CN101320164B - Back light module unit and LCD - Google Patents

Abstract

The invention discloses a backlight module group which comprises a light guide plate, a light-emitting diode array light source, a reflecting sheet, at least one optical film and a frame; wherein, the light-emitting diode array light source comprises a plurality of light-emitting diodes and a circuit board; the frame is used for bearing the above members. When the members are installed on the frame, the light-emitting diode array light source is positioned at one edge of the frame, and the light-emitting diodes are positioned below the circuit board. A cavity is formed above the optical film on the frame and is used for containing the liquid crystal display panels.

Description

Module backlight and LCD

[technical field]

The invention relates to a kind of module backlight and LCD, particularly relevant for a kind of employing light emitting diode (LED) as the module backlight of light source and use the LCD of this module backlight.

[background technology]

Module backlight (Backlight Module) is applied to LCD (LCD), and its function is that the display panels (LCDPanel) to LCD provides one evenly, the light source of high brightness, makes its normally show image.The main light source of module backlight has cold cathode fluorescent lamp (Cold CathodeFluorescent Lamp usually, CCFL) and light emitting diode (LED), wherein cold cathode fluorescent lamp have electric and optical characteristics stable, life-span is long, shatter-proof, advantage such as shock-resistant, but cold cathode fluorescent lamp also has a lot of shortcomings, as be unfavorable for environmental protection, can produce electromagnetic radiation during startup, the low-temperature zone task performance is poor, driving voltage height or the like, and more main be, owing to be subject to the processing procedure of cold cathode fluorescent lamp, its fluorescent tube size is difficult to do carefullyyer, so if adopt cold cathode fluorescent lamp as light source on module backlight, then the thickness of module backlight just is difficult to improve.For example: the tube diameter minimum that is used for the cold cathode fluorescent lamp of notebook computer is 1.8 millimeters, and the light inlet side of wedge shape light guide plate must be kept 2.0 millimeters, and the thickness of final integral module backlight will reach more than 5 millimeters; If cold cathode fluorescent lamp is applied in large-sized liquid crystal indicators such as monitor, LCD TV, then the thickness of whole module backlight will be up at least 1 centimetre.In a word, the genetic prerequisite of cold cathode fluorescent lamp determines the thickness of its module backlight to be bound to greater than more than 5 millimeters.In addition, on its physical characteristics a lot of defectives are arranged also.Therefore, be necessary to use new light source, replace conventional lighting sources, eliminate problem and puzzlement that existing light source is derived whereby.

Light emitting diode (LED) is as a kind of new type light source, with its low suppling voltage, and low-power consumption, the long-life, characteristics such as radiationless all have quite good application in many occasions.Appearance along with the continuous lifting, particularly superhigh brightness LED of lumination of light emitting diode brightness in recent years makes the application of light emitting diode more extensive.For example, replace as back light with light emitting diode that the original electroluminescence sheet of hand-held device (EL) is backlight, (CCFL) is backlight for cold cathode fluorescent lamp, not only can make circuit design more succinct easily, and can have higher outer the being subjected to property of resisting strenuously.When light emitting diode is applied on the hand-held device,,, therefore generally all adopt flexible circuit board (FPC) as electrical vector because of small screen required light emitting diode negligible amounts backlight as personal digital assistant device (PDA), digital camera, mobile phone etc.But when on large scale is backlight, using light emitting diode, because of needs produce high briliancy, therefore required light emitting diode quantity must increase a lot of, even reach more than the twice, corresponding light source heat also can increase, this moment is if continue to adopt flexible circuit board as electrical vector, because the hardness deficiency of flexible circuit board, many more the planarizations that just cannot say for sure to demonstrate,prove flexible circuit board more of the light emitting diode quantity of being carried, thereby can cause the " loaded " position height of light emitting diode different, and influence the homogeneity of integrated light source.Therefore, existingly can not be directly applied on the large scale liquid crystal display device with the small screen backing structure of flexible circuit board as the electrical vector of light emitting diode.

