JP3618888B2 - Object detection device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an object detection device that detects, for example, an obstacle in front of a traveling automobile.
[0002]
[Prior art]
Ranging sensor using infrared as an in-vehicle obstacle detection sensor that detects obstacles in front of and behind the vehicle and issues an alarm to the driver, or controls the engine and brakes using the detection signal Is used. This is because infrared rays are emitted in a predetermined direction to detect reflected light reflected from the object to be measured, and a warning signal is output when the distance output has a predetermined change with respect to the normal state. It is something that is made to come out.
[0003]
There is a first example of a distance measuring sensor used for detecting such an object that functions as shown in the timing chart of FIG. As shown in FIG. 5 (a), the object detection is normally performed once in a distance measuring operation by repeating a narrow pulse-like light emission L 8 to 16 times within a short time ts (several ms to several tens of ms). (In FIG. 5, three pulses are used for ease of understanding.) The reflected light from the object is detected by the light receiving element, and this is output as a light receiving signal to the integrating circuit, and this is integrated by the integrating circuit. Min The distance is calculated, and a warning signal AL is output when the data is larger than a predetermined value set in advance.
[0004]
FIG. 5B shows a waveform when an obstacle is present immediately before the light emission L1. FIG. 5C shows a state in which the warning signal AL is output after the calculation time ta has elapsed after the light emission L1 ends. In a vehicle-mounted sensor or the like, this distance measuring operation is continuously repeated at a period t1, and the distance to the obstacle is always calculated. The reason for emitting light multiple times is that there is little reflected light, especially during long-distance ranging, so that the reflected light can be integrated multiple times to obtain a sufficient signal level and at the same time affected by noise. This is because it is difficult to improve reliability.
[0005]
Further, as a second example, a related art similar to this is shown. However, as shown in FIG. 6A, in order to reduce the power consumption, the light emitting element is caused to emit light at relatively long regular intervals, and a predetermined number of times ( FIG. 6 shows the case of three times.) Min And then the product Min There is also a method of outputting the warning signal AL when the value is larger than a predetermined value set in advance. Each waveform in FIG. 6 is the same as that in FIG. 5, and (b), (d), and (f) are waveforms BT indicating the presence of an obstacle, and (c), (e), and (g). Is a waveform AL indicating the timing at which the distance measuring sensor detects an obstacle and outputs a warning.
[0006]
According to the second prior art, as shown in FIG. 6 (f), the warning signal AL is output if two pulses out of the reflected light of the three pulses detect an object. That is, an obstacle that appears between the light emission L21 in the next distance measurement period K2 immediately after the light emission L11 in the distance measurement period K1 can be detected by the light emission of the light emission L12 and L13.
[0007]
[Problems to be solved by the invention]
In the first prior art described above, when an obstacle appears immediately before the light emission L1, as shown in FIG. 5B, the warning signal L is output as shown in FIG. 5C. Is output after the time ta for calculation has elapsed. However, when an obstacle appears immediately after the light emission L1, as shown in FIG. 9D, the warning signal AL is output after the next light emission L2, as shown in FIG. Therefore, when high-speed detection such as that used for monitoring obstacles ahead of passenger cars is required, the interval of the period t1 must be set very small. Therefore, this conventional technique has a drawback that not only the number of times of light emission of the light emitting element increases and power consumption increases, but also the life of the light emitting element is shortened due to heat generation. In other words, there is a problem that there is a limit to improving the obstacle detection speed in consideration of the lifetime of the light emitting element.
On the other hand, when this is mounted on a relatively low speed vehicle such as a transport vehicle in a factory, the high-speed detection is not required, so the period t1 may be set slightly longer. Has a problem that an obstacle appearing between the light emission L1 and L2 as shown by the dotted line in FIG. 5D cannot be detected.
[0008]
In the case of the second prior art, as shown in FIGS. 6D, 6E, 6F, and 6G, after the obstacle appears, the warning signal is output. The time from the minimum tb = (1/3 × t1) + ta to the maximum tc = (4/3 × t1) + ta is required. For this reason, there is a time difference 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 the same as in the first conventional technique. There is a problem that causes inconvenience that the output of the system becomes slow.
