TW200528864A - Plane light source apparutus and light-guide body therefor - Google Patents

Abstract

A plane light source apparatus with edge illumination design is provided, capable of preventing low brightness at the corners of the light incident surface when a light is emitted from the light outgoing surface of the light-guide body, and avoiding low-quality display images when observed at an inclining angle. The plane light source apparatus includes a primary light source 1 and a panel-shaped light-guide body 3. The light-guide body 3 has a light incident surface 31, a light outgoing surface 33, and a back surface 34. The plane light source apparatus further includes a frame 7 for covering the rim of the light outgoing surface 33, and defining an effective luminance part F. On the light outgoing surface 33 having light diffusibility property, compared with the average light diffusion region occupying the most part corresponding to the effective luminance part F, the high light diffusion region is located outside the area corresponding to the luminance part of the primary light source 1, and close to the light incident surface 31 or at least one part of its neighboring side edge. Most part of the high light diffusion region is located outside the area corresponding to the effective luminance part F.

Description

200528864 16049pif.doc IX. Description of the invention: [Technical field to which the invention belongs] The present invention relates to a light guide body used for a surface with an edge illumination method, and particularly to a surface light source device for reducing the brightness of the hu-j and its recognition. And the light guides it uses. The standard device is suitable for use as a display unit for display televisions such as portable notebook computers and video recording TVs, night crystal TVs, etc. As a portable electronic device such as a mobile phone, the # panel and indicators of various devices are relatively small, and the backlight of the crystal display device is used as a guide for stations and public facilities. The backlight of a liquid crystal display device, or the backlight of a liquid crystal display device used as a marking device for traffic signs on highways and general roads. [Prior art] The crying night crystal display device can be used as a display for portable notebook computers, etc., or as a display unit for LCD TVs and video-integrated LCD TVs, etc., and can be widely used in various other fields. Applications. Liquid crystal display device = This is composed of a backlight and a liquid crystal display element. As a backlight, from the standpoint of simplification of the liquid crystal display device, an edge lighting method is often used. In the known technology, as a backlight of an edge illumination method, the following method is widely used, that is, at least one end surface of a rectangular plate-shaped light guide is used as a bismuth surface, and a straight tube type is arranged along the light incidence end surface. Fluorescent lamp isocortic or cup-shaped primary light source ', and the light emitted by the primary light source is introduced from the light incident end face of the light guide into the light guide, and from 200528864 16049pif.doc as the light guide The light exit surface of one of the principal surfaces is emitted. In recent years, in liquid crystal display device towels, it is required to select as large a ratio as possible =: =: shape size ratio 'to improve display efficiency. Second, the clothing also requires that the size of the light-emitting surface be increased as much as possible. A is stored in a frame shape around the light-emitting surface in the ancient style, and it needs to be shrunk; it is called [装 部 架]). In this case: the line shape or rod configuration of the light incident end face of the body, the body, the mouth, and the body == :; Second, the reduction of this size-the aspect can be reduced by the length of the second f even if it is shorter than the opposite light guide The body light strikes the surface ',,', and now it is a new problem of Wei Tong. It means that at least one end of the primary light source; Second, the end forms a non-light-emitting portion that does not actually emit light. Therefore, as a non-light-emitting portion The amount of light emitted from the corner of the light guide corresponding to the non-light portion corresponding to the light incident end face is reduced, and the brightness of the portion is reduced, resulting in uneven brightness. Japanese Patent Laid-Open No. 2.169033 is a technique for revealing a light, that is, on the light-emitting surface of the light guide plate, in the area where the second parent is lower, such as the corners and sides of the light incident side, Moreover, in, for example, Japanese Patent No. 200528864 16049pif.doc, this patent system, Miscellaneous Work No. 3 and Japanese Patent Publication, both are on the light emitting surface or light emitting surface. Track or increase the average tilt using this method, can prevent the light guide The brightness of the light incident surface of the exit surface is reduced, but when viewed obliquely from the normal side of the light exit surface, the angle is formed or the average tilt is increased, and the brightness is bright. It can be seen that it is used as a backlight of a display device. The use of the month / will sometimes cause the quality of the displayed image to be inferior. Summary of the invention] One source, strong, this 'the purpose of the present invention is to provide a small t-wheel of surface light with an edge illumination method' even to improve the light-emitting surface The ratio of the size to the external size is reduced to # 山 杧 's size, which can also prevent the light from being emitted from the light exit surface of the light guide! The brightness of the corners, etc. on the side of the surface is reduced, and it is used as a display device. When a light lamp is used, the problem of poor image quality is not returned when viewed from an oblique direction. In addition, an object of the present invention is to provide a light guide for a light source device, which can be used in such a surface light source device, ^ The characteristics of the surface light source device are shown in the following. ~ A reference is made to the present invention. As a method for solving the above-mentioned problems, the present invention proposes a light guide device of the present invention. The surface light source device includes a primary light source and a light guide. The body guides the light emitted from the primary light source, and has a light incident end face from which the emitted light = incident light enters, and the light to be guided is provided on the back face and the back face opposite to the light exit face. It is characterized by covering the periphery of the light exit surface of the light guide and delimiting the frame of the surface light source device and the light emitting part; the light exit surface and the back of the light guide are less than 200528864 16049pif.doc It has light diffusivity; at least one of the above diffusive surfaces on the light exit surface and the back surface corresponds to