JP4818348B2 - Lighting device - Google Patents

Description

  The present invention relates to an illumination device using a light emitting diode (LED) that can replace an illumination device using an incandescent bulb or a fluorescent lamp.

  In general, the characteristics of light-emitting diodes (hereinafter referred to as LEDs) are (1) long life because of semiconductor elements, no sudden disconnection like incandescent bulbs, and (2) no thermal or discharge light emission Therefore, the lighting and extinguishing speed is fast, (3) high electricity-light conversion efficiency and low power consumption (about 1/8 of incandescent bulb, about 1/2 of fluorescent lamp), (4) the element itself is very small, etc. It has been known. For this reason, various lighting devices using LEDs have been proposed. In addition, it is expected that LED lighting equipment will be put to practical use from the viewpoint of reduction of lighting energy (resource conservation), which is a problem in recent years, and disposal of waste including lead and mercury (environmental protection) such as used light bulbs. Has been.

  However, the emission spectrum of the LED is sharp, and it has been widely used as a monochromatic light source for lighting of displays of automobile instruments and audio equipment. However, until it replaces an illumination device using an incandescent bulb or a fluorescent lamp. Has not reached. Also, until recently, the emission brightness of green LEDs and blue LEDs was lower than the emission brightness of red LEDs, so white light sources combining these LEDs of each color were theoretically possible, but have not been put into practical use. It was.

  The present invention has been made to solve the above-described problems of the conventional example, and provides an illuminating device capable of replacing an illuminating device using an incandescent bulb or a fluorescent lamp while using an LED as a light source. It is aimed.

In order to achieve the above object, the illumination device of the present invention uses, as a light source, a light emitting diode unit composed of a single light emitting diode that emits light having a first spectral spectrum distribution, for example, as shown in FIGS. A plurality of the light emitting diode units are two-dimensionally arranged on a substrate, and light emitted from the plurality of light emitting diode units is guided to have an incident surface on which the emitted light is incident and an output surface opposite to the incident surface. It is incident on the light plate, so as to face the emission surface, by disposing a display panel having a light shielding portion excluding the light emitting portion and a front Symbol emitting portion formed in a predetermined pattern, SL before the light incident on the light guide plate It is intended to either the light emitting portion, et al emitted prior SL-emitting portion
Contains a phosphor emitting fluorescence having a second spectral distribution by receiving light emitted from the light emitting diode itself, it characterized that you placing the light emitting diode unit directly below the light blocking part.

As described above, the illumination device of the present invention uses a light emitting diode unit made up of a single light emitting diode that emits light having a first spectral spectrum distribution as a light source, and two-dimensionally arranges a plurality of the light emitting diode units on a substrate. The light emitted from the plurality of light emitting diode units is incident on a light guide plate having an incident surface on which the emitted light is incident and an output surface opposite to the incident surface, and is opposed to the output surface. , by placing the display panel having a light shielding portion excluding the light emitting portion及 beauty front Symbol emitting portion formed in a predetermined pattern, before the light incident on the light guide plate Symbol
Is intended to emit one light emitting portion, et al, prior SL-emitting portion, contains a phosphor which emits fluorescence having a second spectral distribution by receiving light emitted from the light emitting diode itself, the shielding the light emitting diode unit characterized that you directly under the section. In other words, the light-emitting diode is almost a monochromatic light source, but since it uses re-emission by phosphors, it is possible to obtain emission colors over a wide wavelength range and to replace lighting devices using light bulbs or fluorescent lamps. It becomes. In addition, the initial cost of a light emitting diode is higher than that of a lighting device using a light bulb or fluorescent lamp, but it has high electrical-light conversion efficiency and low power consumption. Therefore, the total lighting cost can be reduced.

In addition, by using any one of light emitting diodes having a short wavelength and high power as a single light emitting diode, and using a light emitting diode that emits substantially white light as a phosphor cap, the power consumption of the lighting device further reduction of the possible and that Do not.

  Moreover, it is possible to provide an illuminating device that can be used as a display unit such as an audio device by configuring the phosphor sheet to include a light emitting unit formed in a predetermined pattern and a light shielding unit excluding the light emitting unit. It becomes.

