. When printing the desired type on the type wheel, when the conductive pattern corresponding to the desired type comes into contact with the detection brush and generates a signal, electricity is applied to the electromagnet that operates the hammer, and the type is printed on the recording paper. be done. As described above, the detection mechanism of the present invention is used in such fields.

Conventionally, the surface of a detection plate used in a detection mechanism was relatively smooth because it was plated on the surface of a material.

However, this smooth-surfaced detection plate has a drawback in that non-conducting materials such as dust generated when it slides tend to get caught in the contact portion with the brush body, causing poor conduction.

In addition, since the smooth surfaces are in contact with each other at the contact point with the brush body, the surface pressure is low, which tends to cause poor conduction, and if the surface pressure is increased, the brush body is likely to wear out.

The present invention solves these drawbacks, and its purpose is to maintain good continuity at the contact portion between the detection plate and the brush body for a long time. Another object of the present invention is to improve the adhesion of the plating to the material.

The present invention is to make the surface of the conductor pattern part of the detection plate uneven by adding lines or the like.

EMBODIMENT OF THE INVENTION Hereinafter, the structure of this invention will be explained about an Example based on drawing.

In the detection mechanism shown in FIG. 1, 1 indicates a detection plate and 2 indicates a brush body. The brush body 2 is positioned so as to be in contact with the surface of the detection plate 1, and as the detection plate 1 rotates, it passes over the conductor pattern 3 and the non-conductor pattern 4 of the detection plate 1, and receives an electrical signal. Detect it.

FIG. 2 is a cross-sectional view taken from the -' side of FIG. 1.

At this time, when FIG. 3 shows an enlarged view of part A of the conductive pattern 3 in FIG. 1, the surface of the conductive pattern 3 has streaks 5.

Of course, the line 5 is the circular pattern part 3 in Figure 1.
It is also attached to

By forming the lines 5 on the conductor pattern 3, as shown in FIG. The conductivity of the contact portion 7 is ensured.

Further, since the surface of the conductor pattern is wavy, the contact pressure with the brush body 5 is higher than that in contact between two smooth surfaces, so that the conductivity of the contact portion 7 is improved from this point as well.

The striped pattern is concentric circles as shown in Figure 3.
Either the parallel lines shown in FIG. 5 or the twill pattern shown in FIG. 6 may be used.

In addition, the cross-sectional shape of the lines is sawtooth as shown in Figure 7.
It may be either an intermittent valley shape shown in FIG. 8 or an intermittent mountain shape shown in FIG. 9.

In this example, the contact life was increased by more than 30 times compared to a detection plate with a smooth surface.

As described above, the present invention provides minute irregularities in the conductor pattern of the detection plate detected by the rotating position brush body, and (a) the actual surface of the conductor that directly contributes to conduction is reduced to a fraction of that of the conductor pattern;
(b) The minute irregularities on the conductor surface increase the actual surface area when the conductor is plated. (c) Foreign matter such as dust that would impede continuity is removed into the recess, improving continuity reliability;
A plurality of contact pieces are formed on the brush body, and (d) the probability that all the contact pieces are out of contact with the conductor at the same time is greatly reduced, so reliability can be further improved.

In addition, the minute irregularities are made into arc-shaped lines whose center is the same as the rotation center of the detection plate, and (d) the brush body continuously contacts many arc-shaped rings forming the lines, so that the conductor Wear of the pattern and brush body is reduced and durability can be further improved.

[Brief explanation of drawings]

Fig. 1 is a plan view of one embodiment of the present invention, Fig. 2 is a side cross-sectional view of the embodiment of Fig. 1, Fig. 3 is an enlarged view of the conductor detection pattern, and Fig. 4 is an enlarged concept of the contact portion. Figures 5 and 6 are the striped plane patterns, and Figures 7 and 6 are
8 and 9 show cross-sectional shapes of the lines. 1...Detection plate, 2...Brush body, 3...Conductor pattern, 4...Nonconductor pattern, 5...Stripes,
6... Nonconductor dust, 7... Contact portion, 8... Surface plating.

Claims (1)

[Claims for Utility Model Registration] (1) A disc-shaped detection plate having a plurality of conductive patterns arranged corresponding to the positions of the type on a type wheel and rotated as the type wheel rotates, and the conductor pattern. In a detection mechanism for a printer that prints desired characters, the brush body has a brush body that detects the position of the characters, and a plurality of contact pieces are formed on the brush body, and the conductive pattern is arranged on the detection plate. 1. A detection mechanism for a printer, characterized in that the conductive pattern is arranged radially on its surface, and furthermore, minute irregularities are provided on the surface of the conductive pattern. (2) The detection mechanism for a printer according to claim 1, wherein the minute irregularities are arcuate lines whose center is the same as the center of rotation of the detection plate.