JP2009077344A - Visible light communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-speed visible light communication system capable of being applied to an LED illuminating apparatus using a high-power white light emitting LED. <P>SOLUTION: A visible light communication system 1 comprises: an illuminating unit 8 which has a plurality of solid light-emitting elements 32 configured by a blue light emitting LED bare chip and a yellow fluorescent body excited by light in a first wavelength region irradiated from the LED bare chip to emit light in a second wavelength region, and which transmits arbitrary information by modulating a direct current to be supplied to at least some of the plurality of solid light-emitting elements 32 based on the arbitrary information; and a light reception unit 4 receiving the arbitrary information transmitted from the illuminating unit 8. In the visible light communication system 1, the light reception unit 4 has a wavelength filter 143 which transmits at least a part of the light in the first wavelength region, and which does not transmit the light in the second wavelength region, and a light reception element 142 which receives light passed through the wavelength filter 143. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a visible light communication system, and more particularly, to a visible light communication system using a solid light emitting element as a light source.

  In recent years, environmental awareness has increased, and solid-state light-emitting elements, particularly light-emitting diodes (hereinafter referred to as LEDs), have attracted attention as new light sources that can replace incandescent lamps, fluorescent lamps, mercury lamps, and other lamps. This is because the light-emitting diode is a light source that has a longer life than the above-described lamps and does not contain harmful substances such as mercury and lead, that is, it is an environmentally friendly light source.

  Among LEDs, a so-called high power LED having an input capacity of 1 W or more has a high emission intensity and is optimal for lighting applications. In addition, the light conversion efficiency of high-power LEDs has been improved year by year, and illumination using high-power LEDs as a light source is also expected to become an energy-saving light source.

  Here, since the LED is an electronic element, the response is high. Therefore, the light emission can be easily modulated. Taking advantage of this, attention has been focused on a visible light communication system in which an illumination unit using a high power LED is used as a transmitter.

  In the visible light communication system, the direct current supplied to the LED is modulated based on various information (for example, information obtained from the Internet). Light emission from the LED supplied with the modulated direct current is modulated based on the various information. The modulated light emission is received by a light receiving unit including a light receiving element. Then, communication is performed by demodulating.

  One of the merits of the visible light communication system is high security. Since the communication uses visible light, information leakage can be easily avoided by blocking the light.

On the other hand, the visible light communication system has a problem. That is, the communication speed is slow. In view of the above, the visible light communication system disclosed in Patent Document 1 includes red, green, and blue LEDs, respectively, and independently controls the light emission to multiplex the visible light. It is supposed that an optical signal can be transmitted. Thus, a visible light communication system capable of high-speed communication can be provided.
JP 2007-81703 A

  However, the visible light communication system disclosed in Patent Document 1 is considered problematic in the following respects.

  In the visible light communication system of Patent Document 1, red, green, and blue LEDs are used as described above. However, in an LED illumination unit that is realized by using a high-power LED, normally white light is emitted. High power LED is used. Therefore, it can be said that it is difficult to apply the visible light communication system of Patent Document 1 using red, green, and blue LEDs.

  This invention is made | formed in view of the said situation, Comprising: It aims at providing the high-speed visible light communication system applicable to the LED illuminating device using high power LED of white light emission.

  In order to achieve the above object, a plurality of elements comprising a bare chip and a phosphor part that is excited by light in the first wavelength region emitted from the element part and emits light in the second wavelength region. A solid-state light-emitting element, and a transmission unit that transmits the arbitrary information by modulating a direct current supplied to at least a part of the plurality of solid-state light-emitting elements based on the arbitrary information, and transmitted from the transmission unit In the visible light communication system configured by the light receiving unit that receives the arbitrary information, the light receiving unit transmits at least part of the light in the first wavelength region and the light in the second wavelength region. And a light receiving element for receiving the light transmitted through the filter unit.

  By using a filter with this configuration, it is possible to exclude the light emission wavelength component of the phosphor part and receive only the light emission wavelength component of the element part in the light receiving unit. Therefore, in realizing visible light communication, the influence of the phosphor part can be eliminated. The phosphor part has a slow response speed, which is an obstacle to speeding up visible light communication. Therefore, by eliminating this influence, there is an effect that the speed of visible light communication can be increased.

  Here, an optical element for condensing light may be installed in the light emitting direction of the solid state light emitting element to which a direct current modulated based on the arbitrary information is supplied.

  With this configuration, there is an effect that the light intensity (light density) of light used for visible light communication can be increased, and stable visible light communication can be realized.

  Here, the light receiving element may be an element corresponding to a communication speed of at least a communication speed of 10 Mbytes / second or more.

  With this configuration, the light receiving element can reliably receive a signal (modulated light) from the transmission unit, and has an effect of enabling high-speed visible light communication.

Here, the filter unit may transmit light having a wavelength region of 470 nm or less.
In a general solid-state light emitting device that emits white light, light emitted from the phosphor portion does not include light in a wavelength region of 470 nm or less. Therefore, this configuration has an effect of reliably eliminating the influence of the fluorescent part.

  Here, the direct current supplied to the plurality of solid state light emitting elements is generated by a power supply device using an alternating current power supply, the power supply device converts the alternating current into a pulsating flow, and the passage of the pulsating flow / Selection means for selecting non-passage and performing transformation of the pulsating flow that has passed, and designation means for performing designation relating to transformation to the selection means, wherein the selection means includes a winding ratio (secondary winding). A plurality of transformers having different numbers of wires / number of windings on the primary side), and the designation means is any one of the plurality of transformers based on the instantaneous value of the pulsating flow at an arbitrary time. One may be designated as a transformer for transformation.

  According to this configuration, the alternating means is converted into the pulsating flow by the converting means, and the passage means / non-passing of the pulsating flow is selected by the selecting means. That is, there is an effect that a smoothing capacitor (electrolytic capacitor) is not required because the pulsating flow passes / does not pass.

  Further, the designation means designates a transformer to be used for conversion according to the instantaneous value of the pulsating flow. Although a plurality of transformers are provided, since the winding ratios are different from each other, the transformation ratio (secondary side output voltage / primary side input voltage, which is the same value as the winding ratio) is also different. Therefore, the selection means performs transformation of different transformation ratios according to the instantaneous value of the pulsating flow. This also has the effect of improving the power factor and realizing high power supply efficiency.

  Here, the plurality of transformers included in the selection means include a first transformer having a winding ratio of 1 / n and a winding ratio of 1 / m (n> m). A second transformer, wherein the designation means designates the first transformer when the instantaneous value of the pulsating flow at the arbitrary time is equal to or greater than a predetermined threshold, and the pulsating flow at the arbitrary time. The second transformer may be specified when the instantaneous value of is less than or equal to the predetermined threshold.

  According to this configuration, when the instantaneous value of the pulsating flow is higher than the predetermined threshold, the first transformer can perform transformation, and when the instantaneous value of the pulsating flow is lower than the predetermined threshold, the second transformer can perform the transformation. it can.

  Since the second transformer has a larger winding ratio than the first transformer, the second transformer performs a transformation with a higher transformation ratio than the first transformer, and there is an effect that the distribution angle can be expanded.

  Here, the power supply device further includes instruction means for instructing the selection means of a duty ratio that is a time ratio of passage / non-passage of the pulsating flow, and the instruction means includes a predetermined period of the pulsating flow. On the basis of the average value, the estimated waveform of the pulsating flow is obtained, and based on the comparison result between the instantaneous value of the pulsating flow at a predetermined time and the estimated instantaneous value of the pulsating flow at the predetermined time based on the estimated waveform, A duty ratio may be indicated. In addition, when the instantaneous value of the pulsating flow at a predetermined time exceeds the estimated instantaneous value of the pulsating flow at the predetermined time based on the estimated waveform, the instruction unit is lower than the duty ratio immediately before the predetermined time. When the duty ratio is instructed and the instantaneous value of the pulsating flow at a predetermined time is lower than the estimated instantaneous value of the pulsating flow at the predetermined time based on the estimated waveform, the duty ratio is higher than the duty ratio immediately before the predetermined time. A ratio may be indicated.

  According to this configuration, the duty ratio can be specified based on the value of the pulsating flow measured in advance. This is advantageous in that it is possible to prevent the power supply device and the plurality of solid state light emitting elements from failing even when sudden fluctuations in the value of the pulsating current (for example, voltage fluctuations of an AC power supply) occur. is there.

  Here, the predetermined period may be at least a period corresponding to a half cycle of the AC power supply.

  According to this structure, there exists an effect that an estimated waveform can be calculated | required reliably. The pulsating current has a half period of the AC power supply, and the estimated value can be reliably calculated by obtaining an average value within a period corresponding to this period.

  Here, the electric capacity of the first transformer may be larger than the electric capacity of the second transformer.

  The first transformer transforms when the instantaneous value of the pulsating flow is higher than a predetermined threshold value. Therefore, a large amount of power is input. Therefore, by setting the electric capacity larger than that of the second transformer, there is an effect that the reliability of the power supply device can be improved.

  Here, the power supply device further has a substantially circular shape, a main single-sided mounting board on which a part of circuit elements constituting the power supply device is mounted, and a circuit that is substantially semicircular and constitutes the power supply device. A first sub-single-sided mounting board on which a remaining part of the element is mounted, the power supply device is a columnar type, a mounting surface of the main single-sided mounting board, a mounting surface of the first sub-single-sided mounting board, May be configured to face each other. The power supply device further includes a second sub single-sided mounting board, a photocoupler, and a microcomputer, and includes a microcomputer unit including the specifying unit and the instruction unit, and the microcomputer unit. A microcomputer power supply unit to be driven, the microcomputer unit and the microcomputer power supply unit are mounted on the second sub-single-sided mounting board, and the power supply device includes a mounting surface of the second sub-single-sided mounting board, The main single-sided mounting board may be configured to face the mounting surface. Here, the height of the power supply device may be substantially equal to the highest circuit element among the circuit elements constituting the power supply device. Here, the main single-sided mounting board and the first sub-single-sided mounting board may be arranged and mounted such that the distance between the main single-sided mounting board and the first sub-single-sided mounting board is substantially equal to the height of the circuit element. Any one of the transformers may be used.

