WO2007004530A1

WO2007004530A1 - Illumination light communication device and illumination light communication method

Info

Publication number: WO2007004530A1
Application number: PCT/JP2006/313048
Authority: WO
Inventors: Kazuo Kuroda; Akira Imamura; Kei Tanaka
Original assignee: Pioneer Corporation
Priority date: 2005-06-30
Filing date: 2006-06-30
Publication date: 2007-01-11
Also published as: JPWO2007004530A1; JP4676494B2

Abstract

White light emitting diodes (11A, 11A, ...) emits illumination light modulated by communication information. A light quantity control unit (13) controls generation of the illumination light or modulation by a modulation unit (12) so that the light quantity of the illumination light per a predetermined period is constant. For example, the light quantity control unit (13) performs biphase encoding for the communication information.

Description

Specification

Illumination light communication apparatus and illumination light communication method

Technical field

The present invention relates to an illumination light communication apparatus and an illumination light communication method for communicating information using illumination light.

Background art

[0002] Currently, development of illumination optical communication technology is underway. Illumination light communication technology is generally a technology that communicates information using illumination light emitted from illumination devices such as luminaires installed in the house and illumination lights installed outdoors. .

In illumination light communication, a light emitting diode (LED) is often used as a light source of illumination light irradiation means. With the recent progress of LED technology, LED can produce bright white illumination light. The LED can switch between light emission and non-light emission at high speed. By utilizing such LED characteristics, it is possible to modulate illumination light with digital information (a panelless signal) and transmit digital information via the illumination light. Then, the illumination light modulated by the digital information is received by the light receiving element, and the digital information is extracted from the electrical signal corresponding to the illumination light, thereby realizing the reception of the digital information. Thus, information communication using illumination light is realized.

[0004] For example, Japanese Patent Laid-Open No. 2004-229273 discloses a method for performing information communication using illumination light.

Patent Document 1: Japanese Patent Application Laid-Open No. 2004-229273

Disclosure of the invention

Problems to be solved by the invention

By the way, in illumination light communication, illumination light emitted from a light source such as a lighting fixture is modulated by digital information (pulse signal). As a result, the brightness of the illumination light changes at high speed. In other words, the illumination light flashes rapidly.

[0007] Although the illumination light is blinking, the blinking speed is high. Therefore, each change in the brightness of the illumination light corresponding to the change in the level of the pulse signal is directly detected through the human eye. It cannot be recognized.

[0008] However, when there is a bias in the arrangement of 0 and 1 in digital information, the brightness of the illumination light seen over a relatively long period of time changes. This change in brightness is relatively slow, so it may be directly perceivable through the human eye.

[0009] For example, if 0 continues in digital information, the low level continues in the pulse signal, and the illumination light is dark or the illumination light is off for a long period. As a result, humans feel that the illumination light has become dark. On the other hand, if 1 continues in digital information, humans feel that the illumination light has become brighter.

[0010] For example, when illumination light emitted from a light source such as a lighting fixture is modulated with digital information due to such circumstances, flickering that can be directly recognized by humans may occur in the illumination light depending on the contents of digital information. there is a possibility. This is not preferable because it lowers the performance that is essentially required for lighting fixtures, lighting, etc., that is, the performance of illuminating and maintaining the brightness of an object.

[0011] The present invention has been made in view of the above-described problems, and a first object of the present invention is to provide illumination light that can be directly recognized by humans even if the illumination light is modulated by information. It is an object of the present invention to provide an illumination light communication device, an illumination light communication method, and a computer program that can reduce flicker.

[0012] A second problem of the present invention is to provide an illumination light communication device, an illumination light communication method, and a computer program capable of stabilizing the brightness (luminance) of illumination light modulated by information. is there.

Means for solving the problem

In order to solve the above problems, an illumination light communication apparatus according to the present invention is an illumination light communication apparatus that communicates information via illumination light, a light source that emits illumination light that is visible light, and the light source A modulation unit that modulates emitted illumination light based on the information, and a light amount control unit that controls light emission by the light source so that the light amount per predetermined period of the illumination light modulated by the modulation unit is constant. And.

In order to solve the above problems, an illumination light communication method of the present invention is an illumination light communication method that communicates information via illumination light that is visible light emitted from a light source, and is based on the information. Therefore, a modulation step for modulating the illumination light, and a light amount control step for controlling light emission from the light source so that the light amount per predetermined period of the illumination light modulated in the modulation step is constant.

In order to solve the above problems, a computer program of the present invention causes a computer to function as the illumination light communication device of the present invention (including various aspects thereof).

[0016] In order to solve the above problems, a computer program product in a computer-readable medium clearly embodies a computer-executable program instruction, and the computer is used as the illumination optical communication device ( However, these functions are included).

[0017] According to the computer program product of the present invention, the computer program product is read into a computer from a recording medium such as a ROM, CD-ROM, DVD-ROM, or hard disk storing the computer program product, or For example, if the computer program product, which is a transmission wave, is downloaded to a computer via communication means, the illumination light communication apparatus of the present invention described above can be implemented relatively easily. More specifically, the computer program product may be composed of computer-readable code (or computer-readable instructions) that function as the illumination light communication device of the present invention described above.

[0018] These effects and other advantages of the present invention will become apparent from the embodiments described below.

Brief Description of Drawings

FIG. 1 is a block diagram showing a first embodiment of an illumination light communication apparatus of the present invention.

FIG. 2 is an explanatory diagram showing a specific example when the illumination light communication device in FIG. 1 is applied to an indoor illumination device.

FIG. 3 is an explanatory diagram showing a specific example when the illumination light communication apparatus in FIG. 1 is applied to an illumination lamp.

4 is a block diagram showing in detail the internal structure of the illumination light communication device in FIG. 1.

FIG. 5 is an explanatory diagram showing communication information sent from an information source.

