JPH11260135A - Lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a color of an article from looking like another color by the irradiated light by comprising at least two kinds of light sources emitting lights of different wavebands, and a fluorescent material for expanding the waveband of at least one kind of light source. SOLUTION: Different fluorescent materials 22a, 22b, 22c corresponding to LED chips 16a, 16b, 16c of R, G, B are applied to an upper face of a mold resin 21 covering the LED chips. The fluorescent materials 22a, 22b, 22c are respectively mounted on the positions where only the lights emitted from the LED chips 16a, 16b, 16c are passed. Whereby the waveband of the outgoing light is expanded before the lights of three colors emitted from the LED chips 16a, 16b, 16c are mixed. That is, only the light of with the waveband expandable by the fluorescent materials 22a, 22b, 22c, are passed through the fluorescent materials, so that the impairing of the intensity of the outgoing light of the total lighting system can be reduced by making the lights permeate through the fluorescent materials.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device mainly used for indoor (indoor) lighting, and more particularly to a lighting device using light sources of two or more colors.

[0002]

2. Description of the Related Art Conventionally, incandescent lamps and fluorescent lamps are mainly used as light sources for indoor lighting devices. Instead of these light sources, light emitting diodes (LEDs), which are fixed light emitting elements using semiconductors, are used. It has been considered that the light source is used as a light source for indoor lighting. That is, LEDs are small,
Due to its features such as high brightness and long life, it is expected as a lighting means in the future. At present, its conversion efficiency is not so good at about 1/6 that of general fluorescent lamps, so it is not widely used in the field of lighting. However, considering the above features and the possibility of LEDs, in the near future, LED Could become the mainstream of lighting. By the way, in order to use an LED as a light source for an indoor lighting device, since the LED is originally a point or linear light source, it must be changed to a planar light source.

Conventionally, as a planar light source device using an LED as a light source, a surface light source device for a backlight of a liquid crystal display screen of various electric appliances and the like has been known. A light guide type surface light source device using a conventional LED as a light source is shown in a perspective view of FIG. 1 and a sectional view of FIG. The surface light source device 100 includes a light guide plate 2 for confining light, a light emitting unit 3 and a reflection plate 4. The light guide plate 2 is formed of a transparent resin having a large refractive index such as a polycarbonate resin or a methacryl resin, and a diffusion pattern P is formed on the lower surface of the light guide plate 2 by uneven processing or dot printing of a diffuse reflection ink. I have. The light emitting section 3 has a so-called point light source 3b such as a plurality of LEDs mounted on a circuit board 3a, and faces a side surface (light incident surface 7) of the light guide plate 2. Reflector 4
Is formed of, for example, a white resin sheet having high reflectivity, and both side portions thereof are attached to the lower surface of the light guide plate 2 by the double-sided tape 8.

As shown in FIG. 2, light f emitted from the light emitting section 3 and guided from the light incident surface 7 to the inside of the light guide plate 2 is totally reflected inside the light guide plate 2 so that 2 is trapped inside. When the light f inside the light guide plate 2 enters the diffusion pattern P, the light f is diffusely reflected, and the light f reflected toward the light exit surface 6 at an angle smaller than the critical angle of total reflection is transmitted from the light exit surface 6 to the outside. To be taken out. Further, the light f transmitted through a portion of the lower surface of the light guide plate 2 where the diffusion pattern P does not exist is reflected by the reflection plate 4 and returns to the inside of the light guide plate 2 again, so that loss of light amount from the lower surface of the light guide plate 2 is prevented. Can be.

Means for realizing an indoor lighting device using an LED as a light source include a method of enlarging a light guide type surface light source device as shown in FIGS. 6 and 7 and a method similar to a conventional lighting device. A method of spreading light using a bulk, a diffusion member, or the like can be considered. In any case, when the LED is used as a light source of the lighting device, whitening of the light source is inevitable. As a method of whitening this light source, for example,
A method of using three types of LEDs that emit light of three primary colors of red (R), green (G), and blue (B) and mixing the light emitted from these three LEDs to produce white light, A method of applying a fluorescent material that generates ultraviolet rays to the surface of the LED and emitting white light is mentioned. However, considering the light conversion efficiency and the possibility of color adjustment, the former whitening by mixing the three colors is more effective. It is.

