| 摘要 |
PROBLEM TO BE SOLVED: To provide an illuminating device of vehicle instrument capable of inhibiting a heat generation rise of a resistor, while making mounting space of circuit board small by connecting the resistor linked to a light source in common. SOLUTION: This device includes a plurality of light sources 1 which are connected to a power supply side at one side of the light sources 1, a limiting resistor 2 which is formed between the light sources 1 and the power supply and is connected with the plurality of light sources 1 in common, a voltage detection means 3 which detects the voltage supplied from the power supply, and a control means 4 in which a duty ratio is established based on the voltage value, and a PWM drive is carried out so that the plurality of light sources 1 may light alternatively based on the duty ratio. COPYRIGHT: (C)2009,JPO&INPIT
|
