JPS6013210A - Distance measuring device - Google Patents

Abstract

PURPOSE:To make it possible to perform accurate measurement in a broad range, by providing two pairs of light receiving parts, in which a convergent optical system and a detecting element form one pair, and making the pairs to perform the long-distance measurement and the short-distance measurement, respectively. CONSTITUTION:A convergent optical system 14 is separated by a specified base-line length AN from a light projecting axis of a light source device 12 and has a parallel optical axis. A semiconductor light-position detecting element 15 is provided along the reference plane of the light axis of the optical system 14 and the light projecting axis of the device 12 so that the element is perpendicular to the optical axis of the optical system 14 and the light receiving surface is separated from said optical axis. A convergent optical system 16 is separated by another specified base-line length AF, which is larger than the optical system 14. The system is in parallel with a light-projecting optical axis and has an optical axis in a reference plane. The light receiving surface of a semiconductor optical- position detecting element 17 is set along the reference plane and the element 17 is arranged in perpendicular to the optical axis of the optical system 16. The light receiving surface end is separated from the optical axis and receives the reflected light from the point, which is father than the element 15. The light receiving part comprising the optical system 14 and the element 15 measures the short distance, and the light receiving part comprising the optical system 16 and the element 17 measures the long distance, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a distance measuring device that automatically calculates the distance to an object using a semiconductor device detection element.

(Prior Art) First, a semiconductor device detection element and a conventional distance measuring device using this element will be described.

A semiconductor device detection element is capable of outputting information regarding the position of light incident on the element. If the distance to the object is determined based on the incident position of the light, the distance to the object can be determined by calculating the output of the semiconductor device detection element.

FIG. 2 is a schematic diagram for explaining the basic configuration of a semiconductor device detection element.

A conductive layer 8 different from the substrate is formed on one surface of the semiconductor substrate 7 of the semiconductor device detection element 3 .

A resistive layer 9 is formed on this conductive layer 8;
Two electrodes 10a and 10b are provided at both ends of the group F.
Both i and 7 are provided with an i11 electrode 11.

When a point-like light beam enters between the electrodes 10a and 10b, a current flows to the electrode 4i10a. Electric 4! Current I2 to rA1ob,
13 flows to the electrode 11.

Between those currents I3 = 1. A +12 relationship is established. If the resistance of the resistance layer 9 is made uniform, the distance L1. Incident point of light flux and electrode 1
If the distance of 1m of ob is F'JII L 2, then LI I
The relationship I=L2I2 holds true.

If the calculation is performed based on this relationship, the semiconductor device detection element 3
The incident point P of the luminous flux incident on is expressed by the following formula (1)% formula% (1) where P is the origin at the midpoint of the electrodes 10a and 10b, and ffi
This is the incident point of the light beam expressed in coordinates with the pole 10a in the positive direction. 1 (is a conversion constant to the length unit (m rn ).

Figure 1 shows a conventional example of a distance measuring device using this type of body light position detection element.This conventional example uses the distance measurement results to automatically control the automatic steering of 1V transportation of cargo, etc. It is intended for this purpose.

A light source 1 that projects a light beam and a converging optical system 2 that receives reflected light from an object to be measured are provided apart by a base line length A.

The optical axis of the light beam and the optical system 2 are parallel. The light-receiving surface of the semiconductor device detection element 3 described above is located in a focal plane perpendicular to the optical axis, and is fixed such that the optical axis is located between the detection electrodes 1'Oa and Iob.

When the distance to the object to be measured is l, the base line length is A, and the focal length of the optical system 2 is b, the following equation (2) holds between them.

A/β=P/b (2) The output current of each electrode of the semiconductor device detection element 3 is calculated by the calculation device 4.
The calculation results 7!1 are sent to the conveyance vehicle advancing angle θ calculation unit 5, and the respective outputs 11. β2 and θ are outputted to the drive section 6 of the steering control device for the one-way vehicle, where 6 is provided.

Next, the configuration of the arithmetic unit 4 will be explained with reference to FIG.

Detection electrodes 10a, 10 of the semiconductor device detection element 3 described above
The currents I, , 12 from b are respectively connected to the differential input terminals of the /JliS\amplifier A1 of the arithmetic unit 4, and the output thereof is connected to the sample bold circuit S1.

