JPS58191916A - Optical position sensor - Google Patents

Abstract

PURPOSE:To relate directly the change of the position of an incident light and a photocurrent characteristic to each other, by forming deformed parts in end parts of a sub-region near a main region, where the position of the incident light is detected, to enhance the carrier gathering capability more than the other parts. CONSTITUTION:Deformed parts 26b and 25b projecting toward a locus 12 of an incident spot light are formed in an end part 26a of the second sub-region 26 near the first main region 23 and an end part 25a of the first sub-region 25 near the second main region 24 in an optical position sensor 21. In accordance with the intensity and the position of incidence of the incident spot light 11, photocurrents are led out from the part between the first electrode 28 and the third electrode 30 and the part between the second electrode 29 and the third electrode 30.

Description

[Detailed description of the invention]

Technical Field The present invention relates to an optical position sensor, and is particularly suitable for an active type distance detection device that uses the principle of triangulation. The present invention relates to an optical position sensor capable of outputting an electrical signal according to the distance of the object. Prior Art The applicant has already disclosed in Japanese Patent Application No. 56-44818,
We have proposed an optical position sensor that is compatible with the above type of distance detection device. The present invention relates to an improvement of this type of optical position sensor. First, the optical position sensor disclosed in Japanese Patent Application No. 56-44818, which forms the background of the present invention, will be explained. FIG. 1 shows an optical system 1 of a distance detection device. Light emitting element 1
and the projection lens 2 constitute a light beam projector that projects a light beam toward an object to be measured. An imaging lens 3 is arranged at a fixed distance d from the projection lens 2, and an optical position sensor 4 is arranged on its rear surface. Reflected light enters the optical position sensor 4 at different positions depending on the distance to the object to be measured. FIG. 2 shows the appearance of a camera 5 equipped with such a distance detection device by way of example. The projection lens 2 and the imaging lens 3 are arranged at the positions of the windows 6a and 6b. FIG. 3 shows the optical position sensor 4 in FIG.
The pattern configuration of the light receiving surface of the optical position sensor proposed in No. 44818 is shown. This optical position sensor 4 is constructed using, for example, a silicon semiconductor. In FIG. 3(a), which is a planar pattern, P-type diffusion regions 9 and 10 are formed in a fi Q semiconductor substrate 8, each of which has first and second main regions 9aj extending in the Y-axis direction.
lOa and the first and second sub-regions 9b extending in the X-axis direction
, lQb. Distance j1 between main areas 9a and 103 and distance 12 between sub areas 9b and 10b
For example, a pattern of 0 and 1 is rotationally symmetric. When this optical position sensor 4 is incorporated into a distance detection device,
The reflected light J1 of the light beam from the object to be measured is reflected in the main areas 9a and 1.
The optical system is configured such that the light is incident on a dotted line 12 at an equal distance from the sub-regions 9b and 10b between 01 and 01. FIG. 3(b) shows a cross section taken along the dotted line 12 in FIG. 3(a). Now, as shown in FIG. 3(a), an ammeter At is connected between the area 9 and the substrate 8, and an ammeter A2 is connected between the area 10 and the substrate 8, and a spot light 11 of a constant intensity is connected.
12" on the dotted line, and move the spot light] in the X-axis direction to adjust the spot light position X and ammeter A1, A.
Examining the relationship between the current ip+ flowing in 2 and IP2, the 4th
Results are obtained as shown in the graph shown by the solid line in the figure. In the graph of FIG. 4, the horizontal axis represents the distance X from the right edge of the P-type diffusion region 9a to the center of the spotlight 11, and the vertical axis represents the current on a polygon scale. Note that the current is shown as a relative value. This means that even if you change the intensity of the spot light to a different value and measure it, you will still get the same graph. It means everything. During measurement, even if the irradiation area of the spot light changes slightly, the total energy of the light remains the same.
