CN100365488C - Direct type backlight - Google Patents
Direct type backlight Download PDFInfo
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- CN100365488C CN100365488C CNB2004100747143A CN200410074714A CN100365488C CN 100365488 C CN100365488 C CN 100365488C CN B2004100747143 A CNB2004100747143 A CN B2004100747143A CN 200410074714 A CN200410074714 A CN 200410074714A CN 100365488 C CN100365488 C CN 100365488C
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- diffuser plate
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- type backlight
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/1336—Illuminating devices
- G02F1/133602—Direct backlight
- G02F1/133606—Direct backlight including a specially adapted diffusing, scattering or light controlling members
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/1336—Illuminating devices
- G02F1/133602—Direct backlight
- G02F1/133604—Direct backlight with lamps
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/1336—Illuminating devices
- G02F1/133602—Direct backlight
- G02F1/133608—Direct backlight including particular frames or supporting means
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- Physics & Mathematics (AREA)
- Nonlinear Science (AREA)
- Mathematical Physics (AREA)
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Planar Illumination Modules (AREA)
- Liquid Crystal (AREA)
Abstract
This invention provides a direct backlight with further reduced number of parts and capable of improving light emitting quality level by controlling the deformation of a diffuser panel. This direct backlight is provided with a diffuser panel solid frame part 3 wherein a diffuser panel 4 transmitting and diffusing light from a light source 10 and a frame part 5 provided in the periphery of the diffuser panel 4 are integrally molded, and a lower frame 2 having an opening part 11 where the diffuser panel 4 is disposed and in which the light source 10 is disposed. The diffuser panel 4 has a thickness changing part h where the thickness continuously increases from a central side to a peripheral edge side.
Description
Technical field
The present invention is about a kind of direct-type backlight.
Background technology
Employed backlight such as liquid crystal indicator roughly is divided into the backlight of side light type and the backlight of full run-down type.Wherein, the backlight of full run-down type is suitable for maximizing, obtaining the feature of high briliancy etc. easily because of having, and is used widely so can be used as large-scale planar emission apparatus especially.And, in liquid crystal indicator,, also use the backlight of full run-down type more and more as for example employed planar emission apparatus of large-scale picture more than 15 inches.
Utilize diagram that known general direct-type backlight is described.Here, be to describe as an example with the occasion of utilizing display parts such as liquid crystal panel and optical sheet.Fig. 7 is the sectional drawing with the plane of the long limit orthogonal of the light source 31 of wire.As shown in Figure 7, this backlight by most bar light sources (lamp) 31, as have peristome and have the lower frame 32 of the case of light source 31 in inside, in the set reflection horizon 33 of the inner face of lower frame, be provided with the upper ledge 34 of the frame shape of display part such as liquid crystal panel 40, the optical sheet 35 and the diffuser plate 36 of clamping constitutes between upper ledge 34 and lower frame 32.Light source 31 uses the fluorescent lamp of cold cathode cast.Upper ledge 34 is provided with and is used to keep the resin making of display parts such as liquid crystal panel to lead flange 37.Example as shown in Figure 7 is such, and in known direct-type backlight, upper ledge 34 and diffuser plate 36 be respectively as different members, and only form members separately by diffuser plate 36.And diffuser plate 36 is the certain plate-like members (for example with reference to patent documentation 1 and patent documentation 2) of thickness in its entire scope.
[patent documentation 1]: the spy of Japanese Patent Laid Open Publication opens flat 10-106342 communique.
[patent documentation 2]: the spy of Japanese Patent Laid Open Publication opens the 2002-182184 communique.
In above-mentioned this known direct-type backlight, exist diffuser plate to be easy to generate the problem of distortion such as bending.Why produce such distortion, be because the influence of diffuser plate deadweight and external stress, timeliness change, from the influence of the heat of reflector plate etc.When producing distortion such as bending on the diffuser plate, produce distortion such as bending as diffuser plate, the diffusion uniformity that then sees through light descends, so descend as the luminous grade of backlight.And, under the situation of using such display part of liquid crystal panel for example and optical sheet,, can on these optical sheets and liquid crystal panel, also produce distortion along the distortion of diffuser plate, cause liquid crystal display inhomogeneous.And, because upper ledges etc. respectively are integral with diffuser plate, thus also exist the number of components of backlight to increase, because of the packing engineering number of the handling cost of member and backlight increases the problem that the assembly cost that causes increases.
Summary of the invention
The purpose of this invention is to provide and a kind ofly form in view of this situation, can suppress the distortion of diffuser plate and improve luminous grade, and the few direct-type backlight of the number of components.
Direct-type backlight of the present invention comprise diffuser plate that makes light transmission that light source sends and diffusion and the frame portion that around this diffuser plate, is provided with integrally formed diffuser plate one frame portion, have peristome that disposes aforementioned diffuser plate and the lower frame that light source is arranged in internal configurations; It is characterized in that: aforementioned diffuser plate has the variation in thickness portion that increases continuously from its central side direction perimeter sides thickness.
So, diffuser plate and frame portion are suppressed the distortion of this diffuser plate by integrally formed so can utilize frame portion that diffuser plate is reinforced, and the number of components is reduced.In addition, the deadweight equal stress of utilizing variation in thickness portion to make to act on the diffuser plate is disperseed, and diffuser plate is become be difficult to bending.
