TWM526038U - Light guide plate and lighting device thereof - Google Patents

Description

Light guide plate and its lighting fixture

The creative department is related to the field of light guide plates, in particular, a light guide plate capable of presenting a batwing type projection light type and a lighting fixture formed by using the light guide plate.

According to the basic requirements of the luminaire, the illumination effect can be felt by the object or person at different positions from the illuminating device. Therefore, the current projection light type requirement of a lighting fixture using a light-emitting diode (hereinafter referred to as LED) as a light source will be required to exhibit a batwing pattern in which the light intensity on both sides is greater than the central light intensity. In order to make the LED lamp reach the illumination effect of the batwing type light distribution curve, the conventional method is to respectively set a corresponding lens for each LED, and accordingly, the light emitted by each lens is assembled to form a desired light type. In this way, it is necessary to set the lens for the LED one by one, and the production cost is relatively increased. Therefore, if a single lens is used in combination with the reflector body of the lamp body to adjust the light distribution curve, the projection light pattern cannot be effectively maintained at an optimum state.

In view of the fact that the technical development of the light guide plate has gradually matured, due to its excellent light adjustment characteristics, it has been frequently used in LED lighting fixtures in recent years, and the light guide plate characteristics can be utilized to make the projected light type more perfect. In the case of a luminaire with a side-in type light source, the light enters the light guide plate and is then subjected to the characteristics of the light guide plate to form a surface light source, which is limited by the optical characteristics of the LED, and generally forms more light at a distance from the light entrance side. Therefore, in order to adjust the projection light type of the luminaire, a reflective element may be disposed to adjust the light state with the light guide plate, for example, a plurality of reflective elements are arranged in the luminaire and their positions and angles are individually adjusted to gradually form a batwing projection light pattern. However, this way will increase the design and combination of lamps. The difficulty is high, and the light is transmitted by the reflective element for reflection and reflection, which causes energy loss and causes insufficient light intensity of the lamp.

Therefore, in order to achieve the purpose of controlling light, the conventional design method directly adjusts the appearance of the light guide plate structure. For example, in order to form the luminaire as the aforementioned batwing light type, it is a common practice to design the light guide plate to be non-equal thickness. Such as a wedge-shaped plate body; or use a plurality of different shapes of light guide plates to piece together and adjust the light source setting position according to the desired light type. However, in this way, the shape of the light guide plate needs to be customized according to various light types. Therefore, many restrictions are imposed on the production, and the general light guide plate process adopts an injection molding process. When it is desired to produce light guide plates of different shapes, The corresponding mold cores were designed separately and could not meet the goal of rapid mass production.

Therefore, how to make the light-guide type control of the light guide plate easier and more accurate, and also meet the practical needs at the production level, is the subject of improvement in this field. The present author conceives a light guide plate and a lighting fixture formed by using the light guide plate, and hopes to effectively solve the above-mentioned defects and problems.

The purpose of this creation is to provide a light guide plate and a lighting fixture thereof, which are used to lay out a specific distribution pattern on the opposite surface of the light guide plate, thereby effectively controlling the light exit direction, thereby making the overall light output a batwing type light distribution curve.

In order to achieve the above objective, the present invention discloses a light guide plate comprising: a light incident side disposed oppositely to receive light; and a light emitting surface, the two ends being respectively connected to the light incident side for emitting light a reflecting surface disposed opposite to the light emitting surface and respectively connected to the light incident side, and receiving a light reflected from the reflective sheet back into the light guide plate; a first dot group disposed on the light emitting surface, the first The layout density of the dot group is gradually decreasing from the second light side toward the center. The light-receiving capability of the light-emitting surface is gradually decreased from the second light-incident side toward the center; and a second network dot group is disposed on the reflective surface, and the layout density of the second network dot group is gradually increased from the second light-incident side toward the center Distributing such that the light-receiving capability of the reflecting surface is gradually increased from the second light-incident side toward the center; thereby, after the light enters the light guide plate, the first mesh point group and the second half-dot group are emitted through the light-emitting surface A batwing type light distribution curve is formed. The first dot group and the second dot group disposed on the light emitting surface and the reflecting surface can effectively control the light exiting direction to obtain a batwing type projection light type.

In one embodiment, the first mesh point group is disposed at a density corresponding to 0 in a central region of the corresponding light guide plate, and the second mesh dot group is disposed at a density of 0 adjacent to the second light incident side region, thereby Accurately control the light path and the light exiting pattern to improve the accuracy of light distribution.

