CN102454941A - Light diffusion plate, surface light source device and liquid crystal display device with the light diffusion plate, light diffusion plate and method for manufacturing liquid crystal display device - Google Patents

Abstract

The invention provides a light diffusion plate, a surface light source device and a liquid crystal display device with the light diffusion plate, a light diffusion plate and a method for manufacturing the liquid crystal display device. The light diffusing plate (50) is arranged on the incident surface side of a liquid crystal panel, wherein a plurality of optical components (53) extending in a first direction at an interval of Pl are arranged parallel to each other in a second direction orthogonal to the first direction. The spacing of pixels in the second direction of the liquid crystal panel is set to be L / N (=Pp), wherein L is the width of the liquid crystal panel in the second direction and N is 1080 or 768. The spacing of interference fringes adopting a periodic structure in the second direction is set to be Pm1= Pp * Pl / (Pp - Pl) and Pm2 = 0.5Pp * Pl / (0.5Pp - Pl), wherein Pl satisfies the relationship of Pm1 < 1500 mu m or Pm1 >= 10000 mu m and Pm2< 1500 mu m or Pm2 >=10000 mu m, while N is1080 and 768.

Description

The manufacturing approach of light diffusing sheet, the planar light source device that contains it and liquid crystal indicator, light diffusing sheet and liquid crystal indicator

Technical field

The present invention relates to light diffusing sheet, contain the manufacturing approach of the planar light source device of light diffusing sheet, the liquid crystal indicator that contains light diffusing sheet, light diffusing sheet and the manufacturing approach of liquid crystal indicator.

Background technology

In the backlight unit of transmissive displays such as LCD (transmission image display device), use point source of lights such as linear light source, LED such as CCFL.Thereby backlight unit will be through converting planar light into from the light diffusion of linear light source or point source of light with light diffusing sheet.In the past, use the light diffusing sheet of the mode of the light scattering that utilizes the diffusant particle always.But, in recent years, cut down the cost degradation low consumption electrification of bringing, the requirement of slimming in order to tackle by the fluorescent tube number, use the light diffusing sheet that optical element portions such as lens or prism are arranged at surperficial figuration gradually.Because on this figuration diffuser plate, each other be set side by side with a plurality of optical element portion, so the figuration diffuser plate has periodic structure almost parallel.On the other hand, because liquid crystal panel also is to be arranged with a plurality of pixels at certain intervals, so have periodic structure.To have the figuration diffuser plate of periodic structure and liquid crystal panel and the time spent with periodic structure, the relation of width (spacing) because of both produces interference stripes sometimes.When producing the interference stripes in number mm cycle, human eye is discerned these interference stripes easily.Therefore, the remarkable problem that descends of display quality that has display.

As the technology that prevents this interference stripes, the technology of known patent document 1 (TOHKEMY 2007-11292 communique) record for example.In the technology of patent documentation 1 record; Through and with light diffusing sheet and diffusion barrier; To be formed at the spacing optimization of the optical element portion (protuberance) of light diffusing sheet based on the mist degree of pel spacing, diffusion barrier and full light transmittance, reach the generation that suppresses interference stripes thus.

But, exist the formula ground that does not for example meet formulism in the patent documentation 1 to produce the situation of interference stripes.In addition, in the past, because for FHD (Full High Definition; Full HD) liquid crystal panel, WXGA (WideeXtended Graphics Array; The widescreen XGA) different types of liquid crystal panel pixel count such as liquid crystal panel is different, so even liquid crystal panel big or small identical, also need be to various liquid crystal panels preparation light diffusing sheets.Therefore, expectation can be to the general light diffusing sheet of different types of liquid crystal panel.

Therefore, the purpose of this invention is to provide can suppress more reliably interference stripes and can with the light diffusing sheet of diverse liquid crystal panel and usefulness, the planar light source device that contains light diffusing sheet, the liquid crystal indicator that contains light diffusing sheet, the manufacturing approach of light diffusing sheet and the manufacturing approach of liquid crystal indicator.

Summary of the invention

Light diffusing sheet of the present invention is arranged on the light diffusing sheet of the plane of incidence side of liquid crystal panel, possess the 1st of the liquid crystal panel side and with the 1st opposed the 2nd in one side at least on a plurality of optical element portion that forms.Each optical element portion is extending as the 1st direction of liquid crystal panel long side direction, and a plurality of optical element portion is disposed at and the 1st direction the 2nd direction of quadrature roughly side by side.And, a plurality of optical element portion is made as P in the spacing of the 2nd direction _l[μ m] is made as L [μ m] with liquid crystal panel at the width of the 2nd direction, and a plurality of pixels that liquid crystal panel is had are made as L/N [μ m] at the pel spacing of the 2nd direction, and (wherein, N is 1080 or 768, L/N ≠ P _l, 0.5 (L/N) ≠ P _l), will be made as P in the interference stripes spacing of the interference stripes of the periodic structure of the 2nd direction based on a plurality of optical element portions and a plurality of pixel _m1 [μ m] and P _m2 [μ m] are respectively with formula (1) and formula (2) expression P _m1 and P _m2, under above-mentioned situation, above-mentioned P _lBe the value that satisfies following relation: for N is the arbitrary value in 1080 and 768, P _mThe 1st, P _m1＜1500 μ m or P _m1>=10000 μ m and P _mThe 2nd, P _m2＜1500 μ m or P _m2>=10000 μ m.

${\mathrm{<figure-callout\; id="1"\; label="P\; m"\; filenames="HSA00000609740200011.png,HSA00000609740200021.png"\; state="\{\{state\}\}">P</figure-callout>}}_{m}1=\frac{\frac{L}{N}\&CenterDot;P_l}{|\frac{L}{N}-P_l|}\&CenterDot;\&CenterDot;\&CenterDot;\left(1\right)$

${\mathrm{<figure-callout\; id="2"\; label="P\; m"\; filenames="HSA00000609740200021.png,HSA00000609740200051.png"\; state="\{\{state\}\}">P</figure-callout>}}_{m}2=\frac{0.5\frac{L}{N}\&CenterDot;P_l}{|0.5\frac{L}{N}-P_l|}\&CenterDot;\&CenterDot;\&CenterDot;\left(2\right)$

When to containing when using above-mentioned light diffusing sheet for the liquid crystal panel of the pixel of (L/N) configuration P with the pel spacing of the 2nd direction _mThe interference stripes spacing of 1 expression is less than 1500 μ m or more than the 10000 μ m.Thus, be difficult to visuognosis and go out periodic structure and spacing P by pel spacing (L/N) _lThe interference stripes that produce of periodic structure.Discoveries such as the inventor: remove pel spacing (L/N) by the pixel that has with liquid crystal panel and be the periodic structure in cycle and with the spacing P of optical element portion _lBeyond the interference stripes that produce for the periodic structure in cycle, also producing with 1/2 of pel spacing (L/N) sometimes is the interference stripes in cycle.The spacing of these interference stripes is represented with formula (2).And, in above-mentioned light diffusing sheet of the present invention, because P _lBe to make P _m2 also less than 1500 μ m or the value more than the 10000 μ m, is the interference stripes in cycle so also very difficult visuognosis goes out with 1/2 of pel spacing.Therefore, through using above-mentioned light diffusing sheet, it is in sight to let interference stripes be difficult for more reliably.

Be used for the spacing P of regulation optical element portion _lPel spacing (L/N) in N be 1080 or 768.And, spacing P _lBe according to being the arbitrary value P in 1080 and 768 for N _m1 and P _m2 all satisfy above-mentioned condition mode confirm.Therefore, with spacing P _lThe light diffusing sheet of configuration optical element portion is the liquid crystal panel combination of L/1080 with the pel spacing of the 2nd direction side by side, and still the pel spacing with the 2nd direction is the liquid crystal panel combination of L/768, all can realize being difficult for the state that visuognosis goes out interference stripes.That is, so long as have the liquid crystal panel of certain width L, even light diffusing sheet 2 kind liquid crystal panel and the usefulness different with kind (for example FHD, WXGA) then also can reduce interference stripes more reliably.

In light diffusing sheet of the present invention, can be that above-mentioned optical element portion is a protuberance.

Planar light source device of the present invention is a planar light source device from light to liquid crystal panel that supply with, possesses: to the light source portion of liquid crystal panel output illumination light and the light diffusing sheet of the present invention that between light source portion and liquid crystal panel, is provided with.

In this planar light source device, the light of being exported by light source portion outputs to the liquid crystal panel side through light diffusing sheet.Because be formed with a plurality of optical element portion at the face of the liquid crystal panel side of light diffusing sheet, so when penetrating light diffusing sheet, penetrate along various directions easily.Thus, the light from light source portion forms planar light and shines liquid crystal panel.Because the light diffusing sheet that planar light source device has is above-mentioned light diffusing sheet of the present invention; So no matter the pel spacing with this light diffusing sheet and the 2nd direction is the liquid crystal panel combination of L/1080, still the pel spacing with the 2nd direction is the liquid crystal panel combination of L/768, all can realize being difficult for the state that visuognosis goes out interference stripes.

Liquid crystal indicator of the present invention possesses: liquid crystal panel, and to the light source portion of liquid crystal panel output illumination light, and the light diffusing sheet that between light source portion and liquid crystal panel, is provided with.In this liquid crystal indicator, with the pixel count of the direction of the long side direction quadrature of above-mentioned liquid crystal panel be 1080 or 768.Above-mentioned light diffusing sheet possess the 1st of the liquid crystal panel side and with the 1st opposed the 2nd in one side at least on a plurality of optical element portion that forms, each optical element portion extends in above-mentioned the 1st direction, a plurality of optical element portion is disposed at above-mentioned the 2nd direction side by side.A plurality of optical element portion is made as P in the spacing of the 2nd direction _l[μ m] is made as L [μ m] with liquid crystal panel at the width of the 2nd direction, and a plurality of pixels that liquid crystal panel is had are made as L/N [μ m] at the pel spacing of the 2nd direction, and (wherein, N is 1080 or 768, L/N ≠ P _l, 0.5 (L/N) ≠ P _l), will be made as P in the interference stripes spacing of the interference stripes of the periodic structure of the 2nd direction based on a plurality of optical element portions and a plurality of pixel _m1 [μ m] and P _m2 [μ m] are respectively with formula (3) and formula (4) expression P _m1 and P _m2, under above-mentioned situation, above-mentioned P _lBe the value that satisfies following relation: for N is the arbitrary value in 1080 and 768, P _mThe 1st, P _m1＜1500 μ m or P _m1>=10000 μ m and P _mThe 2nd, P _m2＜1500 μ m or P _m2>=10000 μ m.

