JPH0511050A - Radar for measuring distance between vehicles - Google Patents

Abstract

PURPOSE:To make it possible to perform highly reliable measurement without diffusing a laser beam by forming both upper and rear surfaces of the lens of a laser-beam transmitting part in parallel at a head lamp. CONSTITUTION:A distance to a target vehicle is measured by the measurement of the time from the projection of the laser light on an automobile from a laser light emitting part 12 to the reception of the reflected light with a laser-light receiving part 13. At this time, a head lamp lens 14 whose surface becomes the convex curved surface is attached to the opening part of the front surface of a head lamp case 11. The light transmitting part of the bulb light at the inner surface of the lens 14 undergoes prism machining. The light transmitting part of the laser light from the light emitting part 12 is formed as a flat machined part 15. For the machined part 15, the inner surface of the lens 14 is formed in the convex shape. The machined part 15 is polished by secondary machining so as to obtain the flat surface. Then, the facing position of the machined of the machined part 15 at the outer surface of the lens 14 is polished and machined into a flat surface 16 in parallel with the part 15. Thus, the laser beam can be cast on the target material without diffusing the laser beam and without decreasing the transmittance by forming the flat surface 16 so that both upper and rear surfaces are in parallel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inter-vehicle distance measuring radar in which a light emitting portion and a light receiving portion of a laser radar device are provided in a headlight case.

[0002]

2. Description of the Related Art There is a conventional inter-vehicle distance measuring radar used to measure the distance between front and rear traveling vehicles by a succeeding vehicle, as shown in FIGS.
That is, in this radar, a laser light emitting portion 3 and a laser light receiving portion 4 are incorporated in a headlamp case 2 that houses a headlamp bulb 1, and a transparent headlamp lens 5 is placed on the front surface of the headlamp case 2. Wear
The headlamp bulb 1, the laser emitting section 3 and the laser receiving section 4 are waterproof and dustproof.

[0003]

However, in the general headlamp lens 5, as shown in FIG. 2, prism processing or curved surface processing is performed to condense light or increase the brightness of light. Therefore, when the laser light from the laser emitting portion 3 is transmitted through the headlamp lens 5 itself, the laser light is spread by the prism surface or the curved surface, and as a result, an effective laser beam cannot be obtained. The problem was that it was difficult to catch the target object and the ranging system deteriorated.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the related art. Headlights such as headlamps and fog lamps, for example, a laser beam transmitting portion of a lens of a headlamp has a To provide an inter-vehicle distance measuring radar in which both front and back surfaces are parallel to each other and are formed on a flat surface portion so that a laser beam reflected from a laser emitting portion can be irradiated to a predetermined target without being diffused. is there.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on the embodiments shown in the drawings.

In FIG. 3, reference numeral 11 is an example of a headlamp, which has a headlamp bulb (not shown) similar to that described in the conventional example, a laser emitting section 12, and a laser receiving section 13 as a headlamp. A headlamp lens 14 having a convex curved surface is attached to the front opening of the headlamp case 11 as a case. On the inner surface of the headlamp lens 14, the light-transmitting portion of the bulb light is prism processed, but the light-transmitting portion of the laser light from the laser emitting portion 12 is formed on the flattened portion 15. ..

As shown in FIG. 4, the flattened portion 15 has
When the headlamp lens 14 is molded, the inner surface of the lens 14 is formed into a convex shape in advance so that it can be easily polished into a flat surface.
Polished to 6 to form a flat surface. Then, the facing surface of the flattened portion 15 on the outer side surface of the lens 14 is ground to a flat surface 16 parallel to the flattened portion 15, so that the convex flattened portion 15 ensures the polishing position. And the ease of processing can be obtained.

