Analysis of Light Leakage Caused by Color Filter between Crossed Polarizers

Utsumi, Yuka; Hiyama, Ikuo; Tomioka, Y.; Kondo, K.; Matsuyama, S.

doi:10.1143/jjap.46.1047

Cited by 13 publications

(13 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The origins for depolarization are rather complicated; they may come from the diffraction effect of patterned thin-film transistors (TFTs) and electrode, scattering effect from LC layer and color filter (CF) array, misalignment of crossed polarizers, and rubbing scratches, etc [8,[14][15][16][17][18][19][20]. Figure 2 schematically depicts some of them.…”

Section: Depolarization Effectmentioning

confidence: 99%

“…To improve CR, increasing the polarizer thickness is a straightforward approach. However, more evidences reveal that polarizer is no longer the limiting factor [8][9][10][11][12]. In fact, it is fairly easy to get CR>100,000:1 with two high-quality crossed polarizers, but the final CR of an LCD is still limited to 5,000:1, which is mainly governed by the depolarization effect inside the LCD panel.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Depolarization effect in liquid crystal displays

Chen

Tan

et al. 2017

Opt. Express

View full text Add to dashboard Cite

We develop a rigorous model to simulate an LCD's contrast ratio (CR) and viewing angle by considering the depolarization effect in thin-film transistor substrate, LC layer, color filter (CF) array, etc. To mitigate the depolarization effect, we propose a new device structure by adding a thin in-cell polarizer between LC layer and CF array. Based on the analysis using our new model, the maximum CR of a multi-domain vertical alignment (MVA) LCD can reach > 20,000:1, while for the fringe-field switching (FFS) mode it can reach > 3000:1. We also discuss other approaches to further enhance the CR. Our model is a powerful tool to analyze the CR degradation mechanism and to guide the future LCD device and material optimizations.

show abstract

Section: Depolarization Effectmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Depolarization effect in liquid crystal displays

Chen

Tan

et al. 2017

Opt. Express

View full text Add to dashboard Cite

show abstract

“…Light leakage by scattering in the various layers of an LCD panel can be as large as that caused by residual retardation in the LC layer [64][65][66]. Light scattering from the color fi lter layer in particular has the largest contribution to light scattering in an LCD [66][67][68]. To minimize scattering from the color filter, technologies for reducing the size of color pigments and increasing the degree of pigment dispersion have been developed.…”

Section: Contrast Ratiomentioning

confidence: 99%

“…Th e ability of an LCD panel to display a continuous and vivid color spectrum is determined by the absorption spectra of the color fi lters forming the panel and the spectral character of the backlight. Th e color fi lter material is composed of a basic resin and colorants, and the quality of colorants is the most important factor in achieving superior color performance [67,68]. Dye colorants were used originally in LCDs, but were later replaced with pigment colorants, which off er greater heat resistance and durability.…”

Section: Color Performancementioning

confidence: 99%

Technical evolution of liquid crystal displays

2009

View full text Add to dashboard Cite

I n 1888, more than a century ago, the Austrian botanist FriedrichReinitzer discovered an intermediate state of matter between isotropic liquid and lattice-structured crystal [1][2][3]. Th is state, later termed liquid crystal (LC), remained merely a novelty for many years until suitable applications for the technology began to become apparent. From the late 1960s, following the realization that various display applications were possible, the popularity of liquid crystal as a research fi eld expanded rapidly, attracting the interest of many scientists who made fundamental contributions to the technologies that have led to the spectacular success of liquid crystal displays (LCDs) [3][4][5][6][7][8][9][10][11][12][13]. Th e development of the twisted nematic (TN) [4] and supertwisted nematic (STN) [5] cell confi gurations, along with the necessary manufacturing technologies [6][7][8][9], resulted in the birth of the LCD industry in the late 1970s and early 1980s. The subsequent development of thin-film transistor (TFT) technology provided a further boost to the industry in the late 1980s [14,15]. Th e boom was signifi cantly supported by the advancement of material technologies such as the highly reliable manufacturing of liquid crystal base materials, and the development of polymers for the alignment layer, color fi lter materials, and sheet-type polarizers formed from the poly(vinyl alcohol)-iodine complex.In the 1990s, LCDs occupied an important position in the display market primarily through notebook applications, although the cathode ray tube (CRT) continued to dominate the desktop monitor and television markets. Th e plasma display panel (PDP), which appeared in the commercial market in 1997, pioneered the large-area fl at panel display market. It was widely predicted at the time that PDPs would maintain the lead in the large-area display market and that LCDs in small-display information technology (IT) applications would soon be replaced by new technologies such as displays based on organic light-emitting diodes (OLEDs) [16,17]. Such predictions were based on the belief that the LCD technology suff ered from serious limitations in terms of both off -axis image quality and moving picture quality, and also that it had proved diffi cult to obtain reasonable manufacturing yields of large-area TFT panels. However, these predictions, as we now know, turned out to be incorrect. Th e application of LCDs has expanded rapidly in recent years from purely information technology (IT) applications to the television and mobile display markets, and now even to very-large-area digital information displays (DIDs).Interestingly, while LCDs penetrated the traditional territories of other display technologies including CRTs and PDPs, attracting inevitable and heavy competition from these technologies, the most critical competitors were in fact alternative LCD technologies. A range of LCD modes and technologies are now applied in the same areas of application and are compared directly with one another in the market. In applicat...

show abstract

“…On the other hand, most color filters contain nanoparticles that cause light scattering. Figure 1 presents a schematic diagram of the vector expression of the electric field, and light leakage caused by the scattering effect at the color filter when a color filter is sandwiched between two crossed polarizers [1][2][3]. The linearly polarized light is obtained after light passes through the input polarizer, and the oscillation direction of the light is parallel to the transmission axis of the polarizer.…”

Section: Introductionmentioning

confidence: 99%

Size Effect of Light Scattering on the Nano-Sized Color Filter Pigment in Liquid Crystal Display

Jhun¹,

Gwag²

2014

Journal of the Optical Society of Korea

View full text Add to dashboard Cite

This study examined the effects of particle size on the light scattering of a nano-sized color filter pigment used to obtain a range of colors in liquid crystal displays. The contrast ratio is one of the most important characteristics of liquid crystal displays. When a color filter is located between two crossed polarizers, the size of the pigment can give rise to a decrease in the contrast ratio due to Rayleigh scattering by the nanoparticles in the filter. The size effect of the color filter pigment on the contrast ratio was investigated in terms of the depolarization parameter. As an experimental result, the depolarization parameter increased with decreasing pigment size. Therefore, a smaller pigment size can reduce light leakage caused by light scattering in the color filter between two crossed polarizers. The depolarization function was also proposed as a useful function for predicting the decrease in the contrast ratio of the color filter.

show abstract

Analysis of Light Leakage Caused by Color Filter between Crossed Polarizers

Cited by 13 publications

References 5 publications

Depolarization effect in liquid crystal displays

Depolarization effect in liquid crystal displays

Technical evolution of liquid crystal displays

Size Effect of Light Scattering on the Nano-Sized Color Filter Pigment in Liquid Crystal Display

Contact Info

Product

Resources

About