WO2008004309A1 - Appareil émetteur, appareil récepteur, procédé de transmission et procédé de réception - Google Patents

Appareil émetteur, appareil récepteur, procédé de transmission et procédé de réception Download PDF

Info

Publication number
WO2008004309A1
WO2008004309A1 PCT/JP2006/313604 JP2006313604W WO2008004309A1 WO 2008004309 A1 WO2008004309 A1 WO 2008004309A1 JP 2006313604 W JP2006313604 W JP 2006313604W WO 2008004309 A1 WO2008004309 A1 WO 2008004309A1
Authority
WO
WIPO (PCT)
Prior art keywords
transmission
unit
data
visible light
display
Prior art date
Application number
PCT/JP2006/313604
Other languages
English (en)
Japanese (ja)
Inventor
Takatoshi Kageyama
Original Assignee
Panasonic Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Panasonic Corporation filed Critical Panasonic Corporation
Priority to PCT/JP2006/313604 priority Critical patent/WO2008004309A1/fr
Publication of WO2008004309A1 publication Critical patent/WO2008004309A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/11—Arrangements specific to free-space transmission, i.e. transmission through air or vacuum
    • H04B10/114—Indoor or close-range type systems
    • H04B10/1141—One-way transmission

Definitions

  • Transmission device and reception device and transmission method and reception method
  • the present invention relates to a transmission device and a reception device capable of communication using visible light, and a transmission method and a reception method.
  • Patent Document 1 discloses a display device that displays a figure with visible light emitted from a light source and transmits information by visible light communication, a receiving device that receives and outputs information transmitted by the display device, and a predetermined device.
  • a visible light communication display system is described that includes identification information and a transmission device that transmits visible light information to be transmitted by visible light communication to a display device.
  • Patent Document 2 describes a mobile terminal provided with a light receiving unit for visible light that faces the same direction as the light receiving lens of the camera, in addition to a camera included in a general mobile terminal with a camera. ing. This makes it possible to receive visible light communication information at the light receiving unit when a lighting fixture that performs visible light communication is displayed on the camera display using the camera as a viewfinder. .
  • Patent Document 3 a zero-crossing time of an AC commercial power supply is detected, and during a certain reservation time synchronized with the zero-crossing time, a signal of lighting device power is transmitted or communication between communication devices is performed. An illumination device used in an optical communication system is described.
  • Patent Document 1 Japanese Unexamined Patent Application Publication No. 2006-050528
  • Patent Document 2 Japanese Patent Laid-Open No. 2005-218067
  • Patent Document 3 Japanese Unexamined Patent Publication No. 2006-074323
  • the receiving station When using the visible light communication technology as described above, the receiving station receives the visible light coming from the display unit of the transmitting station, so that information contained in the visible light is received. It is necessary to provide a photoelectric conversion unit such as a photodiode in the light receiving unit of the receiving station.
  • the light receiving unit of the receiving station has a somewhat wide predetermined range determined by the characteristics of the lens of the optical system provided in the light receiving unit that does not receive only visible light coming from a light source existing at a certain point. Visible light from all light sources in the range is received simultaneously.
  • a display unit such as an electric bulletin board
  • a plurality of light sources are provided on one electric bulletin board, a plurality of light sources are controlled independently, Each light source power can also transmit different information simultaneously.
  • the information transmitted for each area (light source) of the display unit can be distinguished, and visible light communication can be applied to various applications. become.
  • the light receiving unit of the receiving station simultaneously receives visible light of all the light source powers within a certain wide range as described above, and thus exists, for example, on one electronic bulletin board. Multiple light source powers that receive multiple visible lights cannot be received separately. Therefore, even when the transmitting station transmits a plurality of independent information using visible light using a plurality of light sources, the receiving station cannot receive the plurality of information independently. There is also a possibility that a plurality of visible light signals interfere with each other and the transmitted information cannot be demodulated correctly by the receiving station.
  • the present invention has been made in view of the above circumstances, and when different signals are transmitted from a plurality of transmission sources by visible light, the receiving station distinguishes the plurality of visible light signals. It is an object of the present invention to provide a transmitting device and a receiving device, a transmitting method and a receiving method.
