Abstract:
Die Erfindung betrifft einen elektrooptischen Entfernungsmesser, insbesondere Laser-Distanzmesser, mit einer Sendeeinheit zur Aussendung von intensitätsmodulierter optischer Strahlung, einer Empfangseinheit zum Empfang eines von einem Zielobjekt zurückgeworfenen Anteils der optischen Strahlung durch ein photosensitives elektrisches Bauelement und Umwandlung in ein elektrisches Empfangssignal, einem Eingangsfilter zur Filterung des Empfangssignals, einem Analog-Digital-Wandler zur Digitalisierung des gefilterten Empfangssignals und einer elektronischen Auswerteeinheit, welche auf Basis einer Signallaufzeit anhand des digitalisierten Empfangssignals eine Distanz vom Entfernungsmesser zum Zielobjekt ermittelt. Das Eingangsfilter ist eine zeitdiskret und wertkontinuierlich implementierte, insbesondere digitale, Filterstruktur.
Abstract:
Es wird ein Laserscanner (10) zur Erfassung und Abstandsbestimmung von Objekten in einem Überwachungsbereich (20) mit einem Lichtsender (12) zum Aussenden eines Sendelichtstrahls (16) mit einer Vielzahl aufeinanderfolgender Einzellichtpulse, einer drehbaren Ablenkeinheit (18) zur periodischen Ablenkung des Sendelichtstrahls (16) in den Überwachungsbereich (20), einer Winkelmesseinheit (30) zur Erzeugung von Winkelpositionssignalen (62) in Abhängigkeit von einer Winkelstellung der Ablenkeinheit (18), einem Lichtempfänger (26) zum Erzeugen von Empfangssignalen aus dem von Objekten in dem Überwachungsbereich (20) remittierten oder reflektierten Sendelicht (22), einem Histogrammspeicher (32a, 32b) mit einer Vielzahl von Speicherplätzen, in denen jeweils ein Abschnitt eines Empfangssignals aufakkumulierbar ist, und mit einer Auswertungseinheit (32) angegeben, welche dafür ausgebildet ist, in einem dem Histogrammspeicher (32a, 32b) entnommenen Histogramm (110) einen zu einem Objekt gehörigen Empfangspuls zu identifizieren und daraus mittels eines Lichtlaufzeitverfahrens den Abstand des Objekts zu bestimmen, wobei das Histogramm (110) über ein Zeitintervall gesammelt ist, das einem Winkelpositionssignal (62) zugeordnet ist. Dabei sind mindestens zwei Histogrammspeicher (32a, 32b) vorgesehen, um ein erstes Histogramm und ein zweites Histogramm in überlappenden Zeitintervallen zu sammeln.
Abstract:
Measurements on a sheet (12), for example measurement of the movement of the sheet in a printer, can be performed by directing a measuring beam (8) towards the sheet and utilizing the effects of self-mixing in a diode laser (2) and Doppler shift in the measuring beam caused by the movement. The measuring method and a dedicated, cheap and compact, sheet sensor (1) may be used for determining different parameters and in different sheet processing apparatus.
Abstract:
The present invention relates to a pulsed coherent laser radar system comprising a single-frequency transmitter laser (1) which generates laser pulses. The laser pulses pass a beam splitter (2) which splits the energy of the pulses and conducts a first part to the output unit (12, 13) of the system for transmitting laser radar pulses. A second part is conducted to a first optical fibre (4) and further to an input of a first fibre-optic coupler (5), which connects part of the energy of each pulse to a fibre-optic ring, which comprises a second fibre-optic coupler (6). An output (A3) of the second coupler conducts part of the energy of each pulse remaining in the fibre-optic ring while a second output (A4) discharges pulses in a pulse train with a pulse frequency dependent on the time of a pulse passing round in the fibre-optic ring. The pulse train is combined in a detection device with return pulses from targets, frequency information about the return pulses being recovered.
Abstract:
This invention is a device and method for the measurement of optical path length. A frequency chirped electromagnetic wave source, such as a laser beam, is split into two branches. A reference branch is projected directly onto a photosensor, while a probe branch is launched towards a target whose distance relative to the reference path is to be determined. A reflected wave from the target is collected and mixed with the reference onto a photosensor. Due to the unequal path lengths traveled by the reference and the reflected probe laser beams as well as the chirped nature of their frequencies, a certain optical frequency difference exists between the two beams. This frequency difference is linearly proportional to the relative optical path length difference between the two laser beams and the relative optical path length can be readily determined by using a photosensor that generates photocurrents linearly proportional to the relative optical frequency differences between the reference and reflected branches.
Abstract:
Characteristics of a target are measured by a radar or sonar. Pulses (101, 102, 103) are transmitted and in between (X) the transmissions of pulses a signal is received which depends on the transmitted pulses and on the distribution of the characteristics measured at different ranges. The distribution at different ranges of the characteristics measured is determined by representing it by means of a substantially linear system of equations in which the variables are the values of the characteristics measured at desired ranges, and by solving the system of equations for the variables. The transmitted pulses form a cyclically repeated pulse code or a continuously changing pulse train.
Abstract:
A LiDAR apparatus, including: a laser to generate an optical signal; modulation components configured to receive the optical signal as an input and to output at least two corresponding modulated optical signals at respective output ports, wherein each modulated optical signal is modulated by a corresponding pseudo-random bit sequence, and: (i) the optical signals have respective different delays such that the modulations do not overlap in time; or (ii) the pseudo-random bit sequences have low cross-correlation; for each of the at least two modulated optical signals, a corresponding optical transmitter configured to transmit the corresponding modulated optical signal towards a corresponding surface spaced from the LiDAR apparatus by a corresponding distance, and a corresponding optical receiver configured to receive a portion of the transmitted optical signal scattered and/or reflected by the surface, the received portion of the optical signal having a phase shift and/or Doppler shifted angular frequency due to radial motion of the LiDAR apparatus relative to the surface; at least one photodetector to receive the optical signals received by the optical receivers, interfered with a reference beam, and to generate a corresponding output signal; at least one analogue to digital converter to generate a digital signal representing the output signal from the at least one photodetector; and a digital signal processing component configured to process the digital signal to generate LiDAR data representing the distances to the surfaces and/or relative velocities of the surface(s) with respect to the apparatus.
Abstract:
발명의 실시 예에 개시된 표면발광 레이저소자는 복수의 제1에미터가 배열된 제1영역; 복수의 제2에미터가 배열된 제2영역을 포함하며, 상기 제2영역의 면적은 상기 제1영역의 면적보다 작으며, 상기 제2영역은 상기 제1영역의 센터 영역에 배치되며, 상기 제1에미터와 상기 제2에미터는 별도로 구동될 수 있다.