Computer graphics processing and selective visual display system – Plural physical display element control system – Display elements arranged in matrix
Reexamination Certificate
1999-05-06
2003-01-14
Hjerpe, Richard (Department: 2673)
Computer graphics processing and selective visual display system
Plural physical display element control system
Display elements arranged in matrix
C345S075100, C345S075200, C345S077000, C345S169000, C345S169000
Reexamination Certificate
active
06507328
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to field emission displays, and, more specifically, to a method and apparatus for controlling the brightness of a pixel by controlling the temperature of a temperature sensor in the pixel.
BACKGROUND OF THE INVENTION
In field emission displays, fast response time and high contrast are best achieved by active matrix designs—i.e., designs that employ a current switching device, conventionally one or more transistors, at each pixel of the display.
Conventional active matrix displays are fabricated on either a silicon substrate or a dielectric (typically glass) substrate.
An active matrix flat panel display having transistors fabricated from single-crystal silicon on a silicon substrate currently is feasible only for small displays. For a display area larger than several square centimeters, it is impractical to produce such a large transistor array without excessive defects, and such a large silicon substrate is undesirably fragile.
An active matrix flat panel display having thin film transistors (TFT's) fabricated on a glass substrate is much more suitable for a large area display. Such TFT designs are conventionally used for liquid crystal displays because they overcome the stated shortcomings of displays fabricated on silicon substrates. However, TFT designs are much less suitable for field emission displays, because thin film transistors typically have much higher leakage current than single-crystal silicon transistors. This leakage current is acceptable for liquid crystal displays, but not for field emission displays, because the latter are current-controlled rather than voltage-controlled and typically have time-averaged pixel currents on the order of only 10
−8
ampere or less.
Accordingly, there is a need for a field emission display that overcomes the shortcomings of single-crystal transistor arrays on silicon substrates and TFT arrays on dielectric substrates.
SUMMARY OF THE INVENTION
The invention is an active matrix display that does not require a transistor or similar current switching device at each pixel. Instead, the display employs in each pixel a temperature-controlled current source which provides to the field emitters of the pixel an amount of electrical current that varies in response to the temperature of a temperature sensor. Each pixel further includes a thermoelectric heat transfer circuit which transfers heat to or from the sensor in an amount that varies in response to the video signal. Consequently, the video signal controls the temperature of the sensor within a pixel's temperature-controlled current source, which controls the current flow through the pixel's field emitters.
REFERENCES:
patent: 3970887 (1976-07-01), Smith et al.
patent: 5075596 (1991-12-01), Young et al.
patent: 5186670 (1993-02-01), Doan et al.
patent: 5229331 (1993-07-01), Doan et al.
patent: 5391259 (1995-02-01), Cathey et al.
patent: 5587128 (1996-12-01), Wilding et al.
patent: 5721472 (1998-02-01), Browning et al.
patent: 5770919 (1998-06-01), Tjaden et al.
patent: 5909200 (1999-06-01), Hush
patent: 5910792 (1999-06-01), Hansen et al.
patent: 5970719 (1999-10-01), Merritt
patent: 6034480 (2000-03-01), Browning et al.
U. Birkholz et al., “Fast semiconductor thermoelectric devices”, Sensors and Actuators, vol. 12, pp. 179-184 (1987).
Fink, editor, “Electronic Engineers Handbook”, McGraw Hill, article entitled “Electronic Energy Conversion Methods” at pp. 27.2-27.12 (1975).
A. Hochbaum, “Thermally addressed smectic liquid crystal displays”, Optical Engineering, vol. 23, No. 3, pp. 253-260 (1984).
L.A. Johnson, “Controlling temperatures of diode lasers and detectors thermoelectrically”, Lasers and Optronics, Apr. 1988, pp. 109-114.
Lu and Davies, “Thermally and electrically addressed dye switching LCDs”, Mol. Cryst. Liq. Cryst., vol. 94, pp. 167-189 (1983).
Hjerpe Richard
Lesperance Jean
Micro)n Technology, Inc.
Stern Robert J.
LandOfFree
Thermoelectric control for field emission display does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Thermoelectric control for field emission display, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thermoelectric control for field emission display will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3058068