In order to prevent the light level of the first halftone group and the second halftone group from being too low, the light is not able to be emitted according to the predetermined path. In another embodiment, the first network of the group and the second network of the network are smooth. Groove.

In addition, in the second embodiment, the second network dot group is disposed on the reflective surface according to a light extraction capability distribution curve, and the light extraction capability distribution curve is reduced according to an initial light extraction capability distribution curve. Forming the light extraction capability of the light side region; wherein the initial light extraction capability distribution curve is formed by combining a first distribution curve and a second distribution curve; the first distribution curve is obtained from one of the The light entering the light guide plate on the light-incident side can emit light in a region where the light-emitting side faces the light-injecting side to the center of the light-guiding plate, and the second distribution curve is such that the light-incident side enters the light guide plate from the other light-incident side. The light can be totally emitted in a region where the light exiting the light entrance side to the center of the light guide plate. The second network point group is disposed on the reflecting surface according to the light-receiving power distribution curve formed by reducing the light-collecting ability of the initial light-receiving power distribution curve adjacent to the light-input side region, thereby effectively preventing the light from being guided by the first network point group at the light guide plate and The second network of groups affects the neighbors Excessive light is formed in the near-light-in side region, and the light intensity in the central portion of the light-emitting surface is weakened, which does not conform to the required light distribution curve.

In one embodiment, the present invention also discloses a lighting fixture, comprising: a light guide plate comprising: a light-incident side, which is oppositely disposed; a light-emitting surface, the two ends are respectively connected to the light-incident side for emitting light; The surface is disposed opposite to the light-emitting surface, and the two ends are respectively connected to the light-incident side; a first network dot group is disposed on the light-emitting surface, and the distribution density of the first network dot group is gradually decreasing from the second light-incident side toward the center. The light-receiving capability of the light-emitting surface is gradually decreased from the second light-incident side toward the center; and a second network dot group is disposed on the reflective surface, and the layout density of the second network dot group is gradually increased from the second light-incident side toward the center Distributing such that the light-receiving ability of the reflecting surface is gradually increased from the two-into-light side toward the center; a reflecting sheet is disposed corresponding to the reflecting surface for reflecting light back into the light guiding plate; and two light bars respectively corresponding to The light-incident side is disposed to provide light to the light guide plate; and the light entering the light guide plate passes through the first halftone group and the second halftone group to form a batwing-shaped light distribution curve when the light exits the light-emitting surface. Through the arrangement of the first dot group and the second dot group of the light guide plate, the light exiting direction of the light bar incident on the light guide plate can be effectively controlled, thereby obtaining a batwing type projection light pattern.

Similarly, in order to improve the precision of the light distribution, in one embodiment, the first dot group is disposed at a density corresponding to a central region of the light guide plate, and the second dot group is adjacent to the second light incident region. The layout density is 0.

Further, in order to prevent the surface roughness of the first halftone group and the second halftone group from being poor, the fine microstructure affects the light path. In still another embodiment, the first halftone group and the second halftone group are smoothed. Curved groove.

In the second embodiment, the second network dot group is disposed on the reflective surface according to a light extraction capability distribution curve, and the light extraction capability distribution curve is based on an initial light extraction capability distribution curve. a line that is formed by reducing a light-receiving capability of the light-receiving side region; wherein the initial light-harvesting power distribution curve is formed by a first distribution curve and a second distribution curve; the first distribution curve The light from one of the light-incident sides entering the light guide plate can emit light in a region where the light-emitting side faces the light-input side to the center of the light guide plate, and the second distribution curve is from another The light entering the light guide plate on the light incident side can emit light in a region where the light exiting the light incident side to the center of the light guide plate. The second network point group is set according to the light extraction capacity distribution curve, which can effectively prevent the light-emitting surface from forming excessive light in the adjacent two-light-inside side region, and the light-emitting surface central region has insufficient light output to form a batwing type projection light type.

In summary, the light guide plate and the illumination device disclosed in the present invention are configured to directly control the light exit direction through the first mesh point group and the second mesh point group respectively disposed on the light emitting surface and the reflecting surface of the light guide plate, thereby obtaining the batwing type matching. Light out of the light curve. The first dot group makes the light-receiving ability of the light-emitting surface gradually decrease from the light-incident side toward the center, and the second dot group makes the light-receiving ability of the reflecting surface gradually increase from the second light side toward the center to adjust the incident light into the light guide plate. The light forms the desired light. In addition, the first network point group and the second network point group may also be arranged as smooth curved grooves to prevent the surface micro-structure of the first network point group and the second network point group from affecting the light guiding path.

