JP2010009785A - Hollow type surface lighting device - Google Patents

Abstract

By disposing an LED light source in a hollow light guide region in a unit case, the light from the LED light source can be emitted efficiently and evenly from the entire surface light emitting unit. Therefore, it is possible to provide a hollow surface illumination device that can emit illumination light with high brightness and high uniformity without being converted into a large-sized liquid crystal display device.
SOLUTION: A hollow unit case 1 in which a light emitting surface member is disposed on the front side and a bottom surface side of the unit case that faces the light emitting surface member, and is hollowly introduced into a space between the light emitting surface member. A light reflecting surface member 2 that forms a light region, and a LED light source 17 that is configured by arranging and mounting a plurality of LEDs on a wiring board and arranged in the hollow light guide region are provided.
[Selection] Figure 1

Description

  The present invention relates to a hollow surface illumination device that emits illumination light having a uniform luminance distribution from a light emitting surface, such as a backlight unit of a liquid crystal display device.

  In recent years, a light source of a backlight unit for a liquid crystal display device is being replaced with an LED instead of a cold cathode discharge lamp. This is because the LED does not contain mercury, which is a harmful substance, and is suitable as an environmentally conscious light source, and the power consumption can be greatly reduced by recent significant improvement in luminous efficiency. The backlight unit having an LED as a light source has been mainly used for small devices such as mobile phones and mobile terminals so far, but recently, a large-sized liquid crystal display such as a 20-inch-type liquid crystal monitor or a liquid crystal television is used. It has come to be adopted by the device.

  In the case of a large liquid crystal display device, the backlight unit is required to have high luminance. For this reason, a light source is arranged on the side portion of the light guide plate, which is generally used in a small backlight unit, emits light, is guided from the side surface to the light guide plate and diffused and reflected, and the surface on the front side of the light guide plate A sidelight system such as that disclosed in Patent Document 1 that emits light from a light emitting unit is not employed as a backlight of a large liquid crystal display device. As a backlight unit for a large-sized liquid crystal display device, as described in Patent Document 2, a direct-type backlight unit in which an LED light source is disposed immediately below a surface light emitting unit is generally used.

  In such a direct type backlight unit, since the light source is an LED, if the distance between a large number of arranged LEDs and the surface light emitting part is too close, it is recognized as uneven brightness and uneven color, and the liquid crystal display illuminated by it Deteriorating quality.

  This phenomenon appears more prominently when a high-power LED having a power of 1 W class or more is used as a light source in order to realize high luminance. On the other hand, increasing the distance between the LED and the surface light emitting part (diffusion plate) in order to reduce luminance unevenness and color unevenness leads to an increase in the thickness of the entire device, which is preferable against the recent trend of thinning. Absent.

In addition, in the apparatus of patent document 1, since the reflector for guiding radiated light to the hollow light guide region is formed, and the size of the reflector becomes large in design in order to reduce luminance unevenness in the vicinity of the light source. As a result, the entire unit is also enlarged.
JP 2006-106212 A JP 2005-316337 A

  The present invention has been made in view of the above-described conventional technical problems, and is a hollow surface illumination device that can widen the light emitting surface without increasing the thickness, and further increase the brightness. It is another object of the present invention to provide a hollow surface illumination device capable of achieving high uniformity.

  The hollow surface illumination device of the invention of claim 1 is a hollow unit case in which a light emitting surface member is disposed on the front side, and a bottom surface side of the unit case that faces the light emitting surface member. A light reflecting surface member that forms a hollow light guide region in the space between the LED light source and an LED light source that is configured by arranging and mounting a plurality of LEDs on the wiring board in a row. It is characterized by that.

  According to a second aspect of the present invention, in the hollow surface illumination device according to the first aspect, the LED light source is attached to a side surface of a support bar attached to the light reflecting surface member.

  According to a third aspect of the present invention, in the hollow surface illumination device according to the second aspect, the LED light source is attached to both side surfaces of the support bar.

