JP5350072B2 - lighting equipment - Google Patents

Description

  The present invention relates to a lighting fixture having a light emitting diode element and a phosphor.

  In recent years, light-emitting diode elements (LED elements) have been used as light sources in many lighting fixtures. Light-diffusing types such as ceiling lights and base lights, and light-condensing types such as downlights and spotlights. LED elements are used in a wide variety of lighting fixtures.

  The light source using the LED element is a single color light source using a single color LED element, a white light source combining a plurality of single color LEDs such as red, green, and blue, a single color LED element such as blue, and a fluorescent light such as yellow that is a complementary color thereof. There are white light sources combined with phosphors that emit light. Among these light sources, a white light source combining a blue LED element and a yellow phosphor is generally used for lighting fixtures because of its high emission intensity and efficiency.

  A conventional lighting apparatus having this type of white light source will be described with reference to FIG. In the lighting device 100, a blue LED element 121 and a yellow phosphor 122 covering the blue LED element 121 are provided in the vicinity of the center of the bottom surface of the bottomed and uncovered casing 103, and a translucent cover 104 is attached to the opening of the casing 103. Yes. Opposite to the opening of the housing 103, a light distribution control member 106 such as a milky white plate or a glare cut plate is provided by an appropriate support member (not shown). The cross-sectional hatching of the yellow phosphor 122 and the translucent cover 104 is not shown.

  The light emitted from the blue LED element 121 enters the yellow phosphor 122. The yellow phosphor 122 absorbs part of incident light and emits yellow fluorescence having a longer wavelength than the absorbed blue light. The yellow light is emitted from the yellow phosphor 122. On the other hand, of the light incident on the yellow phosphor 122, the light that has not been absorbed passes through the yellow phosphor 122 as blue light. In other words, yellow light and blue light are emitted from the yellow phosphor 122, and white light is obtained by mixing the yellow light and the blue light. Therefore, the white LED 102 is configured by the blue LED element 121 and the yellow phosphor 122.

  However, since the white LED 102 has a larger area of the yellow phosphor 122 that emits yellow light than the blue LED element 121 that emits blue light, the light ray locus L101 of yellow light that does not mix blue light and yellow light. Occurs. That is, as shown in FIG. 14A, the yellow light irradiation range 112 is larger than the blue light irradiation range 111, and the direct light from the white LED 102 interferes with the light distribution control member 106. As shown in FIG. 14B, in the light distribution control member 106, yellow color unevenness 114 due to poor color mixing occurs around a white range 113 with good color mixing. Similarly, uneven color occurs on the irradiation surface of the lighting apparatus 100.

  As a measure for reducing such color unevenness, as shown in FIG. 15, a diffusion sheet 107 for diffusing light is provided in the vicinity of the opening of the housing 103 so that blue light (indicated by a dotted line arrow L121) is obtained. A lighting fixture 110 that diffuses yellow light (indicated by a solid line arrow L122) and mixes colors is known (see, for example, Patent Document 1). However, in such a luminaire, since the transmittance of the diffusion sheet 107 is low, the illumination efficiency is low, and since the illumination light is diffused by the diffusion sheet 107, it cannot be condensed.

  There is also known an illumination device that emits white light by irradiating a yellow phosphor with a blue LED array (see, for example, Patent Document 2). However, in such an illuminating device, since there is leakage light that is emitted from the blue LED array and does not enter the yellow phosphor, the illumination efficiency is low. In addition, a space is required between the blue LED array and the yellow phosphor, which increases the size of the lighting device.

  Moreover, the illuminating device provided with the condensing lens containing a light-diffusion agent is known (for example, refer patent document 3). However, in such an illuminating device, since a condensing lens is used, stray light and leakage light are generated, and illumination efficiency is low. Further, since the color unevenness is reduced by the content of the light diffusing agent, the color unevenness reducing effect and the light collecting effect are not compatible.

JP 2009-43611 A JP 2007-294379 A JP 2008-34321 A

  The present invention solves the above-mentioned problem, and aims to reduce the uneven color of the irradiated surface and prevent the reduction of the illumination efficiency due to the reduced uneven color in a lighting fixture having a light emitting diode element and a phosphor. And

In order to achieve the above object, the invention of claim 1 is a light emitting device comprising a light emitting diode element and a phosphor that receives light emitted from the light emitting diode element and converts the wavelength of part of the light to emit the light. and the diode package accommodating the light emitting diode package, a lighting fixture having a housing, a having an opening for irradiating the light emitted from the light emitting diode package is emitted from the front Symbol LED package An optical auxiliary member that receives light and expands and emits the light is provided only in the vicinity of the opening edge of the housing .