In the liquid crystal indicator of large-size, module backlight adopts hardness ordinary circuit board (PCB) preferably usually, even metal-base circuit plate (MCPCB) is as the carrier of light emitting diode, as shown in fig. 1.Several light emitting diodes 91 in the available liquid crystal display 900 are positioned over a side of light guide plate 90, and the circuit board 93 of carrying light emitting diode 91 is positioned at the below of the side of light guide plate 90, and display panels 92 covers the top of light guide plate 90.Reflector plate 94 is configured in the below of light guide plate 90, can be with in the light reflected back light guide plate 90 that spills from light guide plate 90 bottoms, to improve the light utilization rate.Several optical thin films 95 are stacked and placed on the light-emitting face of light guide plate 90, for the light of revising from the light-emitting face ejaculation of light guide plate 90.Yet, the thickness of this available liquid crystal display is at least the summation of the thickness of display panels 92, light guide plate 90, reflector plate 94, several optical thin films 95 and circuit board 93, add the thickness of outside framework, do not meet the trend of current electronic product slimming in fact.Therefore, be necessary to improve the module backlight of light emitting diode, in the hope of obtaining more desirable product.

[summary of the invention]

The LCD that fundamental purpose of the present invention is to provide a kind of module backlight of compact conformation and uses this module backlight, thus make whole LCD have less thickness.

Other purpose of the present invention and advantage can be further understood from the disclosed technical characterictic of the present invention.

In order to achieve the above object or other purpose, the present invention adopts following technical scheme: a kind of module backlight, include a light guide plate, a light emitting diode matrix light source, a reflector plate, at least one optical thin film, and a framework, wherein light guide plate has a light entrance face, a lower surface and a light-emitting face; The light emitting diode matrix light source is disposed at the side of the light entrance face of light guide plate, and the light emitting diode matrix light source package contains the circuit board of several light emitting diodes with light-emitting area and these light emitting diodes of carrying; Reflector plate is disposed at the below of the lower surface of light guide plate; Optical thin film is disposed at the top of the light-emitting face of light guide plate; Framework is in order to carry above-mentioned member, it has several frames and a diapire, inside front at the wherein frame of framework also has a gulde edge, this gulde edge is parallel with described frame, and frame all is separated from each other in level and vertical direction therewith, is formed with a gap between this gulde edge and described frame.Reflector plate is positioned at the diapire of this framework.The light emitting diode matrix light source is positioned at the frame place that is provided with gulde edge of framework, and light emitting diode is positioned at the below of circuit board, wherein the circuit board of light emitting diode matrix light source is positioned at the outside of gulde edge and a space of described frame top, and these light emitting diodes of light emitting diode matrix light source are positioned at described gap, and the light-emitting area of light emitting diode is towards the light entrance face of light guide plate.Above framework and optical thin film, define a cavity, be used for accommodating a display panels.

In order to achieve the above object or other purpose, the present invention also adopts following technical scheme: a kind of LCD, include a light guide plate, a light emitting diode matrix light source, a reflector plate, at least one optical thin film, a framework, and a display panels, wherein light guide plate has a light entrance face, a lower surface and a light-emitting face; The light emitting diode matrix light source is disposed at the side of the light entrance face of light guide plate, and the light emitting diode matrix light source package contains the circuit board of several light emitting diodes with light-emitting area and these light emitting diodes of carrying; Reflector plate is disposed at the below of the light diffusingsurface of this light guide plate; Optical thin film is disposed at the top of the light-emitting face of this light guide plate; Framework is in order to carry above-mentioned member, it has several frames and a diapire, inside front at the wherein frame of framework also has a gulde edge, this gulde edge is parallel with described frame, and frame all is separated from each other in level and vertical direction therewith, is formed with a gap between this gulde edge and described frame.Reflector plate is positioned at the diapire of framework.The light emitting diode matrix light source is positioned at the frame place that is provided with gulde edge of framework, and light emitting diode is positioned at the below of circuit board, wherein the circuit board of light emitting diode matrix light source is positioned at the outside of gulde edge and a space of described frame top, and these light emitting diodes of light emitting diode matrix light source are positioned at described gap, and the light-emitting area of these light emitting diodes is towards the light entrance face of light guide plate, the top of framework and optical thin film defines a cavity, and display panels is contained in the cavity of framework.Display panels is positioned at the inboard of the gulde edge of framework, and the circuit board upper surface is to the summation of the vertical range between the outside surface of display panels less than circuit board thickness and display panels thickness.

