JPH10170653A - Distance measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a distance measuring device which can prevent irregular reflection from causing faulty recognition. SOLUTION: The distance measuring device has a light receiving/transmitting component 10 in which a luminescent part 1 casts scanning light SB to an objective, a light receiver 2 receives its reflected light RB, and then the distance to the objective is determined, includes a luminescent hole 13 and a light receiving hole 14 adjacent each other, and is removably equipped with a shade cylinder 50 which optically separates the luminescent hole 13 from the light receiving hole 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distance measuring device for measuring an inter-vehicle distance, for example, by displaying and warning a measured distance to maintain a safe inter-vehicle distance and prevent a rear-end collision or a collision. In particular, the present invention relates to a distance measuring device which can be preferably applied to an accident avoidance device for avoiding erroneous recognition due to irregular reflection.

[0002]

2. Description of the Related Art An accident avoidance device of this kind, for example, a rear-end collision warning device measures a distance between a vehicle and a vehicle in front by irradiating a laser beam in front of the vehicle and receiving light reflected by the vehicle in front. The distance between vehicles is displayed to drive the vehicle while maintaining a safe distance between vehicles, and is used for predicting the risk of rear-end collision or collision to prevent accidents.

In the conventional inter-vehicle rear-end collision warning device, one laser beam is emitted only in one direction. Therefore, it is impossible to detect a vehicle ahead of the vehicle even if the vehicle is slightly out of the detection area. It has been pointed out that a sign, a signboard or the like or an oncoming vehicle is detected and a false alarm is likely to occur.

[0004] For this purpose, a laser beam from a laser diode is applied to a mirror, and the mirror is reciprocally rotated at a predetermined angle in the horizontal direction, thereby increasing the irradiation area of the laser beam to be applied forward. Alarm devices have also been proposed. According to such a multi-beam scan type inter-vehicle rear-end collision warning device, not only the detection area of the preceding vehicle is widened, but also on a curved road, the information of the reflected light is processed to change the direction of the detection area. Can be selected according to

[0005]

By the way, the radar unit 10 of the conventional inter-vehicle collision warning device has a structure as shown in FIG.
The radar unit 10 is attached to the front of the vehicle, for example, between the front grille FG and the front bumper FB, so that the radar unit 10 is slightly exposed to the outside so as not to impair the appearance.

However, when the radar unit 10 is mounted in such a position, water droplets W and the like attached to the lens of the light emitting unit cause irregular reflection as shown in FIG. 12 in the laser beam SB, and the front grill FG or the front bumper F
There is a possibility that the laser light reflected by B may directly enter the light receiving unit. When such reflected light enters, the inter-vehicle collision warning device determines that the target object is present at a short distance and sounds an alarm.

[0007] Such a problem can be solved by taking measures to prevent water droplets from adhering to the glass of the light emitting section. However, since the radar section is to be mounted in the traveling direction of the vehicle, raindrops, morning dew, etc. In practice, it was difficult to prevent the adhesion of water.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems of the prior art, and has as its object to provide a distance measuring apparatus capable of preventing erroneous recognition due to irregular reflection.

[0009]

In order to achieve the above object, a distance measuring apparatus according to the present invention irradiates a target with scanning light from a light emitting unit, and receives the reflected light by a light receiving unit. A distance measuring device having a light emitting and receiving unit for measuring a distance to the object, wherein the light emitting opening and the light receiving opening are provided adjacent to each other. It is characterized by having a light-shielding wall for partitioning.

The distance measuring device of the present invention has a light-shielding wall that optically separates the light-emitting port and the light-receiving port. Therefore, even if the scanning light from the light-emitting section causes irregular reflection near the exit of the light-emitting port, the light-shielding wall is used. The irregularly reflected scanning light is not directly guided to the light receiving port. That is, even if the light emitting / receiving unit is mounted, for example, at a position deep between the front grill and the front bumper, the diffusely reflected light is guided by the light shielding wall to the tip of the light shielding wall. Is not detected by the light receiving unit. Therefore, erroneous recognition due to irregularly reflected light is reliably prevented.

In the distance measuring device according to the present invention, the light shielding wall is a cylindrical body provided in one of the light emitting port and the light receiving port, or the light shielding wall is formed of the light emitting port and the light receiving port. It is preferable to be an angle-shaped body provided at any one of the mouths and having a boundary surface between the light emitting port and the light receiving port and upper and lower surfaces thereof.

