| 摘要 |
PROBLEM TO BE SOLVED: To provide a DC/AC inverter for a cold-cathode lamp which is capable of causing a cold-cathode lamp, which is backlit and used in a liquid crystal display module, to illuminate rapidly, smoothly and with a stable brightness from its start-up till a stable brightness state. SOLUTION: There are provided a temperature sensor part 18 for detecting ambient temperature of a cold-cathode lamp 20 and an oscillation frequency variable control circuit part 19 for changing, based on an output of this temperature sensor part 18, an oscillation frequency of an inverter proper 21 so as to be reversely proportional to the ambient temperature of the cold-cathode lamp 20. Brightness of the cold-cathode lamp 20 thereby increases rapidly while temperature of the cold-cathode lamp 20 also rises rapidly, because the oscillation frequency is high when the ambient temperature of the cold-cathode lamp 20 is low. When the temperature of the cold-cathode lamp 20 becomes high, the oscillation frequency becomes low and therefore an increase in brightness is suppressed and a feedback action brings about a rapid and smooth transition to a stable illumination state. |