  • a first aspect of the present invention is a transmission device capable of communication using visible light, and includes a plurality of display units arranged at different positions, and transmission information about each of the plurality of display units. And controlling at least one of the modulation unit that modulates visible light output from the display unit and the display unit and the modulation unit, so that the plurality of display units are different from each other.
  • a transmission device including a transmission timing control unit that transmits data at the timing described above.
  • the plurality of signals transmitted as visible light from the plurality of display units provided in the transmission device are transmitted at different timings under the control of the transmission timing control unit. Therefore, on the receiving side, since a plurality of independent signals coming from a plurality of display units are received at different timings, the plurality of signals are separated based on the difference in timing. be able to.
  • a second aspect of the present invention is the transmission apparatus according to the first aspect, wherein the transmission timing control unit is configured to turn on / off display of each of the plurality of display units and start and end of the modulation.
  • a transmission apparatus that synchronizes with the timing of is provided.
  • This configuration facilitates determination of transmission timing. Further, on the receiving side, it is possible to simplify the detection of the display on the display unit and the display of the transmitted data or the timing of transmission, or one of them can be omitted.
  • the third aspect of the present invention is the transmission device according to the first or second aspect, wherein the transmission timing control unit is configured to transmit the data to the display unit, There is provided a transmission device that emits light with different light amounts during a period in which data is not transmitted.
  • the transmission timing control unit causes each of the display units to emit light with different amounts of light during a period in which data is transmitted and a period in which data is not transmitted. It is possible to determine which display unit is transmitting data based on the difference in the amount of light received.
  • the present invention provides the transmission apparatus according to any one of the first to third aspects, wherein the reception apparatus that receives information transmitted by the plurality of display units captures an image.
  • the transmission timing control unit includes the imaging unit that performs transmission
  • the transmission timing control unit sets the length of time for transmitting the data to each of the plurality of display units to be greater than or equal to the frame period of the imaging unit of the reception device.
  • a transmitting device to be defined is provided.
  • the length of time from the start to the end of data transmission for each of the plurality of display units is equal to or greater than the shooting frame period in the imaging unit of the receiving device.
  • the fifth aspect of the present invention is the transmission apparatus according to the fourth aspect, wherein the transmission timing control unit shifts the time of the data in order with respect to each of the plurality of display units.
  • the transmission state is switched, and the first time difference from the start of data transmission from one of the plurality of display units to the start of data transmission from the next display unit, or the Provided by a transmission apparatus that determines the second time difference from the end of data transmission from one of the plurality of display units until the start of data transmission from the next display unit to the frame period or more. It is what is done.
  • the present invention is a receiving device capable of communication using visible light, receiving visible light from a display unit of a transmitting device, demodulating the received visible light, and obtaining data. Based on the received data reception unit, the imaging unit that captures an image, the timing of change in visible light received by at least one of the light receiving unit and the imaging unit, and the captured image
  • a receiving device includes a reception control unit that specifies a position of a display unit that has transmitted the received data.
  • the present invention provides the receiving device according to the sixth aspect, wherein the reception control unit has a predetermined pixel difference between a plurality of frames based on an image captured by the imaging unit.
  • the above-described and periodically changing area is detected as a data transmission area, and the data transmission area is A receiving device that is specified as a data transmission source is provided.
  • the reception device according to the seventh aspect, wherein the reception control unit is configured to increase a pixel difference between a plurality of frames for each of the data transmission areas.
  • a receiving apparatus that generates a timing signal based on the timing signal and associates each of the data transmission areas with the received data using the timing signal is provided.
  • the receiving device according to any one of the sixth to eighth aspects, wherein the transmission source of at least the specified data among the images captured by the imaging unit And a display unit that simultaneously displays the received data and the received data on the same screen.
  • the present invention is the receiving apparatus according to the ninth, wherein the display unit is selected by a predetermined input operation when there are a plurality of transmission sources of the data
  • a receiving device that displays the transmitted information as well as the transmission power is provided.
  • the present invention relates to the reception device according to the ninth aspect, wherein the display unit is located closest to the center of the image when there are a plurality of transmission sources of the data.
  • Existing transmission A receiving apparatus that displays information on the transmitted power is provided.
  • a transmission method of a transmission device capable of data communication using visible light communication, wherein a modulation unit displays the display according to transmission information for each of the plurality of display units.
