TWI661250B - Backlight module and display device - Google Patents

Abstract

The invention provides a backlight module, which includes a bottom plate, a plurality of light sources, a reflection sheet, and one or more light control devices. The reflection sheet covers the bottom plate and allows the light source to emit light through the bottom plate. A plurality of pre-cut lines are formed on the reflective sheet; these pre-cut lines respectively pass between a part of adjacent light sources. The light regulating device is disposed on the reflection sheet and covers at least one light source. The light generated by the light source is emitted to the light regulating device, and the light regulating device controls the light. At least part of the light regulation device is aligned with at least part of the pre-secant line.

Description

Backlight module with reflection sheet

The present invention relates to a backlight module with a reflective surface; specifically, the present invention relates to a backlight module with a pre-cut line design on the reflective surface.

Flat and curved display devices have been widely used in various electronic devices, such as mobile phones, personal wearable devices, televisions, host computers for transportation, personal computers, digital cameras, handheld video games, and the like. However, with the continuous improvement of specifications such as resolution and narrow bezels, the optical design in display devices has also been tested.

Taking a liquid crystal display device as an example, its optical performance is usually related to a backlight module disposed behind the display panel. Taking a traditional direct-type backlight module as an example, in order to achieve better light utilization efficiency, a reflective plate is usually provided on the back side of the direct-type light source to recover unused light and enter the backlight module again. In addition, in order to change the optical optical behavior, various optical elements are provided on the reflecting plate. However, since the reflecting plate is easily swollen by moisture or heat, the optical elements disposed on the reflecting plate are simultaneously lifted or deformed, thereby affecting the optical performance. In addition, when an optical element is assembled on a reflective plate, it is usually easy to assemble due to the inability to align it, which also affects the optical performance of the product.

An object of the present invention is to provide a backlight module, which can reduce the bulging condition of the reflective sheet contained in the backlight module.

The purpose of the present invention is to provide a backlight module, which can improve the efficiency during assembly.

The backlight module includes a bottom plate, a plurality of light sources disposed on the bottom plate, a reflection sheet, and one or more light control devices. The reflection sheet covers the bottom plate and allows the light source to emit light through the bottom plate. A plurality of pre-cut lines are formed on the reflective sheet; these pre-cut lines respectively pass between a part of adjacent light sources. With this setting, when a part of the reflection sheet is expanded due to moisture, heat or other reasons, the state of the reflection sheet's bulge will be partially limited to the range limited by the part of the pre-cut line, and the affected area will be reduced. . On the other hand, the state of the comprehensive bump caused by the expansion of the reflecting sheet can also be dispersed in a plurality of areas defined by the pre-cut line, thereby reducing the possibility of the bump height being too high at a specific position.

The light regulating device is disposed on the reflection sheet and covers at least one light source. The light generated by the light source is emitted to the light regulating device, and the light regulating device controls the light. At least a part of the light control device is aligned with at least a part of the pre-cut line; with this arrangement, the light control device can be easily assembled on the reflection sheet. In addition, since the bulging condition of the reflecting sheet is suppressed by the influence of the pre-cut line, the distance between the top plate and the light source does not change too much, and the optical performance is stabilized.

100‧‧‧ floor

300‧‧‧ light source

500‧‧‧Reflector

501‧‧‧perforation

510‧‧‧pre-cut line

511‧‧‧ intersection

513‧‧‧pre-slit

530‧‧‧Reflector Block

700‧‧‧light control device

710‧‧‧Top plate

730‧‧‧Side plate

731‧‧‧ positioning end

733‧‧‧foot

735‧‧‧ anchor

750‧‧‧ convex

900‧‧‧ Optical diaphragm

FIG. 1 is an exploded view of components of an embodiment of a backlight module; FIG. 2 is a plan view of an embodiment of a backlight module; Fig. 3 is a schematic diagram of another embodiment of a backlight module; Fig. 4 is a schematic diagram of another embodiment of a backlight module; Fig. 5 is a schematic diagram of an embodiment of a light modulation device having a convex portion; and Fig. 6 is an embodiment of a backlight module Sectional view; FIG. 7 is a sectional view of another embodiment of a reflective sheet.