[0009]
[Means for Solving the Problems]
In order to solve the above problem, the present invention provides a relatively large pulse interval of the light emission pulses by the light emitting means, and by providing a plurality of integration circuits corresponding thereto, the integration values of the plurality of pulses are obtained. Of luminous cycle It is possible to output to the judging means at a timing shifted by one pulse.
The judging means compares the final value of the integrated value with the reference value by the latch signal output from the signal generating means to each integrating circuit, and warns when the integrated value is judged to be larger than the reference value. The signal can be output.
The signal generation means Of luminous cycle A latch signal is output to each integrating circuit at a timing shifted by one pulse, and an integrated value is input to the determining means for each pulse transmission to make a determination.
[0010]
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 the 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 memory Of luminous cycle The digital value of the received light signal for each predetermined period is stored, and this stored value is stored by the control signal output from the signal generating means. Of luminous cycle It is possible to output to the determination means at a timing shifted by one pulse.
The determination means sequentially compares the inputted 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]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, the object to be measured for detecting the approach of an object or the like is detected by a light emitting means such as an LED and the light emitted from the light emitting means is reflected by the object to be measured, and the reflected light is reflected by a PSD or the like. This is done by receiving light with the light receiving means.
The reflected light received by the light receiving means can be output as a light reception signal to a plurality of integration circuits. The light emitting means can emit light at a constant cycle by the light emission pulse output from the signal generating means, and the light receiving signal output in accordance with this is a light receiving signal that changes in strength depending on the position of the object to be measured. Can be output.
[0012]
Each integrating circuit clears the received light signal and newly integrates the reset signal output from the signal generating means. The reset signal is preferably output at intervals of the number of pulses corresponding to the number of integration circuits, and the reset signal to each integration circuit is preferably output at intervals shifted by one pulse. Further, it is preferable that the integration value integrated before and after the output of the reset signal by the integration circuit is latched immediately before the output of the reset signal and output to the determination circuit. Therefore, each integrating circuit receives the output of the latch signal from the signal generating means each time the number of received light signals corresponding to the number of integrating circuits is integrated, and outputs the data of the integrated value. An integral value is output every time.
[0013]
The determination means compares the integral value data output from each integrating circuit for each pulse with the preset reference value data, and if the integral value data is larger than the reference value data, a warning signal It is desirable to enable output.
The integration circuit described above is preferably configured by an integration unit that integrates the received light signal and a holding unit that holds the integration value integrated by the integration unit. The integration unit integrates the received light signal every time it is reset by the reset signal output from the signal generation unit, and the holding unit holds the latch signal output from the signal generation unit immediately before the reset signal is output. It is preferable that the integrated value can be output to the determination means.
[0014]
The circuit can be simplified if the received light signal is converted into a digital signal by an analog-digital conversion circuit in advance and output to the determination means via a latch circuit without using the integration circuit in the above-described embodiment.
It is desirable that the signal generating means sequentially inputs the input data by outputting a data input signal to the latch circuit to a plurality of random access memories (RAM), and enables the memory data to be output to the determining means by the control signal. . Each memory adds the data output from the latch circuit by a predetermined number of times, and outputs the control signal to the determination means by the input of the control signal. It is desirable to output to.
[0015]
The determination means has a built-in memory in which predetermined distance data is stored, and sequentially compares each input memory data. If it is determined that the memory data is larger than the distance data, a warning signal is output. Set to enable output.
The number of data signals output to each memory is counted by a counter built in the signal generating means. This count value is shifted by one pulse for each memory, so that each count is shifted by one pulse. It is preferable to make the determination.
[0016]
【Example】
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 a distance measuring target TX such as an object, and the reflected light is received by the light receiving means 2. A type photosensor is adopted. As the light emitting means 1, for example, an infrared ray generator is adopted, and as the light receiving means 2, a position detecting element (PSD) or the like is adopted.
[0017]
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 can output a signal indicating that an object has been detected, that is, a light reception signal Sa, to the three integration circuits 3a, 3b, and 3c by receiving the reflected light from the distance measurement target TX. Each integrating circuit 3a, 3b, 3c includes integrating units 3a1, 3b1, 3c1 for integrating the received light reception signals, and holding units 3a2, 3b2, 3c2 for holding integrated values integrated by the integrating units.
