JPWO2008010274A1 - Visible light communication device - Google Patents

Abstract

The presence / absence of visible light communication and communication contents can be easily viewed by a user, and CN deterioration due to visible display of communication contents is prevented, thereby improving communication quality. A first visible light LED 11 that emits light for foreground, a second visible light LED 12 that emits light for background, and has a light emission wavelength band different from that of the first visible light LED 11, and foreground light and background Display control unit 10 for driving the first visible light LED 11 and the second visible light LED 12 so that the information for visible light communication is superimposed on both of the light for use and the output light of the first visible light LED 11 A display information adding unit 13 that adds display information related to information for visible light communication, and a focus unit 14 that projects the foreground light and the background light onto the projection surface in a focused state. Display information on the foreground and background in different bands is displayed on the projection surface so as to be visible, and information for visible light communication is included in both the foreground and background light.

Description

  The present invention relates to a visible light communication apparatus that performs communication using visible light.

  In the visible light communication, information added as visible light information is transmitted using visible light such as a display or illumination visible to human eyes. In visible light communication, visible light emitted from a light source is modulated in accordance with transmission information and transmitted in a state where information is superimposed on the transmission side, and transmission information is acquired by demodulating the received visible light on the reception side. It is like that. In conventional visible light communication, whether or not information is transmitted by visible light communication, and what information is transmitted, despite the fact that visibility is the biggest feature. It was difficult to recognize.

  As a communication device using visible light, for example, Patent Document 1 discloses a wireless communication device that uses visible light as a guide for an irradiation area such as infrared light in wireless communication using invisible light such as infrared communication. . This conventional wireless communication device is arranged so that the visible light optical axis is aligned with the center of the infrared irradiation region, etc., so that the irradiation position of the visible light beam can be visually observed instead of the invisible infrared irradiation region. By checking, it is determined that the infrared ray is in a position where it can be transmitted. The conventional example described in Patent Document 1 uses visible light as a guide for infrared rays or the like for communication, and the user recognizes what the information content to be transmitted is until the communication is actually successful. I can't.

  As a visible light communication apparatus, for example, Patent Document 2 discloses a visible light communication display system and a visible light communication illumination system. The display device in the visible light communication display system displays a figure composed of a plurality of light sources that emit visible light and transmits information by visible light communication. In the display device, visible light information for transmission In addition, it is determined whether or not the predetermined identification information received together with the identification information of the device matches, and if they match, the light source is modulated and visible light information is transmitted.

  The conventional example described in Patent Document 2 shows a configuration in the case where visible light communication is performed on a display board using an LED (Light Emitting Diode) or the like. When this conventional display device is installed on a ceiling or the like, the contents of visible light communication cannot be grasped unless the user looks up. Further, when the illuminance of the display device is increased, the display device cannot be seen as characters or figures.

  FIG. 11 is an explanatory diagram showing a band of output light in a communication device using infrared light and visible light. The example of FIG. 11 simulates the configuration described in Patent Document 1, and corresponds to the case where communication is performed using infrared rays from the infrared light source 101 and the visible light from the visible light source 102 is used only for display. In this case, the light receiving band 105 of the infrared light receiving element corresponds to only the light in the infrared band λx1 emitted from the infrared light source 101. In addition, data is not superimposed on the light in the visible light band λx2 emitted from the visible light source 102. In this state, the user cannot actually visually recognize the infrared irradiation area with which the user is communicating, and cannot view the information content.

  FIG. 12 is an explanatory diagram showing a band of output light in a communication device using two visible lights. The example of FIG. 12 is a combination of the visible light communication and the example of FIG. 11, performs communication using the first visible light from the first visible light source 111, and transmits from the second visible light source 112. This corresponds to the case where the second visible light is used only for display. In this case, the visible light band λx1 of the first visible light emitted from the first visible light source 111 and the visible light band of the second visible light emitted from the second visible light source 112 in the human visible band. λx2 is included, and these two bands of light are visible. Further, data is transmitted only by the first visible light transmitted from the first visible light source 111, and the data is not superimposed on the second visible light from the second visible light source 112. It is. In this state, when a general visible light receiving element having the entire visible light band as the light receiving band 106 is received, the second visible light from the second visible light source 112 becomes noise, and communication is performed. The first visible light from the first visible light source 111 for use causes CN degradation.

JP-A-9-69815 JP 2006-50528 A

  In the conventional visible light communication apparatus, the contents of transmission information when performing visible light communication cannot be easily visually confirmed. Further, when visible light communication is performed using illumination, it is not possible to distinguish from illumination that is not used as illumination for data transmission. Further, when visible light of another band is used to display the communication contents so as to be visible, the visible light for display becomes noise for visible light communication, and CN deteriorates. Occurs.

  The present invention has been made in view of the above circumstances, and allows the user to easily recognize the presence / absence of visible light communication and the communication content, and can prevent the CN deterioration due to the visible display of the communication content. An object is to provide an optical communication device.

  The visible light communication device of the present invention includes a visible light source and outputs visible light of a plurality of different colors. At least one of the plurality of colors of output light is foreground light, A visible light output unit that outputs at least one as background light, and a light source control that drives the visible light source so that information for visible light communication is included in both the foreground light and the background light And display for adding display information related to the visible light communication information to the foreground light or the background light so as to be visible in a state of being projected on the projection surface of the output light. An information adding unit; and a projection unit that projects the foreground light and the background light onto a projection surface.

  Thereby, when irradiating the output light for visible light communication, display information related to the information for visible light communication is displayed on the projection surface so as to be visible, so that the display information based on the foreground and the background having different wavelength bands is used. Thus, the user can easily visually recognize whether or not visible light communication is being performed and the communication contents. In addition, by including information for visible light communication in both foreground light and background light, CN degradation can be achieved without the foreground or background becoming a noise component when displaying the communication content. Can be prevented.

  In addition, the present invention is the above visible light communication device, wherein the visible light output unit includes the first visible light source that emits the foreground light as the visible light source, and the background light. And a second visible light source having a light emission wavelength band different from that of the first visible light source.

  Thereby, for example, the display information can be visually recognized by outputting foreground and background light respectively by the first visible light source and the second visible light source such as visible light LEDs having different emission center wavelengths. Visible light communication can be performed while displaying.

  Further, the present invention is the above visible light communication device, wherein the visible light output unit transmits the foreground light and the background light. And a second filter having a different transmission band.

  Thus, for example, by using a visible light source such as a white light LED, the optical path is branched into two, and the foreground and background light are transmitted and output by the first filter and the second filter, respectively. Visible light communication can be performed while displaying the display information in a visible manner.

  The present invention is the above visible light communication device, wherein the visible light output unit includes a visible light source that outputs white light, and a filter that transmits one of the foreground light and the background light. And at least.

  This makes it possible to visually recognize display information by branching the optical path into two using a visible light source such as a white light LED, and transmitting and outputting at least one light for foreground and background using a filter. Visible light communication can be performed while displaying.

  The present invention is the above visible light communication device, wherein the display information adding unit includes a transmission region control member that blocks or transmits a part of the region in order to form the display information on a projection plane. And

  Thus, for example, by using a transmission region control member such as a liquid crystal panel, a partial area of foreground light or background light is blocked or transmitted, so that display information is formed on the projection surface and displayed in a visible manner. be able to.

  Further, the present invention is the above visible light communication device, further comprising a contrast control unit that controls a color of the output light so that the foreground light and the background light have a contrast of a predetermined value or more. Shall.

  Thus, in the contrast control unit, for example, a light receiving unit that receives reflected light from the projection surface and detects the RGB component thereof, a contrast determination unit that calculates a brightness difference and a color difference from the RGB component and determines the contrast, Foreground and background by adjusting the color of the output light with a color adjustment unit that adjusts the color of at least one of the foreground light and background light so that the contrast value is equal to or greater than a predetermined value The contrast of the display can be made appropriate, and the user can recognize the display information more clearly.

  Moreover, this invention is said visible light communication apparatus, Comprising: The focus adjustment part which adjusts the focus state of the said display information in the said projection surface shall be provided.

  Accordingly, the focus adjustment unit includes, for example, an AF unit that detects a focus state of display information on the projection surface, a lens driving unit that drives an optical lens of the projection unit according to the output of the AF unit, and the like. By adjusting the position of the optical system on the optical path, the focus of the display information can be adjusted appropriately, and the user can recognize the display information more clearly.

  The visible light communication method of the present invention outputs visible light of a plurality of different colors from a visible light source, and at least one of the plurality of colors of output light is foreground light, and at least one of the other colors. Output as background light, driving the visible light source to include information for visible light communication in both the foreground light and the background light, and the foreground light Or adding the display information related to the visible light communication information to the background light so that the display information can be viewed in a state projected onto the projection surface of the output light, and the foreground light and Projecting the background light onto a projection surface.

  Thereby, when irradiating the output light for visible light communication, display information related to the information for visible light communication is displayed on the projection surface so as to be visible, so that the display information based on the foreground and the background having different wavelength bands is used. Thus, the user can easily visually recognize whether or not visible light communication is being performed and the communication contents. In addition, by including information for visible light communication in both foreground light and background light, CN degradation can be achieved without the foreground or background becoming a noise component when displaying the communication content. Can be prevented.

  ADVANTAGE OF THE INVENTION According to this invention, while the presence or absence of visible light communication and communication content can be made visible easily by a user, the visible light communication apparatus which can prevent CN degradation by the visible display of communication content can be provided.

