WO1996005466A1 - Planar light source using light diffusing sheet - Google Patents

Planar light source using light diffusing sheet Download PDF

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Publication number
WO1996005466A1
WO1996005466A1 PCT/JP1995/001608 JP9501608W WO9605466A1 WO 1996005466 A1 WO1996005466 A1 WO 1996005466A1 JP 9501608 W JP9501608 W JP 9501608W WO 9605466 A1 WO9605466 A1 WO 9605466A1
Authority
WO
WIPO (PCT)
Prior art keywords
light
surface
sheet
height
light source
Prior art date
Application number
PCT/JP1995/001608
Other languages
French (fr)
Japanese (ja)
Inventor
Michiko Takeuchi
Toshikazu Nishio
Taiji Ishii
Original Assignee
Dai Nippon Printing Co., Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to JP6210694 priority Critical
Priority to JP6/210694 priority
Application filed by Dai Nippon Printing Co., Ltd. filed Critical Dai Nippon Printing Co., Ltd.
Priority claimed from US08/619,623 external-priority patent/US5944405A/en
Publication of WO1996005466A1 publication Critical patent/WO1996005466A1/en

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Classifications

    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS, OR APPARATUS
    • G02B6/00Light guides
    • G02B6/0001Light guides specially adapted for lighting devices or systems
    • G02B6/0011Light guides specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033Means for improving the coupling-out of light from the light guide
    • G02B6/005Means for improving the coupling-out of light from the light guide provided by one optical element, or plurality thereof, placed on the light output side of the light guide
    • G02B6/0051Diffusing sheet or layer
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS, OR APPARATUS
    • G02B5/00Optical elements other than lenses
    • G02B5/02Diffusing elements; Afocal elements
    • G02B5/0205Diffusing elements; Afocal elements characterised by the diffusing properties
    • G02B5/021Diffusing elements; Afocal elements characterised by the diffusing properties the diffusion taking place at the element's surface, e.g. by means of surface roughening or microprismatic structures
    • G02B5/0215Diffusing elements; Afocal elements characterised by the diffusing properties the diffusion taking place at the element's surface, e.g. by means of surface roughening or microprismatic structures the surface having a regular structure
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS, OR APPARATUS
    • G02B5/00Optical elements other than lenses
    • G02B5/02Diffusing elements; Afocal elements
    • G02B5/0205Diffusing elements; Afocal elements characterised by the diffusing properties
    • G02B5/021Diffusing elements; Afocal elements characterised by the diffusing properties the diffusion taking place at the element's surface, e.g. by means of surface roughening or microprismatic structures
    • G02B5/0221Diffusing elements; Afocal elements characterised by the diffusing properties the diffusion taking place at the element's surface, e.g. by means of surface roughening or microprismatic structures the surface having an irregular structure
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS, OR APPARATUS
    • G02B5/00Optical elements other than lenses
    • G02B5/02Diffusing elements; Afocal elements
    • G02B5/0273Diffusing elements; Afocal elements characterized by the use
    • G02B5/0278Diffusing elements; Afocal elements characterized by the use used in transmission
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS, OR APPARATUS
    • G02B6/00Light guides
    • G02B6/0001Light guides specially adapted for lighting devices or systems
    • G02B6/0011Light guides specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033Means for improving the coupling-out of light from the light guide
    • G02B6/0035Means for improving the coupling-out of light from the light guide provided on the surface of the light guide or in the bulk of it
    • G02B6/0038Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS, OR APPARATUS
    • G02B6/00Light guides
    • G02B6/0001Light guides specially adapted for lighting devices or systems
    • G02B6/0011Light guides specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033Means for improving the coupling-out of light from the light guide
    • G02B6/005Means for improving the coupling-out of light from the light guide provided by one optical element, or plurality thereof, placed on the light output side of the light guide
    • G02B6/0053Prismatic sheet or layer; Brightness enhancement element, sheet or layer
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS, OR APPARATUS
    • G02B6/00Light guides
    • G02B6/0001Light guides specially adapted for lighting devices or systems
    • G02B6/0011Light guides specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0065Manufacturing aspects; Material aspects

Abstract

A planar light source used as a back light source has a light guide plate (1), a light source member (3), a light diffusing sheet (8), a lens sheet (4) and a transmitting display element (6). The light diffusing sheet (8) comprises a transparent base material not containing particles of a light diffusing agent, the surface of the sheet (8) having fine random recesses and projections (41), this finely recessed and projected surface having a roughness of not less than the wavelength of the light from the light source and not more than 100 νm. The light diffusing sheet is made so that, when a cumulative frequency distribution curve of the height of these fine recesses and projections (41) is drawn by taking a percentage of the cumulative frequency distribution of the height of the fine recesses and projections (41) on a vertical axis and the height of the fine recesses and projections on the horizontal axis, the mentioned curve has a projecting portion curved toward a lower portion of the coordinates with an average value of the heights of the fine recesses and projections larger than a median value thereof. If a surface light source is made in this manner, light of a uniform and high brightness is emitted in a desired angular range alone, and surface emission with no unevenness of brightness in different parts of the plane is obtained.

Description

Surface light source art using bright 钿 嘗 light diffusing sheet

The present invention is a backlight of the transmissive display device such as a liquid crystal display ^ S, lighting advertising relates to useful surface light source ΐ $ ξΜ signs, etc., more particularly to a surface light source using the light diffusion sheet.

BACKGROUND

Conventionally, as a surface light source for a backlight used in a liquid crystal display device (LCD), etc., it is known as follows.

The first method, Etsujirai Bok was sexual flat light guide member: ^; things are known. In such ^ a surface light source used to ¾, light from or one side end surface of the transparent ^ lightguide comprising a flat plate is λ ί, ^:! To take advantage of total internal reflection flat plate guiding light is universally propagated to the entire region of the optical plate, and summer to release its propagation was light ~ ¾ a light guide ¾® light diffusing elevation critical angle less than Shako and without in plate, the expansion tfc¾ from the surface of the light guide plate ( Japan Kunizane HirakiAkira 5 5 1 6 2 2 0 No. 1).

The surface light source of the second ^], has on one side ^, a lens sheet in which the other surface and the smooth surface, before Iotakushi ^ - Bruno ^; on the surface of the light guide plate of the surface light source of those, Again the Hanaremen above, by using light focusing action of the lens, the expansion tfc¾ Shako what was to diffuse isotropically uniform within a desired angular range (Japanese real No. 4 one 1 0 7 2 0 No. 1) there is.

Furthermore, said Renzushi - bets, when dispersing the light diffusing agent particles such as T io 2 used in combination with adefovir extinguishing transparent diffuser extinguishing transparent sheet) formed by the transparent resin, a single, vanishing Ade only transparent diffuser that used by laminating a light guide (U.S. Patent No.

4 7 2 9 0 6 7 No., Japanese Sho 6 1 5 5 6 8 4 No.) than the light source of the light Eneru ghee is intensively distributed by the desired limited angular range, and, its within angular range are also known to expand f fe highly uniform isotropy can be obtained.

However, in the conventional art described above, as in the first method, but only providing the light scattering plate for guiding the light 颠, with respect to the normal direction of the emission light is the light guide surface 6 0 degree angle would be relatively sharp distribution peak of Ru is the brightness is the most '¾g | and luminance mosquito 环足 direction (front direction), light energy force exactly Ie ^ without lateral , a phenomenon in which the 'reading was seen.

Further, in the prior art, such as the second scheme, a lenticular lens disposed the unit lens section of the triangular pillar prism in the light emitting plane of the light guide to many ^ when edge layer as Ren Zushito the is the light energy ratio or Kunar released in 3 0 '~ 6 0 ° in angle around the ^ direction ¾ exit surface forces, in fact, part of the 2 to 4 c MGG from the light guide plate side end until even is a high brightness, it J ^ LS seat mow the gradual luminance is lowered, the end of the light source and the opposite side there ^ is that darkened noticeably.

In addition, in the case where the attractive consumption transparent expansion I ^ is, because the light diffusion t ^ j particles of the diffusion plate in absorbs the light, P «¾ that the light energy is produced ^ also been filed.

Ρ that further, the equal thickness fringe of such Newton rings generated by light bonding of the lens sheet and the light guide plate surface. ¾ ^ it was also.