  According to a fourth aspect of the present invention, in the hollow surface illumination device according to the first aspect, the light reflecting surface member has a curved surface shape based on the arrangement of the LED light sources and the shape of the hollow light guide region.

  According to a fifth aspect of the present invention, in the hollow surface illumination device according to the first aspect, the LED light source has an optical axis in a direction parallel to the surface of the reflective surface member, with the wiring board attached to the reflective surface member. It is characterized by that.

  According to a sixth aspect of the present invention, in the hollow surface illumination device according to the fifth aspect, the LED light source includes a plurality of LEDs that emit light in at least two directions.

  According to a seventh aspect of the present invention, in the hollow surface illumination device according to the fifth aspect, the unit case has a square shape or a cylindrical shape.

  According to the present invention, by arranging the LED light source in the hollow light guide region in the unit case, the light of the LED light source can be emitted efficiently from the entire surface light emitting unit, and as a result, To provide a hollow surface illumination device that can emit illumination light with high brightness and high uniformity, and can be used as a backlight unit of a large liquid crystal display device by expanding the light emitting surface without increasing the thickness. it can.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a perspective view showing a hollow surface illumination device according to a first embodiment of the present invention. 2 is an explanatory view showing a cross-sectional structure of the unit case 1 in FIG. This embodiment shows an example applied to a backlight unit for a liquid crystal display device.

  The backlight unit, which is a hollow surface illumination device according to the present embodiment, includes a rectangular unit case 1, a light emitting surface member 3, and a front frame 4. The unit case 1 has a front opening surface, and the light emitting surface member 3 is disposed so as to close the front opening surface. The light emitting surface member 3 is formed by overlapping optical sheets such as diffusion sheets 3B and 3C and a lens sheet 3D on at least the light transmission diffusion plate 3A, and includes a hollow light guide region 10 and a light reflection surface described later. By uniformly diffusing, scattering, or emitting the light reflected on the member 2, the brightness unevenness on the light emitting surface is eliminated and the uniformity is increased. Then, the unit case 1 is covered with the front frame 4 from the light emitting surface member 3 side and integrated with the unit case 1 to assemble the backlight unit of the present embodiment.

  The unit case 1 is made of a metal having a high thermal conductivity such as an aluminum alloy, and a light reflecting surface member 2 is provided on the bottom surface. As shown in FIG. 2, the light reflecting surface member 2 has a curved surface 12 in which the distance from the front opening surface of the unit case 1 increases as the distance between the pair of opposing sides of the unit case 1 increases. A space portion in the unit case 1 sandwiched between the light emitting surface member 3 and the light reflecting surface member 2 disposed on the front opening surface of the unit case 1 becomes the hollow light guide region 10.

  In the present embodiment, a light source having a plurality of LEDs is arranged in the hollow light guide region 10. In order to arrange the light source in the hollow light guide region 10, one support bar 15 is attached on the curved surface 12 of the light reflecting surface member 2 of the unit case 1. The support bar 15 has both side surfaces substantially perpendicular to the curved surface 12 of the light reflecting surface member 2, and is arranged so that the longitudinal direction of both side surfaces is perpendicular to the bending direction of the curved surface 12 of the light reflecting surface member 2. The The longitudinal direction of the support bar 15 extends over substantially the entire region of the unit case 1 in the lateral direction, for example. The support bar 15 has a gap with the light emitting surface member 3 in the height direction and is formed relatively thin in the width direction (short direction). LED mounting boards 16 are attached to both side surfaces extending in the longitudinal direction of the support rod 15, that is, both side surfaces perpendicular to the curved direction of the curved surface 12. The LED mounting board 16 has substantially the same dimension as the longitudinal dimension of the support bar 15.

  The LED mounting substrate 16 is configured using a metal such as a high thermal conductivity aluminum-based or copper-based alloy or a ceramic such as aluminum nitride. The LED mounting substrate 16 is fixed to both side surfaces of each support bar 15 with a high thermal conductive double-sided tape, sheet, grease, or the like interposed therebetween.

