JP2019200929A - LED lighting device - Google Patents

Abstract

To provide an LED lighting device that has high use efficiency of light emitted from an LED and can provide planar lighting with uniform light intensity in a longer direction.SOLUTION: An LED lighting device comprises: a light guide body which is formed thin and long to have the same cross section in a longer direction, and comprises a convex reflecting surface on an upper or lower surface, a convex light emission surface on the lower or upper surface, and incidence surfaces on side surfaces; and a light source part which comprises a plurality of LED chips arranged opposite a side surface on one side or both sides of the light guide body and mounted side by side on a substrate in the longer direction. At least a part of the reflecting surface is formed as a light diffusion part roughened into a frosted glass-like shape. Light beams emitted from the respective LED chips of the light source part are reflected by the internal surface of the light guide body respectively and irregularly reflected by the light diffusion part of the reflecting surface to be mixed and then emitted from the light emission surface, thereby providing lighting with uniform light intensity in the longer direction.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an LED illumination device for performing linear illumination on an object, for example.

Conventionally, for example, in the manufacturing process of a band-shaped poultice, after applying an adhesive containing a poultice drug to a band-shaped substrate, the adhesive is weakened by irradiating the adhesive with ultraviolet light. It is adjusted to.
The adhesive is irradiated with ultraviolet light at a predetermined location while the belt-shaped poultice is transported at a predetermined speed by a belt conveyor, and is irradiated with linear ultraviolet light extending in a direction perpendicular to the transport direction by the belt conveyor. It is done by.

In order to generate such linear ultraviolet light, for example, a plurality of ultraviolet LED light sources arranged side by side in the transverse direction perpendicular to the conveying direction, that is, in the width direction of the band-shaped poultice are used. ing.
However, in such an LED light source, a plurality of ultraviolet LED light sources are required, and the obtained linear ultraviolet light illumination varies in the width direction, particularly in the vicinity of the middle between the LED light sources, The lighting becomes dark.
For this reason, in the band-shaped poultice material, the adhesive force varies in the width direction.

  In contrast, Patent Documents 1 to 4 disclose LED light source devices, respectively.

Patent Document 1 includes a light guide and a large number of LEDs that emit light from the side surface of the light guide toward the inside of the light guide, and light emitted from the LEDs is mixed inside the light guide. The LED is irradiated to the outside from the lower surface of the light guide, and each LED is composed of three colors of LEDs, a red LED, a green LED and a blue LED, which are alternately arranged at equal intervals on the flexible substrate. There has been disclosed a visual inspection light characterized in that a reflection film is provided that reflects light diffused inside the light guide toward the lower surface of the light guide.
According to this visual inspection light, it is possible to irradiate light with a color necessary for visual inspection of an inspection object without requiring a color filter or a mechanism for mounting the color filter.

Further, Patent Document 2 includes a columnar light guide, and a columnar shape including a light emitting diode structure of two or more different light emission colors that make light incident on the columnar light guide from an end of the columnar light guide. A columnar light emitter is disclosed, which is a light emitter, and each light emitting diode structure is formed of a plurality of single-color LED thin films arranged two-dimensionally on a substrate.
According to this columnar light emitter, light from a small number of light emitting diodes is incident from the end of the columnar light emitter, and in the columnar light emitter that realizes side light emission, a plurality of light emitting diode structures are arranged to achieve high luminance. In addition, it is possible to avoid the complexity of the line when adjusting the emission color by adjusting the luminance of each element.

JP 2010-192125 A JP 2012-204197 A

Here, in the light for visual inspection according to Patent Document 1, a reflective film is provided on the upper surface of the light guide, and according to the description of the specification, the reflective film is coated with white paint on the upper surface of the light guide. It is formed by coating.
However, when ultraviolet light is used as illumination light, the wavelength is short, so the reflective film coated with white paint has poor reflectivity of ultraviolet light, and the efficiency of use as illumination light is greatly reduced. There is.

In the columnar light emitter according to Patent Document 2, in the second aspect, the light guide has at least one strip-shaped light reflecting layer along the longitudinal direction. According to the specification, this belt-like light reflecting layer is formed by printing, applying, or the like with a white pigment or a scattering material on the outside or inside of the light guide, or a part of the light guide is mixed with a reflector. It is formed by using a resin, or is made of a metal polishing surface, a metal deposition film, a mirror surface provided with metal plating, a reflecting material in which prisms or glass beads are embedded.
However, in the reflective layer made of white pigment, the reflectance of ultraviolet light is poor as described above, and it is possible to reflect ultraviolet light even in the case of a reflective layer of other configurations, but the configuration and manufacture of the reflective layer itself. There is also a problem that the process becomes complicated and the manufacturing cost becomes high.