[0006]

However, in the conventional illuminating device using three kinds of LEDs for emitting light of three primary colors of R, G and B as a light source, light of a wide wavelength band is used. Since the light cannot be emitted, when the light emitted from these light sources is irradiated on the object, there is a problem that the color of the irradiated object changes and appears.

FIG. 3 shows L of three primary colors of general R, G and B.
It is a figure which shows the spectrum of ED. As is well known, R,
If there are light sources of three primary colors G and B, all colors can be reproduced.
However, this means that when the light emitted from the light source is directly viewed like a display, all colors can be equivalently reproduced in R, G, and B, and the light emitted from the lighting device is equivalent. When an object is irradiated with light and the light reflected by the object is once viewed, it is not always necessary to emit only R, G, and B light.

FIG. 4 is a diagram showing an example of a reflection spectrum of an object which looks yellow under sunlight. When such an object is illuminated by the illumination device having the light sources of the three primary colors R, G, and B shown in FIG. 3, there is almost no emission light corresponding to the yellow wavelength band from the illumination device. There is almost no reflected light from an object that looks yellow, and the color of the object changes. When an LED is used as the light source, this tendency is particularly strong because the wavelength band of the light emitted from the LED is narrow. In order to improve this, a light source having a broader spectrum such as a broken line in FIG. 3 should be used instead of a light source that emits only light of the three primary colors R, G, and B as shown by the solid line in FIG. is necessary. FIG. 5 is a diagram showing reflected light from the yellow object shown in FIG. When the light from the light source having the broad spectrum shown in (1) is irradiated, the amount of reflected light from the yellow object is larger than that in the case where only the light of the three primary colors R, G, and B shown in (1) is irradiated. I understand.

To make the spectrum broad,
In addition to LEDs of three colors R, G, and B, LEDs that emit light in the wavelength band between R and G and light in the wavelength band between G and B shown in FIG. 6 may be used. However, in this method, five types of LEDs are used, and the circuit becomes complicated, which is not practical.

In addition to using a light source having the above five types of LEDs, there is a method using a fluorescent material as a method for expanding the wavelength band of emitted light. However, even if a fluorescent material is used, it is not possible to freely control the wavelength band. Therefore, as shown in FIG. 7, when only an LED that emits light of one wavelength band is used as the original light source. However, the light spread by the fluorescent material may be intense only in a part of the wavelength band, or light in the original wavelength band of the light source may remain. or,
When shifting light on the short wavelength side to the long wavelength side, if the shift width is wide, energy loss is large and there is a problem in energy efficiency.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a wide wavelength band without complicating a circuit connected to a light source or increasing only a part of the wavelength band. To provide an illuminating device capable of emitting the light of the object and preventing the color of the illuminated object from changing and appearing when the emitted light is illuminated on the object. Aim.

[0012]

In order to achieve the above-mentioned object, the invention according to claim 1 provides at least one of two or more types of light sources that emit light of different wavelength bands.
And a fluorescent material that extends the wavelength band of the light source.

In this configuration, using a fluorescent material,
Since the wavelength band of at least one of the two or more types of light sources having different wavelength bands can be widened, the use of the light source having the widened wavelength band and the light source of another wavelength band enables illumination. Light in a wide wavelength band can be emitted from the device. Thus, when the emitted light is irradiated on the object, it is possible to prevent the color of the irradiated object from changing and appearing.

