Free-form optical lens for ultra-thin direct-lit LED backlight system

Abstract

Disclosed is a free-form curved surface optical lens (300) of an ultrathin direct LED backlight system, enabling the light emitted by an LED light source (100) to form a uniformly illuminated rectangular spot on a screen, the distance between the LED light source (100) and the screen being not greater than 30 mm. The lens (300) comprises an incident surface and an exit surface; a hemispherical hollow cavity for installing an LED (100) is provided in the center of the bottom of the lens (300), and the incident surface is comprised of the hemispherical surface (301) of the hemispherical hollow cavity; the outer side surface of the lens (300) is a free-form curved surface (302), the free-form curved surface being the exit surface. The lens does not need any other auxiliary device for light distribution, thus reducing light energy loss of a light distribution system and improving light energy utilization, while satisfying the ultra-thin design requirement of a large direct backlight system and reducing costs. In addition, a hemispherical hollow cavity for installing an LED provided in the center of the bottom of the lens facilitates installation of an LED light source and a heat dissipation device, and improves the heat dissipation efficiency of the entire backlight system.

Description

technical field [0001] The invention relates to the technical field of LED backlight modules, in particular to a free-form surface optical lens of an ultra-thin direct-type LED backlight system. Background technique [0002] Compared with traditional CCFL light sources, LEDs used as backlight sources for liquid crystal displays have great advantages, mainly reflected in high brightness, good uniformity, and wide color gamut. At present, the backlight system of large-size LCD generally adopts the side-type backlight structure, but this kind of backlight system usually has the problem that the center of the module is bright, the surrounding is dark, the overall brightness is not high, and the system energy utilization rate is not high. As the size increases, especially for large-size liquid crystal displays above 55 inches, it is difficult to process the light guide plate in the backlight system, and the weight of the module itself is increased due to the use of the light guid...

AI Technical Summary

Problems solved by technology

[0003] Aiming at the ultra-thin design problem faced by the large-size direct-type LED backlight system, the present invention provides a free-form optical lens for the ultra-thin direct-type backlight system, which makes the light emitted by the LED light source form a rectangle with uniform illumination on the screen The light spot, and the distance between the LED light source and the screen is very close (not greater than 30mm), so that the backlight system does not need to be equipped with diffusion film and brightness enhancement film light optical components, achieving ultra-thin design and reducing costs

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