The invention provides a backlight module, which is preferably applicable to a display device. The display device preferably includes a non-spontaneous display panel such as a liquid crystal display panel or an electrophoretic display panel; and it can be preferably applied to a computer monitor, a television, a monitor, or a vehicle host. In addition, the display device can also be applied to other electronic devices, for example, as a display screen of a mobile phone, a digital camera, a handheld game instrument, and the like.

As shown in FIG. 1, the backlight module includes a base plate 100, a plurality of light sources 300, a reflection sheet 500, and one or more light control devices 700. The base plate 100 is preferably made of plastic or metal for carrying the light source 300 and a circuit for controlling the light source 300. The light source 300 is preferably a point light source, such as a light emitting diode, but is not limited thereto. The light sources 300 are preferably arranged in a matrix of rows and columns on the base plate 100 to form rows and columns in different directions. However, in different embodiments, the light sources 300 may be arranged in other ways.

The reflection sheet 500 covers the bottom plate 100 and allows the light source 300 to pass through the reflection sheet 500 to emit light outward. Preferably, the reflective sheet 500 is formed with a plurality of perforations 501, and the light source 300 is located in the perforations 501, so that light can be emitted outward. As shown in FIG. 1, a plurality of pre-cut lines 510 are formed on the reflective sheet 500. In a preferred embodiment, the pre-cut lines 510 are formed by riding stitches, that is, a plurality of collinear slits are arranged at intervals. To form. However in different embodiments In this case, the pre-cut line 510 may also be a slot line that does not cut through the reflective sheet 500, or may have other structures that can weaken strength at a specific position. As shown in FIG. 1, these pre-cut lines 510 respectively pass between portions of adjacent light sources 300; in other words, light sources 300 are arranged on both sides of the pre-cut line 510, and the pre-cut lines 510 pass therethrough. In this embodiment, the pre-cut lines 510 are parallel to each other, thereby defining the reflective sheet 500 into a plurality of side-by-side strips.

With this arrangement, when a part of the reflective sheet 500 swells due to moisture, heat, or other reasons, the raised state of the reflective sheet 500 will be partially limited to the range restricted by the partial pre-cut line 510 section, and reduced. Scope of influence. On the other hand, the situation that the reflective sheet 500 has a full-scale bulge due to expansion can also be dispersed in a plurality of areas defined by the pre-cut line 510, reducing the possibility of the bulge height being too high at a specific position.

As shown in FIG. 1, the light control device 700 is disposed on the reflection sheet 500 and covers at least one light source 300. Preferably, the light generated by the light source 300 is emitted to reach the light regulating device 700, and the light regulating device 700 regulates the light. For example, the light control device 700 may reflect part of the light to different positions and then allow the light to leave the light control device 700 and reach the optical film 900 above, thereby making the light distribution more uniform, but not limited thereto; the light control device The 700 can also adjust other forms of light, such as travel direction, phase, color, etc. In this embodiment, the light source control device 700 is formed in a long shape, and has a top plate 710 and two opposite side plates 730. The top plate 710 is formed in a long rectangular shape and extends along the rows or columns of the light source 300 arrayed, and the two side plates 730 are respectively bent and protruded from the relatively long ends of the top plate 710. The top plate 710 is preferably formed with a plurality of light exit holes 711 to allow light to pass through. The light exit holes 711 may also be preferably disposed on the side plate 730. The two side plates 730 may be parallel to each other, but may also be opened outward or contracted inward relative to the top plate 710. Each side plate 730 has a positioning end 731 far from the top plate 710, and the light regulating device 700 has a positioning end 731 is disposed on the reflective sheet 500 and covers the light source 300 in one row, half row, one column, or half column.

