Abstract: The invention relates to a lighting device for generating output illumination having at least one directional characteristic. The lighting device includes at least one light-emitting device and at least one optical element disposed in an optical path of the light-emitting device. The lighting device also includes a screen-like member for changing at least one physical property of light passing therethrough and an optical device for generating an intermediate image on the screen-like member. The screen-like member and the optical device are located in the optical path between the light-emitting device and the optical element projecting the intermediate image.

Abstract: The invention relates to a lighting device (1) comprising at least one light-emitting device (3) and at least one optical element (7) in an optical path (15) of the light-emitting device (3) for generating output illumination having at least one directional characteristic. The lighting device according to the invention further comprises a screen-like member (5) for changing at least one physical property of light passing through it and an optical device (4) for generating an intermediate image (9) on the screen-like member (5), both located in the optical path (15) between the light-emitting device (3) and the optical element (7), wherein the optical element (7) is an optical element (12) for projecting said image (9). The invention further relates to a corresponding method of generating output illumination having a plurality of directional characteristics.

Abstract: A method and device for recording information signals on a partly recorded writable record carrier (11), e.g., an optical disc. An information signal represents at least one information unit. The record carrier has a recording track which includes preformed track position information indicative of locations for recording the information units. From the information signal, a modulated signal is generated having successive frames, each frame including a synchronizing signal. The modulated signal is recorded at a one of the locations, while maintaining a fixed relationship between the track position information and the synchronizing signals. In the event that the location is after and adjacent to an already recorded location, the recording is started at a link position (31) before the end of a last frame of the earlier recorded information signal, at a predefined distance before a first synchronizing signal (30) of the modulated signal.

Abstract: A method and device for recording information signals on a partly recorded writable record carrier (11), e.g., an optical disc. An information signal represents at least one information unit. The record carrier has a recording track which includes pre-formed track position information indicative of locations for recording the information units. From the information signal, a modulated signal is generated having successive frames, each frame including a synchronizing signal. The modulated signal is recorded at a one of the locations, while maintaining a fixed relationship between the track position information and the synchronizing signals. In the event that the location is after and adjacent to an already recorded location, the recording is started at a link position (31) before the end of a last frame of the earlier recorded information signal, at a predefined distance before a first synchronizing signal (30) of the modulated signal.

Abstract: A record carrier (1) is described comprising a servo track (4) indicating an information track (9) intended for recording information blocks represented by marks having lengths expressed in channel bits, which servo track (4) has a periodic variation of a physical parameter. The periodic variation is modulated for encoding record carrier information, such as addresses. The modulation is a bi-phase modulation in which a data bit of the record carrier information is encoded by a first predetermined number of variations of a first phase followed by the same number of variations of a second phase inverse to the first phase. A recording and/or playback device has a demodulator for retrieving data bits of the record carrier information from a first predetermined number of variations of a first phase followed by the same number of variations of a second phase inverse to the first phase.

Abstract: A record carrier (1) is described comprising a servo track (4) indicating an information track (9) intended for recording information blocks represented by marks having lengths expressed in channel bits, which servo track (4) has a periodic variation of a physical parameter. The periodic variation is modulated for encoding record carrier information, such as addresses. The modulation is a bi-phase modulation in which a data bit of the record carrier information is encoded by a first predetermined number of variations of a first phase followed by the same number of variations of a second phase inverse to the first phase. A recording and/or playback device has a demodulator for retrieving data bits of the record carrier information from a first predetermined number of variations of a first phase followed by the same number of variations of a second phase inverse to the first phase.

Abstract: A method and device for recording information signals on a partly recorded writable record carrier (11), e.g. an optical disc. An information signal represents at least one information unit. The record carrier has a recording track which comprises preformed track position information indicative of locations for recording the information units. From the information signal a modulated signal is generated having successive frames, each frame including a synchronizing signal. The modulated signal is recorded at a one of said locations, while maintaining a fixed relationship between the track position information and the synchronizing signals. In the event that the location is after and adjacent to an already recorded location, the recording is started at a link position (31) before the end of a last frame of the earlier recorded information signal at a predefined distance before a first synchronizing signal (30) of the modulated signal.

Abstract: A method and device for recording information signals on a partly recorded writable record carrier (11), e.g. an optical disc. An information signal represents at least one information unit. The record carrier has a recording track which comprises preformed track position information indicative of locations for recording the information units. From the information signal a modulated signal is generated having successive frames, each frame including a synchronizing signal. The modulated signal is recorded at a one of said locations, while maintaining a fixed relationship between the track position information and the synchronizing signals. In the event that the location is after and adjacent to an already recorded location, the recording is started at a link position (31) before the end of a last frame of the earlier recorded information signal at a predefined distance before a first synchronizing signal (30) of the modulated signal.

Abstract: A record carrier (1) is described comprising a servo track (4) indicating an information track (9) intended for recording information blocks represented by marks having lengths expressed in channel bits, which servo track (4) has a periodic variation of a physical parameter. The periodic variation is modulated for encoding record carrier information, such as addresses. The modulation is a bi-phase modulation in which a data bit of the record carrier information is encoded by a first predetermined number of variations of a first phase followed by the same number of variations of a second phase inverse to the first phase. A recording and/or playback device has a demodulator for retrieving data bits of the record carrier information from a first predetermined number of variations of a first phase followed by the same number of variations of a second phase inverse to the first phase.

