Design and implementation of a wavelet‐based addressing technique (WAT)

Abstract

-The design and implementation of a wavelet-based addressing technique capable of displaying gray shades is presented. The hardware complexity of the display drivers has been reduced by adding a few analog multiplexers that are common to the drivers. The controller was implemented by using a low-cost complex programmable logic device (CPLD) and it was demonstrated by displaying 16 gray shades in a liquid-crystal display.

Scanning Matrix Displays With Wavelets

“…10. The first [2] and second [5] prototype use Haar wavelets to display 8 and 16 gray shades by selecting three rows at a time [2]. The third display is driven by modified slant wavelets to demonstrate that complexity of the controller does not depend on the complexity of the wavelets and just the data bits are adequate (not necessary to take the orthogonal transform of data) and the supply voltage is lower than that of multi-line successive approximation technique [6].…”

“…Liquid crystal displays respond to the RMS voltage of the electric field and the expression of RMS voltage across a pixel is given in (4) Energy delivered to the pixel during is proportional to the following expression: (5) and (6) The order of summation and integration is changed second term in (6). This term is useful for de-multiplexing as shown in Figs.…”

P‐178: Modified Discrete Cosine Transform for Addressing Liquid Crystal Displays

“…There are several addressing techniques for displaying gray shades in passive matrix liquid crystal displays (LCDs). Amplitude modulation [1], pulse height modulation [2], successive approximation techniques [3,4] and wavelets based techniques [5][6][7] are some of the techniques that can be used to display gray shades. Grayscale to grayscale response times i.e.…”

P‐123: A Method to Achieve Uniform Gray Scale to Gray Scale Response Times in LCDs

“…Uniform switching times was achieved with modified discrete cosine transform to drive LCD and was demonstrated in SID'08 1 . Main objective of this work is to achieve uniform switching times with multi-line addressing techniques like wavelets based techniques [2][3][4] that are capable of displaying a large number of gray shades without flicker.…”