JPH09265592A - Body detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the detection precision of the body detecting device, reduce the power consumption, and prolong the life. SOLUTION: This device reflects light emitted by a light emitting means 1 by a body TX as a distance measurement object, converts it into a light receiving signal Sa by a photodetecting means 2, and outputs it to plural integrating circuits 3a, 3b, and 3c. A signal generating means 4 can output a light emission signal Pa to the light emitting means and output a reset signal to the integration parts of the respective integrating circuits and a latch signal to a holding part. The reset signal and latch signal can be outputted while one pulse delayed behind the light emission signal Pa which is outputted in specific cycles. When the light receiving signal Sa varies greatly after one light emission pulse is sent, that is outputted to a decision means 5 with the latch signal right after it. The decision means 5 outputs an alarm signal Se when the value of a data signal inputted from an integrating circuit is larger than a reference value. Even when the intervals of the light emission pulses are made long, the body can be detected early.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an object detection device for detecting obstacles and the like in front of a running automobile.

[0002]

2. Description of the Related Art Infrared rays are used as a vehicle-mounted obstacle detection sensor for detecting an obstacle in front of or behind a vehicle to give an alarm to a driver and controlling the engine and brakes by using the detection signal. The distance measuring sensor used is used. This is to detect the reflected light reflected from the object to be measured by emitting infrared rays in a predetermined direction and to output a warning signal when the distance output has a predetermined change from the normal state. It was made to be released.

As a first example of the distance measuring sensor used for detecting such an object, there is one which is made to function as shown in the timing chart of FIG. To detect an object, as shown in FIG. 5A, normally, one distance measuring operation repeats narrow pulsed light emission L 8 to 16 times within a short time ts (several ms to several tens ms). (In FIG. 5, three pulses are provided to facilitate understanding.) The reflected light from the object is detected by the light receiving element, and this is output to the integrating circuit as a light receiving signal, which is integrated by the integrating circuit and the distance is calculated. Is calculated, and the warning signal AL is output when the data is larger than a preset predetermined value.

FIG. 5B shows a waveform when an obstacle is present immediately before the light emission L1. FIG. 5C shows light emission L1.
The warning signal AL is being output after the lapse of the calculation time ta after the completion of. In a vehicle-mounted sensor or the like, this distance measuring operation is continuously repeated at a cycle t1 to constantly calculate the distance to the obstacle. The reason for emitting light multiple times is that the reflected light is small especially when measuring a long distance, so that the reflected light is integrated multiple times to obtain a sufficient signal level, and at the same time it is affected by noise. This is to make it difficult and improve reliability.

As a second example, which is a conventional technique similar to this, as shown in FIG. 6A, in order to reduce power consumption, the light emitting elements are caused to emit light at relatively long equal intervals.
There is also a method in which the reflected light is integrated a predetermined number of times (three times in FIG. 6), and then the warning signal AL is output when the integrated value is larger than a preset predetermined value. Each waveform in FIG. 6 is similar to that in FIG. 5, (b), (d), (f) are waveforms BT indicating the existence of obstacles, and (c), (e), (g). Is a waveform AL indicating the timing at which the distance measuring sensor detects an obstacle and outputs a warning.

According to the second prior art, as shown in FIG. 6 (f), the warning signal AL is output when two pulses of the reflected light of three pulses detect an object. is there. That is, an obstacle that appears immediately after the light emission L11 in the distance measurement period K1 and during the light emission L21 in the next distance measurement period K2 can also be detected by the light emission L12 and L13.

