J. Capon

Evaluation of a 64 x 64 CdSe TFT addressed ACTFEL display demonstrator

An operating ACTFEL (AC thin-film electroluminescent display), addressed with TFTs, has been demonstrated. To achieve this, the authors used self-healing electrodes, limited the power supplied to the display, and used a stepped annealing cycle for the TFTs. The display could be driven with 10-V external drivers at a frame rate of 50 Hz and an EL driving frequency of 100 Hz.<<ETX>>

CdSe-based thin-film integrated optical sensors

Abstract A fabrication method for photoconductive CdSe films, together with a photolithographic process is presented. Two types of films were realized. The first type has a low resistivity (102 Ω cm), a moderate sensitivity and is semi-transparent. The second type of film has a high resistivity (108 Ω cm) and is very sensitive. It is shown that the films meet the requirements of two applications: a luminance sensor and a linear image sensor.

Thin Film Cadmium Selenide Technology in Large Area Active Matrix High Resolution Displays

This paper considers the acceptability of an active matrix technology based on thin film polycrystalline CdSe for the industrial manufacture of large area high pixel density active matrix flat panel displays.

A lensless contact-type image sensor based on a CdSe photoconductive array

Abstract A fabrication process for a lensless contact-type photoconductive image sensor is presented. Using this technology a 200 dots per inch (dpi) sensor has been realized. Novel features are the metallic light shield and the self-aligmnent between the light shield and the photoconductive sensor element. Gains greater than 1000 are easily achieved, while the current-light characteristic is superlinear. It is also shown that the application of a positive potential to the light shield improves the speed by a factor of two. In this way, linescan times of 1 ms are obtained. It is finally shown that the realized sensor satisfies the requirements of the G3 facsimile mode.

Active matrix with integrated drivers on soda-lime glass using poly-CdSe and poly-Ge

— For the first time, a poly-CdSe active matrix with poly-CdSe/poly-Ge integrated driver circuits was realized. Despite compromises in device performance, induced by combining the existing driver and matrix technologies, excellent circuit results were obtained, with inverter delays down to 30 ns in a 25-μm technology.

OPTIMISATION OF THE DESIGN OF A DISCRETE CdSe - FLC OASLM

Abstract We present an OASLM based on a CdSe photoconductor in combination with a ferroelectric liquid crystal. Instead of using homogeneous layers, we have developed a discrete design, in which the pixels are connected to busbars through photoconductive rectangular strips. This approach lowers the resolution of the device, but also has some advantages: dark switching can easily be eliminated, thin photoconductor layers can be used, and a dielectric mirror is no longer necessary.

Geometric design of lensless photoconductive contact‐type image sensors

— Two figures of merit of the imaging process in a lensless photoconductive contact-type image sensor are described. One figure is proportional to the signal-to-noise ratio and the other figure is a measure of the strength of aliasing effects. A simple analytical model, based on a realistic “one-strip” geometry, is presented. Using this model, the effects of five geometric parameters on these figures are analyzed. It is shown that in optimizing the geometry, trade-offs will have to be made between a high signal-to-noise ratio and a good suppression of aliasing effects. The model described can be used to carry out first-order calculations in order to optimize the sensor geometry.