TW502129B - Planar lighting device and light guides used therein and method of making light guides - Google Patents

Abstract

A light guide member (2) includes a first light guide section (2A), which is a non-scattering light guide region, and a second light guide section (2B) which is a scattering light guide section and is made of material of the same composition as that of the first light guide section (2A), but mixed with scattering particles. Therefore, while the concentration of the scattering particles in the second light guide section (2A) is retained as high as possible, the gradient of the light scattering power can be increased to thereby allow a light exit surface to exhibit a high brightness and uniformity in luminance over the entire surface thereof. Also, the first light guide section (2A) and the second light guide section (2B) are formed by bonding them in the thicknesswise direction by the effect of a cohesive strength exhibited by material themselves therefore. Accordingly, there is no need to separately mold and then bond the first and second light guide sections (2A, 2B), the light guide member (2) can be molded at a time, accompanied by increase in productivity. In addition, since no bonding agent is used at the interface, the flatness can be secured with high precision.

Description

502129 Case No. 88120391_Year Month Amendment _ ^ V. Description of the Invention (1)! The present invention relates to the use of a backlight (or back light) for liquid crystal displays that enables light from a light source to enter the light guide. Surface lighting device in which light is scattered and emits illumination light from the I exit surface of the light guide body, and a light guide body I and a molding method for the light guide body used therefor.

II In the past, a flat lighting device such as a backlight for a liquid crystal display has a flat plate-shaped light guide and a rod-shaped light source arranged on the end face thereof, so that the light incident from the light source into the light guide is scattered. It is well-known that a bright light is emitted from the light-exiting surface of the light guide, and the entire back surface of the liquid crystal is evenly illuminated. In recent years, with the increase in the light-emitting area of the light guide, the required size of the planar lighting device has become larger and larger, and at the same time, the requirement for thinning has become stronger. Of course, with this large-scale and The uniformity and uniformity of the illumination brightness required for thinning is also more urgent. I. Conventional device (1) As shown in the thirteenth figure, a light guide 42 having a transparent resin plate having a high light transmittance, such as an acrylic resin plate I, and a reflection plate 27 | A flat lighting device composed of a light source 4 such as one of the cold cathode tubes disposed on the end face 46 of the light guide body. This device is to form the reflective surface 44 of the light guide body 42 by using screen printing, sandblasting and other techniques to form a fine The dot-like random reflection layer I 2 9 allows light emitted from the light source 4 to enter the transparent resin plate 42 and propagate through the random 1 reflection layer 29, and is then emitted from the emission surface 45. Similar to this, a planar lighting device in which a random reflection layer is formed on one side of a transparent resin plate has the advantage of being easily reduced in thickness. I. Another configuration of the conventional device (2) is as shown in FIG. 14. | It has a light guide body 70 formed by mixing scattered particles having a different refractive index from the matrix into the matrix I of a transparent resin, and A flat lighting device of a rod-shaped light source 4 such as a cold-cathode tube disposed on an end surface thereof is also known. Also, wedge

^ 2129 _3 Case number 88120391 V. Description of the invention (2) It is also known that the light guides are superimposed in the original direction of the plate and a flat light guide replaces the light guide of the conventional device (2). This kind of training device (3) is shown in the fifteenth figure, 'the first light guide portion 80A formed of a transparent resin (non-scattered light-guiding area)' and the scattering in the transparent resin is mixed with different inflection rates. The second light guide portion 8 of the scattered light guide area formed by particles overlaps with the thickness direction of the light guide plate 80 (such as Japanese Patent Application Laid-Open No. 7-134298, US Patent No. 899, 552). There is also a conventional device (d). As shown in the sixteenth figure, two pieces of wedge-shaped light guides 90 and 90 which have scattered light particles with different concentrations of transparent resin mixed with each other and change their light dispersion are determined by the thickness of the plate. The plane lighting device (Japanese Unexamined Patent Publication No. "" ") is superimposed to form a light guide plate 90. According to the above-mentioned conventional practice, the light sources f, ^ t L, clothes 1 and 2), (4) have light. Comparison of multiple flat 5 3 3 flat lighting devices with different scatter performance compared with the above-mentioned conventional device (2)

Therefore, .6 adjusts the first dispersive performance throughout the entire output surface of the light guide plate. When the output surface is loose, and t ^ ⑽ J is small, the uniformity of brightness is easy to obtain. |, The conventional device developed for the enlargement and thinning of the rβ I device (five) has the device shown in Figure 10 and Figure 10. This device consists of: as the conventional device (four) ^ ^ 妁 by two A light-guiding light guide f composed of a piece of wedge-shaped light-guiding portions 51A and 51B * a mountain-shaped light-guiding body 50 formed in a triangular prism shape, and a relative lighting device. The plane formed by a pair of light sources ^ 4 at the two end faces of the body M will form a polygonal pyramidal shape, and the light sources will be arranged on the clothes. Can be obtained by incident =. The shape of the mountain shape can be, for example, a triangular pyramid shape and a quadrangular pyramid shape, but it can be sanctified to form an extremely flat mountain shape. This conventional device (six) has, for example, a flat view of a quadrangular pyramid (pyramid type) as shown in the perspective view of the eighth figure A. Case No. 88120391, Description of the Invention ^ Mountain-shaped ίΛ, 视 _. Light guide 1 0. The eighteenth β circle shows the guideline of the 1V-! V line in FIG. 18A. This light body is formed by the first light portion (non-scattered area) with an inverted quadrangular pyramid (pyramid) recess. 11 And a second guide (scattered area) 12 having a quadrangular pyramid-shaped convex portion 12. The forming method of the light guides of the conventional devices (3) to (6) is generally known as a method of forming two light guides respectively and then attaching them to a body. According to the above-mentioned conventional devices (1) and (2), it is suitable for a small output area: However, if the output area is increased to increase its size, it is difficult to obtain high brightness and uniformity (uniformity) of brightness. . Because the conventional device (1) ^ compensates for the phenomenon that the brightness decreases as it moves away from the light source, it is necessary to change the random reflectance that is linked to the light distance (the distance from the end face of the light guide), such as increasing mouse reflection as the distance from the light source increases. Layer, the uniformity of brightness is not tolerable. As for the conventional device (2), because the light source is single, the highlight cannot be obtained. The conventional device (2) is described below. Area) 80A and the second light guide (scattered guide ° after molding, bonding with adhesive, because molding, knife, workability is not good, the production cost is also high, in addition, there are It is difficult to ensure the accuracy of the plane. The conventional device (4) uses the concentration of two guide particles to change the light dispersion performance. The two light guides 2 have different dispersion differences, that is, light dispersion. The gradient of chaotic performance is limited; when phase = particle concentration type, the amount of light emitted must follow the field far away from the light / N, and the distance between the sleeping tea and the eagle is the same as that of the large light. And the increase, when the gradient of distracting sexual offenders is small, then Unable to stay away

Page 8 ___ 疋 · 's position guarantee must be 502129 _ Case No. 88120391 _ year and month correction _ > I 1 ~ V. Description of the invention (4): The amount of injection is required, so there is a problem that the uniformity of brightness cannot be obtained . In addition, if the scattered particle concentration of one light guide is reduced to a relatively low level; (for example, 0.01% by weight), it is difficult to make the light guide.