These points ^ Subeku,

1. Japanese Patent Laid-1 one 2 4 5 2 2 0 No., actual Hei 6 - 1 5 0 0 good urchin described in No. 8, the pattern shape of a halftone dot such light diffusing SL¾ morphism layer of the light guide ¾® and then, and smaller the closer the ®¾t of the pattern to the light source, thereby greatly enough away from the light source light; correcting the luminance distribution in an attempt to equalize,

2. Japanese Patent 3 - 9 3 0 6 No. to correct the luminance distribution of using a light source within the light guide ¾® on two places or more of the side end portion of the light guide plate as described, attempts to equalize , 3. as in Japanese JP 6 2 3 2 2 6 JP etc., on the surface or back surface of the light guide plate, the linear prism rows that partially reflecting partially transmitting light (prismatic Renchikiyura first lens ) were engraved, and corners of the prism surface, the thickness of the light guide plate is varied depending on the location, the light guide plate over the entire surface, an attempt to obtain an output light having a substantially uniform luminance and direction and the like has been made both full it is difficult to equalize the brightness, for example, there are l drawback called himself first dot of the light diffusing morphism layer when viewed from the light emitting surface side intended from being transmitted visible, also, hen himself than those of 2 was also disadvantage of space and consumption am¾ of light or the like positions 置全 body becomes twice J¾ ±.

For those of the three, the force of the light guide plate, 'becomes complicated, on the design and manufacture is extremely difficult to completely dot of light 拡贩 morphism layer ^! That it or t arbitrariness that visualization ^ is rarely 0

An object of the present invention is to solve the problems ^ s beauty ^^ described above, consumption power, outgoing, ^ tm without increasing the size of the location, uniform and high brightness ¾ only within a desired angular range ^ achieved, ^: is the child provides no variation surface light source luminance depending on the location in the plane.

Disclosure of the Invention

According to the present invention, the object is made of a transparent substrate containing no light particles, having a random fine irregularities on the surface, the fine small irregularities wavelength £ Lh of the source light, Ι Ο Ο μ πι following surface is roughness, depicting the percentage of the cumulative frequency distribution of the height of the fine small irregularities on the vertical axis, the cumulative ¾ ^ ^ cloth curve in height between the connexion fine small irregularities on the horizontal axis the height of the fine irregularities and a to come, it becomes convex curve downward of 該累 away number distribution curve coordinates, and, achieved by the average value of the height of the small irregularities surface light source using the optical sheet is larger than the intermediate value It is.

On ^: diffusion sheet, provided with ¾S on «exit face of the light guide having at least the light guide body or body cavity of an optical flat plate having a layer morphism a light source arranged and S® on one surface of the side end surface be able to.

The upper S ^ Ffitic sheet, the light source is housed within the rear and your image covering ^ morphism previous remarks himself windows run Puhausu with the configuration window to the front of the light source is open and has a wall surface of the light source It may be provided so as to cover.

When said light guide is made of sexual flat plate, it is possible to make the light guide surface and the plane having a wavelength less surface roughness of the source light.

On the previous remarks sheet, convex or concave one ^ alkylene; column sheet or two ^ Reference column sheet can be ¾®. Further, the ¾m sheet can be ¾s similar separate diffusion sheet.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a perspective view showing an example of a type display device using an edge light type surface light source of the present invention.

2, Oh a perspective view showing an example of a permeable shows apparatus using a direct type surface light source of the present invention.

Figure 3 is an example cross-sectional view of the edge light type surface light source of the present invention, showing a case of forming a group on the light diffusing sheet B.

Figure 4 is a perspective view showing an example of a lens sheet used in the present invention.

Figure 5 is a perspective view showing another example of a lens Sea Bok used in the present invention.

Figure 6 is a perspective view showing still another example of the lens sheet used in the present invention. Figure 7 is a perspective view showing another example of the lens sheet used in the present invention.

Figure 8 is a perspective view showing a "^ when the lens sheet used in the present invention is a two roots.

9, to proceed toward the inside of the light guide plate to the outside, Ru sectional view showing an o

Figure 1 0 is a sectional view showing that the light guide plate exuded by tunneling ^ is traveling waves again in the lens sheet.

Figure 1 1 is, in case of using the light rat sheet of the present invention, traveling toward the light guide plate to the outside but is totally reflected part is a sectional view showing that part. Figure 1 2 is a diagram showing an example of a manufacturing method of an optical super sheet of the present invention.

Figure 1 3 is a perspective view showing an example of the light diffusing sheet of the invention made by the method shown in FIG 2.

1 4 is a cross-sectional view of Etsujiraito type surface light source of the prior art, showing a case where no lens sheet.

Figure 1 5 is a perspective view of a prior art edge-light type surface light source, showing a case where a force sliding plane Les Nzushi one preparative ^ and.

Figure 1 6 is a cross-sectional view of FIG 5.

1 7 takes Te ^ ^ odor to ® the optical sheet ^ according to the invention, the surface roughness Tatehe, i.e. ^! Of the percentage of the depth R cumulative ¾ ^ distribution of valleys, the horizontal axis surface roughness, i.e. a view showing a cumulative frequency distribution curve f (R) in the case were convex depth R of the valley of ^ Si.

Figure 1 8 is a cross-sectional view of a mold having the characteristics of cumulative S ^ cloth curve f A (R) of FIG 7.

Figure 1 9 is a cross-sectional view of the characteristics with ^ !! ^ !! in FIG 7 of the formation 献数 distribution curve f B (R).

2 0, when subjected to chromium mat plated to use roll ^ 凹麵, an under Katsuhito ^ K formed by metal chromium micro bunching (spherical) particle assembly is a sectional view schematically showing.

2 1, ^ the height of the optical sheet according to the present invention, i.e. the optical M: shea one Bok surface roughness, and with respect to its distribution, the vertical axis in the surface roughness, i.e. cumulative height R of the mountain ¾¾ ^ takes a percentage of the fabric, the surface roughness on the horizontal axis, i.e. in the mountain height R a convex was cumulative release number distribution curve ί (R), a convex or below 該累 positions cloth curve, the average value ≥ middle is a diagram showing a case also meet the relationship of values.

2 2 is a partially enlarged measuring Fig was that the light sheet and standing ^ <spoon with cumulative distribution characteristic of FIG 1.

2 3, the present invention due to light ¾¾ Sea Bok of the height, i.e. the light ¾m surface roughness of the sheet, and for its distribution 忧態, the vertical axis in the surface roughness, i.e. the mountain height R of the formation fabric taking the percentage, the horizontal axis in the surface roughness, i.e. in the height R of the mountain was convex cumulative frequency distribution curve ί (R), is convex to the cumulative frequency distribution curve f 吓, the relationship between the average value ^ median it is a diagram showing a case where is satisfied.

2 4 is a partially enlarged measurement diagram ized stereoscopic optical sheet one bets ¾g with cumulative ¾ ^ number distribution characteristic of FIG 3.

2 5 ^ of the height of the light ¾m sheet according to the present invention, that is, the surface roughness of the light diffusing sheet, and for its distribution 优態, the vertical axis in the surface roughness, i.e. cumulative height R of the mountain Personal Protection for First Aid or Rescue Personnel ^ taking the percentage of the fabric, the horizontal axis in the surface roughness, i.e. the height R of the mountain convex was cumulatively ¾¾¾ ^ in cloth curve f (R), a 5 2% of the average force rather ^ values ​​of R, and cumulative StSlfc ^ If the convex portion and the upper cloth curve or "T is made from a portion of the convex Oh a diagram showing a ^) o

2 6 is a partially enlarged measuring ¾61 view of an optical ¾¾ sheet ^ turned into stand with cumulative ¾ ^^ fabric properties in FIG 5.

2 7 ^^ the height of the optical sheet according to the present invention, that is, the surface roughness of the light sheets, and for its distribution 忧態, the vertical axis in the surface roughness, i.e. cumulative ¾¾ number distribution of the height R of the mountain take percentage, the horizontal axis in the surface roughness, i.e. in the height R of the mountain was convex Formation ¾¾¾ distribution curve f (R), is a diagram illustrating a case where 該累 ^ cloth curve has become Ei ^ .

