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World's First LCD Module
:: 23 May, 2007
NEC LCD Technologies, Ltd. today announced development of the world's first thin-film-transistor (TFT) liquid crystal display (LCD) prototype module with a DRAM frame memory system, corresponding to 1 8-bit color (262k colors), embedded onto the glass substrate of the LCD screen. The results of this research will be presented on May 24 at SID 2007, being held at the Long Beach Convention Center in California from May 20 to 25.
News Inside News :
Key Features-
The new LCD module has been realized by a combination of NEC LCD Technologies' own unique value integrated TFT-LCD (VIT) technology and low-temperature poly-silicon (LTPS) TFT technology, and includes the following key features.
(1) Successful design of a system LSI onto the glass substrate of the screen, utilizing a record-breaking 400,000 transistors in the peripheral circuits. The LCD integrates the peripheral circuits, including the frame memory system that incorporates a 230k-bit DRAM and a front-end picture decoder, a picture encoder, 6-bit DAC, and a controller.
(2) Adoption of NEC's proprietary graphical data compression / decompression technology, smart pixel-data codec (SPC), enables a reduction in the amount of memory required to store the data of one screen image by two thirds that required by original data that doesn't employ any kind of codec, thereby contributing to a reduction in circuit area and power consumption.
(3) Adoption of a RGB horizontal stripe for the pixel arrangement enables high density, a polychrome display, and optimization of cell layout of the graphics frame memory, simultaneously. This kind of pixel arrangement enables greater minimization of the circuit area on the glass substrate, which generally increases along with pixel density, as compared with RGB vertical stripe arrangements.
(4) The newly-developed controller enables simultaneous and independent access for writing and reading in graphics frame memory, and achieves a data transfer rate of approximately 30 frames per second, enabling smooth display of a variety of digital movie contents.
Recently, the market has seen a rapid rise in the introduction of new kinds of portable devices, such as personal digital assistants (PDAs), personal navigation devices (PNDs), smartphones and portable multimedia players (PMPs). The progression of a networked information society is concurrently creating a demand for display devices that provide a range of diverse features simultaneously, including small size, short depth, light weight, high density, high luminance, polychrome display, and low power consumption.
Accordingly, the market is seeking a reduction in the amount of display power consumption, as displays consume the greatest amount of energy in portable devices. Embedding the graphics frame memory into an LCD module is one solution as it enables preservation of the image signal transferred from the system as one set of screen data. As a result, the graphics frame memory enables screen output by reading the data preserved in the graphics frame memory when the same screen is viewed, as opposed to receiving a new image signal from the system. This realizes a significant reduction in power consumption due to reduced signal communication between the display device and the system.
Currently, graphics frame memory is realized by a COG-mounting method that attaches system-LSI chips, made on a silicon substrate, directly onto the glass substrate of the LCD. However, this poses a problem for timely manufacturing of new LCD modules as the lead time for mass production of system LSI chips is very long.
"The market is already eagerly awaiting the advancement of system-on-glass LCDs as they will eliminate the need to develop LSI chips, thereby shortening development cycles significantly, and allowing us to bring the right products to our customers and the markets faster than ever before," said Hideki Asada, Senior Manager of Research Department at NEC LCD Technologies. "Embedding the frame memory onto the glass substrate is a completely new breakthrough in system-on-glass LCD technology, and will enable significant reductions in display power consumption. This kind of new technology demonstrates the leading innovation that drives NEC LCD Technologies, and provides all of our customers with a competitive edge."
Through further development of its VIT technology to integrate peripheral circuits necessary for LCD image display, NEC LCD Technologies aims to realize a Zero Chip Display TM, which would enable direct connection to the MPU bus line of the system.
About LTPS-TFT mass production line at NEC LCD Technologies’ Akita plant -
1. Higher density through integration of peripheral circuitry
Value Integrated TFT-LCD (VIT) technology used to integrate peripheral circuitry on the glass substrate of the LCD module, enables a significant reduction in the glass substrate periphery wiring and the number of connections with external circuits, resulting in four times higher density than that of conventional 3.5-inch quarter video graphic array (QVGA) products.
2. High luminance and high reflectance ratios, even with high density
The combination of NEC LCD Technologies' proprietary super-reflective, natural light TFT-LCD technology (SR-NLT) and LTPS technology, which achieves high transmissivity, allows simultaneous realization of high luminance of 200cd/m2 and a high reflective ratio of 10%, even with a high density of 200 pixels per inch. Moreover, it achieves a high contrast ratio of 150:1. These factors jointly combine to realize bright and crystal clear display in any kind of ambient light environment.
3. Equipped with touch-panel, timing controller, and DC-DC converter
Equipped with a touch-panel, timing controller, and a DC-DC converter, the new module offers a range of benefits to manufacturers of portable information devices, from a reduction in development costs and lead time, to the miniaturization of portable information devices.
NEC LCD Technologies has been developing higher value-added, small-sized LCD modules for next generation PDAs, PNDs and various portable terminals in recent years, with a focus on LCD modules for high-end professional and industrial fields.
Conatact USA -
NEC Electronics America, Inc
Display Business Unit
2880 Scott Boulevard Santa Clara, CA 95050
Press ContactsIn Japan
Diane Foley
NEC LCD Technologies
d-foley@ax.jp.nec.com
+81-3-3798-6511
Release link: http://www.nec.co.jp/press/en/0705/2301.html
Tags: LCD Module , DRAM Frame-Memory System , Glass Substrate , TFT-LCD (VIT) techn ,
