Koninklijke Philips Corporation N.v.

U.S. Philips Corporation

U.S. Phillips Corporation

Peter Coops

Derk Visser

Joris Jan Vrehen

Adrianus J Duijvestijn

Petrus Theodorus Jutte

Antonius H Holtslag

Jacobus P Heemskerk

Antonius H M Holtslag

Jacobus P J Heemskerk

Dirk C Van Eck

Mark Thomas Johnson

Bernardus Hendrikus Wilhelmus Hendriks

Cornelis Petrus Hendriks

Daan Anton Van Den Ende

Willem G Opheij

Martinus P Bierhoff

Eduard Gerard Marie Pelssers

Roland Alexander Van De Molengraaf

Ronald Reindert Drenten

Pascal Jean Henri Bloemen

Valentina Lavezzo

Joannes H Sieben

Antonius H M Akkermans

Peter De Zoeten

Andreas J Bressers

Robertus Johannes Heeman

Rene Leonardus Jacobus Marie Ubachs

Jozef P H Benschop

Martinus P M Bierhoff

An actuator or sensor device comprises an electroactive polymer (EAP) arrangement which extends between fixed opposite ends. The electroactive polymer arrangement comprises a passive carrier layer and an active electroactive polymer layer, wherein at or adjacent the ends, the passive carrier layer and the active EAP layer are mounted with one over the other in a first order, and at a middle area between the ends, the carrier layer and the active EAP layer are mounted in an opposite order. This enables internal stresses and moments within the electroactive polymer arrangement to be used more effectively to contribute to displacement or actuation force.

Actuator or sensor device based on an electroactive or photoactive polymer

The invention relates to an optical scanning device for scanning in a first mode a first information layer () of an information carrier and in a second mode a second information layer () of the information carrier. The optical scanning device comprises a radiation source () for generating a radiation beam (), an objective system () for focusing an entrance beam on an information layer and an optical element () arranged between the radiation source and the objective system, for converting said radiation beam into a diverging entrance beam in the first mode and a converging entrance beam in the second mode.

Optical scanning device

An optical information storage system has a multi-recording-layer record carrier and a scanner device for the carrier. The scanner produces a radiation beam which is compensated for spherical aberration for a single height of the scanning spot with the stack of layers. The height of the stack is determined by the maximum spherical aberration permissible for the system. The number of layers in the stack is determined by the minimum distance between layers, which depends on the crosstalk in the error signals due to currently unscanned layers.

Multi-layer information storage system with focus and radial positioning error detection

An optical device for scanning an optical record carrier () has a radiation source () that can emit two radiation beams of different wavelength along different optical paths (). The emitted radiation is focused on the record carrier and reflected back to a detection system (). A beam combineris arranged in the optical path between the radiation source and the detection system for combining the two radiation beams on one optical path, thereby allowing the use of a single detection system for both radiation beams. The beam combiner includes a grating that passes one of the beams undiffracted and diffracts the other beam mainly in the first order. The profile of the grating lines show alternating slanting grooves and slanting lands.

Optical device for scanning an optical record carrier

An optical scanning device for scanning an optical record carrier includes a radiation source and a beam splitter arranged to pass a first portion of the source beam to the record carrier, and a second portion to an intensity sensor. A signal detector is arranged in the path of the beam reflected by the record carrier. False radiation reflected by the signal detector can be prevented from reaching the intensity sensor by tilting the signal detector. A polarization filter may be arranged in front of the intensity sensor to prevent false radiation reflected by the radiation source and by the signal detector from reaching the intensity sensor.

An optical scanning device for scanning a recordable optical disk ( ) with a laser beam having a linear polarisation. A quarter wave plate ( ) is used to alter the polarisation of the beam on reflection from the disk. A partially polarising beam splitter ( ) is used and arranged such that a proportion of intensity of the incident beam passed is greater than a proportion of intensity of the reflected beam. A relatively high optical signal power at the disk ( ) can be achieved for recording purposes whilst allowing the beam splitter ( ) to be manufactured in a relatively efficient manner.

Multi-layer optical record carrier not requiring spherical aberration correction

A device for optically scanning an information plane having tracks. Radiation is supplied by a radiation source focused on the information plane by an objective system. The beam reflected by the information plane is incident on a dividing element, for example a grating which divides the beam into two halves along a dividing line. Two sub-gratings at both sides of the dividing line each form a detection beam from one half of the beam, which detection beams are detected each by a detector. A focus error signal is generated from the detector signals by forming a difference signal of the two detector signals and dividing this difference signal by the sum signal of the two detector signals. The focus error signal is relatively insensitive to the position accuracy of the detectors with respect to the detection beams.

