JPH04355305A - Light position detector - Google Patents

Abstract

PURPOSE:To enable a position detection accuracy to be improved and a digital data to be output by providing a bias electrode which gives a bias potential to a resistance layer and a photoelectric conversion layer and two or more position detection electrodes and light position detection elements. CONSTITUTION:When a light source 7 according to an LED is driven and emits light by a constant current drive 24 of a position detection circuit 20, a slit plate 9 which travels on a light position detection element A is uniformly irradiated by a light diffusion plate and one portion of this flux of light passes through a rectangular slit 91 and then enters the element A as an incidence beam 6. A light current is generated at a light electromotive force layer 4 by the beam 6 and passes through a resistance layer 3 and then is detected as light currents ia and ib by detection electrodes 2a and 2b. This current is non-inversely amplified by 21a and 21b, appears as currents Va and Vb, and is added. The result of addition is divided 23 and an analog voltage Vn corresponding to a light incidence position x of the element A is output.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical position detector capable of improving position detection accuracy with respect to a light incident position.

0002

[Prior Art] Recently, in order to detect the linear or angular displacement of an object with high durability and reliability, instead of a position detector using a variable resistor that uses electrical contact, radiation emitted from a moving object is being used. Alternatively, the light reflected and transmitted by the moving object is received by an optical position detection element equipped with a resistive layer, and the linear displacement or angular displacement of the moving object is detected in a non-contact manner based on the light receiving position of the optical position detection element. An optical position detector is used.

As such an optical position detector and its optical position detecting element, a structure in which a silicon photovoltaic layer and a resistive layer are laminated, as disclosed in Japanese Patent Application Laid-Open No. 61-271413 and Japanese Patent Application Laid-open No. 63-32305, has been proposed. An optical position detector is known.

Next, such a conventional example will be explained. FIG. 9 is an exploded perspective view of an optical position detection element using a silicon semiconductor of a conventional optical position detector, and FIG. 10 is a configuration explanatory diagram showing the configuration of the optical position detector.

First, in FIG. 9, A is an optical position sensing element, and 1 is a substrate. The substrate 1 is shown here as a transparent plate glass.

Further, 2a and 2b are position detection electrodes,
It is formed by depositing a metal such as Al on a substrate, and 3 is a transparent resistance layer (hereinafter referred to as a resistance layer). This resistance layer 3 is formed into a band shape by sputtering or vapor deposition so that both ends thereof overlap the detection electrodes 2a and 2b.

[0007] 4 is a silicon semiconductor layer, and here,
This shows the case where amorphous silicon semiconductor (a-Si) is used, and by vapor deposition method such as plasma CVD method,
A P layer, an I layer, and an N layer are formed in this order on the resistance layer 3, and the PIN
forming a photovoltaic layer of the structure. Hereinafter, this will be referred to as a photovoltaic layer.

Reference numeral 5 denotes a bias electrode, which is also formed of a metal such as Al by vapor deposition on the detection area of the photovoltaic layer.

Next, the configuration of the optical position detector shown in FIG. 10 will be explained. In this FIG. 10, 7 is a light source such as an LED, and when the photovoltaic layer 4 is an a-Si layer,
A visible light source is usually used because of its light-receiving sensitivity characteristics.

A light diffusing plate 8 is disposed in front of the light source 7, that is, on the right side in FIG. The light diffusing plate 8 uniformly diffuses the emitted light from the light source 7, so that the movable slit plate 9 is illuminated with substantially the same illuminance.

A rectangular slit 91 is provided in a part of the movable slit plate 9. The incident light beam 6 passes through this slit 91 and enters the optical position detection element A.

On the other hand, 20 is a position detection circuit. The detection electrodes 2a and 2b at both ends of the optical position detection element A are connected to each inverting input terminal ((-) input terminal) of the non-inverting amplifiers 21a and 21b in the position detection circuit 20, respectively.

The bias electrode 5 of the optical position sensing element A is connected to a bias potential (here, ground potential).

Each non-inverting input terminal ((+) input terminal) of the non-inverting amplifiers 21a, 21b is connected to a bias potential, and a resistor is connected between the inverting input terminal and the output terminal of the non-inverting amplifiers 21a, 21b. is connected.

