Appeal No. 96-1378
Application 08/096,626
switches to transfer analog voltages to the display elements. In appellants
invention, the digital video signals are converted to pulse width signals that
control TFTs which are biased to operate as current sources, thereby causing
the display elements to be charged to voltage levels determined by the
duration of the respective pulse width signals.
Claim 1, which is representative, reads as follows:
1. A method of driving an active matrix display device having sets of
row and column conductors and an array of display elements each comprising
first and second electrodes with electro-optical material therebetween, the
first electrodes being connected to the drain of a respective TFT whose source
and gate are connected respectively to a column and a row conductor, in which
selection signals are applied to the row conductors and in which video
information signals are converted into corresponding time dependent signals,
characterised in that the time dependent signals are applied to the column
conductors and in that during the application of a selection signal to a row
of TFTs the TFTs are biased to act as current sources such that their
associated display elements are charged to a level dependent on the duration
of the applied time dependent signal.
The examiner relies on the following references:
Ohwada et al. (Ohwada) 4,750,813 Jun. 14, 1988
Young 5,095,304 Mar. 10, 1992
A. The ' 102(b) rejection
Claims 1-12 and 16-23 sta nd rejected under 35 U.S.C. ' 102(b) as
anticipated by Young. Since appellants have indicated (Brief at 7) that all
of these claims stand or fall together, we will consider only claim 1.
Young discloses a matrix display device whose construction permit s a
pair of rows of display elements 12 to share a single row conductor 14.
Referring to Figure 1, this as accomplished by using n-channel TFTs 11 and p-
channel TFTs 12 to control the display devices in the upper and lower rows,
respectively, of each pair, thereby permitting the upper row to be selected by
applying a positive pulse to the conductor and the lower row to be selected by
a negative pulse (Fig. 2). We do not agree with the examiner that Young
2
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