  On the LED mounting substrate 16, a plurality of LEDs 17 are mounted in a row or in a plurality of rows. The LED 17 mounted on the LED mounting substrate 16 may be a red, green, or blue three-color LED arranged in a quantity ratio for combining with a desired white chromaticity, or a combination of a blue LED chip and a yellow phosphor. A plurality of LEDs that emit white light are used. The light emitted from the LED 17 mounted on the LED mounting substrate 16 has an optical axis parallel to the light reflecting surface member 2 as indicated by an arrow in FIG. The emitted light passes through the hollow light guide region 10 and is directly irradiated onto the light emitting surface member 3, and after being reflected by the light reflecting surface member 2, is irradiated onto the light emitting surface member 3.

  The light reflecting surface member 2 is configured by laminating a material having high reflectivity and diffuse reflectivity, such as a white PET film or white ink, on a metal or resin material. The curved surface 12 of the light reflecting surface member 2 is shaped to change the distance from the light emitting surface member 3 so that the luminance distribution on the light emitting surface member 3 is uniform. In addition to the above, the light diffusive reflective material may be a highly reflective aluminum having a specular reflectivity coated with a light transmissive diffusing material.

  In the backlight unit of the above embodiment, as shown in FIG. 2, the light from the LED 17 of the LED mounting substrate 16 passes through the hollow light guide region 10 and reflects the curved surface 12 of the light reflecting surface member 2 directly or. Thus, the light is emitted uniformly over the entire area of the light emitting surface member 3.

  As described above, in the present embodiment, the LED 17 serving as a light source is disposed in the hollow light guide region 10 and is reflected by the light reflecting surface member 2 having a curved shape so as to enter the light emitting surface member 3. The utilization efficiency of light from the LED 17 can be improved, and the amount of light can be further increased. Thereby, the number of LED arrangements can be reduced, and a high-brightness backlight can be designed. In addition, a wide light emitting surface can be obtained without increasing the thickness of the unit case 1.

(Modification)
In the said embodiment, the linear support rod 15 was employ | adopted and LED17 was arrange | positioned at the both sides | surfaces of the support rod 15 at linear form. However, when the light emitting area is large, a plurality of light sources may be arranged by providing a plurality of support rods in the hollow light guide region. Further, not only the number of support bars arranged in the hollow light guide region but also the shape of the support bars and the arrangement position on the unit case 1 can be set as appropriate.

  FIG. 3 is an explanatory view showing the cross-sectional structure of the unit case, the shape of the bottom surface of the light reflecting surface member, and the reflection of light in a modified example having a different number of support bars. FIG. 3A shows an example with two support bars, and FIG. 3B shows an example with three support bars.

  The modified example of FIG. 3A employs a unit case 21 instead of the unit case 1. The unit case 21 is different from the unit case 1 of FIG. 1 in that a light reflecting surface member 22 is provided on the bottom surface. As shown in FIG. 3A, the light reflecting surface member 22 has a ridge line 11 parallel to a pair of sides orthogonal to the longitudinal direction of the unit case 21. Further, the light reflecting surface member 22 has a front opening surface of the unit case 21 as the distance between the ridge line 11 and each side of the unit case 21 parallel to the ridge line 11 increases. A curved surface 23 that increases the distance from. A space portion in the unit case 21 sandwiched between the light emitting surface member 3 and the light reflecting surface member 22 disposed on the front opening surface of the unit case 21 is a hollow light guide region 10.

  Two support rods 15 are arranged in parallel with the short direction of the unit case 21 at two locations on the curved surface 23 having the largest distance from the front opening surface of the unit case 21. Each support bar 15 extends substantially in the entire length of the unit case 21 in the short direction. LED mounting boards 16 are attached to both side surfaces of each support bar 15 extending in the longitudinal direction. The LED mounting board 16 has substantially the same dimension as the longitudinal dimension of the support bar 15.

  The emitted light of the LED mounted on the LED mounting substrate 16 passes through the hollow light guide region 10 and is directly irradiated onto the light emitting surface member 3 as shown by the arrow in FIG. The light emitting surface member 3 is irradiated after being reflected by the member 22.