${\mathrm{<figure-callout\; id="1"\; label="P\; m"\; filenames="HSA00000609740200011.png,HSA00000609740200021.png"\; state="\{\{state\}\}">P</figure-callout>}}_{m}1=\frac{\frac{L}{N}\&CenterDot;P_l}{|\frac{L}{N}-P_l|}\&CenterDot;\&CenterDot;\&CenterDot;\left(3\right)$

${\mathrm{<figure-callout\; id="2"\; label="P\; m"\; filenames="HSA00000609740200021.png,HSA00000609740200051.png"\; state="\{\{state\}\}">P</figure-callout>}}_{m}2=\frac{0.5\frac{L}{N}\&CenterDot;P_l}{|0.5\frac{L}{N}-P_l|}\&CenterDot;\&CenterDot;\&CenterDot;\left(4\right)$

In this liquid crystal indicator, the light of being exported by light source portion outputs to the liquid crystal panel side through light diffusing sheet.Because on the face of the liquid crystal panel side of light diffusing sheet, be formed with a plurality of optical element portion, so when penetrating light diffusing sheet, penetrate along various directions easily.Thus, the light from light source portion forms planar light and shines liquid crystal panel.

Because the spacing P of the light diffusing sheet that liquid crystal indicator has _lBe to make P _mThe interference stripes spacing of 1 expression is less than 1500 μ m or the value more than the 10000 μ m, goes out by pel spacing (L/N) and spacing P so be difficult for visuognosis _lThe interference stripes that produce of periodic structure.Because the spacing P of the optical element portion of light diffusing sheet _lBe to make P _mThe interference stripes spacing of 2 expressions also is less than 1500 μ m or the value more than the 10000 μ m, and to go out with 1/2 of pel spacing (L/N) be the interference stripes in cycle so also be difficult for visuognosis.Therefore, in liquid crystal indicator, it is in sight interference stripes to be difficult for.

In addition, be used for the spacing P of regulation optical element portion _lPel spacing (L/N) in N be 1080 or 768.And, P _lBe according to being the arbitrary value P in 1080 and 768 for N _m1 and P _m2 all satisfy the mode of above-mentioned condition and definite.Therefore, with spacing P _lThe light diffusing sheet of configuration optical element portion is the liquid crystal panel combination of L/1080 with the pel spacing of the 2nd direction side by side, still the pel spacing with the 2nd direction is the liquid crystal panel combination of L/768, all can realize being difficult for the state that visuognosis goes out interference stripes.

Promptly; The formation of above-mentioned liquid crystal watch device is following formation: so long as the 2nd direction has the liquid crystal panel of width L; Even the pixel count that then identical light diffusing sheet is made up the 2nd direction is the pixel count of 1080 liquid crystal panel (for example FHD liquid crystal panel) or the 2nd direction is 768 liquid crystal panel (for example WXGA liquid crystal panel), also can reduce interference stripes more reliably.

Above-mentioned liquid crystal indicator of the present invention can further possess between liquid crystal panel and light diffusing sheet and contains the optics membranous part of a slice blooming at least.The haze value H (%) of this optics membranous part satisfies 95≤H≤99.9.

At this moment, be arranged between liquid crystal panel and the light diffusing sheet, go out interference stripes so be difficult for visuognosis more because haze value H satisfies the blooming of above-mentioned condition.

The manufacturing approach of light diffusing sheet of the present invention is to make the method for following light diffusing sheet; This light diffusing sheet is arranged on the plane of incidence side of liquid crystal panel, have confession a plurality of optical element portion of extending as the 1st direction of liquid crystal panel long side direction with the 2nd direction of the 1st direction quadrature on the face of configuration side by side; This manufacturing approach possesses: design the spacing P of a plurality of optical element portion in the 2nd direction _lThe operation of [μ m] and based on the above-mentioned spacing P that is designed _l, form a plurality of optical element portions in the one side that has transmittance and become the plate body of light diffusing sheet and make the operation of light diffusing sheet.At the above-mentioned spacing P of design ₁Operation in, when to liquid crystal panel configuration light diffusing sheet, liquid crystal panel is made as L [μ m] at the width of the 2nd direction, a plurality of pixels that liquid crystal panel is had are made as L/N [μ m] at the pel spacing of the 2nd direction, and (wherein, N is 1080 or 768, L/N ≠ P _l, 0.5 (L/N) ≠ P _l), will be made as P in the interference stripes spacing of the interference stripes of the periodic structure of the 2nd direction based on a plurality of optical element portions and a plurality of pixel _m1 [μ m] and P _m2 [μ m] are respectively with formula (5) and formula (6) expression P _m1 and P _m2, under above-mentioned situation, with above-mentioned P _lConfirm as the value of relation below satisfying: for N is the arbitrary value in 1080 and 768, P _mThe 1st, P _m1＜1500 μ m or P _m1>=10000 μ m and P _mThe 2nd, P _m2＜1500 μ m or P _m2>=10000 μ m.

${\mathrm{<figure-callout\; id="1"\; label="P\; m"\; filenames="HSA00000609740200011.png,HSA00000609740200021.png"\; state="\{\{state\}\}">P</figure-callout>}}_{m}1=\frac{\frac{L}{N}\&CenterDot;P_l}{|\frac{L}{N}-P_l|}\&CenterDot;\&CenterDot;\&CenterDot;\left(5\right)$

${\mathrm{<figure-callout\; id="2"\; label="P\; m"\; filenames="HSA00000609740200021.png,HSA00000609740200051.png"\; state="\{\{state\}\}">P</figure-callout>}}_{m}2=\frac{0.5\frac{L}{N}\&CenterDot;P_l}{|0.5\frac{L}{N}-P_l|}\&CenterDot;\&CenterDot;\&CenterDot;\left(6\right)$

In above-mentioned manufacturing approach, the pel spacing (L/N) with respect to the liquid crystal panel that uses utilizes formula (5) and formula (6) to come design pitch P _lThen, make light diffusing sheet based on this design load.Therefore, when the liquid crystal panel that contains the pixel that is configured for (L/N) with the 2nd direction pel spacing is used the light diffusing sheet of manufacturing, P _mThe interference stripes spacing of 1 expression is less than 1500 μ m or more than the 10000 μ m.Therefore, be difficult for visuognosis and go out periodic structure and spacing P by pel spacing (L/N) _lThe interference stripes that produce of periodic structure.In the light diffusing sheet of above-mentioned manufacturing approach manufacturing, because according to P _mThe interference stripes spacing of 2 expressions also is to confirm P less than 1500 μ m or the mode more than the 10000 μ m _lValue, to go out with 1/2 of pel spacing (L/N) be the interference stripes in cycle so also be difficult for visuognosis.Therefore, through said method, also make interference stripes be difficult for descried light diffusing sheet more reliably even can produce with the liquid crystal panel combination.

The spacing P that is used for regulation optical element portion _lPel spacing (L/N) in N be 1080 or 768.And, spacing P _lBe according to being the arbitrary value P in 1080 and 768 for N _m1 and P _m2 all satisfy above-mentioned condition mode confirm.Therefore, with spacing P _lThe light diffusing sheet of configuration optical element portion is the liquid crystal panel combination of L/1080 with the pel spacing of the 2nd direction side by side, still the pel spacing with the 2nd direction is the liquid crystal panel combination of L/768, all can realize being difficult for the state that visuognosis goes out interference stripes.Promptly; Through above-mentioned manufacturing approach; Can produce following light diffusing sheet: so long as have the liquid crystal panel of certain width L, even 2 kinds of then different with kind (for example FHD, WXGA) liquid crystal panels are also with the light diffusing sheet that also can reduce interference stripes more reliably.

The operation of the above-mentioned light diffusing sheet of manufacturing that the manufacturing approach of light diffusing sheet of the present invention possesses can comprise: make the operation as the resin sheet of above-mentioned plate body through extrusion molding; In the one side of resin sheet, push the spacing P that has with to design _lThe opposite mould of a plurality of optical element portion that is configured is as the roller of transfer mold, thereby this transfer mold is transferred to the operation of said one side; With cut out that transfer printing has transfer mold and be formed with in one side a plurality of optical element portion resin sheet the regulation zone and form the operation of light diffusing sheet.

In the method, through after forming resin sheet, will have and spacing P to design _lThe roller of the transfer mold that a plurality of optical element portion of arranging is corresponding is by the one side that is pressed in resin sheet, thereby forms a plurality of optical element portion in the one side of resin sheet.Then, through cutting out the regulation zone that is formed with a plurality of optical element portion, thereby obtain light diffusing sheet as the resin sheet of plate body.

The manufacturing approach of liquid crystal indicator of the present invention possesses: to have confession a plurality of optical element portion that the 1st direction is extended with the 2nd direction of the 1st direction quadrature on side by side the operation that designs of the light diffusing sheet of the face of configuration, promptly design the spacing P of a plurality of optical element portion in the 2nd direction _lThe operation of [μ m]; Based on the spacing P that designs _l, form a plurality of optical element portions in the one side that has transmittance and become the plate body of light diffusing sheet and make the operation of light diffusing sheet; And between liquid crystal panel and light source portion, dispose the light diffusing sheet of manufacturing and the operation of assembling liquid crystal indicator according to the consistent mode of the long side direction of the 1st direction and liquid crystal panel.The pixel count of the 2nd direction of above-mentioned liquid crystal panel is 1080 or 768.In addition, at design pitch P _lIn the operation of [μ m], liquid crystal panel is made as L [μ m] at the width of the 2nd direction, a plurality of pixels that liquid crystal panel is had are made as L/N [μ m] at the pel spacing of the 2nd direction, and (wherein, N is 1080 or 768, L/N ≠ P _l, 0.5 (L/N) ≠ P _l), will be made as P in the interference stripes spacing of the interference stripes of the periodic structure of the 2nd direction based on a plurality of optical element portions and a plurality of pixel _m1 [μ m] and P _m2 [μ m] are respectively with formula (7) and formula (8) expression P _m1 and P _m2, under above-mentioned situation, with above-mentioned P _lConfirm as the value that satisfies following relation: for N is the arbitrary value in 1080 and 768, P _mThe 1st, P _m1＜1500 μ m or P _m1>=10000 μ m and P _mThe 2nd, P _m2＜1500 μ m or P _m2>=10000 μ m.

${\mathrm{<figure-callout\; id="1"\; label="P\; m"\; filenames="HSA00000609740200011.png,HSA00000609740200021.png"\; state="\{\{state\}\}">P</figure-callout>}}_{m}1=\frac{\frac{L}{N}\&CenterDot;P_l}{|\frac{L}{N}-P_l|}\&CenterDot;\&CenterDot;\&CenterDot;\left(7\right)$

${\mathrm{<figure-callout\; id="2"\; label="P\; m"\; filenames="HSA00000609740200021.png,HSA00000609740200051.png"\; state="\{\{state\}\}">P</figure-callout>}}_{m}2=\frac{0.5\frac{L}{N}\&CenterDot;P_l}{|0.5\frac{L}{N}-P_l|}\&CenterDot;\&CenterDot;\&CenterDot;\left(8\right)$

In above-mentioned manufacturing approach, utilize formula (7) and formula (8) to come design pitch P _lAfter, design based on this and to make light diffusing sheet.Be configured between liquid crystal panel and the light source portion through the light diffusing sheet that will make so as described above, thereby assemble out liquid crystal indicator.