Furthermore, since it is easy to make the thickness of the phosphor cap and the phosphor sheet uniform, the distribution of the phosphor in the phosphor cap and the phosphor sheet can be made uniform. As a result, it is possible to equalize the luminance and color of relapse light from these phosphors cap and the phosphor sheet.

(First embodiment)
It explained first embodiment of the lighting device. The first embodiment relates to an indoor lighting device provided on a ceiling or a wall surface. FIG. 1 is a perspective view showing an appearance and a configuration of a lighting device according to the first embodiment, and FIG. 2 is a sectional view thereof. FIG. 3 is a partial cross-sectional view showing the configuration of the LED used in the first embodiment.

  As shown in FIG.1 and FIG.2, the illuminating device 100 of 1st Embodiment is the milky white translucent cover member 110, and the base member 120 holding the some LED unit 200 arranged in two dimensions. The circuit board 130 provided on the inner side of the base member 120 and the control switch 140 for adjusting the amount of light installed at a location distant from the lighting device 100 are configured. The circuit board 130 is connected to a commercial AC power supply 150.

  As shown in FIG. 2, the LED mounting surface 121 of the base member 120 is formed so that the center portion thereof is convex according to the shape of the cover member 110. Further, the surface of the LED mounting surface 121 is mirror-finished or metal-plated so as to reflect light toward the cover member 110.

  In the first embodiment, the shape of the cover member 110 base member 120 is circular as an example. However, the shape is not limited to this, and may be a polygon such as a square, a rectangle, a hexagon, or any other shape. Also good. The LED units 200 are arranged in a circular shape or a polygonal shape according to the shapes of the cover member 110 and the base member 120. What is necessary is just to select the arrangement | sequence space | interval of each LED unit 200 suitably according to the directivity of the LED unit 200, its magnitude | size, emitted light intensity, etc. FIG.

  When brightness (light quantity) adjustment is performed in a lighting device using LEDs, the number of LED units 200 to be lit is adjusted. The control circuit provided on the circuit board 130 selects the LED units 200 to be lit according to the signal from the control switch 140 and controls their on / off. For example, when the light quantity is maximum, all the LED units 200 are turned on, and when the light quantity is minimum, only a few LED units 200 located in the center are turned on. Alternatively, a predetermined number of LED units 200 may be lit in a distributed manner.

  In an example of the LED unit 200 shown in FIG. 3, a resin-made phosphor cap 220 including a phosphor is provided outside a known single LED 210. As is well known, the emission spectrum of an LED is sharp and is substantially a monochromatic light source. Therefore, in the present embodiment, the LED unit 210 is once caused to emit light, and the phosphor included in the phosphor cap 220 receives light from the LED unit 210 and re-emits white light, for example. . The emission color of the single LED 210 is not particularly limited, and a red LED, a blue LED, an ultraviolet LED, or the like that has recently been put into practical use may be used. Specifically, Ga: ZnO red LED, GaP: N green LED, GaAsP red LED, GaAsP orange / yellow LED, GaAlAs LED, InGaAlP orange / yellow LED, GaN blue LED, SiC blue LED, II -VI group blue LED etc. can be mentioned.

  As an example of the single LED 210, a blue LED having a peak wavelength of 470 nm is used, and when a YAG phosphor is used as an example of the phosphor included in the phosphor cap 220, the spectrum distribution of the blue LED and the YAG phosphor is shown in FIG. Shown in As apparent from FIG. 4, since the YAG phosphor is re-emitted, yellow and red light that is hardly included in the blue LED spectrum distribution is emitted, and the LED unit 200 as a whole is almost white. It can be seen that light is emitted.

  In general, LEDs have strong directivity, and the brightness is high when the LED is viewed from the front. However, it is known that the brightness decreases as the angle at which the LED is observed increases, and no light emission is observed. Yes. However, the directivity of the LED unit 200 as a whole can be reduced by covering the single LED 210 with the phosphor cap 220 containing the phosphor. The reason is considered as follows.