[Fig. 6] Pulse signal corresponding to communication information before bi-phase encoding processing, pulse signal corresponding to communication information after no-phase encoding processing, and pulse signal after waveform inversion processing It is a wave form diagram which shows a number.

FIG. 7 is a block diagram showing a second embodiment of the illumination light communication apparatus of the present invention.

FIG. 8 is a circuit diagram showing a more specific aspect of the second embodiment of the illumination optical communication apparatus of the present invention.

FIG. 9 is a block diagram showing a third embodiment of the illumination light communication apparatus of the present invention.

FIG. 10 is a circuit diagram showing a more specific aspect of the third embodiment of the illumination optical communication apparatus of the present invention.

FIG. 11 is a block diagram showing a fourth embodiment of the illumination light communication apparatus of the present invention.

FIG. 12 is a circuit diagram showing a more specific aspect of the fourth embodiment of the illumination optical communication apparatus of the present invention.

FIG. 13 is a waveform diagram showing a pulse signal generated by adding an adjustment pulse signal to the pulse signal generated by the pulse signal generation circuit.

FIG. 14 is a block diagram showing a fifth embodiment of the illumination light communication apparatus of the present invention.

FIG. 15 is a waveform diagram showing a pulse signal generated by a pulse signal generator, a pulse signal divided by a pulse divider, and a pulse signal in which the number of divided pulses is changed by a node number controller.

Explanation of symbols

1, 60, 70, 80, 90, 100, 110, 120 Illumination light communication device

11, 66, 86, 106, 126 Light source

12, 61, 81, 101, 121 Modulator

13, 63, 83, 104, 124 Light intensity controller

41 Bi-Faise Coder Processing Unit

42, 62, 82, 102, 122 Pulse signal generator

43 Waveform inversion section

51 Communication information

64 Light intensity detector

65, 85 Amplitude controller

84 Integration value acquisition unit 105 Adjustment pulse signal controller

123 Norse division

125 Norse number control unit

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the best mode for carrying out the present invention will be described in each embodiment in order with reference to the drawings.

[0022] (First embodiment)

FIG. 1 shows a first embodiment of the illumination light communication apparatus of the present invention. An illumination light communication device 1 in FIG. 1 is a device that communicates information via illumination light. The illumination light communication device 1 can communicate information of various forms, types and contents. However, it is desirable that the form of information communicated by the illumination light communication device 1 is digital information expressed by a binary code. However, if it is analog information, for example, the analog information may be converted into binary digital information by an analog-to-digital converter and then communicated. If multi-value digital information is used, for example, by a signal processing circuit, Communication can be performed after converting this into binary digital information. Hereinafter, for convenience of explanation, information communicated via illumination light is referred to as “communication information”.

The illumination light communication device 1 includes a light source 11, a modulation unit 12, and a light amount control unit 13 as shown in FIG.

[0024] The light source 11 spontaneously emits illumination light. The illumination light is visible light. The illumination light is preferably white light. The light source 11 is preferably a light emitting diode (LED). Further, the light source 11 is preferably a light emitting diode that emits white light, that is, a white light emitting diode. However, the light source 11 may be configured by a combination of a blue light emitting diode, a green light emitting diode, and a red light emitting diode instead of the white light emitting diode. In addition, other light-emitting elements that emit visible light spontaneously and can switch between light emission and non-light emission at high speed (for example, organic electroluminescence elements, inorganic electroluminescence elements, or silicon light-emitting diodes) are used instead of light-emitting diodes. The light source 11 may be composed of elements, etc.

The modulation unit 12 modulates illumination light emitted from the light source 11 based on communication information. light The amount control unit 13 controls the light emission by the light source 11 so that the amount of illumination light modulated by the modulation unit 12 per unit time is constant. Specifically, the light quantity control unit 13 controls the generation of illumination light by the light source 11 or the modulation of illumination light by the modulation unit 12. Further specific description of the modulation unit 12 and the light amount control unit 13 will be described later.

FIG. 2 shows a specific example when the illumination light communication device 1 is applied to an indoor lighting device.

The indoor lighting device 20 in FIG. 2 has both a function as indoor lighting and a function of communicating communication information through illumination light.

As shown in FIG. 2, in the indoor lighting device 20, the light emitting diode array plate 21 is provided with a plurality of white light emitting diodes 11A, 11A,. These white light emitting diodes 11 A are covered with a transparent cover 22. The light emitting diode arrangement IJ plate 21 is attached to the attachment unit 23, and is further attached to the ceiling 24 via the attachment unit 23. In addition, a modulation unit 12 and a light amount control unit 13 are provided inside the mounting unit 23.

[0028] The white light emitting diode 11A emits white illumination light. The modulation unit 12 modulates the illumination light based on communication information sent from the information source. That is, the white light emitting diode 11A emits illumination light modulated based on communication information. As a result, the indoor lighting device 20 communicates information with various devices such as information appliances, personal computers, and AV (Audio Vidual) devices that are exposed to illumination light indoors via illumination light. Can communicate. For example, the indoor lighting device 20 communicates communication information with a refrigerator 31 having a communication function, a PDA (Personal Digital Assistance) 32, a notebook personal computer 33, a DVD recorder 34 having a communication function, and the like. Can do.

[0029] The light amount control unit 13 controls the amount of illumination light emitted from the white light emitting diode 11A so that the amount of illumination light modulated by the modulation unit 12 per unit period is constant. This stabilizes the brightness of the illumination light emitted by the white light emitting diode 11A and reduces flickering of the illumination light.

FIG. 3 shows a specific example when the illumination light communication device 1 is applied to an illumination lamp. The illuminating lamp 30 in FIG. 3 has both a function as outdoor illumination and a function of communicating communication information through illumination light. As shown in FIG. 3, in the illuminating lamp 30, a plurality of white light emitting diodes 11B, 11B,... In addition, a modulation unit 12 and a light amount control unit 13 are provided in the storage box 42 provided at the lower end of the column 41.

