JP2810863B2 - Light receiving position detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light receiving position detecting device suitable for level measurement of construction and mechanical work, and more particularly to a device for receiving a light beam emitted and detecting the center position of the light beam in the light receiving region. About. The present invention also provides a light beam emitted by being rotated along a plane including the beam emission point by a light beam emission device disposed at a predetermined position.
The present invention relates to a device that receives a light beam intermittently passing at a position different from the predetermined position and detects a center position of the light beam in the light receiving region. Further, the present invention relates to an apparatus for detecting a center position of a light beam in a light receiving area based on outputs of a plurality of light receiving elements which are appropriately arranged in a direction intersecting a light beam passing direction to form a light receiving area.

[0002]

2. Description of the Related Art An example of this type of light receiving position detecting device is disclosed in Japanese Utility Model Laid-Open No. 4-59409 (Japanese Utility Model Application No. 2-10).
1372). According to this, in the coarse detection mode, the light receiving elements are divided into groups that are consecutive in position, and the light receiving elements in the group obtained by the level detecting means (digital circuits 13A, 13B, 13C) dedicated to each group are used. The level detects which group of light receiving elements the beam to be measured has passed. Then, in the fine detection mode, in the group through which the beam to be measured has passed, light receiving signals of three levels corresponding to the respective light receiving amounts are obtained from at least three light receiving elements for receiving the beam to be measured, and these three light receiving signals are obtained. By detecting where the signal level is located on the Gaussian distribution of the measured beam, the center position of the measured beam is detected.

Another example is disclosed in Japanese Patent Application Laid-Open No. H4-1382.
No. 14 (Japanese Patent Application No. 3-53200) is also known. According to this, in the coarse detection mode, the light receiving elements are divided into groups that are consecutive in position, and the light receiving levels of the light receiving elements in the group obtained by the level detecting means (digital circuits 11A and 11B) dedicated to each group are used. It detects which group of light receiving elements the beam under measurement has passed. In the fine detection mode, in a group through which the beam to be measured has passed, the time (passing time) crossing each light receiving surface from at least three light receiving elements that receive the beam to be measured is detected, and the three passing times are detected. The center position of the beam to be measured is detected by detecting where in the spot of the measurement beam the position corresponding to the spot is detected.

[0004] However, these conventional examples employ a redundant circuit configuration for processing the light receiving signals of all the installed light receiving elements. That is, a signal processing system (in the above example, the digital circuit 1) for detecting the level of the received light signal and detecting the transit time of the measured beam.
3A to 13C and a configuration corresponding to the analog circuits 14A to 14F.
1B and a configuration corresponding to the time detection circuit 12) are a circuit element and a circuit configuration for processing the light reception signals from all the light reception elements, although the light reception signals are obtained only from some of the light reception elements. Are provided for each of the light receiving signals. For example, in the above example, as a matter of course, if the number of light receiving elements increases, the number of inputs of the digital circuits 13A to 13C or the number of digital circuits must be increased, and the circuit scale increases by the increase. The same can be said for the other examples.

[0005]

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a light receiving position detecting device which can contribute to a reduction in circuit scale. The present invention also provides
It is an object of the present invention to provide a light receiving position detecting device capable of processing a light receiving signal with a configuration as small as possible for a large number of light receiving elements.

[0006]

According to the present invention, there is provided a light receiving position detecting device for receiving a beam to be measured and detecting a center position of the received beam, the light receiving position detecting device comprising: A light receiving means comprising a plurality of light receiving elements having light receiving surfaces arranged in a direction intersecting with the light receiving element, a selecting means for selecting one of the light receiving elements according to a selection control signal, and a light receiving element selected by the selecting means Signal processing means for performing signal processing on the received light signal; and control means for calculating the center position from the processing output of the signal processing means and generating the selection control signal based on the processing output of the signal processing means. It is characterized by.

