Abstract: An optical scanning device includes a radiation source; an optical lens system with an optical axis for focusing a radiation beam supplied, in operation, by the radiation source into a scanning spot on an information carrier, the lens system including a housing, a first lens which is secured in the housing in a fixed position, and a second lens which, viewed in a direction parallel to the optical axis, is elastically suspended in the housing; a first actuator for displacing the lens system in a direction parallel to the optical axis; a first control unit for controlling the first actuator by means of a first control signal; a second actuator for displacing the second lens relative to the first lens in a direction parallel to the optical axis; and a second control unit for controlling the second actuator by means of a second control signal, and in which during operation, the first control unit also controls the second actuator by means of a third control signal which is proportional to the first control signal

Abstract: An optical disk drive for reading and/or writing information from/on an optical disk includes an auxiliary lens to compensate for optical aberrations and a servo loop for positioning the auxiliary lens relative to a main lens. The servo loop includes an actuator for driving the auxiliary lens and a controller to feed the actuator coil with a drive current dependent on a position signal which is derived from the actual inductance of the actuator coil and a reference signal which indicates a desired position of the scan element. The disk drive also includes an inductance influencing device to vary the inductance of the actuator coil as a function of the position of the scan element.

Abstract: An optical scanning device for scanning an optically readable record carrier (1) includes a radiation source (5), a radiation-sensitive detection system (7), and an optical scanning unit for focusing a scanning beam (3) produced by the radiation source to a scanning spot (9) on the record carrier. The scanning unit including a lens system having an optical axis (13), which lens system includes a first lens unit having a main lens (15) and a second lens unit having an auxiliary lens (17). The scanning device further includes a first detection unit involved in detection of the main lens with respect to the record carrier, and a second detection unit involved in detection of the auxiliary lens.

Abstract: A scanning device for an optical disc record carrier includes a turntable and a positioning device which is movable relative to the turntable in a plane transverse to the axis of rotation thereof. The positioning device includes a radiation source unit and an actuator unit having a carrier which supports several different objective lenses and which is movable parallel to the access of rotation. The scanning device further includes actuating apparatus for moving the actuator unit and the radiation source unit relative to one another between discrete operating positions in at least the plane transverse to the axis of rotation, so as to place a respective lens in position for scanning a respective one of several different types of optical discs having mutually different substrate thicknesses and/or information densities.

Abstract: An optical unit for optically scanning a surface, particularly an information surface of a recording medium. The unit may include a frame, a radiation source unit, a rotatable mirror unit, and an objective system for forming a scanning spot on the information surface. The objective system has an entrance pupil and an optical axis. From an optical point of view, the rotatable mirror unit is situated between the radiation source unit and the objective system, suspension means being provided for movably supporting the objective system relative to the frame. The suspension means allow a longitudinal movement of the objective system along the optical axis and a pivotal movement of the objective system about a pivot which coincides with the point of intersection of the optical axis and the entrance pupil. Actuating means drive the objective system in accordance with these movements. Alternatively, the optical unit may include an optical beam deflection unit.

Abstract: A device for electromagnetically scanning information tracks on a record carrier, such as an optical tape, via a scanning beam is described. On this tape, information tracks are arranged substantially parallel and substantially transverse to a transport direction of the record carrier. The device is provided with a scanning unit for scanning, with the beam always following parallel scanning paths, and a control system for controlling an angle of the scanning paths with respect to the transport direction, dependent on a tilt signal. According to the invention, the device is provided with angle-measuring means for generating the tilt signal dependent on a tracking error signal which is indicative of a difference between a scanning path and the relevant information track. In addition to a tilt signal, a speed signal may also be derived from the tracking error signal. Both the tilt signal and the speed signal are derived from the tracking error signal in a captured and in a non-captured state of operation.

Abstract: An optical apparatus for scanning a tape-shaped record carrier, which apparatus uses a mirror polygon for scanning tracks extending perpendicularly to the tape travel direction. Since at least one facet, or a part thereof, of the mirror polygon extends at a different angle to the axis of rotation, the scanning spot is periodically moved transversely to the track direction, so that a tracking signal can be generated.

Abstract: An optical scanning device is described, which is provided with a scanning element having a reflecting measuring reference face (31), and a position detection system (80) which supplies, inter alia, a measuring signal (S.sub.z) for the position of the scanning element in a direction perpendicular to the reference face. By implementing the scanning element in a very thin form and by correcting said measuring signal (S) by means of the polygon bending signal (S.sub.b) supplied by the position detection system, a very rapid and accurate scanning can be realized.

Abstract: An electron-beam-pumped laser includes a cathode ray tube containing a laser crystal, an electron gun for producing an electron beam including a multi-element focusing electrode layer on an inner surface of the tube for effecting focusing of the beam on the laser crystal, and a multi-element deflection electrode layer on an inner surface of the tube for effecting scanning of the beam across the laser crystal. The laser crystal is disposed on a metal heat-conductive support which is adapted for accurately positioning the laser crystal in closely spaced relationship with respect to the electron gun and to a laser light emitting window of the tube.

Abstract: A position detection system (80) is described for detecting movements of an object (20) in at least five degrees of freedom, which system comprises a radiation source (33), a beam splitter (36) for forming a first measuring sub-beam (45) and a second measuring sub-beam (50), a reflector (38) arranged in the path of one of these measuring beams (45, 50) and a composite radiation-sensitive detection system (60). The first measuring sub-beam (45) is used for detecting displacements along three mutually perpendicular axes (X, Y, Z), and the second measuring sub-beam (50) is used for detecting rotations about at least two of these axes.