  According to this configuration, there is an effect that a cylindrical power supply can be realized.

  ADVANTAGE OF THE INVENTION According to this invention, the high-speed visible light communication system applicable to the LED illuminating device using high-power LED of white light emission can be provided.

  The visible light communication system according to the present invention performs visible light communication by receiving, with a light receiving unit, modulated light emitted from an illumination unit using a white light emitting high power LED as a light source.

  High-power LEDs emitting white light usually have a yellow phosphor disposed in the light-emitting direction of an LED bare chip emitting blue light to obtain pseudo-white light. The response speed of the phosphor is usually slower than the response speed of the LED bare chip. Therefore, it becomes an obstacle to speeding up visible light communication.

  In the light receiving unit according to the present invention, the light emission component of the phosphor is excluded by using the wavelength filter, and at least a part of the light emission component of the LED bare chip is received. Thus, the visible light communication system according to the present invention realizes high-speed visible light communication.

  Hereinafter, embodiments of a visible light communication system according to the present invention will be described in detail with reference to the drawings.

First, the configuration of the visible light communication system of the present invention will be described.
FIG. 1 is a perspective view showing an appearance of a visible light communication system 1 according to the present invention. The visible light communication system 1 includes an illumination unit 8 and a light receiving unit 4. The illumination unit 8 includes a power supply device 2 and a light source unit 3. The illumination unit 8 corresponds to the transmission unit of the present invention.

  FIG. 2 is a cross-sectional view showing the structure of the A direction surface of the power supply device 2. FIG. 3 is a cross-sectional view showing the structure of the light source unit 3 in the B direction. FIG. 4 is a sectional view showing the structure of the light receiving unit 4 in the C direction.

  The power supply device 2 has a cylindrical shape and includes a housing 5 and an outlet 6. The power supply device 2 converts alternating current power into direct current and supplies direct current to the light source unit 3.

The casing 5 has an external shape of the power supply device 2. Here, the circuit element which comprises the power supply device 2 is accommodated in the housing | casing 5 inside. The casing 5 may be made of a resin material, but is preferably made of a material having high thermal conductivity (preferably 200 W · m ⁻¹ · K ⁻¹ or more). The inventors selected aluminum as a material having high thermal conductivity and high workability, and constituted the casing 5 using aluminum.

  The outlet 6 is used for the power supply device 2 to use a commercial AC power supply, and connects the commercial power supply 41 and the power supply device 2.

The connection cable 7 is an electric cable that connects the power supply device 2 and the light source unit 3.
Further, the power supply device 2 includes a plurality of circuit elements and a substrate 33 therein.

  The light source unit 3 causes a solid light emitting element such as an internal high power LED to emit light using a direct current supplied from the power supply device 2. The light source unit 3 includes a housing 31, and includes a plurality of solid light emitting elements 32, a substrate 33, and a protective translucent plate 34 inside the housing 31.

The casing 31 has a substantially U-shaped cross section. The casing 31 is made of a metal having a high thermal conductivity (preferably, a metal having a thermal conductivity of 200 W · m ⁻¹ · K ⁻¹ or more). For example, the housing part 31 is made of aluminum. The reason why aluminum is used for the housing part 31 is that it is inexpensive, easy to form, has good recyclability, has a thermal conductivity of 200 W · m ⁻¹ · K ⁻¹ or more, and heat dissipation characteristics. Is high.

  Further, it is desirable that the casing 31 is made of aluminum and then anodized. Alumite treatment increases the surface area and enhances the heat dissipation effect.

  The protective translucent plate 34 has translucency and is disposed in the light emitting direction of the solid state light emitting device 32. The protective translucent plate 34 is formed in a flat plate shape. By integrally combining the casing 31 and the protective translucent plate 34, the cross section becomes a substantially square shape. The protective translucent plate 34 is formed of transparent glass, acrylic resin, polycarbonate, or the like.

  Fine irregularities may be formed unevenly on the front or back surface of the protective translucent plate 34 by surface treatment. This surface treatment can be easily performed, for example, by applying a sandblast method. The protective translucent plate 34 protects the solid state light emitting element 32 and the like disposed inside the lighting unit 8. Further, the protective translucent plate 34 plays a role of diffusing light emitted from the solid state light emitting device 32. The light emitted from the solid state light emitting element 32 has a strong directivity and tends to be irradiated locally. By diffusing the light emitted from the solid-state light emitting element 32 with the surface-treated protective translucent plate 34, the directivity of the light can be weakened and the light can be irradiated uniformly over a wide area.

  However, it is important not to form fine irregularities on the optical path of the solid state light emitting device 32 mounted on the substrate 33a. This is due to the following reason.

  The solid state light emitting device 32 mounted on the substrate 33a emits light used for visible light communication. Here, in order to use for visible light communication, it is desirable that the light from the solid state light emitting element 32 be within a predetermined irradiation range. In order to perform visible light communication, light intensity (light density) that can be reliably received by the light receiving element is required, and it may be difficult to perform visible light communication well with diffused light. Therefore, fine irregularities are not formed on the optical path of the solid state light emitting device 32 mounted on the substrate 33a.

  The substrate 33 is disposed inside a hollow structure formed by the casing portion 31 and the protective translucent plate 34. There are two types of substrates 33: a substrate 33a on which a solid light emitting element 32 that emits light used for visible light communication is mounted, and a substrate 33b on which a solid light emitting element 32 that emits light for normal illumination is mounted. Provided. However, there is no difference in performance between the substrate 33a and the substrate 33b, and when there is no need to distinguish between them, they are simply referred to as the substrate 33.

The board | substrate 33 is formed in the surface of the surface facing the protective translucent board 34 inside a hollow structure. The substrate 33 is made of a metal having a high thermal conductivity (preferably a metal having a thermal conductivity of 200 W · m ⁻¹ · K ⁻¹ or more). Preferably, the casing 31 is made of the same material. For example, the substrate 33 is made of aluminum.

  The plurality of solid state light emitting elements 32 are disposed on the substrate 33. The plurality of solid state light emitting elements 32 are, for example, LEDs.

  The inventors used so-called high-power LEDs each having a power consumption of 1 W or more as the solid-state light-emitting element 32, and adopted surface-mounted LEDs. The high power LED has a high luminous intensity and is suitable for lighting device applications. The emission color of the solid state light emitting element 32 is preferably a daylight color, a daylight white color, a white color, a warm white color or a color corresponding to a light bulb color. Specifically, for example, the plurality of solid-state light emitting elements 32 include daylight colors, daylight whites, whites, and warm whites defined in 4.2 “Chromaticity Range” of JISZ9112 “Classification by light source color and color rendering of fluorescent lamps”. Or it emits light corresponding to the color of the bulb. Hereinafter, light corresponding to daylight color, daylight white, white, warm white, or light bulb color is collectively referred to as white.

  Here, among the plurality of solid state light emitting elements 32, those mounted on the substrate 33a are supplied with modulated direct current to be used for visible light communication. That is, the light emission of the solid state light emitting device 32 mounted on the substrate 33a is modulated. This modulation is performed based on information obtained from the Internet (not shown), for example.

  On the other hand, among the plurality of solid state light emitting devices 32, those mounted on the substrate 33b are supplied with normal (unmodulated) direct current. The number of solid-state light emitting elements 32 mounted on the substrates 33a and 33b is not limited. You may set arbitrarily according to the intensity | strength of the illumination (light) to obtain with the illumination unit 8, the intensity | strength of light required in order to implement | achieve visible light communication, etc.

  Moreover, it is preferable to make the housing | casing part 31 and the board | substrate 33 contact each other. This is because if air enters between the housing part 31 and the substrate 33, heat conduction between the housing part 31 and the substrate 33 is hindered, which makes it impossible to perform more efficient heat treatment. is there. That is, it is preferable to increase the adhesion between the casing 31 and the substrate 33 by configuring the casing 31 and the substrate 33 with the same material. Furthermore, it is preferable to perform press working to further improve the adhesion.

  When performing the press work, a material having adhesiveness (for example, an adhesive or a double-sided tape without a base material) (not shown) is sandwiched between the casing portion 31 and the substrate 33, and the adhesiveness between the two. Is preferably increased.

  When using a double-sided tape, it is important to select one that does not contain a substrate. This is because the base material has a low thermal conductivity, so that the heat conduction from the casing 31 to the substrate 33 is hindered.

  It is also preferable to divide the substrate 33 into a plurality of pieces. This is to prevent the adhesion between the casing 31 and the substrate 33 from deteriorating when the temperature of the light source unit 3 rises when the linear expansion coefficients of the casing 31 and the substrate 33 are different. is there. By dividing the substrate 33, the length in the longitudinal direction of each substrate 33 is shortened. Thereby, the expansion amount per one board | substrate 33 becomes small. Therefore, it becomes easy to absorb the difference in expansion between the casing portion 31 and the substrate 33 with an adhesive material, so that the adhesion between the casing portion 31 and the substrate 33 can be easily maintained. This method of dividing the substrate 33 is particularly effective when the length of the light source unit 3 in the longitudinal direction is long.

  An optical element 35 is disposed on the optical path of light emitted from the solid state light emitting element 32 mounted on the substrate 33a. The optical element 35 is, for example, a condenser lens. The condensing angle α of the light emitted from the solid light emitting element 32 mounted on the substrate 33a by the optical element 35 may be arbitrary, but irradiation is required by the light emitted from the solid light emitting element 32 mounted on the substrate 33a. It is decided according to the range. The optical element 35 is fixed and arranged at a predetermined position by the support 36.

  FIG. 5 is a schematic diagram of illumination realized by the illumination unit 8. An illumination area (irradiation area) by the solid-state light emitting element 32 mounted on the substrate 33 a is an area 201. An illumination area in the entire illumination unit 8 is an area 202. As described above, the illumination area (irradiation area) by the solid light emitting element 32 mounted on the substrate 33a is limited by the effect of not forming fine irregularities on the optical path in the optical element 35 and the protective translucent plate 34. The In this region, the light intensity for stably performing visible light communication is realized.

  The light receiving unit 4 includes a light receiving element 142 inside the housing portion 141. A wavelength filter 143 is provided in the light receiving direction of the light receiving element 142. The light receiving unit 4 is installed at a position where the light emitted from the solid light emitting element 32 mounted on the substrate 33a can be received (in the region 201 in FIG. 5).

