29.2: <i>Distinguished Paper</i>: Wide Viewing LCDs using Novel Microstructure Film

Yamamoto, Etsuko; Yui, Hideomi; Katsuta, Shohei; Asaoka, Yasushi; Maeda, Tsuyoshi; Tsuda, Yusuke; Kondo, K.

doi:10.1002/j.2168-0159.2014.tb00104.x

Cited by 9 publications

(6 citation statements)

References 7 publications

(9 reference statements)

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“…Recently, Sharp demonstrated a reflecting type DF with tapered micro-cavities fabricated by roll-to-roll process [46], [47]. To reduce ambient reflection, they applied a black matrix on top of the diffuser that covers the area where lights are not extracted from LCs, so that the ambient contrast ratio is increased.…”

Section: Quasi-collimated Backlight and Engineered Diffusermentioning

confidence: 99%

A High Performance Single-Domain LCD With Wide Luminance Distribution

Gao

Luo

Zhu

et al. 2015

J. Display Technol.

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In this paper, we review the device structures and present the simulation results of four single-domain LCDs with a quasi-collimated backlight and a free-form optics-engineered diffuser. Such a non-emissive LCD exhibits similar luminance distribution to an emissive OLED, while keeping high transmittance, high contrast ratio over a large (80 ) viewing cone, with low ambient reflection, indistinguishable color shift, and negligible off-axis grayscale distortion.Index Terms-Fringe field switching, in-plane switching, liquid crystal display (LCD), OLED-like luminance distribution, single domain.

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Section: Quasi-collimated Backlight and Engineered Diffusermentioning

confidence: 99%

A High Performance Single-Domain LCD With Wide Luminance Distribution

Gao

Luo

Zhu

et al. 2015

J. Display Technol.

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“…In the case of TN-LCD, we could drastically improve the viewing angle characteristics by just attaching the film to the surface 11)-16) . However, in the case of 4-domain VA-LCD, improvement effects by attaching the film were limited 15) . Therefore, for VA-LCD, we optimized the backlight (BL) distribution and the LC alignment direction as well as the scattering profile of the microstructure film.…”

Section: Introductionmentioning

confidence: 99%

[Paper] Design of VA-LCD System with Microstructure Film for Wide Viewing

Ochi

Asaoka

Nango

et al. 2017

MTA

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122 BackgroundVertical alignment (VA) mode liquid crystal display (LCD) is widely used especially in large size display market because it shows very high contrast ratio in the normal direction and wide viewing characteristics, achieved by many efforts 1)-7) . However, much wider viewing angle is required in the movement of high definition from Full-High Definition (FHD) to UltraHigh Definition (UHD) because of its short preferred viewing distance 8)9) . As a reasonable method to measure viewing angle of display, the color viewing angle has been suggested 10) . This is angular range of low color shift from the normal direction. In particular, the color viewing angle is defined as the angle range within the noticeable threshold of ∆u'v' = 0.015, where u'v' is average value of 9 colors (dark skin, light skin, blue, green, red, yellow, magenta, cyan and gray in the Macbeth Chart). UHD display should require the color viewing angle above 100°, which is horizontal viewing angle at the preferred viewing distance.Some approaches such as the capacitive coupled method and the two-TFT method have been proposed to improve the gamma curve of VA-LCDs 4)6) . However, the color viewing angle did not reach 100°and also these methods require complex electronic circuits. In addition, the manufacturing cost and device power consumption increase when two TFTs are used in each unit pixel.To overcome these drawbacks, we achieved outstanding wide viewing angle characteristics by applying the microstructure film without these complex circuit technologies. This film can control the scattering characteristics with the shapes of the internal air-micro cavities capped by black dots. In the case of TN-LCD, we could drastically improve the viewing angle characteristics by just attaching the film to the surface 11)-16) . However, in the case of 4-domain VA-LCD, improvement effects by attaching the film were limited 15) . Therefore, for VA-LCD, we optimized the backlight (BL) distribution and the LC alignment direction as well as the scattering profile of the microstructure film. Feature of the Microstructure FilmThe microstructure film is attached to the surface of LCD. It is composed of a transparent polymer layer, airmicro cavities, black dots and a base film, as shown in Abstract We have developed a wide viewing VA-LCD system with the microstructure film. This film is attached on LC panel and scatters incident lights from LC panel by reflection at internal air cavities to improve the viewing angle characteristics. In this system, we have optimized LC alignment directions and BL distribution as well as the scattering profile of the film. LC panel has two-domain LC aligned pixel (each LC director is antiparallel in vertical direction) and wide viewing angle in horizontal direction. Backlight distribution is collimated to horizontal direction. To distribute lights in horizontal direction to vertical direction, we designed and fabricated the microstructure film which had rhombus shaped air cavities. This display system indicated smaller color s...