In the distance measuring device according to the present invention, it is preferable that the light shielding wall is provided so as to be detachable from the light emitting and receiving unit. By doing so, maintenance workability such as cleaning is improved.

In the distance measuring apparatus according to the present invention, it is preferable that a drain groove hanging from a light emitting port or a light receiving port provided with the light shielding wall is formed on an outer surface of a casing of the light emitting and receiving unit. Raindrops and morning dew flying from the front of the vehicle easily adhere to the light-emitting or light-receiving port provided with the light-shielding wall, and are difficult to remove. However, by forming a drain groove, such waterdrops are guided to the outside of the light-shielding wall. be able to.

In the distance measuring device of the present invention, the axial length of the light shielding wall is not particularly limited, and does not need to reach the front of the vehicle. This is because light that is irregularly reflected at least in the vicinity of the light emitting port cannot enter the light receiving port as it is by the light shielding wall.

The distance measuring device of the present invention has a function of measuring at least the distance to an object. The following distance warning device, the following distance warning device, the rear side warning device, the automatic following device, the following distance device The present invention can be applied to various types of accident avoidance devices such as automatic maintenance driving devices, collision speed reduction devices, accident avoidance automatic operation devices, and corner deceleration devices.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a horizontal sectional view showing an embodiment of a light emitting / receiving section of an inter-vehicle collision warning device using the distance measuring device of the present invention, FIG. 2 is a perspective view thereof, and FIG. FIG. 6 is an enlarged perspective view of a portion A in FIG.
FIG. 7 is a block diagram showing an embodiment of an inter-vehicle collision warning device using the distance measuring device of the present invention, and FIG. 8 is an operation and light emission of a stepping motor in the embodiment of the inter-vehicle collision warning device using the distance measuring device of the present invention. 6 is a time chart illustrating a relationship between the operation of a unit and a light receiving unit.

First, as shown in FIG. 1, a light emitting / receiving section (radar section) 10 according to the present embodiment includes a first casing 11
And a second casing 12, in which the light emitting unit 1, the light receiving unit 2,
A mirror 3 and a stepping motor 4 are built in.

Light emitting unit 1 composed of a laser diode or the like
Is mounted on a printed circuit board 1a on which a control circuit of the laser diode 1 is formed, and when a light emission signal from a controller 20 described later is received, the vertical light transmission angle of the scanning light SB is about 2 ° and the horizontal Light transmission angle of direction is about 2 °
The mirror 3 is irradiated with the laser spot light LS so that

The mirror 3 is mounted directly on the output shaft 4a of the stepping motor 4 while being mounted on the mirror holder 3a, and reflects the laser spot light LS from the light emitting section 1 toward the light emitting port 13.

The stepping motor 4 used in the present embodiment is of a so-called hybrid type, and detailed description is omitted. However, the stepping motor 4 includes a rotor composed of a permanent magnet and a rotor core, and a stator composed of a coil and a stator core. Small teeth are formed on both the rotor core and the stator core, and the rotor core is further divided into two. The hybrid type stepping motor 4 has a higher torque than other types of PM type and VR type, and has extremely excellent positioning accuracy, and thus is suitable for the stepping operation of the mirror 3 according to the present embodiment. However, in the distance measuring device of the present invention, a PM type or VR type stepping motor other than the HB type can be used.

The operation signal to the stepping motor 4 is transmitted from the controller 20 via a harness (not shown). In order to detect the current rotational position of the stepping motor 4, the photo interrupter 5 as position detecting means is used. Is provided.

As shown in FIG. 6, the photointerrupter 5 has a concave portion 5a through which a light shielding portion 3b formed integrally with the mirror holder 3a can pass.
A slit 5b is formed in each of the horizontal planes a, and a light shielding portion 3b is formed by an infrared LED embedded in one slit 5b and a photo IC embedded in the other slit 5b.
Is detected. Photo interrupter 5 of the present embodiment
Outputs a high-level signal to the controller 20 when the light-shielding portion 3b is detected, that is, when light is shielded.

A light receiving port 14 is formed in the second casing 12 of the light emitting / receiving section 10 adjacent to the light emitting port 13 described above, so as to receive the reflected light RB reflected by the object. .

Here, the light receiving section 2 includes a photodiode,
The light receiving element 2 is mounted on a third casing 15 while being mounted on a printed circuit board 2a on which a control circuit for the light receiving element is formed.

