JP2013114965A - Led lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To alleviate color unevenness at an edge part of a pattern area, particularly seen when an irradiation pattern area is observed, in a lighting device structured to use a light guide member for mixing LED light of different emission colors.SOLUTION: In a far field region where irradiation patterns superpose each other by transition of alignment of LEDs as light irradiation sources for each irradiation pattern using a plurality of light guide members, feeling of color unevenness is alleviated as each irradiation pattern compensate lacking light colors for the other in light color mixing shortage areas at an edge part of each irradiation pattern area.

Description

  The present invention relates to an LED lighting device created by a combination of a plurality of emission colors.

In recent years, lighting devices that can change the color temperature (hereinafter, abbreviated as a color temperature variable lighting device) have been put on the market taking advantage of the fact that LEDs can be easily dimmed and controlled to blink. The variable color temperature illumination device combines the light of two types of white light sources, a high color temperature light source and a low color temperature light source, which are a combination of a blue LED and a phosphor, and adjusts the mixed light state of both to follow the black body locus. In general, it can be changed.
Further, there is a method of obtaining white by mixing light emission colors using red, green and blue LEDs which are the three primary colors of light. Although this method has a missing spectral component (yellow) in part, any color can be obtained by adjusting the amount of light of each LED, which is used for effect lighting.

In the above-described color temperature variable illumination device, the light source size becomes large because a plurality of LED light sources are used, so that the light mixture state tends to be insufficient, and the desired illumination light color cannot be obtained depending on the position and distance of the irradiation target. There is.
Therefore, in order to satisfy a desired light source size according to the optical system constituting the color temperature variable illumination device, a plurality of LED chips having different color temperatures or light colors are contained in one package to form a multi-package, and one light emitting source Are used as a color tone variable light source.

  However, since the color-tunable light source using the multi-package is generally used by providing a light diffusing means inside and outside the package in order to improve color mixing, the light loss often increases. Further, when a variable color temperature lighting device is prepared by arranging a plurality of multi-package color-tunable light sources, due to variations in LED elements, individual color correction (driving conditions are set for each of the multi-package color-tunable light sources). The current situation is that it is necessary to adjust the color and unify the colors.

  Therefore, a single package (a package containing only one LED chip) for each color temperature or light color applying binning (selection for color variation between package solids and light intensity variation of LED elements) performed by an LED supplier. If an LED light source can be used to achieve a variable color temperature lighting device that sufficiently ensures color mixing, the aforementioned light loss can be reduced, and the LED light sources for each color can be individually selected and combined. The color correction work of the above-described color temperature variable illumination device should be easy.

  In Patent Document 1, a light emitting unit having a plurality of LED light sources by a combination of an LED element and a phosphor so as to emit light of different colors is used without using a complicated driving method, and the color of the combined light from the plurality of light sources. A light emitting device capable of controlling temperature is disclosed. The light-emitting device has a plurality of single-package LEDs arranged on a substrate on which electrical wiring is patterned. As described above, the light-emitting device can be selectively mounted based on binning with respect to variations in emission color and luminous intensity. It seems to be easy to adjust.

JP 2008-283155 A

  However, when the light-emitting device according to Patent Document 1 is used for illumination, an equivalent light source size as an illumination light source is increased because of the configuration in which the combined light from the plurality of LED light sources on the substrate is irradiated. Color unevenness may occur on the irradiated surface. In particular, when the light distribution angle of the light emitting part is narrowed and applied to a spotlight or the like, it is very difficult to suppress color unevenness within the irradiated range even if the light distribution is controlled using an optical member. turn into.

  The present invention has been made in view of the above problems, and the object of the present invention is to use a plurality of single-package LED light sources of different emission colors and mix the light to adjust the color. In the color temperature variable illumination device, it is intended to reduce color unevenness in the pattern area, which is observed particularly when the irradiation pattern area is observed.

In order to achieve the above object, according to the first aspect of the present invention,
n is an integer of 3 or more,
A set of LEDs is formed by being adjacently arranged on the substrate so that the center of the light emitting portion of each of the n LEDs having different emission wavelength distribution characteristics is located at the apex of the regular n-gon,
On the substrate, there are n sets of LED groups of the organization, and the n sets of LED groups are distributed and arranged so that the LED arrangement center point S is located at the apex of the regular n-gon,
n light guide members are arranged in front of the LED irradiation direction in each of the LED groups, and the light guide member is connected to one bar-shaped light guide trunk and one end of the light guide trunk. And n light guide branches connected to the light guide branch,
The n light guide branches are uniformly inclined to the light guide branch with respect to the central axis of the light guide trunk, and the center of the incident surface coincides with the center of the light emitting part of each of the n LEDs constituting the LED group. To counter,
The other end portion of the light guide trunk portion is configured to oppose the incident portion of the light distribution control means as a light exit surface, and is an LED illumination device of a type that irradiates the light emission colors of each LED by mixing colors. Yes,
The above-described object is achieved by providing the LED lighting device characterized in that the n LEDs in each LED group are set so that their positional relationship satisfies the following condition (a) or (b). The
(A) The n LEDs in each LED group, including the positional relationship with each other, are arranged to rotate by [2π / n] ° with respect to the dispersion center point P of the LED group.
(B) The positional relationship of the n LEDs in each LED group is the n sets of LED groups that are dispersedly arranged while maintaining the positional relationship of the n LEDs in each LED group defined in the condition (a). Arrangement of at least two arbitrary LED groups is equivalent to the arrangement replaced by translation while maintaining the positional relationship of the LEDs.