[0032] The white light emitting diode 11B emits white illumination light. The modulation unit 12 modulates the illumination light based on communication information sent from the information source. As a result, the illumination lamp 30 communicates communication information with the equipment in the place where the illumination light strikes, for example, the communication equipment provided in the automobile passing under the illumination light 30 via the illumination light. be able to.

[0033] The light amount control unit 13 controls the light amount of the illumination light emitted from the white light emitting diode 11B so that the light amount per predetermined period of the illumination light modulated by the modulation unit 12 is constant. Thereby, the brightness of the illumination light emitted from the white light emitting diode 11B is stabilized, and flickering of the illumination light is reduced.

FIG. 4 shows the internal structure of the illumination light communication device 1 in FIG. 1 in detail. As shown in FIG. 4, the light quantity control unit 13 includes a bi-fading encoding processing unit 41. The modulation unit 12 includes a panelless signal generation unit 42 and a waveform inversion unit 43. The bi-phase coding processing unit 41, the pulse signal generation unit 42, and the waveform inversion unit 43 can be configured by a microcomputer, a multiprocessor, or the like in which an arithmetic device, a control device, a logic circuit, and a memory element are incorporated. .

The operation of the illumination light communication apparatus 1 will be described with reference to FIGS. 5 and 6. Figure 5 shows communication information sent from information sources. FIG. 6 shows a pulse signal P11 corresponding to the communication information before the bi-phase encoding process, a pulse signal P12 corresponding to the communication information after the phase code process, and a pulse signal P13 after the waveform inversion process.

First, communication information 51 is sent to the information source power illumination light communication device 1. When the illumination light communication device 1 is applied to the indoor lighting device 20 as shown in FIG. 2, the information source is provided in any place of the building including the room where the indoor lighting device 20 is provided, for example. Main computer (eg personal computer). When the illumination light communication device 1 is applied to an illumination lamp 30 as shown in FIG. 3, the information source is, for example, a communication base, a computer server provided in an information center of an intelligent transportation system (ITS), etc. In The

As shown in FIG. 5, synchronization information 52 and a reception blank 53 are added to the communication information 51 sent from the information source. The synchronization information 52 is information for synchronizing the information source and the illumination light communication device 1. The reception blank 53 is provided for two-way communication between the illumination light communication device 1 and a communication device (for example, the refrigerator 31, the PDA 32, the notebook personal computer 33, the DVD recorder 34, etc. in FIG. 2). Blank. That is, the illumination light communication device 1 transmits the communication information 51 to the communication device via the illumination light. In response to this, the communication device transmits response information to the illumination light communication device 1 through a wireless communication medium such as white visible light or infrared light. The illumination light communication device 1 receives this response information. The reception blank 53 is provided to secure time for receiving the response information.

Further, a header 54 is provided at the head of the communication information 51. The header 54 includes identification information for identifying individual communication devices that communicate with the illumination light communication device 1. For example, when the illumination light communication device 1 communicates with four communication devices such as the refrigerator 31, the PDA 32, the notebook personal computer 33, and the DVD recorder 34 in FIG. Such identification information is included. That is, when the refrigerator 31 is given an identification number such as “01”, PDA 32 as “02”, notebook personal computer as “03”, and DVD recorder 34 as “04”, “01”, “ Identification information indicating “02”, “03” or “04” is included in the header 54. Each communication device can determine whether or not the communication information 51 transmitted from the illumination light communication device 1 is the communication information 51 addressed to itself based on the identification information. As a result, the illumination light communication device 1 can communicate with one of a plurality of communication devices.

[0039] Now, when the communication information 51 is sent from the information source to the illumination light communication device 1, the communication information 51 is first supplied to the bi-fade coding processing unit 41. The bi-phase encoding process unit 41 performs a phase encoding process on the communication information 51. Subsequently, the pulse signal generation unit 42 generates a pulse signal P12 corresponding to the communication information 51 that has undergone the bi-face coding process by the bi-phase code processing unit 41.

[0040] The bi-fading encoding process is, for example, the following process. That is, the bifaise mark If the noise signal corresponding to the communication information 51 before the encoding process is, for example, the pulse signal PI 1 in FIG. 6, the high-level part of the pulse signal P11 has a duty ratio of 50 in the bi-phase encoding process. Converted to% 1st pulse a. Furthermore, the low-level partial force duty ratio of the pulse signal P11 is converted to a second pulse b having a phase force S180 degrees different from the first pulse a with a 50% duty ratio. In this way, the pulse signal P11 is converted into a pulse signal P12 having a duty ratio of 50% as a whole.

[0041] Subsequently, the waveform inverting unit 43 causes the pulseless signal P11 corresponding to the communication information 51 before the bi-phase coding process to be low in the pulse signal P12 corresponding to the communication information 51 after the phase-phase code processing. Invert the waveform of the section corresponding to the section of level). That is, as shown in FIG. 6, the waveform inversion unit 43 inverts a portion corresponding to the second pulse b of the pulse signal P12. As a result, the noise signal P12 is converted into the pulse signal P13. According to this waveform inversion process, in the pulse signal P13, the pulse always rises at a position corresponding to the position where the level of the pulse signal P11 is inverted. Thus, by performing signal processing based on the rising position of the pulse in the pulse signal P13, the original information, that is, the communication information 51 before the bi-phase encoding process can be restored easily and with high accuracy.

Subsequently, the pulse signal P13 is supplied from the waveform inversion unit 43 to the light source 11. The light source 11 emits illumination light modulated by the pulse signal P13, that is, illumination light whose brightness changes in accordance with the waveform of the pulse signal P13.

[0043] Since the average frequency of the pulse signal P13 is, for example, about 100 kHz or more, a change in the brightness of the illumination light corresponding to the waveform of the pulse signal P13 cannot be directly recognized by human eyes. Further, since the pulse signal P13 is a pulse signal having a duty ratio of 50% as a whole, the amount of illumination light modulated by the noise signal P13 per predetermined period (for example, about 0.5 to 1 second) is almost equal. It becomes constant. As a result, regardless of the contents of the communication information 51, that is, the arrangement state of “1” and “0” in the communication information 51, the brightness of the illumination light emitted from the light source 11 is maintained over a long period of time (the light source 11 is Will be almost constant).