[0007]

In the first prior art described above, as shown in FIG. 5B, when an obstacle appears immediately before the light emission L1, the warning signal L is output as shown in FIG. c)
As shown in FIG. 5, there is no problem because the light emission L1 is output after the time ta for the calculation has elapsed. However, as shown in (d) of the same figure, when an obstacle appears immediately after the light emission L1, the warning signal AL is output after the next light emission L2 as shown in (e) of the same figure. Therefore, when high-speed detection such as that used for front obstacle monitoring of a passenger car is required, the interval of the cycle t1 must be set to be very small. Therefore, this conventional technique has a drawback in that not only the number of times the light emitting element emits light increases, power consumption also increases, but also the life of the light emitting element is shortened due to heat generation. In other words, considering the life of the light emitting element, there is a problem that there is a limit to the improvement in the obstacle detection speed. On the other hand, when it is mounted on a vehicle having a relatively low speed, such as a carrier vehicle in a factory, a high speed detection is not required, so the cycle t1 may be set slightly longer. Has a problem that an obstacle appearing between the light emissions L1 and L2 as shown by a dotted line in FIG. 5D cannot be detected.

Further, in the case of the second prior art, FIG.
As shown in (d), (e), (f), and (g), at least tb from the appearance of the obstacle to the output of the warning signal.
= (1/3 × t1) + ta to maximum tc = (4/3 × t
1) + time is required. Therefore, there is a time lag between the appearance of the obstacle and the output of the warning signal depending on the timing of the appearance of the obstacle. Therefore, when high-speed detection is required, the warning signal is generated as in the first conventional technique. However, there is a problem that the output of is delayed.

[0009]

In order to solve the above problems, the present invention makes the pulse interval of the light emission pulse by the light emitting means relatively large, and provides a plurality of integration circuits corresponding to this. The integrated value of a plurality of pulses can be output to the determination means at a timing shifted by one pulse. The determination means compares the final value of the integrated value with the reference value by the latch signal output from the signal generation means to each integration circuit, and warns when the integrated value is larger than the reference value. The signal can be output. The signal generating means is
A latch signal is output to each integrator circuit at a timing shifted by one pulse, and the integrated value is input to the determination means and determination is performed each time each pulse is transmitted.

In another means of the present invention, the circuit is simplified by digitally configuring a plurality of integrating circuits. That is, the light reception signal converted into a digital signal by the analog-digital conversion circuit is output to the determination means via the latch circuit and the signal generation means. This means is provided with a plurality of memories, each of which stores the digital value of the received light signal at a predetermined cycle, and the stored value is shifted by one pulse by the control signal output from the signal generating means. It can be output to the judging means. The determination means sequentially compares the input stored value with predetermined distance data set in the built-in memory, and can output a warning signal when the stored value becomes larger than the distance data.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The detection of an object to be measured for detecting the approach of an object or the like according to the present invention is performed by a light emitting means such as an LED and the light emitted from this light emitting means is reflected by the object to be measured, This reflected light is received by a light receiving means such as PSD. The reflected light received by the light receiving means can be output to a plurality of integration circuits as a light reception signal. The light emitting means can emit light at a constant cycle by the light emitting pulse output from the signal generating means,
The light reception signal output in response to this can output a light reception signal whose strength changes depending on the existing position of the target object.

Each integrating circuit clears the received light signal and newly integrates it by the reset signal output from the signal generating means. It is preferable that the reset signal is output at intervals of the number of pulses corresponding to the number of integration circuits, and the reset signals to each integration circuit are output at intervals of one pulse. Also, the integrated value integrated before and after the output of the reset signal by the integrator circuit is
It is preferable that the reset signal is latched immediately before the output of the reset signal so that it can be output to the determination circuit. Therefore, each integrating circuit receives the output of the latch signal from the signal generating means and outputs the integrated value data every time the number of light receiving signals corresponding to the number of integrating circuits is integrated. The integrated value is output every time.

The judging means compares the integrated value data output from each integrating circuit for each pulse with preset reference value data, and when the integrated value data is larger than the reference value data, It is desirable to be able to output a warning signal. It is desirable that the integration circuit described above be configured by an integration unit that integrates the received light signal and a holding unit that holds the integrated value integrated by the integration unit. The integrator integrates the received light signal each time it is reset by the reset signal output from the signal generator, and the holder holds the latch signal output from the signal generator immediately before the reset signal is output. It is preferable that the integrated value can be output to the determination means.

