Other

Hitachi, Ltd.

Mitsuhiko Ota

Takeshi Shimano

Masayuki Inoue

Shigeru Nakamura

Kunikazu Ohnishi

Shinji Fujita

Yukio Fukui

Yasuyuki Sugi

Koichi Sakita

An imaging device includes an imaging element, a phase plate to modulate the optical transmission function of the optical image of the object, and an optical system for focusing the optical image modulated via the optical plate on the imaging surface of the imaging element, a spatial filter processing unit for image restoration processing to remove modulation by an optical phase filter by implementing two-dimensional spatial filtering processing on the image focused on the imaging surface of the imaging element. Modulation characteristics applied to the optical system by the phase plate are respectively different in the horizontal and vertical directions crossing at right angles along the flat surface of the imaging surface perpendicular to the optical axis.

Imaging device using an optical phase filter that moduates a optical transfer function of an optical image of an object

A valve device is provided. The valve device of the present invention includes a planetary component and two valve plates. The two valve plates are disposed on a hole portion of the planetary component opposite to each other, so as to provide a quick opening and closing with a relatively high opening and closing speed, and to reduce the space occupied. Therefore, the provided valve device does not need to perform adjustment (processing) to reduce the operating force on the sluice valve or to assure the closing function of the valve. Further, the function and the producibility of the valve are improved significantly.

Valve device

An optical detector for detecting at least three optical beams reflected by an optical information recording medium and outputting an electric signal, the optical detector having three light receiving areas each of which receives a respective one of the three optical beams and each of which has four light receiving surfaces, twelve signal lines to transmit an electric signal obtained on respective ones of the four light receiving surfaces of the three light receiving areas, selected ones of the twelve signal lines connected to the four light receiving surfaces of different ones of the three light receiving areas being joined together within the optical detector, and less than nine signal output lines formed by joining the selected ones of the twelve signal lines extend from the optical detector to a signal processing circuit.

Optical detector having three light receiving areas

It is desirable to greatly reduce the disturbance that arises in a focusing error signal by a astigmatic detection method and offset that arises in the tracking error signal by a push-pull method when reproducing various information storing disks, such as a DVD-RAM disk. It is also desirable to provide an optical disk apparatus which is able to reproduce a variety of high density optical disks, such as DVD-RAM and DVD-ROM disks, as well as conventional disks, such as CD, CD-ROM, CD-R disks, by using a simple optional head. For this purpose, an optical disk apparatus irradiates three optical beams produced by a diffraction grating on the specified position of an optical disk and detects reflected light using a specified optical detector divided into twelve parts.

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Yokohama, Japan

Mitsuhiko Ota