  • a method of transmitting data is provided.
  • a receiving method of a receiving device capable of data communication using visible light communication, wherein the light receiving unit receives visible light from the display unit of the transmitting device, and Demodulating the received visible light and receiving data; an image capturing unit capturing an image; a timing of a change in visible light received by at least one of the light receiving unit and the image capturing unit; And a step of specifying the position of the display unit that transmitted the received data based on the received image.
  • signals having different transmission powers are transmitted by visible light.
  • a transmission device, a reception device, a transmission method, and a reception method that enable a receiving station to distinguish and receive a plurality of visible light signals.
  • FIG. 1 is a block diagram showing an overview of a visible light communication system according to a first embodiment.
  • FIG. 2 is a time chart showing an operation example of the visible light communication system according to the first embodiment.
  • FIG. 3 is a schematic diagram showing an example of averaged image information and image information at each time point obtained by photographing the mobile terminal according to the first embodiment with a camera.
  • FIG. 4 is a front view showing an example of a display screen on the mobile terminal according to the first embodiment.
  • FIG. 5 is a time chart showing a specific example of an internal signal of the mobile terminal according to the first embodiment.
  • FIG. 6 is a flowchart showing the operation of the pixel area detection unit of the mobile terminal according to the first embodiment.
  • FIG. 7 is a flowchart showing the operation of the timing signal generator of the mobile terminal according to the first embodiment.
  • FIG. 8 is a flowchart showing the operation of the timing comparison unit of the mobile terminal according to the first embodiment.
  • FIG. 9 is a flowchart showing the operation of the display control unit of the mobile terminal according to the first embodiment.
  • FIG. 10 is a block diagram showing the configuration of the visible light communication transmitter according to the second embodiment.
  • FIG. 11 is a block diagram showing a configuration of a mobile terminal according to the second embodiment.
  • Pixel area detection unit Timing signal generation unit Timing comparison unit Pixel region storage unit Display control unit Reception information storage unit Image storage unit Display unit
  • FIG. 1 is a block diagram showing an overview of a visible light communication system according to the first embodiment.
  • a visible light communication transmitter 10 that is an example of a transmitter capable of communication using visible light
  • a mobile terminal 30 that is an example of a receiver.
  • Data communication is performed using a visible light 21 signal.
  • the visible light communication transmitter 10 includes N display units 11 (1) to L 1 (N) and N drive units 12 (1) to 12 (N).
  • each display unit 11 one or a plurality of light emitting elements can be used, and for example, a display that can transmit controllable transmitted light or reflected light as visible light 21 like a liquid crystal display is used. You may do it. However, since communication is performed using visible light 21, it is necessary to use a display that can emit visible light 21 that is sufficiently stronger than the surrounding brightness.
  • N display units 11 (1) to L I (N) are arranged in parallel at different positions with a predetermined interval or more therebetween.
  • the directions of the N display units 11 (1) to L 1 (N) are aligned so that each can emit visible light 21 in the same direction.
  • the display switching unit 13 gives a predetermined display switching signal to display, for example, an advertisement to each of the display units 11 (1) to 11 (N), and the display units 11 (1) to 11 (N) Controls the display (lit Z off). Specifically, for example, information such as graphics and characters is displayed on the display units 11 (1) to 11 (N).
  • N drive units 12 (1) to 12 (N) function as an example of a modulation unit and display visible light 21 including transmission information in each display unit 11 (1) to: L 1 (N)
  • the display of each of the display units 11 (1) to 11 (N) is controlled in accordance with the transmission information input in this manner. Specifically, the display light amount of the display unit 11 that is lit by the control of the display switching unit 13 is modulated according to the transmission information, and the modulated visible light 21 is generated.
  • the timing control unit 14 functions as an example of a transmission timing control unit, and individually transmits information as visible light 21 for each display unit by displaying the display units 11 (1) to 11 (N).
  • a timing signal is generated and applied to each of the driving units 12 (1) to 12 (N).
  • the information to be transmitted (transmission information) is divided into multiple groups in advance, and whether to use the deviation of N display units 11 (1) to 11 (N) to transmit the information of each group Predetermined.
  • the transmission information of each group is applied to any one of the drive units 12 (1) to 12 (N) via the timing control unit 14, and by modulating the display brightness of the corresponding display unit 11, It is emitted as visible light 21 containing transmission information.
