Funai Electric Company Ltd.

Tsuyoshi Eiza

Shinya Shimizu

Tetsuya Shihara

Shinya Shimitzu

An aberration correction apparatus comprising a liquid crystal device which includes a first electrode layer that is formed with regions divided concentrically, a second electrode layer that is formed with regions divided concentrically, and a liquid crystal that is sandwiched in between the first electrode layer and the second electrode layer, and which transmits an incident light beam therethrough, an objective lens which condenses the light beam transmitted through the liquid crystal device, and a liquid-crystal-device drive circuit which drives the liquid crystal device, wherein the liquid-crystal-device drive circuit impresses a potential which belongs to a predetermined region included in a liquid crystal characteristic that is a relationship between potentials impressed on the respective electrode layers sandwiching in the liquid crystal therebetween and a phase change magnitude of the light beam transmitted through the liquid crystal, on the concentric regions formed in the first electrode layer, and it impresses a potential which belongs to a region included in the liquid crystal characteristic and exhibiting a smaller phase change magnitude per unit drive voltage than in the predetermined region, on the concentric regions formed in the second electrode layer, whereby an aberration of the light beam is corrected.

Aberration correction apparatus

A liquid crystal element for correcting wave aberration included in an optical disc apparatus, is controlled by a liquid crystal element control unit which has a memory portion that stores information about a variation with time of orientation direction of liquid crystal in the case where a voltage is applied to the liquid crystal, with respect to at least one type of voltage value. The liquid crystal element control unit has a drive voltage deciding portion that obtains time period after a predetermined drive voltage is applied to the liquid crystal element until a reproduced signal obtained by processing an electric signal converted by the light detecting unit becomes optimal, and decides a drive voltage to be applied to the liquid crystal element based on the obtained time period, the information stored in the memory portion, and the predetermined drive voltage.

Optical disc apparatus

A pressure sensor portion includes a plurality of pressure sensors arranged in a plurality of rows and a plurality of columns inside a pressure-sensor-equipped carpet. The pressure sensor portion senses a pressure applied to the surface thereof and outputs a pressure value to a control portion. In an initial learning mode, a storage portion stores, as an initial value, the pressure value output from the pressure sensor portion. In a sensing operation mode, the control portion outputs to a modem portion a data signal indicating that an abnormal event is sensed, when the pressure value output from the pressure sensor portion is larger than the initial value stored in the storage portion by at least a prescribed threshold value. The modem portion superimposes the data signal received from the control portion on a power carrier wave (with a frequency of 50-60 Hz) and outputs the data signal to a power supply plug.

Security system and monitoring method using power line communication technology

An optical disk apparatus having an aberration correcting unit for correcting aberrations generated on the recording surface of an optical disk based on received correcting signals, a servo signal generating unit for generating servo signals based on the reflection lights from the optical disk and predefined parameters, and a birefringence detecting unit that detects the degrees of birefringent portions on the recording surface based on received the servo signals and generates the correcting signals for correcting aberrations according to the detected degrees of the birefringent portions and outputs the correcting signals.

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Osaka, Japan

Tsuyoshi Eiza