The block diagram which shows schematic structure of the visible light communication apparatus which concerns on embodiment of this invention. Explanatory drawing which shows the zone | band of the output light of the visible light communication apparatus which concerns on embodiment of this invention Explanatory drawing which shows typically the projection state of the output light of the visible light communication apparatus in embodiment of this invention The block diagram which shows the detailed structure of the visible light communication apparatus which concerns on the 1st Embodiment of this invention. The block diagram which shows the detailed structure of the principal part of the visible light communication apparatus which concerns on the 2nd Embodiment of this invention. Explanatory drawing which shows the band of visible light source and output light in the visible light communication apparatus of this embodiment The block diagram which shows the detailed structure of the visible light communication apparatus which concerns on the 3rd Embodiment of this invention. The flowchart which shows the operation | movement procedure of contrast adjustment of the visible light communication apparatus in 3rd Embodiment. The block diagram which shows the detailed structure of the visible light communication apparatus which concerns on the 4th Embodiment of this invention. The flowchart which shows the operation | movement procedure of the focus adjustment of the visible light communication apparatus in 4th Embodiment. Explanatory drawing which shows the zone | band of the output light in the communication apparatus using infrared rays and visible light Explanatory drawing which shows the zone | band of the output light in the communication apparatus using two visible lights

Explanation of symbols

10 Display Control Unit 11 First Visible Light LED
12 Second visible light LED
DESCRIPTION OF SYMBOLS 13 Display information addition part 14 Focus part 15 Projection surface 16 Portable apparatus 20, 40, 50, 60 Visible light communication apparatus 21 Communication function part 22, 52, 62 Display control part 23, 43, 53, 63 Optical system 28 Memory 29 LED Control unit 30 Transmission control unit 31 Reception control unit 32 Liquid crystal control unit 33 PD for visible light
34 Polarizing plate 35 Liquid crystal panel 36 Optical lens 37, 65 Lens position adjusting unit 38, 66 Lens driving unit 41 Visible light LED
42 Optical splitter 45, 46 Filter 54 Contrast analysis unit 55 Filter control unit 57, 58 Tunable filter 59 RGB filter 64 AF unit 67, 68 Mirror

  In the following embodiment, the structural example applied to the illuminating device as a visible light communication apparatus is shown. As a light emitting unit of the visible light communication device of the present embodiment, a light emitting element using an LED (Light Emitting Diode) is used.

  FIG. 1 is a block diagram showing a schematic configuration of a visible light communication apparatus according to an embodiment of the present invention. The visible light communication apparatus according to the present embodiment includes a display control unit 10, a first visible light LED 11, a second visible light LED 12, a display information adding unit 13, and a focusing unit 14.

  The display control unit 10 controls the display mode of light emitted for visible light communication, together with output control of data transmitted from the visible light communication device. The display control unit 10 has a function of controlling the display information adding unit together with the function of the light source control unit, and includes modulation data for visible light communication for modulating the first visible light LED 11 and the second visible light LED 12, and The display information adding unit 13 outputs the display information to be added and projected. Here, it is assumed that the modulation data and the display information are related. As a modulation method, for example, a method such as amplitude modulation or phase modulation may be used. Further, the modulation data output to the first visible light LED 11 and the second visible light LED 12 are the same.

  Each of the first visible light LED 11 and the second visible light LED 12 is a visible light source that emits visible light, and realizes the function of the visible light output unit. The first visible light LED 11 and the second visible light LED 12 have different wavelengths of output light and emit different colors. Each of the first visible light LED 11 and the second visible light LED 12 modulates the output light of the LED according to the modulation data from the display control unit 10.

  The display information adding unit 13 adds the display information received from the display control unit 10 to the output light of the first visible light LED 11 modulated with the modulation data. Specifically, the display information adding unit 13 has a part that transmits the output light of the first visible light LED 11 and a part that does not transmit, such as a slit and a mask, and changes these transmission / non-equalization parts. A possible transmissive region control member is provided, and display information such as characters, symbols, and figures is added according to display information from the display control unit 10. Further, if a liquid crystal panel is used as a transmission region control member of the display information adding unit 13 instead of a slit, a mask, etc., more various display information can be added.

  The focus unit 14 includes an output optical system and has a function of a projection unit. The focus unit 14 projects the output light of the first visible light LED 11 modulated with modulation data and added with display information onto a projection surface such as a floor surface or a wall surface. And focus and focus on the image. Specifically, the focus unit 14 is configured to have a projection optical lens or the like as an output optical system. Further, a projection lens drive mechanism for focusing may be provided.

  FIG. 2 is an explanatory view showing a band of output light of the visible light communication apparatus according to the embodiment of the present invention, and FIG. 3 is an explanatory view schematically showing a projection state of output light of the visible light communication apparatus in the embodiment of the present invention. It is.

  In the present embodiment, light having a plurality of different wavelengths is output from a visible light source, one is used as foreground light to which display information such as characters is added, and the other is projected onto a projection surface such as a floor or a wall as background light. Thereby, the contents of visible light communication can be visually displayed as display information based on the background and foreground.

  As shown in FIG. 2, in the human visible band, the first visible light LED 11 outputs light with display information added to the foreground whose emission center wavelength is the wavelength λ1, and the second visible light LED 12 emits the emission center. The light which becomes the background of the wavelength λ2 is output. Further, the output light of the first visible light LED 11 and the output light of the second visible light LED 12 having different colors are modulated by the same modulation data, and the visible light communication data is superimposed and transmitted. The wavelengths λ1 and λ2 of these output lights are in the human visible band and may be different colors from each other. If the combination of colors having a contrast of a predetermined value or more is easy to recognize, λ1 and The magnitude relationship and value of λ2 are arbitrary.

  As shown in FIG. 3, the output light for information display (foreground display) from the first visible light LED 11 and the output light for background display from the second visible light LED 12 are the floor surface, wall surface, and the like. Is projected on the projection plane 15 in a focused state. At this time, the output light from the first visible light LED 11 and the output light from the second visible light LED 12 are projected in a superimposed state. As a result, the user can easily visually recognize the contents of visible light communication based on the display information of the background and foreground. Further, the portable device 16 such as a cellular phone can acquire data by visible light communication by receiving and demodulating visible light modulated in the visible light irradiation region 17 from the visible light LEDs 11 and 12.

  In this case, the reception band B1 of the visible light receiving element in the portable device 16 on the receiving side includes both the wavelength λ1 of the foreground light and the wavelength λ2 of the background light to which the display information is added. Since data is superimposed on both lights, there is no problem that one visible light provided for information display becomes noise. Therefore, even when the light receiving unit of the portable device 16 is located in a display information portion such as characters and figures in the projection light for visible light communication, data communication is possible without CN deterioration.

  Thus, in this embodiment, the display information added to the output light from the first visible light LED 11 allows the contents of visible light communication to be visually displayed and can be easily recognized by the user. . Further, the intensity of light modulated for visible light communication can be increased by the output light from the two visible light LEDs 11 and 12 for foreground and background. Further, since the output light from the first visible light LED 11 and the output light from the second visible light LED 12 are modulated by the same modulation data, CN deterioration due to display of communication contents can be eliminated, and visible light is visible. High communication quality of optical communication can be maintained.

Below, the structural example of a visible light communication apparatus is shown in some embodiment.
(First embodiment)
FIG. 4 is a block diagram showing a detailed configuration of the visible light communication apparatus according to the first embodiment of the present invention. The visible light communication device 20 according to the first embodiment includes a communication function unit 21, a display control unit 22, and an optical system 23.

  The communication function unit 21 includes a transmission unit 24 and a reception unit 25, and is connected to a network 26 by wire or wireless, and can perform bidirectional communication with other communication devices 27. Examples of the network 26 include various wireless such as W-LAN (Wireless Local Area Network: wireless LAN), UWB (Ultra Wide Band), Bluetooth (registered trademark), ZigBee (trademark), mobile phone network, and Internet network. A connection form of communication means by wire can be used.

  The display control unit 22 includes an LED control unit 29, a transmission control unit 30, a reception control unit 31, and a liquid crystal control unit 32, and performs output control for visible light LEDs 11 and 12 that are visible light sources, and for visible light Input signal processing from a visible light PD (Photo Diode) 33 which is a light receiving element is performed. A memory 28 for storing data is provided, and is connected to the communication function unit 21 and the display control unit 22.

  The optical system 23 includes a first visible light LED 11, a second visible light LED 12, a visible light PD 33, a polarizing plate 34, a liquid crystal panel 35, and an optical lens 36. Here, as shown in FIG. 2, the first visible light LED 11 and the second visible light LED 12 have a light emission wavelength in the visible light region, but have emission center wavelengths different from λ1 and λ2, respectively. Although not an essential component, the display control unit 22 includes a lens position adjustment unit 37 and the optical system 23 includes a focusing unit that focuses output light from the first visible light LED 11 on the projection surface. A lens driving unit 38 may be provided so that the position of the optical lens 36 can be adjusted.

  Here, the 1st visible light LED11 and the 2nd visible light LED12 implement | achieve the function of a visible light output part. Further, the LED control unit 29 and the transmission control unit 30 realize the function of the light source control unit. In addition, the liquid crystal control unit 32 and the liquid crystal panel 35 realize the function of the display information adding unit. Further, the optical lens 36 realizes the function of the irradiation unit.

  In the visible light communication apparatus 20 having such a configuration, the communication function unit 21 communicates with the communication device 27 via the network 26 by the transmission unit 24 and the reception unit 25, and transmits and receives data. . Data received by the communication function unit 21 is sent to the memory 28 where it is stored and stored as information.

  The LED control unit 29 of the display control unit 22 acquires from the memory 28 data of information to be transmitted (contents such as music and weather forecast) and information such as characters and graphics to be displayed, and display data based on this data Is output to the liquid crystal control unit 32. At the same time, the LED control unit 29 generates modulation data of the transmission signal based on data of information to be transmitted and information to be displayed such as characters and graphics, and outputs the modulation data to the transmission control unit 30. The liquid crystal control unit 32 controls the liquid crystal panel 35 so that a predetermined portion can be transmitted so that characters, figures, and the like to be displayed can be displayed based on the display data.