[0018]
In addition to the light emission pulse signal Pa, the signal generating means 4 can output latch signals Pb, Pd, Pf for latching each holding unit of the integrating circuit 3 and reset signals Pc, Pe, Pg to each integrating unit. The integrating units 3a1, 3b1, and 3c1 are reset for each predetermined distance measurement period by the reset signals Pc, Pe, and Pg output from the signal generating circuit 4, and the holding units 3a2, 3b2, and 3c2 are also latched. By inputting the signals Pb, Pd, and Pf, an integrated value obtained by integrating the output data Sa from the held light receiving means 2 can be output to the judging means 5 as output signals Sb, Sc, and Sd.
[0019]
The judging means 5 receives the output signals Sb, Sc, Sd from the integrating circuits 3a, 3b, 3c and compares them with the reference voltage Vth preset in the judging means 5 for each output. Is larger than this, the warning signal Se can be output to the outside (see FIG. 2). Of course, when these output signals are below the reference voltage, the detectable state is maintained as it is.
[0020]
Next, the operation of this embodiment will be described with reference to the timing chart of FIG.
In FIG. 2, (a) is a light emission pulse Pa having a narrow width output at a predetermined period T1 (for example, 20 ms) for causing the light emitting means 1 to emit light periodically. (D), (h), and (l) are output signals Sb0, Sc0, and Sd0 of the integrating units 3a1, 3b1, and 3c1 of the integrating circuits 3a, 3b, and 3c, respectively. (B), (f), and (j) hold the output signals Sb0, Sc0, and Sd0 of the integrating units 3a1, 3b1, and 3c1, respectively, so that the latches are output after the time Ta has elapsed since the emission pulse was output. Signals Pb, Pd, and Pf. (C), (g), and (k) are reset signals Pc, Pe, and Pg for resetting the output signals Sb0, Sc0, and Sd0 of the integrating units 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.
[0021]
Assuming that there is no object TX or a remote object, the light emitting means 1 is output by the signal generating means 4 and emits light according to the light emission pulse Pa shown in FIG. In the case of receiving a single reflected light and outputting it as a light receiving signal, the output signal Sa of the light receiving means 2 is small, so that accurate data processing is difficult. Therefore, as shown in FIG. 2 (d), the received light signals of the light emission pulses Pa1, Pa2, Pa3 can be integrated like vb1, vb2, vb3 by the integrating unit 3a1 of the integrating circuit 3a. The holding unit 3a2 of the integrating circuit 3a holds this voltage vb3 by the latch signal Pb1 immediately after the light emission pulse Pa3, and outputs this voltage vb3 to the determination means 5 as an output signal Sb. This is shown as voltage Vb3 in FIG. The signal Vb3 input to the determination means 5 is compared with a reference voltage Vth that is a preset internal reference signal. The reference voltage Vth is indicated by a one-dot chain line in FIGS. 2 (e), (i), and (m). The reference voltage Vth is higher than the output voltage of the integration circuit when the object TX is not present or far away, and lower than the output voltage of the integration circuit when the object TX is equal to or less than a predetermined distance. Is set to a value. Therefore, Vb3 <Vth, and the warning signal Se of the determination means 5 remains at a low level as shown in FIG. 2 (n).
[0022]
Next, when the signal generating means 4 outputs the reset signal Pc1 and resets the integrating section 3a1, the above operation is repeated every three pulses from the next light emission pulse Pa4 as before. Therefore, the output signal Sb of the integration circuit 3a changes when the latch signal Pb is output, and is every 60 ms in this embodiment.
The other integration circuits 3b and 3c perform the operations of integration, holding, and reset in the same manner as described above, but the latch signal Pd that holds the output signal of the integration circuit 3b is 1 of the emission pulse Pa than the latch signal Pb. The latch signal Pf that is output with a delay of the period and holds the output signal of the integration circuit 3c is output with a delay of one more period than the latch signal Pd. 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.
