1312047 九、發明說明 【發明所屬之技術領域】 本發明係關於具有從背面照射透射型或半透射型面板 之背光機構之顯示裝置之導光體。 【先前技術】 近年來，桌上型或筆記型電腦等之顯示裝置，採用薄 型且容易觀看之具有背光機構之液晶顯示裝置。 如第1圖所示，此種背光係大致爲長方體形狀之導光 體1 0 1，以一側面1 a作爲入射面1 0 1 a、以一方之主面作 爲出射面l〇lb、以另一方之主面作爲反射面i〇ic，反射 面1 0 1 c則形成以與入射面1 0 1 a平行之方向作爲長邊方向 之複數個斜面l〇ld作爲偏向元件。 此外，該背光具有以與導光體101之入射面l〇la爲 相對之方式配置之光源102、以與導光體1〇1之出射面 l〇lb爲相對之方式配置之棱鏡片1〇3、以及以與導光體 101之反射面l〇lc爲相對之方式配置之反射片。 此種背光時’從光源1 0 2出射之光，從導光體1 〇 1之 入射面l〇la入射至導光體1〇1內部，並在反射面1〇1(；與 出射面1 0 1 b之間重複全反射且前進。此光利用形成於反 射面1 0 1 c之斜面1 0 1 d進行反射，而逐漸朝出射面丨〇 i b 方向前進’到達臨界角時，即從出射面1 〇 1 b出射至外部 。一部份之光會從反射面lc洩光》 從導光體101之出射面l〇lb出射至外部之光，在透 -6- 1312047 射稜鏡片1 0 3時會產生折射而朝垂直於導光體1 01之出射 面101b之方向前進，並入射至夾著該稜鏡片103以與導 光體1 〇 1爲相對之方式配設之圖上未標示之液晶面板。反 射片1 0 4係由例如銀片所構成’用以反射從導光體1 0 1之 反射面l〇lc漏出之光使其回到反射面101c。 依據傳統方法，因爲形成於反射面之斜面與反射面之 夾角爲一定，從導光體之出射面出射之光之分佈會產生偏 光。因此，爲了使從導光體之出射面出射之光成爲均勻分 佈，只能利用從導光體出射之光之一部份而有光源光之利 用效率降低之問題，而難以兼顧出射光之均勻性與光之利 用效率。 【發明內容】 有鑑於上述情形，本發明之目的係在提供可從出射面 出射均勻分佈之光，且可提高光源光之利用效率之導光體 〇 爲了解決上述課題，本發明之導光體係透明塑膠構件 所構成之大致爲長方體形狀，以一側面作爲入射面，以大 致垂直於入射面之一方之主面作爲出射面，並以與出射面 相對之另一方之主面作爲反射面，反射面係以與入射面平 行之方向作爲長邊方向，並形成對於反射面，朝入射面之 方向傾斜之複數個斜面，使從入射面入射之光利用反射面 之斜面，偏向出射面之方向並從出射面出射，以從入射面 至與入射面相對之反入射面爲止之距離作爲橫軸，以該距 1312047 離之斜面與反射面所形成之角度0作爲縱軸，且反射面與 出射面之間之厚度爲tmm，橫軸方向之入射面至反入射面 爲止，具有：角度0爲1° X(t/0.6)〜3° x(t/0.6)之非活性區 域；包含角度0爲 Γ x(t/0.6)〜1.3° x(t/0.6)之最低角度區 域在內，入射面與反入射面之中點之角度Θ爲1.2°x (t/0.6)〜1.8° x(t/0.6)之活性區域；以及角度0爲1.5° X (t/0.6)〜4.5°x(t/0.6)之反入射區域；且，活性區域之最低 角度區域，係以活性區域之始端作爲其始端，以連接中點 之角度0與反入射面區域之始端角度0之直線的交點作爲 終端，從前述最低角度區域之終端至前述反入射區域之始 端爲止，前述角度呈現線性增加。 非活性區域應爲入射面朝向反入射面之方向之2mm〜 4 · 5 m m之區域。 最低角度區域應爲橫軸方向之2mm〜4.5mm之區域。 反入射面區域應爲反入射面朝向入射面之方向之5mm 〜1 0mm之區域。 非活性區域與活性區域之間配設著過渡區域，該過渡 區域之非活性區域之終端之角度0與活性區域之始端之角 度0應以線性變化進行連結。 出射面上應具有棱鏡片。 依據本發明，可提供可從出射面出射均勻分佈之光， 且可提高光源光之利用效率之導光體。 【實施方式】 -8- 1312047 以下，參照圖面，針對本實施形態之導光體進行說明 。第2圖係本實施形態，第2圖（a)係導光板之上面圖、第 2圖（b)係橫剖面圖、第2圖（c)係斜視圖。此外，爲了參照 上的方便，圖中設定著XYZ軸。 第2圖中，導光體所使用之構件係一般使用之透明塑 膠構件。該塑膠構件可從丙烯酸、聚碳酸酯、以及環烯聚 合物當中選擇使用。此外，導光體之形狀係大致爲長方體 形狀。 本實施形態時，導光體1係以一側面作爲入射面1 a， 以大致垂直於入射面la之一方之主面作爲出射面lb，並 以與出射面lb相對之另一方之主面作爲反射面lc，該反 射面lc係以與入射面ia平行之方向作爲長邊方向，於反 射面1 c形成朝入射面1 a之方向傾斜之複數個斜面丨d。 該導光體1時，來自光源2之朝入射面la入射之光 ’在反射面lc與出射面lb之間重複全反射並朝與入射面 1 a相對之反入射面1 e之方向前進。其間，在形成於反射 面lc之斜面Id逐漸朝出射面lb方向前進，並在到達出 射面1 b之臨界角時，即從出射面1 b出射。 其次’參照第3圖，針對反射面1 c之斜面1 d之構成 進行說明。第3圖（a)係以從導光體1之入射面la至反 入射面1 e爲止之距離作爲橫軸，並以該距離之斜面之角 度0 (反射面角度）作爲縱軸。第3圖（b)係配設著後述之過 渡區域時之圖，第3圖（c)係以曲線連結後述之角度變化點 時之圖。 -9- 1312047 首先，針對第3圖（a)之反射面lc之斜面id之構成進 行說明。此處，導光板1之厚度，亦即，出射面lb與反 射面lc間之距離爲tmm。 非活性區域係從入射面1 a朝向反入射面1 e之方向之 2mm〜5mm 之區域，角度 0 =1° x(t/0.6)〜3。x(t/〇 6)(折線 5)。從入射面la附近之出射面lb觀看時，應爲角度0 =1.5。〜2.7。。 非活性區域中’角度β若小於1 ° x(t/0.6)，則入射面 la附近之出射面lb之亮度會降低而成爲均勻性惡化之主 要原因。另一方面’角度0若大於3。x(t/0.6)，則因爲入 射面1 a附近之出射光量會增加過多，而無法維持出射面 整體之均勻性。 反入射區域係從反入射面le朝向入射面la之方向之 5mm〜lOmm之區域，角度0=l.5。x(t/o·6)〜4.5。χ(t/O.6)( 折線6)。以保持反入射面1 e附近之出射面1 b之出射光之 均勻性而言，應爲角度0=1.8°〜2.5°。 反入射區域中，角度0若小於1.5。x(t/0.6)，則光會 從反入射面le漏出’而成爲出射光之均勻性惡化之主要 原因。另—方面，角度Θ若大於4.5°x(t/0_6)，因爲來自 光源2之入射之光之光量在到達反入射光面之前即用 完’無法維持出射面1 b整體之出射光之均勻性。 活性傾城具有入射面la與反入射面ie之中點之角度 0 = l_2°x(t/0.6)〜1.8°X(t/0.6)(折線 7)及角度 0 =；Tx(t/0.6) 〜1 _3° x(t/0_6)之最低角度區域（折線9)。該最低角度區域 -10- 1312047 係以活性區域之始端成爲其始端（點9a)，並以連結前述中 點之任意角度與β =1.5° x(t/0_6)〜4.5。x(t/0.6)之反入射面 區域之始端角度（點6a)之直線（折線8)與該最低角度區域 之0 =Γ x(t/0_6)〜1，3° x(t/0.6)相交之點（點9b)作爲終端， 從最低角度傾城之終端（點9b)至反入射區域之始端（點6a) 爲止，角度Θ爲線性增加（折線8)。以有效利用來自光源2 之光之觀點而言，前述中點之角度0應爲0=1.4〜1.6°。 最低角度區域應爲橫軸方向之2mm〜4.5mm。 非活性區域之終端（點5 a)與活性區域之始端（點9 a)之 間，應配設角度逐漸變化之過渡區域。參照第3圖（b)，該 過渡區域之角度Θ可以爲由非活性區域之終端（點1 0 a)之 角度6» =1° x(t/0.6)〜3° x(t/0.6)與最低角度區域之始端（點 l〇b)之角度0 =1° x(t/0.6)〜1.3° x(t/0.6)呈線性變化並連結 而成（折線1 〇)。 