In addition, in the conventional devices (2) to (6), due to the difference between the angles of the reflecting surface and the exit surface of the end face of the wedge-shaped light guide, the light rays that enter the wedge-shaped light guide from the light source will be repeatedly emitted and reflected in the wedge. , So that the light emitted from the exit surface interferes with each other, and a bright line (glow I-line) bright spot is generated near the light source on the exit surface. In order to eliminate this bright spot, another light must be arranged near the light source i in the past. Reflective material or light absorbing material. t _!. | In addition, the conventional devices (2) to (6) have the problem that a bright spot different from the foregoing occurs on the exit surface near the light source. For example, as in the conventional device (2) of FIG. 14, the electrode portions 4a at both ends of the light source (cold cathode tube) 4 hardly emit light. Therefore, the light source 40 faces the light guide body facing the electrode portion 4a. Insufficient brightness on both sides of the 70 i causes the brightness of the exit surface of the side to decrease, | resulting in bright spots of outgoing light. Therefore, in order to prevent the occurrence of this bright spot, the light source 40 must be arranged so that both ends thereof extend beyond the side surface 70b of the light guide 70, and this excess portion will become a frame portion of the display screen, and it is quite difficult to narrow the frame of the display screen. On the other hand, as in the conventional method (3) to (6), the light guides are formed into I _ type methods. For example, after the first and second light guides are separately molded, they are mutually bonded with an adhesive or the like. The method of bonding together is known. However, according to this method, the workability of bonding after molding is not good, and the cost is also increased. Moreover, it is difficult to ensure accuracy because an adhesive is used at the bonding interface. This phenomenon is particularly noticeable when the light guide is made larger and thinner. at this time,

Page 9: 502129 Case No. 88120391_Year Month Amendment_: V. Description of the invention (5) From the viewpoint of productivity, if there is a flat mountain or slope shape corresponding to large and thin, use conventional technology The following problems are caused by the injection molding method. In other words, when the light guide is injection-molded, generally, as shown in FIG. 18B, an injection port 13 corresponding to the molding die is provided at a portion of the outer portion (peripheral side portion) forming the display surface of i. The reason is that when the injection port 14 of the corresponding molding die is set on the opposite part of the display surface, a tiny burr (injection mark) will be left on the display surface after molding, and this burr becomes a flaw pair. Display effects have a negative effect. Therefore, it is only possible to inject the resin material from the outer side, but when the bottom top portion 11a of the bottom recessed portion of the first light guide portion 11 is formed to be thin (i.e., the cavity of the molding die: the gap is narrowed), The resin is difficult to flow to this part, and it becomes necessary to increase the thickness of the bottom top portion 11a to a considerable degree due to |, and it is difficult to reduce the thickness. In addition, if the resin is injected from the periphery (outside) part, the flow distance of the resin from the outer side of the side to the outer side of the other side is too long, and the force and load on the injection pressure increase, resulting in excessive deformation of the resin. , Causing uneven resin distribution | i, causing uneven brightness problems. j | Furthermore, when the first light guide portion 11 is formed by the injection molding method, and then the second light guide portion 12 is preformed, the top portion 11a of the inner bottom I of the bottom concave portion of the first light guide portion 11 is thin. Due to the relationship of the injection pressure, the pressure will be concentrated in this part and the heat (temperature) will increase. Therefore, when the resin of the second light guide part 12 flows, the resin distribution unevenness occurs at the bottom top part 11a. This causes a problem that occurs when the brightness is uneven. The present invention aims to solve the problems described above, and provides a planar lighting device that can obtain uniform brightness even if the size and thickness are reduced, and is used for

Case number 88120391

Amendment V. Description of the invention (6) The high-quality light guide and the ancient planar lighting device of the tubular light self-light guide adopt the same part, and the phase light is scattered in the direction of the thickness of the scattered light guide plate. And the law of refraction at the end face of the light guide travels while the light diffuses. It can be emitted for light guide. Roots and their distribution effects Lighting products In order to achieve the above-mentioned, the productive molding method. A flat plate-shaped guide ^ is provided as a source of a configuration example of the present invention, and the light from the light source is incident on = arranged on the opposite end surface of the exit surface to emit illumination light, the light of the enemy light is dispersed, and the material composition belongs to non- ^ ^ The above light guide system separately describes the material composition of the second light guide section of the first light guide area that is refracted by the light guide area, and is formed by superimposing the scattered particles of different scattered particles, so that from: The self-adhesive force depends on the price of Xinglinshan M. It is required that the light emitted from the light source incident on the exit surface of the self-guided precursor of the light guide to emit the illumination light. According to the present invention, the plane “Zhaomingzhuang W” device is basically based on the incident light having a refractive index greater than that of air. Therefore, according to Snell's Law, the light is combined and reflected inside the light guide._ Only The light incident on the scattered particles is scattered here, and the scattered phenomenon will be generated repeatedly, so that the imported light is only at the interface between the body and the air, and the angle of the light is smaller than the critical angle. The choice of the intensity of the emitted light will also change. Therefore, these design factors will greatly affect the quality, and it goes without saying. Generally speaking, the flat lighting device should be able to emit bright and uniform light. According to the composition of the present invention, The ^ I surface lighting device, in which light enters from the end surface of the light guide and guides the light, is the so-called edge lighting type, which can increase the concentration of scattered particles in the light guide plate and increase the amount of light emitted. 'But if the concentration is excessively increased, the light emission will be particularly promoted in the part close to the light source, and the brightness will decrease sharply as it moves away from the light source.

