A memory‐in‐pixel reflective‐type LCD using newly designed system and pixel structure

Abstract

-A 7.03-in. extended graphics array reflective LCD prototype has been developed by using memory-in-pixel (MIP) technologies with a newly designed system and pixel structure. The MIP system comprising a MIP backplane and a display driver has been optimized to reduce power consumption. The MIP backplane has specific circuits that allow accessing row drivers randomly, and the display driver manages which row should be accessed. Thus, the system is capable of showing a mixture of still and moving images, resulting in low power consumption. A dithering block embedded in the display driver enables to select an appropriate dithering algorithm according to the types of images and the position on the screen. In addition, the novel pixel structure, "three divided patterns", has been designed to improve image quality and to provide visibility in dark environments. The latter is based on a novel approach; interpixel area is used for an aperture to transmit light from the backlight, and the fringe field from adjacent pixel electrodes is used to control LC directions. The feature of the pixel structure is also effective for obtaining equivalent gamma between reflective and transmissive images.

74‐3: Development of New Error‐Diffusion Dithering Method for Reflective Memory‐In‐Pixel (MIP) LCD

“…This is why reducing the number of colors from the original image is inevitable for the MIP LCDs. When displaying an image on the MIP LCD, if we convert the original 8 bits to 3 bits simply by aborting the lower 5 bits, a tone jump is observed [1]. Error-diffusion dithering [4] can be used, then, as a color-reduction method, to improve the tone jump.…”

“…Error-diffusion dithering produces better results than ordered dithering in terms of image quality. However, when displaying a moving image, fluttering emerges on an image [1]. Figure 2 (a).…”

“…Instead, reflective LCDs in electrically controlled birefringence (ECB) mode are more suitable for displaying moving image. By applying MIP technology to the reflective LCD, we have realized a ultralow power consumption display [1] [2]. Figure 1 shows an example of a sub-pixel arrangement using the dithering method to display 32 colors (3-bit RGBW).…”

51-1: Reflective Full-Color LCD Using LTPS TFT at 1Hz with Measures against Photo Leakage Current

“…We previously reported the adoption of a memory-in-pixel (MIP) LTPS technology and newly designed scattering layer technology for our commercial wearable device products [3,4]. We also reported another type of reflective LCD with analog gray scales [5] and performed a detailed investigation of the mechanism that produced flicker and image persistence.…”

Reflective full‐color LCD using low‐temperature polysilicon TFTs in low‐frequency driving: Analysis of image persistence and flicker with scientific CMOS camera

“…We reported a reflective LCD with memory‐in‐pixel (MIP) LTPS technology, which is adopted in our commercial products for wearable devices. The MIP LTPS technology achieves ultralow power consumption, one‐tenth or less of that of non‐MIP reflective LCDs and 2% or less of that of transmissive LCDs.…”