[background technology]
Because the liquid crystal of panel of LCD itself is not had a characteristics of luminescence, thereby, for reaching display effect, need to give the LCD panel that one planar light source device is provided, as module backlight, its role is to area source abundant to panel of LCD supply brightness and that be evenly distributed.
As shown in Figure 1, the module backlight 1 of prior art compriseslight source 10, light guide plate 12 and blooming piece, and according to the function difference, blooming piece can have: reflector plate 11, diffusion sheet 13 and blast sheet 14.Wherein reflector plate 11 is that the light that will penetrate bottom surface of light guide plate is reflected in the light guide plate 12 once more, thereby improve the utilization factor of light, diffusion sheet 13 makes light form diffuse reflection and evenly diffusion, can eliminate the clear zone that microstructure forms on the light guide plate 12, brighteningpiece 14 plays converging ray, improves the effect of brightness.
Light guide plate is the important component part of module backlight, its principle of work is to utilize polymethylmethacrylate (PMMA), or polycarbonate transparent light guide materials such as (PC) light that will send by light source, import from an incidence surface (side) of light guide plate, utilize total reflection principle to make light be diffused into whole plate face, when irradiate light arrives the microstructure of light guide plate reflecting surface (lower surface), total reflection condition destroys, light will penetrate from the exiting surface (upper surface) of light guide plate, finish conversion, thereby play illuminating effect to area source.
Brightness value is an important technology index of LCD, and the light extraction efficiency that therefore improves entire aphototropism mould is very necessary.Prior art takes corresponding construction to realize this purpose usually on light guide plate.
As shown in Figure 2, anotherprior art module 2 backlight, it comprises alight guide plate 27 andlight source 20, and this light guide plate exiting surface forms atack coat 26 and a plurality ofmicro-prism structure 25, and thismicro-prism structure 25 comprises anincidence surface 21, anexiting surface 23 andsidewall 22 at least one and light guide plate formation angle.This micro-prism structure vertical direction that incident ray can be led, thereby can improve the emitting brightness of whole light guide plate preferably, but the angle of above-mentioned microstructure complexity is arranged so that this module backlight is difficult for preparation, is difficult to have by the ejection forming technique volume production light guide plate of above-mentioned microstructure.
In view of this, provide a kind of can increase substantially brightness and be easy to the light guide plate of moulding and module backlight real in necessary.
[summary of the invention]
To a kind of light guide plate that has higher brightness and be easy to moulding be described with embodiment below, and a kind of module backlight that adopts this light guide plate.
A kind of light guide plate, it comprises an incidence surface, one exiting surface adjacent with this incidence surface, one reflecting surface relative with this exiting surface, this reflecting surface is provided with a plurality of V-type bulge-structures, this V-type bulge-structure has two base angles, the span at the base angle of wherein contiguous incidence surface be 86 degree to 90 degree, be that 41.8 degree are to 45.8 degree away from the span at the base angle of incidence surface.
A kind of module backlight, the light source that it comprises a light guide plate and is positioned at least one side of this light guide plate, this light guide plate comprises an incidence surface, one exiting surface adjacent with this incidence surface, one reflecting surface relative with this exiting surface, this reflecting surface is provided with a plurality of V-type bulge-structures, and this V-type bulge-structure has two base angles, the span at the base angle of wherein contiguous incidence surface be 86 degree to 90 degree, be that 41.8 degree are to 45.8 degree away from the span at the base angle of incidence surface.
Compared to prior art, described module backlight has following advantage: because the base angle of V-type bulge-structure is arranged in the above-mentioned scope, perpendicular to the direction of light guide plate incidence surface do not need brightness enhancement film light can be directed at ± angulars field of view of 10 degree in, the brightness that the brightness enhancement film of only need arranging in pairs or groups promotes other direction gets final product, this module backlight reduces the use of a brightness enhancement film, can reduce the cost of module backlight.In addition, V-structure is a convex type, makes things convenient for processing of product die and ejection formation.
[embodiment]
To light guide plate of the present invention, adopt the module backlight of this light guide plate to be described in further detail below in conjunction with accompanying drawing and a plurality of embodiment.
Please consult Fig. 3 and Fig. 4 simultaneously, preferred embodiment one of the present invention provides a kind of module backlight 30.Thismodule 30 backlight comprises alight guide plate 31 and is positioned at thelight source 33 of theselight guide plate 31 1 sides, thislight guide plate 31 is by polymethylmethacrylate (PMMA), or polycarbonate (PC) is made, it comprises anincidence surface 311, oneexiting surface 313 adjacent with thisincidence surface 311, one reflectingsurface 312 relative with thisexiting surface 313, this reflectingsurface 312 is provided with a plurality of V-type bulge-structures 32, and this V-type bulge-structure 32 has two base angle θ1, θ2, wherein the base angle ofcontiguous incidence surface 311 is θ1, its span be 86 degree to 90 degree, be θ away from the base angle ofincidence surface 3112, its span is that 41.8 degree are to 45.8 degree.
These a plurality of V-type bulge-structures 32 are the strip bulge-structure parallel withincidence surface 311, and far away more apart fromincidence surface 311, and these a plurality of V-type bulge-structure 32 arranging densities are close more, and size is big more.Its base angle θ1Span be 86 the degree to 90 the degree, base angle θ2Span be 41.8 degree to 45.8 degree, adjust θ1And θ2Value, the bright dipping briliancy of may command light guide plate 31.The H that rises of this V-type bulge-structure 32 is set between 0.001 millimeter to 0.02 millimeter.
After thelight guide plate 31 of light through being provided with V-type bulge-structure 32 of sending fromlight source 33, penetrate fromexiting surface 313, we can be by measuring the brightness value of Instrument measuring different visual angles.