1‧‧‧Lighting fixtures

10‧‧‧Light guide plate

101‧‧‧light side

102‧‧‧Glossy surface

103‧‧‧reflecting surface

104‧‧‧First site group

105‧‧‧Second network group

11‧‧‧reflector

12‧‧‧Light strips

A‧‧‧ light extraction capacity distribution curve

B‧‧‧Initial light extraction capacity distribution curve

B ₁ ‧‧‧first distribution curve

B ₂ ‧‧‧second distribution curve

Figure 1A is a schematic diagram of the light guide plate of the creation (1).

Figure 1B is a schematic diagram of the light guide plate of the creation (2).

Figure 2 is a side view of the assembly of the creation.

Figure 3 is a schematic diagram of the application of this creation.

Figure 4A is a schematic diagram of the initial light extraction capacity distribution curve of the creation.

Figure 4B is a schematic diagram of the distribution curve of the light-taking ability of the creation.

In order to improve the light-lighting adjustment performance of the light guide plate used in the luminaire, the creator adopts a method of simultaneously setting the microstructure on both sides of the light guide plate to control the light-emitting direction to form a specific light type, and the detailed technical contents are as follows. Please refer to the drawings 1A~1B, 2, 3, 4A and 4B, which are respectively schematic diagrams of the light guide plates, assembly side view, application diagram, initial light extraction capacity distribution curve and light extraction capacity distribution curve. schematic diagram. In one embodiment, a light guide plate 10 is disclosed, which includes a light incident side 101, a light exit surface 102, a reflective surface 103, a first dot group 104, and a second dot group 105.

The two light incident sides 101 are oppositely disposed to receive side light, and the light emitting surface 102 and the reflecting surface 103 are also disposed opposite to each other, and respectively adjacent to the two light incident sides 101. The light-emitting surface 102 is configured to form light, and the reflective surface 103 is configured to receive light reflected from the reflective sheet 11 back into the light guide plate 10.

The first halftone dot group 104 is disposed on the light exiting surface 102, and the density of the first mesh dot group 104 is gradually decreased from the second light incident side 101 toward the center, so that the light extraction capability of the light exiting surface 102 is gradually decreased from the second light incident side 101 toward the center. The second dot group 105 is disposed on the reflecting surface 103, and the density of the second dot group 105 is gradually increased from the second light side 101 toward the center, so that the light receiving capability of the reflecting surface 103 is gradually shifted from the second light side 101 toward the center. increase. The light-receiving capability of the light-emitting surface 102 and the reflective surface 103 indicates that the smooth surface 102 and the reflective surface 103 are damaged by the first halftone dot group 104 and the second halftone dot group 105, thereby destroying the total reflection phenomenon after the light enters the light guide plate 10. Since the ability to emit light is formed, the light output amount of the light-emitting surface 102 and the reflection surface 103 can be controlled by the density of the first halftone dot group 104 and the second halftone dot group 105. Thereby, after the light enters the light guide plate 10, the first halftone dot group 104 and the second halftone dot group 105 are transmitted to form a batwing-type light distribution curve when the light-emitting surface 102 emits light. In detail, when the light After entering the light guide plate 10 from the light-incident side 101, the density of the first dot group 104 is gradually decreased from the light-incident side 101 toward the center, so that part of the light is formed from the light-emitting surface 102 near the light-incident side 101. When the light is emitted, part of the light is emitted from the reflecting surface 103 and reflected from the reflecting sheet 11 corresponding to the reflecting surface 103, reflected back to the reflecting surface 103, and then transmitted through the second dot group 105 having a higher laying density in the center of the light guiding plate 10, and is turned toward the light. Light is formed at the center of the face 102. Adjusted by the first halftone dot group 104 and the second halftone dot group 105, the light can be projected from the light exiting surface 102 to be projected to form a batwing type projection light type with a larger amount of light emitted from the side of the light guide plate 10 than the center of the light guide plate 10. .