2 8 is a partial expansion of ¾g light ¾t¾ sheet without that the edges of the right-angled isosceles triangle cross-section with a cumulative frequency distribution characteristic of FIG 7; a ^ visual view.

2 9, the height of the light diffusing sheet of the protrusion according to the present invention, that is, the surface roughness of the light diffusing sheet, and with respect to their distribution t condition, the surface on the horizontal axis roughness, i.e. cumulative ¾ of the height R of the mountain ^ ^ takes a percentage of the fabric, the horizontal axis in the surface roughness, i.e. the height R of the mountain in convex was cumulatively ¾ ^ ¾ distribution curve ί (R), 該累 number distribution curve ~ ^ above the convex, the ~ arr it is convex, a diagram and illustrates a case where the average value <an intermediate value.

3 0 is a stereoscopic phased partial enlarged measuring ¾ ^ figure of the light diffusing sheet ^ with cumulative ¾¾ number distribution characteristic of FIG. 2 9 0

3 1, the height of the protrusions of the light diffusing Sea Bok according to the invention, that is, the surface roughness of the light diffusing sheet, and for its distribution 忧態, the vertical axis in the surface roughness, i.e. cumulative height R of the mountain ¾¾ taking the percentage of the fabric, the horizontal axis in the surface roughness, i.e. the cumulative ¾ was convex height R of the mountain ^ number distribution curve f (R), a convex curve below over 該累 number distribution curves force "the entire If is a diagram illustrating a.

3 2 is a partially enlarged measurement diagram ized standing iffi the 3¾g light diffusing Sea Bok with cumulative ¾¾ number distribution characteristic of FIG 1.

Figure 3 3 is an angle distribution diagram of the emitted light luminance of the surface light source (^ Example 9, mi of the present invention.

3 4, the angle distribution diagram of the emitted light luminance of the surface light source Example 8) of the present invention.

BEST MODE FOR CARRYING H¾ the invention

Hereinafter, a surface light source according to the present invention, and a display device using the same, reference to be described.

Figure 1 shows an edge light type surface light source according to the present invention. In the figure, 1 represents a light guide plate, the light guide plate 1 is made from a solid over flat plate. The light source on a side end face of the light guide plate 1, for example, linear light source 3 is provided along it. Behind the light source 3 anti Ikyo 5 is provided. The light emitted from the light source 3, directly or is reflected by the reflecting mirror 5 enters the inside of the light guide plate 1, for example, the internal reflection, as shown in FIG. 3, or direct outside from the light guide plate 1 It is released to. The rear surface of the light guide plate 1 picolinimidate 2 is eclipsed set. Opposite face and Personal Protection for First Aid or Rescue Personnel * layer 2 of the light guide plate 1 is formed as ^ exit surface.

Light ¾m sheet 8 is provided in contact with the exit surface, the light emitted through the ^ ¾ exit face is 3ϋ light sheet 8. Light ^^ optical sheet 8 is 删 over type display device 6 ¾ @ the lens sheet 4. Between the light-diffusing sheet 8 and the light guide plate 1, and optical SSI! [Void 9 forces between the sheet 8 and the lens sheet 4 'is formed. On the surface of the sheet 8 facing these gaps 9, ^ 4 1 force later, 'is formed. The light guide plate 1, instead of a solid, can be hollow. In this case, exit face and the surface in contact with the I屬 2 real light guide plate 1 in the respectively l¾ shape is between is a rectangular parallelepiped cavity.

The straight-T plane light source shown in FIG. 2, the light source 3 is a line or ^ source, are housed in lamp house 5. Ranpuno, mouse 5 covers the back ^ ¾ beauty side of the light source 3, and functions as a reflecting surface for reflecting light toward the optical sheet 8 from the light source 3.

1 and 2, 1 0 0 generally designates a surface light source, 2 0 0 generally showing a display device.

According to the present invention, 1 random minute irregularities positions on the entire surface of the light-diffusing sheet 8 (e.g. grain 觀, satin finish, etc.) be one obtained by forming a said micro-irregularities of the source light Hachosha, 1 0 0; with um below the surface roughness. The percentage of cumulative distribution of the fine small irregularities of the height in the vertical axis, when depicting the height of the fine small irregularities and on the horizontal axis of the go-between fine small irregularities the height of the cumulative ¾ ^^ cloth curve, 該累 ¾ ^ number distribution curve becomes a curve that includes a convex portion toward the lower side of the coordinates, and, is larger than the intermediate value of the average value pixel of the height of the fine small irregularities.

Light-diffusing sheet 8 for use in the present invention is formed from 體材. As here ttS material, poly (meth) acrylate (where where (meth) acrylic acid, acrylic IK is the same used. The following meanings of methacrylic acid.), Po Li (meth) alone or co-polymer of (meth) acrylic acid esters such as Echinore acrylate, polyethylene terephthalate evening or polybutylene terephthalate Polje ester of polycarbonate, polystyrene, thermoplastic resin such as polymethyl pentene butter, some ^, ultraviolet or electrodeposition on by connexion crosslinking-cured transparent ultraviolet or electrostatic ¾ | hardening resin, transparent glass such, transparent ceramic box, etc. force "is used.

The ultraviolet or electrostatic ^ curable resin, (meth) Akuriroiru group in (meth) § methacryloyl Ruo carboxymethyl heavy ^ ft unsaturated bond such as group or Pureborima to have a epoxy group, oligomers, and z or were mixed monomer appropriately * ^ things can be used. Incidentally, throughout this specification incense, (meth) Akuriroiru is used in the sense of § click acryloyl or Metakuriroiru.

These Pureborima, as the oligomer, urethane (meth) Akurireto, polyester (meth) Akurireto, epoxy (meth) Akurireto etc. Akuri rate, unsaturated polyesters, and the like.

Further, examples of the monomer, Jipentaerisuri Torupen evening (meth) Akurire, tri trimethylolpropane tri (meth) Akurireto the like.

Some of these materials, unlike the conventional light diffusion FCS (US 4 7 2 9 0 6 7 No., etc.), it is important that at all does not contain a light ffitfciJ particles.

Additional 3 ^ ¾§ material, in the case of light-diffusing sheet 8 for edge light type surface light source typically uses those 5 to 2 0 0 // thickness of M¾g.

Further, when used in a direct type surface light source, the light-diffusing sheet 8 itself is able to support its own weight or an external force, ^ is the thickness of 1 to 1 O mmmg not to occur.

Further, the light 赚 sheet 8 may be a single layer structure as shown in FIG. 1, two-layer structure as shown in FIG. 1 3, or may be a multilayer structure of three layers £ Lh. The above optical sheet 8 surface, wavelength J¾ ± a height of source light, 1 0 0 // m 4 1 was made Te following infinitesimal irregularities, ^ fetts material embossed pressurized E on the surface by heat pressing, be directly formed by sandblasting process or the like, or it is possible to produce other, ^ has a projection 4 1 on the flat surface of the wood: in cowpea to form the material layer is also possible. Specifically, Japanese Patent 5-

1 6 9 0 1 5, U.S. Patent No. 4 5 7 6 8 5 0 No. etc. disclosed that by Roles ^ and the ultraviolet or electrostatic ^ with a curable 榭脂 ^: resistance of the substrate film 1 2 of the surface ^ 4 1 the better to β ^ Ι '^ used.

Wei 4 1 formed on the light-diffusing sheet 8, in addition to be isotropic diffusion transliteration light, between the smooth flat 1 0 and the light-diffusing sheet 8 of the surface of the light guide plate 1 as shown in FIG. 3 and, Roh or, Ru object der be gaps 9 of the wavelength of the source light (the dimension delta chi) at least partially formed between the smooth flat 7 ¾® the ¾¾¾ sheet 8 of the lens sheet 4. As to gap light total reflected power of a smooth plane 1 0 of the light guide plate 1 that it waves full of source light, 'sufficiently no longer occur, ¾ £ 4 1 height of unevenness 1 0 0 m Exceeded by is disadvantageous become uneven shape of the protrusions 4 1 is conspicuous in the case of.