On the other hand, the current I3 from the common electrode 11 mentioned above is connected to the operational amplifier A2, and its output is supplied to the sample and hold circuit S2.
connected to.

These sample bold circuit S and sample hold circuit S2 are bolded for a certain period of time by pulses from a pulse generator C1 that generates sample bold pulses, and the output of Sl (TI-12) is the dividend of the next divider D1. The output of S2 (Il+12) is input to the divisor section of Dl.

If the output of the divider D1 is VD, then the above (11, I2
From equation 1, VD= (II I2)/ (If +12)=A −
b/jl! ......The following relational expression (3) is given.

As is clear from equation (3), VD is the distance to the object to be measured!
It is inversely proportional to iltβ.

When this VD is input to the next lookup table T1, the lookup table T1 outputs the distance l1Suit to the target 11111 constant object corresponding to VD.
Outputs +.

FIG. 9 is a schematic diagram for explaining the principle of an angle detecting device for a carrier using two distance measuring devices configured as described above.

As shown in FIG. 12, two distance measuring devices having a similar configuration are mounted on the side of the carrier C so that their optical axes are perpendicular to the traveling direction ('J+-).

The measured distance of distance measuring device I from the front in the direction of travel is β1
, the distance measured by the distance measuring device H is assumed to be β2.

These measured distance outputs β1, 12 are calculated by the calculator 0 shown in FIG.
1, and in this arithmetic unit 01, (jl!2−
1! , ) /LO is calculated.

Here it is. is the distance between the light sources projecting the respective light beams of the two distance measuring devices mentioned above.

The above-mentioned transport vehicle traveling angle θ is such that the first general transport vehicle traveling direction is the wall W.
The following equation holds true with the angle formed between

tanθ= (j!2A!+) /Lo...1
However, 7!1 is the output of the distance measuring device attached to the front of the vehicle in the direction of travel.

The output of the arithmetic unit 01 -(7!2-(11)/Lo) is input to the next lookup table T2, and θ that satisfies the above-mentioned equation (4) is output from I2.

These values θ, A, . J2 are input to the drive unit 6 of the steering control device described above.

In this way, by using two distance measuring devices, it is possible to obtain information necessary for automatic steering.

However, as mentioned above, as is clear from equation (2),
Since the incident position of the light spot on the semiconductor device detection element 3 is inversely proportional to the distance ff1tp to the object to be measured, as the distance to the object to be measured increases, the positional displacement of the detection element on the light-receiving surface becomes smaller, resulting in accurate detection. I can't get the value.

The measurement range is large, and there is a one-digit difference between the lower limit and the second limit, and even a measurement range of, for example, 0.2 m to 2 m is a problem.

(Object of the Invention) An object of the present invention is to provide a distance measuring device that solves the above-mentioned problems.

(Structure and operation) In order to achieve the above object, a distance measuring device according to the present invention includes a light source device that projects a small-diameter light beam in the direction of a measured object, and a light source device that is spaced apart from the projection optical axis of the light source device by a certain base line length. a first convergent optical system arranged to strike an optical axis parallel to the projection optical axis direction; and a base whose light receiving surface is formed by the optical axis of the first convergent optical system and the projection optical axis of the light source device! a first semiconductor, which is perpendicular to the optical axis of the first converging optical system along the 1ζ plane, the end of the light-receiving surface is disposed apart from the front axis, and has a pair of detection electrodes and a -J1=conducting electrode; a device detection element; and a second device, which is arranged apart from the optical axis of the light source device by another fixed baseline length that is larger than the fixed baseline length, and has an optical axis parallel to the projection optical axis direction and within the reference plane. a converging optical system, a light receiving surface is arranged along the reference plane at right angles to the optical axis of the second converging optical system, an end of the light receiving surface is arranged apart from the front axis, and a pair of detection electrodes and a common Detection of a pair of a second semiconductor device detection element having an electrode and receiving reflected light from a place farther than the reflected light received by the light receiving surface of the first semiconductor device detection element, and the first semiconductor device detection element. a first position calculator that calculates the incident position from the output of the first position calculator; a first converter that converts the output of the first position calculator into a distance to the object to be measured; and the second semiconductor device detection element. a second position calculator that calculates the incident position from the outputs of the pair of detection electrodes; a second converter that converts the output of the second position calculator into a distance to the object to be measured; A device that compares the outputs of the second semiconductor device detection element to determine which semiconductor device detection element is outputting a signal corresponding to the object to be measured, and outputs the output of the converter corresponding to the semiconductor device detection element. It consists of an arithmetic unit consisting of one constant.