  The light emitted from the single LED 210 is incident on the phosphor cap 220, but not all the light is directly incident on the phosphor cap 220, but a part of the light is reflected on the surface of the phosphor cap 220 and the LED Return to the unit 210 side. The light reflected to the LED unit 210 side is reflected again by the surface of the LED unit 210 and travels toward the phosphor cap 220 side. Since the same phenomenon as described above is repeated on the surface of the phosphor cap 220, by repeating such reflection infinitely, the light emitted from the single LED 210 is scattered and enters almost the entire phosphor cap 220. Since the phosphor cap 220 contains the phosphor almost uniformly, it is considered that almost the entire phosphor cap 220 serves as a light source and emits light.

  Note that the LED mounting surface 121 of the base member 120 is not necessarily formed so that the central portion is convex, and may be a flat surface.

(Second Embodiment)
It described implementation form of lighting apparatus according to the present invention. The second embodiment relates to an illuminating device used for a display unit of an audio device for automobiles, an instrument, an air conditioner, or the like. Figure 5 is a perspective view showing the appearance and configuration of an illumination device of the second embodiment according to the present invention, FIG. 7 is a sectional view showing a configuration of a second embodiment shaped state according to the present invention.

As shown in FIG. 5, the illumination device 300 according to the second embodiment includes a substrate 310 having a reflective surface 311, a light guide plate 320 provided on the reflective surface 311 and formed of a transparent resin such as acrylic, The light guide plate 320 is provided on the opposite side of the mirror surface 311 and includes a light transmitting portion 331 that transmits light such as characters and figures and a display plate 330 that includes a light shielding portion 332 that does not transmit light. The light guide plate 320 is formed with a recess 321 that faces the LED unit 210 provided on the substrate 310 and accommodates the LED unit 210 . As the single LED 210 , the single LED used in the first embodiment is used.

The light emitted from the single LED 210 enters the light guide plate 320 from the interface of the recess 321 of the light guide plate 320 and travels straight through the light guide plate 320. When the light traveling inside the light guide plate 320 reaches the interface between the light guide plate 320 and the reflective surface 311 of the substrate 310 or the light shielding portion 332 of the display plate 330, the light is reflected at the interface and travels straight through the light guide plate 320 again. This light repeats this reflection until it reaches the light transmitting portion 331 and exits from the light guide plate 320 or attenuates.

  Since the translucent portion 331 is formed in the shape of a predetermined character, symbol, or the like, the observer can recognize the character, symbol, or the like by the light emitted from the translucent portion 331. The display plate 330 may be, for example, a resin molded product colored in black or the like, or a light shielding portion 332 printed with a black paint or the like on the exit surface of the light guide plate 320.

FIG. 7 shows a sectional view of the configuration of the embodiment according to the present invention. In Figure 7, the application of two-color molding technique resin, the light emitting unit 334 corresponding to the transparent portion is molded with a resin containing fluorescent material, molding the light-shielding portion 332 with a resin containing a light-shielding pigment. In Figure 7, instead of the light emitted from the light transmitting portion 331, the phosphor of the light emitting portion 334 emits light directly disposed at a position of the transparent portion 331.

In the configuration are shown in FIG. 6, but observing the light passing through the transparent portion 331, since the configuration according to the present invention are shown in FIG. 7 emits light directly from the light emitting portion 334, the appearance of the characters and symbols Slightly different.

(Third embodiment)
It explained a third embodiment of the lighting device. The third embodiment relates to an illumination device for a liquid crystal panel used as a display unit of a car navigation system for automobiles, a video camera, a mobile phone, a personal computer, or the like. FIG. 8 is a perspective view showing the appearance and configuration of the lighting apparatus of the third embodiment, and FIG. 9 is a sectional view thereof. FIG. 10 is a cross-sectional view showing a configuration of a modification of the third embodiment.

  As illustrated in FIGS. 8 and 9, the illumination device 400 according to the third embodiment includes a light guide plate 410 that has an emission surface 411 and a reflection surface 412 and is formed of a transparent resin such as acrylic, and the light guide plate 410. The light emitting portion 420 is provided so as to face the incident surface 413 substantially orthogonal to the light emitting surface 411. The exit surface 411 of the light guide plate 410 is disposed so as to face the entrance surface of the liquid crystal panel 500.

