JP2012226964A - Illumination apparatus and illumination equipment equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illumination apparatus, improved in light utilization efficiency by raising coupling efficiency from a light source to a light guide plate without accompanying the processing of the light guide plate, and attaining simultaneously both of space illumination as a direct illumination and ceiling area illumination as an indirect illumination.SOLUTION: The illumination apparatus includes a flat-plate light guide plate 13 and the light source, and irradiates the emitting light from the light source as direct illumination light from the front face side of the light guide plate 13 by guiding inside the light guide plate 13. Further, the light, which is not irradiated as the direct illumination light and is emitted from the outer periphery end part of the light guide plate 13, is guided inside a frame 20 by the frame 20 of light transmission member provided at the outer periphery of the light guide plate 13, and, then, is irradiated to a direction (for example, ceiling side) different from the front face side of the light guide plate 13 as the indirect illumination light.

Description

  The present invention relates to an illumination device that emits light from a light source in a planar shape by a light guide plate, and an illumination device including the illumination device.

  Conventionally, in an illuminating device, an LED (Light Emitting Diode) capable of saving energy by using low power consumption and low heat generation is used instead of an incandescent bulb. That is, since much of the supplied power is used for light emission, that is, the light emission efficiency is high, the LED lighting requires less power to produce the same brightness as the conventional incandescent lighting. In addition, the low power consumption is characterized by the fact that less heat is generated for the power that has been lost as heat in the prior art, and the lighting apparatus has a low heat generation.

  In recent years, lighting fixtures using LEDs have emerged not only for LED bulbs that replace incandescent bulbs but also for ceiling lights that are fixed to the ceiling.

  For example, Patent Literature 1 discloses a lighting fixture that can illuminate a ceiling surface by emitting light toward the side and back of the fixture body using LEDs.

  The lighting fixture 100 disclosed in Patent Document 1 is a ceiling-mounted ceiling light for residential use. As shown in FIGS. 14 (a) and 14 (b), the fixture main body 110 and the front surface of the fixture main body 110 are provided. And a light-transmitting cover 101 that covers the side surfaces, and a light control body 102 that emits light from the peripheral edge portion 101a of the light-transmitting cover 101 toward the side and back of the instrument main body 110.

  And the instrument main body 110 is equipped with the light emitting module 120 which has several LED, and the lighting device 111 which lights LED. As shown in FIGS. 14C and 14D, the light emitting module 120 includes a base 121, a plurality of LED chips 122a mounted on the base 121, and yellow fluorescence excited by the LED chips 122a. And a semiconductor light emitting element 122 configured to emit white light with high luminance and high output.

  With this configuration, it is possible to provide a lighting fixture 100 that can radiate light toward the side and back of the fixture main body 110 to brighten the ceiling surface.

  By the way, in this kind of lighting fixture 100, since the several light emitting module 120 is arranged side by side on the substantially whole surface of a ceiling light, the number of the semiconductor light emitting elements 122 increases and it becomes high cost.

  In order to solve this problem, for example, Patent Document 2 discloses a technique used for a backlight of a liquid crystal display device.

  As shown in FIG. 15, the backlight 200 for a display device disclosed in Patent Document 2 is provided with a light emitting diode 201 below the light guide plate 210 so that its optical axis is orthogonal to the light guide plate 210. . Then, immediately above the light emitting diode 201 on the surface of the light guide plate 210, curved reflecting surfaces 211 and 211 are formed so as to reflect light from the light emitting diode 201 toward both ends of the light guide plate 210. A reflective sheet 202 is provided below the light emitting diode 201.

  With the above configuration, the number of the light emitting diodes 201 can be reduced because the light emitting diodes 201 need only be disposed on the center line of the light guide plate 210.

  Furthermore, Patent Document 3 discloses a lighting fixture that includes a ceiling light that performs planar irradiation by a combination of a linear light source and a mirror. In the illuminating device disclosed in Patent Literature 3, light is emitted from a light source provided at an outer edge portion of the instrument body toward a curved mirror on the center side, and is reflected by reflecting the light.

JP 2010-140797 A (published on June 24, 2010) JP 2006-49324 A (published February 16, 2006) JP 2009-9898 A (released on January 15, 2009)

  However, in the display device backlight 200 disclosed in the above-described conventional Patent Document 2, the light guide plate 210 must be formed with reflecting surfaces 211 and 211 having curved surfaces. Therefore, since the light guide plate 210 has to be processed, the cost increases, and in particular, the processing of the large light guide plate has a problem that the area is large and difficult.

  Further, in the backlight 200 for a display device disclosed in Patent Document 2, the amount of light emitted to the liquid crystal panel side is too large immediately above the light emitting diode 201 in the light guide plate 210, so that the entire light guide plate is uniformly irradiated. Has the problem of being difficult.

  In addition, the illumination device disclosed in Patent Document 3 has a problem that the thickness of the device increases due to the use of a curved mirror.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide an illumination device that enables uniform irradiation over the entire light guide plate without increasing the number of light sources and processing the light guide plate. And providing a lighting device including the same.

In order to solve the above-described problems, an illumination device according to the present invention includes a flat light guide plate and a light source disposed on the back side of the light guide plate, and the light emitted from the light source is incident on the light guide plate. And illuminating the incident light from at least the front surface side of the light guide plate while totally reflecting and guiding the light inside the light guide plate,
An optical coupling member that couples light emitted from the light source so that light is incident obliquely on the light guide plate is provided between the light guide plate and the light source, and
An irradiation direction control unit for controlling the direction of light emitted from the outer peripheral end of the light guide plate is provided at the outer peripheral end of the light guide plate.

  In the illuminating device of the present invention, the light source and the optical coupling member are disposed on the back side of the flat light guide plate, and the optical coupling member transmits the light emitted from the light source to the flat light guide plate. The light is combined so that it is incident obliquely. For this reason, the light emitted from the light source arranged on the back side of the light guide plate is coupled to the light guide plate through the optical coupling member and is incident obliquely, and the end of the light guide plate is totally reflected inside the light guide plate. On the way, the total reflection condition is broken by the optical path conversion element, and the light is irradiated from the surface side of the light guide plate.