  • the visible light communication transmitter 10 can individually transmit different types of independent transmission information as visible light 21 from the N display units 11 (1) to 11 (N).
  • the transmission information sent by the visible light communication transmitter 10 on the visible light 21 can be received using the portable terminal 30 shown in FIG.
  • the mobile terminal 30 for example, a mobile phone terminal can be assumed.
  • the mobile terminal 30 includes an imaging unit 31, a visible light receiving unit 32, a demodulating unit 33, a pixel region detecting unit 34, a timing signal generating unit 35, and a timing comparing unit 36.
  • the imaging unit 31 can capture an image of a subject as a two-dimensional image and output information of the captured image.
  • the visible light receiving unit 32 includes a photoelectric conversion element that generates an electrical signal corresponding to the intensity of received light, such as a photodiode.
  • a photoelectric conversion element that generates an electrical signal corresponding to the intensity of received light, such as a photodiode.
  • the direction in which the light detection sensitivity of the visible light receiving unit 32 is maximized and the direction in which the imaging unit 31 captures are aligned with each other.
  • the demodulator 33 demodulates the received signal generated by the visible light 21 received by the visible light receiver 32 and extracts information transmitted by the visible light communication transmitter 10. Visible light reception
  • the unit 32 and the demodulation unit 33 function as an example of a light receiving unit.
  • the image storage unit 41 temporarily holds the image information 22 obtained by photographing by the imaging unit 31.
  • the pixel area detection unit 34 detects a special pixel area included in the image based on the frame unit image information 22 obtained by photographing by the imaging unit 31, and a pixel representing this pixel area An area signal 23 and a pixel area image 24, which is image information in the pixel area, are generated.
  • the pixel area is detected as a set of pixels having a luminance of a predetermined level or higher.
  • the pixel area storage unit 37 temporarily holds one or a plurality of pixel area images 24 detected by the pixel area detection unit 34.
  • the timing signal generator 35 compares the pixel area signal 23 output from the pixel area detector 34 with respect to a plurality of frames of image information between frames, and determines the timing based on the luminance difference between frames! Generate signal 25.
  • the timing comparison unit 36 separates the reception information 27 for each transmission source by comparing the reception information 27 output from the demodulation unit 33 with the timing signal 25 output from the timing signal generation unit 35. At the same time, the separated reception information 27 is associated with each pixel area detected by the pixel area detection unit 34. The result of this processing is sent as a display control signal 28 to the display control unit 38.
  • the reception information storage unit 39 stores the reception information 27 output from the demodulation unit 33.
  • the display control unit 38 controls the display unit 42 and displays the image information 22 obtained by the imaging of the imaging unit 31 on the display unit 42. If there is a detected pixel area in the image information 22, this pixel area is also displayed. If there is a selected pixel area, the content of the reception information 27 associated with the display control signal 28 is displayed on the display unit 42.
  • the pixel region detection unit 34, the timing signal generation unit 35, the timing comparison unit 36, and the display control unit 38 function as an example of a reception control unit.
  • the display unit 42 is a device having a screen capable of displaying information such as a two-dimensional image and characters, and is used, for example, to display information as shown in FIG.
  • the key input unit 43 has an input unit such as a button and accepts an input operation from the user.
  • FIG. 2 is a time chart showing an operation example of the visible light communication system according to the first embodiment. In the operation example shown in FIG. 2, for the sake of convenience, it is assumed that the display unit 11 (1) to 11 ⁇ ) shown in FIG. 1 has three display units A, B, and C. ing.
  • visible light 21 (A) is emitted from the display unit A of the transmitter 10 for visible light communication
  • visible light 21 (B) is emitted from the display unit B
  • visible light 21 (C) is emitted from the display unit C. Is done.
  • the visible light receiving unit 32 receives visible light 21 (A), visible light 21 (B), and visible light 21 (C) respectively coming from the visible light communication transmitter 10. To do. However, visible light 21 (A), visible light 21 (B), and visible light 21 (C) are emitted from a plurality of transmission sources (light sources) that are close to each other. Even if a signal is extracted from the light, it is very difficult to determine whether any of the visible light 21 (A), visible light 21 (B), and visible light 21 (C) is a transmitted signal.