Zunawaji, a pair of converging optical system and semiconductor device detection element 2m long
Since the set number measurement distance Nli fffi is divided and measured so that one set takes charge of the short distance range and the other set takes charge of the long distance range, highly accurate distance measurement can be performed. The arithmetic unit automatically determines which set to use.

(Description of Embodiment) 401 is a block diagram showing an embodiment of a distance measuring device according to the present invention.

The light from the light source 12 that emits light with a small diameter is transmitted to the projection optical system 1.
3 and projected toward the object to be measured.

The first converging optical system 14 is a converging optical system having an optical axis parallel to the projection optical axis direction, which is disposed at a constant normal length ΔN to the optical axis of the light source 12, and has a focal length bN. .

The light condensing surface of the first semiconductor device detection element 15 is arranged perpendicular to the optical axis of the first focusing optical system 14 .

The X-axis (see FIG. 2) of the first semiconductor device detection element 15 corresponds to the light tA12. The optical axis of the projection optical system 13,
It is located in a plane that includes the optical axis of the first converging optical system 14, and the light receiving surface 111j1 is a certain length P from the optical axis of the first converging optical system 14. They are located N distances apart.

Here, PON means that at the measurement distance H handled by the first semiconductor device detection element 15, the position on the light-receiving surface where the point-like incident light beam forms an image when nN is maximum is slightly closer to the effective light-receiving position than one end. (positive direction of the X axis).

The second converging optical system 16 is disposed apart from the optical axis of the light source 12 by a certain base line length AF, and its optical axis is parallel to the projection optical axis direction and is parallel to the projection optical axis direction. It lies within a plane formed by the optical axis of the projection optical system 13 and the optical axis of the first converging optical system 14.

Note that the aperture of the second converging optical system I6 is the same as that of the optical system 1.
The focal length is about 3 times the aperture of 4.4 and the focal length is bp.

The light-receiving surface of the second semiconductor device detection element 17 is perpendicular to the optical axis of the second converging optical system 16 and the X-axis (see FIG. 2).
is the light source 12. It lies within a plane formed by the optical axis of the projection optical system 13 and the optical axis of the first converging optical system 14. Also, one end of the light receiving surface is at a constant 1 iP from the optical axis of the second converging optical system 16.
. It is located at a distance of F. Here, PoF means that when the measurement distance xp handled by the second semiconductor device detection element 17 is maximum, the position on the light-receiving surface where the point-like incident light beam forms an image is slightly smaller than the effective light-receiving position (IIIJ (X-axis In the figure, Bl'
If βF is the effective amount of light received by the second semiconductor device detection element 17, the imaging position of the point-like incident light beam is X
It is arranged at a position slightly inside from the position on the axis (BF-P.F).

The output current of each electrode of the first and second semiconductor device detection elements 15.17 is connected to a distance output generator 18,
This distance output is connected to the angle output calculation section 19 together with the other distance output.

At the same time, this angle output is also connected to the steering control drive section of the 20 conveyance vehicles. The light source 12 is a light source drive unit 21
Driven by.

Further explanation will be given using an actual design example when the measurement distance l is 0.2 m to 2 m.

From the above formula (2), p=A-b/I2...■ Effective light receiving length of each semiconductor device detection element Let BF=BN=12rnm=B.

From the above formula, the minute displacement Δp of the light point P is Δp = A b/Δβ
It is expressed as

Here, Δp=B/300=40 μm is the maximum value of the dispersion, that is, the maximum value of the resolution of the detection element −300. This is because the signal current obtained from the detection element is on the order of several nanoamperes.

In the second semiconductor device detection element 17, Δp
is inversely proportional to β, so the measurement distance p=2000rnrn
If the measurement stability is 1%, then Δp = A ll
/ 3000~Ab/2020≧40μm From this relational expression, 8・b=AP−bP≧8080・・・・■Here, IIF
Minimum value of - Maximum value of AN - Measurement switching distance - 600rnm
shall be.

