JP5985364B2 - Light source unit and lighting device - Google Patents

Description

  The present invention relates to a side-edge type light source unit and an illuminating device using a one-side incident type light guide plate.

  Conventionally, in a lighting device such as a liquid crystal display device used for a liquid crystal TV, a side edge (also referred to as a side light or an edge light) that emits light incident on a side surface from a light source in a planar shape in order to reduce the thickness. An optical system having a type of light guide plate is often used.

  In such a side-edge type light guide plate, a light source such as an LED (Light Emitting Diode) is disposed so as to face an end face of the light guide plate (hereinafter also referred to as an “incident end face”). Light enters from each incident end face. The incident light propagates while reflecting inside the light guide plate and is emitted from the light exit surface of the light guide plate.

  By the way, in the edge light type light source unit using the one-side incident type light guide plate, light is emitted from the light guide plate in a direction biased with respect to the light incident direction, so that the light is strongly emitted to the opposite side of the light incident side. Orientation characteristics. For this reason, in order to arrange a plurality of light source units and use them for illumination that seamlessly shines between the light source units, it is necessary to illuminate the entire light emitting surface of the light source units. Has a problem that the luminance on the side opposite to the light incident side is large, and conversely, the luminance on the light incident side is small.

  Here, an edge light type light source unit using a light guide plate is a technique that has been widely used in liquid crystal display devices in the past, but such problems do not occur in liquid crystal display devices. The reason is that the liquid crystal display device only needs to emit light to the portion of the liquid crystal panel, and the frame portion that is the frame portion of the liquid crystal panel does not need to shine. In other words, in the application of the liquid crystal display device, it is only necessary to consider the luminance of the central portion of the illumination device where the lower portion of the liquid crystal panel is located, and it is not necessary to consider the luminance distribution of the outer frame portion of the illumination device.

  For example, a surface light source device disclosed in Patent Document 1 is known as a technique for improving the luminance distribution of the entire light source unit in a side edge type light source unit using a light guide plate of this type of one-side incidence type.

  As shown in FIG. 8, the planar light source 100 disclosed in the above-mentioned Patent Document 1 is a point-like or linear light source 101 and light from the light source 101 is incident from a side surface 102 a, and almost from a planar one surface 102 c. A plurality of planar light source units 110 each including a light guide plate 102 that uniformly irradiates are provided. A mountain-shaped irregular reflection member 103 is provided on the upper surface side of the light source 101 existing between the adjacent planar light source units 110 so as to cover the light source 101. Further, a light diffusing plate 105 is provided on one surface 102c side of the plurality of planar light source units 110 with a constant interval H.

  The planar light source 100 can be easily increased in size by simply arranging a plurality of planar light source units 110 for introducing light from the side surface of the light guide plate 102 in parallel to form a large planar light source. In addition, an inexpensive planar light source that can uniformly illuminate even a large display panel such as an electric signboard is provided. Here, it is necessary to increase the distance between the light guide plate 102 and the light diffusing plate 105 by about 10 to 20 mm. However, there is no shadow at the seam at the position of the light diffusing plate 105, and a uniform planar light source can be obtained. it can.

JP 2009-2111915 A (published September 17, 2009)

  By the way, in the planar light source 100 disclosed in the above-mentioned conventional patent document 1, a joint exists between the planar light source units 110, and a mountain-shaped irregular reflection member 103 is provided at the joint.

  However, the planar light source 100 disclosed in Patent Document 1 improves the luminance distribution of the seams between the light guide plates when using a plurality of light guide plates instead of a single light guide plate 210, and as a whole lighting device If it grasps | ascertains, it can be said that the objective is improving the luminance distribution of the center part of an illuminating device in the structure which uses a some light guide plate for the center part of an illuminating device. Therefore, it is impossible to improve the luminance distribution of the outer frame portion of the housing that stores the entire plurality of light guide plates. As a result, when the lighting device is used for indoor lighting, the indoor illumination directed toward the outside of the lighting device is decreased, and a plurality of the lighting devices are arranged adjacent to each other so that the outer frames of the housings are adjacent to each other. When applied as a lighting device, there is a problem in that a decrease in luminance at the outer frame portion of the housing is not reduced, and the joint between the lighting devices is easily visible.

  Further, the mountain-shaped irregular reflection member 103 has a mountain shape formed of an isosceles triangle. For this reason, in the side-edge type light source unit using the one-side incident type light guide plate, the isotropic side is used as the irregular reflection member 103 from the viewpoint of having the orientation characteristic that the light is strongly emitted to the opposite side of the light incident side. As in the case of a triangular chevron, when the inclination angles are made equal, it is difficult to make the brightness of the joints between the planar light source units 110 sufficiently uniform with other portions. .

