JP2000230900A - In-vehicle alcohol detector - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To remotely detect an alcohol component in a traveling vehicle while the traveling state of the vehicle is maintained. SOLUTION: A laser diode 1 emits a pulsed laser beam LB1 having an alcohol absorption wavelength λ1 toward a traveling vehicle, and a laser diode 2 emits a pulsed laser beam LB2 having a reference wavelength λ2 with a time lag. Both laser beams LB1, LB2 are detected by a common photodiode 3. When the alcohol concentration data Da obtained by subtracting the received light amount data D1 of the alcohol absorption wavelength λ1 from the received light amount data D2 of the reference wavelength λ2 is equal to or greater than a predetermined threshold value Dref, the microprocessor 12 determines that there is an alcohol component in the vehicle and outputs an alcohol detection signal. Output Sa.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-vehicle alcohol detecting device for remotely detecting whether or not an alcohol component is present in a running vehicle itself.

[0002]

2. Description of the Related Art Drunk driving causes serious traffic accidents. Conventionally, when checking whether there is a possibility of drunk driving, the following is performed. Have the traveling vehicle stop temporarily, have the driver breathe into the balloon, set the balloon on the alcohol detector, or
Exhaled air is directly blown onto a hand-held alcohol detector to detect the presence of alcohol components.

[0003]

In the above-mentioned conventional method, it is necessary to temporarily stop all running vehicles in principle before confirming that the user is drinking alcohol. Therefore, it often induces traffic congestion. It takes a lot of trouble and time to check one vehicle at a time for every vehicle stopped. If you breathe in the driver's breath or look at the flushing condition on your face and find that there is a possibility of drinking,
The above-mentioned inspection is performed, but the inspection is a manual method and requires the cooperation of a driver, so that it takes time and effort.

[0004]

SUMMARY OF THE INVENTION The present invention is intended to solve such a problem, and is to detect an alcohol component in a vehicle remotely while the vehicle is running without temporarily stopping the vehicle. is there.

According to a first aspect of the present invention, there is provided an in-vehicle alcohol detecting apparatus for emitting a laser beam having an alcohol absorption wavelength into a room of a traveling vehicle, and converting the laser beam into an electric quantity by entering the laser beam. Means, and means for detecting the presence or absence of the alcohol component in the vehicle based on the change in the amount of electricity. Light having a certain wavelength in the infrared wavelength range is absorbed by an alcohol component and has a property that its energy level is attenuated. Light is emitted from the outside of the vehicle to the alcohol diffusion region floating in the vehicle, and the light passing through the alcohol diffusion region is attenuated. If the light is not coherent, a large amount of scattering occurs. Since the light is significantly attenuated, it is difficult for an effective amount of light to enter the incident means. Therefore, a laser beam is used as coherent light. For example, 2.75 μm and 9.52 μm are known as alcohol absorption wavelengths. Absorption by the alcohol component reduces the incident energy level. By electrically detecting this, the alcohol component in the vehicle can be detected. At this time, since the laser beam is emitted from the outside of the vehicle and is incident and detected outside the vehicle, the presence or absence of the alcohol component in the vehicle can be remotely detected. Since the laser beam propagates at the speed of light and performs signal processing electronically, it is possible to make extremely high-speed determinations. Therefore, without stopping the running vehicle, the alcohol component in the vehicle can be maintained in the running state. Can be remotely detected. The detection is very fast and requires less effort and effort. The fact that the alcohol component is detected does not necessarily mean that the driver drinks alcohol. It is said that there is an alcohol component in the vehicle, and there is a possibility of drunk driving based on that fact.

According to a second aspect of the present invention, there is provided an alcohol detecting apparatus for a vehicle.
A configuration is provided that emits a laser beam having a reference wavelength not absorbed by alcohol together with a laser beam having an alcohol absorption wavelength. Even if dust or window glass is present in the optical path of the laser beam and the received light amount is attenuated, the detection accuracy is improved by eliminating the influence.

According to a third aspect of the present invention, there is provided an in-vehicle alcohol detecting apparatus.
The laser beam having the alcohol absorption wavelength and the laser beam having the reference wavelength are emitted in the same optical path.
The two laser beams pass through almost the same spatial region in the alcohol diffusion region in the vehicle, thereby maximizing the original meaning of the reference light.

According to a fourth aspect of the present invention, there is provided an in-vehicle alcohol detecting apparatus.
The laser beam having the alcohol absorption wavelength and the laser beam having the reference wavelength are both pulsed, and both pulsed laser beams are emitted with a time difference.
A single light receiving element may be commonly used for both laser beams as an incident means for capturing the laser beams. Since the light is emitted intermittently as a pulse, interference between the two laser beams is avoided.

According to a fifth aspect of the present invention, there is provided an alcohol detecting apparatus for a vehicle.
A laser beam emitting unit and a laser beam incident unit are arranged to face each other across a road, and are configured as a transmission type. Since the distance from the emitting means to the incident means is fixed and the time required for the laser beam to reach is uniformly determined, the possibility of erroneous detection is reduced.

According to a sixth aspect of the present invention, there is provided an alcohol detecting apparatus for a vehicle.
A laser beam emitting unit and a laser beam incident unit are arranged close to one side of a road, and are configured as a reflection type. This is advantageous in terms of cable laying because it is not a separate arrangement across the road but an integrated arrangement on one side of the road. In the case of the reflection type, adjustment of the optical axis is easier than in the case of the transmission type.