此外，亦可去除第3圖（b)所示之橫軸方向之角度0之 角度變化點1 1，而如第3圖（C)所示，以曲線1 2連結各角 度變化點。如此，角度變化爲曲線方式，可以抑制反射面 lc之反射光量之急速變化，實現從出射面lb出射之光之 均勻化。 其次，針對從導光體1之出射面1 b出射光之作用進 行說明。依據史奈爾定律’光從折射率較大之物質進入折 射率較小之物質時，光之相對於界面之入射角大於臨界角 時爲全反射，臨界角以下時爲折射。丙烯酸之臨界角約爲 42°，聚碳酸酯約爲39°。將其應用於本實施形態之導光體 -11 - 1312047 1，來自光源2之朝某方向前進之光在導光板1中前進之 導光時，會以依配設於反射面1 C之斜面1 d之傾斜角度0 逐漸縮小角度之方式來進行重複反射，而使相對於出射面 1 b之入射角逐漸變小。依據該原理實施導光時，相對於出 射面1 b之臨界角以上之光一定有成爲小於臨界角的時候 ，才能進行折射並從出射面1 b出射。 依據以上所述之原理，配設反射面1 c可以減少反入 射面1 e之漏光，而增加從出射面1 b出射之光量，且可從 出射面lb出射均勻之光。 此外，光源2應爲發光二極體（LED)，然而，亦可使 用螢光燈等。此外，於導光體1之出射面lb之上面配設 稜鏡片，可以利用該稜鏡片使出射面1 b出射之光產生偏 向而朝向垂直於出射面lb之方向前進。 實施例 以下，利用實施例針對本發明進行說明。組裝由光源 '導光體、以及1片稜鏡片所構成之面光源裝置來進行光 學特性之檢測。光源係使用 LED(日亞化學製NESW020)4 燈。 第4圖係本發明之實施例。第4圖（a)係反射面之構成 之實施圖，第4圖（b)係前述反射面之出射面之觀察圖、第 4圖（c)係觀察到之第4圖（b)之出射面之亮度分佈。 本實施例時，利用於反射面1 c形成如第4圖（a)所示 之構成之斜面Id，實現第4圖（b)所示之大致均勻之觀察 -12- 1312047 及如第4圖（c)所示之亮度3000〜5600cd/m2之大致均勻之 売度分佈。 【圖式簡單說明】 第1圖係傳統之實施形態之導光體之剖面圖。 第2圖係本發明之實施形態之導光體，第2圖（a)係上 面圖、第2圖（b)係橫剖面圖、第2圖（c)係斜視圖。 第3圖係本發明之實施形態之導光體之關係圖。 第4圖係本發明之實施例，第4圖（a)係反射面之構成 之實施圖、第4圖（b)係出射面之觀察圖、第4圖（c)係出 射面之亮度分佈圖。 【主要元件符號說明】 1 :導光體 1 a :入射面 1 b =出射面 1 C :反射面 1 d :斜面 1 e :反入射面 2 :光源 101 :導光體 1 0 1 a :入射面 1 〇 1 b :出射面 1 〇 1 C :反射面 -13- 1312047 1 0 1 d :斜面 102 :光源 103 :稜鏡片 1 0 4 :反射片[Technical Field] The present invention relates to a light guide body having a display device of a backlight mechanism that illuminates a transmissive or transflective panel from the back side. [Prior Art] In recent years, a display device such as a desktop type or a notebook computer has a liquid crystal display device having a backlight mechanism which is thin and easy to view. As shown in Fig. 1, such a backlight is substantially a rectangular parallelepiped light guide body 110, with one side 1 a as an incident surface 1 0 1 a and one main surface as an exit surface l lb, The main surface of one side serves as a reflecting surface i〇ic, and the reflecting surface 1 0 1 c forms a plurality of inclined surfaces l〇ld which are parallel to the incident surface 1 0 1 a as a longitudinal direction. Further, the backlight has a light source 102 disposed to face the incident surface 10a of the light guide 101, and a prism sheet 1 disposed to face the exit surface 110b of the light guide 1〇1. 3. A reflection sheet disposed in a manner opposite to the reflection surface l lc of the light guide 101. In such a backlight, the light emitted from the light source 102 enters the inside of the light guide body 1〇1 from the incident surface l〇1a of the light guide body 1〇1, and is on the reflection surface 1〇1 (; and the exit surface 1) The total reflection is repeated between 0 1 b and advances. This light is reflected by the slope 10 1 1 d formed on the reflection surface 1 0 1 c, and gradually proceeds toward the exit surface 丨〇 ib 'to reach the critical angle, that is, from the exit The surface 1 〇1 b is emitted to the outside. A part of the light will leak from the reflecting surface lc". The light exiting from the exit surface l〇lb of the light guiding body 101 to the outside is transmitted through the -6-1312047. At 3 o'clock, the refraction is generated and proceeds in a direction perpendicular to the exit surface 101b of the light guide body 101, and is incident on the figure which is disposed so as to oppose the light guide body 1 〇1. In the liquid crystal panel, the reflection sheet 104 