JP6300147B2 - Lighting device - Google Patents

Description

  The present invention relates to an illumination device using an LED as a light source.

  LEDs are attracting attention as light sources for illuminating devices that replace incandescent lamps and fluorescent lamps because they can emit light with high brightness at low power and have a long lifetime. As an illumination device using such an LED, a disk-shaped housing, a power feeding portion provided at the center of the housing for feeding power to the LED, and a plurality of annularly arranged around the power feeding portion The LED provided with the LED is known (for example, see Patent Document 1). The light emitted from the LEDs is subjected to light distribution control by a lens provided facing each LED, and then diffused by a diffusion cover provided on the light emission surface side of the lens and irradiated to the outside. The diffusion cover is attached to a diffusion cover attachment portion provided at the peripheral edge of the housing.

JP 2013-48167 A

  However, in the lighting device as described above, the power feeding unit is arranged at the center of the device, and the diffusion cover mounting portion is arranged at the peripheral portion of the device, so that the LEDs are arranged up to the center and the peripheral portion of the device. I can't. Therefore, it is difficult for light emitted from the LED to reach the center and the peripheral portion of the device, and when the illumination device is viewed from the light output surface side, the center and the peripheral portion of the device become dark and poor in appearance.

  This invention solves the said subject, Comprising: In the illuminating device which uses LED as a light source, the light radiate | emitted from LED can reach the center and peripheral part of an apparatus, and the illuminating device with good appearance is obtained. The purpose is to provide.

The illumination device of the present invention includes a flat housing, a light source unit provided on one surface of the housing, and an optical member that controls light distribution of light emitted from the light source unit, and the light source The unit has a plurality of LEDs, the plurality of LEDs are arranged so that each optical axis is orthogonal to one surface of the housing, and the optical member is provided for each of the plurality of LEDs. A plurality of lenses, the plurality of lenses covering the LED, a dome-shaped incident surface on which light from the LED is incident, a medium portion on which light incident from the incident surface propagates, and the medium portion And the incident surface refracts the light from the LED in a direction in which the angle with respect to the optical axis becomes larger, and the emission surface is in contact with the optical axis. The angle formed by the propagation direction of light propagating through the medium portion is defined as the first refraction angle θ1. And the angle between the propagation direction of the light emitted from the emitting surface and the optical axis when the second refraction angle .theta.2, the value of .theta.2 / .theta.1 is increased once continuously with increasing .theta.1 decreases later, and θ1 is characterized in that it is configured so that shape of smaller than maximum in the range of 10 to 30 degrees.

  The exit surface is preferably configured in a shape such that the value of θ2 / θ1 is 1.1 or more.

  It is preferable that the casing has a reflecting portion that is bent toward the optical member and reflects light at a peripheral portion thereof.

  It is preferable that the optical member further includes a connection portion that connects the plurality of lenses to each other, and is formed as one member.

  It is preferable that the housing has an opening at a central portion thereof, and a power feeding unit that controls power feeding to the plurality of LEDs is disposed in the opening.

  It further comprises a diffusion cover for diffusing light emitted from the optical member, and the diffusion cover is configured to have a shape such that the distance from the casing decreases from the central portion toward the peripheral portion. preferable.

  It is preferable that the diffusion cover has a high diffusion portion having a light diffusibility higher than that of the peripheral portion at the center thereof.

  The diffusion cover preferably has a diffusion layer for diffusing light on the outer surface or the inner surface thereof.

  The diffusion layer preferably includes a diffusing agent that diffuses light.

  When the diffusion cover is made of a light-transmitting resin and the diffusion layer is provided on the inner surface thereof, the diffusion cover preferably has a fine uneven structure on the outer surface.

  According to the present invention, a large amount of light emitted from the LED is emitted not only in the front direction of the lens (in the direction of the optical axis of the LED) but also on the side of the lens. It is possible to improve the appearance of the lighting device by reaching the periphery.