According to a seventh aspect of the present invention, there is provided an in-vehicle alcohol detecting device.
A plurality of laser beam emitting means are arranged at different positions in the height direction, and the same number of laser beam incident means are arranged at different positions in the height direction.
Although the height position of the window glass differs depending on the vehicle type such as small, medium, and large, corresponding to this, any vehicle type can be a detection target.

[0012] According to an eighth aspect of the present invention, there is provided an alcohol detecting device for a vehicle.
The laser beam emitting means is configured to scan the laser beam in a vertical direction. This is particularly important in the reflection type. With the reflection type, it is difficult to predict where the emitted laser beam will be reflected in the vehicle. If the optical path is narrowed down to a single value, the probability of causing a detection error increases. The laser beam scan can capture the reflected light from anywhere.

According to a ninth aspect of the present invention, there is provided an in-vehicle alcohol detecting apparatus,
The means for injecting the laser beam and converting it into an electric quantity is configured such that a time corresponding to limiting the reflected light from the vehicle within the road width range is set as the conversion gate time.
The reflected light is reflected from an unspecified portion even outside the vehicle. In many cases, the reflected light is attenuated. Therefore, the above configuration specifies a vehicle traveling on a road as a target.

According to a tenth aspect of the present invention, the in-vehicle alcohol detecting device is disposed obliquely forward or obliquely above a detection area such that a laser beam is emitted from a windshield of a traveling vehicle near a road to the inside of the vehicle. Even if an infrared cut film is stuck to the side window glass of the vehicle, it is possible to detect the presence or absence of the alcohol component in the vehicle by irradiation from the windshield.

The in-vehicle alcohol detecting device according to the eleventh aspect is configured to capture an image of the vehicle using the alcohol detection signal as a trigger signal, and to transmit image information of the captured vehicle to the center. Remote checking system will be more effective.

According to a twelfth aspect of the present invention, the in-vehicle alcohol detection device is configured to close the vehicle stop gate with the alcohol detection signal as a trigger signal. This is, for example, installed at a tollgate at the entrance of a highway, and for a vehicle in which an alcohol component is detected, the gate is closed for the time being to avoid the approach as it is. This is effective in preventing accidents on expressways.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of an in-vehicle alcohol detecting apparatus according to the present invention.

[Embodiment 1] Embodiment 1 relates to a transmission type in-vehicle alcohol detecting apparatus. FIG.
FIG. 2 is a block diagram illustrating an electrical configuration of the in-vehicle alcohol detection device according to the first embodiment. In FIG. 1, reference numerals 1,
2 is a laser diode as a laser beam emitting means, and 3 is a photodiode as a laser beam incident means. One laser diode 1, the alcohol component: is to emit a laser beam LB1 pulsed at the same frequency as the frequency of the absorption spectrum of (C ₂ H ₅ OH ethanol). OH in alcohol component
Since the absorption spectrum of the group is 2.75 μm and the absorption spectrum of the CCO group is 9.52 μm, here, the laser diode 1 emits a pulsed laser beam LB1 having any one of these frequencies. I do. In any case, it becomes infrared light (1 μm = 1000 n)
m). Since the current laser diode is a semiconductor laser, it can be said that 2.75 μm is easier to realize under normal temperature conditions. If a carbon dioxide laser is used, 9.5
Although 2 μm is possible, the cost burden increases.

Let the wavelength of the laser beam LB1 be λ1,
This is called "alcohol absorption wavelength". The other laser diode 2 emits a pulsed laser beam LB2 having a wavelength band deviating from the absorption spectrum of the alcohol component and having a wavelength immediately adjacent to the alcohol absorption wavelength λ1, and the wavelength is set to λ2. It will be referred to as “reference wavelength”. The reference wavelength λ2 is set to be closest to the alcohol absorption wavelength λ1 in order to correspond to the spectral sensitivity characteristics of the photodiode 3. This is because the photodiode 3 needs to detect both laser beams LB1 and LB2 having different wavelengths of λ1 and λ2. For example, alcohol absorption wavelength .lambda.1 = 2.7
When it is set to 5 .mu.m, the reference wavelength .lambda.2 = 2.70 .mu.m or .lambda.2 = 2.80 .mu.m.

While the laser beam LB1 of the alcohol absorption wavelength λ1 emitted from the laser diode 1 has a property of being easily absorbed by the alcohol component,
The laser beam LB2 of the reference wavelength .lambda.2 emitted from the laser diode 2 has a sufficiently high transmittance to the alcohol component and has the property of hardly absorbing.
The positional relationship and the directional relationship of the two laser diodes 1 and 2 are determined so that the laser beams LB1 and LB2 emitted from the respective laser diodes 1 and 2 travel substantially in the same optical path. This is to increase the detection accuracy by passing through almost the same spatial portion in the alcohol diffusion region floating in the vehicle.

The reason for using the laser beam LB2 of the reference wavelength λ2 is as follows. If dust or the like other than the alcohol component is present in the air in the optical path, or if the window glass of the vehicle is present, the beam energy is attenuated by absorption, but this effect is eliminated.
As the photodiode 3, an avalanche photodiode having high sensitivity and high response speed is preferable.