The output terminals of the non-inverting amplifiers 21a and 21b are connected to the (-) input terminal of the adder 22, and the non-inverting amplifier 21
The voltages Va and Vb generated at the output ends of the adders a and 21b are applied to the (-) input end of the adder 22.

The (+) input terminal of the adder 22 is connected to a bias potential, and the output terminal of the adder 22 is connected to one input terminal of a divider 23. The other input terminal of this divider 23 is connected to the output terminal of the non-inverting amplifier 21a.

Further, within the position detection circuit 20, a constant current drive circuit 24 is provided. This constant current drive circuit 2
4 drives the light source 7.

Next, the operation will be explained. The light source 7 is driven by a constant current drive circuit 24 to emit light. This light flux is diffused by the light diffusing plate 8 and evenly illuminates the movable slit plate 9 moving above the optical position detection element A, and a part of this light flux is transmitted through the rectangular slit 91 of the slit plate 9. A rectangular slit-shaped light beam 6 is incident on the optical position sensing element A.

The light beam 6 incident on the optical position sensing element A passes through the substrate 1 and the resistive layer 3 and reaches the photovoltaic layer 4, and a part of it is further reflected by the bias electrode 5 and becomes light again. The incident light beam 6 generates a photovoltaic force in the photovoltaic layer 4, and a photocurrent i corresponding to the amount of incident light is generated. The current is divided into position detection electrodes 2a and 2b provided at both ends.

At this time, the distance X from the position detection electrode 2b to the light incident position is such that the photocurrent divided into the position detection electrodes 2a, 2b is ia, ib, and the position detection electrodes 2a, 2b are
Assuming that the length between them (light receiving length) is L, X/L=ia/(i
a+ib)...given by (1).

The photocurrents ia and ib are each connected to a non-inverting amplifier 21.
A and 21b perform current-to-voltage conversion, and output voltages Va and Vb from the output terminals of non-inverting amplifiers 21a and 21b, respectively, are input to an adder 22, where they are added together.

The addition result of the adder 22 is sent to the divider 23
sent to. The divider 23 executes the division Va/(ia+ib) corresponding to the right side of equation (1) above, and outputs an analog voltage Vx corresponding to the light incident position X of the photodetecting element A.

Therefore, the position of the movable slit plate 9 is known by moving the movable slit plate 9 and detecting the incident position of the light beam 6 passing through the rectangular slit 91 on the optical position detection element A.

[0024]

[Problems to be Solved by the Invention] Since the conventional optical position detector is configured as described above, the position output is an analog output calculated from the ratio of extremely small photocurrents, so it is susceptible to the effects of external noise, etc. Therefore, the S/N ratio is poor, and the offset error of the position output is large due to the input offset error of the non-inverting amplifiers 21a and 21b used in the position detection circuit 20. In particular, the error due to temperature changes in the input offset is caused by the circuit. This was a big problem because it could not be removed.

In order to reduce the influence of this input offset, it is possible to reduce the thickness of the resistive layer 3 of the optical position sensing element A to increase the resistance value.
When the thickness of the sensor is reduced, the variation in the thickness becomes relatively large, and the linearity of the position output becomes worse.

Furthermore, since the output is an analog value, there is a problem that it cannot be applied to digital applications such as encoders.

The invention as claimed in claim 1 has been made to solve the above-mentioned problems, and aims to provide an optical position detector that improves position detection accuracy and is capable of digital output.

Another object of the invention is to provide an optical position detector that can improve position detection accuracy and provide digital output.

In addition to the object of the invention of claim 1, the invention of claim 3 has an object to obtain an optical position detector which can simplify the circuit configuration and further reduce the cost.

[0030]

Means for Solving the Problems The optical position detector according to the invention of claim 1 includes a photoelectric conversion layer, a resistive layer laminated thereon, a bias electrode that applies a bias potential to the photoelectric conversion layer, and at least two or more positions. An optical position sensing element that has a detection electrode and whose photocurrent conversion rate changes periodically depending on the incident position of the light beam, and outputs an analog calculation value corresponding to the ratio of the divided photocurrent output from the position detection electrode. This device is provided with analog output means for outputting pulses corresponding to the photoelectric conversion efficiency, and digital output means for outputting pulses corresponding to the photoelectric conversion efficiency.

