Juris Andrejs Asars

A High Resolution Rapid-Scanning Spectrometer

A Czerny-Turner type spectrometer has been designed and operated as a rapid scanning instrument by placing a rotating mirror near the exit slit. Using a helium-neon gas laser, resolution of 0.027 A has been measured at scanning rates of 0.4 A/microsec. Data have been taken with the scanning rate of 6 A/microsec, which could have been increased an order of magnitude if desired. A scanning range of 1-600 A depending on the grating and mirrors used has been obtained. Applications shown included the shift and shape of xenon spectral lines in a pulsed arc discharge. The associated electronics required for synchronization are included.

Test Station For Thin Film Electroluminescent (TFEL) Edge Emitter Array, A Potential Low-Cost, All Solid State Imaging Device

A test station was developed to evaluate the TFEL edge emitter array in various imaging applications. It consists of 400-dpi and 20-dpi resolution edge emitter array test samples, a sample mount that accepts both kinds of edge emitters, and an electronic drive system. The drive system provides variable drive frequency and excitation voltage, internal test patterns, and an option for external data input. As an example of its capabilities, electrophotographic printing samples are shown.

Gray scale and resolution enhancement capabilities of edge emitter imaging stations

Westinghouse has developed a thin film electroluminescent (TFEL) edge emitting imaging station for use in electrophotographic printing. The physical and electrical drive characteristics offer unique opportunities for gray-scale printing and resolution enhancement. The physical dimension of the light-emitting element in the process direction is less than to micrometers . In addition, the light output of the edge-emitting array is not Lambertian but, rather, is highly directed. The majority of light is emitted in a wedge with a 30 deg half angle measured form the plane of the device. The array is activated by an ac waveform. Light emission occurs as the field across the device changes direction. The rise time to peak light emission is a few microsecond(s) and the decay is a few hundred microsecond(s) . This allows an array element to be turned on and off several times during the exposure of a single 300 dot-per-inch pixel in a low-speed printer. This paper provides a detailed description of the physical dimensions, electronic drive system, and light emission characteristics of edge-emitting array. Several print samples are shown illustrating the gray scale and resolution enhancement capabilities.

Development of full-size thin film electroluminescent Edge Emitter array for electrophotographic applications

A full size 400 dpi Edge Emitter array was designed and constructed. The light-emitting edge is 8. 18 inches long capable of printing across the full width of the page. An Edge Emitter head was assembled consisting of three components: a 400 dpi Edge Emitter array a circuit board containing the channel driver ICs and a SELFOC R lens array in a frame. The frame also provided the means of mounting in a 6 ppm electrophotographic printer. Pages of graphics and alphanumerics were printed to demonstrate capabilities of the Edge Emitter array. 1.

A Multiplexed Drive Mode For A TFEL Edge Emitter Array

The already low cost of the thin-film electroluminescent (TFEL) edge emitter imaging station will be further reduced by implementation of a multiplexed drive system. Therefore, the multiplexing modes for TFEL edge-emitting devices were examined. Several multiplexing modes were tested and 12.5% duty cycle was selected as having the potential to be the most economical. It was demonstrated that the output power required for printing can be maintained at this level of multiplexing.