Light guide plate with embedded diffraction element

Abstract

The invention relates to a light guide plate with embedded diffraction elements, which comprises three superimposed slave light guide plates. The slave light guide plates are arranged independently and respectively comprise a light inlet surface, a bottom surface and a light outlet surface, wedge-shaped bevel are formed among the light inlet surfaces and the bottom surfaces, incident light can be fully transmitted in the slave light guide plates due to the wedge-shaped bevels, and the light outlet surfaces are provided with diffraction regions at intervals so that emergent light fields of the three slave light guide plates cannot be overlapped. Novel diffraction elements are embedded in the diffraction regions of the slave light guide plates and adopt shining surface-coated gratings, and the inclined surfaces of the shining gratings are coated with dielectric films. The three slave light guide plates can be respectively used for transmitting R, G and B beams, the diffracted beams can be transmitted to corresponding pixel positions of a liquid crystal panel, and no color filter is needed. When the collimated light beam is coupled into the light guide plate disclosed by the invention, the brightness of the whole panel is uniform, and the rate of light utilization is high.

Description

technical field [0001] The invention relates to the field of liquid crystal backlight display, in particular to a light guide plate with a new type of diffraction element embedded inside without a color filter. Background technique [0002] The light guide plate is widely used in the liquid crystal backlight system. The traditional liquid crystal backlight system is composed of a light source, a light guide plate, a reflector and a prism sheet. Spread it into the light guide plate to form a uniform backlight on the LCD panel. figure 1 It is an example of a diffraction grating backlight system in a published patent. The system uses a transmissive rectangular sawtooth grating, and changes the diffraction direction and efficiency by changing the grating period and sawtooth depth, so that the RGB three primary colors pass through the first-order diffraction of the grating, and then exit perpendicular to the waveguide surface after passing through the collimating micro-mirror gr...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to solve the problem that the high-order diffraction order cannot be suppressed by using a rectangular sawtooth grating in the existing diffraction backlight system, and to provide a light guide plate embedded with a diffraction element, so that the diffraction grating only produces a first-order diffraction order. In order to make the most efficient use of the incident energy and ensure the uniformity of the light field

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