If bF=roomm, then the following relational expression can be obtained from equation (2).

P when n=2000mm is P2O00, g=60Q
P when m m is P (if you take ioo, P2O00
= (ΔIi X100)X2000...■P60
0 = (AF xi 00) /600... ■The above formulas ■ and ■ are changed to P 600 - P 2000 - effective light receiving length of the detection element B - 2 = 10 mm, f' + W <,
AF #85.7mm. At this time, AP-bF −=
8570, which satisfies the relationship (2) above.

Therefore, P in FIG. F is o from the above formula 0 F = P 2000-0.5 = (85,7 x 100) x 2000-0.5 = 3.7
85mm 0 Similarly, in the detection element 15, if the measurement distance p (-old 606≧40
IJm From this relational expression, AN-bN≧2424... ■ If bN = 60 mm, P in the ■ equation when 12 = 600 rn is P60Q, 7! If P when =200rrtm is P2O0, then P6O0= (AIJ x 60) /G OO...
■P2O0= (ANx60) X200...■P
200-P 600-J light receiving length of the detection element B-2
=IO(mrn), AN=59rnrn.

At this time, AN −bN =3QOO, which satisfies the above formula 0. Therefore, poN in Fig. 4 =])600 -1 - (50X60)X600-1 = 4 mm Also, the openings of the first and second converging optical systems 14 and 16 i\
The ratio is determined by the following relationship. First semiconductor device detection element 15. The amount of light incident on the light receiving surface of the second semiconductor device detection element 17 is inversely proportional to the square of the measurement distance, and proportional to the square of the apertures of the first and second converging optical systems 14.1G.

Therefore, if the aperture of the first converging optical system 14 is dN and the aperture of 1G is dF, then when the following relationship holds, the long-distance measurement system and the short-distance measurement system can obtain approximately the same amount of received light.

((dN/dP) 2)” = C (600/2000) 2)” Therefore, dN/dF=3/10.

In FIG. 4, the coordinates of the detection element 15 are set as shown in FIG. 2 above.

The light flux incident point p=BN/2 is βN-old 14 (minimum).

1)=-BN/2 corresponds to /N=MAX (maximum).

Corresponding to the above equation (2), the following equation (3) holds true.

AN/j! N = (Po N -1-(BN /2
) 4-P) /bN. . . . (3) Here, BN is the effective light receiving length of the semiconductor device detection element 15 of ff11, and its center corresponds to the origin (0, 0) in FIG.

Similarly, coordinates as shown in FIG. 2 are set for the second semiconductor device detection element 17. Light flux incidence point P=BF/2
is βF=old N (minimum)〈#I! , maximum of N, P=-B
P/2 corresponds to AP=MAX (maximum). Then, the following equation (4) holds true.

AF /ilF = (Po F + (BP / 2
) +P) /bF (4) Here, BF is the effective light receiving length of the second semiconductor device detection element 17, and its center corresponds to the origin (0, O) of the coordinates. And the first and second semiconductor device detection elements 15.17
Since the amount of incident light is proportional to the square of the effective light-receiving aperture of the first and second converging optical systems 14 and 16, taking this into account,
The aperture of the first converging optical system 14 is set to about 1/3 of that of the second converging optical system 16.

Next, the configuration of the arithmetic unit 18 will be explained with reference to FIGS. 5 and 6.

Detection electrodes 10a, 10 of first semiconductor device detection element 15
The outputs 11N, 12N of b are connected to a subtracter A3, and the output of the common electrode is connected to an amplifier A4.

Detection electrodes 10a, 10 of second semiconductor device detection element 17
The outputs 11F and I2F of b are connected to a subtracter A5, and the output of the common electrode is connected to an amplifier A6.

Sampling bold circuit 33. S4, 35.36 receives clock φ1 from clock generator C2 (see Figure 7)
is connected. Sampling hold circuit s3. S
4. S5. S6 is A3°A4. Δ5. This is a sampling and holding circuit that samples and holds the output of A6 at the rising edge of clock φ1.