502129 _Case No. 88120391_ Year, Month, and Day Amendment V. Description of the Invention (7) The bright spots in the emission surface are enlarged, in other words, the concentration of scattered particles needs to be | regulated below a certain limit.丨 On the other hand, if the light guide is composed of two light guides, if the I output area is to be enlarged, the concentration of scattered particles in the two light guides is poor, that is, light scattering performance. The gradient is better. When the size is large, it is necessary to increase the light emission amount as the distance from the light source. If the gradient of the light scattering performance is small, the necessary emission amount cannot be ensured at a position far from the light source. i

I Therefore, for example, as in the case of the conventional device (IV), two kinds of borrowing and mixing are used. 丨

When the concentration of scattered particles in clear resin varies and their respective light scattering is changed 丨 The light guide formed by the light guide of the performance will not be able to obtain uniform bright I

Degree, or uniformity can be obtained, but the brightness of the entire surface is reduced. I The light guide according to the present invention is composed of a first light guide in a non-scattered light guide region and a second light guide in a scattered light guide region mixed with scattered particles. ) In comparison, the concentration of scattered particles in the second light guide portion can be increased as much as possible to increase the gradient of the light scattering performance, so the entire exit surface can obtain high brightness and uniform brightness. In addition, the gradient of the light scattering performance can be increased, which can reduce the mutual interference of the emitted light caused by the angle difference between the reflective surface and the outgoing surface of the wedge-shaped light guide, thereby preventing the outgoing surface.丨

Bright light-like bright spots occur near the light source. Therefore, it is not necessary to provide a light reflecting material or a light absorbing material in the vicinity of the light source as in the conventional technique. In addition, the first resin forming the material of the first light guide portion and the second light guide portion may have different light scattering properties due to the mixing ratio of the fine particles. Therefore, the first resin and the second resin have different light scattering properties. The material itself can use materials of the same composition. The interface of materials with the same composition is naturally easy to adhere when laminated. In addition, the same material has the same refractive index, which means that it is equivalent to

Page 12 88120391

Fifth, the invention is that there is no interface, and the white B 61 mesh will not cause reflection at the interface, so it will not cause the disadvantage of uneven brightness. The reason of the interface: 仏 uses Ϊ:: Ϊ Κ: Even if the resin is made of materials with different compositions, the refractive index difference is, for example, a few halves within 0.1. This brightness ^ does not cause reflection at the interface. No, it's uneven. Long shots will not cause the light guide to be caused by the first light guide. It is best to have a structure that is higher than the first light guide and the second light guide. The first light guide of the second guide of f is equal to ^^^ and has a concentration of scattered particles. 2 According to the thickness direction of the plate [stack: Shier 2. Each light guide uses the third light guide port of the material π to form . Therefore, when the scattered particles are densely produced or thinned, the gradient of J; P; first scattered properties is more *, even if the size is larger than 21. Use the maximum plate thickness within the thickness of the plate to save the flat lighting of the other components of this month. # 罾 光 体 和 面 光光 体: set, with a flat plate-shaped guide from the light source into the light guide ;: : &Quot; ::: (rod-shaped) light source, ... is emitted from the surface, which is characterized by u :: the first light guide part and f guide 3 made of light from the light guide body are made of the same-composition The thickness direction of the material plate is overlapped: the adhesive force of the material itself is used to guide the light guide and the second light guide according to the thickness of the material; ^ 5 the concentration of scattered particles in the material, the first; and Similarly, the light scattering performance of the latter is higher than that of the previous one, which is gradually reduced. Fan- 逡! The leading part is formed as it moves away from the end face of the light guide. ，， # ，， Pass away from the end face of the light guide and thicken the side of the light body, and face toward: the light-adjusting portion of the electrode portion of the light source end. The thickness of the body end surface and the side plate of the light guide gradually increases. Zengliang

Page 13 502129 Case No. 88120391 Amendment Date __ V. Description of the Invention (9): According to the above structure, the light guide has a second light guide section provided at the end of the light source with high light scattering performance. On the side of the electrode part, a brightness adjustment section where the thickness of the end face of the light guide and the side panel of the light guide gradually increases. Therefore, the thickness of the second light guide portion on the side of the light guide body can be increased to compensate for the insufficient amount of light in the electrode portion of the light source, and the interior of the second light guide portion on the side of the light guide body is scattered. Increasing the number of times to increase the amount of light can improve the brightness without changing the exit angle of the side of the light guide. Since the emission angle is not changed on the side of the light guide, that is, there is no disorder in the emission direction, a uniform brightness and high brightness can be obtained. The brightness adjustment part is integrally provided with the body part and is interposed between the body parts of the first light guide part and the second light guide part, and on the end face of the light guide body I and the side surface of the light guide body. Triangular sides are formed on the two sides of the connection line as a common side, and a triangular cone shape with a triangular bottom surface is formed on the body portion. Therefore, the light guide body can be sufficiently improved only by the small brightness adjustment portion. The brightness of the side. In the flat lighting device of the present invention, the first resin and the second resin forming the second light guide are sequentially laminated and formed into a type II flat plate-shaped light guide. The second resin of the two light guides is ejected in sequence | The molding method of laminating and forming a flat plate-shaped light guide is to firstly make the first tree! The grease is injected into the first molding module i I composed of the first mold and the second mold to mold the first light guide portion, and then the second mold is opened and retained in the first mold In the state with the first light guide portion, the second molding module is bonded to the first mold, and then the second resin is injected into the second molding module to form the second light guide portion. The first light guide portion and the second light guide portion are laminated and integrated into one body.

Page 14 502129 Case No. 88120391_Year Month Day Amendment V. Description of the invention (10) According to the above method, because the first light guide part is formed by using a mold,

I i Open the second mold and leave the first light guide part in the first mold state. The mold for the second light guide part is joined to the first mold to form the second light guide part. As long as the mold replaces the second light guide part forming mold with the second mold, the second light guide part can be laminated and formed on the first light guide part. In this way, the complicated procedures of forming the first light guide part and the second light guide part separately and then attaching the conventional method can be avoided, and the composite light guide body can be formed once, so the productivity is greatly improved; It is not necessary to use an adhesive at the interface, which can ensure the accuracy of the plane. Moreover, the first and second light guides are sequentially molded in the mold, which can ensure that the thickness of each light guide is not too thick, which can shorten n! The cooling time of the resin can shorten the production cycle. In addition, the first resin and the second resin may have different light scattering properties due to different mixing ratios of the rhenium particles added, and the materials of the first resin and the second resin use the same composition. Due to the use of the same composition of materials, it is easy to join together at the interface during lamination. Also, because the same material has the same refractive index, it forms as if there is no interface, and it will not cause reflection on the boundary surface, so it will not cause the interface. The unevenness of the brightness 丨 generated by the reflection. The light guide is composed of a first light guide having an inverted mountain-shaped recess and a second light guide having a mountain-shaped shape. The first light guide is configured to remove the first tree grease from the bottom surface corresponding to the recess, The injection port of the first molding die set at the vertex is injected and molded. According to the method described above, the injection port of the first molding die is set at the top end of the bottom surface of the concave portion of the first light guide portion. Therefore, (1) the first resin can be directly injected from the narrowest part of the cavity of the mold cavity. And flow from the narrow gap to the wide