  The present invention has been made in view of the above-described conventional problems, and an object thereof is to achieve uniform luminance distribution in the vicinity of an outer frame portion in a side-edge type light source unit using a one-side incident type light guide plate. Accordingly, it is an object of the present invention to provide a light source unit and an illuminating device that can prevent uneven brightness between the light source units when a plurality of such light source units are arranged.

In order to solve the above-described problem, a light source unit according to an aspect of the present invention includes a light guide plate that emits light incident from a light incident portion that is one side end surface from an output surface, and a light incident portion of the light guide plate. A light source unit including a light source that makes light incident on the light guide plate, of the light emitted from the light exit surface of the light guide plate on the light incident portion side of the light guide plate and the opposite side facing the light incident portion. And a light guide plate that emits light from the light guide plate at the light incident portion side of the housing. The angle between the surface and the extension surface to the light source side is the light incident portion side inclined portion angle θ1, and the extended surface outward of the opposite side end portion of the exit surface of the light guide plate in the inclined portion on the opposite side of the housing Is the opposite side inclined portion angle θ2,
θ1> θ2
It is characterized by having a relationship.

  In order to solve the above-described problem, the lighting device according to one embodiment of the present invention includes the light source unit described above.

  In order to solve the above problems, a lighting device according to one embodiment of the present invention is characterized in that a plurality of the light source units described above are arranged.

  According to one aspect of the present invention, the luminance distribution in the vicinity of the outer frame portion of the side edge type light source unit using the one-side incident type light guide plate is made uniform, and a plurality of such light source units are arranged side by side. There is an effect of providing a light source unit and an illumination device that can prevent luminance unevenness between the light source units.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the light source unit which concerns on Embodiment 1 of this invention, Comprising: It shows the structure of a light source unit. (A) is a top view which shows the structure of the said light source unit, (b) is a perspective view which shows the structure of the said light source unit. (A) (b) is a figure which shows the orientation characteristic of the emitted light from the light guide plate in the said side edge type light source unit using the light guide plate of the one side incidence type. It is sectional drawing which shows the direction of the emitted light from the light-guide plate in the said side edge type light source unit using the light guide plate of the single side incidence type. (A) is a top view of the brightness nonuniformity of the light-diffusion member of the light source unit which shows the A1-A1 'direction and A2-A2' direction of Fig.2 (a), (b) is a part of the part shown to (a). It is a top view of the brightness nonuniformity of the light-guide plate of a light source unit, (c) is sectional drawing of the light source unit which shows the structure of the part shown to (a). FIG. 3 is a distribution diagram showing a luminance distribution in the A1-A1 ′ direction of FIG. FIG. 3 is a distribution diagram showing a luminance distribution in the A2-A2 ′ direction of FIG. (A) is sectional drawing which shows the structure of the conventional light source unit, (b) is a top view which shows the structure of the said conventional light source unit.

  One embodiment of the present invention is described below with reference to FIGS.

  The configuration of the light source unit according to the present embodiment will be described with reference to FIGS. 1 and 2A and 2B. FIG. 1 is a cross-sectional view showing the configuration of the light source unit of the present embodiment. FIG. 2A is a plan view showing the configuration of the light source unit, and FIG. 2B is a perspective view showing the configuration of the light source unit.

  In the present embodiment, a lighting device such as a ceiling light can be cited as an example of a lighting device including a light source unit. However, the light source unit and the lighting device are not limited to this. A lighting device is also provided with a plurality of light source units arranged side by side.

  As shown in FIGS. 2A and 2B, the light source unit 1 of the present embodiment has a rectangular outer shape, and a plurality of LEDs (Light Emitting Diodes) as light sources on one side of the long side. ) A group 4 is provided, and an opposing surface reflecting member 7 is provided on the other side of the long side.

  In the light source unit 1 of the present embodiment, the size of the light extraction area is, for example, 907 mm × 510 mm. The LED group 4 uses LEDs in which 72 LED packages having a width of 5.6 mm and a height of 3.0 mm are arranged in a row, and light is incident from one end surface of the long side of the light guide plate 10 described later. The thickness of the light guide plate 10 is, for example, 3.0 mm.

  That is, as shown in FIG. 1, the light source unit 1 includes a chassis 2, an LED substrate 3, an LED group 4, a reflection sheet 5, a light diffusing member 6 as a cover member, an opposing surface reflecting member 7, a light guide plate 10, and a housing. The frame 20 is provided. Here, the frame 20 refers to an outer frame portion configured to surround the periphery of the light guide plate 10 in the casing. The housing is not necessarily configured integrally, and the portion covering the lower surface of the light guide plate 10 and the frame portion may be configured separately.