  The transmission control unit 30 outputs the modulation data from the LED control unit 29 to the first visible light LED 11 and the second visible light LED 12, and drives the visible light LEDs 11 and 12 to emit light. Thereby, visible light modulated by the modulation data corresponding to the information to be transmitted is emitted from the visible light LEDs 11 and 12 according to the respective emission wavelengths. Here, the first visible light LED 11 and the second visible light LED 12 transmit the same information (contents) by visible light communication, and thus are turned on and off in synchronization. Note that the transmission rate of data transmitted by visible light communication (modulated data superimposed on visible light) in the two visible light LEDs 11 and 12 is the same rate synchronized as described above. It is also possible to set different transmission rates depending on the device configuration and usage state, such as when the values are different.

  The output light from the first visible light LED 11 passes through the polarizing plate 34 to become light having a predetermined polarization, and then passes through the liquid crystal panel 35 to transmit and block a predetermined portion corresponding to display contents. . The light transmitted through the liquid crystal panel 35 is emitted through the optical lens 36 and projected onto the projection surface as light for displaying the foreground information. The output light from the second visible light LED 12 is emitted as it is and projected onto the projection surface as background light. At this time, the data for visible light communication and the display information related thereto can be transmitted from another communication device 27 or the like via the network 26 to change the communication contents as appropriate.

  The visible light PD 33 receives an upstream optical communication signal from the mobile device 16 and the like, and outputs the received signal to the reception control unit 31. The reception control unit 31 performs reception signal processing such as preamplification and error correction, and outputs reception data to the communication function unit 21. This reception data is transmitted as transmission data from the transmission unit 24 of the communication function unit 21 and transmitted to the target communication device 27 via the network 26.

  As described above, in the first embodiment, two visible light LEDs are provided as visible light sources, and the first visible light LED 11 outputs foreground light for displaying display information such as characters indicating communication contents. The second visible light LED 12 outputs background light for the display information. Further, the output light of both the first visible light LED 11 and the second visible light LED 12 is modulated with modulation data corresponding to information to be transmitted, and the data for visible light communication is superimposed.

  Thereby, the content of visible light communication is visually displayed by the display information by a foreground and a background, and a user can recognize the communication content easily. In addition, since the output lights from the two visible light LEDs 11 and 12 are both modulated by the modulation data for visible light communication, the intensity of the light for visible light communication is increased by adding these two output lights. Data can be received anywhere within the visible light irradiation area. Therefore, even when communication contents are displayed, noise in the visible light band can be reduced, and CN deterioration in visible light communication can be prevented.

(Second Embodiment)
FIG. 5 is a block diagram showing a detailed configuration of the main part of the visible light communication apparatus according to the second embodiment of the present invention. FIG. 6 is an explanatory diagram showing a visible light source and a band of output light in the visible light communication apparatus.

  The second embodiment is an example in which the configuration of the optical system of the first embodiment is changed and a single light source is used as a visible light source. Constituent elements similar to those in the first embodiment are denoted by the same reference numerals, description of the same configuration and operation is omitted, and here, the description will focus on parts different from those in the first embodiment.

  The optical system 43 of the visible light communication device 40 includes a visible light LED 41, an optical splitter 42, a first filter 45, a second filter 46, a visible light PD 33, a polarizing plate 34, a liquid crystal panel 35, and an optical lens 36. Configured.

  Here, the visible light LED 41, the optical branching device 42, the first filter 45, and the second filter 46 realize the function of the visible light output unit.

  The visible light LED 41 as a visible light source is a light emitting LED that emits white light, and has an output band characteristic such that the emission wavelength covers almost the entire visible band of a human as shown in FIG. Here, modulation data corresponding to information to be transmitted from the transmission control unit 30 is input to the visible light LED 41, and visible light modulated by this modulation data is emitted from the visible light LED 41. The light splitter 42 is configured by a prism or the like, and branches the output light from the visible light LED 41 into two optical paths. The first filter 45 and the second filter 46 are respectively disposed on the two outgoing optical paths branched from the optical splitter 42.

  The first filter 45 has an output band characteristic such that the transmission band has a center wavelength λ1 as shown in FIG. 6B, and selectively transmits light having the wavelength λ1. The second filter 46 has an output band characteristic such that the transmission band is almost the entire visible band as shown in FIG. 6A or the center wavelength λ2 as shown in FIG. The output light from the LED 41 is transmitted as it is, or the light of wavelength λ2 is selectively transmitted.

  The light of wavelength λ1 that has passed through the first filter 45 passes through the polarizing plate 34 to become light having a predetermined polarization, and then corresponds to the display content related to information to be transmitted through the liquid crystal panel 35. The predetermined part is transmitted and blocked. At this time, the liquid crystal panel 35 is controlled by the liquid crystal control unit 32 so that a predetermined portion can be transmitted based on the display data, and is driven so as to display characters, figures, and the like to be displayed by the transmitted light. Then, the light transmitted through the liquid crystal panel 35 is emitted through the optical lens 36 and projected onto a projection surface such as a floor or a wall as light for displaying foreground information. The white light or the light having the wavelength λ2 that has passed through the second filter 46 is emitted as it is and projected onto the projection surface as background light.

  In the above example, the foreground light that passes through the first filter 45 is light of wavelength λ1, and the background light that passes through the second filter 46 is white light or light of wavelength λ2. In the case where the light for wavelength λ2 is light, the first filter 45 transmits the entire visible band as it is, and the foreground light for displaying display information such as characters indicating communication contents is white light. It is good. When white light is used as output light, the first filter 45 and the second filter 46 may not be provided.

  As described above, in the second embodiment, the optical path is divided into two by using one visible light source, and a specific wavelength band is transmitted and extracted by each filter. The same function as when having a plurality of visible light sources in the form can be realized. In other words, output light of different colors is emitted for the foreground and the background, and the display information for the foreground and the background is projected onto the projection plane in a state where the data for visible light communication is superimposed on both lights, thereby making the visible light visible. The contents of optical communication can be displayed visually. Thereby, the user can easily recognize the communication contents while preventing the CN deterioration in the visible light communication.

(Third embodiment)
FIG. 7 is a block diagram showing a detailed configuration of the visible light communication apparatus according to the third embodiment of the present invention. FIG. 8 is a flowchart showing an operation procedure of contrast adjustment of the visible light communication apparatus according to the third embodiment.

  The third embodiment is an example in which the configuration of the optical system and the display control unit of the second embodiment is changed to provide a foreground / background contrast adjustment function for output light including display information. Constituent elements similar to those in the first and second embodiments are denoted by the same reference numerals, description of the same configuration and operation is omitted, and here, the description will focus on parts that are different from the first and second embodiments. .

  The display control unit 52 of the visible light communication device 50 includes a contrast analysis unit 54 and a filter control unit 55 in addition to the LED control unit 29, the transmission control unit 30, the reception control unit 31, and the liquid crystal control unit 32. In the optical system 53, a first wavelength tunable filter 57 and a second wavelength tunable filter 58 are arranged on the two outgoing optical paths branched from the optical branching device 42, respectively. The wavelength tunable filters 57 and 58 are configured to be able to change the wavelength band of the transmitted light according to the control signal from the filter control unit 55. In addition, an RGB filter 59 that separates light into wavelengths of R, G, and B colors is detachably disposed on the incident light path of the visible light PD 33.

  Here, the visible light LED 41, the optical branching device 42, the first wavelength tunable filter 57, and the second wavelength tunable filter 58 realize the function of the visible light output unit. In addition, the RGB filter 59, the visible light PD 33, the contrast analysis unit 54, the filter control unit 55, the first wavelength tunable filter 57, and the second wavelength tunable filter 58 realize the function of the contrast control unit.

  The output signal of the visible light PD 33 is input to the contrast analysis unit 54 together with the reception control unit 31. The RGB filter 59 has a moving function, and is disposed in front of the visible light PD 33 only when the contrast analysis of the incident light is performed by the contrast analysis unit 54, and retracts from the incident light path of the visible light PD 33 after contrast adjustment. That is, during normal operation without contrast analysis, the RGB filter 59 moves so that transmission light from an external portable device or the like enters the visible light PD 33 without passing through the RGB filter 59.

  The filter control unit 55 receives the analysis result from the contrast analysis unit 54 and controls the transmission wavelength band of the wavelength tunable filters 57 and 58 according to the contrast analysis result. As a result, the wavelength band of light transmitted through the wavelength tunable filters 57 and 58 (color of visible light to be output) is adjusted.

  Considering the visibility of display information, even if the contrast between the foreground and background of the output light is set to a predetermined value or more in advance, depending on the floor surface and wall material, color etc. Display information such as visualized characters may be difficult to see. For this reason, in the present embodiment, the contrast between the foreground and the background is calculated by detecting the reflected light from the projection surface, and the color (wavelength) of the output light is adjusted so that the contrast becomes higher than a predetermined value.

  Here, the contrast between the foreground having display information projected on the projection plane and the surrounding background will be described. When analyzing the contrast of the output light, the foreground light and the background light are respectively emitted, reflected from the projection surface and incident, and the light that has passed through the RGB filter 59 is received by the visible light PD 33, and contrast analysis is performed. The unit 54 measures the intensity in each of the colors R, G, and B. Thereafter, the brightness difference and the color difference are calculated.

From the values of each color of R, G, and B, the lightness V can be calculated by the following calculation formula, for example.
V = ((R × 299) + (G × 587) + (B × 114)) / 1000 (1)

Using the above equation (1), the foreground brightness Vf and the background brightness Vb are calculated, and the difference between them is calculated to calculate the brightness difference ΔV.
ΔV = Vb−Vf (2)

Further, the color difference ΔE between the foreground and the background is calculated by, for example, the following calculation formula.
ΔE = (max (Rb, Rf) −min (Rb, Rf)) + (max (Gb, Gf) −min (Gb, Gf))
+ (Max (Bb, Bf) −min (Bb, Bf)) (3)
Here, max () represents the maximum value, min () represents the minimum value, Rb represents the background R value, Rf represents the foreground R value, and the same applies to G and B.

