WO2010067817A1

WO2010067817A1 - Illumination apparatus

Info

Publication number: WO2010067817A1
Application number: PCT/JP2009/070600
Authority: WO
Inventors: 良二横谷
Original assignee: パナソニック電工株式会社
Priority date: 2008-12-09
Filing date: 2009-12-09
Publication date: 2010-06-17
Also published as: JP2010140674A; JP5167099B2

Abstract

An illumination apparatus is provided with an LED chip, a substrate on which the LED chip is mounted, a dome-shaped colour conversion member having an aperture, a vertex and optical transmissivity, and a reflective mirror. The colour conversion member contains fluorescent particles that emit yellow light when excited by blue light emitted from the LED chip. Also, the colour conversion member is mounted on the substrate in such a way that the aperture is blocked by the substrate and that the LED chip is arranged on the central axis (M) thereof passing through the vertex and the centre of the aperture. The reflective mirror has an internal face that is formed so as to open out from the base end to the leading end thereof. This internal face includes a curved surface of rotation that is formed by rotating part of a parabolic curve positioned outside the vertex about the central axis thereof. The parabola has a focal point that is positioned on the colour conversion member, which is disposed along the central axis, in the range from the vertex to the open end thereof but excluding the central axis. Consequently, colour unevenness produced by the optical illumination pattern can be reduced.

Description

Lighting device

The present invention generally relates to a lighting device, and more specifically, blue light emitted from a light emitting diode (LED) as a light emitting element and yellow light emitted from phosphor particles by being excited by the blue light are mixed. The present invention relates to an illumination device that emits white light.

Conventionally, various lighting devices including a light emitting element and a reflecting mirror for controlling the light distribution of the light emitted from the light emitting element have been provided. An example of this is published in Japan on November 30, 2001. It is described in Japanese Patent Publication No. 2001-332104. The inner surface of the reflecting mirror includes a parabola formed by rotating one parabola having a focal point at the position of the light emitting element about the axis of symmetry of the parabola, and is emitted from the light emitting element. Can be efficiently reflected in a desired direction.

Also, an example of this type of lighting device is shown in FIG. The illuminating device A 'includes an LED chip 1 that is a light emitting element that emits blue light, a substrate 2 on which the LED chip 1 is mounted, a color conversion member 4, and a reflecting mirror 8'.

The color conversion member 4 has translucency, and further contains phosphor particles that are excited by blue light emitted from the LED chip 1 and emit yellow light. The color conversion member 4 is formed in a dome shape having an opening and a vertex from a part of a hollow spheroid as shown in FIG. The color conversion member 4 is disposed on a central axis M1 in which the opening is closed by the substrate 2 and the LED chip 1 passes through the point P4 located at the apex and the point P6 at the center of the opening. Is mounted on the substrate 2 as described above.

As shown in FIG. 7, the reflecting mirror 8 ′ has an inner surface 8 b ′ formed so as to expand from the proximal end to the distal end, and the inner surface 8 b ′ is attached to the substrate 2 so as to surround the color conversion member 4. Installed. The reflecting mirror 8 ′ reflects the light emitted from the LED chip 1 through the color conversion member 4.

The inner surface 8b 'of the reflecting mirror 8' includes a paraboloid formed by rotating about a parabola having a symmetry axis that coincides with the central axis M1. The parabola has a focal point set at a point P1 that intersects the central axis M1 on the LED chip 1. Therefore, for example, as shown in FIG. 7, the light emitted from the LED chip 1 to an arbitrary point P3 on the surface of the color conversion member 4 is a point P2 where a straight line passing through the point P1 and the point P3 intersects with the inner surface 8b ′. (See arrow D11) and reflected in a direction along the central axis M1 (see arrow D12).

Here, the color conversion member 4 is formed in a dome shape from a part of an ellipsoid that is almost a sphere, and the point P1 is located at the center of the ellipsoid. Accordingly, the straight line passing through the points P1 and P2 substantially coincides with the normal extending from the point P3 with respect to the tangent plane at the point P3 on the surface of the color conversion member 4. Similarly, for a straight line passing through the point P1 and an arbitrary point on the inner surface 8b ', the straight line is an intersection (not shown) where the straight line on the surface of the color conversion member 4 and the color conversion member 4 intersect. It substantially coincides with the normal extending from the intersection with respect to the tangent plane at.