The circuit can be simplified by converting the received light signal into a digital signal by an analog-digital conversion circuit in advance without using the integrating circuit in the above-described embodiment and outputting the digital signal to the judging means via the latch circuit. . It is preferable that the signal generating means outputs the data input signal to the latch circuit to sequentially input the input data to a plurality of random access memories (RAM), and to output this memory data to the determining means by a control signal. .
Each memory adds the data output from the latch circuit a predetermined number of times and outputs the data to the determination means when a control signal is input. The control signal is sequentially output to each memory for each light emission pulse output. It is desirable to output to.

The judging means has a built-in memory in which predetermined distance data is stored, and the inputted memory data are sequentially compared. When it is judged that the memory data is larger than the distance data, Set to enable warning signal output. The number of data signals output to each memory is counted by a counter incorporated in the signal generating means. This count value is deviated by one pulse for each memory. It is preferable to make the determination.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, as the optical sensor S in the first embodiment, a light beam emitted by the light emitting means 1 is applied to the object to be measured TX such as an object and the reflected light is received by the light receiving means 2. Type optical sensor is adopted. An infrared generator, for example, is adopted as the light emitting means 1, and the position detecting element (PS
D) etc. are adopted.

The light emitting means 1 can emit light at a predetermined timing by a light emission pulse signal Pa output from a signal generating means 4 described later. The light receiving means 2 is the TX to be measured.
By receiving the reflected light from, the signal indicating that the object is detected, that is, the received light signal Sa, is transferred to the three integration circuits 3a,
It is possible to output to 3b and 3c. Each integrating circuit 3a, 3b,
Reference numeral 3c is an integrating unit 3a1, 3 for integrating the received light signal.
It is composed of b1 and 3c1 and holding units 3a2, 3b2 and 3c2 which hold the integrated value integrated by this integrating unit.

In addition to the light emission pulse signal Pa, the signal generation means 4 latches a latch signal P for latching each holding portion of the integrating circuit 3.
b, Pd, Pf and reset signals Pc, P to the respective integrators
e and Pg can be output. Each integration unit 3a1, 3b1,
3c1 is reset by the above-mentioned reset signals Pc, Pe, Pg output from the signal generation circuit 4 every predetermined distance measuring period, and the holding sections 3a2, 3b2, 3c2 are also latched signals Pb, Pd, Pf. By the input, the integrated value obtained by integrating the output data Sa from the held light receiving means 2 can be output to the determining means 5 as output signals Sb, Sc, Sd.

The judging means 5 includes respective integrating circuits 3a, 3b, 3
The output signals Sb, Sc, and Sd from c are received, and the output signals Sb, Sc, and Sd are compared with the reference voltage Vth set in advance in the determination means 5 for each output. It is possible to output a warning signal Se (see FIG. 2). Of course, when these output signals are equal to or lower than the reference voltage, the detectable state is maintained as it is.

Next, the operation of this embodiment will be described with reference to the timing chart of FIG. In FIG. 2, (a) is a narrow emission pulse Pa output at a predetermined period T1 (for example, 20 ms) that causes the light emitting means 1 to emit light periodically. (D), (h), and (l) of FIG.
The output signals Sb0, Sc0, Sd0 of the integrators 3a1, 3b1, 3c1 of b, 3c, respectively. FIG.
Since (f) and (j) hold the output signals Sb0, Sc0, and Sd0 of the integrating units 3a1, 3b1, and 3c1, respectively,
The latch signals Pb, Pd, and Pf are output after the time Ta has elapsed since the light emission pulse was output. The same figure (c),
(G) and (k) are reset signals Pc, Pe and Pg for resetting the output signals Sb0, Sc0 and Sd0 of the integrators 3a1, 3b1 and 3c1, respectively. These reset signals can reset the output signal of the integration unit after the output of the integration circuit is held by the holding unit by the latch signal.