In above-mentioned direct-type backlight, aforementioned diffuser plate also can adopt only by constituting that the aforementioned thicknesses change section forms.So, diffuser plate is whole to form variation in thickness portion, so form a kind of central portion from diffuser plate to periphery, the formation that thickness increases continuously makes the bending of diffuser plate reach Min..And, because central portion is than periphery briliancy height, so particularly the backlight of using as image can obtain high luminous grade.
And aforementioned diffuser plate also can adopt by constituting that the certain uniform thickness portion of variation in thickness portion, thickness that increases continuously from its central side direction perimeter sides thickness forms.In uniform thickness portion, transmitance becomes necessarily, makes briliancy even easily, so by making uniform thickness portion and variation in thickness portion appropriate combination, can make the homogeneity and the crooked control of briliancy and deposit.In this case, the aforementioned thicknesses change section is located at the periphery of aforementioned diffuser plate, and the center side that aforementioned uniform thickness portion is located at the aforementioned thicknesses change section is good.So, can utilize equal thickness that the briliancy of diffuser plate central portion is become evenly, and utilize variation in thickness portion to suppress the bending of diffuser plate.And, owing to central portion increases than the periphery briliancy, so particularly the backlight of using as image can obtain high luminous grade.
The thickness of diffuser plate is more than the 0.5mm and be good below 5mm.This is because as thin than 0.5mm, then rigidity is not enough and deform easily, and is not enough and make luminous grade low with the diffusion in time.And because, as thick than 5mm, then deadweight becomes excessive and is easy to generate bending, and the use amount of material increases and manufacturing cost is risen simultaneously.And, be the scope of 0.5～5mm by the thickness that makes diffuser plate, the thickness difference that can suppress diffuser plate is excessive and make briliancy become too inhomogeneous.
The surface smoothing ground of aforementioned diffuser plate carries out continuously for good.This be because, carry out continuous part if exist unsmoothly, then the luminous of this part becomes inhomogeneous, and luminous grade is descended.
Since make diffuser plate and frame portion form one, thus the distortion of diffuser plate suppressed, and the number of components is reduced.In addition, owing to be provided with variation in thickness portion, institute is so that act on deadweight equal stress dispersion on the diffuser plate, and makes diffuser plate be difficult to bending.
Description of drawings
Fig. 1 is the exploded perspective view of the direct-type backlight of first example of the present invention.
Fig. 2 is the planimetric map of diffuser plate one frame portion of the direct-type backlight of Fig. 1.
Fig. 3 is the sectional drawing of the direct-type backlight of Fig. 1.
Fig. 4 is the sectional drawing of the A-A line of Fig. 2.
Fig. 5 (a)～(d) all is the sectional drawing of the variation of diffuser plate one frame portion.
Fig. 6 is the sectional drawing of the direct-type backlight of second example of the present invention.
Fig. 7 is the sectional drawing of known direct-type backlight.
Symbol description
1: direct-type backlight;
2: lower frame; 2a: inwall;
3: diffuser plate one frame portion;
4: diffuser plate; 4a: the outside of diffuser plate (surface);
4b: the inner face of diffuser plate (surface);
5: frame portion; 5a: the first difference in height portion;
5b: the second difference in height portion; 5c: guide protrusion;
6: direct-type backlight; 7: local heavy section;
10: light source; 11: peristome;
12,13: optical sheet; 14: double-sided belt;
15: reflecting plate; 20: liquid crystal panel;
31: light source; 32: lower frame;
33: the reflection horizon; 34: upper ledge;
35: optical sheet 36: diffuser plate;
37: guiding flange;
C: central point; G: inverse change part;
T: uniform thickness portion; T1: the minimum thickness of diffuser plate 4;
T2: the maximum ga(u)ge of diffuser plate 4; T5: the thickness of frame portion 5;
H: the h1 of variation in thickness portion: curved surface variation in thickness portion;
H2: planar thickness change section;
K: angle part
Embodiment
Figure 1 shows that the expansion strabismus mode figure that the summary of the direct-type backlight 1 that the liquid crystal indicator of first example of the present invention is used constitutes, Fig. 3 is its sectional drawing (sectional drawing of the section vertical with the long side direction of light source 10).This direct-type backlight 1 be included in the top have the lower frame 2 of the case shape of peristome 11, at most root light sources 10 of the inside of this lower frame 2 configuration parallel to each other.In addition, direct-type backlight 1 also comprises for the aforementioned peristome 11 that stops up lower frame 2 on this peristome 11 the diffuser plate one frame portion 3 of configuration, 2 optical sheets 12 of the configuration that overlaps each other along the outside of this diffuser plate one frame portion 3,13, the double-sided belt 14 that the optical sheet 12 and the diffuser plate one frame portion 3 of diffuser plate one frame portion 3 sides in these optical sheets 12,13 are adhered each other.
In addition, as the material of lower frame 2, be fit to adopt exothermicity and physical strength, the good metals such as aluminium of shape stability.And, between the bottom surface and light source 10 of lower frame 2, for the luminescence efficiency that strengthens direct-type backlight 1 and improve briliancy, be provided with reflecting plate 15.