In this liquid crystal indicator, the pixel count of the 2nd direction of liquid crystal panel (with the direction of long side direction quadrature) is 1080 or 768.Thus, based on the interference stripes spacing P of the pel spacing (L/N) of the 2nd direction (with the direction of long side direction quadrature) of liquid crystal panel _m1 is that arbitrary value in 1080 and 768 all is less than 1500 μ m or more than the 10000 μ m for N.Therefore, be difficult for visuognosis and go out interference stripes by the periodic structure generation of spacing (L/N) and spacing Pl.

In above-mentioned liquid crystal indicator, P _lFeasible interference stripes spacing P based on 1/2 (L/N) _m2 is that arbitrary value in 1080 and 768 also is less than 1500 μ m or more than the 10000 μ m for N.Therefore, also being difficult for visuognosis, to go out with 1/2 of the pel spacing (L/N) of the 2nd direction be the interference stripes in cycle.

Therefore; Can produce liquid crystal indicator through said method with following formation; Promptly; So long as the 2nd direction has the liquid crystal panel of width L, be 768 liquid crystal panel (for example WXGA liquid crystal panel) even the pixel count that then identical light diffusing sheet is made up the 2nd direction is the pixel count of 1080 liquid crystal panel (for example FHD liquid crystal panel) or the 2nd direction, also can reduce the formation of interference stripes more reliably.At this moment, be that the pixel count of 1080 liquid crystal panel (for example FHD liquid crystal panel) and the 2nd direction is that 768 liquid crystal panel (for example WXGA liquid crystal panel) is made light diffusing sheet respectively owing to need not pixel count to the 2nd direction, so can realize the reduction of manufacturing cost.

In the operation of the above-mentioned liquid crystal indicator of assembling of liquid crystal indicator of the present invention; Can be between liquid crystal panel and light diffusing sheet, further to dispose to contain the optics membranous part of a slice blooming at least, the haze value H (%) of optics membranous part satisfies 95≤H≤99.9.

At this moment, because through the further hidden interference stripes of optics membranous part ability, so can produce the further liquid crystal indicator that has suppressed the visuognosis of interference stripes.

The operation of the above-mentioned light diffusing sheet of manufacturing that the manufacturing approach of liquid crystal indicator of the present invention possesses can comprise: make the operation as the resin sheet of above-mentioned plate body through extrusion molding; In the one side of resin sheet, push the spacing P that has with to design _lThe opposite mould of a plurality of optical element portion that is configured is as the roller of transfer mold, thereby this transfer mold is transferred to the operation of said one side; With cut out that transfer printing has transfer mold and be formed with in one side a plurality of optical element portion resin sheet the regulation zone and form the operation of light diffusing sheet.

In the method, through after forming resin sheet, push the spacing P that has with to design in the one side of resin sheet _lThe roller of the transfer mold that a plurality of optical element portion of arranging is corresponding, thus a plurality of optical element portion formed in the one side of resin sheet.Then, through cutting out the regulation zone that is formed with a plurality of optical element portion, thereby obtain light diffusing sheet as the resin sheet of plate body.

Description of drawings

Fig. 1 is the stereogram of formation that schematically shows an embodiment of liquid crystal indicator of the present invention.

Fig. 2 is the sketch map of section constitution at the II-II line place of the liquid crystal indicator represented of Fig. 1.

Fig. 3 is the stereogram of formation that schematically shows an embodiment of light diffusing sheet of the present invention.

Fig. 4 is the sectional view along the IV-IV line of Fig. 3.

Fig. 5 (a) is the sketch map of the liquid crystal indicator represented of Fig. 1.Fig. 5 (b) is the sketch map by the periodic structure of the interference stripes of the periodic structure generation of light diffusing sheet and liquid crystal panel.Fig. 5 (c) is the sketch map of the transmittance graph of liquid crystal panel.Fig. 5 (d) is the sketch map of the transmittance graph of light diffusing sheet.

Fig. 6 is the accompanying drawing of an example of the pixel image of expression during with the FHD liquid crystal panel of 32 inches of VA mode activated.

Fig. 7 (a) is that expression will have spacing P _lThe spacing and the spacing P of interference stripes of the fashionable generation of liquid crystal panel set of periodic structure body and 32 inches FHD in cycle _lBetween the accompanying drawing of relation.Fig. 7 (b) is that expression will have spacing P _lThe spacing and the spacing P of interference stripes of the fashionable generation of liquid crystal panel set of periodic structure body and 40 inches FHD in cycle _lBetween the accompanying drawing of relation.

Fig. 8 is the sketch map of the section constitution of the liquid crystal indicator when containing the optics membranous part.

Fig. 9 is the flow chart of an embodiment of the manufacturing approach of expression light diffusing sheet of the present invention.

Figure 10 (a) be light diffusing sheet manufacturing installation one the example sketch map.Figure 10 (b) is the part enlarged drawing of Figure 10 (a) region alpha.

Figure 11 is implementation condition and the chart of evaluation result in expression embodiment and the comparative example.

The specific embodiment

Below, with reference to description of drawings embodiment of the present invention.In the explanation of accompanying drawing,, and omit repeat specification to identity element mark prosign.In addition, the dimension scale of accompanying drawing is not necessarily consistent with the object of explanation.

Fig. 1 is the stereogram of formation that schematically shows an embodiment of liquid crystal indicator of the present invention.Fig. 2 is the sketch map of section constitution at the II-II line place of the liquid crystal indicator represented of Fig. 1.

Liquid crystal indicator 1 is so-called full run-down type LCD.Liquid crystal indicator 1 possesses liquid crystal panel 10 that plan view shape is an essentially rectangular and liquid crystal panel 10 is supplied with the back light source system (planar light source device) 20 of illumination light.In following explanation, for liquid crystal indicator 1, liquid crystal panel 10 sides are called the front side, back light source system 20 sides are called rear side or rear side.In addition, for the convenience of explaining, will be called the z direction towards the direction (thickness direction of liquid crystal panel 10) of liquid crystal panel 10 sides from back light source system 20.In addition, the plan view shape of liquid crystal panel 10 (shape of seeing from the z direction), long side direction (the 1st direction) is called the y direction, will be called the x direction with the short side direction (the 2nd direction) of long side direction quadrature.

Liquid crystal panel 10 has: contain the liquid crystal cells 12 of a plurality of pixels 11 (with reference to Fig. 2) and at the thickness direction of the liquid crystal cells 12 a pair of polarizer 13,14 from sandwich liquid crystal cells 12.Liquid crystal panel 10 is FHD (full HD) liquid crystal panel or WXGA (widescreen XGA) liquid crystal panel.Usually, the pixel count of FHD liquid crystal panel is 1080 pixels at short side direction, is 1920 pixels at long side direction.Usually, the pixel count of WXGA liquid crystal panel is 768 pixels at short side direction (x direction), is 1280 pixels at long side direction.

As liquid crystal cells 12, for example can use the known liquid crystal cells such as TFT type liquid crystal cells that utilize active matrix to drive.As the type of drive of liquid crystal panel 10, known modes such as VA mode capable of using, IPS mode and TN mode.In the formation that Fig. 1 and Fig. 2 represent, because polarizer 13 is positioned at back light source system 20 sides, so the surperficial 13a of polarizer 13 is illumination light planes of incidence to liquid crystal panel 10.

Back light source system 20 possesses: the resinous lamp box 30 of open front face side, be arranged on a plurality of light sources 40 in the lamp box 30 as light source portion, and be arranged on the lamp box 30 and clog the light diffusing sheet 50 of the peristome of lamp box 30.Wherein, though a plurality of light source 40 corresponding to light source portion, lamp box 30 can be the part of light source portion.

Erect the side wall portion 32 that is provided with the square frame shape integratedly and constitute lamp box 30 at the edge part of tabular bottom wall portion 31.Lamp box 30 is slim case shape.Being arranged on the example of a plurality of light sources 40 in the lamp box 30 as shown in Figure 1 is linear light source.In this embodiment, short of special instruction, light source 40 describes with linear light source.The example of the linear light source that uses as light source 40 is cylindric lamps such as fluorescent tube (cold-cathode tube), Halogen lamp LED, tungsten lamp.The example of the diameter of this linear light source is 2mm～4mm approximately.Here, though light source 40 is linear light sources, light source 40 is not limited to linear light source, also can be point source of light.The example of point source of light is light emitting diode (LED).When light source 40 is point source of light, also can as shown in Figure 2ly use as full run-down type.

The formation of the light diffusing sheet 50 that back light source system 20 has then, is described.Fig. 3 is the stereogram of formation that schematically shows an embodiment of light diffusing sheet of the present invention.Fig. 4 is the sketch map along the section constitution of the IV-IV line of Fig. 3.For convenience of description, x direction, y direction and the z direction of using Fig. 1 to represent are based on the formation with the state description light diffusing sheet 50 that disposes light diffusing sheet 50 as illustrated in fig. 1.

Light diffusing sheet 50 is that plan view shape is a rectangle and have the plate body of transmitance roughly.Like Fig. 3 and shown in Figure 4, light diffusing sheet 50 be from rear side according to the order of back layer 52 and substrate layer 51 at the range upon range of 2 layers of light diffusing sheet that have substrate layer 51 and back layer 52 to form of thickness direction.

With thickness t 2 additions of thickness t of substrate layer 51 1 and back layer 52 and the example of gross thickness T of light diffusing sheet 50 are 0.1mm～10mm.The example of the thickness t 1 of substrate layer 51 is 0.05mm～9mm.The example of the thickness t 2 of back layer 52 is 0.03mm～1mm.The raw material of light diffusing sheet 50 is not special to be limited, and can use known translucent resin.

The example of the refractive index of translucent resin is 1.46～1.62.The example of translucent resin is acrylic resin, phenylethylene resin series, Merlon, polyethylene, polypropylene, cyclic polyolefin, cyclic olefin copolymer, PETG, MS resin (copolymer of methyl methacrylatestyrene resin), polystyrene resin, AS resin (acrylonitritrile-styrene resin resin) etc.

Can be identical as the Resin A of substrate layer 51 raw materials and resin B as back layer 52 raw materials, also can be different.In addition, Resin A and resin B can be used above-mentioned illustrative translucent resin separately separately, also can make up more than 2 kinds.The combination of Resin A and resin B is the combination of translucent material of the same race preferably.Further preferred resin A, B all contain phenylethylene resin series.Special preferred resin A and resin B all are only to be made up of phenylethylene resin series.