The optical position detector according to the second aspect of the invention further includes digital output means for outputting a pulse corresponding to the sum of divided photocurrents in the same dimension direction among the divided photocurrents output from the position detection electrodes. It was established.

Further, in the optical position detector according to the invention of claim 2, the light source is arranged so that the sum of the divided photocurrent values in at least the same dimension direction among the divided photocurrents output from the position detection electrodes is constant. The device is provided with a control means for controlling the amount of light emitted by the light emitting device, and a digital output means for outputting a pulse corresponding to the output of the control means.

[0033]

[Operation] In the optical position detection element according to the invention of claim 1, a photocurrent is generated in the photoelectric conversion layer by an incident light beam emitted from a light source, and the position detection electrode shunts and detects the photocurrent flowing through the resistance layer. The analog output means outputs an analog calculated value corresponding to the ratio of the divided photocurrents detected by the position detection electrode, and the digital output means outputs pulses in response to changes in the photocurrent conversion rate of the optical position detection element. Output.

Further, the digital output means in the invention of claim 2 acts to output a pulse corresponding to the sum of divided current values in the same dimension direction among the divided photocurrents output from the position detection electrodes. .

Furthermore, the control means in the invention of claim 3 controls the amount of light from the light source to keep at least the sum of the divided photocurrent values in the same dimension direction constant among the divided photocurrents output from the optical position sensing element. At that time, the digital output means outputs a pulse in response to the output of the control means.

[0036]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the optical position detector of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration explanatory diagram showing the overall configuration of one embodiment, FIG. 2 is a developed configuration diagram of an optical position detection element applied to the embodiment of FIG. 1, and FIGS. 3 to 5 are optical position detection An example of a pattern of a transparent resistance layer of an element is shown.

1 to 5, the same parts as in FIGS. 14 and 15 are designated by the same reference numerals and will be explained. First, in FIG. 1, the basic configuration is the same as the conventional example, but the configurations of the resistive layer 3 and the position detection circuit 20 in the optical position sensing element A are different from the conventional example.

A in FIG. 1 is an optical position sensing element,
Position detection electrodes 2a, 2 made of Al or the like are placed on a transparent glass substrate 1.
b is laminated by vapor deposition or the like.

On this transparent glass substrate 1, a detection electrode 2a is provided.
, 2b and both ends overlap each other by ITO or SnO2 sputtering.
The resistive layer 3 is formed by depositing the resistive layer 3 to a thickness of 000 Å.

Furthermore, on this resistance layer 3, plasma CV
An a-Si photovoltaic layer 4 of approximately several thousand angstroms is laminated in the order of P layer, I layer, and N layer with a width wider than the width of the resistance layer 3 by vapor deposition or sputtering such as D, and finally, Al, etc. The bias electrode 5 is almost connected to the resistive layer 3 except for the lead connection part 51.
It is formed by vapor deposition or the like to have the same width.

[0041] At this time, the resistance layer in the detection region, excluding the glue portions 33a and 33b that overlap the detection electrodes of the resistance layer 3, connects the center resistance portion 31 connecting the glue portions 33a and 33b along the long axis of the detection region and perpendicular thereto. It consists of a plurality of branch-like resistance parts 32 provided at a predetermined pitch.

That is, branch-shaped resistance parts 32 are formed symmetrically with respect to the central resistance part 31 in a fishbone shape. The number N of branch resistor sections 32 is the maximum number N of digital outputs,
The pitch is determined by considering the digital output accuracy and the incident light beam diameter, and if the incident light beam diameter is made small,
It is easy to set the pitch to 0μ.

As shown in FIG. 6, when the rectangular incident beam 6 moves over the detection area of the optical position sensing element A having the resistive layer 3, the photocurrent ia flowing through the position sensing electrode 2a is as shown in FIG. Also, as shown in FIG. , is the minimum.

