JP2012194150A - Optical encoder and electronic device - Google Patents

Abstract

An optical encoder that can output a movement information signal with one signal line and can detect relative position information and movement direction with high accuracy and is optimal for miniaturization of a module.
In this optical encoder, a light-on part 6 whose moving direction is a reference dimension W and a light-off part 7 twice the reference dimension W are alternately formed. The first movement information signal A is generated by the first AND circuit 111 from the first light receiving signal S1 of the first light receiving elements 51, 61, 71 of the light receiving unit 2 and the second light receiving signal S2 of the second light receiving elements 52, 62, 72. Generated. The second movement information signal B is generated by the second AND circuit 112 from the third light receiving signal S3 of the third light receiving elements 53, 63, 73 and the fourth light receiving signal S4 of the fourth light receiving elements 54, 64, 74. The third movement information signal C is generated by the third AND circuit 113 from the fifth light receiving signal S5 of the fifth light receiving elements 55, 65, 75 and the sixth light receiving signal S6 of the sixth light receiving elements 56, 66, 76.
[Selection] Figure 1A

Description

  The present invention relates to an optical encoder and an electronic apparatus, and more particularly to an optical encoder that detects a position, a moving speed, a moving direction, and the like of a moving body using a light receiving element. The present invention relates to an optical encoder suitable for use in automation equipment.

  Conventionally, in Patent Document 1 (Japanese Patent Application Laid-Open No. 2010-8367), a rotating member composed of a magnetic body in which wide magnetic poles and narrow magnetic poles are alternately arranged is provided. A magnetic encoder capable of obtaining output signals having different pulse width orders and detecting the rotation direction of a rotating member is disclosed.

  Further, in Patent Document 2 (Japanese Utility Model Laid-Open No. 61-80407), by providing a rotating plate that is a moving body in which a plurality of slits having different lengths are provided, adjacent signals have different voltage values. A pulse encoder capable of detecting the rotation direction of a rotating plate by obtaining a pulse signal is disclosed.

  By the way, in the magnetic encoder disclosed in Patent Document 1, since output signals having different pulse widths are obtained alternately, it is possible to detect the direction with one system of output signals. In this magnetic encoder, signals with different pulse widths can be obtained, but the resolution decreases on the longer pulse width side. Moreover, in the magnetic encoder of Patent Document 1, since the signal period of the rotating member varies, there is a possibility that the comparison of the pulse widths cannot be accurately performed when the speed of the rotating member varies rapidly.

  On the other hand, in the pulse encoder of Patent Document 2, since the voltage value of the pulse signal varies greatly depending on the light amount variation and variation of the light source, the voltage variation of the pulse signal due to the change in the slit length may not be accurately detected. There is.

  For the above reasons, there is a need for an encoder that can output a movement information signal with a single signal line and can detect relative position information and movement direction with high accuracy and is optimal for miniaturization of a module.

JP 2010-8367 A Japanese Utility Model Publication No. 61-80407

  SUMMARY OF THE INVENTION An object of the present invention is to provide an optical encoder that can output a movement information signal with a single signal line and that can detect relative position information and movement direction with high accuracy and is optimal for downsizing of a module. There is.

In order to solve the above problems, an optical encoder of the present invention includes a light emitting unit,
A light receiving section having a plurality of light receiving elements arranged in one direction in a region where light from the light emitting section can reach;
A light-on portion that makes the light incident on the light receiving element when passing through the position corresponding to the light receiving element and a state in which the light does not enter the light receiving element when passing through the position corresponding to the light receiving element A plurality of light-off portions, and a moving body through which the light-on portion and the light-off portion pass through a position corresponding to the light receiving element when moving in the one direction,
The moving body is
A light-on part whose dimension in the moving direction is a predetermined reference dimension;
A light-off part adjacent to the light-on part and having a dimension in the moving direction that is twice the reference dimension,
The light on part and the light off part are alternately arranged in the moving direction,
The light receiving part is
Having at least one light receiving element group composed of six light receiving elements of the first, second, third, fourth, fifth, and sixth arranged adjacent to each other in the moving direction,
Each light receiving element of the light receiving element group has a dimension in the moving direction that is a half of the reference dimension.
In addition, a signal processing unit that generates three movement information signals that are inputted with the output signals of the respective light receiving elements of the light receiving element group and that are sequentially out of phase,
The signal processor is
The output signal of the first light receiving element and the output signal of the second light receiving element are subjected to a mutual logic operation to generate the first movement information signal, and the output signal of the third light receiving element and the fourth signal The second movement information signal is generated by performing a mutual logic operation on the output signal of the fifth light receiving element, and a logical operation is performed on the output signal of the fifth light receiving element and the output signal of the sixth light receiving element. It has a logic operation part which generates the 3rd movement information signal.