In this embodiment, the printed circuit board 2a
Is attached to the third casing 15, a member 8 made of a light-impermeable material such as urethane rubber is interposed between the printed board 2 a and the third casing 15. Scanning light SB
This prevents the light from entering the gap between the printed board 2 a and the third casing 15 and being detected by the light receiving unit 2. Further, by employing an elastic body such as urethane rubber, the printed circuit board 2a can be compressed and attached to the third casing 15, whereby the gap between the printed board 2a and the third casing 15 and the printed board 2a The plurality of through-holes (not shown) opened in the above can be reliably shielded.

The third casing 15 has a function of holding a protective glass and a condenser lens between the third casing 15 and the second casing 12. That is, the light-emitting port 13 is provided with the protective glass 6a via an O-ring, and the light-receiving port 14 is provided with
The Fresnel lens 7 is provided via an O-ring, and these are sandwiched between the second casing 12 and the third casing 15.

In this embodiment, the protective glass 6b and the Fresnel lens as the condenser lens 7 are employed.
The protective glass 6b can be omitted by disposing a toward the inside. That is, the flat surface 7b of the Fresnel lens 7 serves as a protective glass to protect the light emitting and receiving unit 10 from dust, sand, raindrops, and the like from the front, while the condensing action of the reflected light RB on the Fresnel surface 7a. It is activated and detected by the light receiving unit 2. By doing this,
Since the transmittance required for transmission through the protective glass 6b, which is conventionally required, does not decrease, the detection accuracy, that is, the light receiving sensitivity is increased, and the cost can be reduced by the omission of the protective lens 6b.

On the front of the controller 20 shown in FIG.
A main power button 21, a digital display unit 22 for displaying the distance L from the object detected by the light emitting and receiving unit 10, a speaker 23 for emitting an alarm sound such as a rear-end collision alarm or an inter-vehicle alarm, for adjusting the volume of the alarm sound. Volume lamp 24, a warning lamp 25 for displaying warnings such as a rear-end collision warning and a vehicle-to-vehicle warning with three-color lamps, a user setting button 26 for setting warning timing and canceling the vehicle-to-vehicle warning sound,
a, 6b and a lens dirt warning lamp 27 for warning dirt on the condenser lens 7, and an adjustment mode switch 28 for executing an adjustment mode when the light emitting and receiving unit 10 of the head-to-head collision warning device is mounted on a vehicle. ing.

The digital display unit 22 displays the distance L to the object in meters as it is. Based on the measured distance L, a warning sound and a warning lamp alert the driver to danger. I also do.

In this embodiment, when the safe distance L between the vehicle in front and the vehicle ahead is maintained, the warning sound is not emitted, and the warning lamp 25 is turned off or lights up in green or orange. When the distance L from the vehicle in front is shorter than the safe inter-vehicle distance, an intermittent warning sound is emitted and the warning lamp 25 lights up in red. Further, when the distance L between the vehicle and the vehicle in front is extremely short and there is a possibility of collision, a continuous warning sound is sounded and all the red, orange and green warning lamps 25 are used and these are blinked. .

The user setting button 26 is a button for setting respective alarm timings of an inter-vehicle alarm and a rear-end collision alarm. For example, when the mode button 26a is pressed, the alarm timing of the inter-vehicle alarm is set, and the UP and DOW are set.
Using the N button 26b, the range of the warning timing (the reference value of the inter-vehicle distance to be warned) can be switched by the numerical values of 1 to 20 displayed on the digital display unit 22. When the mode button 26a is further pressed, the mode for setting the alarm timing of the rear-end collision alarm is set, and the UP and DOWN buttons 26
1 to 20 displayed on the digital display unit 22 using
The range of the warning timing (the reference value of the rear-end collision distance to be warned) can be switched by the numerical value of. Further, the ON / OFF of the alarm is switched by these buttons 26a and 26b.

In this embodiment, the adjustment mode switch 28 for confirming the mounting position of the light emitting / receiving unit 10 on the vehicle is provided by:
Inside the controller 20, the controller 2
It is provided at a position where it can be operated via a small hole opened in the finisher 20f. In other words, it is a behind switch (hidden switch). As described above, by setting the adjustment mode switch to a dedicated switch, an adjustment operator such as a dealer can easily find the switch 28. In addition, since the switch is configured as a behind switch, the switch cannot be input unless a tool or the like is used, and a general user other than the adjustment operator does not input the adjustment mode switch 28 by mistake.
Furthermore, since it is constituted by a behind switch, it does not impair the space of the finisher 20f of the controller 20 and does not impair the appearance.