The disassembled perspective view of the illuminating device which concerns on one Embodiment of this invention. The perspective view of the lens which comprises the said illuminating device. The II sectional view taken on the line of FIG. The figure which shows the mutual relationship of angle (theta) 1 and (theta) 2 in the said lens. The figure which shows the light distribution curve of the light radiate | emitted from the said lens. The sectional side view of the modification of the said lens. The figure which shows the mutual relationship of angle (theta) 1 and (theta) 2 in the said lens. The figure which shows the light distribution curve of the light radiate | emitted from the said lens. The sectional side view of the said illuminating device, and its partially expanded view. (A) is an enlarged view of the area | region enclosed with the broken line of FIG. 9, (b) is a figure which shows the modification of (a). The figure which shows the uniformity degree of the light irradiated from the said illuminating device. The figure which shows the uniformity degree of the light irradiated from the conventional illuminating device. The disassembled perspective view of the illuminating device which concerns on other embodiment. FIG. 14 is a cross-sectional view taken along the line I-I in FIG. 13.

  An illumination device according to an embodiment of the present invention will be described with reference to FIGS. This illuminating device is a ceiling light attached to a ceiling surface of a living space or the like.

  As shown in FIG. 1, the lighting device 1 includes a disk-shaped housing 2, a light source unit 3 provided on one surface (mounting surface 21) of the housing 2, and a distribution of light emitted from the light source unit 3. An optical member 4 that controls light and a diffusion cover 5 that diffuses light emitted from the optical member 4 are provided. The housing 2 has an opening 22 at the center thereof, and a power feeding unit 6 that controls power feeding to the light source unit 3 is fitted into the opening 22.

  The housing 2 is attached to the ceiling surface via an attachment surface opposite to the mounting surface 21. The housing 2 has a plurality of diffusion cover attachment portions 23 used for attaching the diffusion cover 5 to the peripheral portion of the mounting surface 21. The mounting surface 21 has a visible light reflectivity of, for example, 75 to 95% by applying a white paint or vapor deposition of a light reflective metal material. The housing 2 is formed, for example, by pressing and cutting an aluminum plate or steel plate having a predetermined rigidity.

  The light source unit 3 includes a plurality of LEDs 31 and a wiring board 32 on which the LEDs 31 are mounted. The wiring board 32 has a donut plate shape, and is attached to the mounting surface 21 of the housing 2 so that the center thereof coincides with the center of the housing 2. The plurality of LEDs 31 are mounted on a surface opposite to the surface attached to the mounting surface 21 of the wiring board 32, and are arranged on four concentric circles centered on the center of the housing 2. These LEDs 31 are arranged such that their optical axes are orthogonal to the mounting surface 21. The LED 31 includes, for example, a blue LED chip that emits blue light, a sealing material that seals the blue LED chip, and a phosphor that is dispersed in the sealing material and converts blue light into yellow light. The white LED emits white light by mixing blue light and yellow light with each other. The wiring board 32 is made of an insulating material such as glass epoxy resin and has a wiring pattern (not shown) connected to each LED 31. Each wiring pattern is connected to a lighting circuit (see later) of the power feeding unit 6.

  The optical member 4 has a donut plate shape that is substantially the same size as the wiring board 32, and is provided so as to cover the LEDs 31 of the light source unit 3. The optical member 4 includes a plurality of lenses 41 provided to face each of the LEDs 31 and a connection portion 42 that connects the plurality of lenses 41 to each other, and is configured as one member. Thus, by comprising the optical member 4 as one member, the assembly of the illuminating device 1 becomes easy and assembly efficiency can be improved. The optical member 4 is made of a resin having translucency and electrical insulation, such as polycarbonate resin, acrylic resin, or polystyrene resin, and is screwed to the housing 2.

  The diffusion cover 5 has substantially the same diameter as that of the housing 2 and has a circular dome shape that is convex in the light emitting direction (upward in the figure). The diffusion cover 5 is provided so as to cover the optical member 4, and has a plurality of engagement portions (not shown) that engage with the diffusion cover attachment portion 23 of the housing 2 on the inner peripheral surface thereof. The diffusion cover 5 is detachably attached to the housing 2 by engaging these engagement portions with the diffusion cover attachment portion 23.