  According to the optical encoder of the present invention, the first, second, and third movement information signals having phases shifted in order corresponding to the moving direction of the moving body can be obtained. With the information signal, highly accurate relative position information can be obtained and the moving direction of the moving body can be detected. The first, second and third movement information signals can be logically summed and output to one signal line, and the movement information signals are out of phase with each other. Is stored in a memory or the like, so that the moving direction of the moving body can always be detected.

In the optical encoder of one embodiment, the signal processing unit is
A sum of received light currents based on output signals from the respective light receiving elements of the light receiving element group is used as a reference current, and the output signal is AD converted using the reference current and input to the logic operation unit. .

  According to the optical encoder of this embodiment, the output signal from each of the light receiving elements can be converted to the logic operation unit by converting the output signal from the light receiving element as a pulse signal with little waveform variation. A pulse signal with little waveform variation is obtained as the first to third movement information signals output from the logic operation unit. In general, the current (output signal) obtained from the light receiving element can be in a form close to a sine wave, not a pulse, due to fluctuations or variations in the amount of light.

In the optical encoder of one embodiment, the logical operation unit is
A first logical product circuit that generates a first movement information signal by taking a logical product of an output signal of the first light receiving element and an output signal of the second light receiving element;
A second AND circuit that takes the logical product of the output signal of the third light receiving element and the output signal of the fourth light receiving element to generate the second movement information signal;
A third AND circuit that takes the logical product of the output signal of the fifth light receiving element and the output signal of the sixth light receiving element to generate the third movement information signal;
A logical sum circuit that takes a logical sum of the first movement information signal, the second movement information signal, and the third movement information signal;

  According to the optical encoder of this embodiment, the first to third movement information signals are respectively divided into a period corresponding to one period by the light-on part and the light-off part of the moving body and six minutes of the one period. And the phase is shifted in order by 1/3 period. An output signal having a pulse width corresponding to one-sixth of the one cycle and a cycle of the one-third cycle is obtained from the OR circuit.

  Therefore, according to the output signal of the OR circuit, high-accuracy relative position information can be obtained and output to one signal line, and the first to third movement information signals are sequentially out of phase. By storing the order of the first to third movement information signals in a memory or the like, the movement direction of the moving body can always be detected.

In the optical encoder of one embodiment, the signal processing unit is
A circuit unit for making the pulse voltage values of the first, second, and third movement information signals different from each other;

  According to the optical encoder of this embodiment, the first, second, and third movement information signals can be easily discriminated, and in the subsequent stage, a single signal is obtained by ORing the movement information signals. In addition, the moving direction of the moving body can be easily detected from the signal of this one system.

In the optical encoder according to an embodiment, the circuit unit is
The first, second, and third movement information signals are input and the first, second, and third movement information signals are generated by different constant voltage values generated by resistance division according to the first, second, and third movement information signals. 2 is a resistance dividing circuit that outputs a third pulse voltage.

  According to the optical encoder of this embodiment, the first to third pulse voltages with different constant voltage values corresponding to the first to third movement information signals are output by the resistance dividing circuit. It is possible to suppress the fluctuation of the pulse voltage due to the influence of the load caused by connecting to the circuit.

  In addition, the electronic apparatus according to an embodiment includes an optical encoder, so that position detection and movement detection can be performed with high accuracy and high resolution, and can be output to one signal line. A smaller electronic device can be realized by downsizing.

  According to the optical encoder of the present invention, the first, second, and third movement information signals whose phases are sequentially shifted in the movement direction of the moving body are obtained. Highly accurate relative position information can be obtained, and the moving direction of the moving body can be detected. The first, second and third movement information signals can be logically summed and output to one signal line, and the movement information signals are out of phase with each other. Is stored in a memory or the like, so that the moving direction of the moving body can always be detected.

