JPS6073314A - Distance measuring apparatus - Google Patents

Abstract

PURPOSE:To position a photographing lens steadily in the specified place, by, in triangulation distance measurement, by determining an output between a common electrode of semiconductor light position detecting element and respective detecting electrode at the set value after sweeping from low amplifying to high amplifying ratio on its distance measuring condition. CONSTITUTION:An output of clock pulse generating circuit 1 is supplied directly or via a time forming circuit 2 to AND gate 3 and a spot light is irradiated to a specimen from an infrared light emission diode 5 through a transistor 4. A reflected light is received by a semiconductor light position detecting element 6 provided with a common electrode 10 and a pair of detecting electrodes 9a, 9b. The detected output is swept from low to high amplifying ratio by an AC amplifying circuits 13, 14 provided with gain adjusting input terminals 13a, 14a and an output after passing through BPF15, 16 is supplied to detecting circuits 17, 18. The detecting output is compared with the reference voltages Vr1-Vr3 through DC amplifying circuits 21, 22 and supplied to FF36-38. Depending upon the output conditions of FF36-38, determinations are made as to near, medium and far distances of the specimen subject to measurement and a photographing lens can be set at the specified position.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a distance measuring device used in a camera, etc., which projects light emitted from a light emitting element toward an object to be measured,
The present invention relates to an improvement in a triangular distance measuring device in which the reflected light is received by a semiconductor device detection element having a common electrode and a pair of detection electrodes.

Conventionally, a dual-type measuring device has been proposed in Japanese Patent Application Laid-Open No. 177107/1983.

Generally, when distance measurement is performed by receiving reflected light from a distance measurement target of light projected from a light emitting element by a light receiving element, the intensity of the reflected light is 1
The degree of error varies by more than 1,000 times depending on the foul rate of the object to be measured, the distance jijfj, etc. Therefore, the amplifier circuit that amplifies the output of the light receiving element needs to have a dynamic range of 60 dB or more.

Possible ways to widen the optical range are to logarithmically compress the output of the light-receiving element or to adjust the gain of the amplifier circuit, but in the former case, the amount of light received is large ( 11γ, which has a small output difference, has the disadvantage of poor S/N ratio, and the latter requires a feedback system, which has the disadvantage of increasing unstable factors such as oscillation.

To provide a distance measuring device which gradually increases the distance from zero or a very small value and determines the distance measuring state when it reaches a certain set value that is easy to determine by a comparator circuit, and sets the photographing lens at a predetermined position.

Hereinafter, the present invention will be explained in detail based on the drawings.

First, in Figure 1, ■ is the clock pulse generation circuit (
Oscillation frequency f O = 16 KHz, hereinafter written as O8C), 2 is a time forming circuit (time t = 25 ms)
, 3 is an AND gate, 4 is a transistor, and 5 is an infrared light emitting diode (hereinafter referred to as IRD) as a light emitting element that projects a spot light onto the object to be measured.

Reference numeral 6 denotes a semiconductor device detection element, which has a relatively large semiconductor substrate 7 having an equal surface, and a semiconductor layer 8 of a conductivity type different from that of the substrate 7 is formed on one side of the semiconductor substrate 7.

A resistive layer 9 is formed on the semiconductor layer 8, and a pair of electrodes (for detection) 9a are provided at both ends of the resistive layer 9.
, '9b are provided, and a common electrode 1 is provided on the semiconductor substrate 7.
0 is set.

11 and 12 are AC amplifier circuits, respectively, 13 and 14 are AC amplifier circuits equipped with gain (amplification factor) adjustment input terminals 13a and 14a, respectively, and 15 and 16 are bandpass filter circuits (center frequency f'o=], 6 KHz, respectively). , and below BPF
), 17 and 18 are each a detection circuit, 19 and 20 are each a detection circuit, 21 and 22 are each a DC amplifier circuit, 23 is an inverter, 24 is a transistor, 25 is a constant current circuit, 26 is a capacitor, and 27 is a Current amplification circuit, 28
．． 29 and 30 are comparator circuits (FCMP
), 31 is a constant current circuit, 32° 33 and 34
are the inverting input terminal r-(-) of CMP28 and CMP2, respectively.
The basic voltages Vr+ and Vr2. 35 is an ant gate, 36 and 37 are D type flip-flop circuits, and 38 is an R and S type flip-flop circuit (the flip-flop circuits are hereinafter commonly referred to as FF). ) and are connected as shown in the figure.