[0007]

According to the light receiving position detecting device of the present invention, one of the light receiving elements is selected according to the selection control signal, and signal processing is performed on the light receiving signal of the selected light receiving element. Then, the center position of the beam to be measured is calculated based on the light receiving signal subjected to the signal processing, and a selection control signal is generated.

[0008]

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

FIG. 1 shows the configuration of a light receiving position detecting device according to an embodiment of the present invention.

In FIG. 1, a light receiving section 10 has a light receiving area formed by a plurality of light receiving elements Ra to Rh and La to Lh provided so that respective light receiving surfaces are exposed on an apparatus panel. Each of the light receiving elements Ra to Rh and each of the light receiving elements La to Lh is composed of, for example, a photodiode, and is linearly arranged at predetermined equal intervals g0. Light receiving elements Ra to R belonging to the first array position
h and the light receiving elements La to Lh belonging to the second array position
Are arranged at a predetermined distance gLR, and the array of the light receiving surfaces of the light receiving elements Ra to Rh is arranged on the right side toward the panel, and the array of the light receiving surfaces of the light receiving elements La to Lh is arranged on the left side. You. Therefore, the light receiving elements Ra to Rh and La to Lh are arranged in a staggered manner. The adjacent right and left light receiving surfaces (for example, the light receiving surfaces of the light receiving elements La and Ra) are connected to the light receiving portion 10 of the laser beam 1 as the measured beam.
Are desirably arranged so that there is no gap in a direction intersecting (preferably orthogonally) to the passing direction with respect to. This is because, when the laser beam 1 passes through the gap, only a part of the laser beam 1 that has passed can be received. The arrangement of the light receiving elements is not limited to the staggered shape. This is shown in more detail in FIG.

In FIG. 2, (a) shows the shape of the spot of the beam 1 to be measured, which spot is substantially circular with a diameter R and passes through the light receiving area of the light receiving section 10. In the light receiving section 10, the light receiving surfaces of the light receiving elements are arranged in a staggered manner as shown in FIG. That is, the rectangular light receiving surfaces of the left light receiving element are linearly connected, and one of the rectangular light receiving surfaces of the right light receiving element is arranged in parallel over two adjacent light receiving surfaces of the left light receiving element. This more specifically shows the arrangement of each light receiving element shown in FIG. In this way, the adjacent right and left light receiving surfaces have no gap in the direction intersecting the direction in which the laser light 1 passes through the light receiving unit 10 (hereinafter, referred to as an array direction), and the laser light Can be received. In addition, in FIG. 2B, the distance between the adjacent right and left light receiving surfaces (for example, the light receiving surfaces of the light receiving elements Le and Re) is set to be not more than one-fourth of the diameter R of the circular spot 1. The above-mentioned light receiving element can receive the laser beam 1 passing therethrough at the same time. In order to form a light receiving region where each light receiving surface has no gap as in (b), a light receiving element in which one side of a rectangular light receiving surface along the arrangement direction is R / 2 is adopted.

On the other hand, instead of such a staggered arrangement,
The light receiving region may be formed in a single linear array as shown in FIG. That is, the light receiving surfaces are arranged in a line in the arrangement direction without any gap. If the distance between the adjacent light receiving surfaces (for example, the light receiving surfaces of the light receiving elements Se and Sf) is set to be equal to or less than one-fourth of the diameter R of the circular spot 1, it can be replaced with the one in FIG. Four or more light receiving elements
The passed laser light 1 can be received at the same time.
In order to form a light receiving region where each light receiving surface has no gap as in (c), a light receiving element in which one side of a rectangular light receiving surface along the arrangement direction is R / 4 is adopted.