In the a-Si photovoltaic conversion layer 4,
Since the carrier diffusion length in the layer plane direction is short, photocurrent is generated only in the overlapped portion of the a-Si photocurrent layer 4 and the resistive layer 3, and therefore within the irradiation area of the incident light beam. The amount of photocurrent is maximum when the transparent resistance layer 3 is on the branch-shaped resistor section 32 where the area occupied is the widest, and conversely, when it is between the branch-like resistor sections 32 where the area occupied by the resistor 3 is the smallest. However, the maximum and minimum values of the total photocurrent do not change depending on the position of the incident beam 6.

On the other hand, the photocurrent value on one side (here,
ia) shows a maximum and minimum at the same position as the total photocurrent value, but the maximum and minimum values become larger as the incident beam 6 is closer to the detection electrode (here, 2a).

[0046] Here, the explanation returns to FIG. 1. In FIG. 1, the detection circuit 20 includes a comparator 25, which serves as a digital output means, to compare the output of an adder 22 and the output of a constant current drive circuit 24.
A digital position output Px is output from 5. The other configurations are the same as those in FIG. 15.

Next, the operation will be explained. When the LED light source 7 is driven by the constant current drive circuit 24 of the position detection circuit 20 to emit light, the slit plate 9 moving above the optical position detection element A is uniformly irradiated by the light diffusion plate, and this luminous flux is A part of the beam passes through the rectangular slit 91 and enters the optical position sensing element A as the incident beam 6.

A photocurrent is generated in the a-Si photovoltaic layer 4 by the incident light beam 6, and this photocurrent passes through the resistance layer 3 and is detected as photocurrents ia and ib by the detection electrodes 2a and 2b, respectively. Ru.

Here, the behavior of the amount of photocurrent when the incident beam position moves from the detection electrode 2a to the direction of 2b is already shown in FIG.
, as shown in FIG.

The photocurrents ia and ib are current-to-voltage converted by the non-inverting amplifiers 21a and 21b, respectively, and appear as currents Va and Vb at the output terminals of the non-inverting amplifiers 21a and 21b, respectively, and these voltages Va and Vb are applied to the adder. 22 is added.

The result of the addition in the adder 22 is divided by Va/(Va+Vb) corresponding to the right side of equation (1) above in the divider 23 serving as an analog output means, and the light of the optical position detection element A is An analog voltage Vx corresponding to the incident position X is output.

Here, as shown in FIGS. 7 and 8, the photocurrent ia
, ib change with maximum and minimum depending on the incident position X of the incident light beam 6, but the position output Vx is given by the ratio of the two as in equation (1), so
The output changes linearly.

On the other hand, the total current equivalent voltage (Va+Vb) added by the adder 22 is sent to the constant current drive circuit 24 by the comparator 25.
When the total current equivalent voltage (Va+Vb) is higher than the comparison voltage VSH, "H" is output, and conversely, when it is lower,
"L" is output. Therefore, the output of the comparator 25 becomes a digital position output Px that digitally changes with respect to the incident position of the incident light beam 6, as shown in FIG.

In other words, in this embodiment, not only the conventional analog output of the position but also the digital output of the position is possible. Therefore, for example, the position can be determined by inputting the digital output to a counter and integrating the number of pulses. It can also be used as an encoder, such as for measurements.

In this case, the direction of movement can be determined by differentiating the analog voltage. In addition, as explained in the conventional example, the position analog output Vx has a non-negligible offset error, but since the digital value is determined by the pattern pitch of the resistive layer 3 of the optical position sensing element, such offset error can be essentially ignored. Therefore, if the analog output Vx is corrected using the digital output Px as a reference, there is an advantage that position detection accuracy can be greatly improved.

In the above embodiment, the resistive layer 3 of the optical position sensing element A has a fishbone-like pattern consisting of the central resistive portion 31 and the branch resistive portions 32, but as shown in FIGS. 3 to 5, Other patterns can also be used.

Even with the same fishbone pattern as in the above embodiment,
The configuration shown in FIG. 5 allows the total resistance between the detection electrodes to be increased, which is advantageous in reducing offset errors in analog position output.

In addition, in FIG. 4, the sensor electrodes are formed in a comb-teeth shape, and although some perturbation due to position occurs in the analog position output, the total resistance between the detection electrodes can be made even larger than in FIG. 5, and the offset error is further improved. can.