  In view of the above points, the present invention has a simple configuration, particularly when ultraviolet light is used as illumination light, and the use efficiency of light emitted from the LED is high, and the linear shape has a uniform luminous intensity in the longitudinal direction. An object of the present invention is to provide an LED lighting device that can perform illumination.

  According to the present invention, the above object is formed in an elongated shape so as to have the same cross-sectional shape in the longitudinal direction, a convex reflecting surface on the upper surface or the lower surface, a convex light emitting surface on the lower surface or the upper surface, and both side surfaces. A light guide made of a translucent material having an incident surface, and a plurality of LED chips that are arranged to face one or both side surfaces of the light guide and are mounted side by side on the substrate in the longitudinal direction And at least part of the reflecting surface is formed as a light diffusing portion, and the light emitted from each LED chip of the light source portion is the inner surface of the light guide. The LED illumination is characterized in that it is reflected by the light diffused by the light diffusion portion of the reflection surface, mixed with light, then emitted from the light emission surface and illuminated with a uniform luminous intensity in the longitudinal direction. Achieved by the device.

  Further, the light diffusing portion constituting at least a part of the reflecting surface is subjected to a roughened surface processing or a plurality of linear shapes in a ground glass shape.

According to the above configuration, the light emitted from each LED chip of the light source unit enters the light guide from the side surface of the opposing light guide, and on the inner surface of the light guide, that is, the upper surface, the lower surface, the end surface, and both side surfaces. After repeating the reflection, the light exits from the light exit surface to the outside of the light guide.
At that time, the light incident on the light diffusion portion of the reflection surface of the inner surface of the light guide is diffused by being diffusely reflected and diffused by the fine uneven shape by the rough surface processing of the light diffusion portion, so that the light guide body is diffused. The incident light is sufficiently mixed in the light guide and then emitted outward from the light exit surface of the light guide.
As a result, the entire light exit surface of the light guide emits light evenly, so that the illumination light emitted from the light exit surface of the light guide is sufficiently diffused in the longitudinal direction, and substantially in the longitudinal direction. It becomes the linear illumination light of uniform luminous intensity.
Here, the light diffusing portion is formed by roughening a part of the reflection surface of the light guide body into a ground glass shape or processing to form a plurality of lines, so that it can be easily and simply configured. It can be manufactured at low cost.
Furthermore, the illumination light emitted from the light exit surface is more effectively diffused and has a uniform intensity in the longitudinal direction due to irregular reflection in a fine uneven shape by roughening the light diffusion portion.

The LED illumination device according to the present invention is preferably characterized in that the radius of curvature of the reflecting surface of the light guide is selected to be larger than the radius of curvature of the light exit surface.
According to this configuration, since the curvature radius of the reflection surface is large, the light reflected by the reflection surface is emitted while being scattered toward the opposite light emission surface. For this reason, the illumination light emitted from the light exit surface becomes scattered light and can effectively illuminate the object.

The LED lighting device according to the present invention is preferably characterized in that the light diffusing portion is provided at least in a region near the center in the lateral direction of the reflecting surface.
According to this configuration, the light diffusion portion is formed in a region extending in the longitudinal direction near the center in the lateral direction on the reflection surface of the light guide member, and effectively diffuses and reflects light with a small area on the reflection surface. And the processing cost of the light diffusing portion can be reduced.

The LED lighting device according to the present invention is preferably characterized in that the plurality of LED chips of the light source unit are ultraviolet light LED chips that emit ultraviolet light.
According to this configuration, the ultraviolet light emitted from each LED chip of the light source unit enters the light guide body from the side surface of the opposing light guide body, and the inner surface of the light guide body, that is, the upper surface, the lower surface, the end surface, and both side surfaces. After repeating the reflection, the light exits from the light exit surface to the outside of the light guide.

  At that time, of the inner surface of the light guide, the ultraviolet light that has entered the light diffusing portion of the reflecting surface is diffused by being reliably diffused and diffused by the rough surface processing of the light diffusing portion. The ultraviolet light is sufficiently mixed and then emitted outward from the light exit surface of the light guide.