Device for optically scanning information tracks on a plane using two subbeams

Multi-layer information storage system with improved aberration

An optical information storage system has a multi-recording layer record carrier and a scanner device for the carrier. The scanner produces a radiation beam which is compensated for spherical aberration for a single height of the scanning spot with the stack of layers. The height of the stack is determined by the maximum spherical aberration permissible for the system. The number of layers in the stack is determined by the minimum distance between layers, which depends on the crosstalk in the error signals due to currently unscanned layers.

Optoelectronic devices in which optoelectronic components comprising a diode laser are fastened on a carrier plate having good heat conduction, and in which the carrier plate is provided with connection conductors for the components which are separated from the carrier plate by an electrically insulating medium, are used inter alia in equipment for optical reading and/or writing of information carriers such as CD (audio) or CDROM. The known device is comparatively expensive, especially because of the necessity of using a special connector when a flexible connection is desired. According to the invention, the electrically insulating medium comprises a strip-shaped flexible foil which carries conductor tracks, extends over and beyond the carrier plate, is fastened on the carrier plate, and has a void above the carrier plate in which the diode laser is present. As a result, the device has a flexible connection possibility without a special connector being necessary, while in addition--as in the known device--a good alignment, listening, and heat removal of the diode laser are possible. The manufacture and modification of the device according to the invention are also simpler and cheaper. Preferably, the device comprises within the void also a photodiode and a monitor diode, while the components are screened by means of a cover which is fastened on the carrier plate and which comprises a window containing one or several optical gratings. Such a so-called LDGU (=Laser Detector Grating Unit) is particularly suitable for use in the equipment mentioned above. The invention also relates to a favourable method of manufacturing such an optoelectronic device.

Optoelectronic device and method of manufacturing same with an

An optical scanning apparatus, which includes a radiation source (7) supplying a scaning beam (b.sub.1), an objective system (8) for focusing the scanning beam (b.sub.1) to a scanning spot (S.sub.1) in an information plane (2) to be scanned, and a first diffraction element (9) for deforming the beam reflected by the informatin plane (2) in such a way that a focus-error signal can be derived therefrom. The apparatus also includes a second diffraction element (10) for forming two auxiliary beams (b.sub.2, b.sub.3) by means of which a tracking-error signal can be derived, which second diffraction element has such a size and is arranged at such position that the beams originating from the first diffraction element (9) do not traverse the second diffraction element.

Apparatus for optically scanning an information plane

Optical scanning apparatus which includes a diode laser producing a radiation beam which is focussed by a lens system on a reflecting information plane to be scanned thereby. The reflected radiation is diffracted by a composite diffraction grating which includes a pair of sub-gratings, forming respective radiation spots on respective pairs of radiation detectors. The detectors in each pair are separated by a separating strip, the separating strips being substantially parallel to or co-linear with the bonding line between the sub-gratings. Such arrangement achieves correction for wavelength variations of the radiation beam, as well as fairly wide tolerances in the relative positioning of the various optical elements of the apparatus.

Apparatus for optically scanning a radiation-reflecting information plane

Apparatus for scanning a radiation-reflective information plane (2). A scanning beam of radiation (b) from a diode laser (4) is focused by an objective lens (6) on the information plane and the beam reflected therefrom is deflected by a composite diffraction grating (9) so as to form two asymmetrical radiation spots (V.sub.1, V.sub.2) respectively focused on respective pairs of photodiodes (18, 19; 20, 21). The relative outputs of the photodiodes in each pair control focusing of the scanning beam on the information plane. The photodiodes in each pair are separated by a strip (22',23') positioned so that it is at an acute angle to the line (22, 23) along which the asymmetrical reflected radiation spot formed on the relevant diode pair becomes displaced as a result of variations in the wavelength of the scanning beam. Such angle is set so the separating strip is on the line along which the center of the intensity distribution of such radiation spot becomes displaced as a result of such variations. Consequently, such variations do not affect the relative outputs of the photodiode pairs and so are prevented from affecting focusing of the scanning beam on the information plane.

Apparatus for optically scanning a radiation-reflective information plane

An apparatus for scanning the information plane of an optical record carrier with a radiation beam from a diode laser. The reflected radiation from the information plane is separated from the scanning beam and split into two sub-beams by a composite diffraction grating which also functions to focus the respective sub-beams on respective pairs of photodetectors. The composite grating consists of two sub-gratings which adjoin along a common bounding line, the sub-gratings having varying gratings periods and curved grating strips. Movement of the composite grating in the direction of the bounding line changes the axial imaging distance of the sub-beams from the grating, permitting adjustment of such distance to compensate for changes in the axial distance between the diode laser and the photodetector. The diode laser and photodetectors can therefore be assembled together as a single integrated unit.

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Eindhoven, Netherlands

Peter Coops