It is a figure which shows the structure of the moving body and light-receiving part of 1st Embodiment of the optical encoder of this invention. It is a figure which shows the structure of the signal processing part of the said 1st Embodiment. It is a wave form diagram which shows the waveform of six pulsed light reception signals which the signal processing part of the said 1st Embodiment produces | generates. It is a wave form diagram which shows the waveform of the 1st-3rd movement information signal produced | generated by the logical product circuit of the logical operation part of the said 1st Embodiment. It is a wave form diagram which shows the logical sum waveform of the 1st-3rd movement information signal produced | generated with the OR circuit of the logical operation part of the said 1st Embodiment. It is a circuit diagram which shows the principal part of the signal processing part of 2nd Embodiment of the optical encoder of this invention. It is a circuit diagram which shows the principal part of the signal processing part of 3rd Embodiment of the optical encoder of this invention. It is a wave form diagram which shows the waveform of the 1st-3rd movement information signal produced | generated by the signal processing part of the said 2nd Embodiment. It is a wave form diagram which shows the logical sum waveform of the 1st-3rd movement information signal produced | generated by the signal processing part of the said 2nd Embodiment.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

(First embodiment)
FIG. 1A schematically shows the configuration of the first embodiment of the optical encoder of the present invention.

  The first embodiment includes a moving body 1, a light receiving unit 2, and a light emitting unit 3. The light emitting unit 3 is composed of a light emitting element such as an LED (light emitting diode).

  The moving body 1 is movable in the direction indicated by the arrow G1 or G2, and the light-on parts 6 and the light-off parts 7 are alternately arranged adjacent to each other in the movement direction. The light-on part 6 has a reference dimension W in which the dimension of the moving body 1 in the moving direction is predetermined. The light-off unit 7 has a moving dimension of the moving body 1 that is twice the predetermined reference dimension W. The light-on unit 6 makes light from the light emitting unit 3 enter the light receiving element when passing through a position corresponding to the light receiving element of the light receiving unit 2. Further, the light-off unit 7 prevents the light from entering the light receiving element when passing through a position corresponding to the light receiving element.

  The light receiving unit 2 includes a first light receiving element group 31, a second light receiving element group 32, and a third light receiving element group 33 that are arranged adjacent to each other in the moving direction. The first light receiving element group 31 includes six first, second, third, fourth, fifth, and sixth light receiving elements 51, 52, 53, which are arranged adjacent to each other in the moving direction. 54,55,56. Each of the six light receiving elements 51 to 56 has a dimension in the moving direction that is a half of the reference dimension W. Therefore, the phase of the light receiving signals output from the light receiving elements 51 to 56 is shifted by 60 ° when one pitch P (= 3 W) of the moving body 1 is 360 °.

  The second light receiving element group 32 includes six first, second, third, fourth, fifth, and sixth light receiving elements 61, 62, which are arranged adjacent to each other in the moving direction. 63, 64, 65, 66. Each of the six light receiving elements 61 to 66 has a dimension in the moving direction that is a half of the reference dimension W. Therefore, the light reception signals output from the respective light receiving elements 61 to 66 are shifted in phase by 60 ° when one pitch P (= 3 W) of the moving body 1 is 360 °.

  The third light receiving element group 33 includes first, second, third, fourth, fifth and sixth light receiving elements 71, 72, which are arranged adjacent to each other in the moving direction. 73, 74, 75, 76. Each of the six light receiving elements 71 to 76 has a dimension in the moving direction that is a half of the reference dimension W. Therefore, the phase of the light receiving signals output from the light receiving elements 71 to 76 is shifted by 60 ° when one pitch P (= 3 W) of the moving body 1 is 360 °. Each of the light receiving elements 51 to 56, 61 to 66, and 71 to 76 includes a photodiode or the like.

  Further, in this embodiment, the current distributors 11 to 16 connected to the first to sixth light receiving elements 51 to 56 of the first light receiving element group 31 and the first of the second light receiving element group 32. Current distributors 17 to 22 connected to the sixth light receiving elements 61 to 66, and current distributors 23 to 22 connected to the first to sixth light receiving elements 71 to 76 of the third light receiving element group 33 28. Further, in this embodiment, as shown in FIG. 1B, current-voltage converters 81 to 87, attenuators 90, comparators 101 to 106, and first, second, and third AND circuits 111 and 112. , 113 and a logical sum circuit 121. The comparators 101 to 106 constitute an AD conversion unit, and the first to third logical product circuits 111 to 113 and the logical sum circuit 121 constitute a logical operation unit.

  As shown in FIGS. 1A and 1B, the current distributors 11, 17, and 23 are connected to a current-voltage converter 81. The current distributors 12, 18, 24 are connected to a current / voltage converter 82. Further, the current distributors 13, 19, 25 are connected to a current / voltage conversion unit 83. The current distributors 14, 20, and 26 are connected to the current / voltage conversion unit 84. The current distributors 15, 21, 27 are connected to a current / voltage converter 85. The current distributors 16, 22, and 28 are connected to a current / voltage converter 86.

