Nicholas Lawrence

9.1: Combined Image Decompression and Display Driving Using Wavelet-Based Multiple Line Addressing

A novel method of generating column waveforms for multiple-line addressing (MLA) of STN-LCDs is proposed. Row waveforms are designed based on a matrix representation of multi-scale discrete wavelet transforms (DWTs), leading to a low-power system suitable for mobile communication devices.

Optical design of a tiled large-area photoluminescent liquid-crystal display

We outline a novel imaging approach in tiling liquid-crystal panels seamlessly in a photoluminescent liquid-crystal display (PLLCD) architecture. The optical design of a tiled PLLCD is presented in this paper. The key advantages of the front-face and rear-face optical design are reviewed.

Integrated image decompression and display driving for portable communication devices using DWTs

In portable communication devices there is a strong incentive to extend battery life through reduced power consumption of all system elements. This paper proposes a novel integration of image decompression and passive-matrix liquid crystal display driving through the application of DWT methods to the field of Multiple Line Addressing (MLA). This eliminates for the first time the need for data conversion between the decoded image and a format suitable for input to the display drivers. This is achieved by exploiting an inherent property of the liquid crystal to perform a 1-D inverse wavelet transform on the compressed incoming data. The paper presents a comparison of system performance for different wavelets, taking into account image compression rates, display performance and circuit complexity. It also presents a detailed system architecture and a discussion of the benefits and possible applications for such a scheme.

Design of a tiled PL-LCD large-area display

We investigate aspects of the design of a large area display based on seamless tiling of Photoluminescent LCD (PL-LCD) panels. This paper discusses and illustrates the design methodology involved in optically tiling PL-LCD panels to make arbitrarily large displays. Suitable magnification, image quality and throw were achieved through optimization of the front-face optical system. In addition, active and passive-matrix drive schemes were investigated with regard to the throughput, contrast-ratio and video-rate performance.