  In the light source unit 1, the chassis 2, the reflection sheet 5, the light guide plate 10, and the light diffusion member 6 are arranged in order from the bottom. Here, in the light source unit 1 of the present embodiment, the light emitting surface side of the light guide plate 10 is described as the upper side. However, when the light source unit 1 is used in lighting equipment such as a ceiling light, the lower side is the light guide plate 10. The light emitting surface side.

  The chassis 2 is provided on the side opposite to the emission surface 11 of the light guide plate 10, thereby covering the back side of the light source unit 1. In the present embodiment, the chassis 2 uses, for example, an aluminum sheet metal member having a thickness of 0.5 mm.

  An LED group 4 as a light source is mounted on the LED substrate 3. Here, in the present embodiment, the light source is preferably the LED group 4 in order to save space. However, in the present invention, the light source is not necessarily limited to this and is a light source of another light emission method such as CCFL. It does not matter.

  The light guide plate 10 receives light emitted from the LED group 4 mounted on the LED substrate 3, and receives the received light between the emission surface 11 and the back surface of the light guide plate 10 and in a direction parallel to the light guide direction. The light is propagated inside the light guide plate 10 while being totally reflected between the both side surfaces, and is mainly emitted from the emission surface 11. For this reason, the light guide plate 10 is made of a transparent material having high light transmittance, and is made of, for example, PMMA (acrylic), PC (polycarbonate), PS (polystyrene), or the like.

  In the present embodiment, the light guide plate 10 has a plate shape and the emission surface 11 has a quadrangular shape.

  As shown in FIG. 1, a plurality of light extraction patterns 8 that are light diffusion portions are formed on the back surface of the light guide plate 10 at intervals. The light extraction pattern 8 can also be disposed on the light exit surface 11 side of the light guide plate 10.

  For example, the light extraction pattern 8 is formed by printing dots on the back surface of the light guide plate 10. For example, UV ink is used for printing. However, the present invention is not necessarily limited to this, and it may be a diffusing ink containing other diffusing particles, or ink jet printing or a light guide plate 10 provided with irregularities such as a prism shape.

  As described above, by forming the light extraction pattern 8 on the back surface of the light guide plate 10, the optical path of the light propagating through the light guide plate 10 can be changed. Specifically, the light extraction pattern 8 diffuses the incident light when light propagating through the light guide plate 10 enters the light extraction pattern 8 formed on the back surface of the light guide plate 10. Change the direction of light travel. As a result, at least a part of the light diffused by the light extraction pattern 8 is emitted from the emission surface 11 to the outside without being totally reflected by the emission surface 11.

  The reflection sheet 5 re-enters the light guide plate 10 with the light reflected from the rear surface of the light guide plate 10 while the total reflection condition is broken while the light incident on the light guide plate 10 from the LED group 4 is guided, or The light is transmitted and light is extracted to the light emitting surface 12 side. In the present embodiment, the reflection sheet 5 uses, for example, a resin sheet having a trade name “E6D6 (manufactured by Toray Industries, Inc.)” having a thickness of 0.3 mm.

  The light diffusing member 6 is provided above the light exit surface 11 of the light guide plate 10 and protects the light guide plate 10 and also diffuses the light emitted from the light guide plate 10 to suppress unevenness in light quantity, that is, uneven brightness. It has a function to do. The light diffusing member 6 is preferably a light shade made of glass fiber from the viewpoint of flexibility during installation. However, the present invention is not necessarily limited thereto, and may be a diffusion material, a diffusion plate having fine bubbles, or another type of light diffusion member such as Japanese paper or cloth. In the present embodiment, the light diffusion member 6 uses a resin sheet made of a trade name “light shade (manufactured by Nittobo Co., Ltd.)” using glass fiber as a material. It is arranged at a position of 10.5 mm above the light guide plate 10.

  The frame 20 covers the periphery of the light guide plate 10 in a frame shape, the bottom surface side supports the chassis 2, and the front surface side supports the light guide plate 10. The frame 20 is preferably composed of an aluminum (Al) extruded member in consideration of heat dissipation when the LED group 4 is directly or indirectly arranged. However, it is not limited to the aluminum (Al) profile extrusion member, and may be a sheet metal member or a resin member of other metal.

  Thus, as shown in FIG. 1, the light source unit 1 according to the present embodiment includes a rectangular light guide plate 10 that emits light incident from the light incident portion 12 that is one side end surface from the exit surface 11; Since the LED group 4 that enters light into the light incident portion 12 of the light guide plate 10 is provided, the edge light type light source unit 1 using the one-side incident type light guide plate 10 is provided.

