Polarizing optical element, LCD device, polarized light source and method thereof

Abstract

A low-color washout polarizing optical element comprises a cholesteric liquid crystal film and a wavelength retarding sheet. The wavelength retarding sheet is obtained by combining one or more O-plate phase difference films and is arranged on the cholesteric liquid crystal film, wherein, the wavelength retarding sheet has the functions of polarization status switching and chromatic aberration compensation. Furthermore, the low-color washout polarizing optical element can be further combined with a backlight module or a liquid crystal display unit to provide a polarization backlight source or an LCD with simple structure, full-visual angle low-color washout and high luminance.

Description

technical field [0001] The invention relates to an optical element, in particular to a combined polarized optical film with low color shift, a backlight module and a liquid crystal display containing the optical film. Background technique [0002] Liquid crystal display is a kind of display that does not emit light by itself. In order to display images, it is usually necessary to use a backlight module that emits light as a light source. Under the action of an electric field, liquid crystal cooperates with polarizing materials, and its function is like a light valve. Combined with the arrangement of electrodes and electrode switches The arrangement can adjust the intensity of the light, which can produce different bright and dark points in the space and present vivid images. [0003] Traditional polarizers are formed of dichroic materials, which contain, for example, iodide ion complexes or dichroic dyes, which make them absorb light differently on two mutually orthogonal ax...

AI Technical Summary

Problems solved by technology

[0007] However, the traditionally used 1 / 4 wavelength retardation film is usually A-plate type, such as figure 1 As shown, the optical axis 14 of the A-plate type 1 / 4 wavelength retardation film is parallel to the direction of the film surface, and the combination of the A-plate type 1 / 4 wavelength retardation film and the cholesteric liquid crystal film is often easily observed at a large viewing angle. The different tones of the original backlight source are color shift. When the color shift is serious, it will affect the accuracy of the image color at a large viewing angle. Therefore, an integrated functional optical film is urgently needed. To improve this phenomenon and increase the practicability of brightening technology

[0008] Many solutions have been proposed to improve this phenomenon. For example, U.S. Patent No. 5,731,886 is to set a positive C-plate (C-plate) compensation film on the 1 / 4 wavelength retarder to compensate for the color shift phenomenon. However, this method It will increase the type and thickness of materials, and increase the steps and complexity of the process, making it difficult to homogenize large areas

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