Abstract: A record carrier is described comprising a servo track indicating an information track intended for recording information blocks represented by marks having lengths expressed in channel bits, which servo track has a periodic variation of a physical parameter. The periodic variation is modulated for encoding record carrier information, such as addresses. The modulation is a bi-phase modulation in which a data bit of the record carrier information is encoded by a first predetermined number of variations of a first phase followed by the same number of variations of a second phase inverse to the first phase. A recording and/or playback device has a demodulator for retrieving data bits of the record carrier information from a first predetermined number of variations of a first phase followed by the same number of variations of a second phase inverse to the first phase.

Abstract: An optical record carrier (1) is provided with tracks having a groove (4) wobbled in a radial direction and predetermined positions (18) along the track. Embossed pits (19) at the predetermined positions represent addressing information. The phase of the wobble near the predetermined positions depends on whether a pit is present (19) on a predetermined position or not (20).

Abstract: An optical disk has tracks with a groove wobbled in a radial direction and addressing information at predetermined positions along the track. Embossed pits at the predetermined positions represent addressing information. The phase of the wobble near the predetermined positions depends on whether a pit is present on a predetermined position or not.

Abstract: An optical record carrier has parallel tracks for recording user information in a pattern of optically detectable marks, the tracks being provided with control information. The tracks are grouped in pairs of neighboring tracks. The control information in both tracks of a pair is identical and the control information in tracks of different pairs is different. The identity of the control information reduces the effect of crosstalk on neighboring tracks.

Abstract: A drive of a display device based on polymer LEDs, for example pixels arranged in the form of a matrix, in which the lifetime is increased by writing the information from an interlaced signal each time into two successive rows. The driving may be based on voltage control at which voltages across the pixels define the picture to be displayed, but may alternatively be based on current control.

Abstract: The invention relates to a radiation source unit for supplying shortwave optical radiation, and to a method of assembling such a unit. The radiation source unit comprises a diode laser and a waveguide of a non-linear optical material for converting the diode laser radiation into radiation having a smaller wavelength. The diode laser is provided in a bush having a first end and a second, open end. The second end is adapted to accommodate a first holder in which a lens system is arranged for imaging the exit plane of the diode laser on the entrance plane of the waveguide. At a side of the first holder remote from the diode laser a second holder is secured in which the waveguide is arranged. Said holders are aligned and fixed with respect to each other in such a way that the chief ray of the diode laser beam, the optical axis of the lens system and the axis of the waveguide are in alignment, and that the diode laser beam is focused on the entrance aperture of the waveguide.

Abstract: Device (1) for raising the frequency of electromagnetic radiation. The device (1) comprises a diode laser (3) for generating the radiation, and a non-linear optical medium (11) in which a first optical waveguide (9) is arranged for guiding a fundamental wave of the diode laser radiation while forming a higher harmonic wave. Moreover, the device (1) comprises a wavelength stabilizer (5) for stabilizing the wavelength of the fundamental wave. The wavelength stabilizer (5) is constituted by a second optical waveguide (13) with a refractive index grating extending in its longitudinal direction and whose selection wavelength is electrically controllable by means of an electrode structure (15; 29).

Abstract: A II-VI semiconductor diode laser has a strained layer disposed on top of the structure. This strained layer, having a thickness of between about 0.05 microns and 2 microns, is either a single film or a stack of films, preferably of metal. The strain field produced by this layer in the semiconductor layer structure produces a change in the refractive index of the structure, due to the photo-elastic effect. By virtue of this effect a strain-induced waveguide is provided in the diode laser, with a strained layer in an edge, stripe or window structure. Furthermore, a tensely-strained layer covering the entire structure is used to produce a strain field similar to that which occurs when the structure is bent. This strain field will produce strain-enhanced gain in the underlying structure, which allows for operation of the laser at a lower threshold current.

Abstract: A doubler for a pulsed multimode laser diode. A controllable feedback loop controls the laser output such that one of the output wavelengths, or the average of two of them, fall within the acceptance bandwidth of a non-linear optical medium. Alternatively, radiation emitted from the pulsed laser is reflected over a path length such that reflected energy reenters the laser during the build-up of a following pulse.

Abstract: A blue-green II/VI semiconductor injection laser utilizing a Zn.sub.1-u Cd.sub.u Se active layer (quantum well) having Zn.sub.1-x Mg.sub.x S.sub.y Se.sub.1-y cladding layers and ZnS.sub.z Se.sub.1-z guiding layers on a GaAs substrate. These devices are operable in a pulse mode at room temperature.

Abstract: An optical device (7) for use in optical write, read, inspection or measuring apparatuses comprising a diode laser (8) for generating a radiation beam (11) and an optical system (9) for concentrating and guiding the radiation beam. The diode laser is a pulsed laser and a feedback element is arranged in the radiation path at a specific distance (d) from the diode laser. By giving the element a suitable reflection coefficient, a stabilized radiation beam is obtained. The beam direction can be varied by rendering the wavelength adjustable and by making use of a dispersive element.