Returning to FIG. 1 again, each light receiving element of the light receiving section 10 supplies an electric signal (light receiving signal) of a level corresponding to the amount of received light to the switch circuit 20. Switch circuit 20
Has a plurality of switches each of which receives each light receiving signal from the light receiving unit 10 as a signal input. The signal output terminals of the switches to which the light receiving signals of the right light receiving elements Ra to Rh are supplied are commonly connected to each other, and the common connection terminal is led to the level adjustment circuit 31 via the line A. The signal output terminals of the switches to which the light receiving signals of the left light receiving elements La to Lh are supplied are commonly connected to each other, and the common connection terminal is led to the level adjustment circuit 32 via the line B. The switch circuit 20 is further supplied with a control signal DS from the microcomputer 70, and relays on / off control of each switch, that is, one of the light receiving signals to the lines A and B according to the control signal.

Light receiving signals supplied through lines A and B are supplied to amplifiers 41 and 4 in level adjusting circuits 31 and 32, respectively.
2 is performed. Level adjustment circuits 31, 32
Is composed of, for example, an attenuator formed by a network of resistance elements, and control signals DL1, D1 from the microcomputer 70.
The amount of attenuation is set in accordance with L2, and the light receiving signals of lines A and B are attenuated by the set amount of attenuation, and amplifiers 41 and 4 are used.
Feed to 2. The amplifiers 41 and 42 include the level adjustment circuit 3
A / D by amplifying the level-adjusted received light signal from
The signals are supplied to (analog / digital) converters 51 and 52 and pulse conversion circuits 61 and 62. A / D converters 51, 5
Reference numeral 2 digitizes the amplified light receiving signals from the amplifiers 41 and 42 and supplies the digitalized signals to the microcomputer 70. The pulse conversion circuits 61 and 62 convert the amplified light receiving signals from the amplifiers 41 and 42 into pulses and supply the signals to the microcomputer 70.

The microcomputer 70 receives the digitized signal and the pulse-converted output signal, and displays the display 8 based on the received signal and in accordance with a processing sequence described later.
The control signal DS to the switch circuit 20 and the control signals DL1 and DL2 to the level adjusting circuits 31 and 32 are generated.

Next, main operations of the light receiving position detecting device having such a configuration will be described.

FIGS. 3 to 5 show a processing procedure for detecting the center position of the received light beam including the switch selection control executed by the microcomputer 70. FIG.

In FIG. 3 to FIG. 5, when the process proceeds to this processing routine, the microcomputer 70 first connects the light receiving elements Ra to Rd of the upper half of the right light receiving element to the line A, and connects the lower half of the left light receiving element. Light receiving elements Le to Lh
Is supplied to the switch circuit 20 so that is connected to the line B (step S1). After the connection, when the beam under measurement 1 passes through the light receiving unit 10, the microcomputer 70 sets the A / D converter 51 corresponding to the line A to the A / D converter 51.
Then, based on the output signal of the A / D converter 52 corresponding to the line B, it is determined which of the light receiving elements corresponding to the line has received the beam 1 to be measured (step S2). If it is determined that the received light signal is obtained only from the line A, the process proceeds to step S11. If it is determined that the received light signal is obtained only from the line B, the process proceeds to step S21, and the received light signal is received from both the lines A and B. If it is determined that it has been obtained, the process proceeds to step S3.

When it is determined in step S2 that light receiving signals have been obtained from both the lines A and B, the microcomputer 70 determines that the beam to be measured 1 has crossed substantially the center of the light receiving unit 10, and The light receiving element Rd at the center of the right light receiving element is connected to the line A, and the light receiving element Le at the center of the left light receiving element adjacent to the light receiving element Rd is connected to the line B.
The control signal DS is supplied to the switch circuit 20 so as to connect to (step S3).

