Seiko Instruments Inc

Kabushiki Kaisha Daini Seikosha

Seiko Instruments & Electronics Ltd.

Seiko Instruments Inco.

Yukito Kawahara

Satoshi Machida

Masahiro Yokomichi

Hiroshi Mukainakano

Yoshikazu Kojima

Tsutomu Matsuhira

Hiroyuki Fujita

Masato Higashi

Kentaro Kuhara

Toru Shimizu

Tooru Shimizu

Minoru Ariyama

Eiichi Iwanami

Kenji Yoshida

Yoshihiro Shibuya

Noritoshi Ando

A scanning circuit has path switches connected between a plurality of data flip-flop circuits of the scanning circuit for sequentially reading an output signal in synchronism with a clock. A plurality of control signal lines select the path switches to arbitrarily skip reading of the flip-flop circuits that do not require the scanning circuit and always fix a potential of the skipped data flip-flop circuit. Only the arbitrary data is read, and in the case where unnecessary data exists, reading is skipped, to thereby increase the read rate.

Scan circuit and image sensor having scan circuit

A photoelectric converter capable of reducing random noise has a photoelectric conversion circuit that generates an optical signal in correspondence to incident light, a reset circuit connected to an output terminal of the photoelectric conversion circuit, and a first amplification circuit connected to output terminals of the photoelectric conversion circuit and the reset circuit. A first electric charge transfer unit has a terminal connected to an output terminal of the amplification circuit and a terminal connected to a first capacitor. Second and third electric charge transfer units have terminals connected to second and third amplification circuits and other terminals connected to second and third capacitors, and the second and third amplification circuits are connected to the first and second capacitors, respectively. A source follower amplifier has a gate connected to the third electric charge transfer unit and the third capacitor, and a channel selection circuit is connected to a source of the source follower amplifier. A common signal line is connected to an output terminal of the channel selection circuit, a first current source is connected to the common signal line, and a second current source is connected to the source of the source follower.

Photoelectric converter and a method of driving the same

A photoelectric converter capable of reducing random noise comprises a photoelectric conversion circuit for generating an optical signal in correspondence to incident light, a reset circuit connected to an output terminal of the photoelectric conversion circuit, and an amplification circuit connected to output terminals of the photoelectric conversion circuit and the reset circuit. An electric charge transfer unit has one terminal connected to an output terminal of the amplification circuit and another terminal connected to a capacitor. A source follower amplifier has a gate connected to the electric charge transfer unit and the capacitor, and a channel selection circuit is connected to a source of the source follower amplifier. A common signal line is connected to an output terminal of the channel selection circuit, a first current source is connected to the common signal line, and a second current source is connected to the source of the source follower.

A linear image sensor comprises linear image sensor ICs each having light receiving elements arranged according to a preselected resolution level for outputting output signals in accordance with an amount of light received. Switch elements interconnect output terminals of adjacent two or more of the light receiving elements for switching between the preselected resolution level of the light receiving elements to at least one other resolution level constituting a fraction of the preselected resolution level. First amplifier circuits are is connected to output terminals of the light receiving elements. Sample and hold circuits temporarily hold outputs of the first amplifier circuits. Second amplifier circuits are connected to output terminals of the sample and hold circuits. Reading switch elements read outputs of the second amplifier circuits. Scanning circuits control the reading switch elements.

Linear image sensor

A fingerprint reading system is provided, which is capable of enhancing versatility when actually used, increasing productivity and reducing costs. An illumination device emits the light from a rear surface side of an active matrix liquid crystal cell. A light guiding plate provided on a surface side of the active matrix liquid crystal cell, transmits the light coming from the rear surface side and deflects the light coming from the surface side toward one side end surface. A light receiving device provided on the side of one side surface of the light guiding plate receives the light exiting from this one side surface. A drive circuit makes the active matrix liquid crystal cell pinpoint-irradiate a fingerprint in contact with the light guiding plate by pinpointing with the light emitted from the illumination device and makes the light receiving device pinpoint-receive the light reflected by the fingerpoint, thereby obtaining an image of the fingerprint.

Fingerprint reading device and method thereof

To eliminate after-image due to residual charges to provide an output form that is easy to obtain effective on-light output. The outputs of photo-diodes are read out as sequential signal outputs on a common signal line through connected amplifiers , and two states of before and after resetting the photo-diodes are outputted in order for each light receiving element.