Reference numerals 4 and 5 denote laser diodes 1 and 2, respectively.
The driver 6, 6, 7 is an output light detection photodiode for individually detecting the laser beams LB1, LB2 emitted from the laser diodes 1, 2 at the output port, and 8 is the output light detection photodiode 6, 6. This is a difference circuit for taking a difference voltage ΔW (= W1−W2) between the output detection voltages W1 and W2, and feeding the difference voltage ΔW back to one driver 5 as a control voltage. The driver 5 is configured to adjust the emission intensity of the laser diode 2 so that the differential voltage ΔW becomes zero by feedback control. As a result, the emission intensities of both laser beams LB1 and LB2 are always kept equal, and the laser beam LB2 of the reference wavelength λ2 plays a good role as its original reference light. In addition,
The output of the difference circuit 8 may be fed back to the driver 4.

Reference numeral 9 denotes an amplifier, 10 denotes a peak hold circuit (sample and hold circuit), 11 denotes an A / D converter,
12 is a microprocessor and 13 is a timing signal generation circuit. The above components are connected as shown. The timing signal generation circuit 13 generates required timing signals based on the reference clock φ0, and outputs them to both drivers 4 and 5, the peak hold circuit 10 and the A / D converter 11. Microprocessor 1
Numeral 2 is such that the pulsed laser beams LB1 and LB2 emitted from the laser diodes 1 and 2 do not interfere with each other, and the emission timings are shifted from each other so as to be incident on the common photodiode 3 at a shifted timing. The timing of the drivers 4 and 5 is controlled via the timing signal generating circuit 13.
The laser beam LB2 of the reference wavelength .lambda.2 is emitted first in terms of timing.

As shown in the timing chart of FIG.
The period T0 of the pulsed laser beams LB1 and LB2 is 2
0 to 40 μsec, and both laser beams LB1 and L
The delay time ΔT, which is the timing shift of B2, is 1 to 10
μsec. In the state shown, ΔT ≒ T0 / 2, but this is not always necessary. The delay time ΔT is determined in consideration of the time required for storing the data of the preceding laser beam LB2 in the RAM (random access memory) in the microprocessor 12.

The pair of laser diodes 1 and 2 and the emitted light detecting photodiodes 6 and 7 constitute a light projecting unit 21, and the single common photodiode 3 constitutes a light receiving unit 22. There is no problem when the delay time .DELTA.T is relatively small. However, when the delay time .DELTA.T is set to be relatively large, the output light detecting photodiode 7 and the difference circuit 8 corresponding to the preceding laser beam LB2 having the reference wavelength .lambda.2 A delay circuit having a required delay time ΔT may be inserted between the points (point A in the figure).

FIG. 2 is a schematic perspective view showing an installation state on a road. As shown in FIG. 2, a light emitting unit 21 having a pair of laser diodes 1 and 2 and a light receiving unit 22 having a common single photodiode 3 are provided on both sides of a road 100 with respect to the traveling direction of the vehicle 200. They are arranged so as to be orthogonal to each other. The emission directions of the laser beams LB1 and LB2 of the pair of laser diodes 1 and 2 built in the light projecting section 21 are directed to the light receiving section 22 (photodiode 3). Is aimed at. The light projecting unit 21 and the light receiving unit 22 transmit the laser beams LB1 and LB2 from the light projecting unit 21 to the vehicle 200.
, Through the air inside the vehicle, exiting from the window glass, and entering the light receiving unit 22. This is because the alcohol component in the alcohol diffusion region 300 in the vehicle is optically detected by infrared spectroscopy.

Next, the operation of the in-vehicle alcohol detecting device according to the first embodiment configured as described above will be described.

First, based on the timing chart of FIG. 3A, the vehicle 200 is driven by the pulsed laser beams LB1, LB1 and LB2.
The operation when the light has not yet reached the optical path of LB2 will be described. That is, the laser beam is transmitted through the outside air. Reference wavelength λ from laser diode 2
2 when the laser beam LB2 is emitted.
At the timing t2 when the delay time ΔT has elapsed, the laser diode 1 emits the laser beam LB1 having the alcohol absorption wavelength λ1. In the photodiode 3 on the light receiving side, the laser diodes 1 and 2 on the emitting side are used.
The laser beam enters after a lapse of a required time τ obtained by dividing the separation distance by the speed of light. That is, the timing t0
At a timing t1 when the required time τ elapses further, a laser beam LB2 having a reference wavelength λ2 is incident, and a pulse-like detection voltage V2 is generated. At a timing t3 when the required time τ elapses from the timing t2, a laser beam LB1 having an alcohol absorption wavelength λ1 is incident, and a pulse-like detection voltage V1 is generated. Since there is no alcohol component in the optical path, no energy absorption occurs even if the wavelength of the laser beam LB1 is the alcohol absorption wavelength λ1. Even if dust or the like is present in the optical path and energy absorption occurs, the degree of absorption is substantially equal between the two laser beams LB2 and LB1.
There is no level difference between the detection voltages V2 and V1 (for convenience of description, the suffix "2" is described before "1").
It is assumed that the photodiode 3 itself outputs the amount of current according to the received light energy level, but here it is assumed that current-voltage conversion is being performed. The configuration can be easily realized by resistance division (not shown).

In the state shown, t2 is later than t1. It is for the following reasons. The delay time ΔT is set to 5 μsec = 5000 ns. The width of road 100 is 2
0 m. If this 20 m is divided by the speed of light 3 × 10 ⁸ m / sec, the required time to reach τ = 66.6 ns. That is, τ≪ΔT. In the state shown, τ and Δ
The magnitude relationship of T indicates a tendency and is not strictly numerical. The cycle T0 is 20 to 30 .mu.sec.