  As a result, unlike the conventional side-edge type light guide plate, the backlight is directly under the light guide plate, so that the frame size can be reduced. In addition, since the gap between the light source and the light guide plate for avoiding the thermal expansion required in the side edge type light guide plate is not required, the coupling efficiency from the light source to the light guide plate is increased and the light utilization efficiency is improved. be able to.

  Also, in the present invention, by providing a light coupling member separate from the light guide plate, light is incident on the flat light guide plate at an angle, so that the incident light is guided while being totally reflected inside the light guide plate. To be lighted. As a result, the incident light from the light source can be guided inside the light guide plate via the optical coupling member without processing the light guide plate.

  Therefore, it is possible to provide an illuminating device that can increase the coupling efficiency from the light source to the light guide plate and improve the light utilization efficiency without processing the light guide plate.

  Furthermore, in the illumination device of the present invention, an irradiation direction control unit that controls the direction of light emitted from the outer peripheral end of the light guide plate is provided at the outer peripheral end of the light guide plate. Moreover, at least a part of the controlled light can be irradiated to the back side of the light guide plate. If the illuminating device of this invention is used, both the space illumination as direct illumination and the ceiling illumination as indirect illumination can be implement | achieved simultaneously. In the conventional side-edge type light guide plate, the end portion (outer peripheral edge portion) is used as a light incident portion, so that the light extraction function cannot be given to the end portion of the light guide plate.

  In the illumination device according to the aspect of the invention, the irradiation direction control unit includes a light transmissive member provided on an outer periphery of the light guide plate, and the light transmissive member is emitted from an outer peripheral end of the light guide plate. After the light to be guided is guided inside, at least a part of the light can be irradiated in a direction different from the surface side of the light guide plate.

  According to said structure, the said irradiation direction control part can be easily obtained by the light transmissive member comprised, for example with resin.

  Moreover, in the illuminating device of this invention, a part which permeate | transmits a part of light radiate | emitted from the outer peripheral edge part of the said light-guide plate, and reflects a part between the said light-guide plate and the said light transmissive member. It can be set as the structure by which the permeation | transmission reflection member is provided.

  According to said structure, it becomes possible to change the ratio of direct illumination light and joint illumination light by selecting the reflectance of the said partially transmissive reflection member.

  In the illumination device of the present invention, a reflective member that guides light inside the light transmissive member and reflects light emitted to the surface side of the light transmissive member is provided on a surface side of the light transmissive member. It can be set as the structure provided. Moreover, the said reflection member can be set as the structure arrange | positioned so that it may become in parallel with the said light-guide plate.

  According to said structure, the light guided to the surface side (for example, indoor side) of the said light transmissive member can be reflected, and the irradiation light quantity to the back side (for example, ceiling side) can be increased.

  Moreover, in the illuminating device of this invention, the said light transmissive member is a 1st protrusion part arrange | positioned in parallel with the said light guide plate on the surface side of the said light guide plate, and the said light guide plate on the back surface side of the said light guide plate. It can be set as the structure which has the 2nd protrusion part arrange | positioned in parallel. In addition, the first protrusion and the second protrusion may have different protrusion lengths.

  According to said structure, the ratio of the extraction light quantity on the surface side and the extraction light quantity on the back surface side can be changed by changing the size of the said 1st protrusion part and said 2nd protrusion part.

  In addition, a lighting device according to the present invention includes the above-described lighting device.

  The present invention has an effect of providing an illumination device that increases the coupling efficiency from the light source to the light guide plate and improves the light utilization efficiency without processing the light guide plate. Furthermore, the present invention controls the irradiation direction of the light incident on the light guide plate, and the irradiation direction control unit capable of irradiating a part of the light to the back side of the light guide plate is provided at the outer peripheral end portion. Both spatial lighting and ceiling lighting as indirect lighting can be realized simultaneously.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view illustrating a configuration of a main part of a lighting device in a ceiling light as a lighting device according to an embodiment of a lighting device including a lighting device according to the present invention. (A) is a perspective view from the surface side which shows the structure of the said ceiling light, (b) is a perspective view from the back surface side which shows the structure of the said ceiling light. It is a perspective view which shows the structure of the light source module in the said illuminating device. (A) is sectional drawing which shows the optical path when the light radiate | emitted from LED injects into a light-guide plate via the optical coupling member which has a paraboloid, (b) is principal part sectional drawing which shows the optical path near LED. It is. (A) is sectional drawing which shows the optical path when the light radiate | emitted from LED injects into a light-guide plate via the optical coupling member which has an elliptical surface, (b) is principal part sectional drawing which shows the optical path of LED vicinity. is there. (A) is sectional drawing which shows the optical path when the light radiate | emitted from two LED injects into a light-guide plate through the optical coupling member which has a paraboloid and an ellipsoid, and radiate | emits from the surface side of a light-guide plate, (B) is a perspective view which shows the strip | belt-shaped light source module provided in the back surface of the light-guide plate. (A) is a top view which shows the said light-guide plate, (b) is a graph which shows the luminance distribution on the string which passes on the point A * B of (a). It is a top view which shows the total reflection conditions in the outer periphery of the light-guide plate which consists of a disk in the light which injected into the light-guide plate from the said light source module. (A) shows the structure of the modification of the said light-guide plate, Comprising: It is a top view which shows a rectangular light-guide plate, (b) is a top view which shows the light-guide plate which chamfered the rectangular corner | angular part, (C) is a top view which shows an elliptical light-guide plate, (d) is a top view which shows a rhombus-shaped light-guide plate. It is a perspective view which shows the structure of the modification of the light source module in the said illuminating device, Comprising: A frame-shaped light source module. It is sectional drawing which shows the toning illumination in the said illuminating device. (A)-(e) is sectional drawing which shows one Embodiment of a structure of the principal part of the illuminating device in this invention. It is sectional drawing which shows one Embodiment of a structure of the principal part of the illuminating device in this invention. (A) is sectional drawing which shows the structure of the conventional lighting equipment, (b) is a top view which shows the structure of the lighting equipment, (c) is sectional drawing which shows the structure of the illuminating device in the lighting equipment. FIG. 6D is a plan view showing the configuration of the illumination device in the illumination device. It is a cross section which shows the structure of the backlight applied to the conventional liquid crystal display device.