  3B employs a unit case 31 instead of the unit case 1. In the modification shown in FIG. The unit case 31 is different from the unit case 1 of FIG. 1 in that a light reflecting surface member 32 is provided on the bottom surface. As shown in FIG. 3B, the light reflecting surface member 32 has two ridge lines 34 parallel to a pair of sides orthogonal to the longitudinal direction of the unit case 31. Further, the light reflecting surface member 32 has a unit case between the ridge line 34 and each side of the unit case 31 parallel to the ridge line 34 so that the distance between the ridge lines 34 or between each side parallel to the ridge line 34 increases. 31 has a curved surface 33 whose distance from the front opening surface of 31 is increased. A space portion in the unit case 31 sandwiched between the light emitting surface member 3 and the light reflecting surface member 32 arranged on the front opening surface of the unit case 31 becomes the hollow light guide region 10.

  Three support rods 15 are arranged in parallel with the short direction of the unit case 31 at three locations on the curved surface 33 having the longest distance from the front opening surface of the unit case 31. The support bar 15 extends substantially in the entire length of the unit case 31 in the short direction. The LED mounting substrate 16 is attached to both side surfaces extending in the longitudinal direction of the support bar 15, that is, both side surfaces parallel to the ridge line 34. The LED mounting board 16 has substantially the same dimension as the longitudinal dimension of the support bar 15.

  The emitted light of the LED mounted on the LED mounting substrate 16 passes through the hollow light guide region 10 and is directly irradiated to the light emitting surface member 3 as shown by the arrow in FIG. The light emitting surface member 3 is irradiated after being reflected by the member 32.

  3A and 3B, the LED 17 serving as a light source is also arranged in the hollow light guide region 10 and reflected by the light reflecting surface members 22 and 32 having a curved shape to form the light emitting surface member 3. Since it is made to enter, the utilization efficiency of the light from LED17 can be improved without enlarging an apparatus, and a light quantity can be raised more.

  FIG. 4 is an explanatory view showing another modification example in which the shape and arrangement of the support bars are different. FIG. 4A to FIG. 4D show the unit case as viewed from above.

  Each modification of FIG. 4 is obtained by changing the shape and arrangement of the support rods (array light source) so that light is emitted in two different directions in the hollow light guide region 10. In each example shown in FIG. 4, it is possible to easily realize a backlight in which the brightness uniformity pattern in the light emitting surface is changed.

  That is, FIG. 4A shows an example in which a unit case 41 is employed instead of the unit case 1. The unit case 41 is different from the unit case 1 in the curved surface shape of the light reflecting surface member on the bottom surface. On the light reflection surface member of the unit case 41, two bent support bars 42 and 43 are arranged. The support bars 42 and 43 are bent in a square shape so as to be close to the side surface of the unit case 41 at the center in the longitudinal direction. Also in the support rods 42 and 43, LED mounting boards 16 (not shown) on which the LEDs 17 are mounted are attached to both side surfaces.

  Although not shown, the light reflecting surface member of the unit case 41 is suitable for reflecting the light from the LEDs 17 of the LED mounting substrate 16 attached to the support rods 42 and 43 to the light emitting surface member 3 without unevenness. It is formed in a curved shape.

  FIG. 4B shows an example in which a unit case 61 is employed instead of the unit case 1. The unit case 61 is different from the unit case 1 in the curved surface shape of the light reflecting surface member on the bottom surface. Two support bars 62 are disposed on the light reflecting surface member of the unit case 61. The support bar 62 is arranged so that the longitudinal direction is parallel to the longitudinal direction of the unit case 61. Also in the support rod 62, LED mounting boards 16 (not shown) on which the LEDs 17 are mounted are attached to both side surfaces.

  The light reflecting surface member of the unit case 61 has a curved shape having a ridge line parallel to the support rod 62 and is suitable for reflecting light from the LEDs 17 of the LED mounting substrate 16 to the light emitting surface member 3 without unevenness. It is formed in a curved shape.