  The edge light type light source unit 1 using such a one-side incident type light guide plate 10 has an orientation characteristic that light is emitted from the light guide plate 10 in a direction deviated from the light incident direction. Therefore, light is emitted strongly to the side opposite to the light incident side.

  Specifically, as shown in FIGS. 3A and 3B, the orientation characteristics of the emitted light from the light guide plate 10 in the edge light type light source unit 1 using the one-side incident type light guide plate 10 is about 75. A brightness of intensity 1 can be obtained at a degree, but at about 60 degrees, the intensity decreases to 0.8, and at about 45 degrees, the intensity decreases to 0.4.

  As a result, the light emitted from the light guide plate 10 in the edge light type light source unit 1 using the one-side incident type light guide plate 10 has a large luminance on the side opposite to the light incident side of the light emitted from the light guide plate 10. Conversely, there is a problem that the luminance on the light incident side is reduced.

  Therefore, in the light source unit 1 of the present embodiment, as shown in FIG. 1, first, the light incident portion 12 side of the light guide plate 10 and the opposite side surface 13 as the opposite side facing the light incident portion 12 are A frame 20 is provided as a casing, each of which includes an inclined portion for guiding light emitted from the light exit surface 11 of the light guide plate 10 toward the side of the light guide plate 10 to the side of the light guide plate 10. ing. That is, in the frame 20, an inclined portion for raising light upward is provided on the light incident portion 12 of the light guide plate 10 and the opposite side surface 13 thereof.

  Specifically, in the light source unit 1 of the present embodiment, the cross-sectional shape of the frame 20 becomes an inclined shape as it proceeds in the direction of the light diffusing member 6 on the exit surface 11 side, as shown in FIG. Yes. The inclined shape of the frame 20 is provided on all four sides of the light source unit 1.

  Specifically, the LED side inclined portion 20a is provided on the side where the LED group 4 is provided, and the opposing surface side inclined portion 20b is provided on the side where the opposing surface reflecting member 7 is provided. Furthermore, as shown in FIG. 2A, other surface side inclined portions 20c and 20c are provided on the other pair of surfaces, respectively.

  The LED side inclined portion 20a, the opposing surface side inclined portion 20b, and the other surface side inclined portions 20c and 20c of the frame 20 are provided with inclined portion reflecting members 21 made of a reflective sheet, respectively, thereby providing a light guide plate. Among the light emitted from the 10 emission surfaces 11, the light emitted toward the side of the light guide plate 10 is guided to the upper side of the emission surface 11.

  The inclined portion reflecting member 21 has a highly reflective light scattering surface, and for example, a trade name “E6D6 (manufactured by Toray Industries, Inc.)” having a thickness of 0.3 mm is used. Note that the inclined portion reflecting member 21 is not limited to the above-described reflecting sheet, but is a type in which a highly reflecting paint is applied to the frame 20, a coloring process by anodizing, or a highly reflecting plastic represented by polycarbonate. It may be a member.

  In this case, as shown in FIG. 4, the light is emitted from the light guide plate 10 in a direction deviated in the light incident direction, so that the light is strongly emitted to the opposite side of the light incident portion 12. As a result, strong light strikes the opposing surface-side inclined portion 20b, so that the luminance of the opposing surface-side inclined portion 20b is high, and conversely, the luminance of the LED-side inclined portion 20a on the light incident portion 12 side is low.

  Here, in the present embodiment, the relationship between the light incident portion side inclined portion angle θ1 of the LED side inclined portion 20a and the opposed side inclined portion angle θ2 of the opposed surface side inclined portion 20b is set to satisfy θ1> θ2. .

  That is, the opposed side inclined portion angle θ2 of the opposed surface side inclined portion 20b is relaxed, and the light incident portion side inclined portion angle θ1 of the LED side inclined portion 20a is made steep.

  By setting such an inclination angle, it is possible to improve the luminance distribution. Specifically, when the inclination angle is steep, the projected area of the inclined portion when viewed from the light emitting direction of the light source unit 1 is narrowed, and light is concentrated on a narrow projected area, resulting in high brightness. . On the other hand, when the inclination angle is gentle, the projected area of the inclined portion when viewed from the light emitting direction of the light source unit 1 is increased, so that the luminance is reduced.

  As a result, in the present embodiment, the luminance is increased at the light incident portion 12 and the luminance is decreased at the opposed side surface 13, so that the luminance distribution can be made uniform as a whole. That is, the luminance C1 on the LED side inclined portion 20a side≈the luminance C2 on the opposed surface side inclined portion 20b side can be set.

