Abstract: An optical pickup device has a semiconductor laser emitting light which is in turn branched via a diffraction grating into at least three beams of light including a main beam and two sub beams which are in turn condensed via an objective lens on an optical disk at a guide groove and reflected by the optical disk to provide three reflections of light which are in turn received by detectors, each divided into two regions, respectively, to generate a tracking error signal. The diffraction grating is divided into three regions including a first region, a second region and a third region located intermediate therebetween, each having a periodical structure out of phase, the periodical structure having grating grooves in a direction determined depending on the phase of the second region to incline relative to a direction perpendicular to the guide groove of the optical disk.

Abstract: An optical pickup device has a semiconductor laser emitting light which is in turn branched via a diffraction grating into at least three beams of light including a main beam and two sub beams which are in turn condensed via an objective lens on an optical disk at a guide groove and reflected by the optical disk to provide three reflections of light which are in turn received by detectors, each divided into two regions, respectively, to generate a tracking error signal. The diffraction grating is divided into three regions including a first region, a second region and a third region located intermediate therebetween, each having a periodical structure out of phase, the periodical structure having grating grooves in a direction determined depending on the phase of the second region to incline relative to a direction perpendicular to the guide groove of the optical disk.

Abstract: In a lens holding system of the present invention, at least two lens protection sections protruding from a surface of a lens holding section are provided, which surface faces the optical recording medium, the lens protection sections sandwiching an objective lens therebetween. A distance between each of the lens protection sections and the optical recording medium is smaller than a distance between the objective lens and the optical recording medium. Accordingly, according to the structure mentioned above, because each of plural lens protection sections is independently provided, spaces between (i) adjacent lens protection sections and (ii) each of the lens protection sections and the lens holding section are easily formed. This makes it possible to easily perform attachment/detachment of the objective lens to/from the lens holding section. Further, a region for releasing heat is easily formed by the space provided between adjacent lens protection sections mentioned above.

Abstract: A light radiated from a light source is divided by a grating into a main beam for detecting information signals and sub-beams for tracking, and thus irradiates a mini disk. The beams reflected by the mini disk are converged through a concave cylindrical mirror on a second light detector composed of adjacently disposed divided light receiving elements H (light receiving parts A and B) and J (light receiving parts C and D) and light receiving elements E1, F1, E2 and F2. The concave cylindrical mirror shapes the reflected beams so that spots of the reflected beams converged on the second light detector take elliptic shapes that are flattened in a direction in which the main beam for detecting the information signals and the sub-beams for tracking are arranged. In this manner, reliability of an optical head can be improved without increasing the size of the light receiving elements and without causing interference between a main spot and sub-spots.

Abstract: A document processing system includes an input device for inputting into the system document information, including line pitch information relating to lines of the document information. The document information is divided into at least two regions. Also provided is a document memory for storing the document information. The system also includes a line pitch information memory for storing a plurality of line pitch information relating to the lines of the document information in each of the regions. Also included are first and second deriving devices. The first deriving device derives, in accordance with line pitch information relating to one of the regions, a position of the line to be printed subsequently in one of the regions. The second deriving device derives, in accordance with the line pitch information relating to the other one of the region, a position of the line to be printed subsequently in the other one of the regions.