  Therefore, even if the light emitted from the light source part is ultraviolet light, it is surely irregularly reflected by the light diffusion part of the reflecting surface of the light guide, so unlike conventional reflectors with white paint with poor reflectivity, etc. Since the ultraviolet light is efficiently diffusely reflected, illumination light with a higher luminous intensity can be obtained.

The LED lighting device of the present invention is characterized by including a reflecting plate for reflecting light at a position facing the reflecting surface of the light guide.
According to this configuration, it is possible to improve the reflection efficiency by reflecting the light leaking from the reflection surface of the light guide by the reflection plate.

  As described above, according to the present invention, a linear structure having a simple configuration and high utilization efficiency of light emitted from the LED, and having a uniform luminous intensity in the longitudinal direction, particularly when ultraviolet light is used as illumination light. It is possible to provide an LED lighting apparatus that can perform the above-described illumination.

It is a schematic perspective view which shows the whole structure of 1st embodiment of the LED lighting apparatus by this invention. It is a schematic plan view which shows the whole structure of the LED lighting apparatus of FIG. It is an expanded sectional view which follows the AA line of the LED lighting apparatus of FIG. 4A to 4C are diagrams showing the configuration of the reflecting surface of the light guide. It is a schematic side view which shows the use condition of the LED lighting apparatus of FIG. It is an expanded sectional view similar to FIG. 3 in 2nd embodiment of the LED lighting apparatus by this invention.

Hereinafter, the present invention will be described in detail based on the embodiments shown in the drawings.
1-4 has shown the structure of 1st embodiment of the LED lighting apparatus by this invention.
1 to 4, the LED lighting device 10 includes a light guide 11 that extends in the longitudinal direction, and a light source unit 12 that is disposed along both sides of the light guide 11.

The light guide 11 is made of a translucent material such as plastic or glass (specifically, a material having translucency with respect to light emitted from the light source unit 12 described later), and is arranged in the longitudinal direction. It extends and has the same cross-sectional shape in the longitudinal direction.
As shown in FIG. 3, the light guide 11 includes a convex reflecting surface 11a on the upper surface, a convex light exit surface 11b on the lower surface, and incident surfaces on both side surfaces 11c and 11d.
In addition, in FIG. 3, although both the side surfaces 11c and 11d are formed as a plane, it may be a cylindrical surface having a curvature instead of a plane.

The reflecting surface 11a is formed in a convex shape upward, for example, a cylindrical surface shape, and its radius of curvature is R1.
Further, in the illustrated case, the entire reflecting surface 11a is formed as a light diffusion portion 11e.
As shown in FIG. 4A, the light diffusing portion 11e is formed by roughing the entire upper surface of the light guide 11 into a ground glass shape, and has a minute uneven shape.
In addition to the roughened surface processing in the frosted glass shape, for example, processing for forming a plurality of straight lines in the length direction of the light guide 11 (FIG. You may form the light-diffusion part 11e by carrying out the process which forms a several diagonal line (FIG.4 (c)).
Here, the above processing is performed by any known processing method, and may be performed by, for example, mechanical processing such as sandblasting, chemical processing such as etching, laser processing, or the like.

The light exit surface 11b is formed in a downward convex shape, for example, a cylindrical surface shape, and its radius of curvature is R2.
Here, the radius of curvature R2 of the light exit surface 11b is selected to be larger than the radius of curvature R1 of the reflective surface 11a. (R1 <R2)

  As shown in FIGS. 1 to 3, the light source unit 12 faces the side surfaces 11 c and 11 d of the light guide 11 described above and extends in the longitudinal direction, that is, with respect to the side surfaces 11 c and 11 d. It arrange | positions so that it may extend in parallel at intervals.

  As shown in FIG. 2, the light source unit 12 is composed of a plurality of LED chips 12b mounted on the substrate 12a extending in the longitudinal direction at regular intervals with respect to the longitudinal direction. A drive current is supplied by a drive circuit (not shown) to emit light.

The substrate 12a has a known configuration, and is selected to have a sufficient size for arranging the LED chips 12a described above, and a drive circuit and the like are mounted as necessary.
The substrate 12a may be divided into a plurality of parts in the longitudinal direction.

  Each LED chip 12b is an ultraviolet LED chip in the case of illustration, and emits ultraviolet light when a drive current is supplied from a drive circuit (not shown).