  • the timing control unit 14 of the visible light communication transmitter 10 performs transmission timing control as shown in FIG. 2, for example. That is, the timing at which the visible light 21 (A) appears, the timing at which the visible light 21 (B) appears, and the timing at which the visible light 21 (C) appears are controlled to be different from each other.
  • the visible light communication transmitter 10 transmits visible light 21 (A) at a timing including time tl, and similarly transmits visible light 21 (B) at a timing including time t2.
  • Visible light 21 (C) is transmitted at a timing including time t3
  • visible light 21 (A) is transmitted at a timing including time t4
  • visible light 21 (B) is transmitted at a timing including time t5.
  • Visible light 21 (C) is transmitted at the timing including time t6. That is, the visible light 21 (A), the visible light 21 (B), and the visible light 21 (C) are sent out sequentially and periodically at different timings.
  • each display unit A, B, C For information transmitted from each display unit A, B, C to each visible light 21 (A), visible light 21 (B), visible light 21 (C), each display unit A, B, Sent by modulating the amount of light emitted from C.
  • FIG. 2 only the portions including information such as visible light 21 (A), visible light 21 (B), and visible light 21 (C) are illustrated, but the information is transmitted! /, Etc.
  • Light is emitted at a predetermined light intensity slightly weaker than during transmission.
  • Each display A, B, C is issued only while information is being transmitted. The amount of light increases, but because it is a moment, it cannot be captured by the human eye. in this way
  • the timing control unit 14 controls each of the display units 11 (1) to 11 () so that light is emitted with different amounts of light during a period in which data is transmitted and a period in which data is not transmitted. As a result, the receiving mobile terminal can determine which display unit is transmitting data depending on the amount of light.
  • control is performed so that the display modulation timings of the display units A, B, and C are synchronized with each other.
  • the timing control unit 14 provided on the visible light communication transmitter 10 allows the mobile terminal 30 to easily separate a plurality of visible lights 21 (A), 21 (B), and 21 (C). Implement special timing control. As specific contents of timing control, for example, the following control is assumed.
  • Condition 1 The frame period T (for example, 1Z60 seconds) when the imaging unit 31 on the mobile terminal 30 captures the length of one cycle from when each display unit starts sending a signal to when the force ends. ) Determined above.
  • Condition 2 The length of time difference from when one display unit (for example, display unit A) starts sending a signal until the next display unit (for example, display unit B) starts sending the signal is Set to frame period T or more.
  • Condition 3 The length of the time interval from when one display unit (for example, display unit A) finishes sending a signal until the next display unit (for example, display unit B) starts sending the signal is The frame period is set to T or more.
  • the display units A, B, and C are within the field of view of the imaging unit 31. If all are included, as shown in FIG. 3, the pixel information 51 (A), 51 (B), and 51 (C) corresponding to the display of the three display portions A, B, and C are regarded as bright areas. Appears in 50.
  • FIG. 3 is a diagram showing an example of image information obtained by photographing with the mobile terminal power S camera according to the first embodiment, and FIG. 3 is a schematic diagram showing an example of image information at each time point. is there.
  • image information 50 (t6) represent image information 50 taken at each time point corresponding to times t0, tl, t2, t3, t4, t5, and t6 shown in FIG.
  • the pixel information 51 (A), 51 (B), and 51 (C) are illuminated in the image information 50 (tO) taken at the time tO.
  • the image information 50 (tl) taken at time tl appears to shine more strongly than the pixel area 51 (A) power corresponding to the display unit A than the other pixel areas 51 (B) and 51 (C).
  • the pixel area 51 (B) corresponding to the display unit B appears to shine more strongly than the other pixel areas 51 (A) and 51 (C).
  • the image information 50 (t3) shows that the pixel area 51 (C) corresponding to the display portion C is more shining than the other pixel areas 51 (A) and 51 (B).
  • the image information 50 (t4) shows that the pixel area 51 (A) corresponding to the display portion A shines stronger than the other pixel areas 51 (B) and 51 (C).
  • the pixel area 51 (B) corresponding to the display unit B appears to shine more strongly than the other pixel areas 51 (A) and 51 (C).
  • the pixel area 51 (C) corresponding to the display unit C appears to shine more strongly than the other pixel areas 51 (A) and 51 (B).
