Patent application number | Description | Published |
20080219119 | Optical pickup and optical disc unit - Provided is an optical pickup which can eliminate a problem of causing a focus error signal and a tracking error signal to fluctuate due to interference of a signal light beam with a return light beam from another recording surface of a multi-layer optical disc during reproduction, | 09-11-2008 |
20090129217 | OPTICAL INFORMATION RECORDING APPARATUS - A rewritable optical disk apparatus, optical information recording and reproducing apparatus or the like is allowed to automatically and properly adjust the optical system to the optimum focal condition regardless of the readout signal detector's positional error and the residual aberration in the optical system. The spherical aberration and defocus are coarsely adjusted using the amplitude (PP amplitude) of the tracking error signal and then finely adjusted using the amplitude (RF amplitude) of the readout signal. Since the spherical aberration can properly be adjusted, it is possible to raise the reliability of the readout signal. | 05-21-2009 |
20100034071 | DIFFRACTION GRATING, OPTICAL PICKUP AND OPTICAL DISC DEVICE - Undesired disturbance components leak eventually into various detection signals and reproduction signals as stray optical beams reflected from recording layers other than a reproduction layer overlap with signal beams on a light reception surface of an optical detector and interference occurs between them when an optical disc having multi-layered recording layers is reproduced. A diffraction grating having a specific grating groove pattern is arranged immediately ahead of an optical detector or in a return optical path. Such optical unit averages the disturbance components resulting from interference between a signal beam and a stray beam and can satisfactorily improve influences of leak. | 02-11-2010 |
20100124153 | OPTICAL PICKUP AND OPTICAL INFORMATION REPRODUCING DEVICE - An optical pickup and an optical information recording and reproducing device in which spherical aberration correction control after a disc is loaded can be efficiently made in a short time. Before an information recording medium is loaded into a drive, an optical axis direction position of a concave lens is preset to a state so as to optimize a converging spot on a recording surface of a single-layered medium of as a first recording medium or a predetermined layer (first layer having a substrate thickness of 0.1 mm) of a medium having two or more layers to which the recording/reproduction is executed by a laser light source. After the information recording medium is loaded, if it is determined to be a second (third) recording medium to which the recording/reproduction is executed by a laser light source, setting of the optical axis direction position of the concave lens is changed. | 05-20-2010 |
20100124161 | OPTICAL PICKUP AND OPTICAL INFORMATION REPRODUCING DEVICE - An optical pickup and an optical information recording and reproducing device in which spherical aberration correction control after a disc is loaded can be efficiently made in a short time. Before an information recording medium is loaded into a drive, an optical axis direction position of a concave lens is preset to a state so as to optimize a converging spot on a recording surface of a single-layered medium of as a first recording medium or a predetermined layer (first layer having a substrate thickness of 0.1 mm) of a medium having two or more layers to which the recording/reproduction is executed by a laser light source. After the information recording medium is loaded, if it is determined to be a second (third) recording medium to which the recording/reproduction is executed by a laser light source, setting of the optical axis direction position of the concave lens is changed. | 05-20-2010 |
20100148045 | PHOTODETECTOR, DIFFRACTION GRATING, OPTICAL PICKUP AND OPTICAL DISC APPARATUS - The present invention provides a photodetector capable of generating highly accurate tracking and focusing error signals free of variations in light quantity caused by interference, in an optical pickup with a two-wavelength multilaser. The photodetector comprises first three light receiving areas arranged linearly to receive three light beams respectively resulting from splitting of a light beam emitted from a laser light source of a first wavelength and second three light receiving areas arranged linearly to receive three light beams respectively resulting from splitting of a light beam emitted from a laser light source of a second wavelength longer than the first wavelength. The distance between both-end light receiving areas out of the first three light receiving areas is longer than the distance between both-end light receiving areas out of the second three light receiving areas. | 06-17-2010 |
20100226229 | OPTICAL PICKUP DEVICE - In a multilayer disc has an increased number of recording layers) spaced by spacing from each other, a generation interval between focus error (FE) signals detected from the respective recording layers becomes small. This causes mutual interference between the FE signals and a resulting undesired offset and the like in the signals, leading to a significantly deteriorated quality of the FE signals. To avoid this, in an optical pickup device according to the present invention, detection surfaces are newly added at positions adjacent to the FE signal detection surfaces, a predetermined detection signal obtained from the newly-added detection surfaces is multiplied by a predetermined coefficient value depending on the spacing between the recording layers, and the multiplied signal is subtracted from the original FE signal. As a result, mutual interference between the FE signals can be remarkably reduced. | 09-09-2010 |
20100322047 | OPTICAL PICKUP AND OPTICAL DISC APPARATUS - When recording/reproducing an optical disc having a recording layer of multi-layer structure, an unwanted optical beam reflected from a recording layer other than a target layer for recording/reproduction is incident on a photodetector to cause an unwanted disturbance component to leak to a detection signal, giving rise to a degradation in the quality of a tracking control signal. In an optical pickup apparatus, for suppression of the degradation, an optical element is mounted having a diffraction area for diffracting part of the optical beam and light receiving planes for sub-optical beams are provided each of which has a light shielding zone or dead zone of a predetermined width on its central sectioning line. | 12-23-2010 |