  An embodiment of the present invention will be described below with reference to FIGS.

  A configuration of a ceiling light as a lighting device including the lighting device of the present embodiment will be described with reference to FIGS. 1, 2 (a) to 2 (b), and FIG. 3. FIG. 1 is a cross-sectional view showing a configuration of a main part of a lighting device in a ceiling light, FIG. 2 (a) is a perspective view showing the configuration of the ceiling light, and FIG. 2 (b) is a ceiling light. FIG. 3 is a perspective view from the rear surface side showing the configuration of FIG. 3, and FIG. 3 is a perspective view from the front surface side showing the configuration of the light source module. In the present specification, unless otherwise specified, the “front surface” direction is the direction of the light irradiation surface in the lighting device of the present invention, the “back surface” direction is the opposite direction, and the “side surface” direction is The direction is orthogonal to both the front surface direction and the back surface direction. That is, when the lighting device of the present invention is installed as a ceiling light on the ceiling, the “front surface” is the room (floor) side, and the “back surface” is the ceiling side.

  As shown in FIG. 2A, the ceiling light 1 includes, for example, a disk-shaped lighting device 10, and the disk-shaped lighting device 10 includes a frame 20 on the outer periphery thereof. On the back surface of the ceiling light 1, as shown in FIG. 2B, a light source module 30 is provided on the diameter of the disk. The diameter of the ceiling light 1 is, for example, 550 mm, and the thinnest part is, for example, 10 mm. In addition, about the shape and each dimension of the ceiling light 1, it is not restricted to this.

  As shown in FIG. 1, the lighting device 10 of the ceiling light 1 includes a diffusion sheet 11, an air layer 12, a light guide plate 13, and a light source module 30 that are provided in order from the front side. A portion of the back surface of the light guide plate 13 where the light source module 30 is not provided is provided with a reflection sheet 14 and a back chassis 15 that are openings.

  As shown in FIG. 3, the light source module 30 is provided with a sheet-like heat sink 32 on a light source holder 31 formed in a strip shape. On the heat sink 32, for example, an LED as a light source is provided. (Light Emitting Diode) LED substrates 34a and 34b on which light emitting portions 33a and 33b (see FIG. 1) each composed of a chip and a phosphor are mounted are provided. Spacers 36a and 36b are formed on the LED boards 34a and 34b to provide a gap between the LED boards 34a and 34b and the optical coupling member 35 described later. Due to this gap, it is possible to prevent the optical coupling member 35 from coming into contact with the light emitting portions 33a and 33b and damaging the light emitting portions 33a and 33b. However, the present invention is not limited to this, and the light emitting units 33a and 33b may be in close contact with the optical coupling member 35 as long as the light emitting units 33a and 33b are not damaged. Since the semiconductor light emitting part has a very fine size, the description of the light emitting part is omitted in FIG. 3 in order to prevent the drawing from being complicated. Moreover, in this Embodiment, although the light emission parts 33a * 33b are used as a light source, it is not necessarily this, For example, it is also possible to use an organic EL light emitting element or an inorganic EL light emitting element.

  Here, in the present embodiment, the light emitting units 33a and 33b are a combination of a blue LED chip and a yellow phosphor, a combination of a blue LED chip, a red phosphor and a green phosphor, a blue LED chip, a red LED chip and a green LED. It is composed of a combination of chips, an organic EL element and the like. Further, the light emitting units 33a and 33b emit light having a color temperature of 2000K to 6000K. That is, red light in the morning sun or sunset has a color temperature of about 2000K, and sunlight has a color temperature of about 5000K to 6000K. In addition, in the light source used with the backlight of a liquid crystal display device, the light emission part of color temperature 10000K-20000K is used, for example.

  A plurality of the light emitting portions 33a and 33b are provided in parallel in two rows, and an optical coupling member 35 is provided above the light emitting portions 33a and 33b.

  That is, as shown in FIG. 1, the ceiling light 1 of the present embodiment includes a light guide plate 13 that irradiates light on the surface side, a light coupling member 35 as an optical element that couples light to the light guide plate 13, and the above The light coupling member 35 includes light emitting portions 33a and 33b that emit incident light, and the light guide plate 13, the light coupling member 35, and the light emitting portions 33a and 33b are arranged in this order from the front surface side to the back surface side of the lighting device 10. It consists of what is arranged. Therefore, the illuminating device 10 in the ceiling light 1 of the present embodiment is a illuminating device 10 directly under the light source in which the light emitting portions 33 a and 33 b are provided on the back side of the light guide plate 13.

  Here, in this embodiment, as shown in FIGS. 4 (a) and 4 (b), the optical coupling member 35 is a belt having a substantially semi-cylindrical cross section provided between the light guide plate 13 and the light emitting portions 33a and 33b. It consists of a rod-like body having a substantially U-shaped cross section. The material of the optical coupling member 35 is made of the same resin as that of the light guide plate 13. If the same material is used, the refractive index can be made the same, so that light is smoothly incident on the light guide plate 13 from the optical coupling member 35. The refractive index of the light guide plate 13 may be slightly higher than the refractive index of the optical coupling member 35. Further, the material is not limited to resin, and a material such as glass may be used. In addition, by forming a side wall (not shown) with a white resin or the like around the light emitting portions 33a and 33b and performing light distribution control, the coupling efficiency to the optical coupling member 35 can be improved.

  Specifically, as shown in FIG. 4A, the optical coupling member 35 has a surface on the light guide plate 13 side of the optical coupling member 35, and a top flat surface 35 a that abuts the flat light guide plate 13. It has a shape having curved surfaces 35b and 35c on both ends from the top flat surface 35a.