According to a second aspect of the present invention, there are provided at least two types of light sources for emitting lights having different wavelength bands, a fluorescent material for expanding the wavelength band of at least one of the light sources, and two or more types of light sources. Color mixing means for mixing light having different wavelength bands from the light source, and the fluorescent material is disposed between the light source and the color mixing means at a position where only light reacting with the fluorescent material passes therethrough. In this configuration, in addition to the above-described operation, only the light in the wavelength band that responds to the fluorescent material is incident on the fluorescent material. Can be prevented.

The light source may be a light emitting diode. Thus, the above-described effect can be obtained in a lighting device using an LED having characteristics such as small size, high luminance, and long life as a light source.

In the above, two or more kinds of fluorescent materials may be used. Accordingly, the wavelength bands of two or more types of light sources having different wavelength bands can be broadened, so that the wavelength band of light emitted from the lighting device can be easily broadened.

[0017] At least one kind of fluorescent material may be used to broaden the wavelength band of the light source on the shortest wavelength side. As a result, using a light source with this widened wavelength band,
Since the light in the short wavelength region can be emitted, when the emitted light is irradiated on an object having a color corresponding to the light in the short wavelength region, the color of the irradiated object may change and appear. Can be prevented.

The wavelength band of at least one light source may include light having a wavelength of 500 nm or less. Accordingly, light in a short wavelength region of 500 nm or less can be emitted. When the emitted light is irradiated on an object having a color corresponding to light in the short wavelength region, the color of the irradiated object changes. Can be prevented from being seen.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 8 is a schematic external view of the lighting device according to the present embodiment. The schematic configuration of the illuminating device 11 is the same as the conventional LED backlight shown in FIGS. 1 and 2, and includes a light guide plate 13 (color mixing means) which is a flat transparent medium for confining and guiding light. A sheet or thin reflector 14 provided on a flat plate on the non-emission surface side of the light guide plate 13, a diffusion plate 15 provided on a flat plate on the emission surface side of the light guide plate 13, and a light guide plate 13. The light source module 16 (approximately 1 width) is installed so that light is incident from the end face.
00 mm). The light source module 16 has R, G, and B emitting red (λ = 680 nm), green (λ = 565 nm), and blue (λ = 450 nm) light, respectively.
Are built in. The size of the light guide plate 13 is, for example, 1000 mm × 1000 mm × 10
mm.

The respective lights of R, G and B introduced into the light guide plate 13 from the light source module 16 are mixed in the light guide plate 13 to produce white light. At this time, as described in the above-mentioned description of the “problem to be solved by the invention”, R, G, B
Even if only the light emitted from the three types of LEDs is used, it is not possible to emit light in the entire wavelength band of visible light, so that there is a problem that colors are not reproduced depending on the target object. To solve this problem, a fluorescent material is used to generate light in a wavelength band that has not been emitted from the original LED, and light that has been expanded in this wavelength band is mixed with light emitted from another LED. Broadening the entire wavelength band of the emitted light. Thus, ideal illumination light can be efficiently generated.
Such light is reflected by R, G, and B shown by solid lines in FIG.
It is difficult to generate even if only the light emitted from the kind of LED is used, and it is also difficult to generate even if only the light transmitted through the fluorescent material shown by the solid line in FIG. 7 is used.

The positions where the fluorescent material is provided are (1) the light source module 16, (2) the reflection plate 14 or the diffusion plate 15, and (3)
An extraction pattern portion (diffusion pattern P shown in FIG. 2) provided on the non-emission surface side of the light guide plate 13 can be considered.
However, when the light source module 16 is provided with a fluorescent material, the fluorescent material is irradiated with light before the light of each color is mixed. Therefore, if the fluorescent material is applied only to the portion where the light of the necessary color is transmitted, it is possible to prevent the light of the unnecessary color that does not correspond to the fluorescent material from being incident. This can reduce a decrease in the intensity of the emitted light of the entire lighting device 11 due to transmission of the fluorescent material, so that energy efficiency can be improved.

