JPH04110685A - Laser radar device - Google Patents

Abstract

PURPOSE:To enable a high-speed scanning to be made by performing scanning using a scanning mirror for directing laser light toward a target and receiving reflection laser light and a wedge prism part for rotating mutually opposite directions by synchronizing a scanning mirror which receives reflection laser light and a plurality of wedge prisms with a same declination quantity at a high refractive index. CONSTITUTION:A wedge prism part 5 allows two wedge prisms 5a and 5b which are of a high refractive index material and a same declination quantity to be synchronized and rotated in opposite directions. Also, when the declination quantity is large, wedge angle becomes large in the case of glass materials such as BK-7 so that the wedge angle can be reduced to approximately 1/3 by using a material with a large refractive index such as ZnSe. A side-direction scanning mirror 6 discharges laser light to a target 8 and receives light which is reflected from the target. Thus, a high-speed scanning can be performed even if a reception effective diameter becomes longer by allowing two wedge prisms 5a and 5b with a high refractive index to be rotated in opposite directions while synchronizing them and then scanning them in combination with the mirror 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laser radar device, and particularly to a laser radar device that is capable of high-speed scanning even when the receiving effective diameter becomes large.

[Conventional technology]

In conventional laser radar devices, when performing scanning, the light receiving optical axis is scanned in the vertical and horizontal directions simultaneously with one mirror, or in the vertical and horizontal directions with one mirror each. The distance to the target was displayed on the display screen.

(Problem to be Solved by the Invention) In the conventional laser radar device described above, when it is desired to increase the field of view of the screen of the display device and increase the frame rate,
Mirror scanning must be done quickly. Also, since the repetition frequency of the laser must be increased,
Generally, the peak value of the laser output becomes lower. Therefore, in order to obtain a sufficient reception margin, it is necessary to increase the effective reception diameter. As a result, a large mirror must be scanned at high speed, but there is a drawback that high speed scanning cannot be done due to the drive performance of the mirror.

An object of the present invention is to eliminate such drawbacks, and to provide a laser radar device that can perform high-speed scanning even when the receiving effective diameter is large, in order to increase the field of view of the screen of a display device and increase the frame rate. It is.

[Means for Solving the Problems] The laser radar device of the present invention includes: a scanning mirror that directs a laser beam at a target and receives reflected laser beam from the target; and two wedges having a high refractive index and the same amount of deflection angle. and a wedge prism section that synchronizes the prisms and rotates them in mutually opposite directions, and by scanning using the scanning mirror and the wedge prism section,
Perform high-speed scanning.

In addition, the laser radar device of the present invention synchronizes a laser transmitter that generates a laser beam and a start pulse, a mirror that reflects the laser beam, and two wedge prisms that have a high refractive index and the same amount of deviation. A wedge prism part that irradiates the target with laser light and rotates it in opposite directions, a horizontal scanning mirror that receives the reflected laser light, a condensing lens that collects the laser light, and a start pulse that emits a start pulse when the laser light is received. It has a light receiving part that generates light and a display part that displays the distance to the target, and when irradiating the target with laser light, the laser beam sent from the laser transmitting part at the same time as the start pulse is sent to the mirror, wedge prism part, and When irradiating a target through a horizontal scanning mirror and receiving reflected laser light from the target, the reflected laser beam is received by the light receiving section through the horizontal scanning mirror, the wedge prism section, and the condensing lens, and the starting point is The distance between the pulse and the stop pulse from the light receiving section is measured and displayed on the display section.

[Example] Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a device block diagram showing one embodiment of the present invention.

This device includes a laser transmitting section 1, a light receiving section 2, a condensing lens 3, a mirror 4, a wedge prism section 5, a horizontal scanning mirror 6, and a display section 7.

The laser light transmitting section 1 generates a laser beam (for example, Q-3W) and transmits it to the mirror 4, and at the same time generates a start pulse and transmits it to the display section 7.

The mirror 4 reflects the laser beam from the laser sending section 1 onto the wedge prism section.

The wedge prism section 5 synchronizes two wedge prisms 5a and 5b made of a high refractive index material and having the same amount of deviation, and rotates them in opposite directions. Also, if the amount of declination is large,
Since a glass material such as BK-7 has a large wedge angle, the wedge angle is reduced to about ⅓ by using a material with a high refractive index such as Zn5e.

The horizontal scanning mirror 6 emits a laser beam to a target 8 and receives reflected light from the target.

The condensing lens 3 condenses the light received by the horizontal scanning mirror onto the light receiving section 2 .

The light receiving section 2 receives the light collected by the condensing lens 3 and sends out a stop pulse to the display section 7.

The display section 7 counts the time between the start pulse from the laser transmitting section and the stop pulse from the light receiving section 2, converts it into distance data, and displays it as data of the current scanning position in shading or the like.

FIG. 2 shows the amount of displacement in the χ axis (horizontal direction) and the Y axis (vertical direction) during scanning using the wedge prism section and the lateral scanning mirror of the apparatus of this embodiment.

When scanning is performed, scanning as shown in FIG. 2 is performed.

When emitting a laser beam to the target 8, the laser beam generated by the laser transmitter 1 is sent to the mirror 4. Wedge prism part 5
．． Firing through the transverse scanning mirror 6. Further, the laser light transmitting section 1 transmits a start pulse to the display section 7 at the same time as the laser beam is generated.

The reflected light from the target 8 is transmitted to the lateral scanning mirror 6 wedge prism section 5. The light is received by the light receiving section 2 via the condensing lens 3. A stop pulse is then sent from the light receiving section 2 to the display section 7. The display unit 7 counts the time between the start pulse from the laser transmitting unit 1 and the stop pulse from the light receiving unit 2, converts it into distance data, and displays the data of the current scanning position on the display unit 7. etc.

[Effects of the Invention] As explained above, the present invention rotates two high refractive index wedge prisms in opposite directions in synchronization with each other and performs scanning in combination with a horizontal scanning mirror. This has the effect of allowing high-speed scanning even if the receiving effective diameter becomes large. It also has the effect of being smaller and lighter.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a device showing an embodiment of the present invention. FIG. 2 is a diagram showing an example of scanning by the apparatus of FIG. 1. 1... Laser transmitting section 2... Light receiving section 3...Condensing lens 4...Mirror 5... Wedge prism section 6... Lateral scanning mirror 7...Display section 8... Goal Agent Patent Attorney Yoshiyuki Iwa

Claims (2)

[Claims] (1) A scanning mirror that directs the laser beam to the target and receives the reflected laser beam from the target, and a wedge prism unit that synchronizes and rotates two wedge prisms with a high refractive index and the same amount of deflection in opposite directions. and a laser radar device that performs high-speed scanning by scanning using the scanning mirror and the wedge prism section. (2) Synchronize and rotate a laser transmitter that generates a laser beam and a start pulse, a mirror that reflects the laser beam, and two wedge prisms that have a high refractive index and the same amount of deflection in opposite directions. a wedge prism section, a horizontal scanning mirror that irradiates a target with laser light and receives reflected laser light from the target, and a condenser lens that collects the laser light;
It has a light receiving part that generates a stop pulse when light is received, and a display part that displays the distance to the target. When irradiating the target with laser light, the laser beam sent from the laser transmitting part at the same time as the start pulse is mirrored. , to irradiate the target through the wedge prism section and the horizontal scanning mirror, and to receive the reflected laser beam from the target, the reflected laser beam is sent to the light receiving section through the horizontal scanning mirror, the wedge prism section, and the condensing lens. A laser radar device that receives light, measures a distance from the start pulse and the stop pulse from the light receiving section, and displays the distance on a display section.