FIG. 3 shows a case where a pattern is cut out into a rectangular shape, and in this case as well, the resistance between the detection electrodes can be increased.

FIG. 10 is an explanatory diagram of the configuration of an optical position detector according to a second embodiment of the present invention. In the detection circuit 20, a comparison-integration amplifier 26, an output amplifier 28, and a light source drive circuit 27 are further connected. has been done.

That is, the voltage Va appearing at the output terminal of the ratio inverting amplifier 21a is
−) It is designed to be added to the input end. The (+) input terminal of this output amplifier 28 is grounded, and the analog output Vx is output from the output terminal.

Further, the output of the adder 22 is applied to the (-) input terminal of the comparison-integration amplifier 26, and the (+) input terminal of the comparison-integration amplifier 26 is connected to the reference voltage V.
ref is applied.

The output of the comparison/integration amplifier 26 is input to one input terminal of the comparator 25 and the input terminal of the light source driving circuit 27. At the other input terminal of the comparator 25,
A comparison voltage VSH is applied, and a digital position signal Px is outputted from the output terminal. Further, the light source drive circuit 27 replaces the constant current drive circuit 24 in FIG. 1, and drives the light source 7.

Next, the operation of the second embodiment of the invention shown in FIG. 10 will be explained. The addition result (Va+
Vb) is set to a predetermined reference voltage Vref by the comparison/integration amplifier 26.
The result is compared and integrated with the light source drive circuit 2.
7 is driven.

As a result, the amount of light emitted from the light source 7 is controlled so that the total photocurrent value of the optical position sensing element A is always constant (that is, so that the denominator of equation (1) is constant). . That is, the comparison and integration amplifier 26 and the light source drive circuit 27 control the light source 7 so that at least the sum of the divided photocurrent values in the same dimension direction among the divided photocurrents output from the position detection electrodes 2a and 2b is constant. It constitutes a control means for controlling the amount of light emission.

One photocurrent equivalent value Va is the output amplifier 28
The signal is amplified and output as an analog position output Vx.

The incident position of the light beam 6 is on the transparent resistive layer 3.
Since the photocurrent conversion rate is at a maximum when the resistor is located above the branch resistor 32, the output of the comparator-integral amplifier 26 takes a minimum value that reduces the amount of light emitted from the light source 7.

On the other hand, when the incident position is between the branch resistor sections 32, the photocurrent conversion rate is at its lowest, so the output of the comparator and integral amplifier 26 is at its maximum value.

That is, the output of the comparison/integration amplifier 26 is compared with a predetermined reference voltage VSH by the comparator 25, and a digital position output Px is obtained as a comparison result. Since the analog position output Vx is given in the form of a photocurrent ratio as in the first embodiment, it shows a linear output with respect to position.

In this second embodiment, the same effects as in the first embodiment can be obtained, and since there is no need to use the divider 23, the circuit can be constructed at low cost.

Next, a third embodiment of the present invention will be described. FIG. 11 is a developed configuration diagram of the optical position sensing element A of the third embodiment, in which a bias electrode 5 made of Al or the like is laminated by vapor deposition or the like on a substrate 1 made of polished ceramic or plastic such as polyimide resin, and further, The central photovoltaic layer 4 is formed by masking the a-Si photovoltaic layer 4 and the resistive layer 3.
1. The branch-shaped photovoltaic layer 42 is laminated so as to overlap the central resistance section 31 and the branch-shaped resistance section 32, respectively.

Finally, the glue portions 33a and 33b of the resistance layer 3
Detection electrodes 2a and 2b made of Al or the like are laminated by vapor deposition or the like to form an optical position detection element A.

According to such a configuration, since the a-Si photovoltaic layer 4 itself is patterned, there is no need to consider the carrier diffusion length in the layer direction, and the pitch can be made even thinner, improving the accuracy of digital output. It has the advantage of increasing the

The photovoltaic layer 4 may be a photodiode layer formed by ion doping on single crystal Si and patterned by etching.

