Browsing by Author "Wen, CH"

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Automatic mura detection system for liquid crystal display panels
(2006-01-01)
Fang, LT
;
Chen, HC
;
Yin, IC
;
Wang, SJ
;
Wen, CH
In this paper, we propose an automatic inspection system, which can automatically detect four types of muras on an LCD panel: cluster mura, v-band mura, rubbing mura, and light leakage mura. To detect cluster muras, the Laplacian of Gaussian (LOG) filter is used. A multi-resolution approach is proposed to detect cluster muras of different scales. To speed up the processing speed, this multi-resolution approach is actually implemented in the frequency domain. To detect v-band muras, we check the variation tendency of the projected I-D intensity profile. Then, v-band muras are detected by identifying these portions of the I-D profile where a large deviation occurs. To detect rubbing muras, we designed a frequency mask to detect distinct components in the frequency domain. To detect light leak muras, we apply image mirroring over the boundary parts and adopt the same LOG filter that has been used in detecting cluster muras. All four types of mura detection are integrated together in an efficient way and simulation results demonstrate that this system is indeed very helpful in detecting mura defects.
Automatic mura detection system for liquid crystal display panels - art. no. 60700G
(2006)
Fang, LT
;
Chen, HC
;
Yin, IC
;
Wang, SJ
;
Wen, CH
In this paper, we propose an automatic inspection system, which can automatically detect four types of muras on an LCD panel: cluster mura, v-band mura, rubbing mura, and light leakage mura. To detect cluster muras, the Laplacian of Gaussian (LOG) filter is used. A multi-resolution approach is proposed to detect cluster muras of different scales. To speed up the processing speed, this multi-resolution approach is actually implemented in the frequency domain. To detect v-band muras, we check the variation tendency of the projected I-D intensity profile. Then, v-band muras are detected by identifying these portions of the I-D profile where a large deviation occurs. To detect rubbing muras, we designed a frequency mask to detect distinct components in the frequency domain. To detect light leak muras, we apply image mirroring over the boundary parts and adopt the same LOG filter that has been used in detecting cluster muras. All four types of mura detection are integrated together in an efficient way and simulation results demonstrate that this system is indeed very helpful in detecting mura defects.
LOG filter based inspection of cluster Mura and vertical-band Mura on liquid crystal displays
(2005)
Chen, HC
;
Fang, LT
;
Lee, L
;
Wen, CH
;
Cheng, SY
In this paper, we propose the use of Laplacian of Gaussian (LOG) filters in the detection of Cluster Mura defects and Vertical-Band Mura defects on Liquid Crystal Displays. To detect Cluster Mura defects, 2-D LOG filters with their shapes matching the shapes of Cluster Mura are adopted. The optimal threshold for the detection of Cluster Mura is determined based on the SEMU formula. On the other hand, to detect Vertical-Band Mura, a 1-D LOG filter is used over the projected I-D intensity profile to check if the variation tendency of the intensity profile is changed. The portions with inconsistently intensity variation are regarded as the portions where V-Band Muras occur. The simulation results demonstrate the LOG filters are very useful in the detection of Mura defects.
Nanoimprinting-lithography-induced self-aligned liquid crystals for novel multifunctional optical films
(2006-02-13)
Chiu, CH
;
Kuo, HL
;
Chen, PC
;
Wen, CH
;
Liu, YC
Polymerizable nematic liquid crystal (LC) was adopted as a resist for our newly developed nanoimprinting lithography process. Liquid crystal molecules were self-aligned during imprinting process without precoated alignment layer. The large patterned area was able to achieve 4x4 cm(2) at very low impriting pressure, 1.5 bar. The optical anisotropic was verified through polarized optical microscopy and the retardation was measured by polarized ultraviolet/visible spectrometer. The micrograted LC films prepared by this novel method offer the potential applications for a LC alignment layer within LC cells, as well as preparation of optical anisotropic films. (c) 2006 American Institute of Physics.
Structural equation modeling to determine passenger loyalty toward intercity bus services
(2005)
Wen, CH
;
Lan, LW
;
Cheng, HL
;
運輸與物流管理系註：原交通所+運管所
;
Department of Transportation and Logistics Management
This paper investigates passenger loyalty to intercity bus services and identifies important factors influencing loyalty. The relationships between passenger loyalty and other latent factors, including satisfaction, service value, service quality, sacrifice, switching costs, attractiveness of competitors, and trust are hypothesized and tested. Factor analysis is used to extract the latent service quality factors from a large number of service quality indicators. Structural equation models are then developed to elucidate the causal relationships of passenger loyalty and the latent factors. The empirical results have confirmed the proposed hypotheses. Satisfaction has the most significant influence on passenger loyalty. Service value, switching costs, and trust have direct and positive effects on loyalty, whereas attractiveness of competitors has a direct negative effect. The indirect effect of service quality, via service value and satisfaction, on passenger loyalty is also significant. From the empirical results, managerial implications for the bus carriers are addressed.
Super high birefringence isothiocyanato biphenyl-bistolane liquid crystals
(2004-11-01)
Gauza, S
;
Wen, CH
;
Wu, ST
;
Janarthanan, N
;
Hsu, CS
We have designed, synthesized, and evaluated the physical properties of some high birefringence (An) isothiocyanato biphenyl-bistolane liquid crystals. These compounds exhibit Deltan = 0.7-0.8 at room temperature and wavelength lambda = 633 nm. Laterally substituted short alkyl chains and fluorine atom eliminate smectic phase and lower the melting temperature. The moderate melting temperature and very high clearing temperature make those compounds attractive for eutectic mixture formulation. A eutectic mixture based on those compounds was formulated and its physical properties evaluated. The simulated absorption spectra agree reasonably well with the measured results.