The LED lighting device according to the present invention is configured as described above, and each LED chip 12b emits light by supplying a driving current to each LED chip 12b of the light source unit 12 on both sides by a driving circuit (not shown). Then, ultraviolet light is emitted.
Thereby, the ultraviolet light emitted from each LED chip 12 b of each light source unit 12 enters the light guide 11 from the opposite side surfaces 11 c and 11 d of the light guide 11 facing each other.

  The ultraviolet light incident on the light guide 11 is repeatedly reflected on the inner surface of the light guide 11. That is, the ultraviolet light that has entered the light guide 11 is reflected by the reflection surface 11a on the upper surface of the light guide 1, or is reflected by both side surfaces 11d and 11c of the light guide 11, and the light on the reflection surface 11a. Diffusely diffused by the minute uneven shape of the diffusion portion 11e.

In this way, the ultraviolet light that is repeatedly reflected and diffused on the inner surface of the light guide 11 is sufficiently mixed in the light guide 11, and the light exit surface 11 b that is the lower surface of the light guide 11. The light exits from the bottom. At that time, the entire light exit surface 11b of the light guide 11 emits light evenly.
Here, since the radius of curvature R2 of the light exit surface 11b is larger than the radius of curvature R1 of the reflective surface 11a, the ultraviolet light reflected by the inner surface of the reflective surface 11a exits from the light output surface 11b as scattered light after reflection.

Therefore, the ultraviolet light incident on the reflecting surface 11a from the inside of the light guide 11 is diffused and reflected by irregular reflection in the width direction and the longitudinal direction as a whole, and the reflecting surface 11a and the outgoing light are reflected in the width direction. The light is focused and reflected by the cylindrical shape of the surface 11b.
Thus, the ultraviolet light emitted downward from the light exit surface 11b on the lower surface of the light guide 11 is converged and thinned in the width direction and diffused in the longitudinal direction to become uniform illumination light as a whole.
In addition, a reflector (not shown) having a good reflectivity of ultraviolet light made of a plate-like member (for example, made of aluminum) having a length similar to the length of the light guide 11 is provided on the upper portion of the light guide 11 main body. 2) is reflected, it is possible to reflect the ultraviolet light leaking from the reflecting surface 11a of the light guide 11 and improve the reflection efficiency.

When adjusting the adhesive force of the adhesive by irradiating the above-mentioned poultice material with ultraviolet light using the LED lighting device 10 having such a configuration, it is installed and operated as shown in FIG. To do.
That is, in FIG. 5, the LED lighting device 10 is arranged so that the longitudinal direction thereof coincides with the width direction of the belt conveyor 20 with respect to the long band-shaped poultice material 21 conveyed by the belt conveyor 20.

And the illumination light L by the planar ultraviolet light is irradiated with respect to the strip | belt-shaped poultice material 21 conveyed by the predetermined speed from the LED lighting apparatus 10. FIG. As a result, the band-shaped poultice 21 is irradiated with ultraviolet light for the time required to pass through the linear ultraviolet light L, and the ultraviolet light irradiation cures the components of the adhesive, resulting in adhesive strength. Is weakened.
Therefore, the adhesive force is adjusted by the ultraviolet irradiation time, that is, the ultraviolet light beam passage time. By adjusting the conveying speed of the belt conveyor 20, the adhesive force can be adjusted by the ultraviolet light irradiation.

FIG. 6 shows a configuration of a second embodiment of the LED lighting device according to the present invention.
In FIG. 6, the LED lighting device 30 has substantially the same configuration as the LED lighting device 10 shown in FIG. 3.
That is, the LED illuminating device 30 is different from the LED illuminating device 10 shown in FIG. 3 in that the light diffusion layer 11f is formed only on a part of the reflecting surface 11a on the upper surface of the light guide 11, that is, in the central portion in the width direction. It has a different structure only in that it is.

According to the LED illumination device 30 having such a configuration, the ultraviolet light emitted from the individual LED chips 12b of the light source units 12 is opposed to the light guide as in the LED illumination device 10 illustrated in FIGS. 11 enters the light guide 11 from both side surfaces 11c and 11d.
Then, the ultraviolet light that has entered the light guide 11 is repeatedly reflected on the inner surface of the light guide 11. In other words, the ultraviolet light that has entered the light guide 11 is reflected by the reflection surface 11a on the upper surface of the light guide 1, or is reflected by the both side surfaces 11d and 11c of the light guide 11, and one of the reflection surfaces 11a. Diffusely diffused by the minute uneven shape of the light diffusion portion 11f formed in the portion.