According to invention of Claim 2 of this invention,
In the planar illumination device formed by arranging a plurality of LED illumination devices according to claim 1 as a structural unit so that the light irradiation surfaces are in the same plane in a staggered pattern,
n is 3, 4 and 6
A regular n-gon shape connecting the LED arrangement center points S of the n LED groups distributed and arranged in the LED illumination device;
There is a congruent relationship between two or three adjacent LED illuminating devices, and a regular n-gon shape connecting the LED arrangement center points S of n groups of LED groups approaching near the center between the LED illuminating devices, The planar illumination device is characterized in that the arrangement interval between the LED illumination devices is determined so that the regular n-gons thereof are plane-filled, and thus a planar shape using a plurality of the LED illumination devices. An illuminating device can be provided, which has an advantage that color unevenness can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, it can provide the LED lighting apparatus which is excellent in color rendering property and has few color nonuniformity.

FIG. 1 is a diagram showing an LED arrangement in each LED group according to the present invention. FIG. 2 is a diagram showing the arrangement of each LED group on the substrate of the illumination device of FIG. 6 according to the present invention. FIG. 3 is a diagram showing an example in which the LED arrangement in FIG. 2 is changed. FIG. 4 is a diagram schematically showing the positional relationship between the LED groups on the substrate according to the present invention, each LED arrangement for knitting the LED groups, and the irradiation pattern of each LED irradiated on the screen. FIG. 5 is a diagram illustrating an example of LED arrangements for knitting LED groups and LED groups on a substrate arranged according to the present invention according to conditions different from those in FIG. 2. FIG. 6 is a perspective view showing an example of the illumination device of the present invention. FIG. 7 is a schematic cross-sectional view showing the internal configuration of the illumination device of FIG. FIG. 8 is a diagram showing an example of LED groups on the substrate of the lighting device of FIG. FIG. 9 is a perspective view showing a light guide member of the illumination device of FIG. 10A and 10B are diagrams illustrating the light guide member of FIG. 9, in which FIG. 10A is a front view and FIG. 10B is a side view. FIG. 11 is a diagram for explaining an example of the shape of the light guide branch entrance surface in the light guide member of FIG. 9. FIG. 12 is a perspective view of a light distribution control lens array of the illumination device of FIG. FIG. 13 is a perspective view of a light distribution control lens on the surface side opposite to FIG. FIG. 14 is a diagram illustrating an example of a drive unit in the illumination device. FIG. 15 is a diagram schematically showing an irradiation pattern from a set of LED groups. FIG. 16 is an example in which a planar illumination device is constructed using a plurality of illumination devices according to the present invention, and is a diagram clearly showing only the LED arrangement as seen from the irradiation direction. FIG. 17 is an example in which a planar lighting device is constructed based on the present invention, in which the lighting device used in the example of FIG. 16 is changed in the number of LED groups mounted on the substrate and the number of LEDs. It is the figure which clarified only the LED arrangement | positioning seen from.

  The basic configuration of the lighting device according to the present invention is a rod-shaped light guide having a plurality of light guide branches for enhancing the color mixing of light from a plurality of LED light sources having different emission colors (hereinafter referred to as LEDs). Each light guide branch and each LED are individually coupled using an optical member to emit mixed color light. Hereinafter, the basic mechanism and function of the present lighting device and the features according to the present invention will be described in detail with reference to the drawings.

  FIG. 6 is a perspective view showing an example of a lighting device according to the present invention, and FIG. 7 is a schematic cross-sectional view showing an internal configuration of the lighting device 1 of FIG. The illuminating device 1 is an illuminating device capable of toning a plurality of LEDs of different emission colors. In this example, the color is adjusted by receiving a power supply and an LED drive control signal from the outside.

  The illuminating device 1 also serves as a substantially cylindrical housing 40 having an enlarged inner diameter in the irradiation direction, a light distribution control lens array 60 that also serves as a front cover provided on the front surface of the housing 40, and a radiator on the rear surface of the housing 40. And a cable 70 for connecting from the radiator 50 to an external power source and a drive signal supply source. Inside the housing, the light source 20, the substrate 11 on which the light source 20 is mounted, the light guide member 30 provided in front of the light source in the irradiation direction, the light distribution control lens array 60 incorporating the prism portion 63, and the light guide. The holding member 12 for supporting the member 30 is accommodated. The light source 20 is a plurality of single package LEDs mounted on the substrate 11. In order to suppress the generation of electromagnetic interference waves, it is desirable that an LED driver for driving each LED and a drive unit such as a DC / DC converter are mounted on the substrate 11 (not shown). The heat generated by each LED is transferred to the radiator 50 through the substrate 11 by the radiator 50 that also serves as a lid portion provided on the back surface of the substrate 11, and is dissipated into the air.

  FIG. 8 is a front view of the board 11 when the board 11 on which the light source 20 is mounted is viewed from the irradiation direction of the lighting device, that is, from the left-hand side of FIG. The substrate 11 is a metal base substrate having a shape substantially matching the internal cross-sectional shape of the mounting position in the housing 40, and is made of aluminum or copper as a base metal, and an insulating layer and a conductor wiring layer having a predetermined pattern are laminated on the component mounting surface. This is a so-called metal base circuit board. In this example, it is circular. A plurality of single package LEDs 21, 22, and 23 are mounted on the component mounting surface side that is the light irradiation direction side of the substrate 11, and are electrically connected to the conductor wiring layer.