As long as you keep it constant, you won't see any change in the graph. Now, looking at the graph of FIG. 4, it can be seen that the flow 1 p 1 <1 where the spot light 11 moves away from the main region 9a and is located near the main region 9a] is drastically reduced. Similarly, the current IP2 also sharply decreases where the spot light is located near the main region 9a. Regarding the current IPI, the graph is approximately on a straight line in the range where the spot light is 600 μm deep from the main region 9a, but it deviates from that in the region beyond that. The same applies to the current Ip2. Currents IPI and I that exhibit such current characteristics
The incident position of the spot light can be detected from P2. However, it is desirable that the current characteristics with respect to the position of the spot light be on a straight line in the graph of FIG. 4 over the entire area sandwiched between the main regions 9a and 102. In other words, when detecting the incident position of the spotlight by processing the output lightning current using a circuit as described below, it is advantageous for circuit design and adjustment if the current characteristics are linear over the entire area. This is because. Purpose This invention provides an optical position sensor for detecting the position of incident light as described above, which has improved charging current characteristics with respect to the incident light position VC, and in particular has improved characteristics in a low current region. A fundamental object of the present invention is to provide an optical position sensor in which a linear relationship is established between a change in the position of incident light and a corresponding change in the logarithmic value of the photocurrent over an effective light-receiving area. For other purposes, light for detecting the position of incident light as described in "-" is also used. ☆We provide a complete range of sensors. Summary To summarize the invention, on one surface of a first type semiconductor substrate, a first main region and a second main region of a second type, which have different properties from that of the semiconductor substrate, are formed with the same width and parallel to each other. At the same time,
The entire substrate area sandwiched by the first and second main regions forms a second type of first sub-region and second sub-region that are sandwiched substantially perpendicularly to the sandwiching direction of the first and second main regions. the first main region and the first sub-region are connected to a first electrode;
a main region and the second sub-region are connected to a second electrode, the substrate is connected to a third electrode, and the first main region extends into a substrate region sandwiched by the first and second main regions. What is the photocurrent depending on the intensity of the incident light and the incident position when light whose incident position can change in a direction almost perpendicular to the direction of the incident light? In the optical position sensor, the light is emitted from between the first and third electrodes and between the second and third electrodes, the end of the second sub-region proximate to the first main region and the second At least a deformed portion protruding in a direction facing the trajectory of the incident light is formed at each end of the first sub-region adjacent to the main region, and by forming the deformed portion, This makes it possible to obtain an optical position sensor with improved charging current characteristics. If L<cs, the semiconductor substrate is of n-type, and the P-type head region is formed by impurity diffusion treatment. Embodiments The present invention will be explained below based on embodiments shown in the accompanying drawings. FIG. 5 shows the first embodiment and shows a plane pattern of the optical position sensor 2. In FIG. 5, an n-type semiconductor substrate 22
A first main region 23 and a second main region 24 having a polarity different from that of the semiconductor substrate 22, that is, P type, are formed on one surface of the semiconductor substrate 22. These main regions 23 and 24 are preferably created by impurity diffusion treatment, but the first main region 23 and the second main region 23
The main regions 24 have the same width and are formed parallel to each other. On the other hand, 25 is a sub-region, and 26 is a second sub-region, both of which are made into a P-type by a diffusion process, and which form a substrate region '1 27 sandwiched between the first and second main regions 23 and 24. The first and second main regions 23 and 24 are formed so as to be sandwiched at right angles to the sandwiching direction. In this example,
The first main region 23 and the first sub-region 25 are connected at their bases to form a 15-shape. A first electrode 28 is attached to this base.
is provided. In addition, the second main area 24 and the second sub area 26
are connected at their bases to form an L-shape, and a second electrode 28 is provided at the bases. 30 is a third electrode provided on the substrate 22. Substrate area 2 sandwiched between first and second main areas 23 and 24
7, a spot light 1 whose incident position changes in a direction perpendicular to the extending direction of the first main region 23 (a direction along the dotted line 12);
is incident. Depending on the intensity and the incident position of this incident spot light 11, the first lightning pole 28 and the third electrode 30
A photocurrent is derived from between the second lightning pole 29 and the third lightning pole 30. In this way, in the optical position sensor 21, the first main area 23
The end portion 26a of the second sub-region 26 adjacent to the second main region 24 and the end portion 25a of the first sub-region 25 adjacent to the second main region 24 are each deformed to protrude in the direction facing the trajectory 12 of the incident I spot light. Portions 26b and 25b are formed. The deformed parts 26b and 25b have the same rectangular shape, and are respectively similar to the second sub-region 2.