On the other hand, as shown in FIG. 7, light incident on the point P2 from the point P4 positioned at the vertex of the color conversion member 4 (see arrow D21) is reflected in a direction intersecting the direction along the central axis M1. (See arrow D22). Further, the light (see arrow D31) incident on the point P2 from the point P5 located near the opening end of the color conversion member 4 is also reflected in a direction intersecting with the direction along the central axis M1 (see arrow D32).

That is, in the overall light irradiation pattern irradiated forward from the illumination device A ′, light emitted in the direction of the arrow D11 and reflected in the direction of the arrow D12 is distributed at the center of the irradiation pattern. Is done. Further, light emitted in the direction of the arrow D21 and reflected in the direction of the arrow D22 or light emitted in the direction of the arrow D31 and reflected in the direction of the arrow D32 is distributed to the periphery of the irradiation pattern. The A straight line passing through the points P4 and P2 and a straight line passing through the points P5 and P2 extend from the points P4 and P5 with respect to the tangent plane at the points P4 and P5 on the surface of the color conversion member 4. Intersects without matching each normal.

The illumination device A ′ configured as described above irradiates white light by mixing the blue light emitted from the LED chip 1 and the yellow light excited by the blue light and emitted from the color conversion member 4.

Incidentally, the light emitted from the point P3 has different light distribution characteristics between blue light and yellow light as shown in FIG. Specifically, the light distribution characteristic is such that yellow light diffuses in a substantially circular shape (curve A in FIG. 8), whereas blue light has an elliptical shape with the major axis direction in the direction of arrow D11. Shows light distribution characteristics that extend (curve b). That is, among the light emitted from the point P3, the light emitted in the direction of the arrow D11 that coincides with the direction normal to the tangent plane at the point P3 has the highest blue light ratio. Conversely, the light emitted in the direction of the arrow D41 that does not coincide with the normal direction has a high proportion of yellow light. Thus, the ratio of the blue light to the light emitted in the direction coincident with the normal direction becomes higher because the blue light transmitted through the color conversion member 4 does not collide with the phosphor particles in the color conversion member 4. This is because many components are contained.

Therefore, in the irradiation pattern of the light irradiated as a whole from the illumination device A ′, the central part of the irradiation pattern has a blueish color, and the peripheral part of the irradiation pattern has a yellowish color. There was a problem that the color unevenness was conspicuous between the central part and the peripheral part.

Therefore, an object of the present invention is to provide an illuminating device that can reduce color unevenness generated in a light irradiation pattern.

The illuminating device of the present invention includes a light emitting element, a substrate on which the light emitting element is mounted, a dome-shaped color conversion member having an opening, an apex, and translucency, and a reflecting mirror. The color conversion member is mounted on the substrate such that the opening is closed by the substrate and the light emitting element is disposed on a central axis passing through the apex and the central portion of the opening. The color conversion member includes phosphor particles that are excited by light emitted from the light emitting element and emit light having a color different from that of the emitted light. The reflecting mirror has an inner surface formed so as to expand from the proximal end to the distal end. The reflecting mirror is mounted on the substrate such that the inner surface surrounds the color conversion member, and controls the light distribution of light emitted from the light emitting element through the color conversion member. In the first aspect of the present invention, the inner surface includes a rotating curved surface formed by rotating a part of a curve located outside the apex of one parabola around the central axis. The parabola has a focal point set at a position excluding the central axis between the apex of the color conversion member and the opening end along the central axis. In this invention, the parabola has a focal point set at a position excluding the central axis between the apex of the color conversion member along the central axis and the opening end, so It is possible to provide an illuminating device that can reduce color unevenness generated in an irradiation pattern.

In the second feature of the present invention, the focal point is set on a surface of the color conversion member or on a virtual curved surface along the surface inside the color conversion member. A normal extending through the focal point with respect to the tangent plane at the position is set so as to intersect the rotating curved surface. In the present invention, since the normal extending through the focal point is set so as to intersect the rotating curved surface, color unevenness occurring in the light irradiation pattern can be further reduced.