Light diffusing sheet 50 can contain light diffusing agents such as light diffusion particle.As light diffusing agent, so long as refractive index is different with the translucent resin of formation light diffusing sheet 50, can then be not particularly limited seeing through the particle of the light diffusion of light diffusing sheet 50.Inorganic is that the example of light diffusing agent is calcium carbonate, barium sulfate, titanium oxide, aluminium hydroxide, silica, glass, talcum, mica, white carbon, magnesia, zinc oxide etc.Can use with aliphatic acid etc. illustrative light diffusing agent is implemented material after the surface treatment as light diffusing agent.The example of organic system light diffusing agent is styrenic particle, acrylic acid series polymeric compounds particle, siloxane-based polymers particle etc.Preferred organic system light diffusing agent is that weight average molecular weight is that 500,000～5,000,000 high molecular polymer particle, the gel percentage when being dissolved in acetone are the above cross-linking polymer particles of 10 quality %.

When light diffusing sheet 50 contained light diffusing agent, the cooperation ratio of light diffusing agent was that light diffusing agent is 0.01～1 weight portion with respect to translucent resin 100 weight portions, is more preferably 0.001～0.01 weight portion.Light diffusing agent can use as masterbatch with the translucent resin combination as the raw material of main composition light diffusing sheet 50.From the viewpoint of light diffusing, the absolute value of the difference of the refractive index of the translucent resin of light diffusing sheet 50 main materials and the refractive index of light diffusing agent is 0.01～0.20, is more preferably 0.02～0.15.

In light diffusing sheet 50, can further add additives such as ultra-violet absorber, heat stabilizer, anti-oxidant, weather resisting agent, light stabilizer, fluorescent whitening agent, processing stabilizers.

The example of ultra-violet absorber is that phenyl salicytate is that ultra-violet absorber, benzophenone series ultra-violet absorber, triazine are that ultra-violet absorber, BTA are ultra-violet absorber.When adding ultra-violet absorber, for ultra-violet absorber, with respect to the ultra-violet absorber that for example can add 0.1～3 weight portion as translucent resin 100 weight portions of light diffusing sheet 50 main materials.If in this scope, then can suppress ultra-violet absorber and ooze out, and can keep the outward appearance of light diffusing sheet 50 well to the surface.

The example of heat stabilizer is manganese compound, copper compound etc.Heat stabilizer for example can add with ultra-violet absorber.At this moment,, can add the heat stabilizer below 2 weight portions, more preferably add heat stabilizer with the ratio of 0.01～1 weight portion with respect to 1 weight portion of the ultra-violet absorber in the translucent resin.

Examples of antioxidants is hindered phenol compound, hindered amine compound.With respect to translucent resin 100 weight portions, for example can add the anti-oxidant of 0.1～3 weight portion.

Light diffusing sheet 50 have back layer 52 last with faces substrate layer 51 opposition sides (the 2nd face) 50a, spread all over whole and roughly be distributed with fine recess or protuberance (below, be called jog) equably.Face 50a is so-called delustring face.The a plurality of micro concavo-convex portion that face 50a go up to form for example can form through embossing processing.The surface configuration of face 50a can be represented with the surface roughness of face 50a.The surface configuration of face 50a can be represented with the arithmetic average roughness Ra that used face 50a and the surface roughness of 10 mean roughness Rz.The example of the arithmetic average roughness Ra of face 50a is the value for example measured according to ISO-1997, is 0.5 μ m～25 μ m, is preferably 1 μ m～20 μ m.In addition, the example of 10 mean roughness Rz of face 50a is the value for example measured according to ISO-1997, is 5 μ m～110 μ m, is preferably 10 μ m～100 μ m.And, face 50a also can be satisfy simultaneously as Ra and Rz the face of illustrative above-mentioned value.

Substrate layer 51 last, be formed with a plurality of protuberances 53 with faces back layer 52 opposition sides (the 1st face) 50b.Each protuberance 53 extends in y direction (the 1st direction).A plurality of protuberances 53 are arranged in x direction (with the direction of bearing of trend quadrature, the 2nd direction).In other words, on the surface of substrate layer 51, a plurality of protuberances 53 form many strips.Example with cross sectional shape y direction (bearing of trend) quadrature each protuberance 53 is a semicircle shape.At this moment, each protuberance 53 is the cylindrical lens shape.

As shown in Figure 4, a plurality of protuberances 53 can have d [μ m] at interval between adjacent projection 53.Distance between the center of adjacent projection 53 (below, be called spacing) is being made as P _lWhen [μ m], height ha of protuberance 53 [μ m] and spacing P _lRatio (ha/P _l) example be 0.2～0.8.Wherein, though have certain interval d between the adjacent protuberance 53, can be d=0.At this moment, P _lWidth corresponding to protuberance 53.Above-mentioned spacing P _lMean P _lThe spacing of [μ m].This expression be for after state the difference of other spacing.Below in the explanation, also adopt same expression sometimes for other spacing.

The spacing P of protuberance 53 _lBeing in light diffusing sheet 50 being assembled into liquid crystal indicator 1 (Fig. 1 with reference to) time, according to being difficult for the value that mode that visuognosis goes out interference stripes is confirmed, and is can be for onesize FHD liquid crystal panel and WXGA liquid crystal panel also with the spacing P of light diffusing sheet 50 _lSpacing P is described _l

At first, utilize Fig. 5 (a), Fig. 5 (b), Fig. 5 (c) and Fig. 5 (d) that the generation of interference stripes is described.Fig. 5 (a) is the sketch map of the liquid crystal indicator 1 represented of Fig. 1.Among Fig. 5 (a), the face 50a of light source 40 sides of light diffusing sheet 50 is schematically illustrated as tabular surface.Fig. 5 (b) is the sketch map by the periodic structure of the interference stripes of the periodic structure generation of light diffusing sheet 50 and liquid crystal panel 10.Fig. 5 (c) is the sketch map of the transmittance graph of liquid crystal panel 10.Fig. 5 (d) is the sketch map of the transmittance graph of light diffusing sheet.

Because a plurality of protuberances 53 in the x direction with spacing P _lSide by side, so a plurality of protuberance 53 has cycle P in the x direction _lPeriodic structure.Based on the transmittance graph S1 of this periodic structure with S1=E ₁Cos (2 π (x/P _l)) expression." E in the formula ₁" amplitude of expression transmittance graph S1.

Liquid crystal panel 10 contains a plurality of pixels 11.A plurality of pixels 11 are arranged in x direction and y direction regularly.Therefore, liquid crystal panel 10 has certain periodic structure in x direction and y direction.When the spacing with the pixel 11 of the x direction of liquid crystal panel 10 (orientation of a plurality of protuberances 53 or with the direction of the bearing of trend quadrature of protuberance 53) is made as P _p[μ m] (wherein, P _p≠ P _lAnd 0.5P _p≠ P _l) time, the transmittance graph S2 based on the periodic structure of x direction of liquid crystal panel 10 uses S2=E ₂Cos (2 π (x/P _p)) expression." E in the formula ₂" amplitude of expression transmittance graph S2.When the image size with the x direction of liquid crystal panel 10 be made as L (μ m), when the pixel count of x direction is made as N (N is the integer more than 1), spacing P _pAvailable P _p(μ m)=L/N representes.

In the liquid crystal indicator 1, spacing P _lPeriodic structure and spacing P _pPeriodic structure overlapping on above-below direction.Therefore, seeing through light that light diffusing sheet 50 obtains with liquid crystal panel 10 representes with S=S1S2 based on the contrast S of above-mentioned periodic structure.Wherein, S1S2 is suc as formula shown in (9).

$\mathrm{<figure-callout\; id="1"\; label="S"\; filenames="HSA00000609740200011.png,HSA00000609740200021.png"\; state="\{\{state\}\}">S</figure-callout>}1\&CenterDot;\mathrm{<figure-callout\; id="2"\; label="S"\; filenames="HSA00000609740200021.png,HSA00000609740200051.png"\; state="\{\{state\}\}">S</figure-callout>}2=\frac{A\&CenterDot;\mathrm{<figure-callout\; id="2"\; label="B"\; filenames="HSA00000609740200021.png,HSA00000609740200051.png"\; state="\{\{state\}\}">B</figure-callout>}}{2}\&CenterDot;\left[\cos \right\{2\mathrm{\&pi;x}/\left(\frac{P_p\&CenterDot;P_l}{P_p+P_l}\right)\}+\cos \{2\mathrm{\&pi;x}/\left(\frac{P_p\&CenterDot;P_l}{\left|P_p{-P}_l\right|}\right)\left\}\right]\&CenterDot;\&CenterDot;\&CenterDot;\left(9\right)$

Shown in (9) and Fig. 5 (b), contrast S comprises radio-frequency component and low-frequency component.Radio-frequency component is not gone out by visuognosis because frequency is high, and low-frequency component is gone out by visuognosis as so-called interference stripes.Thus, shown in (9), based on spacing P _pPeriodic structure and spacing P _lThe spacing P of interference stripes of periodic structure _m1 [μ m] representes with formula (10).Below, the spacing of interference stripes is also referred to as the interference stripes spacing.

${\mathrm{<figure-callout\; id="1"\; label="P\; m"\; filenames="HSA00000609740200011.png,HSA00000609740200021.png"\; state="\{\{state\}\}">P</figure-callout>}}_{m}1=\frac{P_p\&CenterDot;P_l}{|P_p-P_l|}\&CenterDot;\&CenterDot;\&CenterDot;\left(10\right)$

The inventor etc. are conscientiously research repeatedly, and the result finds that in the liquid crystal panel 10, also having transmissivity is 0.5P with (1/2) pel spacing _pSituation about changing.Transmissivity is with 0.5P shown in Fig. 6 _pOne example of situation about changing.Fig. 6 is the accompanying drawing of the pixel image when showing the liquid crystal panel 10 that shows with the FHD (full HD) of 32 inches of VA mode activated with 200.X direction among Fig. 6 and y direction are corresponding to x direction and the y direction of Fig. 1～Fig. 3 etc.

Think this 0.5P _pThe cause in cycle be: because wide viewing angleization, in a pixel 11, near the differently-oriented directivity difference of the liquid crystal molecule central authorities of x direction.Fig. 6 is the situation of VA pattern, and the situation of IPS pattern also is same.During the IPS pattern, think 0.5P _pThe cause in cycle be: because comb electrode, near the differently-oriented directivity difference of the liquid crystal molecule central authorities of the x direction in a pixel 11.

As stated, also comprise cycle 0.5P at liquid crystal panel 10 _pPeriodic structure the time, the spacing P of the interference stripes that accompany with this periodic structure _m2 [μ m] represent with formula (11).