The detection voltage V2 amplified by the amplifier 9
, V1 are input to the peak hold circuit 10 with a time difference equal to the delay time ΔT, are peak-held by the peak hold circuit 10, and are output to the A / D converter 11. The A / D converter 11 converts the analog detection voltages V2 and V1 peak-held under predetermined timing control from the microprocessor 12 into digital received light amount data D2 and D1, and sends the data to the microprocessor 12. The peak hold circuit 10 is reset by a predetermined timing control from the microprocessor 12. It is assumed that the hold time of the peak hold circuit 10 is sufficiently shorter than the delay time ΔT. The peak hold circuit 10 is reset from when λ2 enters until λ1 comes. Microprocessor 1
2 controls the timing of the peak hold circuit 10 and the A / D converter 11 in synchronization with the timing control of the drivers 4 and 5 corresponding to the laser diodes 1 and 2. FIG. 3A shows a state in which the vehicle 200 has reached the laser beams LB1 and LB2 and the air in the vehicle that does not contain alcohol components is blown by the laser beam LB1.
, LB2 are transmitted. The same is true even if the interior of the vehicle is contaminated by tobacco smoke or the like.

The microprocessor 12 stores the received light amount data D2 and D1 input at required timings in RAM, respectively.
(Random access memory), the alcohol concentration data Da is calculated by Da = D2-D1, and is compared with a predetermined threshold value Dref which is a criterion for determining the presence or absence of an alcohol component. If Da ≧ Dref, it is determined that there is an alcohol component, and if Da <Dref, it is determined that there is no alcohol component. In the case of FIG. 3A, D2ＤD1
Therefore, Da ≒ 0 <Dref, and it is determined that there is no alcohol component.

Next, based on the timing chart of FIG. 3 (b), as shown in FIG.
LB2 is the alcohol diffusion area 300 inside the vehicle 200
The operation when light is transmitted will be described. It goes without saying that the timing situation is the same as in the case of FIG. Reference wavelength λ emitted from laser diode 2
Laser beam LB2 of alcohol diffusion region 300
Since the energy is not absorbed by the alcohol component, the amplitude of the detection voltage V2 remains the same as that in the case of FIG. However, laser diode 1
Since the laser beam LB1 of the alcohol absorption wavelength λ1 emitted from the laser beam absorbs energy and is attenuated by the alcohol component, the amplitude of the detection voltage V1 is as shown in FIG.
It becomes smaller than the case. That is, V2> V1. These detection voltages V2, V1 are converted into received light amount data D2, D1 by the A / D converter 11 with a time difference equal to the delay time ΔT, and are taken into the microprocessor 12. D2> D1. When the concentration of the alcohol component in the vehicle is equal to or higher than the predetermined threshold value, the alcohol concentration data Da = D2−D1 ≧ Dref, and the microprocessor 12 determines that the alcohol component is present. And
An alcohol detection signal Sa is output.

There are various applications for using the alcohol detection signal Sa. In order to inform the observer or driver of the driving situation of the vehicle,
A patrol light may be operated, or an alarm buzzer may be operated. Furthermore, it is also conceivable to use it for timing control of imaging of a vehicle (this will be described later).

Next, the operation when the pulsed laser beams LB1 and LB2 are cut off by the window frame (front pillar / center pillar) of the vehicle, the driver or the like will be described with reference to the timing chart of FIG. . The timing situation is the same as in the case of FIG. When both the laser beam LB2 of the reference wavelength .lambda.2 emitted from the laser diode 2 and the laser beam LB1 of the alcohol absorption wavelength .lambda.1 emitted from the laser diode 1 are cut off by a window frame, a driver, or the like, a photodiode is provided at a predetermined timing. 3 for each detected voltage V
2, V1 becomes substantially zero. Therefore, both the received light amount data D2 and D1 become substantially zero, the alcohol concentration data Da = D2-D1 <Dref, and the microprocessor 12 determines that there is no alcohol component.

By the way, both received light amount data D2, D1
Can be used to recognize that the vehicle 200 has reached the optical paths of the laser beams LB1 and LB2 based on the fact that is substantially zero. That is, the received light amount data D2 and D1 are acquired at a time difference equal to the delay time ΔT from each other at the required two timings given to the A / D converter 11 by the microprocessor 12, and at these two timings. Since both of the received light amount data D2 and D1 are substantially zero, it is possible to recognize the arrival or passage of the vehicle.

As described above, the presence or absence of the alcohol component in the vehicle can be remotely detected from the outside while the traveling vehicle is kept in a running state without stopping.

As a modification of the first embodiment, the light receiving section 22
It is conceivable to use two photodiodes in. One is a photodiode for detecting only the component of the alcohol absorption wavelength λ1, and the other is a photodiode for detecting only the component of the reference wavelength λ2. An optical filter satisfying the above requirements may be provided for each photodiode. Note that an amplifier, a peak hold circuit, and an A / D
The converter will be connected. In this method, since the input ports of the respective A / D converters in the microprocessor 12 are separate, the timing relationship between the laser beam LB2 emitted from one laser diode and the laser beam LB1 emitted from the other laser diode. Has no restrictions. That is, the delay time ΔT may be provided in the same manner as described above, or the delay time ΔT may be synchronized with just. In place of the intermittent pulse-shaped laser beam, a continuous emission method may be used as long as the timing control of the sampling of the received light data is accurately performed.

As another modification, the emission timing of the laser beam LB1 having the alcohol absorption wavelength λ1 may be set ahead of the emission timing of the laser beam LB2 having the reference wavelength λ2.