Abstract: A tape-like record carrier (109) is disclosed which comprises paths (A, B). Each path (A, B) contains substantially parallel tracks (1) the path width (1s) in length and the direction of the tracks is transverse to the longitudinal direction of the path (A, B). The diameters (10) of the paths have various directions. The ends of the paths (1) are overlapping. In these overlapping areas the tracks (1) belonging to the various paths are positioned in interlineated manner. Said record carrier (109) is advantageous in that no time is lost during recording or reading when a path is changed. Furthermore, a recording and reading device is disclosed which are applicable in combination with the record carrier.

Abstract: An optical unit (1) is provided for optically scanning a surface, particularly an information surface of a recording medium (9). The unit comprises a frame (13), a radiation source unit (15), a rotatable mirror unit (17), and an objective system (19) for forming a scanning spot on the information surface, which objective system has an entrance pupil (19b) and an optical axis (19a). From an optical point of view, the rotatable mirror unit is situated between the radiation source unit and the objective system, suspension means being provided for movably supporting the objective system relative to the frame. The suspension means allow a longitudinal movement of the objective system along the optical axis and a pivotal movement of the objective system about a pivot which coincides with the point of intersection of the optical axis and the entrance pupil. Actuating means drive the objective system in accordance with these movements.

Abstract: A scanning device for repeatedly scanning a scanning surface of a record carrier (e.g., a tape) by means of a first and a second scanning spot produced by respective scanning beams. The scanning spots perform synchronous movements along a first and a second scanning path, respectively, having different given scanning directions, as a result of which, the distance, viewed in a direction transverse to the scanning paths, between the first and the second scanning spot changes during scanning. The scanning device can be used in a recording and/or read apparatus which further includes a detection system for converting radiation emanating from the second scanning spot into a corresponding detection signal, and a measurement circuit which derives a position measurement signal indicative of deviation of track pitch based on a deviation in a relationship between the detection signal and a reference signal indicative of the position of the first scanning spot on the first scanning path.

Abstract: An optical scanner for a disc placed on a turntable, having a scanning device mounted on a slide which is movable radially with respect to the turntable. The slide includes a body made of two thin plates which are parallel to each other and the direction of movement. The plates have patterns of raised portions which face each other. The plates are fixed to each other at locations where the raised portions contact each other.

Abstract: An optical scanning device for realizing in a recording layer of an optical tape a longitudinal path (i.e. pattern) of substantially parallel tracks. The device includes an optical system for focusing a radiation beam at the recording layer, which radiation beam causes a scanning spot to develop on the recording layer. The tracks are formed by the optical tape being cyclically scanned, through use of a polygon mirror, via the scanning spot and displaced relative to the optical system in a direction transverse to the scanning direction. The device further includes an optoelectrical measuring unit for deriving a measuring signal indicative of the track pitch of the successively produced tracks. The velocity of the displacement of the optical tape is controlled as a function of the measuring signal.

Abstract: A scanning device comprises a stationary section (1) with a frame (3) and a section (5) which is movable along a first axis (Z) and a second axis (X) oriented transversely of the first axis and which comprises a lens (7) having an optical axis (7a) parallel to the first axis. The scanning device comprises a focusing coil (13) for moving the lens along the first axis and two mutually parallel pairs of tracking coils (15a, 15b; 17a, 17b) for moving the lens along the second axis. The tracking coils of each pair are disposed along a line (19; 21) parallel to the second axis and have coil axes (23a, 23b; 25a, 25b) oriented transversely of a plane defined by the first axis and the second axis. Pairs of magnet poles (27a, 2b; 29a, 29b) are arranged at opposite sides of the lens, the magnet poles being spaced apart and being situated between two bounding planes (31; 33) oriented transversely of the second axis.

Abstract: An optical scanning device for scanning a tape-like record carrier. The device includes an optical system for focusing a radiation beam at the record carrier, which radiation beam causes a scanning spot to occur on the record carrier. The device also includes a rotary polygon mirror which causes the scanning spot to be displaced transversely to the direction of the tape with a specific repetition rate. The tape-like record carrier is moved with a certain velocity in the longitudinal direction of the tape relative to the scanning device. In this manner, the record carrier is scanned in accordance with a track pattern formed by a longitudinal path of substantially parallel tracks which have a substantially constant track pitch and a track direction transverse to the longitudinal direction of the record carrier. During operation, vibrations occur which cause displacements to occur of the scanning spot over the recording layer transverse to the scanning direction.

Abstract: A scanning device carried on a slide has a section which is movable relative to the slide in the direction of slide movement and in a focusing direction transverse to that direction. An actuator controls both directions of relative movement during normal scanning. To permit free movement in the focusing direction without friction during periods of high acceleration or deceleration of the slide, a mechanical stop limits the relative movement in the direction of slide movement. To prevent friction from impeding focusing movement, the stop is compliant in the focusing direction.

Abstract: An electron-optical display device includes a cathode ray tube having a cylindrical neck of very small external diameter, such as .ltoreq.15 mm, the inner surface of the neck having thereon a helical multi-element layer electrode formed of a high ohmic resistance material, which electrode constitutes a focusing lens. In combination with a deflection system of correspondingly small diameter and operating at high scanning frequencies, this makes it possible to use a very small scanning spot of high luminance and without requiring excessive deflection energy. The device may be used as a television image projection tube or as an electron beam pumped scanning laser.

Abstract: An optical-strength element, elongated in a direction transverse to the radiation beam at the location where the beam impinges on the element, directs the portion of the beam entering the objective system in a direction parallel to the entry axis of the objective system. A scanning element causes the radiation beam to scan along the length of the element as the objective system is moved along its stroke, thereby moving the focussed spot of the beam along the surface to be optically scanned.