JPH0225442B2 - - Google Patents

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 optical position detection element.

(Prior Art) First, a conventional distance measuring device using a semiconductor optical position detecting element will be described.

A semiconductor optical position 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 light, the distance to the object can be determined by calculating the output of the semiconductor optical position detection element.

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

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

A resistive layer 9 is formed on the conductive layer 8 , two electrodes 10 a and 10 b are provided at both ends of the resistive layer 9 , and a common electrode 11 is provided on the substrate 7 .

When a point-like beam of light enters between the electrodes 10a and 10b, a current _{of 1} is applied to the electrode 10a, and a current of 1 is applied to the electrode 10b.
₂ and ₃ flow to the electrode 11.

A relationship of ₃ = ₁ + ₂ is established between these currents. If the resistance of the resistive layer 9 is made uniform, the distance L ₁ between the incident point of the luminous flux L and the electrode 10a, the luminous flux L
Assuming that the distance between the incident point of and the electrode 10b is L ₂ ,
The relationship L _{1 1} = L _{2 2} holds true.

Calculating based on this relationship, the incident point P of the luminous flux L incident on the semiconductor optical position detection element 3 is as follows (1)
It is given by Eq.

P=K( _1-2 )/( ₁ + ₂ )...(1) where P is the incident point of the light beam expressed in coordinates with the origin at the midpoint between the electrodes 10a and 10b and the electrode 10a in _the positive direction. K is a conversion constant to length unit (mm).

A conventional example of a distance measuring device using this semiconductor optical position detection element is shown in FIG. The purpose of this conventional example is to automatically control the steering of a conveyance vehicle for cargo, etc., using distance measurement results.

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 separated 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 position detection element 3 described above is in a focal plane perpendicular to the optical axis, and the optical axis is located between the detection electrodes 10a,
10b.

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/l=P/b...(2) The output current of each electrode of the semiconductor position detection element 3 is connected to the calculation device 4, and the calculation result _l1 is sent to the conveyance vehicle advancing angle θ calculation section 5, and each of these Output l ₁ , l ₂ ,
It is output to the drive section 6 of the steering control device of the conveyance vehicle where θ is 6.

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

Detection electrode 1 of the semiconductor optical position detection element 3 described above
Currents ₁ and ₂ from 0a and 10b are respectively connected to differential input terminals of an operational amplifier A1 of the arithmetic unit ₄ , and the output thereof is connected to a sample and hold circuit _S1 .

On the other hand, the aforementioned current ₃ from the common electrode 11 is connected to an operational amplifier _A2 , and its output is connected to a sample and hold circuit _S2 .

These sample and hold circuits _S1 and _S2 are held for a certain period of time by pulses from a pulse generator _C1 that generates sample and hold pulses, and the output ( ₁ - ₂ ) of _S1 is sent to the next divider D. is input to the dividend part of ₁ , and the output of S ₂ ( _1
+2 ) is input to the divisor part of _D1 . If the output of the divider _D1 is VD, then from the above equations (1) and (2), the following relational expression is obtained: VD = ( ₁ - ₂ ) / ( ₁ + ₂ ) = A・b/l (3) Given.

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

When this VD is input to the next lookup table _T1 , the lookup table _T1 outputs the distance _l1 to the object to be measured corresponding to the VD as its output.

FIG. 12 is a schematic diagram for explaining the principle of an angle detecting device for a transport vehicle using two distance measuring devices configured as described above.

As shown in FIG. 12, two distance measuring devices having similar configurations are attached to the side of the carrier C so that their optical axes are perpendicular to the traveling direction.

Assume that the distance measured by the distance measuring device from the front in the direction of travel is l ₁ and the measured distance by the distance measuring device is l ₂ .
These measured distance outputs l ₁ and l ₂ are calculated by the calculator shown in Figure 3.
It is input to O ₁ , and in this arithmetic unit O ₁ , (l ₁ −
l ₂ )/L ₀ is calculated.

Here, L ₀ is the distance between the light sources projecting the respective light beams of the two distance measuring devices mentioned above.

