JP2004282389A - Illumination light communication device and illuminating element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illumination light communication device capable of performing communication also when the lighting is off and capable of effectively utilizing infrared communication. <P>SOLUTION: In the case of performing communication by using illumination light when the illumination is on, switches 12, 13 are turned on, a signal modulated in an optical modulation part 11 in accordance with information is superposed to a power waveform for the illumination with a power distributer 15 and the illumination 16 is driven in a modulated state. When the illumination is off, the switches 12, 13 are turned off, a switch 14 is turned on and a communication part 17 is driven in a modulated state by the optical modulation part 11. The communication part 17 can be constituted so as to include an infrared light emitting element part to perform infrared communication when the illumination is off. Consequently communication can be performed not only when the of illumination is on but also when the lighting is kept off. The communication device can be constituted of one element integrating the illumination part 16 and the communication part 17, so that a compact system can be constituted. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an illumination light communication technique using illumination light for communication.
[0002]
[Prior art]
Lighting is widely used as an indoor or outdoor light source, and incandescent lamps and fluorescent lamps are widely used as light sources at present. In recent years, in addition to these light sources, light emitting diodes (LEDs) have been used as light sources for illumination.
[0003]
FIG. 8 is a configuration diagram of an example of a general white LED. In the figure, 31 and 41 are LED elements, 32 is a red light emitting element section, 33 is a green light emitting element section, 34 is a blue light emitting element section, 42 is a light emitting element section, and 43 is a fluorescent agent. In the example of the white LED shown in FIG. 8A, a red light emitting element portion 32 that emits red light, a green light emitting element portion 33 that emits green light, and a blue light emitting element that emits blue light are included in the LED element 31. 3 shows a configuration in which the units 34 are arranged side by side. The red, green, and blue lights emitted from the respective light emitting element units are mixed and visually recognized as white light.
[0004]
In the example of the white LED shown in FIG. 8B, a blue or ultraviolet light emitting element portion 42 is provided in the LED element 41, and a fluorescent agent 43 is provided around the light emitting element portion 42. I have. The LED element 41 is similar to a fluorescent lamp. When the blue or ultraviolet light emitted from the light emitting element section 42 is irradiated on the fluorescent agent 43, the fluorescent agent 43 emits white light. This results in the emission of white light.
[0005]
Since such a single LED element has a small amount of light emission for use in illumination at present, it is usually used as a plurality of LED arrays. In the following description, the LED array may be referred to as an LED. Such an LED array is used for, for example, some traffic signals, rear lamps of automobiles, desk lamps, foot lights, and the like. LEDs have excellent features such as long life, small size, and low power consumption as compared with conventional illumination light sources such as incandescent light bulbs and fluorescent lamps, and thus are promising as future illumination light sources.
[0006]
In addition, a light emitting element such as an LED has a characteristic that a response speed is very fast because no extra heat time is required. Focusing on this fast response speed and the fact that it can be electrically controlled, research is currently being conducted to superimpose a signal on illumination light using an LED to provide a signal transmission function. For example, it is described in Non-Patent Document 1 and the like.
[0007]
In the case of lighting, in many cases, light is radiated from a high position to prevent a shadow from being cast over a certain area, for example, by installing a lighting device widely on a ceiling or a wall, or by building a pole. In general, in wireless communication including light, shadowing that causes a communication failure due to a decrease in signal strength in the shadow of an object poses a problem. However, as described above, the lighting is often installed so as not to cast shadows. Therefore, using the lighting for communication means that communication can be performed without shadowing. In addition, since large illumination power can be used, there is an advantage that communication quality can be improved.
[0008]
However, since this illumination light communication uses illumination light, there is a problem that it cannot be used if the illumination is turned off. Of course, it is sufficient to turn on the light even when the light is unnecessary. However, turning on the light when not necessary from the viewpoint of energy saving may not be understood by the user in some cases. For example, the light cannot be turned on at night or the like. Often. If the light is turned off, communication cannot be performed, and there is a problem that communication cannot be performed when the user is absent, at night, or when using a projector.