Page 15 502129 Case No. 88120391 Rev. i ________________—— — | 丨 V. Description of the Invention (11)! Ί The gap and the injection port at the outer edge of the resin flow from a wide place into a narrow place; In comparison, even if the gap is narrow, it can be shot easily and smoothly. (2); 丨 The resin flowing distance from the center top to the outer edge of each side is shortened. Therefore, from the point of (1), even if the gap of the mold six can be shot even if it is narrow, the thickness at the top of the bottom surface can be made thinner. As a result, the thickness of the light guide can be reduced and the size can be matched. From the point 丨 | (2), because the corresponding injection pressure and load are relatively reduced, the resin is deformed; I ^ 丨 is also relatively reduced, so it will not cause uneven molding, and can obtain uniform brightness 丨 | i 丨 degree . In addition, even if the first resin uses low fluidity, that is, high viscosity (high score i

I S I resin, high melting point, high heat resistance), because the flow distance is short: it can be sent to the surrounding edge with a small injection pressure, so it can be formed into a thin meat and thin the light guide.丨 · Also, a small mark formed by the residual material (injection mark) will be left on the top surface of the bottom surface of the first light guide section, but after the first light guide section is formed |

Continue molding the second molding (second light guide), that is, two-stage molding, II; | while the second resin in the second light guide is along the first molding (first light guide)! ) When flowing, the residual material trace left by the first light guide can be melted and disappeared by its high temperature. The second light guide section is formed by injecting the second resin from the injection port of the second | molding die formed at the outer edge of the second light guide section. Since the injection port is provided on the outer side of the second molding die, there will not be any flaws or marks on the display surface, so its display effect will not be affected. | I It is preferable that the melting rate of the second resin in the second light guide portion is greater than that of the first resin in the first light guide portion by 10 g / 10 minutes or more. Here, the so-called Melt Index (hereinafter referred to as MI) refers to a thermoplastic tree extruded from small holes of a predetermined diameter and length at a certain temperature and pressure.

Page 16 502129 — _fE 88120391 ^ V. Description of the invention (12) The rate of fat outflow ’is the fluidity of Shuyuezhi. When the MI of the second resin is smaller than that of the first resin [not more than 10 g / 10 min, unevenness of the light guide may occur; when the MI of the second resin is greater than 10 g / 1 10 ffiin, The fluidity is good, and the injection pressure can be reduced without unevenness, so the brightness is uniform. In addition, the MI of the first and second resins can be changed to a desired value by changing the mixing ratio of the particles, and the first and second resins are materials of the same composition as described above, as long as the particles of each resin are changed The M I value can be adjusted by the mixing ratio. Therefore, the light guide with the above characteristics can be easily produced, and the yield can be improved.

The following describes the preferred embodiments of the present invention with reference to the accompanying drawings: It must be stated that the following embodiments and drawings are for illustration and description only and are not intended to limit the scope of the present invention. In fact, The scope of the invention should be defined by the following patent claims. In the drawings, the same component symbols used in the multi-faceted drawings represent the same components. Detailed description of specific embodiments: The first figure is an explanatory diagram of a flat lighting device according to a first embodiment of the present invention. " The lighting device is composed of a flat plate-shaped light guide 2 and a pair of rod-shaped (tubular) light sources 4 opposite to the two end faces 2a of the light guide 2, and the light guide 4 enters the light guide 2 The scattered light is scattered here and the illumination light is emitted from the exit surface 5 of the light guide 2. In order to improve the light utilization efficiency of 1%, the part of the light source 4 facing away from the light guide end surface 2a is covered with a reflection cover 27. The light-reflecting surface 6 of the light guide 2 is provided with a light-reflecting layer 29 through an air layer, and the light-emitting surface 5 is also covered with a chirped light-polarizing layer (polarizing layer) 2 6 that enhances light condensing through the air layer. The above light guides 2 are made of materials each using the same composition

Page 17 Non-recommended L-region L powder workers with different first rates ^ Mixed in the above materials for refraction and good use ί As proof of scattered light-guiding areas ί: Γ: the adhesive force of the material itself Also, for example, a light guide 邛 2B is made by injection molding to make the hot material, and the above-mentioned guides are formed by the injection molding method of the plate thickness direction ΐ. Ρ, +, 'Dang! ⑷ 2 A ′ 2 Β in the thickness direction of the # 2 fan light guide body end face 2 a position and locally change white "Possession: follower away, for example, the brightness of the Λ illumination light. ♦ As shown in the figure. The first light guide portion 12 is formed into a curved hill as viewed from the side 2b. As shown in the second embodiment of FIG. 2A, the chain m ί ^ ^ Shouyou 2 except the first made of the same material The light guide part 2 and the second light guide part 2β are made of bangs and contain scattered particles with a concentration higher than that of _s _ ^ _ ^^^^^^^ I. The first and second section 2C of the light section 2B The light guides 2A, 2β, and 2C α are the same as the one guide, and the Lugu a # is used as a reason for the use of the material's own adhesive force m — 1 "^ g 7 A, a guide, ， 2. 26 In the first embodiment of 26, for example, in the second A, the scattered particle concentration of each light guide portion is set to 0 wt% (transparent) in the first light guide portion, and the second The light guide part 2β is 0.2 wt% (transparent), the second light guide part 0 is 02 wt%, a third light guide part, C is 1 wt%; and in the second figure b, the first light guide part is set ^ Is 0% by weight 'The second light guide portion 2B is 0.4% by weight. The plate thickness of each light guide portion is set to the size shown in each figure. The average concentration in the I section is shown in the second A diagram In the figure: (3χ 0.lx 0.2) / 4 = 0. 05 (wt%) :

) U2129 1 ^^ ~ ^^ tM_88l20391 __Yuanyue Yue! V. Description of the invention (14) (3 · 5x 0 + 0.5 · 4 · 4) /4=0.05 (wt%) Therefore, the average concentration of the second A-circle and the second B-graph are equal. . The average concentration in the section II, in the second diagram A: (lx 0 + 2x 0.2 + lx 1) / 4 = 0.35 (wt%) and in the second diagram B: (〇 · 5x 0+ 3.5x 〇 · 4) /4=0.35 (wt%) Therefore, the average concentrations of the second A graph and the second B graph are equal. . The average concentration at section 11 is also the same as that of the second A and second B graphs.

