JP5238902B2 - Lighting device - Google Patents

Description

  Embodiments of the present invention relate to a linear illumination device such as a fluorescent lamp using a light source having a narrow spot-like light distribution such as a light emitting diode (LED).

As a lighting device, a fluorescent lamp is generally used, but there is a problem of using mercury.
In recent years, LEDs and EL (electroluminescence) have been developed as light sources that do not use mercury, and the use of LED light sources in illumination devices is accelerating.

  However, a general surface-mount type LED light source has a configuration in which an LED chip that emits blue or ultraviolet light is sealed with a sealing resin containing a phosphor that converts visible light having a long wavelength such as red or green. The light source image has a light distribution with a strong directivity that emits light strongly in the normal direction of the surface of the sealing resin.

  For this reason, when an LED light source is used as an illumination device, there is a problem that a strong granular high-luminance portion corresponding to an LED feels dazzling or uncomfortable, or a desired illuminance space cannot be obtained due to an uneven light distribution. It was.

  As a technique for using a point-like light source having a strong directivity such as an LED as a uniform planar illumination device, there is a side incident illumination device used for a backlight of a liquid crystal display device. However, in such a side-light-entering illumination device, it is necessary to dispose parts that are not directly involved in illumination, such as a light source unit and a reflection unit, outside the irradiated region, and it is necessary to provide an undesired frame portion as the illumination device. There wasn't.

  Moreover, the structure which arrange | positions a light source on the back surface side of an irradiation area | region using a light guide and a lens as a prior art which does not make a frame in an illuminating device is proposed. However, in this configuration, the direction in which the light from the light source is emitted is the same as the direction in which the light from the illuminating device is emitted, and luminance unevenness due to the light source is likely to appear even if a light guide or a lens is used.

  Moreover, although the prior art of the fluorescent lamp type illuminating device which can mount LED in three dimensions and can irradiate in all directions is proposed, it has imposed a big burden on the manufacturing side.

Japanese Patent No. 4106676 Japanese Patent No. 4067387 JP 2004-319238 A JP 2010-27282 A JP 2010-238483 A

  The subject of this invention is illumination which can control irradiation light distribution easily from omnidirectional irradiation to narrow light distribution, without showing a point light source image, even if it uses a point-like strong light source like LED Providing equipment.

According to the embodiment, the illumination device includes a light source and a light incident portion through which light enters from the light source, from the outside into the cylindrical outer surface of the tube formed in the shape to guide light incident from the light source lighting device An irradiation region to irradiate, and one curved light guide unit that guides the incident light from the light incident unit to the cylindrical irradiation region, and guides light emitted from the light source A light guide,
Irradiated region and the light guide portion is formed in a spiral shape surrounding the light source, at least a portion of the irradiated region emits light to the direction of the light opposite incident on the light incident portion, wherein The thickness of the end portion of the light guide portion on the light incident portion side is formed to be thicker than the thickness of the irradiation region .

FIG. 1 is a cross-sectional view illustrating a lighting device according to a first embodiment. FIG. 2 is a perspective view schematically showing the appearance of the lighting device. FIG. 3 is a cross-sectional view showing a first modification of the first embodiment. FIG. 4 is a cross-sectional view showing a second modification of the first embodiment. FIG. 5 is a cross-sectional view showing a third modification of the first embodiment. FIG. 6 is a cross-sectional view showing a fourth modification of the first embodiment. FIG. 7 is a cross-sectional view illustrating a lighting device according to a second embodiment. FIG. 8 is a cross-sectional view illustrating a lighting device according to a third embodiment. FIG. 9 is a cross-sectional view illustrating a lighting device according to a fourth embodiment. FIG. 10 is a cross-sectional view showing a first modification of the fourth embodiment. FIG. 11 is a cross-sectional view showing a second modification of the fourth embodiment.

Hereinafter, illumination devices according to various embodiments will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 shows a cross section of the fluorescent lamp type illumination device according to the first embodiment, and FIG. 2 schematically shows the appearance of the illumination device. The illuminating device 10 is an elongated illuminating device in which LED light sources are linearly arranged. As shown in FIG. 2A, for example, a rod-shaped three-dimensional shape that is extended linearly by about 1.2 m, or FIG. As shown to b), it has the cyclic | annular form extended in the curve shape.