The traveling angle θ of the transport vehicle described above is an angle formed between the traveling direction of the transport vehicle and the wall W, and the following equation is established.

tanθ=(l ₂ −l ₁ )/L ₀ (4) where l ₁ is the output of the distance measuring device attached to the front part of the transport vehicle in the traveling direction.

The output of the arithmetic unit O ₁ = (l ₂ −l ₁ )/L ₀ is input to the next lookup table T ₂ , and θ that satisfies the above-mentioned equation (4) is output from T ₂ .

These θ, θ ₁ and θ ₂ are input to the drive section 6 of the steering control device mentioned above.

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

However, as mentioned above, as is clear from equation (2), the incident position of the light spot on the semiconductor position detection element 3 is inversely proportional to the distance l to the object to be measured, so as the distance to the object to be measured increases. The positional displacement of the detection element on the light-receiving surface becomes small, making it impossible to obtain accurate values.

The measurement range is large, and there is a one-digit difference between the lower limit and the upper limit, and even a measurement range of, for example, 0.2 m to 2 m poses 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 and having an optical axis parallel to the projection optical axis direction; and a light receiving surface on a reference plane formed by the optical axis of the first convergent optical system and the projection optical axis of the light source device. a first semiconductor optical position detection element that is perpendicular to the optical axis of the first converging optical system, the end of the light receiving surface is disposed apart from the optical axis, and has a pair of detection electrodes and a common electrode; , a second converging optical system disposed apart from the optical axis of the light source device by another fixed base length larger than the fixed base length, parallel to the projection optical axis direction and having an optical axis within the reference plane; , 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 away from the optical axis, and has a pair of detection electrodes and a common electrode. and a second semiconductor optical position detecting element that receives reflected light from a place farther than the reflected light received by the light receiving surface of the first semiconductor optical position detecting element, and a pair of detection of the first semiconductor optical position detecting 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 optical position detector. a second position calculator that calculates the incident position from the outputs of the pair of detection electrodes of the element; a second converter that converts the output of the second position calculator into a distance to the object to be measured; and the first The outputs of the second semiconductor optical position detection element are compared to determine which semiconductor optical position detection element is outputting a signal corresponding to the object to be measured, and the output of the converter corresponding to the semiconductor optical position detection element is determined. It is composed of an arithmetic device consisting of a determiner that outputs an output.

In other words, two pairs of a converging optical system and a semiconductor position detection element are provided, and the measurement distance is divided into two pairs, with one pair handling the short distance range and the other pair handling the long distance range, which improves accuracy. Can measure high distances. The arithmetic unit automatically determines which set to use.

(Description of Embodiment) FIG. 4 is a block diagram showing an embodiment of a distance measuring device according to the present invention.

Light from a light source 12 that emits small-diameter light is focused by a projection optical system 13 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 direction of the projection optical axis, which is disposed apart from the optical axis of the light source 12 by a certain base line length AN, and has a focal length bN.

The first semiconductor position detection element 15 has a converging surface arranged at right angles to the optical axis of the first focusing optical system 14 .

x of the first semiconductor optical position detection element 15
The axis (see FIG. 2) is within a plane that includes the optical axes of the light source 12, the projection optical system 13, and the optical axis of the first converging optical system 14, and one end of the light receiving surface is located in the converging optical system 14.
It is placed at a position a fixed length P ₀ N away from the optical axis of.

Here, P ₀ N is the first semiconductor position detection element 15
At the measurement distance lN handled by the sensor, the position on the light-receiving surface where the point-like incident light beam L forms an image when lN is maximum is slightly closer to the effective light-receiving position (in the positive direction of the x-axis) than one end. be.

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 direction of the projection optical axis and the optical axis of the light source 12 and the projection optical system 13. is within the plane formed by the optical axis of the converging optical system 14.

