JP6501052B2 - Light module, lighting device and display device - Google Patents

Description

  The present invention relates to a light module that emits light to the environment, a lighting device including a plurality of light modules, and a display device.

  In Patent Document 1, in a light emitting device used for a backlight unit of a display device provided with a display panel, light can be irradiated to the irradiated body so that the brightness becomes uniform in the surface direction of the irradiated body, A light emitting device that can be thinned is described. The backlight unit is provided on a printed circuit board, a plurality of light emitting units provided on the printed circuit board, a base, an LED chip, and a lens, and a periphery of the light emitting unit. And a first reflecting member.

JP 2012-216747 A

  There is a need for a lighting device that is thinner and provides more uniform lighting effects.

One embodiment of the present invention is a light module having a light emitting device having at least three light emitting surfaces on the side surface, and a reflective area disposed around the light emitting device. The reflection area includes a diffuse reflection area at least a part of which is disposed in front of the exit surface, and a specular reflection area which is disposed between adjacent diffuse reflection areas in a direction in which the exit surface is not directed .

  By arranging the diffuse reflection area so as to extend in front of the emission surface and arranging the specular reflection area between the adjacent diffuse reflection areas, it is possible to improve the luminance other than in front of the emission surface. Therefore, by arranging a plurality of light modules on the light emitting surface of the lighting device, it is possible to provide a lighting device which can obtain a thinner and more uniform lighting effect.

The expansion | deployment perspective view which expand | deploys and shows an illuminating device. The figure which shows a lighting board | substrate. The top view which shows an optical module. FIG. 2 is a perspective view showing an optical module. 5 (a) shows the light distribution of the light module in the horizontal direction, FIG. 5 (b) shows the light distribution of the light module in the vertical direction, and FIG. 5 (c) shows the light distribution angle curve of the single LED. The perspective view which shows a different light module. The perspective view which shows a further different light module. The expansion | deployment perspective view which expand | deploys and shows another light module further. The top view which shows a different illumination board.

  FIG. 1 shows the illumination device in an expanded state. The illumination device 1 covers the front side 2 c of the cover 2 opposite to the illumination substrate 10 and the illumination substrate 10 disposed on the thin box-shaped cover 2 whose upper side is opened, the lower surface of the cover 2. And a diffusion plate 5. In this example, the cover 2 includes a back surface on which the square illumination substrate 10 is installed, and a square side surface 2b. The illumination substrate 10 may be integral with the cover 2. The cover 2 may be rectangular, other polygonal, circular or elliptical. The front side 2c and the back side 2a of the cover 2 are relative directions, and when the lighting device 1 is mounted on a ceiling, the front side 2c of the cover 2 faces downward, and when mounted on a wall , The front side 2c of the cover 2 faces sideways.

  It is possible to mount a translucent display substrate 6 such as an LCD substrate instead of the diffusion plate 5 or by overlapping the diffusion plate 5. The lighting device 1 may be a backlight of the display device 7 or may be incorporated in the display device 7.

  FIG. 2 shows a front view of the cover 2 in which the illumination substrate 10 is disposed. The surface on the front side of the illumination substrate 10 (hereinafter referred to as the upper surface) is a light emitting surface 10a that emits light for illumination, and a plurality of light modules 20 are arranged vertically and horizontally on the diffusely reflective substrate surface 10b. There is. That is, at least a part of the plurality of light modules includes a portion which is two-dimensionally arranged at equal intervals with the direction of the exit surface being aligned. The diffusely reflective substrate surface 10b is a so-called matte surface, and may be roughened to diffusely reflect light, or a diffuse reflective sheet such as a white reflective sheet may be attached.

  On the light emitting surface 10a of the illumination substrate 10, 16 light modules 20 are arranged in a matrix of 4 × 4 in the vertical and horizontal directions. The number of optical modules 20 is not limited to this, and the direction in which the optical modules 20 are arranged is preferably, but not limited to, the direction orthogonal to the side surface 2 b of the cover 2. Or it may not only be parallel but be oblique. Furthermore, it is preferable that a diffuse reflection sheet be attached to the inner side surface 2 b of the cover 2.