In order to make the light-emitting type more conform to the requirements of the batwing type, it is preferable that the first dot group 104 has a density of 0 in the central region of the corresponding light guiding plate 10, and the second halftone group 105 is adjacent to the second light-incident side 101. The layout density is 0, that is, the first halftone dot group 104 is not disposed at the center of the light guide surface 102 corresponding to the light guide plate 10, and the second mesh dot group 105 is not disposed at the reflective surface 103 adjacent to the second light incident side 101. In the case of the network dot arrangement, the accuracy of the light distribution can be effectively improved. In the present embodiment, the first halftone group 104 and the second halftone group 105 take the aspect as an example, and as in the first, the first and the second. As shown in the figure, the creation is not limited to this.

In order to avoid the light level adjustment efficiency of the surface of each of the first halftone dot group 104 and the second halftone dot group 105, in the present embodiment, the first halftone dot group 104 and the second halftone dot group 105 are smooth and curved. The groove is formed to prevent the surface flatness of the first halftone dot group 104 and the second halftone dot group 105 from being insufficient, so that the light is affected by the light source to cause the light direction to be shifted. The first halftone dot group 104 and the second halftone dot cluster 105 are formed by laser processing and are semicircular or bowl-shaped grooves.

In this embodiment, the layout of the second halftone dot group 105 is set on the reflective surface 103 according to a light extraction capability distribution curve A, and the light extraction capability distribution curve A reduces the adjacent two light into the light according to an initial light extraction capability distribution curve B. The light extraction capability of the side 101 region is formed. The initial light extraction capability curve B is formed by joining a first distribution curve B ₁ and a second distribution curve B ₂ . The first distribution curve B ₁ is such that one of the light entering side of the light entering side of the light guiding plate 10 can enter the light guiding plate 10 . All of the light-emitting surface 102 corresponding to the light-incident side 101 to the center of the light guide plate 10 emits light. The second distribution curve B ₂ causes the light entering the light guide plate 10 from the other light incident side 101 to be completely emitted from the light incident surface 102 corresponding to the light incident side 101 to the center of the light guide plate 10, as shown in FIGS. 4A and 4B. . The initial light extraction capability curve B is such that the light entering the light guide plate 10 from the light entrance side 101 passes through the second halftone dot group 105 to destroy the total reflection phenomenon, and then uniformly emits light on the light exit surface 102, and is dependent on the light guide plate material and the light source. The curves formed by various factors such as the type and the size of the light guide plate can be obtained by the above-mentioned various changes based on the simulation test basis, and then the respective curves are integrated by weighting calculation to obtain the initial light extraction capacity distribution curve B. At this time, the light type projected by the light-emitting surface 102 is a uniform state, that is, the light-emitting brightness of each region of the light-emitting surface 102 is the same. In order to obtain the batwing type projection light pattern, it is necessary to adjust the light exiting state, and the present invention sets the first halftone dot group 104 in synchronization with the illuminating surface 102 to adjust the partial light ray direction. As described above, since the layout density of the first halftone dot group 104 is gradually decreased from the adjacent light incident side 101 region toward the center, if the second mesh dot group 105 structured according to the initial light extraction capability distribution curve B is maintained, the structure will be maintained. After entering the light guide plate 10 from the light incident side 101, the light is emitted by the second mesh point group 105 and then reflected out to the light guide plate 103, and then reflected back to the light guide plate 10 by the reflection sheet 11, and the above action is repeated to cause energy loss, resulting in energy loss. The brightness of the light emitted from the center of the light-emitting surface 102 is insufficient. Therefore, the light-receiving capability of the region adjacent to the second light-incident side 101 of the initial light-taking capability distribution curve B is lowered and the second network dot group 105 is disposed according to the arrangement thereof to prevent the above-mentioned situation from occurring.

The second and third figures show the application state of the light guide plate 10. A part of the light entering the light guide plate 10 from the light incident side 101 is first affected by the first dot group 104 of the light exit surface 102, and The light exiting surface 102 is adjacent to the light incident side 101, and a portion of the light is continuously reflected in the light guide plate 10 until a portion of the second halftone dot group 105 contacting the reflective surface 103 emits light, and the light is reflected back through the reflective sheet 11. At the center of the reflecting surface 103, the optical path is adjusted by the second halftone group 105 of the area, and light is emitted from the central area of the light emitting surface 102. Thereby, the layout patterns of the first halftone dot group 104 and the second halftone dot group 105 are distributed as described above to control the light outgoing direction to form a batwing type projection light pattern.