  The casing 141 has a substantially U-shaped cross section. The material is not particularly limited, and may be a resin material or a metal material.

  The light receiving element 142 is sensitive to the emission color (emission wavelength) of the LED bare chip of the solid state light emitting element 32 (the inventors adopt high power LEDs). In addition, it has a response speed that can cope with visible light communication of high-speed communication. For example, it has a response speed that can withstand a communication speed of 10 Mbytes / second or more.

  The light (modulated light) from the solid light emitting element 32 mounted on the substrate 33a received by the light receiving element 142 is converted into an electrical signal. This electrical signal is sent to a computer (not shown) and demodulated. Thereby, visible light communication is realized.

  The wavelength filter 143 corresponds to the filter part of the present invention, and the emission wavelength of the LED bare chip (corresponding to the element part of the present invention) of the solid light emitting element 32 (the inventors adopt a high power LED). It is a filter that transmits at least a part of components and does not transmit the emission wavelength from the phosphor (corresponding to the phosphor portion of the present invention).

  Here, as the solid-state light emitting element 32, a high power LED is employed as described above. High-power LEDs that emit white light are generally configured by disposing yellow phosphors (YAG phosphors) in the light emission direction of LED bare chips that emit blue light (GaN-based LED bare chips). That is, a white light emitting high power LED emits pseudo white light by mixing blue light from a blue light emitting LED bare chip and light emitted from a yellow phosphor excited by the blue light. ing. FIG. 6A schematically illustrates this. In FIG. 6A, the horizontal axis represents wavelength, and the vertical axis represents emission intensity as a relative value.

  FIG. 6A (a) shows the emission wavelength distribution of a blue light emitting LED bare chip, FIG. 6 (b) shows the emission wavelength distribution from a yellow phosphor, and FIG. 6 (c) shows the light emission of a white light emitting high power LED. The wavelength distribution is shown. The light emission wavelength region of the blue light emitting LED bare chip in FIG. 6A (a) corresponds to the first wavelength region of the present invention, and the light emission wavelength region from the yellow phosphor in FIG. This corresponds to the second wavelength region.

  Thus, the wavelength component of wavelength 470 [nm] or less is not included in the emission wavelength from the yellow phosphor. Therefore, the wavelength filter 143 is configured to transmit only the wavelength component having a wavelength of 470 [nm] or less. For example, a filter having light transmission characteristics as shown in FIG. 6B is configured as the wavelength filter 143.

  FIG. 6B is an example of the wavelength filter 143, in which the horizontal axis indicates the wavelength and the vertical axis indicates the light transmittance. As shown in this figure, the light transmittance is about 0 [%] for light having a wavelength of 470 [nm] or more. That is, the wavelength filter 143 does not transmit light having a wavelength of 470 [nm] or more.

  Here, the light emission wavelength from the LED bare chip includes light of 470 [nm] or less with sufficient intensity. The wavelength filter 143 has a function of transmitting light having a wavelength of 470 [nm] or less as in the example shown in FIG. 6B. As described above, only the light emitted from the LED bare chip emitting blue light can be received by the light receiving element 142.

  Here, it is known that the response speed of the yellow phosphor is slower than that of the blue light emitting LED bare chip. Therefore, conventionally, in the case where a visible light communication system is configured using light emitted from an LED, the problem of the response speed of the yellow phosphor has been raised as a factor limiting the communication speed. The present invention solves the problem of the response speed of the yellow phosphor.

  As described above, the wavelength filter 143 transmits at least a part of the light emission component of the blue light emitting LED bare chip among the light emitted from the white light emitting high power LED. In addition, the light emitting component of the yellow phosphor is not transmitted. Therefore, the light emitting component of the yellow phosphor does not reach the light receiving element 142, and only the light emitting component from the blue LED bare chip reaches. Therefore, the influence of the yellow phosphor is eliminated, and high-speed communication can be realized.

  Here, about the illumination unit 8 which concerns on the visible light communication system 1 of this invention, it is the illumination unit using the solid light emitting element 32, specifically, high power LED. One feature of LEDs is that they have a significantly longer life than other light sources such as fluorescent lamps.

  For this reason, the lighting unit 8 using LEDs is naturally required to have long-term stability (maintenance-free). Therefore, the power supply device 2 that is a component of the lighting unit 8 must also be configured to have stability over a long period of time.

  Below, it demonstrates in detail regarding the illumination unit 8 centering on this power supply device 2. FIG. FIG. 7 is a functional block diagram of the lighting unit 8 of the present invention.

  The illuminating unit 8 is an illuminating device that illuminates by emitting a plurality of solid state light emitting elements using an AC power source, and includes a rectifying unit 42, a measuring unit 43, a selecting unit 44, a detecting unit 45, and a microcomputer. A unit 46 and a light emitting unit 47 are provided.

  The lighting unit 8 supplies direct current to a light emitting unit 47 composed of one or a plurality of solid state light emitting elements using an alternating current power source supplied from a commercial power source 41 which is an external power source, and emits solid state light emitting elements. Let

  The commercial power source 41 corresponds to an AC power source according to the present invention. Specifically, it is a power source that is supplied from an electric power company to ordinary households, offices, etc., and supplies alternating current to the lighting unit 8.

  The rectification unit 42 corresponds to the conversion means according to the present invention, and converts the voltage of the sine wave of the power source into a pulsating flow. Specifically, the AC voltage supplied from the commercial power supply 41 is full-wave rectified, and the full-wave rectified waveform is output to the measurement unit 43.

  The measuring unit 43 constitutes a part of the specifying unit of the present invention. The current value (instantaneous value) of the pulsating current is detected. The detected pulsating current value is sent to the microcomputer unit 46.

  The selection unit 44 corresponds to selection means according to the present invention, and selects an ON time during which the pulsating flow output from the rectifying unit 42 is allowed to pass and an OFF time during which the pulsating flow is not allowed to pass (hereinafter referred to as a duty ratio). . Thus, a pulsating voltage with a controlled duty ratio is generated. Specifically, the full-wave rectified waveform output from the rectification unit 42 and passed through the measurement unit 43 is divided at predetermined time intervals. The divided full-wave rectified waveform is converted into a pulse-shaped waveform voltage within each period of the predetermined time interval. The control of the duty ratio is based on an instruction from the microcomputer unit 46.

  The voltage of the pulsating current whose duty ratio is controlled is transformed and output by one transformer among the plurality of transformers included in the selection unit 44.

  Here, among the plurality of transformers, the designation of one transformer to perform the transformation is performed by the microcomputer unit 46 according to the voltage value (instantaneous value) at an arbitrary time of the pulsating current output from the rectifier 42. .

  In addition, the plurality of transformers included in the selection unit 44 means that the winding ratio (hereinafter referred to as winding ratio) between the primary side and the secondary side of an arbitrary transformer is a predetermined transformer winding. Different from line ratio. That is, all the transformers included in the selection unit 44 have different winding ratios.

  The transformer transforms the voltage sent to the primary side according to the winding ratio to the secondary side and outputs it. Therefore, the fact that all the transformers have different winding ratios means that all transformers are transformed with different transformation ratios.

  The reason why a plurality of transformers having different winding ratios is provided is to increase power supply efficiency and suppress generation of harmonics. Details will be described later.

  The detection unit 45 detects the operating point of the light emitting unit 47 in a state where the power supply device 2 is driven by being supplied with direct current. Here, the operating point is calculated by a product of forward voltages generated when a current is passed through the solid state light emitting device 32 constituting the light emitting unit 47, that is, a product of (current) × (forward voltage). .

The microcomputer unit 46 corresponds to a designation unit and an instruction unit (part) of the present invention.
First, the microcomputer unit 46 instructs one of the transformers included in the selection unit 44 according to the voltage value (instantaneous value) of the pulsating current output from the rectification unit 42 as instruction means, and performs the transformation. .

  Further, as part of the instruction unit, the current value (instantaneous value) of the pulsating flow detected by the measurement unit 43 is read, and the average current within a predetermined period is measured. From the average current within the period, a waveform of current estimated to flow through the measurement unit 43 (hereinafter referred to as an estimated waveform) is obtained.

  The predetermined period for obtaining the average current is preferably longer than a period corresponding to ½ of the period of the commercial power supply 41 (the reciprocal of the frequency). This is because the current flowing through the measurement unit 43 is obtained by full-wave rectification of the commercial power supply 41, and the waveform is practically repeated at a frequency twice that of the commercial power supply 41 (1/2 period). Therefore, in order to obtain a desired average current, a period corresponding to ½ of the cycle of the commercial power supply 41 is required.

  After obtaining the estimated waveform, the current value (instantaneous value) of the pulsating current detected by the measurement unit 43 at the present time is compared with the estimated current value (instantaneous value) of the pulsating current based on the estimated waveform.

  Based on the comparison result, the duty ratio is designated in the selector 44. That is, if the current value (instantaneous value) of the pulsating flow detected by the measurement unit 43 is larger than the estimated current value (instantaneous value), the selection unit 44 is instructed to have a lower duty ratio than the previous duty ratio.

  If the current value (instantaneous value) of the pulsating flow detected by the measurement unit 43 is smaller than the estimated current value (instantaneous value), the selection unit 44 is instructed to have a higher duty ratio than the previous duty ratio.

  As an instruction means, another method for designating the duty ratio to the selection unit 44 is as follows.

  First, based on the operating point detected by the detecting unit 45 and a reference operating point set in advance in the microcomputer unit 46 (hereinafter referred to as a reference operating point), the target operating point of the light emitting unit 47 is set. (Hereinafter referred to as the target operating point) is determined. Then, the microcomputer unit 46 instructs the selection unit 44 on the duty ratio so as to realize the target operating point.

  The light emitting unit 47 corresponds to the light source unit 3 according to the present invention, and emits the plurality of solid state light emitting elements 32. That is, one or a plurality of solid state light emitting elements 32 are provided. The solid light emitting element 32 is, for example, an LED.

  Here, the light emitting unit 47 includes a light emitting unit 47a including a solid light emitting element 32 mounted on a substrate 33a provided for visible light communication, and a solid light emitting element 32 mounted on a substrate 33b provided for visible light communication. And the light emitting unit 47b.

