Sharp Kabushiki Kaisha Corporation

Shapr Kabushiki Kaisha

Masahiro Hirokane

Hideki Morii

Akihisa Iwamoto

Takayuki Mizunaga

Yuuki Ohta

As a result of being provided with an enable signal generating unit that supplies, to an LED driver, an enable signal that is dependent on a low state period of a PWM signal, it is possible to realize a light emitting diode driver circuit that can suppress a booster circuit starting up suddenly and an excess current flowing in a power source in the case where the PWM signal enters a high state (on state) after having been held in a low state (off state) for a prescribed period or longer.

Light emitting diode driving circuit, display device, lighting device, and liquid crystal display device

A display panel drive circuit includes a shift register constructed of unit circuits connected in stages. The unit circuits generate signal line selection signals, respectively, which signal line selection signals are made active for a respective certain period of time to form a respective pulse, and the pulses are outputted successively from respective unit circuits in order of ordinal number starting from a first stage until an end stage. In at least one embodiment, each of the unit circuits receive (i) clock signals generated based on a sync signal received from outside of the display panel drive circuit, (ii) a start pulse signal generated based on the sync signal, or a signal line selection signal generated in a stage different from its own stage, and (iii) a clear signal. The clear signal is made active in a case where anomalousness is included in the sync signal, and no pulse is outputted from the shift register until a subsequent vertical scanning period starts. This configuration achieves a display panel drive circuit which prevents display disorder or holds down increase in load given to a power source, each of which occurs in a case where anomalousness is included in the sync signal.

Shift register and liquid crystal display device for detecting anomalous sync signal

A display device, in at least one embodiment, includes: a gate driver including a plurality of shift register stages each provided so as to correspond to each row, the gate driver outputting a gate signal for turning on switching elements in the each row; and a source driver outputting a data signal in accordance with an image to be displayed. For a row (first row) located at an outermost position from which scanning by use of the gate signal starts, a dummy line is provided. The dummy line is driven by a gate start pulse inputted into a shift register in the first row.

Growing community of inventors

Osaka, Japan

Masahiro Hirokane