Sanyo Electric Co., Ltd.

Semiconductor Components Industries, LLC

Sanyo Semiconductor Co., Ltd.

Tomoshi Yoshida

Kazunori Nohara

Ryuji Yamamoto

Nobuyuki Ohtaka

Tetsuya Tokunaga

Kensuke Goto

Mamoru Yamaguchi

Norikazu Katagiri

A liquid-crystal-driving circuit includes: resistors connected in series between first and second potentials lower than the first potential; one or more voltage follower circuits to impedance-convert one or more intermediate potentials between the first and second potentials, to be outputted, respectively, the intermediate potentials generated at one or more connection points between the resistors, respectively; a common-signal-output circuit to supply common signals to common electrodes of a liquid crystal panel, respectively, the common signals being at the first, second, or one or more intermediate potentials in a predetermined order; and a segment-signal output circuit supplies segment signals to segment electrodes of the liquid crystal panel, respectively, the segment signals being at the first and second potentials, or the intermediate potentials according to the common signals, wherein the segment-signal output circuit increases impedances of the segment signals only for a first period when the of segment signals potentials are switched.

Liquid crystal driving circuit

A light-emitting-element driving circuit is provided which comprises a voltage boosting circuit unit which supplies a boosted voltage to a light-emitting element, a current circuit unit which drives the light-emitting element with a current, a normal feedback loop path through which a voltage of the light-emitting element is input as a feedback voltage to the voltage boosting circuit unit, a backup feedback loop path through which a voltage of the light-emitting element is input as the feedback voltage to the voltage boosting circuit unit, an abnormality detection circuit unit which compares the feedback voltage which is input through the normal feedback loop path to the voltage boosting circuit unit and a predetermined determination voltage, to detect abnormality, and a switching circuit which switches from the normal feedback loop path to the backup feedback loop path when the abnormality detection circuit unit has detected the abnormality.

Light-emitting-element driving circuit

A light-emitting element driving circuit () comprises a luminosity determining unit () which determines luminosity, outputs a luminosity determination result, and outputs brightness change information, a brightness setting unit () which outputs brightness setting information and outputs brightness change information, a light-emitting element driving unit () which drives a light-emitting element with a current of a current value corresponding to the brightness setting information, a detecting and comparing unit () which compares a terminal voltage of the light-emitting element and a predetermined voltage, a voltage boost determining unit () which determines whether or not a terminal voltage of the light-emitting element is to be boosted based on at least one of the luminosity change information and the brightness change information, and a voltage boosting circuit section () which boosts the terminal voltage of the light-emitting element when it is determined that the voltage is to be boosted and does not boost the terminal voltage of the light-emitting element when it is determined that the voltage is not to be boosted.

Light-emitting element driving circuit

A power circuit outputs and applies an AC voltage and a DC voltage to respective terminals of a capacitor, so as to obtain an AC output voltage shifted in accordance with the DC voltage component. The power circuit comprises a first voltage adjuster for outputting an AC voltage and a first DC voltage, and a second voltage adjuster for outputting a second DC voltage. For a predetermined duration after turning on power, the power circuit supplies the first DC voltage from the first voltage adjuster and the second DC voltage from the second voltage adjuster, for application to respective terminals of the capacitor. After the predetermined duration has passed, the power circuit changes the voltage output from the first voltage adjuster to the AC voltage, and supplies the AC voltage and the second DC voltage for application to the respective terminals of the capacitor. With this arrangement, a required potential can be quickly achieved at the time of turning on power.

Power circuit applying AC voltage and DC voltage to respective terminals of a capacitor, for outputting AC voltage shifted in accordance with the DC voltage

A power circuit outputs and applies an AC voltage and a DC voltage to respective terminals of a capacitor, so as to obtain an AC output voltage shifted in accordance with the DC voltage component. The power circuit includes a first voltage adjuster for outputting an AC voltage, a second voltage adjuster for outputting a DC voltage, a first output terminal which outputs the AC voltage from the first voltage adjuster, and a second output terminal which outputs the DC voltage from the second voltage adjuster. The first output terminal is connected to one end of the capacitor, while the second output terminal is connected to the other end of the capacitor. The power circuit controls impedance between the first output terminal and the first voltage adjuster.

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Nishinomiya, Japan

Tomoshi Yoshida