JP2012227043A - Lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain luminance unevenness on a light-emitting surface in a lighting device.SOLUTION: The lighting device 1 includes a light source part 2, a reflecting part 3, and a case 4 housing the reflecting part 3 and the light source part 2. The light source part 2 includes a plurality of LEDs 20 arranged in array and an elongated optical member 21 for controlling light distribution of light emitted from the LEDs 20. The optical member 21 includes an incident surface 25 formed into a gutter-shaped concave part surrounding the LEDs 20, and an emission surface 26 place on the opposite side from the incident surface 25. Those surfaces 25, 26 include curved surfaces 25a, 26a curved to cover extreme ends of the LEDs 20 at either end part in a length direction. The curved surfaces 25a, 26a are structured so as curvatures of the incident surface 25 and the emission surface 26 to be continued. With this structure, since refraction angles of light to be incident to or emitted from them are not locally changed at end parts of the incident surface 25 and the emission surface 26, light from the light source part 2 can be uniformly emitted to restrain luminance unevenness on the light-emitting surface.

Description

  The present invention relates to a lighting device using a plurality of solid state light emitting elements as a light source.

  A light-emitting diode (hereinafter referred to as an LED) is attracting attention as a light source for a lighting device that can replace incandescent lamps and fluorescent lamps because it can emit light with high luminance at low power and has a long lifetime. However, since the amount of light of an LED alone is smaller than that of a fluorescent lamp, a plurality of LEDs are used in a general lighting device using an LED as a light source.

  Such an illuminating device using a plurality of LEDs is used to realize a surface light source used in main illumination, such as an office base light or a household ceiling light. However, since an LED is generally a point light source, even if a diffusion panel or the like is provided on the exit surface, the brightness in the front direction of the LED is increased, giving a graininess peculiar to the LED light source on the light emitting surface of the lighting device. May cause glare. Therefore, light is led out from the LEDs arranged on the outer edge of the device body in the horizontal direction, and the light is reflected in the vertical direction using a reflector inclined toward the center of the device body, and diffused. There exists what irradiates through a panel (for example, patent document 1).

  The structure of this type of lighting device is shown in FIGS. As illustrated in FIG. 6A, the lighting device 101 includes a pair of light source units 102, a reflection unit 103 that reflects light from the light source unit 102, and a rectangular housing that houses the reflection unit 103 and the light source unit 102. A body 104 and a light diffusing panel 105 that diffuses and radiates the light reflected by the reflecting portion 103. In FIG. 6B, the light diffusion panel 105 is not shown. The light source units 102 are disposed so as to face each other with the reflection unit 103 disposed in the center of the housing 104 interposed therebetween. As illustrated in FIG. 6B, the light source unit 102 includes a plurality of light emitting units (LEDs) 120 and a long optical member 121 that controls light distribution of light emitted from the LEDs 120.

  As shown in FIG. 6C, the optical member 121 includes an incident surface 125 formed in a bowl-shaped recess 124 surrounding the LED 120, an exit surface 126 positioned on the opposite side of the incident surface 125, and an incident surface 125. And a reflecting surface 127 that collimates the incident light. The light emitted from the light source unit 102 in the horizontal direction is reflected by the reflecting unit 103, enters the light diffusing panel 105, is diffused by the light diffusing panel 105, and is irradiated outside the illumination device 101 (FIG. 6). (See (a)).

JP 2008-300203 A

  However, in this type of lighting device 101, as shown in FIG. 6D, the end of the incident surface 125 in the longitudinal direction is formed by a surface 125a perpendicular to the longitudinal direction. In this case, the refraction angle of the light incident from the LED 20 locally changes at the corner between the vertical surface 125a and the incident surface 125. Therefore, even when the light diffusion panel 105 is provided, luminance unevenness occurs at the corners of the light emitting surface of the lighting device 1 as shown in FIG. A portion surrounded by a broken line in FIG. 7 corresponds to a portion surrounded by a white broken line in FIG. This type of lighting device 101 irradiates light in a wide installation space, and normally the lighting device itself is not appreciated, but the light emitting surface of the lighting device may enter the field of view of the user, etc. If there is uneven brightness on the light emitting surface, there is a risk of discomfort to the user or the like.

  The present invention solves the above-described problems, and an object of the present invention is to provide an illumination device that can uniformly irradiate light from a light-emitting surface and can suppress uneven brightness.