Next, the operation of FIG. 1 will be explained with reference to FIG. 2.

When a power switch (not shown) is closed at the start of the operation, power is supplied to each part of the circuit, and the FF
36, 37 and 38 are released from reset.

Then, the clock pulse generation circuit 1 operates, and 625
At the same time that a clock pulse with a period of .mu.s is generated, the output of the time forming circuit 2 is inverted to the "l-■" level for a time of t=25 ms.

Therefore, the clock pulse is applied to the ant gate 3 for that time.
, and in response to this, the I/Run star 4 does not repeat the 1, 1, pass, and shut off cycles, and as a result, the IRD 5 lights up in pulses.

The projected light caused by the lighting of the IRD 5 is reflected from the distance measurement target force and is received by the semiconductor device detection element 6.

In this step, when the reflected light spot X hits between the electrodes (for detection) 9a and 9b, the following relationship holds true at the point of incidence via the resistance layer 9.

l3=II+I2 Then, if the resistance of the resistance layer 9 is made uniform, the distance between the incident point of the reflected light spora)X and the electrode 9a is lr, and the distance between the incident point and the electrode 9b is 12. 11 ・I +
The relationship: =+ 2 ・I2 holds true.

Based on this condition, the light reception outputs at points a and a'' are generated superimposed on the DC component due to natural light, as shown in (2).

Furthermore, the outputs at points b and b' after the AC amplifier circuits 11 and 12 are amplified and appear as shown at @.

- On the other hand, the output of the time forming circuit 2 is “H” for 111 of 25 m5.
” level, the output of the inverter 23 is “
Since the transistor 24 is turned off and the transistor 24 is cut off, the capacitor 26 is charged with a constant current by the constant current circuit 25. If the constant current is 1 and the capacitance of the capacitor 26 is C, then the output terminal C of the current amplifier circuit 27 The voltage V at the point rises north as shown by O due to the relational expression of V-, (]/C)I, and t.

That is, in the AC amplifier circuits 13 and 14, the potentials of the gain adjustment input terminals], 3a, and i4a, respectively, gradually increase from a low level.
H, the amplification factor is swept from zero or a low amplification factor to a high amplification factor, and the outputs at points d and d' become like the waveform shown at @.

Also, the outputs at points e and e after B))F]5 and 16 are obtained by setting the center frequency fo and the oscillation frequency fO of O3 and CI to the same value, so as shown in ■ It appears as if the waveform of ■ has been amplified. Furthermore, the detection circuit 17 and I
The output waveforms at points f and f' after 8 are as shown in θ, and the output voltages Vg and Vg' at points g and g' after DC amplifier circuits 21 and 22 which have passed through circuits J9 and 20 are teeth,
As shown in (2), it gradually increases from a predetermined value.

As shown in Fig. 2, the distance measurement target is short-range ((9
, then (a 1.) , (a 2
), the reflected light spot X is largely biased to the left with respect to the semiconductor device detection element 6, so that the output voltage Vg at point g is more than the output voltage Vg at point g'. and its output voltage Vg is higher than the reference voltage Vr.
+, the output of the CMP 28 is inverted to the l'-HJ level, and during the previous time [(the AND gate 35 to which the J level signal was applied opens and its output becomes l'-I
-Flip to IJ level. On the other hand, at that point, the output voltage g' at point g has not even reached the reference voltage r3, so the outputs of the CMPs 29 and 30 are both at the "H" level.

Therefore, the FFs 36 and 37, which are clocked by the rising signal of the output of the AND gate 35 to the [H, J level], both read the signal of the "H" level and output the "H" level signal to the husband's output terminals Q1 and O2. (2) The FF 38 stores a signal at the ('' level and uses its rising signal as a set pulse, and the output terminal Q3 is inverted to the [(J level).