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“…The third approach was to attach a diffusing film to the surface of LCD, which caused a blur in the frontal image and degraded a contrast ratio under the bright ambient light owing to its backscattering . Therefore, we have developed a new microstructure film to solve these issues by just attaching it to the surface of TN‐LCD …”

Section: Introductionmentioning

confidence: 99%

“…In addition, the improvement effect of viewing angle characteristics of the microstructure film is not limited to the TN‐LCD. We have applied this technology to multidomain vertical alignment (MVA)‐LCD …”

Section: Introductionmentioning

confidence: 99%

“…[8][9][10] Therefore, we have developed a new microstructure film to solve these issues by just attaching it to the surface of TN-LCD. [11][12][13][14][15] In addition, the improvement effect of viewing angle characteristics of the microstructure film is not limited to the TN-LCD. We have applied this technology to multidomain vertical alignment (MVA)-LCD.…”

Section: Introductionmentioning

confidence: 99%

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Optical design and roll‐to‐roll fabrication process of microstructure film for wide viewing LCDs

Katsuta¹,

Yamamoto²,

Asaoka³

et al. 2014

J Soc Info Display

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-We have developed a new microstructure film for wide viewing liquid crystal displays (LCDs). By attaching it to the surface of a conventional LCD, the viewing angle characteristics of LCD has drastically improved without causing a blur of the frontal image and a decrease in the contrast ratio under bright ambient light conditions. This film can be applied to various LC modes including twisted nematic and multidomain vertical alignment by changing its internal micrometer-size 3D structure. Further, this film can be mass-produced efficiently by self alignment roll-to-roll process.Keywords -optical film, microstructure, liquid crystal display, wide viewing angle, self-alignment, rollto-roll processing.DOI # 10.1002/jsid.249 BackgroundTwisted nematic (TN) mode liquid crystal display (LCD) is still widely used especially in middle-size display, such as small TV, mobile phone, and PC monitor because TN-LCD has many advantages: high transmissivity, fast response speed, wide operating temperature range, high durability, and existing many fabrication lines. One of the disadvantages of TN-LCD is direction dependence of viewing angle characteristics, but previously, it was not a serious issue in the use of middle-size display because middle-size display is viewed from almost a fixed direction. However, new applications of middle-size display such as a tablet computer are recently growing, and with this trend, the improvement of viewing angle characteristics of TN-LCD has been highly expected. Various efforts have ever been investigated to improve the viewing angle characteristics of TN-LCD. They are mainly classified into three approaches. The first approach was to divide a pixel into subpixels or multidomains, 1-5 which required complicated fabrication processes. The second approach was to insert optical compensation films between glasses and polarizers, which still had a grayscale inversion with asymmetric viewing angle characteristics especially at high polar angles.6,7 The third approach was to attach a diffusing film to the surface of LCD, which caused a blur in the frontal image and degraded a contrast ratio under the bright ambient light owing to its backscattering.8-10 Therefore, we have developed a new microstructure film to solve these issues by just attaching it to the surface of TN-LCD. 11-15In addition, the improvement effect of viewing angle characteristics of the microstructure film is not limited to the TN-LCD. We have applied this technology to multidomain vertical alignment (MVA)-LCD. 15In this paper, we mainly report the details of optical design and roll-to-roll fabrication process of our microstructure film. System structure and characteristicsThe structure of our system is shown in Fig. 1. The difference from the conventional system is only a film attached to the surface of the conventional LCD. There were approaches of attaching a diffusing film to the surface of LCD so far, but they usually needed a collimated backlight for preventing the blur of the frontal image. Our system, however, does...

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29.2: Distinguished Paper: Wide Viewing LCDs using Novel Microstructure Film

Cited by 9 publications

References 7 publications

A High Performance Single-Domain LCD With Wide Luminance Distribution

A High Performance Single-Domain LCD With Wide Luminance Distribution

[Paper] Design of VA-LCD System with Microstructure Film for Wide Viewing

Optical design and roll‐to‐roll fabrication process of microstructure film for wide viewing LCDs

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