a region other than the light emitting portion of the primary light source, and is close to the light emission end surface or a region adjacent thereto. At least-partly, compared with the general light diffusive area which occupies most of the area where the effective light-emitting portion is located, the light-diffusing high light diffusive area is formed; most of the high light diffusive area is located in! Out of the corresponding area and / or in the corresponding low luminance area of the aforementioned primary. Light section In one embodiment of the present invention, an intermediate light diffusive region is provided between the high light diffusive region and-the diffusive region ', and two are located in the middle of these regions. In the embodiment of the present invention, at least a portion of the high-quality region is located at a position corresponding to or at least one corner portion of the light-emitting end surface side of the light guide. In each of the embodiments of the present invention, the light diffusivity can be imparted by roughening the light emission surface and the back surface. In the example, the surface light source device further includes a light deflecting element, and the light deflecting element is firstly arranged on the light exit surface of the light guide body. 'The light deflecting element is on the light incident surface; ΐ: guide: ^ The light enters the Xia Gorge and is parallel to each other to make edges ^ The mirror row has light from the light exit surface of the light guide, respectively. The light emitted by the person is reflected by the second edge of the inner surface = the younger brother-/ f In one embodiment of the present invention, the primary light source is formed in a linear shape, and at least one end has a light-emitting end surface pair facing the light guide. To the set of non-ii 20 0 528 864 0 c Shao. In the yoke example of the present invention-meeting point = light field, the super-light-diffusion region uses super-depth; the average value of the measured inclination angle is 8 degrees or more 25: deep-producing shape, In an example of the month, in the degree distribution of the inclination angle measured by the two ivv, 1 'micromirrors in the * high light diffusivity region, the component of the tilt φ, and the upper angle is more than 30%. In the second embodiment of the present invention, the mean thickness measured by a super-depth shape measurement microscope (mean thickness) is 0.35 μm or more and 0.6 μm or less. In this month's yoke example, the Rz (ten-point average thickness) measured by the super-deep shape measurement mirror using a super-depth shape measurement is 3 > m or more. / In the embodiment of the present invention, the middle The average value of the inclination angle of the fissured region measured by a super-depth shape measuring microscope is 4 degrees or more and 12 degrees or more. According to an embodiment of the present invention, in the degree distribution of the inclination angle measured by the super / woody shape measuring microscope in the intermediate light diffusive region, the component having an inclination of 10 degrees or more is 5% or more and 40% or less. In a consistent embodiment of the present invention, the intermediate light diffusivity region is measured with a super-depth shape measuring microscope = Ra is measured from 0. 18 μm to 0 43 μm. In the example of the target of the present invention, the Rz of the intermediate light diffusing region measured by a super-depth shape measuring microscope is 16 μm to 4.0 μm. By using the surface light source device of the present invention as described above, a surface light source device with an edge illumination method and a light guide used therefor can be provided. Since it can be on the light exit surface or inner surface of the light guide body, in areas other than the area corresponding to the light emitting part of the primary light source, the area of the side end surface is up to / f, a = close to the incident light. The end portion or the A portion of the area adjacent to it; the upper portion is formed to occupy and diffuse the high light diffusion with high diffusivity of the effective light-emitting portion; the general light diffusivity area, the light portion is preferably all located in a wide area The non-light-emitting portion 大 _ 大 of the large-scale light source is outside the area corresponding to the non-light-emitting portion of the primary light source and the outside of the area corresponding to the size of the initial frame. The light guides stop at opposite positions such as the adjacent corners of the face, and can also prevent the brightness of the effective light-emitting part from decreasing, and use the main and ^ in the sturdy-strong moonlight. When not observing, no / down '§ Viewing the display image from an oblique direction does not have the problem of poor image quality. [Persistent Embodiment] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The partial light source is shown as part of an embodiment using the surface light source device of the present invention. FIG. 2 is a partial cut-away plan view of the “diagonal perspective view”. As shown in the figure, the structure of the surface light source device includes at least: One side end emerges from the t-incident end face 31, and a surface substantially orthogonal to it is used as the light guide 3, the light guide body 3, and the light incident end face 31 of the light guide body 3 to the light guide. The linear primary light source 1 covered by the reflector 2 1. The light deflecting element 4 arranged on the light emitting surface of the light Γ3, the light arranged opposite to the light guide 35, and the back surface 34 on the opposite side of the light emitting surface 33 The peripheral portion of the reflective element exit element 4 and therefore covers the light emission 7 of the light guide 3. The peripheral portion and the frame 7 which delimits the effective light-emitting portion F of the surface light source device constitute the housing of the surface light source device. &Amp; 200528864 16049pif.doc The light guide 3 is arranged parallel to the XY plane and has a rectangular plate shape as a whole. The light guide 3 has four side end faces, and at least one of the side end faces is parallel to the γζ plane. Light person shoots end 3 丨. Light incidence # 面 31 and primary light source 丨 face to face Let the light incident end face 31 emitted from the primary light source 丨 be directed toward the inside of the light body 3. In the present invention, the source can also be aligned on the other side 等 of the side end face 32 and the like opposite to the light incident end face 31. The two main surfaces that are approximately orthogonal to the light incident end surface 31 of the light guide 3 are substantially parallel to each other, and one of the surfaces (upper in the figure) forms a light exit surface 33. At least one of the light emitting surface% or the back surface% is provided with a directional emitting mechanism composed of a rough surface, and the light emitted from the light incident end surface 31 is guided to the light guide body 3, and the light emitting surface is emitted. 