  FIG. 3 shows a schematic configuration of the optical module 20 in a plan view, and FIG. 4 shows an appearance of the optical module 20 in a perspective view. The optical module 20 includes a square wiring board 24 and a light emitting device 25 disposed at the center of the upper surface 24 a of the wiring board 24. The light emitting device 25 includes four side-emitting LEDs 30 each having an exit surface 31 on the side. The four LEDs 30 are combined such that the main light emitting axes 39 are parallel to the upper surface 24 a of the wiring board 24 and face the four corners of the wiring board 24. The four LEDs 30 are turned by 90 degrees each on the upper surface 24 a of the wiring substrate 24, and form a square rectangular light emitting device 25 as a whole when viewed from the upper surface as a whole. Therefore, the emission surface 31 which emits light is provided on each of the four side surfaces 26 of the light emitting device 25.

  The upper surface 24 a of the wiring substrate 24 is a reflection area including a diffuse reflection area 21 in which at least a portion is disposed in front of the emission surface 31 and a specular reflection area 22 disposed between the adjacent diffuse reflection areas. A reflection environment around the light emitting device 25 is constructed. The diffuse reflection area 21 has a width obtained by removing about half of each emission surface 31 from the width of each side surface 26 from immediately below each side surface 26 of the light emitting device 25 in the direction of each main light emission axis 39. It is a generally rectangular area extending towards the corners. The shape of the diffuse reflection area 21 is not limited to a rectangle. It may be a shape in which at least a part is disposed in front of the emission surface 31. The diffuse reflection area 21 further extends toward the corner of the wiring board 24 and is preferably disposed in the area including the corner of the wiring board 24. The diffuse reflection area 21 may be formed by processing the upper surface 24 a of the wiring substrate 24 in a matte state, or may be formed by adhering a diffusive sheet such as white.

  The specular reflection area 22 disposed between the diffuse reflection areas 21 is a substantially triangular shape in the upper surface 24 a of the wiring board 24 from just under the front of the corner of the square light emitting device 25 toward each side of the wiring board 24. In the present example, the light emission area 31 extends in front of each light emission surface 31 with a width of about half. The specular reflection area 22 is an area where there is little diffusion of light and light from one side is reflected and emitted to another side, and is a so-called area with luster. The specular reflection area 22 may be an area obtained by processing a member such as metal into a state having little unevenness, or may be an area formed by attaching a specular reflection sheet such as a highly reflective metal thin film. The surface of the wiring board 24 may be a highly reflective area which is the wiring board 24 itself.

  The light distribution characteristic of the optical module 20 is shown in FIG. FIG. 5 (a) shows the light distribution in the horizontal direction, and FIG. 5 (b) shows the light distribution in the vertical direction. FIG. 5C shows a light distribution angle curve of a single LED as a reference.

  In FIG. 5A, the horizontal light distribution 62 with the vertical angle θ of 90 degrees (the angle from the normal line 69, the normal line 69 is 0 degree) shown in FIG. 4 and the vertical angle θ of 55 degrees And the light distribution 61 of the The main light emission axis 39 is located at a horizontal angle φ of 0 degrees, 90 degrees, 180 degrees, and 270 degrees.

  In FIG. 5B, the light distribution distribution 63 in the vertical direction (vertical angle direction) in the plane having a horizontal angle φ of 45 degrees, and the light distribution in the vertical direction (vertical angle direction) in the plane having a horizontal angle φ of 0 degrees Distribution 64 is shown. Moreover, this light distribution shows not only the case of 45 degrees but also the light distribution 63 similar to the case of 135 degrees, 225 degrees, 315 degrees and 45 degrees, and not only the case of 0 degrees but also 90 degrees, A light distribution 64 similar to the case of 180 degrees and 270 degrees and 0 degrees is shown.

  In the light module 20, two LEDs 30 are respectively main emitting axes 39 when the horizontal angle φ between the two LEDs 30 is 45 degrees, 135 degrees, 225 degrees and 315 degrees. It emits light in the direction of 45 degrees. According to the light distribution characteristics of the individual LEDs 30 in FIG. 5C, the light distribution intensity of 45 degrees is the highest light emission intensity at 0 degrees, that is, 1/1/2 of the light distribution intensity of the main light emission axis 39 It becomes. Therefore, the intensities at the horizontal angles φ of 45 degrees, 135 degrees, 225 degrees, and 315 degrees are √2, ie, about 1.4 times, because the two LEDs 30 contribute.

