Abstract: The invention relates to a method for detecting particles, having the steps of: receiving (S1) a measurement signal; calculating (S2) at least one estimated noise value using the received measurement signal; and detecting (S3) the particles using the measurement signal on the basis of at least one detection criterion, wherein the at least one detection criterion depends on the at least one calculated estimated noise value.

Abstract: The invention relates to a method for determining the absolute value of the flow velocity (v) of a particle-transporting medium. At least two measurement laser beams (L_i) with linearly independent, non-orthogonal measurement directions (b_i) are emitted. The measurement laser beams (L_i) scattered at particles are detected and one measurement signal (m_i) is generated in each case for each measurement laser beam (L_i).

Abstract: The invention relates to an optical lens (10) for a photodiode-equipped device, which is arrangeable at and/or in the photodiode-equipped device in such a way that light beams (14) emitted by at least two photodiodes of the photodiode-equipped device transmit into the optical lens (10) through a light entrance side (S1) of the optical lens (10) and emerge from the optical lens (10) at a light exit side (S2) of the optical lens (10), and for which a central longitudinal axis (16) extending centrally through the light entrance side (S1) and centrally through the light exit side (S2) is definable, wherein the light entrance side (S1) of the optical lens (10) and the light exit side (S2) of the optical lens (10) are embodied in each case as a freeform surface for off-axis projection in such a way that the light beams (14) emitted by the photodiodes (32) arranged on a circular path around the central longitudinal axis (16) are focused off-axis by means of the optical lens (10).

Abstract: A method reduces false-positive particle counts detected by an interference particle sensor module, which has a laser and a light detector. The method including: emitting laser light; providing a high-frequency signal during the emission of the laser light, a modulation frequency of the high-frequency signal being between 10-500 MHz; detecting an optical response by the light detector in reaction to the emitted laser light while providing the high-frequency signal, which is arranged such that a detection signal caused by a macroscopic object positioned between a first and second distance is reduced in comparison to a detection signal caused by the macroscopic object at the same position without providing the high-frequency signal. The high-frequency signal is provided to a tuning structure of the particle sensor module which is arranged to modify a resonance frequency of an optical resonator comprised by the laser sensor module upon reception of the high-frequency signal.

Abstract: An optical particle sensor device comprises an optical emitter device for emitting a multitude of measurement laser beams; a detector device for detecting the measurement laser beams scattered on particles in the vicinity of the optical particle sensor device and for generating a single measuring signal assigned to this for each measurement laser beam; and an evaluation device for determining at least one estimated particle value for the number of particles per volume using at least one single measurement signal, wherein the evaluation device determines at least two estimated particle values for the number of particles per volume, which are based on at least partially different single measurement signals and/or a different number of single measurement signals, and on the basis of at least part of the estimated particle values, determines at least one output value for the particle load.

Abstract: A system for determining a particle contamination and a method for determining a particle contamination in a measurement environment is provided in which individual particles in the measurement environment are detected (S1), wherein a) an estimate of the number of particles per volume in the measurement environment is ascertained (S2), b) an estimate of the number of particles per volume and characterization information describing the particle source in the measurement information are taken as a basis for ascertaining an output value for the particle contamination in the measurement environment (S3), and c) context-related data are made available and the characterization information is estimated on the basis of the available context-related data (S4).

Abstract: The invention relates to a method for determining the absolute value of the flow velocity (v) of a particle-transporting medium. At least two measurement laser beams (L_i) with linearly independent, non-orthogonal measurement directions (b_i) are emitted. The measurement laser beams (L_i) scattered at particles are detected and one measurement signal (m_i) is generated in each case for each measurement laser beam (L_i).

Abstract: The invention relates to a method for detecting particles, having the steps of: receiving (S1) a measurement signal; calculating (S2) at least one estimated noise value using the received measurement signal; and detecting (S3) the particles using the measurement signal on the basis of at least one detection criterion, wherein the at least one detection criterion depends on the at least one calculated estimated noise value.

Abstract: A system for determining a particle contamination and a method for determining a particle contamination in a measurement environment, is provided in which individual particles in the measurement environment are detected (S1), wherein a) an estimate of the number of particles per volume in the measurement environment is ascertained (S2), b) an estimate of the number of particles per volume and characterization information describing the particle source in the measurement information are taken as a basis for ascertaining an output value for the particle contamination in the measurement environment (S3), and c) context-related data are made available and the characterization information is estimated on the basis of the available context-related data (S4).

Abstract: The invention relates to an optical particle sensor device (1), comprising an optical emitter device (2), which is designed to emit a multitude N of measurement laser beams (Li) into a vicinity of the optical particle sensor device (1); a detector device (3), which is designed to detect the measurement laser beams (Li) scattered on particles in the vicinity of the optical particle sensor device (1) and to generate to generate a single measuring signal (Ei) assigned to this for each measurement laser beam (Li); and an evaluation device (4), which is designed to determine at least one estimated particle value for the number of particles per volume using at least one single measurement signal (Ei).

Abstract: The invention relates to an optical lens (10) for a photodiode-equipped device, which is arrangeable at and/or in the photodiode-equipped device in such a way that light beams (14) emitted by at least two photodiodes of the photodiode-equipped device transmit into the optical lens (10) through a light entrance side (S1) of the optical lens (10) and emerge from the optical lens (10) at a light exit side (S2) of the optical lens (10), and for which a central longitudinal axis (16) extending centrally through the light entrance side (S1) and centrally through the light exit side (S2) is definable, wherein the light entrance side (S1) of the optical lens (10) and the light exit side (S2) of the optical lens (10) are embodied in each case as a freeform surface for off-axis projection in such a way that the light beams (14) emitted by the photodiodes (32) arranged on a circular path around the central longitudinal axis (16) are focused off-axis by means of the optical lens (10).