[0009]
On the other hand, infrared communication has been widely used, and standardization such as IrDA has been performed. In infrared light communication, communication with high power cannot be performed because there is concern about the influence on the human body such as eye safe. In addition, due to the characteristics of light, if an obstacle such as a user is present, the communication quality is easily affected by shadowing, which deteriorates communication quality. For this reason, the range of use has been narrowed, and there have been cases where stable use is not possible.
[0010]
[Non-patent document 1]
Toshihiko Komine, Yuichi Tanaka, Masao Nakagawa, "A Fusion System of White LED Lighting Signal Transmission and Power Line Signal Transmission", IEICE Technical Report, IEICE, March 12, 2002, Vol. 101, no. 726 pp. 99-104
[0011]
[Problems to be solved by the invention]
The present invention has been made in view of the above-described circumstances, and enables communication even when the light is turned off, and also uses an illumination light communication device that effectively uses infrared light communication and an illumination light communication device that uses the same. It is an object to provide a suitable lighting element.
[0012]
[Means for Solving the Problems]
The present invention relates to an illumination light communication device, comprising: an illumination unit that emits light to illuminate; a modulation unit that modulates illumination light by controlling blinking or a light amount of the illumination unit according to data; Communication means for transmitting by the optical communication system, and switching means for switching the operation of the modulation means and the communication means in accordance with the lighting and extinguishing of the lighting means, the switching means, the lighting means is turned off The communication means is switched so as to operate when the communication device is in operation. The communication means can be configured to transmit data using infrared light communication.
[0013]
In this way, the illumination light modulated by the modulation means is emitted by the illumination means, illumination light communication is performed, and communication means conventionally used such as infrared light communication is combined to light the illumination means. When it is turned on, illumination light communication is performed, and when it is turned off, communication by communication means such as infrared light communication is performed. Thus, communication can be continued even when the light is turned off.
[0014]
When performing infrared light communication as the communication means, the infrared light emitting element portion capable of selectively emitting infrared light is built in a plurality of LED elements provided in the illumination means. Can be. This eliminates the need to separately provide a communication means used when the light is turned off, and allows infrared light communication to be performed using the illumination means arranged so as not to cast shadows indoors, thereby reducing the influence of shadowing. And stable infrared light communication can be performed.
[0015]
The present invention also provides an illumination light communication device, comprising: illumination means for emitting light for illumination; and modulation means for modulating illumination light by controlling blinking or light quantity of the illumination means in accordance with data, wherein the modulation means Performs modulation control in accordance with the data while supplying sufficient power to the lighting means during lighting in response to an instruction to switch on and off, and performs modulation control in accordance with the data when turned off. In order to make the lighting means flicker as much as necessary for communication.
[0016]
Even in such a configuration, it is possible to perform communication at the time of lighting having a sufficient light amount as illumination and communication at the time of extinguishing by light emission required only for communication when the light amount is unnecessary. Therefore, the user can turn on and off the lighting, and can perform light communication even when the light is turned off.
[0017]
Furthermore, the present invention is a lighting element that emits illumination light, including an illumination light emitting element unit that emits white light for illumination, and an infrared light emitting element unit that emits infrared light for infrared communication. It is characterized by the following. Communication using illumination light can be configured by performing modulation driving separately from the infrared light emitting element unit, and illumination light communication by the illumination light emitting element unit is performed when lighting is performed as described above. When the light is turned off, infrared light communication can be performed by the infrared light emitting element unit. As a result, communication can be performed even when the light is turned off, which cannot be performed by the conventional illumination light communication. In addition, there is no need to provide a separate communication means for infrared light communication, and the effect of shadowing can be reduced to perform stable infrared light communication, thereby increasing the possibility of infrared light communication. it can.
[0018]
Note that, as a configuration of the lighting element, a configuration in which a red, blue, and green light emitting element section and an infrared light emitting element section are arranged side by side, or a blue or ultraviolet light emitting element section and a light emitting element section provided around the light emitting element section. A configuration in which an illumination light emitting element portion and an infrared light emitting element portion made of a fluorescent agent are juxtaposed can be applied.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a block diagram showing a first embodiment of the illumination light communication device of the present invention. In the figure, 11 is a light modulation unit, 12 to 14 are switches, 15 is a power distributor, 16 is a lighting unit, 17 is a communication unit, 21 is an information terminal, and 22 is a light receiving unit. The illumination unit 16 is provided with a light source for performing illumination by light emission. As the light source, a semiconductor light emitting element having a high-speed response characteristic such as a white LED element is used, and illumination light communication is possible by blinking or controlling the amount of light. The communication unit 17 can transmit data by an optical communication method other than the illumination light, for example, infrared light communication. Note that the illumination unit 16 and the communication unit 17 can be configured in the same element as described later. Of course, they may be configured separately.