  The lighting device 10 is mounted on an elongated rectangular plate-like base material 12 extending over almost the entire length of the lighting device, an elongated rectangular substrate 14 supported on one surface of the base material 12, and the substrate. And a substantially cylindrical elongated light guide 18 provided so as to surround them.

  The base material 12 is formed of, for example, an aluminum extrusion material, and the substrate 14 is supported on the upper surface thereof. Moreover, the base material 12 has a plurality of heat radiation fins 20 projecting from the lower surface thereof, and these heat radiation fins 20 extend in the axial direction to the lighting device. Support portions 22 are formed on both side edges of the substrate 12. The base material 12 supports the substrate 14 as described above, and ensures heat dissipation from the light source and the strength of the lighting device 10.

  The light source is, for example, a plurality of white LEDs 16 mounted on the substrate 14, and these LEDs 16 are arranged in a line along the longitudinal direction of the lighting device 10 at a predetermined pitch P, for example, 6 mm, for example. ing. As described above, the light guide 18 and the light source are arranged in a line in one direction, and the light guide 18 has a straight tube shape. The substrate 14 supplies necessary power to the LED 16 to light the LED. Covers 23 are attached between both ends of the linear light guide 18 or between both ends of the annular light guide 18. For example, a lighting circuit (not shown) for driving the LED 16 is provided in the cover.

  The light guide 18 is formed in a substantially cylindrical shape by, for example, a transparent resin extruded material having a refractive index larger than that of air, and has a cross-sectional diameter 2R of, for example, 26 mm. The interval between the adjacent LEDs 16, that is, the arrangement pitch P of the LEDs 16 is set to be smaller than the radius R of the light guide 18.

  The light guide 18 includes a convex light incident portion 24 whose upper portion facing the LED 16 is recessed toward the substrate 14, that is, the center side of the light guide 18. It extends over the entire length along the axial direction. Thereby, the cross section of the light guide 18 is formed in a substantially heart shape. The light guide 18 is formed in a symmetrical shape with respect to a center line C passing through the center thereof.

  The light incident portion 24 is in contact with the upper surface of the substrate 14. Further, the light incident portion 24 is formed with a recess 26 that extends over the entire length in the axial direction of the light guide 18. The LED 16 mounted on the substrate 14 is located in the recess 26. Thereby, the light emitted from the LED 16 enters the light incident part 24.

  The light guide 18 branches left and right from the light incident portion 24 and extends above the base 12, and then passes outside of both side edges of the base 12 to cover the lower side of the base 12. After guiding incident light, the light guide 18 has a shape that branches right and left directly above the LED 16, and its side surface is inclined so as to reflect and enter light obliquely emitted from the LED 16. 97% of the light emitted from the LED 16 enters the light guide 18. In the light guide 18, a substantially lower half of the cross section, that is, a portion extending from the side edge of the substrate 12 to the lowest end constitutes an irradiation region 30 that emits light to the outside. The irradiation region 30 is formed in a substantially wedge shape in which the thickness gradually decreases from the side edge of the substrate 12 to the lowest end, and the lowest end portion has the smallest thickness.

  Furthermore, the light guide 18 integrally has convex fixing portions 32 that protrude from the inner surfaces of both side portions, and these fixing portions 32 are fitted to the support portions 22 of the base material 12. Thereby, the light guide 18 is fixed and supported by the base material 12, and it is ensured that the positional relationship with the LED 16 is constant.

  In FIG. 1, the main light emission direction from the LED 16 is vertically upward with respect to the surface of the substrate 14, and the light emitted from the LED 16 enters the light guide 18 from the light incident portion 9. The incident light propagates while being repeatedly reflected in the light guide 18, and while being guided inside the light guide 18, the tube is inverted and is emitted outward from the wedge-shaped irradiation region 30. (Indicated by an arrow in FIG. 1).

  Thus, in the illuminating device 10, the light incident portion 24 of the light guide 18 is disposed on the back surface side of the irradiation region 30, that is, on the opposite side with respect to the substrate 14, and the main light emission direction of the LED 16 that is a light source is It is above the substrate 14. On the other hand, the main light emission direction of the irradiation region 30 is downward with respect to the substrate 14 and is directed in the direction opposite to the main light emission direction of the LED 16.

