| 摘要 |
<p>A memory circuit contains a variable threshold transistor arranged to receive optically coded information from an external light source. A WRITE voltage pulse is applied between the gate electrode and the substrate during the WRITE interval. The source and drain elements of the transistor are left "floating" during a WRITE interval whereupon the conduction threshold of the transistor assumes a level dependent upon the amplitude and duration of the WRITE voltage pulse and the intensity of the light received from the external source. Subsequently applied READ voltages produce a drain current having a magnitude indicative of the intensity of the light received during the occurrence of the WRITE voltage pulse.</p> |
