JPH0552953A - Vehicle-mounted distance-measuring device - Google Patents

Abstract

PURPOSE:To enable transmitted light power to be reduced to a level which is safe for a human body even if a light beam is cast at an operation for performing alignment, etc., of the optical axis of a device. CONSTITUTION:This device is provided with a transmission part 2 for transmitting pulse light, a light-reception part 3 which receives reflected pulse light, and a distance-detection part 4 for detecting the distance to a reflecting body according to the light-transmission pulse and the light-reception pulse. Then, a manual switching means 5 for switching an operation state manually and a power-down control means 6 for reducing the transmitted power to a level which is safe for the human body by this manual switching means 5 are provided, thus enabling the optical axis of the deice to be aligned and the safety of a worker to be secured at the time of maintenance and inspection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle-mounted distance measuring device for transmitting pulsed light, receiving reflected pulsed light reflected from a reflector and detecting the distance to the reflector.

[0002]

2. Description of the Related Art An example of a conventional distance measuring device is shown in 48
11.4 of "Laser Handbook" published by Asakura Shoten
Some are listed under Laser Radar.
FIG. 3 is a block diagram for explaining the outline of the conventional device. In the figure, 1 is an LD power supply for supplying a laser diode which is a light emitting element, 2 is a light-transmitting unit formed of a laser diode for transmitting pulsed light, 3 is a light-receiving unit for receiving reflected pulsed light from a reflector, Reference numeral 4 denotes a distance detection unit that detects the distance from the light transmission timing from the light transmission unit 2 and the light reception timing from the light reception unit 3.

Next, the operation will be described with reference to FIG. The LD power supply 1 supplies power to the laser diode of the light transmitter 2. The light transmitting unit 2 generates and transmits a light transmitting pulse for distance measurement. The sent pulsed light comes back to a reflector (not shown) and is received by the light receiving unit 3. The light-transmitting timing signal from the light-transmitting unit 2 and the light-receiving timing signal from the light-receiving unit 3 are input to the distance detecting unit 4, and the distance to the reflector is detected from the time interval between the light-transmitting pulse and the light-receiving pulse and the distance data is detected. Is output.

[0004]

The conventional distance measuring device is constructed as described above. An in-vehicle range finder that mounts such a device on a vehicle to measure a range uses a light beam with a very high output because the range is measured up to a distant place. Therefore, when the device is mounted on the vehicle and after that, when performing normal adjustments such as optical output adjustment and optical axis adjustment, it is possible that the worker will be exposed to a high-power transmission beam. There was a problem that it was very dangerous if done.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to obtain a vehicle-mounted distance measuring device in which it is not dangerous even if an operator performing an optical axis adjustment is irradiated with a light beam. It is an object.

[0006]

SUMMARY OF THE INVENTION A vehicle-mounted distance measuring device according to the present invention comprises a light transmitting means for transmitting pulsed light, a light receiving means for receiving pulsed light reflected back by a reflector, and the light transmitting means. In a vehicle-mounted distance measuring device having a distance detecting means for detecting a distance to a reflector based on a light pulse and a light receiving pulse, a manual switching means for manually switching the operating state,
This manual switching means is provided with power down control means for reducing the transmitted light power to a level safe for the human body.

[0007]

Since the on-vehicle distance measuring device according to the present invention is provided with the power down control means for reducing the traveling power to a safe level for the human body by the manual switching means, the manual switching means facilitates the operation such as the optical axis adjustment. It is possible to output a safe level of transmitted light power.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numerals 1 to 4 are the same parts as in the conventional example shown in FIG. 5 is a manual switching means for manually switching the operating state, and 6 is this manual switching means 5
Is a power down control means for reducing the light transmission power to a level safe for the human body.

Next, the operation will be described. The LD power supply 1 supplies power to the laser diode of the light transmitter 2. The light transmitting unit 2 generates and transmits a light transmitting pulse for distance measurement.
The transmission of such a light transmission pulse is normally performed during light transmission. The transmitted pulsed light comes back to the reflector and is received by the light receiving unit 3. The light-transmitting timing signal from the light-transmitting unit 2 and the light-receiving timing signal from the light-receiving unit 3 are input to the distance detecting unit 4, and the distance to the reflector is detected from the time interval between the light-transmitting pulse and the light-receiving pulse and the distance data is detected. Is output. The above is the function of the normal operation during traveling. On the other hand, the operator performs the manual switching means 5 when the device is mounted on the vehicle and when the optical axis is adjusted during maintenance and inspection thereafter. The power down control means 6 detects that the state of the manual switching means 5 has been switched, and performs control such that the voltage of the LD power supply 1 is reduced so that the output is at a safe level for the human body. in this case,
The light transmission beam is not emitted when the manual switching means 5 is not operated.

