Completely integrated contact-type linear image sensor

A new contact-type linear image sensor has been developed, which integrates a-Si:H photodiode and poly-Si TFT driving circuits on a quartz substrate. The C-MOS shift register of poly-Si TFT can operate in the frequency range from dc to 2 MHz. The sensor contains 848 bits with the density of 8 bits/mm on the substrate of 2 × 125 mm size. A readout time of less than 1 µs, a S/N ratio higher than 40 dB, and a saturation exposure of 0.89 lx . s are obtained.