[0020]
The light modulator 11 and the power divider 15 correspond to the modulation means of the present invention, and modulate the illumination light by controlling the blinking or light amount of the illumination unit 16 according to data. In this example, the optical modulator 11 modulates input data according to a predetermined modulation method, superimposes the modulated data on a power waveform, and communicates with the power distributor 15 via the switch 13 and via the switch 14. Input to the unit 17. Thus, ON / OFF control and light amount control for the illumination unit 16 and the communication unit 17 are performed.
[0021]
The power distributor 15 mainly supplies power to the lighting unit 16. At this time, when power is supplied from the light modulation unit 11 on which the modulated data passed through the switch 13 is superimposed, the power is supplied to the illumination unit 16.
[0022]
The switches 12 to 14 constitute switching means of the present invention, and switch ON / OFF of each switch according to an external instruction such as an instruction to turn on and off the lighting means. The switch 12 switches ON / OFF of power supply to the power distributor 15, and switches on and off of the illumination. The switch 13 switches whether or not to supply modulated data to the power divider 15. When the illumination unit 16 is performing illumination, the switch 13 transmits data using the illumination light (illumination). (Optical communication) or not. The switch 14 switches whether or not to supply the modulated data to the communication unit 17. Either the switch 12 or the switch 13 is turned on, or both are turned off.
[0023]
FIG. 2 is a diagram illustrating an example of an operation performed by turning on / off the switches 12 to 14. When the switch 12 is turned on and the switch 13 is turned off by turning on and off the switches 12 to 14, the switch 14 is turned on. When the switch 14 is turned on, as shown in FIG. 17 is performed. In FIG. 2, “infrared light communication” is described as performing infrared light communication as communication by the communication unit 17, but communication by the communication unit 17 is not limited to this. If the switches 12 and 13 have the same setting and the switch is OFF, only the illumination is performed and no communication is performed as shown in FIG. The illumination light in this case is not used for communication. When the switch 12 is OFF, the switch 13 is ON, and the switch 14 is ON, while performing illumination by the illumination unit 16 as shown in FIG. However, the same data communication is performed. In the same case, if the switch 14 is OFF, illumination by the illumination unit 16 and communication by the illumination light are performed as shown in FIG. When both the switches 12 and 13 are OFF, the illumination unit 16 is not used. When the switch 14 is ON, communication by the communication unit 17 is performed as shown in FIG. For example, neither illumination nor communication is performed as shown in FIG.
[0024]
For example, when communication is performed when illumination is required, the switch 12 is turned on, the switch 13 is turned off, and the switch 14 is turned on as shown in FIG. When the switch 12 is turned off, the switch 13 is turned on, and the switch 14 is turned on or off as shown by ▼, communication using the communication unit 17 or communication using illumination light from the illumination unit 16 can be performed. When illumination is unnecessary, the communication unit 17 can perform communication by turning off the switches 12 and 13 and turning on the switch 14 as shown in FIG.
[0025]
As described above, when using the illumination, communication using the illumination light is possible, and even when the illumination is turned off, communication is possible. When infrared light communication is adopted as the communication method of the communication unit 17 as described above, since infrared light is invisible, even when communication is performed, brightness is not perceived by a human, and thus illumination is not performed. Communication can be performed with the lights off.
[0026]
FIG. 3 is a schematic diagram showing an example of the illumination element of the present invention suitable for use in the illumination light communication device of the present invention. FIG. 4 is an example of the illumination element of the present invention applied to the illumination light communication device of the present invention. It is explanatory drawing of an example. In the figure, the same parts as those in FIG. 8 are denoted by the same reference numerals, and redundant description will be omitted. Reference numeral 35 denotes an infrared light emitting element unit. As shown in FIG. 8, a general LED for illumination naturally emits only visible light and does not emit infrared light. Therefore, when infrared communication is performed by the communication unit 17 as described above, it is necessary to separately provide an infrared LED as the communication unit 17. Of course, the LEDs used in the illumination unit 16 and the communication unit 17 may be separately provided, but both have a similar structure and can be integrally configured. One example of this is shown in FIG.