is composed of, for example, a silver sheet for reflecting light leaking from the reflection surface l lc of the light guide body 110 to return it to the reflection surface 101c. The angle between the inclined surface of the reflecting surface and the reflecting surface is constant, and the distribution of the light emitted from the exit surface of the light guiding body is polarized. In order to make the light emitted from the exit surface of the light guide body evenly distributed, only one part of the light emitted from the light guide body can be used, and the utilization efficiency of the light source light is lowered, and it is difficult to balance the uniformity of the emitted light with In view of the above circumstances, an object of the present invention is to provide a light guide body that can emit light that is uniformly distributed from an exit surface and that can improve the utilization efficiency of light source light. The transparent plastic member of the light guiding system of the invention has a substantially rectangular parallelepiped shape, with one side as an incident surface, a main surface perpendicular to one of the incident surfaces as an exit surface, and the other main surface opposite to the exit surface. The reflecting surface has a direction parallel to the incident surface as a longitudinal direction, and a plurality of inclined surfaces that are inclined toward the incident surface with respect to the reflecting surface, so that the light incident from the incident surface is deflected by the inclined surface of the reflecting surface. The direction of the exit surface is emitted from the exit surface, and the distance from the incident surface to the opposite incident surface opposite to the incident surface is taken as the horizontal axis. 12047 The angle formed by the inclined surface and the reflecting surface is taken as the vertical axis, and the thickness between the reflecting surface and the emitting surface is tmm, and the incident surface in the horizontal axis direction is opposite to the incident surface, and the angle 0 is 1° X ( t/0.6)~3° x(t/0.6) inactive area; including incident angle and back incident, including the lowest angle region where angle 0 is Γ x(t/0.6)~1.3° x(t/0.6) The angle of the midpoint of the surface is 1.2° x (t/0.6) to 1.8° x (t/0.6) of the active region; and the angle 0 is 1.5° X (t/0.6) to 4.5° x (t/0.6) The opposite angle region; and the lowest angular region of the active region, with the beginning of the active region as its starting end, with the intersection of the angle between the angle 0 of the midpoint and the angle 0 at the beginning of the incident plane region as the terminal, from the aforementioned minimum The aforementioned angle appears to increase linearly from the end of the angular region to the beginning of the aforementioned incident incident region. The inactive area should be an area of 2 mm to 4 · 5 m of the direction of the incident surface toward the counter-incident surface. The lowest angle area should be an area of 2 mm to 4.5 mm in the horizontal axis direction. The area of the anti-incidence surface should be an area of 5 mm to 10 mm from the direction of the incident surface toward the incident surface. A transition region is disposed between the inactive region and the active region, and the angle 0 between