Information from the vehicle speed sensor 30 of the vehicle is input to the controller 20. When the vehicle speed becomes 1 km / h or more, an inter-vehicle alarm and a rear-end collision alarm are executed, and these alarms do not operate below this speed. It has become. Further, information from the steering wheel angle sensor 40 of the vehicle is input to the controller 20, and the microcomputer or the electronic circuit of the controller 20 selects the effective direction of the scanning light by recognizing the traveling direction of the own vehicle. It is processed. The details will be described later.

In the inter-vehicle collision warning device of the present embodiment, the mirror 3 is reciprocally rotated by the stepping motor 4,
As shown in the upper right diagram of FIG. 8, the scanning light SB is
That is, scanning is performed in the order of →→→→→. At this time, the output shaft 4a of the stepping motor 4 is not reciprocated continuously, but is temporarily stopped for a very short time, and at the time of the stop, the laser beam LS from the laser diode 1 is applied to the mirror 3.

The upper part of FIG. 8 shows the scanning direction of the scanning light as a step of the stepping motor 4, the middle part shows the light emission timing of the laser diode 1, and the lower part shows the light reception timing of the reflected light, that is, the light receiving condition of the photodiode 2. ing. The steps of the stepping motor 4 are (Step 1) → (Step 2) → (Step 3) → (Step 4) → (Step 5).

As described above, while the stepping motor 4 is rotating, light emission from the laser diode 1 is not performed.
The laser diode 1 emits light when the rotation of the motor stops in each step. In the present embodiment, four phases,
The stepping motor 4 having a step angle of 0.9 deg was used, and the stop hold time of the mirror 3 was set to 10 μsec.

The operation timing of the stepping motor 4 and the light emission timing of the laser diode 1 are controlled by a microcomputer or an electronic circuit of the controller 20, and are controlled by the motor 4 detected by the photo interrupter 5.
Is used.

In the inter-vehicle collision warning device of this embodiment, when the mirror 3 is reciprocally rotated, the mirror 3 is temporarily stopped for a predetermined time, and the laser beam LS is applied to the mirror 3 when the mirror 3 is stopped. In comparison with irradiating a laser beam while rotating, there is no rotational vibration error, and the scanning light SB
Becomes significantly more accurate.

The light emitting and receiving unit 10 of the headway collision warning device according to the present invention.
As shown in FIG. 5, is mounted between the front grille FG and the front bumper FB of the vehicle, for example, but it is necessary to adjust the optical axis of the laser beam at the time of mounting to check the operation. Further, even after mounting, optical axis correction and operation confirmation may be performed. In such a case, with the vehicle stopped, a tool such as a screwdriver is inserted into a small hole formed in the finisher 20f of the controller 20, and the adjustment mode switch 28 is pressed. Then, as described above, the vehicle normally does not operate unless the vehicle speed becomes 1 km / h or more. However, by pressing the adjustment mode switch 28, the adjustment mode is set for 30 seconds, and the laser beam is emitted from the laser diode 1, This reflected light is received by the light receiving unit 2, and a normal operation of measuring the distance to the target is performed. This 3
In 0 seconds, a reference reflector is installed at a known distance in front of the host vehicle, the optical axis of the laser beam is adjusted, and the mounting state of the light emitting and receiving unit 10 is checked. Also check if it works properly. When 30 seconds have elapsed, the timer operates and the adjustment mode is automatically canceled.

As described above, in this embodiment, by inputting the adjustment mode switch 28, the laser beam is emitted from the laser diode 1 for a predetermined time even when the vehicle is stopped. Since the distance to the target object can be measured by receiving the light, the optical axis of the light emitting / receiving unit 10 can be adjusted and the operation can be confirmed within the predetermined time. In addition, since the operation is automatically canceled after operating for a predetermined time, there is no problem in terms of safety. Note that the maintenance time of the adjustment mode is not limited to 30 seconds described above.

In particular, in the present embodiment, a light-shielding tube 50 is attached to the light-emitting opening 13 in order to prevent erroneous recognition due to irregular reflection when the light-emitting / receiving unit 10 is mounted in a deep position in the vehicle as shown in FIG. ing. That is, a light-shielding cylinder 50 formed of a cylindrical body capable of optically shielding the laser beam SB and having a threaded portion 52 formed at a base end thereof is formed by a threaded portion formed around the light emitting port 13 of the second casing 12. It is screwed into and installed. Further, when the light-shielding tube 50 is attached to the light-emitting port 13, as shown in FIG. A groove 60 is formed on the outer surface of the second casing 13.