[0027]
In the example shown in FIG. 3, as shown in FIG. 8A, an LED that emits three colors of red, green, and blue light and emits white light is provided with an infrared light emitting element unit 35. . Even when the infrared light emitting element section 35 is provided in this manner, the size of the package is almost the same as that of a general LED, and is about several mm in width and about several mm in height.
[0028]
When such a lighting element is applied to the illumination light communication device, the wiring of the red light emitting element section 32, the green light emitting element section 33, and the blue light emitting element section 34 is connected to the power distributor 15 as shown in FIG. In this way, it receives power supply during illumination and modulated power supply during illumination light communication. Further, the infrared light emitting element section 35 can be configured to be connected to the light modulation section 11 via the switch 14 and to be modulated and driven by the light modulation section 11 when the switch 14 is closed. . Further, the common electrode may be grounded together with the light modulation unit 11, the power distributor 15, and the like.
[0029]
For normal illumination, the red light emitting element section 32, the green light emitting element section 33, and the blue light emitting element section 34 emit light, and visually emit white illumination light with three colors of light. By modulating this illumination light at high speed, illumination light communication is possible. Further, although the infrared light emitting element section 35 does not visually recognize even if it emits light, wireless communication using infrared light becomes possible by modulating the emitted light at high speed.
[0030]
By switching the switches 12 to 14 as described above, the illumination light communication in which the red light emitting element section 32, the green light emitting element section 33, and the blue light emitting element section 34 are modulated at high speed, and the infrared light emitting element section 35 is operated at high speed. The communication with the modulated infrared light communication can be appropriately switched and used. For example, when illumination is required and communication is also required, the red light emitting element section 32, the green light emitting element section 33, and the blue light emitting element section 34 emit light and modulate at high speed to transmit information. As a result, the optical power required for illumination can be used for communication, and high-speed, high-quality communication can be performed. If illumination is not required but communication is required, communication is performed by modulating and driving the infrared light emitting element unit 35 to emit infrared light. In this case, since the infrared light is not visible, communication can be performed in a state where the infrared light is turned off. In addition, there are usually no people when the light is turned off, and the influence on the human body such as eye safe can be reduced.
[0031]
Of course, even when performing illumination, the infrared light emitting element section 35 may be modulated and driven to perform communication using infrared light. In this case, the receiving side needs to always receive only infrared light, and does not need to correspond to a plurality of wavelengths, so that the configuration can be simplified.
[0032]
Alternatively, when illumination is performed, the red light emitting element section 32, the green light emitting element section 33, and the blue light emitting element section 34 are modulated and driven, and the infrared light emitting element section 35 is also modulated and driven. Can also communicate. In this case, since all the power can be used, higher-speed and higher-quality communication can be performed than each of the above-described methods.
[0033]
In the configuration shown in FIG. 3, the red light emitting element section 32, the green light emitting element section 33, the blue light emitting element section 34, and the infrared light emitting element section 35 can be driven independently of each other. Multiple pieces of information can be transmitted simultaneously.
[0034]
FIG. 5 is a schematic view showing another example of the illumination element of the present invention suitable for use in the illumination light communication device of the present invention. FIG. 6 is an illumination light communication of the present invention of another example of the illumination element of the present invention. It is explanatory drawing of the example of application to an apparatus. In the figure, the same parts as those in FIG. 8 are denoted by the same reference numerals, and redundant description will be omitted. 44 is an infrared light emitting element section. In the example shown in FIG. 5, an infrared light emitting element section 44 is provided in the LED element 41 having the configuration shown in FIG. 8B.
[0035]
When such a lighting element is applied to the illumination light communication device, the wiring of the light emitting element unit 42 is connected to the power distributor 15 as shown in FIG. Receive a modulated power supply. Further, the infrared light emitting element section 35 can be configured to be connected to the light modulation section 11 via the switch 14 and to be modulated and driven by the light modulation section 11 when the switch 14 is closed. . Further, the common electrode may be grounded together with the light modulation unit 11, the power distributor 15, and the like.