[0023]
That is, the output signals Sb, Sc, Sd of the integration circuits 3a, 3b, 3c provide an output signal obtained by integrating the output signal Sa of the light receiving means 2 for three periods of the light emission pulse for each period of the light emission pulse Pa. become.
Now, assuming that the object TX approaches within a predetermined distance in the period T spanning the light emission pulses Pa7 and Pa8, the output signal Sa of the light receiving means 2 increases more than usual, and the output voltage Sb0, Sc0 and Sd0 increase as vb4, vc3, and vd2, respectively, as shown in (d), (h), and (l) of FIG. Immediately after this, since the latch signal Pd2 for holding the output signal of the integrating circuit 3b is output, as shown in FIG. 2 (i), the output signal Sc outputs its voltage vc3 as Vc3.
[0024]
This signal Vc3 is output to the determination means 5 and compared with the internal reference voltage Vth. At this time, Vc3> Vth as described above. For this reason, as shown in FIG. 2 (n), the output signal Sc of the determination means 5 changes to a high level, and it is possible to notify the outside of the approach by outputting the warning signal Se.
[0025]
Similarly, a signal Sd of voltage Vd3 is output to the integrating circuit 3c by the latch signal Pf2, and a signal Sb of voltage Vb6 is output to the integrating circuit 3a by the latch signal Pb3. Since the integration 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. Is possible. The integrating circuit 3b performs only one integration for the light emission pulse Pa7, but even in this case, the output voltage rises due to the reflected light from the light emission pulses Pa5 and Pa6, and can exceed the reference voltage Vth by the light emission pulse Pa7. The approach of TX can be detected.
[0026]
That is, in the configuration of the present embodiment, the integration result of the previous three pulses is sequentially output for each light emission pulse, so that the warning signal Se is output within one cycle of the light emission pulse, that is, within T1 + ta after the object TX appears. Will be. In addition, when light is emitted with the same period as the conventional example, the speed at which an obstacle is detected can be approximately tripled. By providing a larger number of integration circuits by the same method, the detection speed can be improved. When the detection speed is not so necessary, the life of the light emitting element is made longer than that of the conventional example by slowing the cycle of the light emission pulse. Can be extended.
[0027]
In this embodiment, the integration unit and the holding unit of the integration circuit are all configured by analog circuits. However, the present invention is not limited to this, and an analog-digital conversion circuit is provided after the integration unit in each integration circuit. It is also possible to convert the analog amount into a digital amount, hold it, and output a warning signal in comparison with a predetermined digital amount reference signal stored in the determination means.
[0028]
Next, a second embodiment will be described with reference to the block diagram shown in FIG. About the light emission means 1 and the light reception means 2, since the thing similar to 1st Example is employ | adopted, description is abbreviate | omitted here. The timing charts using common symbols will be described using FIG. 2 used in the first embodiment as they are.
The light reception signal Sa output from the light receiving means 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 reception signal Sa into a digital signal, and can output the digital data signal SA to the latch circuit 32. The latch circuit 32 can output the held digital data SA as a signal SJ to the signal generating means 33.
[0029]
In addition to outputting the light emission pulse Pa to the light emitting means 1, the signal generating means 33 can output a control signal Pi to the A / D converter 31 and can output a data input signal Pj to the latch circuit 32. . Further, the signal generating means 33 has three counters composed of N1, N2 and N3.
[0030]
From the signal generating means 33, the data signals SBO, SCO, SDO output from each counter can be input to the three memories 34b, 34c, 34d. The memory 34 is a random access memory (RAM), and is rewritten and cleared by control signals Pk, Pl, and Pm output from the signal generating means 33. These memories 34 function corresponding to the integrating circuit in the first embodiment, and the memory 34b converts the light emission pulses Pa shown in FIG. 2 (a) into [Pa1, Pa2, Pa3], [Pa4, The result of digital addition of the received light signals Sa output by the three pulse groups Pa5, Pa6], [Pa7, Pa8, Pa9] is output. Similarly, the memory 34c outputs the addition result by the three pulse groups of the light emission pulses [Pa2, Pa3, Pa4], [Pa5, Pa6, Pa7], [Pa8, Pa9, Pa10]. Further, the memory 34d can output the addition result by three pulse groups of [Pa3, Pa4, Pa5], [Pa6, Pa7, Pa8], [Pa9, Pa10, Pa11]. That is, the memory 34 obtains three types of signals obtained by integrating the output signal Sa of the light receiving means 2 for three periods whose timing is shifted by one period of the light emission pulse for each period of the light emission pulse Pa.