  FIG. 4C shows an example in which a unit case 71 is employed instead of the unit case 1. The unit case 71 is different from the unit case 1 in the curved surface shape of the light reflecting surface member on the bottom surface. On the light reflecting surface member of the unit case 71, two support bars 72 and 73 are arranged. The support bars 72 and 73 are formed in a U shape, and LED mounting boards 16 (not shown) on which the LEDs 17 are mounted are attached to both side surfaces.

  The light reflecting surface member of the unit case 71 is formed in a curved surface shape suitable for reflecting light from the LEDs 17 of the LED mounting substrate 16 attached to the support rods 72 and 73 to the light emitting surface member 3 without unevenness. .

  FIG. 4D shows an example in which a unit case 81 is employed instead of the unit case 1. The unit case 81 is different from the unit case 1 in the curved surface shape of the light reflecting surface member on the bottom surface. On the light reflecting surface member of the unit case 81, two support bars 82 and 83 are arranged. The support rods 82 and 83 are formed in a substantially arc shape, and LED mounting boards 16 (not shown) on which the LEDs 17 are mounted are attached to both side surfaces.

  The light reflecting surface member of the unit case 71 is formed in a curved shape suitable for reflecting light from the LEDs 17 of the LED mounting substrate 16 attached to the support rods 82 and 83 to the light emitting surface member 3 without unevenness. .

(Second Embodiment)
FIG. 5 is a perspective view showing a second embodiment of the present invention. In FIG. 5, the same components as those of FIG. The present embodiment is an example in which a side view LED (Side View LED) that irradiates light in the horizontal direction is used as a light source. 6 is an explanatory view showing a cross-sectional structure of the unit case in FIG.

  The present embodiment employs a unit case 91 instead of the unit case 1. The unit case 91 is different from the unit case 1 of FIG. 1 in that a light reflecting surface member 92 is provided on the bottom surface. As shown in FIG. 6, the light reflecting surface member 92 has a curved surface 93 whose distance from the front opening surface of the unit case 91 increases as the distance between a pair of opposing sides of the unit case 91 increases. A space portion in the unit case 91 sandwiched between the light emitting surface member 3 and the light reflecting surface member 92 disposed on the front opening surface of the unit case 91 becomes the hollow light guide region 10.

  One LED mounting substrate 94 is disposed in the center of the curved surface 93 having the longest distance from the front opening surface of the unit case 91 in parallel with the short direction of the unit case 91. The LED mounting substrate 94 extends in the longitudinal direction over substantially the entire region of the unit case 91 in the lateral direction. Side view LEDs 95 are arranged and mounted on the upper surface of the LED mounting substrate 94.

  The light emitted from the side view LED 95 mounted on the LED mounting board 94 passes through the hollow light guide region 10 and is directly irradiated onto the light emitting surface member 3 as shown by the arrow in FIG. After being reflected by 92, the light emitting surface member 3 is irradiated.

  In the present embodiment, one LED mounting board 94 is attached on the curved surface 93 of the light reflecting surface member 92 of the unit case 91. The LED mounting substrate 94 extends substantially over the entire region of the unit case 91 in the short direction, for example, perpendicular to the curved direction of the curved surface 93 of the light reflecting surface member 92. Side-view LEDs 95 each having an optical axis parallel to the curved surface 93 are attached to the upper surface of the LED mounting substrate 94.

  The LED mounting substrate 94 is configured using a metal such as a high thermal conductivity aluminum-based or copper-based alloy or a ceramic such as aluminum nitride. The LED mounting substrate 94 is fixed to the light reflecting surface member 92 with a high thermal conductive double-sided tape, sheet, or grease interposed therebetween.

  FIG. 7 is an explanatory diagram showing a mounting state of the side view LED 95 on the LED mounting board 94. In FIG. 7A, the side view LEDs 95 are mounted in a line. As the side view LED 95 mounted on the LED mounting substrate 94, the red, green, and blue three-color LEDs arranged in a quantity ratio for synthesis into a desired white chromaticity, or a blue LED chip and a yellow phosphor are used. A plurality of LEDs that emit white light in combination are used.

