| 摘要 |
PROBLEM TO BE SOLVED: To perform illumination brighter than usual as necessary even while suppressing battery consumption low by a simple configuration, in a light source unit attached and detached to/from a portable endoscope body. SOLUTION: An output voltage Vout output from a DC/DC converter is applied to the anode terminal of an LED light source L1. To the cathode terminal of the LED light source L1, monitor resistors R3 and R4 are connected in parallel. A switch element Q3 is provided to the route of the resistor R3 and a switch element Q4 is provided to the route of the resistor R4. A monitor voltage generated by the monitor resistor R3 or the monitor resistors R3 and R4 is transmitted to the switching regulator U1 of the DC/DC converter, and the output voltage Vout is controlled so that a current flowing to the LED light source L1 becomes a fixed value corresponding to the monitor voltage. The ON/OFF of the switch element Q3 is linked with an attachment detection switch SW2 linked with the attachment/detachment of the light source unit, and the ON/OFF of the switch element Q4 is further linked with the ON/OFF of a light control switch SW3. COPYRIGHT: (C)2011,JPO&INPIT
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