CN102243325A - Optical diaphragm - Google Patents

Abstract

The present invention provides an optical film, comprising: a substrate film and a plurality of prisms. The prisms are connected to the substrate film in an array mode, each prism is provided with a pair of lower prism faces and a pair of upper prism faces, the upper prism faces are correspondingly connected with the lower prism faces, an included angle is formed between each upper prism face and the corresponding lower prism face, and a space is formed between every two prisms to expose one section of the upper surface of the substrate film. The invention can improve the utilization rate of light, increase the brightness of products and reduce the cost.

Description

an optical film

technical field

The invention relates to an optical film, in particular to an optical film capable of increasing the brightness of a liquid crystal display.

Background technique

Liquid crystal display (Liquid Crystal Display, abbreviated as LCD) has the characteristics of high quality, thin thickness, low power consumption and low radiation. It has been widely used in information technology, multimedia technology and other fields, and has gradually become the mainstream flat-panel display device. Because the liquid crystal material itself does not emit light, it is necessary to configure a backlight module for the display screen to provide an additional light source. Since light-emitting diodes (LEDs) have the characteristics of no pollution, long life, shock resistance, impact resistance and no pollution, LEDs have become mainstream as a backlight source for liquid crystal displays (LCDs).

In the backlight module, the light from the LED enters the optical film after being reflected by the light guide plate. Generally, the display will use optical film to concentrate the light to ±35° positive viewing angle to increase brightness. The traditional optical film is a prism structure with a single continuous angle. The light is refracted by the angle of the prism and then emitted. cannot be used effectively.

In view of this, how to design a new type of optical film to increase the utilization rate of light to improve the brightness of the product is a problem that technicians in the industry need to solve urgently.

Contents of the invention

Aiming at the defect that the thickness of the optical film is relatively thick in the prior art, the invention provides an optical film.

According to the present invention, an optical film is provided, including: a base film and a plurality of prisms. A plurality of prisms are arranged on the substrate film in an array, and each plurality of prisms has a pair of lower prism surfaces and a pair of upper prism surfaces, the upper prism surfaces are connected to the lower prism surfaces correspondingly, and the upper prism surfaces are connected to the corresponding An included angle is formed between the lower prism surfaces, wherein there is a gap between two prisms, exposing a segment of the upper surface of the substrate film.

Preferably, a peak angle is formed between a pair of upper prism faces.

Preferably, the included angle is smaller than the peak angle.

Preferably, the surface of the connecting element may be flat, structured or roughened.

Preferably, the upper surface has a refractive index.

Preferably, the substrate film is a highly permeable substance.

Preferably, the backlight module further includes a backlight.

Preferably, the backlight is LED.

By adopting the invention, the utilization rate of light can be improved, the brightness of products can be increased, and the cost can be reduced.

Description of drawings

Readers will have a clearer understanding of various aspects of the present invention after reading the detailed description of the present invention with reference to the accompanying drawings. in,

Fig. 1 shows a schematic structural view of an optical film in the prior art;

Fig. 2 shows according to the present invention, the structural representation of optical film;

Detailed ways

The specific implementation manners of the present invention will be described in further detail below with reference to the accompanying drawings.

FIG. 1 shows a schematic structural diagram of an optical film in the prior art. Referring to FIG. 1 , the optical film 10 includes a base film 110 and a plurality of prisms 120 . Wherein, a plurality of prisms 120 are connected to the substrate film 110, and each prism 120 has a single fixed angle and is connected with each other to form an array. The substrate film 110 is divided into an active area 1 and an inactive area 2, the active area 1 is located in the direction of the normal viewing angle, and the ineffective area 2 is located in the direction of the non-orthogonal viewing angle. As shown in FIG. 1 , the light 11 enters the prism 120 after being reflected, and is refracted by the prism 120 to fall into the effective area 1 . However, the light 12 with a large viewing angle enters the prism 120 after being reflected, and after being refracted by the prism 120 , it can only enter the invalid area 2 . In this way, the utilization rate of light is very low, which greatly affects the brightness of products such as liquid crystal displays. The reason for this problem is that the prism 120 has only a single fixed refraction angle.

Fig. 2 shows a schematic structural diagram of an optical film according to the present invention. Referring to FIG. 2 , the optical film 20 includes a base film 210 and a plurality of prisms 220 . Wherein, the base film 210 is made of a high-transmittance material. A plurality of prisms 220 are connected to the substrate film 210 in an array, and each prism 220 has a pair of upper prism surfaces 221 and a pair of lower prism surfaces 222, and the upper prism surfaces 221 and the lower prism surfaces 222 are correspondingly connected and connected to each other. form an angle β. In addition, a peak angle α is formed between the pair of upper prism surfaces 221 , and α<β. There is a certain distance between two adjacent prisms 220 , exposing an upper surface 230 of the substrate film 210 . The base film 210 can be divided into an active area 3 and an inactive area 4 , the active area 3 is located in the direction of the normal viewing angle, and the inactive area 4 is located in the direction of the non-orthogonal viewing angle.

As shown in FIG. 2 , because the substrate film 210 has a high transmittance, the light 21 can pass through the substrate film 210 and enter the lower prism surface 222 of the prism 220 , and then come out and fall into the active area 1 after being refracted. The light 22 enters the lower prism face 222 of the prism 220 through the substrate film 210, then arrives at an upper prism face 221 of another prism 220 adjacent to the prism 220 after refraction, and then passes through the reflection of the upper prism face 221. Can fall into valid zone 1. The light 23 passes through the upper surface 230 of the substrate film 210, because the upper surface 230 has a refractive index, the above-mentioned light 23 can be refracted to an upper prism surface 221 of the prism 220, and then it can also be reflected by this upper prism surface 221 Falls into valid zone 1. In this way, the large-angle light is reflected by the angle change of the prism 220 and concentrated in the direction of the positive viewing angle, which can improve the utilization rate of light and improve the brightness of the product. In this embodiment, the upper surface 230 is a plane, which can increase the light extraction rate. In another embodiment, the upper surface can also be a structured surface or a rough surface.

As can be seen from the above embodiments, the advantage of adopting the present invention is that the large-angle light that cannot enter the direction of the normal viewing angle is reflected by the angle change of the prism, and can also be concentrated in the direction of the normal viewing angle, which improves the utilization rate of light. Can enhance the brightness of the product.

Hereinbefore, specific embodiments of the present invention have been described with reference to the accompanying drawings. However, those skilled in the art can understand that without departing from the spirit and scope of the present invention, various changes and substitutions can be made to the specific embodiments of the present invention. These changes and replacements all fall within the scope defined by the claims of the present invention.

Claims (8)

1. An optical film, characterized in that, comprising: a substrate film; and A plurality of prisms are arranged on the base film in an array, and each of the plurality of prisms has a pair of lower prism surfaces and a pair of upper prism surfaces, and the upper prism surfaces correspond to the lower prism surfaces connected, and an angle is formed between the upper prism surface and the corresponding lower prism surface, Wherein, there is a gap between two of the plurality of prisms, exposing a section of the upper surface of the substrate film. 2. The backlight module according to claim 1, wherein a peak angle is formed between the pair of upper prism surfaces. 3. The backlight module according to claim 1, wherein the included angle is larger than the peak angle. 4. The backlight module according to claim 1, wherein the upper surface can be a plane, a structured surface or a rough surface. 5. The backlight module as claimed in claim 1, wherein the upper surface has a refractive index. 6. The backlight module according to claim 1, wherein the base film is a highly transparent material. 7. The backlight module as claimed in claim 1, further comprising a backlight. 8. The backlight module according to claim 7, wherein the backlight source is an LED.

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