the end of the inactive region of the transition region and the angle 0 at the beginning of the active region should be linked in a linear change. The exit surface should have a prism sheet. According to the present invention, it is possible to provide a light guide body which can emit light uniformly distributed from the exit surface and which can improve the utilization efficiency of the light source light. [Embodiment] -8 - 1312047 Hereinafter, a light guide of the present embodiment will be described with reference to the drawings. Fig. 2 is a view of the present embodiment, and Fig. 2(a) is a top view of the light guide plate, a cross-sectional view of Fig. 2(b), and a perspective view of Fig. 2(c). Further, for convenience of reference, the XYZ axis is set in the figure. In Fig. 2, the member used for the light guide is a transparent plastic member which is generally used. The plastic member can be selected from among acrylic acid, polycarbonate, and cycloolefin polymers. Further, the shape of the light guide body is substantially a rectangular parallelepiped shape. In the present embodiment, the light guide 1 has one side surface as the incident surface 1 a, and a principal surface that is substantially perpendicular to one of the incident surfaces 1a as the exit surface lb, and the other main surface opposite to the exit surface lb The reflecting surface lc has a direction parallel to the incident surface ia as a longitudinal direction, and a reflecting surface 1 c forms a plurality of inclined surfaces 丨d inclined toward the incident surface 1a. In the light guide 1, the light ' incident from the light source 2 toward the incident surface 1a is repeatedly totally reflected between the reflection surface 1c and the emission surface 1b, and proceeds in the direction opposite to the incident surface 1e facing the incident surface 1a. In the meantime, the slope Id formed on the reflecting surface lc gradually advances in the direction of the exit surface lb, and when it reaches the critical angle of the exit surface 1b, i.e., exits from the exit surface 1b. Next, the configuration of the inclined surface 1d of the reflecting surface 1c will be described with reference to Fig. 3. In Fig. 3(a), the distance from the incident surface la of the light guide 1 to the counter incident surface 1 e is taken as the horizontal axis, and the angle 0 (reflected surface angle) of the slope of the distance is taken as the vertical axis. Fig. 3(b) is a diagram in which a transition region to be described later is arranged, and Fig. 3(c) is a diagram in which a point change point to be described later is connected by a curve. -9- 1312047 First, the configuration of the slope id of the reflection surface lc of Fig. 3(a) will be described. Here, the thickness of the light guide plate 1, that is, the distance between the exit surface lb and the reflection surface lc is tmm. The inactive region is a region of 2 mm to 5 mm from the incident surface 1 a toward the direction of the counter incident surface 1 e, and the angle 0 = 1 ° x (t / 0.6) 3 . x(t/〇 6) (polyline 5). When viewed from the exit surface lb near the entrance face la, it should be angle 0 = 1.5. ~2.7. . When the angle ? is less than 1 ° x (t / 0.6) in the inactive region, the luminance of the exit surface lb near the incident surface la is lowered to cause a