  Then, the brightness difference and the color difference calculated in the contrast analysis unit 54 are evaluated, and the contrast is adjusted by controlling the transmission bands of the wavelength tunable filters 57 and 58 by the filter control unit 55. The evaluation of brightness difference and color difference may be based on a desirable contrast value on a computer display proposed by the World Wide Web Consortium (W3C). In the present embodiment, as an example, a description will be given of the case where the contrast is adjusted so that the brightness difference between the background and the foreground is 125 or more, and the color difference between the background and the foreground is 500 or more. That is, the filter control unit 55 adjusts the wavelength variable filters 57 and 58 so that the brightness difference ΔV ≧ 125 and the color difference ΔE ≧ 500.

  Note that the contrast of the output light is adjusted by configuring the visible light LED with a plurality of LEDs having different emission center wavelengths, and switching the LED to be used among the plurality of types of LEDs, thereby projecting light onto the projection surface. The wavelength may be changed.

  Next, an example of contrast adjustment will be described with reference to FIG. Here, a case where the background is white light is shown as an example.

  First, the liquid crystal control unit 32 controls the liquid crystal panel 35 to close the entire area of the liquid crystal panel 35 so as to block the foreground light so that the background light is emitted. In this state, white light as background light is emitted and irradiated onto a projection surface such as a floor or a wall (step S1). The reflected light from the projection surface of the white light is received by the visible light PD 33 via the RGB filter 59 and analyzed by the contrast analysis unit 54 (step S2), and the R, G, B values of the background light are calculated. Each is calculated (step S3).

  Next, the liquid crystal control unit 32 controls the liquid crystal panel 35 so that the foreground light is transmitted and emitted by opening the entire area of the liquid crystal panel 35 or the like. In this state, light of a predetermined color as foreground light is emitted and irradiated onto a projection surface such as a floor or a wall (step S4). Then, the reflected light from the projection surface of the light of a predetermined color is received by the visible light PD 33 through the RGB filter 59 and analyzed by the contrast analysis unit 54 (step S5), and the foreground light R, G, Each B value is calculated (step S6).

  Thereafter, the contrast analyzer 54 calculates the lightness difference ΔV and color difference ΔE between the background and foreground of the illumination color from the R, G, B values of the background light and the R, G, B values of the foreground light (step S7). Then, the calculation result of the brightness difference and the color difference is determined (step S8). Here, if the brightness difference ΔV ≧ 125 and the color difference ΔE ≧ 500, the process is terminated. On the other hand, when the lightness difference and the color difference do not satisfy the above conditions, the filter control unit 55 adjusts the wavelength variable filter 57 to change the color of the foreground light (step S9). In addition, when the brightness difference or the color difference is too small, it is determined whether the background color needs to be adjusted (step S10), and the wavelength control filter 58 is adjusted by the filter control unit 55 as necessary to change the color of the background light. Change (step S11). After that, the process returns to step S1, the same processing is executed, the contrast is analyzed again, and the procedures of S1 to S8 are repeated until the brightness difference ≧ 125 and the color difference ≧ 500.

  Note that the R, G, and B values of the foreground light can also be obtained from the set values of the wavelength variable filter 57 in the filter control unit 55. In this case, the brightness difference and the color difference may be calculated from the R, G, B values of the background light calculated by the contrast analysis unit 54 and the R, G, B values of the foreground light acquired by the filter control unit 55.

  As described above, in the third embodiment, by providing the contrast adjustment function between the foreground and the background in the output light including the display information, the user can visually display the contents of the visible light communication by the display information. The display information can be recognized more clearly.

(Fourth embodiment)
FIG. 9 is a block diagram showing a detailed configuration of a visible light communication apparatus according to the fourth embodiment of the present invention. FIG. 10 is a flowchart showing an operation procedure of focus adjustment of the visible light communication apparatus according to the fourth embodiment.

  The fourth embodiment is an example in which the configuration of the optical system and the display control unit of the first embodiment is changed, and a focus adjustment function is provided on the projection plane of output light including display information. Constituent elements similar to those in the first to third embodiments are denoted by the same reference numerals, description of the same configuration and operation is omitted, and here, the description will focus on parts different from the first to third embodiments. .

  The display control unit 62 of the visible light communication device 60 includes an AF (autofocus) unit 65 and a lens position adjustment unit 65 in addition to the LED control unit 29, the transmission control unit 30, the reception control unit 31, and the liquid crystal control unit 32. ing. The AF unit 65 includes a light receiving element and a calculation unit, and determines the focus state of display information on the projection plane. The in-focus state is determined using a known phase difference detection method or contrast detection method used in a camera or the like. As the light receiving element, a CCD or the like is used, and in the case of the phase difference detection method, a line sensor is provided, and in the case of the contrast detection method, an image sensor is provided.

  In the optical system 63, a mirror 67 and a mirror 68 are disposed between the liquid crystal panel 35 and the optical lens 36 on the optical path from the first visible light LED 11, and the AF unit 65 receives the reflected light from the mirror 68. It is configured to receive light. The mirror 67 is composed of a half mirror or the like, and transmits the output light from the first visible light LED 11 as it is, while reflecting reflected light having display information from a projection surface such as a floor or a wall incident from the opposite direction. Have The optical system 63 includes a lens driving unit 38 that adjusts the position of the optical lens 36 in the optical axis direction.

  Here, the mirror 67, the mirror 68, the AF unit 65, the lens position adjusting unit 65, and the lens driving unit 38 realize the function of the focus adjusting unit.

  For example, when a visible light communication device applied to a lighting device or the like is installed on a ceiling or the like, it takes time and effort to adjust the focus of display information such as characters after being once installed. For this reason, in the present embodiment, an autofocus function for automatically adjusting the focus of display information is provided, and the display information on the projection surface is adjusted so as to be in focus.

  In the visible light communication device 60 configured as described above, the output light from the first visible light LED 11 passes through the polarizing plate 34 and becomes light having a predetermined polarization, and then passes through the liquid crystal panel 35. A predetermined portion corresponding to the display content is transmitted and blocked. Then, the light transmitted through the liquid crystal panel 35 passes through the mirror 67 and is emitted through the optical lens 36, and is projected onto the projection surface as light for displaying foreground information. Reflected light from the projection surface enters through the optical lens 36 and is reflected by the mirror 67, further reflected by the mirror 68 and received by the AF unit 65.

  The AF unit 65 determines the focus state of display information such as characters in the reflected light from the projection surface, and sends the determination result to the lens position adjustment unit 65. The lens position adjustment unit 65 sends a control signal to the lens driving unit 38 according to the output of the AF unit 65 to adjust the position of the optical lens 36. At this time, if the result of the determination by the AF unit 65 is not in focus, the lens position adjusting unit 65 calculates an adjustment amount and sends a control signal to the lens driving unit 38. The lens driving unit 38 adjusts the position of the optical lens 36 in the optical axis direction based on the control signal from the lens position adjusting unit 65 so as to match the focus. In this way, focus adjustment is performed on the projection surface of the foreground output light including display information.

  Next, an example of focus adjustment operation will be described with reference to FIG. First, the LED control unit 29 determines whether display information data such as characters and graphics to be displayed in the communication function unit 21 has been received (step S21). When the display information is not received, the LED control unit 29 drives and irradiates only the second visible light LED 12 (step S28). Thereby, the visible light communication device 60 functions as illumination.

  When the display information is received, the LED control unit 29 outputs display data based on the display information data to the liquid crystal control unit 32, and the liquid crystal control unit 32 displays characters, figures, and the like to be displayed based on the display data. The liquid crystal panel 35 is controlled so that a predetermined portion can be transmitted so that the image can be displayed (step S22). Then, the first visible light LED 11 and the second visible light LED 12 are irradiated to project the display information onto a projection surface such as a floor or a wall (step S23), and the reflected light including the display information from the projection surface is reflected to the AF unit 64. (Step S24).

  Then, it is determined whether or not the display information received by the AF unit 64 is in an in-focus state (Step S25). On the other hand, if it is not in focus, the lens position adjustment unit 65 instructs the adjustment amount so as to be in focus (step S26), and the lens driving unit 66 adjusts the position of the optical lens 36 based on the instruction. This is performed (step S27). Thereafter, returning to step S24, the same processing is executed to determine and adjust the in-focus state again, and the procedures of steps S24 to S27 are repeated until the display information such as characters and figures projected on the projection surface is in focus. .

  As described above, in the fourth embodiment, by providing the focus adjustment function on the projection plane of the output light including the display information, the user can display the contents of the visible light communication by the display information. Information can be recognized more clearly.

  In addition, as a visible light communication apparatus, it is also possible to combine suitably the structure of said 1st Embodiment to 4th Embodiment.

  In addition, portable devices that communicate with the visible light communication device include mobile phones, personal digital assistants (PDAs), notebook personal computers (PCs), portable music players such as built-in memory and HDD types, digital cameras, and electronic dictionaries. It can also be applied to speakers, headphones, etc.

  According to each of the above-described embodiments, the contents of visible light communication can be visually displayed by display information based on the foreground and background having a predetermined contrast. Can be easily recognized. In addition, by superimposing modulation data on both the foreground and background, CN deterioration due to visible display of communication contents can be prevented, and communication quality can be improved.

  Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

  The present invention enables the user to easily recognize the presence / absence of visible light communication and the communication content, and has the effect of preventing CN deterioration due to the visible display of the communication content. Useful for visible light communication devices and the like.

  The present invention relates to a visible light communication apparatus that performs communication using visible light.

  In the visible light communication, information added as visible light information is transmitted using visible light such as a display or illumination visible to human eyes. In visible light communication, visible light emitted from a light source is modulated in accordance with transmission information and transmitted in a superimposed state on the transmission side, and transmission information is acquired by demodulating the received visible light on the reception side. It is like that. In conventional visible light communication, whether or not information is transmitted by visible light communication, and what kind of information is transmitted by the user, despite being the most characteristic of being visible. It was difficult to recognize.