6. It is created integrally with the first sub-region 25, and is of course P type. As can be clearly seen from FIG. 5, this rectangular deformed portion 26b
, 25b is, in other words, the locus 12-1 of the spotlight
In other words, the distance at the end portions 26a, 2 with the deformed portions 26b, 25b is shortened by the distance dl in the other portions.
The distance to the locus 12 of the subregion 26°25 other than 5a is longer than the deformed portions 26b and 25b by dl. The length of the portion indicated by reference numeral d8 corresponds to a range D8 in which improvement of the current characteristics is planned as shown in the graph of FIG. However, it is not necessary that ds=Da, and it can be determined appropriately by adjusting experimentally. Furthermore, the edges 25C and 26C of the first and second sub-areas may be located in areas extending in the Y-axis direction of the second and first main areas 24.23. Further, the distance d4 between the main area and the sub area is, for example, 10
It is about 0 μm. What should be noted here is that the first and second sub-areas 25
．． 26 is that the trajectory of the incident light has a part closer to I- and a part farther away in the Y-axis direction. Note that FIG. 6 shows the deformed portion 25b (therefore, the deformed portion 26
The same applies to b). Figures (a) and (b) are examples of protruding steps, and the inner garden (C) is an example of protruding with a radius. FIG. 7 shows a second embodiment of the present invention, and is a more specific example showing an electrode pattern in addition to a P-type diffusion region pattern. Note that the same reference numerals as in FIG. 5 indicate the same or corresponding parts. FIG. 7(b) is a schematic view of the cut end surface taken along the line B-B in FIG.
A transparent insulating thin film layer 31 of Si02) is provided, and a required aluminum electrode layer 331 is provided thereon. Now, in FIG. 7(a), P type diffusion regions 23 and 2
4 constitutes first and second main regions, and P-type diffusion region 25
and 26 form the first and second sub-areas. Each of the four regions is different from the first embodiment and is formed separately from each other. 25a is a deformed portion of the first sub-region 25; 26a is a deformed portion of the first sub-region 25;
is the deformed portion of the second sub-region 26. The first and second sub-areas 25, 26&″x, respectively, the entire area 25 by aluminum electrode plates 33, 34.
．． 26 is a portion 25d, 2 from which the silicon oxide film has been removed.
It is connected to aluminum electrode plates 33 and 34 through 6d. The first and second main regions 23,24 each have their ends 23
The portions a and 24a are connected to aluminum electrodes 33 and 34, respectively. Further, the n-type semiconductor substrate 22 is connected to the electrode 30. 1st. Second and third electrodes 33, 34
, 30 are bonded with lead wires 35, 36, 37, and a photocurrent is taken out to the outside via these lead wires. FIG. 8 is a plan pattern diagram showing the third embodiment. In this embodiment, as can be seen in comparison with the first embodiment in FIG. A deformed portion is formed in the The first deformed portions 25'b, 26'b protruding by a distance d5 are equivalent to the deformed portions 25b, 26b in FIG. 5, but the second deformed portion 25e. 26e uniformly protrudes by a distance d6 on the opposite side to the direction in which the moving locus 12 of the spot light is viewed. Although the second deformed portions 25e and 26e have a rectangular shape in the illustration, they may have any shape shown in FIGS. 6(a), 6(b), and 6(C). As in the third embodiment, the photocurrent characteristics can be better improved by widening the width of the end of the sub-region. In addition, for example, due to restrictions on the size of the sensor itself, dl (5th
ds (Fig. 8) cannot be made large.