Now, assuming that the object TX is not present or is distant, the light emitting means 1 is output by the signal generating means 4 and emits light in accordance with the light emitting pulse Pa shown in FIG. 2 (a). In the case of receiving a single reflected light and outputting this as a received light signal, since the output signal Sa of the light receiving means 2 is small, accurate data processing is difficult. Therefore, as shown in FIG. 2D, the light emission pulses Pa1, Pa2, P
The light receiving signal of a3 can be integrated by the integrating unit 3a1 of the integrating circuit 3a like vb1, vb2, vb3.
The holding unit 3a2 of the integrating circuit 3a holds the voltage vb3 by the latch signal Pb1 immediately after the light emission pulse Pa3, and outputs it as the output signal Sb to the determination means 5.
This is shown as voltage Vb3 in FIG. The signal Vb3 input to the determination means 5 is compared with a preset reference voltage Vth which is an internal reference signal. The reference voltage Vth is shown by the alternate long and short dash line in FIGS. 2 (e), 2 (i) and 2 (m). The reference voltage Vth is the object TX
Is set to a value that is higher than the output voltage of the integration circuit when there is no object or at a distance, and is lower than the output voltage of the integration circuit when the object TX is below a predetermined distance. . Therefore, Vb3 <Vth, and the warning signal Se of the determination means 5 remains at the low level as shown in FIG. 2 (n).

Next, the signal generating means 4 causes the reset signal Pc1.
Is output and the integrating unit 3a1 is reset, the above operation is repeated every three pulses from the next light emission pulse Pa4 as before. Therefore, the output signal Sb of the integrating circuit 3a changes when the latch signal Pb is output, which is every 60 ms in this embodiment. Other integration circuits 3b and 3c
In the same manner as described above, operations such as integration, holding, and reset are performed, but the latch signal Pd that holds the output signal of the integrating circuit 3b is 1 of the light emission pulse Pa rather than the latch signal Pb.
The latch signal Pf, which is output with a delay by the period and holds the output signal of the integrating circuit 3c, is 1 more than the latch signal Pd.
It is output with a delay of the cycle. Similarly, the reset signal Pe for resetting the integration circuit 3b is output with a delay of one cycle of the light emission pulse Pa from the reset signal Pc output to the integration unit 3a1. Similarly, the reset signal Pg for resetting the integration circuit 3c is output with a delay of one cycle from the reset signal Pe.

That is, the light emitting pulse Pa is set to 1 by the output signals Sb, Sc, Sd of the integrating circuits 3a, 3b, 3c.
An output signal obtained by integrating the output signal Sa of the light receiving means 2 for three cycles of the light emission pulse is obtained every cycle.
Now, assuming that the object TX approaches within a predetermined distance in the period T that spans the light emission pulses Pa7 and Pa8, the light receiving means 2
Output signal Sa of FIG. 2 increases more than usual, and the output voltages Sb0, Sc0, Sd0 of the integrators of the respective integrator circuits are respectively vb as shown in (d), (h) and (l) of FIG.
4, vc3, vd2. Immediately after this, a latch signal Pd2 for holding the output signal of the integrating circuit 3b
2 (i), the output signal Sc outputs its voltage vc3 as Vc3.

This signal Vc3 is output to the judging means 5,
Although it is compared with the internal reference voltage Vth, Vc3> Vth at this point as described above. Therefore, FIG.
As shown in (n), the output signal Sc of the determination means 5 changes to the high level, and the warning signal Se is output to notify the approach of the object to the outside.

Similarly, the latching signal Pf2 outputs the signal Sd of the voltage Vd3 to the integrating circuit 3c, and the integrating circuit 3a outputs the signal Sb of the voltage Vb6 by the latching signal Pb3. Since the integrator circuits 3a and 3c integrate the output signal Sa of the light receiving means 2 with respect to both the light emission pulses Pa7 and Pa8, the output signal can surely exceed the reference voltage Vth. It is possible. The integrating circuit 3b emits a light emission pulse Pa7.
However, even in this case, the output voltage is increased by the reflected light from the light emission pulses Pa5 and Pa6, and the reference voltage V is increased by the light emission pulse Pa7.
Since th can be exceeded, the approach of the object TX can be detected.