As long achieved objective force of the, ¾G4 1 is may be any irregularities, the most uniform luminance distribution and or points get these in uniform luminance angular ft ^ cloth and light 21® in a desired diffusion angle preferred embodiment, fine irregularities positions at random on the surface of the light 赚 sheet 8 (eg if grain 觀, satin finish, etc.) is obtained by forming on the entire surface, yet wavelength 1 0 0 m of the fine small irregularities source light or less of the surface roughness. Typically, the vertical axis represents the percentage of the cumulative distribution of the height of the good sea urchin fine small irregularities in Figure 3 1, RuiHanare cloth curve of in a go-between fine small irregularities in the height horizontal axis the height of the fine small irregularities when painted, 該累 away minutes fabric curves force, downward of 'coordinate it becomes a curve comprising a portion of the convex, and the average value of the height of the fine small irregularities becomes larger than the intermediate value it is obtained by forming manner.

With this manner, the light L 1, L 2 S or the like color λ! Ί light-diffusing sheet 8 as shown in FIG. 3, isotropically light acts as 該雜 group 4 first force "Light to diffuse the incident light will have a uniform angular distribution, high luminance surface light source can be obtained with high quality without the conspicuous Mataami punctate pattern.

Further, the group 4 1 shape 2 2, as shown in FIG. 2 4, or 1 8, ^ 1 9; as shown manner, be made narrower in accordance recesses go valley preferable. For example 該魏 group 4 1 cross section sinusoidal curve is randomly changed cycle amplitude such as to each period Saikuroido curve, or sand blasting, by mill engraving or the like, random, and there in cross-section curve valley has decreased narrow Te, the distance between the depth and the adjacent protrusion tangent is more than the wavelength of the source light, not more than 1 0 0 ^ m, and to ®ϋ a fine concavo-convex pattern so as to satisfy the cumulative frequency distribution numbers condition of the. Such shapes, angular distribution of the average "· ½ of the transmitted light, the transmittance of the height, to such, from the total reflection of a point such as Do at the interface of the light guide plate surface and the optical sheet ^ in F is there.

Moreover, such a job is the aforementioned JP-5 - when adopting a SSi i method of after curing to the, as in the method of 1 6 9 0 1 5 JP words may be a thing of the missing. In other words, ¾ϊϋ force ^ ability of the medium to spread the I and ^ !! recess, Moshiku is because the ®ϋ.

As a method for forming the light ¾ f [sheet 8, for example, ¾Y method, hot pressing method

(曰本 Kunitoku HirakiAkira 5 6 - 1 5 7 3 1 0 JP SL, the After embossing by roll embossing to the thermoplastic resin film of the ultraviolet curable, method of curing the film by irradiating ultraviolet rays ( Japanese Sho 6 1 - 1 5 6 2 7 3 JP SL, ultraviolet or electrostatic ^ curable resin is applied to the roll ^ ± that engraved lens shape by filling the concave portion, through said resin i state roll ^ in: in either irradiated with ultraviolet rays from the back of the coated transparent substrate film film, and then irradiated with ultraviolet rays to cure the resin after 1® transferred to a transparent substrate film and cured resin ! ¾ it is a substrate film adhered from the roll ^ !! |, and roll ^ how to ® lenses dish cured resin layer (Japanese Patent Laid 5 - 1 6 9 0 1 5, U.S. Patent can have use the fourth 5 7 6 8 5 0 No. etc.) and the like.

Lens sheet 4 used in the present invention, for example, the direction the unit lens 4 2 of the prism body as shown in FIG. 4 ^ a manner | Personal Protection for First Aid or Rescue Personnel and by arranging 1 comprising ¾Yi: Len E Retsushi over preparative (broad lenticular lens), or hemisphere or the like around as shown in FIG. 5 is a Second lens array sheet over bets and formed by a so-called eye lens Wadakama is used.

Here the unit lens 4 circles as 2 cross-sectional shape, elliptical, cardioid, oval Rankin, Saikuroido or Inboriyuto continuous smooth curve, such as curve, some have triangular, square, or hexagonal, etc. Multi rectangular portion or used whole.

These unit lenses may be such concave of such convex or 7, in FIG. Among these, preferred are designed, ease of manufacture, the light ^ characteristics lack of (half-value angle, the luminance peak of which can be the side lobe light Me direction), isotropic within half angle luminance, I¾y direction a cylindrical or elliptical cylinder from the viewpoint of the luminance). Particularly normal direction long axis Natsuta elliptical cylinder surface light source, the brightness or Ku preferred.

These lens sheet can also be used in the l ti ¾ formation but two directions (± downward, lateral direction) using the columnar lenses two lenses as shown in FIG. 8 in order to control the light diffusion angle of the seat, the, may be ¾S to S¾. In this case, Ren ® orientation those forces were also two in the same direction as shown in FIG. 8, '^! Is a over-sex or K most good good, ^ υϋ lens of each lens sheet facing against ( Ren ® may be sandwiched between is) as between the two lens sheets.

The lens sheet 4 is formed of ^ ¾¾S material. Here ^: The ¾S material, can be used a material similar to that of the light-diffusing sheet 8 described above. Typically, thermoplastic resins such as acrylic or polycarbonate, ultraviolet or electrostatic ^ curable (meth) § acrylate shelves effect or the like is used.

Additional ^: ½¾ material, when used as a lens sheet, typically, 2 0 to 1 OO To.

^: As good as high resistance required to substrate, but no light is most preferable, when used as a lens sheet, a light wearing feS some applications, bran consumption transparent or adefovir may be erased translucent .

Here, the absolute consumption transparent refers to a property of the ¾ light substantially uniformly ^ isotropically in all directions in a half solid angle, for use in an optical isotropic diffusing synonymous. In other words, absolute The extinguishing, transparent an angle between ^ direction of the surface of the ½s material when the ų, transmission in when brought into λ! Ί the f light beam from ί® (Λ ί angle i = O e) c 0 s distribution light ¾ ^ angular distribution I G .Θ) is expressed by the following equation,

1 ° (the = de m -cos - 90. ≤0≤9 Ο β

(Where 0 is' ^ the angle formed by the Ν, I 0 mp the direction of ¾ @ light,)

Or means that the similar distribution to that.

The light guide plate i.e. light guide used in the present invention, a flat plate of a transparent material, or both of the flat transparent material having a body cavity can be used. And power, and, also in order to universally distributed throughout light guide light source light by utilizing total reflection at the light guide body portion, also in order to give ¾S for supporting the light diffusion sheet 8, transparent it is good preferable to use a plate material.

For the above reasons, in the present invention are use the plates were created in the light guide plate of transparent material 1 (FIG. 1). Opposite surface 10 of the light scattering reflection employment of the light guide plate 1 is a plane, finishing the surface roughness than the wavelength of the source light. Surface roughness as referred to herein have to evaluate the average value of the difference between the crest and the valley portion of 5¾g group rather than the average, such Rashi value of Gigun (irregularities), for example, JI SB-0601 or Ru is measured in ten-point average roughness Rz and the like of the I SO standards. Normally, the light from the light source is allowed ^^, its wavelength is 4-0 8 0.5;. Since Ru um der, surface roughness and 0. 4 um or less. As for the distance between ^ protrusion is evaluated by the average value of the unevenness such as the mean spacing S m of IS 0 standard. ^ Approach as ί ±± gel method in this for roughness, for example, heat pre-scan of the parent faceplate, injection using a form of specularity, (casting) Rise, performed by a lens or the like t Ru Precision use the polishing or the like, is it good, 0

As the material of the light guide plate 1, the lens Sea Bok materials similar: to choose from δ¾ material. Usually, an acrylic resin having a thickness of 1 to 1 O MMSS; is polycarbonate Ichito 榭脂 plate or the like is used.

The light source 3 used in the present invention is preferable in terms of linear light sources of fireflies ^^ like to obtain the luminance of the entire surface uniformly, such as incandescent bulbs; ^: It is also possible to use a source. Light source 3 is in addition provided to isolate the outer side edge of the light guide plate 1 as shown in FIG. 1, the side end portion of the light guide plate 1 or a through-hole, or a portion of the side edge provided notches, part of the light source or it is also such that Sl¾ the entire inside of the light guide plate.

In terms of average improvement in improving the luminance in-plane distribution of luminance, it is also possible to 增設 to another light source 3 '(not Shimese Figure) the other side edge portion opposing the light guide plate 1 a. The number of the light sources is even one as in FIG. 1, or may be two or more as shown in FIG. Of course, 2 ®m2U in the such edge light type surface light source Figure 1: but it may also be arranged to the light source on a side end face of the o

Those known as the reflecting mirror 5, for example parabolic pillars, hyperbolic pillar, member of such elliptic cylinder, those having a thin metal film by vapor deposition or plated like an inner surface which is recessed with a plate or the like is used.

