CN201110928Y - A circuit board and backlight - Google Patents

Abstract

The utility model discloses a circuit board. A point light source is arranged on one side of the circuit board. On the side plate, between the light outlet of the point light source and the edge of the circuit board vertically opposite It has a layer of light-absorbing material. The utility model also discloses a backlight source using the circuit board. The utility model makes the brightness of the light incident on the light incident surface of the backlight module uniform, thereby improving the luminous effect.

Description

A circuit board and backlight

【Technical field】

The utility model relates to the field of liquid crystal displays, in particular to a circuit board capable of improving the luminous effect of a backlight and a backlight source using the circuit board.

【Background technique】

As a white light type backlight source for small and medium-sized color liquid crystal displays, LEDs (Light Emitting Diodes) are usually used as light emitting sources. As shown in Figures 1 and 2, after the LED 13 is soldered to the circuit board 12 (usually using a flexible circuit board) through the pad 30, it is then mounted on the backlight module 11 to form a backlight. The light source can be divided into point light source and line light source. The existing backlight generally adopts LED point light source. To obtain a uniform luminous effect in the visible area 111 of the backlight module 11, it is necessary to ensure that the light is visible from the light outlet of the LED to the backlight. The nearest point of the region reaches a certain distance. Due to the characteristics of the point light source and the limitation of the structure of the backlight module 11, and the light outlet of the LED is closely attached to the light incident surface of the light guide plate, the distance L1 from the closest point of the LED point light source to the visible area of the backlight module is relatively short. The light emitted from the LED point light source and entering the light guide plate through a short distance route has no time to disperse into a uniform plane to emit light, which is easy to produce bright spots near the light source in the visible area of the liquid crystal display, affecting the luminous effect of the backlight .

【Content of invention】

The purpose of the utility model is to solve the problems in the prior art, to provide a circuit board with LED point light sources, so that the brightness of the light incident on the visible area of the backlight module is uniform.

Another object of the present utility model is to provide a backlight source, which reduces bright spots on the part of the liquid crystal display near the light source in the visible area.

In order to achieve the above object, the utility model provides a circuit board, one side of the circuit board is provided with a point light source, on the side plate, from the light outlet of the point light source to the line vertically opposite There is a layer of light absorbing material between the edges of the plate.

In a preferred solution, the point light source is a light-emitting diode, the length of the light-absorbing material layer in a direction parallel to the light-emitting diode is equal to or greater than the width of the light-emitting diode outlet, and the light-absorbing material layer is in direct contact with the light-emitting diode light outlet. right.

The circuit board is a flexible circuit board, and the light-absorbing material layer is a silk-screened black ink layer or other dark color ink layers.

In order to achieve the above object, the utility model also provides a backlight, including a backlight module and a circuit board for providing light sources, the backlight module includes a light guide plate and an optical film, the light guide plate has a light incident surface, A light-emitting surface and a reflecting surface, the optical film is covered on the light-emitting surface of the light guide plate, a point light source is provided on one side of the circuit board, and the light-emitting port of the point light source faces and is close to the light guide plate The light incident surface has a light-absorbing material layer on the side plate surface of the circuit board, between the light outlet of the point light source and the edge of the circuit board vertically opposite to it, and the light-absorbing material layer faces the The light emitting surface or reflective surface of the light guide plate.

The beneficial effects of the utility model compared with the prior art are:

1. The utility model has a light-absorbing material layer between the light outlet of the point light source on the circuit board and the edge of the circuit board vertically opposite to it. The circuit board is applied to the backlight module. Because the vertical distance between the point and the line is the shortest, the intensity of the light obtained by the part of the light incident surface perpendicular to the light outlet is the largest, so the light-absorbing material layer can be used to absorb the intensity of this part of the light, so that this The intensity of part of the light is reduced, and finally the brightness of the light incident on the visible area of the backlight module is uniformized, the backlight luminous effect is improved, and the light source near the visible area of the LCD display is avoided due to the point light source and the structure of the backlight frame. highlights.

2. The light-absorbing material is preferably black ink, which has the best light-absorbing effect.

3. The utility model is simple and easy to implement, and the production cost is low.

【Description of drawings】

FIG. 1 is a schematic diagram of an existing backlight flexible circuit board in a backlight module;

FIG. 2 is a schematic diagram of an existing backlight flexible circuit board;

Fig. 3 is the schematic diagram of the flexible circuit board of the utility model embodiment;

FIG. 4 is a structural schematic view of the flexible circuit board assembled on the light guide plate of the present invention.

The features and advantages of the utility model will be described in detail through embodiments in conjunction with the accompanying drawings.