  Therefore, it is possible to provide the light source unit 1 that can achieve uniform luminance distribution in the side edge type light source unit 1 using the one-side incident type light guide plate 10.

  Further, since the configuration of the present embodiment is a side-edge type light source unit 1 using a one-side incident type light guide plate 10, it is lighter than a side-edge type light source unit using a both-side incident type light guide plate. In addition, since only half of the substrate and the like are required, an inexpensive light source unit 1 can be provided.

  Moreover, in the light source unit 1 of this Embodiment, it is preferable that both the light incident part side inclination part angle | corner (theta) 1 and the opposing side inclination part angle | corner (theta) 2 are 90 degrees or less. Thereby, the light emitted above the opposing side surface 13 of the light guide plate 10 can be guided above the light incident portion 12 by the reflection of the opposing surface side inclined portion 20b.

In the light source unit 1 of the present embodiment, the light incident portion side inclined portion angle θ1 and the opposing side inclined portion angle θ2 are:
60 ° ≦ θ1 ≦ 90 °, 45 ° ≦ θ2 <90 °
It is preferable to have the relationship

  As a result, it is possible to provide the light source unit 1 that can surely eliminate the uneven brightness and make the brightness distribution uniform by evaluating the experimental angular range described later.

  Further, in the light source unit 1 of the present embodiment, the light guide plate 10 has a pair of vertical surfaces 14 and 14 that are perpendicular to one side end surface that is the light incident portion 12 and the emission surface 11 and that face each other (see FIG. 2 (a)), and the frame 20 includes other surface side inclined portions 20c and 20c as inclined portions on the pair of vertical surfaces 14 and 14 side of the light guide plate 10, respectively. It is preferable that the inclination angles of the other surface side inclined portions 20c and 20c on the vertical surfaces 14 and 14 side are the same. The light guide plate 10 is rectangular in the present embodiment, but is not necessarily limited thereto, and may be a polygon such as a hexagon.

  Thereby, in the relationship between the LED side inclined portion 20a of the light incident portion 12 in the frame 20 and the opposed surface side inclined portion 20b on the opposed side surface 13 side in the frame 20, the inclination angles are made different from each other. By providing the other surface side inclined portions 20c and 20c also on the vertical surfaces 14 and 14, the luminance unevenness on the other surface inclined portions 20c and 20c side of the other pair of vertical surfaces 14 and 14 can be eliminated. In this case, the other surface-side inclined portions 20c and 20c of the other pair of vertical surfaces 14 and 14 have the same luminance condition, and therefore it is not necessary to change the inclination angle. Therefore, it is preferable that the inclination angles of the other-surface inclined portions 20c and 20c on the pair of vertical surfaces 14 and 14 are the same. Thereby, the shapes of the other surface side inclined portions 20 c and 20 c are symmetrical with respect to the vertical surfaces 14 and 14 with the light guide plate 10 interposed therebetween.

  As a result, it is possible to provide the light source unit 1 that can further uniform the luminance distribution of the entire light guide plate 10.

  The light source unit 1 of the present embodiment preferably includes the light diffusion member 6 that covers the entire upper surfaces of the light guide plate 10 and the frame 20, and the entire upper surfaces of the light guide plate 10 and the frame 20 are preferably light emitting surfaces. .

  That is, the light diffusing member 6 can diffuse light that has reached the light diffusing member 6 at various angles to obtain a substantially uniform diffusing surface (Lambertian) light distribution. For this reason, in this Embodiment, it has two effects largely. The first effect is an effect of making the luminance uniform between the light guide plate 10 and the inclined surface portion of the frame 20, and thereby, between the light guide plate 10 portion and the inclined surface portion of the frame 20. The luminance difference is small and the boundary can be made inconspicuous. Therefore, since the light emitting surface can be extended not only to the light guide plate 10 but also to the inclined surface portion of the frame 20, the problem of being a dark portion in the frame 20 can be solved. The inclined surface preferably extends to the vicinity of the edge that is the outermost part of the frame 20.

  The second effect is an effect of extending the light emitting region to the outside of the inclined surface. As described above, it is desirable that the inclined surface extends as much as possible to the vicinity of the edge that is the outermost part of the frame 20, but the inclined surface cannot be completely extended to the edge due to design constraints. A portion that is not an inclined surface may remain at the edge. Even in such a case, the light diffusing member 6 covers the entire upper surface of the frame 20 including the edge, so that the light from the inclined surface is diffused inside the light diffusing material 6 and then is more than the edge. By emitting the part, the light emitting region can be extended to the outside of the inclined surface.