[0044] As described above, in the illumination light communication device 1, the communication code is used for the communication code. Processing is performed, the duty ratio of the pulse signal corresponding to the communication information is set to 50%, and the illumination light is modulated by this pulse signal. Therefore, the amount of illumination light per predetermined period can be made almost constant. Accordingly, the brightness (luminance) of the illumination light can be stabilized, and flickering of the illumination light that can be directly recognized by humans can be reduced. As a result, when the illuminating light communication device 1 is applied to an indoor lighting device (see Fig. 2), an illuminating lamp (see Fig. 3), etc., the original performance as these lightings, that is, light is applied to the object to make it brighter. Maintaining that brightness will help maintain and improve performance.

[0045] In addition, the illumination light communication apparatus 1 employs a configuration in which the amount of illumination light is made constant by performing no-phase code delay processing. As a result, the configuration is simpler than when using a configuration that detects the amount of illumination light and feeds back the detection results to adjust the amount of illumination light (for example, the illumination light communication device 60 described later). Power to reduce the number of parts.

It should be noted that the modulation unit 12 in FIGS. 1 to 4 is a specific example of the modulation means, and the light quantity control unit 13 is a specific example of the light quantity control means. 4 is a specific example of the bi-phase encoding processing means, the pulse signal generation section 42 is a specific example of the pulse signal generation means, and the waveform inversion section 43 is a specific example of the waveform inversion means. It is an example.

[0047] (Second embodiment)

FIG. 7 shows a second embodiment of the illumination light communication apparatus of the present invention. The illumination light communication device 60 in FIG. 7 detects the light amount of the illumination light per predetermined period, and changes the amplitude of the pulse signal for modulating the illumination light so that the detected light amount is constant. The configuration is adopted.

That is, in the illumination light communication device 60, the modulation unit 61 includes a pulse signal generation unit 62. The light quantity control unit 63 includes a light quantity detection unit 64 and an amplitude control unit 65.

[0049] The operation of the illumination light communication device 60 is as follows. When communication information is sent from the information source, the pulse signal generator 62 generates a pulse signal corresponding to the communication information. The light source 66 emits illumination light whose brightness changes in accordance with the waveform of the pulse signal generated by the pulse signal generation unit 62. The light quantity detection unit 64 detects the light quantity per predetermined period of the illumination light emitted from the light source 66. The amplitude control unit 65 is a light amount detected by the light amount detection unit 64. The amplitude of the pulse signal generated by the pulse signal generation unit 62 is changed so that becomes a predetermined light quantity.

[0050] Fig. 8 shows a more specific example of the illumination light communication device 60 according to the second embodiment of the present invention. 8 includes a pulse signal generation circuit 71, an amplifier 72, a white light emitting diode (white LED) 73, a light receiving element 74, an integration circuit 75, a reference value output circuit 76, and a comparator 77. Yes. The light receiving element 74 is provided in a place where the illumination light emitted from the white light emitting diode 73 strikes. Taking the indoor lighting device 20 in FIG. 2 as an example, the light receiving element 74 is attached to, for example, the center of the inner surface of the transparent cover.

[0051] The operation of the illumination light communication device 70 is as follows. When communication information is sent from the information source, the pulse signal generation circuit 71 generates a pulse signal P21 corresponding to the communication information. For example, the pulse signal P21 having high and low amplitudes corresponding to the codes “1” and “0” in the communication information is generated. The amplifier 72 amplifies the pulse signal P21 and supplies it to the white light emitting diode 73 as the pulse signal P22. The white light emitting diode 73 emits illumination light modulated by the pulse signal P22, that is, illumination light whose brightness changes in accordance with the waveform of the pulse signal P22.

[0052] Subsequently, the light receiving element 74 receives the illumination light emitted from the white light emitting diode 73, generates an electrical signal whose amplitude changes in accordance with the intensity of the illumination light, and uses this electrical signal as an integration circuit 75. To supply. The integrating circuit 75 generates an integrated value per predetermined period (for example, about 0.5 to 1 second) of the electric signal, and supplies the integrated value to one input terminal of the comparator 77. A predetermined reference value is input from the reference value output circuit 76 to the other input terminal of the comparator 77. The comparator 77 compares the integrated value supplied from the integrating circuit 75 with a predetermined reference value, and supplies a DC control signal having a voltage corresponding to the difference between the two to the amplifier 72.

The amplifier 72 changes the amplification factor according to the voltage of this control signal. As a result, the amplitude of the pulse signal P22 changes according to the voltage of the control signal, that is, the difference between the integrated value supplied from the integrating circuit 75 and the predetermined reference value. More specifically, when the integrated value supplied from the integrating circuit 75 is larger than a predetermined reference value, the voltage of the control signal supplied from the comparator 77 to the amplifier 72 becomes negative, which causes the amplifier to The gain of 72 decreases. Therefore, the amplitude of the pulse signal P22 is reduced, and as a result, the amount of illumination light per predetermined period is reduced. On the other hand, when the integral value supplied from the integration circuit 75 is smaller than a predetermined reference value, the voltage of the control signal supplied from the comparator 77 to the amplifier 72 becomes positive, and thereby the amplification factor of the amplifier 72 increases. Therefore, the amplitude of the pulse signal P22 increases, and as a result, the amount of illumination light per predetermined period increases. By repeating such an operation, the amount of illumination light per predetermined period converges to a constant amount.