  Further, the current distributors 11 to 28 are connected to the current-voltage converter 87, and the current-voltage converter 87 is connected to the attenuator 90. Therefore, the light receiving signals output from the 18 light receiving elements 51 to 56, 61 to 66, and 71 to 76 of the first to third light receiving element groups 31 to 33 pass through the 18 current distributors 11 to 28. Then, it is input to the current-voltage converter 87 and converted to a light reception signal by voltage, and further input to the attenuator 90 and attenuated by a quarter, and then the inversion of the comparators 101 to 106 as a reference signal. Input to the input terminal.

  On the other hand, the light receiving signals output from the first light receiving elements 51, 61, 71 of the first to third light receiving element groups 31 to 33 are passed through the current distributors 11, 17, 23 in the current / voltage converter 81. The received light signal is converted into a voltage and input to the non-inverting input terminal of the comparator 101. The light reception signals output from the second light receiving elements 52, 62, and 72 of the first to third light receiving element groups 31 to 33 are transmitted through the current distributors 12, 18, and 24 by the current / voltage conversion unit 82. The received light signal is converted into a voltage and input to the non-inverting input terminal of the comparator 102. The light reception signals output from the third light receiving elements 53, 63, and 73 of the first to third light receiving element groups 31 to 33 are transmitted through the current distributors 13, 19, and 25 to the current / voltage conversion unit 83. The received light signal is converted into a voltage and input to the non-inverting input terminal of the comparator 103.

  Similarly, the light reception signals output from the fourth light receiving elements 54, 64, and 74 of the first to third light receiving element groups 31 to 33 pass through the current distributors 14, 20, and 26, and the current / voltage conversion unit 84. Is converted into a received light signal by voltage and input to the non-inverting input terminal of the comparator 104. Similarly, the light reception signals output from the fifth light receiving elements 55, 65, and 75 of the first to third light receiving element groups 31 to 33 pass through the current distributors 15, 21, and 27, and the current / voltage conversion unit 85. Is converted into a received light signal by voltage and input to the non-inverting input terminal of the comparator 105. Similarly, the light reception signals output from the sixth light receiving elements 56, 66, and 76 of the first to third light receiving element groups 31 to 33 are sent through the current distributors 16, 26, and 28 to the current-voltage conversion unit 86. Is converted into a received light signal by voltage and input to the non-inverting input terminal of the comparator 106.

  The comparator 101 compares the light reception signals from the three first light receiving elements 51, 61, 71 with the reference signal from the attenuator 90, and the first light reception of the pulse waveform as shown in FIG. The signal S1 is output. The first light receiving signal S1 has a period T corresponding to one pitch P of the moving body 1 and a pulse width T / 3 corresponding to the reference dimension W of the moving body 1.

  Further, the comparator 102 compares the received light signals from the three second light receiving elements 52, 62, and 72 with the reference signal from the attenuator 90 to generate a second pulse waveform as shown in FIG. The light reception signal S2 is output. The second light receiving signal S1 has a period T corresponding to one pitch P of the moving body 1 and a pulse width T / 3 corresponding to the reference dimension W of the moving body 1, and is equal to the first light receiving signal S1. The phase is shifted by 1/6 period (T / 6).

  Further, the comparator 103 compares the light reception signals from the three third light receiving elements 53, 63 and 73 with the reference signal from the attenuator 90 to generate a third pulse waveform as shown in FIG. The light reception signal S3 is output. The third light receiving signal S3 has a period T corresponding to one pitch P of the moving body 1 and a pulse width T / 3 corresponding to the reference dimension W of the moving body 1. The phase is shifted by 1/6 period (T / 6).

  Further, the comparator 104 compares the received light signals from the three fourth light receiving elements 54, 64, 74 with the reference signal from the attenuator 90, and generates a fourth pulse waveform as shown in FIG. The light reception signal S4 is output. The fourth light receiving signal S4 has a period T corresponding to one pitch P of the moving body 1 and a pulse width T / 3 corresponding to the reference dimension W of the moving body 1, and the fourth light receiving signal S4 corresponds to the third light receiving signal S3. The phase is shifted by 1/6 period (T / 6).

  Further, the comparator 105 compares the received light signals from the three fifth light receiving elements 55, 65, and 75 with the reference signal from the attenuator 90, and generates a fifth pulse waveform as shown in FIG. The light reception signal S5 is output. The fifth light receiving signal S5 has a period T corresponding to one pitch P of the moving body 1 and a pulse width T / 3 corresponding to the reference dimension W of the moving body 1, and the fifth light receiving signal S5 corresponds to the fourth light receiving signal S4. The phase is shifted by 1/6 period (T / 6).

