JPH05133765A - Rotary encoder - Google Patents

Abstract

PURPOSE:To provide a rotary encoder, with which chattering is prevented at the time of sliding to ensure good sense of sliding and which can generate a high resolution easily, by arranging so that signals are taken out of position information display patterns provided on the surface of a cord plate even if a vibrator does not pass the level difference of the display patterns. CONSTITUTION:Position information display patterns 2, 3 are provided with comb-teeth parts 2b, 3b having a constant pitch, and a resistance pattern 4 in a ring-shaped band form overlapping on these comb-teeth parts 2b, 3b is provided on a cord plate 1, and a common slider 7 is slid on this resistance pattern 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary encoder which generates a rotation amount signal and a rotation direction signal in accordance with the rotation of a cord plate or a slider.

[0002]

2. Description of the Related Art On a code plate of a rotary encoder, there are usually two kinds of position information display patterns (hereinafter referred to as A phase pattern and B phase pattern) arranged in a radial and annular constant pitch. Both patterns and a common pattern arranged concentrically are provided, and the phases of the A-phase pattern and the B-phase pattern are shifted from each other by a quarter pitch. A pulse generated each time the slider comes into contact with the A-phase pattern by the terminal derived from the common pattern and the terminal derived from the slider that relatively rotates and slides along the A-phase pattern. A signal can be output, and similarly, the terminal derived from the common pattern and the terminal derived from the slider that relatively rotates and slides along the B-phase pattern cause the slider to move to the B-phase. Since it is possible to output the pulse signal generated each time the pattern comes into contact with the pattern, it is possible to extract two pulse signals having a phase difference of 90 degrees. As a result, the rotation speed signal is obtained by counting the number of pulse signals, and the rotation direction signal is obtained from the difference signal between the two pulse signals.

[0003]

However, in the conventional rotary encoder described above, the slider moves relative to the code plate while moving toward and away from the position information display pattern. There was a problem that chattering was likely to occur during sliding due to the step of the display pattern, and it was difficult to say that the sliding feel was good. Even if the two types of position information display patterns of the A and B phases are arranged on the code plate with high accuracy, a slider that slides on the A phase pattern and a slider that slides on the B phase pattern If the relative position deviates from the regular positional relationship, the phase difference of the output signals also deviates, and there is a problem that it is difficult to obtain high resolution.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a rotary encoder which can prevent chattering during sliding, can expect a good sliding feeling, and can easily obtain high resolution. To do.

[0005]

The above-mentioned object of the present invention is provided with a code plate provided with a position information display pattern, and a slider that relatively rotates and slides on the code plate,
In a rotary encoder that changes an output signal according to a positional relationship between the slider and the position information display pattern, the position information display pattern has comb teeth with a constant pitch, and a ring-shaped strip that overlaps the comb teeth. This is achieved by providing the resistance pattern of (1) on the code plate and sliding the slider on the resistance pattern.

[0006]

According to the above means, it is possible to output the resistance value according to the shortest distance between the contact portion of the slider and the comb tooth portion of the position information display pattern. Functions as a rotary encoder without contacting or separating
The slider can be smoothly slid on the resistance pattern. Further, if the code plate is provided with two types of position information display patterns of A and B phases and the resistance pattern concentrically,
The phase difference between the signal extracted from the A-phase pattern and the signal extracted from the B-phase pattern can be defined only by the code plate, and the slider is not required to have high positional accuracy.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view showing a code plate and a slider of a rotary encoder according to a first embodiment of the present invention. Two types of position information display patterns (A phase pattern and B phase pattern) provided on the code plate are shown. ) Are partially omitted from the drawing.

In the rotary encoder code plate 1 shown in FIG. 1, an A-phase pattern 2 in which a comb tooth portion 2b is formed on the inner peripheral side of an annular flat portion 2a and an annular flat portion having a smaller diameter than the A-phase pattern 2 are formed. B is formed by protruding comb teeth 3b on the outer peripheral side of 3a.
The phase pattern 3 and the resistance pattern 4 as a common pattern in which the comb tooth portions 2b and 3b are laminated on the surface of the A- and B-phase patterns 2 and 3 by exposing the annular flat portions 2a and 3a in the shape of a ring. Are provided concentrically, and the comb tooth portion 2b of the A phase pattern 2 and the comb tooth portion 3b of the B phase pattern 3 are opposed to each other.
And are out of phase with each other by a quarter pitch. Then, the first slider 5 is provided on the annular flat portion 2a of the A-phase pattern 2, the second slider 6 is provided on the annular flat portion 3a of the B-phase pattern 3, and both comb tooth portions 2b, The common sliders 7 are elastically contacted with the resistance patterns 4 exposed between the portions 3b, respectively.
Also, the common sliders 5, 6, 7 slide on the annular flat portions 2a, 3a and the resistance pattern 4, respectively.

