CN-121995567-A - Novel collimation highlight type backlight module

CN121995567ACN 121995567 ACN121995567 ACN 121995567ACN-121995567-A

Abstract

The invention relates to the technical field of semiconductor display, in particular to a novel collimation highlight type backlight module. The backlight module comprises a light guide plate, a light source, a reflective membrane and an optical lamination arranged on the light emitting surface of the light guide plate. The light-emitting surface of the light guide plate is provided with a continuous columnar curved surface microstructure, and the dot surface is provided with triangular prism dot structures which are distributed according to a specific rule. The core of the invention is that the optical lamination comprises at least four prism film layers, wherein the prism extending directions of at least two film layers are orthogonally arranged, and the light is subjected to multistage beam splitting and precise collimation through the synergistic effect of the microstructure of the light guide plate and the multi-layer orthogonal prism film layers. The invention can greatly shrink the view angle of emergent light in the horizontal and vertical directions at the same time on the premise of not obviously sacrificing brightness, realizes an omnibearing excellent peep-proof effect, has a compact structure, and is particularly suitable for side-entry display equipment with high requirements on privacy protection and light weight.

Inventors

ZHUANG MENGRU
Cai Jimei
ZHANG YU
CHEN LIANG

Assignees

博晶科技(滁州)有限公司

Dates

Publication Date: 20260508
Application Date: 20260306

Claims (7)

1. Novel high bright formula backlight unit of collimation, its characterized in that includes: the light guide plate is provided with a light incident surface, a dot surface adjacent to the light incident surface and a light emergent surface opposite to the dot surface; the light emitting sources are arranged on one side of the light incident surface of the light guide plate; the reflecting membrane is arranged outside the dot surface of the light guide plate; The optical lamination comprises at least four prism film layers, wherein the prism extending directions of at least two prism film layers are mutually overlapped in an orthogonal mode and are used for splitting and collimating light rays from the light-emitting surface of the light guide plate so as to achieve shrinkage of light angles in the direction perpendicular to the light-emitting surface.
2. The novel collimating and highlighting backlight module as claimed in claim 1, wherein the optical stack comprises a first prism film, a second prism film, a third prism film and a microstructure film sequentially arranged along the light emitting direction.
3. The novel collimating and highlighting backlight module according to claim 2, wherein the prism extension direction of the first prism film is orthogonal to the prism extension direction of the second prism film, and the prism surface of the first prism film is disposed toward the light guide plate, the prism extension direction of the third prism film is identical to or orthogonal to the prism extension direction of the second prism film, and the microstructure film is disposed at the outermost side of the optical stack.
4. The novel collimation highlight type backlight module as set forth in claim 3, wherein the light-emitting surface of the light guide plate is provided with a continuous columnar curved surface microstructure, and the dot surface is provided with a plurality of inwardly concave triangular prism dot structures arranged according to a certain arrangement method.
5. The novel collimating and highlighting backlight module as claimed in claim 4, wherein said triangular prism dot structures are arranged on said dot surface according to a predetermined mathematical rule.
6. The novel collimating and highlighting backlight module as claimed in claim 3, wherein the light-emitting surface of the microstructure film is provided with a pyramid microstructure, and the light-incident surface is provided with an optical film with preset haze.
7. The novel collimating and highlighting backlight module as claimed in claim 3, wherein the full width at half maximum of the viewing angle distribution of the outgoing light rays of the backlight module in the horizontal direction and the vertical direction is not more than 40 °.

Description

Novel collimation highlight type backlight module Technical Field The invention relates to the technical field of semiconductor display, in particular to a novel collimation highlight type backlight module. Background With the popularization of mobile electronic devices and the enhancement of public privacy protection consciousness, the demands of display devices with peep-proof functions in the fields of business, finance, personal privacy protection and the like are increasingly highlighted. The core of the peep-proof display technology is to control the visual angle of the display so that the screen content is only visible in a small angle range in front of the display, thereby preventing bystanders from peeping from the side. Currently, one of the mainstream technologies for realizing display peep prevention is to add a peep prevention film (PRIVACY FILM) outside a backlight module or a panel of a Liquid Crystal Display (LCD). The privacy film is generally based on the Micro-structured louver (Micro-louver) grating principle, and blocks large-angle light rays through built-in black light absorbing strips or Micro-structures with specific angles, so that the viewing angle is limited. For example, a typical privacy film may achieve a viewing angle limit of about ±30° in the left-right direction (with a brightness drop of 5% as the viewing angle boundary). However, this solution has the obvious disadvantage that, firstly, the grating structure blocks and absorbs most of the light, resulting in a significant reduction in the front brightness of the display (typically more than 50% loss), and the backlight power has to be increased to maintain the perceived brightness, thereby increasing the overall power consumption and cost. Secondly, the traditional peep-proof film is generally effective only in a single direction (such as a horizontal direction), the peep-proof effect in a vertical direction is limited, and the omnibearing privacy protection is difficult to realize. Furthermore, the additional film layer also increases the thickness of the module, which is not beneficial to the design of the light and thin equipment. The other technical idea is to realize light collimation (Collimation) by optical design from the backlight module, namely, light is emitted in a direction close to being perpendicular to a screen, and a narrow viewing angle is naturally formed. One existing collimated backlight scheme uses a direct down backlight in combination with a complex multi-layer Brightness enhancement film (Brightness ENHANCEMENT FILM, BEF) and a condenser lens structure. Although the scheme can achieve better collimation effect, the structure is complex, the thickness is large, the cost is high, and the scheme is difficult to be applied to the side-entry backlight module with strict limit on the thickness. For the side-entry backlight module, light collimation and peeping prevention are more difficult to realize. The side-entry backlight relies on a light guide plate (Light Guide Plate, LGP) to convert a side-entry line light source into a surface light source, and its own optical design aims at making the light emission uniform and having a certain diffusivity so as to meet the requirement of wide viewing angle display. In order to realize peep prevention, the prior art generally simply superimposes the peep prevention film on a conventional film (such as a diffusion film and a brightness enhancement film) of a side-entry backlight module, which also brings the problems of large brightness loss and unidirectional peep prevention. Although there are studies on specially designing the dot or light-emitting microstructure of the light guide plate to collect light, for example, arranging a prism structure on the light-emitting surface of the light guide plate or designing a reflection structure with a specific angle on the dot surface, these schemes can only initially compress the viewing angle in a certain direction, the collimation of the emitted light is insufficient, the viewing angle shrinkage is limited, and it is difficult to effectively match with the downstream optical film to realize the synergistic collimation in all directions (horizontal and vertical directions), resulting in poor final peep-proof effect, reduced brightness uniformity or difficult process control. Therefore, there is a lack of an efficient and compact collimating optical solution suitable for a side-entry backlight module that can achieve an overall excellent privacy effect without significantly sacrificing brightness. Disclosure of Invention Aiming at the problem that the side-in type backlight module in the prior art is difficult to achieve high brightness, omnibearing peeping prevention and structural compactness, the invention provides a novel collimation high-brightness type backlight module and a core light guide plate thereof, and aims to realize directional guide and precise collimation of light from a light source end through th