The planimetric map that Fig. 2 observes diffuser plate one frame portion 3 for side from the outside, Fig. 4 is the sectional drawing of the A-A line of Fig. 2.As shown in Figure 4, diffuser plate one frame portion 3 by make from the light transmission of light source 10 and diffusion and forms light-emitting area diffuser plate 4, constitute in the set frame portion 5 on every side of this diffuser plate 4.Frame portion 5 is thick than diffuser plate 4.And the outside 4a of diffuser plate 4 is the plane.And the outside 4a of diffuser plate 4 is a rectangle, and the liquid crystal panel of formation and liquid crystal indicator corresponding shape roughly.
And the whole summary of frame portion 5 is shaped as rectangle (rectangle), but at its outside four jiaos, is provided with along the outstanding guide protrusion 5c that is provided with of the periphery of second 5b of difference in height portion.4 guide protrusion 5c have respectively along the long limit of rectangular second 5b of the difference in height portion periphery and the part of minor face.And, as liquid crystal indicator,, be embedded in the liquid crystal panel of representing with imaginary line among Fig. 3 20 as on direct-type backlight 1, liquid crystal panel 20 being installed then in the inboard of this guide protrusion 5c.So, utilize guide protrusion 5c can limit liquid crystal panel 20 the moving of direction in face, liquid crystal panel 20 is fixed in the diffuser plate one frame portion 3.And, though different with this first example, also can adopt at this guide protrusion 5c and be embedded in optical sheet 12,13, and utilize the formation that moves of guide protrusion 5c restriction optical sheet direction in face.
Like this, in diffuser plate one frame portion 3, the restraint device that moves as the outside that is limited in this diffuser plate one frame portion 3 set member ( optical sheet 12,13 and liquid crystal panel 20 etc.) direction in face, be provided with guide protrusion 5c and the 5a of difference in height portion, 5b, install easily so this member ( optical sheet 12,13 and liquid crystal panel 20 etc.) becomes.And, because these restraint devices (guide protrusion 5c and the 5a of difference in height portion, 5b) are as diffuser plate one frame portion 3 and integrally formed, so compare with the situation that liquid crystal panel clamping flange etc. is installed as different component, the number of components reduces, and packing engineering also tails off.
As shown in Figure 3, in 2 optical sheets 12,13, the optical sheet 12 of diffuser plate 4 sides is incorporated in the difference in height of first 5a of difference in height portion flexible being provided with of considering to cause because of heat under the state of a fixed gap.And the optical sheet that the outside disposed 13 of optical sheet 12 is big than optical sheet 12 areas, and second 5b of difference in height portion and optical sheet 13 are fixed by double-sided belt 14.So, optical sheet 13 performance covers optical sheet 12 as the function of lid, and optical sheet 12 is incorporated among first 5a of difference in height portion, so can like a cork most optical sheets be fixed on the outside of diffuser plate 4.In addition, fixedly be difficult with most optical sheets and known diffuser plate (being integral in addition).This be because, when diffuser plate is dull and stereotyped and utilizes paste and sticker etc. fixedly endways, the distortion of diffuser plate (bending) can cause the bending of optical sheet, and, owing to need and to place beyond the light-emitting zone, with the fixed part of the sticker fixation ends of pasty state so have the drawback that makes diffuser plate increase and backlight self is maximized.
It is all integrally formed by identical resin for diffuser plate one frame portion 3.So, because diffuser plate one frame portion 3 is a resin system, so be shaped easily, and owing to diffuser plate 4 is made of identical resin with frame portion 5, so the material property difference between diffuser plate 4 and the frame portion 5 tails off, can suppress by both contraction difference produce crooked, and make distortion obtain suppressing more effectively by this crooked diffuser plate that causes 4.And, be resin system as diffuser plate one frame portion 3, then to compare insulative properties good for metal situation with frame portion 5, so the heat of backlight is difficult to pass on the liquid crystal panel.
In addition, though qualification that the material of diffuser plate one frame portion 3 has nothing special, but when making diffuser plate 4 and frame portion 5 for same material, with as the seeing through the good and moulding easiness of light diffusion function and be good of diffuser plate 4, be good particularly with the polycarbonate resin of white color system (milky), acrylic resin, acrylic resin etc. to the insulative properties excellent material of liquid crystal panel etc.And, as adopting injection molding, the productivity of the one-piece type upper ledge of diffuser plate is improved, so better as integrally formed method.
As shown in Figure 4, diffuser plate 4 and frame portion 5 are by the diffuser plate 4 in the integrally formed diffuser plate one frame portion 3, thickness is not certain value in its entire scope, is made of to the certain t of uniform thickness portion of the h of variation in thickness portion, thickness that perimeter sides thickness increases continuously the center side from this diffuser plate 4.The h of variation in thickness portion is located at the periphery of diffuser plate 4, and the t of uniform thickness portion is positioned at the center side (center side of diffuser plate 4) of the h of variation in thickness portion.As a result, the section of diffuser plate 4 forms the shape (with reference to Fig. 4) that slightly is arch.It is a tabular all for the t of uniform thickness portion, and the central point c of the t of uniform thickness portion (falling to the vertical line of outside 4a of diffuser plate 4 and the intersection point of this outside 4a from the center of gravity of the t of uniform thickness portion), consistent with the central point c of diffuser plate 4 (falling to the vertical line of outside 4a of diffuser plate 4 and the intersection point of this outside 4a from the center of gravity of diffuser plate 4).By this, the peripheral part that focuses on diffuser plate 4 certainly of diffuser plate 4 is disperseed equably.