  In order to solve the above problems, an illumination device according to the present invention includes a light source unit, a reflection unit that reflects light from the light source unit, and a housing that houses the reflection unit and the light source unit. The light source unit includes a plurality of light emitting units arranged in an array, and a long optical member that controls light distribution of light emitted from the light emitting unit, and the optical unit The member has an incident surface formed in a bowl-shaped recess surrounding the light emitting portion, and an exit surface located on the opposite side of the entrance surface, and the entrance surface and the exit surface are both ends in the longitudinal direction. Part has a curved surface that is curved so as to cover the outermost part of the light emitting part, and these curved surfaces are configured such that the curvatures of the incident surface and the outgoing surface are continuous. To do.

  In the illuminating device, it is preferable that two light source portions are provided, and the light source portions are arranged to face each other with the reflection portion interposed therebetween.

  In the illuminating device, it is preferable that the curved surface has a certain curvature around the outermost end portion of the light emitting portion.

  According to the illumination device of the present invention, the longitudinal ends of the entrance surface and the exit surface are configured as continuous curved surfaces, so that the refraction angle of the light incident on and exiting from these is also set. It will not change locally. Therefore, the light from the light source unit is uniformly irradiated, and uneven brightness on the light emitting surface can be suppressed.

(A) is sectional side view of the illuminating device which concerns on the 1st Embodiment of this invention, (b) is the sectional view on the AA 'line of (a), (c) is the same illuminating device shown to (a). The enlarged view of a light source part, (d) is the enlarged view of the edge part of the light source part shown to (b). (A) The perspective view seen from the entrance plane side of the optical member of the illumination device, (b) is the perspective view seen from the exit plane side. The figure which shows the luminance distribution in the corner part of the light-diffusion panel of the same illuminating device. (A) is the sectional side view of the illuminating device which concerns on the 2nd Embodiment of this invention, (b) is the sectional view on the AA 'line of (a), (c) is the same illuminating device shown to (a). The enlarged view of a light source part, (d) is the enlarged view of the edge part of the light source part shown to (b). The figure which shows the luminance distribution in the corner part of the light-diffusion panel of the same illuminating device. (A) is a sectional side view of a conventional lighting device, (b) is a transverse sectional view of the device, (c) is an enlarged view of a portion surrounded by a dashed line shown in (a), and (d) is (b). The enlarged view of the edge part of the location enclosed with the broken line shown in FIG. The figure which shows the luminance distribution in the corner part of the light-diffusion panel of the same illuminating device.

  A lighting device according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 3. As illustrated in FIG. 1A, the illumination device 1 according to the present embodiment includes a light source unit 2, a reflection unit 3 that reflects light from the light source unit 2, and a housing that houses the reflection unit 3 and the light source unit 2. 4 and a light diffusing panel 5 that diffuses and radiates the light reflected by the reflecting portion 3. The housing 4 is a bottomed rectangular member having one surface opened, and includes a bottom surface portion 41, a side surface portion 42 erected on four sides of the bottom surface portion 41, and an opening portion surrounded by the side surface portions 42. 43. The light source unit 2 is arranged on one inner side surface of the side surface portion 42 of the housing 4 so as to guide light toward the center of the housing 4. The reflecting portion 3 is disposed to be inclined from the bottom surface portion 41 side of one side surface portion 42 provided with the light source portion 2 to the opening 43 side of the other side surface portion 42.

  The bottom surface portion 41 is a structural member that supports the mounting portion (not shown) of the lighting device 1, the side surface portion 42, and the light diffusion panel 5, and a plate material such as an aluminum plate or a steel plate having a predetermined rigidity has the above shape. It has been pressed. The side surface portion 42 is a structural member that connects the bottom surface portion 41 and the light diffusing panel 5 and to which the light source portion 2 is attached, and is formed of the same material as the bottom surface portion 41. The bottom surface portion 41 and the side surface portion 42 may be integrally formed. In addition, the light source part 2 is not restricted to the side part 42, For example, you may attach to the bottom face part 41 by another attachment tool (not shown). In addition, if the side part 42 is formed using a light transmissive diffusing resin material, light can be irradiated from the side part 42. In this case, the light diffusing panel 5 and the side surface portion 42 may be integrally formed. The opening 43 is configured from the outer edge of the side surface portion 42, and is provided with a holding portion (not shown) that holds the light diffusion panel 5. The bottom surface portion 41 and the side surface portion 42 are members constituting the appearance of the lighting device 1, and the outer surface thereof is appropriately subjected to a treatment such as coating or plating. The inner surface may be coated with a white paint having light reflectivity.

  The reflection unit 3 is a member that guides the light emitted from the light source unit 2 to the light diffusing panel 5. For example, a metal or resin is used as a base material, and a white coating is applied to the surface thereof, or aluminum, silver, or the like is used. A highly reflective material is vapor-deposited and mirror-treated.