It is also possible to compensate for the deterioration in characteristics due to the geometrical shape by projecting a small amount in the direction facing the locus 12 as shown in FIG. In addition, in FIGS. 5 and 6, the first main and sub P diffusion regions are formed integrally with each other. Similarly, the second main and sub-P diffusion regions are also formed integrally with each other, but they do not necessarily have to be formed integrally, and may be formed separately as already shown in FIG. Each may be connected externally later. Further, in each embodiment, circular spot light 11 is shown to be incident, but slit-shaped light that does not cover the sub-region may be used. However, if a blocking part is provided in the sub-region, the length of the slit light will not be a problem. Furthermore, in the above embodiment, the main region of the substrate is n-type. Sub-area? Although the substrate is of P type, the main region and the sub region may be of N type. FIG. 9 is a graph showing the photocurrent characteristics of the optical position sensor obtained from each of the examples described above. Curve shown by solid line/1
1/2 is the actual value. The end region Ds where the output current decreases relatively sharply in the conventional monogastric sensor
The characteristics (indicated by the dotted curve !'l+!'2 in the figure) have been improved, and nearly linear characteristics have been obtained over the entire measurement region. Here, the reason why the current characteristics can be improved by the present invention will be discussed. When light enters. Carriers that become photocurrent are created at the incident position, and these carriers diffuse in various directions. In the process of spreading, carriers disappear. Carriers that have reached the P-type region without disappearing are taken out as photocurrent. The density of carriers increases closer to the source. Therefore, it is understood that in the region of improved current characteristics, if the p-type region is brought closer to the trajectory of the incident light, the photocurrent can be increased. Furthermore, it is understood that increasing the area of the P-type region increases the amount of carrier absorption and increases the photocurrent. In other words, the present invention increases the carrier collection capacity at the end of the sub-region closer to the opposing main region relative to other parts. Next, FIG. 10 shows an automatic focus adjustment device for a camera using the optical position sensor according to the present invention described above. The automatic focus adjustment device shown in FIG. 10 continuously adjusts the photographing lens of a camera that continuously takes pictures, such as a cine camera or a video camera. When adjusting the focus, a light beam is periodically and repeatedly projected toward the subject, and each time a photoelectric beam containing information on the subject distance is sent from the optical position sensor 21. This photoelectric current is converted by the signal processing circuit described below into a signal suitable for the servo system including the photographic lens, and the photographic lens is continuously brought into focus at the side temperature 10. 40 is periodically lit in accordance with a timing pulse output from the light emitting unit control signal generation circuit 41. The photocurrent extracted from the P-type diffusion region 23.24 of the optical position sensor 21 is input to a current-voltage conversion circuit 42.43. The above current-voltage conversion circuits 42 and 43 are the optical position sensor 2]
In response to an alternating current component of incident light whose intensity changes relatively quickly, such as ripples contained in fluorescent lamp light, there is a linear relationship with the logarithm of the photocurrent of that alternating component. When light whose intensity changes over time is not incident, a voltage signal at a level equal to the constant voltage Vrefs given from the constant voltage circuit 44 is output. Note that the circuit that performs the above operation is described in this application.
Since this circuit is explained in detail in Japanese Patent Application Laid-Open No. 56-29112 filed by the applicant, a detailed explanation will be omitted with only an example of the circuit configuration shown in FIG. Now, when light from a subject illuminated by a fluorescent lamp is incident on the optical position sensor 21, the current-voltage conversion circuits 42 and 43 output the constant voltage ■refa 1f! −
A ripple voltage that changes above and below the average level is output. Further, when the reflected light of the light beam is incident, a voltage signal corresponding to the sum of the intensity of the incident light and the intensity of the ripple component of the light from the fluorescent lamp is output. Note that a constant voltage Vre f l that acts as a reverse bias voltage for the optical position sensor 21 is applied from a constant voltage circuit 44 to the semiconductor substrate 36 of the optical position sensor 21 . When the subject is in the short distance zone, the light reflected from the light beam from the subject is input to an area close to the main diffusion area 23;
As the distance to the subject increases, the incident position of the reflected light approaches another main diffusion region 24. However, when the distance to the subject exceeds a certain level, reflected light with sufficient intensity for detection cannot be obtained. Therefore, the effective light-receiving area of the optical position sensor 21 is defined as the closest distance at which the photographing lens can be focused, the average reflectance of various objects, and the maximum distance at which the reflected light of the light beam can be detected from an object having reflection characteristics. It can correspond to the zone between. Now, considering the case where only the VC beam light is incident on the optical position sensor 2, the output voltages Voutl and Vout 2 of the current voltage conversion circuits 42 and 43 are the logarithmic compression values of the photocurrent of the optical position sensor 21. Corresponding to this, the output voltages Vout1 and VouL2 are adjusted according to changes in the incident position of the beam light.