  When direct current is supplied to the light emitting unit 47a, a modulation unit (not shown) is provided between the light emitting unit 47a and modulation is performed based on information obtained from the Internet or the like.

FIG. 8 is a diagram showing a schematic circuit configuration of the illumination unit 8.
The illumination unit 8 shown in FIG. 7 can be realized by taking the configuration of a schematic circuit diagram as shown in FIG. A modulation unit (not shown) provided between the light emitting unit 47a and the detection unit 45, which are components of the light emitting unit 47, is omitted.

  The rectifying unit 42 includes an inductor 51, an inductor 52, a capacitor 53, and a diode bridge 54.

  The inductor 51, the inductor 52, and the capacitor 53 are protection circuits that protect against external disturbances. Therefore, the capacitor 53 is not a smoothing capacitor. By the way, the smoothing capacitor is required to have a large capacity. Therefore, an ordinary electrolytic capacitor is used. However, this type of capacitor has problems in size and life.

  The capacitor 53 is intended to protect the lighting unit 8 from external disturbance as described above, and may have a small capacity. Therefore, for example, a small and long-life capacitor such as a ceramic capacitor is used.

The diode bridge 54 is a full-wave rectifier that outputs a full-wave rectified alternating current. FIG. 9 is a diagram illustrating an output waveform of the diode bridge that rectifies the alternating current.

  The diode bridge 54 rectifies an AC waveform as shown in FIG. 9A, and forms and outputs a full-wave rectified waveform as shown in FIG. 9B.

  The measurement unit 43 includes a resistor 55. The pulsating current value output from the diode bridge 54 is detected. The detected current value is notified to the controller unit 69.

  The selection unit 44 includes a driver 56, a field effect transistor (hereinafter referred to as FET) 57, a driver 58, an FET 59, a transformer 60, and a transformer 61.

  Here, although two transformers are configured, three or more transformers may be used. By increasing the number of transformers, there is a merit that the power efficiency and the power factor are further increased. However, there is a demerit that the volume of the power supply device 2 is increased by increasing the number of transformers.

  According to the experiments by the inventors, it has been confirmed that the desired power supply efficiency and power factor can be obtained by using two transformers. Then, there were two transformers.

  Further, the transformer may be a type in which a center tap is added to the primary coil side. The transformer with the center tap added to the primary coil prevents the transformer core from being unnecessarily magnetized by alternately using two parts centered on the center tap of the primary coil. be able to. Therefore, it is possible to increase the reliability of the transformer, and there is an effect that it is possible to contribute to extending the life of the power supply device 2.

  Here, when using three or more transformers or a type in which a center tap is added to the primary coil side as a transformer, it goes without saying that drivers and FETs are further required accordingly.

  For the selection unit 44, the controller unit 69 designates a transformer that performs transformation. This is because the transformer that performs the transformation at an arbitrary time is any one of the transformer 60 and the transformer 61.

  The controller unit 69 sends a control signal instructing the duty ratio to be realized to the driver (any one of the driver 56 and 58) on the side of the transformer (either the transformer 60 or 61) that performs the transformation. It is done.

  The driver (either driver 56 or driver 58) to which the control signal is sent generates a drive signal for the FET (FET 57 or FET 59) connected to the driver.

  The FET (either FET 57 or FET 59) selects a pulsating flow (full-wave rectified waveform) through / non-passing, whereby a pulsed pulsating flow (pulse-shaped waveform) with a duty ratio instructed from the controller unit 69. Is generated. The FET (either FET 57 or FET 59) supplies this pulsating pulsating current to the primary side of the connected transformer (any one of the transformer 60 and the transformer 61).

  The transformer (any one of the transformer 60 and the transformer 61) transforms the pulsed pulsating current supplied to the primary side from the connected FET (any one of the FET 57 and FET 59), and the secondary side thereof is transformed. Output.

  Here, the transformer 60 and the transformer 61 have different winding ratios. The winding ratio is the number of secondary windings / the number of primary windings, and the transformation ratio is the same value as the winding ratio. The transformation ratio here refers to the input voltage to the primary side of the transformer as the denominator and the output voltage on the secondary side as the numerator.

  If the winding ratio of the transformer 60 is 1 / n, the winding ratio of the transformer 61 is 1 / m, and the relationship between n and m is n> m. That is, the turns ratio of the transformer 60 is smaller than the turns ratio of the transformer 61. Therefore, the transformation ratio of the transformer 60 is also smaller than the transformation ratio of the transformer 61.

  In the inventor's test, the winding ratio of the transformer 60 was 1: 0.4, and the winding ratio of the transformer 61 was 1: 1. In this case, the transformation performed by the transformer 60 is a step-down voltage, and the transformation performed by the transformer 61 is an equal magnification transformation (that is, only the action of insulating the primary side and the secondary side).

  Further, as described above, when the transformer 60 and the transformer 61 are not operated at the same time and the voltage value of the pulsating current is higher than a predetermined threshold value, the controller unit 69 designates the transformer 60 and the transformer 60 At 60, a step-down is performed.

  On the other hand, when the voltage of the pulsating current is lower than a predetermined threshold, the controller unit 69 designates the transformer 61 and the transformer 61 performs boosting.

  By doing in this way, it becomes possible to improve power supply efficiency and to improve a power factor.

  The detection unit 45 includes a diode 62, a diode 63, a capacitor 64, a resistor 65, and a resistor 66.

  The pulse waveform output from the transformer (either one of the transformer 60 and the transformer 61) in the selection unit 44 is smoothed (noise removed) by the circuit elements from the diode 62, the diode 63, and the capacitor 64. . Here, the capacitor 64 may be a capacitor having a small capacity, not an electrolytic capacitor.

  The smoothed pulse-like waveform output from the transformer (any one of the transformer 60 and the transformer 61) is supplied to the light emitting unit 47.

  At this time, the current flowing through the light emitting unit 47 can be detected by the resistor 65, and the forward voltage of the light emitting unit 47 can be detected by the resistor 66. Information on the current value and the voltage value detected by the resistor 65 and the resistor 66 is sent to the controller unit 69.

  The microcomputer unit 46 includes a controller unit 69 and a power supply unit 101.

  The power supply unit 101 includes a transformer 67 and a diode 68. The alternating current supplied from the commercial power supply 41 is converted into a direct current using the transformer 67 and the diode 68 and supplied to the controller unit 69. Here, the transformer 67 is separate from the transformer 60 and the transformer 61 and is independent of each other.

  Therefore, the power supply unit 101 is insulated from the circuit elements of the power supply device 2 that supplies direct current to the light emitting unit 47.

The controller unit 69 mainly has the following three functions.
First, the controller unit 69 monitors the voltage value of the commercial power supply 41, and based on this, the current voltage value (instantaneous value) of the pulsating current output by the diode bridge 54 by full-wave rectifying the alternating current. Is estimated.

  The voltage value (instantaneous value) of the pulsating current output by the diode bridge 54 after full-wave rectification of alternating current is obtained by inserting a resistor (not shown) between the terminals A and A ′. The value may be read by the controller unit 69.

  The controller unit 69 sends a control signal indicating a duty ratio to be realized to the driver 56 or 58 based on the estimated or read voltage value (instantaneous value at the present time) of the pulsating current.

  Specifically, the voltage of the pulsating current recorded in the internal memory (not shown) in advance is a predetermined threshold (this threshold is the configuration of the light emitting unit 47 (forward voltage, etc.), the winding ratio of the transformer 61, etc. And the voltage value (instantaneous value) of the current pulsating current are compared.

  The controller unit 69 sends a control signal to the driver 56 when the voltage value (instantaneous value) of the pulsating flow is higher. If the pulsating voltage value (instantaneous value) is lower, a control signal is sent to the driver 58.

  A driver that has not been sent a control signal does not operate, so the transformer on the driver side does not transform. Therefore, the transformer 60 and the transformer 61 do not transform at the same time.

  Here, as described above, the transformation ratio of the transformer 60 is smaller than the transformation ratio of the transformer 61. In addition, a control signal is sent to either the driver 56 or the driver 58 based on the above-described criteria. Therefore, when the voltage value (instantaneous value) of the pulsating current is higher than the threshold value, the transformer 60 performs transformation (transformation with a small transformation ratio). On the other hand, when the voltage value (instantaneous value) of the pulsating current is lower, the transformer 61 performs transformation (transformation with a large transformation ratio).

  The reason for this will be described with reference to FIGS. FIG. 10 shows the output waveform of the transformer (terminal B, terminal voltage) when the full-wave rectified waveform (pulsating current voltage) output from the diode bridge 54 shown in FIG. B ′ voltage waveform). FIG. 10A shows an output waveform when only the transformer 60 is used. FIG. 10B shows an output waveform when only the transformer 61 is used. FIG. 10C shows an output waveform when the transformer 60 and the transformer 61 are used.

  In practice, the full-wave rectified waveform (pulsating flow) is pulse-shaped because it is supplied to the transformer 60 or the transformer 61 after the duty ratio is controlled. Is displayed.

  FIG. 11 shows the current flowing through the resistor 55 constituting the measuring unit 43 when the transformation in FIG. 10 is performed. FIG. 11A corresponds to FIG. 10A, and the same applies to the following.

  First, the case where voltage transformation is performed using only the transformer 60 will be described. The transformer 60 has a winding ratio smaller than that of the transformer 61, so that the transformer ratio is also smaller than that of the transformer 61. As a result, the voltage waveform at the terminals B and B ′ (voltage waveform output from the transformer 60) is low as shown in FIG.

  Here, the light-emitting unit 47 (light source unit 3) is connected to the power supply device 2 as a load. The light emitting unit 47 includes one or more solid light emitting elements 32.

  A forward voltage exists in the solid state light emitting device 32. Therefore, the light emitting unit 47 has a forward voltage based thereon, and no current flows through the light emitting unit 47 unless a voltage higher than the forward voltage is applied.

  Therefore, when only the transformer 60 is used, an output waveform from the transformer 60 is as shown in FIG. At this time, no current flows through the resistor 55 in a portion that does not exceed the forward voltage. That is, as shown to Fig.11 (a), a flow angle will become narrow (a power factor will become low).