  The optical module 20 of this example does not have a circular light distribution characteristic, but has a light emission distribution of high intensity in the diagonal direction of the lattice arrangement in which the distance to the adjacent light source becomes large. Further, the light emission distribution is weaker in the direction parallel to the vertical and horizontal sides where the distance to the adjacent light modules 20 is relatively smaller than in the diagonal direction. These light distribution characteristics are unlikely to be affected by the difference in the distance between the light modules 20 depending on the direction even when the plurality of light modules 20 are arranged in a grid in the longitudinal and lateral directions.

  Furthermore, in the optical module 20, by combining the diffuse reflection area 21 and the specular reflection area 22, the light distribution characteristic in the direction with a vertical angle θ of 90 degrees or less can be changed from circular to a characteristic having a strong distribution in the diagonal direction. It is effective in eliminating dark spots in the diagonal direction.

  That is, when the upper surface (reflection area) 24a of the wiring substrate 24 of the optical module 20 is constituted only by the diffusion surface, the light distribution characteristic strong in the diagonal direction of such an optical module is 90 degrees vertical angle, ie parallel to the upper surface 24a. It is limited to the in-plane vicinity. Therefore, the light distribution of the vertical angle toward the diffusion plate 5 on the middle point (diagonal middle point) with the light modules 20 adjacent in the diagonal direction approaches a circle. Therefore, even if the distribution in the diagonal direction is increased simply by combining the four LEDs 30, it is not possible to sufficiently achieve the dark point elimination of the diagonal midpoint.

  In the optical module 20 of this example, the diffuse reflection area 21 and the specular reflection area 22 are disposed on the upper surface 24 a of the wiring substrate 24, and as shown in FIG. Also in the diagonal direction 62, that is, the horizontal angles 45 degrees, 135 degrees, 225 degrees, and 315 degrees have high strength. Therefore, the optical module 20 has a distribution in the vertical direction toward the diffusion plate 5, for example, an angle between the main light emission axis 39 and the intensity of the main light emission axis 39 (horizontal direction .phi. A light distribution can be provided such that the intensity in the direction of 135 degrees, 225 degrees, 315 degrees) is 1.2 times.

  Furthermore, as shown in FIG. 5 (b), the light distribution in the direction perpendicular to the central angle (the horizontal direction φ is 45 degrees, 135 degrees, 225 degrees, 315 degrees) in the middle direction of the main light emission axis 39 Distribution of bat wing shape with a peak near This is similar to the light distribution obtained by combining a wide diffusion lens with a light source arranged so that the main emission is perpendicular to the surface to be irradiated, and the diffusion plate 5 and the display substrate 6 (display panel) The light distribution is optimal for uniformly illuminating the Furthermore, the light distribution characteristic realized by the diffusion lens is a circular distribution centered on the light source, but as described above, the light distribution of the optical module 20 differs in intensity distribution depending on the direction of the horizontal angle φ, When a plurality of optical modules 20 are arranged in a square lattice, ideal light distribution characteristics are obtained.

  Therefore, it is possible to provide the lighting device 1 and the display device 7 that can suppress the decrease in the light utilization rate by the diffusion plate 5 using a highly directional light source such as the LED 30, and still obtain a thin and uniform lighting effect. . For example, the distance between the light emitting surface 10 a and the inner surface of the diffusion plate 5 is P with respect to the distance between the optical modules 20 (the distance between the center of a certain optical module and the center of the shortest optical module adjacent to the optical module) P It has been confirmed that, even with the illumination device 1 of P / 2, the dark spots in the diagonal direction can hardly be seen.

  A different example of the optical module 20 is shown in FIG. The optical module 20 includes a square wiring board 24 and a light emitting device 25 disposed at the center of the upper surface 24 a of the wiring board 24. The light emitting device 25 has a configuration in which four side surface light emitting type LEDs 30 provided with light emitting surfaces 31 on the side surfaces are combined such that the light emitting surfaces 31 face in four directions. The upper surface 24 a of the wiring substrate 24 includes the diffuse reflection area 21 disposed in front of the light emission surface 31 and the specular reflection area 22 disposed between the adjacent diffuse reflection areas. The diffuse reflection area 21 is narrow immediately below the emission surface 31 and spreads toward the corners (four corners) of the wiring board 24. The specular reflection area 22 disposed between the diffuse reflection areas 21 extends in a band shape from immediately below the front of the corner portion of the light emitting device 25 toward each side of the wiring board 24.