  • the image information 50 of each frame is continuously captured using the imaging unit 31 with the position of the mobile terminal 30 fixed, the difference between the positions of the display units A, B, and C and The difference in lighting Z extinction state appears as each pixel area 51 on the image information 50. Therefore, if the image information 50 of a plurality of frames is compared, it is possible to identify the display unit that transmits information using the visible light 21 at that time.
  • the mobile terminal 30 for example, as shown in FIG. 5, it is possible to separate the received signal for each pixel area 51 and associate each separated received information with a specific pixel area 51.
  • FIG. 6 is a flowchart showing the operation of the pixel area detection unit of the mobile terminal according to the first embodiment.
  • the pixel area detection unit 34 receives each pixel in the image information 22 Check the brightness of (step S12).
  • step S13 it is identified whether or not a pixel region that is a set of pixels having a luminance equal to or higher than a predetermined threshold is detected (step S13).
  • the data of the pixel group at the corresponding location is extracted from the image information 22 as the pixel area image 24 for each detected pixel area.
  • the extracted pixel region image 24 is sent to the pixel region storage unit 37 and stored (step S14).
  • Step S 16 When a pixel area is detected (No in step S13), it is checked whether or not the detected pixel area exists in the image information 22 currently being processed and the image information 22 of the previously processed frame ( Step S 16). If the detected pixel area exists (Yes in step S16), a pixel area signal 23 indicating the existence of the corresponding pixel area is generated for each pixel area (step S17).
  • the pixel area signal 23 includes information indicating the position and size of the area in the image and outputs the information to the timing signal generator 35.
  • the process shown in FIG. 6 is repeatedly performed to process the image information 22 of each frame every time the imaging unit 31 captures an image.
  • FIG. 7 is a flowchart showing the operation of the timing signal generator of the mobile terminal according to the first embodiment.
  • the pixel area signal 23 output from the above-described pixel area detection unit 34 is input (step S21)
  • the pixel area signal 23 input this time is a simple illumination or the like.
  • the position and size are compared with a signal assigned as a non-pixel area that is not recognized as the display unit 11 on the visible light communication transmitter 10 (step S22). If it corresponds to a non-pixel area (Yes in step S22), the process ends.
  • step S22 when the pixel region does not correspond to the non-pixel region (No in step S22), the difference in luminance between a plurality of frames of the image is compared for the region corresponding to each input pixel region signal 23 (step S23). ).
  • a timing signal is generated for each pixel area in accordance with each input pixel area signal 23.
  • Step S24 a signal whose level changes in units of frames is generated when the difference in brightness between a plurality of frames detected in step S23 becomes larger than a predetermined value. For example, as shown in FIG. 5, each timing signal maintains a constant level for a period of one frame or more, and the level changes in units of one frame or a plurality of frame periods.
  • step S25 For each timing signal generated in step S24, the presence or absence of a change in level is monitored (step S25). That is, since each display unit 11 on the visible light communication transmitter 10 periodically blinks, the brightness of the pixel area corresponding to each display unit 11 periodically changes and the timing signal also periodically. Changes appear.
  • step S25 when the timing signal does not change over a long period such as several tens of times of the frame period (Yes in step S25), the display unit 11 on the corresponding pixel region power visible light communication transmitting device 10 Since it is likely to correspond to noise such as simple lighting, the position and size of this area are stored as a non-pixel area so that the area of the corresponding pixel area signal 23 can be identified as noise in step S22. (Step S26).
  • step S25 If the change of the timing signal can be confirmed (No in step S25), the timing signal 25 generated for each pixel region signal 23 is sent to the timing comparison unit 36 (step S27).
  • FIG. 8 is a flowchart showing the operation of the timing comparison unit of the mobile terminal according to the first embodiment.
  • the timing comparison unit 36 receives the reception information 27 from the demodulation unit 33 (step S31). That is, the demodulated unit 33 demodulates the modulated electric signal generated by the visible light receiving unit 32 by receiving the visible light 21, thereby acquiring the information transmitted by the visible light communication transmitting device 10 as the received information 27.
  • the timing comparison unit 36 receives the timing signal 25 (one or more) generated by the timing signal generation unit 35 (step S32).