That is, in the configuration of the present embodiment, since the integration results of the three pulses before that are sequentially output for each light emission pulse, after the appearance of the object TX, the warning signal Se is generated within one light emission pulse cycle, that is, within T1 + ta. Will be output. When light is emitted in the same cycle as the conventional example, the speed of detecting an obstacle can be tripled. By using a similar method, the detection speed can be improved by providing a larger number of integration circuits. If the detection speed is not so required, the life of the light emitting element can be shortened by delaying the light emitting pulse cycle. Can be extended.

In the present embodiment, the case where the integrating section and the holding section of the integrating circuit are all configured by analog circuits is shown, but the present invention is not limited to this, and analog-digital after the integrating section in each integrating circuit. A conversion circuit may be provided so that the analog amount is once converted into a digital amount and held, and the warning signal is output by comparing with a reference signal of a predetermined digital amount stored in the determination means.

Next, the second embodiment will be described with reference to the block diagram shown in FIG. Since the light emitting means 1 and the light receiving means 2 are the same as those in the first embodiment,
Here, the description is omitted. It should be noted that the timing chart using common symbols will be described using the FIG. 2 used in the first embodiment as it is. The light receiving signal Sa output from the light receiving unit 2 can be output to an analog-digital conversion circuit (hereinafter referred to as “A / D converter”) 31. The A / D converter 31 converts the received light receiving signal Sa into a digital signal and outputs the digital data signal SA.
Can be output to the latch circuit 32. Further, the latch circuit 32 outputs the digital data SA held therein to the signal S.
J can be output to the signal generating means 33.

The signal generating means 33 outputs a light emitting pulse Pa to the light emitting means 1, outputs a control signal Pi to the A / D converter 31, and outputs a data input signal Pj to the latch circuit 32. It is possible. Further, the signal generating means 33 incorporates three counters N1, N2 and N3.

From the signal generating means 33, the data signals SBO, SCO, SDO output from the respective counters 34b,
The data can be input to the three memories 34c and 34d.
A random access memory (RAM) is used as the memory 34, and rewriting and clearing are performed by the control signals Pk, Pl, Pm output from the signal generating means 33. These memories 34 function as the integrator circuit in the first embodiment, and the memories 34b.
Changes the light emission pulse Pa shown in FIG.
a2, Pa3], [Pa4, Pa5, Pa6], [Pa
[7, Pa8, Pa9], the result of digitally adding the received light signals Sa output by the three pulse groups is output. Similarly, the memory 34c stores the light emission pulse [Pa2,
Pa3, Pa4], [Pa5, Pa6, Pa7], [P
a8, Pa9, Pa10], the addition result of the three pulse groups is output. Further, the memory 34d has [Pa3, P
a4, Pa5], [Pa6, Pa7, Pa8], [Pa
[9, Pa10, Pa11], the addition result by the three pulse groups can be output. That is, the memory 34 can obtain three kinds of signals obtained by integrating the output signal Sa of the light receiving means 2 for three cycles in which the timing is shifted by one cycle of the light emission pulse for each cycle of the light emission pulse Pa.

Each memory 34 stores stored data S according to the control signals Pk, Pl and Pm output from the signal generating means 33.
B, SC, SD are output to the determination means 35. Judgment means 3
5 has a built-in memory 35a in which predetermined distance data (reference data) Mt is stored. The determination means 35 outputs the warning signal Se when any one of the data [M1], [M2], [M3] of the output signals SB, SC, SD from each memory 34 becomes larger than the reference signal [Mt]. Output is possible. In the above configuration, the latch circuit 3
2, the signal generation means 33, and the determination means 35 can all be configured by a so-called control circuit (CPU) including a calculation means.

