JPH11352140A - Vehicle speed measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle speed measuring device which is small and excellent in convenience and economy, and by which the speed of a vehicle running on a road can be measured with high accuracy and displayed. SOLUTION: This vehicle speed measuring device 1 is equipped with a laser beam light emitting means 4, a deflection means 6 in which a galvanomirror deflecting the beam light to the two-dimensional direction is used, a light receiving means 5 by which reflected light of the laser beam light is received, a display control means 7 by which the measured speed of a vehicle is displayed, and a control means 2 by which the speed of the vehicle is calculated. The speed of a vehicle passing on a road can be measured and displayed by this device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle speed measuring device for measuring the speed of a running vehicle.

[0002]

2. Description of the Related Art A conventional vehicle speed measuring device emits a radio wave toward a vehicle traveling on a road, measures a frequency difference between a returning radio wave and the emitted radio wave, and measures a Doppler effect of measuring a speed. The ones to use are known.

In a conventional vehicle speed measuring device,
A plurality of infrared rays are projected from an infrared speed sensor installed on the road, and vehicles passing below are detected by the reflected light of the infrared sensor, and the speed is determined by the time difference between the reflected light detection times between two points in the traveling direction. Some are also known to measure

FIG. 5 is a conceptual diagram showing an example of a conventional vehicle speed measuring device of the infrared sensor type. In FIG. 5, the speed measurement sensor 20 includes an infrared light emitting unit, a reflected infrared light receiving unit, a phase difference detecting unit, a calculating unit, and the like.

[0005] The speed measuring sensor 20 constructed as described above
Are the light beams (R
a, Rb, Rc, Rd) and outputs the reflected beam (Ra
r, Rbr, Rcr, Rdr) are received by four independent reflected infrared light receiving units.

The speed measuring sensor 20 always detects the phase difference between the light beams (Ra, Rb, Rc, Rd) and the reflected beams (Rar, Rbr, Rcr, Rdr) of each of the four systems by a phase difference detecting unit. Then, the distance between the speed measurement sensor 20 and the reflection surface is calculated. The measurement vehicle 12 is a vehicle that measures speed.

When the measurement vehicle 12 does not exist in the vehicle speed measurement area, the light-emitting beam is reflected on the road surface, and the phase difference from the reflected beam always has a constant value. Measurement vehicle 12
Enters the vehicle speed measurement area and passes any one of the four emission beams, for example, the emission beam Ra
Is reflected by the measurement vehicle 12, and the phase difference between the light-emitting beam Ra and the reflected beam Rar is reduced.

The phase difference is detected by a phase difference detecting section, and the distance between the speed measuring sensor 20 and the reflection surface of the measuring vehicle 12 is calculated by the calculating section. Is compared with the distance between the road surface and the reflective surface. When the distance of the reflecting surface is equal to or less than the set value, it is detected that the measuring vehicle 12 has entered the measuring area, and two points in the traveling direction, for example, the reflected beams Rar, R
If the time difference at the time of vehicle detection based on the cr or the reflected beams Rbr and Rdr is obtained, the emission beams Ra, Rb, R
Since the distances of the radiation points c and Rd are known, if the distance R between the two radiation points in the traveling direction is divided by the transit time difference Δt (R / Δt) by the arithmetic unit, the speed of the measurement vehicle 12 is obtained. Is required.

R represents the distance between the road surfaces of the light-emitting beams Ra and Rc or the road surface between the light-emitting beams Rb and Rd, and Δt denotes the distance between the light-emitting beams Ra and Rc or the light-emitting beams Rb and Rd. Represents the time difference between passing.

The vehicle speed measurement area has a side of 1.2 m in consideration of the width of a one-lane road being 3.3 m.
The measurement vehicle 1
A speed of 2 is reliably detected in this area. As described above, the conventional infrared sensor type vehicle speed measuring device is
The vehicle speed of the passing measuring vehicle 12 can be measured based on the time difference of the measuring vehicle 12 crossing the optical axis of the projected infrared ray at a plurality of locations in the designated area.

[0011]

A conventional vehicle speed measuring device using the Doppler effect speed measuring method has a problem that it is difficult to make adjustments in accordance with installation of an antenna for receiving emitted radio waves.

Further, in the conventional vehicle speed measuring device using an infrared ray method for projecting a plurality of infrared rays, since the detection of the measuring vehicle 12 is performed only at the four corners of the measuring area, two wheels are required even if the vehicle enters the measuring area. In the case of a measuring vehicle 12 that does not cross the optical axis of infrared rays, such as a car, there is a problem that the speed cannot be detected.

