초록 ▼

A laser scanner which operates pursuant to the elapsed time principle and which has a pulsed laser that directs successive light pulses into a monitored region. The laser scanner further has a light receiving arrangement for receiving light pulses reflected by an object in the monitored region and t

A laser scanner which operates pursuant to the elapsed time principle and which has a pulsed laser that directs successive light pulses into a monitored region. The laser scanner further has a light receiving arrangement for receiving light pulses reflected by an object in the monitored region and that generates electric received signals which are fed to an evaluation unit for determining a distance between the object and the laser scanner based on the elapsed time between the emission of the light pulse and the receipt of the reflected pulse and the speed of light from which a distance signal is formed that is representative of the distance between the object and the scanner. There is a light diverter unit between the pulsed laser and the monitored region which continuously directs light pulses along different directions into the monitored region. A light source is provided which emits a light measuring signal of reduced strength which is also continuously directed into the monitored region in continuously changing directions. The light receiving arrangement is configured to receive the light measuring signal reflected by the object in the monitored region and to generate a reflection signal that is representative of the reflection characteristics of the object. The light pulses and the receiving signals are changeable in dependency of the reflection signal.

대표청구항 ▼

What is claimed is: 1. A laser scanner operating on the basis of the elapsed light transmission time principle comprising a pulsed laser (13) adapted to direct successive light pulses (10) into a monitored region, a light receiving arrangement (17) for receiving light pulses (10) reflected by an ob

What is claimed is: 1. A laser scanner operating on the basis of the elapsed light transmission time principle comprising a pulsed laser (13) adapted to direct successive light pulses (10) into a monitored region, a light receiving arrangement (17) for receiving light pulses (10) reflected by an object (12) in the monitored region and directing corresponding received electric signals to an evaluation unit (16) which generates a distance signal reflecting a time difference between an emission and a receipt of the lightpulse (10) and the speed of light and which is representative of a distance between the laser scanner (1) and the object, a light diverting unit (5) arranged between the pulsed laser (13) and the monitored region which continuously changes a direction of the light pulses (10) directed into the monitored region, a light source emitting light measuring signals (9) of a reduced strength arranged so that the light diverting unit (5) also continuously changes a direction of the light measuring signals directed into the monitored region, the light receiving arrangement (17) being positioned to receive light measuring signals (9) reflected by the object in the monitored region and configured to generate a reflection signal that is representative of the reflection of the light measuring signals (9) by the object, and wherein the light pulses (10) or the received electric signals are variable in dependency of the reflection signal. 2. A laser scanner according to claim 1 including an electronic signal processor (20) coupled to the light receiving arrangement (17) for adjusting a detection sensitivity of the light receiving arrangement (17) for a light pulse (10) to be received in dependency of the reflection signal. 3. A laser scanner according to claim 1 including an avalanche photodiode (21), and wherein the light receiving arrangement (17) is adapted to adjust an amplification for the received light pulses (10) by the avalanche photodiode in dependency of the reflection signal. 4. A laser scanner according to claim 1 wherein the light measuring signals (9) have a reduced power that is substantially smaller than, and in particular is approximately 1% of, a power of the light pulses (10). 5. A laser scanner according to claim 1 wherein the light source comprises the pulsed laser (13). 6. A laser scanner according to claim 1 including a control unit (22) for the pulsed laser (13) configured to adjust an output power of the light pulses (10) in dependency of the reflection signal. 7. A laser scanner according to claim 1 wherein the light measuring signal (9) is a continuing constant light signal which overlies the light pulses (10). 8. A laser scanner according to claim 1 wherein the light receiving arrangement (17) includes a separator for separating the received light measuring signals (9) and the received light pulses (10). 9. A laser scanner according to claim 8 wherein the separator is a frequency splitter. 10. A laser scanner according to claim 7 wherein the constant light signal is a modulated signal. 11. A laser scanner according to claim 1 wherein the light measuring signal (9) is a light pulse measuring signal. 12. A laser scanner according to claim 11 wherein the light pulse measuring signal is followed by a light pulse (10) which has a temporal distance of less than 1 μs. 13. A laser scanner according to claim 11 wherein the distance signal representative of the distance between the object and the laser scanner (1) is generated on the basis of the light pulse measuring signal. 14. A laser scanner according to claim 1 including a light diverting unit (5) and wherein the light receiving arrangement (17) is configured to evaluate several successive light measuring signals (9) generated during a single rotational sensing movement of the light diverting unit. 15. A laser scanner according to claim 1 wherein a light diverting unit (5) comprises a rotatable unit, and wherein the light receiving arrangement (17) is configured to evaluate several light measuring signals (9) caused by different rotating motions of the light diverting unit and received from the monitored region along a common direction. 16. A laser scanner according to claim 1 wherein the light receiving arrangement (17) comprises a regulator, wherein the light measuring signals define an actual value that is to be compared with a predetermined desired value and that is adjustable for setting the light pulses (10) or the received signals. 17. A laser scanner according to claim 1 wherein the control unit (22) comprises a control circuit for controlling one of the pulsed laser (13) and the light source with first and second avalanche transistors (T1, T2), wherein the first transistor (T1) is provided for generating the light pulses (10) and the second transistor (T2) is provided for generating the light measuring signals (9). 18. A laser scanner according to claim 17 wherein each of the first and second transistors (T1, T2) have separate high voltage potentials (HV1, HV2) forming a voltage supply on respective collectors of an output circuit, and wherein the transistors (T1, T2) include resistors (R1, R2) and a charging capacitor (C1, C2) for generating the output power for the pulsed laser (13). 19. A laser scanner according to claim 18 wherein a collector contact of the second transistor (T2) includes a resistor (R3) and a serially connected inductivity (L2) for adapting at least one of a time constant and a dampening for an LC resonant circuit to the inductivity (L2) and the charging capacitor (C2).