  As a communication device using visible light, for example, Patent Document 1 discloses a wireless communication device that uses visible light as a guide for an irradiation area such as infrared light in wireless communication using invisible light such as infrared communication. . This conventional wireless communication device is arranged so that the visible light optical axis is aligned with the center of the infrared irradiation region, etc., so that the irradiation position of the visible light beam can be visually observed instead of the invisible infrared irradiation region. By checking, it is determined that the infrared ray is in a position where it can be transmitted. The conventional example described in Patent Document 1 uses visible light as a guide for infrared rays or the like for communication, and the user recognizes what the information content to be transmitted is until the communication is actually successful. I can't.

  As a visible light communication apparatus, for example, Patent Document 2 discloses a visible light communication display system and a visible light communication illumination system. The display device in the visible light communication display system displays a figure composed of a plurality of light sources that emit visible light and transmits information by visible light communication. In the display device, visible light information for transmission In addition, it is determined whether or not the predetermined identification information received together with the identification information of the device matches, and if they match, the light source is modulated and visible light information is transmitted.

  The conventional example described in Patent Document 2 shows a configuration in the case where visible light communication is performed on a display board using an LED (Light Emitting Diode) or the like. When this conventional display device is installed on a ceiling or the like, the contents of visible light communication cannot be grasped unless the user looks up. Further, when the illuminance of the display device is increased, the display device cannot be seen as characters or figures.

  FIG. 11 is an explanatory diagram showing a band of output light in a communication device using infrared light and visible light. The example of FIG. 11 simulates the configuration described in Patent Document 1, and corresponds to the case where communication is performed using infrared rays from the infrared light source 101 and the visible light from the visible light source 102 is used only for display. In this case, the light receiving band 105 of the infrared light receiving element corresponds to only the light in the infrared band λx1 emitted from the infrared light source 101. In addition, data is not superimposed on the light in the visible light band λx2 emitted from the visible light source 102. In this state, the user cannot actually visually recognize the infrared irradiation area with which the user is communicating, and cannot view the information content.

  FIG. 12 is an explanatory diagram showing a band of output light in a communication device using two visible lights. The example of FIG. 12 is a combination of the visible light communication and the example of FIG. 11, performs communication using the first visible light from the first visible light source 111, and transmits from the second visible light source 112. This corresponds to the case where the second visible light is used only for display. In this case, the visible light band λx1 of the first visible light emitted from the first visible light source 111 and the visible light band of the second visible light emitted from the second visible light source 112 in the human visible band. λx2 is included, and these two bands of light are visible. Further, data is transmitted only by the first visible light transmitted from the first visible light source 111, and the data is not superimposed on the second visible light from the second visible light source 112. It is. In this state, when a general visible light receiving element having the entire visible light band as the light receiving band 106 is received, the second visible light from the second visible light source 112 becomes noise, and communication is performed. The first visible light from the first visible light source 111 for use causes CN degradation.

JP-A-9-69815 JP 2006-50528 A

  In the conventional visible light communication apparatus, the contents of transmission information when performing visible light communication cannot be easily visually confirmed. Further, when visible light communication is performed using illumination, it is not possible to distinguish from illumination that is not used as illumination for data transmission. Further, when visible light of another band is used to display the communication contents so as to be visible, the visible light for display becomes noise for visible light communication, and CN deteriorates. Occurs.

  The present invention has been made in view of the above circumstances, and allows the user to easily recognize the presence / absence of visible light communication and the communication content, and can prevent the CN deterioration due to the visible display of the communication content. An object is to provide an optical communication device.

  The visible light communication device of the present invention includes a visible light source and outputs visible light of a plurality of different colors. At least one of the plurality of colors of output light is foreground light, A visible light output unit that outputs at least one as background light, and a light source control that drives the visible light source so that information for visible light communication is included in both the foreground light and the background light And display for adding display information related to the visible light communication information to the foreground light or the background light so as to be visible in a state of being projected on the projection surface of the output light. An information adding unit; and a projection unit that projects the foreground light and the background light onto a projection surface.

  Thereby, when irradiating the output light for visible light communication, display information related to the information for visible light communication is displayed on the projection surface so as to be visible, so that the display information based on the foreground and the background having different wavelength bands is used. Thus, the user can easily visually recognize whether or not visible light communication is being performed and the communication contents. In addition, by including information for visible light communication in both foreground light and background light, CN degradation can be achieved without the foreground or background becoming a noise component when displaying the communication content. Can be prevented.

  In addition, the present invention is the above visible light communication device, wherein the visible light output unit includes the first visible light source that emits the foreground light as the visible light source, and the background light. And a second visible light source having a light emission wavelength band different from that of the first visible light source.

  Thereby, for example, the display information can be visually recognized by outputting foreground and background light respectively by the first visible light source and the second visible light source such as visible light LEDs having different emission center wavelengths. Visible light communication can be performed while displaying.

  Further, the present invention is the above visible light communication device, wherein the visible light output unit transmits the foreground light and the background light. And a second filter having a different transmission band.

  Thus, for example, by using a visible light source such as a white light LED, the optical path is branched into two, and the foreground and background light are transmitted and output by the first filter and the second filter, respectively. Visible light communication can be performed while displaying the display information in a visible manner.

  The present invention is the above visible light communication device, wherein the visible light output unit includes a visible light source that outputs white light, and a filter that transmits one of the foreground light and the background light. And at least.

  This makes it possible to visually recognize display information by branching the optical path into two using a visible light source such as a white light LED, and transmitting and outputting at least one light for foreground and background using a filter. Visible light communication can be performed while displaying.

  The present invention is the above visible light communication device, wherein the display information adding unit includes a transmission region control member that blocks or transmits a part of the region in order to form the display information on a projection plane. And

  Thus, for example, by using a transmission region control member such as a liquid crystal panel, a partial area of foreground light or background light is blocked or transmitted, so that display information is formed on the projection surface and displayed in a visible manner. be able to.

  Further, the present invention is the above visible light communication device, further comprising a contrast control unit that controls a color of the output light so that the foreground light and the background light have a contrast of a predetermined value or more. Shall.

  Thus, in the contrast control unit, for example, a light receiving unit that receives reflected light from the projection surface and detects the RGB component thereof, a contrast determination unit that calculates a brightness difference and a color difference from the RGB component and determines the contrast, Foreground and background by adjusting the color of the output light with a color adjustment unit that adjusts the color of at least one of the foreground light and background light so that the contrast value is equal to or greater than a predetermined value The contrast of the display can be made appropriate, and the user can recognize the display information more clearly.

  Moreover, this invention is said visible light communication apparatus, Comprising: The focus adjustment part which adjusts the focus state of the said display information in the said projection surface shall be provided.

  Accordingly, the focus adjustment unit includes, for example, an AF unit that detects a focus state of display information on the projection surface, a lens driving unit that drives an optical lens of the projection unit according to the output of the AF unit, and the like. By adjusting the position of the optical system on the optical path, the focus of the display information can be adjusted appropriately, and the user can recognize the display information more clearly.

  The visible light communication method of the present invention outputs visible light of a plurality of different colors from a visible light source, and at least one of the plurality of colors of output light is foreground light, and at least one of the other colors. Output as background light, driving the visible light source to include information for visible light communication in both the foreground light and the background light, and the foreground light Or adding the display information related to the visible light communication information to the background light so that the display information can be viewed in a state projected onto the projection surface of the output light, and the foreground light and Projecting the background light onto a projection surface.

  Thereby, when irradiating the output light for visible light communication, display information related to the information for visible light communication is displayed on the projection surface so as to be visible, so that the display information based on the foreground and the background having different wavelength bands is used. Thus, the user can easily visually recognize whether or not visible light communication is being performed and the communication contents. In addition, by including information for visible light communication in both foreground light and background light, CN degradation can be achieved without the foreground or background becoming a noise component when displaying the communication content. Can be prevented.

  ADVANTAGE OF THE INVENTION According to this invention, while the presence or absence of visible light communication and communication content can be made visible easily by a user, the visible light communication apparatus which can prevent CN degradation by the visible display of communication content can be provided.

  In the following embodiment, the structural example applied to the illuminating device as a visible light communication apparatus is shown. As a light emitting unit of the visible light communication device of the present embodiment, a light emitting element using an LED (Light Emitting Diode) is used.

  FIG. 1 is a block diagram showing a schematic configuration of a visible light communication apparatus according to an embodiment of the present invention. The visible light communication apparatus according to the present embodiment includes a display control unit 10, a first visible light LED 11, a second visible light LED 12, a display information adding unit 13, and a focusing unit 14.

  The display control unit 10 controls the display mode of light emitted for visible light communication, together with output control of data transmitted from the visible light communication device. The display control unit 10 has a function of controlling the display information adding unit together with the function of the light source control unit, and includes modulation data for visible light communication for modulating the first visible light LED 11 and the second visible light LED 12, and The display information adding unit 13 outputs the display information to be added and projected. Here, it is assumed that the modulation data and the display information are related. As a modulation method, for example, a method such as amplitude modulation or phase modulation may be used. Further, the modulation data output to the first visible light LED 11 and the second visible light LED 12 are the same.

  Each of the first visible light LED 11 and the second visible light LED 12 is a visible light source that emits visible light, and realizes the function of the visible light output unit. The first visible light LED 11 and the second visible light LED 12 have different wavelengths of output light and emit different colors. Each of the first visible light LED 11 and the second visible light LED 12 modulates the output light of the LED according to the modulation data from the display control unit 10.

  The display information adding unit 13 adds the display information received from the display control unit 10 to the output light of the first visible light LED 11 modulated with the modulation data. Specifically, the display information adding unit 13 has a part that transmits the output light of the first visible light LED 11 and a part that does not transmit, such as a slit and a mask, and changes these transmission / non-equalization parts. A possible transmissive region control member is provided, and display information such as characters, symbols, and figures is added according to display information from the display control unit 10. Further, if a liquid crystal panel is used as a transmission region control member of the display information adding unit 13 instead of a slit, a mask, etc., more various display information can be added.