【Detailed ways】

The backlight source includes a flexible circuit board and a backlight module for providing light sources. The backlight module includes a light guide plate and an optical film. The light guide plate is plate-shaped. The light guide plate has a light incident surface, a light exit surface for emitting light, and The reflective surface that reflects the light incident from the light incident surface, one of its narrow sides is the light incident surface, and the wide side intersecting with the light incident surface is the light exit surface, and the opposite of the light exit surface is the reflective surface, which is usually made into On the dot side, the optical film covers the light-emitting surface of the light guide plate. An LED point light source is provided on one side of the flexible circuit board, and there is a light-absorbing material on the side plate of the circuit board between the light outlet of the point light source and the edge of the circuit board vertically opposite to it. layer, the light-absorbing material layer is preferably a black ink layer. For a white light backlight module using LEDs as point light sources, the surface color of the flexible circuit board on the side where the LEDs are attached can directly affect the final luminous effect. Therefore, the white ink layer 31 is also silk-screened on the side of the flexible circuit board 12 where the LED is attached to the area outside the light-absorbing material layer, so that the light emitted by the LED can be injected into the light guide plate of the backlight module without being affected as much as possible. .

As shown in Figure 3, it is a structural schematic diagram of the flexible circuit board 12. On the side board surface of the flexible circuit board 12 pasted with the LED 13, several pairs of pads 30 for welding the LEDs are included. Facing an edge of the flexible circuit board, a black ink layer 32 is silk-screened between each pair of LED pads 30 and the edge portion vertically opposite to it, and the black ink layer 32 corresponds to each pair of pads 30 one by one. Arranged, and the center of the black ink layer 32 is located on the centerline of each pair of pads 30, so that the black ink layer 32 and the light outlet of the LED soldered on the pads 30 can face directly.

As shown in Fig. 4, it is a structural schematic diagram when the flexible circuit board is assembled on the light guide plate. The light outlet of the LED 13 faces and is close to the light incident surface 141 of the light guide plate 14. The preferred way is that the LED light outlet is close to the light guide plate. On the light incident surface, the black ink layer 32 faces the light emitting surface of the light guide plate 14 , or the black ink layer faces the reflective surface of the light guide plate.

The light emitted from the LED point light source and enters the light guide plate through a short distance, because the intensity of the black ink 32 absorbing light is weakened, even if the light does not have time to disperse into a uniform plane to emit light, it can effectively eliminate or reduce bright spots. This embodiment is simple and easy to implement, and there is no need to add other costs except for the black ink.

Since the light outlet of the LED has a certain width, the length of the black ink layer 32 in the direction parallel to the LED is preferably equal to or greater than the width of the light outlet, so that each part of the light incident surface of the backlight module receives light with relatively uniform brightness.

Similarly, printing a piece of other dark ink on the place where the black ink is silk-screened can also eliminate or lighten the bright spots. In addition, the use of inks of other colors can also appropriately change the background color of the light-emitting area of the backlight module, so as to easily realize different background colors of the backlight and obtain different color-shifted lighting effects.

The utility model improves backlight luminescence by arranging light-absorbing materials such as silk screen printing ink on the flexible circuit board, and has good effect, simple method and low cost.

The above content is a further detailed description of the utility model in combination with specific preferred embodiments, and it cannot be assumed that the specific implementation of the utility model is only limited to these descriptions. For those of ordinary skill in the technical field to which the utility model belongs, on the premise of not departing from the concept of the utility model, some simple deduction or replacement can also be made, which should be regarded as belonging to the protection scope of the utility model, such as flexible circuit The board can also be replaced by an ordinary circuit board, and the LED point light source can also be replaced by other point light sources.

Claims (6)

1. A circuit board, one side of the circuit board is provided with a point light source, characterized in that: on the side plate, between the light outlet of the point light source and the edge of the circuit board vertically opposite to it There is a light-absorbing material layer between them. 2. The circuit board according to claim 1, wherein the point light source is a light emitting diode, and the length of the light-absorbing material layer in a direction parallel to the light emitting diode is equal to or greater than the width of the light outlet of the light emitting diode and The light-absorbing material layer is directly opposite to the light outlet of the light-emitting diode. 3 . The circuit board according to claim 2 , wherein the circuit board is a flexible circuit board, and the light-absorbing material layer is a silk-screened black ink layer or other dark-colored ink layers. 4 . 4. A backlight source, comprising a backlight module and a circuit board for providing a light source, the backlight module includes a light guide plate and an optical film, the light guide plate has a light incident surface, a light exit surface and a reflective surface, the The optical film is covered on the light-emitting surface of the light guide plate, and a point light source is arranged on one side of the circuit board, and the light-emitting port of the point light source faces and is close to the light-incident surface of the light guide plate, and is characterized in that: On the side plate of the circuit board, there is a layer of light-absorbing material between the light outlet of the point light source and the edge of the circuit board vertically opposite to it, and the layer of light-absorbing material faces the light outlet of the light guide plate. surface or reflective surface. 5. The backlight according to claim 4, wherein the point light source is a light emitting diode, and the length of the light-absorbing material layer in a direction parallel to the light emitting diode is equal to or greater than the width of the light outlet of the light emitting diode and The light-absorbing material layer is directly opposite to the light outlet of the light-emitting diode. 6 . The backlight according to claim 5 , wherein the circuit board is a flexible circuit board, and the light-absorbing material layer is a silk-screened black ink layer or other dark-colored ink layers.

Images