  With the above effects, the entire surface including the frame 20 can be used as the light emitting surface by covering the inclined portion of the frame 20 and the entire upper surface of the light guide plate 10 with the light diffusion member 6.

  Therefore, the frame 20 does not become a dark portion, and in particular, in the form in which the plurality of light source units 1 are arranged in a plane, it is possible to suppress the conspicuous portion from being noticeable.

  Moreover, the illumination device of the present embodiment includes the light source unit 1 of the present embodiment. Thereby, the light source unit 1 of this Embodiment is applicable to the illuminating device which illuminates the inside of a room.

  Moreover, in the illuminating device of this Embodiment, the light source unit 1 of this Embodiment is arranged in multiple numbers. As a result, the luminance distribution in the side edge type light source unit 1 using the one-side incident type light guide plate 10 is made uniform, and luminance unevenness between the light source units 1 when a plurality of such light source units 1 are arranged is prevented. A lighting device can be provided.

  In the edge light type light source unit 1 using the one-side incident type light guide plate 10 described above, the light incident portion side inclined portion angle θ1 of the LED side inclined portion 20a of the frame 20 and the opposite side inclined portion of the opposite surface side inclined portion 20b. An experiment was conducted to obtain an appropriate value of the angle θ2.

  In the experiment, first, the light incident portion side inclined portion angle θ1 = opposing side inclined portion angle θ2 = 30 ° was set, and the occurrence of luminance unevenness at that time was confirmed. For the measurement, a two-dimensional color luminance meter having a trade name “CA-2000 (manufactured by Konica Minolta Co., Ltd.)” was used.

  The results are shown in FIGS. 5 (a), (b) and (c). 5A is a plan view showing luminance unevenness of the light diffusing member of the light source unit showing the A1-A1 ′ direction and the A2-A2 ′ direction of FIG. 2A, and FIG. FIG. 5C is a cross-sectional view of the light source unit showing the configuration of the portion shown in FIG. 5A. 5A and 5B, the left side represents luminance unevenness near the light incident portion 12, and the right side represents luminance unevenness near the opposing side surface 13. FIG. 5A shows the luminance unevenness when the light diffusing member 6 is arranged, and FIG. 5B shows the luminance unevenness when the light diffusing member 6 is removed.

  As shown in FIG. 5 (a), the light incident part side inclined part angle θ1 = the opposed side inclined part angle θ2, and the vicinity of the light incident part 12 despite the same inclination angle. It can be seen that the decrease in luminance is greater than the decrease in luminance near the opposite side surface 13.

  Further, the luminance distribution when the light diffusing member 6 is removed shows that the luminance is different between the vicinity of the light incident portion 12 and the vicinity of the opposite side surface 13 as shown in FIG. Compared to the luminance on the light guide plate 10 that is about 45 mm apart, 331/932 * 100 = 36% in the vicinity of the light incident part 12 and 601/864 * 100 = 70% in the vicinity of the opposite side surface 13.

  This is because the light distribution characteristic of the light emitted from the light guide plate 10 is such that more light reaches the counter-surface-side inclined portion 20b through the LED-side inclined portion 20a and rises to the upper surface. Accordingly, it can be seen that even if the inclined portions have the same angle, even when the light diffusing member 6 is disposed, a luminance difference is generated between the vicinity of the light incident portion 12 and the vicinity of the opposite side surface 13.

  Next, in order to obtain appropriate values for the light incident portion side inclined portion angle θ1 of the LED side inclined portion 20a of the frame 20 and the opposed side inclined portion angle θ2 of the opposed surface side inclined portion 20b, θ1 and θ2 are respectively set to 90 ° and 60 °. The luminance distribution was determined when the angle was 45 °, 30 °. In the measurement, the two-dimensional color luminance meter of the above-mentioned brand name "CA-2000 (made by Konica Minolta Co., Ltd.)" was used.

  The result will be described with reference to FIGS. FIG. 6 is a distribution diagram showing the luminance distribution in the A1-A1 ′ direction of FIG. 2A, that is, the luminance distribution near the light incident portion 12. FIG. 7 is a distribution diagram showing the luminance distribution in the A2-A2 ′ direction of FIG.

  As shown in FIGS. 6 and 7, when compared with the case of θ1 = θ2, the luminance decrease rate from θ1 = θ2 = 90 ° is always larger in θ1. Then, it can be seen that the smaller the θ1, the larger the θ2, the smaller the luminance drop.

  At this time, the luminances near the inclined portions of θ1 = 60 ° and θ2 = 45 ° are substantially the same.

  From this, it can be seen that in general, θ1 and θ2 are 90 ° or less, and it is preferable that θ1> θ2.