And, the thickness distribution of diffuser plate 4 at the t of uniform thickness portion for the thinnest, at the periphery (being the periphery of diffuser plate 4) of the h of variation in thickness portion for the thickest.And the minimum thickness t1 that makes diffuser plate 4 is more than the 0.5mm, and to make the maximum ga(u)ge t2 of diffuser plate 4 be below the 5mm.And the thickness of frame portion 5 (maximum ga(u)ge) t5 is thick than the maximum ga(u)ge t2 of diffuser plate 4.
As previously mentioned, the outside 4a of diffuser plate 4 is the plane, thus by the inner face 4b that makes diffuser plate 4 on the whole for on-plane surface, can be on diffuser plate 4 wall thickness change in addition.Owing on the surface of diffuser plate 4 (outside 4a and inner face 4b), do not have difference in height, so can not produce abnormal luminous (this difference in height is revealed as the part of muscle shape etc. on light-emitting area) of causing because of this difference in height.And single on the surface of diffuser plate 4 (outside 4a and inner face 4b) just do not have difference in height, and whole maintenance is continuous smoothly.That is, the critical place of t of uniform thickness portion and the h of variation in thickness portion is continuous smoothly, and the surface of the h of variation in thickness portion (inner face and the outside of the h of variation in thickness portion) is also continuous smoothly.In addition, Fig. 4 is the sectional drawing of the A-A line of Fig. 2, but with the direction of its orthogonal, promptly the sectional drawing of the B-B line of Fig. 2 (omitting diagram) also forms the shape identical with Fig. 4.That is, the variation in thickness of the h of variation in thickness portion can change along the long side direction of rectangle diffuser plate 4 and the either direction of short side direction.And diffuser plate 4 has the thickness distribution of concavees lens shape.
In addition, as shown in Figure 4, diffuser plate 4 makes the section configuration on the section of the optional position of the short side direction of diffuser plate 4 and long side direction (section vertical with the outside 4a of diffuser plate 4), and is vertical with outside 4a and about the shape of the straight line tx formation line symmetry of the central point of the section line by this outside 4a.In addition, utilize the central point c by diffuser plate 4 and the section configuration of the arbitrary plane vertical, form the line symmetry by this central point and to the straight line tz vertical with the section line of outside 4a with the outside 4a of diffuser plate 4.By this, the thickness distribution of diffuser plate 4 forms the state of symmetry, so the deadweight of diffuser plate 4 is disperseed more equably, and the distortion of the diffuser plate 4 that causes because of this deadweight is controlled extremely effectively, and the briliancy of diffuser plate 4 distributes and also forms the state of symmetry, and luminous grade is improved.
Adopt the direct-type backlight 1 that as above constitutes to play following such action effect.
Because diffuser plate 4 and frame portion 5 be by integrally formed, and utilize frame portion 5 and diffuser plate 4 be reinforced, so that the distortion of diffuser plate 4 be inhibited.In addition, because make thickness (maximum ga(u)ge) t5 of frame portion 5 thick, so utilize the stiffening effect of the diffuser plate 4 of frame portion 5 further to improve than the maximum ga(u)ge t2 of diffuser plate 4.And, to compare for the situation of different component with diffuser plate 4 with frame portion 5, the number of components of direct-type backlight 1 reduces.
In addition, utilize the h of variation in thickness portion, the deadweight equal stress that acts on the diffuser plate 4 is disperseed, and diffuser plate 4 is difficult to produce crooked.
And because at the t of uniform thickness portion, the transmitance of light is certain and makes briliancy even easily, thus by making t of uniform thickness portion and the h of variation in thickness portion appropriate combination, can make the homogeneity of briliancy and crooked control simultaneously and deposit, and obtain required briliancy and distribute.And because the h of variation in thickness portion is located at the periphery of diffuser plate 4, the t of uniform thickness portion is located at the center side of the h of variation in thickness portion, so the briliancy of the central portion of diffuser plate 4 becomes evenly, and can suppress the bending of diffuser plate 4.Particularly to the bending that deadweight caused because of diffuser plate 4, because the uniform thickness portion t thin than the h of variation in thickness portion is configured in the central portion of diffuser plate 4, and make the central portion lightweight of this diffuser plate 4 by this, so when obtaining the gravity stress dispersion effect that utilizes the h of variation in thickness portion, because of the bending that deadweight caused of diffuser plate 4 improves extremely effectively.
And, because the uniform thickness portion t thin than the h of variation in thickness portion is located at the center side of the h of variation in thickness portion,, forms and compare the form that central portion is brighter with the periphery of diffuser plate 4 so the briliancy in the diffuser plate 4 distributes.Because under the central portion situation bright than periphery, light-emitting area has good-looking tendency, so luminous of high grade.Particularly under the situation of the picture of publishing picture with projections such as liquid crystal panels, make the central portion situation bright of picture can make image good-looking, so can obtain being particularly suitable for the luminous grade of employed device used for image display backlight in liquid crystal panel and LCD TV etc. than periphery.
