Abstract: A lithographic device comprising a mask table (5), a projection system (3), a substrate table (1) which is displaceable relative to the projection system (3) by means of a drive unit (21), and a measuring system (39) for measuring a position of the substrate table (1) relative to the projection system (3). A stationary part (157) of the drive unit (21) is fastened to a machine frame (85) of the lithographic device, while a stationary part (51, 53, 55) of the measuring system (39) is fastened to a reference frame (89) of the lithographic device which is dynamically isolated from the machine frame (85) by means of dynamic isolators (95). This prevents vibrations caused in the machine frame (85) by reaction forces of the drive unit (21) from being transmitted to the reference frame (89), so that the accuracy of the measuring system (39) is not adversely affected by such vibrations.

Abstract: A positioning device with a drive unit with which an object table is displaceable over a guide which is fastened to a first frame thereof. A stationary part of the drive unit is fastened to a second frame thereof and dynamically isolated from the first frame while a reaction force of the object table arising from a driving force exerted by the drive unit on the object table is transmittable exclusively into the second frame.

Abstract: A magnetic-tape player has a drive arrangement for winding a tape between two reel hubs. The drive arrangement can drive both reel hubs with different transmission ratios by a motor and four transmission devices. The drive arrangement is controlled entirely by a cam disc capable of counterclockwise rotation.

Abstract: A device for measuring the angular velocity of a rotating object (35) is described, which device comprises a first disc (23) moving with the object and having a rotationally symmetrical pattern of interruptions (24), and a second disc (29) having a similar pattern and a detector (34) which receives radiation passed by the patterns and converts it into an electric measuring signal. The device is very accurate, reliable and compact. The linear velocity of an elongated object, for example a recording tape, can also be measured with the device.

Abstract: A positioning device includes a table (5, 69), which is displaceable in two coordinate directions (X, Y) by means of Lorentz forces of electric linear motors over a base (3) and is guided over the base (3) by means of a static gas bearing, which has an air gap thickness independent of the coil systems and magnet systems (15-21, 37-43) in the motors. The positioning device is particularly suitable for the manufacture of masks with patterns for integrated circuits.

Abstract: A linear motor comprising first and second motor sections which are movable relative to one another along a motor axis. The first motor section includes a coil support carrying a coil system and the second motor section includes a magnet support carrying at least one pair of magnets which, at least when viewed along the motor axis, are spaced at a distance from one another to form a gap and which are arranged to cooperate with the system of coils across an air gap. The system of coils of the first motor section comprises a set of three coils arranged in line viewed along the motor axis, i.e. two peripheral coils and one central coil. The central coil has a coil length at least substantially equal to said distance between the pair of magnets of the second motor section. The central coil is disposed at least substantially completely opposite the gap between the magnets in a neutral position of the motor sections relative to each other.

Abstract: An optical lithographic device having a machine frame (1) to which is fastened a lens system (11) having a vertical optical main axis (13). Below the lens system (11), a positioning device (35) is fastened on a support member (3) of the machine frame (1), by means of which device an object table (27) is displaceable relative to the lens system (11) over a guide surface (5) of the support member (3) extending perpendicular to the optical main axis (13).The device is provided with a force actuator system (67) fastened to a reference frame (83) and controlled by a feedforward control system (95). The force actuator system (67) exerts a compensatory force on the support member (3) with a direction opposite to a direction of a reaction force simultaneously exerted by the positioning device (35) on the support member (3), and with a value which is substantially equal to a value of the said reaction force.

Abstract: A positioning device includes a table (101, 213) guided by a carriage (15, 199), the carriage (15, 199) being displaceable in two coordinate directions (X, Y) with respect to the base (3) and the table (101, 213) being displaceable with respect to the carriage (15, 199) in the same coordinate directions (X, Y) solely by Lorentz forces, while in a third coordinate direction (Z) the position of the table (101, 213) is determined by a static gas bearing. The two-step positioning device is particularly suitable for use in opto-lithographic devices.

Abstract: A scanning unit for an optical disc record carrier includes a radiation-sensitive detection system having a plurality of detection elements on which is formed a reflected image of the scanning spot on the track structure of the record carrier. A tracking error signal is derived by combining the output signals of detection elements situated on respective sides of a boundary line between two halves of the detection system, and comparing with each other the combined signals from both halves. Several different such tracking error signals are derived, for boundary lines having different orietations with respect to the direction of the track instantaneously being scanned. The tracking error signal corresponding to a boundary line most nearly parallel to the direction of such track will be of greatest amplitude, and is selected as the tracking error signal used for controlling the scanning unit to follow the center line of such track.

Abstract: A positioning device with a drive unit with which an object table is displaceable over a guide which is fastened to a first frame thereof. A stationary part of the drive unit is fastened to a second frame thereof and dynamically isolated from the first frame while a reaction force of the object table arising from a driving force exerted by the drive unit on the object table is transmittable exclusively into the second frame.