  The LED includes a first LED 21, a second LED 22, and a third LED 23 that form one LED group 25, and three sets of LED groups 25 are mounted on the substrate 11. Therefore, a total of nine LEDs are mounted. Note that the single package LED to be used is a surface mount type LED, and in order to increase the coupling efficiency with the light guide member 30, it is preferable to have a light emission opening above the mounting surface like a PLCC package product.

In FIG. 8, a dark color resist or silk printing is applied to the component mounting surface side of the substrate 11. By covering the conductor wiring layer and the insulating layer, stray light reaching the surface of the substrate 11, that is, light with insufficient mixed light leaking from the surface of the light guide member 30 or the coupling portion between the light guide member and each LED, covers the entire surface. The light is reflected in the direction of 43 and enters the illumination light through the light distribution control lens 60, thereby preventing deterioration in illumination quality.

Various combinations of the emission colors of the LEDs 21, 22, and 23 in FIG. 8 are possible.
For example, it is assumed that the LEDs 21, 22, and 23 emit red, green, and blue light emission colors that are the three primary colors of light. Red, green, and blue are AlGaInP-based red light emission, and each LED may emit light at a wavelength specific to the band gap of the substrate material used for each, such as a combination of InGaN-based green and blue. If the three types of phosphors of red, green, and blue are excited using radiant light (or near-ultraviolet rays), the electrical characteristics of the LEDs 21, 22, and 23 can be substantially uniform, and LED driving From a viewpoint, it is superior.

  As another example, the first LED 21 is a pseudo white light emitting LED having a color temperature of 3000K, for example, and the second LED 22 is a pseudo white light emitting LED having a color temperature of 6500K, for example. The LED 21 and the LED 22 are both mounted with a blue light emitting LED chip with an InGaN-based semiconductor light emitting layer, and the blue light emitting LED chip is covered with a mold resin mixed with a yellow fluorescent material, so that the blue light from the semiconductor light emitting layer and the phosphor The pseudo white light is irradiated by the synthesis of yellow light. The difference in color temperature is created by making a difference in the emission wavelength distribution of the InGaN-based blue light-emitting element, the mixing ratio of the phosphor, the spectral characteristics of the phosphor, and the like. For example, a red LED is used as the third LED 23. This is to compensate for the spectrum of the red region, which tends to be deficient in pseudo white in the LEDs 21 and 22. A red light emitting LED chip with an AlGaInP-based semiconductor light emitting layer is mounted as the red light emitting LED 23, and the red light that covers the red light emitting LED chip with a molding resin is irradiated.

  9 and 10 show the light guide member 30 disposed in front of the light source 20 in the irradiation direction, omitting the substrate fixing portion (flange portion). The light guide member 30 includes a columnar light guide trunk 35, a light guide branch 34, and three light guide branches 31, 32, 33, and is integrally formed of a transparent resin such as an acrylic resin. The ends of the light guide branches 31, 32, 33 are the light guide branch entrance surfaces 36, 36, 36 facing the LEDs 21, 22, 23, and the ends of the light guide trunk 35 are the light guide trunk exit surface 37. The light emitted from the LEDs 21, 22 and 23 incident on the optical member 30 is irradiated. As shown in FIG. 10A, the light guide branches 31, 32, 33 are arranged so that the centers of the three incident surfaces 36 face each other in accordance with the arrangement of the emission centers of the LEDs 21, 22, 23 described above.

Each light guide branch entrance surface 36 improves the coupling efficiency with the LEDs 21, 22, 23, adjusts the refraction direction with the center as a convex shape, and forms a reflecting prism portion around it, thereby tilting the central convex portion The device has been devised to solve the problem that the reflected light component increases and the internal capture decreases with the surface as it is.
Specifically, as shown in FIG. 11, the first LED 21 includes a first incident surface 36a corresponding to the center of the first LED 21 to the outer periphery of the element, and a reflecting prism portion on the outer peripheral side of the first incident surface 36a. The first incident surface 36a is an inclined surface whose center, that is, the optical axis side of the LED 21, is a distance close to the LED 21 and is a distance away from the LED 21 toward the outer peripheral side of the LED 21. The traveling direction of light incident from the first incident surface 36a is adjusted by appropriately adjusting the tilt angle. In this example, the inclination angle is set so that the refraction angle proceeds substantially parallel to the central axis of the light guide branch 31. The reflecting prism portion is composed of a second incident surface 36b and an inclined reflecting surface 36c. The second incident surface 36b is substantially parallel to the optical axis of the LED element 21, and a part of the direct light from the LED element 21 and a part of the reflected light from the first incident surface 36a are incident thereon. The inclined reflecting surface 36c is an inclined surface having the same inclination direction as that of the first incident surface 36a. The light incident on the second incident surface 36b travels toward the inclined reflecting surface 36c, and is an angle that becomes a reflecting surface that reflects on the inclined reflecting surface 36c in a direction parallel to the central axis of the light guide branch 31. And The inclined reflecting surface 36c is preferably a reflecting surface using internal reflection based on Snell's law, but a reflecting film may be provided on the surface. That is, in the light guide branches 31, 32, and 33, the internal reflection is reduced by moving straight in parallel with the respective central axes as much as possible.

The light from the LED incident from the light guide branch entrance surface 36 travels through the light guide branches 31, 32, 33 to the light guide branch 34, and the emission colors of the LEDs are mixed. Since the central axis of the light guide trunk 35 and the central axes of the three light guide branches 31, 32, 33 are not parallel but are integrated with a predetermined inclination angle, in the light guide trunk 35, The light incident on the light guide trunk travels while repeating internal reflection.
Thereby, the irradiation light of three LED 21,22,23 is mixed substantially uniformly.

