PURPOSE: To reduce manufacturing cost considerably by forming a large number of thin film transistors constituting a memory part and a control circuit part on a base plate and a thin film photosensor for light signal entry and exit and a liquid crystal shutter thereon.

CONSTITUTION: A metal film (m) is deposited entirely over a base plate 11. The metal film (m) is patterned to simultaneously shape source electrodes 26 and 36 and drain electrodes 27 and 37 for TFT 21 for memory use and TFT 31 for control use and a pair of electrodes 43 and 44 for a thin film photosensor 40 and the memory TFT 21, the control TFT 31 and n-type semiconductor layers 25, 35 and 42 of the thin film photosensor 40 are patterned into the same shape as the electrodes 26, 27, 36, 37, 43 and 44, respectively, to simultaneously complete the memory TFT 21, the control TFT 31 and the thin film photosensor 40. A protective insulating film 70 is deposited entirely over the base plate 11 to cover the memory TFT 21, the control TFT 31 and the thin film photosensor 40 and a liquid crystal shutter 50 is formed on the protective insulating film 70.