Abstract: An optical switch system including an optical switch apparatus which includes a light source emitting light of a certain wavelength, a single optical fiber cable for transmitting the light to a terminal switch, radiating means for radiating the light transmitted over the optical fiber cable, a reflector that is provided in the optical path of the radiated light at such a position that the reflected light will reach the radiating means, a shutter adapted to be inserted into or removed from the optical path of the radiated light, and a light extractor for detecting the reflected light wave that has passed through a return path in the optical fiber cable.

Abstract: A vehicle headlamp having a projector-type light source assembly capable of emitting a highly coherent light beam. In order to make the headlamp appear larger than the light source assembly, a lamp housing is provided which is much larger in size than the light source assembly mounted therein, with the consequent provision of an annular space around the light source assembly within the lamp housing. Disposed in this annular space is an outline expander plate of transparent material having a multiplicity of minute cavities of cone shape formed in its rear face. The outline expander plate transmits by internal total reflection the light incident edgewise thereon. While so traveling through the outline expander plate, the light is reflected by the surfaces of the conical cavities generally in the forward direction of the headlamp, thereby making the complete surface area of the headlamp appear glowing.

Abstract: An AC power control apparatus including a power circuit for supplying an AC current to a load, and a circuit connected to a power supply, for initiating energization of the load at a zero-cross point of an AC current waveform. A control circuit for controlling the change of energization time between a current turn on time to a current turn off time in units of AC waveform cycles, and a detector for detecting an AC zero level. From a given polarity of the AC current waveform, the initiating energization of the load and deenergization of the load at a zero-cross point of the AC current waveform is from the same polarity as the given polarity of the AC current waveform.

Abstract: An AC power control apparatus includes a plurality of power supply circuits for generating powers having different maximum values, a switching circuit for, after an AC current is continuously set in a desired turn on control state, alternately selecting a first power supply circuit used until that time and a second power supply circuit for supplying a power approximating a power supplied to a load at that time from the plurality of power supply circuits, a turn on time control circuit for gradually shortening a turn on time of the first power supply circuit while gradually prolonging a turn on time of the second power supply circuit until the turn on time of the second power supply circuit corresponds to the entire period, and a circuit for changing the turn on time of the power supply circuit in units of periods of the AC current.