That is, in this rotary encoder, when the code plate 1 rotates, the shortest distance between the contact portion of the common slider 7 and the comb tooth portion 2b of the A-phase pattern 2 changes.
The resistance value corresponding to this shortest distance can be output by the terminal 8 derived from the first slider 5 and the terminal 10 derived from the common slider 7. Similarly, when the code plate 1 rotates, the shortest distance between the contact portion of the common slider 7 and the comb tooth portion 3b of the B-phase pattern 3 also changes. Therefore, the resistance value corresponding to this shortest distance is set to the second value. Terminal 9 derived from the slider 6
And the terminal 10 derived from the common slider 7 can output. Therefore, it is possible to extract two output signals whose phases are shifted by 90 degrees while corresponding to the change in the resistance value, and by using the waveform-shaped output signals, the rotation speed signal and the rotation direction signal can be obtained. 5 to 7 function as a rotary encoder without coming into contact with and separating from the comb tooth portions 2b and 3b.

As described above, in the above embodiment, the common slider 7 is used.
By outputting the resistance value according to the shortest distance between the contact point portion of and the both comb tooth portions 2b and 3b, the first, second and common sliders 5, 6 and 7 are formed into annular flat portions 2a, 3a and Since it can be smoothly slid on the resistance pattern 4, that is, the sliders 5 to 7 are designed so as not to pass through the steps of the A and B phase patterns 2 and 3 on the surface of the code plate 1. Also, chattering during sliding can be prevented, and a good sliding feeling can be expected. Also, the annular flat portions 2a, 3
The positions of the first and second sliders 5 and 6 that slide on a do not affect the output value, and the signal extracted from the A-phase pattern 2 and the signal extracted from the B-phase pattern 3 are one common slider. Since the output value changes according to the sliding position of 7, the phase difference between the signals extracted from these patterns 2 and 3 is defined only by the code plate 1, and each of the sliders 5
7 is not required to have high position accuracy, and as a result, it is easy to improve the resolution.

In the above embodiment, gold or silver is used as the material of the A phase pattern 2 and the B phase pattern 3, and carbon is used as the material of the resistance pattern 4.

FIG. 2 is a perspective view of a main part of a code plate of a rotary encoder according to a second embodiment of the present invention, in which parts corresponding to those in FIG. 1 are designated by the same reference numerals.

In this embodiment, the shapes of the A-phase pattern 2 and the B-phase pattern 3 are the same as those of the first embodiment.
A resistance pattern 4 exposed in an annular shape between the annular flat portions 2a and 3a of the B-phase patterns 2 and 3 is laminated and formed on the surfaces of the comb teeth 2b and 3b. The tips of 2b and 3b are covered. Therefore, even when the distance between the comb teeth 2b and 3b facing each other is narrow, the common terminal 7 sliding on the resistance pattern 4 as the code plate 1 rotates contacts the comb teeth 2b and 3b. There is no worry, and there is an advantage that the code plate 1 can be easily downsized as compared with the first embodiment.

FIG. 3 is a perspective view of a main part showing a code plate of a rotary encoder according to a third embodiment of the present invention.
The same reference numerals are given to the portions corresponding to 2.

In this embodiment, the ring-shaped resistance pattern 4 is used.
Are laminated and formed on the surfaces of the comb-teeth portion 2b of the A-phase pattern 2 and the comb-teeth portion 3b of the B-phase pattern 3 as in the second embodiment, but the comb-teeth portion 2b of the A-phase pattern 2 is formed. By extending the tip end of the comb tooth portion 3b of the B-phase pattern 3 to the inner peripheral side of the code plate 1, in other words, the tip end of the comb tooth portion 3b of the code plate 1 rather than the tip end of the comb tooth portion 2b. By extending to the outer peripheral side, the common slider 7 is allowed to pass alternately on the comb teeth 2b and 3b via the resistance pattern 4.

That is, in the case of the first and second embodiments,
If the sliding position of the common slider 7 is displaced in the radial direction of the code plate 1, the amplitude of the output value differs between the signal extracted from the A-phase pattern 2 and the signal extracted from the B-phase pattern 3, and this common If the displacement of the slider 7 is large, the detection accuracy may be significantly deteriorated even if the output value is waveform-shaped. However, in the case of the third embodiment, the common slider 7 is replaced by the comb tooth portion 2.
The common slider 7 which will pass alternately on the comb tooth portions 2b and 3b if it is positioned on the outer peripheral side of the tip end of b and on the inner peripheral side of the tip end of the comb tooth portion 3b. The shortest distance is the same in both the A-phase pattern 2 and the B-phase pattern 3, and there is no fear that the amplitude of the output value differs between the signal extracted from the A-phase pattern 2 and the signal extracted from the B-phase pattern 3. Therefore, there is an advantage that high reliability can be secured even if the sliding position of the common slider 7 with respect to the code plate 1 is roughly set.

FIG. 4 is a perspective view of a main part showing a code plate of a rotary encoder according to a fourth embodiment of the present invention.
The same reference numerals are given to the portions corresponding to 3.