[0036]
During normal illumination, white light is emitted by irradiating the fluorescent agent 43 with blue light or ultraviolet light emitted by the light emitting element unit 42. At this time, the illumination light can be used for communication by modulating and driving the light emitting element section 42 at high speed. In addition, by performing the modulation driving of the infrared light emitting element section 44, wireless communication using infrared light can be performed although it is not visible visually.
[0037]
As in the example shown in FIG. 3, for example, when illumination is required and communication is also required, the light emitting element unit 42 is modulated and driven to transmit information. As a result, the optical power required for illumination can be used for communication, and high-speed, high-quality communication can be performed. If illumination is not required but communication is required, communication is performed by driving the infrared light emitting element unit 44 in a modulated manner to emit infrared light. In this case, since the infrared light is not visible, communication can be performed in a state where the infrared light is turned off. In addition, there are usually no people when the light is turned off, and the influence on the human body such as eye safe can be reduced.
[0038]
Of course, similarly to the example shown in FIG. 3, when performing illumination, the infrared light emitting element unit 44 is modulated and driven to perform communication using infrared light, or the light emitting element unit 42 and the infrared light Both the light emitting element units 44 may be driven by modulation. In the configuration shown in FIG. 5, it is possible to separately drive the light emitting element unit 42 and the infrared light emitting element unit 44 to transmit different data in parallel. Different data cannot be sent for each blue wavelength.
[0039]
FIG. 7 is a block diagram showing a second embodiment of the illumination light communication device of the present invention. Reference numerals in the figure are the same as those in FIG. In the first embodiment, when communication is performed in a state where the illumination is turned off, the communication is performed by the communication unit 17 separately provided. In the second embodiment, an example is shown in which the communication unit 17 is not provided and the illumination unit 16 performs communication even when the light is turned off.
[0040]
In this example, the switch 12 is used for switching on and off the illumination, and the switch 13 is used for switching whether or not to perform communication.
[0041]
The power distributor 15 drives the illumination unit 16 in accordance with the on / off of the switch 12 and the switch 13, and when performing communication, transmits while supplying sufficient power to the illumination unit 16 during lighting when lighting. The modulation control according to the information to be transmitted is performed, and the modulation control according to the information to be transmitted is performed when the light is turned off, so that the illumination unit 16 blinks as necessary for communication.
[0042]
For example, when the switch 12 and the switch 13 are closed, the illumination unit 16 is modulated in an illumination state to realize illumination light communication. When the switch 12 is open and the switch 13 is closed, the illumination unit 16 is driven according to the modulation signal from the light modulation unit 11 and the illumination unit 16 emits light for a very short time according to the information to be transmitted for communication. I do. If the light is emitted for a very short time, it will not be visually perceived. Therefore, even if the light is actually emitted, it appears to the human eye that the light is turned off, so that communication can be performed even when the light is turned off. When the switch 12 is closed and the switch 13 is open, normal illumination is performed. When the switches 12 and 13 are open, the light is turned off and no communication is performed.
[0043]
In this way, by controlling the lighting unit 16 to emit light for a very short time according to information without turning on the lighting unit 16 continuously when the light is turned off, the lighting unit 16 is turned off by visible light using the lighting unit 16 while the light is turned off for human eyes. Communication can be performed.
[0044]
As described above, in addition to communication using light emission for a very short time, communication can be performed by causing the illumination unit 16 to emit light at a light intensity that is low enough to allow communication. In this case, the light is not completely turned off. However, for example, it is considered that, in the case of a light amount of a security ball or the like, it is often allowable even when the light is turned off.
[0045]
【The invention's effect】
As is apparent from the above description, according to the present invention, it is possible to provide an illumination light communication device capable of performing communication even when the light is turned off, and to provide a lighting element suitable for use in such an illumination light communication device. There is an effect that can be.
[0046]
In the case of lighting equipment, it may be used constantly for 24 hours, but in some cases, it may be turned off when it is absent, when there is sunlight around, or when using a projector. In such a case, if information is to be transmitted only by the illumination light, there is a problem since the illumination must be turned on when the information flows. According to the present invention, communication is enabled even when the light is turned off by using infrared light communication when the light is turned off, or by performing communication in a short time or with a weak light intensity.