On the smooth plane 1 0 of the light guide plate 1, by laminating the light ¾f Nto 8, further its ¾ lens sheet 4 on the light sheet 8) g to. At that time, the lens ® Len Zushito 4 as in Figure 3 on the outer (opposite side of the plane 1 0), and the smooth surface 7 of Renzushi one bets 4 to face ^ side of the group 4 1 optical sheet 8 by placing, between Gigun 4 1 smooth surface 1 0 and Hikari拡 diffusing sheet 8 of the smooth surface 7 and the optical sheet 8 and / or the light guide plate 1 of the lens Zushito 4, the wavelength of the source light; gap I 9 There to allow at least some content.

Area ratio K of the gap portion 9, i.e.,

Kappa = (wavelength; I Hokusatsu Ζ light guide plate full table of part of the gap h, XI 00% is required equalizing H¾ plane distribution of luminance, utilization efficiency of light energy, the dimensions of the light guide plate i ^ force is determined, usually, the ratio K is 80% KUI, more preferably 90% Ri: the force.

The reason for this result of the experiment, such as FIG. 16, when both the surface roughness force, 'are brought into close contact with the surface 7 of the smooth surface of the light guide plate 10 and the lens sheet under wavelength than the light, the light source side the part of the distance y from the side edge, the majority of the input light from the line light source 3 is released at all to the other side end portion side opposite without morphism anti abruptly decreases rather luminance force in the portion of y This is because was that mosquitoes ^ Akira becomes dark and.

As a result of the actual measurement, the ^: part of the length y and the light guide plate 1 light propagation direction of the full-length Y J »> i.e. for (Figure 15), (y / Y) X 100 (%) is 10 to 20 % was found to be extent.

Therefore, in order to evenly distribute the amount of light energy that enters from the light source 3 to the light guide plate plane 10 in the entire length Y is 10 to 20% of Λί light to planar 10 unavoidable even by ^, It is 必 to totally reflect the remaining 90 to 80% occurred.

Generally,

(Total reflection ¾≤Ζ total Λί X100%

= (Wavelength scan voids some portion of the area Ζ light guide plate full table ®¾ of) XI 00 (%) = Κ

From being approximated, the Κ 80~90% i: and Senebanara will be no, before the term ^ has been derived.

Light reflecting layer 2 used in the present invention, the light a layer having a capability to expand ffcS Isa can be configured as follows. ① on one side of the light guide ¾, pigments highly highly masking and whiteness, for example, it is formed by painting a white employment dispersed titanium dioxide, a powder such as aluminum.

② sandblasting ¾Pai, the uneven pattern surface of the light guide plate forming the is vanishing mm unevenness by embossing or the like, is subjected to deposition or plated or the like to form aluminum, chromium, a metal thin film 餍 such as silver.

③ the like in the formed concealing having low white fe® the matte surface to form a metallic thin film layer by vapor deposition or the like.

④ to form a dot-like white layer, by Yasu 增 the ®¾ of the white portion farther from the light source, the attenuation of ¾B from the light source 3 may be corrected.

¾ ±, but primarily been described in an edge light type surface light source, a light sheet and a lens sheet sets of the present invention ^ is ^ ^ what can be done using the direct type surface light source shown in FIG. 2. Further, it is also possible to use it two J¾ is ± laminated depending on the optical sheet 8 of the present invention. Furthermore, if the required light ¾Tfcft (half-value angle, etc.) of target widely also good is had only one light diffusing sheet 8 of the present invention, or be composed of multiple layers it is only in the surface light source thing was .

As shown in FIG. 1 4, the mechanism of action of the surface light source of the edge light type, of λ! Ί the light guide plate 1 directly to the smooth plane 1 0 of the light guide plate A! Ru Hf from the light source 3, incident on the light beside L 1 is lambda I angle (angle between the normal of the surface 1 0) since it is less than the critical angle decreases to morphism is released as some percentage power light LIT incident ^ fi. Yotsute thereto, emission of light 2¾S near is formed. Meanwhile, L 2 directly λ! Ί relatively away from the light source 3 is λ! Ί angle is large, since the critical angle J¾ ±, further become totally reflected light L 2 R not released to the outside sent to distant, male (turbulent) with light 拡贩 picolinimidate second light ¾m® reflected light L

Advance in all directions become a 2 S. These some percentage is λ! Ί to the surface 1 0 less than the critical angle, the further what percent of the emitted light. Emission light at a portion distant from the O connexion light source 3 on such a principle is formed. Here, on the smooth plane 1 0 of the light guide plate 1, the smooth surface 7 of the lens sheet 4 in the non-Len Chikaraku smooth plane, the state of being stacked in a direction in contact with the surface 1 0 1 6 It is shown. Usually, the refractive index of the material which is both 1.5 is around, the difference between the cross is not large. Therefore, the difference in ¾Jg is any, becomes almost optically to the lens sheet 4 and the light guide plate 1 as shown in FIG. 1 6. Then, since the unit lens 4 2 of the surface of Renzushi Ichito 4 has a relative smooth plane 1 0, input to the light guide plate with light 2¾5 near ^ majority of S, for example L 1, L 2, L 3 is to morphism entering below the critical angle, some percentage is directly emitted, light reflected also returned to the most force source direction, not propagated in the distance. Of course, directly incident on distant Ren ® from the light source, From there emitted light to become e.g. forces also L 4 etc. present in FIG. 1 6, the amount is less than if the Fig 4.

Therefore, as described above, light emitted from the surface light source, the light source-side vicinity, i.e., 1 0-2 0% majority at the total ®¾ of the light guide plate is become that become concentrated.

- How, in the present invention, as shown in FIG. 1, between the light diffusing forms a Gigun 4 1 on the surface of the sheet 8, whereby the light guide plate 1 smooth plane 1 0 and the lens sheet 4, at least partially to form a gap 9.

In the gap portion 9, typically, refractive index 1. Since the light guide plate 1 and the refractive index of 5§¾ 1. 0 雖 air layer (or true ^) adjacent the the mosquito surface 1 0 as a surfactant, Fig 4 same optical total reflection as in occurs. Therefore, as shown in FIG. 3, in the region of the light source 3 near away from the plane 1 0! Below a critical angle λ to ί and ¾® to go by connexion emitted light gills u ¾Fe source 3 the ray LIT region after total reflection at the interface between the airspace 9, of light diffusion IfcS picolinimidate 2 O connexion emitted light L 2 T less than the critical angle among the shines expansion iicR in the resulting et al.

Of course, among the L 2 T, ¾g group 4 1 and the plane 1 0 and force, 'a portion of the light λ! Ί the area in contact is not totally reflected, others as a transmitted emission light is there. If ®¾ ratio K of the gap portion 8 0-9 0, it becomes the entire surface substantially uniform luminance distribution, as described above.

Further, in the present invention, 雜 4 1 of the height (i.e. gap portion 9), the wavelength of the source light; by you 1, has become in terms 1 0 ^ Iryoku real ones.

The reason is that, as shown in FIG. 9, when entering from the internal light guide plate 1 electrically to the smoothing plane 1 0 of the light guide plate 1 ^ SL 1 is all S i to reflected light L 1 R, strictly speaking, light the electrodeposition magnetic field does not mean that entirely absent in (or vacuum) in the gap portion 9, "^ tunnel field LIV force transmitted through the interface 1 0 by Le effect, 'are present. However, this electromagnetic field 1 V exponentially decays, the order in the amplitude of the order of the wavelength of the light retraces to zero the light guide plate 1 side.

Therefore, the gap 9 if large enough 钜離 than the wavelength of light, ^ HL l would not at all enter into in the gap portion 9 of the lens sheet 4.

Incidentally, the lens sheet 4 approximately the same refractive index as the light guide plate 1 as shown in FIG. 1 0, with respect to the plane 1 0 of the light guide plate, the brute 雠厶 X≥i5 less than the wavelength scan of light, (delta chi Kusu), electromagnetic field LIV of top Symbol is completely enters the lens sheet 4 in not a reduction, resulting in Ji ^ again traveling wave and summer Te ¾1 light L 1 T force.