Please refer to the figures 2, 3, 4A and 4B. In another embodiment, the present invention discloses a lighting fixture 1 comprising a light guide plate 10, two light bars 12 and a reflection sheet 11, and the light guide plate 10 includes two The light incident side 101, a light exiting surface 102, a reflecting surface 103, a first halftone dot group 104 and a second halftone dot group 105.

The light incident side 101 of the light guide plate 10 is disposed opposite to each other, and the light emitting surface 102 and the reflecting surface 103 are also disposed opposite to each other and connected to the two light incident sides 101, respectively. The first halftone dot group 104 is disposed on the light exiting surface 102, and the density of the first mesh dot group 104 is gradually decreased from the second light incident side 101 toward the center, so that the light extraction capability of the light exiting surface 102 is gradually decreased from the second light incident side 101 toward the center. The second dot group 105 is disposed on the reflecting surface 103, and the density of the second dot group 105 is gradually increased from the second light side 101 toward the center, so that the light receiving capability of the reflecting surface 103 is gradually shifted from the second light side 101 toward the center. increase.

The reflection sheet 11 is disposed corresponding to the reflection surface 103 to reflect the light back into the light guide plate 10. The light strips 12 are respectively disposed corresponding to the light incident sides 101 to provide light to the light guide plate 10, whereby the light entering the light guide plate 10 passes through the first halftone dot group 104 and the second halftone dot group 105 to emit light on the light exiting surface 102. Batwing light distribution curve.

Preferably, the density of the first halftone dot group 104 in the central region of the corresponding light guide plate 10 is 0, and the density of the second mesh dot group 105 in the region adjacent to the light incident side 101 is 0, which is more favorable for controlling light. In the light direction, get a better batwing light distribution curve, as shown in Figure 2. Shown. In addition, in order to prevent the surface flatness of the first halftone dot group 104 and the second halftone dot group 105 from affecting the light exiting direction, the first halftone dot group 104 and the second halftone dot cluster 105 may be smooth curved grooves and may pass through the thunder. Injection molding.

The second halftone dot group 105 is disposed on the reflective surface 103 according to a light extraction capability distribution curve A, and the light extraction capability distribution curve A is based on an initial light extraction capability distribution curve B, and the lower adjacent light incident side 101 region is taken. Formed by light power. The initial light extraction capacity distribution curve B is formed by joining a first distribution curve B ₁ and a second distribution curve B ₂ , and the first distribution curve B ₁ is such that one of the light entering sides 101 enters the light guide plate 10 . The light can be emitted from the light-emitting surface 102 corresponding to the light-emitting side 101 to the center of the light-guiding plate 10, and the second distribution curve B ₂ is such that the light entering the light-guide plate 10 from the other light-incident side 101 can be corresponding to the light-emitting surface 102. All the areas from the light side 101 to the center of the light guide plate 10 are emitted. Please refer to Figures 4A and 4B for details. The formation of the light extraction capability profile A has been described before, and thus the description thereof will not be repeated.

For the application state of the lighting fixture 1, as shown in FIG. 3, after the light bar 12 is turned on to enter the light guide plate 10, the light is transmitted through the first halftone group 104 and the second halftone group 105, and some light is first from the light emitting surface 102. The light-incident side 101 region emits light first, and some of the light is reflected in the light guide plate 10 and is affected by the second second dot group 105 to be emitted outward from the reflective surface 103. The light is reflected by the reflective sheet 11 to the center of the reflective surface 103. Then, the second network point group 105 of the area controls the light path to emit light from the central area of the light-emitting surface 102, thereby obtaining a batwing type light distribution curve.

In summary, the light guide plate and the illumination lamp disclosed in the present invention control the light exit direction through the first mesh group and the second mesh group of the light exit surface and the reflective surface of the light guide plate, and then form a batwing type when the light exit surface is emitted. Projected light pattern to provide the desired light pattern. The density of the first dot group is gradually decreased from the light entering side toward the center, and the density of the second dot group is gradually decreasing from the second light side toward the center. The configuration is increased to effectively control the light path and the light exiting direction of the light entering the light guide plate, and the brightness of the light emitted from the adjacent light entrance side is greater than the brightness of the light emitted from the center of the light guide plate. In addition, the first dot group and the second dot group can be formed by laser processing, and are smooth curved grooves to prevent the surface flatness of the dots from affecting the light guiding path.

