High Contrast, High Resolution CDT from Samsung

As competition in the display market grows fiercer, there is a growing need for improved cathode ray tubes (CRT) image quality. Current models feature dark-tinted panels, large screens, and high-resolution CRTs. In order to meet the challenge of these competing trends, Samsung Display Devices has developed a new color display tube (CDT) which has a high-contrast ratio, dark-tinted appearance, and superior color gamut.
 The high-contrast ratio was achieved by using high-contrast phosphors. High-contrast phosphor is heavily coated with a pigment of corresponding color. In order to minimize the reduction in phosphor luminance due to thick layers of pigment, nano-sized pigment (of 20-50nm, where 1nm = 10-9 m) was used while typical pigment size is in the range of 0.2-1.0 зн ( 1зн = 10-6 m).
 As the size of particle decreases, it tends to form strong aggregates. Therefore, it is much more difficult to handle and disperse uniformly. To overcome this difficulty, a new milling process and pigmentation technique were developed. Furthermore, due to modified surface properties, Samsung found it almost impossible to implement the high contrast phosphors in its current production lines. A major problem was the weak adherence of phosphor particles to the panel surface. To compensate, photo-resist photo-sensitivity had to be increased two-fold and the UV scatterer had to be over-coated on the phosphor surface.
 By employing high-contrast phosphors, the new CDT demonstrates a 20 percent increase in contrast ratio and a 15 percent increase in color gamut. The display's contrast ratio matches that of the leading brands in the industry. The color gamut, on the other hand, is unprecedented to the point the new CDT produces images which are closer to natural color than any other CDT on the market. High-contrast phosphors can also be applied to other display devices such as color picture tubes for conventional TVs, plasma display panels (wall-hanging TVs), and other flat display devices (e.g., field emission displays).
 By the improved performance of its new CDT, Samsung Display Devices has proven once again its world leadership in cathode ray tube (CRT) technology.

Samsung Display Devices

575, Shindong, Paldal-ku, Suwon-shi, 442-390, Korea
82-331-210-7114
82-331-210-7788

Explosive Welding Technology for Tube-to-Tubesheet Joints

A Hanjung Heavy Industries nuclear power plant
steam generator made using the expansion process.

Hanjung R&D Center has successfully applied the expansion process to tube-to-tubesheet welding. The expansion process involves the welding of tubes to tubesheets by applying super-high pressure from an explosion using sheaths. A sufficiently tight seal is thus formed between tube and tubesheet to support the axial tube load. The center's Industrial Technology Development Team created a Korean first by achieving a succession of nuclear steam generation tube expansions by explosive welding technology.
 The new application of this technology means it is possible to expand many tubes simultaneously. The explosive expansion joint method is superior to the existing mechanical method by roll expander by virtue of the following advantages:

1. The production speed of the explosive method is far faster.
2. There is little or no discontinuity in the smoothness of the inner tube surface  and in stress corrosion cracking.
3. There is a minimal amount of mechanical hardness created, thus extending the  life of the incorporated products.

The technology can be utilized in various power and industrial applications, such as nuclear power plant steam generators and heat exchangers. Hanjung now plans to apply the technology to other explosive application techniques such as explosive jet-cutting, cladding and cleaning.

HANJUNG R&D Center

555, Kigok-dong, Changwon-shi, Kyongnam, Korea
Tel : 82-551-78-3762
Fax : 82-551-78-8546

High-speed Shadow Mask Pattern Inspection Machine

A new pattern inspection machine for detecting errors in shadow masks has been developed by LG Electronics Inc. The shadow mask is a key component in a color display tube. In addition, the shadow mask plays a important role in determining screen quality due to the inherent characteristics of the tube manufacturing process. Nevertheless, despite its importance, assurance of its quality has relied entirely on visual inspection rather than instrumentation. Visual inspection of the shadow mask consists of two stages, macro inspection and micro inspection. Macro inspection simply involves a check for the uniformity in the intensity of brightness through a shadow mask and a selection process to reject products showing non-uniformity. Micro inspection involves a verification process for selected products using a portable microscope. A new high-speed pattern inspection machine developed by LG Electronics has two advantages which enable it to be effectively applied in the production process to reveal defects in photo mask manufacture.

 Firstly, it provides high-speed macro inspection by high-resolution CCD (Charge Coupled Device) cameras using LG's own image enhancement filter with a high S/N (Signal to Noise) ratio. Its level of precision enables it to detect defects as low as an eight percent error in normal pattern size. An eight percent error detection rate in pattern size means that for all practical purposes human inspection can be replaced with this system.