  Further, the comparator 106 compares the received light signals from the three sixth light receiving elements 56, 66, and 76 with the reference signal from the attenuator 90, and generates a sixth pulse waveform as shown in FIG. The light reception signal S6 is output. The sixth light receiving signal S6 has a period T corresponding to one pitch P of the moving body 1 and a pulse width T / 3 corresponding to the reference dimension W of the moving body 1. The sixth light receiving signal S6 corresponds to the fifth light receiving signal S5. The phase is shifted by 1/6 period (T / 6).

  Next, the first light reception signal S1 output from the comparator 101 and the second light reception signal S2 output from the comparator 102 are input to the first logical product circuit 111, and the logical product of both is obtained. As a result, the first AND circuit 111 outputs a first movement information signal A having a pulse waveform with a period T and a pulse width T / 6 as shown in FIG. The third light reception signal S3 output from the comparator 103 and the fourth light reception signal S4 output from the comparator 104 are input to the second logical product circuit 112, and the logical product of both is obtained. As a result, the second AND circuit 112 outputs a second movement information signal B having a pulse waveform with a period T and a pulse width T / 6 as shown in FIG. The second movement information signal B is out of phase with the first movement information signal A by one-third period (T / 3). The fifth light reception signal S5 output from the comparator 105 and the sixth light reception signal S6 output from the comparator 106 are input to the third logical product circuit 113, and the logical product of both is obtained. As a result, the third AND circuit 113 outputs a third movement information signal C having a pulse waveform with a period T and a pulse width T / 6 as shown in FIG. The third movement information signal C is out of phase with the second movement information signal B by a third period (T / 3).

  Next, the first, second, and third movement information signals A, B, and C are input to the OR circuit 121 and ORed to obtain an OR output signal having a pulse waveform as shown in FIG. U is output from the OR circuit 121. This logical sum output signal U is a pulse waveform having a period T / 3 and a pulse width T / 6. As shown in FIG. 4, the logical output signal U includes a pulse generated by the first movement information signal A, a pulse generated by the second movement information signal B, and a pulse generated by the third movement information signal C. They appear in the order of C. The waveform of the logical sum output signal U shown in FIG. 4 is a waveform when the moving body 1 moves in the direction of the arrow G1. When the moving body 1 moves in the direction of the arrow G2, in contrast to the output signal U shown in FIG. 4, an OR output in which pulses appear in the order of the third, second, and first movement information signals C, B, and A. A signal is obtained from the OR circuit 121.

  As described above, according to the optical encoder of this embodiment, the first, second, and third movement information signals A, B, and C that are sequentially shifted in phase corresponding to the movement direction of the moving body 1 are obtained. It is done. In this embodiment, three pulses of movement information signals A, B, and C having the first, second, and third pulse widths (T / 6) are obtained in one period T corresponding to one pitch P of the moving body 1. It is done. Thereby, highly accurate relative position information is obtained, and the moving direction of the moving body 1 can be detected. The first, second, and third movement information signals A, B, and C can be logically summed by the logical sum circuit 121 and output as a logical sum output signal U to one system signal line. Here, the first, second, and third movement information signals A, B, and C obtained from the first, second, and third AND circuits 111, 112, and 113 are sequentially out of phase. By storing the order of each movement information signal in a memory or the like, the movement direction of the moving body 1 can always be detected.

  In this embodiment, the eighteen light receiving elements of the first, second, and third light receiving element groups 31, 32, and 33 are used as reference signals (reference voltages) input to the inverting input terminals of the comparators 101 to 106. A current obtained by summing 18 received light signals from the elements 51 to 56, 61 to 66, and 71 to 76 via the current distributors 11 to 28 is converted into a voltage by the current-voltage conversion unit 87, and the amplitude is 4 by the attenuator 90. A reference signal made in one-half is used. However, adjustment is required according to the amount of light sneaking to the light-off portion 7 side. Therefore, the six comparators 101 to 106 use the reference signal, and the first to sixth light receiving elements 51 to 56 of the first, second, and third light receiving element groups 31, 32, and 33, respectively. The received light signals from 61 to 66 and 71 to 76 can be AD converted. Since the current input to the current-voltage converter 87 is twice the received light current input to two of the current-voltage converters 81 to 86, the attenuator 90 reduces the amplitude to a quarter. Use the reference signal.

