Title :
An optical flip-flop sensor array with digital outputs
Author :
Wouters, S.E. ; Lian, W.
Author_Institution :
Dept. of Electr. Eng., Delft Univ. of Technol., Netherlands
Abstract :
A two-dimensional optical flip-flop sensor array is presented. It consists of 64 flip-flop sensors, each of which contains two phototransistors with different light sensitivity. Each flip-flop sensor senses the light intensity and converts it to a series of ones and zeros. It is operated by turning on and off the supply current with a high frequency. During the absence of light, the flip-flop is totally symmetrical, and as a result the number of ones and zeros is equal. Light causes an asymmetry in the flip-flop that changes the ratio of ones and zeros. A fully digital output is obtained by counting the number of ones. A triangle-wave voltage is applied to the flip-flop in order to vary the threshold of the flip-flop. It is demonstrated that a large array of sensors with on-spot A/D conversion can be realized using the flip-flop sensor technique
Keywords :
flip-flops; photodetectors; digital outputs; flip-flop sensor; flip-flop sensor array; light intensity; optical flip-flop; phototransistors; sensor array; threshold; Circuits; Current supplies; Flip-flops; Frequency; Intelligent sensors; Optical arrays; Optical sensors; Photoconductivity; Sensor arrays; Threshold voltage;
Conference_Titel :
CompEuro '89., 'VLSI and Computer Peripherals. VLSI and Microelectronic Applications in Intelligent Peripherals and their Interconnection Networks', Proceedings.
Conference_Location :
Hamburg
Print_ISBN :
0-8186-1940-6
DOI :
10.1109/CMPEUR.1989.93413