The first divider D2 includes sampling and holding circuits S3 and S
From the output of step 4, calculate (I IN - 12N) / (11N + 12N).

The second divider D3 includes sampling and holding circuits S5 and S.
From the output of step 6, calculate (I IF-12F) / (I IF+12F).

The output of the sampling hold circuit S4 (1'IN+I2N) and the output of the sampling bold circuit S6 (11F+12F>) are connected to the third judger DM, and perform the calculations necessary for the following equation (5). .

DM - (IIF+12F)/, (IiN+l2N)
≧D8...(5) D2= (I lN-l2N) / (I IN+ r
2N)≦DB (6) FIG. 8 is a graph showing the relationship between DM and measurement distance l.

In the figure, the measured switching distance βB is 7! Almost corresponds to N(-old X)-=j2F(-old N).

FIG. 9 shows the relationship between D2 in equation (6) and the position (0°P) of the incident light beam.

In the figure, as l increases from near #=6B, where P approaches -BN/2, D2 loses its linearity with respect to P and becomes extremely curved.

In other words, the measurement stability by the first semiconductor device detection element 15 becomes extremely poor. Therefore, in advance, ju11 in Figure 4
'1, the value D2 of the divider D2 becomes larger than DB (smaller in absolute value) at the switching point where DH=D8 in the above equation (5), and the value D2 of the divider D2 shown in FIG. is enough P
Each configuration is determined so that the position maintains linearity.

If the determiner M satisfies either formula (5) or (01), the distance Ml is determined by the second semiconductor device detection element 17.
Make a decision to measure f.

Therefore, when neither f5) nor equation (6) is satisfied, it is determined that the distance is measured by the first semiconductor device detection element 15.

FIG. 6 is a block diagram showing the detailed configuration of the determination circuit M included in the arithmetic unit 18 of FIG.

The divider DM included in the determination circuit M is the DM of the above equation (5).
This is a divider that calculates = (IIF+l2F)/(IIN+12N), and its output (DM) is connected to 2 to the comparator.

The comparator 2 makes a judgment based on equation (5) (determination of D to 1≧DA), and its logical output (1, O) is connected to one input terminal of the OR circuit E1.

On the other hand, the output of the divider D2 is connected to 1 in a comparator, where the above-mentioned equation (6) is determined (determination of D2≦DB),
Its logic output (1, 0) is connected to the other input terminal of the OR circuit E1.

When either of formulas (51 and (6)) is satisfied, the output of the OR circuit E1 becomes "1", and the determiner M makes a determination to measure the distance using the output of the second semiconductor device detection element 16.

The output of the OR circuit E1 is connected to the command unit I (
The command section includes a selection circuit SM composed of a semiconductor switch and an analog memory based on the output of the OR circuit E1.
Outputs an opening/closing command signal to I and SM2.

The selection circuit SM2 includes a divider D2. The output of D3 is connected, and the selection circuit SMI is connected to the sample and hold circuit S,...
The output of S6 is connected.

Command unit (2) (For example, when the output of the OR circuit E1 is "L", the selection circuit SM2 outputs the contents of D3, (IIF-1210/(11F+12F>).

Also, the contents of 86 in the selection circuit SMI, (11F+I2F) is output.

Further, when the output of the logical sum circuit E1 is 0'', the command unit l( makes the selection circuit S'M2 output the contents of D2, (I IN - I 2N) / (I IN Toka 2N).

In addition, the contents of 55 in the selection circuit SMI, (11N+I2N) is output.

FIG. 7 shows the clock timer-1.

The clock φ1 is a sample bold pulse output from the clock generator C2, and the sample bold circuit s3. s4. S5. Make S6 sample bold.

φG1 is a command signal to the selection circuit SMI.
It is output in synchronization with the falling edge of the first clock pulse t. The selection circuit SMI connects the signal of the sample and hold circuit S4 or 56, which is bolded at tl of the clock φ1, to the light source driving section 21 until the falling edge of C3.

From the falling edge of the clock pulse t3, the next signal φG1 is input to the selection circuit SMI by the command unit. This results in
The determined one (I, +1
2) is connected.

The light source driver 21 outputs a drive current to the light source 12 that is inversely proportional to the amount of received light by dividing this reference value (Il + I2).
A drive current is output to the light source 12 so as to eliminate changes in the amount of light received by the detection element due to changes in the measurement distance.