  Thereby, the six comparators 101 to 106 obtain first to sixth light receiving signals S1 to S6 as pulse signals with little waveform variation as shown in FIG. Therefore, the first to third AND circuits 111 to 113 forming the logical operation unit can obtain pulse signals with little waveform variation as the first to third movement information signals A to C. Therefore, highly accurate movement information of the moving body 1 can be obtained.

(Second embodiment)
Next, a second embodiment of the optical encoder of the present invention will be described. The second embodiment differs from the first embodiment only in that a circuit unit 310 shown in FIG. 5 is provided instead of the OR circuit 121 shown in FIG. Therefore, in the second embodiment, differences from the first embodiment will be mainly described.

  The circuit unit 310 includes a first transistor 301, a second transistor 302, and a third transistor 303, and the emitters of the first, second, and third transistors 301, 302, and 303 are connected to a power supply voltage. The collectors of the first, second, and third transistors 301, 302, and 303 are connected to the output terminal 305. A resistor 304 is connected between the output terminal 305 and the ground.

  In this embodiment, the current amplification factor of the first transistor 301 is made larger than the current amplification factor of the second transistor 302, and the current amplification factor of the second transistor 302 is made the current amplification factor of the third transistor 303. It was larger than the amplification factor.

  Then, the first movement information signal A from the first AND circuit 111 is inputted to the base of the first transistor 301, and the second movement information signal B from the second AND circuit 112 is inputted to the first transistor 301. The third movement information signal C from the third AND circuit 113 is input to the base of the third transistor 303.

  As a result, as shown in FIG. 7, a current X having a pulse waveform corresponding to the first movement information signal A flows through the collector of the first transistor 301. A current Y having a pulse waveform corresponding to the second movement information signal B flows through the collector of the second transistor 302. A current Z having a pulse waveform corresponding to the third movement information signal C flows through the collector of the third transistor 303. The amplitude of the current X corresponding to the first movement information signal A is larger than the amplitude of the current Y corresponding to the second movement information signal B, and the amplitude of the current Y is the third movement information signal C. Is larger than the amplitude of the current Z corresponding to.

  Therefore, when the currents X, Y, and Z having the pulse waveform flow through the resistor 304, the voltage X1 due to the current X, the voltage Y1 due to the current Y, and the voltage Z1 due to the current Z are applied to the output terminal 305 as shown in FIG. Is output as an output signal Q.

  As shown in FIG. 8, the output signal Q includes a pulse waveform voltage X1 corresponding to the first movement information signal A, a pulse waveform voltage Y1 corresponding to the second movement information signal B, and third movement information. A voltage Z1 having a pulse waveform corresponding to the signal C appears in the order of X1, Y1, and Z1. The waveform of the output signal Q shown in FIG. 8 is a waveform when the moving body 1 moves in the direction of the arrow G1. When the moving body 1 moves in the direction of the arrow G2, the output signal Q shown in FIG. 8 is contrary to the voltage Z1, V1 corresponding to the third, second, and first movement information signals C, B, A. An output signal in which pulses appear in the order of Y 1 and X 1 is obtained from the output terminal 305 of the circuit unit 310.

  As described above, according to the second embodiment, the voltages corresponding to the first, second, and third movement information signals A, B, and C whose phases are sequentially shifted in accordance with the moving direction of the moving body 1. An output signal Q obtained by superimposing pulses of X1, Y1, and Z1 is obtained. This output signal Q is a pulse voltage X1, which becomes a movement information signal of first, second, and third three pulses having a pulse width (T / 6) in one period T corresponding to one pitch P of the moving body 1. Y1 and Z1 appear, and the pulse voltages X1, Y1 and Z1 have different voltage values. Therefore, according to the output signal Q, it is easy to discriminate the pulse voltages X1, Y1, and Z1 from the first, second, and third movement information signals A, B, and C. In addition, the moving direction of the moving body 1 can be easily detected from the output signal Q of one system.

(Third embodiment)
Next, a third embodiment of the optical encoder of the present invention will be described with reference to FIG. In the third embodiment, the first to third movement information signals A to C from the three AND circuits 111 to 113 and the OR output signal U from the OR circuit 121 are input. Only the point provided with the dividing circuit 510 is different from the first embodiment. Therefore, in the third embodiment, differences from the first embodiment will be mainly described.