[0054] As described above, the illumination light communication devices 60 and 70 detect the light amount of the illumination light per predetermined period, and the pulse for modulating the illumination light so that the detected light amount becomes constant. The amplitude of the signal is changed. Thereby, the light quantity per predetermined period of illumination light can be made substantially constant. Therefore, the brightness (luminance) of the illumination light can be stabilized, and flickering of the illumination light that can be directly recognized by humans can be reduced.

[0055] In addition, the illumination light communication devices 60 and 70 detect the light amount of the illumination light actually emitted per predetermined period, and feedback control the light amount of the illumination light per predetermined period using the detection result. The configuration is adopted. For this reason, the amount of illumination light can be made constant with high accuracy.

Note that in the illumination light communication device 70, an integration value for a predetermined period is generated by the integration circuit 75 and used for comparison by the comparator 77. However, an average value may be used instead of the integral value. For example, the integrated value per predetermined period generated by the integrating circuit 75 may be divided by the length of the predetermined period to generate an average value and used for comparison by the comparator 77.

In FIG. 7, the modulation unit 61 is a specific example of the modulation means, and the light quantity control unit 63 is a specific example of the light quantity control means. Further, the pulse signal generation unit 62 is a specific example of the pulse signal generation unit, the light amount detection unit 64 is a specific example of the light amount detection unit, and the amplitude control unit 65 is a specific example of the amplitude control unit. In FIG. 8, a pulse signal generation circuit 71 is a specific example of pulse signal generation means. The white light emitting diode 73 is a specific example of the light source. The light receiving element 74 and the integrating circuit 75 are specific examples of the light amount detecting means. Further, the reference value output circuit 76, the comparator 77, and the amplifier 72 are specific examples of the amplitude control means. [0058] (Third embodiment)

FIG. 9 shows a third embodiment of the illumination light communication apparatus of the present invention. The illumination light communication device 80 in FIG. 9 obtains an integral value per predetermined period of the noise signal for modulating the illumination light, and the pulse is adjusted so that the obtained integral value becomes constant. A configuration that changes the amplitude of the signal is adopted.

That is, in the illumination light communication device 80, the modulation unit 81 includes a pulse signal generation unit 82. The light quantity control unit 83 includes a light quantity detection unit 84 and an amplitude control unit 85.

[0060] The operation of the illumination light communication device 80 is as follows. When communication information is sent from the information source, the pulse signal generation unit 82 generates a pulse signal corresponding to the communication information. The light source 86 emits illumination light whose brightness changes in accordance with the waveform of the pulse signal generated by the pulse signal generation unit 82. The integral value acquisition unit 84 acquires an integral value per predetermined period of the pulse signal supplied from the pulse signal generation unit 82 to the light source 86. The amplitude control unit 85 changes the amplitude of the pulse signal generated by the pulse signal generation unit 82 so that the integral value acquired by the integration value acquisition unit 84 becomes a predetermined reference value.

FIG. 10 shows a more specific example of the illumination light communication device 80 according to the third embodiment of the present invention. The illumination light communication apparatus 90 in FIG. 10 includes a pulse signal generation circuit 91, an amplifier 92, a white light emitting diode (white LED) 93, an integration circuit 94, a reference value output circuit 95, and a comparator 96.

The operation of the illumination light communication apparatus 90 is as follows. When communication information is sent from the information source, the pulse signal generation circuit 91 generates a pulse signal P31 corresponding to the communication information. For example, a pulse signal P31 having high and low amplitudes corresponding to the codes “1” and “0” in the communication information is generated. The amplifier 92 amplifies the pulse signal P31 and supplies it to the white light emitting diode 93 as the pulse signal P32. The white light emitting diode 93 emits illumination light modulated by the pulse signal P32, that is, illumination light whose brightness changes in accordance with the waveform of the pulse signal P32.

The pulse signal P32 output from the amplifier 92 is also supplied to the integrating circuit 94. The integration circuit 94 generates an integration value per predetermined period (for example, about 0.5 to 1 second) of the pulse signal P32 and supplies this integration value to one input terminal of the comparator 96. Other than comparator 96 A predetermined reference value is input from the reference value output circuit 95 to the other input terminal. The comparator 96 compares the integrated value supplied from the integrating circuit 94 with the reference value, and supplies a DC control signal having a voltage corresponding to the difference between the two to the amplifier 92.

The amplifier 92 changes the amplification factor according to the voltage of this control signal. As a result, the amplitude of the pulse signal P32 changes in accordance with the voltage of the control signal, that is, the difference between the integrated value supplied from the integrating circuit 94 and the reference value. More specifically, when the integrated value supplied from the integrating circuit 94 is larger than the reference value, the voltage of the control signal supplied from the comparator 96 to the amplifier 92 becomes negative, which causes the amplification factor of the amplifier 92 to increase. Go down. Therefore, the amplitude of the pulse signal P32 is reduced, and as a result, the amount of illumination light per predetermined period is reduced. On the other hand, when the integral value supplied from the integration circuit 94 is smaller than the reference value, the voltage of the control signal supplied from the comparator 96 to the amplifier 92 becomes positive, and thereby the amplification factor of the amplifier 92 increases. Accordingly, the amplitude of the pulse signal P32 increases, and as a result, the amount of illumination light per predetermined period increases. By repeating such an operation, the amount of illumination light per predetermined period converges to a constant amount of light.

[0065] As described above, in the illumination light communication devices 80 and 90, the integral value per predetermined period of the pulse signal for modulating the illumination light is obtained, and the obtained integral value is constant. The amplitude of the pulse signal is changed. Thereby, the light quantity per predetermined period of illumination light can be made substantially constant. Therefore, the brightness (luminance) of the illumination light can be stabilized, and flickering of the illumination light that can be directly recognized by humans can be reduced.

[0066] In addition, in the illumination light communication devices 80 and 90, an integral value per predetermined period of the pulse signal actually supplied to the light source 93 is acquired, and the light per predetermined period of the illumination light is obtained using this integral value. A configuration that feedback controls the amount is adopted. For this reason, the amount of illumination light can be made constant with high accuracy.