Furthermore, as in the first embodiment, the transparent substrate 1
Position detection electrodes 2a, 2b, resistance layer 3, photovoltaic layer 4 on top
It is clear that a similar detection element can be obtained even if the bias electrodes 5 and 5 are stacked in this order.

FIG. 12 is a developed configuration diagram of an optical position sensing element A according to a fourth embodiment of the present invention, and FIG. 13 is a diagram showing the configuration of a fourth embodiment using the optical position sensing element A shown in FIG. It is an explanatory diagram.

The fourth embodiment differs from the above embodiments in that it is applied to two-dimensional position detection.

First, in FIG. 12, position detection electrodes 2a, 2b for detecting the position in the X direction and position detection electrodes 2c, 2d in the Y direction are laminated on a transparent substrate 1, and a mesh resistance layer 3, This is a two-dimensional optical position sensing element A in which a photovoltaic layer 4 and a bias electrode 5 are laminated in this order.

In such a two-dimensional optical position sensing element A, the total sum of photocurrent flowing through the detection electrode 2 due to the incident light beam 6 reaches its maximum when the incident light beam 6 reaches the intersection of the meshes of the resistive layer 3. , it becomes minimum when it reaches between the meshes.

Next, in FIG. 13, the position detection circuit 20
When the light source 7 is driven by the constant current drive circuit 24,
The emitted light from the light source 7 is transmitted through a fiber 1 whose tip moves in both the X and Y directions.
0 to the two-dimensional position sensing element A.
is incident.

This incident light beam 6 causes the photovoltaic layer 4 to
The photocurrent generated flows through the mesh resistance layer 3 and reaches the detection electrode 2a.
~2d, and the photocurrents ia and ib are detected by the non-inverting amplifier 2.
1a and 21b, and the adder 22a performs current-voltage conversion, and adds one photocurrent equivalent voltage Va and the addition result (Va
+Vb) is divided by the divider 23a and output as the X-direction analog position output Vx.

The other photocurrent ic, id is connected to the non-inverting amplifier 2.
1c and 21d, the current is converted into voltage, and added by an adder 22b, and one photocurrent equivalent voltage Vc and the addition result (Vc+
Vd) is divided by the divider 23b and output as the Y-direction analog position output Vy.

Furthermore, the addition results (Va+Vb), (Vc+
Vd) is compared with the reference voltage VSH by comparators 25a and 25b, and the comparison results are output as digital position outputs Px and P, respectively.
Output as y.

[0084]

As described above, according to the invention of claim 1, a resistive layer is laminated on a photoelectric conversion layer, a bias potential is applied to the photoelectric conversion layer from a bias electrode, and at least two or more position detection electrodes are provided. , an optical position sensing element is provided in which the photoelectric conversion layer or resistance layer is patterned so that the ratio of the photoelectric conversion layer or resistance layer to the light beam irradiation area periodically changes depending on the incident position of the light beam, and The analog calculation value corresponding to the ratio of the divided photocurrents to be output is output by the analog output means, and the digital output means generates a pulse corresponding to the change in the photocurrent conversion rate, so that it can be used digitally. In addition to being applicable to methods, it can also be applied to reduce the S/N ratio peculiar to analog output,
This has the effect of improving position detection accuracy by improving output offset errors.

According to the second aspect of the invention, the digital output means is configured to output a pulse corresponding to the sum of the divided photocurrent values in the same dimension direction among the divided photocurrents output from the position detection electrode. Therefore, it is possible to improve the position detection accuracy and correspond to digital applications.

Furthermore, according to the third aspect of the invention, the amount of light emitted by the light source is controlled so that the sum of the divided photocurrent values in at least the same dimension direction among the divided photocurrents output from the position detection electrodes is constant. The digital output means outputs pulses in response to the output of the control means, which improves position detection accuracy and enables digital use. Since this is no longer necessary, the circuit configuration is simplified, which has the effect of leading to cost reduction.

[Brief explanation of drawings]

FIG. 1 is a configuration explanatory diagram showing the overall configuration of an optical position detector according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of an optical position sensing element applied to the embodiment of FIG. 1;

FIG. 3 is a plan view showing a different example of the pattern of the resistive layer of the optical position sensing element in the embodiment of FIG. 1;

4 is a plan view showing a different example of the pattern of the resistive layer of the optical position sensing element in the embodiment of FIG. 1; FIG.