  Next, a case where voltage transformation is performed using only the transformer 61 will be described. The transformer 61 has a winding ratio larger than that of the transformer 60, and therefore the transformation ratio is also larger than that of the transformer 60. Accordingly, the voltage waveform at the terminals B and B 'in this case is as shown in FIG. 10B, which is higher than that in FIG. Therefore, a region exceeding the forward voltage of the light source unit 3 (light emitting unit 47) is widened. This contributes to widening the flow angle as shown in FIG. That is, the power factor is improved.

  Next, the case where voltage transformation is performed by the transformer 60 and the transformer 61 of the present invention will be described. FIG. 10C shows voltage waveforms at terminals B and B ′ when the operation method of the transformer 60 and the transformer 61 of the present invention is implemented.

  In the present invention, when the voltage (instantaneous value) of the full-wave rectified waveform (pulsating flow) shown in FIG. 9B is higher than the threshold value recorded in the internal memory (not shown) of the controller unit 69, the transformer If the voltage is lower than the threshold value, the voltage is changed by the transformer 61.

  Accordingly, the voltage waveform at the terminals B and B ′ in this case is a portion where the voltage (instantaneous value) of the full-wave rectified waveform (pulsating flow) shown in FIG. 9B is low, as shown in FIG. Only the corresponding part has a substantially trapezoidal waveform as if it was lifted.

  Therefore, even when the voltage (instantaneous value) of the full-wave rectified waveform (pulsating flow) is low, boosting (or equal-magnification transformation) is performed, so that the output from the transformer is the forward direction of the light emitting unit 47. The region exceeding the voltage will be expanded, and the distribution angle will be expanded.

  By doing in this way, when the transformer 60 and the transformer 61 are used with the operation method of the present invention, the flow angle is widened as compared with FIG. 11A as shown in FIG. This is the same level as in FIG. Therefore, the power factor can be improved as in the case where only the transformer 61 is used.

  Here, in the power supply device 2 according to the present invention, the reason for performing the transformation using not only the transformer 61 but also the transformer 60 and the transformer 61 is to improve the power efficiency.

  The power supply efficiency when performing the transformation using the transformer 60 and the transformer 61 according to the operation method of the present invention is about the same as the case where the transformation is performed using only the transformer 60 and the power supply efficiency. A 10% improvement is evident in the inventors' testing.

  Here, the power efficiency is the ratio of the power supplied to the light emitting unit 47 to the power of the commercial power supply 41 supplied to the power supply device 2.

  Even if the transformer 61 is used for the purpose of improving the power factor, the power supply efficiency is low, which is a problem. On the other hand, in the case of the present invention in which transformation is performed using the transformer 60 and the transformer 61, the power efficiency is greatly improved as compared with the case where the transformation is performed using only the transformer 61. Is done.

  Therefore, the present invention that performs transformation using the transformer 60 and the transformer 61 can not only improve the power factor but also realize high power supply efficiency.

  In the solid state light emitting device 32, current does not flow unless a voltage higher than the forward voltage is applied as described above. However, it is not preferable to apply a voltage that is too high with respect to the forward voltage. In such a case, the current flowing through the solid state light emitting device 32 increases, and as a result, there is a risk that the solid state light emitting device 32 may fail.

  From this point of view, it is not preferable to perform transformation using only the transformer 61 because the voltage applied to the solid state light emitting element 32 becomes higher.

  Here, Japanese Patent Application Laid-Open No. 2003-250272 discloses a switching power supply with an improved power factor. However, a smoothing capacitor is used to improve the power factor. Here, the smoothing capacitor generally requires a high capacity, and an electrolytic capacitor is usually used.

  It is said that the electrolytic capacitor is likely to be deteriorated due to an increase in the outside air temperature and the life characteristics thereof are not sufficient. Therefore, there is a concern about using this electrolytic capacitor in a power supply device in a lighting device using LEDs having a long life.

  Therefore, it is difficult to use the switching power supply disclosed in Japanese Patent Application Laid-Open No. 2003-250272 as the power supply device for driving the LEDs as described above.

  On the other hand, in the power supply device 2 of the lighting unit 8, by using the transformer 60 and the transformer 61, it is possible to provide not only an improvement in power factor but also a power supply device with high power supply efficiency. Also, no smoothing capacitor is used. Therefore, the method of performing the transformation using the transformer 60 and the transformer 61 according to the present invention has a very high technical value.

  Here, the transformer 60 should have a larger electric capacity than that of the transformer 61. This is because the transformer 60 performs transformation when the voltage value (instantaneous value) of the pulsating current is large, and the current value (instantaneous value) flowing therethrough increases as the voltage value of the pulsating current increases. It is. Therefore, it is necessary to select a transformer having an electric capacity that can cope with it.

  By doing in this way, since the failure of the transformer 60 can be prevented, the reliability of the power supply device 2 can be improved.

  On the other hand, the transformer 61 performs voltage transformation when the voltage value (instantaneous value) of the pulsating current is small. Therefore, the current value (instantaneous value) flowing through it becomes small, and there is no need to select a transformer having a large electric capacity. Selecting a capacitor having an unnecessarily large electric capacity means that the transformer 61 becomes large, leading to an increase in the size of the power supply device 2. Therefore, it is preferable to select an appropriate transformer.

  As a second function of the controller unit 69, an average current (average current of a full-wave rectified waveform (pulsating current) output from the diode bridge 54) flowing through the resistor 55 constituting the measurement unit 43 is obtained. The period for obtaining the average current is preferably longer than the period corresponding to ½ of the cycle of the commercial power supply 41.

  Based on this average current, an estimated waveform estimated to flow through the measurement unit 43 is obtained. This estimated waveform (estimated waveform) is used to indicate the duty ratio to the selection unit 44.

  As a third function of the controller unit 69, a duty ratio is designated for a driver (either driver 56 or driver 58) to which a control signal is sent.

  The designation of the duty ratio is obtained by an operating point obtained from a current flowing through the light emitting unit 47 detected by the resistor 65 and a voltage applied to the light emitting unit 47 detected by the resistor 66, and a reference operating point serving as a reference. This is done to achieve the target operating point.

  Here, the reference operating point may be set by an external signal receiver or an external input switch (not shown), for example, a remote controller. Further, it may be stored in advance in an internal memory (not shown) of the controller unit 69.

  Also, the duty ratio is specified using the estimated waveform described above. This detects the current value (instantaneous value) of the pulsating current flowing through the resistor 55 constituting the measuring unit 43 at the present time. Then, the estimated current value obtained at the present time based on the estimated waveform is compared with the measured current value (instantaneous value) at the present time, and the duty ratio is designated based on the magnitude relationship.

  Here, the power supply unit 101 includes a transformer 67 and a diode 68, converts the alternating current supplied from the commercial power supply 41 into direct current using the transformer 67 and the diode 68, and supplies direct current to the controller unit 69. . Here, the transformer 60, the transformer 61, and the transformer 67 are different individuals and are independent of each other. Therefore, the power supply unit 101 is insulated from the circuit elements of the power supply device 2 that supplies direct current to the light emitting unit 47.

  In addition, an operation instruction to the driver 56 and the driver 58 that realizes the target operation point determined by the microcomputer unit 46 is performed via a signal line that connects the controller unit 69, the driver 56, and the driver 58. Here, the signal line connecting the controller unit 69 to the driver 56 and the driver 58 is electrically insulated by using, for example, a photocoupler in the middle.

  As described above, the controller unit 69 and the selection unit 44 are configured to be electrically insulated. For this reason, for example, noise generated in the selection unit 44 or the like can be prevented from entering the controller unit 69. This prevents the controller unit 69 from malfunctioning and improves the safety of the power supply device 2 itself. That is, the reliability of the lighting unit 8 is increased.

  Here, regarding the DC power supply in the backlight device described in Japanese Patent Application Laid-Open No. 2004-303431, the microcomputer corresponding to the controller unit 69 of the power supply device 2 is electrically insulated from the transistors corresponding to the FETs 57 and 59 of the present invention. It has not been. Therefore, there is a risk of malfunction due to noise or the like.

  However, as described above, in the lighting unit 8 of the present invention, the controller unit 69, the selection unit 44, and specifically, the FET 57 and the FET 59 are electrically insulated, and there is a risk of malfunction due to noise. This reduces the reliability of the lighting unit 8.

  Here, the controller unit 69 instructs the duty ratio via the photocoupler as described above. The controller unit 69 is configured by using a microcomputer or the like, and smoothes the full-wave rectified waveform (pulsating flow) input from the terminal pair A, A ′ which is the input terminal pair in the selection unit 44 without smoothing. Control to generate a desired pulse waveform directly from the wave rectification waveform (pulsating flow) is realized.

  As a result, it becomes unnecessary to use a smoothing capacitor, so that the volume of the power supply device 2 can be greatly reduced and the reliability can be improved. Hereinafter, the reason will be described in detail.

  In the constant current DC power source described in JP-A-8-241133, a full voltage rectified waveform (pulsating flow) is once smoothed and a pulse voltage waveform having desired characteristics is obtained. In order to perform this smoothing, an electrolytic capacitor having a large capacity is used. Specifically, in FIG. 8, electrolytic capacitors are connected to terminal pairs A and A ′, which are input terminal pairs in the selection unit 44. Moreover, the electrolytic capacitor has a problem that the volume is large and the apparatus is enlarged. Furthermore, there is a problem that the capacity easily changes due to the influence of the ambient temperature. Moreover, the electrolytic capacitor has a short life and has a problem of stability.

  In addition, in the DC power source in the backlight device described in Japanese Patent Application Laid-Open No. 2004-303431, although it is not necessary to use an electrolytic capacitor, there is a problem in terms of safety and stability as described above.

  However, the power supply device 2 of the present invention solves all of these problems, can achieve a long life (high reliability), and is suitable for a lighting device using LEDs.

Next, operation | movement of the illumination unit 8 is demonstrated using figures.
FIG. 12 is a flowchart showing the operation of the lighting unit 8.