  In the light emitting unit 420, a plurality of LED units 200 are arranged so as to face the incident surface 413 of the light guide plate 410 and to be parallel to the hand direction of the incident surface 413. The LED unit 200 (see FIG. 3) used in the first embodiment is used.

  Light emitted from the LED unit 200 enters the light guide plate 410 from the incident surface 413 of the light guide plate 410 and travels straight through the light guide plate 410. When the light traveling inside the light guide plate 410 reaches the interface between the reflection surface 412 or the emission surface 411 of the light guide plate 410 and the air, the light is reflected at the interface and travels straight through the light guide plate 410 again. This light repeats this reflection until it reaches the exit surface 411 and exits from the light guide plate 410 or attenuates. Note that the reflection surface 412 is inclined so as to be closer to the emission surface 411 as the distance from the incident surface 413 increases, so that the amount of light emitted from the emission surface 411 toward the liquid crystal panel 500 becomes uniform.

  In the modification shown in FIG. 10, a phosphor sheet 430 formed of a resin containing a phosphor is provided so as to face the emission surface 411 of the light guide plate 410. Further, instead of the LED unit 200 including the phosphor cap 220, the single LED 210 is used. In this modification, the liquid crystal panel 500 is not directly illuminated with the light emitted from the emission surface of the light guide plate 410, but is emitted from the phosphor of the phosphor sheet 430 provided so as to face the emission surface 411. Illuminate 500.

( Reference example )
Next, the LED unit 210, the phosphor cap 220, the phosphor sheet 430, and the like used in each of the above embodiments were prototyped, and the results are shown.

Reference example 1

  1.5 parts of NKP-8306 (phosphor name, manufactured by Nippon Fluorescent Chemical Co., Ltd.) as a fluorescent substance was dispersed in silicone rubber, and a phosphor cap 220 having a thickness of 0.5 mm was molded using a mold and a heat press. Further, as the single LED 210, in accordance with the CIE (International Lighting Commission) standard colorimetric system (hereinafter referred to as chromaticity coordinates), chromaticity coordinates x = 0.1490, y = 0.1203. Blue LEDs were used. When the phosphor cap 220 was attached to the blue LED 210 to emit light, yellowish diffuse white light with chromaticity coordinates of x = 0.3912 and y = 0.4322 was observed.

In this case, the luminance of the single blue LED 210 was 32 cd / m ² , but the luminance was increased to 66 cd / m ² by attaching the phosphor cap 220 and changing the color tone, thereby reducing the directivity specific to the LED. The luminescent color was diffused from the entire surface of the phosphor cap 220.

Reference example 2

  By changing the addition amount of NKP-8306 (phosphor name, manufactured by Nippon Fluorochemicals, Inc.) as a fluorescent substance to 1.25 parts, 1.07 parts, 0.94 parts, 0.83 parts and 0.75 parts, The phosphor caps 220 having a thickness of 0.5 mm were molded using the same mold and heating press as in Production Example 1 after being dispersed in silicone rubber. When these phosphor caps 220 were mounted on a blue LED 210 having chromaticity coordinates of x = 0.1490 and y = 0.1203 to emit light, the results of diffuse emission colors shown in Table 1 below were obtained. .

As is clear from the results in Table 1, it was confirmed that the emission color could be controlled by the amount of fluorescent material added. In particular, in the above case, it was observed that the emission color when 1.25 parts of the fluorescent material was dispersed had the highest luminance of 70 cd / m ² .

  In addition, the thickness of the phosphor cap 220 may be uniform, or the thickness of the phosphor cap 220 may be partially changed to diffuse the emission color or change the color tone, and design according to the purpose. Can do.

Reference example 3

  NKP-8306 (phosphor name, manufactured by Nippon Fluorescent Chemical Co., Ltd.) was used as a fluorescent substance, and this was mixed with gadolinium oxide as an additive in a ratio of 10: 2. 0.75 part of this mixture was dispersed in silicone rubber, and a phosphor cap 220 having a thickness of 0.5 mm was molded using a mold and a heat press. When this phosphor cap 220 is attached to the blue LED alone 210 whose emission color is chromaticity coordinates x = 0.1490 and y = 0.1203, chromaticity coordinates x = 0.2971 and y = 0.3485. A bluish diffuse white light was observed.