Compared to prior art, the light emitting diode matrix light source of the present invention's module backlight and LCD is that upside-down mounting is in framework, be that its light emitting diode is the below that is positioned at circuit board, make circuit board upper surface (promptly with the carrying light emitting diode the opposite another side of face) to the vertical range between the outside surface of display panels, summation less than circuit board thickness and display panels thickness, promptly have at least the thickness of a part of display panels to offset, thereby reach the purpose that reduces height and compact conformation with the thickness of the circuit board of this light source.

[description of drawings]

Fig. 1 is for adopting the existing back light module unit structure synoptic diagram of metal-base circuit plate.

Fig. 2 is the STRUCTURE DECOMPOSITION synoptic diagram of the module backlight of one embodiment of the invention.

Fig. 3 is the part-structure enlarged diagram of one embodiment of the invention module backlight shown in Fig. 2.

Fig. 4 is the structural representation of the light emitting diode matrix light source of one embodiment of the invention module backlight shown in Fig. 2.

Fig. 5 is the cross-sectional view of one embodiment of the invention module backlight shown in Fig. 2.

Fig. 6 is the cross-sectional view of LCD of the present invention.

[embodiment]

The direction term of being mentioned in following examples, for example: upper and lower, left and right, front or rear etc. only are the directions with reference to annexed drawings.Therefore, the direction term of use is to be used for illustrating not to be to be used for limiting the present invention.

Please refer to Fig. 2 to shown in Figure 5, the present invention's module 1 backlight includes a light guide plate 10, a light emitting diode matrix light source 20, a reflector plate 30, several layers of optical thin film 40 and a framework 50.

Light guide plate 10 is in order to the directing light direction, and it has a light entrance face 11, a lower surface 12, and a light-emitting face 13.

Light emitting diode matrix light source 20 is light entrance face 11 sides that are disposed at light guide plate 10, it includes several light emitting diode 21 (see figure 4)s, and be used for carrying the circuit board 22 of the hard of light emitting diode 21, wherein circuit board 22 can be metal-base circuit plate (MCPCB), it not only can be used as the electrical vector of light emitting diode 21, can also the heat that light emitting diode 21 produces can be conducted to other member (metalwork 60 as described later) by circuit board 22 as the heat conduction carrier of light emitting diode 21.In the present embodiment, circuit board 22 is to be strip, has certain thickness, and light emitting diode 21 linearly type is arranged in the surface of circuit board 22.When being installed in light emitting diode matrix light source 20 on the framework 50, light emitting diode 21 is the lower surfaces that are positioned at circuit board 22, and the light-emitting area 210 of light emitting diode 21 is the light entrance faces 11 towards light guide plate 10.

Reflector plate 30 is the belows that are disposed at light guide plate 10, and is posted by the lower surface 12 of light guide plate 10, can be with in the light reflected back light guide plate 10 that spills from light guide plate 10 bottoms, to improve the light utilization rate.

Several layers of optical thin film 40 are the light-emitting faces 13 that are stacked and placed on light guide plate 10, and for the light of revising from light-emitting face 13 ejaculations of light guide plate 10, these optical thin films 40 can be diffusion barrier and prismatic lens etc.

Framework 50 is in order to carry above-mentioned all members.In the present embodiment, framework 50 is plastic frames, has the diapire 55 that four frames 51,52,53 and 54 and for example are hollow outs.In other embodiments, diapire 55 does not need hollow out.Opposite with prior art, above-mentioned light emitting diode matrix light source 20 is a wherein frame 51 place's (see figure 5)s that are installed in framework 50 in the mode that circuit board 22 is positioned at light emitting diode 21 tops.Please consult Fig. 2 and Fig. 3 in detail, frame 51 inside fronts are provided with a gulde edge 56, and itself and frame 51 are all disconnected from each other in the horizontal and vertical directions, so are formed with a gap 57 between gulde edge 56 and the frame 51.As shown in Figure 5 and Figure 6, the circuit board 22 of light emitting diode matrix light source 20 is positioned at the outside of gulde edge 56 and the space of frame 51 tops, the light emitting diode 21 of light emitting diode matrix light source 20 is then in the gap 57 between gulde edge 56 and frame 51, and the light emitting diode in the present embodiment 21 is the side light-emitting diode (led), thereby the light that light emitting diode 21 is launched can 57 ejaculations from the gap.Above-mentioned reflector plate 30 is to be installed on the diapire 55 of framework 50, and an end of reflector plate 30 is inserted in the reserved location of the below of light emitting diode 21.And light guide plate 10 is below (see figure 5)s that level is inserted gulde edge 56, for the location, and be positioned on the same surface level with light emitting diode 21, and its light entrance face 11 is to face mutually with the light-emitting area 210 of light emitting diode 21, can accept to come from the light of light emitting diode 21 like this.In other embodiments, if the width of circuit board 22 is bigger, light guide plate 10 can also further be inserted the below of circuit board 22, in case leak-stopping light also can further improve stability of structure.Optical thin film 40 then is positioned at the top of the light-emitting face 13 of light guide plate 10.