  First, in S91, the commercial power supply 41 is turned on to the power supply device 2 of the lighting unit 8 and power feeding is started. Then, the controller unit 69 starts operation. Here, immediately after the commercial power supply 41 is turned on, the operation of the controller unit 69 is started, but power is not supplied to the selection unit 44 and the selection unit 44 is not activated. The reason for adopting this method is to increase the safety of the power supply device 2. This is because, when the controller unit 69 is activated first, if an abnormality occurs in the power supply device 2, the commercial power supply 41, or the light emitting unit 47, the operation can be stopped immediately.

  Another reason for adopting this method is that it is necessary to detect the frequency of the commercial power supply 41 before the selection unit 44 is driven (this detection is performed in the controller unit 69). Even in Japan, the frequency of the commercial power supply 41 is 50 Hz in the eastern Japan region and 60 Hz in the west Japan region. In order to perform the desired control as described above using the controller unit 69, it is necessary to detect the frequency of the commercial power supply 41.

  Next, in S92 of FIG. 12, the duty ratio is determined by the microcomputer unit 46 or the like. This will be described in detail later with reference to FIG.

  Next, in S93 of FIG. 12, the microcomputer unit 46 creates a control signal. This will be described in detail later with reference to FIG.

  Next, in S94 of FIG. 12, the microcomputer unit 46 and the like specify (correct) the duty ratio based on the average current of the pulsating flow measured by the measuring unit 43. Details will be described later with reference to FIG.

  Next, in S95 of FIG. 12, it is confirmed whether a stop signal is input from the microcomputer unit 46, an external input switch (not shown) or the like, and if the stop signal is input, the operation of the power supply device 2 is stopped ( If YES in S95). This corresponds to, for example, a user using the lighting unit 8 turning off the light emitting unit 47 of the lighting unit 8, that is, stopping the power supply to the power supply device 2 of the lighting unit 8. At this time, the selection unit 44 stops the operation for a predetermined time before the controller unit 69. In other words, the controller unit 69 ends the instruction to the selection unit 44 within that time. Here, the predetermined time is desirably about 0.2 [s] to 1 [s].

  The reason for taking such a method is to increase the safety of the power supply device 2 in the lighting unit 8.

  If no stop signal is input (NO in S95), the process returns to S92 and the above-described operation is repeated.

  FIG. 13 is a flowchart for explaining the operation of determining the duty ratio in the lighting unit 8.

  In S101, the microcomputer unit 46 checks whether the reference operating point has been changed.

  Here, the operating point is a value obtained by the product of the current value flowing through the light emitting unit 47 detected by the resistor 65 and the forward voltage value applied to the light emitting unit 47 detected by the resistor 66. The unit of the operating point is watt [W], which is equivalent to electric power. The forward voltage is determined by the characteristics and the number of solid state light emitting elements included in the light emitting unit 47.

  Moreover, since the light emitting part 47 having a solid light emitting element is a current control element, the light emission intensity of the light emitting part 47 is determined by the magnitude of the current flowing therethrough.

  Therefore, the reference operating point is determined from the forward voltage corresponding to the characteristics of the light emitting unit 47 to be used and the current value corresponding to the light emission intensity required in the light emitting unit 47.

  As described above, the light emission intensity of the light emitting unit 47 is determined by the magnitude of the current flowing through the light emitting unit 47. In other words, the emission intensity of the light emitting unit 47 can be freely changed, that is, dimmed by setting the magnitude of the current flowing through the light emitting unit 47.

  Here, dimming corresponds to changing the reference operating point of the light emitting unit 47. Further, by changing the reference operating point of the light emitting unit 47, the light emission intensity of the light emitting unit 47 at that time can be increased (lightened) or weakened (darkened).

  Here, FIG. 14 is a diagram for explaining changing the light emission intensity by changing the setting of the reference operating point of the light emitting unit 47. FIG. 14A shows a reference operating point indicating the light emission intensity at that time (initial). In order to make the light emission intensity of the initial light emitting unit 47 stronger (brighter), the reference operation point is moved and set as shown in FIG. Conversely, when it is desired to weaken (darken) the light emission intensity of the initial light emitting section 47, it may be set by moving as shown in FIG.

  The reference operating point may be set by an input from an external input switch (not shown) connected to the microcomputer unit 46, or by an input from an external signal receiving device (not shown) connected to the microcomputer unit 46. You can go. In this way, the setting of the reference operating point can be changed from outside, that is, the light emitting unit 47 can be dimmed from outside.

  If the reference operating point has been changed (YES in S101), the process proceeds to S102. If no change has been made (NO in S101), the process proceeds to S103.

  Next, in S102 of FIG. 13, the microcomputer unit 46 reads the reference operating point. This is because the controller unit 69 is provided with information input from an external input switch (not shown) connected to the microcomputer unit 46, an external signal receiving device (not shown) connected to the microcomputer unit 46, or the like. This is performed by reading out information related to a reference operating point stored in an internal memory (not shown).

  The reference operating point is stored as a target operating point in an internal memory (not shown) provided in the controller unit 69.

Next, in S103 of FIG. 13, a target operating point is determined.
First, the current value flowing through the light emitting unit 47 detected by the resistor 65 and the forward voltage value applied to the light emitting unit 47 detected by the resistor 66 are measured to obtain the current operating point.

  The detected operating point is compared with the reference operating point, and a target operating point is set based on the result.

  FIG. 15 is a diagram for explaining that the target operating point is reset when the actually detected operating point of the light emitting unit 47 is out of the predetermined operating range from the reference operating point.

  FIG. 15A is a diagram illustrating a response when the detected operating point changes to the upper left in the drawing, that is, when the detected operating point is outside the upper limit range of the predetermined operating range. This corresponds to a case where the forward voltage of the light emitting unit 47 decreases due to an increase in the ambient temperature or the like, and the current flowing therethrough increases accordingly. In this case, the light emitting unit 47 emits light that is stronger (brighter) than the desired light emission intensity. For this reason, a control operation point is determined and set as a new target operation point. By doing so, the predetermined operating range (here, when the current value based on the reference operating point of the current flowing through the light emitting unit 47 is 100, the range of 95 to 105, that is, the range of ± 5% is set as the predetermined operating range. The operating point will be within.

  Note that the predetermined operation range does not have to be within a range of ± 5%, but may be as wide as a range of ± 10%. However, the wider it is, the greater the change in the light emission intensity of the light emitting section 47, which gives the user a sense of incongruity, so it is necessary to set an appropriate range. In the tests by the inventors, this value is adopted because there is no sense of incongruity within the range of ± 5%.

  As shown in FIG. 15B, when the detected operating point fluctuates to the lower right in the figure, that is, when the detected operating point is outside the lower limit range of the predetermined operating range, the case of FIG. Similarly, a control operation point is determined, and this is set as a target operation point.

  If the detected operating point is within the predetermined operating range, it is used as a new target operating point as it is.

  In S104 of FIG. 13, the microcomputer unit 46 calculates a duty ratio for realizing the target operating point. In other words, the microcomputer unit 46 determines the duty of the voltage of the pulsating current input to the primary side of the transformer (either the transformer 60 or the transformer 61) of the selection unit 44 for realizing the target operating point. Determine the ratio.

  In S105 of FIG. 13, the microcomputer unit 46 creates a control signal necessary for realizing the duty ratio calculated in S104. Details will be described later.

  In S106 of FIG. 13, the microcomputer unit 46 determines whether or not the target operating point matches the actual operating point.

  This measures the current value flowing through the light emitting unit 47 detected by the resistor 65 and the forward voltage value applied to the light emitting unit 47 detected by the resistor 66 to obtain the current operating point.

  Then, the detected operating point is compared with the target operating point (set in S102 or S103). If it does not deviate from a predetermined operating range (for example, a range of ± 5%) from the target operating point (YES in S106), the determination of the duty ratio is ended.

  If it is outside a predetermined operation range (for example, a range of ± 5%) from the target operation point (NO in S106), the process proceeds to S107.

  In S107 of FIG. 13, the duty ratio is corrected so that the operating point is within a predetermined operating range (for example, a range of ± 5%) from the target operating point. Then, return to S105 and repeat.

FIG. 16 is a flowchart for explaining the operation of creating a control signal.
In S <b> 131, a signal (control signal) for controlling the selection unit 44 is generated in the controller unit 69 so that the duty ratio can be controlled in the selection unit 44.

  Here, the voltage input to the selection unit 44 is a full-wave rectified waveform (pulsating flow) as shown in FIG. It is necessary to generate electric power necessary to realize the target operating point using the voltage of the full-wave rectified waveform (pulsating flow) shown in FIG. 9B. Therefore, the following method is used.

  First, as shown in FIG. 9A, the zero cross point of the AC voltage of the commercial power supply 41 is detected. Here, the detection of the zero cross point is performed every time the AC voltage waveform supplied from the commercial power supply 41 crosses the zero cross point. This is because the AC voltage waveform supplied from the commercial power supply 41 may cause subtle frequency fluctuations, and the subtle frequency fluctuations deteriorate the accuracy of control in the selection unit 44. In order to prevent deterioration in control accuracy in the selector 44, the zero cross point is detected every time the AC voltage waveform crosses the zero cross point.

  Next, as shown in FIG. 9B, the full-wave rectified waveform (pulsating flow) is divided at predetermined time intervals with the zero cross point as a reference point. The time interval may be set in the range of about 2 [μs] to 20 [μs], and 4 [μs] was optimal in the experiments by the inventors.

  Next, necessary power is realized in each section. Here, power is a product of voltage and current as a matter of course. Therefore, the controller unit 69 generates a control signal for controlling the selection unit 44 so as to change the duty ratio so that necessary power can be obtained in all the sections.

  In S132, the microcomputer unit 46 monitors the voltage value of the commercial power supply 41, and estimates the voltage value (instantaneous value) of the pulsating current output by the rectifying unit 42 by full-wave rectifying the alternating current based on this.

  Note that the voltage value (instantaneous value) of the pulsating current output by the rectifying unit 42 after full-wave rectification of alternating current is measured by measuring the voltage between the terminals A and A 'in FIG. It may be read by the unit 46.

  If the voltage value (instantaneous value) of the pulsating flow is equal to or greater than a threshold value (which depends on the configuration of the light emitting unit 47) (YES in S132), the process proceeds to S133. On the other hand, if it is below the threshold voltage (NO in S132), the process proceeds to S134.