 Secondly, it provides micro inspection with a normal CCD camera and auto focusing unit. It incorporates an algorithm to calculate distortions due to dust using image-processing and fuzzy logic techniques, so enabling it to distinguish between a defective product and a good one. The system registers three results: "OK," "NG," and "Gray." Shadow masks registering Gray should be reinspected.

 Therefore, through the integration of macro and micro inspection in one system, both high throughput and high levels of reliability in an automated inspection process can be achieved. Besides finding a ready application with photo mask manufacturers, the system can also be used by manufacturers of flat panel displays such as LCDs and PDPs with a small modification in the micro inspection algorithm.

LG Electronics, Inc.

Cheol Kee Hong / LG-PRC (Production Engineering Research Center)
19-1, Cheongho-ri, Jinwuy-myun, Pyungtaik-shi, Kyongki-do, Korea, 451-713
Tel : 82-333-660-7160
Fax : 82-333-660-7387
E-mail : ckhong@lge.co.kr

A New Generation of Secondary Battery Tester

The rapid development of the information and communication industries has boosted demand both for products such as cellular phones, camcorders, and notebook PCs, and for small-sized secondary batteries to power them. The most popular small-sized secondary batteries are the lithium-ion, lithium-polymer, and nickel-hydrogen types.
 An essential element in the production of these batteries is the charging and discharging tester, but their expense as a result of their high level of accuracy works its way down to unit costs and militates against their competitiveness. Accordingly, Power Tech Co. discerned a niche in the market for highly accurate but less expensive charging and discharging testers.
 Power Tech's tester has the following advantages:

1) Because of the precision of its components, it provides accuracy to within 0.01 percent. 2) By using low temperature coefficient parts, it records high stability during temperature changes. 3) Various operational modes available including constant current, voltage, power, resistance and voltage-dependent constant current modes. 4) Continuous control is possible when changing from charging to discharging mode. 5) Error correction is performed by software instead of variable resistors to minimize the possibility of long-term deviation. 6) Calibration is automatically accomplished by the interface of the measuring instrument with the PC. 7) The operating software is based on Windows 95 for operator convenience.

 These testers are ideal for the charging and discharging testing, plus the formation and grading of lithium-ion, lithium-polymer, and nickel-hydrogen batteries. Demand for small-sized secondary batteries is increasing and many large Korean industrial concerns are ready to invest in the market both at home and abroad.

 Due to the length of time involved in charging and discharging, large-volume testers are more suitable for mass-production. So, given the mass-capability of Power Tech's new tester its market potential is excellent. In addition, its marketability is enhanced by the fact its high throughput will result in lower secondary battery unit production costs. In addition, Power Tech's tester offers a real edge on the competition because of its high performance at a reasonable price.

Power Tech Co., Ltd.

690-3, Kumjung-dong Kunpo-shi, Kyongki-do, Korea
Tel : 82-343-56-7346, Fax : 82-343-56-3084
E-mail : d09183@nuri.net

A CDMA Cellular/PCS Network Optimization Tool

The EmDM II has been designed for the optimization of CDMA network troubleshooting, quality measurement, maintenance, benchmarking, and phone quality measurement and benchmarking.

 It features automated testing functions using GPS location data and three test handsets to monitor CDMA parameters and CAI messages in real time while logging them for post-processing analysis.

 It can be installed in a vehicle to carry out testing while in motion, or hand-carried for testing within buildings and subways. Designed to be portable, it is equipped with an internal battery and a large LCD for parameter monitoring.

 It can be used during the pre-launch stage for network service optimization and also during the post-launch optimization stage for maintaining the quality of your network at the highest level.

 As a Windows-based post-processing analysis tool, IDA II offers the necessary elements of all kinds of field optimization requirements to provide a precisely analyzed solution of your CDMA network problems. IDA (Integrated Data Analysis) allows engineers to analyze data in spread sheet, statistical, mapping, and graphical forms along with a replay function to satisfy their testing requirements.

 It can also be used to comparatively measure the quality of phones used by your subscribers. A separate analysis software package is provided to analyze the quality of phones for benchmarking purposes.

Willtech, Inc.

Seok Young Bldg. 21-5, Keoyou-dong, Songpa-ku, Seoul, Korea
Tel : 82-2-430-9155
Fax : 82-2-430-9157
Internet : www.willtechinc.com
E-mail : wti@juno.willtech.co.kr

* The items featured in this article have been selected by the Korea Industrial Technology Association (KITA) after undergoing a one-year market evaluation period.