In one embodiment, the normal line is set to intersect the tip of the reflecting mirror. In this embodiment, since the normal is set so as to intersect the tip, it is possible to uniquely determine the most efficient external dimensions of the reflector that can improve color intensity and reduce color unevenness. Can be determined.

In the third feature of the present invention, the inner surface includes a plurality of rotating curved surfaces arranged so as to be adjacent to each other along the central axis. The plurality of rotating curved surfaces are respectively formed from a plurality of parabolas having focal points set at different positions between the apex of the color conversion member and the opening end. In this invention, the plurality of rotating curved surfaces are respectively formed from a plurality of parabolas having focal points set at different positions between the apex of the color conversion member and the opening end, so that the light irradiation pattern It is possible to provide an illuminating device that can more efficiently reduce uneven color.

In one embodiment, the plurality of rotating curved surfaces include a first rotating curved surface and a second rotating curved surface disposed adjacent to the first rotating curved surface on the tip side of the reflecting mirror. The first and second rotating curved surfaces are respectively formed from first and second parabolas having first and second focal points. The first focus is set closer to the vertex of the color conversion member than the second focus. In this embodiment, since the first focal point is set at a position closer to the vertex of the color conversion member than the second focal point, an illumination device capable of performing better light distribution is provided. be able to.

In one embodiment, the plurality of focal points are respectively set at positions on a surface of the color conversion member or on a virtual curved surface along the surface inside the color conversion member. A plurality of normals extending through the focal point with respect to the tangential plane at the position are set so as to intersect the plurality of rotating curved surfaces, respectively. In this embodiment, the plurality of normals extending through the focal point are set so as to intersect with the plurality of rotating curved surfaces, respectively, so that it is possible to further reduce the color unevenness generated in the light irradiation pattern. it can.

In one embodiment, a normal line corresponding to a focal point of a parabola that forms a rotation curved surface included in the tip of the reflecting mirror among the plurality of rotation curved surfaces is set to intersect with the tip. In this embodiment, the normal line corresponding to the focal point of the parabola that forms the rotation curved surface included in the tip of the reflecting mirror among the plurality of rotation curved surfaces is set so as to intersect with the tip. It is possible to uniquely determine the outer dimension of the reflecting mirror that is most efficient so as to reduce the color unevenness while improving the luminous intensity as described above.

Preferred embodiments of the invention are described in further detail. Other features and advantages of the present invention will be better understood with reference to the following detailed description and accompanying drawings.
1 shows Embodiment 1 of the present invention, FIG. 1A is a longitudinal sectional view, and FIG. 1B is a schematic diagram showing a partial section of the reflecting mirror of FIG. 1A. It is a front view except the transparent cover of Embodiment 1 of the present invention. It is a schematic diagram which shows the one part cross section of the reflective mirror of Embodiment 2 of this invention. It is a schematic diagram which shows the one part cross section of the reflective mirror of the modification of Embodiment 2 of this invention. It is a schematic diagram which shows the one part cross section of the reflective mirror of Embodiment 3 of this invention. It is explanatory drawing about Embodiment 3 of this invention. It is a longitudinal cross-sectional view of an example of the conventional illuminating device. It is explanatory drawing of an example of the conventional illuminating device.

(Embodiment 1)
Hereinafter, the first embodiment will be described with reference to FIGS. 1 and 2. For the sake of clarity, similar elements are assigned the same reference signs as the illumination device A ′ described in the background art.

The illumination device A of the present embodiment includes an LED chip 1, which is a light emitting element, a substrate 2, an optical member 3, a color conversion member 4, and a reflecting mirror 8, as shown in FIGS. In addition, the lighting device A includes a housing 6, an insulating sheet 7, a holding frame 9, and a transparent cover 10. However, the transparent cover 10 is not shown in FIG.

A GaN blue LED chip is used for the LED chip 1 of the present embodiment. Moreover, although the illuminating device A is provided with the single LED chip 1, it is not limited to this, You may provide the several LED chip 1. FIG.

The substrate 2 is made of an insulating ceramic substrate such as an alumina ceramic substrate or an aluminum nitride substrate. However, a glass epoxy resin substrate may be used in addition to the ceramic substrate. An energization wiring pattern (not shown) made of a metal material such as a copper material is formed on the front side of the substrate 2. The LED chip 1 is bonded to a die pad portion (not shown) formed of a part of the wiring pattern of the substrate 2 using various bonding materials such as solder and silver paste. The substrate 2 is fixed to the inner bottom portion 6d of the housing 6 with a plurality of fixing screws 61 together with the elastic insulating sheet 7 formed substantially in the same shape as the substrate 2. Here, for the insulating sheet 7, for example, an organic green sheet that is an epoxy resin sheet that is highly filled with fused silica to increase thermal conductivity is used. This organic green sheet has a characteristic that the resin fluidity during heating is high and the adhesion to the uneven surface is high. Therefore, it is possible to prevent a gap from being generated between the insulating sheet 7 and the substrate 2 and the inner bottom portion 6d.

The optical member 3 is for sealing the LED chip 1 mounted on the substrate 2 as shown in FIGS. 1A and 2. And since the optical member 3 is formed in convex lens shape with translucent sealing materials, such as a silicone resin, for example, it concentrates the blue light radiated | emitted from LED chip 1 toward the front.

As shown in FIGS. 1A and 2, the color conversion member 4 is formed in a dome shape having an opening and a vertex by dividing a hollow spheroid in half at the center in the major axis direction. The ratio of the major axis dimension to the minor axis dimension of the spheroid is set to 6: 5. However, the color conversion member 4 may be formed of a hollow sphere other than the spheroid.

The color conversion member 4 is translucent and contains phosphor particles that are excited by blue light emitted from the LED chip 1 and emit yellow light. More specifically, the color conversion member 4 is made of a mixed material made by uniformly dispersing the phosphor particles in a transparent silicone resin. The phosphor particles may be, for example, those that emit red light in addition to those that emit yellow light. Further, instead of the silicone resin, for example, epoxy resin, acrylic resin, polycarbonate, glass, or the like may be used.

The color conversion member 4 is disposed on a central axis M1 where the opening is closed by the substrate 2 and the LED chip 1 passes through the point P4 where the LED chip 1 is located at the apex and the point P6 at the center of the opening. As described above, the substrate is mounted on the substrate 2 with the major axis direction directed toward the central axis M1. In addition, the edge part of the said opening and the board | substrate 2 are adhere | attached with adhesive agents, such as an epoxy resin, for example.

An air layer 5 is provided between the optical member 3 and the color conversion member 4 as shown in FIG. 1A. Therefore, blue light that collides with the phosphor particles in the color conversion member 4 and is scattered toward the optical member 3 side, or yellow light that is emitted from the color conversion member 4 toward the optical member 3 side passes through the optical member 3. Thus, absorption by the substrate 2 or the like can be suppressed. In addition, since the air layer 5 is provided, the LED chip 1 and the optical chip can be used even when a part of the component comes into contact with the color conversion member 4 when the housing 6, the reflecting mirror 8, and the transparent cover 10 are attached. The impact transmitted to the member 3 can be reduced.

The reflecting mirror 8 has an inner surface 8b formed so as to expand from the proximal end to the distal end as shown in FIGS. 1A and 2. Further, an insertion port 8 a is provided through the base end of the reflecting mirror 8. The reflecting mirror 8 is mounted on the substrate 2 so that the inner surface 8b surrounds the color conversion member 4 by inserting the color conversion member 4 from the insertion port 8a with the base end side facing rearward. As a material of the reflecting mirror 8, a metal material having a high reflectance of light incident from the phosphor particles of the LED chip 1 and the color conversion member 4 such as aluminum is used. In particular, desired reflectivity is secured by evaporating aluminum, silver, or the like on the inner surface 8b of the reflecting mirror 8. In addition to the metal material, a highly heat-resistant resin or the like may be adopted as the material of the reflecting mirror 8.

The housing 6 is formed in a bottomed cylindrical shape having an opening on the front end side by a metal material such as aluminum as shown in FIG. 1A, and the LED chip 1, the substrate 2, and the reflecting mirror 8 are accommodated therein. In addition, a plurality of screw holes 6 c are formed in the vicinity of the front end of the side wall 6 b of the housing 6 over the entire circumference. The transparent cover 10 is formed in a disc shape having an outer diameter that is slightly larger than the inner diameter of the housing 6 by a light-transmitting material such as acrylic resin, polycarbonate, glass, or the like. The transparent cover 10 is placed on the outer flange portion 8c extending outward from the front end edge of the reflecting mirror 8. The holding frame 9 includes an annular portion 9a formed in an annular shape, and a protruding portion 9b that protrudes rearward from the rear surface of the annular portion 9a over the entire circumference of the annular portion 9a. However, the inner diameter of the annular portion 9 a is set smaller than the inner diameter of the housing 6, and the outer diameter is set larger than the outer diameter of the housing 6. Further, a plurality of screw insertion holes 9c are provided through the entire protrusion 9b.

Here, the front end of the side wall 6b of the housing 6 is fitted inside the protruding portion 9b in a state where the outer flange portion 8c of the reflecting mirror 8 and the transparent cover 10 are placed. The plurality of mounting screws 91 are inserted into the screw insertion holes 9c of the protruding portion 9b and screwed into the screw holes 6c of the side wall 6b, so that the holding frame 9 is attached to the housing 6. Further, the transparent cover 10 is mounted so as to be held between the holding frame 9 and the outer flange portion 8c so as to close the opening of the housing 6.

In the illumination device A configured as described above, the blue light emitted from the LED chip 1 and transmitted through the optical member 3 and the color conversion member 4 and the yellow light emitted from the phosphor particles of the color conversion member 4 are mixed. It is irradiated with white light.

As a feature of this embodiment, the inner surface 8b of the reflecting mirror 8 rotates a part of a curve located outside the point P7 located at the apex of the parabola Pa1 around the central axis M1 as shown in FIG. 1B. The rotation curved surface 8d formed by (1) is included. Here, the parabola Pa1 has a focal point F1 set at a position excluding the central axis M1 between the apex of the color conversion member 4 and the opening end along the central axis M1. 1B is a cross-sectional view schematically showing only the surface of the color conversion member 4 and the inner surface 8b of the reflecting mirror 8 on the right side of the central axis M1 of the illumination device A shown in FIG. 1A. The vertical axis in FIG. 1B coincides with the central axis M1, and the horizontal axis coincides with the direction orthogonal to the central axis M1. And the numerical value described in each of the vertical axis | shaft and horizontal axis | shaft of FIG. 1B represents the distance to each direction from the point P1 located in the center part of LED chip 1 which is an origin.

FIG. 1B shows the result of the simulation of the light path with respect to the inner surface 8b of the present embodiment formed in this way. Straight lines D1 to D6 in the drawing represent various light paths emitted from a position corresponding to the focal point F1 on the surface of the color conversion member 4 and incident on the inner surface 8b. However, the straight line D1 coincides with the normal direction extending through the focal point F1 with respect to the tangent plane at the focal point F1 on the surface of the color conversion member 4. Arrows D7 to D12 represent light paths when the various incident lights are reflected by the inner surface 8b.

From FIG. 1B, unlike the conventional illumination device A ′, not only light radiated in a direction coinciding with the normal direction (straight line D1) but also light radiated in a direction intersecting the normal direction (straight line D2). It can be seen that D6) are also reflected by the inner surface 8b in the direction along the central axis M1. Here, as described in the background art, among the light radiated from the focal point F1, the light having a route along the straight line D1 that coincides with the normal direction has the highest ratio of blue light, and conversely with the normal direction. The light emitted to the straight lines D2 to D6 that intersect without matching each other has a high ratio of yellow light. In particular, the ratio of the yellow light is the highest in the light that travels along the straight line D6 having the largest angle with the normal direction.

That is, as shown in FIG. 2, when the path that the focus F1 follows when the focus F1 is rotated about the central axis M1 is a circle X1, the inner surface 8b of the present embodiment radiates from a position corresponding to the circle X1. As a result, not only light with a high ratio of blue light but also light with a high ratio of yellow light can be reflected in the direction along the central axis M1. On the other hand, the light radiated from the position other than the circle X1 to the inner surface 8b is reflected in the direction intersecting with the central axis M1 as usual.