The top of framework 50 and optical thin film 40 defines a cavity 58, and display panels 80 promptly is placed in the cavity 58.As shown in Figure 6, display panels 80 is positioned at the inboard of the gulde edge 56 of framework 50, and the top of light guide plate 10 and optical thin film 40.Circuit board 22 then is positioned at the outside of gulde edge 56, and the top of light emitting diode 21.Because in one embodiment, light guide plate 10 and light emitting diode 21 can be positioned on the same surface level, and the thickness of optical thin film 40 very little (optical thin film 40 thickness among Fig. 5 and Fig. 6 only for the signal, but not its actual (real) thickness), therefore, relative vertical range between the lower surface of display panels 80 bottoms and circuit board 22 (promptly carrying the surface of light emitting diode 21) can be very short, almost can regard as to be positioned on the same surface level.In other words, LCD 100 of the present invention can be by the height of adjustment frame 51 and the size of gulde edge 56, display panels 80 and circuit board 22 are placed in same height, and can select the gauge of circuit board 22 according to the thickness of display panels 80, thereby display panels 80 and circuit board 22 are positioned at the space of sustained height, overcome that the circuit board of display panels and carrying light emitting diode is in different surface levels respectively and causes the bigger problem of integral thickness in the prior art, reduced the integral thickness of LCD 100.

The LCD 100 of preferred embodiment of the present invention also includes a metalwork 60, it is the lengthwise shape, and cross-section structure is the half-open shape of the mouth as one speaks, and metalwork 60 is coated on the frame that light emitting diode matrix light source 20 is installed 51 of framework 50, like this can fixing circuit board 22.Metalwork 60 has the vertical edge 63 of a level narrow limit 61, one horizontal broadside 62 and narrow limit 61 of a connection level and horizontal broadside 62, wherein the narrow limit 61 of level has a surface of contact 610, and surface of contact 610 abuts in the upper surface (promptly with another opposite surface of face of carrying light emitting diode 21) of circuit board 22, derive with the heat that light emitting diode 21 is distributed, be beneficial to heat radiation; Horizontal broadside 62 is the bottoms that are posted by a frame 51 of framework 50, one fixed screw 70 passes through hole 620 (see figure 3)s on the horizontal broadside 62 successively and is positioned at screw 520 on another frame 52 that is connected with frame 51 of framework 50, in this way metalwork 60 is installed on the framework 50, and can further increases the structural stability of module 1 backlight.

Please reach LCD 100 simultaneously with reference to available liquid crystal display 900 shown in Figure 1 by one embodiment of the invention shown in Figure 6.Can learn obviously that from figure the thickness of available liquid crystal display 900 mainly includes the thickness of circuit board 93, the thickness of light guide plate 90, the thickness of display panels 92, and the thickness of reflector plate 94 and several optical thin films 95; The thickness of LCD 100 of the present invention mainly includes the thickness of light guide plate 10, the thickness of display panels 80, and the thickness of reflector plate 30 and several optical thin films 40.In addition, comparison diagram 1 and Fig. 6, the LCD 100 of one embodiment of the invention, the upper surface of circuit board 22 (promptly with another opposite surface of face of carrying light emitting diode 21) is to the vertical range between the outside surface of display panels 80, less than the summation of circuit board 22 thickness and display panels 80 thickness.Therefore, circuit board 21 does not need to occupy certain thickness space separately among the present invention, thereby has reduced the thickness of LCD 100.