In FIG. 9, the modulation unit 81 is a specific example of the modulation means, and the light quantity control unit 83 is a specific example of the light quantity control means. The pulse signal generation unit 82 is a specific example of the pulse signal generation unit, the integral value acquisition unit 84 is a specific example of the integration value acquisition unit, and the amplitude control unit 85 is a specific example of the amplitude control unit. In FIG. 10, a pulse signal generation circuit 91 is a specific example of a panelless signal generation means. The white light emitting diode 93 is a specific example of the light source. is there. Further, the integration circuit 94 is a specific example of the integrated value acquisition means. Reference value output circuit

95, a comparator 96, and an amplifier 92 are specific examples of the amplitude control means.

[0068] (Fourth embodiment)

FIG. 11 shows a fourth embodiment of the illumination light communication apparatus of the present invention. In the illumination optical communication device 100 in FIG. 11, the adjustment pulse signal is added to the pulse signal corresponding to the communication information, and the illumination light is modulated by the pulse signal to which the adjustment pulse signal is added. Then, the amplitude of the adjustment pulse signal is changed so that the amount of illumination light per predetermined period is constant.

That is, in illumination light communication apparatus 100, modulation section 101 includes pulse signal generation section 102 and adjustment pulse addition section 103. The light quantity control unit 104 includes an adjustment pulse signal control unit 105.

The operation of the illumination light communication apparatus 100 is as follows. When communication information is sent from the information source, the pulse signal generation unit 102 generates a first pulse signal corresponding to the communication information. Subsequently, the adjustment pulse adding unit 103 generates the second pulse signal by adding the adjustment pulse signal to the first panelless signal generated by the noise signal generating unit 102. The light source 106 emits illumination light whose brightness changes according to the waveform of the second pulse signal generated by the adjustment pulse adding unit 103. The adjustment pulse signal control unit 105 changes the amplitude of the adjustment pulse signal so that the amount of illumination light emitted from the light source 106 per predetermined period is constant. As a method of changing the amplitude of the adjustment pulse signal in order to make the amount of light constant, the amount of illumination light emitted from the light source 106 is detected in substantially the same manner as the illumination light communication device 60 described above. A method of performing feedback control based on the above can be used. Alternatively, it is possible to use a method of obtaining the integral value of the second pulse signal supplied to the light source 106 and performing feedback control based on the integral value, in substantially the same manner as the illumination light communication device 80 described above. .

FIG. 12 shows a more specific example of the illumination light communication apparatus 100 that is the fourth embodiment of the present invention. The illumination light communication device 110 in FIG. 12 includes a pulse signal generation circuit 111, an adjustment panelless generation circuit 112, an amplifier 113, a pulsed circuit 114, a white light emitting diode (white LED) 115, a light receiving element 116, and an integration circuit. 117, reference value output circuit 118 and comparator 119 It has.

The operation of illumination light communication apparatus 110 is as follows. When communication information is sent from the information source, the pulse signal generation circuit 111 generates a pulse signal P41 corresponding to the communication information. Further, the adjustment pulse generation circuit 112 generates an adjustment pulse signal P42. The amplifier 11 3 amplifies the adjustment no-less signal P42. Then, the pulsed circuit 114 adds the amplified adjustment pulse signal P42 to the pulse signal P41, thereby generating a noise signal P43.

FIG. 13 shows the waveform of the pulse signal P43 obtained by adding the adjustment pulse signal P42 to the pulse signal P41. The pulse signal P41 is, for example, a signal whose amplitude becomes a high level or a low level corresponding to codes “1” and “0” in the communication information. On the other hand, the frequency, duty ratio, and length (total signal length of one unit) of the adjustment pulse signal P42 are determined in advance as initial values, and are constant, for example. However, the amplitude of the adjustment pulse signal P42 changes due to a change in the amplification factor of the amplifier 113. The reception period in FIG. 13 corresponds to the reception blank 53 in FIG.

Such a pulse signal P43 is supplied from the pulse addition circuit 114 to the white light emitting diode 115. The white light emitting diode 115 emits illumination light modulated by the pulse signal P43, that is, illumination light whose brightness changes in accordance with the waveform of the pulse signal P43.

Subsequently, the light receiving element 116 receives the illumination light emitted from the white light emitting diode 115, generates an electrical signal whose amplitude changes according to the intensity of the illumination light, and uses this electrical signal as an integration circuit 117. To supply. The integration circuit 117 generates an integration value per predetermined period (for example, about 0.5 to 1 second) of the electrical signal and supplies the integration value to one input terminal of the comparator 119. A predetermined reference value is input from the reference value output circuit 118 to the other input terminal of the comparator 119. The comparator 119 compares the integrated value supplied from the integrating circuit 117 with a reference value, and supplies a DC control signal having a voltage corresponding to the difference between the two to the amplifier 113.

The amplifier 113 changes the amplification factor according to the voltage of this control signal. As a result, the amplitude of the adjustment pulse signal P42 changes according to the voltage of the control signal, that is, the difference between the integrated value supplied from the integrating circuit 117 and the predetermined reference value. More specifically, the integration circuit 117 When the integral value supplied to the power is larger than a predetermined reference value, the voltage of the control signal supplied from the comparator 119 to the amplifier 113 becomes negative, thereby reducing the amplification factor of the amplifier 113. Therefore, the amplitude of the adjustment pulse signal P42 is reduced, and as a result, the amount of illumination light per predetermined period is reduced. On the other hand, when the integrated value supplied from the integrating circuit 117 is smaller than a predetermined reference value, the voltage of the control signal supplied from the comparator 119 to the amplifier 113 becomes positive, and thereby the amplification factor of the amplifier 113 is increased. Goes up. Therefore, the amplitude of the adjustment panelless signal P43 increases, and as a result, the amount of illumination light per predetermined period increases. By repeating such an operation, the amount of illumination light per predetermined period converges to a constant amount.