When it is determined in step S2 that a light receiving signal has been obtained only from the line A, the microcomputer 70 determines that the beam to be measured 1 has traversed above the light receiving section 10, and determines that the right light receiving element Upper light receiving element R
a, Rb are connected to the line A, and the upper light receiving elements Lc, Ld of the left light receiving element located below the light receiving elements Ra, Rb.
Is supplied to the switch circuit 20 so that is connected to the line B (step S11). After such a connection,
When the measured beam 1 passes through the light receiving unit 10, the microcomputer 70 sets the A / D converter 5
Based on the output signals of the A / D converter 52 corresponding to the line 1 and the line B, it is determined which line the light receiving element has received the beam under measurement 1 (step S1).
2). When it is determined that the light receiving signal is obtained only from the line A, the process proceeds to step S14, and when it is determined that the light receiving signal is obtained only from the line B, the process proceeds to step S16, where the light receiving signal from both the lines A and B is received. If it is determined that is obtained, the process proceeds to step S13. Step S1
When it is determined that the light receiving signal is obtained from both the lines A and B in the microcomputer 2, the microcomputer 70
The measured beam 1 is composed of light receiving elements Ra and Rb and light receiving element Lc,
Ld and the control signal DS to the switch circuit 20 so that the light receiving element Rb of the right light receiving element is connected to the line A and the left light receiving element Lc adjacent to the light receiving element Rb is connected to the line B. (Step S1)
3). If it is determined in step S12 that a light receiving signal has been obtained only from the line A, the microcomputer 70 sets the light beam to be measured 1 to the light receiving element Ra and the light receiving element L
The control signal DS is supplied to the switch circuit 20 so that the right light receiving element Ra is connected to the line A and the left light receiving element Lb adjacent to the light receiving element Ra is connected to the line B. (Step S14). Thereafter, when the beam to be measured 1 passes through the light receiving unit 10, the microcomputer 70 sets the A / D converter 51 corresponding to the line A to “A”.
Then, based on the output signal of the A / D converter 52 corresponding to the line B, it is determined which line the light receiving element corresponding to has received the beam 1 to be measured (step S15). If it is determined that the light receiving signal has been obtained, the process proceeds to step S14. If it is determined that the light receiving signal has been obtained only from the line B, the process proceeds to step S11, and it is determined that the light receiving signal has been obtained from both the lines A and B. Moves to step S4. If it is determined in step S12 that a light receiving signal has been obtained only from the line B,
The microcomputer 70 determines that the measured beam 1 has crossed between the light receiving element Rc and the light receiving element Ld,
A control signal DS is supplied to the switch circuit 20 so that the right light receiving element Rc is connected to the line A and the light receiving element Ld of the left light receiving element adjacent to the light receiving element Rc is connected to the line B (step S16). Thereafter, when the measured beam 1 passes through the light receiving unit 10, the microcomputer 70 determines which of the two based on the output signals of the A / D converter 51 corresponding to the line A and the A / D converter 52 corresponding to the line B. It is determined whether the light receiving element corresponding to the line has received the beam under measurement 1 (step S17). If it is determined that the light receiving signal has been obtained only from the line A, the process proceeds to step S11, and the light receiving signal only from the line B. If it is determined that the light receiving signal has been obtained, the process proceeds to step S, and if it is determined that the light receiving signals from both the lines A and B have been obtained, the process proceeds to step S4.

