Abstract: A power supply circuit capable of reducing the power consumption during the standby state of an electric appliance. The power supply circuit for supplying the electric appliance with voltages to drive and control the electric appliance, includes a controller for controlling the operation of the electric appliance, a DC-DC converter for outputting a fixed voltage V.sub.1 and a variable voltage V.sub.2, and a regulator for converting the fixed voltage V.sub.1 derived from the DC-DC converter into a specified voltage and supplying the specified voltage to the controller 16 for the electric appliance. The DC-DC converter identifies the state of the air conditioner. When the electric appliance is identified to be in the standby state, the DC-DC converter reduces the fixed voltage V.sub.1, which is inputted to the regulator to a voltage lower than a voltage outputted in the operative state.

Abstract: A method and an apparatus for decoding image signals capable of achieving a reproduction of the image signals with a high image quality by using a relatively low speed inverse orthogonal transform device.

Abstract: An optical sensor comprising a light detector, a converging lens located between the light detector and a light source, the light rays from which are detected by the light detector, and a light shielding means provided on a part of the converging lens, the shielding means shielding light rays emitted from the light source, thereby reducing dependence of the amount of light rays to be detected upon angles of incidence with which the light rays enter into the converging lens of the optical sensor.