Therefore, the illuminating device A of the present embodiment conventionally has a ratio of yellow light distributed to the central portion of the irradiation pattern by the amount of light emitted from the position corresponding to the circle X1 on the surface of the color conversion member 4. It is possible to raise the ratio of the blue light distributed to the peripheral portion of the irradiation pattern from the conventional illumination device A ′. Thus, it is possible to reduce the difference between the ratio of blue light and yellow light in the central portion of the irradiation pattern and the ratio of blue light and yellow light in the peripheral portion, and to reduce the color unevenness that occurs in the irradiation pattern. it can. In the above description, the case where the focal point F1 is set on the surface of the color conversion member 4 is taken as an example. However, the present invention is not limited to this and may be set inside the color conversion member 4. Similar effects can be obtained.

(Embodiment 2)
The illuminating device A of this embodiment is demonstrated referring FIG. 3A and B. FIG. However, for the sake of clarity, the same reference numerals as those of the lighting device A of the first embodiment are assigned to similar elements. The illuminating device A of this embodiment is characterized in that it includes a reflecting mirror 80 having an inner surface 80b as follows. Here, FIGS. 3A and 3B are sectional views schematically showing only the surface of the color conversion member 4 and the inner surface 80b of the reflecting mirror 80 on the right side of the central axis M1 of the illumination device A of the present embodiment, as in FIG. 1B. is there.

The inner surface 80b includes first and second rotating

curved surfaces

82b and 83b arranged so as to be adjacent to each other along the central axis M1 as shown in FIG. 3B. However, the second rotating curved surface 83b is adjacent to the front end of the first rotating curved surface 82b. More specifically, first, as shown in FIG. 3A, first and second focal points F1 and F3 having different first and second focal points F2 and F3 set between the vertex of the color conversion member 4 and the opening end. There are two parabolas Pa2 and Pa3. Needless to say, at this time, the first and second focal points F2 and F3 are set at positions other than on the central axis M1. Then, as shown in FIG. 3A, the intersection of the first parabola Pa2 and the second parabola Pa3 is a point C1, the first parabola Pa2 is outside the vertex and inside the point C1 is a curve E1, and the second The outside of the parabola Pa3 from the point C1 is defined as a curve E2. By rotating these two curves E1 and E2 around the central axis M1, the above-described first and second rotating

curved surfaces

82b and 83b are formed.

FIG. 3B shows the result of the simulation of the light path with respect to the inner surface 80b of the present embodiment formed in this way. Straight lines G1 to G3 in the drawing represent light paths emitted from a position corresponding to the first focal point F2 on the surface of the color conversion member 4 and incident on the inner surface 80b. Further, straight lines G4 and G5 in the drawing represent light paths emitted from a position corresponding to the second focal point F3 on the surface of the color conversion member 4 and incident on the inner surface 80b. Arrows G6 to G10 represent light paths when the various incident lights are reflected by the inner surface 8b.

The light emitted from the first and second focal points F2 and F3 from FIG. 3B is incident on the first and second rotating

curved surfaces

82b and 83b on the inner surface 80b and travels in the direction along the central axis M1. It can be seen that it is reflected (see arrows G6 to G10). That is, when the first and second focal points F2 and F3 are rotated about the central axis M1, the first circle and the second circle follow the paths that the first and second focal points F2 and F3 follow, respectively (see FIG. The inner surface 80b of the present embodiment can reflect light emitted from positions corresponding to the first circle and the second circle in a direction along the central axis M1. . On the other hand, the light radiated from the position other than the first circle and the second circle to the inner surface 80b is reflected in the direction intersecting with the central axis M1 as usual.

Here, in the illumination device A, since the optical member 3 formed in a convex lens shape is disposed, the blue light emitted from the LED chip 1 is condensed forward. That is, the luminance of the illumination device A is lower as it is closer to the substrate 2 on the surface and inside of the color conversion member 4 and higher as it is closer to the top of the color conversion member 4.

Therefore, the amount of light reflected in the direction along the central axis M1 is increased in the illuminating device A of the present embodiment compared to the illuminating device A of the first embodiment, and blue light and yellow light in the central portion of the irradiation pattern are increased. The difference between the ratio and the ratio of the blue light and the yellow light in the peripheral portion can be further reduced, and the color unevenness generated in the irradiation pattern can be further reduced.