If it is determined in step S2 that a light receiving signal has been obtained only from the line B, the microcomputer 70 determines that the beam to be measured 1 has crossed the lower side of the light receiving section 10, and the microcomputer 70 determines Lower light receiving element R
e, Rf are connected to the line A, and the light receiving elements Lg, Lh below the left light receiving element located below the light receiving elements Re, Rf.
Is supplied to the switch circuit 20 so that is connected to the line B (step S21). After such a connection,
When the measured beam 1 passes through the light receiving unit 10, the microcomputer 70 sets the A / D converter 5
Based on the output signals of the A / D converter 52 corresponding to the line 1 and the line B, it is determined which of the lines the light receiving element has received the beam 1 to be measured (step S2).
2). When it is determined that the received light signal is obtained only from the line A, the process proceeds to step S26. When it is determined that the received light signal is obtained only from the line B, the process proceeds to step S24, and the received light signal is received from both the lines A and B. If it is determined that it has been obtained, the process moves to step S23. Step S2
When it is determined that the light receiving signals from both the lines A and B are obtained in the microcomputer 2, the microcomputer 70
Means that the beam 1 to be measured has light receiving elements Re and Rf and light receiving element L
g, Lh, the switch circuit 2 connects the right light receiving element Rf to the line A, and connects the left light receiving element Lg adjacent to the light receiving element Rf to the line B.
The control signal DS is supplied to 0 (step S13). When it is determined in step S22 that the light receiving signal has been obtained only from the line B, the microcomputer 70
Judging that the beam under measurement 1 has crossed between the light receiving elements Rg and Lh, the right light receiving element Rg is connected to the line A, and the left light receiving element Lh adjacent to the light receiving element Rg is connected to the line B. Control signal DS to the switch circuit 20
Is supplied (step S24). Thereafter, when the measured beam 1 passes through the light receiving unit 10, the microcomputer 7
0 is based on the output signals of the A / D converter 51 corresponding to the line A and the A / D converter 52 corresponding to the line B,
It is determined which line the light receiving element corresponding to has received the beam under measurement 1 (step S25). If it is determined that a light receiving signal has been obtained only from line A, step S2 is performed.
1 and if it is determined that the light receiving signal has been obtained only from the line B, the process proceeds to step S24, where the lines A and B
If it is determined that the light receiving signal has been obtained from both of them, the process proceeds to step S4. If it is determined in step S22 that the light receiving signal has been obtained only from the line A, the microcomputer 70 sets the light beam to be measured 1 to the light receiving element Re.
And the control signal DS to the switch circuit 20 so as to connect the right light receiving element Re to the line A and to connect the left light receiving element Lf adjacent to the light receiving element Re to the line B. (Step S2)
6). Thereafter, when the measured beam 1 passes through the light receiving unit 10, the microcomputer 70 determines which of the two based on the output signals of the A / D converter 51 corresponding to the line A and the A / D converter 52 corresponding to the line B. It is determined whether the light receiving element corresponding to the line has received the beam under measurement 1 (step S27). If it is determined that the light receiving signal has been obtained only from the line A, the process proceeds to step S3, and the light receiving signal only from the line B. If it is determined that is obtained, step S21
When it is determined that the light receiving signal has been obtained from both the lines A and B, the process proceeds to step S4. Thus, the beam 1 to be measured is assumed to have been received in the vicinity of its center position. No two reception signals are guided from the light receiving element (specific light receiving element) to lines A and B (end of coarse detection). Thereafter, when the beam to be measured 1 passes through the light receiving unit 10, the microcomputer 70 outputs a signal based on the output signals of the A / D converter 51 corresponding to the line A and the A / D converter 52 corresponding to the line B. The light receiving signal level of the specific light receiving element is captured (step S4). Further, the microcomputer 70
Is connected to the line B of the other light receiving element adjacent to the right light receiving element of the specific light receiving element to obtain a light receiving signal from the light receiving element one pitch outside the specific light receiving element,
A control signal DS is supplied to the switch circuit 20 so that the other right light receiving element adjacent to the left light receiving element among the specific light receiving elements is connected to the line A (step S5).

For example, when the process proceeds from step S3 to step S4, the central light receiving element Rd which is a specific light receiving element.
, Ld are taken in, and the other light receiving element Ld adjacent to the light receiving element Rd is connected to the line B.
The other light receiving element Re adjacent to the light receiving element Le is connected to the line A.

After the connection, when the beam under measurement 1 passes through the light receiving section 10, the microcomputer 70 outputs the output of the A / D converter 51 corresponding to the line A and the output of the A / D converter 52 corresponding to the line B. Based on the signal, the level of each light receiving signal of the outer light receiving element is captured (step S
6). Next, the microcomputer 70 proceeds to step S
Based on the four light receiving signal levels captured in steps 4 and 6, an operation for finding the center position of the beam 1 to be measured with a resolution of one pitch or less on the light receiving surface, that is, fine detection is performed (step S 7). Then, the microcomputer 70 controls the display of the display 80 so as to display the center position of the measured beam 1 obtained by the calculation (step S8), and terminates the present routine.