[0031]
Each memory 34 outputs stored data SB, SC, SD to the determination means 35 in response to control signals Pk, Pl, Pm output from the signal generation means 33. The determination unit 35 has a built-in memory 35a in which predetermined distance data (reference data) Mt is stored. The determination means 35 outputs a warning signal Se when any of the data [M1], [M2], [M3] of the output signals SB, SC, SD from the memories 34 becomes larger than the reference signal [Mt]. Output is possible. In the above configuration, all of the latch circuit 32, the signal generating unit 33, and the determining unit 35 can be configured by a so-called control circuit (CPU) including an arithmetic unit.
[0032]
Next, the operation of the second embodiment will be described with reference to the flowchart of FIG.
All the operations in this flowchart are performed by the signal generating means 33. In FIG. 4, (Sn) (n = 0 to 16) shown outside the frame 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 and the flow starts (S0), each memory 34 is reset to the initial value (S1) and at the same time, [N1] is set to 0. [N2] is set to 1 and [N3] is set to 2 (S2).
[0033]
The signal generating means 33 outputs the light emission pulse signal Pa as described above, the output signal Sa of the light receiving means 2 is converted into a digital signal, and subsequently held by the latch circuit 32, and then the data input signal Pj is latched. The data SJ output to and stored is fetched (S3, S4). Since [N1] is now 0, the flow goes to (S7) via (S5), sets [N1] to 3, and clears the memory data [M1] in the memory 34b. Next, the data SJ is written to the memory data [M1], [M2], and [M3] of the memories 34b, 34c, and 34d (S10). For this reason, the contents of the memories 34b, 34c, and 34d are the same at the initial time point. Since (1) is subtracted from the contents of each counter in (S11), [N1] = 2, [N2] = 0, and [N3] = 1.
[0034]
Here, the contents [M1], [M2], [M3] of each memory are compared with the predetermined distance data [Mt] in (S12), (S13), (S14), and the contents of the memory are more If it is larger (that is, if the distance to the object is smaller), a warning signal is output in (S15). If the contents of any memory are smaller than the predetermined distance data [Mt], the warning signal Se is reset (S16), and the process returns to (S3) and repeats the above sequence. At the initial time, since the latter, that is, [M1], [M2] and [M3] <[Mt], the process returns to (S3) and has the next data input signal Pj.
[0035]
Returning to (S3), since [N2] = 0 this time, the flow proceeds to (S6), (S8), (S10), (S11), and as a result, [N1] = 1, [N2] = 2 and [N3] = 0. Here, the data [M1] in the memory 34b is incremented once by adding the data SJ to twice, and the data M2 in the memory 34c is cleared in (S8), so the data SJ is read once. Then, the data M3 in the memory 34d is stored twice as in [M1], and the process returns to (S3). Similarly, since [N3] = 0 this time, the process proceeds to (S9), (S10), and (S11). As a result, [N1] = 0, [N2] = 1, and [N3] = 2. In the memory 34b, the data SJ is added three times, the memory 34c is added twice, and since the memory 34d is cleared in (S9), it is read once and returns to (S3).
[0036]
Thereafter, the above steps are repeated. By repeating the above operation, the light receiving means 2 for three periods whose timing is shifted by one period of the light emission pulse for each period of the light emission pulse Pa according to the contents [M1], [M2], and [M3] of the memory. Thus, three types of output signals obtained by integrating the output signal Sa are obtained.
When the object TX approaches the optical sensor S during the sequence, the data SJ increases, and any one of the values [M1], [M2], and [M3] of each memory is determined from the predetermined distance data [Mt]. Is determined on the route of Yes in (S12), (S13), and (S14), and the warning signal Se is output in (S15). Further, if the object TX is not approached thereafter, (S16) is passed, so the warning signal Se is reset.