5 is a plan view of patterns showing different examples of the resistive layer of the optical position sensing element in the embodiment of FIG. 1; FIG.

6 is an explanatory diagram showing the relationship between the photocurrent output and the incident position of the optical position sensing element in the embodiment of FIG. 1. FIG.

7 is a waveform diagram of the output current ia in the optical position sensing element of FIG. 6. FIG.

[Figure 8] Combined output current (
ia+ib) waveform diagram.

9 is a waveform diagram of pulse output in the embodiment of FIG. 1. FIG.

FIG. 10 is a configuration explanatory diagram showing the overall configuration of an optical position detector according to a second embodiment of the present invention.

11 is an exploded perspective view of an optical position sensing element applied to the embodiment of FIG. 10. FIG.

FIG. 12 is an exploded perspective view of another embodiment of the optical position sensing element applied to the present invention.

FIG. 13 is a configuration explanatory diagram showing the overall configuration of an optical position detector according to a third embodiment of the present invention.

FIG. 14 is an exploded perspective view of a conventional optical position sensing element.

FIG. 15 is a configuration explanatory diagram showing the overall configuration of a conventional optical position detector.

[Explanation of symbols]

A Optical position sensing element 1 Board 2a Position detection electrode 2b Position detection electrode 2c Position detection electrode 2d Position detection electrode 3 Resistance layer 4 Photovoltaic layer 5 Bias electrode 6 Incident light beam 7. Light source 9. Moving slit plate 20 Position detection circuit 21a Non-inverting amplifier 21b Non-inverting amplifier 21c Non-inverting amplifier 21d Non-inverting amplifier 22 Adder 22a Adder 22b Adder 23 Divider 23a Divider 23b Divider 24 Constant current drive circuit 25 Comparator 26 Comparative and integral amplifier 27 Light source drive circuit 28 Output amplifier

Claims (3)

[Claims] 1. A photoelectric conversion layer that generates a photocurrent using a light beam emitted from a light source, a resistance layer laminated on the photoelectric conversion layer, a bias electrode that applies a bias potential to the photoelectric conversion layer, and a photocurrent that flows through the resistance layer. an optical position detection element having at least two or more position detection electrodes that shunt and detect the photocurrent, and configured such that the photocurrent conversion rate changes periodically depending on the incident position of the light beam; , an optical device comprising an analog output means for outputting an analog calculation value corresponding to the ratio of the divided photocurrents output from the position detection electrode, and a digital output means for outputting a pulse corresponding to the change in the photocurrent conversion rate. position detector. 2. A photoelectric conversion layer that generates a photocurrent using a light beam emitted from a light source, a resistance layer laminated on the photoelectric conversion layer, a bias electrode that applies a bias potential to the photoelectric conversion layer, and a photocurrent flowing through the resistance layer. an optical position sensing element that is provided with at least two position detection electrodes that shunt and detect the photocurrent and is configured such that the photocurrent conversion rate changes periodically depending on the incident position of the light beam; digital output means for outputting a pulse corresponding to the sum of divided photocurrent values in the same dimension direction among the divided photocurrents output from the detection electrode; and digital output means for outputting a pulse corresponding to the change in the photocurrent conversion rate. Optical position detector with 3. A photoelectric conversion layer that generates a photocurrent using a light beam emitted from a light source, a resistance layer laminated on the photoelectric conversion layer, a bias electrode that applies a bias potential to the photoelectric conversion layer, and a photocurrent flowing through the resistance layer. an optical position detection element that is provided with at least two position detection electrodes that shunt and detect the photocurrent, and is configured such that the photocurrent conversion rate changes periodically depending on the incident position of the light beam;
an analog output means for outputting an analog value corresponding to a ratio of divided photocurrents output from the position detection electrode; and a sum of divided photocurrent values in at least the same dimension direction among the divided photocurrents output from the position detection electrode; An optical position detector comprising a control means for controlling the amount of light emitted from the light source so that the amount of light emitted from the light source is constant, and a digital output means for outputting a pulse corresponding to the output of the control means.