  However, in FIGS. 6 and 7, under the conditions of θ1 = 45 ° and θ2 = 30 °, the luminance at the upper part of the inclined portion is drastically decreased, so that the dark portion was visually recognized alone.

Therefore, the light incident part side inclined part angle θ1 and the opposing side inclined part angle θ2 are:
60 ° ≦ θ1 ≦ 90 °, 45 ° ≦ θ2 <90 °
Is determined to be optimal.

  By providing the frame 20 with the LED-side inclined portion 20a and the opposing surface-side inclined portion 20b having the light incident portion-side inclined portion angle θ1 and the opposed-side inclined portion angle θ2, the luminance distribution can be made uniform. Is possible.

  Further, if the light source units 1 of the present embodiment are arranged in parallel at the respective angles, the luminance in the vicinity of the light incident portion 12 and the luminance in the vicinity of the opposite side surface 13 of the other light source unit 1 at the joint. Can be substantially matched. Therefore, it is possible to eliminate the luminance difference between the seams when the light source units 1 of the present embodiment are connected.

  Note that the present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the claims, and can be obtained by appropriately combining technical means disclosed in the present embodiment. Embodiments are also included in the technical scope of the present invention.

(Summary)
In order to solve the above-described problem, the light source unit 1 according to one aspect of the present invention includes a light guide plate 10 that emits light incident from a light incident portion 12 that is one side end surface from an output surface 11, and the light guide plate. 10, a light source unit 1 including a light source (LED group 4) that emits light to 10 light incident portions 12. The light incident portion 12 side of the light guide plate 10 and a facing side (facing side surface) facing the light incident portion 12. 13), an inclined portion (LED-side inclined portion 20a) for guiding light emitted toward the side of the light guide plate 10 out of the light emitted from the output surface 11 of the light guide plate 10 to the upper side of the output surface 11. In addition, a housing (frame 20) provided with the opposing surface side inclined portion 20b) is provided, and an inclined portion (LED-side inclined portion 20a) on the light incident portion 12 side of the housing (frame 20). Light source (LED group) on the exit surface 11 of the light guide plate 10 ) Side is defined as the light incident portion-side inclined portion angle θ1, and the guiding portion at the inclined portion (opposing surface-side inclined portion 20b) on the opposite side (opposing side surface 13) of the casing (frame 20) is used. When the angle formed with the surface extending from the opposite side (opposite side surface 13) end of the light exit surface 11 of the optical plate 10 is the opposite side inclined portion angle θ2,
θ1> θ2
It is characterized by having a relationship.

  According to the above invention, the light source unit is an edge light type light source unit using a one-side incident type light guide plate. In the edge light type light source unit using such a one-side incident type light guide plate, the light emitted from the light guide plate has a high luminance on the side opposite to the light incident side, and conversely, the luminance on the light incident side becomes small. There's a problem.

  Therefore, in the light source unit of the present invention, the light emitted from the light exit surface of the light guide plate toward the side of the light guide plate on the light incident portion side of the light guide plate and the opposite side facing the light incident portion. Cases each provided with an inclined portion for guiding the emitted light above the emission surface are provided.

  In addition, the relationship between the light incident portion side inclined portion angle θ1 and the opposing side inclined portion angle θ2 in the inclined portion is set to satisfy θ1> θ2.

  As a result, the luminance is increased on the light incident portion side and the luminance is decreased on the opposite side, so that the luminance distribution can be made uniform as a whole.

  Therefore, it is possible to provide a light source unit that can achieve uniform luminance distribution in the vicinity of the outer frame portion in the side edge type light source unit using the one-side incident type light guide plate.

  In the light source unit 1 according to one aspect of the present invention, it is preferable that both the light incident portion side inclined portion angle θ1 and the opposing side inclined portion angle θ2 are 90 ° or less.

  Thereby, the light radiate | emitted to the opposing side of a light-guide plate can be guide | induced to the light-incidence part side by reflection of an inclination part.

In the light source unit 1 according to one aspect of the present invention, the light incident portion side inclined portion angle θ1 and the opposing side inclined portion angle θ2 are:
60 ° ≦ θ1 ≦ 90 °, 45 ° ≦ θ2 <90 °
It is preferable to have the relationship

  As a result, it is possible to provide a light source unit that can surely eliminate luminance unevenness and make the luminance distribution uniform by evaluating an experimental angular range.

