This invention relates to a semiconductor luminescent device including a control electrode.
Semiconductor luminescent diodes emit light by a forward current flow through the PN junction involved. In order to control the luminescent output from a luminescent, it is required to externally connect a switch element such as a transistor or a variable impedance element to each semiconductor luminescent diode. Such a switch element has an inherent power loss and is required to have a current rating similar to that of the corresponding semiconductor luminescent diode. Thus the conventional semiconductor luminescent diodes are disadvantageous because the control of their luminescent output is expensive.
There have been already known luminescent elements including a control electrode for control of the luminescent output, for example, luminescent switching elements having a four layer PNPN structure and the control or gate electrode disposed in ohmic contact with either one of the intermediate layers to be formed into a thyristor configuration. Once such an element has been turned on with an associated source of direct current connected thereacross, it continues to remain on to emit light unless the current decreases to less than the holding current. This means that the control of the luminescent output requires a transistor or another variable impedance element for externally controlling the on-state or forward current.
It is an object of the present invention to provide a novel semiconductor controlled luminescent device.
It is another object of the present invention to provide a new and improved semiconductor controlled luminescent device including an extremly simple control circuit.
It is still another object of the present invention to provide a new and improved semiconductor controlled luminescent device controlled with low power loss.
It is a further object of the present invention to provide a new and improved semiconductor controlled luminescent device having an extremly high control speed.