  According to a second aspect of the present invention, in the lighting apparatus according to the first aspect, a reflecting mirror that collects light emitted from the light emitting diode package and reflects the light toward the opening of the housing is provided in the housing. It is what.

  According to a third aspect of the present invention, in the lighting apparatus according to the first or second aspect, the optical auxiliary member is a concave lens.

  According to a fourth aspect of the present invention, in the lighting apparatus according to the first or second aspect, the optical auxiliary member includes a plurality of prisms.

  According to the invention of claim 1, a part of the light wavelength-converted by the phosphor is irradiated through the vicinity of the opening edge of the housing without being mixed with the light emitted from the light emitting diode element, Although it becomes light including color unevenness, since this light is expanded by the optical auxiliary member, the range irradiated with light that is not mixed is expanded. For this reason, the color contrast between the irradiation range of the light that is not mixed and the irradiation range of the mixed light is weakened and is difficult to be recognized by the human eye, and color unevenness is reduced. On the other hand, since the irradiated light cannot be expanded except in the vicinity of the opening edge of the housing, a reduction in illumination efficiency is prevented.

  According to the second aspect of the invention, in addition to the effect of the first aspect of the invention, the mixed color light of the light from the light emitting diode element and the light from the phosphor can be collected by the reflecting mirror.

  According to invention of Claim 3, since an optical auxiliary member has a concave curved surface, an irradiation surface outline can be made smooth and the appearance of an irradiation surface improves.

  According to the fourth aspect of the present invention, color unevenness is reduced without increasing the thickness of the optical auxiliary member as compared with the concave lens.

Sectional drawing of the lighting fixture which concerns on the 1st Embodiment of this invention. The enlarged view of the part A of FIG. Sectional drawing of the housing in the instrument. (A) (b) (c) is an end elevation which shows the example of a shape of the XX cross section of FIG. 3, respectively. The perspective view of an example of the housing in the instrument. The perspective view of an example of the light emitting diode package in the instrument. The perspective view of another example of the light emitting diode package in the instrument. Sectional drawing of the lighting fixture which concerns on the 2nd Embodiment of this invention. The perspective view of the lighting fixture which concerns on the modification of the embodiment. Sectional drawing of the lighting fixture which concerns on the 3rd Embodiment of this invention. The enlarged view of the part B of FIG. Sectional drawing of the prism in the instrument. Sectional drawing of the conventional lighting fixture. (A) is sectional drawing explaining the irradiation range by the instrument, (b) is a top view explaining the color nonuniformity by the instrument. Sectional drawing of another conventional lighting fixture.

(First embodiment)
A lighting apparatus according to a first embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 1 and 2, in the lighting fixture 1, a light emitting diode package 2 (hereinafter referred to as an LED package) is accommodated in a housing 3, and the housing 3 has, for example, a bottomed and uncovered cylindrical shape. A circular opening 31 in plan view for irradiating light emitted from the LED package 2 is provided. The LED package 2 includes a light emitting diode element 21 (hereinafter referred to as an LED element) and a phosphor 22 that receives light emitted from the LED element 21 and converts the wavelength of a part of the light to emit the light. In order to protect the inside of the housing 3, a translucent cover 4 is provided in the opening 31 of the housing 3. The translucent cover 4 is made of a transparent material having a high transmittance such as acrylic or glass. Further, a concave lens 5a is provided as an optical auxiliary member that emits light emitted from the LED package 2 in the vicinity of the opening edge of the housing 3 and spreads the light. In the present embodiment, the concave lens 5a is formed by forming the transparent cover 4 so that the thickness of the transparent cover 4 gradually increases from the center of the opening 31 of the housing 3 toward the opening edge. The translucent cover 4 may be omitted. In this case, a concave lens formed in an annular shape in plan view is provided in the vicinity of the opening edge of the housing 3 as an optical auxiliary member. In the present embodiment, the light distribution control member 6 is provided to face the opening 31. The light distribution control member 6 is made of a milky white plate or a glare cut plate, and is provided by an appropriate support member (not shown), controls the light distribution of light emitted from the LED package 2, and has a predetermined irradiation range. The brightness can be made uniform or the glare can be reduced. Depending on the lighting fixture, such a light distribution control member may be omitted. The cross-sectional hatching of the phosphor 22 and the translucent cover 4 is not shown.