In the illumination device A of the present embodiment, the second focus F3 is set at a position closer to the vertex of the color conversion member 4 than the first focus F2 as described above. Therefore, the distance from the first and second focal points F2 and F3 to the corresponding first and second rotating

curved surfaces

82b and 83b can be kept small, and a better light distribution can be performed.

By the way, if only the outer dimensions of the color conversion member 4 are increased without changing the outer diameter of the tip of the reflecting mirror 8 of the first embodiment, the curvature of the parabola Pa1 increases. As a result, the position of the focal point F1 moves to the lower luminance side of the color conversion member 4, and the luminous intensity in the direction along the central axis M1 of the illumination device A decreases. On the other hand, if an attempt is made to increase the outer diameter of the color conversion member 4 while maintaining the position of the focal point F1 near the high luminance peak of the color conversion member 4, the curvature of the parabola Pa1 decreases, and as a result, the reflecting mirror 8 The overall external dimensions are increased.

However, the lighting device A of the present embodiment has first and second rotating

curved surfaces

82b and 83b. Therefore, when the outer dimensions of the color conversion member 4 are to be increased, the curvature of the first parabola Pa2 may be increased to decrease the curvature of Pa2 of the second parabola. That is, even if the position of the first focal point F2 moves to the lower luminance side, the position of the second focal point F3 can be maintained near the high luminance vertex of the color conversion member 4, and the illumination device A Can be suppressed. In addition, although the outer diameter of the second rotating curved surface 83b is larger than before increasing the outer dimension of the color conversion member 4, the outer diameter of the first rotating curved surface 82b can be reduced, so that The enlargement of the illumination device A can be suppressed.

The first and second focal points F2 and F3 described above are set on the surface of the color conversion member 4, but the same effect can be obtained even if they are set inside the color conversion member 4. Moreover, although the case where the above-mentioned inner surface 80b includes two rotating curved surfaces is given as an example, other than this, for example, three rotating curved surfaces or four rotating curved surfaces may be included. Furthermore, in addition to including a plurality of rotating curved surfaces, the inner surface 80b includes, for example, a rotating curved surface 83b and an inclined surface 84b extending straight from the rear end portion of the rotating curved surface 83b toward the substrate 2 as shown in FIG. But you can.

(Embodiment 3)
The illuminating device A of this embodiment is demonstrated referring FIG. However, for the sake of clarity, the same reference numerals as those of the lighting device A of the first embodiment are assigned to similar elements. The illuminating device A of the present embodiment is characterized in that it includes a reflecting mirror 8 having an inner surface 8b as follows. Here, FIG. 5 is a cross-sectional view schematically showing only the surface of the color conversion member 4 and the inner surface 8b of the reflecting mirror 8 on the right side of the central axis M1 of the illumination device A, as in FIG. 1B.

The inner surface 8b of the present embodiment is substantially the same as the inner surface 8b of the first embodiment, and includes a rotating curved surface 8d formed based on the parabola Pa1. As shown in FIG. 5, the tangent plane at the focal point F1 on the surface of the color conversion member 4 is defined as a surface Y1. Further, a normal line extending through the focal point F1 with respect to the surface Y1 is defined as a line H1.

Here, before explaining the operation of the present embodiment, the light intensity and color unevenness of the illumination device A will be described with reference to FIG. As described in the second embodiment, the luminance of the illumination device A including the convex lens-shaped optical member 3 is lower as it is closer to the substrate 2 on the surface and inside of the color conversion member 4 and is closer to the vertex of the color conversion member 4. high. Therefore, considering only increasing the luminous intensity of the illumination device A, it is desirable to place the focal point F1 at the apex of the color conversion member 4 as shown in FIG. However, in this case, only the light having a high yellow light ratio is reflected by the inner surface 8b and emitted in the direction along the central axis M1, so that the yellow light is easily collected at the central portion of the illumination pattern. As a result, uneven color occurs in the illumination pattern.