  The light diffusing panel 5 is a milky white material obtained by adding a light diffusing material such as particles based on calcium carbonate to a translucent resin such as an acrylic resin or a polycarbonate, so that the inner size of the opening 43 is substantially the same shape. It is a rectangular plate member formed and processed. The light diffusing panel 5 may be a transparent glass plate or a resin plate whose surface or back surface is subjected to a sand blasting process to have a rough surface or a textured surface. Further, the light diffusing panel 5 is not limited to the illustrated plate-like member, and may be, for example, a cover-like member protruding in the light derivation direction (not shown).

  As shown in FIG. 1B, the light source unit 2 includes a plurality of light emitting units (LEDs) 20 arranged in an array, and a long optical member 21 that controls the light distribution of light emitted from the LEDs 20. And a substrate 22 on which the LEDs 20 are mounted, and an optical member 21 and a holder 23 that holds the substrate 22. In FIG. 1B, the light diffusion panel 5 is not shown.

  The LED 20 combines, for example, an LED chip that emits blue light and a phosphor material that converts blue light such as YAG phosphor into yellow light, and emits white light by mixing blue light and yellow light. A so-called white LED is preferably used. The LEDs 20 are mounted on the substrate 22 so as to be substantially equally spaced in an array. It is also possible to use a plurality of LEDs 20 with different emission colors, arrange them in an array, and mix the emitted light of each LED 20 to realize a predetermined color of irradiation light.

  The substrate 22 is a long plate-like member formed so that a plurality of LEDs 20 can be mounted in an array. As the base material, for example, a general-purpose substrate plate such as glass epoxy resin is preferably used. It is done. The substrate 22 has recesses in which the LEDs 20 are embedded at regular intervals along the longitudinal direction. The bottom surface of the recesses is electrically connected to a wiring pattern (not shown) for supplying power to the LEDs 20. A terminal portion is formed. The LED 20 may be configured by mounting a blue LED chip in a concave portion of the substrate 22 and filling the concave portion with a yellow phosphor. The holder 23 is a member that holds the optical member 21 and the substrate 22 in the housing 4 and also radiates heat generated from the LEDs 20 to the housing 4 and is made of a material having high thermal conductivity such as aluminum.

  The optical member 21 is a long lens member for efficiently guiding the light emitted from the plurality of LEDs 20 arranged in an array to the reflecting portion 3, and is a translucent resin such as acrylic resin or polycarbonate. Formed by. As shown in FIG. 1 (c), the optical member 21 includes an incident surface 25 formed in a bowl-shaped recess 24 (see also FIG. 2A described later) surrounding the LED 20, and the opposite side of the incident surface 25. And a reflecting surface 27 that collimates the light incident from the incident surface 25.

  As shown in FIG. 1D, the incident surface 25 and the exit surface 26 are curved so as to cover those at the extreme ends of the LEDs 20 arranged in an array on the substrate 22 at both ends in the longitudinal direction of the optical member 21. The curved surfaces 25a and 26a are configured such that the curvatures of the entrance surface 25 and the exit surface 26 are continuous. In the cross section of the optical member 21 in a top view, the curves constituting the entrance surface 25 and the exit surface 26 have tangent lines at any point, and when this curve is plotted on coordinates, it can be differentiated by a differentiable function. Can be represented. In addition, the cross-sectional shape of both end portions in the longitudinal direction of the optical member 21 is also in the cross-section D1 along the direction of light emission from the LED 20 and orthogonal to the longitudinal direction of the optical member 21, and also in the cross-section D2 parallel to the substrate 22 The shape is as shown in FIG.

  As shown in FIG. 2A, the incident surface 25 is provided in the bowl-shaped recess 24 along the longitudinal direction of the optical member 21, and the bowl-shaped recess 24 includes the recess bottom surface 24a and the recess side surfaces on both sides thereof. 24b. The reflection surfaces 27 are provided on both sides of the incident surface 25 in the longitudinal direction. The concave bottom surface 24a is a surface facing the LED 20, and its central portion slightly protrudes in the direction of the LED 20, and refracts light from the LED 20 to generate parallel light. The concave side surface 24b refracts light from the LED 20 and guides it to the reflection surface 27, and the reflection surface 27 totally reflects this light to generate parallel light. The generated parallel light is emitted from the emission surface 26 as shown in FIG. In FIG. 2A, alternate long and short dash lines 25 (c), 26 (c), and 27 (c) are cross-sectional lines of the entrance surface 25, the exit surface 26, and the reflection surface 27 shown in FIG. And corresponding to the D1 cross-section line shown in FIG.