  The broken line hatching in FIG. 7A indicates the emitted light from the side view LED 95. The side view LEDs 95 include side view LEDs 95a and 95b having different emission directions. Note that the emission directions of the side view LEDs 95a and 95b are preferably opposed or back to back (for example, 180 degrees different from each other). The side view LEDs 95a and 95b are alternately arranged. In the side view LED 95a, the emission direction is directed to the right side of the drawing, and in the side view LED 95b, the emission direction is directed to the left side of the drawing.

  As shown by the arrow in FIG. 6, the light emitted from the side view LED 95 has a horizontal optical axis on the light reflecting surface member 92, passes through the hollow light guide region 10, and is directly irradiated onto the light emitting surface member 3. At the same time, the light emitting surface member 3 is irradiated after being reflected by the light reflecting surface member 92.

  The light reflecting surface member 92 is configured by laminating a material having high reflectivity and diffuse reflectivity, such as a white PET film or white ink, on a metal or resin material. The curved surface 93 of the light reflecting surface member 92 is shaped to change the distance from the light emitting surface member 3 so that the luminance distribution on the light emitting surface member 3 is uniform. In addition to the above, the light diffusive reflective material may be a highly reflective aluminum having a specular reflectivity coated with a light transmissive diffusing material.

  According to the embodiment configured as described above, as shown in FIG. 6, the light from the side view LED 95 of the LED mounting substrate 94 passes through the hollow light guide region 10 and directly or of the light reflecting surface member 92. The curved surface 93 is reflected and emitted uniformly over the entire light emitting surface member 3.

  Since the side view LED 95 serving as a light source is disposed in the hollow light guide region 10 and is reflected by the light reflecting surface member 92 having a curved surface shape, the light is incident on the light emitting surface member 3. Efficiency can be improved and the amount of light can be further increased. Thereby, the number of LED arrangements can be reduced, and a high-brightness backlight can be designed. Further, high brightness can be obtained without increasing the size of the unit case 91, that is, the size of the device.

(Modification)
In the second embodiment, the side view LEDs are arranged on the LED mounting substrate 94 so that the light emitting surfaces (filled portions) are in a line. On the other hand, an arrangement method shown in FIG. 7B may be adopted in order to narrow the range where light is not irradiated.

  In FIG. 7B, the side view LED 96 on the LED mounting board 94 includes side view LEDs 96a and 96b having different emission directions. Note that the emission directions of the side view LEDs 96a and 96b are preferably opposed or back to back (for example, 180 degrees different from each other). By arranging the side view LEDs 96a and 96b alternately in a staggered manner, it is possible to prevent a gap from being generated in the emission range of the emitted light from the side view LEDs 96a and 96b.

  In the second embodiment, the example in which one LED mounting board 94 is employed and the side view LED 95 is disposed on the upper surface of the LED mounting board 94 has been described. Also in the present embodiment, as in the first embodiment, the number of LED mounting boards 94 and the arrangement position on the unit case 91 can be set as appropriate.

  FIG. 8 is an explanatory view showing a modified example in which a plurality of LED mounting boards are employed. FIG. 8 shows the cross-sectional structure of the unit case, the bottom shape of the light reflecting surface member, and the light reflection. FIG. 8A shows an example with two LED mounting boards, and FIG. 8B shows an example with three LED mounting boards.

  The modified example of FIG. 8A employs a unit case 101 instead of the unit case 91. The unit case 101 is different from the unit case 91 of FIG. 5 in that a light reflecting surface member 102 is provided on the bottom surface. As shown in FIG. 8A, the light reflecting surface member 102 has ridge lines 104 parallel to a pair of sides orthogonal to the longitudinal direction of the unit case 101. In addition, the light reflecting surface member 102 has a front opening surface of the unit case 101 as the distance between the ridgeline 104 and each side of the unit case 101 parallel to the ridgeline 104 increases. A curved surface 103 having a large distance from. A space portion in the unit case 101 sandwiched between the light emitting surface member 3 and the light reflecting surface member 102 disposed on the front opening surface of the unit case 101 is a hollow light guide region 10.