The light source whose wavelength band is broadened by the fluorescent material is effective not only for the light guide type surface light source shown in FIG. 8, but also for the indirect illumination shown in FIG. 9 and the direct illumination shown in FIG. . The lighting device 11 shown in FIG.
Projection light source 3 with built-in R, G, and B LEDs
0, a diffuse reflector 31 that diffusely reflects light emitted from the projection light source 30. The illumination device 11 shown in FIG. 9 includes a light source 40 in which three types of R, G, and B LEDs are arranged in an array, and a diffusion plate 41 that diffuses light emitted from the light source 40. It is a lighting device. Also when using these lighting devices 11, it is desirable that the fluorescent material is located at a position before the light is mixed.

Next, an example of installing a fluorescent material on the LED emission side will be described with reference to FIG. FIG.
1) and (a2) are examples of fluorescent material installation when a plurality of LED chips are molded in a horizontal line, and (b1) and (b)
2) (b3) is an example of fluorescent material installation when individual LED chips are individually molded. Also, (a1)
(B1) is a fluorescent material setting example when a fluorescent material is applied to the surface of the LED mold resin, (b2) is a fluorescent material setting example when the fluorescent material is dispersed in the mold resin, (a)
2) (b3) is an example of setting a fluorescent material when a fluorescent material is applied on the LED chip. Hereinafter, each installation example will be described.

In the installation example shown in (a1), R, G,
The LED chips 16a, 16b, 1 are placed on the upper surface of the mold resin 21 covering the B LED chips 16a, 16b, 16c.
6c corresponding to different fluorescent materials 22a, 22c
b, 22c are applied. Each fluorescent material 22a, 22
b, 22c are LED chips 16a, 16b,
It is arranged at a position where only the light emitted from 16c passes. In the installation example shown in (a2), the fluorescent materials 22a, 22b, and 22c are applied to the R, G, and B LED chips 16a, 16b, and 16c themselves, instead of the mold resin 21 and the mold resin 23, respectively. In both installation examples, the R, G, and B LED chips 16a, 1
Before the three colors of light emitted from 6b and 16c are mixed,
The wavelength band of the emitted light is widened using the fluorescent materials 22a, 22b, and 22c. Thereby, each fluorescent material 2
Since only the light that can widen the wavelength band by the light emitting elements 2a, 22b, and 22c passes through these fluorescent materials 22a, 22b, and 22c, the light emitted from the entire lighting device 11 by transmitting these fluorescent materials is transmitted. The decrease in strength can be reduced.

In the installation example shown in (b1), the fluorescent material 22c is applied to the surface of the mold resin 23 that covers the LED chip 16c of B color. In the installation example shown in (b2), the fluorescent material 22c is dispersed in the mold resin 23 that covers the LED chip 16c of B color. (B3)
In the installation example shown in FIG. 7, the fluorescent material 22c is applied to the LED chip 16c of B color itself. In any of these installation examples, the wavelength band of the emitted light is broadened using the fluorescent material 22c before the light emitted from the B LED chip 16c is mixed with the light of the other LED chips. These (b1)
In any of the installation examples (b2) and (b3), the fluorescent material 22
Since only light that can expand the wavelength band of the light passes through the fluorescent material 22c, it is possible to reduce a decrease in the intensity of the outgoing light of the entire lighting device 11 due to the transmission of the fluorescent material 22c.

The fluorescent material used for broadening the wavelength band may be of two or more types. By using two or more kinds of fluorescent materials, it is possible to broaden the wavelength band of the emitted light of the LED of a plurality of colors. Therefore, compared to the case where broadening is performed using one kind of fluorescent material, the lighting device The entire wavelength band of the emitted light can be broadened.
Further, as shown in FIG. 12, the fluorescent material may not be applied to all the light sources. FIGS. 12A and 12B show the light source module 16 in the case where the fluorescent material is separately applied to each color of the LED, and in the case where the same color LED is divided into a case where the fluorescent material is applied and a case where the same color is not applied. It is a figure showing each LED. The G and B LEDs in the light source module 16 shown in (a) have fluorescent materials 22b, which can broaden the wavelength band of light emitted from the G and B LEDs, respectively.
22c is applied, but no fluorescent material is applied to the R LED. Further, the G and B LEDs in the light source module 16 shown in (b) are classified into LEDs coated with the fluorescent materials 22b and 22c and LEDs not coated even if the colors of the LEDs are the same.