deterioration in uniformity. On the other hand, the angle 0 is greater than 3. x(t/0.6), because the amount of light emitted near the incident surface 1a is excessively increased, and the uniformity of the entire exit surface cannot be maintained. The anti-incident region is a region of 5 mm to 10 mm from the direction of the incident surface le toward the incident surface la, and the angle is 0 = 1.5. x(t/o·6)~4.5. χ (t/O.6) (polyline 6). In order to maintain the uniformity of the outgoing light of the exit surface 1 b near the incident surface 1 e , it should be an angle of 0 = 1.8 ° to 2.5 °. In the anti-incident area, the angle 0 is less than 1.5. When x(t/0.6), the light leaks out from the counter incident surface le, and the main cause of the deterioration of the uniformity of the emitted light is the cause. On the other hand, if the angle Θ is greater than 4.5°×(t/0_6), the amount of light from the incident light from the light source 2 is used up before reaching the anti-incident surface. “The uniformity of the outgoing light of the exit surface 1 b cannot be maintained. Sex. The active city has an angle of the point between the incident surface la and the counter-incident surface ie 0 = l_2°x(t/0.6)~1.8°X(t/0.6) (line 7) and angle 0 =; Tx(t/0.6) The lowest angle area (polyline 9) of ~1 _3° x(t/0_6). The lowest angle region -10- 1312047 is the beginning of the active region (point 9a), and is connected to any angle of the aforementioned midpoint and β = 1.5° x (t / 0_6) ~ 4.5. The line at the beginning end angle (point 6a) of the anti-incident surface area of x(t/0.6) (the broken line 8) and the lowest angle area are 0 = Γ x(t/0_6)~1, 3° x(t/0.6) The point of intersection (point 9b) serves as the terminal, and the angle Θ increases linearly (line 8) from the terminal of the lowest angle (point 9b) to the beginning of the incident area (point 6a). From the viewpoint of effectively utilizing the light from the light source 2, the angle 0 of the aforementioned midpoint should be 0 = 1.4 to 1.6. The lowest angle area should be 2mm~4.5mm in the horizontal axis direction. A transition zone with a gradually changing angle should be provided between the terminal of the inactive area (point 5 a) and the beginning of the active area (point 9 a). Referring to Fig. 3(b), the angle Θ of the transition region may be the angle from the end of the inactive region (point 10 a) 6» =1° x(t/0.6)~3° x(t/0.6) The angle from the beginning of the lowest angle region (point l〇b) 0 = 1 ° x (t / 0.6) ~ 1.3 ° x (t / 0.6) linearly changes and is connected (polyline 1 〇). Further, the angle change point 1 1 of the angle 0 in the horizontal axis direction shown in Fig. 3(b) can be removed, and as shown in Fig. 3(C), the angle change points are connected by the curve 12. In this way, the angle change is a curved mode, and the rapid change in the amount of reflected light of the reflecting surface lc can be suppressed, and the light emitted from the exit surface lb can be made uniform. Next, the action of emitting light from the exit surface 1 b of the light guide 1 will be described. According to Snell's law, when light enters a substance with a small refractive index from a substance with a large refractive index, total light is reflected when the incident angle of the light is greater than the critical angle, and is refracted below the