  Two LED mounting boards 94 are arranged in the central portion of the curved surface 103 having the longest distance from the front opening surface of the unit case 101 in parallel with the short direction of the unit case 101. Each LED mounting substrate 94 extends in the longitudinal direction over substantially the entire region of the unit case 101 in the lateral direction. Side view LEDs 95 are arranged and mounted on the upper surface of the LED mounting substrate 94.

  The light emitted from the side view LED 95 mounted on the LED mounting substrate 94 passes through the hollow light guide region 10 as shown by the arrow in FIG. After being reflected by 102, the light emitting surface member 3 is irradiated.

  8B employs a unit case 111 instead of the unit case 91. In the modification shown in FIG. The unit case 111 is different from the unit case 91 of FIG. 5 in that a light reflecting surface member 112 is provided on the bottom surface. As shown in FIG. 8B, the light reflecting surface member 112 has two ridge lines 114 parallel to a pair of sides orthogonal to the longitudinal direction of the unit case 111. Further, the light reflecting surface member 112 has a unit case between the ridgeline 114 and each side of the unit case 111 parallel to the ridgeline 114, so that the distance between the ridgelines 114 or each side parallel to the ridgeline 114 increases. 111 has a curved surface 113 whose distance from the front opening surface of 111 becomes large. A space portion in the unit case 111 sandwiched between the light emitting surface member 3 and the light reflecting surface member 112 disposed on the front opening surface of the unit case 111 becomes the hollow light guide region 10.

  Three LED mounting boards 94 are arranged in parallel with the short direction of the unit case 111 at three locations on the curved surface 113 having the largest distance from the front opening surface of the unit case 111. The LED mounting substrate 94 extends in the longitudinal direction over substantially the entire region of the unit case 111 in the lateral direction. Side view LEDs 95 are mounted on the upper surface of each LED mounting board 94. The light emitted from the side view LED 95 mounted on the LED mounting substrate 94 passes through the hollow light guide region 10 and is directly irradiated onto the light emitting surface member 3 as shown by the arrow in FIG. The light emitting surface member 3 is irradiated after being reflected by the reflecting surface member 112.

  Also in the modified examples of FIGS. 8A and 8B, the side view LED 95 serving as a light source is disposed in the hollow light guide region 10 and is reflected by the light reflecting surface members 102 and 112 having a curved shape, thereby emitting the light emitting surface member. Therefore, the utilization efficiency of light from the side view LED 95 can be improved without increasing the size of the apparatus, and the amount of light can be further increased.

  FIG. 9 is an explanatory view showing a modified example in which the shape and arrangement of the LED mounting substrate are different. FIG. 9 shows the unit case as viewed from above.

  FIG. 9A shows an example in which a unit case 121 is employed instead of the unit case 91. The unit case 121 is different from the unit case 91 in the curved surface shape of the light reflecting surface member on the bottom surface. Two LED mounting boards 124 are arranged on the light reflecting surface member 122 of the unit case 121. The LED mounting substrate 124 is disposed so that the longitudinal direction is parallel to the longitudinal direction of the unit case 121. In each LED mounting substrate 124, the side view LED 95 is mounted on the upper surface.

  The light reflecting surface member 122 of the unit case 121 has a curved shape having a ridge line parallel to the LED mounting substrate 124, and reflects light from the side view LED 95 of the LED mounting substrate 94 to the light emitting surface member 3 without unevenness. It is formed in a curved surface shape suitable for.

  FIG. 9B shows an example in which a unit case 131 is employed instead of the unit case 91. The unit case 131 is different from the unit case 91 in the curved surface shape of the light reflecting surface member on the bottom surface. Two LED mounting boards 135 and 136 are arranged on the light reflecting surface member 132 of the unit case 131. The LED mounting boards 135 and 136 are arranged in a square shape, and a side view LED 95 is mounted on each upper surface.