  The curved surfaces 35b and 35c can be, for example, a cross-sectional parabola shown in FIG. However, the present invention is not necessarily limited to this, and as shown in FIGS. 5A to 5B, the cross section may be an ellipse. In addition, a curved shape such as an arch shape, or obliquely from the top flat surface 35 a. Even if it is a plane inclined in a straight line, any shape that can effectively couple light to the light guide plate may be used.

  The surface of the optical coupling member 35 opposite to the light guide plate 13 side, that is, the lower end of the optical coupling member 35 is a lower flat surface 35d as shown in FIG. The spacers 36a and 36b are formed, and serve as spacers that prevent the light emitting portions 33a and 33b and the optical coupling member 35 from colliding with each other. The light emitting portions 33a and 33b are bonded to the LED substrates 34a and 34b, respectively. The spacers 36a and 36b are adhesively fixed to the LED boards 34a and 34b by applying an adhesive or the like. As shown in FIGS. 4A and 4B, the light emitting portions 33a and 33b are formed with a slight gap between the light coupling members 35, but the light emitting portions 33a and 33b are not limited thereto. The light emitting portions 33a and 33b may be in close contact with the optical coupling member 35 as long as they do not damage the light.

  In addition, a concave portion 35e is formed in the central portion on the lower end side of the optical coupling member 35. However, the configuration is not limited to this, and the concave portion 35e may not be present, and the optical coupling member 35 may have a substantially semicircular cross section. That is, in the present embodiment, it is only necessary to secure an optical path to the light guide plate 13 for the light reflected by the curved surfaces 35b and 35c. Therefore, a portion that does not become the optical path can be cut out as a recess 35e. Thereby, cost reduction and weight reduction can be achieved. It is also possible to provide a reflection means such as a reflection sheet (not shown) in the recess 35e. Thereby, even if stray light may be generated in the vicinity of the top flat surface 35a, a part of the stray light can be reflected to the light guide plate 13 side to improve irradiation on the surface side.

  Light emitting portions 33a and 33b are provided close to the optical coupling member 35 on the lower side (back side) of the lower flat surfaces 35d and 35d of the optical coupling member 35, respectively. As shown in FIGS. 4B and 5B, these light emitting portions 33a and 33b are present on the end side (side surface side) from the focal position F of the curved surfaces 35b and 35c having a cross-section parabola or a cross-section ellipse. It is preferable to do. Thereby, for example, as shown in FIG. 4A, for example, the light emitted from the light emitting portion 33 a is reflected by the curved surface 35 b of the parabolic parabola of the optical coupling member 35, and the reflected light is the top of the optical coupling member 35. It reaches the flat surface 35a and enters the light guide plate 13 obliquely while maintaining the arrival direction. Then, the light incident on the light guide plate 13 is reflected by the inside of the right side of the light guide plate 13 shown in FIG. The angle of traveling through the light guide plate 13 is changed by colliding with the light scatterer, the total reflection condition is broken, the light is emitted from the light guide plate 13, reflected by the reflection sheet 14, and further passed through the light guide plate 13. The light emitted from the surface of the light guide plate 13 is emitted from the ceiling light 1 through the diffusion sheet 11. Note that the light emitted from the light emitting unit 33b also proceeds symmetrically with the light from the light emitting unit 33a, as shown in FIG. That is, FIG. 6A schematically shows how the light from the left and right light emitting portions 33a and 33b passes through the optical coupling member 35, enters the light guide plate 13, and propagates through the interior thereof. is there.

  Such an optical path is the same in the optical coupling member 35 having an elliptical cross section shown in FIGS.

  Thus, by making the shape of the curved surfaces 35b and 35c in the optical coupling member 35 into a cross-sectional parabola or a cross-sectional ellipse, the light emitted from the light emitting portions 33a and 33b is reflected by the curved surfaces 35b and 35c having a cross-sectional parabola or a cross-sectional ellipse. Thus, the light can be efficiently combined and incident on the light guide plate 13 from the top flat surface 35a, and the illumination light can be emitted from the ceiling light 1 as shown in FIG. Incidentally, in the comparison between the cross-section parabola and the cross-section ellipse, the cross-section ellipse can be coupled so that the light is focused and incident on the light guide plate 13, so that the coupling efficiency can be increased.

  As a result, in the illuminating device 10 in the ceiling light 1 of the present embodiment, as shown in FIG. 6B, a strip-shaped light source module 30 is provided across the center of the disc-shaped ceiling light 1, that is, on the center line. As a result, as shown in FIG. 7A, the luminance distribution shown in FIG. 7B is obtained in a string passing through points A and B that are about ± 1/3 of the radius in the X-axis direction from the center of the light guide plate 13. The light emitted from the light guide plate 13 having the above can be obtained. As a result, the ceiling light 1 of the present embodiment can obtain a uniform and smooth luminance distribution.

  Here, the luminance distribution of the disk-shaped ceiling light 1 in the present embodiment will be described.

  That is, in the present embodiment, as shown in FIG. 8, in the disc-shaped light guide plate 13, the light P emitted from the light source module 30 provided on the center line reaches the outer peripheral end 13a. Here, since the light guide plate 13 of the present embodiment is made of, for example, an acrylic plate, the radial direction (normal direction to the tangent line Q) at the outer peripheral end 13a is orthogonal to the light source module 30 according to Snell's law. The angle θ formed by the direction is divided into a region S1 that is not totally reflected and regions S2 and S2 that are totally reflected with a boundary of about 42 degrees. The region S1 that is not totally reflected is a central side portion of the diameter, and the regions S2 and S2 that are totally reflected are both side portions of the diameter. For this reason, in the present embodiment, the brightness of the entire light guide plate 13 is further uniformed by adjusting the arrangement pattern of the light scattering portion which is an optical path conversion element (not shown).