  In the optical member 21 configured in this way, the end portions of the incident surface 25 and the output surface 26 are configured as curved surfaces 25a and 26a, and these are smoothly continuous surfaces. When entering and exiting these, the refraction angle does not change locally, and light is emitted uniformly. FIG. 3 shows the luminance distribution at the corners of the light diffusing panel 5. In FIG. 3, a portion surrounded by a white broken line corresponds to a portion surrounded by a white broken line in FIG. Further, the black-painted portion in the figure corresponds to the shade by the holding frame 51 that holds the light diffusion panel 5. According to the figure, the luminance at the corner of the light diffusing panel 5 is higher than that of the conventional lighting device (see FIGS. 6D and 7 described above) in which the end of the incident surface is not configured as a curved surface. It can be seen that unevenness can be suppressed. Therefore, according to the illuminating device 1 of this embodiment, there is little brightness nonuniformity of a light emission surface, and it can improve appearance.

  Next, an illumination device according to a second embodiment of the present invention and an illumination device using the illumination device will be described with reference to FIG. As shown in FIGS. 4 (a) and 4 (b), the illumination device 1 of the present embodiment includes two light source units 2, and these light source units 2 are arranged so as to face each other with the reflection unit 3 interposed therebetween. It is what. Further, a reflecting plate having a V-shaped cross section is used for the reflecting portion 3.

  According to this configuration, since light is irradiated from both ends of the housing 4, the luminance of the entire light emitting surface can be made more uniform than when light is irradiated from one side. Moreover, since there are two light source parts 2, a brightness | luminance can be made high and it can use suitably for the large illuminating device 1 which illuminates a wide space.

  In addition, in the illumination device 1 of the present embodiment, the curved surfaces 25a and 26a at both ends of the incident surface 25 and the emission surface 26 have a plurality of LEDs 20 arranged in an array as shown in FIG. The LED 20 is formed to have a certain curvature around the LED 20 at the extreme end. That is, the curved surfaces 25a and 26a are formed so as to include a part of a perfect circular arc centering on the LED 20 at the extreme end. In addition, the cross-sectional shape orthogonal to the longitudinal direction of the optical member 21 is the same as that of the said 1st Embodiment, as shown in FIG.4 (c).

  According to this configuration, since the light emitted radially from the LED 2 is incident substantially perpendicular to the curved surface 25a of the incident surface 25, the incident angle is reduced, and according to Snell's law, the light in the optical member 21 The refraction angle of the light guided through the light becomes small. Further, since this light is also incident substantially perpendicular to the curved surface 26a of the emission surface 26, the refraction angle of the light emitted from the emission surface 26 is also reduced. That is, the traveling direction of the light emitted radially from the LED 2 hardly changes. Therefore, light is emitted from the end of the emission surface 26 without unevenness. As a result, as shown in FIG. 5, when the light emitted from the end of the optical member 21 is reflected by the reflecting unit 3 and emitted from the light diffusion panel 5, luminance unevenness at the corner of the light emitting surface is reduced. It can suppress more effectively.

  In addition, this invention is not restricted to the said embodiment, A various deformation | transformation is possible. For example, a quadrangular pyramid-shaped reflecting plate in which the light source part 2 is provided on the four sides of the side part 42 of the rectangular housing 4 and the reflecting part 3 protrudes at the center part may be used. Moreover, the surface of the reflection part 3 may be formed so as to have light diffusibility by graining or the like.

DESCRIPTION OF SYMBOLS 1 Illuminating device 2 Light source part 20 LED (light emission part)
21 Optical member 24 Incident surface 25a Curved surface 25 Output surface 26a Curved surface 3 Reflecting portion 4 Housing

Claims (3)

An illumination device comprising: a light source unit; a reflection unit that reflects light from the light source unit; and a housing that houses the reflection unit and the light source unit,
The light source unit includes a plurality of light emitting units arranged in an array, and a long optical member that controls light distribution of light emitted from the light emitting unit,
The optical member has an incident surface formed in a bowl-shaped recess surrounding the light emitting unit, and an exit surface located on the opposite side of the incident surface,
The entrance surface and the exit surface have curved surfaces that are curved so as to cover the outermost part of the light emitting unit at both ends in the longitudinal direction,
These curved surfaces are configured so that the curvatures of the entrance surface and the exit surface are continuous.   The lighting device according to claim 1, comprising two of the light source units, and the light source units are arranged to face each other with the reflection unit interposed therebetween.   The lighting apparatus according to claim 1, wherein the curved surface has a certain curvature around the endmost portion of the light emitting unit.