[Second Embodiment] A second embodiment relates to a reflection type in-vehicle alcohol detecting device. FIG.
FIG. 9 is a block diagram showing an electrical configuration of the in-vehicle alcohol detection device according to the second embodiment. The same reference numerals as in FIG. 1 of the first embodiment denote the same elements in the second embodiment (FIG. 4), and a description thereof will not be repeated. The configuration specific to the second embodiment is as follows. On the light receiving side, between the amplifier 9 and the peak hold circuit 10,
A comparator 15, a gate circuit 16, and an integrator 17 are inserted. Reference numeral 14 denotes a variable resistor for generating a reference voltage for the comparator 15. The light projecting unit 21 is of a scan type as described later with reference to FIG.

In the case of the reflection type, the dynamic range of the received light signal is larger than that of the transmission type. This is because light reflected from various places in the vehicle is captured. The energy levels of the reflected light from the whitish part and the reflected light from the darkish part are several thousand times different.
If the sensitivity of the amplifier 9 is adjusted to very weak reflected light, the output of the amplifier 9 will be saturated (saturated) in the case of reflected light of high intensity. For this reason, in the case of the reflection type, the detection voltage V of the laser beam LB2 having the reference wavelength λ2 is used.
A simple comparison of the peak value between No. 2 and the detection voltage V1 of the laser beam LB1 having the alcohol absorption wavelength λ1 cannot be adopted. Therefore, the comparator 15 and the integrator 17 are used. This will be described with reference to FIG. The voltage signal input from the amplifier 9 to the comparator 15 is output as "H" from the comparator 15 when the voltage signal is higher than the reference voltage Vref generated by the variable resistor 14. The time width of the output signal from the comparator 15 depends on the magnitude of the voltage detected by the photodiode 3.
That is, as the detection voltage increases, the time width of the output signal increases. Even if the level of the detection voltage is several thousand times, the time width does not become so large, and the time width does not saturate. Although the difference in the time width may be directly obtained by the microprocessor 12, the difference is converted into the voltage difference by the integrator 17. That is, the difference in the detected voltage at the photodiode 3 is converted into a time width by changing the range, and the time width is converted again into a voltage difference. This is because the processing with the voltage is easier than the processing with the time width. The output voltage from the integrator 17 is peak-held by the peak hold circuit 10, A / D-converted by the A / D converter 11, and the data is sent to the microprocessor 12. After transmitting the data, the peak hold circuit 10 is cleared.

Various specific examples of the circuit configuration of the gate circuit 16 are conceivable, such as those shown in FIGS.

In FIG. 6, reference numerals 31 and 32 are delay circuits, 33 and 34 are one-shot multivibrators, 35 and 36 are AND gates, and 37 is an OR gate. The input terminal of the delay circuit 31 is connected so that the timing signal Sb output from the timing signal generation circuit 13 to the driver 4 is input to the input terminal of the delay circuit 32.
Are connected such that the timing signal Sc output to the controller is input. The output signal Sb1 of the delay circuit 31 is output to the one-shot multivibrator 33, and the output signal Sb2 of the one-shot multivibrator 33 is ANDed.
It is connected so that it is inputted to one input terminal of the gate 35. Similarly, the output signal Sc1 of the delay circuit 32 is output to the one-shot multivibrator 34, and the output signal Sc2 of the one-shot multivibrator 34 is set to AN.
It is connected so as to be inputted to one input terminal of the D gate 36. The output terminal of the comparator 15 is connected to the other input terminal of each of the AND gates 35 and 36. The output terminals of both AND gates 35 and 36 are O
The OR gate 37 is connected to two input terminals of the R gate 37.
Is connected to the input terminal of the integrator 17.

The gate circuit 16 of FIG. 7 is a more simplified one. One-shot multivibrator 3 for both
Output terminals 3 and 34 are connected to two input terminals of the OR gate 38, and the output terminal of the OR gate 38 and the comparator 15
Are connected to the two input terminals of the AND gate 39, and the output terminal of the AND gate 39 is connected to the input terminal of the integrator 17.

In the case of the reflection type, the laser beams LB1, L
If there is only one optical path for B2, the probability of making a mistake in capturing the reflected beam should be abnormally high. The laser beams LB1 and LB2 which are incident from the window glass of the vehicle and have passed through the alcohol diffusion region in the vehicle enter a certain portion in the vehicle and are reflected therefrom. This reflection often becomes irregular reflection. Therefore, the probability of reflection along the original optical path is very low. Therefore, the laser beams LB1, L
It is configured to scan B2.

FIG. 8 shows this state. 41 is a half mirror and 42 is a polygon mirror. The half mirror 41 is provided at an angle of 45 ° with respect to the basic optical axis 43 from the half mirror 41 to the polygon mirror 42, and the half mirror 4
1. A laser diode 1 for emitting a laser beam LB1 having an alcohol absorption wavelength .lambda.1 to be reflected from the laser diode 1.
The laser diode 2 which emits a laser beam LB2 having a reference wavelength .lambda.2 so as to transmit through the half mirror 41 is arranged so that its emission axis 44 is perpendicular to the basic optical axis 43. The axis 45 is arranged so as to be on an extension of the basic optical axis 43, and the photodiode 3 is also arranged so that its incident axis substantially coincides with the emission axis 45. Assuming that the direction of the rotation axis of the polygon mirror 42 is horizontal, the trajectories of the laser beams LB1 and LB2 scanned by the polygon mirror 42 are scanned on a plane perpendicular to the road 100. The laser beam LB1 incident on the inside of the vehicle 200 through the window glass
, LB2 are reflected from all over the vehicle. Some of them will have the incident axis and the reflection axis that are displaced with time due to scanning coincide with each other, and travel from the polygon mirror 42 to the photodiode 3 while passing through the basic optical axis 43 through the original optical path. The positions of the laser diode 1 and the laser diode 2 may be interchanged.

