William D. Turner

The electronic document display : A 6.3-million-pixel AMLCD

This paper describes 6.3-million-pixel active-matrix displays in monochrome and color (1.6 million color groups) with a diagonal dimension of 33 cm (13 in.), first discussed by Martin et al. in 1993. 1 These displays have the largest number of pixels of any AMLCDs thus far reported. The monochrome display is intended for office-automation applications where there is a requirement for electronically controlled image reproduction with characteristics similar to those of a conventional laser print. This display achieves the resolution, luminance, and viewing angle required for these applications through a binary driving scheme.

High-resolution AMLCD for the electronic library system

The Electronic Library System (ELS), is a proposed data resource for the cockpit which can provide the aircrew with a vast array of technical information on their aircraft and flight plan. This information includes, but is not limited to, approach plates, Jeppeson Charts, and aircraft technical manuals. Most of these data are appropriate for digitization at high resolution (300 spi). Xerox Corporation has developed a flat panel active matrix liquid crystal display, AMLCD, that is an excellent match to the ELS, due to its innovative and aggressive design.

a-Si:H TFT-driven high-gray-scale contact image sensor with a ground-mesh-type multiplex circuit

An A4 page width and 300 dot/inch hydrogenated amorphous silicon thin film transistor (a- Si:H TFT) driven contact image sensor which can read more than 128 gray levels has been developed. Crosstalk due to the coupling between data lines in the multiplex circuit has prevented high gray scale reading. In order to eliminate crosstalk, a sensor with a new multiplex structure has been developed with a ground mesh shield layer inserted at the crossover points between each data line. The ground mesh shield pattern was designed to optimize the gray scale reproduction ratio R. With this sensor, R is more than 0.992 for a single bit, thus achieving 128 levels of gray. This design was compared to the performance of two other sensors, one without a ground mesh shield, the other using a data line meander pattern. This technology is also applicable to higher performance image sensors with greater than 400 dot/inch resolution.

High Resolution Multispectral Linear Focal Plane Using An Area Image Sensor

A technique for building a high resolution linear focal plane using a single low resolution area detector array is described. A silicon area imager is fabricated with an opaque light shield layer having small clear apertures located over the detector elements which define the picture elements. By displacing the apertures sideways from one row of detectors to the next and using the array in conjunction with a multiline data buffer, a line scan resolution equal to the total number of detector elements in the area array is achieved. The design consider-ations and tradeoffs involved in using such a technique will be discussed. A practical realization of such a system will be shown which uses an array built with a 4 X 1024 element configuration to achieve 4096 resolution elements per line. Multispectral capability is achieved by using four such arrays fabricated on the same device with spectral filtering provided by patterned interference filters on the cover slip. Array output and results of device characterization will be shown.

Laser Printing With The Linear TIR Spatial Light Modulator

A linear spatial light modulator has been developed for laser printing. It provides capability for parallel modulation of several thousand points across a line of illumination, which is then imaged onto a photosensitive medium. The spatial light modulator, which has been described previously, utilizes a VLSI silicon chip containing addressing electronics, drive transistors, and a series of metal lines. This chip is pressed against a single crystal piece of lithium niobate, so that flinging fields created by voltage differences between metal lines are proximity coupled into the crystal and generate locally controllable changes in the index of refraction. The device is read out in total internal reflection off the proximity coupling interface, with schlieren readout imaging optics used to convert the phase modulation of the wavefront to a modulated line image. This paper will review the basic device concept, describe some of the device design and operating parameters, discuss printer application considerations, and show results from a breadboard level printer.

VLSI-based image bar for laser beam recording

There are many image bar technologies which make use of a full width light modulator which projects one-to-one onto the photoconductor. An alternative to these full width image bars makes use of a micro image bar, in which all of the drive electronics are integrated on a single monolithic VLSI circuit. The TIR linear spatial light modulator is such a device which is built using an integrated circuit in conjunction with an electro-optic crystal to achieve light modulation.There are many image bar technologies which make use of a full width light modulator which projects one-to-one onto the photoconductor. An alternative to these full width image bars makes use of a micro image bar, in which all of the drive electronics are integrated on a single monolithic VLSI circuit. The TIR linear spatial light modulator is such a device which is built using an integrated circuit in conjunction with an electro-optic crystal to achieve light modulation.