  As shown in FIG. 6, the resistance dividing circuit 510 includes a transistor 503 to which the first movement information signal A is input to the base, a transistor 502 to which the second movement information signal B is input to the base, and the first 3 and the transistor 501 to which the movement information signal C is input to the base. The resistance dividing circuit 510 includes resistors 505, 506, 507, and 508 connected in series to the constant current source 504. The resistance values of the resistors 505 to 508 may be the same value or different from each other. The collector of the transistor 501 is connected to the connection point between the resistors 505 and 506, the collector of the transistor 502 is connected to the connection point between the resistors 506 and 507, and the collector of the transistor 503 is connected to the connection point between the resistors 507 and 508. ing. The resistors 505 to 508 connected in series form a resistance voltage dividing unit.

  The emitters of the transistors 501 to 503 are connected to the ground. The node between the constant current source 504 and the resistor 505 is connected to the base of the transistor 509, the collector of the transistor 509 is connected to the power supply voltage Vcc, and the emitter is connected to the resistor 511. A transistor 513 is connected between the resistor 511 and the ground, and the logical output signal U is input to the base of the transistor 513. An output terminal 512 is connected to a connection point between the collector of the transistor 513 and the resistor 511.

When the pulse based on the first movement information signal A is input to the base of the transistor 503, the transistor 503 is turned on and the resistor 508 is short-circuited, and the resistors 505, 506, and 507 are connected to the constant current source 504. Current Io flows. Here, assuming that the resistance values of the resistors 505, 506, and 507 are R505, R506, and R507, and the base-emitter voltage of the transistor 509 is Vbe, the voltage Vc1 at the connection point P between the emitter of the transistor 509 and the resistor 511 is Is expressed by the following equation (1).
(R505 + R506 + R507) × Io−Vbe = Vc1 (1)

Further, when a pulse based on the second movement information signal B is input to the base of the transistor 502, the transistor 502 is turned on, the resistors 507 and 508 are short-circuited, and the resistors 505 and 506 are connected to the constant current source 504. Constant current Io flows. At this time, the voltage Vc2 at the connection point P is expressed by the following equation (2).
(R505 + R506) × Io−Vbe = Vc2 (2)

Further, when a pulse based on the third movement information signal C is input to the base of the transistor 501, the transistor 501 is turned on, the resistors 506, 507, and 508 are short-circuited, and the resistor 505 is connected to the constant current source 504. Constant current Io flows. At this time, the voltage Vc3 at the connection point P is expressed by the following equation (3).
(R505) × Io−Vbe = Vc3 (3)

  Therefore, Vc1> Vc2> Vc3. Therefore, a pulse of the voltage Va is output between the connection point P and the signal output terminal 512 in synchronization with the input of the pulse of the first movement information signal A of the logical sum output signal U to the base of the transistor 513. In synchronization with the pulse of the second movement information signal B being input to the base of the transistor 513, a pulse of a voltage Vb smaller than the voltage Va is output between the connection point P and the signal output terminal 512. In addition, a pulse with a voltage Vc smaller than the voltage Vb is output between the connection point P and the signal output terminal 512 in synchronization with the input of the pulse based on the third movement information signal C to the base of the transistor 513. .

  Thus, according to the third embodiment, an output signal J in which pulses of the voltages Va, Vb, and Vc are superimposed is obtained from the resistor dividing circuit 510, and the pulses of the voltages Va, Vb, and Vc are Corresponding to the first, second, and third movement information signals A, B, and C whose phases are sequentially shifted corresponding to the moving direction of the moving body 1. This output signal J has a pulse voltage Va, which becomes a movement information signal of the first, second and third three pulses having a pulse width (T / 6) in one cycle T corresponding to one pitch P of the moving body 1. Vb and Vc appear, and the pulse voltages Va, Vb and Vc have different voltage values. Therefore, according to the output signal J, it is easy to discriminate the pulse voltages Va, Vb, Vc from the first, second, and third movement information signals A, B, C, and the resistance voltage dividing output circuit 510 Even in the subsequent stage, the moving direction of the moving body 1 can be easily detected from the output signal J of one system.

  Further, according to the third embodiment, the resistance dividing circuit 510 causes the first to third pulse voltages Va to be generated with different constant voltage values corresponding to the first to third movement information signals A to C. Since Vc is output, it is possible to suppress the fluctuation of the pulse voltage due to the influence of the load caused by connecting to the subsequent circuit.

