| Patent application number | Description | Published |
|---|
| 20080304398 | Optical Head That Improves Read Signal Characteristics - In an optical head operable to record to and read from an optical recording medium, a beam emitted by a light-emitting element is reflected toward the light-emitting element by a first reflective mirror, and this reflected beam is reflected toward the optical recording medium by a second reflective mirror and focused on a recording surface of the optical recording medium. In this case, the first reflective mirror blocks a principal ray of the beam traveling toward the optical recording medium from the second reflective mirror, and the second reflective mirror consists of a plurality of concentric annular mirrors centered on the principal ray of the beam and separated from each other by a predetermined interval. | 12-11-2008 |
| 20090034394 | Optical Pickup - An optical pickup device in which a hologram element has a plurality of different diffraction directions. In the tracking standard state, the hologram element is divided into six areas by a straight line connecting two strength center points of two light beams, and by two straight lines that are perpendicular to the straight line. By adding the amount of light received by an area demarcated by two straight lines that pass the two strength center points, to the amount of light received by one of two outer areas sandwiching the area depending on the type of the light beam, it is possible to obtain a well-balanced tracking error signal for each of the two light beams. | 02-05-2009 |
| 20090168626 | OPTICAL PICKUP DEVICE AND PHOTODETECTOR - An optical pickup device includes: a first light-receiving element for receiving a main beam of a first light beam; second and third light-receiving elements for receiving sub-beams of the first light beam; a fourth light-receiving element for receiving a main beam of a second light beam; and fifth and sixth light-receiving elements for receiving sub-beams of the second light beam. The first through third light-receiving elements are located on a first line with the first light-receiving element sandwiched between the second and third light-receiving elements. The fourth through sixth light-receiving elements are located on a second line with the fourth light-receiving element sandwiched between the fifth and sixth light-receiving elements. The first line and the second line are parallel to each other. | 07-02-2009 |
| 20100014411 | OPTICAL PICKUP DEVICE - A pickup device includes a diffraction grating | 01-21-2010 |
| 20100157778 | OPTICAL PICKUP DEVICE - An optical pickup device includes a diffraction grating | 06-24-2010 |
| 20100177618 | OPTICAL PICKUP DEVICE - An optical pickup device includes a diffraction grating | 07-15-2010 |
| 20100238780 | OPTICAL PICKUP DEVICE - A pickup device includes a diffraction grating | 09-23-2010 |