Next, the operation of the second embodiment will be described with reference to the flowchart of FIG. The signal generating means 33 performs all the operations of this flowchart. In FIG.
Outside the frame, (Sn) (n = 0 to 16) represents the step number, and [Mn] and [Nn] (n = 1 to 3) represent the contents of the memory and the counter, respectively. When the power of the apparatus is turned on or the operation is started to start the flow (S0), each memory 34 is reset to the initial value (S1), and at the same time, [N1] becomes 0.
, [N2] is set to 1, and [N3] is set to 2 (S
2).

The signal generating means 33 outputs the light emission pulse signal Pa as described above, and outputs the output signal Sa of the light receiving means 2.
Is converted into a digital signal and then held by the latch circuit 32, the data input signal Pj is transferred to the latch circuit 3
2 and outputs the stored data SJ (S
3, S4). Since [N1] is now 0, the flow proceeds to (S7) through (S5), sets [N1] to 3 and clears the memory data [M1] in the memory 34b. Next, the data SJ is written in the memory data [M1], [M2], and [M3] of the memories 34b, 34c, and 34d (S10). Therefore, the contents of the memories 34b, 34c, and 34d are the same at the initial point. Since 1 is subtracted from the contents of each counter in (S11), [N1] = 2, [N2] = 0, and [N3] = 1.

Here, (S12), (S13), (S1)
In 4), the contents [M1], [M2], [M3] of each memory are compared with the predetermined distance data [Mt], and if the contents of the memory are larger (that is, the distance to the object is smaller). , (S15), a warning signal is output. Then, if the content of any memory is smaller than the predetermined distance data [Mt], the warning signal Se is reset (S16) and is kept (S16).
Return to 3) and repeat the above sequence. At the initial point, the latter, that is, [M1], [M2] and [M3] <
Since it is [Mt], the process returns to (S3), and the next data input signal Pj is obtained.

Returning to (S3), since [N2] = 0 this time, the flow is (S6), (S8), (S1).
0), (S11), and as a result, [N1] = 1,
[N2] = 2 and [N3] = 0. Where memory 3
In the data [M1] of 4b, the data SJ is added once and 2
Since the data M2 in the memory 34c has been cleared by (S8), the data SJ is read once. Then, as the data M3 in the memory 34d, the data for two times is accumulated similarly to [M1], and the process returns to (S3). Similarly, since [N3] = 0 this time, (S9),
The process proceeds to (S10) and (S11), and as a result, [N1] =
0, [N2] = 1, [N3] = 2, and the memory 34b
The data SJ is added three times, the memory 34c is added twice, and the memory 34d is cleared by (S9), so that the data SJ is read once and the process returns to (S3).

After that, the above steps are repeated. By repeating the above operation, the contents of the memory [M
1], [M2], and [M3], the output signal Sa of the light receiving means 2 is integrated for three cycles of which the timing is shifted by one cycle of the light emission pulse for each cycle of the light emission pulse Pa. An output signal will be obtained. When the object TX approaches the optical sensor S in the middle of the sequence, the data SJ increases, and the values [M1], [M
2] or [M3] is the predetermined distance data [M
t], (S12), (S13), (S1)
The determination is made according to the Yes route of 4), and the warning signal Se is output in (S15). When the object TX is no longer approaching (S16), the warning signal Se is reset.

In order to prevent malfunction, if the initial sequence is from the start of the above flow until the state where all the memories have added the data a predetermined number of times,
During the initial sequence, the contents of each memory are compared with the predetermined distance data [Mt] ((S12) and (S1 in FIG. 4).
3), (S14)) may not be performed. In the above embodiment, the case where there are three memories has been described, but the number of memories, that is, the number of integrating circuits may be any number. With such a configuration, a plurality of integrating circuits can be digitally configured, which is advantageous in that the circuits can be simplified.