In addition, if the distance measurement target is located at a medium distance position,
As shown in FIGS. 2(bl) and (b2), the reflected light spot X is biased to the left with respect to the semiconductor device detection element 6, and
I<12, and in the same operation, the output voltage Vg" is between Vr2 (V+°3), so the output terminal Q1 of FF35 receives a "H" level signal, and the output terminal Q2 of FF37 receives a signal of "H" level. The rLJ level signal is stored respectively, and the FF38
The output terminal Q3 of is inverted to [(J level).

Furthermore, if the object to be measured is located at a boundary position to a long distance, the reflected light spot is at the center of 2 and is in the state of l+612, so its output voltages Vg and g' are equal, and at the time of determination, the output voltage Vg' is higher than the reference voltage Vr2. , FF35 and FF37, respectively, output terminals Q1 and O2 store rLJ level signals, and FF3
The output terminal Q3 of No. 8 is inverted to "II" level.

Furthermore, when the object of measurement 1 exists at a very far position, the reflected light spot However, due to the extremely long distance, the output voltage Vg will not reach the reference voltage Vr+ within the next hour (if the distance measurement target has a small reflectance) ), the output of CMP28 is rL
Since the AND gate 35 closes when the time t ends, the FF 38 is not set and the output terminal Q3 remains at the rLJ level.

Note that at this time, the output of the AND gate 35 is not inverted to the [HJ level, so the FFs 36 and 37 do not perform the reading operation.

That is, as shown in the truth value diagram of FIG. 3, the signal level state of the output terminals Q+ and O2 of FFs 36 and 37 is set to determine near, medium, and jMi'i (i'iif). Yes, and in addition, the output terminal Q of FF'38
When 3 is at the rLJ level, it is set to discriminate far alt' and Wit in priority to the discrimination by FFs 36 and 37.

Furthermore, the standard voltages applied to the CMPs 29 and 30 in FIG. 1 are fixed biases, and the absolute values of the output voltages VgP and Vg are compared.

In the embodiment of FIG. 4, the reference voltages to the CMPs 29 and 30 are provided in the form of dividing the varying output voltage Vg, and therefore the output voltage Vg' is compared as a proportion of the output voltage Vg. . Note that vb of the voltage dividing circuit is biased, for example, at the normal voltage level of the light receiving output circuit of the semiconductor device detection element 6 when the IRD 5 is not operating.

In addition, in the circuit operation shown in FIG. 1, the state of output voltage Vg'' is determined at 11'i when the output of CMP28 is inverted to the 1t level, but the cumulative operation of ant gate 35 and below is Due to the delay time, the determination may lack accuracy.

On the other hand, the feature of the embodiment shown in FIG. 4 is that, as described above, since the output voltage g' is determined based on the ratio, that is, the ratio of the output voltage g' to the output voltage Vg, the accuracy is improved compared to the previous embodiment. can be measured.

Note that the number of steps of the distance measurement output mentioned above can be increased or decreased, and
If the FF 38 determines a long distance, it is also possible to issue an alarm at the same time.

In the above embodiment, the distance measurement output is set to the reference voltage (Vr2°Vr
3) is obtained digitally according to the level and the number of steps, but an example will be described below in which the distance measurement output is further divided into smaller parts.

First, the first one will be explained with reference to FIGS. 5 and 6. Note that the same elements as in the previous embodiment are designated by the same symbols.

In FIG. 5, 41 is a comparator circuit, 42 and 4
3 is a constant current circuit and a resistor that applies a reference voltage Vr to the inverting input terminal (-) of the comparator circuit 41; 44 is an ant gate; 45 is an analog switch; 46 is an inverter;
7 is a capacitor, 48 is a current amplification circuit, and 49 is a comparator circuit (the comparator circuit is hereinafter commonly referred to as C
It is written as MP. ), 50 and 51 are non-inverting input terminals of the CMP 49 (a constant current circuit and a potentiometer that provide a displacement voltage corresponding to the movement of the photographing lens from one extreme position to the other extreme position in the movable range; 52 is a potentiometer);
, S type 7 lip-flop circuit (hereinafter referred to as FF), 53 is an AND gate, 54 is a transistor, 55
is an electromagnet that stops the movement of the operating part ring (lens set ring) of the photographic lens.

Next, in FIG. 6, 56 is a lens set ring,
Eleven springs 57 are arranged so as to be rotatable around the optical axis.
This gives dextrorotation, and the right rotation displaces the photographing lens from an infinity position to a close distance position, and also forms a stepped portion 56a and ratchet teeth 56b.