Image sensor

A low-priced contact type color image sensor formed without the need to provide color filters on a linear image sensor. The color filters are formed on a surface of a document side of a transparent protective glass in direct contact with a document for flattening the light irradiation surface, such that the pitch thereof is equal to that of light receiving elements of a linear image sensor.

Contact type color image sensor

A linear image sensor using phototransistors as light receiving elements has improved after-image characteristics and reduced production costs by providing a light-receiving MOS diode proximate each photosensor, placing the MOS diode in an inversion state during the accumulation of photo-charge so that the accumulated photo-charge is accumulated at a base region of the phototransistors, placing the MOS diode in an accumulating state during a reset operation to return the phototransistors to an initial state after a readout operation has been performed, so that residual charge without reading out is transferred to the base region of the phototransistors and an after-image caused by residual charge is reduced through an emitter of the phototransistors.

According to the present invention, there is provided an image sensor for receiving light reflected from an original copy on which the light has been irradiated and for converting the received light into electrical signals, the image sensor having a simple configuration, no residual image, a small fluctuation in the dark outputs, and a good S/N ratio. In order to achieve such an image sensor, an output terminal of a photodiode is reset to a constant voltage, and an image signal output of the photodiode and the reference voltage output immediately after the photodiode is reset are performed succeedingly, using a clamping circuit.

Image sensor IC, facsimile apparatus and image scanner apparatus using the image sensor ICS

The present disclosure relates to a color image reading device that successively switches three color light sources to irradiate the color original copy and successively reads information on the original using a monochrome image sensor, and which is featured by simple construction and less reading time period. A plurality of image sensor ICs are linearly mounted. A start pulse output terminal of an anterior stage image sensor IC is connected to a start pulse input terminal of a posterior stage image sensor IC, thereby forming an image sensor block. A plurality of those image sensor blocks are provided such that start pulse input terminals of initial stage image sensor ICs in all blocks are connected together. By inputting start pulses to the terminals connected together, image signal outputs are read out simultaneously.

Color image reading device

A method for producing a semiconductor temperature sensor comprises the steps of forming PNP bipolar transistors and PMOS transistors so that a base region of each of the PNP bipolar transistors and a corresponding N-well region of each of the PMOS transistors are formed at the same time, and connecting the PNP bipolar transistors in a Darlington connection.

Method for producing semiconductor temperature sensor

A fingerprint reading system is provided with enhanced versatility and reduced cost. The fingerprint reading sensor includes a group of first electrodes arranged in a plurality of lines extending in a first direction, a group of second electrodes arranged in a plurality of lines extending in a second direction intersecting the first direction above the first electrode group through an interlayer insulating film, and a surface protective film formed of a dielectric material provided on the second electrode group. Drive circuits detect electrostatic capacity between each of the electrodes and a finger touching the surface protective film by sequentially applying a predetermined voltage to both groups of electrodes and measuring a change in the electrostatic capacity at each point where a second electrode crosses over a first electrode.

To eliminate a residual image due to residual charge in an image sensor circuit and provide an effective bright-time output, the image sensor is provided with a reset switch connected to a photodiode. After the potential of the photodiode is held through a first amplifier in two holding circuits as an image signal and an initial signal, the initial signal and the image signal are sequentially output through a second amplifier. By resetting the photodiode to a desired potential to produce an initial signal, a residual image can be eliminated.

Image sensor having unit light receiving circuit with sample-and-hold means

A fingerprint reading device is provided, which is capable of enhancing a versatility when actually used, increasing a productivity and reducing costs. The fingerprint reading device comprises an electrostatic capacity type fingerprint reading sensor provided on a liquid crystal panel, and drive circuits thereof. The fingerprint reading sensor includes detection electrodes arranged in predetermined positions, active elements connected respectively to the detection electrodes, and a protective film provided on the surface thereof.

Fingerprint reading device

To reduce current consumption in a contact type linear image sensor of a multi-chip form, a control circuit controls a clock buffer circuit of the device so that the clock buffer is activated only when a picture signal from a corresponding linear image sensor IC is output. The control circuit inputs a control signal, operates the clock buffer, and drives a shift register when a picture signal is to be read out.

Growing community of inventors

Chiba, Japan

Yukito Kawahara