• 대한전자공학회논문지SD
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• 제39권2호
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• pp.1-6
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• 2002

본 논문에서는 UXGA(Ultra extended Graphics Array)급 TFT LCD Driver를 지원하는 Analog Flat Panel Interface(AFPI)용 Module을 설계하였다. 제안하는 AFPI는 8-b ADC, 자동이득 제어기(AGC), 저잡음 PLL로 구성 되어있다. 8-b ADC는 고속동작과 저전력 기능을 위한 새로운 구조로서 FR(Folding Rate)이 8, NFB(Number of Folding Block)이 2, Interpolation rate이 16이며, 분산 Track and Hold구조를 사용하여 Sampling시 입력주파수를 낮추어 높은 SNDR을 얻을 수 있었다. 또한 Gain과 Clamp을 통제 할 수 있는 Programmable한 AGC, 낮은 Jitter Noise PLL을 설계하였다. 제안된 Module은 0.2㎛, 1-Poly 5-Metal, n-well CMOS공정을 사용하여 제작되었으며, 유효 칩 면적은 3.6mm × 3.2mm이고 602㎽의 전력소모를 나타내었다. 입력 주파수는 10㎒, 샘플링 주파수 200㎒에서의 INL과 DNL은 ±1LSB 이내로 측정되었으며, SNDR은 43㏈로 측정되었다.

• 소성∙가공
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• 제14권3호
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• pp.282-290
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• 2005

Nowadays, TFT-LCD is widely used as display unit of many digital devices. And, the backlight unit(BLU) is used as a light source of TFT-LCD module. In the backlight unit, the most important component is a light guide, which guides the input light to the TFT-LCD module uniformly. Recently, many researchers have focused on improving the efficiency of BLU by changing the design and structure of a light guide. In the present paper, a series of simulation was performed to find the optimal luminance distribution of emanated light from the given geometry as the first step. From the results of simulations for the light guide with given V-groove pattern, the emanated light from it is mostly affected by the groove angle. In the case of acute angle, about 74 degrees was found as optimal angle to satisfy the restrictions of angular luminance distribution, FWHM, the maximum luminance, etc. However, as far as the average luminance value was concerned, the case of 120 degrees(abtuse angle) was found to be the best while prism films were added to the BLU. As a next step the light guide samples of 74 and 120 degrees were manufactured by DSF method, which was recently proposed by the authors. Of course, most of design parameters were chosen by the aid of simulation results. Finally, the results of average luminance values were compared between the simulation and DSF molded samples.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2002년도 International Symposium
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• pp.21-30
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• 2002

According the difference of flex substrate, (reel tape), there are three kind assembly types of LCD driver IC is COG, TCP and COF, respectively. The TCP is the maturest in these types for stability of raw material supply and other specification. And TCP is the major assembly type of LCD driver IC and the huge demand from Taiwan's large TFT LCD panel house since this spring. But due to its package structure and the raw material applied in this package, there is some limitation in fine pitch application of this package type, (TCP). So, COF will be very potential in compact and portable application comparison with TCP in the future. There are three kinds assembly methods in COF, one is ACF by using the anisotropic conductive film to connect the copper lead of tape and gold bump of IC, another is eutectic bonding by using the thermo-pressure to joint the copper lead of tape and gold bump of IC, and last is NCP by using non-conductive paste to adhere the copper lead of tape and gold bump of IC. To have a global realization, this paper will briefly review the status of Taiwan's large TFT panel house, the internal driver IC design house, and the back-end assembly house in the beginning. The different material property of raw material, PI tape is also compared in the paper. The more detail of three kinds of COF assembly method will be described and compared in this paper.

• ETRI Journal
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• 제25권5호
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• pp.288-296
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• 2003

In this study, we present a 260k color TFT LCD driver chip set that consumes only 5 mW in the module, which has exceptionally low power consumption. To reduce power consumption, we used many power-lowering schemes in the logic and analog design. A driver IC for LCDs has a built-in graphic SRAM. Besides write and read operations, the graphic SRAM has a scan operation that is similar to the read operation of one row-line, which is displayed on one line in an LCD panel. Currently, the embedded graphic memory is implemented by an 8-transistor leaf cell and a 6-transistor leaf cell. We propose an efficient scan method for a 6-transistor embedded graphic memory that is greatly improved over previous methods. The proposed method is implemented in a 0.22 ${\mu}m$ process. We demonstrate the efficacy of the proposed method by measuring and comparing the current consumption of chips with and without our proposed scheme.