According to the illuminating device 10 configured as described above, when the illuminating device is viewed from the direction of the irradiation region 30, an unnecessary non-light emitting region is disposed on the back side of the base material 12, and the entire illuminating device 10 appears to shine. Can be. The light from the plurality of LEDs 16 dispersed in a dotted manner spreads in the longitudinal direction of the lighting device 10 while being guided through the light guide 18. Uniform brightness can be achieved. In addition, by appropriately designing the wedge shape of the irradiation region 30, it is possible to spread the light distribution over a wide range including the lateral direction of the light guide 18 while maintaining high efficiency of about 95%.
Thereby, even when a point-like and highly directional light source such as an LED is used, the illumination device can easily control the irradiation light distribution from wide light distribution to narrow light distribution without showing the point light source Can be obtained.

  The component materials and configurations described in the first embodiment can be changed as appropriate. For example, the base 12 may be a molded steel plate, and the light guide is not limited to a circle but may have a more distorted flat elliptical cross-sectional shape.

  Although the light is extracted by the wedge shape of the light guide 18, the light extraction may be performed by using a texture, a groove, a microlens, and a diffusion printing pattern formed on the surface of the light guide, or diffusion mixed in the light guide material. You may do with a filler material. If the light guide body irradiation area is transparent and wedge-shaped as in this embodiment, the direction of the light emitted from the illumination device is aligned with the tangential direction of the irradiation area, so the edge of the cylindrical irradiation area However, it is not preferable because only the shining feeling is obtained. In addition, the installation of the wrinkles and the diffusing member requires a design burden and an extra manufacturing cost. For this reason, kneading the diffusion filler material with the light guide material is simple in terms of manufacturing, and the whole light guide feels shining. In this case, if the diffusion filler material concentration is too high, the distance at which light can be guided becomes short. Therefore, it is desirable to set the plate transmittance of 2 mm to 80 to 95%.

  Next, a modification of the first embodiment will be described. In the various modifications described below, the same components as those in the first embodiment described above are denoted by the same reference numerals, detailed description thereof is omitted, and different portions will be mainly described.

(First modification)
FIG. 3 shows a cross section of the illumination device according to the first modification. According to the first modification, the light guide 18 is formed in a cylinder having a perfect cross section, imitating an existing fluorescent lamp. Since the shape of the light incident part 24 of the light guide 18 is restricted, a dummy circular part 34 having a circular cross section covering the upper side of the light incident part 24 is added to form a cylindrical sectional shape. The dummy portion 34 is integrally formed with the extruded light guide 18, but another member may be bonded.

(Second modification)
FIG. 4 shows a cross section of the illumination device according to the second modification. In the second modification, a light guide blocking unit 35 that blocks the light guide is provided at the thinnest portion of the irradiation region 30 of the light guide 18. The light guide blocking part 35 is formed by, for example, a recess that is recessed toward the center of the light guide 18.

  Considering the strength of the light guide 18, even the thinnest part of the light guide has a thickness of about 0.5 mm, and there is a possibility that light may go around the light guide 18 and return to the light source 16. Sex is conceivable. However, as in the second modification, by providing the light guide blocking part 35 at the thinnest part of the light guide 18, it is possible to extract all the light guided through the light guide 18 to the outside, and the illumination device Efficiency can be improved.

(Third Modification)
FIG. 5 shows a cross section of a lighting device according to a third modification. In the third modification, the outer surface of the irradiation region 30 of the light guide 18 is formed in a step shape having a plurality of step portions 36. In particular, the stepped portion 36 is designed so that the light in the lateral direction generated near the thinnest portion of the irradiation region 30 is directed in the front direction.

  In the first embodiment and the first and second modified examples described above, a light distribution distribution that irradiates a wide range simulating an existing fluorescent lamp as described in JEL801 is used. However, in the third modified example, an irradiation range is set. The angle is set to 85 degrees so that almost no light is emitted in the lateral direction. Thereby, the light emitted from the side surface direction of the illumination device 10, for example, the light in the side surface direction reflected on the window or the TV screen is reduced.

(Fourth modification)
FIG. 6 shows a cross section of a lighting device according to a fourth modification. In the third modified example, the light guide 18 is configured to have an opening 40 in a lower part of the cylindrical shape, that is, a part located on the opposite side of the LED 16 with respect to the substrate 14. The opening 40 extends over the entire length and length of the lighting device 10.

