JP2007080530A - Light-emitting diode luminaire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce dispersion of emission color as to an LED lighting fixture with a plurality of light-emitting diodes emitting white-color light as a light source. <P>SOLUTION: A white-color LED 1 each is apportioned to a plurality of groups against chromaticity coordinates of emission light, for instance, a total of five groups Ga, Gb, Gc, Gd, Ge whose chromaticity coordinates exist in areas near five chromaticity coordinates a to e. Then, if adjacent white-color LEDs 1 are selected and mounted on a printed wiring board 2, for instance, such a combination as groups Ga and Gc, or groups Gb and Gd, that fall in an area of the group Ge, light obtained by mixing of light emitted from the adjacent white-color LEDs 1, 1 gets closer to a targeted white-color light, so that dispersion of emission colors can be lowered. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an LED lighting apparatus using a plurality of light emitting diodes emitting white light as a light source.

2. Description of the Related Art Conventionally, there has been provided an LED lighting device including a plurality of light emitting diodes that emit white light, a printed wiring board on which the plurality of light emitting diodes are mounted, and an appliance body that houses the printed wiring board (for example, , See Patent Document 1).
JP 2005-19299 A

  By the way, there are individual differences in light emitting diodes that emit white light (hereinafter referred to as white LEDs), and variations in the color of the emitted light occur. Accordingly, when a plurality of white LEDs having a large degree of variation with respect to the target light color and shifted in the same direction are arranged adjacent to each other on the printed wiring board, the light emitted from these white LEDs is mixed. The light obtained in this way will deviate significantly from the target white color.

  This invention is made in view of the said situation, The objective is to provide the LED lighting fixture which can reduce the dispersion | variation in luminescent color.

  In order to achieve the above object, a first aspect of the present invention provides a plurality of light emitting diodes that emit white light, a printed wiring board on which the plurality of light emitting diodes are mounted, and an instrument body that houses the printed wiring board. The plurality of light emitting diodes substantially coincide with the target white chromaticity coordinates by color mixture from among a plurality of groups distributed by chromaticity coordinates in a predetermined color system. A set of light emitting diodes selected in (1) and (2) are arranged adjacent to each other on a printed wiring board.

  According to the first aspect of the present invention, the plurality of light emitting diodes substantially coincide with the target white chromaticity coordinate by color mixture from among a plurality of groups distributed by the chromaticity coordinate in the predetermined color system. Since the set of light emitting diodes selected as described above are arranged adjacent to each other on the printed wiring board, the light obtained by mixing the light emitted from these light emitting diodes is close to the target white light and emits light. Color variation can be reduced.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  The external appearance of the LED lighting fixture of this embodiment is shown in FIG. A plurality (36 in the illustrated example) of light emitting diodes (white LEDs) 1 are mounted in two rows on the surface of the printed wiring board 2 formed in the shape of a long strip, and these white LEDs 1 are connected. A conductive pattern (not shown) is formed, and white LEDs 1 adjacent in the longitudinal direction are arranged at equal intervals. On the back surface of the printed wiring board 2, circuit components such as a current limiting resistor are mounted.

  The instrument main body 3 for storing the printed wiring board 2 is formed in a long rectangular box shape with the front opening, and the opening portion is covered with a cover 4 made of a transparent resin molded product with the printed wiring board 2 stored. Blocked.

  Incidentally, the chromaticity coordinates (x, y) of the white LED 1 in a predetermined color system (for example, the XYZ color system) are regions (white regions) M corresponding to white in the xy chromaticity diagram of FIG. (See FIG. 1B). In other words, solids whose chromaticity coordinates fall within the white region M are selected from the manufactured white LEDs and used. The white area M is set to a rectangular area having the chromaticity coordinate e as a center and the four chromaticity coordinates a, b, c, and d as vertices. And in many white LED1 mounted in the printed wiring board 2, it is inevitable that the chromaticity coordinate of white light will vary in the white area | region M by the difference in a lot, individual differences, etc., for example, chromaticity coordinate When the white LEDs 1, 1 of a and b are mounted adjacent to each other on the printed wiring board 2, the chromaticity coordinates of the white light obtained by mixing the light emitted by the two white LEDs 1, 1 are from the target value e. There is a risk of color variations in the emitted light of the entire instrument due to a relatively large shift.

  Therefore, the chromaticity coordinates of the emitted light are examined for the white LED 1 to be used, and a total of five groups Ga, Gb, Gc in which chromaticity coordinates exist in a plurality of groups, for example, areas close to the five chromaticity coordinates a to e respectively. , Gd, Ge are assigned to each white LED 1. If the white LED 1 adjacent on the printed wiring board 2 is mounted by selecting a combination that enters the region of the group Ge by color mixing, for example, the group Ga and Gc or the group Gb and Gd, these adjacent LEDs The light obtained by mixing the light emitted from the white LEDs 1 and 1 is close to the target white light and can reduce variations in emission color.

It is explanatory drawing for demonstrating embodiment of this invention. It is a top view same as the above.

Explanation of symbols

1 White LED (light emitting diode)
2 Printed wiring board 3 Instrument body 4 Cover

Claims (1)

  In an LED lighting apparatus including a plurality of light emitting diodes that emit white light, a printed wiring board on which the plurality of light emitting diodes are mounted, and an instrument body that houses the printed wiring board, the plurality of light emitting diodes are: A set of light emitting diodes selected from a plurality of groups distributed by chromaticity coordinates in a predetermined color system so as to substantially match the target white chromaticity coordinates by color mixing is adjacent on the printed wiring board LED luminaire characterized by being arranged as follows.

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