Abstract: A lithographic apparatus has an illumination system that conditions a beam of radiation. A patterning support supports a patterning device, which serves to impart the beam of radiation with a pattern in its cross-section. A substrate support holds a substrate. A projection system projects the patterned beam of radiation onto a target portion of the substrate. A particle detection system detects a particle on a surface of an object. The particle detection system has a radiation source, which generates an illumination beam of radiation. The illumination beam of radiation is directed along a first optical path to a detection area at the surface of the object. A radiation detector receives a detection beam of radiation from the detection area along a second optical path. The length of the first optical path is made substantially equal to the length of the second optical path.

Abstract: The present invention relates to an analysis apparatus, in particular a spectroscopic analysis apparatus, for analyzing an object, such as blood of a patient, and a corresponding analysis method. To aim the confocal detection volume inside a blood vessel orthogonal polarized spectral imaging (OPSI) is used to locate blood capillaries in the skin. An imaging system (img) with slightly shifted imaging planes (i1, i2) for OPS imaging of blood vessels is proposed to provide auto-focusing. The confocal Raman detection plane (dp) is located in between these two imaging planes (i1, i2). Based on measured amount of defocus for the imaging planes (i1, i2), the focusing of the imaging system (img), the excitation system (exs) for exciting the target region and the detection plane (dp) is located inside the blood vessel (V). Thus, continuous auto-focusing with high accuracy can be achieved. The invention relates also to an optical tracking system for continuously tracking a point of a moving object (obj).

Abstract: The focus of an optical system (20) can be determined in a reliable and accurate way by arranging a first and second test object (62,64) having a periodic structure at different sides of the focal plane (66) of the optical system and determining the difference in modulation depth of the images formed on different areas (32,34) of a radiation-sensitive detection system (30).

Abstract: To enable differentiation between a particle and a ghost particle, a detector system is presented. The detector system is configured to output at least two detector signals corresponding to an intensity of radiation being incident on the detector system. If radiation is received from a ghost particle, not all of the at least two detector signals has a level above a predetermined threshold level, whereas radiation received from a contaminating particle results in all signals having a level above a threshold level. Thus, it may be determined with a high accuracy whether a particle or a ghost particle is redirecting radiation towards the detector system.

Abstract: A lithographic apparatus has an illumination system that conditions a beam of radiation. A patterning support supports a patterning device, which serves to impart the beam of radiation with a pattern in its cross-section. A substrate support holds a substrate. A projection system projects the patterned beam of radiation onto a target portion of the substrate. A particle detection system detects a particle on a surface of an object. The particle detection system has a radiation source, which generates an illumination beam of radiation. The illumination beam of radiation is directed along a first optical path to a detection area at the surface of the object. A radiation detector receives a detection beam of radiation from the detection area along a second optical path. The length of the first optical path is made substantially equal to the length of the second optical path.

Abstract: To enable differentiation between a particle and a ghost particle, a detector system resolves radiation from a ghost particle from radiation from an actual particle. The detector system outputs at least two detector signals corresponding to intensities of radiation being incident on different parts of the detector system or the detector system outputs at least two detector signals corresponding to intensities of radiation with different wavelengths being incident on the detector system. If radiation is received from a ghost particle, not each of the at least two detector signals has a level above a predetermined threshold level, whereas radiation received from a particle results in the signals having substantially a same level above a threshold level.

Abstract: A projection device comprises a matrix (1) of semiconductor lasers, an optical system (2) for projecting the matrix (1) on an element (3) illuminated by the projection device, and a control device (9) for controlling the semiconductor lasers through a feedback device. The feedback device comprises a first detector (13, 14) that generates a first signal representing the detected intensity. The semiconductor lasers are controlled and the intensity of the light spot is adjusted to a desired value by the feedback device. Light from a semiconductor laser is detected by a second detector (18), and a value of the detected signal is stored in an addressable memory cell. The amount of emitted light is stabilized for each semiconductor laser by detection through the second detector (18) and comparison with the value stored in the memory (29) for the relevant controlled semiconductor laser.

Abstract: A projection device comprises a matrix (1) of semiconductor lasers, an optical system (2) for projecting the matrix (1) on an element (3) illuminated by the projection device, and a control device (9) for controlling the semiconductor lasers through a feedback device. The feedback device comprises a first detector (13, 14) for detecting the intensity of a light spot from a semiconductor laser on the illuminated element (3). The first detector (13, 14) generates a first signal representing the detected intensity. In a first adjusting phase, the semiconductor lasers are controlled and the intensity of the light spot is adjusted to a desired value by means of the feedback device. Simultaneously, light originating from a semiconductor laser controlled during the first adjusting phase is detected by a second detector (18), and a value of the detected signal is stored in an addressable memory cell. In this way, the first adjusting phase comprises filling of memory cells for each controllable semiconductor laser.

Abstract: An apparatus is described for reading a flat record carrier on which information is stored in an optically readable track-shaped information structure. By the arrangement in the far field of the information structure and at one side of a plane which is formed by the optical axis of an objective system which is used for reading and a line parallel to the center line of the track portion to be read, of a radiation-sensitive detection system which consists of at least two detectors in approximately the position .beta./2, .beta. being the angle at which a first-order beam is diffracted in the lateral direction of the tracks, centering and focussing errors can be detected without the use of auxiliary beams and additional optical elements.

Abstract: An apparatus is described for reading a record carrier on which information is stored in an optically readable reflecting structure. By projecting two radiation spots one before and one behind the plane of the information structure, it is possible to ascertain whether a read beam is properly focussed on the information structure.

Abstract: An apparatus for reading disc-shaped information carriers which are provided with substantially circular tracks, in which information is stored in coded form, in particular picture information, which information carriers are disposed on a turntable, a read unit supplying a control signal to a control device for maintaining the reading speed constant.The control device comprises at least two mass elements which are connected to the turntable symmetrically relative to the axis of rotation of the turntable, resiliently in the radial direction and rigidly in the tangential direction, which elements are radially movable in response to the control signal.In one control device each element consists of an axially magnetized rod-shaped permanent magnet, which is attached to the turntable by at least one radially flexible leaf spring, a coil being disposed around each magnet, which coil is connected to the control signal.