In this embodiment, a wide resistance pattern 4 is formed on the surfaces of the A-phase pattern 2 and the B-phase pattern 3 having the same shape as the second embodiment so that both comb teeth 2b and 3b can be sufficiently covered. This resistance pattern 4 is formed by stacking and forming
A bifurcated common slider 7 having a sliding portion 7a that slides on the comb tooth portion 2b through the interlocking portion and a sliding portion 7b that also slides on the comb tooth portion 3b through the resistance pattern 4 is used. That is. That is, the common slider 7 has the sliding portion 7a.
Pass over the comb tooth portion 2b, and the sliding portion 7b moves through the comb tooth portion 3b.
As long as it passes above, there is no concern that the amplitude of the output value will differ between the signal extracted from the A-phase pattern 2 and the signal extracted from the B-phase pattern 3. Even if the sliding position of the moving element 7 is roughly set, there is an advantage that high reliability can be secured.

FIG. 5 is a plan view showing a code plate and a slider of a rotary encoder according to a fifth embodiment of the present invention. A part of the A phase pattern and the B phase pattern provided on the code plate are not shown. The same reference numerals are given to the portions corresponding to those in FIGS.

Unlike the first to fourth embodiments, this embodiment is a rotary encoder of a type in which the code plate 1 is fixed and the common slider 7 is rotated, and the A phase pattern 2 and the B phase are used. Since the terminals 11 and 12 are directly derived from the pattern 3, it is not necessary to slide the slider on the A and B phase patterns 2 and 3, but the sliding portion 7c that slides on the resistance pattern 4 is provided. A bifurcated common slider 7 having a sliding portion 7d that slides on the current collecting pattern 13 is attached to a rotatable slider receiver (not shown). When the common slider 7 is rotated, the sliding portion 7c slides on the resistance pattern 4 exposed between the comb tooth portions 2b and 3b of the A and B phase patterns 2 and 3, and both comb teeth are moved. Since the shortest distance to the parts 2b and 3b is changed, the resistance value according to the shortest distance is A,
The terminals 11 and 12 derived from the B-phase patterns 2 and 3 and the terminal 10 derived from the common slider 7 via the current collecting pattern 13 can output the respective signals.

The shapes and arrangements of the A and B phase patterns 2 and 3 and the resistance pattern 4 of the fifth embodiment are the same as those of the first embodiment.
This is equivalent to the embodiment.

Further, in all of the first to fifth embodiments, the rotary encoder in which two kinds of position information display patterns of A and B phases are provided on the code plate so that the rotation direction signal can be obtained is also described. Information display pattern is 1
It goes without saying that the present invention can be applied to a rotary encoder that extracts only the rotation speed signal for each type.

[0024]

As described above, according to the present invention, which outputs the resistance value according to the shortest distance between the contact portion of the slider and the comb tooth portion of the position information display pattern, according to the present invention. Since it is not necessary for the slider to pass through the step of the position information display pattern on the surface, chattering at the time of sliding can be prevented, and sliding feeling is improved, which is a remarkable effect. Further, the output values of the two signals extracted from the two types of position information display patterns provided on the code plate can be made to correspond to the sliding position of one slider on the resistance pattern. The phase difference between the two signals can be defined only by the code plate, and high resolution is easily obtained.

[Brief description of drawings]

FIG. 1 is a plan view showing a code plate and a slider of a rotary encoder according to a first embodiment of the present invention.

FIG. 2 is a main part perspective view showing a code plate of a rotary encoder according to a second embodiment of the invention.

FIG. 3 is a main part perspective view showing a code plate of a rotary encoder according to a third embodiment of the invention.

FIG. 4 is a perspective view of an essential part showing a code plate of a rotary encoder according to a fourth embodiment of the present invention.

FIG. 5 is a plan view showing a code plate and a slider of a rotary encoder according to a fifth embodiment of the present invention.

[Explanation of symbols]

 1 Code Plate 2 A-Phase Pattern (First Position Information Display Pattern) 2a Annular Flat Part 2b Comb Tooth Part 3 B-Phase Pattern (Second Position Information Display Pattern) 3a Annular Flat Part 3b Comb Tooth Part 4 Resistance Pattern 5th 1 slider 6 2nd slider 7 common slider 8, 11 (for A phase pattern) terminal 9, 12 (for B phase pattern) terminal 10 (for common slider) terminal

Claims (3)

[Claims] 1. A code plate provided with a position information display pattern, and a slider that relatively rotates and slides on the code plate, and the position of the slider and the position information display pattern. In a rotary encoder that changes an output signal according to a relationship, the position information display pattern has comb teeth with a constant pitch, and a ring-shaped resistance pattern overlapping the comb teeth is provided on the code plate, and the resistance pattern is provided. A rotary encoder, wherein the slider is slid above. 2. The cord plate according to claim 1,
A first position information display pattern having a comb tooth portion on the inner peripheral side, a second position information display pattern having a comb tooth portion on the outer peripheral side having a smaller diameter than the display pattern, and these first and second positions A rotary encoder, wherein a resistance pattern overlapping both comb teeth of the information display pattern is concentrically provided. 3. The output signal according to claim 1, wherein a terminal derived from a slider sliding on the resistance pattern and a terminal derived from the position information display pattern directly or via another slider. A rotary encoder characterized by generating