| 摘要 |
PROBLEM TO BE SOLVED: To provide an illuminating device for a microscope using LEDs which can stabilize color temperature even if light quantity is increased and decreased. SOLUTION: A sawtooth wave generating circuit 80 is configured to supply a sawtooth wave, and unless a third variable resistor VR3 is adjusted even when a light quantity adjusting knob 44 is operated, a ratio between a first potential difference of the potential of a reference potential input part 71a in a first comparator 71 with respect to ground potential and a second potential difference of the potential of a reference potential input part 72a in a second comparator 72 with respect to the ground potential is not changed. Namely, even if light emission quantity from each LED 10, 20 is changed by the light quantity adjusting knob 44, the rate of a change in the light emission quantity in the first LED 10 and the rate of a change in the light emission quantity in the second LED 20 are made almost equal, thus, even when the light emission quantity from each LED 10, 20 is changed by the light quantity adjusting knob 44, the color temperature of the light from each LED 10, 20, with which an observation object W is irradiated is not changed. COPYRIGHT: (C)2011,JPO&INPIT |