FIGS. 13A and 13B show the LEs of B, respectively.
It is a figure which shows the spectrum at the time of expanding the wavelength band of the emitted light from D and the emitted light from G LED. (A) shows the spectrum of the original light emitted from the B LED, and (a) shows the spectrum when the wavelength band of the emitted light from the B LED is expanded using a fluorescent material. (B)
Shows the spectrum of the original light emitted from the G LED, and shows the spectrum when the wavelength band of the light emitted from the G LED is expanded using a fluorescent material. As shown in these figures, the fluorescent material can extend the wavelength band of the original LED only to the longer wavelength side. Thus, for example, G
The light of (b) in which the wavelength band of the light emitted from the LED of (b) is broadened cannot cover the wavelength band of the short wavelength region. Therefore, it is desirable to use a fluorescent material that spreads light on the short wavelength side as the fluorescent material. Accordingly, light in a short wavelength region can be emitted, so that when the emitted light is applied to an object, it is possible to prevent the color of the irradiated object from changing and appearing. For the same reason, it is desirable that the light source module 16 has an LED on the short wavelength side. FIG. 14 is a diagram illustrating a spectrum when the wavelength band is broadened by the light source module 16 having no LED on the short wavelength side.
In the figure, shows the spectrum of the original light emitted from the G LED, and shows the spectrum of the light when the wavelength band of the emitted light from the G LED is expanded using a fluorescent material.
When there is no R LED on the short wavelength side, even if the wavelength band is broadened, only light in the wavelength band as shown in FIG. 14 can be emitted. Depending on the application, the wavelength band of only the light emitted from the R LED is widened, the wavelength band of only the light emitted from the G LED is widened, or the wavelength band of the light emitted from the G and R LEDs other than B is widened. There is. In addition, the wavelength band of all light may naturally be expanded.

The present invention is not limited to the above embodiment, but can be variously modified. For example, the light source module 16
May be provided with two types of LEDs B and G, and by broadening the wavelength band of the light emitted from these LEDs together, the entire light emitted from the lighting device may be broadened. Equipped with two kinds of LED of R, L of B
By expanding only the wavelength band of the light emitted from the ED,
The entire light emitted from the lighting device may be broadened. Even in such a configuration, light in the short wavelength region can be emitted by spreading the light emitted from the LED of B to the longer wavelength side. It is possible to prevent the changed color of the object from being seen.

[0029]

As described above, according to the illuminating device of the first aspect, the fluorescent material is used and the two different wavelength bands are used.
Since the wavelength band of at least one of the light sources of the at least one type is expanded, the light source having the widened wavelength band and the light source of another wavelength band can be used to generate a wide wavelength band from the lighting device. By emitting light, it is possible to prevent the emitted object from changing its color and appearing when the emitted light is applied to the object. Therefore, a circuit connected to the light source may be more complicated than a case where light of a wide wavelength band is emitted using five types of light sources that cover light of all wavelength bands in the visible light region. Disappears. In addition, compared to the case where the wavelength band of one type of light source is widened and the object is illuminated using only the light source with the widened wavelength band, only light in a part of the wavelength band becomes stronger, It is possible to prevent light in the original wavelength band from remaining. Furthermore, compared to the case where the wavelength band of one type of light source is widened over a wide range, the width over which the wavelength band is widened can be narrowed, so that the energy loss can be reduced.

According to the illumination device of the present invention, the fluorescent material is disposed between the light source and the color mixing means at a position where only light reacting with the fluorescent material passes therethrough. In addition to the effect described in 1, it is possible to prevent only a light in a wavelength band that responds to the fluorescent material from being incident on the fluorescent material, thereby preventing a decrease in light intensity due to light that does not react with the fluorescent material passing through the fluorescent material. it can.

