JP2738067B2 - Rotary encoder - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rotary encoder mainly used for audio equipment.

2. Description of the Related Art A conventional technique will be described with reference to a rotary encoder shown in FIGS. 5 is a side sectional view, FIG. 6 is a plan view of a contact board which is a main part of FIG. 5, FIG. 7 is a plan view of the brush board, and FIG. 8 is a state in which the brush contacts the contact board. FIG. 9 is a plan view of a brush substrate of another conventional rotary encoder. FIG. 10 is a projection diagram showing a state where a brush and a contact substrate, which are main parts of FIG. 9, are in contact with each other. The figure is a pulse signal output example showing the phase characteristics of the A phase and the B phase.

According to FIGS. 5 to 8, the brushes 2, 3, 4 and the terminals 5 are insert-molded on the brush substrate 1. FIG. Brushes 2 and 3
Are arranged at positions different in radius but close to the center of the brush substrate 1 and shifted by a phase difference in the vertical direction. The brush 2 is connected to a terminal 5a, the brush 3 is connected to a terminal 5b, and the brush 4 is connected to a terminal 5c.

The contact board 6 is composed of an operation shaft 8 and a contact plate 9 formed by insert molding, and is constituted by a contact portion 9a and an insulating portion 9b alternately in the rotation direction. The operation shaft 8 is rotatably fitted and held by the brush substrate 1 and the case 10.

Next, in another conventional example shown in FIGS. 9 to 10, the brushes 11, 12, 13 and the terminals 5 are insert-molded on the brush substrate 1 in the same manner as in the above-described conventional example. The brushes 11 and 12 are disposed at positions substantially opposite to each other with respect to the center of the brush substrate 1 and on the same radius at positions shifted by a phase difference in the vertical direction. The brush 11 is connected to the terminal 5a, the brush 12 is connected to the terminal 5b,
13 are connected to the terminals 5c, respectively.

Next, the operation of the above two conventional examples will be described. By rotating the operation shaft 8, the contact board 6 rotates and the brush
By contacting the contact portion 9a and the insulating portion 9b of the contact plate 9 with 2, 3 or 11, 12, pulse signals of A phase and B phase as shown in FIG. 11 are output to the terminals 5a and 5b. . The terminal 5c is a common terminal.

Problems to be Solved by the Invention However, the above conventional rotary encoder is
In the former case, when the outer brush and the inner brush have dimensional variations, the inner brush is disadvantageous to the angular accuracy by the smaller radius, and finally it is the output of the A phase and the B phase. There is a factor that the accuracy of the phase difference gets worse,
Also, due to the problem that the resolution is reduced because the distance of the locus of the inner brush becomes short, and in the latter case, when the positions of the brush substrate and the contact substrate are eccentric, the radial dimension of the two brushes is reduced. Since the difference appears, the accuracy of the output phase difference deteriorates in the same manner as in the former example, so that there is a problem that it is not possible to simultaneously realize the miniaturization and the high resolution.

An object of the present invention is to solve such a conventional problem, and an object of the present invention is to provide a rotary encoder capable of realizing a small size and a high resolution.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention provides a brush that is close to and substantially on the same radius and arranged at a position facing each other,
The miniaturization and high resolution are realized at the same time.

Therefore, according to the present invention, it is possible to increase the outer peripheral distance by arranging the brushes at positions close to each other on substantially the same radius so that the trajectories of the brushes are substantially equal and opposing to each other, and to increase the resolution even when the size is reduced. Can be. Further, even if the contact substrate and the brush substrate are eccentric, the relative positional relationship between the two brushes does not change, so that the phase difference is small and the reliability can be increased.

Embodiment An embodiment of the present invention will be described with reference to the rotary encoder shown in FIGS. FIG. 1 is a side sectional view, and FIG.
FIG. 3 is a plan view of a contact plate which is a main part of FIG. 1, FIG. 3 is a plan view of the brush substrate, and FIG. 4 is a projection view showing a state where the brush and the contact substrate are in contact with each other. According to FIGS. 1 to 4, brushes 15, 16, 17 are insert-molded on a brush substrate 14, as in the conventional example. Further, the brushes 15 and 16 are arranged to be close to the center of the brush substrate 14 on substantially the same radius and to have an angle so that a phase difference appears at a position facing the brush substrate 14. The brush 15 is connected to a terminal 18a, the brush 16 is connected to a terminal 18b, and the brush 17 is connected to a terminal 18c.

Similarly to the conventional example, the contact board 19 is composed of an operating shaft 21 and a contact plate 22 formed by insert molding, and is constituted by a contact portion 22a and an insulating portion 22b alternately in the rotation direction. The operation shaft 21 is rotatably fitted and held by the brush substrate 14 and the case 23.

Next, the operation of the above embodiment will be described with reference to FIG. By rotating the operation shaft 21, the contact board 19 also rotates at the same time, and the brushes 15, 16 contact the contact portions 22a and the insulating portions 22b of the contact plate 22, so that the terminals 18a and 18b have the same shape as the conventional example. Then, A-phase and B-phase pulse signals as shown in FIG. 11 are output. The terminal 18c is a common terminal.

As described above, according to the above embodiment, the brushes 15 and 16 have the advantage that the sliding distance can be maximized and the resolution can be maximized because the brushes 15 and 16 pass through the outermost circumference. In addition, since the brushes are close to each other, there is little effect on angular accuracy even if the size of the brushes varies, and the relative position of the brushes does not change with respect to the eccentricity of the contact board. , The accuracy of the output phase difference between the A phase and the B phase is improved. Therefore, there is an effect that downsizing and high resolution can be simultaneously realized.

Advantageous Effects of the Invention As apparent from the above description, the present invention has an advantage that a high resolution can be realized by arranging the brushes at positions close to each other on substantially the same radius and facing each other. Also,
Even if the size of the brush varies, the angle accuracy is little affected, and the relative position of the brush does not change with respect to the eccentricity of the contact board. The accuracy of the phase difference is improved. And there is an effect that miniaturization and high resolution can be simultaneously realized.

[Brief description of the drawings]

1 is a side sectional view of a rotary encoder according to an embodiment of the present invention, FIG. 2 is a plan view of a contact board which is a main part of FIG. 1, FIG. 3 is a plan view of the brush board, and FIG. FIG. 5 is a projection view showing a state in which the brush contacts the contact board, FIG. 5 is a sectional side view of a conventional rotary encoder, FIG. 6 is a plan view of a contact board which is a main part of FIG. FIG. 8 is a plan view of the brush substrate, FIG. 8 is a projection view showing a state in which the brush contacts the contact substrate, FIG. 9 is a plan view of another conventional rotary encoder brush substrate, and FIG. 11A and 11B are projection views showing a state where the brush and the contact substrate are in contact with each other, and FIG. 11A and FIG. 11B are pulse signal output diagrams showing the A-phase and B-phase position characteristics. 14 ... brush board, 15 ... brush (A phase), 16 ... brush (B
Phase), 17 ... brush (common terminal), 19 ... contact board, 21 ...
... Operation shaft, 22 ... Contact plate, 22a ... Contact part, 22b ... Insulation part, 23 ... Case.

Claims (1)

(57) [Claims] A contact substrate having a comb-shaped electrode pattern formed on an insulating substrate and rotatable, and a signal for slidingly contacting the contact substrate and obtaining two signals out of phase. A rotary encoder, comprising: a brush substrate having a brush, wherein the brushes are arranged at positions close to each other on substantially the same radius and opposed to each other.