In the present invention, ¾S4 1 force on the surface of the optical sheet 8, since you have 'formed between the light guide plate 1 and the light-diffusing sheet 8 as shown in FIG. 1 1, again Z or an optical sheet 8 lens between the seat 4 region and the gap portion 9 having a gap portion 9 are integrated without optically both force (or voids or 賓 connexion also waves full of light) is made and the area. Of these, the total reflectivity of the incident light at a portion where the gap portion 9, 'occur, Do ^ void portion 9, the partial λ! Ί light is ¾1. Shirubeko扳 1 ratio of the area of ​​a portion of the air gap 9 to the total area, totally reflected by the surface 1 0 ^ the ratio !: determines are as defined above. In this way, Ki light energy according to the present ϋ¾ light efficiently de be utilized, it is possible to obtain a uniform and high luminance surface light source. Now, an optical S £ ¾ sheet 8 of the present invention, describes various of ^ 4 1 of characteristics obtained by changing the condition of the roll ^ in H¾ Example 1 to 6, more, of Renzushi over preparative 4 and production example, a surface light source using them, and examples of a display device using the said surface light source, and it «! examples of, will be described with reference to.

(Process of the optical sheet 8)

Roll Okara, in order to peel from it must be light-diffusing sheet 8 a release «i Rukoto has already been described, while the set form a cured resin layer ^ having 5¾S4 1 is the mold M the shape Figure 1 8, 1 9 spread or under Katsuhito in such as

(Overhang) must be in the recess there is no shape that is under force Tsu preparative 5 0 such as shown in FIG. 2 0 becomes ¾tS T.

In the production of light-diffusing sheet 8, the light [delta] £ optical OT ^ Nto 8 | The conditions for both the ¾ characteristics and suitability, in addition to the absence of medium-spreading or undershoot cutlet Bok to said ^ recess, cumulative positions number distribution state of the surface roughness is also important. Ie, electrostatic 逢針 type or light ^; by such a surface roughness measuring instrument (or a in awakened the resin ^ is the same in parts force and has been resin ^ parts, concave convex reverse the relation) of the surface of the valley (concave) depth (S! been mountain ¾g portion of the resin takes the statistics of the height), the surface roughness on the vertical axis as shown in FIG. 1 7, i.e. ^ take a percentage of the cumulative ¾ ^^ cloth of the depth R of the valley of crude to the horizontal axis, ie ^! ! Go-between and the depth R of the valley of, came and drew a cumulative ¾¾ cloth function f (R) curve represented by the following formula (1), even the maximum value Rm a X of R is the same, as shown in FIG. 1 7 of rising force as the curve f B (R) "gradual, if a convex curve below the ^ ¾I of the Ri good der, in the present invention is such a curve is obtained It was carried out designed to.

广 R

f (R) = P (x) dx (1)

X = 0 (where P (x) is the probability density function of the surface roughness R)

Mold cross section when the function rising slope forms a convex curve below catching gradual long 据野 as shown in FIG. 1 7 the curve f B (R) is by illustration schematically exaggerated if, for example, the shape shown in FIG 1 9, such characteristics shaping been ¾ in a mold having a £ 4 1, like those with a cumulative ¾¾¾ cloth curve of f B (R) type height Doo ing o

- How, a rising force sharply as in Figure 1-7, the curve f A (R), if a curve projecting above, sex of the ^ Y becomes poor.

Omomukikin type having characteristics represented by a function such as the curve f A (R) are, for example, the shape shown in FIG 8.

As shown in FIG. 2 0, ^! Because in the case of under-Katsuhito shaped slide into ¾¾D as disconnection of the recess toward the bottom no longer projections 4 1 or TffiSi, for the purposes of the present invention are inappropriate is as described above.

Chromium metal micro bunching (spherical) o Matsutometsuki surface consisting of particles aggregates was found to be a poor ¾Ι resistance for a cross section as in FIG. 2 0 when provided in the concave ¾5®

As already mentioned, Wei 4 1 of the formation positions number distribution curves of height of 1 7 curve f beta

In the case of downwardly convex across cumulative ¾ ^ spans 0% to 1 0 0% as (R) gives a good good of ¾ϋί properties. However, even if part of the upwardly convex part of the formation number distribution curves, cumulative of cumulative distribution curve ¾¾¾ ^ fabric that is 50% (i.e., a point which corresponds to the average value) or the intermediate If than the value through the right, i.e.,

The average value ^ intermediate value

If, in that fluttering of the cured resin layer from the recess, Rukoto force good enough 醒性 was obtained, 'it was confirmed by experiments.

Incidentally, ¾G4 1 height, i.e., the measurement and data analysis of the surface roughness of the light diffusing sheet 8, used as a measuring instrument Co. Kosaka Laboratory Ltd. SURFCORDER SE- 3 0 K, feed rate 0 . 2 imnZ s, and H¾ under the conditions of the measurement length l mm.

(HM example 1)

A light-diffusing sheet 8 shown by the FIG. 1 3, was Rimomoshi by the following steps by using the apparatus shown in FIG 2.

① was prepared take-up roll 1 1 of base material fill beam thickness 5 0 m free fe¾ bright biaxial oriented polyethylene terephthalate evening rate.

The ② metal cylinder surface JIS-B- 0 6 0 roll mold was engraved recess 1 5 randomly 1 of the ten-point average roughness R z is the sandblasting processing by Uni # 8 0 as a 3 8 / zm 1 4 was prepared, which was supplied to the ultraviolet curing resin 1 6 from a T-die type nozzle 2 1 while rotating the US®, filled coating on the surface recesses of the mouth one Le ^ Si 1 4.

③ then unwound at a speed synchronized with the previous remarks substrate film 1 2 rotation circumference of the roll ^ l 4 from the winding roll 1 1 Y¾, a base film roll ^! On 1 4 by the pressing roll 1 3, 該榭stacked contact is through between the fat, mercury lamp 2 3 as it states,

Use 2 3 irradiated with ultraviolet light from the back side of the base film 1 2, the resin is adhered when the crosslinked cured simultaneously with the substrate film 1 2 within the surface recess of the roll ^ l 4.

④ then the substrate film 1 2 traveling with peeling roll 1 8, peeled with adhered Group 4 1 shape 赫 been cured resin thereto, the optical sheet - to give the door 8. Wound as it is the light-diffusing sheet 8, in accordance with then, was used to cut to the desired dimensions.

Incidentally, the ultraviolet curable resin used in this step, a multifunctional polyester § chestnut les over preparative oligomer and ^^ is obtained by adding ^ response initiator.

The resulting ¾S4 1 values ​​are as follows.

KaginunoAtsu = 4 0 jm

The surface roughness R z = 3 8. 4 m (JIS- B- 0 6 0 ten-point average roughness of 1) Haze = 88. 8 (JI SK-7105)

Table ®¾ / measurement transliteration = 1.230832

Surface light = 11 3. (JIS - Z - 8741)

In addition, the as cumulative distribution curve is shown in FIG. 21, "^ minute also has become a distribution curve of a convex to the above, the" average value ^ middle of the relationship between the uneven height in this case Ri meet , dish ¾g41 that are ® is as shown in FIG. 22, ^ !! recess or these sexual cured resin footwear is very good, and the diffusion of the light was also ^?. example 1 under the same conditions, by changing only create conditions for the roll ^ si light sti: sheet

And trees 8.

Rolls in I ^ Example 2, was developed by sandblast processing the surface with spherical sand # 200, ^ values ​​obtained 3¾S41 are as follows.

SokazariAtsu = 40 m

Surface roughness Rz = 5. 62 m (JIS- B- ten-point average roughness of 0601) Haze = 78. 1 (JI SK-7105)

Table ^ 1 / measurement transliteration = 1.019303

Surface light = 11. 2 (JI SZ-8741)

In addition, the cumulative ¾ ^^ cloth curve as shown in FIG. 23, in the same manner as in Example 1, a portion is has become a distribution curve of upward convex of uneven height satisfies the relationship of "average value ≥ middle ^ J and, 41 the shape of which is in as shown in FIG. 24, the «iota of from ^ recess of the cured resin layer is substantially better, also, sexual light was good.