The change in is linear as shown in FIG. 12(a) K. - The arithmetic circuit 45 includes an arithmetic amplifier 46.47 and a resistor 48.
49.50.51, and the following equation (1) is calculated. Vouts=(1+,)(Vout2−Voutt)+
Vref4・−(1) However, in the formula (]), R1
is the resistance value of resistor 48.51, and R2 is the resistance value of resistor 49.5
The resistance value is 0. Further, Vref4 is a constant voltage output from the connection point 54 between the semi-fixed resistors 52 and 53. As can be seen from the above equation ( ), the output V of the arithmetic circuit 45
outa corresponds to the constant voltage ref4K, which is the sum of the voltage difference between the outputs of the current-voltage conversion circuits 42 and 43, multiplied by a constant and added, and the output VOut8 is as shown in Fig. 12 (
As shown in b), it changes linearly with changes in the incident position of the reflected light. What should be noted here is the output voltage Vo of the arithmetic circuit 45.
uta depends on the position of incidence of the reflected light on the optical position sensor 21, but does not depend on its intensity. This is because the photoionization Ip1 and IF5 output by the optical position sensor 21 change depending on the intensity of the incident light, but (Ip2 / Ip
As already mentioned, the value of t'I is constant with respect to the incident position of the incident light if the size is fixed, and the value of t'I is constant with respect to the position of the incident light.
10g1pt=k(Vout2-Voutt)-(2
), this is because (■out2-Voutl) is constant. Note that k is a proportionality constant. Therefore, the output voltage Vouts of the arithmetic circuit 45 corresponds to the subject distance. The analog switch 55 is connected to the light emitting unit control signal generation circuit 41
The output voltage Vouts of the arithmetic circuit 45 is controlled by a signal of
f capacitor 56. While the capacitor 56 and the analog switch 55 are open, the output voltage Vout8f is read. The voltage held by the capacitor 56 is supplied to a servo circuit 58 that drives and controls the photographing lens 57f to the in-focus position. The servo circuit 58 includes a constant current source 59, a potentiometer 60, a constant voltage and pressure circuit 62 composed of a semi-fixed resistor 52.53 and a resistor 61, and a voltage comparison circuit 63.64.
It consists of a motor drive circuit 65 and a photographing lens drive motor 66. In the above-mentioned 1 brain-bo circuit 58, the potentiometer 60
The two sliders 60a and 60b provided on the button 60 are separated by a certain distance on the resistance of the button yometer 60, and are interlocked with a photographing lens 57 driven by a photographing lens drive motor 66 via a gear 66a. , the contact piece group 62'? Slide through. A voltage exceeding the output range of the arithmetic circuit 45 is generated between the terminal 67a of the potentiometer 6o and the drawer b, and when the servo circuit 58 performs the servo operation, the motor drive circuit 65 6
o so that the sliders 60a and 60b sandwich a position on the resistor of the potentiometer 6° which is generating a voltage equal to the voltage Voutll held in the capacitor 56.
The photographing lens drive motor 66 is controlled. The motor drive circuit 65 includes voltage comparison circuits 63 and 6.
