Showing posts with label BLU. Show all posts
Showing posts with label BLU. Show all posts

Friday, June 13, 2008

Carbon nanotubes induced high efficiency plasma backlight panel

Abstract

We fabricated a carbon nanotubes (CNTs) induced plasma backlight panel (CNTs-PBP).

This flat plasma panel has unique properties which are low power consumptions, high luminous efficiency, simple production process and low prime cost. Firstly we used the indium-tin-oxide (ITO) glasses as the substrate of the front and the rear panel. The ITO film is used for the electrodes in the light panel. The phosphor powder which was visible light excited and mixed with the commercial binder (BP-55), then screen printed on the ITO-glass substrates. In this process, we added some CNTs in the phosphor powder. This is the key point about the low breakdown voltage of the plasma generation. After fabricated the panel, we measured the luminance intensity, chromaticity diagram, current and voltage characteristics, emission light spectrum and the Paschen's behavior of the device. Furthermore we optimized the luminance of the device with different methods such as adding a reflection layer behind the rear panel, mixing helium gas into the argon plasma and driven the prototype panel by pulse voltage. In the conclusion, the device has a good luminance 550 cd/m2(nits) and a low power consumption 1.4 W. And we also attempt this approach in a study-commercial 14-inch AC- PBP which fabricated in Chunghwa Picture Tubes, LTD. (CPT) while the presence of the CNTs that increased almost 20% of the luminous efficiency at the commercial
luminance intensity standard (10,000 cd/m2) of the backlight panel.
Author - Hui-Chien Ko

Source

PDF File

Conclusions
The unique geometric structure of CNTs can raise the ionization rate in the gas
discharge was obtained by gas breakdown characteristic and the glowing plasma intensity which are shift Paschen’s curve and enhance plasma spectrum. In this way, the CNTs have an advantage of low power consumption in plasma backlight application.

We have successfully demonstrated a CNTs induced plasma backlight panel and the experiment results indicate that the CNTs can enhanced the luminous efficiency on the plasma backlight panel. The Xe-CNTs-PBP produced a uniform emission light without any light diffuser assistant. The luminance of the Xe-CNTs-PBP is 200 cd/m2 while driven by DC power. With the pulse driven circuit the luminance of the Xe-CNTs-PBP increased ~170% to reach luminance 550 cd/m2 with 1.4 W. These results indicate that CNTs have unique properties which are suitable for used in flat light source. The advantage of using CNTs in such application is low power consumptions and good luminous efficiency which provides a better solution for commercial plasma visible light panel.


Tuesday, May 6, 2008

The high contrast ratio and fast response time of a liquid crystal display lit by a carbon nanotube field emission backlight unit

Young Chul Choi et al 2008 Nanotechnology 19 235306 (5pp) doi: 10.1088/0957-4484/19/23/235306 Help

PDF (943 KB) | References


Young Chul Choi, Ji Won Lee, Su Kyung Lee, Mun Seok Kang, Chang Soo Lee, Kyu Won Jung, Ji Hong Lim, Jong Woon Moon, Myung Ick Hwang, Il Hwan Kim, Yun Hee Kim, Byong Gon Lee, Hyung Rae Seon, Sang Jin Lee, Jong Hwan Park, Yong C Kim and Hun Soo Kim
Display Laboratory 3 Group, Corporate R&D Center, Samsung SDI, 428-5, Gongse-dong, Giheung-gu, Yongin, Gyeonggi 446-577, Republic of Korea
E-mail: hs88.kim@samsung.com

Abstract. We report on the fabrication of a carbon nanotube field emission backlight unit (CNT-BLU) and its application for liquid crystal displays (LCD). The CNT-BLU was operated with locally controllable luminance and impulse-type scanning. The local luminance control, which is based on a very small block size of 1 cm2, consisted of local dimming and local brightening. This resulted in the contrast ratio of the LCD-TV to be as high as 300 000:1. A fast response time of ~5.7 ms was also achieved from the LCD-TV lit by CNT-BLU, originating from the impulse-type scanning. In addition, the CNT-BLU showed long-term emission stability and high luminance uniformity.

Print publication: Issue 23 (11 June 2008)
Received 7 March 2008, in final form 10 April 2008
Published 6 May 2008

Source

Conclusion - from PDF:

4. Conclusion
We have developed an FE-BLU using a CNT emitter (CNTBLU), and then analyzed its field emission characteristics including emission current, stability and uniformity. Well distributed CNTs were precisely integrated into gate holes through simple photolithography and a surface treatment process. The CNT-BLU generated high emission current with long-term stability and the observed emission uniformity was high enough to be used for an LCD-TV. The image characteristics of an LCD-TV lit by the CNT-BLU were evaluated and compared with those by a CCFL. Compared with a CCFL backlight, at least 200 times enhanced contrast ratios and three times improved response times were demonstrated by using the CNT-BLU. These were achieved by fine local luminance control and impulse-type scanning, respectively. Achieving these technologies using CNT emitters is believed to be very promising for the next-generation LCDs with excellent image characteristics.

Wednesday, February 27, 2008

GROUP IV Semiconductor patents

I did a search and found these (will they render CNT, SED, LCD, plasma, OLED to the garbage heap?):

Results of Search in US Patent Collection db for:
AN/"Group IV"
: 2 patents.
Hits 1 through 2 out of 2





PAT. NO.
Title
1 7,122,842 Full-Text Solid state white light emitter and display using same
2 7,081,664 Full-Text Doped semiconductor powder and preparation thereof

LINK

1) includes a BLU embodiment as well as a display embodiment.

This Japanese patent also looks interesting:
United States Patent 6,897,604
Koshida May 24, 2005

Method of generating ballistic electrons and ballistic electron solid semiconductor element and light emitting element and display device

Abstract

A method of generating ballistic electrons with a high controllability by applying an electric field to a nano-structure micro-crystal layer or a semi-insulating layer of a semiconductor to generate ballistic electrons or quasiballistic electrons by a multiple-tunnel effect; and a semiconductor device used in this method and provided with a practical material constitution.


Inventors: Koshida; Nobuyoshi (Tokyo, JP)
Assignee: Japan Science and Technology Corporation (Saitama, JP)
LINK

Saturday, February 2, 2008

Backlight +CNT Patents

LINK

1-3 are assigned to SAMSUNG