Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Kazuhito Funae

Masashi Murakami

Takuya Shibata

The portion of a board corresponding to the surrounding portion of a holeformed through the board is arranged to include a patternless sectionwhere a conductive filmis not provided.

Printed circuit board and method of producing the same

An initial driving voltage fixing a desired luminance of a light-emitting source is set at a voltage lower than that of a power supply; the light-emitting source is driven by applying a light-emitting source driving voltage at the initial driving voltage; and then, a CPU determines whether or not the power supply voltage has dropped down the initial driving voltage. When the power supply voltage has become lower than the initial driving voltage, the CPU applies the light-emitting source driving voltage to the source at the power supply voltage, and holds an undervoltage information of the power supply that the power supply voltage has dropped. When the CPU detennined that the power supply voltage had returned higher than or equal to the initial driving voltage after holding the undervoltage information, the CPU gradually returns the light-emitting source driving voltage to the initial driving voltage.

Growing community of inventors

Tokyo, Japan

Kazuhito Funae