摘要:
A demodulating system (100) for demodulating a phase-modulated input signal (Si) comprises: a complex demodulator (110), having a first input (111) for receiving the phase-modulated input signal (Si) and being designed to perform complex multiplication of this signal with an approximation of the inverse of the phase modulation; a spectrum analyzing device (130) receiving the demodulated product signal produced by the complex demodulator (110) and capable of analyzing the frequency spectrum of the demodulated product signal.
摘要:
A demodulating system (100) for demodulating a phase-modulated input signal (Si) comprises: a complex demodulator (110), having a first input (111) for receiving the phase-modulated input signal (Si) and being designed to perform complex multiplication of this signal with an approximation of the inverse of the phase modulation; a spectrum analyzing device (130) receiving the demodulated product signal produced by the complex demodulator (110) and capable of analyzing the frequency spectrum of the demodulated product signal.
摘要:
A method and optical module for measuring relative movement of an input device and object (15) along at least one measuring axis. A laser device (3) having a laser cavity is provided for generating a measuring beam (13) in respect of each measuring axis. The measuring beam (13) is used to illuminate the object (15) and measuring beam radiation reflected from the object (15) and re-entering the laser cavity generates a self-mixing effect in the laser and causes changes in operation of the laser cavity. A detector (4) is used to generate a measurement signal representative of these changes and an electronic processing circuit (18) selects, in dependence on the speed of relative movement, one of at least two parameters of the measurement signal for use in determining the speed and direction of relative a movement.
摘要:
An optical input device for measuring relative movement between an object (15) and a sensor unit comprising a laser device (3, 5) having a laser cavity for emitting a measuring beam (13, 17) and a respective radiation-sensitive detector (4, 6) for generating a measurement signal representative of changes in the operation of the laser device (3, 5) as a result of measuring beam radiation re-entering the laser cavity. A sensor unit is provided for measuring relative movement along each measuring axis in an action plane, and the resultant measurement signal from one or each of the sensor units is used to determine distance and/or movement of the input device and the object (15) relative to each other along a measuring axis transverse to the action plane by summing the offset frequency of a rising and falling slope of the measurement signal.
摘要:
A method and optical module for measuring relative movement of an input device and object (15) along at least one measuring axis. A laser device (3) having a laser cavity is provided for generating a measuring beam (13) in respect of each measuring axis. The measuring beam (13) is used to illuminate the object (15) and measuring beam radiation reflected from the object (15) and re-entering the laser cavity generates a self-mixing effect in the laser and causes changes in operation of the laser cavity. A detector (4) is used to generate a measurement signal representative of these changes and an electronic processing circuit (18) selects, in dependence on the speed of relative movement, one of at least two parameters of the measurement signal for use in determining the speed and direction of relative movement.
摘要:
An optical input device for measuring relative movement between an object (15) and a sensor unit comprising a laser device (3, 5) having a laser cavity for emitting a measuring beam (13, 17) and a respective radiation-sensitive detector (4, 6) for generating a measurement signal representative of changes in the operation of the laser device (3, 5) as a result of measuring beam radiation re-entering the laser cavity. A sensor unit is provided for measuring relative movement along each measuring axis in an action plane, and the resultant measurement signal from one or each of the sensor units is used to determine distance and/or movement of the input device and the object (15) relative to each other along a measuring axis transverse to the action plane by summing the offset frequency of a rising and falling slope of the measurement signal.
摘要:
A controller for controlling the power of a laser that is used in determining the motion of an object includes a power source that is arranged to supply power pulses to the laser in response to a controller signal. The controller controls the generation of pulses during periods in which a reliable result can be obtained, by detecting the laser radiation that has interacted with pulses reflected from the object, in order to conserve power consumption. Further the power pulses include a heating pulse portion, which serves to stabilize the temperature of the laser and calibrate the laser so that a known lasing wavelength is generated.
摘要:
A controller (7) is disclosed for controlling the power supply to a laser (3) that is used in determining the motion of an object (8). The controller comprises a power source (2) that is arranged to supply power pulses (10, 11) to the laser (3) in response to a controller signal. The controller (7) controls the generation of pulses to those periods in which a reliable result can be obtained, by detecting the laser radiation that has interacted with pulses reflected from the object (8), in order to conserve power consumption. Further the power pulses (10, 11) comprise a heating component (9), which serves to stabilize the temperature of the laser (3) and therefore calibrate the laser (3) so that a known lasing wavelength is generated.
摘要:
The invention relates to a method of encoding user data into codevectors and to a corresponding method of decoding codevectors into user data. In order to be able to use the same ECC decoder for decoding of more than one type of data a method of encoding is proposed comprising the steps of: generating a first block of a fixed first number of data symbols by taking a fixed second number, being smaller than said first number, of user data symbols, and a fixed third number of dummy data symbols, and by arranging said user data symbols and said dummy data symbols in a predetermined order, encoding said first block of data symbols using an ECC encoder (2) to obtain a codeword having a fixed number of symbols, said codeword comprising said first block of data symbols and a second block of a fixed forth number of parity symbols, and generating a codevector by selecting a fifth predetermined number of user data symbols and a sixth predetermined number of parity symbols from said codeword, the sum of said fifth and sixth number being predetermined and smaller than the sum of said second and forth number.
摘要:
An information carrier for holding user information includes access information for accessing the user information, the access information being stored in a pre-determined first region on the information carrier. The information carrier further includes at least one further region different from the first region, the further region comprising dummy information.