The aperture of the second converging optical system 16 is about three times the aperture of the optical system 14, and the focal length is bF. The light receiving surface of the second semiconductor optical position 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 optical axis of the light source 12 and the projection optical system 13. It lies within a plane formed by the optical axis of the first converging optical system 14. Also, one end of the light receiving surface is connected to the second
The convergent optical system 16 is placed at a position a fixed length P ₀ F away from the optical axis of the converging optical system 16 . Here, P ₀ F is the position on the light receiving surface where the point-like incident light beam L forms an image when the measurement distance lF handled by the second semiconductor optical position detecting element 17 is maximum, which is slightly closer to the effective light receiving position than one end ( This position is in the positive direction of the x-axis). In the figure, if BF is the effective light-receiving length of the second semiconductor optical position detection element 17, when lF is minimum, the imaging position of the point-like incident light beam L is from the position on the x-axis (BF + P ₀ F). It is positioned so that it is slightly inside.

first and second semiconductor optical position detection elements 15,
The output current of each electrode 17 is calculated by the distance output calculation device 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 of 20 transport vehicles. The light source 12 is driven by a light source driving section 21.

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

From the above formula (2), p=A・b/l… Effective light receiving length of each semiconductor position detection element BF=BN=12mm=B.

From the above formula, the minute displacement Δp of the light point P is Δp=Ab/Δl
It is expressed as

Here, it is assumed that Δp=B/300=40 μm is the maximum value of dispersion, that is, the maximum value of the resolution of the detection element=300. This means that the signal current obtained from the detection element is
This is due to the fact that it is about nanoA.

In the second semiconductor optical position detection element 17,
From the formula, Δp is inversely proportional to l, so the measurement distance l =
Assuming that the measurement stability is 1% at 2000mm, Δp=Ab/3000−Ab/2020 ≧40μm From this relational expression, A・b=AF・bF≧8080 … Here, the minimum value of lF = the maximum value of lN = measurement Switching distance = 600mm.

If bF=100mm, the following relational expression can be obtained from the equation.

If we take P when l=2000mm as P2000 and P when l=600mm as P600, then P2000=(AF×100)/2000...P600=(AF×100)/600...The above formula is P600-P2000= Solving under the condition that the effective light-receiving length of the detection element B-2 = 10 mm, AF≒85.7 mm. At this time, AF·bF=8570, which satisfies the above relationship.

Therefore, P ₀ F in FIG. 4 becomes P ₀ F = P2000-0.5 = (85.7x100)/2000-0.5 = 3.785 mm from the above formula.

Similarly, in the detection element 15, if the measurement distance l (= MAX) = 600 mm and the measurement stability is 1%, then Δp = AN・bN/600−AN・bN/606≧40μm From this relational expression, AN・bN≧2424 … If bN = 60mm, P in the formula when l = 600m is P600, and P when l = 200mm is P200, then P600 = (AN × 60) / 600 … P200 = (AN × 60 )/200...P200-P600=effective light receiving length of detection element B-2=
Solving with 10 (mm) gives AN=50mm. At this time
AN・bN=3000, which satisfies the above formula.
Therefore, P ₀ N = P600-1 = (50 x 60)/600-1 = 4 mm in Figure 4.
The aperture ratio of is determined by the following relationship. The amount of light incident on the light receiving surfaces of the first semiconductor optical position detection element 15 and the second semiconductor optical position detection element 17 is inversely proportional to the square of the measurement distance, and the apertures of the first and second converging optical systems 14 and 16 are It is proportional to the square of Therefore, the aperture of the first converging optical system 14 is dN, and the aperture of the first converging optical system 16 is
dF, when the following relationship holds, almost the same amount of received light can be obtained in the long-distance measurement system and the short-distance measurement system.

[(dN/dF) ² ] ^1/2 = [(600/2000) ² ] ^1/2 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 lN=MIN (minimum),
P=-BN/2 approximately corresponds to lN=MAX (maximum).

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

AN/lN=[P ₀ N+(BN/2)+P]/bN...(3) Here, BN is the first semiconductor optical position detection element 15
With an effective light receiving length of , this center is the origin (0,
0).

Similarly, coordinates as shown in FIG. 2 are set for the second semiconductor optical position detection element 17. The light flux incident point P=BF/2 corresponds to the maximum of lF=MIN (minimum) <≈lN, and P=-BF/2 corresponds to lF=MAX (maximum). Then, the following equation (4) holds true.

AF/lF=[P ₀ F+(BF/2)+P]/bF...(4) Here, BF is the second semiconductor optical position detection element 17
The effective receiving length is , and this center is the origin of the coordinates (0,
0). Since the amount of incident light on the first and second semiconductor optical position detection elements 15 and 17 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 consideration, The aperture of the first converging optical system 14 is approximately 1/3 that of the second converging optical system 16.