φG2 is a command signal of the selection circuit SM2, which is output after the falling edge of the sampling period t2 following tl. The selection circuit SM2 outputs D2 or D3 to T3N and T3F until the falling edge of C4.

73N is the first converging optical system 14 in FIG. A short-range measurement system using the first semiconductor device detection element 15, T3F is a second converging optical system 16. This is a lookup table for a long-distance measurement system using the second semiconductor device detection element F.

Based on the determination, a command signal is output from the command unit K to T3N, , T3F to instruct which lookup table should be referred to, as shown in FIG.

From the above (IL C31 formula), the look amplifier table T3N for the short-range measurement system has the following formula: IN -AN-bN/ (Pa N + (BN/2) + P)
=3000/C4+ (12/2) +P)=1
/ (IO/3000-1- (1/3000) ・
A characteristic curve as shown in FIG. 11 that satisfies the relational expression Pa-1/((10/3000)+(1/3000)·KN-D2) is input. Here, KN is a conversion constant to length units.

j2F for long-distance measurement lookup table T3F
=AF bP/ (Po F + (BP/2)+P)
=8570/ (3,785+ (12/2) +P)
= 1 / (9,785/8570+ (1/857
0) ・P]= 1 / (9,785/8570+
(1/8570)·KF-D3] A characteristic curve that satisfies the following relational expression is input.

Here, KF is a conversion constant to length units.

Look amplifier table T that receives the command signal from the command unit
2N or T3F outputs a distance signal of 4N or AF to the computing unit 02.

Arithmetic unit 02 corresponds to arithmetic unit 01 described in connection with FIG.

As shown in FIG. 12, the outputs β1. β2 is connected.

Here, (12-β+)/Lo is calculated.

This output is connected to a look-up table T4 corresponding to T2 in FIG.

For T4, θ-tan' (7!2j2+)/Lo (LO>5
00 mm) is input in advance.

This output θ is connected to the next steering control drive section 20.

(Effects of the Invention) As explained above, according to the present invention, two sets of light receiving units each including a convergent optical system and a detection element are provided, and the measurement range is set to the speed ratio δI [for measurement and short distance measurement]. Because they were divided, it was possible to accurately measure a wide measurement range that was not possible with conventional technology.

In addition, if the power supply is driven with a power that is inversely proportional to the output of the common electrode for the detection of the selected semiconductor device, it can respond to changes in the reflectance of the object to be measured (about 1:5) to a certain extent, resulting in stable and highly accurate measurements. was completed.

The distance Fi11 measuring device can be used as a distance and angle detecting device for an automatically traveling one-stop truck.

Two distance measuring devices are placed on the side of the automated guided vehicle, a fixed distance apart in the front and back direction of the guided vehicle, and the optical axis of the light source of the distance measuring device is perpendicular to the side surface of the first general guided vehicle. The distance from the side to the vertical wall is 11H (mm), 12
2 (mm).

Based on the difference between these distances tt, . . . pr2 and the ratio, the angle calculation section calculates the traveling angle of the vehicle between the wall and the transport plane.

By automatically steering the guided vehicle based on this angle output and the distance output 'I+42, the guided vehicle can be steered at a speed of 10 km/h.
/Distance to the wall at H position! I12oomm~2000mm
I was able to run it while holding it.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of the configuration of a conventional distance measuring device. FIG. 2 is a block diagram showing the basic configuration of the semiconductor device detection device for explaining the device. FIG. 3 is a block diagram showing the configuration of the distance calculation device and angle calculation section of the conventional device. FIG. 4 is a block diagram showing an embodiment of a distance measuring device according to the present invention. FIG. 5 is a block diagram showing the configuration of the distance calculation device and the angle calculation section of the apparatus of the embodiment. FIG. 6 is a block diagram mainly showing the configuration of the determiner of the distance calculation device of the embodiment device. FIG. 7 is a waveform diagram showing the clock timing of the clock generator. FIG. 8 is a graph showing the relationship between the output of the third divider and the measured distance β. FIG. 9 is a graph showing the relationship between the magnitude of the output of the divider and the position of the incident light beam. FIG. 10 is a graph for calculating an angle from the outputs of two distance detection devices and the distance between them. FIG. 11 is a graph for calculating distance from the output of the divider. FIG. 12 is a schematic diagram showing the configuration when the distance detection device is applied to a general transportation vehicle. ■...Light source 2...Optical system 3...Semiconductor device detection element 4...Distance calculation device 5...Angle calculation section 6...Steering control drive section 7...Semiconductor substrate 8... - Conductive layer 9... Resistance layer 10a, 10b... Detection electrode ii... Common electrode 12... Light source 13... Projection optical system 14... First converging optical system 16... Second converging optical system 5...First semiconductor device detection element 17...Second semiconductor device detection element 18...Arithmetic device 19...Angle calculation section 20...Steering control drive section 21...Light source drive unit Patent applicant: Hamamatsu Botonics Co., Ltd. Agent: Hisashi Inoro, patent attorney