The light guides of this second A and second B figures are the same as the average yield of each cross section. Therefore, except for the same light scattering performance, in the second A figure: = etc. The minimum plate thickness is lram, and in the case of the second and eighth figure, it is 0.5mm. Particles 瀵 ΐ Ϊ 2A, the light guide 2 of the second embodiment shown in FIG. 1 can be provided with a third light guide 2C with the same scattering increase, so that the gradient of its light scattering performance is more, and: t Even if it is made larger and thinner, the minimum plate thickness can be increased, making molding easier and improving moldability. In this second embodiment, the opposite side of the second light guide portion 2B of the light guide 2 is opposite to the ancient light portion 1A, and has a scattered particle concentration higher than that of the second light guide portion-the second light guide portion 2C. But if the second light guide 2B faces the first

It is also necessary to form the third light guide portion% on one side of one light guide portion 2A side. Three figures show a flat lighting device according to a third embodiment of the present invention. The main unit is composed of a flat plate-shaped light guide 2 and a pair of light sources 4 arranged parallel to each other with their two end faces 2 & The light entering the light guide from the light source 4 is scattered here, and the bright light is emitted from the exit surface 5 of the light guide 2. The light source 4 is, for example, a cold cathode tube. ,

Page 19 ^ 2129 Case No. 88120391 Amendment V. Description of Invention (15). The body = the light-guiding portion 2A and the light scattering performance are higher than this-the light-guiding portion 2 B is hidden in the direction of the thickness of the plate, and ^ _ is formed into a flat ridge-like hill shape. Section: Guide :: The two sections 2β are shaped to form a region with a thick plate thickness away from the light guide end face 2A, and are formed by two pieces of the -light guide section 2A, which are thick apart; ^^ are gradually reduced from the two light sources 4 , To Α 蚯 者 疋 is an inverted mountain-shaped recess. The eighth central portion has the smallest plate thickness and has a second light guide portion 2B having a light guide body portion 15 and a body portion 7 provided with a gradually increasing thickness of the body electrical plate located at the end portion 1 of the light source 4 toward the light guide. Light body end face 2a and light guide body side side degree adjustment section 6a. The main body part 5 has a light guide with a gradually increasing plate thickness at the side of the guide 2 and the side 2b, and the plate thickness at the center portion increases to the farthest away from the light source 4 and the plate thickness portion 2A and the second light guide portion 2B are plate-by-plate. Mountain-shaped protrusions. The first light guide 2 has a flat ridge-like mountain shape, and the two eyes are stacked into the light guide 2. When this light is incident from each end face 2a, it can obtain the relationship of ancient / 邛 2β. When the fourth figure shows the face 70 ° at the end of the light source 4. An example of the side portion 7. For example, the light guide body of the fourth A and four β electrodes 邛 4a is provided on the body portion of the second light guide portion 2β. The brightness adjustment portion 16 is connected between the 16 connection portions 15 and is formed on the light guide body. The end face is two or two. The light part 2A and the body have a boundary line with the boundary between the two faces as =, and the light guide body side face 2b is provided with a triangular cone having a triangular bottom surface ^. Shaped side surface 'and the body portion 15 are formed in the light-scattering _ > portion 16 to cut the electrode portion of the original light source 4 to a light guide portion 2B. The brightness adjustment of the light guide portion 2B is insufficient to compensate for the light guide. The thickness of the light quantity plate on the side of the light guide body side 7 is increased to increase the thickness of the light guide body side = 7 = the second light guide part 2B of the second light guide part 2B. 502129 Case number 88120391 Day Correction I ................................. .............. ~ ^ ........................ ........................................ .................. ^ ^ Ⅴ. Invention description (16) The number of scatterings of j further increases the amount of light, so it is not necessary to change the exit angle of the light guide side 7 While increasing its brightness. Because of this, without changing the exit angle of the side of the wedge-shaped light guide, the exit direction does not vary, and a lighting device with high brightness and high uniformity of brightness can be obtained. Further, in the third embodiment, the brightness adjustment section 16 is formed in a triangular pyramid shape. This is because, as shown in FIG. 4A, the light emitted from the light source 4 other than the electrode portion 4a faces the light guide. The side portion 7 is incident obliquely, and the side portion 7 of the light guide will obtain the amount of oblique incident light as it moves away from the end face 2a of the light guide. Therefore, the attenuation of the brightness is reduced. (Dotted line), as long as the bottom surface of the triangle is formed. The light guide 2 is formed of a material of the same composition, and the first resin and the second resin having different concentrations of scattered particles mixed in this material are sequentially injected into the first molding die and the second molding, respectively. The molds are laminated with each other, so that the first light guide portion 2A and the second light guide portion 2B having high light scattering performance are fused by heat to form a flat plate shape in the thickness direction (ie, a composite molding method). This makes it possible to easily duplicate the synthetic method and use the aforementioned specific first and second molding dies.

I | forms the brightness adjustment section 16. In the third embodiment, the light guide 2 has a second light guide portion 2B that has a prism-shaped mountain shape. However, it is not necessary to form a mountain shape of a polygonal pyramid such as a triangular pyramid or a quadrangular pyramid. Alternatively, if it is not a mountain shape, and only two wedge-shaped light guides with mutually different light scattering properties are formed to overlap in the direction of plate thickness, it may be formed. The sixth circle indicates the light guide used in the first embodiment of the present invention. Molding device for molding method. The light guide body 10 formed by the present invention is formed of a first light guide having an inverted quadrangular pyramid (pyramid) concave portion as shown in FIG. 18A.

P.21 ^ Case No. 88120391_Year Month Day _Amendment 丨 V. Description of the invention (17) " ^ ^ ^-i 2 is composed of a leading portion 11 and a second light guide portion 12 having a quadrangular pyramid-shaped convex portion. The device of the sixth figure is provided with a first molding die 20 and a second molding die 30 sandwiching _ I a mold rotation mechanism 1 with a vertical axis of rotation, and each molding die 1 20 ′ 30 is provided with a The first resin 1 and the second resin 3 are injected into injection devices 18 and 19 in the molds 20 and 30, respectively. In this embodiment, the first resin and the second resin are internally mixed, and the particles with different mixing ratios have different light scattering properties. It is also possible to use a transparent resin without mixed particles for the first resin. First | ★ For molding the first molded object, that is, the first formation of the first light guide 11 | i mold 20 is composed of the first mold 21 and the second mold 24, and the second mold 24 is detachable Composed of two-part modulo 22, 23. The cavity 25 (see FIG. 7A) formed between the first mold and the = mold 24 has a shape that is equal to the first light guide portion η-I =. The injection port 20a of the first molding die 20 is provided corresponding to the vicinity of the bottom top portion 11a of the concave portion forming the first light guide portion 11. In this example, the injection port 20a faces a direction perpendicular to the bottom surface of the first light guide section 丨. The second molding die 30 for molding the second light guide portion 12 is composed of two split molds 32, 33 which are separable from each other. The cavity 35 (see FIG. 7G) formed between the first light guide portion u and the second molding fork 30 has a shape consistent with that of the second light guide portion 12. The injection port 30 of the second molding die 30 is provided corresponding to an outer portion (side portion) where the second light guide portion 12 is formed. In this example, the injection port 30a faces the direction in which the resin is injected into the outer portion of the second light guide portion 12 from the outside. The split mold 23 of the first molding die 20 and the split mold 33 of the second molding die 30 may share a common mold. The mold rotation mechanism 17 can rotate the first mold 21 of the first molding mold 20 in the R direction. The seventh figure shows the steps of a light guide forming method according to an embodiment of the present invention.

