Engineering topics

Tower, John R.

Publications and source records attributed to Tower, John R..

3 records

NASA NTRS1991

Multichip imager with improved optical performance near the butt region

A compound imager consists of two or more individual chips, each with at least one line array of sensors thereupon. Each chip has a glass support plate attached to the side from which light reaches the line arrays. The chips are butted together end-to-end to make large line arrays of sensors. Because of imperfections in cutting, the butted surfaces define a gap. Light entering in the region of the gap is either lost or falls on an individual imager other than the one for which it is intended. This results in vignetting and/or crosstalk near the butted region. The gap is filled with an epoxy resin or other similar material which, when hardened, has an index of referaction near that of the glass support plate.

Kinnard, Kenneth P.↗

NASA NTRS1989

Floating-diffusion electrometer with adjustable sensitivity

The effective capacitance of the floating diffusion in a floating-diffusion electrometer is modified to adjust electrometer sensitivity. This is done by changing the direct potential applied to a gate electrode proximate to the floating diffusion.

Tower, John R.↗

NASA NTRS1987

Charge-coupled-device parallel-to-serial converter

A CCD parallel-to-serial converter comprising two successions of charge transfer stages, recurrently side-loaded with respective ones of parallelly supplied charge packets, then serially unloaded by time-interleaved respective shift register operations. The charge packets converted to time-division-multiplexed serial form are supplied to a shared electrometer, and the electrometer response is de-multiplexed. Preferably, shift register operations are carried forward concurrently at the same rate, but with the final charge transfer stages clocked in phases staggered in time.

Tower, John R.↗