As shown in FIG. 1 and FIG. 2, the light regulating device 700 is located between two parallel and adjacent pre-cut lines 510, and the positioning ends 731 on both sides are respectively aligned with a part or a segment of the two pre-cut lines 510. However, in different embodiments, the light regulating device 700 may also be aligned with a pre-cut line 510 with only one positioning end 731 on one side, or aligned with the pre-cut line 510 by other parts. In this embodiment, the alignment of the positioning end 731 with the pre-cut line 510 means that the vertical projection of the end edge of the positioning end 731 on the reflection sheet 500 overlaps with the pre-cut line 510. However, in different embodiments, the vertical projection of the edge of the positioning end 731 on the reflection sheet 500 is close to the pre-cut line 510 and remains parallel. Preferably, the positioning end 731 may be aligned with the entire pre-cut line 510 or aligned with a certain distance in parallel with the pre-cut line 510; however, in different embodiments, it may be aligned with only a portion of a certain pre-cut line 510 Line segments are aligned. With this arrangement, the light regulating device 700 can be easily assembled on the reflection sheet 500. In addition, since the bulging condition of the reflection sheet 500 is suppressed by the influence of the pre-cut line 510, the distance between the top plate 710 and the light source 300 does not change too much, and the optical performance is stabilized. Especially when the positioning end 731 is aligned with the pre-cut line 510, since the height of the reflection sheet 500 bulging near the pre-cut line 510 is relatively limited, it is easier to limit the change in the distance between the top plate 710 and the light source 300.

In the embodiment shown in FIG. 3, the light control device 700 may be formed into a semi-tubular shape and covered on a row or column of light sources 300. The light control device 700 formed into a semi-tubular shape is also preferably aligned with the pre-cut line 510 with a long side to increase the convenience of assembly.

FIG. 4 shows another embodiment of the present invention. In this embodiment, the pre-cut lines 510 are not only arranged in a single direction, but are staggered between the rows and columns formed by the light sources 300 arranged in an array. In other words, part of the pre-cut line 510 is arranged horizontally and the other part is arranged vertically, so that A plurality of reflection sheet blocks 530 are defined. Preferably, each reflection sheet block 530 is formed with a perforation 501 for receiving the light source 300 or allowing the light source 300 to pass through. When the reflection sheet 500 needs to be removed and reworked due to the need for repair, replacement or other factors in the lower line, the light source 300, only a part of the reflection sheet block 530 that needs to be reworked can be separated along the pre-cut line 510 without reflecting the entire sheet. Piece 500 is removed.

As shown in FIG. 4, in this embodiment, the intersecting pre-cut lines 510 form a plurality of intersection points 511. The positioning end 731 of the side plate 730 extends to fit the foot piece 733 and the reflection sheet 500, and the corner of the foot piece 733 can be used as a positioning point 735 and corresponds to one of the above-mentioned intersections 511 to achieve alignment of the light regulating device 700. effect. In different embodiments, the above-mentioned positioning points 735 can also be formed in other parts of the positioning end 731 of the side plate 730. For example, a hole can be formed in the foot piece 733 as the positioning point 735 to align with the intersection 511.

FIG. 5 shows another embodiment of the present invention. In this embodiment, the positioning end 731 of the light regulating device 700 is provided with a convex portion 750. The convex portions 750 are preferably distributed at intervals along the positioning end 731 to form a whole row of convex tooth structures. The pre-cut line 510 is formed by a plurality of pre-cut slits 513 arranged at intervals. When the light control device 700 is installed, the convex portions 750 can be correspondingly extended into the pre-cut slits 513 to align and position the light control device 700 on the reflection sheet 500.

FIG. 6 is a cross-sectional view of an embodiment of a backlight module. In this embodiment, the pre-cut lines 510 also form a plurality of reflection sheet blocks 530 in a crisscross pattern, and the light sources 300 are respectively distributed in the reflection sheet blocks 530. Preferably, the arrangement of the light source 300 and the closest pre-cut line 510 conforms to the following relationship: L × α < -L

Among them, L: the vertical distance from the center of the light source to the pre-cut line; α: the coefficient of hygroscopic expansion or thermal expansion of the reflector; h: the height of the light source.