Further, since four sets of infrared light-emitting and light-receiving sensors are required, there is a problem that the apparatus is large and complicated, and the price is high. In addition, since the device emits infrared rays and always receives the reflected light, the installation location must be installed above the road surface, and there is a problem that installation work and maintenance are difficult.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to provide a vehicle speed measuring device capable of easily installing the device and measuring a running vehicle speed with high accuracy. Is to provide.

[0015]

In order to solve the above-mentioned problems, a vehicle speed measuring device according to the present invention comprises: a light emitting means for generating a light beam; a deflecting means for deflecting the light beam into a two-dimensional predetermined range; Light receiving means for receiving reflected light of a light beam reflected from a two-dimensional predetermined range; control means for calculating a vehicle speed based on the reflected light received by the light receiving means; Display control means for performing display output.

According to the present invention, there is provided a vehicle speed measuring apparatus comprising: a light emitting means for generating a light beam; a deflecting means for deflecting the light beam into a predetermined two-dimensional range; and a light beam reflected from the predetermined two-dimensional range. Light receiving means for receiving the reflected light, control means for calculating the vehicle speed based on the reflected light received by the light receiving means, and display control means for externally displaying and outputting information on the vehicle speed. The speed of all passing vehicles such as two-wheeled vehicles and four-wheeled vehicles that can deflect the light beam in a two-dimensional predetermined range (detection region) and pass through the detection region can be measured.

Further, the vehicle speed measuring device according to the present invention is characterized in that the control means includes a deflection driving means for supplying a two-dimensional predetermined range of deflection driving signals to the deflection means, and a light emitting means for emitting light at a constant period. , A phase difference detecting means for receiving information from the light receiving means and detecting a phase difference, and calculating a speed based on a synchronization signal of a predetermined period and a signal from the phase difference detecting means. Speed processing means.

Further, the vehicle speed measuring device according to the present invention is characterized in that the control means includes a deflection driving means for supplying a two-dimensional predetermined range of deflection driving signals to the deflection means, and a light emitting means for emitting light at a constant period. , A phase difference detecting means for receiving information from the light receiving means and detecting a phase difference, and calculating a speed based on a synchronization signal of a predetermined period and a signal from the phase difference detecting means. With the provision of the speed processing means, the speed of the measuring vehicle can be measured with high accuracy with a simple configuration.

Further, the deflecting means according to the present invention is characterized in that the deflecting means is a galvanomirror capable of periodically deflecting in a two-dimensional direction using a semiconductor manufacturing process.

The deflecting means according to the present invention is a galvanomirror capable of periodically deflecting in a two-dimensional direction using a semiconductor manufacturing process. Can be performed.

[0021]

Embodiments of the present invention will be described below with reference to the accompanying drawings. According to the present invention, the speed of a running vehicle can be measured with high accuracy by deflecting the light beam with a compact device.

FIG. 1 is an installation image diagram of a vehicle speed measuring device according to the present invention. In FIG. 1, a vehicle speed measuring device 1 is installed on an upright 101 provided in an L-shape from the side of a road 102 such that the center of the vehicle speed measuring device 1 is above the center of the road 102. I do.

The vehicle speed measuring device 1 has a light-emitting unit and a light-receiving unit installed on the road surface of the road 102, and the measurement range ABCD (two-dimensional range) of the light-emitting beam is the speed of all vehicles passing through this range. Can be measured.

When the measuring vehicle 12 enters the measuring range ABCD, the light beam emitted from the vehicle speed measuring device 1 becomes
The phase difference between the reflected beam received and the light beam projected by the vehicle speed measuring device 1 reflected by the measuring vehicle 12 is the phase difference between the projected light beam and the received reflected beam when the measuring vehicle 12 is not present. And the measurement vehicle 12
Is detected.

The vehicle speed measuring device 1 measures the time difference between the time passing through the measurement range AB line and the time passing through the CD line, and since the distance between AC or BD is known in advance, the distance between AC is determined. Dividing by the time difference between the AB line and the CD line gives the speed of the measured vehicle.

When the speed of the measuring vehicle 12 is measured, the vehicle speed measuring device 1
The speed data is transmitted to the display means 13 via the display unit 13 and stored in the display means 13, and the speed is displayed on a display provided on the display means 13 and a display such as an LED.