Next, referring to FIG. 5 and FIG.
The configuration of No. 8 will be explained.

Detection electrode 1 of first semiconductor optical position detection element 15
Outputs 1N and 2N of 0a and 10b are subtracter A ₃
and the output of the common electrode is connected to amplifier _A4 .

Detection electrode 1 of second semiconductor optical position detection element 17
Outputs 1F and 2F of 0a and 10b are subtractor A ₅
and the output of the common electrode is connected to amplifier _A6 .

Sampling and holding circuits S ₃ , S ₄ , S ₅ , and S ₆ receive clock φ ₁ from clock generator C ₂ (see Figure 7).
is connected. sampling hold circuit
S ₃ , S ₄ , S ₅ , and S ₆ are sampling and holding circuits that sample and hold the outputs of A ₃ , A ₄ , A ₅ , and A ₆ respectively at the rising edge of the clock _φ1 .

The first divider _D2 is a sampling hold circuit
Calculate (1N-2N)/(1N+2N) from the outputs of S ₃ and S ₄ .

The second divider _D3 is a sampling hold circuit
Calculate (1F-2F)/(1F+2F) from the outputs of _S5 and _S6 .

The output of the sampling hold circuit _S4 (1N+2N) and the output of the sampling hold circuit _S6 (1F+2F) are connected to the third judger DM, and performs the calculations necessary for the following equation (5).

DM=(1F+2F)/(1N+2N)≧DA
…(5) D ₂ = (1N−2N)/(1N+2N)≦DB
...(6) Figure 8 is a graph showing the relationship between DM and measurement distance l.

In the figure, the measured switching distance lB approximately corresponds to the aforementioned lN (= MAX) = lF (= MIN).

FIG. 9 shows the relationship between D ₂ in equation (6) and the position (0, P) of the incident light beam L.

In the figure, P approaches -BN/2, l=lB
As l increases from the vicinity, D ₂ loses its linearity with respect to P and becomes severely curved.

That is, the measurement stability by the first semiconductor optical position detection element 15 always deteriorates. Therefore, in the configuration shown in FIG. 4, the value D ₂ of the divider D ₂ becomes larger than DB (smaller in absolute value) at the switching point where DM=DA in equation (5), and the fifth Each configuration is determined so that the divider _D3 shown in the figure is at a position where it maintains sufficient linearity with respect to P.

The determiner M determines that the second semiconductor optical position detection element 17 measures the distance when either of the above equations (5) and (6) is satisfied.

Therefore, when neither equations (5) nor (6) are satisfied, it is determined that the first semiconductor optical position detection element 15 should measure the distance.

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 a divider that calculates the equation (5) above, DM=(1F+I2F)/(1N+2N), and its output (DM) is connected to the comparator _K2 .

The comparator _K2 makes a judgment based on equation (5) (DM≧DA judgment), and the logical output (1, 0) is sent to the OR circuit.
Connect to one input terminal of _E1 .

On the other hand, the output of divider D ₂ is connected to comparator K ₁ ,
Here, the above equation (6) is determined (D ₂ ≦ DB), and the logical output (1, 0) is sent to the OR circuit E ₁
is connected to the other input terminal of the

When either of the above formulas (5) or (6) is satisfied, the output of the OR circuit _E1 becomes "1", and the second
A decision is made to measure the distance based on the output of the semiconductor position detection element 16.

The output of the OR circuit _E1 is connected to a command section K, and the command section K sends open/close command signals to the selection circuits _SM1 and SM2, which are composed of semiconductor switches and analog memories, based on the output of the OR circuit E1. Output.

The outputs of the dividers D ₂ and D ₃ are connected to the selection circuit SM2, and the outputs of the sample and hold circuits S ₄ and S ₆ are connected to the selection circuit SM1.

The command unit K causes the selection circuit SM2 to output the contents of _D3 , (1F-2F)/(I1F+2F) when the output of the OR circuit E1 is " ₁ ".