  In S133 of FIG. 16, the microcomputer unit 46 sends the control signal created in S131 to the driver 56.

  As a result, the transformer 61 in the selection unit 44 is not transformed. The transformer 60 performs the transformation. The transformer 60 has a smaller winding ratio than the transformer 61. Therefore, the transformer 60 is also smaller in the transformer 60 than the transformer 61.

  In S <b> 134 of FIG. 16, the microcomputer unit 46 sends the control signal created in S <b> 131 to the driver 58.

  Thereby, the transformer 60 in the selection unit 44 is not transformed. Transformer 61 performs transformation. Note that the transformer 61 has a larger winding ratio than the transformer 60. Therefore, the transformer 61 also has a larger transformation ratio than the transformer 60.

FIG. 17 is a diagram for explaining the instruction (correction) of the duty ratio based on the average value of the pulsating flow.
In S <b> 141, the microcomputer unit 46 obtains an average value of the current flowing through the resistor 55 configuring the measuring unit 43 (the current of the full-wave rectified waveform (pulsating current) output from the diode bridge 54).

  The period for obtaining the average current must be longer than the period corresponding to ½ of the period of the commercial power supply 41.

  In S142 of FIG. 17, the microcomputer unit 46 estimates the waveform of the current estimated to flow through the measuring unit 43 based on the average current value obtained in S141. This estimated waveform (estimated waveform) is stored in an internal memory (not shown) in the controller unit 69.

  In S143 of FIG. 17, the microcomputer unit 46 compares the estimated waveform estimated in S142 with the current value (instantaneous value) flowing through the measurement unit 43 at the present time.

  That is, the microcomputer unit 46 reads a current value (instantaneous value) estimated to flow to the measurement unit 43 at the present time from an estimated waveform stored in its internal memory (not shown). The read value is compared with the current value (instantaneous value) flowing through the measurement unit 43 at the present time.

  If the current value (instantaneous value) flowing through measurement unit 43 at this time is higher than the estimated current value (instantaneous value) (YES in S143), the process proceeds to S144.

  On the other hand, if the current value (instantaneous value) flowing through measurement unit 43 at the present time is lower than the estimated current value (instantaneous value) (NO in S143), the process proceeds to S145.

  In S144 of FIG. 17, the microcomputer unit 46 designates (corrects) the duty ratio. This specifies a low duty ratio relative to the immediately preceding duty ratio.

  The reason for this is to reduce the current flowing through the measurement unit 43. Since it is larger than the estimated current, a low duty ratio is designated with respect to the immediately preceding duty ratio in order to correct it.

  In S145 of FIG. 17, the microcomputer unit 46 designates (corrects) the duty ratio. This designates a high duty ratio with respect to the immediately preceding duty ratio.

  The reason for this is to increase the current flowing through the measurement unit 43. Since it is smaller than the estimated current, in order to correct it, a high duty ratio is designated with respect to the immediately preceding duty ratio.

  In S146 of FIG. 17, the microcomputer unit 46 creates a control signal. This is as described with reference to the flowchart of FIG.

  In S147 of FIG. 17, the microcomputer unit 46 determines whether or not the total number of times since the start (designation) of the duty ratio based on the average value of the pulsating flow has reached the reference number. The reference number may be arbitrarily set.

  If the total number has reached the reference number (YES in S148), this designation (correction) is terminated. On the other hand, if the total number has reached the reference number, the process returns to S143 to continue the designation (correction).

As described above, it is possible to correct the duty ratio based on the pulsating current value.
This makes it possible to quickly detect voltage fluctuations of the commercial power supply 41 and avoid the influence of the lighting unit 8 caused by the change.

  As described above, in the lighting unit 8, the current (instantaneous value) flowing through the measurement unit 43 is monitored, and the duty ratio is controlled based on the current (average value) flowing through the measurement unit 43 measured in advance. To correct.

  From this, even when the voltage of the commercial power supply 41 becomes high, the current value (instantaneous value) flowing through the measurement unit 43 of the illumination unit 8 becomes high, so that the operating point of the light emitting unit 47 becomes high ( That is, it can be avoided that the light emission intensity is increased). Of course, it is possible to cope with the case where the voltage of the commercial power supply 41 becomes low.

  This avoids fluctuations in the light emission intensity of the light emitting unit 47 and provides stable illumination to the user of the lighting unit 8 as well as the power supply device 2 and the light source unit 3 (light emission) due to voltage fluctuations in the commercial power supply 41. This also has an effect on avoiding failure of the part 47).

  The lighting unit 8 uses a solid light emitting element 32. One of the features of the solid state light emitting element 32 is long life, and it is important to prevent the power supply device 2 and the light source unit 3 (light emitting unit 47) from failing in order to fully enjoy this performance.

  FIG. 18 is a diagram illustrating a schematic structure of the substrate 21 constituting the power supply device 2. The board 21 housed in the casing 5 of the power supply device 2 is a board before mounting on which circuit elements are mounted, and includes a main board 151 shown in FIG. 18A, a sub board A152 shown in FIG. And a sub-substrate B153. Here, it goes without saying that the number of sub-boards is not limited to this and may be set freely.

  The main board 151 has a circular shape. FIG. 18A is a view as seen from the direction of the mounting surface of the main board 151. The sub board A152 and the sub board B153 have a semicircular shape. FIG. 18B is a view as seen from the direction of the mounting surface of the main board 151.

  FIG. 19 is a diagram when various circuit elements are mounted on the substrate 21 constituting the power supply device 2. In FIG. 19, circuit elements constituting the power supply device 2 in the illumination unit 8 shown in FIG. 2, such as the transformer 60, are mounted on the main board 151, the sub board A 152, and the sub board B 153.

  FIG. 19A is a view of the main board 151 as viewed from the direction of the mounting surface. FIG. 19A shows the various circuit elements constituting the power supply device 2 in the hatched portion, and shows the main substrate 151 on which the various circuit elements constituting the power supply device 2 are mounted.

  On the other hand, FIG. 19B is a view of the sub board A152 and the sub board B153 as viewed from the direction of the mounting surface. FIG. 19A shows various circuit elements constituting the power supply device 2 with hatched portions, and shows the sub-substrate A152 and the sub-substrate B153 on which the various circuit elements constituting the power supply device 2 are mounted.

  Note that components (controller unit 69, power supply unit 101, photocoupler (not shown), etc.) constituting the microcomputer unit 46 are mounted on the sub-board B.

  FIG. 20 is a diagram illustrating that the main board 151, the sub board A152, and the sub board B153 are arranged to face each other on the mounting surface. 20 shows a mounting surface of the main board 151 on which the various circuit elements shown in FIG. 19A are mounted, and a mounting surface of the sub board A152 and the sub board B153 on which the various circuit elements shown in FIG. 19B are mounted. And are arranged so as to face each other. Here, it is important to note that when the sub-board A152 and the sub-board B153 are arranged so that the mounting surfaces of the main board 151 face each other as shown in FIG. It is to avoid interference.

  Therefore, the distance between the mounting surface of the main substrate 151 and the mounting surfaces of the sub substrate A152 and the sub substrate B153 is the highest among the various circuit elements mounted on the main substrate 151, the sub substrate A152, and the sub substrate B153. Is substantially the same as a high circuit element (here, transformer 60).

  Here, the transformer 60 is a transformer having a larger electric capacity than the transformer 61 as described above, and therefore has a large size (high height).

  Further, when the sub-board A152 and the sub-board B153 are mounted on the mounting surface of the main board 151 so that the mounting surfaces face each other, the sub-board A152 and the sub-board B153 are completely mounted without protruding from the main board 151. It is important to do so.

  By doing as described above, the height of the power supply device 2 is substantially equal to the highest circuit element (here, the transformer 60) constituting the power supply device 2, and a sufficient miniaturization can be realized. .

  Here, as described above, the power supply device 2 is premised on application to a lighting device using a solid-state light emitting element (here, LED). Each LED is very small, and therefore, a small and highly design lighting device that cannot be realized by a conventional lighting device using a fluorescent lamp or the like can be realized by using the LED. Therefore, it is necessary to make the power supply device 2 as small as possible so that the lighting unit 8 can be easily incorporated. This is realized by making the volume ratio of the power supply device 2 constituting the illumination unit 8 to the illumination unit 8 very small.

  Incidentally, as described above, the direct current power source in the backlight device described in Japanese Patent Application Laid-Open No. 2004-303431 is not specified for downsizing. Therefore, application to an illuminating device using LEDs cannot be realized with a DC power source in a backlight device described in Japanese Patent Application Laid-Open No. 2004-303431.

  On the other hand, the power supply device 2 according to the present invention is very compact because circuit elements necessary for the configuration of the power supply device 2 are densified and mounted, thereby realizing a small illumination unit 8 using LEDs. Is preferred. Therefore, I think that its industrial value is great.

  As described above, the visible light communication system 1 of the present invention is transmitted from the illumination unit 8 using the high power LED that obtains pseudo white color by installing the yellow phosphor in the light emitting direction of the blue LED emitting bare chip. The visible light communication signal is received through the wavelength filter 143 that transmits only the light emitted from the blue LED bare chip. As a result, the influence of the yellow phosphor having a slow response speed is eliminated, and high-speed visible light communication can be realized.

  By the way, in the visible light communication system described in Japanese Patent Application Laid-Open No. 2007-81703, red, green, and blue LEDs are provided, and multiplexed visible light signals are transmitted by independently controlling light emission. It is said that it is possible. Thus, a visible light communication system capable of high-speed communication can be provided. However, in an LED illumination device realized by using a high power LED, a high power LED that normally emits white light is used. Therefore, the practicality of the visible light communication system described in Japanese Patent Application Laid-Open No. 2007-81703 using red, green, and blue LEDs is questionable.

  On the other hand, the visible light communication system 1 of the present invention is configured using a normal white light emitting high power LED (a high power LED that obtains a pseudo white color by installing a yellow phosphor in the light emitting direction of a blue light emitting LED bare chip). This is a visible light communication system capable of high-speed communication that is truly practical.