Further, light emitted from the apex of the color conversion member 4 toward the vicinity of the base end of the reflecting mirror 8 (see arrow D61 in FIG. 6) is not easily incident on the inner surface 8b by being blocked by the color conversion member 4 itself. Accordingly, when the focal point F1 is set at the apex of the color conversion member 4, the light distributed to the central portion of the illumination pattern may be reduced, resulting in a decrease in luminous intensity. For these reasons, in order to avoid coincidence between the focal point F1 and the vertex of the color conversion member 4, it is desirable that the normal line H1 extending from the focal point F1 is set to intersect at least the rotating curved surface 8d. . Similarly, for the inner surface 80b of the second embodiment, the two normals extending from the first and second focal points F2, F3 intersect with the corresponding first and second rotating

curved surfaces

82b, 83b, respectively. It is desirable that it is set to be.

On the other hand, the line H1 of the present embodiment is set not only to intersect the rotating curved surface 8d but also to intersect the tip 8e of the reflecting mirror 8 as shown in FIG. That is, the most effective external dimension of the reflecting mirror 8 that can reduce the color unevenness while uniquely improving the luminous intensity by setting the focal point F1 as close to the vertex of the color conversion member 4 as possible is uniquely determined. be able to.

When the focus F1 is set inside the color conversion member 4, a virtual curved surface including the position of the focus F1 and along the surface of the color conversion member 4 is set. The line H1 is defined as a normal extending through the focal point F1 with respect to the tangent plane at the position on the virtual curved surface.

Further, even when a plurality of rotating curved surfaces are included as in the inner surface 80b of the second embodiment, the normal corresponding to the second rotating curved surface 83b included in the tip 80e (see FIG. 3B) of the reflecting mirror 80 intersects the tip 80e. The same effect can be produced by setting so as to.

While the invention has been described in terms of several preferred embodiments, various modifications and variations can be made by those skilled in the art without departing from the true spirit and scope of the invention, ie, the claims.

Claims

A light emitting element;
A substrate on which the light emitting element is mounted;
A dome-shaped color conversion member having an aperture, an apex, and translucency, wherein the aperture is closed by the substrate, and the light emitting element is disposed on a central axis passing through the apex and the central portion of the aperture The color conversion member containing phosphor particles that are mounted on the substrate and are excited by light emitted from the light emitting element to emit light of a color different from the emitted light;
A reflecting mirror having an inner surface formed so as to expand from a base end to a tip end, the inner surface being mounted on the substrate so as to surround the color conversion member, and from the light emitting element through the color conversion member The reflector for controlling the light distribution of the emitted light, and
The inner surface includes a rotating curved surface formed by rotating a part of a curve located outside the vertex of one parabola around the central axis,
The parabola has a focal point set at a position excluding the central axis between the apex of the color conversion member and the opening end along the central axis.
The inner surface includes a plurality of rotating curved surfaces arranged to be adjacent to each other along the central axis,
The plurality of rotating curved surfaces are respectively formed from a plurality of parabolas having focal points set at different positions between the vertex of the color conversion member and the opening end. Lighting device.
The plurality of rotating curved surfaces include a first rotating curved surface and a second rotating curved surface disposed adjacent to the first rotating curved surface on the tip side of the reflecting mirror,
The first and second rotating curved surfaces are formed from first and second parabolas having first and second focal points, respectively.
The lighting device according to claim 2, wherein the first focus is set closer to the vertex of the color conversion member than the second focus.
The focal point is set on a surface of the color conversion member or on a virtual curved surface along the surface in the color conversion member;
The lighting device according to claim 1, wherein a normal extending through the focal point with respect to a tangential plane at the position is set to intersect the rotating curved surface.
The plurality of focal points are respectively set at positions on a virtual curved surface along the surface on the surface of the color conversion member or inside the color conversion member,
4. The illumination according to claim 2, wherein a plurality of normals extending through the focal point with respect to the tangential plane at the position are set so as to intersect the plurality of rotating curved surfaces, respectively. apparatus.
The lighting device according to claim 4, wherein the normal line is set so as to intersect the tip of the reflecting mirror.
6. The normal line corresponding to the focal point of a parabola that forms a rotation curved surface included in the tip of the reflecting mirror among the plurality of rotation curved surfaces is set so as to intersect the tip. The lighting device described.