4, the photographic lens drive motor 66 is driven as shown in Table 1 below. Table 1 However, in Table 1, Vc, Vsl and Vs
sg) respectively, capacitor 56, potentiometer 6
Vouta and Vout6 represent the logic output signals of the voltage comparator circuits 63 and 64, respectively. For example, if the subject is far away and the reflected light of the light beam cannot be detected, as described below, the transistor 68 is made conductive and the capacitor 56 is raised to a voltage higher than the maximum voltage that the arithmetic circuit 45 can output. For example, the camera is charged to the power supply voltage, and the photographic lens 57 is brought to a position predetermined as infinity. When the photographic lens 57 reaches the above position, the photographic lens drive motor 66 is stopped by means using a limit switch (not shown). Next, detection of the incidence of reflected light of the light beam is performed by a voltage comparison circuit. The inverting input terminal of the voltage comparison circuit 69 has a constant N4 voltage Vref2 higher than the average output level (corresponding to VrefB) of the current-voltage conversion circuit 42 by a constant voltage Vth.
is given. Here, the constant voltage Vth Vc is set to a voltage larger than the amplitude of noise included in the output of the current-voltage conversion circuit 42 as a threshold signal for the voltage signal corresponding to the reflected light. By the way, when the subject is illuminated by a fluorescent lamp, ripple components included in the illumination light are detected and appear in the outputs of the current-voltage conversion circuits 42 and 43. In order to distinguish between this ripple component and a signal corresponding to the reflected light of the beam light from the subject and utilize the signal component, the light beam is emitted at a specific phase timing of the ripple component of the illumination light, as described below. and perform detection. As already mentioned, the ripple component is the DC voltage Vre
fs, and is outputted from the current-voltage conversion circuits 42 and 43 in the form shown in FIG. 13(a). As can be seen from Figure 13(a) above, the time

At a time point such as [l], the ripple voltage coincides with the DC voltage VreLB. Therefore, if a light beam with a duration sufficiently short compared to the period of the ripple is emitted in synchronization with such time [1], the corresponding output signal can be treated as if there were no ripple. become. The control signal for detecting the light beam emission is generated by the light emitting unit control signal generation circuit 41 as shown in FIGS. 13(b) and 13(C).
It is generated by the pulse signal shown in . The pulse signal shown in FIG. 13(b) is a pulse signal output from the voltage comparison circuit 71, and corresponds to the comparison result between the reference voltage Vrefa and the ripple voltage. The pulse signal shown in FIG. 13(C) is a pulse outputted by the pulse generator 70 for instructing the emission of a light beam, and has a period of, for example, 100 m5 and a time width of l m s. The light emitting unit control signal generating circuit 41 generates, for example, l m s as shown in FIG. Outputs a timing pulse with a time width. The timing pulse is applied to the analog switch 55 and the control terminal of the latch circuit 72, and is further applied to a light emitting diode drive circuit 76 consisting of an inverter 73, a resistor 74 and a transistor 75, and the light emitting diode 40 is activated in response to the timing pulse. The light is turned on and the analog switch 55 is closed. Furthermore, the latch circuit 72 captures the 1 high 1 or ILX ``low 1'' voltage signal output from the voltage comparator circuit 69 while the timing pulse is being applied, and holds that signal until the arrival of the next timing pulse. In this way, when the reflected light of the light beam is detected and the voltage comparator circuit 59 outputs a high voltage, the pnp transistor 68 is rendered non-conductive, and the capacitor 56
A voltage signal corresponding to the object distance from the arithmetic circuit 45 is stored, and the photographing lens 57 is operated in accordance with the voltage signal 1j2 stored in the capacitor 56. Controlled to focus position. If no reflected light is detected and the latch circuit 72 latches the full voltage, the transistor 68 becomes conductive, the capacitor 56 is charged to a voltage close to the power supply voltage Vcc, and the photographic lens 57 is controlled to a far infinite position. Δ Note that when the light source illuminating the subject does not include a ripple component like the sun, timing pulses are generated as follows. In FIG. 0, a constant voltage vrefa is applied to the inverting input terminal of the voltage comparison circuit 71, but the output voltage is also at the average power Δ level of the current-voltage conversion circuits 42 and 43. In other words, voltages at the same level are input to the two inputs of the voltage comparison circuit 71. However, in reality, the output of the current-voltage conversion circuit 43 is
Noise is superimposed on the constant voltage Vref8K,
This noise becomes the object of comparison, and instead of the periodic pulses shown in FIG. 13(C), the voltage comparison circuit 71 outputs random pulses at a sufficient degree M. A timing pulse is created from the random pulses created in this way and the pulses from the pulse generator 70 in the same manner as in the case where ripples are included, and the distance measuring operation is periodically performed repeatedly and the photographing lens It is emphasized that the position of 57 is controlled. According to the automatic focus adjustment circuit shown in FIG.