See also Fig. 5, set θ earlier2Value be 43.8 the degree, to θ1Be respectively the light guide plate of 86 degree, 89 degree and 90 degree, brightness value when the visual angle from 0 to 180 of using nitometer to measure its vertical incidence surface direction is spent, measure the brightness value of visual angle from 0 to 180 degree of the vertical incidence surface direction of light guide plate that the V-type bulge-structure is not set again, the brightness change curve that gets final product as shown in the figure.
See also Fig. 6, set θ earlier2Value be 43.8 the degree, to θ1Be respectively the light guide plate of 86 degree, 89 degree and 90 degree, brightness value when the visual angle from 0 to 180 of using nitometer to measure its parallel incidence surface direction is spent, measure the brightness value of visual angle from 0 to 180 degree of the parallel incidence surface direction of light guide plate that the V-type bulge-structure is not set again, the brightness change curve that gets final product as shown in the figure.
Set θ
2Value be 43.8 the degree, to θ
1Be respectively the light guide plate of 86 degree, 87 degree, 88 degree, 89 degree and 90 degree, using nitometer to measure its visual angle is 90 brightness values when spending, and compares with the light guide plate of not establishing the V-type bulge-structure, get final product following form:
| The setting of V-type bulge-structure | θ1=86 degree | θ1=87 degree | θ1=88 degree | θ1=89 degree | θ1=90 degree | Do not establish the V-type bulge-structure |
| Brightness (cd/m2) | 9007 | 9281 | 9962 | 10187 | 2725 | 3868 |
From above testing result θ as can be known1Influence to brightness: work as θ2Immobilize θ1Be set in 86 degree between 90 degree the time, this light guide plate will promote brightness more than the twice with respect to the light guide plate that the V-type bulge-structure is not set, and at θ1Be set in 89 when spending, the brightness of this light guide plate reaches maximal value.
Therefore, when light guide plate V-type bulge-structure is set at 43.8 degree away from the base angle of incidence surface, the base angle of contiguous incidence surface is set in 86 degree between 90 degree the time, and this light guide plate has preferable emitting brightness.
See also Fig. 7, set θ earlier1Value be 89 the degree, to θ2Be respectively the light guide plate of 41.8 degree, 43.8 degree and 45.8 degree, brightness value when the visual angle from 0 to 180 of using nitometer to measure its vertical incidence surface direction is spent, measure the brightness value of visual angle from 0 to 180 degree of the vertical incidence surface direction of light guide plate that the V-type bulge-structure is not set again, the brightness change curve that gets final product as shown in the figure.
See also Fig. 8, set θ earlier1Value be 89 the degree, to θ2Be respectively the light guide plate of 41.8 degree, 43.8 degree and 45.8 degree, brightness value when the visual angle from 0 to 180 of using nitometer to measure its parallel incidence surface direction is spent, measure the brightness value of visual angle from 0 to 180 degree of the parallel incidence surface direction of light guide plate that the V-type bulge-structure is not set again, the brightness change curve that gets final product as shown in the figure.
Set θ
1Value be 89 the degree, to θ
2Be respectively the light guide plate of 41.8 degree, 42.8 degree, 43.8 degree, 44.8 degree and 45.8 degree, using nitometer to measure its visual angle is 90 brightness values when spending, and compares with the light guide plate of not establishing the V-type bulge-structure, get final product following form:
| The setting of V-type bulge-structure | θ2=41.8 degree | θ2=42.8 degree | θ2=43.8 degree | θ2=44.8 degree | θ2=45.8 degree | Do not establish the V-type bulge-structure |
| Brightness (cd/m2) | 6429 | 7870 | 10187 | 8492 | 3490 | 3868 |
From above testing result θ as can be known2Influence to brightness: work as θ1Immobilize θ2Be located at 41.8 degree between 45.8 degree the time, this light guide plate will promote brightness more than about twice with respect to the light guide plate that the V-type bulge-structure is not set, and at θ2Be located at 43.8 when spending, the brightness of this light guide plate reaches maximal value.
Therefore, when the base angle of the contiguous incidence surface of light guide plate V-type bulge-structure is set at 89 degree, be set in 41.8 degree between 45.8 degree the time away from the base angle of incidence surface, this light guide plate has preferable emitting brightness.
Be understandable that, as the base angle θ of the contiguous incidence surface of this V-type bulge-structure1Be set at 89 degree, away from the base angle θ of incidence surface2Be set at 43.8 degree, this light guide plate has best emitting brightness.
Be understandable that these a plurality of V-type bulge-structures were arranged in the rectilinear direction interruption cycle parallel with incidence surface, also can increase substantially the emitting brightness of light guide plate.
See also Fig. 9, preferred embodiment two of the present invention provides a kind of module backlight 50.This module 50 backlight comprises a light guide plate 51 and is positioned at the light source 53 of this light guide plate light inlet side that this light guide plate 51 is made by PMMC or PC material, and is provided with a plurality of V-type bulge-structures 52 at its reflecting surface 512.The setting of this V-type bulge-structure parameter is similar to first embodiment, its difference is: this light guide plate 51 be shaped as an intercepted rectangle in right angle, an end of being clipped the right angle is its light inlet side, these a plurality of V-type bulge-structures 52 are for being the concentric circles arcuation bulge-structure in the center of circle with light source 53, and on direction away from light source, these a plurality of V-type bulge-structure 52 arranging densities are close more, and size is big more.
Be understandable that these a plurality of V-type bulge-structures were arranged along the circular arc direction interruption cycle, also can increase substantially the emitting brightness of light guide plate.
Be understandable that the V-type bulge-structure can be a strip, also can be circular-arc, as long as help improving the brightness of light guide plate.