  In the first to third embodiments, the three light receiving element groups 31, 32, and 33 are provided to generate the first to sixth light receiving signals S1 to S6 (S21 to S26). The first to sixth light receiving signals may be generated from the light receiving signals of the first to sixth light receiving elements of one or two light receiving element groups or four or more light receiving element groups. Further, in the first to third embodiments, the comparators 101 to 106 are calculated based on the reference current based on the sum of the received light signals of the 18 light receiving elements of the first, second, and third light receiving element groups 31, 32, and 33. Although the reference voltage is generated, a reference voltage generation source for generating the reference voltage may be separately provided.

DESCRIPTION OF SYMBOLS 1 Mobile body 2 Light-receiving part 3 Light-emitting part 6 Light-on part 7 Light-off part 11-28 Current distribution part 31 1st light-receiving element group 32 2nd light-receiving element group 33 2nd light-receiving element group 51,61,71 1st 1st light receiving element 52,62,72 2nd light receiving element 53,63,73 3rd light receiving element 54,64,74 4th light receiving element 55,65,75 5th light receiving element 56,66,76 1st 6 light receiving elements 81 to 87 current voltage converter 90 attenuator 101 to 106 comparator 111 first AND circuit 112 second AND circuit 113 third AND circuit 121 OR circuit S1 to S6 6th light reception signal A 1st movement information signal B 2nd movement information signal C 3rd movement information signal U OR output signals 301-303 1st-3rd transistor 304 resistance 305 output terminal 310 circuit part X , Y, Z Pulse waveform current X1, Y1, Z1 Pal Voltage Q, J output signal 501-503, 509, 513 transistor 504 constant current source 505-508, 511 resistor 510 resistor divider circuit 512 output terminals Va-Vc first to third pulse voltages

Claims (6)

A light emitting unit;
A light receiving section having a plurality of light receiving elements arranged in one direction in a region where light from the light emitting section can reach;
A light-on portion that makes the light incident on the light receiving element when passing through the position corresponding to the light receiving element and a state in which the light does not enter the light receiving element when passing through the position corresponding to the light receiving element A plurality of light-off portions, and a moving body through which the light-on portion and the light-off portion pass through a position corresponding to the light receiving element when moving in the one direction,
The moving body is
A light-on part whose dimension in the moving direction is a predetermined reference dimension;
A light-off part adjacent to the light-on part and having a dimension in the moving direction that is twice the reference dimension,
The light on part and the light off part are alternately arranged in the moving direction,
The light receiving part is
Having at least one light receiving element group composed of six light receiving elements of the first, second, third, fourth, fifth, and sixth arranged adjacent to each other in the moving direction,
Each light receiving element of the light receiving element group has a dimension in the moving direction that is a half of the reference dimension.
In addition, a signal processing unit that generates three movement information signals that are inputted with the output signals of the respective light receiving elements of the light receiving element group and that are sequentially out of phase,
The signal processor is
The output signal of the first light receiving element and the output signal of the second light receiving element are subjected to a mutual logic operation to generate the first movement information signal, and the output signal of the third light receiving element and the fourth signal The second movement information signal is generated by performing a mutual logic operation on the output signal of the fifth light receiving element, and a logical operation is performed on the output signal of the fifth light receiving element and the output signal of the sixth light receiving element. An optical encoder comprising a logical operation unit for generating the third movement information signal. The optical encoder according to claim 1,
The signal processor is
A sum of received light currents based on output signals from the respective light receiving elements of the light receiving element group is used as a reference current, and the output signal is AD converted using the reference current and input to the logic operation unit. An optical encoder characterized by that. The optical encoder according to claim 1 or 2,
The logical operation unit is
A first logical product circuit that generates a first movement information signal by taking a logical product of an output signal of the first light receiving element and an output signal of the second light receiving element;
A second AND circuit that takes the logical product of the output signal of the third light receiving element and the output signal of the fourth light receiving element to generate the second movement information signal;
A third AND circuit that takes the logical product of the output signal of the fifth light receiving element and the output signal of the sixth light receiving element to generate the third movement information signal;
An optical encoder comprising: a logical sum circuit that takes a logical sum of the first movement information signal, the second movement information signal, and the third movement information signal. The optical encoder according to any one of claims 1 to 3,
The signal processor is
An optical encoder comprising a circuit portion for making the pulse voltage values of the first, second, and third movement information signals different from each other. The optical encoder according to claim 4, wherein
The circuit part is
The first, second, and third movement information signals are input and the first, second, and third movement information signals are different from each other according to constant voltage values generated by resistance division according to the first, second, and third movement information signals. An optical encoder characterized in that it is a resistance divider circuit that outputs second and third pulse voltages.   An electronic apparatus comprising the optical encoder according to claim 1.

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