  The power feeding unit 6 has a lighting circuit (not shown) for driving the LEDs 31 to be lit, and is connected to a commercial AC power supply via a power feeding connector or the like. The lighting circuit includes a transformer, a capacitor, a control IC, and the like for rectifying an alternating current from a commercial alternating current power supply, and controls power feeding from the commercial alternating current power supply to the LED 31 according to a user instruction. Since the power feeding unit 6 is fitted into the opening 22 of the housing 2, the lighting device 1 is made thinner compared to the case where the power feeding unit 6 is arranged on the mounting surface side of the housing without providing such an opening. be able to.

  As shown in FIGS. 2 and 3, the lens 41 covers the LED 31 and has a dome-shaped incident surface 43 on which the light from the LED 31 is incident, and a medium portion 44 through which the light incident from the incident surface 43 propagates (see FIG. 3). And an exit surface 45 from which the light propagated through the medium portion 44 exits. The emission surface 45 further includes a first emission surface 46 that extends within a predetermined range from a location that intersects the optical axis Ax of the LED 31, and a first emission surface 46 that is provided continuously around the first emission surface 46. And two exit surfaces 47. The first emission surface 46 is configured by a smooth curved surface slightly recessed toward the LED 31, and the second emission surface 47 is configured by a smooth curved surface bulging outward.

  The light emitted from the LED 31 (indicated by a broken line arrow in FIG. 3) is refracted in a direction in which the angle with respect to the optical axis Ax becomes larger at the incident surface 43 because the incident surface 43 is configured in a dome shape. Here, the angle formed between the optical axis Ax and the propagation direction of the light propagating through the medium portion 44 is defined as the first refraction angle θ1, and the angle formed between the optical axis Ax and the propagation direction of the light emitted from the emission surface 45 is defined as the second angle. The refraction angle is θ2.

  As shown in FIG. 4, the value of θ2 / θ1 is configured to once increase and then decrease as θ1 increases. In the example shown in FIG. 4, the maximum value (approximately 1.70) is obtained when θ1 is approximately 33 degrees. ). The value of θ2 / θ1 is maintained at approximately 1.6 when θ1 is in the range of 10 to 20 degrees, and gradually increases until θ1 becomes approximately 1.70 (maximum value) when θ1 is in the range of 20 to 30 degrees. It gradually decreases until it becomes approximately 1 in the range of ˜70 degrees. The reason why the value of θ2 / θ1 is not stable when θ1 is in the range of 10 degrees or less is that when θ1 is small, the value of θ2 / θ1 is greatly affected by the measurement error of θ1.

  By configuring the lens 41 as described above, for example, light of θ1 = 10 degrees is emitted from the lens 41 at θ2 = approximately 16 degrees (10 degrees × 1.62), and light of θ1 = 20 degrees is θ2 = approximately. The light is emitted from the lens 41 at 33 degrees (20 degrees x 1.63). Similarly, θ1 = 33 degrees light is emitted at θ2 = approximately 56 degrees, θ1 = 40 degrees light is emitted at θ2 = approximately 66 degrees, and θ1 = 50 degrees light is emitted at θ2 = approximately 75 degrees. Thus, light with θ1 = 60 degrees is emitted at θ2 = approximately 72 degrees, and light with θ1 = 70 degrees is emitted at θ2 = approximately 72 degrees.

  As a result, as shown in FIG. 5, the light emitted from the lens 41 is strongly irradiated in a direction at an angle of about 75 degrees with respect to the optical axis Ax. In addition, since θ2 / θ1 is configured to be smaller than the maximum value in the range of θ1 of 10 to 30 degrees, a predetermined amount of light emitted from the lens 41 is also irradiated in the optical axis Ax direction. The

  As described above, since the lens 41 emits strong light in a direction of 75 degrees with respect to the optical axis Ax, the lens 41 is inclined with respect to the optical axis Ax (for example, 60 degrees with respect to the optical axis Ax). ), The near side of the lens 41 may feel bright and the far side dark. Therefore, as shown in FIG. 6, in the lens 41 a which is a modification of the lens 41, the depression on the LED 31 side of the first emission surface 46 becomes shallower than the lens 41 (the shape is indicated by a broken line), and the first 2 The outward bulge of the emission surface 47 is reduced.