In this embodiment, a warning signal is output when any one of the plurality of integrating circuits detects an object, but the present invention is not limited to this.
If any object is detected, the light emission cycle of the light emission pulse may be increased to a speed allowed by the system, and an alarm may be output after the object is surely approached. Further, in the above embodiment, the integrating circuit is configured to obtain the output signal of the light receiving means for each cycle of the light emitting pulse, but it may be configured to obtain the output signal for each predetermined number of light emitting pulses. For example, three integrating circuits may be provided so that the output signal of the light receiving unit is obtained every two cycles of the light emission pulse, and each integrating circuit may be reset every six cycles of the light emission pulse. Alternatively, the number of integrating circuits that have detected an object may be counted and a plurality of alarm signals may be sequentially output. Further, various applications are possible in which a plurality of reference signals corresponding to the distance value to the object are provided and a plurality of warning signals (for example, signals for changing the type of warning sound) are sequentially output.

[0039]

According to the present invention, the light receiving signals output from the light receiving means are integrated by a plurality of integrating circuits, and the latch signal and the reset signal are output from the signal generating means at a timing shifted by one pulse, thereby making a determination. Since the integrated value can be output to each of the means, the determination result can be output each time the light receiving means outputs the light receiving signal by the determining means. Therefore, even if the light emission cycle of the light emission pulse is relatively long, the approach of the object can be detected quickly and accurately, and the life of the light emitting means is extended. Further, if a memory is used instead of the plurality of integrating circuits and a configuration in which a light reception signal converted into digital data can be output to the determination means, the circuit configuration becomes simple and the manufacturing cost can be effectively reduced.

[Brief description of drawings]

FIG. 1 is a circuit block diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a timing chart for explaining the operation of the first exemplary embodiment of the present invention.

FIG. 3 is a circuit block diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 4 is a flow chart for explaining the operation of the second embodiment of the present invention.

FIG. 5 is a timing chart for explaining the operation of the conventional example.

FIG. 6 is a timing chart for explaining the operation of another conventional example.

[Explanation of symbols]

TX object to be measured (object) 1 light emitting means 2 light receiving means 3a, 3b, 3c integrating circuit 3a1, 3b1, 3c1 integrating part 3a2, 3b2, 3c2 holding part 4, 33 signal generating means 5, 35 determining means 31 analog-digital Conversion circuit (A / D converter) 32 Latch circuit 34 (34b, 34c, 34d) Memory

Claims (3)

[Claims] 1. A light emitting means for emitting light rays to a distance-measuring object at a predetermined interval, and receiving the light ray reflected by the distance-measuring object,
The light receiving means for outputting a light receiving signal, a plurality of integrating circuits for integrating the light receiving signals at different timings, and temporarily holding the integrated value and then outputting a signal of integrated data, the light emitting means and the integrating circuit. A signal generating means for outputting a driving signal and a judging means for comparing each integrated data with preset reference data and outputting a warning signal when the integrated data is larger than the reference data. An object detection device characterized by being provided. 2. The integration circuit according to claim 1, wherein the integration circuit includes an integration unit that integrates the received light signal, and a holding unit that holds an output signal of data of the integrated value after the integration unit has integrated a predetermined number of times. The data of the integrated value can be reset by a reset signal output from the signal generating means after being held in the holding unit. 3. A light emitting means for emitting a light beam to the object to be measured at a predetermined interval, and receiving the light beam reflected by the object to be measured,
A light receiving unit that outputs a light receiving signal, an analog-digital conversion circuit that converts the light receiving signal into a digital signal, a latch circuit that latches the digital data output from the analog-digital conversion circuit at predetermined intervals, A light emitting pulse signal is output to the light emitting means, and a signal generating means for outputting a control signal to the analog-digital conversion circuit and the latch circuit, and the digital data output from the latch circuit are integrated for each predetermined cycle. A plurality of memories to be stored in a memory, the storage data output from each of the memories at sequentially shifted output timings, and preset reference data are compared, and any one of the storage data is more than the reference data. An object detection device, comprising: a determination unit that outputs a warning signal when the value is large.