  Moreover, in the illuminating device 10 of this Embodiment, as shown in FIG. 1, the light of light emission part 33a * 33b is entered from the back surface side of the light-guide plate 13. As shown in FIG. Here, in the backlight field of the liquid crystal display device, a side edge type backlight has been conventionally used. However, the light utilization efficiency of the conventional side edge type backlight is 75%. The light use efficiency of the lighting apparatus 10 of the present embodiment was 88%. Thus, it turns out that the illuminating device 10 of this Embodiment is excellent in light utilization efficiency rather than the conventional side edge type | mold backlight. That is, in the conventional side edge type backlight, since the linear expansion accompanying the temperature rise in the longitudinal direction of the light guide plate is large, it is necessary to provide a gap between the light emitting unit and the light guide plate. Since the emitted light from the light leaks from this gap, the light utilization efficiency could not be increased. In this regard, in the lighting device 10 of the present embodiment, since the light emitting portions 33a and 33b are provided immediately below the light guide plate 13, the expansion dimension is small even when the light guide plate 13 is thermally expanded. Therefore, since it is not necessary to provide a gap, the light utilization efficiency can be increased.

  As a result, in the illumination device 10 of the present embodiment, unlike the conventional side-edge type backlight, there is no light source at the end of the ceiling light 1 as shown in FIG. It is possible to provide the frame 20 directly at the end of the frame. As a result, surface light emission with a frame size of 6 mm or less is possible. Further, by forming the frame 20 from a transparent, translucent or milky white resin material, it is possible to emit light from the entire surface including the frame 20. By optimizing the shape and material of the frame 20, indirect illumination that emits light in the back surface direction is possible.

  By the way, in this Embodiment, although the illuminating device 10 becomes disk shape, for example, it is not necessarily this, As shown to Fig.9 (a)-(d), it can be set as various shapes. . Specifically, FIG. 9A shows a rectangular light guide plate 13, FIG. 9B shows a light guide plate 13 with rectangular corners chamfered, and FIG. 9C shows an elliptic light guide plate 13. FIG. 9D shows a diamond-shaped light guide plate 13.

  In this case, in the rectangular light guide plate 13 shown in FIG. 9A, the light quantity gradually increases in the light guide direction of the light from the light source module 30, that is, in the direction orthogonal to the light source module 30 extending in a strip shape (traveling direction). To decrease. For this reason, the distribution of the dot pattern of the light scattering portion can obtain a uniform luminance distribution from the light guide plate 13 to the surface side by increasing the number of dot patterns as it goes in the traveling direction. On the other hand, in the direction perpendicular to the light guide direction (vertical direction), the amount of light is constant, and as a result, the distribution of the dot pattern of the light scattering portion is also uniform.

  Further, in the light guide plate 13 whose corners of the rectangle shown in FIG. 9B are chamfered, the rectangular portion is the same as that in FIG. That is, the amount of light gradually decreases in the light guide direction (traveling direction) of light from the light source module 30. For this reason, the distribution of the dot pattern of the light scattering portion can obtain a uniform luminance distribution from the light guide plate 13 to the surface side by increasing the number of dot patterns as it goes in the traveling direction. In the direction perpendicular to the light guide direction (vertical direction), the amount of light is constant, and as a result, the dot pattern distribution in the light scattering portion is also uniform.

  On the other hand, in the chamfered portion of the rectangular corner, the light is totally reflected in the direction perpendicular to the light guide direction (vertical direction). As a result, in order to obtain a uniform luminance distribution from the light guide plate 13 to the surface side. Needs to reduce the dot pattern of the light scattering portion as it proceeds in the vertical direction.

  Furthermore, in the elliptical light guide plate 13 shown in FIG. 9C, the light quantity gradually decreases in the light guide direction (traveling direction) of the light from the light source module 30. For this reason, the distribution of the dot pattern of the light scattering portion can obtain a uniform luminance distribution from the light guide plate 13 to the surface side by increasing the number of dot patterns as it goes in the traveling direction. On the other hand, in the direction perpendicular to the light guide direction (vertical direction), the light is totally reflected. As a result, in order to obtain a uniform luminance distribution from the light guide plate 13 to the surface side, the light proceeds in the vertical direction. Accordingly, it is necessary to reduce the dot pattern of the light scattering portion.

  Moreover, in the rhombus-shaped light guide plate 13 shown in FIG. 9D, the amount of light gradually decreases in the light guide direction (traveling direction) of the light from the light source module 30. For this reason, the distribution of the dot pattern of the light scattering portion can obtain a uniform luminance distribution from the light guide plate 13 to the surface side by increasing the number of dot patterns as it goes in the traveling direction. On the other hand, in the direction perpendicular to the light guide direction (vertical direction), the light is totally reflected. As a result, in order to obtain a uniform luminance distribution from the light guide plate 13 to the surface side, the light proceeds in the vertical direction. Accordingly, it is necessary to reduce the dot pattern of the light scattering portion.

  In addition, in this Embodiment, although the light source module 30 of the illuminating device 10 is provided in strip | belt shape, it does not necessarily restrict to this. For example, as shown in FIG. 10, it can be a ring shape that is a frame shape. Thus, by using the frame-shaped light source module 30 that follows the shape of the illumination device 10, it is possible to easily achieve uniform luminance.

  Further, in the light source module 30 of the present embodiment, as described above, the light source module 30 is provided with two rows of light emitting portions 33 a and 33 b along the longitudinal direction of the optical coupling member 35. Therefore, by adjusting the color temperatures of the light emitting sections 33a and 33b in the two rows, as shown in FIG. 11, dimming and toning illumination can be performed. Specifically, the light emitting unit 33a is daylight white and the light emitting unit 33b is a light bulb color. Thereby, it is possible to perform dimming and toning illumination such as irradiating daylight white light outside the ceiling light 1 and illuminating a light bulb color inside the ceiling light 1.

  Further, in the present embodiment, the light source modules 30 are provided in one row, but the present invention is not limited to this, and a plurality of light source modules 30 may be provided. Thereby, improvement in brightness and dimming illumination are possible.