  The LED element 21 is a blue LED element that emits blue light, and the phosphor 22 is a yellow phosphor that converts the wavelength of blue light into yellow light. Blue and yellow are in a complementary color relationship, and mixed light in which blue light and yellow light are mixed becomes white light. The LED package 2 includes a white LED in which the LED element 21 and the phosphor 22 are combined, and an electronic board (not shown) that supplies power to the LED element 21.

  The material of the housing 3 is preferably an insulating material having high strength, for example, plastic. As shown in FIG. 3, for example, the housing 3 has a bottom surface 33 and an inner surface 34, and has an opening 31 facing the bottom surface 33. It is desirable that a part of the bottom surface 33 and the inner side surface 34 of the housing 3 be coated with high reflectivity. In this embodiment, the shape of the casing 3 is a cylinder, that is, an axially symmetric shape as shown in FIG. 4A. However, even if it is a hollow rectangular parallelepiped as shown in FIG. It may be a hollow hexagonal column as shown in (c). The vicinity of the opening edge of the housing 3 is the vicinity of the housing end portion 32 in the opening 31. As shown in FIG. 5, the end portion 32 of the housing 3 may have a shape partially protruding from the housing body 35 for glare cutting.

  The LED package 2 has one white LED and is provided on the bottom surface 33 of the housing 3. In order to increase the brightness of the luminaire, the LED package 2 may have a plurality of white LEDs. When the LED package 2 has a plurality of white LEDs, as shown in FIG. The shape which accommodates white LED23 may be sufficient, and the shape which accommodates the LED package 2 whole may be sufficient as the housing 3 as FIG. 7 shows. When the housing 3 has a shape that accommodates each white LED 23, it is desirable to provide a concave lens 5 a corresponding to each white LED 23.

  Again, a description will be given with reference to FIG. The concave lens 5a refracts light by geometric optics. The shape of the concave lens 5a may be either a spherical surface or an aspherical surface, but the aspherical surface is desirable because it has a higher degree of design freedom, and the lens surface is usually formed on the surface on the light incident side from the LED package 2. The lens surface of the concave lens 5a is formed in a concave curved surface such that the incident angle of incident light smoothly changes in the radial direction of the concave lens 5a. The concave lens 5 a is provided in a region where a light ray locus L <b> 1 of blue light and yellow light out of the light emitted from the LED package 2 passes through the opening 31.

  In the luminaire 1 configured as described above, the light emitted from the LED element 21 is mixed with the light whose wavelength is converted by the phosphor 22 and is emitted as white light from the opening 31 of the housing 3. A part of the light whose wavelength has been converted by the body 22 is not mixed with the light emitted from the LED element 21, but passes through the vicinity of the opening edge of the housing 3 and is irradiated as yellow light. For this reason, the light irradiated from the lighting fixture 1 turns into mixed light which included the color nonuniformity of yellow light in white light. Compared with the case where the concave lens 5a is not provided (see FIG. 13), in the luminaire 1 of this embodiment, the light passing through the vicinity of the opening edge of the housing 3 is expanded by the concave lens 5a. On the irradiated surface or the like, the range 14 irradiated with yellow light is expanded (see FIG. 1). For this reason, the color contrast between the irradiation range 14 of yellow light that is not mixed and the irradiation range of white light that is mixed is weakened and is difficult to be recognized by the human eye, and color unevenness is reduced. On the other hand, since the irradiated light cannot be expanded except in the vicinity of the opening edge of the housing 3, the illumination efficiency can be prevented from being lowered. Moreover, since the concave lens 5a as an optical auxiliary member has a concavely curved lens surface, the contour of the irradiation surface can be made smooth, and the appearance of the irradiation surface is improved.

(Second Embodiment)
A lighting apparatus according to a second embodiment of the present invention will be described with reference to FIG. As shown in FIG. 8, the lighting fixture 10 of the present embodiment collects light emitted from the LED package 2 in the housing 3 in addition to the same configuration as that of the first embodiment, and the housing 3. A reflecting mirror 8 that reflects toward the opening 31 is provided.