  The focus unit 14 includes an output optical system and has a function of a projection unit. The focus unit 14 projects the output light of the first visible light LED 11 modulated with modulation data and added with display information onto a projection surface such as a floor surface or a wall surface. And focus and focus on the image. Specifically, the focus unit 14 is configured to have a projection optical lens or the like as an output optical system. Further, a projection lens drive mechanism for focusing may be provided.

  FIG. 2 is an explanatory view showing a band of output light of the visible light communication apparatus according to the embodiment of the present invention, and FIG. 3 is an explanatory view schematically showing a projection state of output light of the visible light communication apparatus in the embodiment of the present invention. It is.

  In the present embodiment, light having a plurality of different wavelengths is output from a visible light source, one is used as foreground light to which display information such as characters is added, and the other is projected onto a projection surface such as a floor or a wall as background light. Thereby, the contents of visible light communication can be visually displayed as display information based on the background and foreground.

  As shown in FIG. 2, in the human visible band, the first visible light LED 11 outputs light with display information added to the foreground whose emission center wavelength is the wavelength λ1, and the second visible light LED 12 emits the emission center. The light which becomes the background of the wavelength λ2 is output. Further, the output light of the first visible light LED 11 and the output light of the second visible light LED 12 having different colors are modulated by the same modulation data, and the visible light communication data is superimposed and transmitted. The wavelengths λ1 and λ2 of these output lights are in the human visible band and may be different colors from each other. If the combination of colors having a contrast of a predetermined value or more is easy to recognize, λ1 and The magnitude relationship and value of λ2 are arbitrary.

  As shown in FIG. 3, the output light for information display (foreground display) from the first visible light LED 11 and the output light for background display from the second visible light LED 12 are the floor surface, wall surface, and the like. Is projected on the projection plane 15 in a focused state. At this time, the output light from the first visible light LED 11 and the output light from the second visible light LED 12 are projected in a superimposed state. As a result, the user can easily visually recognize the contents of visible light communication based on the display information of the background and foreground. Further, the portable device 16 such as a cellular phone can acquire data by visible light communication by receiving and demodulating visible light modulated in the visible light irradiation region 17 from the visible light LEDs 11 and 12.

  In this case, the reception band B1 of the visible light receiving element in the portable device 16 on the receiving side includes both the wavelength λ1 of the foreground light and the wavelength λ2 of the background light to which the display information is added. Since data is superimposed on both lights, there is no problem that one visible light provided for information display becomes noise. Therefore, even when the light receiving unit of the portable device 16 is located in a display information portion such as characters and figures in the projection light for visible light communication, data communication is possible without CN deterioration.

  Thus, in this embodiment, the display information added to the output light from the first visible light LED 11 allows the contents of visible light communication to be visually displayed and can be easily recognized by the user. . Further, the intensity of light modulated for visible light communication can be increased by the output light from the two visible light LEDs 11 and 12 for foreground and background. Further, since the output light from the first visible light LED 11 and the output light from the second visible light LED 12 are modulated by the same modulation data, CN deterioration due to display of communication contents can be eliminated, and visible light is visible. High communication quality of optical communication can be maintained.

Below, the structural example of a visible light communication apparatus is shown in some embodiment.
(First embodiment)
FIG. 4 is a block diagram showing a detailed configuration of the visible light communication apparatus according to the first embodiment of the present invention. The visible light communication device 20 according to the first embodiment includes a communication function unit 21, a display control unit 22, and an optical system 23.

  The communication function unit 21 includes a transmission unit 24 and a reception unit 25, and is connected to a network 26 by wire or wireless, and can perform bidirectional communication with other communication devices 27. Examples of the network 26 include various wireless such as W-LAN (Wireless Local Area Network: wireless LAN), UWB (Ultra Wide Band), Bluetooth (registered trademark), ZigBee (trademark), mobile phone network, and Internet network. A connection form of communication means by wire can be used.

  The display control unit 22 includes an LED control unit 29, a transmission control unit 30, a reception control unit 31, and a liquid crystal control unit 32, and performs output control for visible light LEDs 11 and 12 that are visible light sources, and for visible light Input signal processing from a visible light PD (Photo Diode) 33 which is a light receiving element is performed. A memory 28 for storing data is provided, and is connected to the communication function unit 21 and the display control unit 22.

  The optical system 23 includes a first visible light LED 11, a second visible light LED 12, a visible light PD 33, a polarizing plate 34, a liquid crystal panel 35, and an optical lens 36. Here, as shown in FIG. 2, the first visible light LED 11 and the second visible light LED 12 have a light emission wavelength in the visible light region, but have emission center wavelengths different from λ1 and λ2, respectively. Although not an essential component, the display control unit 22 includes a lens position adjustment unit 37 and the optical system 23 includes a focusing unit that focuses output light from the first visible light LED 11 on the projection surface. A lens driving unit 38 may be provided so that the position of the optical lens 36 can be adjusted.

  Here, the 1st visible light LED11 and the 2nd visible light LED12 implement | achieve the function of a visible light output part. Further, the LED control unit 29 and the transmission control unit 30 realize the function of the light source control unit. In addition, the liquid crystal control unit 32 and the liquid crystal panel 35 realize the function of the display information adding unit. Further, the optical lens 36 realizes the function of the irradiation unit.

  In the visible light communication apparatus 20 having such a configuration, the communication function unit 21 communicates with the communication device 27 via the network 26 by the transmission unit 24 and the reception unit 25, and transmits and receives data. . Data received by the communication function unit 21 is sent to the memory 28 where it is stored and stored as information.

  The LED control unit 29 of the display control unit 22 acquires from the memory 28 data of information to be transmitted (contents such as music and weather forecast) and information such as characters and graphics to be displayed, and display data based on this data Is output to the liquid crystal control unit 32. At the same time, the LED control unit 29 generates modulation data of the transmission signal based on data of information to be transmitted and information to be displayed such as characters and graphics, and outputs the modulation data to the transmission control unit 30. The liquid crystal control unit 32 controls the liquid crystal panel 35 so that a predetermined portion can be transmitted so that characters, figures, and the like to be displayed can be displayed based on the display data.

  The transmission control unit 30 outputs the modulation data from the LED control unit 29 to the first visible light LED 11 and the second visible light LED 12, and drives the visible light LEDs 11 and 12 to emit light. Thereby, visible light modulated by the modulation data corresponding to the information to be transmitted is emitted from the visible light LEDs 11 and 12 according to the respective emission wavelengths. Here, the first visible light LED 11 and the second visible light LED 12 transmit the same information (contents) by visible light communication, and thus are turned on and off in synchronization. Note that the transmission rate of data transmitted by visible light communication (modulated data superimposed on visible light) in the two visible light LEDs 11 and 12 is the same rate synchronized as described above. It is also possible to set different transmission rates depending on the device configuration and usage state, such as when the values are different.

  The output light from the first visible light LED 11 passes through the polarizing plate 34 to become light having a predetermined polarization, and then passes through the liquid crystal panel 35 to transmit and block a predetermined portion corresponding to display contents. . The light transmitted through the liquid crystal panel 35 is emitted through the optical lens 36 and projected onto the projection surface as light for displaying the foreground information. The output light from the second visible light LED 12 is emitted as it is and projected onto the projection surface as background light. At this time, the data for visible light communication and the display information related thereto can be transmitted from another communication device 27 or the like via the network 26 to change the communication contents as appropriate.

  The visible light PD 33 receives an upstream optical communication signal from the mobile device 16 and the like, and outputs the received signal to the reception control unit 31. The reception control unit 31 performs reception signal processing such as preamplification and error correction, and outputs reception data to the communication function unit 21. This reception data is transmitted as transmission data from the transmission unit 24 of the communication function unit 21 and transmitted to the target communication device 27 via the network 26.

  As described above, in the first embodiment, two visible light LEDs are provided as visible light sources, and the first visible light LED 11 outputs foreground light for displaying display information such as characters indicating communication contents. The second visible light LED 12 outputs background light for the display information. Further, the output light of both the first visible light LED 11 and the second visible light LED 12 is modulated with modulation data corresponding to information to be transmitted, and the data for visible light communication is superimposed.

  Thereby, the content of visible light communication is visually displayed by the display information by a foreground and a background, and a user can recognize the communication content easily. In addition, since the output lights from the two visible light LEDs 11 and 12 are both modulated by the modulation data for visible light communication, the intensity of the light for visible light communication is increased by adding these two output lights. Data can be received anywhere within the visible light irradiation area. Therefore, even when communication contents are displayed, noise in the visible light band can be reduced, and CN deterioration in visible light communication can be prevented.

(Second Embodiment)
FIG. 5 is a block diagram showing a detailed configuration of the main part of the visible light communication apparatus according to the second embodiment of the present invention. FIG. 6 is an explanatory diagram showing a visible light source and a band of output light in the visible light communication apparatus.

  The second embodiment is an example in which the configuration of the optical system of the first embodiment is changed and a single light source is used as a visible light source. Constituent elements similar to those in the first embodiment are denoted by the same reference numerals, description of the same configuration and operation is omitted, and here, the description will focus on parts different from those in the first embodiment.

  The optical system 43 of the visible light communication device 40 includes a visible light LED 41, an optical splitter 42, a first filter 45, a second filter 46, a visible light PD 33, a polarizing plate 34, a liquid crystal panel 35, and an optical lens 36. Configured.

  Here, the visible light LED 41, the optical branching device 42, the first filter 45, and the second filter 46 realize the function of the visible light output unit.

  The visible light LED 41 as a visible light source is a light emitting LED that emits white light, and has an output band characteristic such that the emission wavelength covers almost the entire visible band of a human as shown in FIG. Here, modulation data corresponding to information to be transmitted from the transmission control unit 30 is input to the visible light LED 41, and visible light modulated by this modulation data is emitted from the visible light LED 41. The light splitter 42 is configured by a prism or the like, and branches the output light from the visible light LED 41 into two optical paths. The first filter 45 and the second filter 46 are respectively disposed on the two outgoing optical paths branched from the optical splitter 42.

