Patent application number | Description | Published |
20100135144 | OPTICAL PICKUP DEVICE AND LENS FOR OPTICAL PICKUP - An optical pickup device according to the present invention comprises: a first mirror for reflecting a first light beam outputted from a first light source and letting a second light beam outputted from a second light source pass therethrough; a first object lens for converging the first light beam reflected by the first mirror on an information recording surface of a recording medium; a second mirror for reflecting the second light beam passing through the first mirror; a second object lens for converging the second light beam reflected by the second mirror on the information recording surface of the recording medium; and an achromatic lens for correcting an axial chromatic aberration of the second object lens generated by wavelength variation of the second light beam, wherein the achromatic lens is provided in an optical path between the first mirror and the second mirror. | 06-03-2010 |
20110002117 | OPTICAL DISC DRIVE - An optical disc drive includes: at least one light source; an objective lens configured to focus the light that has been emitted from the at least one light source; a chromatic aberration compensation element, which is arranged on an optical path between the at least one light source and the objective lens in order to compensate for chromatic aberration that has been produced by the objective lens; and an actuator configured to change a position of the objective lens. The actuator changes the position of the objective lens in a tracking direction by a magnitude of an offset, which is determined by a variation in wavelength of the light to be produced when the power of the light emitted from the at least one light source changes. | 01-06-2011 |
20110002216 | OPTICAL PICKUP DEVICE AND OPTICAL DISC DEVICE - Regarding optical pickup devices usable for performing recording on and reproduction from a plurality of types of optical discs, there is a problem that because of the structure of locating many optical elements in a height direction of an optical system, the height of the optical system is increased and so it is difficult to realize a thin and compact optical pickup device. According to the present invention, a first wave plate is located between a first light source and a first mirror, a second wave plate is located between a second light source and a second mirror, and the first wave plate and the second wave plate cause a desirable phase shift to light beams of the first through third wavelengths. Owing to this, the number of optical elements located in the height direction of the optical system can be decreased, and so the height of the optical system can be reduced. | 01-06-2011 |
20110276989 | OPTICAL PICKUP DEVICE AND OPTICAL DISC DRIVE - Has an object of providing an optical pickup capable of realizing tracking control or focus control at a higher level of precision even when relative positions of a light source and a light detector are shifted due to a change in the environmental temperature, long-term deterioration or the like. The optical pickup includes a base member; a light source, fixed to the base member, for emitting a laser beam; an objective lens for collecting the laser beam onto an optical disc; a light detector, fixed to the base member, for detecting the laser beam reflected by the optical disc; fixing means for fixing the light source and/or the light detector to the base member; and a light blocking section for blocking a central portion of the laser beam in a circular shape on an optical path between the collimator lens and the light detector. | 11-10-2011 |
20110317729 | CURRENT DRIVING DEVICE - A current driving device comprises; a three-terminal regulator configuration circuit operative as a three-terminal regulator which drops a voltage of a first electric power supply to a predetermined target output voltage in a state where a main terminal and a control terminal of a power transistor are connected to a main terminal connection terminal and a control terminal connection terminal, respectively; a voltage setting circuit which sets a control voltage corresponding to a target output voltage which is applied from the three-terminal regulator configuration circuit to the control terminal of the power transistor; and a voltage restricting circuit which is connected to the control terminal connection terminal and controls the control voltage applied to the control terminal of the power transistor so that the output voltage of the three-terminal regulator configuration circuit becomes a predetermined voltage or less, upon being supplied with the electric power from the first electric power supply. | 12-29-2011 |
20120155237 | Optical Information Record/Playback Device - An optical information record/playback device of the present invention includes: a light source; a current driver for supplying current to the light source; an optical system for condensing light from the light source onto a recording medium; a monitoring section for monitoring light emission power of the light source; a current driver control section for controlling output current of the current driver; and an arithmetic/control section for controlling an operation of the current driver control section. Before recording information, the arithmetic/control section sequentially conducts a first test light-emission to cause the light source to emit light by using a closed loop circuit and a second test light-emission to cause the light source to emit light by using an open loop circuit, and compares first and second sampling values, which are respectively obtained by sampling the outputs of the monitoring section during the first and second test light-emissions. | 06-21-2012 |
20120287766 | OPTICAL PICKUP DEVICE AND OPTICAL DISC DEVICE - When performing recording/reproduction of information for a given recording layer of an optical disc having three recording layers, influences of reflected light from other recording layers are reduced or removed, thus making it possible to obtain a more stable RF signal or focus error signal. | 11-15-2012 |
20130077456 | OPTICAL PICKUP AND OPTICAL READ/WRITE APPARATUS - In one embodiment, an optical pickup includes an optical system which forms multiple light beams based on the light emitted from a light source and which converges a write beam and a read beam, thereby forming a main spot and a sub-spot, respectively, on an optical storage medium. This optical system converges the write and read beams onto the optical storage medium so that the main spot moves through the same region on the optical storage medium ahead of the sub-spot. The optical pickup further includes a detector for sensing the write and read beams reflected from the storage medium. The detector includes a first photodiode | 03-28-2013 |
20130083640 | OPTICAL READ/WRITE APPARATUS - Disclosed is an improved DRAW technique for writing data on an optical storage medium and reading the data in parallel. In obtaining the optical power of a first light source | 04-04-2013 |