The calculation performed in step S7 is performed as follows. That is, in step S4, line A
The light receiving signal level a obtained through the line A and the light receiving signal level one pitch outside obtained through the line A in step S6 are a ', and the light receiving signal level obtained one line outside through the line B in step S6. , A, a ', b, b'
Is made to correspond to the Gaussian distribution of the beam 1 to be measured, and the center position of the beam 1 to be measured is obtained from the coordinates of the intersection of the straight lines a and b 'and the straight lines a' and b on the coordinates of the Gaussian distribution.

The microcomputer 70 controls the level adjustment circuits 31 and 32 in parallel with this processing, in addition to the center position detection processing shown in FIGS. This control will be described with reference to the waveform diagram shown in FIG.

In FIG. 6, if the output signals of the amplifiers 41 and 42 are clipped at the predetermined clip level VC as shown in FIG. 6A, the microcomputer 70 cannot detect the maximum value of the received signal. Therefore, in the pulse conversion circuits 61 and 62, the output signal of the amplifier is compared with predetermined first and second levels V1 and V2, and (b)
Generates a first pulse signal which goes high when the output signal of the amplifier is higher than the first level V1 as in the case of (a), and when the output signal of the amplifier is higher than the second level V2 as in (c). , A second pulse signal which becomes high level is generated. The microcomputer 70 detects the pulse widths of the first and second pulse signals, that is, the high-level duration, and supplies the clipped signal values from the A / D converters 51 and 52. The maximum value (amplitude) of the received signal supplied to the lines A and B is predicted based on the width. Based on this prediction, the microcomputer 70 specifies the amount of attenuation to be set in the level adjustment circuits 31 and 32 by the control signals DL1 and DL2 so that the maximum value appears in the output signals of the amplifiers 41 and 42.
The level adjustment circuits 31 and 32 connect the resistors corresponding to the designated attenuation amounts to attenuate the light receiving signals of the respective lines to produce input signals of appropriate levels to the amplifiers 41 and 42.

For example, at a certain point in time, the beam 1 to be measured passes through the light receiving section 10, and the pulse widths of the first and second pulse signals obtained at this time are t1 and t2, and are set at this time. Assuming that the attenuation resistance value of the level adjustment circuits 31 and 32 is R, the attenuation resistance value R ′ to be set when the beam under measurement 1 passes through the light receiving unit 10 next is: R ′ = R (1−t1 / t / 2).

In practice, since the waveform of the received signal supplied to each line is not ideal, it is not possible to set an appropriate amount of attenuation by a single level adjustment. Is effective when the level of the received signal is relatively large. Also, this level adjustment control
Step S in the center position detecting process of FIGS. 3 to 5
It is preferable that the processing be completed before step 4 is executed, that is, before the coarse detection ends.

In the center position detecting process shown in FIGS. 3 to 5, the switch circuit 20 is controlled so that the number of light receiving elements connected to the lines A and B is reduced by half each time the beam 1 passes in the coarse detection. However, only one light receiving element may be connected to each line, and the light receiving elements may be connected in order. For example, first, light receiving elements Ra and La are connected to lines A and B, and then R
b, Lb, Rc, Lc, ..., Rg, Lg, Rh, Lh
Are connected. However, the above embodiment in which the number of line connections of the light receiving element is reduced by half is more efficient for selecting a specific light receiving element that is assumed to have received the beam under measurement 1 near its center position. And the number of selections is small.