Example 3)

Example 1 under the same conditions as in, roll ^! (To produce a light sheet 8 only a change of creating conditions.

Roll ^ is that in Example 3, the surface was lightly etched with Shioi h ^ solution or the like, and sand blanking blasting with sand # 200 Later, obtained by further facilities gloss Kuromumetsuki the surface, resulting ¾g characteristic value of 41 is as follows.

The total coating thickness = 40 / zm

Surface roughness Rz = l 6. 1 X £ m (ten-point average roughness of the JI SB-0601) Haze = 89. 5 (JI SK-7105)

Table transliteration / measurement transliteration = 1.104595

Surface light = 12. 5 (JI SZ-8741)

Further, the cumulative frequency distribution curve as shown in FIG. 25, the average value is made from 52% der is, and part of the convex upward and a convex portion or below the cumulative frequency distribution curve of the maximum value. In this case, there is little resistance although sometimes «Ι is. Therefore, the number of near the ho is determined that the critical conditions of ί3¾Ι property.

Is 5¾g41 was been in as shown in FIG. 26, as shown in the characteristic value, the optical properties were good.

Example 4)

Example 1 under the same conditions as to produce a light ¾t Nto 8 to change the only work ^ matter of roll ^.

m mouth one Le used in 4, by cutting a cylindrical surface with Zhong made by forming a ridge of right-angled isosceles triangle cross-section, resulting ^ 41 Sil-shaped cumulative 稹度 number distribution curve as shown in FIG. 27 showed that. This is also intended to strike the critical conditions between the curve f A of FIG. 17 (R) and the curve f B (R) Chikaraku, next shape of ¾g41 is like shown in FIG. 28, ira resistance was son .

(Comparative Example 1)

Under the same conditions as H¾ Example 1 to produce a light ¾ £ fc sheet 8 by changing only the creation condition of the roll ^ Si.

Used in Comparative Example 1 alpha-le is obtained by creating subjected to chromium to mold cylindrical surface mat (kappa erase particle saphenous) plated layer, characteristics of the resulting ^ 41 are as follows.

The total coating thickness = 40 m

Surface roughness Rz = 3. 72 m (JIS- B- ten-point average roughness of 0601) Haze = 82. 6 (JI SK-7105)

Table 賺 Z measurement ® «t = l. 012296

Surface light = 15. 0 (JI SZ-8741)

Further, as shown in the cumulative ¾S number distribution curve Figure 29, ~ ¾ | 5 on the convex, Ri Totsudea one 3TF, and an average value rather an intermediate value, and becomes the case, resulting in the projections 41 section becomes indicate Suyo ones in FIG. 30, «Ϊ resistance was poor.

(H½ Example 5)

Example 1 under the same conditions as were manufacturing the light rat sheet 8 by changing only the creation conditions.

Example 5 was used in ^ are those created by the templating at performs photoelectric 鋅法 polyethylene terephthalate film by kneading calcium carbonate having a particle size of 1 to 10 m, the characteristic values ​​of the obtained 41 it is as follows.

KaginunoAtsu - 40

Surface roughness Rz = 2. 16 m (JIS- B- ten-point average roughness of 0601) Haze = 32. 5 (JI SK-7105)

Table ®¾ / measurement 隨 = 1.012211

Surface light 2RS = 55. 3 (JI SZ-8741)

Further, the cumulative ¾¾¾Fc ^ cloth curve as shown in FIG. 31, becomes convex curve below over the entire area, the cross-sectional of 雜 41 was as shown in Figure 32. Optical properties, from the mold) property been made good.

It shows the characteristics of the light-diffusing sheet 8 obtained in H½ Example 1 to 5 in Table 1 below. Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1

Haze value (%)

JIS-K-7105 88.8 78. 1 89, 5 32.5 82.6

Gross value (%)

JIS-Z-8741 11.3 11.2 12.5 55.3 15.0

Surface area/

1.230832 1.019303 1.104595 1.012211

/ Measurement area 1.012296

t surface roughness μ m μτη β m β m μ m U1

] IS - B- 0601 38.4 5.62 16. 1 2.66 3.72

Of the light guide plate back surface 〇 most Kai~kai XXXXXXXX

Dot concealing property not visible visible visible visible visible visible

Total light transmittance

(%) 84.5 90.5 87.4 87.3 90.6

When the projections 4 1 molding ◎ 〇 △ little heavy O O X

Mold release properties very good good good can release good good good good releasability Call

Example 6)

(Of the lens sheet 4 fi ^ E

As with the optical sheet 8 (β¾ for Ronore ^ etc. differ) by the following steps using the equipment shown in FIG. 12 | were ¾Y.

① was prepared take-up roll 11 of a substrate Fi Lum free fe¾ thickness 100 m bright biaxial oriented polyethylene terephthalate Bok.

② (uneven in the same shape opposite) elliptical, lenticular lens on the metal cylinder surface prepared 15 roll ^ l 4 was engraved, while rotating it around the central axis, an ultraviolet curing from a T-die type nozzle 21 supplying rESIN 16 ^ to the surface, the uneven surface of the lens was filled the S.

③ then 卷出 at a rate synchronized with the rotation circumference of the roll 11 Dry Ichiru ^ 14 Ri 卷取 the previous remarks Ξ¾ material film 12, as fiR light ¾¾¾ sheet 8 and similar apparatus, using a 榭脂, elliptic cylinder to obtain a lenticular lens sheet 4. Winding left the lens sheet 4 Waso, depending on the subsequent ^ and used by cutting into a desired size.

By the way:

Lens;

Unit lenses elliptic cylinder (long axis of the lens sheet '^ oriented in a direction.) Major axis 2b = 230 m

Minor axes 2 a = l 28 # m

Major axis:. 1 / / short axis length = 21) / 23 = 1 80

Repetition period of the lens unit p = l 1

Switching ^ (length along the major axis of the elliptical cylindrical unit lenses) D = 50 m Example 7)

Example 1 § «lens sheet 4 produced by the light ¾¾ί sheet 8 and H¾ Example 6 was i used to prepare a configuration of an edge light type surface light source as shown in FIG. 1. However, as shown in FIG. 8, is perpendicular to one another ^ the two lens sheet 4, and, Ren ® both: out stacked to face the direction.

The light guide plate 1, the light source 3 was prepared which had the following characteristics.

Light guide plate;

Materials; polymethylmethacrylate § methacrylonitrile rate polymerized fat

Shape; tabular it ^ body. Thickness 4 Sir

Surface; center line average roughness was finished to smoothness of less than R z = 0. 1 m at the entire surface.

Backside; off flavor to the light guide plate by printing a transparent Inki circular dot shape, and

Aluminum was placed specular reflective film was vacuum deposited on a polyethylene terephthalate evening rate film [delta].

Dot was formed by silk screen printing using a dispersion of powder city Siri force in the binder one Akuriru based glue effect.

Sequence of halftone dots were arranged in the vertical and lateral directions at a repetition period 5 mm. The diameter of the dot is in close to the light source and 0. 2 mm, and increase in proportion to the distance from the light source, and a 2. 0 mm at the end of the light source and the opposite side.

light source

As a line light source, and it disposed cold-cathode tube type white fluorescent lamp (vanishing force 4 W, pipe diameter 3 mni) to both ends of the light guide plate. Is on the opposite side of the light guide plate placed anti-! ^ Of metal.

Performance of a surface light source by the configuration of RJL were as follows.

• angular distribution of luminance as FIG 3.

• half-value angle (0 h) = 7 2 degrees

• the normal direction brightness (light guide plate central portion) = 2 0 2 5 c dXm 2

• distribution of the light emitting surface of the weave directions luminance; soil within 5%. Substantially uniform even visually. (H¾ Example 8)

In Example 7, without using the lens sheet 4, using only optical sheet 8 created in Example 1.

Others were the same as H¾ Example 7.

Performance of the surface light source of the configuration was found to be as follows.

• angular distribution as Figure 34 brightness.

• half-value angle (0h) = 74 degrees (however, the steeper outside the half-value angle is emitted light of a certain extent without attenuation distribution.)

• fiber direction luminance (light guide plate central portion) = 1497 cd / m 2

• normal direction brightness distribution in the light emitting surface of; Judges within 5%. Substantially uniform even visually. • side lobe ¾ ^ No.