[0037]
Note that if the initial sequence is from when the above flow is started until each memory is in a state in which a predetermined number of data has been added, the contents of each memory and a predetermined amount of time are kept during the initial sequence in order to prevent malfunction. Comparison with the distance data [Mt] ((S12), (S13), (S14) in FIG. 4) may not be performed.
In the above embodiment, the case where there are three memories has been described. However, 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 configured digitally, which has an advantage that the circuit can be simplified.
[0038]
In this embodiment, a warning signal is output when an object is detected in any one of a plurality of integration circuits. However, the present invention is not limited to this, and when any object is detected. May increase the light emission period of the light emission pulse to a speed allowed by the system, and output an alarm after reliably detecting that the object is approaching. In the above embodiment, the integration circuit is configured to obtain the output signal of the light receiving means for each cycle of the light emission pulse. However, the integration circuit may be configured to obtain the output signal for every predetermined number of light emission pulses. For example, three integration circuits may be provided so that the output signal of the light receiving means is obtained every two cycles of the light emission pulse, and each integration circuit may be reset every six cycles of the light emission pulse. Alternatively, the number of integration circuits that have detected the object may be counted and a plurality of alarm signals may be sequentially output. Furthermore, various applications such as providing a plurality of reference signals according to the distance value to the object and sequentially outputting a plurality of warning signals (for example, signals for changing the type of alarm sound) are possible.
[0039]
【The invention's effect】
The present invention integrates the received light signal output from the light receiving means by a plurality of integrating circuits, and outputs the latch signal and reset signal from the signal generating means at a timing shifted by one pulse, thereby providing an integrated value to the determining means. Since each can be output, the determination unit can output the determination result every time the light receiving unit outputs a light reception signal. Therefore, even if the light emission period of the light emission pulse is relatively large, the approach of the object can be detected quickly and accurately, and the life of the light emitting means is prolonged.
Furthermore, if a configuration is employed in which a memory is used in place of a plurality of integration circuits and a light-receiving signal converted into digital data can be output to the determination means, the circuit configuration becomes simple and effective in reducing manufacturing costs.
[Brief description of the drawings]
FIG. 1 is a circuit block diagram showing a configuration of a first 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 embodiment of the present invention.
FIG. 4 is a flowchart 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 integration circuit
3a1, 3b1, 3c1 integration unit
3a2, 3b2, 3c2 holding part
4, 33 Signal generation means
5, 35 judgment means
31 Analog-digital conversion circuit (A / D converter)
32 Latch circuit
34 (34b, 34c, 34d) memory

Claims (3)

A light emitting means for emitting a light beam to the object to be measured at a predetermined cycle ;
A light receiving means for receiving the light beam reflected by the object to be measured and outputting a light reception signal;
A plurality of integration circuits for integrating the light reception signal for a predetermined light emission period partially overlapping different light emission timings ;
Signal generating means for outputting a signal for driving the light emitting means and the integrating circuit;
Compares the reference data set in advance as the upper miracle fraction value, the integrating value is characterized in that it comprises a judging means for outputting a warning signal when a larger than the reference data object Detection device. 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 integration value after the integration unit integrates a predetermined number of times. An object detection apparatus characterized in that the data is held in the holding unit and can be reset by a reset signal output from the signal generating means after being output to the determination means . A light emitting means for emitting a light beam to the object to be measured at a predetermined cycle ;
A light receiving means for receiving the light beam reflected by the object to be measured and outputting a light reception signal;
An analog-digital conversion circuit for converting the received light signal into a digital signal;
A latch circuit for outputting digital data output from the analog-digital conversion circuit for each light emission period;
A signal generating means for outputting a light emission pulse signal to the light emitting means and outputting a control signal to the analog-digital conversion circuit and the latch circuit;
A plurality of memories for storing a predetermined light emission period product amount to be partially overlapping the emission timing different the digital data output from the latch circuit,
A storage data each memory or RaIzuru force, compared with the reference data set in advance, that the stored data when greater than the reference data and a decision means for outputting a warning signal Characteristic object detection device.

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