  Moreover, about the power supply device 2 with which the illumination unit 8 is equipped, the high power factor and high power supply efficiency are implement | achieved simultaneously by mounting the transformer from which two winding ratios differ. Moreover, the electrolytic capacitor which is uneasy about a lifetime characteristic is not used. Therefore, high stability is realized.

  In addition, the visible light communication system 1 of this invention is not limited to the said Example, It can deform | transform and implement freely in the range which does not deviate from the meaning of this invention.

  For example, the LED to be used may be of a type that obtains white by installing an LED bare chip that emits ultraviolet light and a phosphor that emits blue, red, and green in the light emitting direction. In this case, the wavelength filter 143 may be configured to transmit only the emission wavelength of the LED bare chip that emits ultraviolet light.

  The target operating point may be set using the temperature in the light source unit 3 as an index. The solid state light emitting device 32 has a risk of failure due to an increase in temperature.

  In order to avoid this, a temperature sensor (thermistor) or the like is added in the light source unit 3, and the temperature is monitored by the controller unit 69. In addition, when the temperature rises abnormally, the target operating point is set low, thereby lowering the temperature and preventing the solid state light emitting element 32 from failing.

  Three or more transformers may be provided. For example, a transformer that performs step-up, a transformer that performs equal-magnification transformation, and a transformer that performs step-down voltage may be provided.

  If the voltage value (instantaneous value) of the pulsating current output from the rectifier 42 is greater than or equal to the first threshold value, the voltage is transformed by a step-down transformer, and if the voltage value is greater than or equal to the second threshold value and less than the first threshold value. The voltage is transformed by a transformer that performs equal magnification transformation, and if it is less than the second threshold value, the voltage is transformed by a transformer that boosts the voltage. The first threshold is higher than the second threshold, and these are set based on the configuration of the light source unit 3 and the like.

  Also by doing so, it is possible to obtain a power supply device that is optimal for a lighting device that uses a solid-state light emitting element that naturally improves the power factor and has high power supply efficiency.

  Further, although the power supply device 2 has a cylindrical shape, the main substrate 151, the sub substrate A152, and the sub substrate B153 may be rectangular and may have a prismatic shape.

  In the trial production by the inventors, when the power supplied to the light emitting unit 47 is designed to be 100 W at the maximum, the power supply device 2 can be realized with a size of approximately the size of a chopstick box.

  The power supply device 2 is also suitable as a power source that drives not only the LED but also the EL. Furthermore, it is suitable not only for driving a solid-state light emitting device but also as a power supply device for driving a load with a low power factor (for example, a load with a large capacity).

  The present invention can be applied to an illuminating device, and in particular, can be applied to an illuminating device using a solid light emitting element such as an LED as a light source using an AC power source.

It is a perspective view which shows the external appearance of the visible light communication system 1 of this invention. It is sectional drawing which shows the structure of the power supply device 2 of this invention. It is sectional drawing which shows the structure of the light source unit 3 of this invention. It is sectional drawing which shows the structure of the light reception unit 4 of this invention. It is a schematic diagram which shows the illumination area | region (irradiation area | region) of the illumination unit 8 of this invention. It is a figure which shows an example of distribution of the light emission wavelength of the high power LED used as the solid light emitting element. 6 is a diagram illustrating an example of transmission characteristics of a wavelength filter 141. FIG. It is a functional block diagram of the illumination unit 8 of this invention. It is a figure which shows the schematic circuit structure of the illumination unit 8 of this invention. It is a figure explaining the output waveform of the diode bridge which rectifies | straightens alternating current in the power supply device 2 of this invention. It is a figure explaining the voltage waveform between B and B 'in the power supply device 2 of this invention. It is a figure explaining the current waveform which flows into resistance 55 in the power supply device 2 of this invention. It is a flowchart which shows operation | movement of the illumination unit 8 of this invention. It is a flowchart which shows the determination method of the duty ratio of the illumination unit 8 of this invention. It is explanatory drawing explaining a reference | standard operating point. It is a figure explaining a target operating point being reset when the operating point actually detected of the light emission part of this invention has remove | deviated from the predetermined operating range from the reference | standard operating point. It is a flowchart which shows the method of producing the control signal of the illumination unit 8 of this invention. It is a flowchart which shows the designation | designated (correction | amendment) method of the duty ratio based on the average value of the pulsating flow of the illumination unit 8 of this invention. It is a figure which shows schematic structure of the board | substrate which comprises the power supply device 2 of this invention. It is a figure at the time of mounting various circuit elements on the board | substrate which comprises the power supply device 2 of this invention. It is a figure which shows that the main board | substrate and sub board | substrate which comprise the power supply device 2 of this invention are arrange | positioned facing each other in the mounting surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Visible light communication system 2 Power supply device 3 Light source unit 4 Light receiving unit 5 Case 6 Outlet 7 Connection cable 8 Illumination unit 21, 33, 33a, 33b Board | substrate 31, 141 Case part 32 Solid light emitting element 34 Protective translucent board 35 Optical element 36 Support body 41 Commercial power supply 42 Rectification unit 43 Measurement unit 44 Selection unit 45 Detection unit 46 Microcomputer unit 47, 47a, 47b Light emission unit 51, 52 Inductor 53, 64 Capacitor 54 Diode bridge 55, 65, 66 Resistance 56, 58 Driver 57, 59 FET
60, 61, 67 Transformer 62, 63, 68 Diode 69 Controller unit 101 Power supply unit 142 Light receiving element 143 Wavelength filter 151 Main board 152 Sub board A
153 Sub-substrate B
201, 202 area

Claims (15)

Comprising a plurality of solid state light emitting elements composed of an element part composed of a bare chip and a phosphor part that is excited by light in the first wavelength region emitted from the element part and emits light in the second wavelength region; A transmission unit that transmits the arbitrary information by modulating direct current supplied to at least a part of the plurality of solid state light emitting elements based on arbitrary information, and a light receiving unit that receives the arbitrary information transmitted from the transmission unit In a visible light communication system composed of units,
The light receiving unit is
A filter unit that transmits at least a part of the light in the first wavelength region and does not transmit the light in the second wavelength region;
A visible light communication system, comprising: a light receiving element that receives light transmitted through the filter unit. The visible light communication system according to claim 1, wherein an optical element that collects light is installed in a light emission direction of the solid state light emitting element to which a direct current modulated based on the arbitrary information is supplied. The visible light communication system according to claim 1, wherein the light receiving element is an element corresponding to a communication speed of at least a communication speed of 10 Mbytes / second or more. The visible light communication system according to claim 1, wherein the filter unit transmits light in a wavelength region having a wavelength of 470 nm or less. The direct current supplied to the plurality of solid state light emitting elements is generated by a power supply device using an alternating current power source,
The power supply device
Conversion means for converting the alternating current into a pulsating flow;
Selecting means for selecting pass / non-pass of the pulsating flow and transforming the pulsating flow that has passed;
Specifying means for specifying the transformation with respect to the selection means,
The selection means includes a plurality of transformers having different winding ratios (number of secondary windings / number of primary windings),
2. The specification unit according to claim 1, wherein the designation unit designates any one of the plurality of transformers as a transformer to be used for voltage transformation based on an instantaneous value of the pulsating flow at an arbitrary time. Visible light communication system. The plurality of transformers included in the selection means are:
A first transformer having a winding ratio of 1 / n;
A second transformer having a winding ratio of 1 / m (n> m),
The designation means is:
If the instantaneous value of the pulsating flow at the arbitrary time is greater than or equal to a predetermined threshold, the first transformer is designated,
The visible light communication system according to claim 5, wherein when the instantaneous value of the pulsating flow at the arbitrary time is equal to or less than the predetermined threshold value, the second transformer is designated. The power supply device further includes:
An instruction means for instructing the selection means a duty ratio that is a time ratio of the passage / non-passage of the pulsating flow;
The instruction means obtains an estimated waveform of the pulsating flow based on an average value of the pulsating flow for a predetermined period,
The duty ratio is indicated based on a comparison result between an instantaneous value of the pulsating flow at a predetermined time and an estimated instantaneous value of the pulsating flow at the predetermined time based on the estimated waveform. Visible light communication system. The instruction means includes
When the instantaneous value of the pulsating flow at a predetermined time exceeds the estimated instantaneous value of the pulsating flow at the predetermined time based on the estimated waveform, a low duty ratio is indicated with respect to the duty ratio immediately before the predetermined time,
When the instantaneous value of the pulsating flow at a predetermined time is lower than the estimated instantaneous value of the pulsating flow at the predetermined time based on the estimated waveform, a higher duty ratio is indicated with respect to the duty ratio immediately before the predetermined time. The visible light communication system according to claim 7, characterized in that: The visible light communication system according to claim 7, wherein the predetermined period is at least a period corresponding to a half cycle of the AC power supply. The visible light communication system according to claim 6, wherein an electric capacity of the first transformer is larger than an electric capacity of the second transformer. The power supply device further includes:
A main single-sided mounting board on which a part of circuit elements constituting the power supply device is mounted;
A first sub-single-sided mounting board that is substantially semicircular and on which the rest of the circuit elements constituting the power supply device are mounted;
The said power supply device is a column shape, Comprising: The mounting surface of the said main single-sided mounting board | substrate and the mounting surface of a said 1st sub single-sided mounting board | substrate are comprised facing each other. Visible light communication system. The power supply device further includes:
A second sub single-sided mounting board;
A photocoupler,
A microcomputer unit comprising a microcomputer and including the designation means and the instruction means;
A microcomputer power supply unit for driving the microcomputer unit;
The microcomputer unit and the microcomputer power supply unit are mounted on the second sub single-sided mounting board,
The visible light communication system according to claim 11, wherein the power supply device is configured such that a mounting surface of the second sub-single-side mounting substrate faces a mounting surface of the main single-side mounting substrate. The visible light communication system according to claim 12, wherein a height of the power supply device is substantially equal to a highest circuit element among circuit elements constituting the power supply device. The visible light communication according to claim 13, wherein the main single-sided mounting board and the first sub-single-sided mounting board are arranged and mounted such that a distance between the main single-sided mounting board and the first sub-single-sided mounting board is substantially equal to a height of the circuit element. system. The visible light communication system according to claim 14, wherein the circuit element is any one of the plurality of transformers.

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