Alps Electric Co., Ltd.

Ichiro Morishita

Masaru Nakayama

Junichi Saito

Yuichi Umeda

Arao Sato

Kazuhiro Katagiri

Hiroko Hanzawa

Hiroshi Ishikawa

Masatoshi Uchio

Harutaka Sekiya

Yuichi Yasuda

Tomomitsu Muta

Masahiro Tanaka

Masato Iwai

A pair of detecting stations A.sub.i and A.sub.-i on a plane H extends along an axis X. Each of the detecting stations is provided with an iris member and a divided light receiving section. Received light outputs at each of the light receiving elements are defined as R.sub.i, L.sub.i, R.sub.-i, and L.sub.-i, and the following equation is calculated to enable a coordinate (x.sub.0, z.sub.0) of the moving light source to be attained by a simple calculation: S.sub.i =(R.sub.i -L.sub.i)/(R.sub.i +L.sub.i)+(R.sub.-i -L.sub.-i)/(R.sub.-i +L.sub.-i); T.sub.i =(R.sub.i -L.sub.i)/(R.sub.i +L.sub.i)-(R.sub.-i -L.sub.-i)/(R.sub.-i +L.sub.-i).

Coordinate position of moving light source by using separated groups of

An apparatus is disclosed for inclination detection wherein infrared transmitted signal, signal groups S1, S2, S3, . . . including a leader code, a parity bit and bits for data transfer are sequentially transmitted with an interval time t3. At each bit of the signal group S1, '1' and '0' of a binary signal expressing the data are not inverted, at the signal group S2, '1'and '0' expressing the data are inverted, and inversion and non-inversion are repeated every signal group. At bits of each signal group, since a time length expresses '1' and '0', a total time length of each signal group is different from that of other signal group. By repeating sets of inverted and non-inverted signal groups, the time length of each set is averaged, and hence, data processing can be made more efficient.

Apparatus for inclination detection and input apparatus using this

According to the present invention there is provided a space coordinates detecting device wherein a detecting section for detecting light emitted from a light source is provided, thereby permitting detection of a relative angle between a light emitting sections and the detecting section and hence permitting application of the detecting device to an input apparatus. The detecting section is provided with a light sensing element 23 having quartered light sensing portions. In the light emitting section, distinguishable lights are emitted from two light sources. The lights thus emitted are throttled through apertures and applied as separate square light spots S16 and S17 to the light-sensitive surface of the light sensing element 23. By calculating a difference in the detected output among the quartered light sensing portions, it is possible to determine the center I1 of the square light spot S16 and the center I2 of the square light spot S17. A relative rotational angle of the light emitting section and the detecting section with respect to Z axis can be determined by calculating an inclination angle .alpha. on X-Y orthogonal coordinates of a line x connecting both centers I1 and I2.

Space coordinates detecting device and input apparatus using same

An optical system comprises an objective lens for moving along a recording face of an optical disk in the radial direction of the optical disk so that an optical axis thereof is almost perpendicular to the recording face, a reflecting mirror for moving together with the objective lens and whose reflecting axis extends in the radial direction, a detection optical unit, a movable mirror located to incline with respect to the optical axis extending almost parallel to the recording face from the detection optical unit and the reflecting axis of the reflecting mirror, and a mirror drive portion for rotating the movable mirror on an axis almost parallel to the recording face and shaking a light beam radiated from the objective lens onto the recording face in the radial direction. The mirror drive portion rotates the movable mirror on an axis almost parallel to an optical axis extending from the detection optical unit or on an axis almost parallel to a reflecting face of the movable mirror. Reflecting axes of the reflecting face are disposed on the same plane parallel to the recording face.

Optical beam system for optical disk drives

An optical reader which has a light emitting element, a photodetector, a light emitting side lens for converging a light emitted from the light emitting element to a surface to be detected, and a photodetecting side lens for converging a light reflected on the surface to be detected to the photodetector, wherein the light emitting side focus point focused at the light emitting element by the light emitting side lens is set at a position separated from the lens farther than the photodetecting side focus point focused at the photodetector by the photodetecting side lens. Thus, the adverse influence of a regular reflection light can be prevented in a small-sized structure and a detecting accuracy can be enhanced without decreasing the light detecting efficiency of the optical reader.

Optical reader with reduced regular reflection errors

An optical apparatus of an optical pickup including a semiconductor laser, a collimate lens to obtain a parallel light from a laser beam emitted from said semiconductor laser, an objective for collecting on a recording surface of an optical disk the parallel light obtained through the collimate lens, and a light receiving element for detecting a reflection light reflected on the recording surface of the optical disk wherein a numeric aperture NA of said collimate lens is set as 0.14&lt;NA&lt;0.2.

Optical apparatus for optical pickup

An objective lens for an optical memory device comprising a plane surface on one side thereof for emitting a luminous flux oppositely to a disk, and an aspherical surface on the other of the side thereof for receiving a luminous flux reversely to the disk in such a manner that the following conditions (1) and (2) are satisfied:

Objective lens for optical memory device

An improved collimating lens for use in optical memories is disclosed which comprises a first surface for receiving the incident beam which is concave, and a second surface for emitting the outgoing beam which is convex and non-spherical, characterized in that the said lens satisifies some particular conditions. If the collimating lens of the present invention is used, the beam passing through the periphery of the lens can be concentrated, and therefore, the actual number of openings of the objective lens is increased, and at the same time, the coupling efficiency can be improved. Accordingly it is possible to form very tiny spot on the disc, and the transmission rate can also be improved. Further, the appearance of the lens can be favorably shaped when manufacturing the lens, because the lens of the present invention is strong against the difference of the axes.

Collimating lens for use in optical memories

An ojective lens for use in an optical pickup that is employed in a compact disk player, for example. The objective lens has a first aspherical surface on which parallel light rays impinge and a second spherical surface that faces the disk. The aspherical surface lies in a meridian plane of a cartesian coordinate system. The X-axis of this coordinate system is taken on the optical axis, the Y-axis is taken at the apex of the aspherical surface. The aspherical surface which is axially symmetrical is given by

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Sendai, Japan

Ichiro Morishita