The thickness of diffuser plate 4 is more than the 0.5mm and for below the 5mm.Under the thickness of diffuser plate 4 situation thin than 0.5mm, the rigidity of diffuser plate 4 is not enough and be easy to generate distortion sometimes, or the diffusion of light is not enough and make luminous grade low.And under the thickness of diffuser plate 4 situation thick than 5mm, the deadweight of diffuser plate 4 sometimes is excessive and bend easily, or the use amount of material too much makes manufacturing cost rise.In the first above-mentioned example, the thickness that makes diffuser plate 4 is in the scope of 0.5mm～5mm, and can make the problems referred to above is Min..And, be the scope of 0.5mm～5mm by the thickness that makes diffuser plate 4, the thickness difference of diffuser plate 4 that can suppress the h of variation in thickness portion is excessive and make the briliancy excessive uneven problem that becomes.
And, because the surface smoothing ground of diffuser plate 4 is continuous, so can obtain high luminous grade.Carry out continuous part if exist unsmoothly, then the luminous of this part becomes inhomogeneous especially sometimes, makes luminous grade low, but by carrying out smoothly continuously, can make the part (not having crooked part) that does not form the bight on the section line of diffuser plate 4, so luminous grade improves.The surface smoothing ground of diffuser plate 4 is carried out continuously for good, but more preferably, when the outline line of the section of the diffuser plate 4 that consider to utilize the arbitrary plane vertical with the outside 4a of diffuser plate, it is good continuously that the degree that this outline line all can be drawn tangent line with all points on this outline line is carried out smoothly.
In known techniques, in order to prevent to wait the bending of the diffuser plate that causes because of deadweight, the anchor of diffuser plate being supported from inner face side is set near the central portion of diffuser plate 4 sometimes, but in above-mentioned diffuser plate one frame portion 3, because because of deadweight waits the Min. that is bent into cause, so can cut down the number of anchor etc. or anchor not.
Upper ledge 34 (with reference to Fig. 7) in the above-mentioned known techniques is considered metals such as many use stainless steels and aluminium, but in this case, because of the light source heat that particularly electrode distributed, is made the increase in temperature of the better metallic framework of thermal conductivity ratio from aspects such as costs.When liquid crystal panel contacted with this metallic framework, the temperature section raising of the liquid crystal panel of this part made the Temperature Distribution of liquid crystal panel become inhomogeneous, so can produce grade deteriorations such as color deviation on liquid crystal panel.By this, in this case, need between metallicity framework and liquid crystal panel, be provided with heat insulationly with resin (foamed resin liner), and make the guiding flange that liquid crystal panel is carried out stationary positioned also be resin system.As this example, the diffuser plate one frame portion 3 that will contain frame portion 5 utilizes under the situation that resin makes, and pyroconductivity is compared with metal and diminished.By this, can form and a kind of liquid crystal panel is directly installed on liquid crystal indicator in the diffuser plate one frame portion 3, can not need the above-mentioned heat insulation resin of using, and can suppress grade deterioration because of the liquid crystal face face that temperature difference caused in the liquid crystal panel.So, utilizing resin to form under the situation of diffuser plate one frame portion 3, the direct-type backlight of using as liquid crystal display becomes more suitable.
In known backlight as shown in Figure 7, diffuser plate 36 and upper ledge 34 respectively are integral, so consider difference, distortion of both dimensional tolerence, shrinkage factor etc., certain clearance (amount of leaving a blank) are set between the two.Therefore, except the size maximization of backlight, also invade foreign matter (cigarette of chamber dirt, cigarette etc.) easily from the gap.And not good because of the setting of the amount of leaving a blank, diffuser plate 36 can produce distortion sometimes, or the friction and produce scar mutually of diffuser plate 36 and upper ledge 34, or by this mutually the wiping bits that produced of friction to be attached to backlight inner and make luminous grade deterioration.
To this, in the diffuser plate one frame portion 3 of above-mentioned first example, because it is very close to each other between the frame portion 5 of diffuser plate 4, so foreign matter (cigarette of chamber dirt, cigarette etc.) is difficult to invade backlight inside, can suppress because of be attached with the deterioration of the luminous grade that foreign matter causes in the inside of diffuser plate 4 (particularly inner face 4b), and make direct-type backlight 1 miniaturization, and can not produce because of the not distortion of the good diffuser plate that causes 4 of the amount of leaving a blank setting yet.
And, as known techniques (with reference to Fig. 7), upper ledge 34, diffuser plate 36, optical sheet 35 are independent separately respectively, and optical sheet 35 is not fixed under the situation on the diffuser plate 36, owing to these members will be carried out the integral type operation, so cumbersome, and might be, or optical sheet 35 (when optical sheet 35 be most) intrusion foreign matter each other 35 of diffuser plate 36 and optical sheets.Particularly when the lamp 31 of exchange light source, because upper ledge 34, diffuser plate 36, optical sheet 35 are removed respectively separately, except trouble, allotrylic possibility is high.By this, in this case, produced troubles such as in clean room, to carry out the lamp exchange.Shown in this example, by fixed optics sheet 12,13 in diffuser plate one frame portion 3, thereby but one is operated these diffuser plate one frame portions 3 and optical sheet 12,13, so the lamp exchanging operation of light source 10 becomes easily, and can be at 12,13 of optical sheets or optical sheet 12,13 and 4 intrusions of diffuser plate foreign matter when this lamp exchange.