  With such a configuration, it is possible to eliminate light that is emitted from the LED 16 and goes around the cylindrical light guide 18 and returns to the LED 16, and to improve the heat dissipation effect of the LED 16 due to external air convection.

  Next, a lighting device according to another embodiment will be described. In the various embodiments described below, the same components as those in the first embodiment described above will be denoted by the same reference numerals, and detailed description thereof will be omitted, and different portions will be mainly described.

(Second Embodiment)
FIG. 7 shows a cross section of the illumination device according to the second embodiment. In the second embodiment, the basic configuration is the same as in the first embodiment, but a plurality of LEDs 16 are arranged in two rows on the substrate 14 as a light source. The light guide 18 has two light incident portions 24 corresponding to two LEDs. These light incident portions 24 are located on both sides of the center line C of the light guide 18, are in contact with the substrate 14, and have recesses 26 that accommodate the LEDs 16. When the light sources cannot be accommodated in one row, the above-described configuration can provide the same effects as those of the first embodiment described above.

(Third embodiment)
FIG. 8 shows a cross section of the illumination apparatus according to the third embodiment. In the third embodiment, the basic configuration is the same as that of the first embodiment, but the LEDs 16 that are light sources are arranged sideways. That is, the LEDs 16 are arranged in two rows, and the LEDs 16 in one row are arranged in a direction to emit main light toward the side of the light guide 18, and the LEDs in the other row are guided. It arrange | positions in the direction which radiate | emits main light toward the other side of the light body 18, and is provided in 180 degree reverse direction with LED of one row | line | column. Further, the direction in which the main light of these two LEDs 16 is emitted differs from the direction in which light is emitted from the irradiation region 30 of the light guide 18 by approximately 90 degrees. The light guide 18 is formed symmetrically with respect to the center line C.

  According to the third embodiment, since the light source arrangement is in the horizontal direction, the burden on leakage at the curved portion of the light guide 18 is reduced, and the lighting device 10 can be designed more compactly.

  According to the first to third embodiments and the first to third modifications described above, even if a point-like and highly directional light source such as an LED is used, a wide light distribution is achieved without showing a point light source image. It is possible to provide an illuminating device that can easily control irradiation light distribution up to narrow light distribution.

(Fourth embodiment)
FIG. 9 shows a cross section of the illumination device according to the fourth embodiment. In the fourth embodiment, the basic configuration is the same as that of the first embodiment, but the irradiation region 30 is formed in a cylindrical shape, and the light is emitted in all directions so that the light is emitted in the same manner as a conventional fluorescent lamp. Realized. If the curvature of the inner circle side is not made the same at the connecting portion that is connected to the cylindrical irradiation region 30 by light guide, light leaks and unevenness occurs. For this reason, the connection part 31 from the light incident part 24 of the irradiation region 30 is formed to have a thick width obtained by adding the width of the light guide extending from the light incident part 24 and the width of the irradiation region 30 on the upper side of the cylinder. The thickness of the irradiation region guided from the light incident part 24 to the cylindrical irradiation region 30 is formed thicker than the other irradiation regions. By doing so, it is possible to irradiate the entire periphery without causing unevenness of the connection portion.

(First modification)
FIG. 10 shows a cross section of a lighting device according to a first modification of the fourth embodiment. In this modification, the curvature of the light guide portion and the cylindrical irradiation region 30 is reduced by using one portion for guiding light from the light incident portion 24 to the cylindrical irradiation region 30 and arranging the LED 16 eccentrically. It is approaching. Thereby, the cylindrical shape of the irradiation area | region 30 can be formed more compactly.

  In the fourth embodiment shown in FIG. 9, a part of the light guided through the irradiation region 30 flows backward from the connection light guide part on the opposite side and re-enters the LED 16. If it is a structure, the light which guides the irradiation area | region 30 is always counterclockwise, the backflow to LED16 does not occur and an extra efficiency loss does not occur.