  Also in this optical module 20, a light distribution similar to the light distribution shown in FIGS. 5 (a) and 5 (b) can be obtained. The specular reflection area 22 is important for obtaining a strong light distribution in the vertical angle direction of 90 degrees or less in the diagonal direction (the middle direction of the main light emission axes 39), but it may be provided in the diagonal direction, The allowable range of the shape and size of the specular reflection area 22 is wide.

  The diffuse reflection area 21 is important for obtaining a light distribution directly above the light module 20, that is, when the vertical angle θ is in the 0 degree direction. The diffuse reflection area 21 is provided with an appropriate width between immediately before the emission surface 31 provided on the side surface 26 of the light emitting device (LED package) 25 and the specular reflection area 22 on the upper surface 24 a of the wiring substrate 24. is important.

  A further different example of the optical module 20 is shown in FIG. The optical module 20 includes a square wiring board 24 and a light emitting device 25 disposed at the center of the upper surface 24 a of the wiring board 24. The light emitting device 25 has a configuration in which four side surface light emitting type LEDs 30 provided with light emitting surfaces 31 on the side surfaces are combined such that the light emitting surfaces 31 face in four directions. The upper surface 24 a of the wiring substrate 24 includes the diffuse reflection area 21 disposed in front of the light emission surface 31 and the specular reflection area 22 disposed between the adjacent diffuse reflection areas. The diffuse reflection area 21 includes a slope 21 a that reflects light having a vertical angle θ of around 90 degrees in the direction of the diffusion plate 5 with light output in the direction of the main light emission axis 39.

  The specular reflection area 22 includes a convex mirror 22a disposed at an angle so as to reflect light output from the emission surface 31 toward a diagonal midpoint on the diffusion plate 5 which is a surface to be illuminated. The convex mirror 22 a has a cylindrical side surface shape, and is provided so as to protrude from the upper surface 24 a of the wiring substrate 24. Also in this optical module 20, a light distribution equivalent to that shown in FIGS. 5 (a) and 5 (b) is obtained. The specular reflection area 22 may be provided with a concave mirror instead of or in addition to the convex mirror 22a. That is, the specular reflection area includes a convex or concave solid shape. The specular reflection area 22 may comprise a triangular or other polygonal convex or concave specular surface.

  A further different example of the optical module 20 is shown in FIG. The optical module 20 is exposed through the wiring board 24, the LED 30 attached to the center of the wiring board 24, the reflecting plate 29 attached to the upper surface 24 a of the wiring board 24, and the opening 29 a in the center of the reflecting plate 29. And a cover 28 covering the LED 30. The LED 30 is attached to the wiring board 24 so as to have a main light emission axis in the vertical direction. The cover 28 includes windows (openings) 28 a opened at horizontal angles φ of 0 degrees, 90 degrees, 180 degrees, and 270 degrees, respectively. The light emitting device 25 includes the LED 30 and the cover 28, and the light is output with the window 28 a as the emitting surface 31 and the horizontal angle φ as the main light emitting axis 39 with 0 degree, 90 degrees, 180 degrees, and 270 degrees.

  The reflection plate 29 includes a diffuse reflection area 21 disposed so as to partially cover the front surface of the window 28a which is the light emission surface 31, and a specular reflection area 22 disposed between the adjacent diffuse reflection areas 21. The optical module 20 also has a light distribution characteristic according to the light distribution characteristic shown in FIGS. 5 (a) and 5 (b).

  FIG. 9 shows another example of the illumination substrate 10. The light emitting surface 10a of the lighting substrate 10 is covered with a diffusion sheet 10b, and the light modules 20 of the number corresponding to the size and illumination intensity (brightness) of the lighting apparatus are the emitting surfaces 31 of the respective light modules 20. It is arranged so as to be aligned vertically and horizontally. Furthermore, a reflecting rib 15 formed of a quadrangular pyramidal diffuse reflecting material is provided at a midpoint in the diagonal direction in which the optical modules 20 are arranged in the vertical and horizontal directions. Each surface 15 a constituting the quadrangular pyramid faces the direction of the four optical modules 20 located in the four directions of the reflecting rib 15, and reflects the light output from each optical module 20 in the direction of the diffusion plate 5. Therefore, the lighting device 1 can be obtained which extends the distance between the light modules 20 and outputs uniform light from the diffusion plate 5 which is the illuminated surface, or the diagonal middle point between the light modules 20 is dark. The illuminating device 1 which outputs more uniform light which can suppress becoming a point more reliably from the diffusion plate 5 which is a to-be-irradiated surface is obtained.