And, by the thickness distribution of managing suitable variable thickness change section h, or manage the configuration of suitable variable thickness change section h and the t of uniform thickness portion, can distribute to the briliancy of light-emitting area and at random adjust.
And, because diffuser plate 4 and frame portion 5 are one, thus unstable problem can not appear rocking between the two, and the sound that can be sent when shaking direct-type backlight 1 is controlled at Min., forms the high direct-type backlight of quietness.
Fig. 5 (a)～(d) is the sectional drawing of the variation of diffuser plate one frame portion 3.
The integral body that Fig. 5 (a) is depicted as diffuser plate 4 is the situation of the h of variation in thickness portion.That is, 4 of this diffuser plates are by from its central side direction perimeter sides, and the h of variation in thickness portion that thickness increases continuously constitutes.And the part that the thickness of diffuser plate 4 is the thinnest is the position of the central point c (promptly falling to the vertical line of outside 4a of diffuser plate 4 and the intersection point of this outside 4a from the center of gravity of diffuser plate 4) of diffuser plate 4.
So, the integral body of diffuser plate forms variation in thickness portion, so form central portion from diffuser plate to periphery, the formation that thickness increases continuously makes the bending of diffuser plate reach Min..And, because central portion is than the briliancy height of periphery, obtain high luminous grade so particularly can be used as the backlight that image uses.And because the thinnest part of the thickness of diffuser plate 4 is the position of the central point c of diffuser plate 4, so the deadweight that acts on the diffuser plate 4 is disperseed easily equably, the bending that is produced because of deadweight tails off.
And in the variation of this Fig. 5 (a), the outside 4a of diffuser plate 4 is the plane, and the inner face 4b of diffuser plate 4 forms the curved surface of dome shape.And in the sectional drawing of Fig. 5 (a) (sectional drawing on the section parallel with the long limit of diffuser plate 4 and minor face), the section line of inner face 4b keeps certain in its gamut intrinsic curvature.As if like this, the section configuration that makes the inner face of the h of variation in thickness portion is the certain shape of curvature, and the distortional stress that then acts on the diffuser plate 4 disperses easily equably, and the distortion of diffuser plate 4 suppresses effect and strengthens.
In the variation of Fig. 5 (b), the central portion that makes diffuser plate 4 is the t of uniform thickness portion, and the periphery of diffuser plate 4 is the h of variation in thickness portion, and to make the h of this variation in thickness portion be the plane.Like this, the surface of the h of variation in thickness portion not only is a curved surface, also can be the plane.In addition, in the view profile that utilizes the plane vertical, as be the section line of Fig. 5 (b) with the outside 4a of diffuser plate 4, article 2, the situation that different straight lines is reported to the leadship after accomplishing a task, then these 2 straight line angulation θ are good below 20 degree, for better, are special good below 5 degree below 10 degree.This be because, this angle θ is big more, the intersection point of these 2 straight lines is easy to generate abnormal luminous more, sometimes for example on luminescent picture, can demonstrate striped, but angle θ is more little, and aforementioned section line is reported to the leadship after accomplishing a task and partly approached smooth state more, is difficult to occur striped on luminescent picture.
Fig. 5 (c) makes all of diffuser plate 4 be the h of variation in thickness portion, and the h of this variation in thickness portion is by the periphery that is arranged in diffuser plate 4 and utilize planar thickness change section h2 that 2 planes tilting one another in opposite directions form, constitute for the curved surface in the configuration of this planar thickness change section h2 clamping also will constitute the curved surface variation in thickness h1 of portion that 2 planes of planar thickness change section h2 connect smoothly.In the present invention, the surface of diffuser plate 4 also can be adopted and be made the continuous formation of curved surface and plane.And, the different curved surface of curvature is carried out continuously.In these cases, also need to make the surface of diffuser plate 4 to connect continuously, promptly do not have difference in height.And all surface of diffuser plate 4 carries out smoothly continuously for good.In addition, the angle part k in the sectional drawing of Fig. 5 (c) forms the bigger state of aforementioned angle θ, but owing to be beyond the scope of diffuser plate 4, so do not influence luminous grade.
In the variation of Fig. 5 (d), the outside 4a of diffuser plate 4 is the plane, and on the inner face 4b of diffuser plate 4, be located at diffuser plate 4 periphery the h of variation in thickness portion and be located at its inboard t of uniform thickness portion, except circular portion described later, all form the plane, but, pay to have the circle of certain radius R1 to the angle part of reporting to the leadship after accomplishing a task and being produced on this 2 plane.That is, partly pay with radius (R) in aforementioned corner.Utilize this radius (circle), can make each other for the t of uniform thickness portion on plane and the h of variation in thickness portion continuous smoothly.Therefore, can on light-emitting area, not produce striped, and form luminous direct-type backlight of high grade 1.
