Yasuhiro Morii

A study on UV‐curable adhesive sealant for LCD panel

With a view to suppressing the overlap shift between the TFT substrate and the color filter substrate, application of UV sealant is considered in the LCD panel assembly process. The initial tensile strength and moisture resistance of the UV sealant are evaluated and studied. In regard to the initial tensile strength, the stress applied to the sealing part during the glass cutting process, in which the peeling of the seal is most likely, is quantized by a numerical method based on the finite element method. By comparison of this result with tensile intensity tests of the UV sealant, acceptable performance is confirmed. The resistance to moisture is degraded due to large distortions on the interface between the sealant and the glass substrate, since a UV sealant hardened only by UV light has a large shrinkage on solidifying. Such shrinkage is small in a UV sealant that is hardened completely by applying heat after illumination of UV light, and hence presents practically no problem, with a moisture resistance equal to that in conventional heat curing-type sealant. From these results, the UV sealant completely hardened by applying heat after UV light illumination is found to be applicable to TFT-LCD from the point of view of tensile strength and humidity resistance.

53.2: A Novel Optical System LED-Backlight with Excellent Brightness Uniformity for TFT-LCD

We have developed a new LED-backlight structure. By applying this new structure to a 12.1-inch SVGA TFT-LCD, the number of LEDs can be reduced approximately 60% compared with the conventional structure while keeping the same level of brightness uniformity.

L-4: Late-News Paper: New Wide Viewing Angle Transflective TFT-LCD (TF-SWAN Technology)

We have developed the new transflective technology that is named as TF-SWAN. TF-SWAN is based on ECB mode, which uses a new optical design with a combination λ/4 plate. TF-SWAN have realized a high transmittance and wide viewing angle characteristics. We have applied the technology to 8.4″ transflective TFT-LCD. We have confirmed the excellent performances with a wide viewing angle of ±80° in the horizontal direction, high brightness of 300 nits, high contrast ratio of more than 300 and a wide operating temperature range (from −40 to 85 degrees centigrade). Our new technology is suitable for automobile application.

9.5L: Late‐News‐Paper: A 22.2‐in. UXGA‐Wide TFT‐LCD with High Quality Color Performance for Professional Use Monitor Application

We have succeeded in developing 22.2-in. wide viewing angle UXGA-Wide TFT-LCD with a high color reproduction of 96%-NTSC. Our TFT-LCD is first one that can realize Adobe RGB color space completely. It is suitable for photograph and printing industry use monitor. The color reproduction of 96%-NTSC is realized by developing a new CF and new CCFL, and super wide viewing angle is realized by optimizing design of TFT array and panel.

Wide-viewing-angle LCD controlled by a lateral electric field

With the aim of developing a wide viewing angle liquid crystal display (LCD), we are trying to apply in-plane switching (IPS) mode, in which liquid crystal molecules are switched by a lateral electric field, to TFT-LCD. We have studied the detailed relationship between the electro- optical properties and the various panel conditions. From these results, we specified the panel conditions, such as plus 10.4 dielectric anisotropy of liquid crystal material, 3.5 micrometer panel gap and 8 micrometer electrode spacing, to fabricate the IPS mode TFT panel. We have achieved the IPS mode TFT color panel that possessed not only wide viewing angle characteristics over 80 degrees with no reversed image but also a fast response time 50 ms, a low driving voltage compatible with ordinary twisted nematic (TN) mode TFT panel and a fine white balance, (x,y) equals 0.32, 0.34).