Claims (10)

1. module backlight, it is applied to a LCD, this module backlight includes: a light guide plate, a light emitting diode matrix light source, a reflector plate, at least one optical thin film and a framework, and light guide plate has a light entrance face, a lower surface and a light-emitting face; The light emitting diode matrix light source is disposed at the side of the light entrance face of light guide plate, this light emitting diode matrix light source package contains several light emitting diodes and a circuit board, these light emitting diodes have a light-emitting area, and the light-emitting area of these light emitting diodes is towards the light entrance face of light guide plate, these light emitting diodes of circuit board bearing; Reflector plate is disposed at the below of the lower surface of light guide plate; Optical thin film is disposed at the top of the light-emitting face of light guide plate; Framework for carrying light guide plate, light emitting diode matrix light source, reflector plate and optical thin film, this framework has several frames and a diapire, it is characterized in that: the inside front at the wherein frame of framework also has a gulde edge, this gulde edge is parallel with described frame, and frame all is separated from each other in level and vertical direction therewith, is formed with a gap between this gulde edge and described frame; Reflector plate is positioned on the diapire of framework; The light emitting diode matrix light source is positioned at the frame place that is provided with gulde edge of framework, and these light emitting diodes of light emitting diode matrix light source are positioned at the lower surface of circuit board, wherein the circuit board of light emitting diode matrix light source is positioned at the outside of gulde edge and a space of described frame top, and these light emitting diodes of light emitting diode matrix light source are positioned at described gap; Above framework and optical thin film, define a cavity, be used for accommodating a display panels.

2. module backlight as claimed in claim 1 is characterized in that: this module backlight also includes a metalwork, and this metalwork is coated on the frame that the light emitting diode matrix light source is installed of framework.

3. module backlight as claimed in claim 2 is characterized in that: described metalwork has a surface of contact, and this surface of contact is posted by the upper surface of circuit board.

4. module backlight as claimed in claim 1 is characterized in that: these light emitting diodes are side light-emitting diode (led)s.

5. module backlight as claimed in claim 1 is characterized in that: at least one optical thin film is diffusion barrier or prismatic lens.

6. LCD, it includes: a light guide plate, a light emitting diode matrix light source, a reflector plate, at least one optical thin film, a framework and a display panels, light guide plate has a light entrance face, a lower surface and a light-emitting face; The light emitting diode matrix light source is disposed at the side of the light entrance face of light guide plate, the light emitting diode matrix light source includes several light emitting diodes and a circuit board, these light emitting diodes have a light-emitting area, and the light-emitting area of these light emitting diodes is towards the light entrance face of light guide plate, these light emitting diodes of circuit board bearing; Reflector plate is disposed at the below of the lower surface of light guide plate; Optical thin film is disposed at the top of the light-emitting face of light guide plate; Framework is in order to carrying light guide plate, light emitting diode matrix light source, reflector plate and optical thin film, it has several frames and a diapire, it is characterized in that: the inside front at the wherein frame of framework also has a gulde edge, this gulde edge is parallel with described frame, and frame all is separated from each other in level and vertical direction therewith, is formed with a gap between this gulde edge and described frame; Reflector plate is positioned on the diapire of framework; The light emitting diode matrix light source is positioned at the frame place that is provided with gulde edge of framework, and these light emitting diodes of light emitting diode matrix light source are positioned at the lower surface of circuit board, wherein the circuit board of light emitting diode matrix light source is positioned at the outside of gulde edge and a space of described frame top, and these light emitting diodes of light emitting diode matrix light source are positioned at described gap; Above framework and optical thin film, define a cavity, display panels is contained in this cavity, and display panels is positioned at the inboard of the gulde edge of framework, and the circuit board upper surface is to the summation of the vertical range between the outside surface of display panels less than circuit board thickness and display panels thickness.

7. LCD as claimed in claim 6 is characterized in that: this LCD also includes a metalwork, and this metalwork is coated on the frame that the light emitting diode matrix light source is installed of framework.

8. LCD as claimed in claim 7 is characterized in that: this metalwork has a surface of contact, and this surface of contact abuts in the upper surface of circuit board.

9. LCD as claimed in claim 6 is characterized in that: these light emitting diodes are side light-emitting diode (led)s.

10. LCD as claimed in claim 6 is characterized in that: at least one optical thin film is diffusion barrier or prismatic lens.

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