Rohm Co., Ltd.

Toshimitsu Tamagawa

Nobuyuki Yamada

A semiconductor device includes: a plurality of external signal input means; an external input unit having a switch each connected between the external signal input means and a read line and electrically connected for output from the external signal input means on the read line; a shift register receiving an external control signal and an external clock signal and synchronized with the external clock signal to shift successively the external control signal to provide shifted data and output the external control signal to electrically connect the switches in accordance with the shifted data; an output circuit receiving the external control signal from the shift register and externally outputting the external control signal; and a frequency divider circuit dividing the external clock signal in frequency to generate and output an internal clock signal, wherein the output circuit is synchronized with the internal clock signal to externally output the external control signal.

Semiconductor device capable of preventing erroneous operation attributed to electrostatic noise, and input device and scanner capable of preventing electrostatic noise

An image reading device ready to operate at higher speed is built as an IC chip having a plurality of processing sections, of which each has a plurality of image reading photoelectric conversion elements, a plurality of transistors for reading a photoelectric conversion signal from the image reading photoelectric conversion elements, a signal selection circuit for sequentially selecting the plurality of transistors, and a signal output line by way of which the photoelectric conversion signal is transmitted.

Image reading device

In an image reading device having a plurality of photoelectric conversion elements formed in one or more rows on an IC chip and a conductor layer having openings formed therein for limiting light striking the photoelectric conversion elements, a conductor having substantially the same width as the conductor layer is formed in the area extending from the photoelectric conversion element located at each end of the IC chip to the chip edge. This arrangement helps make light shield conditions nearly equal for the photoelectric conversion element located at an end of the IC chip and for the other photoelectric conversion elements.

Image reading device with reduced variations among signal levels

An image-sensing semiconductor device has, in addition to a plurality of photodiodes, a dummy photodiode. The dummy photodiode is fed with a bias repeatedly with a predetermined period, and the plurality of photodiodes are fed with a bias sequentially with a predetermined cycle. The differences between the individual output signals of the plurality of photodiodes and the output signal of the dummy photodiode are calculated sequentially by a differential amplifier.

Image-sensing semiconductor device and image-sensing device

An optical communication device includes an IrDA modulation circuit and an ASK modulation circuit, one of which modulates transmission data. Modulated data is applied to a driver which drives a light emission diode (LED) in accordance with the modulated data. On the other hand, reception data received by a photo-diode is amplified by an amplifier, and reception data outputted from the amplifier is demodulated by an IrDA demodulation circuit or an ASK demodulation circuit. The IrDA modulation circuit, the ASK modulation circuit, the IrDA demodulation circuit and the ASK demodulation circuit are formed by an MOS process, and the driver and the amplifier are formed by a bipolar process. The MOS process and the bipolar process are executed on the same substrate, whereby such circuits are incorporated into a single IC. The IC, the LED and the photo-diode are molded by a resin.

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Kyoto, Japan

Toshimitsu Tamagawa