${\mathrm{<figure-callout\; id="2"\; label="P\; m"\; filenames="HSA00000609740200021.png,HSA00000609740200051.png"\; state="\{\{state\}\}">P</figure-callout>}}_{m}2=\frac{0.5P_p\&CenterDot;P_l}{|0.5P_p-P_l|}\&CenterDot;\&CenterDot;\&CenterDot;\left(11\right)$

Fig. 7 (a) and Fig. 7 (b) are that expression will have spacing P _lThe spacing and the spacing P of interference stripes of transparent periodic structure body and the fashionable generation of liquid crystal panel set in cycle ₁Between the accompanying drawing of relation.Expression measured value among Fig. 7 (a) and Fig. 7 (b).Measured value is obtained as follows.In the liquid crystal indicator (LCD TV) of liquid crystal panel with 32 inches FHD and 40 inches FHD, the above-mentioned periodic structure body of configuration between light source portion and liquid crystal panel.Under this configuration status, through under the state of above-mentioned each liquid crystal indicator show white, in the darkroom, observing interference stripes, thereby measure the spacing of interference stripes.Fig. 7 (a) is to use 32 inches liquid crystal panel, and Fig. 7 (b) is to use 40 inches liquid crystal panel.

In Fig. 7 (a) and Fig. 7 (b), the result when " " expression is adopted by the light diffusing sheet of the actual manufacturing of translucent resin as above-mentioned periodic structure body.Result when on the other hand, the light diffusing sheet model (duplicate) made by silicon is adopted in " zero " expression as above-mentioned periodic structure body.The raw material of periodic structure body is different as stated, but the shape of periodic structure body is identical with the light diffusing sheet of representing like Fig. 3.In Fig. 7 (a) and Fig. 7 (b), the P of formula (10) expression _m1 couple of P _lVariation represent the P of formula (11) expression with solid line _m2 couples of P _lVariation dot.

Shown in Fig. 7 (a) and Fig. 7 (b), the size of measured value and liquid crystal panel 10 irrespectively is mapped on the curve of formula (10) and formula (11) expression.That is, can be regarded as the spacing P that has produced with based on liquid crystal panel 10 _pPeriodic structure and spacing P _lThe different interference stripes of interference stripes of periodic structure.Can understand through Fig. 7 (a) and Fig. 7 (b): the P that calculates by formula (10) and formula (11) _m1 and P _m2 corresponding to having spacing P _lThe spacing of the interference stripes that produce during with liquid crystal panel 10 combinations of the light diffusing sheet 50 of periodic structure.

Then, spacing P is described _lThe condition that satisfies.For the convenience of explaining, when needing additional symbols liquid crystal panel 10 to be the situation of FHD liquid crystal panel and WXGA liquid crystal panel, liquid crystal panel 10 also is called as FHD liquid crystal panel 10f and WXGA liquid crystal panel 10w respectively.Carry FHD liquid crystal panel 10f and WXGA liquid crystal panel 10w respectively and also be called as liquid crystal indicator 1f and liquid crystal indicator 1w as the liquid crystal indicator 1 of liquid crystal panel 10.

Because the pixel count N of the short side direction of FHD liquid crystal panel 10f (x direction) is 1080, so at pel spacing P with the x direction among the FHD liquid crystal panel 10f _pBe made as P _pDuring f, P _pF is expressed as P _pF=L/1080.Because the pixel count N of the short side direction of WXGA liquid crystal panel 10w (x direction) is 768, so at pel spacing P with the x direction among the WXGA liquid crystal panel 10w _pBe made as P _pDuring w, P _pW is expressed as P _pW=L/768.

Using P _pWhen f expression (10) and formula (11), be about to P _pF is updated to the P of formula (10) and formula (11) _pIn and the P that obtains _m1 and P _m2 are called as P _mF1 and P _mF2.This P _mF1 and P _mF2 in addition, is using P with formula (12a) and formula (12b) expression _pWhen w expression (10) and formula (11), be about to P _pW is updated to the P of formula (10) and formula (11) _pIn and the P that obtains _m1 and P _m2 are called as P _mW1 and P _mW2.This P _mW1 and P _mW2 is with formula (13a) and formula (13b) expression.

$P_m\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HSA00000609740200011.png,HSA00000609740200021.png"\; state="\{\{state\}\}">f</figure-callout>}1=\frac{P_{p}f\&CenterDot;P_l}{|P_{p}f-P_l|}\&CenterDot;\&CenterDot;\&CenterDot;\left(12a\right)$

$P_m\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="HSA00000609740200021.png,HSA00000609740200051.png"\; state="\{\{state\}\}">f</figure-callout>}2=\frac{0.5P_{p}f\&CenterDot;P_l}{|0.5P_{p}f-P_l|}\&CenterDot;\&CenterDot;\&CenterDot;\left(12b\right)$

$P_m\mathrm{<figure-callout\; id="1"\; label="w"\; filenames="HSA00000609740200011.png,HSA00000609740200021.png"\; state="\{\{state\}\}">w</figure-callout>}1=\frac{P_{p}w\&CenterDot;P_l}{|P_{p}w-P_l|}\&CenterDot;\&CenterDot;\&CenterDot;\left(13a\right)$

$P_m\mathrm{<figure-callout\; id="2"\; label="w"\; filenames="HSA00000609740200021.png,HSA00000609740200051.png"\; state="\{\{state\}\}">w</figure-callout>}2=\frac{0.5P_{p}w\&CenterDot;P_l}{|0.5P_{p}w-P_l|}\&CenterDot;\&CenterDot;\&CenterDot;\left(13b\right)$

In this embodiment, the spacing P of raised part 53 _lIt is the value that all satisfies following 4 conditions (1)～(4).

Condition (1): P _mF1＜1500 μ m or P _mF1>=10000 μ m

Condition (2): P _mF2＜1500 μ m or P _mF2>=10000 μ m

Condition (3): P _mW1＜1500 μ m or P _mW1>=10000 μ m

Condition (4): P _mW2＜1500 μ m or P _mW2>=10000 μ m

P _mF1 and P _mF2 is the spacing of the interference stripes that can occur when being equipped with light diffusing sheet 50 among the FDH liquid crystal indicator 1f.On the other hand, P _mW1 and P _mW2 is the spacing of the interference stripes that can occur when being equipped with light diffusing sheet 50 among the WGXA liquid crystal indicator 1w.And, spacing P _lIt is the value that all satisfies above-mentioned condition (1)～condition (4).Therefore, if use with spacing P _lThe arranged side by side light diffusing sheet 50 of configuration protuberance 53, then the liquid crystal panel 10 of liquid crystal indicator 1 is that any among FHD liquid crystal panel 10f and the WXGA liquid crystal panel 10w all is difficult for visuognosis and goes out the interference stripes based on pel spacing and 1/2 pel spacing.

Such spacing P _lExample be 30 μ m～700 μ m.Spacing P _lIn illustrative scope, preferably 50 μ m～500 μ m are more preferably 150 μ m～400 μ m.

Go out the viewpoint of interference stripes from further inhibition visual identity, as shown in Figure 8, can between light diffusing sheet 50 and liquid crystal panel 10, possess optics membranous part 60.Fig. 8 is the sketch map of the section constitution of the liquid crystal indicator 1 when containing the optics membranous part.Among Fig. 8, optics membranous part 60 illustrations have a situation of 3 bloomings 61.The kind and the sheet number that constitute the blooming 61 of optics membranous part 60 are selected to get final product according to the mode of the satisfied 95≤H of haze value H (%)≤99.9 of optics membranous part 60.Haze value H is the total mist degree that constitutes all bloomings 61 of optics membranous part 60.Haze value H measures the value that obtains according to JIS-K7136 (ISO 14782).

The example of blooming 61 is diffusion barrier, prism film, reflection-type polarisation diffusion barrier, phase retardation film and light polarizing film etc.Optics membranous part 60 can have the structure that the blooming of the above identical type of overlapping a slice forms, and also can have the structure that a plurality of different types of bloomings form more than overlapping a slice.Wherein, explain as the example of blooming 61 and each film of enumerating.

Diffusion barrier is the film that is used for the light diffusion irradiation of incident.An example of diffusion barrier is with the fixing film that forms of pearl of binding agent on the one side of transparent resin film.Particularly, comprise the TSUJIDEN of Co., Ltd. corporate system " D121U series " and the KIMOTO of Co., Ltd. corporate system " LIGHT UP TM " etc.

The example of prism film is the film that on the face of a side that is configured to liquid crystal panel 10, is formed with a plurality of optically focused property lens.Each optically focused lens extends along a direction.A plurality of optically focused property lens are disposed at the direction with the bearing of trend quadrature of optically focused property lens side by side.The example of fine optically focused property lens comprises protruding laterally convex lens and biconvex lens etc.Fine optically focused property lens can be that the cross section is the prism lens of triangle.

Reflection-type polarisation diffusion barrier is the film that the polarised light that makes regulation saw through, will have the polarised light reflection of the character opposite with the polarised light of this regulation.The example of reflection-type polarisation diffusion barrier can be enumerated: the rectilinearly polarized light of certain vibration direction is seen through, will with the reflection-type linear polarization diffusion barrier of the rectilinearly polarized light reflection of the direction of vibration of this certain vibration direction quadrature; The reflection-type circularly polarized light diffusion barrier of the circularly polarized light reflection that the circularly polarized light of the direction of rotation of regulation is seen through, will be rotated etc. in the direction opposite with the regulation direction of rotation.The example of reflection-type linear polarization diffusion barrier is Sumitomo 3M Co., Ltd. system " DBEF (Dual Brightness Enhancement Film; The reflecting type polarizing brightness enhancement film) ", Nitto Denko Corp's system " NIPOX ".

Phase retardation film is the film with phase difference (delay) that the stretching because of resin molding produces.The example of phase retardation film is Merlon resin film, polysulfones resin film, polyether sulfone resin film, polyarylate resin film, norbornene resin film.The concrete example of phase retardation film is the Kaneka of Co., Ltd. system " ELMEC ", Sumitomo Chemical Co's system " SUMIKALIGHT ".

Light polarizing film is the film that makes along the light transmission of certain orientation vibration.The concrete example of light polarizing film is Nitto Denko Corp's system " NPF ", Sumitomo Chemical Co's system " SUMIKALAN ".

[manufacturing approach of liquid crystal indicator]

One example of manufacturing approach of the liquid crystal indicator of this embodiment then, is described.As shown in Figure 9; Liquid crystal indicator 1 possesses: the design process S10 that light diffusing sheet is designed; Based on the S20 of manufacturing process that manufactures and designs light diffusing sheet 50 among the design process S10, light diffusing sheet 50, liquid crystal panel 10 and the light source 40 of combination manufacturing wait the assembling procedure S30 that assembles liquid crystal indicator 1.Fig. 9 is the flow chart of the manufacturing approach of expression liquid crystal indicator.Explanation constitutes the design process S10 and the S20 of manufacturing process of Opital control board manufacturing approach at first, in order.

< design process >

In design process S10,, confirm the spacing P of protuberance 53 according to the mode that all satisfies above-mentioned condition (1)～(4) based on the picture dimension L of the liquid crystal panel 10 that uses _lThus, having confirmed should be to the relief pattern that is made up of a plurality of protuberances 53 of light diffusing sheet 50 figurations.Wherein, the cross sectional shape of each protuberance 53 is to describe as the design of accomplishing (for example semicircle shape), but in this design process S10, also can design the cross sectional shape of protuberance 53.