• 소성∙가공
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• 제17권6호
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• pp.436-442
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• 2008

As the structure of a mobile phone becomes thin to catch up with a slim product trend, the structural strength and resistance to shock of TFT-LCD module are getting to be reduced. Hence, TFT-LCD module is the strength reinforced by bezel frame. The bezel frame was produced by the multi hemming processes with several folding parts. The determination of the optimal number of hemming part and structure of bezel frame are very important process parameter to obtain the strength of that. The effect of process parameters on strength of bezel frame was investigated by FEA. Based on the result of FEA, the experiment was performed using manufactured hemming die, the result of the experiment was compared with FEA and verified. Also, three point bending tests were performed to check the strength of bezel frame.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 The Korea-Japan Plastics Processing Joint Seminar
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• pp.73-77
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• 2003

The backlight unit(BLU) is used as a light source of TFT liquid-crystalline-display (TFT-LCD) module. In this backlight unit, one of important components is the light guide, which is usually made of transparent polymers. Currently the screen-printing method is mainly used for the light guide as a manufacturing process. However, it has limitation to the flexibility of three-dimensional optical design. In the present paper a new alternative manufacturing method for the light guide with low-cost is proposed. This manufacturing method is named as direct surface forming (DSF), which is very similar to the well-known hot embossing except for partial contact between mold and substrate. The results of this new manufacturing method are presented in terms of processing condition, dimensional accuracy, productivity, etc.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.285-288
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• 2005

A 2.8 inch fully integrated SOP employing a high performance LTPS CMOS TFT technology has been developed for mobile display applications. The LCD module is directly interfaced with 3V 6-bit RGB source via timing control circuitry. The integrated data driver comprises a 6-bit hybrid type DAC with low power analog buffer.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.449-451
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• 2002

We reported the algorithm of driving scheme that enhances moving picture property by improving gray-to-gray response time. Here, we report result of simulation for estimation of driving voltage to reduce response time, and experimental result. We investigated optimization of algorithm so that minimum size of LUT can support to reducing the gray-to-gray response time within 1 frame period, and with single algorithm it is possible to apply the algorithm to various kinds of LC material. So in our system there is no external EEPROM.

• 한국정보통신학회논문지
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• 제11권10호
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• pp.1899-1909
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• 2007

본 논문에서는 TFT-LCD 구동 IC 모듈의 소형화 측면에서 유리한 DC-DC 변환기 회로인 펌핑 커패시터 내장형 크로스-커플드 전하펌프(Cross-Coupled Charge Pump with Internal Pumping Capacitor) 회로가 새롭게 제안되었다. VGH 및 VGL 전하펌프 각각의 입력단과 전하 펌핑 노드를 연결하는 NMOS 및 PMOS 다이오드를 두어, 초기 동작 시 전하 펌핑 노드를 서로 같은 값으로 프리차지하여 대칭 적으로 전하 펌핑을 하도록 하였다. 그리고 첫 번째 전하 펌프의 구조를 다르게 설계하여 펌핑된 전하가 입력단으로 역류되는 현상을 방지하였다. 또한, 펌핑 클럭 구동 드라이버의 위치를 펌핑 커패시터 바로 앞에 두어 기생 저항으로 인한 펌핑 클럭 라인의 전압강하를 방지하여 구동능력을 향상 시켰다. 마지막으로 내장형 펌핑 커패시터를 Stack-MIM 커패시터를 사용하여 기존의 크로스-커플드 전하펌프 보다 레이아웃 면적을 최소화하였다. 제안된 TFT-LCD 구동 IC 용 전하펌프 회로를 $0.13{\mu}m$ Triple-Well DDI 공정을 사용하여 설계하고, 테스트 칩을 제작하여 검증하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.276-279
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• 2005

The proposed Novel OverDriving Technology with Optimum Look-up-Table（LUT）is suggested to be a better solution to reducing the occurrence of overshooting caused by the traditional overdriving method implemented to normally liquid crystal (VA mode). Chunghwa Picture Tubes, LTD. (CPT) has successfully implement this tech into 20 inch TFTLCD TV module at the present day. The proposed technology can speed up gray-to-gray response time of LCD less than one half of frame time. On the side, Optimum LUT construction apply the compression scheme to record total actual grayscale transfer characteristics instead of applying the normal spread method such as linear / non-linear interpolation. The memory space is been reduced and the distortion of the image quality is lesser.