  Thus, in the illuminating device 10 of this Embodiment, between the light guide plate 13 and the light emission parts 33a * 33b, light is incident on the light guide plate 13 from the light emission parts 33a * 33b so as to enter obliquely. An optical coupling member 35 that couples the emitted light is provided. Therefore, the light emitted from the light emitting portions 33a and 33b on the back surface of the light guide plate 13 is coupled to the light guide plate 13 through the optical coupling member 35 and is incident obliquely, and is guided while being totally reflected inside the light guide plate 13. The light travels to the end of the light plate 13, and the total reflection condition is broken at the light scattering portion which is an optical path conversion element, and the light is emitted to the surface side of the light guide plate 13.

  As a result, it is possible to irradiate light from the entire surface of the light guide plate 13 simply by arranging the light emitting portions 33 a and 33 b along the back surface of the optical coupling member 35. As a result, the number of the light emitting parts 33a and 33b can be reduced as compared with the case where the light emitting parts 33a and 33b are arranged on the entire back surface of the light guide plate 13.

  In the present embodiment, by providing a light coupling member 35 that is separate from the light guide plate 13, light is incident obliquely on the flat light guide plate 13 and totally reflected inside the light guide plate 13. Can be guided to the whole. As a result, even without processing the light guide plate 13, incident light from the light emitting portions 33 a and 33 b is guided inside the light guide plate 13 through the optical coupling member 35, and light is uniformly emitted from the light guide plate 13. Can be irradiated.

  Further, in the present embodiment, the light emitting units 33 a and 33 b are arranged so that the optical axis direction of the emitted light toward the optical coupling member 35 is orthogonal to the light guide plate 13. For this reason, since it is not necessary to arrange the light emitting portions 33a and 33b obliquely with respect to the flat light guide plate 13, the light emitting portions 33a and 33b can be easily arranged and the structure is simple.

  In the present embodiment, the light emitting units 33a and 33b emit light having a color temperature of 2000K to 6000K. For this reason, it can be appropriately used as an illumination device such as the ceiling light 1.

  Therefore, it is possible to provide the lighting device 10 that enables uniform irradiation of the entire light guide plate 13 without increasing the number of the light emitting units 33a and 33b and processing the light guide plate.

  Moreover, in this Embodiment, it is not necessary to process the light-guide plate 13, and since light injects from the downward direction, the light-guide plate 13 and the ceiling light 1 can be reduced in thickness. Specifically, a certain amount of thickness is required for processing the light guide plate 13. In this case, for example, when an edge light type light guide plate is considered, if the light guide plate 13 is made thinner than the widths of the light emitting portions 33a and 33b, the optical coupling rate is lowered, so that there is a limit to thinning. In this regard, in the present embodiment, if the light guide plate 13 is thinned, the ceiling light 1 is thinned. Moreover, since the material of the light guide plate 13 can be saved, the cost can be reduced. Further, since the light emitting portions 33a and 33b may be mounted so that the optical axis thereof is perpendicular to the light guide plate 13, the assembly is simple. That is, in the case of the conventional edge light, since it is necessary to attach the light emitting parts 33a and 33b from the side surfaces, the manufacture becomes somewhat difficult.

  Moreover, in the illuminating device 10 of this Embodiment, the optical coupling member 35 is provided in strip | belt shape.

  This eliminates the need for the relationship between the optical coupling member 35 and the light emitting portions 33a and 33b to be 1: 1, and covers the plurality of light emitting portions 33a and 33b with one optical member, thus simplifying the structure of the optical system. can do. In addition, since the light emitting portions 33a and 33b can be provided along the optical coupling member 35, wiring of the light emitting portions 33a and 33b is facilitated.

  In the configuration in which the optical coupling member 35 is provided in a strip shape, the optical coupling member 35 may be a double row. In this case, in particular, it is preferable to arrange them symmetrically with respect to the vertical or horizontal center line of the light guide plate 13 so that the luminance distribution of the double-row optical coupling members 35 is symmetrical. Further, when the optical coupling members 35 are in a double row, the luminance of light emitted from the surface of the light guide plate 13 is such that the luminance at the center of the flat light guide plate 13 is higher than the luminance at the end of the light guide plate 13. It is desirable to arrange in.

  Moreover, in the illuminating device 10 of this Embodiment, the optical coupling member 35 is provided on the centerline of the vertical or horizontal direction in the flat light-guide plate 13. As shown in FIG. This makes it possible to make the luminance symmetric about the vertical or horizontal center line of the light guide plate 13 as an axis. Therefore, it is possible to provide the lighting device 10 suitable for the luminance distribution.

  Moreover, in the illuminating device 10 of this Embodiment, the light source consists of several light emission part 33a * 33b. As a result, the light emitting units 33a and 33b have lower power consumption and lower heat generation than incandescent bulbs, and can save energy.

  Furthermore, the ceiling light 1 as the lighting fixture of the present embodiment includes a lighting device 10. Thereby, the ceiling light 1 provided with the illuminating device 10 which enables uniform irradiation in the whole light-guide plate 13 without the increase in the number of light emission parts 33a * 33b and the process of the light-guide plate 13 can be provided. .

  In the illumination device 10 of the present embodiment, a back chassis 15 that is a flat chassis that holds the light guide plate 13 in a flat surface is provided below the light guide plate 13, and the back chassis 15 is guided. The optical plate holding surface has an opening at a portion where the optical coupling member 35 contacts the light guide plate 13, and the optical coupling member 35 and the light emitting portions 33 a and 33 b are positioned below the light guide plate holding surface of the back chassis 15. Yes.

  With such a configuration, only the optical coupling member 35 and the light emitting portions 33a and 33b protrude on the back surface side of the light guide plate 13. Accordingly, it is possible to reduce the thickness of portions other than the optical coupling member 35 and the light emitting portions 33a and 33b. For this reason, the overall thickness can be reduced. Further, by adopting such a configuration, the heat radiation of the light emitting portions 33a and 33b is excellent. Moreover, since the back chassis 15 functions as a heat sink by connecting the light source module 30 to the back chassis 15, high heat dissipation performance can be obtained. As a result, the light emission efficiency of the light emitting units 33a and 33b is also improved.