< manufacturing process >

In the S20 of manufacturing process, utilize the manufacturing installation 80 of the light diffusing sheet of Figure 10 (a) expression, when making resin sheet 70, the protuberance 53 that designs at the one side 70a of this resin sheet 70 figuration.The manufacturing installation 80 of the light diffusing sheet 50 that Figure 10 representes is described.

Manufacturing installation 80 possesses: will be the sheet forming machine 90 of sheet as the resin extrusion molding of raw material, through extruding with one group of compression roller crowd 100 of the resin sheet of extruding 70 further moulding and the traction that is used to draw resin sheet 70 with roller crowd 110.

Sheet forming machine 90 possesses: be used for the 1st extruder 91 as the Resin A heating and melting of substrate layer 51 raw materials; Being used for will be as the 2nd extruder 92 of the resin B heating and melting of back layer 52 raw materials; Supply with the feed piece 93 of the resin of fusion in the 1st extruder 91 and the 2nd extruder 92, be used for the die head 94 that the resin in the feed piece 93 is extruded with the sheet material state.On the 1st and the 2nd extruder 91,92, be equipped with and be used for resin is put into the hopper 95,96 in the barrel of extruder.

Compression roller crowd 100 has 3 compression rollers 101,102,103.3 compression roller 101～103 each naturally columned metal system rollers.The rotation of each compression roller 101～103 is parallel to each other.In the embodiment of Figure 10 (a) expression, 3 compression rollers 101～103 dispose along vertical direction continuously, and the rotation of 3 compression rollers 101～103 is a level.Wherein, though describe based on the embodiment of Figure 10 (a) expression, the configuration relation of 3 compression rollers 101～103 is not limited to the mode of Figure 10 (a) expression.For example compression roller 101～103 also can dispose by along continuous straight runs continuously.The rotating shaft of 3 compression rollers 101～103 is connected with motor driving mechanisms such as (not shown) separately.

The periphery 101a of compression roller 101 is even surfaces.On the other hand, on the periphery 102a between compression roller 101 and the compression roller 103, be provided with the delustring transfer mold 104 that is used to form the face 50a that contains micro concavo-convex portion as shown in Figure 3 as the compression roller 102 of intermediate calender rolls.The surface of delustring transfer mold 104 is by spreading all over integral body and roughly equally distributed delustring face with the embossing shape that constitutes in the opposite relief pattern of the relief pattern of face 50a to be formed.The example of the arithmetic average roughness Ra of this delustring face is to measure the value obtain, be 6 μ m～30 μ m according to ISO-1997, and the example of 10 mean roughness Rz is to measure the value that obtains, be 45 μ m～150 μ m according to ISO-1997.In Figure 10 (a),, be provided with the intaglio plate transfer mold 105 that is used to form protuberance 53 being positioned on the periphery 103a as the compression roller 103 of lower roll of compression roller 102 downsides.In intaglio plate transfer mold 105, what be formed with a plurality of, strip along the circumferencial direction of compression roller 103 is the groove of reverse mutually with protuberance 53.That is, the cross section with its length direction (circumferencial direction) quadrature of groove has the roughly profile of semicircle arcuation, the spacing P that designs among in the heart distance (spacing) and the design process S10 in the adjacent grooves _lCorresponding.

Should explain that delustring transfer mold 104 can be located on the compression roller 103, intaglio plate transfer mold 105 can be located on the middle compression roller 102.In addition, the periphery 102a of compression roller 102 also can be an even surface.At this moment, the face 50a of the rear side of light diffusing sheet 50 is even surfaces.

Raw material as above-mentioned delustring transfer mold 104 and intaglio plate transfer mold 105 can adopt organic material.Even push the hear resistance that the resin sheet of just having been extruded by mould 94 with the heating and melting state 70 also can be kept the shape of transfer mold repeatedly as long as have as the organic material of the raw material of delustring transfer mold 104 and intaglio plate transfer mold 105.The example of organic material is heat-curing resin and thermoplastic resin etc.

Through utilizing driving mechanism; Compression roller 101 with compression roller 103 be rotated counterclockwise, compression roller 102 is to turn clockwise, thereby compression roller crowd 100 can be on one side implements processing on one side with resin sheet 70 moulding to the two sides of the resin sheet 70 extruded by sheet forming machine 90.

Traction has pair of traction with roller 111,112 with roller crowd 110.Traction is clamped resin sheet 70 with roller 111,112 at the thickness direction of resin sheet 70 from both sides.Traction is with roller 111,112 each naturally columned metal system roller.Shown in Figure 10 (a), pair of traction with roller 111,112 be arranged to can be under the state of keeping the height after just seeing off from compression roller 103 horizontal feed resin sheet 70.

Then, utilize Fig. 9 and Figure 10 (a) that the S20 of manufacturing process of the light diffusing sheet 50 of the manufacturing installation 80 that has used light diffusing sheet 50 is described.As shown in Figure 9, the S20 of manufacturing process comprises that the S21 of sheet material manufacturing process, transfer printing process S22 and light diffusing sheet form operation S23.

(1) S21 of sheet material manufacturing process

In the hopper 95 of the 1st extruder 91, drop into Resin A as substrate layer 51 raw materials.The 1st extruder 91 with the Resin A melting mixing after, the Resin A of melting mixing is supplied to feed piece 93.In the hopper 96 of the 2nd extruder 92, drop into resin B as back layer 52 raw materials.The 2nd extruder 92 with the resin B melting mixing after, the resin B of melting mixing is supplied to feed piece 93.The example of the barrel temperature of the 1st extruder 91 and the 2nd extruder 92 is about 190 °～250 °.Then, the resin in the die head 94 coextrusion feed pieces 93.Thus, shown in Figure 10 (b), extrude 2 layers resin sheet 70 from die head 94.Figure 10 (b) is the part enlarged drawing of the region alpha of Figure 10 (a).In the embodiment of Figure 10 (a) expression, the layer 71 of downside is the layer that should become back layer 52 in the resin sheet of extruding 70, and the layer 72 of upside is the layer that becomes substrate layer 51.

(2) transfer printing process S22

The resin sheet of being extruded by die head 94 70 is extruded roller 101 and sandwiches and push with compression roller 102, is transferred along with the rotation of compression roller 102.At this moment, resin sheet 70 is cooled.Owing on compression roller 102, be provided with delustring transfer mold 104, when compression roller 101 and compression roller 102 extrusion resin sheet materials 70, the shape of delustring transfer mold 104 arranged and form a large amount of fine jogs in the face 70b of resin sheet 70 transfer printing.The surface temperature of preferred compression roller 101 and compression roller 102 is lower than the extrusion temperature of resin sheet 70, and the example of the surface temperature of compression roller 101 and compression roller 102 is about 50 ℃～120 ℃.

After being extruded roller 101 and compression roller 102 extruding, carrying, resin sheet 70 is extruded roller 102 and sandwiches and push with compression roller 103.Thus, the surface configuration of intaglio plate transfer mold 105 is transferred to the face 70a of resin sheet 70.Its result forms a large amount of, strip and the parallel protuberance of flow direction resin sheet 70 (transport direction) on face 70a.The surface temperature of compression roller 103 for example is about 50 ℃～120 ℃.

Resin sheet 70 after being extruded roller 102 as stated and sandwiching and push with compression roller 103, with the state of the periphery driving fit of compression roller 103 under be transferred, seen off from the lower end edge horizontal direction of compression roller 103.

(3) light diffusing sheet forms operation S23

Through utilizing pair of traction to draw resin sheet 70, thereby be manufactured on the resin sheet 70 that the upper and lower surface figuration has the regulation shape with roller 120A, 120B.After further cooling off resin sheet 70,, obtain light diffusing sheet 50 through cutting out expectation size (regulation zone).Usually, to be 4 limits when being equipped on liquid crystal indicator 1 withheld and be assembled into liquid crystal indicator 1 by resin system or metal frame light diffusing sheet 50, thus light diffusing sheet 50 cut out size than the big circle of picture dimension of the liquid crystal indicator 1 that supplies to carry.

Utilize above-mentioned manufacturing approach, can produce Fig. 3 and the illustrative light diffusing sheet 50 of Fig. 4.Then, the assembling procedure S30 that utilizes the light diffusing sheet of making like this 50 to assemble liquid crystal indicator 1 is described.

(assembling procedure)

In assembling procedure S30, as shown in Figure 1, have in the inboard and dispose light diffusing sheet 50 and liquid crystal panel 10 on the lamp box 30 of a plurality of light sources 40 in order, be assembled into liquid crystal indicator 1.Light diffusing sheet 50 is located on the lamp box 30 according to the mode of the peristome that clogs lamp box 30.Light diffusing sheet 50 is consistent with the short side direction of liquid crystal panel 10 with the orientation (x direction) that liquid crystal panel 10 is configured to protuberance 53.When light source 40 is linear light source, dispose them according to the mode of the bearing of trend roughly consistent with the bearing of trend of protuberance 53 (among Fig. 1, being the y direction) of light source (linear light source) 40.In addition, when optics membranous part 60 is set, configuration optics membranous part 60 between light diffusing sheet 50 and liquid crystal panel 10.

When the light source 40 of back light source system 20 is lighted, directly or after the surface reflection by the bottom wall portion 31 of lamp box 30 incide light diffusing sheet 50 from the light of light source 40 output.Because on the face 50b of liquid crystal panel 10 sides of light diffusing sheet 50, form a plurality of protuberances 53 of strip, so penetrate the light time from the light diffusing sheet 50 of light transmission, light penetrates along various directions according to penetrating the position.Thus, spread, penetrated as planar light from the light of light source 40 from the light of light source 40.Owing to penetrate liquid crystal panel 10, pass through the driving displayable image of liquid crystal panel 10 with this planar illumination.

In this embodiment, the spacing P of protuberance 53 _lIt is the satisfy condition value of (1)～condition (4) of the interference stripes spacing of formula (12a), formula (12b), formula (13a) and formula (13b) expression.Wherein, condition (1) and condition (2) are that liquid crystal panel 10 is difficult for the condition that visuognosis goes out interference stripes during for FHD liquid crystal panel 10f.On the other hand, condition (3) and condition (4) are that liquid crystal panel 10 is difficult for the condition that visuognosis goes out interference stripes during for WXGA liquid crystal panel 10w.

Particularly, when light diffusion body 50 made up with FHD liquid crystal panel 10f or WXGA liquid crystal panel 10w, the spacing of the interference stripes that can produce was less than 1500 μ m or more than the 10000 μ m (10mm).Go out interference stripes if be difficult for visuognosis then spacing is thin less than 1500 μ m.On the other hand, if the spacing of interference stripes when to be 10mm above, the tendency that exists contrast to descend on the contrary also is difficult for visuognosis and goes out interference stripes.

