Fujitsu Corporation

Fujitsu Microelectronics Limited

Seiji Yamagata

Tsuyoshi Higuchi

Jun Funakoshi

Toshitaka Mizuguchi

Shinya Udo

Masatoshi Kokubun

Katsuyoshi Yamamoto

Fumitaka Asami

Chikara Tsuchiya

Makoto Yanagisawa

A differential amplifier has a first input terminal to which a voltage of a noise signal of the solid-state imaging device is supplied and a second input terminal to which a voltage of a temporary data signal having the noise signal of the solid-state imaging device superposed thereon is supplied. The differential amplifier inverts an output signal when a magnitude relationship in voltage between the first and second input terminals becomes reverse. A measurement circuit measures a variation amount of a voltage of the second input terminal from when the voltage of the second input terminal begins to vary in a direction to reverse the magnitude relationship to when the output signal of the differential amplifier is inverted, and outputs a measurement result as a digital value indicating a voltage of a real data signal obtained by removing the noise signal from the temporary data signal.

Data read circuit of solid-state imaging device, imaging apparatus, and data read method for solid-state imaging device

A second source follower circuit of a reference voltage generator includes a transistor having the same characteristics as a first source follower circuit of a pixel. Accordingly, the second source follower circuit can generate a second reference voltage according to the change in characteristics of the first source follower circuit. A noise voltage switching circuit outputs a first voltage as a noise voltage to a pixel signal generator when the noise voltage is equal to or lower than the second reference voltage. In a reset state, the noise voltage and the second reference voltage always have a predetermined voltage difference. Therefore, deterioration in image quality can be prevented even when capturing a subject having high brightness. Since a trimming circuit or the like selecting any one of a plurality of reference voltages according to characteristics of a formed transistor becomes unnecessary, the cost of an imaging device can be reduced.

Imaging device

Lower level of data latch holding a digital image data and a positive selector arranged immediately above positive gradation voltage line, for selecting positive analog gradation voltage of positive gradation levels are take as a set, and upper level of data latch holding a digital image data and a negative selector arranged immediately above negative gradation voltage line, for selecting negative analog gradation voltage of negative gradation levels are take as a set. Two sets are arranged in alignment in vertical direction. A plurality of sets of vertically aligned sets are arranged horizontally to shorten a length in horizontal direction with respect to gradation voltage lines.

Semiconductor integrated circuit for driving liquid crystal panel

A method for controlling a solid-state imaging apparatus, which includes a plurality of pixels, includes selecting a resetting element of one of the pixels, resetting a detecting unit connected to the pixel, transmitting to a detecting unit, an electric charge accumulated after photoelectric conversion performed by a photoelectric converting element of the pixel, and providing control to set a second end of a transmitting control signal line to an open state.

Solid-state imaging apparatus and control method with transmission control hold circuit

A circuit for stabilizing an electric current includes a constant voltage supplying circuit configured to supply a constant voltage, and a current generating circuit coupled to the constant voltage supplying circuit to generate an electric current based on a predetermined voltage responsive to the constant voltage and to adjust a current amount of the electric current to a predetermined amount by feedback control based on comparison of the predetermined voltage with a voltage appearing across a predetermined resistance responsive to the electric current.

Current stabilization circuit, current stabilization method, and solid-state imaging apparatus

A differential comparator which outputs positive and/or negative logic signals to an output terminal according to the coincidence/non-coincidence of first and second input signal levels inputted to first and second input terminals, respectively, comprises an offset cancel function composed of an offset capacitor device provided on the differential comparator side of the first and second terminals, a first switch for short-circuiting the first and second input terminals in such a way as to form a closed loop including the offset capacitor device, and a second switch for short-circuiting both the connection point between the offset capacitor device and the differential comparator, and the output terminal.

Differential comparator, analog/digital conversion apparatus and imaging apparatus

A ramp waveform generation circuit which comprises a first reference power supply, and supplies a ramp waveform signal to an analog/digital conversion circuit further comprises a connection circuit for reflecting the amount of fluctuation of the output potential of a second reference power supply which is installed in a noise elimination circuit for eliminating the noise of an analog signal inputted to the analog/digital conversion circuit in the output potential of the first reference power supply.

Ramp waveform generation circuit, analog/digital conversion circuit, imaging device and control method of imaging device

An offset cancel circuit for an operational amplifier comprises a capacitive element for storing a voltage to be amplified by an operational amplifier section and containing an offset, and for feedback-controlling a voltage value of the operational amplifier section based on the stored voltage, and switching elements for switching operation between the storage of the voltage in the capacitive element and the feedback control based on the value of the voltage stored in the capacitive element. The capacitive element and the switching elements can be used to cancel accurately an offset in the operational amplifier section without increasing the gate areas of transistors in the operational amplifier section.

Operational amplifier and its offset cancel circuit

A liquid crystal display panel includes a driver having pairs of first and second D/A converters, corresponding pairs of first and second polarity changeover switches, and plural switching elements. Each of the first D/A converters receives a picture signal and outputs a positive-polarity voltage and each of the second D/A converters receives the picture signal and outputs a negative-polarity voltage. The first polarity changeover switches are connected to the outputs of the first and second D/A converters and alternately output the positive and negative polarity voltages. The second polarity changeover switches are also connected to the outputs of the first and second D/A converters and output a reverse polarity voltages. The switching elements are connected between the outputs of the first D/A converters and the first polarity switch and the output of the second D/A converters and the second polarity changeover switch. The switching elements are actuated until the voltages at the outputs of the first and second D/A converters become substantially equal.

Driver for a liquid-crystal display panel

A constant voltage supplying circuit is disposed between a voltage output terminal of a voltage generation circuit for outputting a voltage having the same polarity as that of a reference voltage, which can be arbitrarily set, and having a greater absolute value than the reference voltage, and a load. This constant voltage supplying circuit includes a first field effect transistor a gate of which is connected to its drain, and to a source of which the reference voltage is supplied, and a second field effect transistor which has the same conductivity type as the first field effect transistor, a gate of which is connected to the drain of the first field effect transistor, a source of which is connected to the voltage output terminal of the voltage generation circuit, and a drain of which is connected to the ground. According to the circuit constitution, the output voltage of the voltage generation circuit can be stabilized to a desired voltage value (the same voltage value as the reference voltage). Even when the constant voltage supplying circuit is fabricated in an integrated circuit, it does not invite the increase of the production process, and thus can limit the increase of the cost of production.

Growing community of inventors

Kawasaki, Japan

Seiji Yamagata