20120127846 | OPTICAL INFORMATION DEVICE AND INTERLAYER MOVEMENT METHOD IN OPTICAL INFORMATION DEVICE - Provided is a method of, in movement between recording layers of an optical disc, resolving a problem caused by an increase in spherical aberration change as a result of widening of a layer interval at which the movement is made and executing appropriate interlayer movement. An upper limit value is defined for a recording layer interval at which the interlayer movement can be made, and if a layer interval from a moving-source layer to a moving-target layer is equal to or larger than the upper limit value, the interlayer movement and spherical aberration correction are once carried out where a predetermined recording layer for which a layer interval is less than the upper limit value is defined as a temporary shelter layer, and the processing is repeated with this temporary shelter layer defined as a new moving-source recording layer to thereby realize favorable interlayer movement to the target layer. | 05-24-2012 |
20120230172 | OPTICAL INFORMATION MEDIUM, OPTICAL INFORMATION RECORDING/REPRODUCING APPARATUS, AND OPTICAL INFORMATION RECORDING/REPRODUCING METHOD - In the related art, writing of BCA data has been performed by a BCA cutter or the like after a user data area was formed. However, according to such a method, individual steps cannot help being provided for a disc manufacturing step in order to form the BCA. A burden on the disc manufacturer is large from a viewpoint of the number of disc producing steps and, further, manufacturing costs. By using a bit forming method similar to a user data area, the BCA manufacturing steps can be reduced. Specifically speaking, by devising a pit depth, a pit width, and a pit pattern, a modulation degree of a BCA portion can be further increased. A detecting method similar to that for the BCA in the related art can be applied. | 09-13-2012 |
20120275002 | SCAN TYPE IMAGE DISPLAY DEVICE - Optical beams emitted by optical sources are incident on a mirror surface of a scan mirror in a substantially vertical direction and reflected in a substantially vertical direction by the scan mirror. The mirror surface of the scan mirror is driven to repeatedly rotate two-dimensionally by a predetermined scan angle by a scan mirror drive circuit. A polarized beam splitter causes the optical beam emitted by the optical source to be incident on the scan mirror through a quarter wave plate, and outputs the optical beam that has been reflected by the scan mirror and passed through the quarter wave plate toward the screen. A scan angle expander is arranged on the output side of the polarized beam splitter, whereby the scan angle of the optical beam is increased by N times. | 11-01-2012 |
20120293775 | SCANNING TYPE PROJECTOR - A scanning type projector for scanning an optical beam emitted from a laser light source has a collimator lens and a scanning device. A beam demagnifying and shaping prism is disposed between the collimator lens and the scanning device. The cross section of the beam that is elliptical is demagnified along the major axis of the ellipse such that the cross section of the beam is shaped. Thus, the cross section of the beam fits within the effective diameter of a deflecting mirror incorporated in the scanning device. The optical beam is reflected efficiently. A bright image can be projected. The resolution is improved by the beam shaping effect. | 11-22-2012 |
20120300276 | OPTICAL BEAM SCANNING DEVICE AND IMAGE DISPLAY DEVICE USING THE SAME - In a scanning image display device including a function to project and display a two-dimensional image on a projection screen using a deflecting unit that repeatedly operates a predetermined reflecting mirror surface to two-dimensionally scan a light beam, a large image distortion inevitably occurs, which is caused by the reflecting mirror surface that repeatedly and two-dimensionally operates for deflection. In order to solve the problem, a free-form surface lens or a wedge or trapezoid prism with a predetermined refractive index and a predetermined vertical angle is disposed in an optical path between the deflecting unit and the projection screen, thereby excellently correcting image distortion that occurs when scanning a light beam. | 11-29-2012 |
20120300602 | OPTICAL INFORMATION PROCESSING DEVICE AND TRACKING CONTROL METHOD THEREOF - An optical information device used with a grooveless multilayer disc including multiple recording layers used to record and reproduce information signals and a guide layer dedicated to detect tracking error signals (TES) can always stably detect the TESs when the distance between the recording layer and guide layer varies due to selection of a target recording layer. For example, a plurality of light spots for detecting the TESs are formed by a holographic grating on the guide layer, but are defocused with respect to each other. The TESs are detected individually from the respective light spots. The TESs are subjected to an addition operation to be a signal for tracking control, thereby extraordinary increasing the defocus dynamic range of the TESs. | 11-29-2012 |
20130003022 | SCAN-TYPE IMAGE DISPLAY DEVICE AND SCAN-TYPE PROJECTION DEVICE - A polarizing prism is shaped in the form of a hexahedron. A polarizing beam splitter film (PBS film) is arranged approximately in a diagonal direction of the hexahedron. The polarizing prism holds a relationship of A | 01-03-2013 |
20130076800 | SCANNING PROJECTION APPARATUS AND SCANNING IMAGE DISPLAY - In a light beam scanning projection apparatus which scans a light beam emitted from a laser light source, an image display apparatus is configured including a plurality of light beams, a reflection mirror for reflecting the light beams to project them onto a screen or the like, and a mirror driving unit for driving the reflection mirror so that the plurality of light beams are incident on the reflection mirror with different optical axes and projected on different projection areas, thereby displaying a single image with a plurality of images. Further, by forming a single image by causing a plurality of the light beams to have predetermined relative angles thereamong so as to make a plurality of images overlap on each other with slight shifts, a scanning projection apparatus is provided with which the luminance of the image is improved while conforming to safety standards. | 03-28-2013 |