JP2005306189A - Light source unit and lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light source unit for reducing distribution irregularity of an optical characteristic. <P>SOLUTION: The light source unit 16 comprises a substrate 18, a plurality of LEDs 20 for emitting light of an optical characteristic distribution pattern. The plurality of LEDs 20 are arranged uniformly on a circle 26 about the optical axis 24 of the lighting device on the substrate 18, and mounted radially about the optical axis 24 of the lighting device. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light source unit including a substrate and a plurality of light emitters arranged on the substrate, and an illumination device using the light source unit.

  For example, an illuminating device such as a map lamp for illuminating a vehicle interior is composed of a light source unit, a lens, a housing, and the like. In many cases, a light source unit, which is a light source of the illumination device, includes a substrate on which a plurality of light emitters such as LEDs (Light-Emitting Diodes) and LDs (Laser Diodes) are arranged. In this light source unit, a plurality of light emitters are evenly arranged on a circle centered on the optical axis of the illumination device. At this time, the light emitters are regularly arranged in the same direction. This facilitates the design of the wiring pattern of the substrate and the mounting work of the light emitter.

JP 2002-374004 A JP-A-6-76049

  However, light emitters such as LEDs and LDs have a non-uniform distribution of various light characteristics such as illuminance and chromaticity, and the distribution pattern often has a predetermined directionality. Therefore, if all the light emitters are arranged in the same direction, the directionality of the light characteristic distribution pattern is promoted, and unevenness in the light characteristic distribution in the entire light source unit is likely to occur.

  In order to solve this problem, Patent Literature 1 and Patent Literature 2 disclose a light source unit in which each LED is rotated and arranged on a substrate. However, these are all arranged in an array of a large number of LEDs, and cannot be applied to a light source unit in which each of the light emitters described above is rotated around the optical axis of the light source unit.

  Accordingly, an object of the present invention is to provide a light source unit in which uneven distribution of light characteristics is reduced, and an illumination device using the light source unit.

  The light source unit of the present invention is a light source unit of an illumination device including a substrate and a plurality of light emitters having a predetermined light characteristic distribution pattern, wherein the plurality of light emitters are arranged on the substrate with light from the illumination device. It is arranged uniformly on a circle centered on the axis, and is attached radially about the optical axis of the illumination device.

  In a preferred embodiment, the light emitter is an LED. Preferably, the LED is a 2IN1 chip LED in which two LED elements are provided in one package.

  Another illumination device according to the present invention uses any one of the above-described light source units.

  Here, the light characteristics indicate various characteristics relating to light such as illuminance (light intensity), chromaticity, and directivity. The lighting device refers to all lighting devices that use a light source unit including a plurality of light emitters as a light source, such as a map lamp and a room lamp used in a vehicle.

  According to the present invention, each light emitter cancels out uneven distribution of optical characteristics. Therefore, it is possible to reduce uneven distribution of light characteristics of the light source unit and the illumination unit using the light source unit.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a top view and a side view of a map lamp 10 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line AA in FIG.

  The map lamp 10 is an illuminating device that is attached to the ceiling of the vehicle compartment and illuminates the vehicle interior. The map lamp 10 includes a light source unit 16 having three LEDs 20, three lenses 14 provided corresponding to the three LEDs 20, a cover body (not shown) covering the three lenses 14, and And a housing 12 to be held.

  The light source unit 16 includes a substrate 18 and three LEDs 20 arranged on the substrate. As will be described in detail later, the LEDs 20 are arranged radially about the optical axis 24 of the map lamp 10.

  The three lenses 14 are provided corresponding to the respective LEDs 20 and guide light from the respective LEDs 20. That is, the three lenses 14 are also arranged on the substrate 18 radially with the optical axis 24 of the map lamp 10 as the center. Each lens 14 has a convex spherical top surface, and a concave portion 14a straddling the LED 20 is formed on the bottom surface. Further, a cover body (not shown) is provided on the upper part of the three lenses 14. The cover body is a substantially circular member, and is formed of a transparent material such as transparent plastic. The light that has passed through the lens 14 passes through the cover body and reaches the interior of the vehicle interior.

  The light emitted from each LED 20 is guided to the vehicle interior through the lens 14 and the cover body. At this time, the light emitted from the LED 20 is slightly diffused by the lens 14 and the cover body, but basically reaches the vehicle interior with the same light characteristic distribution as that emitted from the LED 20. Therefore, it can be said that the light characteristic distribution of the entire map lamp 10 is basically similar to the light characteristic distribution in the light source unit 16.

  The housing 12 is a member that holds the light source unit 16, the lens 14, and the cover body, and a foot portion 12 a for fixing the light source unit 16 and the lens 14 is formed on the bottom surface thereof. The entire map lamp 10 is attached to the passenger compartment ceiling.

  Next, each LED 20 will be described with reference to FIG. The LED 20 used in the present embodiment has a rectangular shape when viewed from above, and a light emitting chip 20a is disposed at the center thereof. A reflector cone is disposed outside the light emitting chip. Furthermore, they have a structure in which they are molded in a cylindrical shape with a transparent resin, and the top part is a lens shape. The light emitting chip 20a is substantially circular when viewed from the upper side, that is, the light emitting side, and electrodes 20b (hatched portions in this figure) are provided at two corners on the diagonal line. And the part except an electrode among the upper surfaces of the light emitting chip 20a becomes the light emission part 20c. For this reason, this LED 20 has a substantially elliptical light emission pattern in which two circles centering on two light emitting portions 20c overlap each other (see FIG. 3B). Accordingly, the distribution of various light characteristics such as light intensity and chromaticity is a distribution corresponding to the substantially elliptical shape. In other words, it can be said that the light characteristic distribution of the light emitted from the LED 20 has a predetermined direction when viewed from the top.

  In the conventional light source unit 16, as shown in FIG. 7, the LEDs 20 are all attached to the substrate 18 in the same direction. That is, when viewed from the top, the three LEDs 20 are arranged at equal positions on a circle 26 centered on the optical axis 24 of the map lamp 10. In addition, the arrangement angles of the LEDs 20 at that time were all the same. In other words, the light characteristics of the LEDs 20 were all distributed in the same direction. For this reason, the light emitted from the LED 20 has been promoted in the directionality of the optical characteristic distribution. As a whole, the map lamp 10 has a problem of uneven illuminance and uneven chromaticity. In particular, when a 2IN1 chip LED in which a plurality of LED elements are provided on a single chip is used as the LED, this problem is remarkable.

  Therefore, in the present embodiment, as shown in FIG. 4, the LEDs 20 are arranged at different angles around the optical axis 24 so as to cancel each other's light emission patterns. That is, the three LEDs 20 are evenly arranged on a circle 26 centered on the optical axis 24 of the map lamp 10, and each LED is made radial with respect to the optical axis 24. In other words, each LED 20 is arranged at an angle such that its long axis always faces the optical axis 24 of the map lamp 10. Specifically, the three LEDs 20 are arranged on a circle centered on the optical axis 24 of the map lamp 10 at intervals of 120 degrees (360/3), and the arrangement angle of each LED 20 is inclined by 120 degrees in order. doing.

  By using such an arrangement position and an arrangement angle, the directivity of the optical characteristic distribution can be canceled out. That is, by changing the arrangement angle of the LED 20, the direction of the light characteristic distribution also changes, and the light characteristic distribution of the entire map lamp 10 becomes non-directional. Furthermore, the light emitted from each LED 20 cancels the directionality of the light characteristic distribution with each other, and the illuminance unevenness and chromaticity unevenness of the map lamp 10 as a whole are reduced. That is, by using the light source unit 16 of the present embodiment, it is possible to obtain an illumination device that has no unevenness in various light characteristic distributions such as illuminance and chromaticity.

  As described above, according to the present embodiment, it is possible to reduce unevenness in various light characteristics such as illuminance and chromaticity of the map lamp 10. In the present embodiment, the map lamp 10 is used, but other lighting devices may be used as long as the lighting device uses the light source unit 16. Moreover, although LED is used as the light emitter of the light source unit 16, other light emitters such as LD (Laser Diode) may be used.

  Furthermore, in the present embodiment, three LEDs as light emitters are used, but a larger number of LEDs may be used. That is, as shown in FIG. 5, four, five, and six LEDs 20 may be provided on one substrate 18. Even in that case, the LEDs 20 are evenly arranged on a circle centered on the optical axis 24 of the lighting device, and the arrangement angles of the LEDs 20 are arranged so as to correspond to the arrangement positions. By doing so, the unevenness of the optical characteristics can be reduced.

  In the present embodiment, the major axis of each LED is directed to the optical axis of the illumination device. However, as shown in FIG. 6, the minor axis of each LED 20 is directed to the optical axis of the illumination device. You may do it. In the present embodiment, the LEDs are evenly arranged on one circle centered on the optical axis, but may be evenly arranged on a plurality of circles having different diameters centered on the optical axis. Good.

It is the upper side figure and side view of the map lamp which are embodiment of this invention. It is AA sectional drawing in FIG. It is a figure which shows the upper side figure and light emission pattern of LED which are used by this Embodiment. It is a schematic top view of a light source unit. It is a schematic top view of the light source unit which is other embodiment. It is a schematic top view of the light source unit which is other embodiment. It is a schematic top view of the conventional light source unit.

Explanation of symbols

  10 map lamp, 12 housing, 14 lens, 16 light source unit, 18 substrate, 20 LED, 24 optical axis.

Claims (4)

A substrate,
A plurality of light emitters having a predetermined light characteristic distribution pattern;
A light source unit of a lighting device comprising:
The light source unit is characterized in that the plurality of light emitters are uniformly arranged on a substrate on a circle centered on the optical axis of the illumination device, and are mounted radially on the optical axis of the illumination device. The light source unit according to claim 1,
The light source is a light source unit characterized by being an LED. The light source unit according to claim 2,
The LED is a 2IN1 chip LED in which two LED elements are provided in one package.   The illuminating device using the light source unit of any one of Claim 1 to 3.

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