The alcohol diffusion region 3 is provided inside the vehicle 200.
When there is 00, the laser beams LB1 and LB2 pass through the alcohol diffusion region 300 on the outward path and the return path. The expression “passing” used here has a different meaning from the transmissive type in terms of the positional relationship between the light projecting unit 21 and the light receiving unit 22. The type of the light emitting and receiving unit is a reflection type. The laser beam LB1 having the alcohol absorption wavelength .lambda.1 absorbs energy in the outward and return paths, whereas the laser beam LB2 having the reference wavelength .lambda.2 is not absorbed.

FIG. 9 is a schematic perspective view showing an installation state with respect to a road. A light projecting unit 21 containing a pair of laser diodes 1 and 2 and a light receiving unit 22 containing a photodiode 3 are arranged close to one side of a road 100.
The emission directions of the laser beams LB1 and LB2 of the pair of laser diodes 1 and 2 built in the light projecting section 21 are set on the road 100.
At right angles to the direction. The incident direction of the photodiode 3 built in the light receiving unit 22 is also perpendicular to the road 100. The laser beams LB1 and LB2 from the light projecting unit 21 pass through the window glass of the vehicle 200, are reflected at any place in the vehicle, and are arranged such that the reflected light enters the light receiving unit 22.

The distance between the vehicle 200 traveling on the road 100 and the light emitting / receiving sections 21 and 22 differs for each vehicle. The separation distance when the vehicle is closest to the light emitting and receiving unit is, for example, 2 m, and the separation distance when the vehicle is farthest is, for example, 10 m. When the separation distance is 2 m, the optical path length of the round trip is 4
m, dividing by the speed of light 3 × 10 ⁸ m / sec,
13. The delay time from emission of the laser beam to reception of the laser beam is 13.
3 nsec. 66.6 when the separation distance is 10 m
nsec. Therefore, as shown in the timing chart of FIG. 10, the delay time .tau.1 of the delay circuits 31, 32 in FIG. 6 or 7 is set to 13.3 ns.
The on-time .tau.2 of the one-shot multivibrators 33 and 34 is 53.3 ns (= 66.6-13.3).

In FIG. 10, Sb2, Sc2 and Se are gate signals, Sd is an output signal of the amplifier 9, and Sg is an output signal of the comparator 15. Sf is the OR gate 37 in FIG.
And the output signal of the AND gate 39 in FIG. 7 is also shown. The time from the timing signal Sc to the timing signal Sb is 1000 to 10000 n
s.

Since it is a reflection type, a gate circuit 16 is required. The rising edges of the gate signals Sb2, Sc2 and Se correspond to the case where the vehicle is closest to the light emitting and receiving unit as described above, and the falling edge corresponds to the case where the vehicle is farthest. The other reflected light is regarded as not being reflected light from the vehicle, and is made to be negligible.

The alcohol component determination processing by the microprocessor 12 is the same as in the first embodiment.

In the case of the second embodiment, the polygon mirror 4
2, the two laser beams LB1, L2
Since the optical path of B2 is justified, there are the following advantages. By always passing the alcohol component floating in the air in the vehicle and having a spatial spread through the same place spatially on the outward and return paths, the accuracy as the reference light by the laser beam LB2 can be improved. Further, since the optical field of view is narrowed, that is, the directivity angle is reduced, the noise component is reduced as much as possible, and the S / N ratio is reduced.
The ratio can be improved.

[Embodiment 3] Embodiment 3 is of a transmission type and is applicable to a plurality of types of vehicles having different heights. As shown in FIG. 11, a plurality of light emitting portions 21a, 21b, 21c are arranged at different heights on one road side of the road 100, and a plurality of light receiving portions 22 are arranged on the other road side.
a, 22b and 22c are arranged at different heights.
One light projecting unit 21a includes the two laser diodes 1 and 2 shown in FIG. The same applies to the light emitting unit 21b, and the same applies to the light emitting unit 21c. The outgoing optical axis of one light projecting unit 21a is horizontal and coincides with the incident optical axis of the opposing light receiving unit 22a. The height of the light projecting unit 21a and the light receiving unit 22a is the same. Light emitting unit 21b and light receiving unit 2
The same applies to the relationship between 2b and the relationship between the light projecting unit 21c and the light receiving unit 22c.

The three light emitting and receiving units having different heights with the road 100 interposed therebetween are arranged in the vehicle 20.
This is because it is considered that the size of 0 is roughly divided into about three types in the height of the window. In the figure, an ordinary car 200a corresponding to a small size and a truck 200b corresponding to a medium size are shown.
And a trailer 200c corresponding to a large size.

FIG. 12 is a block diagram showing an electrical configuration in the case of the third embodiment. A common driver 4 is connected to three laser diodes 1, 1, 1 related to the alcohol absorption wavelength λ1, and a common driver 5 is connected to three laser diodes 2, 2, 2 related to the reference wavelength λ2. It is. Three photodiodes 3,3
3 are connected to OR gates 51 through amplifiers 9, 9, 9, respectively.
Connected to Other configurations are described in Embodiment 1 (FIG. 1)
Therefore, the same portions are denoted by the same reference numerals, and description thereof is omitted.