  The light reflecting surface member 132 of the unit case 131 is formed in a curved surface shape suitable for reflecting light from the side view LED 95 mounted on the LED mounting substrates 135 and 136 to the light emitting surface member 3 without unevenness.

  FIG. 10 is a perspective view showing a modification using a cylindrical unit case. The backlight unit shown in FIG. 10 includes a cylindrical unit case 141, a light emitting surface member 150, and a front frame 160. The light emitting surface member 150 is different from the light emitting surface member 3 only in that the planar shape is circular. Similar to the light emitting surface member 3, the light emitting surface member 150 further has diffusion sheets 150B and 150C, lenses, and at least a light transmission diffusion plate 150A. It is configured by stacking optical sheets such as a sheet 150D. The light emitting surface member 150 uniformly diffuses, scatters, or emits the light reflected by the hollow light guide region 10 and the light reflecting surface member 142, which will be described later, thereby eliminating luminance unevenness on the light emitting surface and improving the uniformity. Work to raise. Then, the unit case 141 is covered with the front frame 160 from the light emitting surface member 150 side, and is united with the unit case 141, whereby the backlight unit of FIG.

  The unit case 141 is different from the unit case 91 of FIG. 5 in that the planar shape is circular. The unit case 141 is provided with a circular light reflecting surface member 142 on the bottom surface. Two LED mounting boards 143 are arranged on the light reflecting surface member 142 of the unit case 141. The LED mounting substrate 143 is arranged in a substantially circular shape along the peripheral surface of the unit case 141. In each LED mounting substrate 143, a side view LED 95 is mounted on the upper surface.

  The light reflecting surface member 142 of the unit case 141 is formed in a curved shape suitable for reflecting the light from the side view LED 95 mounted on the LED mounting substrate 143 to the light emitting surface member 3 without unevenness.

  Other actions and effects are the same as those in the above examples.

1 is a perspective view showing a hollow surface illumination device according to a first embodiment of the present invention. Explanatory drawing which shows the cross-section of the unit case in FIG. 1, the bottom face shape of a light reflection surface member, and reflection of light. Explanatory drawing which shows a modification. Explanatory drawing which shows a modification. The perspective view which shows the 2nd Embodiment of this invention. Explanatory drawing which shows the cross-section of the unit case in FIG. 5, the bottom face shape of a light reflection surface member, and reflection of light. Explanatory drawing which shows the mounting state of the side view LED95 on the LED mounting board 94. FIG. Explanatory drawing which shows a modification. Explanatory drawing which shows a modification. The perspective view which shows a modification.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Unit case, 2 ... Light reflection surface member, 3 ... Light emission surface member, 4 ... Front frame, 10 ... Hollow light guide area | region, 15 ... Support rod, 16 ... LED mounting board, 17 ... LED.

Claims (7)

A hollow unit case in which a light emitting surface member is arranged on the front side;
A light reflecting surface member disposed on a bottom surface side of the unit case facing the light emitting surface member, and forming a hollow light guide region in a space between the light emitting surface member;
A hollow surface illumination device comprising: a plurality of LEDs arranged and mounted on a wiring board; and an LED light source disposed in the hollow light guide region.   The hollow surface illumination device according to claim 1, wherein the LED light source is attached to a side surface of a support bar attached to the light reflecting surface member.   The hollow surface illumination device according to claim 2, wherein the LED light source is attached to both side surfaces of the support rod.   The hollow surface illumination device according to claim 1, wherein the light reflecting surface member has a curved surface shape based on the arrangement of the LED light sources and the shape of the hollow light guide region.   2. The hollow surface illumination device according to claim 1, wherein the LED light source has an optical axis in a direction parallel to a surface of the reflective surface member, wherein the wiring board is attached to the reflective surface member.   The hollow surface illumination device according to claim 5, wherein the LED light source is configured by mounting a plurality of LEDs that emit light in at least two directions.   The hollow surface illumination device according to claim 5, wherein the unit case has a square shape or a cylindrical shape.

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