- [Dan is an electromagnet for the lens-driven release, with an iron core of 58
a, a coil 581] and a permanent magnet 58c. 59 is pivotally connected to the shaft 6o and the spring 61
This is an iron piece lever for the release that is given levorotatory properties by the above, and forms a hook 59a that can engage with the stepped portion 56a of the lens center link 56 and an iron piece 59b that faces the iron core 58a of the electromagnet. . 62 is a pin that limits the left rotation amount of the iron piece lever 59. Reference numeral 63 designates an iron piece lever for 07 rotation which is pivotally mounted on a shaft 64 and given dextrorotation by a spring 65, and includes a hook 63a that can engage with the ratchet teeth 56b of the lens cellar i-ring 56, and An iron piece 63b facing the electromagnet 55, which is the same as the
and is formed.

The potentiometer 51 in FIG. 5 includes a brush 51a supported by a lens set ring 56 and a resistor 51c formed on a substrate 51b, as shown in FIG.
and a conductor 51d.

Therefore, the operations shown in FIGS. 5 and 6 will be explained together with FIG. 2 (see voltages in parentheses).

] Similarly to the double series, in the states shown in Figure 2 (a 1) and (a 2), the output voltage Vg at point g is equal to the output voltage Vg at point g''
, and the potentials at points g and g'' rise by t while maintaining that relationship.

Also, at this stage, the AND gate 44 is closed and the output of the inverter 46 is at the f-I J level, so the analog switch 45 is open and the capacitor 47 is connected to the output voltage Vg at point g'. It's getting charged up.

Then, when the output voltage Vg at point g reaches the reference voltage Vr, the output of the CMP 41 is inverted to rHJ level, and as a result, during the previous time t, is opened and its output is [f(J).
At the same time, the output of the inverter 46 is inverted to the rLJ level and the analog switch 45 is closed. Therefore, the capacitor 47 has an output type L at point g when the output voltage Vg at point g or the reference voltage Vr is reached.
IEVg'' (Vl) is stored.The voltage V1 is amplified by the current amplification circuit 48 and applied to the inverting input terminal (-) of the CMP 49.

In addition, in the CMP 49, since the potentiometer 51 which provides an input terminal to the non-inverting input terminal (+) is located on the high potential side in the initial state, the initial output state is set at the "F(" level).

Therefore, since the ant' gate 53 opens the gate and makes the transistor 54 conductive, the electromagnet 55 is energized and holds the iron piece lever 63 by attraction.

Then, after the previous time t ends, the coil Szb of the electromagnet 58 is connected to the permanent magnet 58' by a circuit operation (not shown).
When pulse-driven in the direction of canceling the magnetic force of C, the iron piece lever 59 rotates to the left due to the tension of the spring 61, and the hook 59a
comes off from the punching portion 56a of the lens set ring 56. As a result, the ring 56 starts turning to the right due to the tension of the spring 57, displacing the photographing lens from the infinity position to the close distance position, and moving the brush 51a towards the resistor 5.
], c J:1 and the conductor 51d''2 are slid to move the potentiometer 51 from the high potential side to the low potential side.

Then, when the potential of the non-inverting input terminal ('-) of the CMP49 decreases to the potential of the inverting input terminal (-), the CMP49
The output is inverted to the rLJ level and the AND gate 53
close. As a result, the transistor 54 is cut off and the electromagnet 55 is demagnetized.
The hook 63a rotates to the right due to the tension of the ratchet 1i.
56b, the right rotation of the lens set ring 56 is stopped, and the photographing lens is fixed at a predetermined position.

In addition, if the object to be measured is located a little further away, for example, as shown in Figure 2 (b 1) and (b 2), the voltage corresponding to ``double memory voltage ■1'' is ■
Changes to 2.

Furthermore, if the measurement 11'-olfactory 1 phenomenon is located at a further distant position, for example, as shown by the solid line in Fig. 2 (CI) and (C2) (reflected light spoiler 1. When the voltage of the detection element 6 is hit by medium heat (S), the voltage changes to 3 which corresponds to the above-mentioned storage voltage V1.