Page 502 502129

If Tiger 88120391 said 5. Description of the invention (18) The paragraph-type flow indicates the country. The following describes the molding method of the light guide 丨 0 according to this figure: ° First, in the state where the first molding die 20 is set (seventh ▲), the first resin of the first light guide 丨 丨i From the injection port of the first molding die 20, 20a is injected into its cavity 25 (seventh B), the temperature of the first resin injected is 240 ~ 270C, and the melting rate MI is 2 ~ The injection pressure of 10g / 10min ranges from goo to UOO kg / cm2. After the first resin i is filled in the cavity holder, it gradually hardens to form the first light guide portion π (seventh C), and then the first mold 24 is opened (seventh D garden). At this time, a slight burr (injection material mark) 2 8 will be left on the concave bottom surface of the first light guide section 丨. \ ί Next, a first light guide is left in the first mold 21 by the mold rotation mechanism 17. In the state of 卩 11, the first die 21 is rotated in the r direction (sixth figure) (seventh figure E) in the same horizontal plane and positioned at the position opposite to the second time (seventh sun). Then, the second: the under-molded mold 30 is bonded to the third (after the seventh frame, the first tree of the second light guide 12 is injected into the cavity 35 from the injection port 30a (the first 7. The injection temperature of the second resin 3 is preferably in the range of 24 to 2700c, which is 12 to 30g / 10mln, and the injection pressure is 600 to 120,000kg / cm2. VII I), open the second molding die 30 (the second resin 3 of the seventh j 12 is injected into the cavity 35 乐 一 一九 4 ® 动 动 # Ｍ 眭 ', the joint surface of the first light guide 11 When the fox is filled, it will melt and disappear previously left in the first light guide, and the first-light ## 9 9 crystal s grabbing seven mouth science exhibition 28 f 徭, the * part 2 is laminated on the first light guide 11. Above, the resin portion 12a formed by the dog outlet 30a is cut off, and the flat plate-shaped light guide body 10 can be formed (picture of the eighteenth person).

Page 23 502129 —__ Case No. 88120391____ Year, Month, and Day Five. Description of the Invention (19) In this case, the first 11 'is formed in the first mold and then stacked in the second mold. There is a time delay in the emission of the resin between the light guides of the second layer. Sometimes, as shown in FIG. 8, the light guide 2 that is formed by injection may have a curved phenomenon such as the first light guide portion i ㈡ side. In order to eliminate this phenomenon, as shown in Figure 8A, the light guide 11 is placed on a flat heat insulation plate 40 facing upward, and as shown in the figure, only the infrared heater 4 i is placed on the top. When heated, the light guide 2 can return to a flat state when left for a while. At this time, the heater 41 is removed from the light guide 2 so that the light guide 2 is as shown in the eighth figure. However, the bending of the light guide 2 can be eliminated. In addition, in this embodiment, the light guide 2 is formed into a 3 'shape by injection, and it is not necessary to use a mold polymerization lamination method. The following describes the structure of the present invention in detail with examples. It is understood that the present invention is not limited by these examples. [Example 1] The first light guide portion and the second light guide portion of the non-scattered light guide region were made by casting and polymerizing with a mold to form the second light guide 2 as shown in the first figure. The first light guide 2 A is a methacrylic painting (MM A) with no added particles. The over-shoulder added as a radical polymerization initiator = 醯 (ΒΡ〇) 50 wt% and as N-laurylsulfide g "H.Wt / ° 'of the chain transfer agent? The inner light guide 2B, which is 389mm long, 286mm wide, and has a thickness ranging from 9mm (the thinnest part) to 1mm (the thickest part) in a curved shape, is formed by pouring a polymer light guide at a temperature of 24 hours under a mold. Add the particles of methyl methacrylate-light-guiding part 12, and the curved dagger 2 on the picture A is in the eighth and eighth state. In this state: the external line is shown by the cold method, but it must be the first in the area. It is obtained by converting the light guide t methyl ester to L-diphenyl% (n-LM). The first central part is concave. (MMA), 502129 88120391

Year five, the description of the invention (20), which is added with TOSPAL 145 grade (Japan Toshiba Silicon Resin Co., Ltd.'s hair resin particle diameter is 4 · 5 # m) 〇 2 ％ and the average sentence, = , And then add peroxymethane (BPO) 0.50 wt% as a radical polymerization initiator and lauric mercaptan (η-L Μ) as a chain transfer agent 0.40 wt% to form . This mixed slurry is injected with the rod ^ = Γ of the two ΓΛ: 'Use the center brightness of 286- ^ ^ -like source 4 and use a crustometer (say Ben Merlot Type 0 0) Brightness of the exit surface 5 of the light guide 2. Using the image analysis to evaluate the brightness distribution of the vertically emitted light, we get about 780 as shown in the device. The cd / m2 'is a flat lighting device with a contrast ratio of about 85 kg and a uniformity of netness. [Embodiment 2]: Scatter: The first light guide in the ϊ region is made by injection molding and will be used. The second light guide in the chaotic V first & domain is polymerized by washing and casting to make a picture A的 光 导体 10。 The light guide 10. The second light guide section 12 uses a gravity feeder to dissolve 100 parts by weight of polymethyl methacrylate particles and TOSPAL 145 grade Shiba Corporation products. The diameter of the resin particles is 4.5㈣) «(spiral specification: L / D = 32, diameter 44_), and after mixing in the cylinder of the extruder with "" to 240 C, after mixing and granulation, it is out of the molding machine at a cylinder temperature of 24 (rc 'mold mold closing pressure It is obtained by injection molding under the conditions of ㈣. The second guide = ^ f 38 9mm, width 286mm, and the thickness from the periphery to the center from 0.5mm (thinnest part) to 3.5nnn (thickest part) changes linearly high Convex quadrangular pyramid shape (gold 502129 amended case number 88120391 i. 5. Description of the invention (21) tower shape). Then 'put this second light guide section 丨 丨 into a mold with a length of 389mffl, a width of 286mm, and a thickness of 9mm. Polymethylpropane particles with no added particles are melted into the molten solution to form a first light guide portion 11 having an inverted quadrangular pyramidal recess, thereby producing a flat plate-shaped light guide. The planar lighting device constituted by the light guide 10 in FIG. 18A and a light source is arranged on each end face thereof. The same measurement as in Example 1 was performed. As shown in the tenth figure, a flat lighting device having a high brightness and high uniformity of about 8500 Cd / m2 in the entire exit surface is obtained, and the contrast ratio is about 90%. [Example 3] I: Scatter The wedge-shaped first light-guiding part and the light-scattering part of the light-guiding area are sequentially formed into a stacking layer two in the molding die:: The second light-guiding part_ is a polymer using a gravity feeder! 10 ° parts by weight and T0SPAL145 grade ( Japanese Toshiba Ishikiki: ίΐ: made ⑽, the diameter of the silicone resin is 4.5 " " 1) 0.60 parts by weight is fed into a two-axis = > machine (spiral specification: L / D = 32, diameter 44mm) Add 埶 to 24.0. [Red 2 produced in 2 mixes:〗 After granulation, feed to injection molding machine, and the same is injected in the pressed vinegar pellets: molding; and: None: =: 1 polymethyl methacrylate thickness The wedge-shaped first pattern from 3 to 40 mm in length and 30 0 in width along the short side is linearly changed from f (thinnest) to 5 mm (thickest part). The light guide portion 80A is laminated in a complementary manner on the ninth guide portion 80B to obtain a flat plate-shaped light guide body. The light guide unit: a heart-shaped illumination device is measured in the same manner as in Example 1 = uniform surface All-round 5 00 cd / m2, bright and dark contrast-Erjian and can emit light from both sides of the exit surface and the reflective surface 5U2129-^ Case No. 88120391 [Embodiment 4]