Therefore, no matter use light diffusing sheet 50 for the arbitrary situation among FHD liquid crystal panel 10f and the WXGA liquid crystal panel 10w, can both suppress interference stripes for liquid crystal panel 10.That is, can be to FHD liquid crystal panel 10f with WXGA liquid crystal panel 10w and with identical light diffusing sheet 50.Its result, the light diffusing sheet that can be used for FHD liquid crystal panel 10f and WXGA liquid crystal panel 10w can be made by identical manufacturing installation 80 (manufacturing line).At this moment, owing to need not prepare or change compression roller 103 according to FHD liquid crystal panel 10f and WXGA liquid crystal panel 10w, so can reduce the manufacturing cost of the liquid crystal indicator 1 that is equipped with FHD liquid crystal panel 10f and WXGA liquid crystal panel 10w respectively.With respectively FHD liquid crystal panel 10f and WXGA liquid crystal panel 10w design, the situation of making light diffusing sheet 50 are compared, can shorten the manufacturing time of liquid crystal indicator 1.

In this embodiment, satisfy condition respectively (2) and the mode of condition (4) is confirmed spacing P according to the interference stripes spacing of formula (12b) and formula (13b) expression _lTherefore; For liquid crystal panel 10 is the situation of FHD liquid crystal panel 10f or WXGA liquid crystal panel 10w; The interference stripes of x direction pel spacing can not only be suppressed to follow, and the visuognosis of the interference stripes due to caused 1/2 pel spacing of transmission change that separately causes by the liquid crystal molecular orientation direction of liquid crystal panel 10 (FHD liquid crystal panel 10f or WXGA liquid crystal panel 10w) can be suppressed.

In addition, shown in Fig. 7 (a) and Fig. 7 (b), formula (10) and formula (11) are corresponding to the spacing of the interference stripes of reality generation.And formula (12a) and formula (13a) are corresponding to formula (10), and formula (12b) and formula (13b) are corresponding to formula (11).Therefore, through confirming P based on the interference stripes spacing of formula (12a), formula (12b), formula (13a) and formula (13b) expression _lThereby, be difficult for visuognosis more reliably and go out interference stripes.

In addition, as shown in Figure 8, when the optics membranous part 60 of the satisfied 95≤H of haze value H (%)≤99.9 is set between light diffusing sheet 50 and liquid crystal panel 10, can further hidden interference stripes.When optics membranous part 60 was set like this, the distance ground (even for example the observation place is near liquid crystal panel 10) that does not for example rely on liquid crystal panel 10 and observation place was difficult for visuognosis and goes out interference stripes.The above situation P in (1)～condition (4) that for example ought satisfy condition _mF1, P _mF2, P _mW1 and P _mIt is effective when some among the w2 is the above condition of 10000 μ m.It the reasons are as follows.That is,,, interference stripes have consequently been suppressed in appearance because of the long contrast of spacing descends when the interference stripes spacing is 10000 μ m when above.Therefore, through optics membranous part 60 is set, thereby, more hidden interference stripes go out interference stripes because of being difficult for visuognosis more reliably.

In addition, for being become, interference stripes are difficult for the state that visuognosis goes out more, preferably according to P _mF1, P _mF2, P _mW1 and P _mThe mode that w2 respectively does for oneself below the 1000 μ m designs P _lAt this moment,, the haze value H (%) of above-mentioned optics membranous part 60 or optics membranous part 60 do not satisfy above-mentioned condition, because the spacing of the interference stripes that generate is below the 1000 μ m, so be difficult to see interference stripes even not being set yet.

According to the embodiment of the present invention of above explanation, can provide can suppress more reliably interference stripes and can with the light diffusing sheet of diverse liquid crystal panel and usefulness, the planar light source device that contains light diffusing sheet, the liquid crystal indicator that contains light diffusing sheet, the manufacturing approach of light diffusing sheet and the manufacturing approach of liquid crystal indicator.

Then, based on the action effect of embodiment and comparative example explanation light diffusing sheet.Below, for the convenience of explaining, to the identical symbol of above-mentioned embodiment corresponding elements mark.Figure 11 is expression embodiment and the implementation condition of comparative example and the chart of evaluation result.

(embodiment)

For the enforcement of embodiment, prepare 32 inches FHD liquid crystal panels and 32 inches WXGA liquid crystal panels as liquid crystal panel 10.Among the embodiment, based on 32 inches FHD and the corresponding P of WXGA liquid crystal panel _pF and P _pW, confirm spacing P according to the mode of (the 1)～condition (4) that satisfies condition _lThe spacing P that confirms _lShown in figure 11 is 250 μ m.

Make light diffusing sheet 50 based on this design load.The manufacturing of the light diffusing sheet 50 in the illustrative embodiment.

< manufacturing of light diffusing sheet >

As the raw material of resin sheet 70, (1) and (2) raw material below preparing.

(1) translucent resin A styrene resin (Japan styrene Co., Ltd. system " HRM40 " refractive index 1.59)

(2) translucent resin B

Styrene resin (Japan styrene Co., Ltd. system " HRM40 " refractive index 1.59)

Then, use the manufacturing installation 80 shown in Figure 10 (a) to make the light diffusing sheet 50 that uses among the embodiment 1.The compression roller 101～103 that constitutes the compression roller crowd 100 of manufacturing installation 80 uses following roller.

Compression roller 101 uses the metal system roller that periphery 101a has been carried out the diameter 450mm of mirror finish.

Compression roller 102 uses the metal system roller of diameter 450mm.On the periphery 102a of compression roller 102, be provided with delustring transfer mold 104.

Compression roller 103 uses the metal system roller of diameter 450mm.On the periphery 103a of compression roller 103, be provided with intaglio plate transfer mold 105.The spacing of the groove that forms on the intaglio plate transfer mold 105 is 250 μ m.

Likewise make the light diffusing sheet 50 that uses among the embodiment with the manufacturing approach of utilizing Fig. 9 and Figure 10 (a) to explain.That is, use temperature in the barrel to be 190 ℃～250 ℃ the 1st extruder 91 and the 2nd extruder 92 melting mixings respectively Resin A and the resin B after, supply to the feed piece 93 of 2 layers of distribution type.Translucent resin A and the amount of translucent resin B put into respectively in the 1st extruder 91 and the 2nd extruder 92 are 100 weight portions.

Then, the resin in the die head 94 coextrusion feed pieces 93 and form 2 layers resin sheet 70 under 250 ℃ of extrusion resin temperature.At this moment, according to the resin that is supplied to feed piece 93 by the 1st extruder 91 becomes substrate layer 51, the resin that supplies to feed piece 93 by the 2nd extruder 92 becomes back layer 52 mode coextrusion.Afterwards, the resin sheet 70 of coextrusion is as described above through compression roller crowd 100.Thus, produce following resin sheet 70: width 1300mm, gross thickness T are 2.0mm (thickness t 1 of substrate layer 51 is that the thickness t 2 of 1.95mm, back layer 52 is 0.05mm), on face 70a, are formed with a plurality of protuberances 53, on face 70b, are formed with micro concavo-convex.At this moment, the surface temperature of compression roller 101 is set at 65 ℃, the surface temperature of compression roller 102 and is set at 77 ℃, the surface temperature of compression roller 103 and is set at 98 ℃.The speed of production of resin sheet 70 is 4.7m/ minute.The resin sheet of so making 70 is cut out according to the mode that is fit to 32 inches liquid crystal indicator 1, obtain light diffusing sheet 50.

< interference stripes evaluation >

Light diffusing sheet of making 50 and liquid crystal panel 10 combinations as the FHD liquid crystal panel constitute liquid crystal indicator 1.Light source 40 is linear light sources.When interference stripes are estimated, as shown in Figure 8, be equipped with the optics membranous part 60 that constitutes by 3 bloomings 61.The blooming 61 that uses all is diffusion barriers.Particularly, use the TSUJIDEN of Co., Ltd. corporate system D121UY/D121UY/D121UZ in order from blooming 61 beginnings of light diffusing sheet 50 sides.Total mist degree of these 3 diffusion barriers, be that the haze value H of optics membranous part 60 is 99.2%.Use the dye technology institute system HM-150 of Murakami K. K., according to the mensuration that JIS-K7136 (ISO 14782) carries out this haze value H.

Make as stated liquid crystal indicator 1 show white that constitutes, in the darkroom from positive and incline direction having or not with the Visual Confirmation interference stripes.Liquid crystal panel 10 is all with the IPS mode activated.

Except that liquid crystal panel 10 be changed to the 32WXGA liquid crystal panel this point, under the condition identical, carry out the visual valuation of interference stripes with the FHD liquid crystal panel.Evaluation result is shown in figure 11.In " interference stripes evaluation " among Figure 11, be expressed as " zero " when not seeing interference stripes, be expressed as when seeing interference stripes " * ".

(comparative example)

In the comparative example, except shown in figure 11 with spacing P _lBe made as 300 μ m this beyond point, likewise make light diffusing sheet with embodiment, the assembling liquid crystal indicator also carries out the visual valuation of interference stripes.Except the spacing of the groove of intaglio plate transfer mold be 300 μ m this point, adopt with embodiment in the same device of the device that uses when making light diffusing sheet 50, likewise make the light diffusing sheet of preparing in the comparative example.The evaluation result of comparative example also is shown in Figure 11.

(comparison of evaluation result)

Shown in figure 11, among the embodiment, based on P _pF, P _pW and P _lThe P that calculates _mF1, P _mF2, P _mW1 and P _mW2 (1)～(4) that satisfy condition respectively.Should explain, in Figure 11, P _mF1, P _mF2, P _mW1 and P _mW2 represent with back two round up and numerical value.On the other hand, in the comparative example, do not satisfy condition (1) and condition (4).And, can be interpreted as: in an embodiment, even a light diffusing sheet 50 makes up the visuognosis that also can suppress interference stripes with FHD liquid crystal panel and WXGA liquid crystal panel.

Should explain, in embodiment and comparative example, show the situation that possesses optics membranous part 60 as stated.Also see interference stripes even optics membranous part 60 likewise is set in comparative example, suppressed interference stripes in an embodiment so can be regarded as.

More than, embodiment of the present invention and embodiment have been described, but the present invention is not limited to the above-described embodiment and examples, can in the scope that does not break away from inventive concept, carry out various changes.

In above-mentioned explanation, the optical element portion that light diffusing sheet 50 has is a protuberance 53 as an example, but optical element portion also can be a recess.In addition, protuberance 53 portions such as optical element such as grade are formed on the face 50b of liquid crystal panel 10 sides, also can be formed on the face 50a, can also be formed on face 50a and face 50b two sides.Light diffusing sheet is illustrated as the light diffusing sheet of 2 layers of structure, but light diffusing sheet also can be 1 layer of structure, can also be the layer structure more than 3 layers.In addition, as the cross sectional shape illustration of protuberance 53 semicircle, but protuberance 53 is so long as produce then not special qualification of shape of the diffusion of light diffusing sheet 50.