  The first filter 45 has an output band characteristic such that the transmission band has a center wavelength λ1 as shown in FIG. 6B, and selectively transmits light having the wavelength λ1. The second filter 46 has an output band characteristic such that the transmission band is almost the entire visible band as shown in FIG. 6A or the center wavelength λ2 as shown in FIG. The output light from the LED 41 is transmitted as it is, or the light of wavelength λ2 is selectively transmitted.

  The light of wavelength λ1 that has passed through the first filter 45 passes through the polarizing plate 34 to become light having a predetermined polarization, and then corresponds to the display content related to information to be transmitted through the liquid crystal panel 35. The predetermined part is transmitted and blocked. At this time, the liquid crystal panel 35 is controlled by the liquid crystal control unit 32 so that a predetermined portion can be transmitted based on the display data, and is driven so as to display characters, figures, and the like to be displayed by the transmitted light. Then, the light transmitted through the liquid crystal panel 35 is emitted through the optical lens 36 and projected onto a projection surface such as a floor or a wall as light for displaying foreground information. The white light or the light having the wavelength λ2 that has passed through the second filter 46 is emitted as it is and projected onto the projection surface as background light.

  In the above example, the foreground light that passes through the first filter 45 is light of wavelength λ1, and the background light that passes through the second filter 46 is white light or light of wavelength λ2. In the case where the light for wavelength λ2 is light, the first filter 45 transmits the entire visible band as it is, and the foreground light for displaying display information such as characters indicating communication contents is white light. It is good. When white light is used as output light, the first filter 45 and the second filter 46 may not be provided.

  As described above, in the second embodiment, the optical path is divided into two by using one visible light source, and a specific wavelength band is transmitted and extracted by each filter. The same function as when having a plurality of visible light sources in the form can be realized. In other words, output light of different colors is emitted for the foreground and the background, and the display information for the foreground and the background is projected onto the projection plane in a state where the data for visible light communication is superimposed on both lights, thereby making the visible light visible. The contents of optical communication can be displayed visually. Thereby, the user can easily recognize the communication contents while preventing the CN deterioration in the visible light communication.

(Third embodiment)
FIG. 7 is a block diagram showing a detailed configuration of the visible light communication apparatus according to the third embodiment of the present invention. FIG. 8 is a flowchart showing an operation procedure of contrast adjustment of the visible light communication apparatus according to the third embodiment.

  The third embodiment is an example in which the configuration of the optical system and the display control unit of the second embodiment is changed to provide a foreground / background contrast adjustment function for output light including display information. Constituent elements similar to those in the first and second embodiments are denoted by the same reference numerals, description of the same configuration and operation is omitted, and here, the description will focus on parts that are different from the first and second embodiments. .

  The display control unit 52 of the visible light communication device 50 includes a contrast analysis unit 54 and a filter control unit 55 in addition to the LED control unit 29, the transmission control unit 30, the reception control unit 31, and the liquid crystal control unit 32. In the optical system 53, a first wavelength tunable filter 57 and a second wavelength tunable filter 58 are arranged on the two outgoing optical paths branched from the optical branching device 42, respectively. The wavelength tunable filters 57 and 58 are configured to be able to change the wavelength band of the transmitted light according to the control signal from the filter control unit 55. In addition, an RGB filter 59 that separates light into wavelengths of R, G, and B colors is detachably disposed on the incident light path of the visible light PD 33.

  Here, the visible light LED 41, the optical branching device 42, the first wavelength tunable filter 57, and the second wavelength tunable filter 58 realize the function of the visible light output unit. In addition, the RGB filter 59, the visible light PD 33, the contrast analysis unit 54, the filter control unit 55, the first wavelength tunable filter 57, and the second wavelength tunable filter 58 realize the function of the contrast control unit.

  The output signal of the visible light PD 33 is input to the contrast analysis unit 54 together with the reception control unit 31. The RGB filter 59 has a moving function, and is disposed in front of the visible light PD 33 only when the contrast analysis of the incident light is performed by the contrast analysis unit 54, and retracts from the incident light path of the visible light PD 33 after contrast adjustment. That is, during normal operation without contrast analysis, the RGB filter 59 moves so that transmission light from an external portable device or the like enters the visible light PD 33 without passing through the RGB filter 59.

  The filter control unit 55 receives the analysis result from the contrast analysis unit 54 and controls the transmission wavelength band of the wavelength tunable filters 57 and 58 according to the contrast analysis result. As a result, the wavelength band of light transmitted through the wavelength tunable filters 57 and 58 (color of visible light to be output) is adjusted.

  Considering the visibility of display information, even if the contrast between the foreground and background of the output light is set to a predetermined value or more in advance, depending on the floor surface and wall material, color etc. Display information such as visualized characters may be difficult to see. For this reason, in the present embodiment, the contrast between the foreground and the background is calculated by detecting the reflected light from the projection surface, and the color (wavelength) of the output light is adjusted so that the contrast becomes higher than a predetermined value.

  Here, the contrast between the foreground having display information projected on the projection plane and the surrounding background will be described. When analyzing the contrast of the output light, the foreground light and the background light are respectively emitted, reflected from the projection surface and incident, and the light that has passed through the RGB filter 59 is received by the visible light PD 33, and contrast analysis is performed. The unit 54 measures the intensity in each of the colors R, G, and B. Thereafter, the brightness difference and the color difference are calculated.

From the values of each color of R, G, and B, the lightness V can be calculated by the following calculation formula, for example.
V = ((R × 299) + (G × 587) + (B × 114)) / 1000 (1)

Using the above equation (1), the foreground brightness Vf and the background brightness Vb are calculated, and the difference between them is calculated to calculate the brightness difference ΔV.
ΔV = Vb−Vf (2)

Further, the color difference ΔE between the foreground and the background is calculated by, for example, the following calculation formula.
ΔE = (max (Rb, Rf) −min (Rb, Rf)) + (max (Gb, Gf) −min (Gb, Gf))
+ (Max (Bb, Bf) −min (Bb, Bf)) (3)
Here, max () represents the maximum value, min () represents the minimum value, Rb represents the background R value, Rf represents the foreground R value, and the same applies to G and B.

  Then, the brightness difference and the color difference calculated in the contrast analysis unit 54 are evaluated, and the contrast is adjusted by controlling the transmission bands of the wavelength tunable filters 57 and 58 by the filter control unit 55. The evaluation of brightness difference and color difference may be based on a desirable contrast value on a computer display proposed by the World Wide Web Consortium (W3C). In the present embodiment, as an example, a description will be given of the case where the contrast is adjusted so that the brightness difference between the background and the foreground is 125 or more, and the color difference between the background and the foreground is 500 or more. That is, the filter control unit 55 adjusts the wavelength variable filters 57 and 58 so that the brightness difference ΔV ≧ 125 and the color difference ΔE ≧ 500.

  Note that the contrast of the output light is adjusted by configuring the visible light LED with a plurality of LEDs having different emission center wavelengths, and switching the LED to be used among the plurality of types of LEDs, thereby projecting light onto the projection surface. The wavelength may be changed.

  Next, an example of contrast adjustment will be described with reference to FIG. Here, a case where the background is white light is shown as an example.

  First, the liquid crystal control unit 32 controls the liquid crystal panel 35 to close the entire area of the liquid crystal panel 35 so as to block the foreground light so that the background light is emitted. In this state, white light as background light is emitted and irradiated onto a projection surface such as a floor or a wall (step S1). The reflected light from the projection surface of the white light is received by the visible light PD 33 via the RGB filter 59 and analyzed by the contrast analysis unit 54 (step S2), and the R, G, B values of the background light are calculated. Each is calculated (step S3).

  Next, the liquid crystal control unit 32 controls the liquid crystal panel 35 so that the foreground light is transmitted and emitted by opening the entire area of the liquid crystal panel 35 or the like. In this state, light of a predetermined color as foreground light is emitted and irradiated onto a projection surface such as a floor or a wall (step S4). Then, the reflected light from the projection surface of the light of a predetermined color is received by the visible light PD 33 through the RGB filter 59 and analyzed by the contrast analysis unit 54 (step S5), and the foreground light R, G, Each B value is calculated (step S6).

  Thereafter, the contrast analyzer 54 calculates the lightness difference ΔV and color difference ΔE between the background and foreground of the illumination color from the R, G, B values of the background light and the R, G, B values of the foreground light (step S7). Then, the calculation result of the brightness difference and the color difference is determined (step S8). Here, if the brightness difference ΔV ≧ 125 and the color difference ΔE ≧ 500, the process is terminated. On the other hand, when the lightness difference and the color difference do not satisfy the above conditions, the filter control unit 55 adjusts the wavelength variable filter 57 to change the color of the foreground light (step S9). In addition, when the brightness difference or the color difference is too small, it is determined whether the background color needs to be adjusted (step S10), and the wavelength control filter 58 is adjusted by the filter control unit 55 as necessary to change the color of the background light. Change (step S11). After that, the process returns to step S1, the same processing is executed, the contrast is analyzed again, and the procedures of S1 to S8 are repeated until the brightness difference ≧ 125 and the color difference ≧ 500.

  Note that the R, G, and B values of the foreground light can also be obtained from the set values of the wavelength variable filter 57 in the filter control unit 55. In this case, the brightness difference and the color difference may be calculated from the R, G, B values of the background light calculated by the contrast analysis unit 54 and the R, G, B values of the foreground light acquired by the filter control unit 55.

  As described above, in the third embodiment, by providing the contrast adjustment function between the foreground and the background in the output light including the display information, the user can visually display the contents of the visible light communication by the display information. The display information can be recognized more clearly.

(Fourth embodiment)
FIG. 9 is a block diagram showing a detailed configuration of a visible light communication apparatus according to the fourth embodiment of the present invention. FIG. 10 is a flowchart showing an operation procedure of focus adjustment of the visible light communication apparatus according to the fourth embodiment.