[Embodiment 4] Embodiment 4 is applicable to a plurality of types of vehicles having different heights, and is of a reflection type. As shown in FIG. 13, only one of the light emitting and receiving units 21 and 22 described in the second embodiment may be installed at an appropriate height position. Laser beam LB in vertical direction
By scanning 1, LB2, it is possible to cope with the difference in height. The fourth embodiment is actually substantially the same as the second embodiment, but is another embodiment for convenience of explanation.

It should be noted that a plurality of such scanning type light emitting / receiving sections may be provided at different positions in the height direction.

[Fifth Embodiment] Some vehicles have an infrared cut film (smoke film) attached to a window glass on a side of the vehicle. In that case, the attenuation of the laser beam is large. Embodiment 5 addresses this.
As shown in FIG. 14, the laser beams LB1, LB are introduced into the vehicle 200 through the windshield 201 of the running vehicle 200.
2 so that the light emitting and receiving units 21 and 22 can be irradiated.
Is disposed obliquely forward with respect to the detection area (target vehicle).
Alternatively, as shown in FIG. 15, the light emitting and receiving units 21 and 22 are arranged so as to irradiate the laser beams LB1 and LB2 from diagonally forward and upward. In the case of the fifth embodiment, needless to say, it is necessary to use a reflection type.

[Embodiment 6] Regardless of whether it is a transmission type or a reflection type, a portable type may be used instead of permanently installing the light emitting and receiving unit. In this case, the driver can be brought to a necessary place when necessary, and a drunk driving check can be performed.

[Seventh Embodiment] As shown in FIG. 16, a vehicle image pickup device 61 is provided in front of a main body 500 of an in-vehicle alcohol detection device. The vehicle imaging device 61 is a so-called CCTV
(Closed Circuit Television). Further, a wired or wireless transmission device 62 is provided. When an alcohol component is detected in the vehicle by the in-vehicle alcohol detection device main body 500, the alcohol detection signal Sa is transmitted as a trigger signal to the vehicle imaging device 61 and the transmission device 62, so that the image of the vehicle can be obtained at a required timing. An image is taken, and the image data is transmitted to the center by the transmission device 62 by wireless transmission 63 or wired transmission 64.

The vehicle imaging device 61 captures the whole shape from the front of the vehicle, and is capable of capturing all necessary information such as vehicle shape, vehicle type, and license plate. Driver imaging is also possible. As for the license plate, vehicle number data as character data may be extracted based on edge extraction in image processing, superimposed on the image data, and transmitted to the center. Specifically, any known one can be applied, and the specific configuration is not directly related to the gist of the present invention, and thus the description is omitted.

[Eighth Embodiment] In an eighth embodiment, drunk driving is checked at a tollgate such as an expressway, and when an alcohol component is detected, entry is prohibited and accidents on the expressway are prevented beforehand. Is what you do. As shown in FIG.
At the toll booth, the in-vehicle alcohol detection device main body 500 is installed at a location just before the booth 71 where the toll collection staff enters. When an alcohol component is detected in the vehicle by the in-vehicle alcohol detection device main body 500, the alcohol detection signal Sa is sent to the vehicle stop gate driving device 72 as a trigger signal, thereby lowering the vehicle stop gate 73 to close the vehicle. . Thereby, the approach of the vehicle 200 in which the alcohol component is detected is suppressed. After that, the toll collection member checks and decides whether or not to pass the vehicle. If the vehicle can be passed, the vehicle stop gate driving device 72 is driven by operating a button to raise and open the gate 73.

[0063]

According to the present invention regarding the in-vehicle alcohol detecting device, it is possible to remotely detect the presence or absence of an alcohol component in a running vehicle without stopping the running vehicle without stopping the running vehicle. . As a result, the labor and labor for the drunk driving check operation can be significantly reduced. By using the reference wavelength with respect to the alcohol absorption wavelength, the influence of the attenuation of the amount of received light due to dust or window glass in the optical path is eliminated, and necessary detection accuracy is secured. By making the laser beam of both wavelengths the same optical path,
Maximize the original significance of the reference light. By making both laser beams pulse-shaped and emitting them with a time difference, a single light receiving element can be used in common, and interference between both laser beams can be avoided to improve detection accuracy.

If the laser beam emitting means and the incident means are opposed to each other with the road interposed therebetween to be a transmission type, the time required for beam arrival is uniformly determined, and the possibility of erroneous detection is reduced. If the emission means and the incidence means are arranged close to one side of the road to be of a reflection type, it is advantageous in terms of cable laying. In order to cope with the difference in the height position of the window glass depending on the vehicle type such as small, medium and large, it is preferable to provide a plurality of emission means and incidence means. When the laser beam is scanned in the vertical direction, even if the reflection inside the vehicle is irregular reflection, or even if it reflects from anywhere in the vehicle, it is reliably detected and the probability of measurement error is reduced. By converting the incident light amount into the electric amount within the gate time, the vehicle running on the road can be specified as a detection target. By irradiating a laser beam from a windshield of a traveling vehicle, it is possible to detect the presence or absence of an alcohol component even in a vehicle having an infrared cut film attached to a side window glass. Performing vehicle imaging using the alcohol detection signal as a trigger,
Closing the parking gate at the tollgate on the highway is effective in preventing accidents.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an electrical configuration of an in-vehicle alcohol detection device according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing an installation state of the in-vehicle alcohol detection device according to the first embodiment.