In FIG. 1, the vehicle speed measuring device 1 is installed at the center of the road 102 in the upward direction as an example. However, the vehicle speed measuring device 1 may be installed at an arbitrary position higher than the vehicle at the upright portion of the column 101.

FIG. 2 is a block diagram of a main part of the vehicle speed measuring device according to the present invention. 2, the vehicle speed measurement device 1 includes a control unit 2, a light emitting unit 4, a light receiving unit 5, a deflecting unit 6, and a display control unit 7. The light emitting means 4
And the deflecting means 6 constitute a light emitting section of the apparatus, and the light receiving means 5
Constitutes a light receiving section of the device.

The control means 2 is composed of various arithmetic means, processing means, memory and the like based on a microprocessor, and generates a timing signal based on a reference clock and generates various control signals.

The control means 2 drives the deflecting means 6 by the deflection driving signal Vs so that the angle range of the laser beam to be irradiated within the measurement range can be set arbitrarily.

Further, the control means 2 takes in the reflected signal Lc of the reflected light Lr received by the light receiving means 5 and outputs the reflected signal Lc
Calculates the phase difference based on the detected vehicle and detects the measured vehicle. Further, the control unit 2 supplies the speed information Vm to the display control unit 7.

The light emitting means 4 is constituted by, for example, a laser oscillation circuit, generates a laser beam light corresponding to the light emission control signal Lk supplied from the control means 2, and projects the light signal Ls to the deflecting means 6. As the laser beam, for example, an infrared laser beam having high convergence is used. The optical signal Ls is pulse-modulated so that it can be determined which optical signal Ls corresponds to the reflected light Lr.

The light receiving means 5 comprises a light receiving element such as a photodiode, receives the reflected light Lr of the optical signal Ls applied to the measuring range ABCD, and receives the reflected signal Lc of the electric signal.
And supplies it to the control means 2.

The display control output means 7 includes a buffer memory,
A display output signal Vo for displaying the speed of the measurement vehicle 12 is output to the external display means 13 based on the speed information Vm supplied from the control means 2.

The deflecting means 6 is constituted by a galvanomirror which is manufactured in a semiconductor process and can be easily deflected in two-dimensional directions. The galvanomirror is driven by the XY two-dimensional based on a deflection driving signal Vs supplied from the control means 2. Displacement in the direction
The light signal Ls emitted from the light emitting means 4 is deflected to detect the measurement vehicle 12 within the measurement range ABCD.
The deflecting unit 6 reflects the reflected light Lr of the optical signal Ls emitted from the light emitting unit 4 and inputs the reflected light Lr to the light receiving unit 5.

FIG. 3 is a block diagram of a main part of another embodiment of the vehicle speed measuring device according to the present invention. The same components as those shown in FIG. 2 are denoted by the same reference numerals. In FIG. 3, a vehicle speed measuring device 1 includes a control unit 2, a light emitting unit 4, a light receiving unit 5, a display control unit 7, a light emitting deflection unit 1
4. The light receiving deflection means 15 is provided.

Referring to FIG. 3, only the parts different from the embodiment of FIG. 2 will be described. In FIG. 3, the light-emitting deflecting means 14 is constituted by a galvanomirror which is manufactured in a semiconductor process and can be easily deflected in two-dimensional directions. The galvanomirror is displaced in the X-Y two-dimensional direction based on the deflection drive signal Vs supplied from the means 2, and the light signal L emitted from the light emitting means 4
s is deflected to detect a measurement vehicle 12 within the measurement range ABCD.

The light-receiving deflecting means 15 includes the light-emitting deflecting means 1.
As in the case of 4, a two-dimensional galvanometer mirror using a semiconductor process is used. The reflected light Lr of the optical signal Ls emitted from the light emitting means 4 is reflected and input to the light receiving means 5.

FIG. 3 shows the light emitting deflection means 14 and the reflected light L
deflecting means 15 for reflecting r and inputting it to light receiving means 5
Are provided separately, and the common deflection drive signal V
As a result, the light-emitting deflecting means 14 and the light-receiving deflecting means 15 are deflected in synchronization with each other, and the reflected light Lr is input to the light-receiving means 5. By performing the deflection separately, the response becomes faster, and accurate vehicle speed measurement becomes possible.