Claims (1)

[Scope of Claims] (1.) A light source device that projects a small-diameter light beam in the direction of the object to be measured, and a light source that is arranged a certain baseline length apart from the projection optical axis of the light source device and that is parallel to the projection optical axis direction. The first with an axis
a converging optical system, and a light receiving surface is perpendicular to the optical axis of the first converging optical system along a reference plane formed by the optical axis of the first converging optical system and the projection optical axis of the light source device, a first semiconductor device detection element having an end of the light-receiving surface disposed apart from the front axis and having a pair of detection electrodes and a common electrode;
a second converging optical system that is disposed apart from the optical axis of the light source device by another fixed base line length that is larger than the fixed base length 51, that is parallel to the projection optical axis direction and has an optical axis within the reference plane; The light-receiving surface is arranged along the reference plane G at right angles to the optical axis of the second converging optical system, and the end of the light-receiving surface is arranged away from the optical axis, and a pair of detection electrodes and a common electrode are arranged. a second semiconductor device having an electrode and receiving reciprocal light from a place that reaches the light-receiving surface of the first semiconductor device detection element rather than the reflected light received by the light-receiving surface of the first semiconductor device detection element;
a semiconductor device detection element, a first position calculator that calculates an incident position from the output of a pair of detection electrodes of the first semiconductor device detection element, and an output of the first position calculator to the object to be measured. a first converter that converts the distance to a distance; a second position calculator that calculates the incident position from the output of the pair of detection electrodes of the second semiconductor device detection element; a second converter that converts the distance to the object to be measured; a semiconductor device detection element that compares the outputs of the first and second semiconductor device detection elements and outputs a signal corresponding to the object to be measured; A distance measuring device comprising an arithmetic device including a determiner that determines the value of the semiconductor device and outputs the output of the converter corresponding to the semiconductor device detection element. (2) The first position calculator of the calculation device converts the output current of the common electrode of the first semiconductor device detection element into the ball 1-
a first sum sampling hold circuit that holds the difference between the outputs of the detection electrodes of the first semiconductor device detection element; The second position calculator of the arithmetic device divides the output current of the common electrode of the second semiconductor device detection element by the output of the first sum sampling bold circuit. a second sum sampling bold circuit that holds the difference between the outputs of the detection electrodes of the second semiconductor device detection element; 2. A distance measuring device according to claim 1, comprising a second divider that divides by the output of the sum-of-2 sampling bold circuit. (3) The determiner of the arithmetic device includes a third divider that calculates a ratio between the output of the first sum sampling bold circuit and the output of the second sum sampling bold circuit; a first comparator that compares the output of the divider with a constant value; a second comparator that compares the output of the third divider with another constant value; 3. The distance measuring device according to claim 2, further comprising a determining section for determining which of the outputs of the semiconductor device detection element is to be used. (4) The distance measuring device according to claim 1, wherein the aperture ratio of the second converging optical system is larger than the aperture ratio of the first converging optical system. (5) The light source device that projects a small-diameter light beam in the direction of the object to be measured includes a light source, a projection optical system, and a light source driver, and the light source driver is driven by the arithmetic unit I/)η'1 2. The distance measuring device according to claim 1, wherein said light source is driven by a power that is inversely proportional to the output of the common electrode of any one of the semiconductor device detection elements determined.