  The cross-sectional shapes of the light guide trunk 35 and the light guide branch 31 are preferably cylindrical as much as possible. When the light guide member is formed by injection molding, the parting line at the time of injection molding is arranged to be avoided from the side surfaces of the light guide trunk 35 and the light guide branch 31 in order to reduce reflection loss on the inner wall. If the die cutting direction is set in the longitudinal direction of the light guide trunk, if the diameter of the exit surface of the light guide trunk becomes too small due to the drafting process, the parting line is formed on the side surface and cutting is performed. It is preferable to perform finishing by polishing.

  Furthermore, depending on the three-pronged structure by the light guide branches 31, 32, 33, if it cannot be molded by injection molding due to the problem of undercut processing, it is created using cast molding. In this case, a transparent epoxy resin as well as acrylic is a preferable option in terms of optical characteristics.

  12 and 13 show perspective views of a light distribution control lens array 60 incorporating a plurality of prisms as light distribution control means. The examples shown in FIGS. 12 and 13 are not necessarily indispensable requirements for the present invention, but a light distribution control means that takes into account the coupling efficiency with respect to the optical system using the light guide member and will be described as a more preferable embodiment. is there. FIG. 12 is a perspective view of the illumination device 1 viewed from obliquely forward in the irradiation direction, and FIG. 13 is a perspective view of the illumination device 1 viewed obliquely from the rear of the irradiation direction. FIG. 13 shows a light distribution control lens array 60. In the lighting device 1, three sets of LED groups 25 are provided, and three light guide members 30 are provided corresponding to the respective LED groups 25. Also has three prism portions 63. The prism portion 63 has a substantially truncated cone shape protruding rearward of the light distribution control lens array 60. It has the outer peripheral surface 64 of the truncated cone-shaped cone slope, and the recessed part 61 provided in the top part. The three prism parts 63 are formed by acrylic resin, and are integrated by being fitted and fixed to a circular opening of a resin disk part 62 produced separately. The resin used for the disc portion 62 is light guide carbon black or the like so that light with insufficient color mixture leaked from the light guide member 30 or the coupling portion between each LED light source and the light guide branch entrance surface 36 is not emitted from the lighting device 1. A resin such as polycarbonate added with a light-shielding pigment dispersed therein is preferred. The disc part 62 is fixed to the lens holding member 12. As shown in FIG. 12, if necessary, the light exit surface of each prism portion 63 is a corrugated surface 65 formed by molding or a rough surface formed by blasting to further increase the degree of color mixing of the LED element group 25. Measures are taken.

  The prism part 63 and the light guide trunk part exit surface 37 are arranged at an appropriate distance, and the prism part 63 is designed so that the light emitted from the light guide trunk part exit surface 37 is directed to the corrugated surface 65 as a substantially parallel light beam. ing. The recess 61 forms a well shape having an inner diameter larger than the outer diameter of the light guide trunk 35. By making the inner diameter of the recess 61 larger than the light guide trunk exit surface 37, the side surface inside the recess 61 and the bottom surface of the recess become the main incident surface of the light irradiated from the exit surface 37. The bottom surface of the recess is a curved surface with a convex central portion. The bottom surface of the recess is disposed so that the center of the light guide trunk exit surface 37 faces each other, and the light emitted from the exit surface 37 is refracted and incident on the bottom surface of the recess to obtain a substantially parallel light beam. The side surface of the concave portion is made into a substantially parallel light beam by the light emitted from the emission surface 37 being refracted and incident on the side surface of the concave portion and then internally reflected by the outer peripheral surface 64. Therefore, if the size of the emission surface 37 is reduced, the distance from the light distribution control lens array 60 and the lens diameter can be reduced.

  If the distance between the LEDs to be mixed is shortened and arranged close to each other, the distance until the irradiation light is mixed can be shortened. When a surface mount type LED is mounted on the substrate 11, the surface mount type LED is small, but when mounted on the substrate 11, the distance between the light emission centers of adjacent LEDs is the reflection frame or external connection terminal. In consideration of the above, it should be separated by several mm. Therefore, the distance between the adjacent light guide branch entrance surfaces 36 is also increased. When the control lens array 60 is reduced, in other words, when the prism portion 63 is reduced, it is necessary to reduce the exit surface 37 of the light guide member 30. If the emission surface 37 is made smaller, the distance from the light distribution control lens array 60 and the lens diameter (the diameter of the prism portion 63) can be made smaller.

  In addition, the light repeats internal reflection in the light guide trunk 35 and uniformly mixes the light incident from the incident surface. At this time, with respect to the degree of color mixing uniformity, the length of the cylindrical portion is determined by the diameter of the cylinder, and the longer the diameter, the better the degree of uniformity.

  When driving the illumination device 1, a method using a commercially available RGB LED driver is easy. FIG. 14 shows an example of driving. The LED driver 101 in the example of FIG. 14 is an RGB LED driver_LP5520 manufactured by National Semiconductor. The LP5520 can drive an LED of up to 60 mA, and is suitable for the current rating of a single package LED used in the present lighting device. In the three LED groups of the lighting device, for example, LED strings are formed in series for each light emission color of the LEDs 21, 22, and 23. The LP5520 is a driver for RGB three-color LEDs. However, the present invention is not limited to this combination of light emission colors, and various combinations are possible. The LP5520 is controlled in luminance from an MCU (micro control unit) 103 by an SPI or I2C interface, and can drive a pulse constant current of each RGB LED string while correcting the color tone by an internal memory. Further, the LP5520 controls the voltage output of the DC / DC converter 102 to an optimum value according to the voltage drop of each LED string.

