Patent ID: 7978158
Filing Date: 2011-07-12
Classification: G09G

Abstract:
1. An electronic appliance comprising a monitor element, a current source for supplying a current to the monitor element, an operational amplifier, a first transistor for amplifying an output of the operational amplifier, a light-emitting element, and a second transistor for driving the light-emitting element, wherein a buffer amplifier is constituted by connecting an output terminal of the operational amplifier to a base of the first transistor, connecting a first terminal of the first transistor to a positive power source, and connecting a second terminal of the first transistor to an inverted input terminal of the operational amplifier, and wherein one electrode of the monitor element and the light-emitting element is connected to a constant potential power source, the other electrode of the monitor element is connected to the buffer amplifier, a potential of the other electrode of the monitor element is set to be the same potential as a potential outputted through an amplifier, and the outputted potential is applied to the other electrode of the light-emitting element through the second transistor.