A 2048-element contact-type linear image sensor for facsimile

In order to realize more compact facsimile equipment, a contact type linear image sensor has been developed. The imager has the same length as the document width and does not require an optical lens system, as the imager virtually contacts the document. A new fabrication process, which combines CdS chemical bath deposition and CdSe vapor deposition, is adopted for photoconductive thin film. The process condition for CdS-CdSe mixing ratio is established to most suitably satisfy facsimile application characteristics, such as spectral response and photo response speed. By paying particular consideration to such structure design as the sensing aperture and scanning circuit, trial 2048-element, 256 mm long imager was successfully fabricated. Evaluation of the trially fabricated imager and its photo-electric conversion unit showed excellent operational properties and utilization for facsimile equipment.