[0047]
In addition, when using infrared light communication, by providing a light emitting element that combines the light emitting element for illumination and the light emitting element for infrared light into one, the infrared light is used when the light is turned off as described above. Communication can be enabled. Furthermore, light from visible light to infrared light can be emitted by the integrated element, and the device configuration can be reduced in size. That is, it is possible to construct a new compact system using integrated lighting elements without using a different system for illumination and illumination, and infrared communication for infrared communication. From a different viewpoint, wireless information transmission using infrared light has been known, but a system has been constructed without any relation to illumination. That is, the transceiver is installed on the ceiling or the like separately from the lighting. Therefore, installation is difficult in a wide area of the ceiling, and there are many cases where use is hindered due to the influence of shadowing. However, by using the lighting element of the present invention, the infrared light communication system and the lighting can be easily realized. Can be integrated with the system. Since the lighting is installed in a wide area such as on a ceiling, it can be easily installed in a wide area even in information transmission, the effects of shadowing are reduced, and the wireless communication by infrared light can be used stably. is there.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a first embodiment of an illumination light communication device according to the present invention.
FIG. 2 is an explanatory diagram of an example of an operation by turning on and off switches 12 to 14;
FIG. 3 is a schematic diagram showing an example of a lighting element of the present invention suitable for use in the illumination light communication device of the present invention.
FIG. 4 is an explanatory diagram of an application example of an example of the illumination element of the present invention to the illumination light communication device of the present invention.
FIG. 5 is a schematic diagram showing another example of the illumination element of the present invention suitable for use in the illumination light communication device of the present invention.
FIG. 6 is an explanatory diagram of an application example of another example of the illumination element of the present invention to the illumination light communication device of the present invention.
FIG. 7 is a block diagram showing a second embodiment of the illumination light communication device of the present invention.
FIG. 8 is a configuration diagram of an example of a general white LED.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Light modulation part, 12-14 ... Switch, 15 ... Power divider, 16 ... Illumination part, 17 ... Communication part, 21 ... Information terminal, 22 ... Light receiving part, 31, 41 ... LED element, 32 ... Red light emitting element Part, 33: green light emitting element part, 34: blue light emitting element part, 35: infrared light emitting element part, 42: light emitting element part, 43: fluorescent agent, 44: infrared light emitting element part.

Claims (8)

An illuminating unit that emits light to illuminate, a modulating unit that modulates illuminating light by controlling blinking or a light amount of the illuminating unit according to data, and a communication unit that transmits the data by an optical communication method other than the illuminating light. Switching means for switching the operation of the modulation means and the communication means in accordance with turning on and off of the lighting means, wherein the switching means operates the communication means when the lighting means is turned off. An illumination light communication device characterized by switching. The illumination light communication device according to claim 1, wherein the communication unit transmits the data by infrared light communication. The illuminating means includes a plurality of LED elements, and the LED elements include an infrared light emitting element portion capable of selectively emitting infrared light, and the infrared light emitting element portion serves as the communication means. The illumination light communication device according to claim 2, wherein the illumination light communication device is used. Lighting means for emitting light to illuminate, and modulation means for modulating illumination light by controlling blinking or light amount of the lighting means according to data, wherein the modulation means responds to an instruction to switch on and off. At the time of lighting, modulation control according to the data is performed while supplying sufficient electric power to perform illumination to the lighting means, and at the time of lighting off, the modulation control according to the data is performed so that the lighting means is required for communication. An illumination light communication device characterized in that only flickering is performed. An illumination element that emits illumination light, comprising: an illumination light-emitting element that emits white light for illumination; and an infrared light-emitting element that emits infrared light for infrared communication. Lighting element. The illumination device according to claim 5, wherein the illumination light emitting device unit can perform communication using illumination light by performing modulation driving separately from the infrared light emitting device unit. The lighting device according to claim 5, wherein the illumination light emitting device unit includes red, blue, and green light emitting device units, and the infrared light emitting device unit is arranged side by side with each light emitting device unit. The lighting element according to any of the preceding claims. The lighting device according to claim 5, wherein the illumination light-emitting element portion includes a light-emitting element portion for emitting blue or ultraviolet light, and a fluorescent agent provided around the light-emitting element portion. element.

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