By providing the light shielding tube 50, the light emitting unit 1
Even if the scanning light SB from the light source causes irregular reflection near the exit of the light emitting port 13, the irregularly reflected scanning light SB is not directly guided to the light receiving port 14 by the inner wall of the light shielding tube 50. That is, even if the light emitting and receiving unit 10 is mounted at a deep position between the front grill FG and the front bumper FB as shown in FIG. 5, the diffused light is guided by the light shielding tube 50 to the tip of the light shielding tube 50. Therefore, even if the diffusely reflected light is reflected by the front grille FG or the front bumper FB, the light is not detected by the light receiving unit 2. Therefore, erroneous recognition due to irregularly reflected light is reliably prevented.

Further, since the light-shielding cylinder 50 of the present embodiment is provided so as to be detachable from the second casing 13, maintenance workability such as cleaning is greatly improved. Furthermore, the light emitting / receiving section 10 of the present embodiment has a drain groove 6.
0, raindrops and morning dew flying from the front of the vehicle easily adhere to the light emitting port 13 provided with the light-shielding tube 50 and are difficult to remove. It can be guided out of 50, and drastic measures against diffuse reflection can be taken.

The axial length of the light-shielding cylinder 50 is not particularly limited, and does not need to reach the front of the vehicle as shown in FIG. This is because light diffusely reflected at least in the vicinity of the light emitting port 13 cannot directly enter the light receiving port 14 by the light shielding tube 50.

The light-shielding wall of the present invention is not limited to the light-shielding tube 50 described above, but can be variously modified. FIG. 3 is a perspective view showing another embodiment of the light emitting and receiving unit 10 according to the present invention. It is composed of an angled body having lower surfaces 50b and 50c. That is, the open surface of the light shielding wall 50 is
There is substantially no effect on preventing the irregularly reflected light from entering the light receiving port 14, so that this is omitted. The angle-shaped light shielding wall 50 can be detachably attached to the second casing 12 by, for example, a pin 54.
Although not shown, the drain groove 60 described above may be provided.

The light-shielding wall of the present invention is not limited to the light-emitting opening 13 but may be attached to the light-receiving opening 14 as shown in FIG. In this case, it may be a cylindrical body or an angled body.

The head-on collision warning device using the distance measuring device of the present invention can be used as follows. FIG.
Is a schematic diagram showing a usage pattern of the inter-vehicle rear-end collision warning device on a curved road, and FIG. 10 is a schematic diagram showing a usage pattern in a case where there is a sudden interrupted vehicle.

On a curved road as shown in FIG. 9, there may be a central divider and an oncoming vehicle V3 in front of the center. If the measurement distance of the central scanning light of the three scanning lights is increased, These reflectors and oncoming vehicle V3
Will be detected. Therefore, when the steering wheel angle sensor 40 recognizes that the vehicle is on a curved road, the measuring distance of the scanning light (scanning beam in the illustrated case) in the curve direction is increased, and the measuring distance of the other scanning light is reduced. . As a result, only the preceding vehicle V2 in the curve direction is detected, and it is possible to extract and measure the inter-vehicle distance and the distance L to only the target related to the rear-end collision warning.

In this case, in the head-on rear-end collision warning device according to the present embodiment, the mirror 3 is temporarily stopped for a predetermined time when the mirror 3 is reciprocally rotated by using the stepping motor 4, and the laser light LS is transmitted to the mirror at this stop. By irradiating No. 3, the rotational vibration error is suppressed and the azimuth angle of the scanning light SB is extremely accurate, so that the accuracy in the curve direction is high,
False alarms can be prevented.

On the other hand, on a straight road as shown in FIG. 10, the forward vehicle V2 normally exists in the traveling direction.
The measurement distance of the central scanning light of one scanning light is set to be large, and the measurement distance of the other scanning light is set to be small. As a result, since the reflector or the oncoming vehicle existing on the front side is not detected, it is possible to appropriately recognize only the required front vehicle V2, and as shown in FIG. Even if there is, it can be detected by the scanning light on both sides.

The embodiments described above are described for the purpose of facilitating the understanding of the present invention, but are not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

That is, the distance measuring device of the present invention is not limited to the above-mentioned inter-vehicle collision warning device, but may be, for example, an inter-vehicle distance alarm device, a rear side alarm device, an automatic following device, an inter-vehicle distance automatic maintenance driving device, a collision speed reduction device. , Accident avoidance automatic operation device,
The present invention can be applied to various accident avoidance devices such as a corner approach deceleration device.