With the above-mentioned setting, even if the swell occurs due to the expansion of the reflection sheet 500 in the reflection sheet block 530, the height of the reflection sheet 500 near the perforation 501 can be limited, for example, not higher than the top surface of the light source 300, so Reduce the impact on optical performance. Specifically, in this embodiment, when the reflection sheet 500 expands to generate a bulge, since the position of the pre-cut line 510 has a weak structural strength, it is more likely to be bent or bent from this position. At this time, the position of the pre-cut line 510 will remain close to the bottom plate 100, and the reflection sheet 500 will generate a bulge between the adjacent pre-cut lines 510 to reduce the situation of excessive bulge in a certain part. At the same time, by the above-mentioned arrangement relationship between the light source 300 and the closest pre-cut line 510, the influence on the optical performance can be further reduced. It must be noted that the above-mentioned setting relationship is not limited to the situation when the pre-cut lines 510 are criss-crossed; it can also be applied when the pre-cut lines 510 are all in the same direction.

In the embodiment shown in FIG. 7, a plurality of pre-cut lines 510 may be provided between two adjacent rows formed by the light sources 300 being arranged. Similarly, a plurality of pre-cut lines 510 may be provided between two adjacent columns in which the light sources 300 may be arranged. With this arrangement, the distance between the light source 300 and the closest to the pre-cut line 510 can be reduced, and the bulging degree of each reflective sheet block 530 can be reduced, so as to reduce the impact on the optical performance caused by the expansion of the reflective sheet 500.

The present invention has been described by the above related embodiments, but the above embodiments are merely examples for implementing the present invention. It must be noted that the disclosed embodiments do not limit the scope of the invention. On the contrary, modifications and equal settings included in the spirit and scope of the scope of patent application are all included in the scope of the present invention.

Claims (7)

A backlight module includes: a base plate; a plurality of light sources respectively disposed on the base plate; a reflective sheet covering the base plate and allowing the light sources to pass through; wherein a plurality of pre-cut lines are formed on the reflective sheet respectively Passes between the adjacent light sources; and at least one light control device is disposed on the reflection sheet, and each of the light control devices covers at least one of the light sources; wherein at least a part of the at least one light control device Aligned with at least part of the pre-cut lines; and the light sources are arranged in a matrix of rows and columns, the pre-cut lines are staggered between the rows and columns formed by the light sources, at least one of the light sources and the closest pre-cut line The setting conforms to the following relationship: L × α < -L, where L: the vertical distance from the center of the light source to the pre-cut line; α: the coefficient of hygroscopic expansion or thermal expansion of the reflective sheet; h: the height of the light source. The backlight module according to claim 1, wherein each of the light regulating devices has: a top plate; and both side plates are respectively bent and protruded from two opposite ends of the top plate; each of the side plates has one far from the top plate Positioning end; wherein, the positioning end of at least one side plate is aligned with one of the pre-cut lines. The backlight module according to claim 2, wherein the pre-cut line aligned with the positioning end includes at least one pre-cut slit, and a convex portion is provided on the positioning end, and the convex portion projects into the pre-cut slit. The backlight module according to claim 2, wherein the light sources are arranged in a matrix of rows and columns, and the pre-cut lines are staggered between the rows and columns formed by the light sources to form a plurality of intersections, each of which is positioned A positioning point is formed on the end corresponding to at least one of the intersections. The backlight module according to claim 1, wherein the at least one light control device extends along a row or column formed by the light sources to cover the corresponding light sources, and is located between two adjacent pre-cut lines. . The backlight module according to claim 1, wherein a plurality of the pre-cut lines are provided between two adjacent rows or two adjacent columns formed by the light sources. The backlight module according to claim 1, wherein the light sources are arranged in a matrix of rows and columns, and the pre-cut lines are staggered between the rows and columns formed by the light sources to form a plurality of reflection sheet blocks, at least in part The reflective sheet blocks are respectively formed with perforations, and the light sources are respectively located in the perforations.