  As described above, the illumination device 1 arranges the plurality of light modules 20 in a grid shape on the illumination substrate 10 covered with the diffuse reflection sheet by the number corresponding to the area of the illuminated surface, and The diffusion plate 5 is disposed. The illumination device 1 can be used as a backlight of the display device 7, and the display substrate 6 may be disposed so as to overlap the diffusion plate 5, or the display substrate 6 may be disposed instead of the diffusion plate 5. Moreover, the illuminating device 1 can be used for the base light etc. which are installed in a ceiling, a wall, etc.

  The light emitting device 25 described above is a rectangular or rectangular box, and includes four side surfaces 26 and an emitting surface 31 provided on each side surface 26. The light emitting device 25 may have three side surfaces 26 and may have an emitting surface 31 oriented in three directions. Further, the side surface 26 may be cylindrical, as long as it has an emission surface 31 oriented in at least three directions. Furthermore, the light emitting device 25 may be a pentagon or more polygon, and may include an emission surface 31 facing in five or more directions.

  In the optical module 20, the light distribution distribution in the direction in which the light emitting surface 31 is not directed by the specular reflection area 22, in particular, the light distribution in such a manner that the intensity in the vertical angle θ direction facing the diffuser plate 5 is high. Since it can improve, it can suppress that a dark point generate | occur | produces between the light modules 20 in the light emission surface 10a in which the several light modules 20 were arranged. Furthermore, by disposing the diffuse reflection area 21 so as to overlap at least a part of the front of the emission surface 31, a light distribution having a certain degree of intensity in the vertical angle θ direction is realized even immediately before the emission surface 31. it can. The main light emission axis 39 of the emission surface 31 is parallel to the upper surface 24 a (reflecting surface) of the wiring substrate 24, and the basic light distribution has a vertical angle θ of 90 degrees. The intensity of θ in the direction of 90 degrees or less, for example, in the direction of 0 degrees can also be ensured, and the light emitting device 25 mounted on the optical module 20 can be prevented from becoming a dark point.

  Therefore, by the optical module 20, it is possible to obtain a light distribution having a sufficient intensity between the main light emitting axes 39 even when the vertical angle θ is 90 degrees or less. In the optical module 20 in which the emitting surface 31 is oriented in four directions, the light intensity in the direction of the specular reflection area 22 is stronger than the light intensity in the direction of the diffuse reflection area 21 and the vertical angle θ is 90 degrees or less, for example It is possible to obtain a four-leaf type light distribution as shown in FIG. 5 (a), which has sufficient light intensity even in the direction of the vertical angle θ of 55 degrees. For this reason, in the illumination device 1 in which the plurality of light modules 20 are arranged, the uniform illumination light in which the dark point is eliminated even in the thin illumination device 1 in which the distance between the light emitting surface 10a and the diffusion plate 5 is short. Can output through the diffusion plate 5.

Reference Signs List 1 illumination device, 10 illumination substrate, 10a light emitting surface 20 light module, 21 diffuse reflection area, 22 specular reflection area

Claims (7)

A light emitting device having at least three exit faces on the side,
A reflective area disposed around the light emitting device;
An optical module having
The reflection area is
A diffuse reflection area at least a part of which is disposed in front of the light exit surface;
A specular reflection area disposed between the adjacent diffuse reflection areas in a direction not facing the emission surface ;
Including light module. In claim 1,
The optical module, wherein the specular reflection area includes a convex or concave solid shape. In claim 1 or 2,
The light emitting device has the emitting surface directed in four directions,
An optical module, which outputs light having a distribution in which the light intensity in the direction of the specular reflection area to which the light emitting surface is not directed is stronger than the light intensity in the direction of the diffuse reflection area. A plurality of optical modules according to any one of claims 1 to 3, further comprising
A lighting device having a light emitting surface on which the plurality of light modules are disposed. In claim 4,
The light emitting device has the emitting surface directed in four directions,
The lighting device, wherein the light emitting surface includes a portion in which at least a part of the plurality of light modules are two-dimensionally arranged at equal intervals with the direction of the light emitting surface aligned. In claim 4 or 5,
An illumination device comprising a diffusion plate disposed to face the light emitting surface. A lighting device according to claim 4 or 5,
A display device comprising: a translucent display substrate disposed to face the light emitting surface.

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