[0053]

As described above, according to the distance measuring apparatus of the present invention, the irregularly reflected light is guided to the tip of the light shielding wall by the light shielding wall, and the irregularly reflected light is reflected by the front grill or the front bumper. Is not detected by the light receiving unit. Therefore, erroneous recognition due to irregularly reflected light is reliably prevented.

In the distance measuring apparatus of the present invention, if the light shielding wall is provided detachably with respect to the light emitting and receiving unit, maintenance workability such as cleaning is improved.

In the distance measuring device according to the present invention, if a drain groove hanging from the light emitting port or the light receiving port provided with the light shielding wall is formed on the outer surface of the casing of the light emitting and receiving section, the water adhering to the light emitting port or the light receiving port is provided. Water droplets can be smoothly guided to the outside of the light shielding wall, and the occurrence of diffuse reflection can be drastically prevented.

[Brief description of the drawings]

FIG. 1 is a horizontal sectional view showing an embodiment of a light emitting / receiving section of an inter-vehicle collision warning device using a distance measuring device of the present invention.

FIG. 2 is a perspective view showing a light emitting and receiving unit of the headway collision warning device shown in FIG.

FIG. 3 is a perspective view showing another embodiment of the light emitting and receiving unit according to the present invention.

FIG. 4 is a perspective view showing still another embodiment of the light emitting and receiving unit according to the present invention.

FIG. 5 is a longitudinal sectional view showing a state where the light emitting and receiving unit according to the present invention is mounted on a vehicle.

FIG. 6 is an enlarged perspective view of a portion A in FIG. 1;

FIG. 7 is a block diagram showing an embodiment of an inter-vehicle collision warning device using the distance measurement device of the present invention.

FIG. 8 is a time chart showing a relationship between the operation of the stepping motor and the operations of the light emitting unit and the light receiving unit in the embodiment of the headway collision warning device using the distance measuring device of the present invention.

FIG. 9 is a schematic diagram showing a use form of an inter-vehicle collision warning device using the distance measuring device of the present invention.

FIG. 10 is a schematic diagram showing another mode of use of a head-to-head collision warning device using the distance measuring device of the present invention.

FIG. 11 is a longitudinal sectional view showing a mounted state of a light emitting and receiving unit of a conventional inter-vehicle collision warning device.

FIG. 12 is an enlarged sectional view of a portion B in FIG. 11;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Laser diode (light emitting part) 1a ... Printed circuit board 2 ... Photodiode (light receiving part) 2a ... Printed circuit board 3 ... Mirror 3a ... Mirror holder 3b ... Shielding part 4: Stepping motor 4b ... Output shaft 5 ... Photo interrupter 6a, 6b ... Protective glass 7 ... Fresnel lens 7a ... Fresnel surface 7b ... Flat surface 8 ... Light opaque member 10 ... Light emitting and receiving unit 20 ... Controller 30 ... Vehicle speed sensor 40 ... Handle angle sensor 50 ... Light shielding wall 52 ... Screw portion 60 ... Water Slots SB: Scanning light RB: Reflected light L: Distance to target V1: Own vehicle V2: Forward vehicle (target) V3: Oncoming vehicle V4: Interrupting vehicle (target)

Claims (5)

[Claims] An object (V) is irradiated with scanning light (SB) from a light emitting section (1), and reflected light (RB) thereof is received by a light receiving section (2).
A distance measuring device having a light emitting / receiving section (10) for measuring a distance (L) from the target object by receiving light at the light emitting port, wherein a light emitting port (13) and a light receiving port (14) are provided adjacent to each other. In the distance measuring device, a light shielding wall (5) for optically separating the light emitting port and the light receiving port is provided.
0) A distance measuring device characterized by having: 2. The distance measuring device according to claim 1, wherein said light-shielding wall is a tubular body provided in one of said light-emitting port and said light-receiving port. 3. The light-shielding wall (50) is provided on one of the light-emitting port and the light-receiving port, and a boundary surface (50a) between the light-emitting port and the light-receiving port and upper and lower surfaces thereof (50).
2. The distance measuring device according to claim 1, wherein the distance measuring device is an angled body having (b, 50c). 4. The distance measuring device according to claim 1, wherein said light shielding wall is provided so as to be detachable from said light emitting and receiving unit. 5. A drain groove (60) hanging from a light emitting port or a light receiving port provided with the light shielding wall (50) is formed on an outer surface of a casing (12) of the light emitting and receiving unit (10). The distance measuring device according to any one of claims 1 to 4, wherein: