Uniform carbon‐nanotube emitter for field‐emission displays

Abstract— The synthesis of carbon‐nanotube (CNT) field emitters for FEDs by thermal chemical vapor deposition (CVD) and their structural and emission characterization are described. Multi‐walled nanotubes (MWNTs) were grown on patterned metal‐base electrodes by thermal CVD, and the grown CNTs formed a network structured layer covering the surfaces of the metal electrode uniformly, which realized uniform distribution of electron emission. A technique for growing narrow MWNTs was also developed in order to reduce the driving voltage. The diameter of MWNT depends on the growth temperature, and it has changed from 40 nm at the low temperature (675°C) to 10–15 nm at the high temperature (900–1000°C). Moreover, narrower MWNTs were grown by using the metal‐base electrode covered with a thin alumina layer and a metal catalyst layer. Double‐walled nanotubes (DWNTs) were also observed among narrow MWNTs. The emission from the narrow CNTs showed a low turn‐on electric field of 1.5 V/μm at the as‐grown layer.     

Influence of fibre length and filler particle size on pore structure and mechanical strength of filler‐containing paper

Test sheets were prepared by incorporating softwood pulp with silica filler, PW‐5 (diameter 4.5 μm) or PW‐20 (15 μm). Length‐weighted averages of fibre were 2.5 (uncut fibre) and 1.25 mm (short‐cut fibre). Pore sizes less than 150 urn were measured by mercury porosimeter. Sheets of short‐cut fibres and mixed with uncut fibres at ratio of 3:1 or 1:3 had larger pore volumes than others tested. When filler content increased, the total pore volume increased for PW‐20 sheets, but it did not for PW‐5 sheets with short‐cut fibres. Tensile index and folding endurance were very much affected by fibre length. Contact number on a fibre was calculated by computer simulation, and it had a linear relation with tensile index of sheet.     

High‐luminance 1.8‐mm‐pixel‐pitch CNT‐FED for ubiquitous color character displays

Abstract— A high‐luminance 1.8‐mm‐pixel‐pitch CNT‐FED for color character displays has been developed. The display panel has 32 × 256 color pixels, and the subpixel size is 0.6 × 1.8 mm. The display panel can provide good visibility when installed even in outdoor locations. The power consumption is low enough for the display to be battery driven. The practical application is the display of important messages regarding the evacuation from disaster areas, even under emergent no‐power conditions similar to the messages on vending machines.     

Practical CNT‐FED structure for high‐luminance character displays

Abstract— A high‐luminance CNT‐FED character display using a simple line rib structure was constructed. The display panel had 48 × 480 dots and the subpixel pitch was 1 mm. The greatest benefit of a display using CNT technology is high luminance performance with low‐power consumption. The luminance of the green‐color dot wasca. 10,000 cd/m² under 1/1 6 duty‐cycle driving at a 6‐kV anode voltage. The high luminance of the display panel can provide good visibility when installed even in outdoor locations, and the power consumption was ca. 4 W at the character displaying module. This, a CNT‐FED for character displays also has potential multifunctionality, which could be battery driven. It should be useful for public displays even under emergency no‐power conditions. In this work, a practical structure and process technologies for making ribs with reasonable cost were developed. The newly introduced 2‐mm‐tall line ribs as spacers were formed by using innovative production processes; i.e., the rib paste was pushed out of a multi‐slit nozzle, and the rib shape was formed by UV‐light irradiation. The developed panel structure and manufacturing processes also had the advantages of size flexibility and high production yield.     

Large‐area FEDs with carbon‐nanotube field emitter

Abstract— Application of carbon nanotubes (CNTs) as field emitters for large‐area FED panels is described. In 1998, we presented the first experimental devices: light‐source tubes for outdoor large‐area displays and a diode‐type flat‐panel display, both with screen‐printed CNT cathodes. The fisrt practical high‐luminance color CNT‐FED panel was built in 1999. It employed the new triode‐structure panel was x‐y addressable. The CNT‐FED structure was further optimized for large‐area display panels by improving the luminous uniformity. This paper also describes the design and performance of a new, experimental, 40‐in.‐diagonal panel, which showed that the CNT‐FED technology is suitable for use in large‐area displays.