[0077] Note that the communication device that has received the illumination light emitted from the illumination light communication device 110 acquires a signal corresponding to the pulse signal P43 from the illumination light, and from this signal, a signal corresponding to the adjustment pulse signal P42. And only the signal corresponding to the pulse signal P41 is extracted. Such an extraction process can be realized as follows, for example. That is, the timing (interval) for adding the adjustment pulse signal P42 to the pulse signal P41 and the length of the adjustment pulse signal P42 per unit are determined in advance in the illumination light communication apparatus 110. As a result, the communication device identifies the signal corresponding to the signal force adjustment pulse signal P42 corresponding to the pulse signal P43 under the state where the illumination light communication device 110 and the communication device are synchronized. Is possible. Therefore, the communication device can extract only the signal corresponding to the panoramic signal P41 from the signal corresponding to the pulse signal P43, and this signal power communication information can be reproduced.

As described above, in illumination light communication apparatuses 100 and 110, the adjustment pulse signal is added to the pulse signal corresponding to the communication information, and the illumination light is modulated by the pulse signal to which the adjustment pulse signal is added. Then, the amplitude of the adjustment pulse signal is changed so that the amount of illumination light per predetermined period is constant. Thereby, the light quantity per predetermined period of illumination light can be made substantially constant. Accordingly, the brightness (luminance) of the illumination light can be stabilized, and flickering of the illumination light that can be directly recognized by humans can be reduced.

In addition, illumination light communication apparatuses 100 and 110 employ a configuration in which an adjustment panelless signal is added to a pulse signal corresponding to communication information. As a result, the amplitude and frequency of the adjustment pulse signal By arbitrarily setting and adjusting initial values such as number, duty ratio, and length, the amount of illumination light can be set and adjusted over a wide range. Therefore, it is possible to widen the range of setting and adjusting the brightness of the illumination, and to realize illumination that can freely control the brightness.

In the illumination light communication devices 100 and 110 described above, a configuration is adopted in which the amplitude of the adjustment pulse signal is changed so that the amount of illumination light is constant, but the present invention is not limited to this. ,. For example, you can change the frequency, duty ratio, or length of the adjustment pulse signal so that the amount of illumination light is constant.

In FIG. 11, the modulation unit 101 is a specific example of the modulation unit, and the light amount control unit 104 is a specific example of the light amount control unit. The pulse signal generation unit 102 is a specific example of the pulse signal generation unit, the adjustment pulse addition unit 103 is a specific example of the adjustment pulse addition unit, and the adjustment pulse signal control unit ₁₀₅ is a specific example of the adjustment pulse signal control unit. It is. Also, craft

In FIG. 2, a noise signal generation circuit 111 is a specific example of the pulse signal generation means. The white light emitting diode 115 is a specific example of the light source. The adjustment pulse generation circuit 112 and the pulse addition circuit 114 are specific examples of adjustment pulse addition means. The light receiving element 116, the integrating circuit 117, the reference value output circuit 118, the comparator 119, and the amplifier 113 are specific examples of the adjustment pulse signal control means.

[0082] (Fifth embodiment)

FIG. 14 shows a fifth embodiment of the illumination light communication apparatus of the present invention. In the illumination optical communication device 120 in FIG. 14, the pulse of the no-less signal for modulating the illumination light is divided into subdivided pulses. Then, the number of subdivided pulses is changed so that the amount of illumination light per predetermined period is constant.

That is, in the illumination light communication apparatus 120, the modulation unit 121 includes a pulse signal generation unit 122 and a pulse division unit 123. The light quantity control unit 124 includes a pulse number control unit 125.

The operation of illumination light communication apparatus 120 is as follows. When communication information is sent from the information source, the pulse signal generator 122 generates a pulse signal P51 corresponding to the communication information. Subsequently, the pulse division unit 123 generates the pulse signal P generated by the noise signal generation unit 122. The 51 pulses (on-pulse) are divided into a plurality of subdivided pulses having a width smaller than the minimum width of the pulse of the pulse signal P51, thereby generating a pulse signal P53. The light source 126 emits illumination light whose brightness changes according to the waveform of the pulse signal P53.

The adjustment pulse signal control unit 105 changes the number of subdivided pulses of the noise signal P53 so that the amount of illumination light emitted from the light source 106 per unit time is constant. As a method of changing the number of subdivided pulses of the pulse signal P53 in order to make the amount of light constant, the amount of illumination light emitted from the light source 126 is detected in substantially the same manner as the illumination light communication device 60 described above. A method of performing feedback control based on the detection result can be used. Alternatively, a method of obtaining an integral value of the pulse signal P53 supplied to the light source 126 and performing feedback control based on the integral value can be used in substantially the same manner as the illumination light communication device 80 described above.

FIG. 15 shows a pulse signal P51 generated by the pulse signal generator 122, a pulse signal P52 divided by the pulse divider 123, and a pulse signal in which the number of divided pulses is changed by the pulse number controller 125. P53 is shown.

The pulse dividing unit 123 divides the pulse W1 of the pulse signal P51 into divided pulses W2 having a width smaller than one half of the minimum pulse width of the pulse signal P51, for example.