  Note that the LED driver and the DC / DC converter are preferably mounted together with the LEDs on the substrate 11 of the lighting device in order to suppress electromagnetic interference. In this case, a control interface and a power supply line are connected as a cable 70 to the lighting device.

  Since the illuminating device 1 described so far uses a bar-shaped light guide member having a plurality of light guide branches, each light guide branch and each LED are individually coupled to emit mixed color light. Although color unevenness on the irradiated surface is considerably reduced, it is still insufficient. When the irradiation pattern is observed, as shown in FIG. 15, the center of the irradiation pattern of each of the LEDs 21 to 23 is offset from the irradiation optical axis, and the screen pattern has a region where the LED light color is not sufficiently mixed at the edge of the irradiation pattern area. Slightly recognized. Of course, if the length of the light guide trunk of the light guide member can be increased by ignoring the practical range, the color unevenness at the edge of the irradiation pattern area should be further reduced. The compactness and convenience required for the device are lost.

  Therefore, in the present invention, each of the irradiation patterns in the three LED groups 25 are also superimposed on each other in the far-field region, and the insufficient light color is compensated for in the insufficient light color mixing region at the edge of each irradiation pattern area. The relative position condition between the LED groups is defined for each light emission color of the LEDs constituting each LED group. Hereinafter, the measures regarding the LED arrangement will be specifically described by way of examples.

  First, FIG. 1 shows the arrangement relationship of three LEDs in each LED group 25. The three LEDs are arranged adjacent to each other so that the center of each light emitting portion is located at the apex of an equilateral triangle (indicated by a broken line). Is done. The point S indicates the LED arrangement center point. As shown in FIG. 2, the three LED groups 25 are distributed on the substrate 11 so that the geometric pattern connected by the LED arrangement center point S of each LED group 25 is an equilateral triangle (indicated by a broken line). Is done. In addition, the point P in the center of FIG. 2 indicates the arrangement center position of the three sets of LED groups 25.

  By adopting such an LED arrangement, by combining the light guide member 30 described above, the irradiation pattern irradiated from the prism portion 63 causes insufficient light color mixing occurring at the three pattern area edges shown in FIG. The size of the area is substantially uniform, and the LED light colors in the light color mixing insufficient area are irradiated to the screen as being rotated by about 120 °.

Here, in the present invention, it is further assumed that the LED positional relationship between the LED groups 25 for each emission color is in accordance with the following condition (a).
(A). Each LED in each LED group 25 is arranged to be rotated by 120 ° with respect to the point P including the mutual positional relationship. Therefore, the relative positional relationship with respect to the point P of the three LEDs (LEDs 21, 22, 23) in each LED group 25 is constant.
However, the arrangement of the three LEDs with respect to the point P is not limited. For example, FIG. 3 shows an LED arrangement according to this LED arrangement rule different from FIG. 2 (the substrate 11 is omitted). 2, one LED in each LED group 25 is installed in parallel to the tangential direction of the circle outside the circle connecting the LED arrangement centers S of the LED groups 25. In FIG. One LED in each LED group 25 is installed in parallel to the tangential direction of the circle.

  As shown in FIGS. 1 to 3, the limited arrangement of the three sets of LED groups 25 on the substrate 11 component mounting surface and the light emission colors between the LED groups 25 according to the condition (a) described above. By determining the LED positional relationship, the arrangement of the light color mixing insufficient region for each LED light color generated at the edge of the pattern area in the irradiation pattern from each of the three sets of LED groups 25 is determined so that the three irradiation patterns are in the far field. The arrangement is such that the insufficient colors when they are superimposed in the region are complemented.

FIG. 4 shows the positions of the LEDs 21, 22, and 23 in the three sets of LED groups 25 on the board 11 component mounting surface when the LED positional relationship between the respective LED groups 25 is in accordance with the condition (a) described above. The relationship and the positional relationship of the irradiation patterns of the LEDs 21, 22, and 23 irradiated on the screen are schematically shown. In FIG. 4, the irradiation patterns A, B, and C by the three groups of LED groups 25 are shown apart from each other, but when the far field region is irradiated as an illumination device, the irradiation patterns A, B, and C are superimposed. Observed to do.
In the light color mixing insufficient region at each irradiation pattern edge described in FIG. 15, the irradiation patterns A, B, and C are overlapped to compensate for the insufficient light color of the light color mixing insufficient region. Each irradiation pattern from the illumination device is integrated, and the color unevenness at the edge of the irradiation pattern area is reduced.

Here, for confirmation, the lighting device 1 in which the measures related to the LED arrangement described above were performed was created with the following configuration, and the effect was confirmed.
■ LED used: PLCC type, red, blue, green
■ 40mm diameter circle connecting the LED center of each LED group 25
■ Light guide member Diameter 4mm Light guide trunk length 30mm
■ Light distribution control lens diameter 24mm
■ Light distribution angle about 40 °
■ Distance from irradiated surface to illumination device light exit surface 1.2m
The color unevenness felt at the edge of the irradiation pattern area was greatly improved. Incidentally, the light distribution by the light distribution control lens is intended to be 40 [deg.], And it is intended that the color unevenness can be remarkably confirmed as an illumination device with a narrow light distribution. It is clear that the color unevenness can be further suppressed by widening the light distribution.

  In order to reduce the color unevenness at the edge of the irradiation pattern area in the present invention, it is necessary that the emission colors and the luminances of the single package LEDs constituting the respective LED groups are adjusted sufficiently evenly. Therefore, as described above, individual single package LEDs are selected based on accurate binning at least in terms of output rank and emission spectrum distribution at the stage of mounting on the substrate 11. This is not easily realized in an assembly process using a so-called multi-color multi-chip package in which LED chips of different light emission colors are incorporated in one package, because the variation in luminance ratio between LED chips becomes an obstacle.

In the far-field region, the LED positional relationship in which the irradiation patterns of the three LED groups 25 are superimposed on each other to compensate for the insufficient light color in the light color mixing insufficient region at the edge of each irradiation pattern area, In addition to the positional relationship based on the above condition (a), the following condition (b) is also conceivable.
(B). The positional relationship of the three LEDs in each LED group 25 is arbitrary in the three groups of LED groups 25 that are dispersedly arranged while maintaining the positional relationship of the three LEDs in each LED group defined in the condition (a). The arrangement of the two LED groups 25 is equal to that of the LED group 25 replaced by the parallel movement while maintaining the positional relationship of the LEDs.

  FIG. 5 shows an example of the positional relationship of each LED in the three sets of LED groups 25 according to this condition (b). In the example shown in the figure, three LED groups 25 having the signs X, Y, and Z in which the positions of the respective LEDs have been determined according to the condition (a) are changed to the position where Z is Y according to the condition (b). Shows a state of being translated and moved to the Z position.

Even as the LED arrangement according to the condition (b), the three irradiation patterns irradiated from the three LED groups 25 are:
The LED light colors in the light color mixture insufficient region generated at the edge portions of the pattern areas are irradiated to the screen as rotation targets of about 120 °. Accordingly, as in the case of the condition (a), the color unevenness at the edge of the irradiation pattern area is reduced.

  Until now, the lighting device 1 has been described with a configuration in which three LED groups formed of three LEDs are mounted on a substrate. However, the lighting device 1 according to the present invention and the LED arrangement for reducing color unevenness are described above. The configuration is not limited.

For example, in the case of a lighting device using four LEDs, the LED arrangement is the same as in the case of a lighting device using three sets of LED groups formed by three LEDs, and an LED formed by four LEDs. Four groups are provided on the substrate, and the LED arrangement center point S of each LED group is arranged to coincide with the position of the apex of the square.
In addition, the conditions (a) and (b) for defining the relative positional relationship of the four LEDs in each LED group with respect to the dispersion center point P of the LED group are (a) the four LEDs in each LED group are positioned relative to each other. Including the relationship, the LED group is arranged to be rotated by [90] ° with respect to the dispersion center point P of the LED group. Therefore, the relative positional relationship of the four LEDs in each LED group with respect to the point P is constant.
(B) The positional relationship of the four LEDs in each LED group is as follows. In the four sets of LED groups that are dispersedly arranged while maintaining the positional relationship of the four LEDs in each LED group defined in the condition (a), Arrangement of at least two arbitrary LED groups is equivalent to the arrangement replaced by translation while maintaining the positional relationship of the LEDs.
It becomes.
Each LED group is combined with a light guide member having four light guide branches, and each LED in each LED group is optically coupled to the light incident surface of the light guide branch. The light emitting surfaces of the light guide trunks of the four light guide members are optically coupled to a light distribution control lens array incorporating four prisms to constitute an illumination device.

  For example, the number of LEDs constituting the LED group is four, and by adding yellow in addition to the three primary colors red, green, and blue, the missing spectral region is complemented and the color rendering is more general as a general illumination. It can be set as the favorable illuminating device.

Furthermore, even in the case of a lighting device using six-color LEDs, six LED groups formed of six LEDs are provided on the substrate, and the LED arrangement center point S of each LED group is located at the apex of a regular hexagon. The above-mentioned conditions (a) and (b) are (a) the six LEDs in each LED group with respect to the dispersion center point P of the LED group including the mutual positional relationship [ 60] ° is arranged for rotation. Accordingly, the relative positional relationship of the six LEDs in each LED group with respect to the point P is constant.
(B) The positional relationship of the six LEDs in each LED group is as follows. In the six sets of LED groups dispersedly arranged while maintaining the positional relationship of the four LEDs in each LED group defined in the condition (a), Arrangement of at least two arbitrary LED groups is equivalent to the arrangement replaced by translation while maintaining the positional relationship of the LEDs.
It becomes. In addition, the combination of the light guide member and the light distribution control lens array is the same as the case of using an LED group using three LEDs or the case of using an LED group using four LEDs.

  For example, by adding orange, yellow, and blue-green LEDs to the three primary color LEDs to obtain six colors, it is possible to realize an illumination device that has less color unevenness and a high average color rendering evaluation coefficient Ra. In general, in order to obtain light having a good color mixture using LEDs of four colors or six colors, the arrangement of the LEDs and the color mixing method become difficult, which is not practical, but the light guide member of the lighting device 1 is used. The present invention can be realized by the optical structure and the color unevenness reduction effect of the present invention.