  The reflecting mirror 8 is used for light control of white light emitted from the LED package 2, and is made of plastic or metal, and preferably has a highly reflective coating on the surface. Can be arbitrarily set. The surface shape of the reflecting mirror 8 has, for example, a parabolic shape with a focus on the vicinity of the LED package 2.

  In the lighting fixture 10 configured as described above, the range 14 irradiated with the yellow light of the light ray locus L1 in which the blue light and the yellow light are not mixed is expanded by the concave lens 5a, and the color unevenness is reduced. Further, the white light of the ray locus L10 in which blue light and yellow light are mixed is light-controlled, that is, condensed by the reflecting mirror 8. In FIG. 8, the illustration of the light ray locus L1 toward the lower left and the light ray locus L10 toward the lower right is omitted, but the light ray locus L1 and the light ray locus L10 exist symmetrically with respect to the optical axis of the LED package 2. .

  The lighting fixture which concerns on the modification of the 2nd Embodiment of this invention is demonstrated with reference to FIG. The lighting fixture 11 of this modification has a plurality of LED packages 2, and a concave lens 5 a and a reflecting mirror 8 are provided corresponding to each LED package 2. A plurality of sets of the LED package 2, the concave lens 5 a and the reflecting mirror 8 are arranged in a plane and accommodated in one housing 30. Thereby, since a light source is disperse | distributed to the some LED package 2, while a glare is suppressed, the brightness (luminous flux) of the lighting fixture 11 increases.

(Third embodiment)
A lighting apparatus according to a third embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 10 and 11, in the lighting fixture 12 of the present embodiment, a plurality of prisms 5b are provided as optical auxiliary members instead of the concave lens 5a of the first embodiment. For example, each of the plurality of prisms 5b is formed in the vicinity of the opening edge so as to be adjacent to each other in a concentric annular shape that is substantially similar to the opening 31 of the housing 3 in plan view, and the prism apex angle is the center of the housing opening 31 in cross-sectional view. The light emitted from the LED package 2 is directed to the prism slope.

  As shown in FIG. 12, it is desirable that the prism 5b has a shape in which the concave lens shape 51 is divided like a Fresnel lens to reduce the thickness.

  The luminaire 12 includes an optical auxiliary member composed of a plurality of prisms 5b, so that the optical auxiliary member does not become thicker than the concave lens, and the range in which the yellow light of the ray locus L1 in which blue light and yellow light are not mixed is irradiated. 14 is expanded by the prism 5b, and uneven color is reduced.

  In addition, this invention is not restricted to the structure of said embodiment, A various deformation | transformation is possible in the range which does not change the summary of invention. For example, in the first embodiment, the concave lens 5a has the concave lens surface formed on the surface on the side on which the light emitted from the LED package 2 enters, but the concave lens surface may be formed on the surface on the light output side. Good. In the third embodiment, the reflecting mirror 8 of the second embodiment may be further provided. The optical auxiliary member that expands and emits the incident light is not limited to the concave lens 5a or the prism 5b, and may be, for example, a GRIN lens that expands the light by a refractive index gradient, or a diffractive lens that expands the light by diffraction. There may be.

1, 10, 11, 12 Lighting fixture 2 Light emitting diode package (LED package)
21 Light-emitting diode elements (LED elements)
22 phosphors 3 and 30 housing 5a concave lens (optical auxiliary member)
5b Prism (optical auxiliary member)
8 Reflector

Claims (4)

A light-emitting diode package having a light-emitting diode element and a phosphor that receives light emitted from the light-emitting diode element and converts the wavelength of a part of the light,
A housing that houses the light emitting diode package and has an opening for irradiating light emitted from the light emitting diode package,
Luminaire light emitted from the front Symbol LED package is incident, characterized in that the optical auxiliary member is provided only on the opening near the edge of the housing for emitting expanded the light.   The lighting fixture according to claim 1, wherein a reflection mirror that collects light emitted from the light emitting diode package and reflects the light toward the opening of the housing is provided in the housing.   The lighting apparatus according to claim 1, wherein the optical auxiliary member is a concave lens.   The lighting apparatus according to claim 1, wherein the optical auxiliary member includes a plurality of prisms.

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