| 摘要 |
PROBLEM TO BE SOLVED: To provide an illuminator for photographing which allows a light emitting diode to efficiently emit light with light quantity efficient for photographing illumination with a simple constitution using a cell source of nominal voltage 3 V. SOLUTION: When a control signalϕ2 from a control means of boosting circuit VP1 comes to 'H', a transistor Q2 is made on and a C1 is charged almost to a source voltage. On the other hand, when the control signalϕ2 comes to 'L', the transistor Q2 is made off and the charging to the capacitor C1 is stopped. Subsequently, when a control signal≃1 comes to 'L', a transistor Q1 is made on, the voltage of minus side of the capacitor C1 is pushed up to the source voltage and, therefore, the voltage of plus side of the capacitor C1 is risen to almost twice the source voltage. At the same time, when a control signalϕ3 is made 'H', a transistor Q3 is made on, the voltage which is almost doubly boosted is supplied to the light emitting diodes LW1, LB1 and LG1 and, on the other hand, the source voltage is directly supplied to LR1, an electric current flows through all the diodes and the light emitting thereof occurs. |