33 'emits directional light in a plane perpendicular to the light emitting end surface 31 and the light exiting surface 33). The peak direction (peak light) of the photometric distribution of the emitted light in the χζ plane distribution forms light emission The angle of the surface illusion is set to (X. In most of the effective light-emitting portions F, the angle α is, for example, 1 () to 40 degrees, and the full width of the half value of the emitted light photometric distribution is, for example, 10 to 40 degrees = in the light guide. The details of the rough surface formed on the light exit surface 33 or the back surface 34 of the body 3 will be described later. In addition, on the other main surface to which the directional light emitting mechanism is not provided, in order to control the i-shape of the emitted light from the light guide 3 on the two planes I ′ parallel to the primary light source) 'It is preferable to form a lens surface in which a plurality of lens rows extending in a direction substantially perpendicular to the light incident surface 3! (Χ direction) are arranged. In the embodiment shown in FIG. 1, the shape of the light exit surface is 200528864. 16049pif.doc Xinzu Youshi. Ye Youdian 34 formed a lens column composed of an array of multiple lens columns extending along the substantially incident opening 31 on the light incidence end surface = 上 上 钱 制 制面 ， On the back surface 34, a rough front surface is opened first == When the rear surface 34 or the light exit surface 33 of the light guide 3 is opened / formed as a transparent formation surface, the lens array can be roughly,

Queues extending in a row, semi-cylindrical lens rows, V-shaped grooves, etc., but queues in which the shape of the ° γ plane is substantially triangular are preferred. In the present invention, when the rear row 34 of the light guide 3 is used as a lens row to form a queuing row formation plane, it is preferable that the vertex angle is within the hull. This is because 'by setting the apex angle to this angle, the emitted light from the body 3 can be appropriately collected, and the brightness of the clothes as a surface light source can be improved, more preferably in the range of 90 to 100 degrees. . In the light guide of the present invention, in order to accurately produce the required prism arrays and obtain stable material performance, it is also possible to suppress the impurities and deformation of the top of the fiber mirror when assembled as f and when used as a light source device. A flat portion or a curved portion is formed at the top of the mirror row. In addition, in the present invention, the light-diffusing fine particles may be mixed and dispersed in the light guide by using in combination with the light-emitting mechanism formed on the light-emitting surface 33 or the back surface 34 as described above. Sexual light emission mechanism. The chirped light incident end surface 31 is preferably roughened in order to adjust the width of the light in the xγ plane and / or the xζ plane. As the method for forming the rough surface, it can be a method of using a milling cutter tool, a method of grinding, a method of grinding with a grindstone, sandpaper, and polishing Xingbi #, sandblasting, electrical discharge machining, electrolytic polishing, 200528864 16049pif.doc can be Ball: for blasting: sandblasting particles used in processing, joints, can use the Z side, ", to adjust the expansion of light in the XY plane, and to form a linear rugged shape in the ζ direction for the J direction The second line of the direction = the part of Lai's light that hits the end face, and the degree of roughening of the light entrance end face 31 during the forming process, in the thickness direction of the light guide body, at an average inclination angle of 5 degrees, the center line The average roughness is set to be 0.005: 0 · 5 μΐη, and the ten-point average thickness Rz is preferably 0.5 to 3 μm. This is because the degree of roughening of the light incident end surface 31 is within this range.玎 Suppresses the occurrence of bright or dark bands on the light exit surface, and can make the bright and dark lines blurred and difficult to find. The average inclination angle ea is more preferably in the range of 2 to 4.5 degrees, and particularly preferably in the range of 2.5 to 3 degrees The average thickness of the center line Ra is more preferably 0.07 to 0.3 μm, and particularly preferably 0.1 to 1 0.25 μηι range. The ten-point average roughness Rz is more preferably in the range of 0.7 to 2.5 μηι, particularly preferably in the range of 1 to 2 μηι. The degree of roughening of the light incident end surface 31 is based on the lengthwise direction based on For the same reason as above, it is preferable that the average inclination angle 0a is 1 to 3 degrees, the average thickness of the center line Ra is 0.02 to 0.15 μm, and the ten-point average thickness Rz is 0.3 to 2 μm. The average inclination angle 0a is more preferable. The best range is 1. 3 to 2.7 degrees, and the best range is 15 to 2.5 degrees. 200528864 16049pif.doc The center of the siege and the average thickness of the line Ra are more preferably 0.3 to 3.0, and the best range is 0.5 to 1.5 μm. The range of μ. ## 光光 3 'Asia is not limited to the shape shown in Figure 1' can use a variety of shapes such as first-incidence & wedge-shaped. The first partial 4 is placed in The light exit surface 33 of the light guide body 3. The two main surfaces 41 and 42 are arranged parallel to each other as a whole, (the two guide surfaces are arranged in parallel. One of the main surfaces 4 and 42 is the main surface on the 33-plane side) and forms a person. Light surface 41, exit surface 42 ° The light exit surface 42 forms the light-transmitting surface of the light guide 3. The light entrance surface 41 forms a plurality of prism arrays arranged parallel to the γ-direction extending dagger. The surface of the prism array is formed with a flat bottom portion with a relatively narrow width between the mirror arrays. The prism array has the same size in the χ direction or a small width compared to the width of the prism array. Considering the utilization efficiency, it is better to arrange the queues continuously in the X direction without providing the Decotan section. FIG. 3 is a schematic diagram showing the light deflection by the light deflection element 4. This is an example of the direction of travel of the peak light from the light guide 3 in the χζ plane, 5 light, and light corresponding to the cloth value). The light exit surface 33 from the light guide 3 is obliquely emitted at an angle α. The bee-valued light is incident on the first plane of the queue, and is completely reflected by the inner plane of the second plane, and is emitted in the direction of the normal line of the light emitting surface 42. In addition, in the case of the ΥZ face sheet), the effect of using the queue of the back surface 34 of the light guide body can be used to 'enhance the brightness of the normal direction of the light-emitting surface 42 in the area of the large criminal area. 200528864 16049pif.doc degree. The shape of the prism surface of the prism array of the light deflecting element 4 is not limited to a single plane, and may be, for example, a cross-sectional convex polygonal shape or a convex curved surface shape, and can achieve high brightness and narrow field of view. That is, in the light deflection element 4, in order to accurately produce the required 稜鏡 shape and stable silk performance, and in the assembly and use as a light source device, 捋 suppresses the wear and deformation of the 稜鏡 top, and can also be used in a prism The top neighbors of the columns form flat top or top curved portions. In this case, it is preferable that the width of the top flat portion or the top curved portion is 3 μm or less, from the viewpoint of suppressing the surface light source device from generating a pattern of uneven luminance due to low luminance and image retention, and more preferably The width of the top flat portion or the top curved portion is preferably 2 μm or less, particularly preferably 1 μm or less. The primary light source 1 is a linear light source extending in the γ direction, and for example, a fluorescent lamp and a cold cathode tube can be used as the primary light source. In this case, the primary light source 1 may not only be disposed opposite to the end surface on one side of the light guide body 3 as shown in FIG. I, but may also be disposed on the side end surface on the opposite side as required. The light source reflector 2 is used to guide the light loss of the primary light source i to the light guide 3 with less loss. As its material ', Guanru can have a plastic phase with a metallic mineral reflection layer on the surface. As shown in the figure, the light source reflector 2 avoids the light deflecting element 4 ′ and proceeds from the end edge of the diffuser element 5 to the end edge portion of the light exit surface of the light guide 3 through the outside of the primary light source 1. Twine. On the other hand, the light source reflector 2 may be wound from the outside of the end edge portion of the light reflecting element 5 toward the end edge portion of the light exit surface of the light deflection element 4 through the outside of the primary light source 1. The disk d 16 200528864 16049pif.doc can also be attached to the same reflective member as the non-spherical ridge 2 on the side end surface of the light guide 3 except for the light incident end surface 31. As the light reflection element 5, for example, a nanosheet having a mineral reflection layer on the surface can be used. In the present invention, it is also possible to use a gold layer or the like as the light reflecting element 5 on the back surface 34 of the lead body 3 instead of the reflection sheet. The light guide 3 and the light deflecting element 4 may be made of a synthetic resin having a high light transmittance. Examples of such synthetic resins include acryl acrylic resin, acrylic resin, polycarbonate resin, polyester resin, and vinyl resin. In particular, methacrylic resins are excellent in terms of light transmittance, heat resistance, mechanical properties, and moldability, and are most suitable. As a kind of methacrylic resin, the resin is mainly composed of methyl methacrylate, and the methyl acrylate based on methacrylate is more than 5% by weight. It is a rough surface or mesh of light deflecting element 4 and light diffusing element 6. Alignment (Tair, etc., and the surface centering of prism rows or semi-cylindrical lens rows, etc.), either by using a mold member with the required surface structure and pressing to form a transparent synthetic resin board, or by screen printing, Extrusion [and injection molding, etc. are shaped at the same time as the molding. Also, heat or photo-curable resins are used to form the structural surface. In addition, it can be resin, acrylic resin, polycarbonate resin, vinyl chloride The family tree is a transparent film made of polyfluorene-imide-based resin, or a transparent substrate such as ^, and is formed with a starting energy-curable resin structure or a lens array structure. This sheet can also be bonded by using The alkane method is formed by joining on another transparent material. As a start-up 200528864 16049pif.doc energy-curable resin, polyfunctional (meth) acrylic compounds, vinyl compounds, ( Based) acrylates, allyl compounds, metal salts of (meth) acrylic acid, etc. By including the above-mentioned primary light source 1, light source reflector 2, light body 3, light deflection element 4, light The light-emitting surface (light-emitting surface 42 of the light deflection element 5) of the surface light source device of the reflective element 5 and the frame body 7 is provided with a transmissive liquid crystal display element 8 as shown in FIG. 4 to constitute the surface light source device of the present invention. A liquid crystal display device serving as a back button. The liquid crystal display element 8 includes an image forming portion 81 for forming an image and a frame portion 82 attached to the outer periphery thereof. In the XY plane, the inner periphery of the frame portion 82 and the surface light source device effectively emit light. The same side of the part F exists in the girl #_ 测测. Therefore, the frame part 82 can be used to delineate the display part of the liquid crystal display device & namely, 'in the XY plane', the display part G and the effective part F The same or located inside A. The liquid crystal display device is viewed by an observer from above in Fig. 4. Hereinafter, the rough surface of the light emitting mechanism constituting the light guide 3 will be explained. Fig. 5 shows the primary light source and the light guide. The model diagram of the relationship between the scattered regions of the body. The ^ plane formed on the light exiting from 33 is not formed in a uniformly diffusive form as a whole, as described below _ 'is a form of high-light diffusivity in the specific domain of Qian. ^ ^ So that most of the effective ridge portion F is formed into a general light diffusive region VIII that can obtain the same light emission characteristics. A "rough surface of the region A" is considered from the point of seeking the two sexual regions in the light emission surface 33, «于Ultra-depth shape 18 200528864 16049pif.doc VfC s "The following is p. °° Name]) The characteristics of the inclination angle of the advanced phase, the shape is determined to be rape, and the angle is more preferably 2.0%. In the following, the ultra-deep 0, ^, 、, and 计 are used to calculate the meter shape (average thickness of the center line), and more preferably, it is equal to or less than 0 · 08_ and equal to or less than 0. Roughness: 0 5 ~ RZ (ten-point average or less) measured by the taste shape measuring microscope. _ Above or below, more preferably above ⑽ 扪, can be __ depth and shape setting conditions I / measurement of light guide 3 The surface roughness is specific. As the measurement PITCH ', it can be the measurement mode · color super depth, DISTANCM 5μm, 0. 〇1μιη. Read R ^ a, ^ under the measurement range (for example, ⑽Array parent ⑴) Grave z. Furthermore, by obtaining a cross-sectional curve by using, for example, a weighted average sergeant 2 file about the measurement range, and obtaining the absolute value of the inclination angle of each measurement point and averaging them, an average inclination can be obtained. The degree distribution of the inclination angle can also be obtained from these measured values. However, as shown in FIG. 2 and FIG. 5, the primary light source 1 has a light-emitting tube 1a, which is disposed opposite to the incident end surface 31 of the light guide and actually emits light. It is attached to at least one end thereof and opposite to the light guide incident end face 31, the white 2 socket 1b. The socket 1b is provided corresponding to the corner portion of the light guide end face side of the light guide 3. Therefore, the light guide The light exit surface of the body, such as uniformly ⑧ 19 2005288 64 16049pif.doc When the light emitting mechanism is formed, the area with a small amount (ie, low brightness) of the socket 丨 b of the primary light source. The representative area of this low-luminance area is the light incident end face side corresponding to the socket lb The corner part is attached with f '. In addition, there is an adjacent part which is adjacent to the falling part and is connected to the light emitting end face. ^,' ,,, ® 6 'The low-luminance areas of the light guides are uniformly equal = Ϊί 源 Luminous tube 1 # Light guide body 3 (_ 丝 «structure fully straight ^ 丨) between the light emitting end face 31 'is disposed with, for example, the same light shielding plate trace as the light deflection element, and the light is emitted from the light guide There is a light on the surface. When you observe it from the light emitting surface side, you can see that the angle of incidence of the light incident end face 3! Normal distribution to the normal of the light incident end face 31) is an angle of two, ^ As shown in FIG. 6, the luminance distribution of the light source 1 is near the junction of the primary part of the light emitting tube and the central part. : The area of Shila is defined as the non-light emitting part. If ==, the part will be in addition to this. Therefore, in the present invention, the non-emitting part corresponding to the non-light emitting part of the light source 1 in the release area is not in the position of a light diffusive area that is more similar to the primary shape. . The high light diffusivity area B _ is strictly the same area as "two = ⑧ 20 200528864 16049pif.doc 1-he. The high light B is mostly located on the area F, which is equal to the effective = expansion area w. Technology Corresponds to the width outside the £ 1, absolutely, said most of the area refers to the area of 80. / ,,; u = hiding series B in its-part of the ㈣ and effective light-emitting section / library: 5k 'It is better to overlap _ points with the low-luminance area D. Low-luminance: less, even if it is located in an area F other than the area corresponding to F, Corresponding configuration

To the rough surface of the light diffusive region B, an ultra-depth shape measurement is used. The average value of the inclination angle measured is 8 degrees or more and 25 degrees or less: = degrees or more and 20 degrees or less. In addition, in using the ultra-deep shape toughness ^ =, the degree distribution of the inclination angle measured by the brother, more than 30% of the inclination angle of 10 degrees or more, more preferably 40% or more, and an inclination angle of 20 degrees The above 20% is 2% to 18%, and more preferably 6% to 10%. In addition, Ra measured by a super-depth shape measuring microscope is 0.35 μm or more and 6 or less, and more preferably 0.4 μm or more and 0.6 μm or less. In addition, it is measured by a super-flavor shape measuring microscope to be not less than 3.5 µm and not more than 12 µm, more preferably not less than 4.0 µm and not more than 10 pm. Further, in this embodiment, an intermediate light diffusive region C is formed which has intermediate light diffusion between the light diffusivity of the high light diffusivity region B and the light diffusivity of the general light diffusivity region A. The intermediate light diffusive S domain C is located between the high light diffusive region B and the general light diffusing region a in the vicinity of the side end surface which is connected to the light incident end surface 31 of the light guide. The rough surface of the intermediate light diffusive region C is measured using a super-depth shape measurement 200528864 i6049pif.doc, and the mirror is tilted, flat, and light below 亀 ΐ: degrees. And 'in the degree distribution of the inclination angle measured by the super-depth shape measurement and the 50-degree tilt angle measured by Brother, 50, 0/0, χ ± 400 / 0ατ, 50 / 〇20 sounds; \ Gongchuan / ο Below 'The inclination angle ^ of the formation * is 2% or more and 18% or less, and more preferably 2% or more and 15% or more. It is preferably 0_ above and 0_ below. The Rz measured by a super depth shape measuring microscope is 4 μη 以上 or more, and more preferably 2.0 μm or more and 3 · 8 μm or less.卩 = In the above-mentioned high light diffusivity region δ and intermediate light diffusivity, domain C, the light diffusivity of these regions is improved. Therefore, light emitted from or near these regions and corresponding to the effective light emitting portion F can be emitted. The amount of light emitted from the area of the face ^ increases. Since most of the high-light diffusive region B is located outside the region corresponding to the effective light-emitting region F or within the region corresponding to the low-luminance region, even when viewed from an oblique direction when used as a backlight of a display device, It can hardly be found that it does not make the quality of the displayed image inferior. Although the light diffusing effect of the intermediate light diffusing region C is not as large as that of the high light diffusing region B, it is not as prominent as the high light diffusing region B. Therefore, even if it is located in the region corresponding to the effective light emitting portion F, no problem occurs. The intermediate light diffusive region C is located between the high light diffusive region B and the general light diffusive region A, and also serves to make the existence of the high light diffusive region B unnoticeable. As the roughness when forming the above-mentioned light diffusive regions A, B, and C 22 200528864 16049pif.doc = square ^ sand Z example S grinding of abrasive stone 'sandpaper, polishing roller, etc. ^ \, EDM, electrolysis Grinding, chemical grinding and other methods. # 工 为佳. Used as a sandblasted sphere I :: J beads and a polygonal shape such as alumina particles used in sandblasting. It is used to stand up to form a low-diffusivity light-diffused Φ 2 1 The horn-shaped particles form a region C and a region B with relatively high light diffusivity. Although the rough surface processing j can be directly applied to the surface of the light guide, the transfer surface of the metal rotary mold can also be added and transferred during molding. ... The following describes modifications of the light guide of the above embodiment. In these drawings, the same reference numerals are given to the parts and the like shown in FIG. 6 described above. 7. In the example shown in FIG. 7, as the high light diffusivity region 8, a region portion B1 located at a corner portion of the light guide and a region portion B2 located near the region portion 扪 and corresponding to the primary light source light emitting portion are provided. All of the high light diffusivity region portions B2 are located in the region F. Due to the presence of the high light diffusivity region portion B2, the light diffusivity of this region is improved, and a part of the light diffused here can be guided to or near the region corresponding to the above-mentioned low-luminance region and emit light efficiently. The area of the capture surface portion corresponding to the portion F increases the amount of emitted light there. In this example, the intermediate light diffusive region C is located in the entire region between the light diffusive region b, particularly the region portion B2 and the general light diffusive region a. In this way, JT makes the presence of the regional part B2 of the Yeonggwang expansion area B less noticeable. & 23 200528864 16049pif.doc In the example of 囷 8, the 咼 light diffusive regions b are all located in the region ρ ,. The shape of the intermediate light diffusing region c is different from the example in FIG. 7, and the area of the two light diffusing regions c in the region corresponding to the effective light emitting portion F is reduced. All the low-luminance areas exist in the area F, _m, and this structure can be better applied. In the example of Fig. 9, as the high-light diffusivity region B, the corner portion of the light guide corresponding to the socket 1a of the light source 1 is extended along the side end surface which is adjacent to the light entrance reference surface. The intermediate light diffusive region c is located within the entire range between the high light diffusive region B and the general light diffusive region A. In the paste, in particular, the light that reaches the side end surface is diffused, and is directed to the vicinity and is an effective light emitting portion? The area where the corresponding light exits the face is, and the amount of emitted light here increases. In the example of 0 to 10, although the lengths of the high-light diffusive region B and the medium diffusive region C are different from those of the example of FIG. 9, the same effect as that of the example of FIG. 9 can be obtained. In the example of 囷 11, although the shape of the diffusive region b and the diffusive region C of the south light is the same as the example of FIG. 9

The same effect as the example of FIG. 9 is achieved. ^ T ^ i, J In the example of FIG. 12, as the high-light diffusivity region b and the divergent region Cj, the example of FIG. 8 and the example of FIG. Silk. In the example of FIG. 13, the shape of the high-light diffusive dispersive region C is a polygon f and the middle is widened iW. It is recognized that Ra 17, has a small shape and has all the back-diffusive regions β. Diffusion of light 24 200528864 16049pif.doc Diffusion zone B is difficult to identify. In the example of FIG. 14, as the high-light diffusive region B and the diffusive region c, a form in which the example of FIG. 5, the example of FIG. 9, and the example of B 1 are combined is used. effect. 7 In the description of the above embodiment, the arrangement of the light diffusive region C between the high light diffusive regions B has been specified by using the effective part F_system of the surface light source device, but it can also be used with a liquid crystal display. The relationship of the department G is defined. In other words, when the surface light p is used as the backlight of the display device, the display portion G is actually recognized. Therefore, the arrangement of the high light diffusivity region B and the intermediate light diffusivity 奁 is compared with that of the display portion G. The relationship is reasonable. But <yes, in the XY plane, the display portion G of the liquid crystal display device is located outside the surface light source device = the effective light emitting portion F does not actually exist. Therefore, the high light diffusivity region B and the intermediate light diffusivity are previously determined. The area c is set within the setting range by using the relationship with the effective light-emitting portion F. As a display device, even if additional quality requirements are required, there is no problem of poor display image quality. '' Examples The present invention will be described below using examples. In this embodiment, the light guide, the surface light source device described in the embodiments of Figs. 1 to 6, and Fig. 14 and the liquid crystal display device manufactured by using them are fabricated. The entire surface of the non-recording steel plate with an effective area of 230 mm x 290 mm and a thickness of 3 mm subjected to red surface processing was sandblasted with glass beads. 25 20052_4 Office H, set the shape of the part other than the rectangular area near the end of the two sides of the east side of the long side of the non-recorded steel plate, near the end of the button side, and each stainless steel plate is made of acrylic resin 20mm Mask the board and use the first grain to sand the first-sandblasting treatment. In order to cover other than the above stainless steel, the triangle area near the two corners of the long side is in the shape of a wide trowel, and a cover plate made of acrylic resin is arranged at a distance of 20 mm from the stainless steel plate. The aluminum particles were subjected to a second blasting treatment. With this, ^ is used for transfer with the general light diffusive area A and the high-light-generating area Bΐ shown in FIG. 14 (the maximum size in the x direction is 50 mm, and the maximum size in the γ direction is 0 mm: These sizes include The size of the area formed by the short side in the X direction and the long side in the γ direction of the light body 3 (the same ρ and B2 below (the χ square is the largest & inch n. 〇mm, the γ direction size 〇5mm)) and the intermediate light diffusive area (7.5 mm in the X direction, 7.0 mm in the Y direction), 14 mm in C2 direction and 3.5 mm in the Y direction. In addition, a transfer surface region corresponding to the high light diffusive region B2 and the intermediate light diffusive region C2 is formed by the first sand blasting process, and is formed to correspond to the high light diffusive region B1 and the intermediate light expansion region C1 by the second blasting process. Area of the transfer surface. On the other hand, on the surface of another non-scale steel plate having an effective area of 230 mm &gt; &lt; 290 mm and a thickness of 3 mm, which has been processed with a sibling surface, cutting processing is performed to form a mirror surface forming surface of the t mirror row shown in FIG. 1. The transfer surface on which the rear surface of the light guide is transferred. The prism row of the prism I column forming surface has a vertex angle of 100. The curvature radius of the top end is 15 μm, and the arrangement pitch is 50 μm. The extending direction of the prism row is perpendicular to the long side of the upper stainless steel plate.

(S 26 200528864 16049pif.doc ~ Using the two metal scale molds made of the above-mentioned non-recording steel plates, wedge-shaped light guide 3 is obtained, 苴 is short 碡 E ^ shaped and + Shouba Homa short side 23mm, long The side is 290mm rectangle, and the thickness is from one long side to the other long side to 0.7_. Use the position of the light guide to measure the shape of the surface. The coordinates of the position where the measurement is made are shown in Figure 14. ^ = The intersection of the short side in the X direction and the long side in the γ direction of the light guide 3 as the origin of the seat. The measurement results of the surface shape of the light guide are shown in Table 丨. [Table 1 Ί ⑧-1 2 3 4 5 6 7 8 --- η 9 Position in Figure 14 ------- B-2 C-2 C-2 C-2 B-1 B-1 C-1 C-1 A Surface shape x (mm) 10.0 10.0 10.0 10.0 1.0 2.0 2.5 3.0 115.0 Measurement position like shape ------- y (mm) 0.3 2.0 2.5 3.0 1.0 2.0 2.5 2.0 145.0 Ra (μηι) -------- 0.48 0.30 0.26 0.31 0.50 0.45 0.38 0.39 0.13 Rz (μηι) -------- 8.4 2.7 2.4 2.9 6.4 4.4 3.8 3.2 1.3 Tilt angle 17.2 6.6 4.6 5.5 12.9 12.9 9.4 8.1 2.3 Average (deg) -------- Tilt angle 100 to 59 19 8 15 53 49 39 30 0 Degrees are distributed in 20. There is a ratio of 32 6 2 3 20 20 11 6 0 (%) 27 200528864 16049pif.doc The side end surface corresponding to the long side of body 3 and the long side of body 3 ( Thick side 2.2_: The long side of the angle will be the cold cathode tube 1 with a non-light emitting part 4mm in length at both ends. The cold cathode tube 1 is a light source reflector (silver reflection made by Liguang Co., Ltd.). The other side end faces are attached with a light spreader 4 ^ °. In this configuration, the light incident end of the light guide faces, and the area of H _ is opposite the cold cathode tube 1 _ light emitting part). The light exit surface of the light body The photometric distribution of the emitted light of 33 UZ ^ 2 5 field series normal line is 7G degrees, half-value full-width tree r, using the refractive index of _acid-based ultraviolet gas hardening = 4 = :::? Formed in thick —Juku- Prism surface is light with curvature of half-two-body 3: exit = the saga column forming surface faces the # in1 "outlet" side of the above-mentioned light guide, and the ridge line and light guide surface of the light guide 31 It is placed in a flat shape, and the plane shape of each edge is placed on the light incident end face 31 side of the leader. ^ The above composition is grouped into a frame, and the width% of the area F shown in ^ is 152. The surface light source I set as shown in Fig. 5 is set to the source of the source. When the primary light source 1 is turned on and the effective light emitting portion F is viewed from the front and the oblique direction, the brightness at the ends of the two corners of the H source side is low and apparent. Phenomenon ⑧ 28 200528864 16049pif.doc etc. Then, a liquid crystal display element 8 is arranged on the prism sheet 4 to obtain a liquid crystal display device. The outer peripheral edge of the display portion G shown in FIG. 4 is located at a position Lmm inward from the outer peripheral edge of the effective light emitting portion F of the surface light source device over the entire circumference. In the liquid crystal display device obtained as described above, when the surface light source device is turned on and the liquid crystal display element is driven, the liquid crystal display device is viewed from the front and the oblique direction by visual observation.

Observation C shows 4 G a inch, and no glow and obvious phenomena appear at the ends of the two corners of the primary light source side. Π τ τ serves a good display image quality. [Brief description of the drawings] η Fig. 1 is a partial perspective view showing a gap by using the present invention. FIG. 2 is a partially cutaway plan view of the surface light source device of FIG. 1.

Figure 3 is a schematic diagram of the light deflection using the light deflection element. A picture 4 shows the use map! A sectional view of a liquid crystal display device composed of a surface light source device and a transmissive liquid crystal display. Figures 5 and 5 are schematic diagrams showing the relationship between the light diffusing regions of the primary light source and the light exit surface of the light guide. FIG. 6 is a diagram illustrating a low-luminance area at a corner portion of the light body. FIG. 7 is an explanatory diagram of a modified example of the light guide. FIG. 8 is an explanatory diagram of a modified example of the light guide. FIG. 9 is an explanatory diagram of a modified example of the light guide. FIG. 10 is an explanatory diagram of a modified example of the light guide. FIG. 11 is an explanatory diagram of a modified example of the light guide. 29 ⑧ 200528864 16049pif.doc Fig. 12 is an explanatory diagram of a modified example of the light guide. FIG. 13 is an explanatory diagram of a modified example of the light guide. FIG. 14 is an explanatory diagram of a modified example of the light guide. [Description of main component symbols] 1: Primary light source la: Luminous tube lb: Socket 2: Light source reflector '3: Light guide 4: Light deflection element 5: Light reflection element 7: Frame 8: Liquid crystal display element 31: Light Incident end face 32: side end face 33: light exit surface Thai 34: back face 41: light entrance face 42: light exit face 81: image forming portion 82: frame portion 100: light shielding plate A:-general light diffusing regions B, Bl, B2: High light diffusion area

(S 30 200528864 16049pif.doc

C, Cl, C2: intermediate light diffusive region D: low luminance region F: effective light emitting portion F ': area outside effective light emitting portion G: display portion ⑧ 31

Claims (1)

200528864 16049pif.doc 10. Scope of patent application: 1. A surface light source device 'The surface light source device includes a primary light source and a light guide, and the light guide will guide light from the primary light source and has A light incident end face where the light emitted from the primary light source enters, a light exit face from which light guided by the light exits, and a back face opposite to the light exit face, are characterized in that they have a light guide body covering the light guide. A peripheral portion of the light exit surface and delimiting a frame of an effective light emitting portion of the surface light source device; at least one of the light exit surface and the back surface of the light guide has light diffusivity; and the light exit surface And at least one side of the back surface having light diffusivity is formed on at least a part of a region other than a region corresponding to the light-emitting portion of the primary light source and close to the light incident end surface or a side end surface adjacent thereto. A high light diffusivity region having a high light diffusivity compared with a general light diffusivity region which occupies most of a region corresponding to the effective light emitting portion; Most of the areas are located outside the area corresponding to the effective light-emitting portion and / or in a low-luminance area corresponding to the non-light-emitting portion of the primary light source. 2. The surface light source device according to item 1 of the scope of patent application, characterized in that an intermediate light diffusive region is provided between the high light diffusive region and the general light diffusive region, and the light diffusivity is located at In the middle of these areas. 3. The surface light source device according to item 丨 in the patent scope, characterized in that at least a part of the light-diffusing region is provided at least at a corner portion of a side of the light incident end face of the light guide Or near 32 200528864 16049pif.doc. 4. The surface light source device according to item 丨 of the patent application scope, wherein the light diffusibility is imparted by roughening at least one of the light exit surface and the back surface. 5. The surface light source device according to item 丨 in the scope of application for a patent, further comprising a light deflecting element, the light deflecting element is disposed on the light exit surface of the light guide, and has a light exit from the light. A light-incident surface of the light incident _ and a light-emitting surface on the opposite side. 6. The surface light source device according to item 5 of the scope of patent application, wherein the light deflecting element has a plurality of light deflecting elements on the light incident surface that extend along the light incident end face of the light guide and are arranged in parallel with each other. The prism array includes a first prism surface on which light from the light exit surface of the light guide is incident, and a second prism surface on which the incident light is reflected by the inner surface. 7. The surface light source device according to item 1 of the scope of application for a patent, wherein the primary light source is formed in a linear shape, and at least one end of the primary light source has a non-luminous light disposed opposite to a light incident end face of the light guide. unit. • 8. The surface light source device according to item 7 of the scope of patent application, wherein at least a portion of the high light diffusivity region is provided at a position corresponding to the non-light emitting portion of the primary light source. 9. The surface light source device according to item 1 of the scope of patent application, characterized in that the average value of the inclination angles measured by the super-depth shape measuring microscope in the high light diffusivity region is 8 degrees or more and 25 degrees or less. 10. The surface light source device according to item 1 of the scope of the patent application, characterized in that in the high light diffusivity region, the degree distribution of the inclination angle measured by the ultra-depth shape measuring microscope 33 200528864 16049pif.doc, the inclination angle The composition above 10 degrees is above 30%. 1L The surface light source device according to item 1 of the scope of patent application, characterized in that Ra (average thickness of center line) measured by the super-depth shape measuring microscope of the high light diffusivity region is not less than 0.35 μm and not more than 0.6 μm . 12. The surface light source device according to item 1 of the scope of the patent application, characterized in that the Rz (ten-point average thickness) measured by the super-depth shape measuring microscope in the high light diffusivity region is not less than 3.5 μm and not more than 12 μm. 13. The surface light source device according to item 2 of the scope of the patent application, wherein the average inclination angle of the intermediate light diffusive region measured by a super-depth shape measuring microscope is 4 degrees or more and 12 degrees or less. The '1 rate' is the surface light source device described in item 2 of the scope of the patent application, characterized in that in the intermediate light diffusive region, the degree distribution of the inclination angle measured by a super-depth shape measuring microscope, the inclination angle is 10 degrees or more. The composition is above 5% and below 40%. 15. The surface light source device according to item 2 of the scope of patent application, characterized in that Ra of the intermediate light diffusing region measured by a super-depth shape measuring microscope is 0.18 μm or more and 0.43 μm or less. 16. The surface light source device according to item 2 of the scope of the patent application, characterized in that the Rz of the intermediate light diffusive region measured by a super-depth shape measuring microscope is not less than 1.6 μm and not more than 4.0 μm. 17. The surface light source device according to any one of claims 1 to 16, the light guide constituting the surface light source device. (E 34