  As shown in FIG. 7, the value of θ2 / θ1 (indicated by a black diamond) in the lens 41a is smaller in the range of θ1 <33 degrees than the value of θ2 / θ1 (indicated by a white square) in the lens 41. It is configured to be large and 1.1 or more in the range of θ1> 60 degrees. By reducing the value of θ2 / θ1 in the range of θ1 <33 degrees, the degree of refraction of the light emitted from the LED 31 in the optical axis Ax direction becomes smaller than that of the lens 41, and thus the optical axis Ax direction from the lens 41a. Increasing the light emitted to. Further, by increasing the value of θ2 / θ1 in the range of θ1> 60 degrees, the light emitted from the LED 31 to the side is largely refracted as compared to the lens 41 (for example, θ2 = 70 degrees light is θ2 = The light emitted to the side of the lens 41a increases.

  Thereby, as shown in FIG. 8, the light emitted from the lens 41a (shown by a solid line) is more irradiated in the direction of the optical axis Ax than the light emitted from the lens 41 (shown by a broken line). Further, the light is irradiated in a direction separated from the optical axis Ax by an angle. In this figure, for ease of understanding, the maximum luminous intensity of light emitted from each of the lenses 41 and 41a is drawn as 1.0. Thus, the light irradiated from the lens 41a is irradiated over a wider range than the light irradiated from the lens 41. Therefore, when the lens 41a is incorporated in the lighting device 1 and the light irradiation surface of the lighting device 1 is viewed from an oblique direction with respect to the optical axis Ax (for example, a direction of 60 degrees with respect to the optical axis Ax), the lens 41 is Compared to when incorporated in the lighting device 1, the back side of the lighting device 1 is less likely to be dark.

  As shown in FIG. 9, the housing 2 has a reflection portion 24 that is bent toward the optical member 4 side and reflects light at the peripheral portion thereof. The reflection part 24 is formed by, for example, bending a part of the housing 2 and applying a white paint or vapor-depositing a light reflective metal material thereto. The reflection unit 24 reflects light (indicated by a broken line arrow) emitted from the lens 41 toward the side of the illumination device 1 and directs the light toward the diffusion cover 5. Thereby, the illumination light brightness | luminance in the peripheral part of the illuminating device 1 can be increased.

  Further, the diffusion cover 5 is configured in such a shape that the distance from the housing 2 becomes smaller from the central part toward the peripheral part. In the illustrated example, the central portion of the diffusion cover 5 is a flat portion 51 formed substantially parallel to the housing 2, and an inclined portion 52 that is inclined at a predetermined angle from the flat portion 51 to the peripheral portion. . By doing so, the incident angle θ3 of the light emitted from the lens 41 and incident on the inclined portion 52 (indicated by a one-dot chain line arrow in the partial enlarged view) to the interface 53 between the diffusion cover 5 and the outside world is reduced. Further, it is possible to improve the light extraction efficiency by suppressing the total reflection of light at the interface 53. In addition, illustration of cross-sectional hatching is abbreviate | omitted in FIG.

  As shown in FIG. 10 (a), the diffusion cover 5 includes a base material 54 made of a translucent resin, a diffusion layer 55 that is laminated on the outer surface (light emission surface) of the base material 54, and diffuses light. Have The base material 54 is made of, for example, an acrylic resin or a polystyrene resin, and gives mechanical strength to the diffusion cover 5. The diffusion layer 55 is configured by a coating film containing a diffusion agent 56 that diffuses light. The diffusing agent 56 is made of, for example, particulate titanium dioxide, particulate silicon dioxide, or particulate ceramic, and is sparsely dispersed at the peripheral portion of the diffusion cover 5 and densely dispersed at the central portion. The central portion of the diffusion cover 5 in which the diffusing agent 56 is densely dispersed is a high diffusion portion 57 having light diffusibility higher than that of the peripheral portion. In the example shown in the figure, the flat portion 51 is the high diffusion portion 57. ing. By providing such a high diffusion portion 57, the light incident on the high diffusion portion 57 is diffused by the diffusing agent 56, and the total reflection of light at the interface 53 is suppressed. Thereby, the light radiate | emitted outside from the high-diffusion part 57 increases, and the irradiation light brightness | luminance in the center part of the illuminating device 1 can be made to increase.