  In the ceiling light 1 of the present embodiment, the light emitting portions 33 a and 33 b are arranged in two rows along the longitudinal direction of the optical coupling member 35. Specifically, the light emitting units 33a and 33b are provided in two rows in parallel along the center line directly below both ends of the lower end chord in the optical coupling member 35 having a semicircular cross section.

  Thus, when the light is incident on the light guide plate 13, the light emitting portions 33a and 33b of the two rows emit light in opposite directions, so that the line passing through the midpoint between the two rows is axially symmetric and both sides of the optical coupling member 35 That is, the light can be guided to both ends of the light guide plate 13. When the line passing through the midpoint between the two rows coincides with the center line of the light guide plate 13, the light guide plate is guided to both ends of the light guide plate with the center line of the light guide plate 13 being axially symmetrical. A luminance distribution that is axially symmetric about the 13 center lines can be obtained. Therefore, the luminance distribution can be made uniform in the light guide plate 13 with a simple structure. That is, when the light emitting part 33a is used alone, there is a possibility that the light above the light emitting part 33a does not transmit light and becomes a dark part. This can be supplemented with light from the other light emitting section 33b.

  Note that the backlight 200 for a display device disclosed in Patent Document 2 has a problem that the luminance directly above the light emitting diode 201 becomes brighter than the surroundings and bright lines are generated, so that a uniform luminance distribution cannot be created. However, this problem can be solved in the present embodiment.

  Moreover, the illuminating device 10 of this Embodiment can be applied to a large planar light source as it is, and the large ceiling light 1 can also be provided. Furthermore, since no member is required around the light guide plate 13, it can be applied to a larger ceiling light 1 by arranging them seamlessly.

  In a side-edge type backlight in a conventional liquid crystal display device, a light source is disposed around the light guide plate, and light incident on the light guide plate from the side surface of the light guide plate is taken out from the liquid crystal panel side (front side). In such a backlight, the end portion (outer peripheral edge portion) of the lighting device is used as a light incident portion. In the illumination device 10 of the present embodiment, unlike a conventional side-edge type backlight, there is no light source at the end of the ceiling light 1, so that light can be extracted from the end of the ceiling light 1.

  In the illumination device 10 according to the present embodiment, with respect to a part of the light incident on the light guide plate 13, the direction of the light can be controlled to irradiate at least a part of the light to the back side of the light guide plate 13. An irradiation direction control unit is provided at the outer peripheral edge. In the illumination device 10 of the present embodiment, the irradiation direction control unit is configured by the frame 20.

  In lighting device 10 of the present embodiment, frame 20 provided on the outer periphery is formed of a resin (such as acrylic resin or polycarbonate) and is provided as a light transmissive member. As described above, the light incident on the light guide plate 13 is emitted from the surface side of the light guide plate 13 and becomes direct illumination light in the middle of traveling while being totally reflected inside the light guide plate 13. However, not all the light is emitted as the direct illumination light, and a part of the light reaches the outer peripheral end of the light guide plate 13 and is emitted therefrom. The frame 20 has a function of controlling light emitted from the outer peripheral end of the light guide plate 13 and using it as indirect illumination light such as ceiling illumination. Note that it is not necessary that all of the light controlled by the frame 20 is irradiated to the ceiling side to become indirect illumination light, and some light may be irradiated from the lighting device 10 to the indoor side.

  The structure of the outer periphery part of the illuminating device of this Embodiment is shown to Fig.12 (a)-(e). In the configuration shown in FIG. 12A, the frame 20 has a U-shaped cross section so as to contact both the front surface of the diffusion sheet 11 and the back surface of the back chassis 15. The frame 20 is formed with a protrusion (first protrusion) 20 </ b> A that contacts the surface of the diffusion sheet 11 and a protrusion (second protrusion) 20 </ b> B that contacts the back surface of the back chassis 15. That is, the protruding portion 20 </ b> A is disposed in parallel with the light guide plate 13 on the front surface side of the light guide plate 13, and the protruding portion 20 </ b> B is disposed in parallel with the light guide plate 13 on the back surface side of the light guide plate 13. The light emitted from the outer peripheral end of the light guide plate 13 and incident on the frame 20 is guided in the frame 20 and emitted not only in the side surface direction but also in the back surface direction, and used as indirect illumination light.

  In this way, the frame 20 performs light control so that light is guided inside and becomes indirect illumination light. For this reason, the frame 20 is required to have a light transmission property, but it is not preferable to use a member having a very high transparency (low light diffusion property), and preferably has a certain degree of light diffusion property. .

  Furthermore, the frame 20 is made of a low-transparency member, so that it is possible to obtain a blinding effect that makes it difficult for the end portions of the diffusion sheet 11 and the light guide plate 13 to be visually recognized. The frame 20 may be colored, for example, milky white. If the frame 20 is colored in this way, the blinding effect can be further enhanced. Further, the surface of the frame 20 may be blasted. By blasting the surface of the frame, it is possible to scatter light transmitted and guided through the frame and change the light distribution applied to the ceiling.

  The lighting device 10 shown in FIG. 12B has a configuration in which a partially transmissive reflecting member 21 such as a half mirror is provided between the light guide plate 13 and the frame 20. In this configuration, a part of the light emitted from the outer peripheral end of the light guide plate 13 is transmitted and can be used as indirect illumination light, and a part of the light is reflected to the light guide plate 13 side and used as direct illumination light. Can do. Thereby, it becomes possible to change the ratio of direct illumination light and joint illumination light by selecting the reflectance of the partially transmissive reflection member 21. In addition, the light reflected by the partially transmitting / reflecting member 21 contributes to an increase in luminance in the peripheral area of the direct illumination light, so that the unevenness of the direct illumination light can be reduced.

  The lighting device 10 shown in FIG. 12C has a configuration in which a reflecting member 22 is formed on the surface side of the frame 20. The reflection member 22 may be formed by, for example, direct plating on the resin surface of the frame 20, or a reflection plate in which a metal plate such as aluminum or SUS is plated and this is attached to the frame 20. May be attached. As the plating, nickel plating or chrome plating can be preferably used.