The first resin and the second resin having different light scattering properties were sequentially injected into the molding die and stacked to form a light guide 2 as shown in the third figure. The first resin uses Aery pet VH grade (manufactured by Mitsubishi Electric Co., Ltd.) 'The second resin uses Delpet 70 FR grade (manufactured by Asahi Kasei Corporation in Japan) mixed with TOSPAL 145 grade (manufactured by Japan Toshiba Silicone Corporation) Silicone resin particle size 4 · 5 // m) 0 · 3 wt% and granulated material, this light guide 2 has a triangular pyramid-shaped brightness adjusting section 1 on a ridge-shaped second light guide section 2B . A pair of parallel light sources 4 are arranged along the longitudinal direction of both end faces of the light guide 2. For example, when the light guide 2 is 15 inches long and the electrode portion 4 a of the light source 4 is 8 mm, as shown in the fourth A and fourth B diagrams, the brightness adjustment portion 16 may be formed on the main body portion 15. It has a triangular pyramid shape in which two triangles formed on the end surface 2a and the side surface 2b have a height of 2 mm (the height of the corner where the end surface 2a and the side surface 2b intersect) and a length of 15 mm.

The above-mentioned light guide 2 was used to measure its relative brightness ratio based on each light guide distance in the aforementioned method, and the results are shown in Fig. 11. In the figure, the horizontal axis is the light guide distance, that is, the distance from the end face 2a (in mm), and the vertical axis is the relative brightness ratio. Curve 61 shows the case where the brightness adjustment section of the present invention is provided, and the relative brightness ratio of the light guide body side portion is 64. 0%; and curve 62 is the case where the brightness adjustment section is not provided as shown in the seventeenth figure. At this time, the relative brightness ratio of the side of the light guide is 5 1 · 1%. From this, it can be seen that the provision of the brightness adjusting portion of the present invention can prevent the effect of reducing the brightness of the side portion of the light guide caused by the electrode portion, so that the size of the frame portion of the display screen can be reduced by about 20 mm. According to the method for forming a light guide according to the present invention, if the light guide is thin and large

Page 27 502129 «-^ _ Case No. 88120391_ Year, month, day and year _ | V. Description of the invention (23) | When the type is, for example, the flatness of the light guide (the ratio of the width to the height in terms of thickness to length) It is especially suitable when it is 10 or more and the size is 120 mm X 90 mm or more. The following light guides of Examples 5, 6 and Comparative Examples were molded by the molding method of the seventh figure, and the compositions of the first resin and the second resin used were different; the same.丨 [Example 5] | I The first resin used Acrypet VH grade (I product made by Mitsubishi Electric Corporation 'MI = 2.0g / 10min ASTH-D1 233), and the second resin used Delpet I 70 FR grade (Asahi Kasei Industrial Co., Ltd. Company product, MbUg / iOmin) mixed with Tospal 145 grade (product of Toshiba Silicone Co., Ltd.) 03% by weight and added to the granulated material (MI = 12g / 10min). The difference between the mi of the first resin and the second resin was 10 g / 10 min, and there was no unevenness in the light guide.丨 [Example 6] I The same resin as in Example 5 was used for the first resin, and Parapet Η-S grade (product of Japan KURARAY Co., Ltd., MI = 22g / 10min) was used for the second resin, and Tospal 145 grade was used. (Manufactured by Toshiba Silicone Co., Ltd.) 0.3% by weight of a granulated material. The difference between the Mϊ | of the first resin and the second resin was 20 g / 10 min, and no unevenness occurred in the light guide. [Comparative Example] The same resin as in Example 5 was used as the first resin, and the second resin was used as the first resin.

Acrypet TF8 grade (products of Mitsubishi Electric Corporation, MI = 10g / 10min) mixed with Tospal 145 grade (products of Toshika Resin Co., Ltd.) 03 comment% | and the materials (MI = 10g / l0min). The difference between the MI of the first resin and the second resin i was 8 g / 10 min, and the light guide was uneven.

Page 28 502129 __ ^ _ Case No. 88120391_ Year Month a_Amended | V. Description of the invention (24) Figure. The horizontal axis represents the distance (mm) from the injection port, and the vertical axis represents the brightness (c d / m 2). Example 6 is shown by a solid line, and Comparative Examples are shown by a broken line, respectively. It can be seen from the figure that the light guide of the comparative example has unevenness, but the light guide of Example 6 has no unevenness, and the uniformity of brightness is quite high. The above is a description of the preferred embodiment of the present invention in conjunction with the drawings. Obviously, those skilled in the art can make various changes and modifications within the foreseeable scope from the contents of this specification. Therefore, all such changes and modifications should be considered as Covered within the scope of the inventions defined by the following patent applications.