Reference example 4

  NKP-8306 (phosphor name, manufactured by Nippon Fluorescent Chemical Co., Ltd.) was used as a fluorescent substance, and this was mixed with gadolinium oxide as an additive at a ratio of 10: 4. 0.75 part of this mixture was dispersed in silicone rubber, and a phosphor cap 220 having a thickness of 0.5 mm was molded using a mold and a heat press. When this phosphor cap 220 is attached to the blue LED unit 210 whose emission color is chromaticity coordinates x = 0.1490 and y = 0.1203, the chromaticity coordinates x = 0.2985 and y = 0.3529. A bluish diffuse white light was observed.

Reference Example 5

  NKP-8306 (phosphor name, manufactured by Nippon Fluorescent Chemical Co., Ltd.) was used as a fluorescent substance, and this was mixed with gadolinium oxide as an additive in a ratio of 10: 6. 0.75 part of this mixture was dispersed in silicone rubber, and a phosphor cap 220 having a thickness of 0.5 mm was molded using a mold and a heat press. When this phosphor cap 220 is attached to the blue LED unit 210 whose emission color is chromaticity coordinates x = 0.1490 and y = 0.1203, the chromaticity coordinates x = 0.3090 and y = 0.3679. A diffuse white color was observed.

Reference Example 6

NKP-8306 (phosphor name, manufactured by Nippon Fluorescent Chemical Co., Ltd.) was used as a fluorescent substance, and this was mixed with gadolinium oxide as an additive at a ratio of 10: 8. 0.75 part of this mixture was dispersed in silicone rubber, and a phosphor cap 220 having a thickness of 0.5 mm was molded using a mold and a heat press. When this phosphor cap 220 is attached to the blue LED alone 210 whose emission color is chromaticity coordinates x = 0.1490 and y = 0.1203, the chromaticity coordinates x = 0.3138 and y = 0.3734. A diffuse white color was observed.

Reference Example 7

  NKP-8306 (phosphor name, manufactured by Nippon Fluorescent Chemical Co., Ltd.) was used as a fluorescent substance, and this was mixed with gadolinium oxide as an additive at a ratio of 10:10. 0.75 part of this mixture was dispersed in silicone rubber, and a phosphor cap 220 having a thickness of 0.5 mm was molded using a mold and a heat press. When this phosphor cap 220 is attached to a blue LED unit 210 whose emission color is chromaticity coordinates x = 0.1490 and y = 0.1203, chromaticity coordinates are x = 0.3254 and y = 0.3890. A diffuse white color was observed.

As is clear from the results of the emission color of the upper Symbol Reference Example 3-7, by increasing the addition amount of the oxidizing gadolinium, it is seen that may effectively excite the wavelength of the blue LED itself 210.

Reference Example 8

40 parts of YAG phosphor (yttrium 28.0 wt%, aluminum 13.6 wt%, gadolinium 56.62 wt%, cerium 1.23 wt%) as a fluorescent substance is dispersed in silicone rubber, and is thickened using a mold and a heating press. A 0.6 mm phosphor cap 220 was molded. Further, as the single LED 210, a blue LED having chromaticity coordinates of x = 0.1275, y = 0.0883, and luminance of 28.95 cd / m ² was used.

When the phosphor cap 20 is attached to the blue LED 210 to emit light, diffuse white light having chromaticity coordinates of x = 0.3192, y = 0.3375, and luminance of 66.36 cd / m ² is observed. It was done.

Reference Example 9

  12.5 parts of YAG phosphor (yttrium 28.0 wt%, aluminum 13.6 wt%, gadolinium 56.62 wt%, cerium 1.23 wt%) as a fluorescent substance is dispersed in silicone rubber to obtain a fluorescent material having a thickness of 0.5 mm. A body sheet was created.

As a blue LED itself 210, using those used above Symbol Reference Example 8, the above phosphor sheet is mounted from a blue emitting LED alone 210 at a distance 5 mm, it was turn on the light-emitting diodes with 20mA of current. The light diffused through the phosphor sheet was measured with a spectral radiance meter “PR-704”. As a result, diffuse white light with chromaticity coordinates of x = 0.2667, y = 0.2725, and luminance of 1629 cd / m ² was obtained. Observed.

