摘要 |
An encoder includes an array of variable resistance photosensors responsive to variations of incident illumination. The array is interconnected in a row and column matrix having row inputs connected to a sampling control device for sequential application of a predetermined voltage to the inputs. The matrix column outputs are connected to a detecting circuit having a current-measuring detector for receiving sensing currents from the outputs and for producing current responsive detection signals in response to the application of the predetermined voltage at the inputs. The outputs are held at a constant voltage, thereby providing effective isolation between the column outputs and eliminating interaction between elements connected to adjacent columns without the need of additional isolation means, such as isolation diodes, at each matrix intersection. |