Sanyo Electric Co., Ltd.

Syuji Motegi

Tetsuya Tokunaga

Hiroyuki Arai

Takeshi Kimura

A driving circuit for a vacuum fluorescent display having a filament, a grid electrode and a segment electrode, the driving circuit comprising a filament driving unit for driving the filament; a grid driving unit for pulse-driving the grid electrode; and a segment driving unit for pulse-driving the segment electrode, wherein the driving circuit comprises a controlling unit for validating or invalidating the output of the filament driving unit at a proper timing.

Driving circuit for vacuum fluorescent display

A driving circuit for a vacuum fluorescent display for pulse-driving a filament of the vacuum fluorescent display with a pulse voltage. The driving circuit comprises a detecting unit for detecting that the level of the pulse voltage is fixed, and outputs a detection signal indicative of the result of the detection. Preferably, the driving circuit comprises a control unit for controlling at least one output of the outputs of the filament driving unit, the grid driving unit and the segment driving unit in order to terminate the driving of at least one of the filament, the grid electrode and the segment electrode, based on the detection signal.

A driving circuit for a vacuum fluorescent display having a filament, a grid electrode and a segment electrode, comprising a grid driving unit for pulse-driving the grid electrode, a segment driving unit for pulse-driving the segment electrode, a first controlling unit for rendering adjustable the duty ratio of the output of the grid driving unit, a second controlling unit for rendering adjustable the duty ratio of the output of the segment driving unit, and a selecting unit for selecting the first controlling unit and/or the second controlling unit.

For changing the content of a display RAM (,) or an accessory RAM (,), various data SDI, such as an instruction code, address data, display data, is initially transferred to a shift register (,). Then, the display data in the shift register (,) is latched by a latch circuit (,). A write operation is carried out during a period from the completion of a shift operation by the shift register (,) using various data SDI in connection with the current display to the completion of a shift operation using various data SDI in connection with the next display, i.e., a period with an operation enable signal CE remaining at an L or H level. As a result, time allowance for writing is ensured, which contributes to reduction of software processing load by an external device.

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Tochigi, Japan

Syuji Motegi