Fig. 6 is the sectional drawing about the direct-type backlight 6 of second example of the present invention.In this direct-type backlight 6, diffuser plate 4 has from its central side direction perimeter sides, the h of variation in thickness portion that thickness increases continuously, and have the local local heavy section 7 that increases of thickness that makes diffuser plate 4 with the position of light source 10 accordingly.In direct-type backlight 6, because the light source of wire 10 is parallel to each other and be provided with side by side, so the also position of corresponding these light sources 10 and parallel to each other and keep at a certain distance away and be provided with of local heavy section 7.In addition, the outside 4a of diffuser plate 4 forms level and smooth continuous curved surface.As a result, the section configuration of the inner face 4b of diffuser plate 4 forms continuous waveform shape.In the example of this Fig. 6, because be provided with local heavy section 7, so the inverse change part g that in the part of diffuser plate 4, exists the thickness of diffuser plate 4 to reduce continuously from its central side direction perimeter sides.Like this, the present invention exists aforementioned thicknesses change section h to get final product at least a portion of diffuser plate 4, also can have inverse change part g in the part of diffuser plate 4.In the example of Fig. 6, constitute the vertex position and the position, the lowest point of the waveform portion of local heavy section 7, when the section of Fig. 6, form towards the outside of diffuser plate 4a and roughly along the position of the circular arc (in Fig. 6, representing) of convex with double dot dash line, even utilize the g of inverse change portion, to not hinder the effect that the h of variation in thickness portion is set as much as possible yet.
As the material behavior of diffuser plate one frame portion 3, with following such be good.At first, with water-intake rate below 0.5%, be preferably below 0.3% for good.Big than 0.5% as water-intake rate, then when inside and outside backlight, environment such as humidity can cause distortion such as warpage not simultaneously.And linear expansion coefficient is 1.5 * 10
-4/ ℃ below be good, 0.7 * 10
-4/ ℃ below for better.Big as linear expansivity, then exist with lower frame 2 and wait the play size of other member to increase such problem.Light transmission rate is being good more than 20%, more than 40% for better.Then can not guarantee luminous lightness as too small, make luminescence efficiency low.And this light transmission rate is being good below 80%, below 65% for better.Then be difficult to guarantee luminous homogeneity sometimes as excessive.The heavy burden flexure temperature is being good more than 100 ℃, more than 120 ℃ for better.Too small as flexure temperature, then, be easy to generate crooked and distortion because of the heat of lamp and phase inverter generation.
As above-mentioned example, under the situation that diffuser plate 4 and frame portion 5 are formed by identical resin, because frame portion 5 is made by the material with photopermeability, so, can produce the situation that frame portion 5 also has light transmission according to specifications such as its thickness, shape or material compositions.Might hinder luminous homogeneity this moment because of the light that sees through from this frame portion 5, makes luminous grade deterioration.In this case,, can prevent to leak and make the luminenscence homogenization of diffuser plate 4, improve luminous grade from the light of frame portion 5 by shade suitably being set in frame portion 5.As the example of this shade, can adopt light screening material coating, utilize thin metal film treatment such as evaporation or photo-shield strip (black band etc.) etc.And, also lower frame 2 can be made by the high material of light-proofness (resin that metal and light-proofness are high etc.), and being provided with on lower frame 2 can be to the light shielding part etc. that light carries out shading that sees through of frame portion 5, as the working hard in shape of lower frame 2, do not produce the unwanted light that sees through from frame portion 5.
And, be the high material of light-proofness by making frame portion 5, and make the transmitance height of the light transmission rate of frame portion 5 than diffuser plate 4, can make redundance also suppress to see through light from frame portion 5.Particularly, can make the resin of diffuser plate 4, and make frame portion 5 be the resin of black for white.In this case, both materials are formed except the toner of painted usefulness, can adopt common resin, and make the rerum natura of diffuser plate 4 and frame portion 5 close to good.As make under the situation that the color of diffuser plate 4 and frame portion 5 has nothing in common with each other the method that can adopt double-colored shaping or polychrome to be shaped.It is integrally formed that this double-colored shaping or polychrome are shaped and also are equivalent to the present invention and are mentioned.
In addition, in above-mentioned example, illustration the direct-type backlight 1 used of a kind of liquid crystal indicator that utilizes liquid crystal panel and optical sheet, but direct-type backlight of the present invention 1 also can be lamp box (light box) and negatoscope (film viewer) etc. certainly.
And, the variation in thickness h of portion of the present invention both can only make variation in thickness along folk prescription to (for example long side direction of light source 10), also can be (for example along twocouese, except the long side direction of light source 10, also have and the vertical and parallel direction of the long side direction of light source 10 with the outside 4a of diffuser plate 4) make variation in thickness.
Claims (6)
1. direct-type backlight comprises:
Diffuser plate one frame portion, it is integrally formed by the frame portion that is provided with around diffuser plate and this diffuser plate, this diffuser plate is light transmission and the diffusion that light source is sent; And
Lower frame has the peristome of the aforementioned diffuser plate of configuration and in internal configurations light source is arranged;
It is characterized in that:
Aforementioned diffuser plate has the variation in thickness portion that increases continuously from its mediad peripheral thickness.
2. direct-type backlight as claimed in claim 1 is characterized in that: aforementioned diffuser plate only is made of the aforementioned thicknesses change section.
3. direct-type backlight as claimed in claim 1 is characterized in that: aforementioned diffuser plate is made of variation in thickness portion that increases continuously from its mediad peripheral thickness and the certain uniform thickness portion of thickness.