As can be seen from the above description, in the present embodiment, a switch circuit is provided in the preceding stage of a signal processing system such as level adjustment, amplification, A / D conversion, and pulse conversion, and is selected by the switch circuit. Only the light receiving signal of the light receiving element is processed. As a result, the signal processing system is utilized by the microcomputer in a so-called time-division manner, so that the size of the signal processing system can be reduced even if the number of light receiving elements increases. In still another aspect, the signal processing system can be kept small irrespective of the number of light receiving elements, so that a considerable effect on weight reduction or power reduction is expected as the number of light receiving elements increases. .

[0031]

As described above in detail, according to the light receiving position detecting device of the present invention, one of the light receiving elements is selected according to the selection control signal, and the light receiving signal of the selected light receiving element is subjected to signal processing. Is applied. Then, the center position of the beam to be measured is calculated based on the light receiving signal subjected to the signal processing, and a selection control signal is generated. As a result, the circuit scale can be reduced, and a light receiving signal can be processed with a configuration as small as possible for a large number of light receiving elements.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a light-receiving position detecting device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing the shape of a spot of a beam to be measured and the arrangement of light receiving elements in the light receiving position detecting device of FIG.

FIG. 3 is a flowchart showing a part of a processing procedure of a center position of a beam to be measured, which is executed by a microcomputer in the light receiving position detecting device of FIG. 1;

FIG. 4 is a flowchart showing another part of the processing procedure for detecting the center position of the beam to be measured, which is executed by the microcomputer in the light receiving position detecting device of FIG.

FIG. 5 is a flowchart showing still another part of the processing procedure of the center position detection of the beam to be measured, which is executed by the microcomputer in the light receiving position detecting device of FIG.

FIG. 6 is a waveform diagram showing an output signal of an amplifier and a converted signal by a pulse conversion circuit in the light receiving position detecting device of FIG. 1;

[Explanation of symbols]

REFERENCE SIGNS LIST 1 beam to be measured 10 light receiving parts Ra, Rb, Rc, Rd, Re, Rf, Rg, Rh light receiving elements La, Lb, Lc, Ld, Le, Lf, Lg, Lh light receiving element 20 switch circuit 31, 32 level adjustment circuit 41, 42 Amplifier 51, 52 A / D converter 61, 62 Pulse conversion circuit 70 Microcomputer 80 Display

Claims (3)

(57) [Claims] 1. A light receiving position detecting device for receiving a beam to be measured and detecting a center position of the received beam, wherein a plurality of light receiving surfaces are arranged in a direction intersecting a passing direction of the beam to be measured. A light receiving means comprising a light receiving element, a selecting means for selecting one of the light receiving elements according to a selection control signal, a signal processing means for performing signal processing on a light receiving signal of the light receiving element selected by the selecting means, Control means for calculating the center position from the processing output of the signal processing means and generating the selection control signal based on the processing output of the signal processing means. 2. The method according to claim 1, wherein the selecting unit relays a light receiving signal from at least one of the light receiving elements belonging to a predetermined first arrangement position to a first output terminal in response to a selection control signal, and is different from the first arrangement position. A light receiving signal from at least one of the light receiving elements belonging to the second array position is relayed to a second output terminal, and the signal processing means outputs a signal corresponding to each light receiving signal from the first and second output terminals, respectively. 2. The light receiving position detecting device according to claim 1, further comprising an amplifier circuit for amplifying, and an A / D converter for digitizing each output signal of the amplifier circuit. 3. The signal processing means according to claim 1, wherein said signal processing means comprises:
A level adjusting circuit that performs level adjustment on each light receiving signal from the output end in accordance with a level control signal and supplies the level adjusting signal to the amplifier circuit; and a level adjusting circuit having an edge when the output signal of the amplifier circuit reaches a first predetermined level. A pulse conversion circuit for generating a second pulse signal having one pulse signal and an edge at the time when the output of the amplifier circuit reaches a second predetermined level;
3. The light receiving position detecting device according to claim 2, wherein said control means generates said level control signal in accordance with a pulse width of said first and second pulse signals.