The manual switching means 5 may be switched, for example, by connecting or disconnecting a connector, or may be turned on or off by a switch.

As the power down control means 6,
In FIG. 1, the voltage of the LD power supply 1 supplied to the laser diode is reduced, but a variable optical attenuator may be placed in front of the laser diode to reduce the light transmittance.

FIG. 2 shows an example in which the light receiving means 3 is also controlled when the safe light transmission power output is controlled by the manual switching means 5, and 7 is an STC release for controlling the light receiving means 3. It is a means.

In FIG. 2, during normal operation during traveling, the sensitivity for detection is initially suppressed to a small state based on the time when the pulsed light is sent out in order to improve the distance measuring ability, and gradually the original detection sensitivity is reached. STC (Sensit)
The ive time control) function may be implemented in the light receiving means. In this way, unnecessary reflection from a short distance, for example, reflection from the road surface or reflection such as rain can be attenuated so as not to be detected. However, if the STC function is maintained, if the manual switching means 5 controls the light output power to be safe, the distance measuring ability at a short distance is deteriorated and the optical axis adjustment cannot be performed. In order to avoid the above, in this embodiment, the STC function is canceled by the STC canceling means 7 so that distance measurement necessary for work such as optical axis adjustment at a short distance can be performed even in a power-down state. is there. This does not impair the distance measuring function required for operations such as optical axis adjustment.

[0014]

As described above, according to the present invention, the manual switching means is provided so that the light transmission power can be reduced to a safe level for the human body and output, so that the optical axis adjustment, maintenance and inspection of the apparatus can be performed. There is an effect that the safety of workers can be secured at times.

[Brief description of drawings]

FIG. 1 is a block diagram of an in-vehicle distance measuring device showing an embodiment of the present invention.

FIG. 2 is a block diagram of a vehicle-mounted distance measuring device showing another embodiment of the present invention.

FIG. 3 is a block diagram of a conventional distance measuring device.

[Explanation of symbols]

 1 LD Power Supply 2 Light Transmitter 3 Light Receiver 4 Distance Detector 5 Manual Switching Means 6 Power Down Control Means 7 STC Release Means

[Procedure amendment]

[Submission date] May 15, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

Next, the operation will be described. The LD power supply 1 supplies power to the laser diode of the light transmitter 2. The light transmitting unit 2 generates and transmits a light transmitting pulse for distance measurement.
The transmission of such a light-transmitting pulse is performed during normal traveling . The transmitted pulsed light comes back to the reflector and is received by the light receiving unit 3. The light-transmitting timing signal from the light-transmitting unit 2 and the light-receiving timing signal from the light-receiving unit 3 are input to the distance detecting unit 4, and the distance to the reflector is detected from the time interval between the light-transmitting pulse and the light-receiving pulse and the distance data is detected. Is output. The above is the function of the normal operation during traveling. On the other hand, the operator performs the manual switching means 5 when the device is mounted on the vehicle and when the optical axis is adjusted during maintenance and inspection thereafter. The power down control means 6 detects that the state of the manual switching means 5 has been switched, and performs control such that the voltage of the LD power supply 1 is reduced so that the output is at a safe level for the human body. in this case,
The light transmission beam is not emitted when the manual switching means 5 is not operated.

Claims (2)

[Claims] 1. A sending means for sending pulsed light, and a light receiving means for receiving the pulsed light reflected by the reflector and returned,
In a vehicle-mounted distance measuring device equipped with a distance detecting means for detecting a distance to a reflector based on the light-transmitting pulse and the light-receiving pulse, a manual switching means for manually switching the operating state and a light-transmitting power by the manual switching means. An in-vehicle distance measuring device comprising a power-down control means for reducing the level to a level that is safe for the human body. 2. When the power down control means for reducing the light transmission power to a level safe for the human body is performed by the manual switching means for manually switching the operating state, the light receiving means gradually increases with reference to the time when the pulsed light is transmitted. 2. The vehicle-mounted distance measuring device according to claim 1, wherein the means for increasing the sensitivity from the smaller one is not provided.