[0088] When the amount of illumination light is larger than a predetermined reference amount of light, the pulse number control unit 125 reduces the number of divided pulses W2 of the pulse signal P52. At this time, as shown in the pulse signal P 53 in FIG. 15, at least the divided pulse (starting divided pulse W2a) located at the rising edge of the pulse W1 and the divided pulse (end) located at the falling edge of the corresponding node W1. The split pulse W2b) remains. That is, the pulse number control unit 125 reduces the number of divided pulses W2 existing between the first divided pulse W2a and the last divided pulse W2b. As a result, in the communication device that communicates with the illumination light communication device 120, the signal corresponding to the pulse signal P51 can be easily and accurately restored based on the signal corresponding to the pulse signal P53. That is, based on the illumination light modulated by the pulse signal P53, the signal corresponding to the pulse signal P51 can be restored easily and with high accuracy, and thus communication information can be easily and accurately reproduced. It becomes possible. [0089] As described above, in illumination light communication apparatus 120, the pulse signal for modulating illumination light is divided into subdivided pulses so that the amount of illumination light per predetermined period is constant. Change the number of subdivision pulses. Thereby, the light quantity per predetermined period of illumination light can be made substantially constant. Therefore, the brightness (luminance) of the illumination light can be stabilized, and flickering of the illumination light that can be directly recognized by humans can be reduced. As a result, when the illuminating light communication device 1 is applied to an indoor lighting device (see Fig. 2), an illuminating lamp (see Fig. 3), etc., the original performance as these lightings, that is, light is applied to the object to make it brighter. The performance of maintaining the brightness can be maintained or improved.

In FIG. 14, the modulation unit 121 is a specific example of the modulation unit, and the light amount control unit 124 is a specific example of the light amount control unit. Further, the pulse signal generation unit 122 is a specific example of the pulse signal generation unit, the pulse division unit 123 is a specific example of the pulse division unit, and the pulse number control unit 125 is a specific example of the pulse number control unit.

In the illumination light communication apparatus described above, the configuration in which the amplitude of the pulse signal or the adjustment pulse signal is changed so that the amount of illumination light is constant has been described, but the present invention is not limited to this. For example, a DC offset may be applied and appropriately changed so that the amount of illumination light is constant.

Further, by adjusting the potential of the pulse signal in the low level period, the amount of illumination light for each predetermined period can be made constant. Furthermore, it goes without saying that the adjustment of the potential during the high level period of the pulse signal may also be performed.

[0091] Further, the present invention can be appropriately changed without departing from the gist or idea of the invention that can be read from the claims and the entire specification, and the illumination light communication device and illumination light accompanied by such a change can be used. A communication method and a computer program for realizing these functions are also included in the technical idea of the present invention.

Industrial applicability

The illumination light communication apparatus and illumination light communication method according to the present invention can be used for illumination light communication in which information is communicated using illumination light, for example. Further, it can also be used for, for example, an illumination optical communication device that is mounted on or can be connected to various computer equipment for consumer use or business use.

Claims

The scope of the claims

[1] An illumination light communication device that communicates information via illumination light,

A light source that emits illumination light that is visible light;

A modulation unit that modulates the illumination light emitted from the light source based on the information, and a light amount per predetermined period of the illumination light modulated by the modulation unit is constant.

An illumination optical communication device comprising: a light amount control unit that controls light emission by the light source.

[2] The illumination light communication apparatus according to claim 1, wherein the light amount control means controls generation of illumination light by the light source or modulation of illumination light by the modulation means.

[3] The illumination optical communication device according to [1], wherein the light source is a light emitting diode.

[4] The light amount control unit includes a bi-phase code processing unit that performs bi-phase encoding processing on the information expressed by a binary code,

The modulation means includes pulse signal generation means for generating a pulse signal corresponding to the information that has been subjected to bi-phase encoding processing by the bi-phase encoding process, and the light source is generated by the pulse signal generation means 2. The illumination light communication apparatus according to claim 1, wherein illumination light whose brightness changes according to the waveform of the pulse signal is emitted.

[5] The modulation means may be configured such that the pulse signal corresponding to the information before the bi-fading encoding process is high level or low level in response to the pulse signal corresponding to the information after the bi-phase encoding process. 5. The illumination light communication apparatus according to claim 4, further comprising waveform inversion means for inverting the waveform of the section corresponding to the section.

[6] The modulation means includes a pulse signal generation means for generating a pulse signal corresponding to the information,

The light source emits illumination light whose brightness changes in accordance with the waveform of the noise signal generated by the pulse signal generation means,

The light amount control means includes A light amount detecting means for detecting a light amount per predetermined period of illumination light emitted from the light source;

The illumination light communication according to claim 1, further comprising: an amplitude control unit that changes an amplitude of the pulse signal so that a light amount detected by the light amount detection unit becomes a predetermined light amount. apparatus.

[7] The modulation means includes a pulse signal generation means for generating a pulse signal corresponding to the information,

The light source emits illumination light whose brightness changes according to the waveform of the pulse signal generated by the pulse signal generation means,

The light amount control means includes

An integral value acquisition means for acquiring an integral value per predetermined period of the pulse signal generated by the pulse signal generation means;

The amplitude control means for changing the amplitude of the pulse signal so that the integral value acquired by the integral value acquisition means becomes a predetermined value. Illumination light communication device.

[8] The modulation means includes

Pulse signal generating means for generating a first pulse signal corresponding to the information represented by a binary code;

Adjusting pulse adding means for generating a second pulse signal by adding an adjusting pulse signal to the first pulse signal generated by the pulse signal generating means,

The light source emits illumination light whose brightness changes according to the waveform of the second pulse signal,

The illumination light communication apparatus according to claim 1, wherein the light amount control means includes adjustment pulse signal control means for changing an amplitude, a duty ratio, or a length of the adjustment pulse signal.

[9] The modulation means includes

Pulse signal generating means for generating a first pulse signal corresponding to the information represented by a binary code; The second pulse signal is divided by dividing the pulse of the first pulse signal generated by the pulse signal generating means into a plurality of subdivided pulses having a width smaller than the minimum width of the first panoramic signal. A pulse dividing means for generating,

2. The illumination light communication apparatus according to claim 1, wherein the light amount control means includes pulse number control means for changing the number of subdivided pulses of the second pulse signal.

[10] An illumination light communication method for communicating information via illumination light that is visible light emitted from a light source,

A modulation step of modulating the illumination light based on the information;

An illumination light communication method comprising: a light amount control step of controlling light emission from the light source so that the light amount per predetermined period of the illumination light modulated in the modulation step is constant.

[11] A computer program for causing a computer to function as the illumination light communication device according to claim 1.