(Second modification)
FIG. 11 shows a cross section of a lighting apparatus according to a second modification of the fourth embodiment. In the modification, there is one light guide part that guides light from the light incident part 24 to the cylindrical irradiation area 30, and the light guide part and the irradiation area are formed in a spiral shape as shown in FIGS. Avoiding confluence. The irradiation region 30 is formed of a material containing a diffusing material, and its transmittance is 80 to 95% at a plate thickness of 2 mm. With this configuration, the light guide 18 can be made thin, and the configuration is less likely to cause unevenness without fine design.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

The present invention has been described in detail above with reference to preferred embodiments thereof. For easy understanding of the present invention, specific embodiments of the present invention will be described below.
(Appendix 1)
A light source;
A light incident part that makes light incident from the light source, and an irradiation region that irradiates the light incident from the light source to the outside of a lighting device, and a light guide that guides light emitted from the light source. Prepared,
At least a part of the irradiation region is directed to the side opposite to the direction of light incident on the light incident portion.
(Appendix 2)
The illumination device according to claim 1, wherein a cross section of an irradiation region of the light guide body is curved in a cylindrical shape, and the light incident portion is installed in the cylindrical internal space.
(Appendix 3)
The light guide has a plurality of step portions that are formed on an outer peripheral surface of the irradiation region and control a direction of light emitted from the irradiation region in a specific direction. Lighting device.
(Appendix 4)
The lighting device according to appendix 2, wherein the light guide has a recess formed in an outer peripheral surface of the irradiation region.
(Appendix 5)
The lighting device according to appendix 2, wherein the light guide has an opening formed on an outer peripheral surface of the irradiation region and positioned on a back side of the light source.
(Appendix 6)
The light source has a plurality of light sources arranged in a line at predetermined intervals in the axial direction of the cylindrical light guide, and the interval between the light sources is smaller than the radius of the light guide. The lighting device according to Supplementary Note 2, wherein

(Appendix 7)
Appendix 1 characterized in that the irradiation area is cylindrical, and the thickness of the irradiation area guided from the light incident portion to the cylindrical irradiation area is thicker than the other irradiation areas. The lighting device described.
(Appendix 8)
The illumination device according to appendix 7, wherein there is one light guide portion that guides light from the light incident portion to the cylindrical irradiation region, and the light guide portion and the irradiation region are formed in a spiral shape. .
(Appendix 9)
The illumination device according to appendix 7, wherein the irradiation region is formed of a material containing a diffusing material and has a transmittance of 80 to 95% at a plate thickness of 2 mm.
(Appendix 10)
The illuminating device according to appendix 1, wherein the light guide and the light source are linearly arranged in one direction, and the light guide has a straight tube shape.

  DESCRIPTION OF SYMBOLS 10 ... Illuminating device, 12 ... Base material, 14 ... Board | substrate, 16 ... LED (light source), 18 ... Light guide, 22 ... Support part, 24 ... Light-incident part, 26 ... Recessed part, 30 ... Irradiation area

Claims (7)

A light source;
A light incident part for allowing light to enter from the light source, an irradiation area that is formed in a cylindrical shape, guides the light incident from the light source, and irradiates the illumination device to the outside from a cylindrical outer surface, and the incident light is incident on the incident light. A curved light guide that guides light from the light part to the cylindrical irradiation region, and a light guide that guides light emitted from the light source,
The light guide part and the irradiation area are formed in a spiral shape surrounding the light source,
At least a part of the irradiation region irradiates light on the side opposite to the direction of light incident on the light incident part ,
The illumination device according to claim 1, wherein a thickness of an end portion of the light guide portion on the light incident portion side is thicker than a thickness of the irradiation region . The illumination device according to claim 1, wherein the irradiation region is formed in a spiral shape wound around one or more rounds . The illumination device according to claim 1 or 2 , wherein an outer peripheral tip of the spiral irradiation region is continuous with an irradiation region on an inner peripheral side, and the irradiation region has a closed cylindrical shape .   The said light guide has a several step part which is formed in the outer peripheral surface of the said irradiation area | region, and controls the direction of the light discharge | released from the said irradiation area | region to a specific direction. The illumination device according to any one of the above. The light source has a plurality of light sources arranged in a line at predetermined intervals in the axial direction of the cylindrical light guide, and the interval between the light sources is smaller than the radius of the light guide. lighting device according to any one of claims 1 to 4, characterized in that. The irradiation region is formed of a material containing the diffusion material, the lighting device according to any one of claims 1 to 5 that the transmittance is characterized in that 80 to 95% in the thickness 2 mm. The said light guide and the said light source are arrange | positioned at linear form connected to one direction, The said light guide has a straight tube | pipe shape, The any one of Claim 1 thru | or 6 characterized by the above-mentioned. Lighting equipment.

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