  The fourth embodiment is an example in which the configuration of the optical system and the display control unit of the first embodiment is changed, and a focus adjustment function is provided on the projection plane of output light including display information. Constituent elements similar to those in the first to third embodiments are denoted by the same reference numerals, description of the same configuration and operation is omitted, and here, the description will focus on parts different from the first to third embodiments. .

  The display control unit 62 of the visible light communication device 60 includes an AF (autofocus) unit 65 and a lens position adjustment unit 65 in addition to the LED control unit 29, the transmission control unit 30, the reception control unit 31, and the liquid crystal control unit 32. ing. The AF unit 65 includes a light receiving element and a calculation unit, and determines the focus state of display information on the projection plane. The in-focus state is determined using a known phase difference detection method or contrast detection method used in a camera or the like. As the light receiving element, a CCD or the like is used, and in the case of the phase difference detection method, a line sensor is provided, and in the case of the contrast detection method, an image sensor is provided.

  In the optical system 63, a mirror 67 and a mirror 68 are disposed between the liquid crystal panel 35 and the optical lens 36 on the optical path from the first visible light LED 11, and the AF unit 65 receives the reflected light from the mirror 68. It is configured to receive light. The mirror 67 is composed of a half mirror or the like, and transmits the output light from the first visible light LED 11 as it is, while reflecting reflected light having display information from a projection surface such as a floor or a wall incident from the opposite direction. Have The optical system 63 includes a lens driving unit 38 that adjusts the position of the optical lens 36 in the optical axis direction.

  Here, the mirror 67, the mirror 68, the AF unit 65, the lens position adjusting unit 65, and the lens driving unit 38 realize the function of the focus adjusting unit.

  For example, when a visible light communication device applied to a lighting device or the like is installed on a ceiling or the like, it takes time and effort to adjust the focus of display information such as characters after being once installed. For this reason, in the present embodiment, an autofocus function for automatically adjusting the focus of display information is provided, and the display information on the projection surface is adjusted so as to be in focus.

  In the visible light communication device 60 configured as described above, the output light from the first visible light LED 11 passes through the polarizing plate 34 and becomes light having a predetermined polarization, and then passes through the liquid crystal panel 35. A predetermined portion corresponding to the display content is transmitted and blocked. Then, the light transmitted through the liquid crystal panel 35 passes through the mirror 67 and is emitted through the optical lens 36, and is projected onto the projection surface as light for displaying foreground information. Reflected light from the projection surface enters through the optical lens 36 and is reflected by the mirror 67, further reflected by the mirror 68 and received by the AF unit 65.

  The AF unit 65 determines the focus state of display information such as characters in the reflected light from the projection surface, and sends the determination result to the lens position adjustment unit 65. The lens position adjustment unit 65 sends a control signal to the lens driving unit 38 according to the output of the AF unit 65 to adjust the position of the optical lens 36. At this time, if the result of the determination by the AF unit 65 is not in focus, the lens position adjusting unit 65 calculates an adjustment amount and sends a control signal to the lens driving unit 38. The lens driving unit 38 adjusts the position of the optical lens 36 in the optical axis direction based on the control signal from the lens position adjusting unit 65 so as to match the focus. In this way, focus adjustment is performed on the projection surface of the foreground output light including display information.

  Next, an example of focus adjustment operation will be described with reference to FIG. First, the LED control unit 29 determines whether display information data such as characters and graphics to be displayed in the communication function unit 21 has been received (step S21). When the display information is not received, the LED control unit 29 drives and irradiates only the second visible light LED 12 (step S28). Thereby, the visible light communication device 60 functions as illumination.

  When the display information is received, the LED control unit 29 outputs display data based on the display information data to the liquid crystal control unit 32, and the liquid crystal control unit 32 displays characters, figures, and the like to be displayed based on the display data. The liquid crystal panel 35 is controlled so that a predetermined portion can be transmitted so that the image can be displayed (step S22). Then, the first visible light LED 11 and the second visible light LED 12 are irradiated to project the display information onto a projection surface such as a floor or a wall (step S23), and the reflected light including the display information from the projection surface is reflected to the AF unit 64. (Step S24).

  Then, it is determined whether or not the display information received by the AF unit 64 is in an in-focus state (Step S25). On the other hand, if it is not in focus, the lens position adjustment unit 65 instructs the adjustment amount so as to be in focus (step S26), and the lens driving unit 66 adjusts the position of the optical lens 36 based on the instruction. This is performed (step S27). Thereafter, returning to step S24, the same processing is executed to determine and adjust the in-focus state again, and the procedures of steps S24 to S27 are repeated until the display information such as characters and figures projected on the projection surface is in focus. .

  As described above, in the fourth embodiment, by providing the focus adjustment function on the projection plane of the output light including the display information, the user can display the contents of the visible light communication by the display information. Information can be recognized more clearly.

  In addition, as a visible light communication apparatus, it is also possible to combine suitably the structure of said 1st Embodiment to 4th Embodiment.

  In addition, portable devices that communicate with the visible light communication device include mobile phones, personal digital assistants (PDAs), notebook personal computers (PCs), portable music players such as built-in memory and HDD types, digital cameras, and electronic dictionaries. It can also be applied to speakers, headphones, etc.

  According to each of the above-described embodiments, the contents of visible light communication can be visually displayed by display information based on the foreground and background having a predetermined contrast. Can be easily recognized. In addition, by superimposing modulation data on both the foreground and background, CN deterioration due to visible display of communication contents can be prevented, and communication quality can be improved.

  Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

  The present invention enables the user to easily recognize the presence / absence of visible light communication and the communication content, and has the effect of preventing CN deterioration due to the visible display of the communication content. Useful for visible light communication devices and the like.

The block diagram which shows schematic structure of the visible light communication apparatus which concerns on embodiment of this invention. Explanatory drawing which shows the zone | band of the output light of the visible light communication apparatus which concerns on embodiment of this invention Explanatory drawing which shows typically the projection state of the output light of the visible light communication apparatus in embodiment of this invention The block diagram which shows the detailed structure of the visible light communication apparatus which concerns on the 1st Embodiment of this invention. The block diagram which shows the detailed structure of the principal part of the visible light communication apparatus which concerns on the 2nd Embodiment of this invention. Explanatory drawing which shows the band of visible light source and output light in the visible light communication apparatus of this embodiment The block diagram which shows the detailed structure of the visible light communication apparatus which concerns on the 3rd Embodiment of this invention. The flowchart which shows the operation | movement procedure of contrast adjustment of the visible light communication apparatus in 3rd Embodiment. The block diagram which shows the detailed structure of the visible light communication apparatus which concerns on the 4th Embodiment of this invention. The flowchart which shows the operation | movement procedure of the focus adjustment of the visible light communication apparatus in 4th Embodiment. Explanatory drawing which shows the zone | band of the output light in the communication apparatus using infrared rays and visible light Explanatory drawing which shows the zone | band of the output light in the communication apparatus using two visible lights

Explanation of symbols

10 Display Control Unit 11 First Visible Light LED
12 Second visible light LED
DESCRIPTION OF SYMBOLS 13 Display information addition part 14 Focus part 15 Projection surface 16 Portable apparatus 20, 40, 50, 60 Visible light communication apparatus 21 Communication function part 22, 52, 62 Display control part 23, 43, 53, 63 Optical system 28 Memory 29 LED Control unit 30 Transmission control unit 31 Reception control unit 32 Liquid crystal control unit 33 PD for visible light
34 Polarizing plate 35 Liquid crystal panel 36 Optical lens 37, 65 Lens position adjusting unit 38, 66 Lens driving unit 41 Visible light LED
42 Optical splitter 45, 46 Filter 54 Contrast analysis unit 55 Filter control unit 57, 58 Tunable filter 59 RGB filter 64 AF unit 67, 68 Mirror

Claims (8)

Including a visible light source and outputting visible light of a plurality of different colors, at least one of the plurality of colors of output light as foreground light and at least one of the other as background light A visible light output section to output,
A light source controller that drives the visible light source so as to include information for visible light communication in both the foreground light and the background light;
A display information adding unit that adds display information related to the visible light communication information to the foreground light or the background light so as to be visible in a state of being projected onto a projection surface of output light. When,
A visible light communication apparatus comprising: a projection unit that projects the foreground light and the background light onto a projection surface. The visible light communication device according to claim 1,
The visible light output unit emits the foreground light as the visible light source, and emits the background light. The first visible light source and the emission wavelength band. Visible light communication apparatus provided with the 2nd visible light source from which they differ. The visible light communication device according to claim 1 or 2,
The visible light output section includes a first filter that transmits the foreground light and a visible light that transmits the background light and has a second filter that has a transmission band different from that of the first filter. Communication device. The visible light communication device according to claim 1,
The visible light output unit includes at least a visible light source that outputs white light, and a filter that transmits one of the foreground light and the background light. The visible light communication device according to any one of claims 1 to 4,
The said display information addition part is a visible light communication apparatus provided with the transmissive area | region control member which interrupts | blocks or permeate | transmits a one part area | region in order to form the said display information on a projection surface. The visible light communication device according to any one of claims 1 to 5,
A visible light communication apparatus including a contrast control unit that controls a color of output light so that the foreground light and the background light have a contrast of a predetermined value or more. The visible light communication device according to any one of claims 1 to 6,
A visible light communication apparatus including a focus adjustment unit that adjusts a focus state of the display information on the projection plane. Outputting visible light of a plurality of different colors from a visible light source, outputting at least one of the plurality of colors of output light as foreground light, and outputting at least one of the other as background light When,
Driving the visible light source to include information for visible light communication in both the foreground light and the background light;
Adding display information related to the visible light communication information to the foreground light or the background light so as to be visible in a state of being projected on a projection surface of output light;
Projecting the foreground light and the background light onto a projection surface.

Images