  The diffusion cover 5 in which the base material 54 is made of a transparent acrylic resin having a thickness of 1.5 mm and the diffusion layer 55 having a thickness of 6 μm is provided on the light emitting surface side thereof has, for example, a transmittance of 67% with respect to light having a wavelength of 555 nm. And a diffusivity of 60%. On the other hand, a general diffusion cover composed only of an acrylic milk white panel having a thickness of 1.5 mm exhibits a transmittance of 61% and a diffusion rate of 61% for light having a wavelength of 555 nm, for example. This result shows that according to the diffusion cover 5, the transmittance can be improved without reducing the diffusion rate as compared with a general diffusion cover.

  As shown in FIG. 10B, the diffusion cover 5 may be configured to have a diffusion layer 55 on the inner surface (light incident surface) of the base material 54. In this case, since the base material 54 made of the translucent resin is exposed to the outside, the glossiness of the translucent resin is conspicuous and the appearance of the lighting device 1 may be deteriorated. Therefore, it is preferable to provide a fine concavo-convex structure 58 on the outer surface of the substrate 54. The concavo-convex structure 58 is formed, for example, by subjecting the outer surface of the base material 54 to sandblasting. By providing such a concavo-convex structure 58, light is irregularly reflected by the concavo-convex structure 58, so that it is difficult for the user to feel the gloss when the diffuser cover 5 is viewed, and the appearance of the lighting device 1 can be improved. The diffusion cover 5 in which the base 54 is made of a transparent acrylic resin having a thickness of 1.5 mm and the diffusion layer 55 having a thickness of 6 μm is provided on the light incident surface side thereof has, for example, a transmittance of 72% for light having a wavelength of 555 nm. And a diffusivity of 53%.

  According to the illuminating device 1, the light emitted from the LED 31 is refracted not only in the front direction (the optical axis Ax direction) of the lens 41 (or 41 a) but also in the entrance surface 43 and the exit surface 45 of the lens 41. A lot of light is irradiated to the side. Thereby, the light from LED31 can reach the apparatus center and a peripheral part. Moreover, since the high-diffusion part 57 and the reflection part 24 are provided, the irradiation light brightness | luminance in the center and peripheral part of the illuminating device 1 can be increased. As a result, as shown in FIG. 11, the illumination device 1 can irradiate light more uniformly than the conventional illumination device shown in FIG. 12, and the appearance of the illumination device 1 is improved.

  Next, lighting devices according to other embodiments will be described with reference to FIGS. 13 and 14. The illuminating device 11 has a different external shape from the illuminating device 1 and has a rectangular shape in plan view.

  In the illuminating device 11, the light source part 3 is made into a rectangular shape in plan view, and in the illustrated example, LEDs 31 are arranged in a matrix on a rectangular wiring board 32. The optical member 4 is also rectangular in plan view. The housing 2 is a rectangular box having an opening on one surface, and houses the light source unit 3 and the optical member 4 so that light from the optical member 4 is emitted from the opening. In addition, the inner side surface of the housing 2 is a reflecting portion 24. The diffusion cover 5 has a rectangular flat plate shape and is held by a rectangular frame body 59. The housing 2, the light source unit 3, and the optical member 4 are accommodated in a case 7. The case 7 is a rectangular box having an opening on one surface, and accommodates the housing 2, the light source unit 3, and the optical member 4 so that light from the optical member 4 is emitted from the opening. The diffusion cover 5 is attached to the case 7 so as to close the opening by fitting the frame body 59 into the opening of the case 7. The distance from the reflector 24 to the nearest LED 31, the distance between the LEDs 31, the distance from the LED 31 to the diffusion cover 5, and the distance from the bottom surface of the housing 2 to the diffusion cover 5 are, for example, 12.1 to 29.25 mm, 15-60 mm, 35.8 mm, and 37.1 mm.