Page 29

502129 Case number 88120391_ 年月 日 __ Brief Description of the Drawings The first figure shows a transparent view of a flat surface of a plane lighting device according to a first embodiment of the present invention. Figure A: The second transparent display of the installation surface is flat. The third display is shown in Figure B. The second and third rounds of the visual inspection JU are compared with the chart. The light guide's state of implementation is shown in the third embodiment. Figure A is the fourth view. The circle is B. The fourth and fifth views are in view of JUJ. The diagram shows the state of the body light guide as shown in the figure, and shows the state of the body light guide. Figure 6 shows the state of the body light guide, which is shown in the figure. Show the table installation _ with Qimo Di used to illustrate the process of the hair light guide to form a complex light emission; two pictures in addition to illustrate the example Table 1 _ French Bafangdi's body Figure light guide # 19 隹 Λ 0 Schematic diagram of the special chart of Figure 9 is the tenth level of the light emitting surface light guide with a light distance of 0 The light guide position of the opposite phase is shown in the figure. The light guide of each line is shown in the table. The figure of the series of ten characteristics of the degree is characterized by the division of light. JH4 Detective Times Second Show •

u ___ DMV ^ UUVP ^ UDUHU ___ ^^ f

Page 30 502129 Case No. 88120391_Year Month and Day Correction Diagram Brief description of the graph, the thirteenth figure shows a transparent view of a flat lighting device with a flat light guide; 1 The fourteenth figure shows a single wedge A perspective view of a planar lighting device having a light guide portion of the light guide; The fifteenth circle shows a perspective view of a planar lighting device having a light guide portion consisting of two pieces of wedges; Perspective view of the plane lighting device of the light guide section: The seventeenth country shows a perspective view of the plane lighting device having a mountain-shaped light guide section!! Ϋ;! I Figure 18A shows a perspective view of an example of a light guide body; 丨Fig. 18B is a cross-sectional view taken along line IV-IV of Fig. 18A.丨 [Description of symbols] | 丨 2, 10 Light guide 2a End face 2b Side | 2A, 11 First light guide 2b, 12 Second light guide 2c Third light guide 4 Light source 5 Exit surface 6 Reflective surface i 丨15 Body part 16 Brightness adjustment part 4a Electrode part 1 I 20 First molding die 21 First mold 24 Second mold i | 30 Third molding die 25, 35 cavity 20a, 30a injection port ''

Page 31

Claims (1)

! No. 88120391 1 · A flat rod light that scatters the material The above material light area is laminated to the light guide body 2. The thickness of the first plate according to the degree of further application of the component 3 · A light plate that flattens its end surface The second light guide made of the same material is an integrated surface lighting device, and the light guide body after the shape (tubular) light source is characterized in that the manufactured second light guide is made of a material that is mixed with a folded second light guide. The above-mentioned end-to-end surface shooting patent has the characteristics of a rod-shaped scrambled structure with three light-guiding directions made of materials, and a light-guiding part that constitutes a light guide at each light-guiding position. The first application is the same as the above, and the layer is a device. (The tubular light guide is: the mixing section and the material are composed of flat plates, and the light exit system emits light with a different light guide efficiency. 'The material used in the thickness of the plate is a localized bright item of bright light. The first guide contains a light source that is flatter than the first material. The light guide system of the exit surface of this material has a dry light guide with light dispersion itself. Face its ends The person who makes the light emitted from the light source incident on the light guide body; The first light guide part of the same composition sub-region and the scattered particles are used as the scattered guide material. The adhesive force of the scattered guide itself depends on the thickness of the plate. The occupancy in the direction changes as it moves away from the above to control the light guide from the above. The lighting device, wherein the light guide body light part and the second light guide part are in the same group, and the scattered particles having high light guide parts have a strong adhesive force, so that the light guide parts and the plate-shaped light guides are relatively arranged to make the light guide The light source is incident on the light guide and emits the illuminating light. The concentration of scattered particles using the same composition is independent of each other. The force of the first light guide is laminated on the thickness direction of each other. 502129 _ Case No. 88120391_ Year Month Date _ Amendment 6. The scope of the patent application and the formation of the first light guide portion gradually decreases as it moves away from the end face of the light guide body, and the second light guide portion has The light guide body has a gradually increasing thickness at the end surface and a light guide side portion disposed on the electrode portion facing the light source end portion, and the brightness is gradually increased toward the light guide end surface and the light guide side panel. Regulatory Department. 4. The flat lighting device according to item 3 of the scope of the patent application, wherein the brightness adjusting portion is connected to the body portion and is interposed between the body portion of the first light guide portion and the body portion of the second light guide portion, and is formed at The end face of the light guide body and the side surface of the light guide body respectively have a triangular side surface with the boundary line of the two surfaces as a common side! And a triangular cone shape with a triangular bottom surface on the body portion. I 5. A light guide used in the flat lighting device described in item 1 of the patent application.丨 6. A light guide used in the flat lighting device described in item 3 of the scope of patent application. 7. A method for forming a light guide according to item 5 of the scope of patent application, which method sequentially ejects a first resin to be formed into a first light guide and a second resin to be formed into a second light guide. Layer forming "to form a flat plate-shaped light guide; characterized in that the first resin is first injected into a first molding mold composed of a first mold and a second mold to mold the first light guide portion, _ Open the second mold, and then, while the molded first light guide part remains in the first mold, join the second molding mold to the first mold, and then inject the second resin into the first mold. While forming the second light guide part in the secondary molding mold, the second light guide part is laminated on the first light guide part to form a light guide. Page 33, 502129, Case No. 88120391_Year Month Amendment_ VI. Application for Patent Fan Yuan 8. —A method of forming the light guide body described in item 6 of the scope of patent application, this method is to form the first The first resin of the light guide portion and the second resin to be formed into the second light guide portion are sequentially ejected and laminated to form a flat plate-shaped light guide body. The special feature is that the first resin is injected into the first mold first. After forming the first light guide part in the first forming mold composed of the first mold and the first mold, I opened the second mold, and then, the first light guide molded in the first mold remained! Part of the In the state, the second molding die is joined to the above-mentioned first mold, followed by I, the second resin is injected into the second molding die to form the second leading part I, and the second light guiding part is made. Laminated on the first light guide portion to form a light guide I body. 9. The light guide forming method according to item 7 or 8 of the scope of patent application, wherein the light guide comprises a first light guide having a concave portion with an inverted mountain shape, and a second light guide having a convex portion with a mountain shape. The first light-guiding portion is formed by injection of a first resin from the first formation corresponding to the vicinity of the bottom and top of the recess; the injection port of the mold is injected into the mold.丨 10. The light guide molding method according to item 7 or 8 of the scope of the patent application, wherein the melting rate (MI) of the second resin of the second light guide portion is larger than that of the first resin of the first light guide I portion. The melting rate is 10g / 10min or more. I 11. The light guide molding method according to item 9 of the scope of the patent application, wherein the second; light guide portion is formed by secondly forming a second resin from a corresponding position at an outer edge portion of the light guide portion. The injection port of the mold is injected into the mold to be molded. «Ρ Page 34