As described above, the vehicle speed measuring means 1 according to the present invention includes the light emitting means 4 for generating a light beam, and the deflecting means 6 (or the light emitting deflecting means 14) for deflecting the light beam into a predetermined two-dimensional range. ), The light receiving means 5 (or light receiving deflection means 15) for receiving the reflected light Lr of the optical signal Ls, and the vehicle speed is calculated based on the reflected light Lr received by the light receiving means 5 (or light receiving deflection means 15). Since the control means 2 is provided, the vehicle speed of the measurement vehicle 12 passing through the measurement range can be measured from the optical signal Ls and the reflected light Lr.

FIG. 4 is a block diagram of a main part of the control means according to the present invention. In FIG. 4, the control unit 2 includes a speed processing unit 8, a deflection driving unit 9, a light emission control unit 10, and a phase difference detection unit 11. The speed processing means 8 is composed of a crystal oscillator, a frequency divider, a synchronizing signal generating means, various arithmetic means, a memory, and the like, and performs synchronization control, speed calculation, and display control.

Further, the speed processing means 8 has a scan time,
In order to accurately measure the phase difference, a reference frequency is generated by a crystal oscillator, and a synchronization control signal Vt is generated based on the frequency obtained by dividing the reference frequency by a frequency divider. 9, supply to the light emission control means 10 and the phase difference detection means 11 to perform synchronization control.

Further, the speed processing means 8 detects the measurement vehicle 12 entering and passing within the measurement range ABCD based on the vehicle detection signal Vc input from the phase difference detection means 11, and further detects the measurement range AB line and the CD line. The speed is calculated by dividing the distance between the two points of the AB line and the CD line by the time difference between the AB and CD from the time of passing between the two points, and the speed is calculated, and the speed information Vm is supplied to the display control means 7. .

The deflection driving means 9 is composed of a signal generating means such as a sweep generator. The deflection plate 6 of the deflection means 6 is controlled by the deflection driving signal Vs to cover the measuring range ABCD of FIG. It is driven to deflect in the axial direction. Note that the deflection driving means 9 may be configured to drive the deflection means 6 intermittently so that the deflection of the deflection means 6 hits the measurement ranges A to E shown in FIG. Good.

The light emission control means 10 is composed of, for example, a pulse generation circuit, and controls the light emission means 4 to emit a laser beam at a constant cycle in accordance with the synchronization control signal Vt from the speed processing means 8. It is controlled by Lk.

The phase difference detecting means 11 comprises an arithmetic circuit, a buffer memory and the like. The phase difference detecting means 11 detects a position based on the reflection signal Lc supplied from the light receiving means 5 and the synchronization control signal Vt supplied from the speed processing means 8. The measurement vehicle 12 is detected by detecting the phase difference, and a vehicle detection signal Vc is output to the speed processing means 8. Note that the phase difference is always a constant value when there is no measurement vehicle 12, and it is determined that the measurement vehicle 12 has entered when the change in the phase difference is continuous.

As described above, the control means 2 according to the present invention
Is a deflection driving means 9 for controlling the deflection means 6, a light emission control means 10 for controlling the light emitting means 4, and a phase difference detection for detecting a measurement vehicle 12 by detecting a phase difference from a reflected signal Lc from the light receiving means 5. Based on the means 11 and the time at which the measuring vehicle 12 is detected, the time required to pass through the measuring range ABCD in FIG. 1 is measured, and the speed processing means 8 for calculating the speed of the measuring vehicle 12 is provided. The speed of the measurement vehicle 12 can be measured with high accuracy.

FIG. 5 is a configuration diagram of a galvanomirror used as a deflection means according to the present invention. In FIG. 5, a galvanomirror 30 includes a silicon substrate 32 which is a semiconductor substrate.
The upper and lower surfaces are sandwiched from above and below on an upper glass substrate 33 and a lower glass substrate 34 made of borosilicate glass or the like, and joined to form a three-layer structure.

The upper glass substrate 33 and the lower glass substrate 34 are provided with concave portions 33A and 34A formed by, for example, ultrasonic processing at the center, respectively.
In this case, the concave portions 33A and 34A are arranged so as to be on the silicon substrate 32 side. With such an arrangement, a swing space of the movable plate 35 on which the reflection mirror 38 is provided is formed, and a closed structure is provided.