Furthermore, when the object to be measured is located at a very long distance cutting position, as shown by the chain lines in FIGS. 2 (CI) and (C2), the foul light spoiler +- 6, the output voltage Vg
within the next time, the output J of CMP4] will not reach the husband JJ-V r (this may happen even if the distance measurement target has a small foul rate), and the output J will be at rLJ level. When the time t ends, the output of the time forming circuit 2 becomes rL.
Once the output returns to the J level, the output of the Antogame 1.44 cannot be inverted to the rHJ level. Therefore, F.F.
52 is not set and the output Q is held at the "I2" level, keeping the AND gate 53 closed.

As a result, the electromagnet 55 is not magnetized from the initial state and has not attracted the iron piece lever 63, so the lens set ring 56 rotates to the right and the ratchet tooth 56b is rotated to the right, similar to the double operation. When the teeth of the hook 63a face the hook 63a,
The iron piece lever 63 immediately rotates to the right, and the hook 63a engages with the ratchet teeth 56b, stopping the right rotation of the lens set ring 56 and fixing the photographing lens at the infinity position.

Next, another embodiment will be described with reference to FIGS. 7 and 8. Note that elements that are the same as those in the previous example are designated with the same ladle numbers.
I'm doing j.

66.67 is CMP, 68.69 and 70 are constant current circuits, resistors and potentiometers, 71° 72 and 73 are Nandt gates (note that the element r- to the north and the output voltage of the current amplification circuit 48 are As input, Nantogame-1-72,73
A window comparator circuit is constructed in such a way that the state of ) 74 is Anotogame-1, 75 is Orgate, 76 is I/Haata, 77-80 is Tou/Jista,
81 is a motor.

Reference numeral 82 denotes a lens set ring, which is arranged rotatably around the optical axis and forms a partial gear 82a. 83
is a pinion, and the motor 8 is the same as that in Fig. 7.
It is fixed to the rotating shaft of 1.

84 is an intermediate gear that meshes with the pinion 83 and the partial gear 82a of the lens set ring 82.

The potentiometer 70 in FIG. 7 is composed of a brush 70a supported by a lens setting ring 82, a resistor 70c and a conductor 70d formed on a substrate 701)-1-, as shown in FIG. There is.

As shown in series 11 and 2, the output voltage of the current amplification circuit 48 is set to increase as the object to be measured becomes near, medium, and far, apart from extremely far distances.

Since it is a window comparator circuit, if the output voltage (Vx) of the current amplifier circuit 48 is higher than the voltage (Vl) at the non-inverting input terminal (Vl) of the CMP 66, the CMP
Since the output of the CMP 66 is at the "I," level and the output of the CMP67 is at the "■-■j level," the output of the Nantes gate 71 becomes the "H" level, and the output of the Nantes gate 72 becomes the "I," level.
At "H" level, the output of Nandoge-1/73 is 1-LJ
level.

On the other hand, the output voltage Vx is the inverting input terminal (-
), the output J of the CMP 66 is at the "■" level and the output of the CMP 67 is at the "Lj level," so the subsequent output state will be in the opposite relationship to that described above.

In both cases, there is a difference in the power of both motor drive circuits, so the motor 81 rotates in each direction to drive the lens set link 82.

Furthermore, when the output voltage Vx is placed in the relationship Vy)Vx)Vz, the outputs of CMP66 and CMP67 are both [11
] level and the output of Nandoge-1・71 is l”L
Since the output is at the J level, the outputs of the Nant gates 72 and 73 are both at the "H" level, and at this time, the motor 81 does not rotate because both motor drive circuits have the same potential.

That is, by operating the potentiometer 70 in conjunction with the movement of the lens setting ring 82 driven by the rotation of the motor 81, the voltages vy and Vz are changed with respect to the output voltage Vx at that time, and Vy)Vx)Vz The photographing lens is fixed at a predetermined position by detecting the relative position of the lens.

Furthermore, as mentioned above, when F F 52 is not set and the output Q is still at [-L] level, the
4 is at the rLJ level, and the output of the OR gate 75 is held at the II1 level, which is the same as when the output voltage Vx is high, so the photographing lens is driven to the extreme distance position.

The operation of detecting the state of Vy:)Vx)Vz is as follows: , it is preferable to provide a limiter.