[Summary of LED layout]
From the above, if the characteristics related to the LED arrangement of the present invention are extended to the case where an LED group formed of n LEDs is used,
There are n LED groups arranged adjacent to each other on the substrate so that the center of each light emitting portion is located at the apex of a regular n-gon, and there are n sets of LED groups composed of the n LEDs. The LED group is dispersedly arranged such that the LED arrangement center point S is located at the apex of the regular n-gon,
The n LEDs in each LED group are determined so that their positional relationship satisfies the following condition (a) or (b).
(A) The n LEDs in each LED group, including the positional relationship with each other, are arranged to rotate by [2π / n] ° with respect to the dispersion center point P of the LED group. Accordingly, the relative positional relationship of the n LEDs in each LED group with respect to the point P is constant.
(B) The positional relationship of the n LEDs in each LED group is the n sets of LED groups that are dispersedly arranged while maintaining the positional relationship of the n LEDs in each LED group defined in the condition (a). Arrangement of at least two arbitrary LED groups is equivalent to the arrangement replaced by translation while maintaining the positional relationship of the LEDs.
And can be expressed comprehensively.
In this case, in the expression of the arrangement configuration of the light guide member in the illumination device, n light guide members are arranged in front of the LED irradiation direction in each of the LED groups, and the light guide member is a single light guide member. A rod-shaped light guide trunk, a light guide branch connected to one end of the light guide trunk, and n light guide branches connected to the light guide branch,
The n light guide branches are uniformly inclined to the light guide branch with respect to the central axis of the light guide trunk, and the center of the incident surface coincides with the center of the light emitting part of each of the n LEDs constituting the LED group. To counter,
An arrangement configuration in which the other end of the light guide trunk is configured to oppose the incident portion of the light distribution control means as the exit surface, and the light emission colors of the LEDs are mixed and irradiated,
Can be summarized.

[Application to surface lighting equipment]
The illuminating device 1 using the present invention can construct a color tone variable type planar illuminating device with a small color mixing property and color variation by arranging a plurality of light emitting surfaces on a plane with the illuminating device 1 as one structural unit. Is possible.

  FIG. 16 shows, for example, a planar illumination device 2 arranged in a zigzag manner using a plurality of illumination devices 1 of LEDs of RGB colors, and only the LED arrangement viewed from the irradiation direction of the planar illumination device 2 is clearly shown. (The external shape of the board | substrate 11 is abbreviate | omitted.) Each LED which comprises the LED group 25 is attached | subjected the code | symbol in RGB. As shown in FIG. 16, in the planar illumination device 2, the LED group 25 in one illumination device 1 and the LED group 25 in another one or two illumination devices 1 adjacent to the LED group 25 are connected between the illumination devices 1. The triangles drawn by connecting the LED arrangement centers of the three groups of LED groups 25 approaching apart from each other are arranged to be regular triangles, and the regular triangles of the three groups of LED groups 25 in one lighting device 1 are arranged. It has a geometrically congruent relationship with the equilateral triangle drawn by connecting the LED arrangement centers, and the plurality of illumination devices 1 are arranged so that the equilateral triangles are filled in a plane.

That is, a triangle drawn by connecting the LED arrangement centers of the LED groups 25 in each illumination device 1 used in the planar illumination device 2 in FIG. 16 is D, and each illumination device 1 in the LED groups 25 in the two illumination devices 1 is D. E is a triangle drawn by connecting the LED arrangement centers of three groups of LED groups 25 that are close to each other and three LED groups 25 in three adjacent lighting devices 1 are separated from each other by three lighting devices 1. If the triangle drawn by connecting the LED arrangement centers of the three LED groups 25 approaching near the center of the lighting device 1 is F,
Triangles D, E, and F are all equilateral triangles, and triangle D ≡ triangle E ≡ triangle F
It is a relationship.

Here, the LED group 25 at the position constituting the triangle D constitutes one lighting device 1 and complies with the condition (a) or the condition (b) related to the LED positional relationship described above.
And the condition regarding the LED positional relationship of the LED group 25 at the position constituting the triangle E is in accordance with the condition (b) when the LED positional relationship of the LED group constituting the triangle D is in accordance with the condition (a), and When the LED positional relationship among the LED groups constituting the triangle D conforms to the condition (b), it conforms to the condition (a).
Furthermore, the conditions regarding the LED positional relationship of the LED group 25 at the position constituting the triangle F are the same as the conditions of the LED positional relationship of the LED group constituting the triangle D.

Therefore, in the planar lighting device 2, the lighting device 1, which is a structural unit, is arranged as described above, so that the lighting devices 1 are not limited to the three LED groups 25 included in the lighting device 1. Thus, the arbitrary three LED groups 25 constituting the equilateral triangle arrangement have the LED positional relationship according to either the above-mentioned condition (a) or condition (b), and the irradiation patterns are also superimposed on each other in the far field region. Thus, it becomes possible to compensate for the insufficient light color in the light color mixing insufficient region at the edge of each irradiation pattern area.
As a result, when a plurality of light emitting surfaces are arranged on a plane with the lighting device 1 as one structural unit, a slight color deviation between the arrangements of the lighting devices 1 is suppressed, and there is little color mixing and color variation. It is possible to construct a color tone variable surface illumination device that can irradiate illumination light.

  Since squares and regular hexagons can be filled in a plane, as in the case of the flat illumination device 2 of the fifth embodiment, the illumination device is composed of four LED groups formed by four LEDs, or six LEDs. If the illuminating device composed of the formed six LED groups is configured according to the characteristics of the illuminating device according to the present invention described above, a plurality of light emitting surfaces are arranged in a staggered manner with these illuminating devices as a structural unit, and color mixing properties Therefore, it is possible to construct a color tone variable surface illumination device with little color variation.