  In the light source unit 1 according to one aspect of the present invention, the light guide plate 10 includes a pair of vertical surfaces 14 and 14 that are perpendicular to one side end surface that is the light incident portion 12 and the emission surface 11 and that face each other. The frame (frame 20) includes inclined portions (other side inclined portions 20c and 20c) on the pair of vertical surfaces 14 and 14 side of the light guide plate 10, respectively. It is preferable that the inclination angles of the inclined portions on the surfaces 14 and 14 side (other side inclined portions 20c and 20c) are the same.

  As a result, the luminance unevenness on the inclined portion side of the other pair of vertical surfaces can be eliminated. As a result, it is possible to provide a light source unit that can make the luminance distribution of the entire light guide plate uniform.

  The light source unit 1 according to one aspect of the present invention includes the light diffusion member 6 that covers the entire upper surface of the light guide plate 10 and the housing (frame 20), and the entire upper surface of the light guide plate 10 and the housing (frame 20). A light emitting surface is preferred.

  Thus, the entire surface including the frame 20 can be used as the light emitting surface by covering the inclined portion of the frame 20 and the entire upper surface of the light guide plate 10 with the light diffusion member 6.

  Accordingly, the frame portion does not become a dark portion, and in particular, in the form in which a plurality of light source units are arranged in a plane, it is possible to suppress the conspicuous portion from being noticeable.

  In order to solve the above-described problem, the lighting device according to one embodiment of the present invention includes the light source unit 1 described above.

  According to said invention, the light source unit of this invention is applicable to the illuminating device which illuminates the inside of a room.

  In order to solve the above-described problem, a lighting device according to an aspect of the present invention is characterized in that a plurality of the light source units 1 described above are arranged.

  According to the above invention, the luminance distribution in the vicinity of the outer frame portion in the side edge type light source unit using the one-side incident type light guide plate is made uniform, and a plurality of light source units of this type are arranged between the light source units. An illumination device that can prevent uneven brightness can be provided.

  The present invention relates to a side-edge type light source unit and an illuminating device using a one-side incident type light guide plate, and to uniformize the luminance distribution in the vicinity of the outer frame portion of the light emitted from the one-side incident type light guide plate. The present invention can be applied to a light source unit and a lighting device.

DESCRIPTION OF SYMBOLS 1 Light source unit 2 Chassis 3 LED board 4 LED group (light source)
DESCRIPTION OF SYMBOLS 5 Reflection sheet 6 Light-diffusion member 7 Opposite surface reflection member 8 Light extraction pattern 10 Light guide plate 11 Output surface 12 Light incident part 13 Opposite side surface 14 Vertical surface 20 Frame (housing)
20a LED side inclined portion 20b Opposing surface side inclined portion 20c Other surface side inclined portion 21 Inclined portion reflecting member θ1 Light incident portion side inclined portion angle θ2 Opposing side inclined portion angle

Claims (7)

In a light source unit comprising: a light guide plate that emits light incident from a light incident portion that is one side end surface from an output surface; and a light source that emits light to the light incident portion of the light guide plate.
Light emitted toward the side of the light guide plate out of the light emitted from the emission surface of the light guide plate on the light incident portion side of the light guide plate and the opposite side facing the light incidence portion above the emission surface And a housing each provided with an inclined portion for leading to
The angle formed by the light incident side extending surface of the light guide plate on the light incident portion side of the inclined portion on the light incident portion side of the casing is defined as a light incident portion side inclined portion angle θ1, and the angle on the opposite inclined portion of the casing is determined. When the angle formed with the surface extending outward of the opposing side end of the light exit surface of the light guide plate is the opposing side inclined portion angle θ2,
θ1> θ2
A light source unit characterized by having a relationship as follows.   2. The light source unit according to claim 1, wherein both the light incident portion side inclined portion angle θ <b> 1 and the opposing side inclined portion angle θ <b> 2 are 90 ° or less. The light incident part side inclined part angle θ1 and the opposing side inclined part angle θ2 are:
60 ° ≦ θ1 ≦ 90 °, 45 ° ≦ θ2 <90 °
The light source unit according to claim 2, wherein: The light guide plate has a pair of vertical surfaces that are perpendicular to one side end surface that is a light incident portion and the emission surface and that face each other, and
The said housing is respectively provided with the inclination part in a pair of perpendicular | vertical surface side of the said light-guide plate, The inclination | tilt angle of this inclination part of a pair of perpendicular | vertical surface side is the same, The Claim 1, 2, or 3 characterized by the above-mentioned. The light source unit described. A light diffusing member that covers the entire top surface of the light guide plate and the housing;
The light source unit according to any one of claims 1 to 4, wherein the entire upper surface of the light guide plate and the housing is a light emitting surface.   An illumination device comprising the light source unit according to claim 1.   6. A lighting device, wherein a plurality of light source units according to claim 1 are arranged.