The silicon substrate 32 is provided with a flat movable plate 35 composed of an outer movable plate 35A formed in a frame shape and an inner movable plate 35B pivotally supported inside the outer movable plate 35A. The outer movable plate 35A includes the first torsion bar 3
6A and 36A, the inner movable plate 35B is supported by the first torsion bars 36A and 36A.
A second torsion bar 36B, 3 whose axial direction is orthogonal to A
At 6B, it is pivotally supported inside the outer movable plate 35A. The outer movable plate 35A, the inner movable plate 35B, the first torsion bar 36A, and the second torsion bar 36B are integrally formed on the silicon substrate 32 by anisotropic etching, and are formed of the same material as the silicon substrate 32.

A pair of outer electrode terminals 39A, 39A formed on the upper surface of the silicon substrate 32 are formed on the upper surface of the outer movable plate 35A.
A is formed by coating a planar coil 37A, which is electrically connected to both ends of the first torsion bar 36A via one portion of the first torsion bar 36A, with an insulating layer. On the other hand, the inner movable plate 35
B, a pair of inner electrode terminals 39B, 39B formed on the upper surface of the silicon
A planar coil 37B that is electrically connected to the first torsion bar 36A via the other portion of the first movable torsion bar 36A from the base coil 6B is covered with an insulating layer.

The plane coil 37A and the plane coil 37B are
It is formed by an electroformed coil method by electrolytic plating. The outer movable plate 35A and the inner electrode terminal 39B are connected to the silicon substrate 3
2 are formed simultaneously with the planar coils 37A and 37B by an electroformed coil method. A reflection mirror 38 is formed at the center of the inner movable plate 35B surrounded by the plane coil 37B.

On the upper glass substrate 33 and the lower glass substrate 34, two pairs of cylindrical permanent magnets 40A to 43A and 40B to 43B are arranged as shown in FIG. Opposing permanent magnets 40 on upper glass substrate 33
A, 41A and the opposing permanent magnets 40B, 41B of the lower glass substrate 34 form a planar coil 3 on the outer movable plate 35A.
A magnetic field acts on 7A, and the outer movable plate 35A is rotated by interaction with a drive current flowing through the planar coil 37A.

On the other hand, the opposing permanent magnets 42A and 43A of the upper glass substrate 33 and the opposing permanent magnets 42B and 43B of the lower glass substrate 34 apply a magnetic field to the planar coil 37B on the inner movable plate 35B, and The inner movable plate 35B is rotated by interaction with the drive current flowing through the coil 37B.

The opposing permanent magnets 40A and 41A have opposite polarities, for example, the upper surface of the permanent magnet 40A is S
If it is a pole, the upper surface of the permanent magnet 41A is arranged so as to be an N pole, and furthermore, the magnetic flux is arranged so as to cross in parallel with the plane coil portion of the movable plate 35. Other opposed permanent magnets 42A and 43A, permanent magnets 40B and 41B, permanent magnet 4
The same applies to 2B and 43B.

The permanent magnets 40A and 40 opposing each other in the vertical direction
The relationship with B is that the upper and lower polarities are the same, for example, the permanent magnet 40
If the upper surface of A is the S pole, the upper surface of the permanent magnet 40B is also arranged to be the S pole. Other vertically facing permanent magnets 41A and 41B, permanent magnets 42A and 42B, permanent magnet 4
3A and 43B are similarly arranged. Thereby, the movable plate 3
Forces act in opposite directions at both ends of 5.

On the lower surface of the lower glass substrate 34, detection coils 45A and 45B and detection coils 46A and 46, which are arranged so as to be electromagnetically coupled to the planar coils 37A and 37B, respectively.
B is formed in a pattern. Detection coil 45A, 45B
Are arranged symmetrically with respect to the first torsion bar 36A, and the detection coils 46A and 46B are arranged symmetrically with respect to the second torsion bar 36B.

The pair of detection coils 45A and 45B are for detecting the displacement angle of the outer movable plate 35A, and are formed based on a detection current which is superimposed on a drive current which flows through the plane coil 37A and which is generated based on the detection current. And detection coil 45
A, the mutual inductance with 45B is outside movable plate 35A
The displacement angle of the outer movable plate 35A can be detected from the mutual inductance change.

On the other hand, the pair of detection coils 46A and 46B can detect the displacement angle of the inner movable plate 35B in the same manner. The displacement of the outer movable plate 35A corresponds to, for example, the displacement in the X-axis direction, and the displacement of the inner movable plate 35B corresponds to the displacement in the Y-axis direction, whereby the two-dimensional displacement of the reflection mirror 38 becomes possible. .

As described above, the deflecting means 6 according to the present invention comprises:
Since the galvanometer mirror 30 can easily perform two-dimensional deflection using a semiconductor manufacturing process, highly accurate two-dimensional deflection can be performed even in a small space on a road on which a vehicle travels.