  • the timing comparison unit 36 compares the timing at which the reception information 27 appears with the timing of a period in which each timing signal 25 is at an effective level. (Step S33). That is, when the information is transmitted by the display of the display units 11 (1) to 11 (N) on the transmission device 10 for visible light communication 10 by the display, the mobile terminal 30 is used as the visible light 21.
  • the pixel region detecting unit 34 simultaneously detects the pixel region, and one tag corresponding to this pixel region is detected.
  • the reception information 27 is detected in a period in which the corresponding pixel area is high in luminance, that is, in a period in which the timing signal 25 is at an effective level. Therefore, it is identified in step S33 whether or not these timings coincide with each other.
  • step S33 If the timings of the timing signal 25 and the reception information 27 match (Yes in step S33), the timing comparison unit 36 compares the pixel area corresponding to the specific timing signal 25 with the matching timing and the current reception.
  • the display control signal 28 indicating the correspondence with the received information 27 is output to the display control unit 38 (step S34).
  • FIG. 5 is a time chart showing a specific example of the internal signal of the mobile terminal according to the first embodiment.
  • FIG. 5 (A) is an example of image information at times tl to t3, and FIGS. 5 (B) and 5 (C).
  • (D) is the timing signal in the pixel areas A to C
  • Fig. 5 (E) is the reception timing of the received information
  • Figs. 5 (F), (G), and (H) are the reception information in the pixel areas A to C. Each timing is shown.
  • each timing signal 25 and reception information 27 appear at timings as shown in FIGS. 5B to 5E.
  • each of the display portions A, B, and C appears as pixel regions 51 (A), 51 (B), and 51 (C) in the captured image information 50, so that the pixel region detection unit 34 displays the image of time tl.
  • Pixel area 51 (A) is detected from information 50 (tl)
  • pixel area 51 (B) is detected from image information 50 (t2) at time t2
  • pixel area 51 ( C) is detected, and three timing signals 25 corresponding to the respective pixel areas 51 (A), 51 (B), and 51 (C) are generated as shown in FIGS. Is done.
  • timing signals 25 are synchronized with the timing at which each display unit 11 of the transmission device 10 for visible light communication transmits information as visible light 21. Therefore, the timing comparison unit 36 compares the timings. Therefore, the received information 27 can be distinguished for each transmission source. Each correspondence information 27 can also identify the correspondence with the pixel area.
  • the reception information 27 transmitted for each pixel region in the image is separated, and the respective reception information 27 is It can be associated with a pixel area.
  • FIG. 9 is a flowchart showing the operation of the display control unit of the mobile terminal according to the first embodiment.
  • step S41 when the image information 22 stored in the image storage unit 41 is input to the display control unit 38 (step S41), the image information 22 is displayed on the screen of the display unit 42. Display (Step S42).
  • the display control unit 38 checks whether or not the display control signal 28 is input (step S43), and if the display control signal 28 is input (Yes in step S43), the input display The pixel area image 24 of the pixel area corresponding to the control signal 28 is extracted from the pixel area storage unit 37 and displayed on the screen of the display unit 42 in a state of being overlaid on the image information 22 (overwrite state) (step S44).
  • a specific pixel area corresponding to the input display control signal 28 (transmission source display unit)
  • the content of the reception information 27 associated with the information is displayed on the screen of the display unit 42 as, for example, character string information (step S45). If the display control signal 28 is not input, only the image information 22 is displayed on the screen of the display unit 42.
  • the method for selecting one pixel area 51 to be noticed among the plurality of pixel areas 51 can be selected automatically or manually. In the case of automatic selection, it is only necessary to select one pixel area 51 that exists closest to the center of the screen among the plurality of pixel areas 51 included in the image information 50.
  • the key input unit 43 accepts an input operation with user power, and the selection target pixel area 51 may be sequentially switched each time an input operation is detected.
  • each display unit 11 (A), (B) The image of (C) can be associated with the information to be transmitted.
  • the image is transmitted from the display unit 11 (C). Since only the information is extracted, the user can extract only the information desired by the image to be photographed, thereby improving usability and convenience.
  • the imaging unit 31 can capture a color image
  • the difference in the color components of each pixel area included in the image information 22 is used only for the data separation. It is also possible to do.