Reference Example 10

Phosphor cap 210 having a thickness of 0.5 mm is dispersed in silicone rubber by dispersing 0.2 part of “LumogenORANGE F” (BASF), which is a perylene-based condensing fluorescent dye, as a fluorescent substance. Was molded. Further, when the blue LED single unit 210 used in the above-mentioned Reference Example 8 was used, and the blue LED single unit 210 was mounted with the phosphor cap 210 to emit light at a current of 20 mA, x = 0. Diffuse white light with 3405, y = 0.3235, and luminance of 2.124 cd / m ² was observed.

(Other embodiments)
In each of the above embodiments, the phosphor is configured to emit white light. However, the present invention is not limited to this, and it goes without saying that a phosphor that emits light bulb color or daylight color may be used. Yes.

  Moreover, in each said embodiment, although comprised so that the phosphor cap 220 containing a fluorescent substance might be covered on the surface of the LED single-piece | unit 210, it is not limited to this, The several LED single-piece | unit 210 contains a fluorescent substance. The structure covered with one cover may be sufficient.

  Further, although silicone rubber is used as the material of the phosphor cap 220, the present invention is not limited to this, and fluorine rubber or the like may be used. That is, any material can be used as long as it transmits ultraviolet light and is hardly deteriorated by ultraviolet light.

  Furthermore, in each of the above-described embodiments, the phosphor cap 220 and the phosphor sheet 430 are used separately from the LED unit 210. However, for example, a white LED or the like in which a phosphor is contained in a resin portion constituting the LED may be used. good.

Is a perspective view showing the appearance and construction of the first embodiment of the lighting device. It is sectional drawing which shows the structure of 1st Embodiment. It is a fragmentary sectional view which shows the structure of LED used in 1st Embodiment. It is a figure which shows the spectrum distribution of blue LED and YAG fluorescent substance. Is a perspective view showing the appearance and construction of the second embodiment of the lighting device according to the present invention. It is sectional drawing which shows the structure of 2nd Embodiment. It is a sectional view showing a configuration of a second embodiment according to the present invention. Is a perspective view showing the appearance and configuration of a third embodiment of the lighting device. It is sectional drawing which shows the structure of 3rd Embodiment. It is sectional drawing which shows the structure of the modification of 3rd Embodiment.

DESCRIPTION OF SYMBOLS 100: Illuminating device 110: Cover member 120: Base member 121: LED mounting surface 130: Circuit board 140: Control switch 150: Commercial AC power supply 200: Light emitting diode (LED) unit 210: LED unit 220: Phosphor cap 300: Illumination Device 310: Substrate 311: Reflecting surface 320: Light guide plate 321: Concave portion 330: Display plate 331: Translucent portion 332: Light shielding portion 334: Light emitting portion 400: Illuminating device 410: Light guide plate 411: Output surface 412: Reflecting surface 413: Incident surface 420: light emitting portion 430: phosphor sheet 500: liquid crystal panel

Claims (3)

A light emitting diode unit composed of a single light emitting diode that emits light having a first spectral spectrum distribution is used as a light source,
A plurality of the light emitting diode units are two-dimensionally arranged on a substrate, and light emitted from the plurality of light emitting diode units is guided to have an incident surface on which the emitted light is incident and an output surface opposite to the incident surface. Enter the light plate,
Said to be opposed to the emission surface, by disposing a display panel having a light shielding portion excluding the light emitting portion及 beauty front Symbol emitting portion formed in a predetermined pattern, SL before the light incident on the light guide plate emitting portion or al Is to emit,
The light emitting unit includes a phosphor that emits fluorescence having a second spectral spectrum distribution upon receiving light emitted from the light emitting diode unit ,
Lighting apparatus characterized that you placing the light emitting diode unit directly below the light blocking part. UV, either the near ultraviolet and blue emitting diodes used as the light emitting diode itself, the lighting device according to 請 Motomeko 1 was used which emits substantially white light as the phosphor. The illuminating device according to claim 1, wherein the substrate surface has a reflecting surface that reflects light emitted from the light emitting diode unit.

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