  In this way, the ultraviolet light diffused by being repeatedly reflected on the inner surface of the light guide 11 is sufficiently mixed in the light guide 11 and downward from the light exit surface 11 b which is the lower surface of the light guide 11. Exit toward. At that time, the entire light exit surface 11b of the light guide 11 emits light evenly.

  In this case, the light diffusing portion 11f is provided only in the vicinity of the center in the width direction on the upper surface of the light guide 11, but the light diffusely reflected in the vicinity of the center in the width direction is shifted to the side without reflecting toward the light exit surface 11b. By doing so, the light is surely diffused and mixed. Thereby, the light radiate | emitted from the light emission surface 11b of the light guide 11 turns into illumination light of a sufficiently uniform luminous intensity regarding the longitudinal direction.

Accordingly, in this case, the rough surface processing of the light diffusion portion 11f with respect to the upper surface of the light guide 11 can be easily performed as the area is small, and the processing time and processing cost can be reduced.
Note that, similarly to the above, the light diffusion portion 11f may be configured by processing to form a plurality of straight lines and diagonal lines.

  Further, similarly to the first embodiment, a reflector having a good reflectivity of ultraviolet light, which is formed of a plate-like member having a length similar to the length of the light guide 11 at the top of the light guide 11 main body. By installing (not shown), it is possible to reflect the ultraviolet light leaking from the reflecting surface 11a and improve the reflection efficiency.

The present invention can be implemented in various forms without departing from the spirit of the present invention.
For example, in the above-described embodiment, the light source unit 12 is provided to face both side surfaces 11c and 11d of the light guide body 11, but not limited to this, the light source unit 12 faces one side surface 11c or 11d. , Only one light source unit 12 may be provided.

In the above-described embodiment, the upper surface of the light guide 11 is the reflection surface and the lower surface is the light output surface. However, the present invention is not limited to this, and the lower surface of the light guide 11 may be the reflection surface and the upper surface may be the light output surface. In this case, the light diffusion portion 11 e or 11 f is formed on the reflection surface on the lower surface of the light guide 11.
Furthermore, in the above-described embodiment, the LED chip 12b of the light source unit 12 is an ultraviolet LED, but is not limited thereto, and may be a single-color LED chip that emits light of other colors or infrared light. It is obvious that multi-color LED chips may be used, and LED chips of a plurality of colors may be mixed.

DESCRIPTION OF SYMBOLS 10,30 LED illuminating device 11 Light guide 11a Reflective surface 11b Light emission surface 11c, 11d Side surface 11e, 11f Light diffusion part 12 Light source part 12a Substrate 12b Ultraviolet light LED chip 20 Belt conveyor 21 Wetting agent

Claims (6)

From a translucent material that is elongated so as to have the same cross-sectional shape in the longitudinal direction, and has a convex reflecting surface on the upper or lower surface, a convex light emitting surface on the lower or upper surface, and an incident surface on both side surfaces. A light guide comprising:
A light source unit composed of a plurality of LED chips arranged opposite to one or both side surfaces of the light guide and mounted in a longitudinal direction on a substrate;
Consists of
At least a part of the reflection surface is formed as a light diffusion portion,
The light emitted from each LED chip of the light source unit is reflected by the inner surface of the light guide and mixed by being diffusely reflected by the light diffusion unit of the reflecting surface, and then emitted from the light emitting surface. Then, the LED illumination device illuminates with a uniform light intensity in the longitudinal direction.   2. The LED lighting device according to claim 1, wherein at least a part of the reflection surface is subjected to a roughened surface processing or a plurality of linear shapes in the light diffusion portion.   The LED illumination device according to claim 1, wherein a radius of curvature of the reflecting surface of the light guide is selected to be larger than a radius of curvature of the light exit surface.   4. The LED lighting device according to claim 1, wherein the light diffusing portion is provided at least in a region near a center in a lateral direction of the reflecting surface. 5.   The LED lighting device according to claim 1, wherein the plurality of LED chips of the light source unit are ultraviolet LED chips that emit ultraviolet light. 6. The LED lighting device according to claim 1, further comprising a reflecting plate for reflecting light at a position facing the reflecting surface of the light guide.

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