critical angle. The critical angle of acrylic acid is about 42° and the polycarbonate is about 39°. When it is applied to the light guide body -11 - 1312047 of the present embodiment, when the light traveling from the light source 2 in a certain direction advances in the light guide plate 1, the inclined surface of the light reflecting surface 1 C is disposed. The tilt angle of 1 d is gradually reduced by the angle to repeat the reflection, and the incident angle with respect to the exit surface 1 b is gradually reduced. When the light guide is implemented according to this principle, when the light above the critical angle of the exit surface 1 b is necessarily smaller than the critical angle, the light can be refracted and emitted from the exit surface 1 b. According to the principle described above, the provision of the reflecting surface 1c can reduce the light leakage of the counter-injecting surface 1e, increase the amount of light emitted from the exit surface 1b, and can emit uniform light from the exit surface lb. Further, the light source 2 should be a light emitting diode (LED), however, a fluorescent lamp or the like can also be used. Further, a cymbal is disposed on the upper surface of the light-emitting surface 1b of the light guide 1, and the light emitted from the exit surface 1b can be deflected by the cymbal to advance in a direction perpendicular to the exit surface lb. EXAMPLES Hereinafter, the present invention will be described by way of examples. The optical light source device consisting of the light source 'light guide and one cymbal is assembled to detect the optical characteristics. The light source is an LED (NEW020 manufactured by Nichia Chemical Co., Ltd.) 4 lamps. Figure 4 is an embodiment of the invention. Fig. 4(a) is a view showing the configuration of the reflecting surface, Fig. 4(b) is an observation view of the exit surface of the reflecting surface, and Fig. 4(c) is an observation of Fig. 4(b). The brightness distribution of the surface. In the present embodiment, the inclined surface Id of the configuration shown in Fig. 4(a) is formed on the reflecting surface 1c, and the substantially uniform observation shown in Fig. 4(b) is realized -12-1312047 and as shown in Fig. 4 (c) A substantially uniform distribution of the luminance of 3000 to 5600 cd/m2 as shown. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional view of a light guide body of a conventional embodiment. Fig. 2 is a light guide of an embodiment of the present invention, and Fig. 2(a) is a top view, Fig. 2(b) is a cross-sectional view, and Fig. 2(c) is a perspective view. Fig. 3 is a view showing the relationship of a light guide body according to an embodiment of the present invention. Fig. 4 is a view showing an embodiment of the present invention. Fig. 4(a) is an embodiment of a configuration of a reflecting surface, Fig. 4(b) is an observation view of an emitting surface, and Fig. 4(c) is a luminance distribution of an emitting surface. Figure. [Description of main component symbols] 1 : Light guide 1 a : Incidence surface 1 b = Exit surface 1 C : Reflecting surface 1 d : Oblique surface 1 e : Reverse incident surface 2 : Light source 101 : Light guide body 1 0 1 a : Incident Face 1 〇1 b : Exit face 1 〇1 C : Reflector face-13- 1312047 1 0 1 d : Bevel 102 : Light source 103 : Sepal 1 0 4 : Reflector