醫例 2)

In Hite Example 7, the thickness of 100 as a light sheet; for biaxially stretched Poryechire down terephthalate film um, as 16 anti agents, ultraviolet light with the addition of shea re force of the particle size distribution 1 to 10 CZM hardness Akurireto resin paint was ffi the 10 m ^ sheets. Average roughness Rz of the surface was 3. Oium.

'Angular distribution of luminance is the same curve as in FIG. 34. However,

• half-value angle (0h) = 76 degrees

• ¾H direction luminance = 1114 cd / m '

• normal direction brightness of the light emitting plane distribution = ± 5% or less

醫例 3)

In Example 7 to prepare a surface light source without optical sheet 8. Chinaminire Nzushito ten-point average roughness Rz of Sffi was Rz≤0. 1 fim.

£ Lt structure of the surface light source, the light source-side end portion direction luminance Woven Λ¾ exit surface has been a high luminance, it decreases rapidly luminance with distance from the light source, the light fi near from a light source (拒離 already luminance to extent feel dark visually in Z entire length of the light guide plate) = 0.2 parts had decreased.

In the display device using the surface light source, and the same of the present invention could be obtained the following effects.

舰赚 sheet - DOO 8 is quite because it is formed of a transparent material that does not contain a light diffusing agent particles, can be realized to improve the high brightness of utilization even without the light source energy light absorption loss due to light diffusion itself.

(^, In the case of Etsujiraito type surface light source according to claim 2 of the present invention, since the optical sheet one bets 8 surface is formed height ^ group power of the wavelength of the source light guide edge light type surface light source when placed on the smooth plane of the optical plate 1, between the lens sheet 4 and the light sheet 8, and / or securely between the light ¾¾ sheet 8 and the light guide plate 1, it can form voids in the wavelength of the source light It was.

Be placed Therefore the lens sheet 4, without interfering with the uniform distribution of the source light to the entire light guide plate 1 by the light total reflection at the light guide plate 1 surface, average brightness at exit surface entirely - and of, It could mosquito <be a high brightness.

¾¾¾ sheet 8 by no longer noticeable dot flutter one emission of light diffusion tfcS morphism layer of light diffusion ¾¾ results in due connexion light guide plate 1 ¾®, it forces to obtain a high-quality surface light source could be '.

Further, Etsujiraito type surface light source of the present invention, since using a light ¾¾ sheet one preparative 8 and the lens sheet 4, it is possible to uniformly distribute the emitted light within a desired angular Gffl, also the emitted light deer There could be obtained entirely uniform brightness distribution without having to concentrate on the light source side.

④ Further, in the case where the light fim sheet 8 of the present invention was placed between the lens sheet 4 and edge-light type surface light source of the light guide plate 1, does not occur the optical contact between the lens sheet 4 and the light guide plate 1, Newton rings it was possible to prevent the occurrence of the equal thickness fringe equal.

®¾ surface, and / or, in the production of optical sheet 8 having a random fine irregularities? ^ In ¾®, ¾I of the use roll ^ 11 is good, and is possible to efficiently manufacture the high quality products did it.

Claims

The scope of the claims
1. «a lightguide having become surface and city exit surface, the line light provided on at least one surface of the side end surface of the lightguide ^: sources and light reflection of the light guide ί * ¾® and belonged to a surface light source comprising a light sheet which is on the previous remarks at the emission surface of the light guide,
Previous remarks ¾fe diffused one metropolitan Do include light ¾H ^ particles, a transparent substrate having a random minute irregularities on the surface, the wavelength fine small irregularities of the source light, 1 0 0 m below the surface roughness is the difference, the percentage of the cumulative frequency distribution of the height of the fine small irregularities on the vertical axis, when depicting the height of the fine small irregularities and on the horizontal axis of the go-between fine small irregularities the height of the formation ^ cloth curve,該累 number distribution curves force, downward of 'coordinate becomes a curve comprising a portion of the convex, and the surface to Toku徽 the average value of the height of the fine small irregularities is greater than the middle value light
2. lightguide consists ¾®ϋ flat plate, before H «surface light according to claim 1, wherein the optical surface is a smooth plane with the following surface roughness of the light source light
3. on the optical 赚Shiichito claim 1 Comments, characterized in that the unit lenses by laminating Reference column sheet or ¾g Reference s column sheet formed by arranging the primary direction or two-dimensional directions on a plane surface light of e
4. The light diffusing sheet, the upper word e¾¾¾ sheet and another optical ¾ having similar physical properties | surface light according to claim 1, characterized in that ί sheet laminated
5. a light source 1 IiLh, is a window to the front open mouth of the light source covers the back beauty ffi value of the light source, the lamp house which is the light source side inner surface force ^ fe ^ reflecting surface, oneself window object an optical [delta] £ surface light source comprising a ¾ sheet that overturn,
Previous remarks Η¾ diffused one metropolitan Do include light particles, a transparent substrate having a random minute irregularities on the surface, the wavelength ah of the fine small irregularities source light, 1 0 0; um below the surface roughness is the difference, Louis height of the fine small irregularities ¾¾¾ ^ the percentage of cloth on the vertical axis, cumulative to the go-between fine small irregularities in the height horizontal axis the height of the fine small irregularities] ^ when depicting the distribution curve to become a curve 該累 ¾ ^ distribution curve comprises a portion of convex downward coordinate and the average value of the height of ¾¾¾ small irregularities and Toku徼 to be larger than an intermediate value plane light
6. ± l¾fe 赚 on a sheet, 1 or 2 ¾ a unit lens in a plane) ΰ ^ alkylene comprising arranged in direction Surface light o of claim 6 §S «g, characterized in that a laminate of bets
7. on words ¾¾ sheet, the surface light alternative according to claim 5, characterized in that the light diffusing sheet Kibi履 having the following physical properties similar to the optical sheet
8. consists beam expansion ¾¾¾ particles contains no transparent substrate, it has a random fine irregularities of less than the wavelength on 1 0 0 μ πι surface roughness on the surface of source light, the height of the fine small irregularities the percentage of the formation ¾S number distribution on the vertical axis, when depicting the cumulative distribution curve of the height of the connexion 繊小 irregularities on the horizontal axis the height of the small irregularities, 該累 cloth curve forces, under direction of 'coordinate It becomes curved recessed portions of convex towards, and the light sheet which is a larger than the intermediate value of the average value pixel of the height of the fine small irregularities.
9. light 5 £ ^ a transparent substrate containing no particles, the surface roughness force to the surface, 'becomes a random fine irregularities of 1 0 0 zm inclusive wavelength of the source light, fine small irregularities of the height of the cumulative ¾S¾ ^ the percentage of cloth on the vertical axis, when depicting the height of the fine small irregularities and on the horizontal axis of the go-between 纖小 irregularities the height of the cumulative distribution curve, 該累 ¾¾¾ distribution curve of coordinates becomes a curve comprising a portion of the convex downward direction, and a light diffusion sheet, which is a larger than the intermediate value of the average value pixel of the height of the fine small irregularities,
And Renzushi one door that was piled ^ "to it,
Characterized by comprising the light diffusion sheet product 牖体.
Ten. Len column or characterized by having a two-dimensional Wei Ren E column 9. Comments of the light diffusing sheet ¾S (* o
PCT/JP1995/001608 1994-08-12 1995-08-11 Planar light source using light diffusing sheet WO1996005466A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP6210694 1994-08-12
JP6/210694 1994-08-12

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US08/619,623 US5944405A (en) 1994-08-12 1995-08-11 Flat light source using light-diffusing sheet with projections thereon
KR1019960701957A KR100215127B1 (en) 1994-08-12 1995-08-11 Surface light source using diffusion sheet of light

Publications (1)

Publication Number Publication Date
WO1996005466A1 true WO1996005466A1 (en) 1996-02-22

Family

ID=13190476

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP1995/001608 WO1996005466A1 (en) 1994-08-12 1995-08-11 Planar light source using light diffusing sheet

Country Status (1)

Country Link
WO (1) WO1996005466A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6445504B1 (en) * 1999-06-11 2002-09-03 Dai Nippon Printing Co., Ltd. Light diffusing film and use thereof

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6445504B1 (en) * 1999-06-11 2002-09-03 Dai Nippon Printing Co., Ltd. Light diffusing film and use thereof

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