In this embodiment, the vehicle speed measuring device 1 is integrated as shown in FIG.
The deflecting means 6 and the light receiving means 5 may be integrated and installed on the support 101 shown in FIG. Further, the light receiving means 5 may be arranged differently from the light emitting means 4 and the deflecting means 6.

[0062]

As described above, the vehicle speed measuring device according to the present invention comprises: a light emitting means for generating a light beam; a deflecting means for deflecting the light beam into a predetermined two-dimensional range;
A light receiving means for receiving the reflected light of the light beam reflected from the predetermined dimension; a control means for calculating a vehicle speed based on the reflected light received by the light receiving means; and displaying the information on the vehicle speed to the outside Output display control means, the light beam can be deflected in a predetermined two-dimensional range (detection area), and the speed of all passing vehicles such as motorcycles and four-wheel vehicles passing through the detection area can be controlled. It is possible to measure and monitor the traffic situation of the vehicle such as speeding of the vehicle and traffic jam.

Further, in the vehicle speed measuring device according to the present invention, the control means includes a deflection driving means for supplying a two-dimensional predetermined range of deflection driving signals to the deflection means, and a light emitting means for emitting light at a constant cycle. , A phase difference detecting means for receiving information from the light receiving means and detecting a phase difference, and calculating a speed based on a synchronization signal of a predetermined period and a signal from the phase difference detecting means. With the provision of the speed processing means, the speed of the measuring vehicle can be measured with high accuracy with a simple configuration, and the economy is excellent.

Further, the deflecting means according to the present invention is a galvanomirror which can be periodically deflected in a two-dimensional direction using a semiconductor manufacturing process. Can be performed.

Accordingly, it is possible to provide a vehicle speed measuring device that can be easily installed and can measure the speed of a running vehicle with high accuracy.

[Brief description of the drawings]

FIG. 1 is an installation image diagram of a vehicle speed measuring device according to the present invention.

FIG. 2 is a block diagram of a main part of a vehicle speed measuring device according to the present invention.

FIG. 3 is a block diagram of a main part of another embodiment of the vehicle speed measuring device according to the present invention.

FIG. 4 is a block diagram of a main part of control means according to the present invention.

FIG. 5 is a configuration diagram of a galvanometer mirror used as a deflection unit according to the present invention.

FIG. 6 is a conceptual diagram of an example of a conventional vehicle speed measuring device using an infrared sensor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vehicle speed measuring device, 2 ... Control means, 4 ... Light emitting means, 5 ... Light receiving means, 6 ... Deflection means, 7 ... Display control means,
8 speed processing means, 9 deflection driving means, 10 light emission control means, 11 phase difference detection means, 12 vehicle, 13 display means, 14 light emission deflection means, 15 light reception deflection means,
20: speed measurement sensor, 30: galvanometer mirror, 101
... Prop, 102 ... Road, 103 ... Transmission path, Lc ... Reflection signal, Lk ... Light emission control signal, Lr ... Reflection light, Ls ... Light signal, Ra-Rd ... Light emission beam, Rar-Rdr ... Reflection beam, Vc ... Vehicle Detection signal, Vm: speed information, Vo: display output signal, Vr: speed measurement sensor, Vs: deflection drive signal, Vt: synchronization control signal.

Claims (3)

[Claims] 1. A vehicle speed measuring device for measuring the speed of a vehicle traveling on a road, comprising: a light emitting means for generating a light beam; a deflecting means for deflecting the light beam into a predetermined two-dimensional range; A light receiving means for receiving the reflected light of the light beam reflected from the predetermined dimension; a control means for calculating a vehicle speed based on the reflected light received by the light receiving means; and displaying the information on the vehicle speed to the outside And a display control means for outputting. 2. The control unit includes: a deflection driving unit that supplies a two-dimensional predetermined range of deflection driving signal to the deflection unit; and a light emission control unit that controls the light emission unit to emit light at a constant cycle. A phase difference detection unit that receives information from the light receiving unit and detects a phase difference, and a speed processing unit that calculates a speed based on a synchronization signal having a predetermined period and a signal from the phase difference detection unit. The vehicle speed measurement device according to claim 1, further comprising: 3. The vehicle speed measuring device according to claim 1, wherein said deflecting means is a galvanomirror capable of periodically deflecting in a two-dimensional direction using a semiconductor manufacturing process.