Optical element, light guiding plate, backlight source and LCD device for synthetizing hologram by computer

Abstract

The optical element is provided with a computer composition hologram which is manufactured based on interference fringe data obtained by a computing method of individually computing the interference with reference to all the combination of a plurality of reference light R reaching the position and a plurality of object light M reaching the same position and summing up the interference data, in computing the interference generated by the reference light and the object light reaching every position on a hologram-formed surface by computer, on the other hand, computing the interference without taking the interference of the reference light R with the reference light R in the position into account.

Description

technical field [0001] The present invention relates to computer-synthesized holograms used in diffusion plates, polarized light separation elements, deflection elements, diffraction elements, and light-splitting elements, etc., light guide plates, backlight sources and liquid crystal display devices using the computer-synthesized holograms. Background technique [0002] It is well known as a liquid crystal display device to adopt the following structure, that is, a pair of polarizers (102) (103) are arranged on the upper and lower sides of the liquid crystal display device (101), and a backlight is arranged on the lower side of the lower polarizer (103). source. In many liquid crystal display devices such as notebook computers, an edge-light type backlight is used as the backlight in order to reduce thickness and realize low power consumption. As shown in Figure 11, the edge light type backlight generally adopts the method of introducing the light from the light source (11...

AI Technical Summary

Problems solved by technology

[0003] In the aforementioned liquid crystal display device with the structure shown in FIG. 11 , since the structure of the brightness enhancing film and the prism sheet is used, there are problems that the structure is complex, the manufacturing efficiency is low, and the number of parts is large, and the manufacturing cost is high.

[0007] However, in the method for producing a hologram described in Patent Document 2 above, unnecessary interference fringes cannot be completely reduced.

In addition, in the method for producing a hologram described in Patent Document 2, the hologram is produced by setting conditions different from those of the actual use state (surrounding environment of the hologram) and making the imaging light incident to form interference fringes. For example, when the hologram is used as an optical element for a light guide plate, since the outgoing light is prone to non-uniformity (the in-plane distribution of the outgoing light and the non-uniform distribution of the outgoing angle), a lot of scattered light (into the unwanted direction) is generated. There is a lot of light emitted in the direction), and the light loss is large, so it is difficult to obtain a high-quality light guide plate with high diffraction efficiency

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