Further, by using a light emitting diode as the light source, a light emitting diode having characteristics such as small size, high brightness and long life can be obtained.
In a lighting device using an ED as a light source, the same effect as that of the second aspect can be obtained.

Further, in the above, by using two or more kinds of fluorescent materials, the wavelength band of two or more kinds of light sources having different wavelength bands can be broadened. Accordingly, light of a wide wavelength band can be emitted from the lighting device using two or more types of light sources having the widened wavelength bands, so that the effect described in claim 1 can be accurately obtained. it can.

Further, by arranging at least one kind of fluorescent material to widen the wavelength band of the light source on the shortest wavelength side, the emitted light is irradiated onto an object having a color corresponding to light in the short wavelength region. In addition, it is possible to prevent the illuminated object from changing its color and appearing.

Further, by setting the wavelength band of at least one light source to include light having a wavelength of 500 nm or less, light in a short wavelength region of 500 nm or less can be emitted. When irradiating an object having a color corresponding to the light of the region, it is possible to prevent the illuminated object from changing its color and appearing.

[Brief description of the drawings]

FIG. 1 is a perspective view of a conventional surface light source device.

FIG. 2 is a cross-sectional view of a conventional surface light source device.

FIG. 3 is a diagram showing a spectrum of a general R, G, and B primary color LED.

FIG. 4 is a diagram illustrating an example of a reflection spectrum of an object that looks yellow under sunlight.

FIG. 5 is a diagram showing reflected light from the yellow object shown in FIG. 4;

FIG. 6 is a diagram showing a spectrum of each LED when five types of LEDs are used.

FIG. 7 is a diagram showing a broadened spectrum when only one type of LED is used as an original light source.

FIG. 8 is a schematic external view of a lighting device according to an embodiment of the present invention.

FIG. 9 is an optical system configuration diagram of indirect illumination.

FIG. 10 is an optical system configuration diagram of a direct illumination.

FIG. 11 is a diagram illustrating an example of installation of a fluorescent material on an LED emission side.

12 (a) and (b) show the light source module in the case where the fluorescent material is separately applied to each color of the LED, and the case where the same color LED is divided into a case where the fluorescent material is applied and a case where the fluorescent material is not applied. It is a figure showing each LED.

FIGS. 13A and 13B are diagrams showing spectra when light emitted from a B LED and light emitted from a G LED are expanded, respectively.

FIG. 14 is a diagram showing a spectrum when a wavelength band is broadened by a light source module having no LED on the short wavelength side.

[Explanation of symbols]

 Reference Signs List 11 lighting device 13 light guide plate (color mixing means) 16a LED chip (light source, light emitting diode) 16b LED chip (light source, light emitting diode) 16c LED chip (light source, light emitting diode) 22a fluorescent material 22b fluorescent material 22c fluorescent material

Claims (6)

[Claims] 1. A device for emitting light having different wavelength bands from each other.
A lighting device comprising: at least one kind of light source; and a fluorescent material that extends a wavelength band of at least one of the light sources. 2. A light source for emitting lights having different wavelength bands from each other.
A light source of at least one kind, a fluorescent material that extends the wavelength band of at least one of the light sources, and a color mixing unit that mixes light of different wavelength bands from the two or more light sources, wherein the fluorescent material is Between the light source and the color mixing means,
An illumination device, wherein the illumination device is arranged at a position where only light reacting with the fluorescent material passes. 3. The lighting device according to claim 2, wherein the light source is a light emitting diode. 4. The lighting device according to claim 1, wherein two or more kinds of fluorescent materials are used. 5. The lighting device according to claim 4, wherein at least one kind of fluorescent material broadens a wavelength band of a light source on the shortest wavelength side. 6. The wavelength band of at least one type of light source,
The lighting device according to claim 1, wherein the lighting device includes light having a wavelength of 500 nm or less.