Ricoh Company, Ltd.

Ricoh Electronic Devices Co., Ltd.

Komatsu Denshi Kinzoku Kabushiki Kaisha

Kuniaki Arai

Masashi Oshima

Masayoshi Danbata

Junichi Kanno

Kaori Matsumoto

Kazuya Togashi

Provided is a protective semiconductor device detecting a disconnection reliably with secondary cells including for each cell: cell-connecting terminals; a first resistance detecting the voltage of each cell; a comparator detecting whether or not the voltage of each cell is in the reference voltage range; a series circuit composed of a second resistance and a first switch element, and including a control circuit controlling ON/OFF of the switch element, wherein the first switch element connects the second resistance to the connecting terminals by turning ON, while disconnecting it by turning OFF, the control circuit maintains a disconnection test signal ON, while turning ON the plurality of first switch elements sequentially and detecting the disconnection between the cells and the connecting terminals based on the output signal from the comparator corresponding to the first switch element turned ON.

Protective semiconductor device for secondary cell

A secondary cell protection circuit configured to protect plural secondary cells connected in series is disclosed that includes plural switching parts configured to be connected in parallel with the secondary cells respectively; and a charge controller configured to turn on the switching part connected to the secondary cell of which cell voltage is greater than or equal to a return voltage, and to turn off the switching part when all cell voltages of the secondary cells become greater than or equal to the return voltage, when the secondary cells are being charged.

Secondary cell protection circuit and battery

In a charging control circuit for controlling charging of a secondary battery, a charging transistor generates a charging current according to a control signal input to a control electrode and outputs the charging current to the secondary battery. The proportional current generation transistor generates and outputs a proportional current proportional to the charging current output by the charging transistor. The constant current charging controller controls the charging transistor so that the proportional current generated by the proportional current generation transistor attains a predetermined first value. The constant current charging controller controls a voltage of a current output terminal of the proportional current generation transistor so that a voltage difference between the voltage of the current output terminal of the proportional current generation transistor and a voltage of a current output terminal of the charging transistor is maintained at a predetermined second value.

Charging control circuit capable of constant current charging

The present invention relates to an optical disc apparatus having a wobble signal detection circuit, an information recording method, adjustment apparatus and method for an optical disc apparatus, a fabrication method for an optical disc apparatus, and adjustment method and apparatus for a phase shift amount. In the present invention, a wobble signal based on wobbling of an information track is supplied to the input side of a filter circuit, and the current phase difference between input and output signals to/from an HPF+LPF path is detected. Then, the phase of a recording start timing signal is adjusted corresponding to the detected phase difference. As a result, it is possible to prevent adverse effect due to the phase difference in the filter circuit.

Optical disc apparatus, information recording method, adjustment apparatus, adjustment method and fabrication method for optical disc apparatus, and method and apparatus for adjusting phase shift amount

A wobbling signal demodulation method is disclosed that is capable of fast and precisely demodulating a wobbling signal without increasing cost of the circuit. The wobbling signal is obtained based on light reflected from a recording surface of an optical disk having a wobbling track formed thereon, and includes a carrier portion having a predetermined basic period and a phase demodulated wave portion including predetermined information. The wobbling signal demodulation method includes a first step of respectively integrating a portion of the wobbling signal corresponding to a first half of the basic period and a portion of the wobbling signal corresponding to a second half of the basic period in synchronization with a clock signal generated from the carrier portion; a second step of generating a digital signal based on a first integration result corresponding to the first half of the basic period and a second integration result corresponding to the second half of the basic period; and a third step of performing a phase demodulation on the phase demodulated wave portion of the wobbling signal based on the digital signal and the clock signal.

Wobbling signal demodulation method, wobbling signal demodulation circuit, and optical disk drive

There is described a method which enables stable manufacture of a high-quality, ultra-thin epitaxial silicon wafer, as well as an epitaxial silicon wafer capable of bearing shipment manufactured by the method. A method of manufacturing an epitaxial silicon wafer having an ultra-thin epitaxial film, by means of forming an epitaxial film on a silicon wafer after having annealed the silicon wafer, includes the steps of: sufficiently smoothing COPs formed in the surface of the silicon wafer by means of appropriately setting annealing conditions according to an size of COPs in the vicinity of a surface of the silicon wafer; and forming an epitaxial film through epitaxial growth.

Method of manufacturing epitaxial silicon wafer

An optical disk apparatus has a plurality of detection switches for improving safety while a mounting area is prevented from being occupied by the detection switches. A cabinet member accommodates component parts of the optical disk apparatus including a circuit board having control circuits that control various functions of the optical disk apparatus. A drawer member is movable between an accommodated position where the drawer member is accommodated in the cabinet member and a non-accommodated position where the drawer member is out of the cabinet member. An optical pickup is mounted on the drawer member so as to emit the laser beam toward the optical disk placed on the placement part. A plurality of drawer member detection switches are provided to detect a position of the drawer member. The drawer member detection switches are arranged on opposite sides of the circuit board in a state where the drawer member detection switches face each other with the circuit board located therebetween.

Growing community of inventors

Kanagawa, Japan

Kuniaki Arai