4. direct-type backlight as claimed in claim 3 is characterized in that: the aforementioned thicknesses change section is located at the periphery of aforementioned diffuser plate, and aforementioned uniform thickness portion is located at the central authorities of aforementioned thicknesses change section.
5. as each the described direct-type backlight in the claim 1～4, it is characterized in that: the thickness of aforementioned diffuser plate is more than the 0.5mm and below 5mm.
6. as each the described direct-type backlight in the claim 1～4, it is characterized in that: the surface smoothing ground of aforementioned diffuser plate is continuous.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004068674A JP4299702B2 (en) | 2004-03-11 | 2004-03-11 | Direct type backlight |
| JP2004068674 | 2004-03-11 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1667467A CN1667467A (en) | 2005-09-14 |
| CN100365488C true CN100365488C (en) | 2008-01-30 |
Family
ID=35038643
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2004100747143A Expired - Fee Related CN100365488C (en) | 2004-03-11 | 2004-09-13 | Direct type backlight |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JP4299702B2 (en) |
| KR (1) | KR100676260B1 (en) |
| CN (1) | CN100365488C (en) |
| TW (1) | TW200530697A (en) |
Families Citing this family (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5057818B2 (en) * | 2007-03-28 | 2012-10-24 | 京セラ株式会社 | Light emitting device |
| CN101295087B (en) | 2007-04-25 | 2010-09-29 | 群康科技(深圳)有限公司 | LCD device |
| KR101353475B1 (en) * | 2007-05-30 | 2014-01-24 | 삼성디스플레이 주식회사 | Light guide plate, backlight assembly including the same and liquid crystal display including the same |
| JP2008300203A (en) * | 2007-05-31 | 2008-12-11 | Toshiba Lighting & Technology Corp | Luminaire |
| JP4941118B2 (en) * | 2007-06-13 | 2012-05-30 | 住友電装株式会社 | Liquid crystal display |
| CN101377588B (en) * | 2007-08-27 | 2012-06-20 | 奇美电子股份有限公司 | Backlight module and diffusing plate thereof, and planar display using the same |
| KR101498020B1 (en) * | 2007-10-02 | 2015-03-11 | 엘지전자 주식회사 | Lighting device and display device including the same |
| TWI577641B (en) * | 2011-03-09 | 2017-04-11 | 友達光電股份有限公司 | System and method for recycling photoresist stripper waste liquid |
| JP5530419B2 (en) * | 2011-11-25 | 2014-06-25 | ミネベア株式会社 | Planar illumination device and manufacturing method thereof |
| TWI477856B (en) * | 2012-03-01 | 2015-03-21 | Au Optronics Corp | Display device |
| JP6131107B2 (en) * | 2013-05-30 | 2017-05-17 | 株式会社ｎｉｔｔｏｈ | Lighting device |
| JP6310683B2 (en) * | 2013-11-22 | 2018-04-11 | 株式会社ｎｉｔｔｏｈ | Light guide plate, lighting device |
| JP6375008B2 (en) * | 2017-03-28 | 2018-08-15 | 株式会社ｎｉｔｔｏｈ | Lighting device |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10104619A (en) * | 1996-09-27 | 1998-04-24 | Matsushita Electric Ind Co Ltd | Back light device |
| US6055029A (en) * | 1996-07-23 | 2000-04-25 | Stanley Electric Co., Ltd. | Backlighting system for a liquid crystal display including an integrally molded light guiding plate and frame with a deformation absorbing means |
| JP2003036713A (en) * | 2001-07-25 | 2003-02-07 | International Manufacturing & Engineering Services Co Ltd | Surface light source device |
| CN2606373Y (en) * | 2003-02-18 | 2004-03-10 | 三和企业股份有限公司 | Improved structure of light conducting board |
-
2004
- 2004-03-11 JP JP2004068674A patent/JP4299702B2/en not_active Expired - Fee Related
- 2004-07-23 TW TW093122030A patent/TW200530697A/en unknown
- 2004-09-13 CN CNB2004100747143A patent/CN100365488C/en not_active Expired - Fee Related
- 2004-10-06 KR KR1020040079395A patent/KR100676260B1/en not_active IP Right Cessation
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6055029A (en) * | 1996-07-23 | 2000-04-25 | Stanley Electric Co., Ltd. | Backlighting system for a liquid crystal display including an integrally molded light guiding plate and frame with a deformation absorbing means |
| JPH10104619A (en) * | 1996-09-27 | 1998-04-24 | Matsushita Electric Ind Co Ltd | Back light device |
| JP2003036713A (en) * | 2001-07-25 | 2003-02-07 | International Manufacturing & Engineering Services Co Ltd | Surface light source device |
| CN2606373Y (en) * | 2003-02-18 | 2004-03-10 | 三和企业股份有限公司 | Improved structure of light conducting board |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4299702B2 (en) | 2009-07-22 |
| TW200530697A (en) | 2005-09-16 |
| CN1667467A (en) | 2005-09-14 |
| KR20050091908A (en) | 2005-09-15 |
| JP2005259496A (en) | 2005-09-22 |
| KR100676260B1 (en) | 2007-01-30 |
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