Abstract: A particle sensor apparatus having an optical emitter device that is configured to emit an optical radiation so that a volume having at least one particle possibly present therein is at least partly illuminatable; an optical detector device having at least one detection surface that is struck by at least a portion of the optical radiation scattered at the at least one particle, at least one information signal regarding an intensity and/or an intensity distribution of the optical radiation striking the at least one detection surface being outputtable; and an evaluation device with which an information item regarding a presence of particles, a number of particles, a particle density, and/or at least one property of particles is identifiable and outputtable, the particle sensor apparatus also encompassing at least one lens element that is disposed so that the emitted optical radiation is focusable onto a focus region inside the volume.

Abstract: A particle sensor apparatus having an optical emitter device that is configured to emit an optical radiation so that a volume having at least one particle possibly present therein is at least partly illuminatable; an optical detector device having at least one detection surface that is struck by at least a portion of the optical radiation scattered at the at least one particle, at least one information signal regarding an intensity and/or an intensity distribution of the optical radiation striking the at least one detection surface being outputtable; and an evaluation device with which an information item regarding a presence of particles, a number of particles, a particle density, and/or at least one property of particles is identifiable and outputtable, the particle sensor apparatus also encompassing at least one lens element that is disposed so that the emitted optical radiation is focusable onto a focus region inside the volume.

Abstract: The invention relates to a velocity determination apparatus for determining a relative velocity between a first object (12), to which the velocity determination apparatus is attachable, and a second object (1). The velocity determination apparatus comprises a laser (3) having a laser cavity (4) for emitting first radiation (5), which is reflected by the second object (1), wherein the reflected radiation interferes with the first radiation (5) within the laser cavity (4). An interference signal detector (7) detects an interference signal depending on the interference within the laser cavity (4) and a velocity determination unit (8) determines the relative velocity based on the interference signal. A reliability value determination unit (9) determines a reliability value for indicating the reliability of the determined relative velocity based on at least one of the group consisting of the detected interference signal, the determined relative velocity and a characteristic of the laser.

Abstract: The invention relates to a velocity determination apparatus for determining a relative velocity between a first object (12), to which the velocity determination apparatus is attachable, and a second object (1). The velocity determination apparatus comprises a laser (3) having a laser cavity (4) for emitting first radiation (5), which is reflected by the second object (1), wherein the reflected radiation interferes with the first radiation (5) within the laser cavity (4). An interference signal detector (7) detects an interference signal depending on the interference within the laser cavity (4) and a velocity determination unit (8) determines the relative velocity based on the interference signal. A reliability value determination unit (9) determines a reliability value for indicating the reliability of the determined relative velocity based on at least one of the group consisting of the detected interference signal, the determined relative velocity and a characteristic of the laser.

Abstract: The present invention relates to an optical scanning device for reading and/or writing on a plurality of tracks on an optical storage medium (1), said scanning device comprising optical means (17) for focusing a plurality of beams, after being reflected from said medium, onto an observation plane (22), and for introducing astigmatism into at least one of said reflected beams, and a photo-detector (18) comprising a plurality of detector segments, arranged in said observation plane (22) to receive said at least one astigmatic reflected beam.

Abstract: A method for controlling an optical disc drive apparatus (1) which comprises: light beam generating means (31) for generating a plurality of N optical beams (32(i)); means (33, 34, 37) for focusing said beams in respective focus spots (F(i)); at least one adjustable member (34) for axially displacing said focus spots; comprises the step of calculating an optimum setting (ZOPTIMUM) for the adjustable member (34), such that the out-of-focus condition for the optical system (30) as a whole is as small as possible. The position of the adjustable member (34) may be controlled to be substantially equal to the said optimum setting (ZOPTIMUM). Or, one specific beam is maintained in a focus condition, the beam having number m=mOPT selected according to mOPT=±INTEGERSQUARE{(N?1)/(2?2)} in case N is odd or mOPT=±INTEGERROUND IN?(N?2)/8) in case N is even.

Abstract: Thus, in conventional, one-dimensional optical storage, the data is arranged in a linear fashion and is read out by a single spot (102). In order to increase data rates and storage capacity, it has been proposed to arrange the data in an isotropic, hexagonal lattice (200) and employ multiple spots (202) for read-out. Due to the high bit-intensity, 2D inter symbol interference (ISI) has a significant effect on bit detection. Aberrations in the readout spots (202) can change the form of ISI and, therefore, hamper 2D bit detection. Thus, a method and apparatus is proposed, wherein by evaluating the ISI of the readout spots (202) by scanning over a known calibration pattern, i.e. a bit pattern selected such that its optical response is characteristic of the shape of the readout spot, the aberrations in the readout spot can be determined and beneficially compensated for, as required.

Abstract: The present invention relates to an optical reader for a two dimensional storage disc, comprising means (21, 22, 14, 15) for generating a plurality of laser beams and projecting said beams onto a rotating disc, means (24, 25, 26) for detecting the beams after being diffracted by the disc, and means (24, 27, 28) for determining a focus error signal (29) based on one of said plurality of beams. The plurality of beams comprises an array of beams having a first polarization, and a dedicated central focus tracking beam having a second polarization, orthogonal to the first polarization. The beams may be generated by a polarization dependent diffraction element. Or a beam having one polarization may be diffracted into a plurality of beams and recombined with a beam having another polarization.

Abstract: A pick-up unit, an optical drive comprising such a pick-up unit, and a method of generating error-signals are described. Light reflected from an information carrier is injected into one or more VCSELs. The spatial intensity distribution of the emission from the VCSEL(s) is used for the generation of error signals in an optical pick-up unit. Alternatively, the relative timing for the switching of individual lasers of an array of VCSELs is used for the detection of error signals.