Browse Prior Art Database

APPARATUS AND METHOD FOR SPEEDING UP DIPLAY RESPONSE

IP.com Disclosure Number: IPCOM000014285D
Original Publication Date: 2000-Jan-01
Included in the Prior Art Database: 2003-Jun-19
Document File: 2 page(s) / 230K

Publishing Venue

IBM

Abstract

Discolsed is an apparatus and method for speeding up display response. In some cases, display devices are not fast enough to show images that change quickly. The disclosed overcomes the slowness by providing a digital method, while prior arts have employed analog circuit techniques such as speedup condensers. The disclosed method modifies input pixel data adaptively so that changes from previous to current pixel data shown or to be shown are amplified in some degree. This is known as overdrive. The present method performs overdrive digitally. The overdriven data compensate low pass filter nature of the display devices /human visual systems and are shown/perceived more quickly. Human psycho-visual system should remove or smooth temporal edginess caused by the overdrive, if any. FIG. 1 shows the conceptual block diagram of the overdrive method in Z-Transfrom domain. Input pixel data, X, is amplified by factor b, while previous output data, Z:sup.-1:esup.Y, is amplified by factor a. Then the amplified previous Y is subtracted from the amplified X and the difference is output as new Y. The system function is Y bX (1 aZ:sup.-1:esup.)

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APPARATUS AND METHOD FOR SPEEDING UP DIPLAY RESPONSE

    Discolsed is an apparatus and method for speeding up display response. In some cases, display
devices are not fast enough to show images that change quickly. The disclosed overcomes the slowness
by providing a digital method, while prior arts have employed analog circuit techniques such as
speedup condensers.

The disclosed method modifies input pixel data adaptively so that changes from previous to current
pixel data shown or to be shown are amplified in some degree. This is known as overdrive. The present
method performs overdrive digitally. The overdriven data compensate low pass filter nature of the
display devices /human visual systems and are shown/perceived more quickly. Human psycho-visual
system should remove or smooth temporal edginess caused by the overdrive, if any.

FIG. 1 shows the conceptual block diagram of the overdrive method in Z-Transfrom domain. Input pixel
data, X, is amplified by factor b, while previous output data, Z:sup.-1:esup.Y, is amplified by
factor a. Then the amplified previous Y is subtracted from the amplified X and the difference is
output as new Y. The system function is

Y = bX / (1 + aZ:sup.-1:esup.)

Following conditions must be met.

    |a| < 1 for stability
b=1+a for zero offset in steady state for STEP input
a > 0 for overdrive (no effect whena=0,a<0for underdrive)
FIG. 2 is a preferred conceptual diagram with above consideration. Note that there are other
equivalent system implementations.

FIG. 3 shows preferred embodiment for hardware implementation based on FIG. 2. The diagram shows one
set of blocks for one color component or gray display systems. For N-color components systems, N such
set of blocks can be used in parallel or single such set of blocks N-times in serial. Also note that
the amplifier factor 'a' can be different for each components to reflect sensitivity of human visual...