Lens, light emitting device and backlight module

Abstract

The invention provides a light incoming surface and a light emitting surface, which are located on the two sides away from each other of the lens and are symmetric with respect to the central axis of the lens. The light incoming surface and the light emitting surface are located in the same coordinate system. The light incoming surface meets a formula 1 (shown in the description), wherein C1 is the curvature of the light incoming surface, r1 is the distance between the center of the lens and the intersecting point between the light incoming surface and the radius perpendicular to the central axis of the lens, u1 is the normalized radius of the light incoming surface, am is the non-spherical coefficient, and Qm is an m polynomial representing that the sum of the am in the formula 1 is equal to the sum of the mean square root of the slope of the light incoming surface. The light emitting surface meets a formula 2 (shown in the description), wherein C2 is the curvature of the light emitting surface, r2 is the distance between the center of the lens and the intersecting point between the light emitting surface and the radius perpendicular to the central axis of the lens, u2 is the normalized radius of the light emitting surface, am is the non-spherical coefficient, Qm is an m polynomial representing that the sum of the am in the formula 2 is equal to the sum of the mean square root of the slope of the light emitting surface.

Description

technical field [0001] The present invention relates to the field of optics, in particular to a lens, a light-emitting device with the lens, and a backlight module with the light-emitting device. Background technique [0002] Backlight modules, as light emitting devices, are widely used in liquid crystal displays of consumer electronic products such as mobile phones, computers, digital cameras, personal digital assistants, rear projection TVs, etc., for lighting up the liquid crystal displays. At present, with the development of display technology, more and more light emitting diodes (light emitting diodes, LEDs) are used as light sources in the backlight module. Generally, a plurality of LEDs in the backlight module are arranged in a matrix and correspond to the shape of the display panel in the liquid crystal display. The brightness distribution of the light emitted by the backlight module is adjusted by the lens placed in front of the LED. However, the central area of ​​...

AI Technical Summary

Problems solved by technology

The brightness distribution of the light emitted by the backlight module is adjusted by the lens placed in front of the LED. However, the central area of ​​the existing backlight module using LEDs is usually too bright, which makes the entire backlight module emit uneven light.

Images