The reflection member 22 reflects the light guided to the indoor side of the frame 20 and can increase the amount of light irradiated to the ceiling side. That is, indirect illumination light to the ceiling can be increased.
For this reason, it is preferable that the reflection member 22 is disposed so as to be parallel to the light guide plate 13. Moreover, the reflection member 22 should just be a reflective surface only in a contact surface with the flame | frame 20, and the surface of the other side (indoor side) is used as a design of the illuminating device 10 by giving arbitrary colors and patterns. be able to.

  Further, the protrusions 20A and 20B formed on the frame 20 need not have the same length. In the illuminating device 10 shown in FIG. 12 (d), the projection portion 20A <the projection portion 20B is formed, and the amount of light extracted on the ceiling side can be made larger than the amount of light extracted on the indoor side. Conversely, the lighting device 10 shown in FIG. 12 (e) is formed so that the protruding portion 20A> the protruding portion 20B, and the amount of extracted light on the indoor side can be made larger than the amount of extracted light on the ceiling side.

  Furthermore, in the configuration of FIGS. 12A to 12E, the diffusion sheet 11 is not attached to the light guide plate 13, and an air layer 12 is provided between the diffusion sheet 11 and the light guide plate 13. ing. Thereby, the light radiate | emitted from the surface of the light-guide plate 13 receives the scattering in the air layer 12, and can improve the uniformity in direct illumination light further. The light guide plate 13 is formed with the dot pattern of the light scattering portion, but the presence of the air layer 12 can prevent the dot pattern from being visually recognized from the surface side. The protruding portion 20 </ b> A in the frame 20 also has a function of supporting the gap between the diffusion sheet 11 that is not attached to the light guide plate 13 and the air layer 12.

  Further, in the configuration of FIGS. 12A to 12E, the frame 20 has a U-shaped cross section including the protruding portions 20A and 20B, but the lighting device of the present invention is limited to this. Instead, as shown in FIG. 13, the frame 20 may have an L-shaped cross section including only the protruding portion 20 </ b> A. That is, the frame 20 can obtain indirect illumination light for illuminating the ceiling if the frame 20 has a portion that can guide light to the ceiling side of the light guide plate 13.

  As described above, in the illumination device 10 of the present embodiment, in addition to the surface of the light guide plate 13, the irradiation direction control unit that irradiates in a direction different from the irradiation direction on the surface of the light guide plate 13 is configured on the outer peripheral edge. Therefore, it can be said that the irradiation direction control unit only needs to be configured by the frame 20 that guides and emits light toward the ceiling. By having such a configuration, a ceiling light that simultaneously realizes both space illumination as direct illumination and ceiling illumination as indirect illumination is provided.

  The reflection sheet 14 is not particularly limited as long as it has a high reflectance, and can be arbitrarily selected by those skilled in the art. The back chassis 15 may have the same shape and the same size as the reflection sheet 14.

  The ratio of the amount of light used for space illumination and the amount of light used for ceiling illumination is preferably 70:30 to 95: 5, more preferably 80:20 to 90:10. The size can be appropriately changed depending on the area and the arrangement site.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and the embodiments can be obtained by appropriately combining the technical means disclosed in each of the embodiments. Is also included in the technical scope of the present invention.

  The lighting device of the present invention and the lighting device including the lighting device can be applied to ceiling-mounted ceiling lights, wall surface lighting attached to wall surfaces, signboards, and the like. And as an application field, it can apply to various lighting fixtures, such as facilities, such as a store and an office, and business.

1 Ceiling light (lighting equipment)
DESCRIPTION OF SYMBOLS 10 Illuminating device 11 Diffusion sheet 12 Air layer 13 Light guide plate 14 Reflective sheet 15 Back chassis 20 Frame (irradiation direction control part, light transmissive member)
20A protrusion (first protrusion)
20B Protrusion (second protrusion)
21 Partially transmitting / reflecting member 22 Reflecting member 30 Light source module 31 Light source holder 33a / 33b Light emitting portion 35 Optical coupling member 35a Top flat surface 35b / 35c Curved surface 35d Bottom flat surface

Claims (8)

A flat light guide plate, and a light source disposed on the back side of the light guide plate. The light emitted from the light source is incident on the light guide plate, and the incident light is totally reflected inside the light guide plate. An illumination device for irradiating from at least the surface side of the light guide plate while guiding light,
An optical coupling member that couples light emitted from the light source so that light is incident obliquely on the light guide plate is provided between the light guide plate and the light source, and
An illumination device, wherein an irradiation direction control unit that controls a direction of light emitted from the outer peripheral end of the light guide plate is provided at an outer peripheral end of the light guide plate. The irradiation direction control unit is composed of a light transmissive member provided on the outer periphery of the light guide plate,
The light transmissive member guides light emitted from an outer peripheral end portion of the light guide plate therein, and then irradiates at least a part of the light in a direction different from the surface side of the light guide plate. The lighting device according to claim 1.   Between the light guide plate and the light transmissive member, there is provided a partially transmissive reflecting member that transmits a part of the light emitted from the outer peripheral end of the light guide plate and reflects a part thereof. The lighting device according to claim 2.   On the surface side of the light transmissive member, there is provided a reflection member that guides light inside the light transmissive member and reflects light emitted to the surface side of the light transmissive member. The illumination device according to claim 2 or 3.   The lighting device according to claim 4, wherein the reflection member is arranged to be parallel to the light guide plate.   The light transmissive member includes a first protrusion disposed in parallel with the light guide plate on the front surface side of the light guide plate, and a second protrusion disposed in parallel with the light guide plate on the back surface side of the light guide plate. The lighting device according to any one of claims 2 to 5, wherein the lighting device includes a portion.   The lighting device according to claim 6, wherein the first protrusion and the second protrusion have different protrusion lengths.   An illumination device comprising the illumination device according to claim 1.