However, the above description is only for the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention; therefore, the equivalent changes or modifications made without departing from the main technical features and scope of the present invention, for example The same means for different sizes or materials of the light guide plate should still be covered by the scope of this creation patent.

1‧‧‧Lighting fixtures

10‧‧‧Light guide plate

101‧‧‧light side

102‧‧‧Glossy surface

103‧‧‧reflecting surface

104‧‧‧First site group

105‧‧‧Second network group

11‧‧‧reflector

12‧‧‧Light strips

Claims (8)

A light guide plate comprises: a light-incident side disposed oppositely to receive light; a light-emitting surface, two ends respectively connected to the light-incident side for emitting light; and a reflecting surface disposed opposite to the light-emitting surface Connected to the light incident side, respectively, and receive a light reflected from the reflective sheet back into the light guide plate; a first dot group is disposed on the light exiting surface, and the first mesh point group is disposed at a density from the second light side toward the center a decreasing distribution, the light-receiving capability of the light-emitting surface is gradually decreased from the second light-incident side toward the center; and a second network dot group is disposed on the reflective surface, and the second mesh point group is disposed at a density from the second light-incident side The central portion is gradually distributed, so that the light-receiving capability of the reflective surface is gradually increased from the second light-incident side toward the center; thereby, after the light enters the light guide plate, the light is transmitted through the first mesh point group and the second network dot group. The batwing type light distribution curve is formed when the light exiting the light. The light guide plate of claim 1, wherein the first dot group has a density of 0 in a central region corresponding to the light guide plate, and the second mesh group has a density of adjacent to the second light entrance region. 0. The light guide plate of claim 1, wherein the first dot group and the second dot group are smooth curved grooves. The light guide plate of claim 1, wherein the second network dot group is disposed on the reflective surface according to a light extraction capability distribution curve, and the light extraction capability distribution curve is based on an initial light extraction capability distribution curve. Forming a light-reducing capability adjacent to the second light-incident side region; The initial light extraction capacity distribution curve is formed by joining a first distribution curve and a second distribution curve; the first distribution curve is such that light from one of the light entering sides of the light guide plate can be The light exiting all the light from the light incident side to the center of the light guide plate, and the second distribution curve is such that the light entering the light guide plate from the other light entrance side can face the light entrance side to the light exiting side to All areas in the center of the light guide plate emit light. A lighting fixture comprises: a light guide plate comprising: a light-incident side, which is oppositely arranged; a light-emitting surface, the two ends are respectively connected with the light-incident side for emitting light; and a reflecting surface is opposite to the light-emitting surface and two The ends are respectively connected to the light incident side; a first dot group is disposed on the light exiting surface, and the density of the first dot group is gradually decreased from the light entering side toward the center, so that the light collecting capability of the light emitting surface is The second light-incident side is gradually reduced toward the center; and a second half-dot group is disposed on the reflective surface, and the distribution density of the second half-dot group is gradually distributed from the second light-incident side toward the center, so that the reflective surface is light-receiving The ability is gradually increased from the second light side toward the center; a reflective sheet is disposed corresponding to the reflective surface for reflecting light back into the light guide plate; and two light strips are respectively disposed corresponding to the light incident side to provide light to the light The light guide plate; the light entering the light guide plate passes through the first halftone dot group and the second halftone dot group to form a batwing light distribution curve when the light exiting the light exiting surface. The lighting fixture of claim 5, wherein the first halftone group has a density of 0 in a central region of the corresponding light guide plate, and the second halftone group is adjacent to the second light incident side region. The layout density is 0. The lighting fixture of claim 5, wherein the first dot group and the second dot group are smooth curved grooves. The lighting fixture of claim 5, wherein the second halftone dot group is disposed on the reflective surface according to a light extraction capability distribution curve, and the light extraction capability distribution curve is based on an initial light extraction capability distribution curve. Forming a light-reducing capability of the light-receiving side region adjacent to the second light-incident region; wherein the initial light-harvesting capacity distribution curve is formed by combining a first distribution curve and a second distribution curve; Light from one of the light-incident sides entering the light guide plate may emit light in a region where the light-emitting side faces the light-injecting side to the center of the light-guiding plate, and the second distribution curve is caused by the other light entering the light. The light entering the light guide plate at the side can be completely emitted in a region where the light exiting the light entrance side to the center of the light guide plate.