  FIG. 17 shows, for example, a planar illumination device 2 ′ using a plurality of illumination devices 1 ′ using four colors of RGBY emission LEDs, and clearly shows only the LED arrangement as seen from the irradiation direction of the planar illumination device 2 ′ ( As in the case of FIG. 16, in the planar illumination device 2 ′, the LED group 25 ′ in one illumination device 1 ′ and another one adjacent to the LED group 25 ′ are omitted. Or in LED group 25 'in two illuminating devices 1', it arrange | positions so that the square drawn by connecting each LED arrangement center of four groups LED group 25 'which approaches between each illuminating device 1' may become a square. The square is geometrically congruent with the square drawn by connecting the LED arrangement centers of the four LED groups 25 ′ in one lighting device 1 ′, and the plurality of lighting devices 1 ′ Arranged so that the square is flat filled There.

Here, D ′ is a quadrilateral drawn by connecting the LED arrangement centers of the LED groups 25 ′ in each illumination device 1 ′ used in the planar illumination device 2 ′ of FIG. 17, and the LED groups 25 in the two illumination devices 1. A square drawn by connecting the LED arrangement centers of the four LED groups 25 'approaching between the respective lighting devices 1' in E ', and each lighting device 1' in the LED groups 25 in the three lighting devices 1 '. F ′, a quadrilateral drawn by connecting each LED arrangement center of four groups of LED groups 25 ′ that are close to each other in the vicinity of the center of the three lighting devices 1 ′, with the lighting devices 1 ′ interposed therebetween.
The squares D ′, E ′, and F ′ are all squares, and the square D ′ ≡ the square E ′ ≡ the square F ′
It is a relationship.

  Similarly, a planar lighting device using a plurality of lighting devices using six colors of LEDs is also possible. However, the regular hexagon that is filled in the plane is formed by connecting the LED arrangement centers of the LED groups of the individual lighting devices as the structural unit, and the three lighting devices, with the three lighting devices being separated from each other. There are only two types of what is drawn by connecting the LED arrangement centers of the six LED groups approaching near the center. Note that the pattern in which regular hexagons are plane-filled is a so-called turtle shell pattern.

The combinations of LED emission colors in the above embodiments are merely examples. For example, in an illuminating device configured by arranging six LED groups using six LEDs, the combination of the LED emission colors of three LED groups and another three LED groups is changed every other group. In addition, the present invention also includes two types of light color ranges that are realized by mixed light, or pseudo white LEDs having different color temperatures for all LED emission colors.

  The illuminating device according to the present invention can be applied as a color temperature variable illuminating device to applications such as display and decorative color illumination in addition to general illumination and effect illumination.

DESCRIPTION OF SYMBOLS 1 Illuminating device 2 Surface illuminating device 11 Board | substrate 12 Lens holding member 20 Light source 21 1st LED
22 Second LED
23 Third LED
25 LED element group 30 Light guide member 31 First light guide branch 32 Second light guide branch 33 Third light guide branch 34 Light guide branch 35 Light guide trunk 36 Light guide branch incident surface 37 Light guide trunk exit surface 40 Housing 50 Radiator 60 Lens array for light distribution control 63 Prism unit 64 Outer peripheral surface 65 Wave surface 70 Cable 101 LED driver 102 DC / DC converter 103 MCU

Claims (2)

n is an integer of 3 or more,
A set of LEDs is formed by being adjacently arranged on the substrate so that the center of the light emitting portion of each of the n LEDs having different emission wavelength distribution characteristics is located at the apex of the regular n-gon,
On the substrate, there are n sets of LED groups of the organization, and the n sets of LED groups are distributed and arranged so that the LED arrangement center point S is located at the apex of the regular n-gon,
n light guide members are arranged in front of the LED irradiation direction in each of the LED groups, and the light guide member is connected to one bar-shaped light guide trunk and one end of the light guide trunk. And n light guide branches connected to the light guide branch,
The n light guide branches are uniformly inclined to the light guide branch with respect to the central axis of the light guide trunk, and the center of the incident surface coincides with the center of the light emitting part of each of the n LEDs constituting the LED group. To counter,
The other end portion of the light guide trunk portion is configured to oppose the incident portion of the light distribution control means as a light exit surface, and is an LED illumination device of a type that irradiates the light emission colors of each LED by mixing colors. Yes,
An LED lighting device, wherein the n LEDs in each LED group are set so that their positional relationship satisfies the following condition (a) or (b):
(A) The n LEDs in each LED group, including the positional relationship with each other, are arranged to rotate by [2π / n] ° with respect to the dispersion center point P of the LED group.
(B) The positional relationship of the n LEDs in each LED group is the n sets of LED groups that are dispersedly arranged while maintaining the positional relationship of the n LEDs in each LED group defined in the condition (a). Arrangement of at least two arbitrary LED groups is equivalent to the arrangement replaced by translation while maintaining the positional relationship of the LEDs. In the planar illumination device formed by arranging a plurality of LED illumination devices according to claim 1 as a structural unit so that the light irradiation surfaces are in the same plane in a staggered pattern,
n is 3, 4 and 6
A regular n-gon shape connecting the LED arrangement center points S of the n LED groups distributed and arranged in the LED illumination device;
There is a congruent relationship between two or three adjacent LED illuminating devices, and a regular n-gon shape connecting the LED arrangement center points S of n groups of LED groups approaching near the center between the LED illuminating devices, A planar illumination device characterized in that an arrangement interval between the LED illumination devices is determined so that the regular n-gons are planarly filled.

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