A 200/400dpi photodiode-array integrated image sensor with a poly-Si TFT driver

A 200/400dpi resolution-selectable linear image sensor with poly-Si TFT (Th in Film Transistor) driver was fabricated on an inexpensive glass substrate using a line-beam excimer laser process. A 400dpi-photodiode array, a 200d pi-photodiode array and a CMOS driver with a decoder circuit were all integ rated on the same substrate. It was operated at 2MHz with a single supply v oltage of 5V successfully. The output signal of the 200dpi-photodiode array was four times larger than the 400dpi array. Excellent spatial resolution was obtained at both resolution settings by our compact imaging configurati on, SOFI (Single Optical Fiber Imaging), using this image sensor. When this image sensor is applied for a hand-held scanner, the user will have a choi ce between fast coarse-resolution and slow fine-resolution scanning.