As light source 40 illustrations linear light source, but also can use point source of lights such as light emitting diode.When using optics membranous part 60, illustration the haze value H of optics membranous part 60 be 95%～99.9%.But the haze value H of optics membranous part 60 can be 90%～99.9%, can be 80%～99.9% in addition.Should explain that from suppressing the descried viewpoint of interference stripes, the preferred lower limit value is high more good more.

So far explanation with liquid crystal panel 10 as FHD liquid crystal panel or the explanation of WXGA liquid crystal panel.But liquid crystal panel 10 is so long as the pixel count of its short side direction is 1080 or 768 liquid crystal panel gets final product.

Claims (10)

1. a light diffusing sheet is characterized in that, is arranged on the light diffusing sheet of the plane of incidence side of liquid crystal panel,

Possess the 1st of said liquid crystal panel side and with said the 1st opposed the 2nd in one side at least on a plurality of optical element portion that forms,

Each said optical element portion extends in the 1st direction as said liquid crystal panel long side direction, and a plurality of said optical element portion is disposed at and said the 1st direction the 2nd direction of quadrature roughly side by side,

A plurality of said optical element portion is made as P in the spacing of said the 2nd direction _l, said liquid crystal panel is made as L at the width of said the 2nd direction, a plurality of pixels that said liquid crystal panel is had are made as L/N at the pel spacing of said the 2nd direction, and wherein, N is 1080 or 768, L/N ≠ P _l, 0.5 (L/N) ≠ P _l, will be made as P in the interference stripes spacing of the interference stripes of the periodic structure of said the 2nd direction based on a plurality of said optical element portions and a plurality of said pixel _m1 and P _m2, respectively with formula (1) and formula (2) expression P _m1 and P _m2, P _l, L, L/N, P _m1, P _m2 unit is μ m,

$P_{m}1=\frac{\frac{L}{N}\&CenterDot;P_l}{|\frac{L}{N}-P_l|}\&CenterDot;\&CenterDot;\&CenterDot;\left(1\right)$

$P_{m}2=\frac{0.5\frac{L}{N}\&CenterDot;P_l}{|0.5\frac{L}{N}-P_l|}\&CenterDot;\&CenterDot;\&CenterDot;\left(2\right)$

At this moment, said P _lBe the value of relation below satisfying: for said N is the arbitrary value in 1080 and 768, said P _mThe 1st, P _m1＜1500 μ m or P _m1>=10000 μ m and said P _mThe 2nd, P _m2＜1500 μ m or P _m2>=10000 μ m.

2. light diffusing sheet as claimed in claim 1, wherein, said optical element portion is a protuberance.

3. planar light source device; It is characterized in that; Be planar light source device from light to liquid crystal panel that supply with, possess: to the light source portion of said liquid crystal panel output illumination light, and claim 1 that between said light source portion and said liquid crystal panel, is provided with or 2 described light diffusing sheets.

4. liquid crystal indicator possesses: liquid crystal panel, and to the light source portion of said liquid crystal panel output illumination light, and the light diffusing sheet that between said light source portion and said liquid crystal panel, is provided with,

With the pixel count as the said liquid crystal panel of the 2nd direction of the 1st direction quadrature of said liquid crystal panel long side direction be 1080 or 768,

Said light diffusing sheet possess the 1st of said liquid crystal panel side and with said the 1st opposed the 2nd in one side at least on a plurality of optical element portion that forms,

Each said optical element portion extends in said the 1st direction,

A plurality of said optical element portion is disposed at said the 2nd direction side by side,

A plurality of said optical element portion is made as P in the spacing of said the 2nd direction _l, said liquid crystal panel is made as L at the width of said the 2nd direction, a plurality of pixels that said liquid crystal panel is had are made as L/N at the pel spacing of said the 2nd direction, and wherein, N is 1080 or 768, L/N ≠ P _l, 0.5 (L/N) ≠ P _l, will be made as P in the interference stripes spacing of the interference stripes of the periodic structure of said the 2nd direction based on a plurality of said optical element portions and a plurality of said pixel _m1 and P _m2, respectively with formula (3) and formula (4) expression P _m1 and P _m2, P _l, L, L/N, P _m1, P _m2 unit is μ m,

$P_{m}1=\frac{\frac{L}{N}\&CenterDot;P_l}{|\frac{L}{N}-P_l|}\&CenterDot;\&CenterDot;\&CenterDot;\left(3\right)$

$P_{m}2=\frac{0.5\frac{L}{N}\&CenterDot;P_l}{|0.5\frac{L}{N}-P_l|}\&CenterDot;\&CenterDot;\&CenterDot;\left(4\right)$

Under above-mentioned situation, said P _lBe the value of relation below satisfying: for said N is the arbitrary value in 1080 and 768, said P _mThe 1st, P _m1＜1500 μ m or P _m1>=10000 μ m and said P _mThe 2nd, P _m2＜1500 μ m or P _m2>=10000 μ m.

5. liquid crystal indicator as claimed in claim 4 wherein, between said liquid crystal panel and said light diffusing sheet, also possesses and comprises the optics membranous part of a slice blooming at least,

The haze value H% of said optics membranous part satisfies 95≤H≤99.9.

6. the manufacturing approach of a light diffusing sheet; It is characterized in that; It is the method for making following light diffusing sheet; This light diffusing sheet is arranged on the plane of incidence side of liquid crystal panel, have confession a plurality of optical element portion of extending as the 1st direction of said liquid crystal panel long side direction with the 2nd direction of said the 1st direction quadrature on the face of configuration side by side

This manufacturing approach possesses: design the spacing P of a plurality of said optical element portion in said the 2nd direction _lOperation and based on the said spacing P that is designed _l, form a plurality of said optical element portions in the one side that has transmittance and become the plate body of said light diffusing sheet and make the operation of said light diffusing sheet, wherein, P _lUnit be μ m,

At the said spacing P of design _lOperation in, when said liquid crystal panel is disposed said light diffusing sheet, said liquid crystal panel is made as L at the width of said the 2nd direction; A plurality of pixels that said liquid crystal panel is had are made as L/N at the pel spacing of said the 2nd direction; Wherein, N is 1080 or 768, L/N ≠ P _l, 0.5 (L/N) ≠ P _l, will be made as P in the interference stripes spacing of the interference stripes of the periodic structure of said the 2nd direction based on a plurality of said optical element portions and a plurality of said pixel _m1 and P _m2, respectively with formula (5) and formula (6) expression P _m1 and P _m2, P _l, L, L/N, P _m1, P _m2 unit is μ m,

$P_{m}1=\frac{\frac{L}{N}\&CenterDot;P_l}{|\frac{L}{N}-P_l|}\&CenterDot;\&CenterDot;\&CenterDot;\left(5\right)$

$P_{m}2=\frac{0.5\frac{L}{N}\&CenterDot;P_l}{|0.5\frac{L}{N}-P_l|}\&CenterDot;\&CenterDot;\&CenterDot;\left(6\right)$

Under above-mentioned situation, with said P _lConfirm as the value of relation below satisfying: for said N is the arbitrary value in 1080 and 768, said P _mThe 1st, P _m1＜1500 μ m or P _m1>=10000 μ m and said P _mThe 2nd, P _m2＜1500 μ m or P _m2>=10000 μ m.

7. method as claimed in claim 6, wherein, the operation of making said light diffusing sheet comprises:

Make operation through extrusion molding as the resin sheet of said plate body,

In the one side of said resin sheet, push the said spacing P that has with to be designed _lThe opposite mould of a plurality of said optical element portion of configuration is as the roller of transfer mold, and with said transfer mold be transferred to said one side operation and

Cutting out transfer printing has said transfer mold and is formed with the regulation zone of the said resin sheet of a plurality of said optical element portion in said one side, and forms the operation of said light diffusing sheet.

8. the manufacturing approach of a liquid crystal indicator is characterized in that, possesses:

To have confession a plurality of optical element portion that the 1st direction is extended with the 2nd direction of said the 1st direction quadrature on side by side the operation that designs of the light diffusing sheet of the face of configuration, promptly design the spacing P of a plurality of said optical element portion in said the 2nd direction _lOperation, P _lUnit be μ m,

Based on the said spacing P that is designed _l, the one side that has transmittance and become the plate body of said light diffusing sheet form a plurality of said optical element portions and make said light diffusing sheet operation and

The operation that between liquid crystal panel and light source portion, disposes the said light diffusing sheet of manufacturing and assemble liquid crystal indicator according to the consistent mode of the long side direction of said the 1st direction and said liquid crystal panel,

Said liquid crystal panel is 1080 or 768 at the pixel count of said the 2nd direction,

At the said spacing P of design _lOperation in, said liquid crystal panel is made as L at the width of said the 2nd direction, a plurality of pixels that said liquid crystal panel is had are made as L/N at the pel spacing of said the 2nd direction, wherein, N is 1080 or 768, L/N ≠ P _l, 0.5 (L/N) ≠ P _l, will be made as P in the interference stripes spacing of the interference stripes of the periodic structure of said the 2nd direction based on a plurality of said optical element portions and a plurality of said pixel _m1 and P _m2, respectively with formula (7) and formula (8) expression P _m1 and P _m2, P _l, L, L/N, P _m1, P _m2 unit is μ m,

$P_{m}1=\frac{\frac{L}{N}\&CenterDot;P_l}{|\frac{L}{N}-P_l|}\&CenterDot;\&CenterDot;\&CenterDot;\left(7\right)$

$P_{m}2=\frac{0.5\frac{L}{N}\&CenterDot;P_l}{|0.5\frac{L}{N}-P_l|}\&CenterDot;\&CenterDot;\&CenterDot;\left(8\right)$

Under above-mentioned situation, with said P _lConfirm as the value of relation below satisfying: for said N is the arbitrary value in 1080 and 768, said P _mThe 1st, P _m1＜1500 μ m or P _m1>=10000 μ m and said P _mThe 2nd, P _m2＜1500 μ m or P _m2>=10000 μ m.

9. method as claimed in claim 8, wherein, in the operation of the said liquid crystal indicator of assembling, further configuration contains the optics membranous part of a slice blooming at least between said liquid crystal panel and said light diffusing sheet,

The haze value H% of said optics membranous part satisfies 95≤H≤99.9.

10. like claim 8 or 9 described methods, wherein, the operation of making said light diffusing sheet comprises:

Make operation through extrusion molding as the resin sheet of said plate body,

In the one side of said resin sheet, push the said spacing P that has with to be designed _lThe opposite mould of a plurality of said optical element portion of configuration is as the roller of transfer mold, and with said transfer mold be transferred to said one side operation and

Cutting out transfer printing has said transfer mold and is formed with the regulation zone of the said resin sheet of a plurality of said optical element portion in said one side, and forms the operation of said light diffusing sheet.

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