Therefore, in this embodiment, the convex portion of the inner surface of the headlamp lens which has been formed in advance is ground to a flat surface, and then the lens surface is ground to a flat surface 16 parallel to the above-mentioned polishing surface. Then, the laser beam emitted from the laser emitting section 12 can be applied to the target object with a thin beam light flux having a diameter of about 15 to 40 mm, for example, without being diffused by the lens 14. Further, since the polishing portion is formed in a convex shape, planar processing is very easy to perform, and partial polishing processing can be inexpensive.

In the above embodiment, the shape of the headlamp lens 14 is a convex curved surface on the front surface side. For example, the headlamp lens 14 'having a concave curved surface surface is shown in FIGS. As described above, by forming the convex-shaped flattened portion 15 on the surface side, the same effect as that of the above-described embodiment can be obtained.

Further, as shown in FIG. 7, the headlamp lens 1
4, the concave step portion 17 indicating the polishing position is previously formed on the inner surface of 4,
The concave step portion 17 and the surface portion corresponding to the concave step portion 17 may be polished by secondary processing.

8 and 9, a through hole 18 is formed in the laser beam transmitting portion of the headlamp lens 14, and the through hole 18 is formed.
A transparent plate 1 which is previously formed on a flat surface 16 parallel to the inside
9 is fitted.

In this embodiment, the flatness of the transparent plate 19 is easily processed, so that the precision of the flat surface of the laser beam transmitting portion is further improved and the processing cost is reduced.

Although the above headlights are all headlamps, they may be fog lamps.

[0014]

As described above, according to the present invention, the laser light signal is projected toward the motor vehicle, the reflected light signal at the target vehicle of the signal is received, and the reflected light signal is received from the time when the signal is projected. In an inter-vehicle distance measuring radar in which the distance to a target vehicle is known by measuring the time to time, a light emitting unit 12 that projects the laser light signal and a light receiving unit 13 that receives the reflected light signal are headlighted. A headlamp lens 1 which is housed in a lamp case 11 and through which the laser light signal is transmitted
Since it is a vehicle-to-vehicle distance measuring radar in which a flat surface portion 16 having front and back surfaces parallel to each other is formed on a part of the front and back surfaces of 4 and 14 ',
According to this, the flat portion 16 does not diffuse the laser beam that passes through the flat portion, and therefore the laser beam is applied to the target object without lowering the transmittance, so that the measurement reliability is improved. It is possible to obtain the effect that the high inter-vehicle distance measurement is realized.

[Brief description of drawings]

FIG. 1 is an explanatory perspective view of a conventional example.

FIG. 2 is a sectional explanatory view of a conventional example.

FIG. 3 is a sectional explanatory view of an example according to the present invention.

FIG. 4 is an enlarged view of a main part in FIG.

FIG. 5 is a sectional explanatory view of another embodiment of the present invention.

FIG. 6 is an enlarged view of a main part in FIG.

FIG. 7 is an enlarged view of a main part showing still another embodiment of the present invention.

FIG. 8 is an explanatory sectional view showing still another embodiment of the present invention.

9 is an enlarged view of a main part in FIG.

[Explanation of symbols]

11 ... Headlamp case 12 ... Laser emitting part 13 ... Laser receiving part 14 ... Headlamp lens 15 ... Flat processing part 16 ... Flat surface 17 ... Recessed step part 18 ... Through hole 19 ... Transparent plate

Claims (1)

Claim: What is claimed is: 1. A laser light signal is projected toward a motor vehicle, a reflected light signal of the signal at the target vehicle is received, and the signal is projected until the reflected light signal is received. In an inter-vehicle distance measuring radar in which the distance to a target vehicle is known by measuring the time of, a light emitting unit (12) for projecting the laser light signal and a light receiving unit (13) for receiving the reflected light signal are provided. While housed in the headlight case (11),
Headlight lens (14) (1) through which the laser light signal is transmitted
An inter-vehicle distance measuring radar characterized in that a flat surface portion (16) having front and back surfaces parallel to each other is formed on part of the front surface and the back surface of 4 ').