Also, make the selection circuit SM1 output the contents of _S6 , (1F+2F).

In addition, in the command unit K, the output of the OR circuit E ₁ A is “0”
When , select circuit SM2 outputs the contents of _D2 , (1N-2N)/(1N+2N).

Also, make the selection circuit SM1 output the contents of _S5 , (1N+2N).

Figure 7 is a clock time chart.

Clock _φ1 is a sample-and-hold pulse output from clock generator _C2 , and when it is "HIGH", it causes sample-and-hold circuits _S3 , _S4 , _S5 , and _S6 to sample and hold.

_φG1 is a command signal to the selection circuit SM1, which is output in synchronization with the falling edge of clock pulse _t1 of clock _φ1 . The selection circuit SM1 connects the signal of the sample and hold circuit _S4 or _S6 held at _t1 of the clock _φ1 to the light source driving section 21 until the fall of _t3 .

From the falling edge of clock pulse _t3 , the next _φG1
is input from the command unit K to the selection circuit SM1. As a result, the determined one ( ₁ + ₂ ) is connected from the determiner M to the light source driving section 21.

The light source driving section 21 divides this reference value (I ₁ +I ₂ ) and outputs a driving current to the light source 12 that is inversely proportional to the amount of received light.

That is, the light source driver 21 outputs a drive current to the light source 12 that eliminates changes in the reflectance of the object to be measured and changes in the amount of light received by the detection element due to changes in the measurement distance.

φG ₂ is a command signal of the selection circuit SM2, which is output after the falling edge of the sampling period t ₂ following t ₁ . The selection circuit SM2 outputs D ₂ or D ₃ to T3N and T3F until the falling edge of t ₄ .

T3N is the first converging optical system 14, the first
T3F is a lookup table for a short-distance measurement system using a semiconductor optical position detection element 15, and a long-distance measurement system using a second converging optical system 16 and a second semiconductor optical position detection element 17.

As shown in FIG. 5, a command signal is output from the command unit K to T3N and T3F to instruct which lookup table should be referred to, as shown in FIG.

From equations (1) and (3) above, the lookup table T3N for the short-range measurement system is: lN = AN・bN/[P ₀ N+(BN/2)+P] = 3000/[4+(12/2)+P ] =1/[10/3000+(1/3000)・P] =1/[(10/3000)+(1/3000)・KN・D ₂ ] Characteristics as shown in Figure 11 that satisfy the relational expression A curve has been input. Here KN is a conversion constant to length units.

For the long-distance measurement system lookup table T3F, lF=AFbF/[P ₀ F+(BF/2)+P] =8570/[3.785+(12/2)+P] =1/[9.785/8570+(1/8570)・P〕 = 1/(9.785/8570 + (1/8570)・KF・D ₃ ) A characteristic curve that satisfies the relational expression is input.
Here KF is a conversion constant to length units.

Upon receiving the command signal from the command section K, the lookup table T2N or T3F outputs a distance signal of lN or lF to the arithmetic unit _O2 .

Arithmetic unit O ₂ is the arithmetic unit explained in relation to Fig. 3.
It corresponds to O ₁ .

As shown in FIG. 12, the outputs l ₁ and l ₂ of the distance measuring device are connected.

Here, (l ₂ −l ₁ )/L ₀ is calculated.

This output is connected to a lookup table _T4 corresponding to _T2 in FIG.

A characteristic table of θ=tan ⁻¹ (l ₂ −l ₁ )/L ₀ (L ₀ >500mm) as shown in FIG. 7 is input into T ₄ in advance.

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

(Effects of the Invention) As explained above, according to the present invention, two sets of light receiving units each including a converging optical system and a detection element are provided,
Because the measurement range was divided into long-distance and short-distance measurements, 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 of the selected semiconductor optical position detection, it can respond to changes in the reflectance of the object to be measured (about 1:5) and achieve stable and high accuracy. The measurement was completed.

The distance measuring device can be used as a distance and angle detecting device for an automatic traveling guided vehicle.

Two distance measuring devices are placed on the side of the automated guided vehicle, a certain 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 of the guided vehicle. Measure the distances l ₁ (mm) and l ₂ (mm) from to the vertical wall.

Based on the difference between these distances l ₁ and l ₂ and the ratio, the angle calculation section calculates the traveling angle of the vehicle between the wall and the side surface of the conveyance vehicle.

By automatically steering the guided vehicle based on this angle output and the distance outputs l ₁ and l ₂ , the guided vehicle can be driven at a speed of about 10 km/h while maintaining a distance of 200 mm to 2000 mm from the wall. Ta.

[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 optical position 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 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 calculating device of the embodiment device. FIG. 7 is a waveform diagram showing the clock timing of the clock generator. Figure 8 is the third
2 is a graph showing the relationship between the output of the divider and the measured distance l. 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 L. FIG. 10 is a graph for calculating an angle from the outputs of two distance detection devices and the distance between them. 11th
The figure 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 transport vehicle. DESCRIPTION OF SYMBOLS 1...Light source, 2...Optical system, 3...Semiconductor optical position detection element, 4...Distance calculation device, 5...Angle calculation unit, 6...
Steering control drive unit, 7... semiconductor substrate, 8... conductive layer, 9... resistance layer, 10a, 10b... detection electrode,
DESCRIPTION OF SYMBOLS 11... Common electrode, 12... Light source, 13... Projection optical system, 14... First converging optical system, 16... Second converging optical system, 15... First semiconductor optical position detection element, 1
7... Second semiconductor optical position detection element, 18... Arithmetic device, 19... Angle computing section, 20... Steering control drive section, 21... Light source drive section.

Claims (1)

[Scope of Claims] 1. A light source device that projects a small-diameter light beam in the direction of an object to be measured, and an optical axis 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. a first converging optical system;
along a reference plane formed by the optical axis of the converging optical system and the projection optical axis of the light source device, perpendicular to the optical axis of the first converging optical system, and the end of the light receiving surface is arranged at a distance from this optical axis. a first semiconductor optical position detection element 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 constant baseline length that is larger than the constant baseline length, is parallel to the projection optical axis direction, and has an optical axis within the reference plane; 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 away from the optical axis, and has a pair of detection electrodes and a common electrode. A second semiconductor optical position detecting element that receives reflected light from a place farther than the reflected light received by the light receiving surface of the first semiconductor optical position detecting element, and a pair of detecting devices for the first semiconductor optical position detecting element. a first position calculator that calculates the incident position from the output of the electrode; 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 optical position 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; The outputs of the second semiconductor optical position detection element are compared to determine which semiconductor optical position detection element is outputting a signal corresponding to the object to be measured, and the output of the converter corresponding to that semiconductor optical position detection element is output. A distance measuring device consisting of an arithmetic device consisting of a determiner. 2. The first position calculator of the calculation device includes a first sum sampling and hold circuit that holds the output current of the common electrode of the first semiconductor optical position detection element, and a first sum sampling and hold circuit that holds the output current of the common electrode of the first semiconductor optical position detection element. a first difference sampling and holding circuit that holds the difference between the outputs of the detection electrodes; and a first divider that divides the output of the first difference sampling and holding circuit by the output of the first sum sampling and holding circuit. The second position calculator of the arithmetic device includes a second sum sampling and hold circuit that holds the output current of the common electrode of the second semiconductor optical position detection element, and the second semiconductor optical position detection element. a second difference sampling and holding circuit that holds the difference between the outputs of the detection electrodes; and a second divider that divides the output of the second difference sampling and holding circuit by the output of the second sum sampling and holding circuit. A distance measuring device according to claim 1, consisting of: 3 The determiner of the arithmetic device includes a third divider that calculates a ratio between the output of the first sum sampling and holding circuit and the output of the second sum sampling and holding circuit, and an output of the first dividing unit. a first comparator that compares the output of the third divider with another 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, comprising a determining section for determining which semiconductor optical position detecting element output is to be used. 4. Claim 1: The aperture of the second converging optical system is larger than the aperture of the first converging optical system.
Distance measuring device as described in section. 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 drive section, and the light source drive section is configured to control any semiconductor light position determined by the arithmetic device. Claim 1, wherein the light source is configured to be driven by a power that is inversely proportional to the output of the common electrode of the detection element.
Distance measuring device as described in section.