FIG. 3 is a timing chart illustrating an operation of the first embodiment;

FIG. 4 is a block diagram showing an electrical configuration of the in-vehicle alcohol detection device according to the second embodiment;

FIG. 5 is a timing chart of a main part of the second embodiment.

FIG. 6 is a circuit configuration diagram of a gate circuit according to a second embodiment;

FIG. 7 is another circuit configuration diagram of the gate circuit according to the second embodiment;

FIG. 8 is a configuration explanatory view of a laser beam scan according to the second embodiment.

FIG. 9 is a perspective view showing an installation state of the in-vehicle alcohol detection device according to the second embodiment.

FIG. 10 is a timing chart illustrating operation of the second embodiment.

FIG. 11 is a conceptual diagram illustrating a configuration of an in-vehicle alcohol detection device according to a third embodiment.

FIG. 12 is a block diagram showing an electrical configuration of the in-vehicle alcohol detection device according to the third embodiment;

FIG. 13 is a conceptual diagram of a configuration of an in-vehicle alcohol detection device according to a fourth embodiment.

FIG. 14 is a conceptual diagram of an in-vehicle alcohol detection device according to a fifth embodiment.

FIG. 15 is a conceptual diagram of the in-vehicle alcohol detection device according to the fifth embodiment.

FIG. 16 is a conceptual diagram of a configuration of an in-vehicle alcohol detection device according to a seventh embodiment.

FIG. 17 is a conceptual diagram of a configuration of an in-vehicle alcohol detection device according to an eighth embodiment.

[Explanation of symbols]

1. Laser diode with alcohol absorption wavelength 2.
... Laser diode of reference wavelength, 3... Photodiode, 4, 5... Driver, 6, 7... Outgoing light detection photodiode, 8.
... peak hold circuit, 11 ... A / D converter, 12 ...
... Microprocessor, 13 timing signal generating circuit, 14 variable resistor, 15 comparator 16
... gate circuit, 17 ... integrator, 21, 21a, 21
b, 21c... light projecting unit, 22, 22a, 22b, 22c
... Light receiving section, 41 half mirror, 42 polygon mirror, 61 vehicle imaging device, 62 transmission device, 6
3 ... wireless transmission, 64 ... wired transmission, 71 ... booth,
72 vehicle stop gate driving device 73 vehicle stop gate 100 road 200 vehicle 200a
Small vehicle, 200b Medium vehicle, 200c Large vehicle, 201 Windshield, 300 Alcohol diffusion region, 500 Alcohol detecting device body in vehicle,
LB1 ... Laser beam of alcohol absorption wavelength, LB
2 laser beam of reference wavelength, λ1 alcohol absorption wavelength, λ2 reference wavelength, Sa alcohol detection signal

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F103 BA00 BA23 CA02 EB02 EB03 EB04 EB05 EB08 EB12 EB16 EC11 ED14 ED18 ED19 ED27 2G059 AA01 AA05 BB01 CC15 CC19 EE01 EE02 FF06 FF09 GG01 GG03 HH01 MM03 GG03 HH03 MM03 FB00

Claims (12)

[Claims] 1. A means for emitting a laser beam having an alcohol absorption wavelength into a room of a traveling vehicle, a means for entering the laser beam and converting the laser beam into an electric quantity, and an alcohol in the vehicle based on a change in the electric quantity. An in-vehicle alcohol detection device, comprising: means for detecting the presence or absence of a component. 2. The in-vehicle alcohol detecting device according to claim 1, further comprising means for emitting a laser beam having a reference wavelength not absorbed by alcohol together with the laser beam having an alcohol absorption wavelength. 3. The in-vehicle alcohol detecting device according to claim 2, wherein a laser beam having an alcohol absorption wavelength and a laser beam having a reference wavelength are emitted in the same optical path. 4. The laser beam according to claim 2, wherein the laser beam having the alcohol absorption wavelength and the laser beam having the reference wavelength are both pulsed, and both pulsed laser beams are emitted with a time difference. The in-vehicle alcohol detection device according to any one of the preceding claims. 5. The in-vehicle alcohol according to claim 1, wherein the laser beam emitting means and the laser beam incident means are opposed to each other across the road and are configured as a transmission type. Detection device. 6. The method according to claim 1, wherein the laser beam emitting means and the laser beam incident means are arranged close to one side of a road and are configured as a reflection type. In-vehicle alcohol detector. 7. The laser beam emitting means according to claim 5, wherein a plurality of laser beam emitting means are arranged at different positions in the height direction, and the same number of laser beam incident means are arranged at different positions in the height direction. In-vehicle alcohol detector. 8. The in-vehicle alcohol detecting device according to claim 6, wherein the laser beam emitting means scans the laser beam in a vertical direction. 9. The device according to claim 4, wherein the means for converting the incident laser beam into an electric quantity sets a time corresponding to limiting the reflected light from the vehicle within the road width range as the conversion gate time. In-vehicle alcohol detection device. 10. The vehicle according to claim 1, wherein a laser beam is emitted obliquely forward or obliquely above the detection area so that a laser beam is emitted from a windshield of the traveling vehicle near the road. In-vehicle alcohol detection device. 11. The apparatus according to claim 1, wherein an image of the vehicle is taken using an alcohol detection signal as a trigger signal, and image information of the taken vehicle is sent to a center.
The in-vehicle alcohol detection device according to any one of the above. 12. The vehicle stop gate is closed by using an alcohol detection signal as a trigger signal.
The in-vehicle alcohol detection device according to any one of claims 1 to 10.