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Patent Issued for Display Apparatus and Liquid Crystal Display Device

September 9, 2014



By a News Reporter-Staff News Editor at Journal of Technology -- From Alexandria, Virginia, VerticalNews journalists report that a patent by the inventors Li, Wang-Yang (Tainan, TW); Wu, Ting-I (Kaohsiung, TW), filed on March 29, 2012, was published online on August 26, 2014.

The patent's assignee for patent number 8817208 is Chi Mei Materials Technology Corporation (Tainan, TW).

News editors obtained the following quote from the background information supplied by the inventors: "The disclosure relates in general to a display apparatus and more particularly to a display apparatus having a diffractive optical element.

"Currently, an image display device mainly comprises a liquid crystal display device, a plasma display device, an OLED display device and an electronic paper display device, etc. The liquid crystal display device is a non-self-luminous display device, and thus usually needs a backlight source for generating light that entering the liquid crystal display panel with a uniform plane profile through an optical film such as a diffusion film, a brightener film, etc, for displaying an image.

"J.P. patent application number 2003-302954, entitled 'SPATIAL OPTICAL MODULATOR, AND PROJECTOR', has disclosed a projector having a projection image of high contrast, at low cost and with a simple construction. An spatial optical modulator having a pair of counter substrate and a TFT substrate and a liquid crystal interposed between the counter substrate and the TFT substrate and modulating incident light from the counter substrate side according to an image signal to emit the modulated light from the TFT substrate side has a wedge prism deflecting incident light to the light emission side of the TFT substrate.

"EP. patent publication number 0567995A1, entitled 'Image display apparatus', has disclosed an image display apparatus includes an image display device such as, a liquid crystal display panel having a plurality of dot-shaped picture elements arranged in a two-dimensional pattern, and a diffraction grating disposed on an optical path through which imagewise rays of light emerging from the device travel.

"U.S. Pat. No. 6,483,612, entitled 'Projection screen apparatus including holographic optical element', has disclosed a screen apparatus includes a holographic optical element and a diffuser. In operation, the holographic optical element receives image light from an image engine or projector and redirects the image light to the diffuser for scattering. The holographic optical element can be designed to substantially collimate, converge, or diverge the image light.

"A twisted nematic (TN) or a super twisted nematic (STN) liquid crystal display device are types of the display devices usually used. Although this kind of the liquid crystal display device has advantage in price, the viewing angle of which is smaller than that of a ordinary wide viewing angle liquid crystal display device, such as a multi-domain vertical alignment (MVA) liquid crystal display device, an in-plane switching (IPS) liquid crystal display device, a fringe field switching (FFS) liquid crystal display device, etc.

"The viewing angle means an angle range in which the display device can display an image quality of which is in a standard range. For example, for a general desktop liquid crystal display device, the main viewing angle is a front view. Therefore, for designers, the display device is designed according to the front view mainly since the optical effect would be affect due to the arrangement of the liquid crystal molecule. Therefore, an observer would find images of different colors and brightness with different oblique s to the liquid crystal display device. At the same time, the image difference increases as the viewing angle increases. Among the liquid crystal display devices usually used, the TN liquid crystal display device has the worst condition. For a TN liquid crystal display device without using any compensating element for viewing angle, usually, an image observed from the side viewing angle of the liquid crystal display device has problems such as serious contrast decreasing (to lower than 10), gray level reversion degrees, etc.

"Therefore, a display apparatus for improving image quality problems such as contrast, gray level reversion, etc is need."

As a supplement to the background information on this patent, VerticalNews correspondents also obtained the inventors' summary information for this patent: "A display apparatus is provided. The display apparatus comprises a liquid crystal display, a first polarizer, a second polarizer and a diffractive optical element. The liquid crystal display device comprises a backlight module and a liquid crystal panel. The liquid crystal panel comprises a first substrate, a second substrate and a liquid crystal layer. The liquid crystal layer is disposed between the first substrate and the second substrate. The first polarizer is disposed on the first substrate. The second polarizer is disposed between the second substrate and the backlight module. Polarizing directions of the first polarizer and the second polarizer have different azimuth angles. The diffractive optical element is disposed on a light emitting side of the first polarizer and has a first diffraction grating and a second diffraction grating. Grating directions of the first diffraction grating and the second diffraction grating have different azimuth angles.

"A display apparatus is provided. The display apparatus comprises a liquid crystal display device for displaying an image and a diffractive optical element. The liquid crystal display device comprises a backlight module and a liquid crystal panel. The liquid crystal panel is disposed on the backlight module and comprises a first substrate, a first alignment film, a second substrate, a second alignment film, and a liquid crystal layer. The first alignment film is disposed on the first substrate. The second alignment film is disposed on the second substrate. Aligning directions of the first alignment film and the second alignment film have different azimuth angles. The liquid crystal layer is disposed between the first alignment film and the second alignment film. The diffractive optical element is disposed on a light emitting side of the liquid crystal display device and comprises a first diffraction grating and a second diffraction grating. An azimuth angle of a grating direction of the first diffraction grating is different from an azimuth angle of a grating direction of the second diffraction grating.

"A liquid crystal display device for displaying an image is provided. The liquid crystal display device comprises a liquid crystal panel and a diffractive optical element. The liquid crystal panel comprises a first substrate, a second substrate and a liquid crystal layer. The liquid crystal layer is disposed between the first substrate and the second substrate. The liquid crystal layer comprises liquid crystal molecules. At least one of the liquid crystal molecules adjacent to the first substrate has a first liquid crystal tilt direction. At least one of the liquid crystal molecules adjacent to the second substrate has a second liquid crystal tilt direction. An azimuth angle of the first liquid crystal tilt direction is different from an azimuth angle of the second liquid crystal tilt direction. The diffractive optical element is disposed on a light emitting side of the liquid crystal panel and comprises a first diffraction grating and a second diffraction grating. An azimuth angle of a grating direction of the first diffraction grating is different from an azimuth angle of a grating direction of the second diffraction grating.

"A display apparatus is provided. The display apparatus comprises a display device for displaying an image and a diffractive optical element. The diffractive optical element comprises pixel unit regions. Each of the pixel unit regions has a long pixel side and a short pixel side adjacent to each other. The diffractive optical element is disposed on a light emitting side of the display device and comprises first grating regions and second grating regions. The first grating regions have a first diffraction grating. The second grating regions have a second diffraction grating. An azimuth angle of the first diffraction grating is different from an azimuth angle of the second diffraction grating.

"The above and other aspects of the disclosure will become better understood with regard to the following detailed description of the non-limiting embodiment(s). The following description is made with reference to the accompanying drawings."

For additional information on this patent, see: Li, Wang-Yang; Wu, Ting-I. Display Apparatus and Liquid Crystal Display Device. U.S. Patent Number 8817208, filed March 29, 2012, and published online on August 26, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8817208.PN.&OS=PN/8817208RS=PN/8817208

Keywords for this news article include: Chi Mei Materials Technology Corporation, Technology.

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Source: Journal of Technology


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