Next, another embodiment will be described with reference to FIG. Note that the same elements as in the previous embodiment are given the same reference numerals.

86 is, for example, a 4-bit A/D converter circuit, 87 -
90 is an anime game-1, and 91 is a 4-bit magnitude comparator, for example! L 92 motor drive circuit; 93 is a motor that drives the lens setting ring by its rotation; 94 is, for example, a 4-hit encoder that digitizes the amount of rotation of the motor 93;

The analog amount of the output voltage of the current amplifier circuit 48 is A, /
By the four output terminals of the D converter circuit 86, rL
J, "LJ, rL", rLj to [I-jJ.

[HJ, [HJ, rHJ] is encoded as one of the 16 stages of digital quantities, and the 16 stages are, for example, divided into 16 from the extremely far distance position to the close distance position.

Therefore, the output of the A/D converter circuit 86 is input to the magnitude comparator circuit 91 through the analogues 1.87 to 90. The lens setting ring is driven by the motor 93 being rotated by the motor drive circuit 92. As a result, the photographing lens is displaced from the infinity position to the close distance position. When the output of an encoder 94 that converts the amount of rotation of the motor 93 into a digital amount matches the human power of the comparator circuit 91, the motor 93 is stopped and the photographing lens is fixed at a predetermined position.

Also, as mentioned above, when the FF52 is not set and the output Q is still at the "L" level, the
Since the outputs of both are held at the "I," level, which is the same as the extremely long distance state described in 10, the photographing lens is fixed at the far position of jHH5 eyes.

In each of the embodiments, if the FF 52 is not set and a long-distance state is set, an alarm may also be issued at the same time.

As described above, the present invention achieves stability by using a simple configuration that sweeps the amplification factor of the amplification circuit from a low amplification factor to a high amplification factor without performing logarithmic compression of the light receiving element output or automatic gain adjustment of the amplification circuit. It is possible to determine the distance measurement state by operating the sensor.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing an embodiment of the present invention, Fig. 2 is an explanatory diagram showing the relationship between the state of the reflected light spot on the light receiving element and the output voltage, and Fig. 3 shows an example of the distance measurement output. Diagrams of truth values, Figures 4 and 5. FIGS. 7 and 9 are partial circuit diagrams showing other embodiments of the present invention, and FIGS. 6 and 8 are partial circuit diagrams of the photographing lens drive mechanism corresponding to FIGS. 5 and 7, respectively. It is an explanatory diagram showing an example. 1......Tarlock pulse generation circuit 2......Time forming circuit 5...
・・・・・・・・・・・・Infrared light emitting diode 6・
......... Semiconductor device detection element 9a
, 9b... Electrode (for detection) 10...
・・・・・・・・・・・・・・・・Common electrode 11.12
．． 13 and 14...AC amplifier circuits 13a and 14a...Gain adjustment input terminals 15 and 16...Band filter circuits 17 and 1
8...Detection circuits 19 and 20...
・・・・・・Hirayuki Circuit 21 and 22・・・・・・・・・
DC amplifier circuits 27 and 48... Current amplifier circuits 51 and 70... Potentiometer 55... Electromagnet 56 and 82... Lens set rings 81 and 93... Motor 86... A/D converter circuit 91... Magnitude Comparator circuit 92...Motor drive circuit 94...
...... Encoder X and X'...
...Reflected Light Spot Patent Applicant Co., Ltd. Copal No. 21-1 6 <, 225m5) No. 41-1 Procedural Amendment (Method) Case I of October 81, 1981 Display Patent Application No. 182530 of 1982 2 Name of the invention Distance measuring device 3 Person making the correction Tokugi Detonjin 2-16-20 Shimura, Itabashi-ku, Tokyo 174 Phone number (9)
65) +111 (+22) Co., Ltd. All drawings b Contents of amendment

Claims (8)