  According to the illuminating device 11 configured as described above, a rectangular illuminating device that can provide the same effects as those of the illuminating device 1 described above can be obtained.

  In addition, the illuminating device according to the present invention is not limited to the above embodiment, and various modifications can be made. For example, the housing may be configured not to have a reflecting portion. In addition, for example, the LED is composed of two types, one that emits daylight color light and the other that emits light bulb color light, and the light color of irradiation light is adjusted by dimming control of these two types of LEDs independently of each other. It is good also as a structure which can do.

1, 11 Lighting device 2 Housing 21 Mounting surface (one surface of housing)
22 Opening (of housing) 24 Reflector 3 Light source 31 LED
4 Optical member 41, 41a Lens 42 Connection part 43 Incident surface 44 Medium part 45 Output surface 5 Diffusion cover 55 Diffusion layer 56 Diffusion agent 57 High diffusion part 58 Uneven structure 6 Feed part Ax (LED) optical axis θ1 First refraction angle θ2 Second refraction angle

Claims (10)

A lighting device comprising: a flat housing; a light source unit provided on one surface of the housing; and an optical member that controls light distribution of light emitted from the light source unit,
The light source unit includes a plurality of LEDs, and the plurality of LEDs are arranged so that each optical axis is orthogonal to one surface of the casing,
The optical member has a plurality of lenses provided for each of the plurality of LEDs,
The plurality of lenses cover the LED, and have a dome-shaped incident surface on which light from the LED is incident, a medium portion on which light incident from the incident surface propagates, and light propagated through the medium portion is emitted. And an exit surface,
The incident surface refracts light from the LED in a direction in which an angle with respect to the optical axis becomes larger,
The exit surface has an angle formed between the optical axis and the propagation direction of light propagating through the medium portion as a first refraction angle θ1, and an angle formed between the optical axis and the propagation direction of light emitted from the exit surface. when the second refraction angle .theta.2, the value of .theta.2 / .theta.1 is continuously decreased after increased once with increasing .theta.1, that a less than maximum in and of .theta.1 10-30 ° range It is comprised in such a shape, The illuminating device characterized by the above-mentioned.   The lighting device according to claim 1, wherein the optical member further includes a connection portion that connects the plurality of lenses to each other, and is formed as one member.   The lighting device according to claim 1, wherein the casing includes a reflection portion that is bent toward the optical member side and reflects light at a peripheral portion thereof. A diffusion cover for diffusing the light emitted from the optical member;
The lighting device according to any one of claims 1 to 3, wherein the diffusion cover includes a diffusion layer that diffuses light on an outer surface or an inner surface thereof.   The illumination device according to claim 4, wherein the diffusion layer includes a diffusing agent that diffuses light.   The diffusion cover has a fine concavo-convex structure on the outer surface when the diffusion cover is made of a translucent resin and the diffusion layer is provided on the inner surface thereof. The lighting device according to claim 5.   The said diffusion cover is comprised in the shape where the distance with the said housing | casing becomes small as it goes to a peripheral part from the center part, The structure of any one of Claim 4 thru | or 6 characterized by the above-mentioned. Lighting equipment.   The lighting device according to any one of claims 4 to 7, wherein the diffusion cover has a high diffusion portion having a light diffusion property higher than that of the peripheral portion at a central portion thereof.   The lighting device according to any one of claims 1 to 8, wherein the exit surface is configured to have a value of θ2 / θ1 of 1.1 or more. The housing has an opening at the center thereof,
10. The illumination device according to claim 1, wherein a power supply unit that controls power supply to the plurality of LEDs is disposed in the opening. 11.