| 摘要 |
PURPOSE:To attain high-order time-division driving and to increase the process speed of a copying machine by driving a thin-film transistor (TR) whose channel length and channel width meet specific requirements on time-division basis and switching respective openings of liquid crystal shutters in a matrix array. CONSTITUTION:A liquid crystal shutter array formed in a matrix is composed of capacitive type load elements having capacity C between segment electrodes and counter electrodes and shutters are opened and closed through thin-film TRs to which the segment electrode 307 and drain electrode 304 of a load element are connected. When the ratio W/L of the length channel length L between the source electrode 303 and drain electrode 304 of this TR and the length channel width W of the drain electrode 304 satisfies an expression I, the TR is driven on high-order time-division basis to increase the S/N of a liquid crystal image and open and close the shutter at a high speed, thereby speeding up the precess of the copying machine. In the expression, (f) is the frame frequency of a gate-on pulse, Vs is the source voltage, and (n) is the number of matrix lines. |