[Claims] (1) A triangular distance measuring device that projects light emitted from a light emitting element toward a distance measurement target and receives the reflected light with a semiconductor device detection element that has a common electrode and a pair of detection electrodes. In, the amplification factor of the amplifier circuit that amplifies the output between the common electrode and each detection electrode in the semiconductor device detection element is subtracted by J'+jf from a low amplification factor to a high amplification factor within a constant ++ri, and the common electrode and When the amplified output between one detection electrode reaches a certain set value, the state of the amplified output between the common electrode and the other detection electrode is determined. Uj:i
M-1i (?;,. (2) Triangle ll! in which the light emitted from the light emitting element is projected toward the distance measurement target, and the reflected light is received by a semiconductor device detection element having a common electrode and a detection electrode of −χ·j! II
In a distance method measuring device, the amplification factor of an amplifier circuit that amplifies the output between the common electrode and each detection electrode in the semiconductor device detection element is swept from a low amplification factor to a high amplification factor within a certain period of time, and the common A distance measuring device characterized in that when an amplified output between an electrode and one detection electrode reaches a certain set value, a common electrode and the other detection electrode are determined to be used for detection. (3) The Wli measuring device according to claim 1 or 2, characterized in that the amplified output between the common electrode and the other detection electrode is compared with a plurality of levels. (4) A patent characterized in that when the amplified output between the common electrode and one of the detection electrodes does not reach a certain set value within a certain distance, the distance measurement output is determined as long distance. A distance measuring device according to claim 1 or 2. (5) The light emitted from the light emitting element is 1liii 171
j The principle of the triangulation distance measurement method in which the reflected light is projected toward the R and J objects and is received by a semiconductor device detection element having a common electrode and a pair of detection electrodes. The amplification factor of the amplifier circuit that amplifies the output between the common electrode and each of the detection electrodes is swept from a low amplification factor to a high amplification factor within a certain period of time, and the amplification factor between the common electrode and one of the detection electrodes is When the detected output reaches a certain set value, the state of the amplified output between the common electrode and the other detection electrode is stored as a voltage value and applied to one input terminal of the comparator circuit. is driven from one extreme position of the movable range to the other extreme position, and in conjunction with the movement of said j514, the potential of the input terminal of The device is characterized in that the driving of the photographing lens is stopped when the electric potentials of both input terminals coincide with each other. (6) Triangulation h in which the light emitted from the light-emitting element r- is projected toward a measuring object, and the reflected η·1 light is received by a semiconductor device detection element having a common electrode and a pair of detection electrodes.
゛1! In the 1llil distance device of the method, the amplification factor of the amplifier circuit that amplifies the output between the common electrode and each detection electrode in the semiconductor device detection element r.i11 is swept from a low amplification factor to a high amplification factor within a certain time When the amplified output between the common electrode and one detection electrode reaches a certain set value, the state of the amplified output between the common electrode and the other detection electrode is stored as a voltage value and the window comparator A potential corresponding to a position within the movable range of the photographic lens is applied to one input terminal of the rake circuit, and a potential corresponding to a position within the movable range of the photographic lens is applied to the other input terminal of the window comparator circuit, and the input voltage is connected between the output terminals of the comparator circuit. The photographing lens is driven by a servo motor that rotates in accordance with the direction of unbalance, and when the potentials of both input terminals of jiir coincide within a predetermined threshold area having a certain width, the rotation of the servo motor is stopped. 1.1' The distance measuring device is characterized in that the driving of the photographing lens is stopped. (7) Distance measurement using a diagonal distance measurement method in which light emitted from a light-emitting element is projected toward a distance measurement target, and the reflected light is received by a semiconductor device detection element having a common electrode and a pair of detection electrodes. In the apparatus, the amplification factor of the amplifier circuit that amplifies the output between the common electrode and each detection electrode in the semi-centric optical position detection element described in 1iif is swept from a low amplification factor to a high amplification factor within a certain period of time, and the common electrode At 115 points where the amplified output between the common electrode and the other detection electrode reaches a certain set value, the voltage value of the amplified output state between the common electrode and the other detection electrode is converted into a digital value and stored. and then change the shooting lens to i]
'While driving from one extreme position to the other extreme position of the movement range, the step amount of the drive is converted into a digital amount by an encoder, and when the digital amount matches the stored digital value, the photographing A rangefinder fi:i:0 characterized by stopping the driving of the lens. (8) If the increased output between the common electrode and one of the detection electrodes does not reach a certain set value within a certain period of time, the photographing lens will be prioritized and stopped at the extreme position on the far side. A distance measuring device according to any one of claims 5 to 7, characterized in that: