TWI356235B - Light guide for use in planar light source device - Google Patents

Description

1356235 16050pif.doc Date of revision: August 23, 2014 is the Chinese manual of No. 94102428. There is no slash correction. 9. Description of the Invention: The present invention relates to a surface light source device using an edge light method and an application thereof The light guide body and the manufacturing method of such a device. In particular, it refers to a surface light source device which reduces the discrimination of luminance unevenness and a light guide body therefor. The surface light source device of the present invention is particularly suitable for the following aspects. For example: the backlight of a liquid crystal display screen of a notebook computer display, a liquid crystal television or a recording and playback integrated liquid crystal television; a display screen of a small electronic device such as a mobile phone mobile phone; a backlight of a small liquid crystal display device such as an indicator of various instruments; A backlight of a liquid crystal display device used as a traffic sign in a station or public facility as a bulletin bar or an advertisement column, and a backlight of a liquid crystal display device used as a traffic sign on a speed highway or a general road. [Prior Art] The liquid crystal display device is widely used as a display for a notebook computer or a liquid crystal television or a display screen of a liquid crystal integrated video television, and is used in a wider range of applications. The liquid crystal display device basically consists of a backlight 'and a liquid crystal display element. From the viewpoint of the lightness of the liquid crystal display device, many products have adopted the edge light method. Conventionally, at least one end face of a rectangular plate-shaped light guide body is used as a light person's shot = η with a straight line of money along the readable end of the wire φ!: the butterfly, the emitted light passes through the guide The light incident end face of the light body is introduced into the guide button (10), and then the second light beam is emitted from the light exit surface. In the recent years, for the liquid crystal display device, the relative size of the 1356235 16050pif.doc is the 94102428 Chinese manual without a slash correction. The date of revision: August 23, 2011 • Screen display The size ratio is only likely to increase 'to increase the display efficiency is getting higher and higher. Therefore, in the surface light source device, the ratio of the size of the light-emitting surface relative to its outer dimension must be made as large as possible, that is, the frame-like structure portion (frame edge) existing around the light-emitting surface should be made as small as possible. On the other hand, the 'surface light source device is also required to be thinner and thinner. To achieve this requirement, the light guide body must be made thinner. In the edge-light type surface light source device, light incident from the primary light source to the light incident end surface of the light guide body, a part of the light is incident on the light exit surface* or the back surface at an incident angle equal to or greater than the critical angle of total reflection, and then passed through the inside. The total reflection is guided by light; the other part of the light is incident on the light exit surface at an angle smaller than the critical angle of total reflection, and part of the light is emitted from the light exit surface. With the thinning of the light guide body (for example, the thickness is about 0.5 mm to 3 mm), when the light emitted from the primary light source is emitted from the vicinity of the light incident end face of the light-emitting surface of the light guide, the high-luminance portion (bright line or bright band) And the low-luminance portion (dark line or dark band) is related to the distance from the incident end face of the light, and exhibits a periodic change. This phenomenon is not particularly problematic when the frame width ratio is large, but in particular, in the above-described surface light source device having a small frame width, it is easy to recognize the problem of unevenness in brightness. + The unevenness of the brightness near the end face of the light incident is related to the surface-surface shape of the light incident end face. Here, as a method disclosed in Japanese Laid-Open Patent Publication No. Hei. No. Hei. The arithmetic mean roughness Ra is set to G G5~G3 handsome. In addition, in the special opening-83512 (patent document 2), light incident 7 1356235 16050pif.doc Revision date: August 23, 100 is the 9th Willow 428, the woven book has no slash correction The average roughness is set to 〇〇5 to 〇3, and the thickness in the direction parallel to the light exit surface is larger than the thickness in the thickness direction of the light guide. Further, for example, Japanese Laid-Open Patent Publication No. 2002-324424 (Patent Document 3) discloses that the maximum height Ry of the light incident end face is set to 3 to 5 μm, and the average thickness is

Ra is set to be 大于 3 or more and less than or equal to Q 6 or less, whereby the light incident end face is made into a structure such as an uneven surface. In the display of Japanese Laid-Open Patent Publication No. 2000-306410 (Patent Document 4), it is revealed that a ridge having an apex angle of 160 to 175 degrees is formed on the light-emitting end surface in a direction parallel to the light-emitting surface. [Patent Document 1] Japanese Laid-Open Patent Publication No. Hei. No. Hei. No. Hei. No. Hei. In the method of the above-mentioned Patent Document No. 4, it is possible to reduce the unevenness in brightness in the vicinity of the light (four) plane by the surface shape of the shot end surface. The thinned light guide of the surface light source device having a small center width is also problematic. That is to say, the light incident end surface and the light exit surface of the structure body will become two: under the light source, and the effect is caused; the vicinity of the light surface from the surface light source device is inclined to be placed on the second W to emit an abnormally strong The light. If it is in the liquid/crystal source, it will cause a deterioration in picture quality. The method of L Wen 1~4 cannot fully suppress this phenomenon. 1356235 16050pif.doc Date of revision: August 23, 100 For the Chinese version of 94102428, the occurrence of the slash correction is made. SUMMARY OF THE INVENTION It is an object of the present invention to provide a surface light source device and a light guide body using the same, which is difficult to see in the vicinity of the incident end face of the light guide body as the light guide body is thinned. The abnormal light in the oblique direction near the end face of the human shot is also reduced.

In order to solve the above problems, the present invention provides a light source device for guiding a light source to be used for a light source device, and to guide light emitted from the primary light source. The light guide for the surface light source includes a light human end surface that emits light emitted from the secondary light source, a light exit surface that emits light guided, and a back surface that faces the light exit surface. The light incident end is an anisotropic _ plane, which is determined according to the ultra-depth shape, and the average tilt angle of the light guide body in the thickness direction of the beam is greater than or equal to 3 degrees and less than or equal to 12 The measured thickness of the guide 依据 according to the ultra-depth shape measurement is 4 and the average thickness is less than or equal to α4μιη; according to the measurement of the ultra-depth ς 』 microscope, the direction perpendicular to the thickness direction of the light guide body is inclined The angle is 1 to 3 degrees' and the average roughness Ra measured in the direction of the thickness of the light guide body according to the measurement of the ultra-depth shape measuring microscope is 〇.〇2~〇. 1 μιη. According to an embodiment of the present invention, in the light incident end surface, the ratio of the composition of the inclination angle number measured in accordance with the measurement of the ultra-precise microscope is 20 degrees or less. According to the present invention - the implementation of the dragon 'in the light human face scarf, 9 1356235 16050pif.doc date of revision: 100 years August 23 曰 is 94102428 Chinese manual without sizing correction measured by the measuring microscope The center line average roughness Ra of the thickness direction of the light guide body is greater than or equal to 〇·2μιη and less than or equal to the thickness of the crucible: root = hair _-implementation, in the light human face, the measurement of the dirty __ according to the ultra-depth shape The ten-point average roughness Rz of the material reading thickness direction is greater than or equal to 〇 plus and less than or equal to 2 (four). According to the present invention, the end face of the light human body has a secret surface, a plurality of mirror rows extending in parallel with each other in a direction perpendicular to the thickness direction of the light guide body, and a cross-sectional shape including a curved lens column forming surface Or having a plurality of mirror rows extending in parallel with the thickness direction of the light guide body (four), and at least a portion of the lens row is a roughened lens column forming surface . In order to solve the above problems, the present invention further provides a surface light source device in which a primary light source is disposed to face the light incident end surface of the light guide for the surface light source device. In an embodiment of the present invention, the surface light source device further includes a light deflecting element disposed on the light emitting surface of the light guiding body and having light incident from light emitted from the light emitting surface of the light guiding body The surface and the light-emitting surface that violates the countermeasure with the light-incident surface. In an embodiment of the invention, the light deflecting element has a plurality of arrays, each of the prism rows extending along the light incident end of the light guide and arranged parallel to each other on the light incident surface, wherein each of the edges The mirror array further includes: a first pupil surface that causes light from the exit surface of the light guide body to enter; and a second pupil surface that reflects the incident light as an inner surface. In one embodiment of the invention, the &apos;primary source is a line source or a point source. In order to solve the above problems, the present invention further provides a surface light source device 1356235 16050 pif.doc as the 94H) 2428 Chinese manual without a slash correction. The date of revision is August 23, 2011. In the above-described light guide for a surface light source device, the light-transmitting synthetic resin is molded by using a molded member, and the shape of the surface of the molded member is transferred to obtain a light guiding material corresponding to the light guiding member. Thereby, a surface corresponding to the light exit surface and the back surface of the light guide material is formed in the same manner as the light exit surface and the back surface. Then, the light incident end surface is formed by cutting the surface of the light guide material corresponding to the light incident end surface to obtain the light guide for the surface light source device. Further, a method of producing a light guide for a surface light source device is also provided, and the light guide for a surface light source device is used, and a light-transmissive synthetic resin is molded using a molded member, and a surface of the molded member is used. The shape is transferred, and the light-emitting end face, the back surface, and the light incident end face are formed, and the light guide for the surface light source device is obtained. According to the present invention, the average tilt angle of the light guide body in the thickness direction of the light guide body for the surface light source device is greater than 3 degrees and 12 degrees or less, which is obtained by measurement of the ultra-depth shape measuring microscope. In the surface light source device, the luminance variation occurring in the vicinity of the light incident end surface of the light guide body due to the lightening of the light guide body in the surface light source device is also not easily recognized, and the vicinity of the light incident end surface can also be reduced. The extraordinary light is emitted in the oblique direction. In addition, in the distribution of the inclination angle number obtained by the measurement of the ultra-depth shape measuring microscope, the existence ratio of the component having the inclination angle of 20 degrees or more is 40% or less, whereby the inclination of the vicinity of the light incident side surface can be sufficiently reduced. • Anomalous light is emitted. The above and other objects, features and advantages of the present invention will become more apparent <RTIgt; <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> </ RTI> <RTIgt; Line revision date of this revision: August 23 of the following year is as follows. [Embodiment] Hereinafter, embodiments of the present invention will be described with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing an embodiment of a surface light source device according to the present invention; and Fig. 2 is a partial cross-sectional view thereof. As shown in the figure, the surface light source device of the present embodiment is configured to include a light guide 3, a linear primary light source 1, a light deflecting element 4, and a light reflecting element 5. At least one side end surface of the light guide body 3 is a light incident end surface 31, and a surface which is slightly orthogonal to this is a light exit surface 33. The primary light source 1 is disposed to face the light incident side surface 31 of the light guide 3, and is covered by the light source reflector 2. The light deflecting element 4 is disposed on the light exit surface of the light guide 3. The light reflecting element 5 is disposed facing the back surface 34 in the opposite direction of the light exit surface 33 of the light guide 3. The light guide 3 is arranged in parallel with the XY plane, and has a rectangular plate shape as a whole. The light guiding body 3 has four side end faces, of which at least one of the two side faces parallel to YZ is used as the light incident end face 31. The light incident end face 31 is disposed to face the primary light source 1. The light emitted from the primary light source 1 is incident from the light incident end surface 31 to the inside of the light guide 3. According to the present invention, the light source may be disposed to face the other side end faces of the side end faces 32 on the opposite side to the light incident end face 31. The two main faces which are slightly orthogonal to the light incident end faces of the light guide 3 are located at positions slightly parallel to the XY faces. One of the faces (the upper surface in the figure) is the light exit face 33. At least one of the light exit surface 33 or the back surface 34 thereof is a directional light emitting device composed of a rough surface. Therefore, the light incident from the light incident surface 31 is guided into the light guide body 3, and the incident light is incident on the light. 1216050pif.doc is the 9th cents 2428 Chinese manual without a slash correction. Amendment date: August 23, 100 The end surface 31 and the light exit surface 33 of the exit surface 33 emit directional light. The == cloth peak direction (peak light) and the light exit surface == degree 疋 is α. If the angle α is, for example, the full width of the half value is, for example, 10 to 4 degrees. &amp;, the emitted light luminosity distribution is formed on the main surface of the light guide body 3. The average angle of the _ 0a 尺 尺 is an angle between 1 and 12 degrees. This angle is more ideal. Within the u range. The method of measuring the average tilt angle will be described later. In order to control the directivity of the light emitted from the light guide 3 on the surface (YZ plane) parallel to the primary light source i, the other main surface on which the directional light emitting means is not disposed is preferably the surface on which the lens _ is formed, and is arranged A plurality of lens columns extending in the vertical direction (x direction) in the spot light incident side surface 3!. Fig. 1 shows a state in which a multi-oil lens _ is formed on a light-emitting surface 33 and a multi-oil lens _ extending along a direction slightly perpendicular to the light-emitting end surface 31 (χ direction) is formed on the back surface 34. According to the present invention, the lens formation surface 'back surface 34 is formed as a rough surface on the light exit surface 33. As shown in Fig. 1, on the back surface 34 of the light guide body 3 Or, on the light exit surface 33, when forming a lens array forming surface for controlling the directivity of the YZ plane, the lens array used may be a ruthenium array, a cylindrical lens array, a V-shaped trench, or the like extending slightly in the x-direction. However, γζ 13 1356235 16050pif.doc can also be used to modify the date: August 23, 2014 as the 94102428 Chinese character description without a slash correction. The shape of the cross section is made into a slightly triangular prism array. According to the present invention, When the tantalum array forming surface is formed on the back surface 34 of the light guiding body 3 as the lens array forming surface, the apex angle is preferably in the range of 85 to 11 Torr. This is because the apex angle is set in this range. Inside 'can make hair from the light guide Light emitted light appropriately set, can improve the brightness of the surface light source device. Better than this angle range between an angle 9〇~1〇〇 degrees.

In the light guide body of the present invention, a desired optical array shape is accurately manufactured to obtain stable optical performance, and in order to prevent wear and deformation of the top of the crucible during assembly work or use as a light source device, A flat portion or a curved portion may be formed on the top of the prism array. Further, in the present invention, it may be used in combination with the light exiting means formed on the light exit surface 33 or the surface 34 thereof to increase the direction in which the corpse is diffusely diffused in the light guide body. Slight light injection mechanism.

The average tilt angle 0a of the light incident body 31 in the thickness direction of the light incident end face 31 is 3 degrees or more and 12 degrees or less. When the average tilt angle of the light guide body thickness direction d (Z direction: see FIG. 2) of the light incident end surface 31 is set, the light distribution in the pupil plane is appropriately adjusted. In particular, light emission (light amount and emission angle distribution) in the vicinity of the light incident end surface of the light guide light exit surface 33 becomes appropriate, and uneven brightness occurring in the vicinity of the light incident end surface caused by the thinning of the light guide body is difficult to use with the eyes. Recognized. If the average tilt angle is less than 3 degrees, the light of the light guide is incident, and the amount of light emitted from the area near the surface is reduced, causing the shell of this area to be too low. On the other hand, if the average tilt angle Ga exceeds 12 degrees, the guide 14 1356235 16050pif.doc is the 94102428 Chinese manual without a scribe correction. Correction date: The amount of light emitted from the vicinity of August 23, 100 will be too much. This will be too high' to achieve the purpose of reducing the unusually strong emission of light in the oblique direction. Light incident end face (4) The average tilt angle ea in the thickness direction of the light guide body 3 is preferably 5 degrees or more and a small value. A more desirable angle range is 6 degrees or more and less than, for example, k can be obtained by measuring an inclination angle using an ultra-deep hybrid measuring microscope (for example, VK_8500 [trade name] manufactured by ENCE Corporation). In other words, i is tilted by the angle t吏? The measurement microscope is used to measure the i-nor and the ten-point average roughness Rz of the light incident end face of the light guide 3, and to determine the respective measurement points (in this case, One: The range that can be measured by human is 110μηη. Therefore, the thickness direction of the light guide is measured except for the nl5 positions except the two ends—the absolute value of the tilt angle, and then the average is obtained, and finally the desired value is obtained. . The light emission characteristics of the average light source device affect not only the above-mentioned certain ί angle, but also the distribution of the inclination angle of the measurement point. In particular, the tilting direction of the oblique direction near the light incident end face is abnormally strong: the main tilt angle of the 'angle number distribution towel' obtained by the above-mentioned ultra-depth shape measuring microscope is larger than 40% of the section 2 twist component, for example. effect. This ratio is preferably less than or equal to 0'. The foot is best suited to reduce the oblique direction near the incident end of the light. 15 丄妁 6235 16050pifd〇c Correction date: August 23, 100 is the 94th yang lion __ occur. According to the ultra-depth shape measuring microscope, it is preferable that the light incident end surface 31 is smaller than the above-described light incident end surface 31, for example, by a rough surface. The method of rough surface can have many choices, such as cutting tools such as secret knives, grinding methods such as ochre, sandpaper, polishing, etc.; sandblasting; electric discharge machining, electrolytic polishing, chemical grinding, etc. The sand particles used may be glassy __ substances, or gasified _ polygonatum. It is more suitable to use polygonal materials because it can produce larger coarse sugar surface with astigmatism effect. By adjusting the cutting and grinding process The machining direction can form a thick (4) of the directionality. In order to adjust the diffusion of light in the χγ plane, the amount of Ζ is taken to form a strip-shaped concave-convex shape in the ζ direction, and in order to adjust the light diffusion in the ΧΖ plane, γ is taken. The machining direction forms a strip-shaped concave-convex shape in the Υ direction. There are many different machining directions, and the machining directions can be combined to form A rough surface having no direction f. By processing such a rough surface, the light incident end surface of the light guide body can be directly processed. In the mold device in which the light-transmitting synthetic resin is formed into a light guide body using a molding material, The surface on which the light incident end face of the surface member is formed is formed with a corresponding transfer forming surface, and is re-transferred onto the light transmissive synthetic resin at the time of molding. The light incident end face 31 can be made to be thinner with the light guide body. Direction (z direction) The direction orthogonal to each other (Y direction) extends parallel to each other, and the lens array forming surface of the complex lens column is substituted for the rough surface. The lens array can use the edge 1356235. 16050pif.doc Revision date: August 23, 100 Japanese Patent No. 94102428 has no scribe correction. Mirror array ^ This lens array includes a shape in which the XZ cross-section shape is curved, in order to take care of the problem of improving light diffusion. Figure 3 shows the formation of a lens. An enlarged schematic view of the cross-sectional shape of the end face of the array of light. In this example, the lens surface 31a is made to have an outwardly-out surface of the curved surface with a radius of curvature. The triangular cymbal shape maintains a maximum distance d. The method of forming the light incident end lens array forming surface is preferably a milling tool or the like. The processing of the lens array forming surface can also be directly performed on the light guiding body. In the mold device in which the light-transmitting synthetic resin is used to form the light guide body using the * molding member, the corresponding transfer forming surface can be formed in advance on the surface on which the light incident end surface of the molded component is formed by transfer. At the time of molding, the 0-light incident end surface 31 is transferred to the light-transmitting synthetic resin as a lens array forming surface which is mutually flat in a direction (γ direction) orthogonal to the thickness direction (Z direction) of the light guide body. The plurality of extended lens arrays may be formed by a roughened lens array forming surface that roughens at least a portion of the lens array. The roughening of the rough surface of the lens array can be exemplified by grinding methods such as sandpaper and polishing, sandblasting, electrolytic polishing, chemical polishing, and the like. These rough surface processing can directly process the light incident end surface formed by the light guide lens array. However, in the mold apparatus in which the light-transmitting synthetic resin is formed into a light guide by using the molded component, the corresponding transfer forming surface can be formed in advance on the surface on which the light incident end surface of the molded component is formed and formed, and Transfer to a translucent synthetic resin. As described above, one of the methods for fabricating the light guide for the surface light source device is that 17 1356235 16050pif.doc is the Chinese manual of No. 94102428, and there is no scribe line correction. This correction date: (10) August η, using the molding material 'will transmit light The synthetic resin is molded, and the light guiding element corresponding to the light guiding body is obtained by replicating the shape of the surface of the molding material. Thereby, the surface of the light guide material corresponding to the light exit surface and the back surface of the light guide body is formed in the same manner as the light exit surface and the back surface. Then, the surface of the light guiding material corresponding to the light incident end surface of the light guide is cut to form a light incident end surface, and a light guide for the surface light source device is obtained. Further, another method for producing a light guide for a surface light source is to form a light transmissive synthetic resin by using a molding material, and to form a light exit surface, a back surface, and a light incident end surface by replicating the surface of the molding material. Thus, the light guide for the surface light source device described above is obtained. Further, at the light incident end surface 31, the center line average roughness Ra of the thickness direction of the light guide body obtained by the measurement of the ultra-depth shape measuring microscope is preferably 〇.2 μιη ' and less than or equal to g 4 gm. The ten-point average roughness Rz of the thickness direction of the light guide body obtained by the measurement of the ultra-depth shape measuring microscope is preferably 大于.7 μιη or more and 2 〇μιη or less. In this range, the ratio of the above-described average inclination angle 0a and the degree distribution of the inclination angle in the degree distribution of the inclination angle of 20 degrees or more can be relatively easily set within the required range. The average inclination angle of the surface property 'the light incident end surface 31' is perpendicular to the longitudinal direction of the light guide body (Z direction) (γ direction) is preferably 1 to 3 degrees; the center line average thickness is 3 For 〇〇2~〇10 points, the average roughness Rz is preferably 0.3~2μηη » The average tilt angle is preferably 1.3~2.7 4' 1.5~2.5 degrees between the range is best. The center line average coarse ^ Ra is better than 03.03~0.08μπι, 〇 〇5~〇 〇7μιη is the best. 10 o'clock ^ 18 1356235 16050pif.doc Amendment date: August 23, 100 is the 94102428 Chinese manual without a slash correction. The average thickness Rz is 0.4~1·7μιη is better, to the range between on 5 divisions. For the best. The light guide 3 is not limited to the shape shown in Fig. 1, and various shapes such as a thick wedge shape may be used as the light incident end surface.

The photo-shift element 4 is disposed on the light exit surface 33 of the light guide 3 . The two main faces 4 42 of the light deflecting element 4 are arranged in parallel with each other as a whole, and are each substantially parallel to the face. The surface (the main surface on the light exit surface side of the light guide body 33) among the main surfaces 4b 42 is the light incident surface 41 and the other 42. The light-emitting surface 42 is a flat surface parallel to the light-emitting surface of the light guide 3. The light incident surface 41 is a tantalum array forming surface which is disposed in parallel with a plurality of tantalum arrays extending in the γ direction. The 稜鏡 array forming surface may be a bottom flat portion having a narrow width between adjacent 稜鏡 arrays (for example, a flat portion having the same or slightly narrower width in the X direction of the 稜鏡 array). In terms of light utilization efficiency, it is preferable that the bottom flat portion is not provided, and the tantalum array is continuously arranged in the X direction.

Fig. 4 is a view showing a state in which the light deflecting element 4 is deflected by light. In this figure, an example of the direction in which the peak light (light corresponding to the emitted light distribution bee) emitted from the light guide 3 in the pupil plane is advanced is shown. The peak light obliquely emitted from the light exit surface 33 of the light guide 3 at an angle α is incident on the first pupil surface of the prism array, and is totally totally reflected by the second prism surface, and is almost along the normal direction of the light exit surface 42. Shoot out. In the facet, the brightness of the normal direction of the light-emitting surface 42 can be sufficiently raised in a wide area due to the action of the array of the back surface 34 of the light guide. In order to provide a reference 'Fig. 5 shows the light incident end face of the light guide exit surface 19 1356235 • · 16050pif.doc is the 94102428 Chinese manual without a slash correction. Amendment date: August 23, near the area of light emission Schematic diagram of the situation. For reference, Fig. 6 is a view showing a light exiting pattern of a light deflecting surface of a surface light source device, particularly a region near the light incident end face of the light guide. As shown in FIG. 5 and FIG. 6, in the central portion region of the light guide light exit surface 33 (a region other than the vicinity of the light incident end surface), as shown in FIG. 4, the peak light of the light incident from the light incident end surface 31 is It is emitted at an angle α from the light exit surface 33, and is incident on the light deflecting element 4 from one of the pupil planes, and is internally reflected by the other surface, and then emitted in the normal direction of the light exiting surface. On the other hand, in the vicinity of the light incident end face of the light guide light exit surface 33, the peak light is emitted at an angle β with the light exit surface 33, and is incident on the light deflecting element 4 from one of the pupil faces, depending on the angle β. The internal reflection of the other prism face of the light deflecting element 4 is received or not received, and is emitted at an angle γ to the light exiting surface. The above-mentioned angle β valley is susceptible to the surface property of the light incident end surface 31 of the light guide body, and is particularly susceptible to the distribution of the average tilt angle 0a and the tilt angle number in the meandering plane. If the average tilt angle 0a is too small 'the angle β is smaller than the angle α, the amount of light emitted from this region is reduced. As a result, the brightness of this area is too low, and the brightness uniformity is liable to decrease. If the average tilt angle 0a is too large, the angle β is larger than the angle α', and the amount of light emitted from this region is increased, whereby the luminance of this region is excessively increased, and the luminance uniformity is liable to lower. If the angle β is larger than the angle α, the light incident on the light deflecting element 4 is not reflected by the internal surface of the prism surface, but exhibits only a component which is emitted by the refraction. If this component becomes too much, the extraordinary light in the oblique direction in the vicinity of the light incident end face becomes conspicuous. 20 I356235 .. 16050pif.doc For the Chinese manual No. 94l〇2428, there is no slash correction. The date of this revision is: August 23, 1 • • If the proportion of the component with a slant angle greater than or equal to 20 degrees in the distribution of the slant angle is too large The light incident on the light deflecting element 4 is not reflected by the internal reflection of the pupil surface, and the component which is emitted only by the refraction action becomes too much. The abnormal light in the oblique direction of the vicinity of the light incident end surface becomes apparent. . To this end, the present invention has a light emission state r which is the same as or similar to the central portion in the vicinity of the light incident end face in the range of the inclination angle, and a ratio of the component in which the inclination angle is greater than or equal to 20 degrees in the distribution of the inclination angle number. The range is set within the above-described specific range, thereby maintaining brightness uniformity and suppressing abnormal light emission in the oblique direction of the vicinity of the light incident end surface. In the light deflecting element 4, it is desirable to accurately produce an ideal 稜鏡 shape in order to obtain stable optical properties. At the same time, in order to avoid wear and deformation of the top of the crucible during reassembly or when used as a light source device, the top of the prism array can be made flat or curved. In this case, the width of the top flat portion or the top curved surface portion is set to be less than or equal to 3 μΠ1 'this is advantageous to prevent the brightness of the surface light source device from being lowered and the brightness due to the retention of the cathode screen $screen image. Inconsistent situation. The width of the top flat portion or the curved surface portion is more preferably 2 μm or less, and preferably 1 μηη or less. The primary light source 1 is a linear light source extending in the γ-axis direction. The primary light source 1 can be, for example, a flash or a cold cathode tube. As shown in Fig. 1, in this case, the 'primary light source 1 can be disposed not only to face the side end face of the light guide body 3' but also can be disposed on the other side end of the opposite side as required. 1 1356235 16050pif.doc For the Chinese manual No. 941〇2428, there is no slash correction. The date of this amendment is: August 23, 100. A point light source such as a light-emitting diode (LED) can be used to discharge a plurality of point light sources at appropriate intervals. The light source reflector 2 is used to reduce the loss of the primary light source and introduce it into the light guide body. The material f can be made as shown in the figure, as shown in the figure, the light source emitter 2 avoids the light deflecting element 4, and passes outside the edge of the light (four) piece 5 through the outer surface of the secondary light source The edge portion of the light-emitting side surface of the light guide 3 is curled. In addition, you can also reverse the light source

The emitter 2 is deflected from the outer side of the secondary light source i from the outer side of the edge portion of the light-reflecting ear 5 toward the light-emitting surface end edge portion of the element 4. It is also possible to provide a reflection member of the light source reflector 2 such as a disc on the side end surface other than the light-emitting end surface 31 of the guide 3. For example, a plastic film having a metal vapor evaporated reflective layer on its surface can be used as the light reflecting member 5. In the present invention, a light reflecting layer or the like can be formed on the back surface 34 of the light guiding body 3 by metal vapor deposition as the reflecting member 5 instead of the reflecting sheet.

The light guide 3 and the light deflecting element 4 of the present invention can be composed of a synthetic resin having a high light transmittance. Such resins may include methacrylic resins, propylene resins, polycarbonate resins, polyester resins, and gas vinyl resins. In particular, methyl ketone fine resin is an excellent material because of its high light transmittance, good heat resistance, excellent mechanical properties, and ease of processing. The mercapto propylene resin is a resin containing methyl methacrylate as a main component, and methyl methacrylate is preferably 80% by weight. Λ or above. The surface structure of the light guide 3 and the rough surface of the light deflecting element 4 is manufactured, or the tantalum array or the double convex 22 1356235 -. 16050pif.doc is the 94102428 Chinese manual without a slash correction date: August 23, 100 In the case of a surface structure such as a lens (lentiCUlarleilS) column, a transparent composite tree can be formed by hot press molding using a molded member having a desired surface structure. Alternatively, it may be screen printing, extrusion molding or injection molding, etc., while the money shape is required for the job. Further, a structural surface is formed by spraying a photo-resin or a photo-curable resin. On the surface of a material such as a polyvinyl acetate resin, an acrylic resin, a polycarbonate resin, a vinylidene resin, or a polymethyl ketone acid imino resin, etc. A rough surface structure or a lens array structure composed of an active energy ray-curable resin. It is also possible to integrate such a sheet into another transparent substrate by means of adhesion, soldering or the like. As the active energy ray-curable resin, a polyfunctional (i)acrylic acid compound, a vinyl compound, a (meth)acrylic acid, an aromatic hydroxy compound, or a metal salt of (meth)acrylic acid can be used. On the light-emitting surface (light-emitting surface 42 of the light deflecting element 5) of the surface light source device including the above-described primary light source 1, light source reflector 2, light guide 3, light deflecting element 4, and light reflecting element 5, The transmissive liquid crystal display element 8 shown in Fig. 2 constitutes a liquid crystal display device using the surface light source device of the present invention as a backlight source. The liquid crystal display device of Fig. 2 can be observed by an observer from above. EXAMPLES Next, the present invention will be described by way of examples and comparative examples. (Embodiment 1) In this embodiment, a light guide body described in the embodiments of Figs. 1 to 4 and a surface light source device using the same are manufactured. The effective area for mirror treatment is 230mmx290mm and the thickness is 23 1356235 16050pif.doc Revision date: August 23, 100. For the 941G2428 Lions Duck, the overall surface of the 3mm unrecorded steel plate is sandblasted using glass beads. On the other hand, on the surface of another unrecorded steel sheet having an effective area of 230 mm x 290 mm and a thickness of 3 mm, the printing surface is transferred by a cutting to form a apex angle 100. A prism column forming surface in which the top end curvature radius 15 μm and the pitch 5 () μηη are continuously arranged.

Using the two formed members obtained by the above method, the transparent acrylic resin is injection-molded, and has a rectangular shape of 23 mm × 29 mm and a thickness which is continuously changed from one long side to the other side by 2.2 mm to 〇 7 mm. One of the main faces is roughened, and the other main face is used as the light guiding material of the 稜鏡 array forming surface.

Using a cutting machine, a side end surface (a side end surface having a thickness of 2.2 mm) corresponding to one side (long side) having a side length of 29 〇 min of the light guiding material is cut along a direction parallel to the main surface to perform roughing. By forming a light incident end surface, a light guide body having a light exit surface composed of a roughened main surface of a light guiding material and a back surface formed by a tantalum forming surface of the light guiding material is formed. Extending in a direction perpendicular to the incident end face of the light). About the light incident end surface of the obtained light guide, the surface = degree in the thickness direction of the light guide was measured. &amp; For the measurement, the ultra-depth shape measuring microscope (VK-8500 type [product name]) of the company (Japan) was used. First, the center line average roughness Ra and the ten point average thickness Rz of the light guide body in the thickness direction of the light incident end face 31 of the light guide body 3 are measured, and Ra, 24 1356235 in the measurement range is read. 16050 pif.doc is Chinese manual No. 94102428 has no slash correction. This correction date: UK) August 23 曰 • 112 value. Use a 100x pair of objective lenses. In the measurement range, the cross-sectional shape in the thickness direction of the light guide was taken out under smooth conditions (simple average soil 2), and the absolute value of the inclination angle of each measurement point was obtained, and after averaging, the average angle of inclination 0a was obtained. Under such measurement conditions, the range that can be measured at one time is left and right. Therefore, 50 μηι′ at both ends of the light guide body in the thickness direction of the light guide body light incident end face are measured at five equal intervals in other regions, and then each parameter is determined. average value. The results are shown in Table 1. The primary light source 1 composed of a cold cathode tube along the longitudinal direction of the light guide 3 is disposed so as to be opposed to the light incident end surface of the light guide 3, and is reused by the light source reflector 2 (silver reflective film manufactured by Liguang Co., Ltd.). . A light-diffusing reflective film (Ε6〇 [trade name] manufactured by Toray Industries, Inc.) was attached to the other side end faces. The light reflecting element 5 composed of the light-scattering reflection sheet is disposed on the back surface 34 which is the surface on which the light-guiding body 3 is formed. Then load the above structure into the frame. The maximum peak value of the exit light illuminance distribution (inside the plane) of this surface light source device is 7 degrees with respect to the normal direction of the light exit surface, and the full width at half value is 22.5 degrees. • On the other hand, a prism sheet is formed using a propylene-based ultraviolet curable resin having a refractive index of 1.5064, which is formed by a plurality of prism columns arranged in series and arranged in a thickness of 125 μm. On one surface of the film, each of the arrays is a convex curved surface having a radius of curvature of 稜鏡μιη and the other side is a planar shape with an interval of 50 μm. The optical deflecting element 4 composed of the obtained cymbal sheet is placed on the side of the light-emitting surface (mat surface) 33 of the light-guide body 3, and the ridge line of the matrix and the light guide 3 are arranged. The light incident end face 31 is flat. 25 1356235 16050pif.doc Revision date: August 23, 2014 is the 94102428 Chinese manual. There is no scribe line correction. The plane shape of each prism column faces the light incident end of the light guide 3. A liquid crystal display element is disposed on the light deflecting element 4. In the surface light source device obtained as described above, when the primary light source i is turned on and the hair is visually observed, the luminance in a region of about 30 mm from the light-emitting person end face 33 toward the x-direction is almost the same as that of the other regions. Light that is specific to the tilt direction of the region near the light guide end face 33 is emitted. $Example 2 The cutting machine roughens one side end surface of the long side of the corresponding light guiding material, and in the second embodiment, the cutting speed at the time of cutting the machine is changed to the slowing-closing speed. Except that the other is carried out in the same manner as in Embodiment 1, thereby obtaining a surface light source device. With respect to the obtained surface light source device, the primary light source i is turned on, and the light-emitting surface is visually observed, and the luminance in the region from the light-guide body light-emitting end face 33 to the x-direction of about 3 mm is almost the same as that of the other regions. of. Further, no specific light is emitted in the oblique direction of the region near the light incident light incident end face 33. Embodiment 3 The cutting machine roughens one side end surface of the long side of the corresponding light guiding material, and in the second embodiment, the cutting speed at the time of cutting by the cutting machine is changed to a slightly faster-point speed. Except that the other is carried out in the same manner as in Embodiment 1, thereby obtaining a surface light source device. Regarding the obtained surface light source device, the primary light source 1 is illuminated to visually measure 26 1^56235. 16050pif.d〇c Revision date: August 23, 2010

For the Chinese manual No. 94102428, there is no underline repair W, and the light-emitting surface is almost the same as the luminance in the region from the light-guide body light-emitting end face 33 to the X direction of about 3 mm ^4. On the other hand, the specific light emission in the oblique direction of the region near the light guide body end face 3S is hardly noticeable. Eight Comparative Example 1 The boring machine ^ is used to make the end face of the long side of the corresponding light guiding material thick, and the second example is the speed of the cutting speed ί when using the cutting machine. Others were carried out in the same manner as in Example 1, whereby a light source device was obtained. The surface light source device is illuminated to illuminate the primary light source 1 to visually measure the left ancient light from the light incident end face 33 toward the Χ direction by about 30 mm darker than the other portions, and observe the dark band, bright &amp; oblique i to the ship The ratio of the area near the light incident end face 33 of the light guide body is also observed. The surface knives are formed by changing the thickness of the one side end surface of the long side of the light guiding material to a non-use manner, thereby obtaining a surface light source device which is observed by the surface light source and observed in the first embodiment. , illuminate the primary light source 1 to visually measure == from the light-injecting body light incident end face 33 to the x direction, the uniformity of the uniformity becomes lower than that of the other portions, and the bright band is observed, and the bright 27 1356235 16050 pif.doc is Chinese manual No. 94102428 No slash correction This revision date: i〇0年年月月23曰[Table 1] Example 1 Example 2 ★Example 3 Comparative Example 1 Comparative example soil average inclination angle θ (°) 8.6 5.0 11.0 2.9 18.0~ Inclination angle 20 degrees or more Component existence ratio (%) 18.0 12.0 22.0 16.0 55.0 Ra ( μιη ) 0.26 0.21 0.28 0.15 0.48 Rz ( μπι) 1.03 0.90 1.40 0.68 2.10 Quality (brightness distribution) Good good good light near the entrance end face Brightness in the vicinity of the light entrance end · (abnormal light emission) Nothing is almost nothing. Although the present invention has been disclosed in the preferred embodiment as above, it is not intended to limit the invention, and anyone skilled in the art will not be able to = Within the spirit of the scope of the invention, when the defined may make various modifications and variations, so the scope of the present invention when attached to the visual range, whichever patent. [Simple description of the map]

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing an embodiment of a surface light source device according to the present invention. Figure 2 is a partial cross-sectional view of the surface light source device of Figure 1. 3 is a partial cross-sectional view of a light guide.

Fig. 4 is a schematic view showing the light deflection _ of the light deflection. The second is a schematic view showing a light-emitting state of the light-emitting body light exiting surface 'particularly, the vicinity of the light incident end face. In particular, the light incident light is incident on the light-emitting surface of the light deflecting element, and the light source is emitted from the vicinity of the end surface. [Main component symbol description] 2: Light source reflector 28 1356235 Revision date: August 23, 2013 16050pif.doc is the Chinese manual of No. 94102428. There is no scribe correction. The light guide body 31: light incident end face 31a: facet 32: side end face 33: light exit face 34: back face 4: light deflecting element 41: light incident surface 42: light-emitting surface 5: light reflecting element 8. liquid crystal display element

29

Claims (1)

1356235 16050pif.doc is the Chinese manual of No. 94102428. There is no slash correction. The date of this amendment is: August 23 of the following year. The scope of application for patents: (4) Another revision of the month 1. A light guide for a surface light source device, and a primary light source combination is used for constituting a surface light source device, and guides light emitted from the primary light source. The light guide for the surface light source device includes a light incident end face and light guided by the light emitted by the primary light source. a light exiting surface emitted by the light and a back surface opposite to the light exiting surface, and characterized in that the light incident end surface is an anisotropic rough surface, and the light guiding is measured according to the measurement of the ultra-depth shape measuring microscope The average inclination angle of the thickness direction of the body is 3 degrees or more and 12 degrees or less, and the center line average roughness Ra of the thickness direction of the light guide body measured by the measurement of the ultra-depth shape measuring microscope is 大于.2 μιη And less than or equal to 0.4 μm, and the average tilt angle in the direction perpendicular to the thickness direction of the light guide body measured by the measurement of the ultra-depth shape measuring microscope ~ 3 degrees, and it was determined by an ultra-depth shape of the center line in a direction perpendicular to the thickness direction of the guide light microscope measurements measured average roughness Ra of 002~0 1μιη. 2. The light guide for a surface light source device according to claim 1, wherein the number of inclination angles of the light guide body in the thickness direction of the light incident end surface measured by the ultra-depth shape measurement microscope The ratio of the presence of the component having a tilt angle of 20 degrees or more in the distribution is 4% or less. 3. The light guide body for a surface light source device according to claim 1, wherein the light incident end surface has an average thickness of ten points in the thickness direction of the light guide body measured by the measurement of the ultra-depth shape measuring microscope. Degree Rz is greater than or equal to 0.7μηη and less than or equal to 2.0μπι, and the thickness direction of the light guide body is 30 1356235 16050pif.doc is the 94102428 Chinese manual without a slash correction straight direction #10 point average roughness Rz is greater than or equal to 〇 〇3 qing and less than 2μπι. ,Inch [The conductor for a surface light source device according to claim 1, wherein the four-light human end face is a rough sugar surface, or a plurality of lenses extending parallel to each other in a direction perpendicular to the thickness direction of the light guide body. a column, ^ and a cross-sectional shape of the lens containing the sister's lens, or having a plurality of columns extending parallel to each other in a direction perpendicular to the thickness direction of the light guide, and at least a portion of the lens column is made The roughened rough face forms a face. 5. A surface light source device, wherein the primary light source is disposed opposite to a light incident end surface of the light guide device for a surface light source device, wherein the light guide device is combined with a primary light source and used for a surface light source device And guiding the light emitted from the primary light source, wherein the light guide body includes a light incident end surface on which the light emitted by the primary light source is incident, a light exit surface emitted by the guided light, and The opposite side of the light exits the surface, Amendment date: August 23, 1st, 4. The mirror is the non-isotropic thick chain surface of the light incident end face, and the average tilt of the thickness direction of the light guide body measured by the measurement of the ultra-depth shape measuring microscope The angle is greater than or equal to 3 degrees and less than or equal to 12 degrees. In the light incident end surface, the center line average roughness Ra of the thickness direction of the light guide body measured according to the measurement of the ultra-depth shape measuring microscope is 0.2 μm or more and less than Is equal to 〇.4μιη, the light incident end face is an anisotropic rough surface, and the direction perpendicular to the thickness direction of the light guide body measured according to the measurement of the ultra-depth shape measuring microscope 31 1356235 16050pif.doc Revision date: 100 years On August 23rd, the Chinese manual of No. 94102428 has an average tilt angle of 丨~3 degrees, and is measured in the direction perpendicular to the thickness direction of the light guide body according to the measurement of the ultra-depth shape measuring microscope. The center line average roughness Ra is 〇.〇2~Ο.ΐμπι. A surface light source device according to claim 5, further comprising a light deflecting member disposed on the light emitting surface of the light guiding body and having light emitted from a light emitting surface of the light guiding body The incident light incident surface and the light exit surface that violates the countermeasure with the light incident surface. 7. The surface light source device of claim 6, wherein the The light-emitting element has a plurality of arrays, each of which extends along the light incident end surface of the light guide body and is arranged parallel to each other on the light-incident surface, wherein each of the arrays further includes: The pupil surface is such that light from the exit surface of the light guide body is incident; and the second pupil surface reflects the incident light as an inner surface. 8. The surface light source device according to any one of claims 5 to 7, wherein the primary light source is a line light source. 9. The surface light source device of any one of clauses 5 to 7, wherein the primary light source is a point light source. A light guide for a surface light source device according to any one of the first to fourth aspects of the present invention, characterized in that a molded member is used. Forming the light-transmitting synthetic resin, and transferring the shape of the surface of the molded component to obtain a light guiding material corresponding to the light guiding member, thereby forming and guiding the light emitting surface and the back surface a surface of the light material corresponding to the back surface of the light material; and a surface corresponding to the light incident end surface of the light guide material 32 1356235 ·. 16050pif.doc is the first side of the 2428 The book has no scribe line correction. This correction date is August 23, 曰. The cutting process is performed to form the light incident end face, and the light guide for the surface light source device is obtained. ^ U. A method for fabricating a light guide for a surface light source device, which is used for producing a surface light source device according to any one of the items 1 to 4, characterized in that the formed member is used for light transmission. The amount of the synthetic resin is small, and the shape of the surface of the formed member is transferred, and the light exit surface, the back surface, and the light incident end surface are formed to obtain the light guide for the surface light source device. 33