Since the relationship between the position of the incident light on I and the output voltage of the arithmetic circuit 45 is linear, it is possible to use a potentiometer 60 with a near characteristic. Adjustments can be made easily. Effects of the Invention As is clear from the detailed explanation above, according to the present invention, in an optical position sensor that includes a pair of main areas and sub areas on a semiconductor substrate surface and detects the position of incident light,
By forming a deformed portion at the end of the pore region near the main region to increase the carrier collection ability compared to other parts of the same region, the output characteristics in the low current region are improved, and the light is incident across the effective light receiving region. It is possible to create a complete set of optical position sensors in which a linear relationship is established between a change in optical position and a corresponding photocurrent characteristic. This simplifies the design of a focus adjustment device using this optical position sensor, and also makes adjustments after assembly extremely easy.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the optical section of a distance measuring device using an optical position sensor, FIG. 2 is an external view of a camera equipped with a distance measuring device, and FIG. 3 is a diagram showing the configuration of a conventional optical position sensor. FIG. 4 is a diagram showing the output characteristics of a conventional optical position sensor, FIG. 5 is a pattern diagram of the embodiment of the present invention, and FIGS. 6(a), (b), (
C) are partial views showing other examples of the deformed portion 25b,
7 shows a second embodiment of the present invention, FIG. 7(a) is a plan pattern diagram, and FIG. 7(b) is a schematic end view taken along line B-H in FIG. 7(a). FIG. 8 is a pattern diagram of the third embodiment of the present invention, FIG. 9 is a graph showing improved photocurrent characteristics, and FIG. 10 is a circuit diagram of an automatic focus adjustment device using an optical position sensor according to the present invention. , FIG. 11 shows the current-voltage conversion circuit 42.
FIG. 12(a) is a circuit diagram showing an example of (also 43). (b) is a graph showing the output characteristics of each part of the circuit in Fig. 10, Fig. 13 (a), (b), (C) and (
d)! ! 10 is a waveform diagram for explaining the circuit operation of FIG. 10. FIG. 22...N-type semiconductor substrate, 23...
P-type first main region, 24... P-type second main region, 25... P-type first sub-region, 26...
...P-type second sub-region, 27...Substrate region sandwiched by the main region, 28.33...First electrode, 2
9.34... Second electrode, 30... Third electrode, 11... Spot light, 12...
... Trajectory of spot light, 25a ... End of first sub-region, 26a ... End of second sub-region, 25b
. 26b...Deformed part. Patent applicant Minolta Camera Co., Ltd. Agent
Person Patent Attorney Jomae Yamabuki and 2 others Figure 2 Figure 4 → Light 4Q4tL [zLam+ [Figure 5 Figure 8 Figure 411 (i!lIλ (li) IN 13
11

Claims (1)

[Claims] (1) A first main region and a second main region of a second type are formed on one surface of a first type semiconductor substrate to be parallel to each other and have the same width, and have a different polarity from the semiconductor substrate. A first sub-region and a second sub-region of a second type are formed to sandwich the substrate region sandwiched by the first and second main regions at a substantially right angle to the direction in which the first and second main regions sandwich the substrate region. a first electrode connecting the first main area and the first sub-area, a second electrode connecting the second main area and the second sub-area, and a third electrode connecting the substrate. Equipped with an electrode of
Injecting light whose incident position can change in a direction substantially perpendicular to the direction in which the first main area extends into a substrate area sandwiched by the first and second main areas, and depending on the intensity and the incident position of the incident light. In the optical position sensor, in which a photocurrent is derived from between the first and third electrodes and between the second and third electrodes, an end of the second sub-area adjacent to the first main area; and a deformed portion protruding at least in a direction facing the trajectory of the incident light is formed at each end of the first sub-region adjacent to the second main region.