Multi-format active matrix displays

A multi-format digital to analogue converter for a data driver for driving data, lines of an active matrix display, the digital to analogue converter being arranged to operate in either low or high resolution modes, and comprising:

• (a) converter input means arranged to receive a digital input containing at least (n+m) bits and representing the switching level of a pixel of the display, where n and m are integers;
• (b) a decoder arranged to receive m bits of said digital input, and also to receive (2m+1) reference voltages each corresponding to a different value of said m bits, and having lower and higher decoder outputs which provide lower and higher decoder output voltages respectively, which are a consecutive pair of said reference voltages, with one of said consecutive pair corresponding to the value of said m bits;
• (c) an n bit digital-to-analogue converter arranged to receive n bits of said digital input, wherein said m bits are more significant than said n bits, and having a converter output which provides a converter output voltage corresponding to said (n+m) bit digital input for supply to said pixel of the display;
• and
• (d) an n bit converter switch for switching said n bit digital-to-analogue converter on in said high resolution mode and off during said low resolution mode, so as to ensure that said n bit digital-to-analogue converter consumes substantially no, or at least less, power in said low resolution mode.

A multi-format data driver for driving data lines of an active matrix display, comprising:

• a multi-format sampling register for a data driver for driving data lines of an active matrix display, the sampling register being arranged to operate in either high, or low resolution modes, and wherein the multi-format sampling resistor includes,
• (a) sampler input means arranged to receive a digital input containing at least (n+m) bits and representing the switching level of a pixel of the display, where n and m are integers:
• (b) a first sampler comprising m sampling circuits, each arranged to sample one of m bits of said digital input;
• (c) a second sampler comprising n sampling circuits, each arranged to sample one of n bits of said digital input, wherein said m bits are more significant than said n bits:
• and
• (d) a second sampler switch arranged to switch said second sampler on in said high resolution mode and off in said low resolution mode, so as to ensure that the second sampler consumes substantially no, or at least less, power when the sampling register operates in said low resolution mode, and
• a multi-format digital to analogue converter for a data driver for driving data lines of an active matrix display, the digital to analogue converter being arranged to operate in either low or high resolution modes, and wherein the multi-format digital to analogue converter includes,
• (e) converter input means arranged to receive a digital input containing at least (n+m) bits and representing the switching level of a pixel of the display, where n and m are integers;
• (f) a decoder arranged to receive m bits of said digital input, and also to receive (2m+1) reference voltages each corresponding to a different value of said m bits, and having lower and higher decoder outputs which provide lower and higher decoder output voltages respectively, which are a consecutive pair of said reference voltages, with, one of said consecutive pair corresponding to the value of said m bits,
• (g) an n bit digital-to-analogue converter arranged to receive n bits of said digital input, wherein said m bits are more significant than said n bits, and having a converter output which provides a converter output voltage corresponding to said (n+m) bit digital input for supply to said pixel of the display, and
• (h) an n bit converter switch for switching said n bit digital-to-analogue converter on in said high resolution mode and off during said low resolution mode, so as to ensure that said n bit digital-to-analogue converter consumes substantially no, or at least less, power in said low resolution mode.