  • FIG. 10 is a block diagram showing the configuration of the visible light communication transmitter according to the second embodiment
  • FIG. 11 is a block diagram showing the configuration of the mobile terminal according to the second embodiment.
  • parts that are the same as those in the first embodiment are given the same reference numerals.
  • this visible light communication transmitter 10B includes a plurality of display units 11 (1) and 11 (2) and a transmission timing control unit.
  • each of the display units 11 (1) and 11 (2) modulates visible light and transmits data.
  • display corresponding to the contents of the data is performed.
  • a display using an LED can be used as each of the display portions 11 (1) and 11 (2).
  • the transmission timing control unit 15 controls the display timing of the plurality of display units 11 (1) and 11 (2) and the modulation timing based on visible light data. To do.
  • the display on each of the display units 11 (1) and 11 (2) is displayed by synchronizing the timing of switching the Z-off and the timing of starting modulation. It is possible to simplify the display of the unit 11 and the display of the transmitted data or the detection of the transmission timing, or omit one of them. This is because if the timing of switching on / off of the display is synchronized with the timing of starting modulation, the other side is detected by detecting either the timing of switching on / off of the display or the timing of starting modulation. This is because the timing is divided.
  • the transmission timing control unit 15 synchronizes the display timing of each of the plurality of display units 11 (1) and 11 (2) and the timing of modulation by visible light data, and at least By performing display and modulation at two or more display units at different timings, two or more data can be separated by the mobile terminal 30B on the receiving side.
  • the transmission timing control unit 15 sets the period of modulation by visible light data to be equal to or greater than the frame period of imaging in the imaging unit 31 of the mobile terminal 30B, thereby transmitting data transmitted from the plurality of display units 11. Separation becomes easy.
  • the timing may be controlled so that the same data is periodically transmitted at the same timing, and used for ambient lighting!
  • the timing may be controlled so that data is transmitted by modulating visible light at every timing when the power supply voltage of the commercial power supply becomes O (V). At that timing, the intensity of ambient illumination light becomes weaker, so the SZN of visible light communication can be improved.
  • Each data length adjusting unit 16 (1), 16 (2) performs the following control.
  • a pilot signal is added or data indicating a data length is added as a header.
  • the mobile terminal 30B shown in FIG. 11 includes an imaging unit 31, a visible light receiving unit 32B, a reception timing detecting unit 46, an associating unit 47, a display unit 42, and a data selecting unit 45. ing.
  • the visible light receiving unit 32B receives and demodulates the modulated visible light 21 coming from the visible light communication transmitting device 10B, and detects the received signal.
  • a photodetector can be used as the visible light receiver 32B.
  • the imaging unit 31 is a device that captures a two-dimensional image. In synchronization with the light receiving operation of the visible light receiving unit 32B, each display unit 11 (1), 11 (2 Take the picture with) as the subject.
  • the imaging unit 31 for example, a CCD camera can be used.
  • the reception timing detection unit 46 detects the modulation timing related to the visible light 21 received by the visible light receiving unit 32B or the transmission start Z end timing of the visible light 21. In addition, the reception timing detection unit 46 detects the switching timing of turning on / off the display in the visible light communication transmitting device 10B based on the image captured by the imaging unit 31.
  • the reception timing detection unit 46 includes the demodulated data of the visible light receiving unit 32B. By detecting the timing of the pilot signal or no signal data from the signal, the modulation timing of the visible light 21 can be detected.
  • a change in luminance is detected by detecting a pixel area composed of a set of pixels having a luminance equal to or higher than a predetermined value from an image captured by the imaging unit 31, and comparing the luminance between frames for each pixel area.
  • Power Visible light communication transmitter 10B display ON / OFF timing can be detected.
  • the associating unit 47 separates the reception information demodulated by the visible light receiving unit 32B at any timing detected by the reception timing detection unit 46, and separates the received information from the separated reception information and the imaging unit 31. Corresponds to the display taken by.
  • the original data is restored by recombining the received pieces of data. You can also. For example, if the data received at the same timing is different, the data until the same data arrives is recombined.
  • transmitting device 10B for visible light communication divides one data into a plurality of data of a predetermined length and transmits the data, a special pilot signal is transmitted so that the head position of the data is also determined on mobile terminal 30B side. I can grasp. In addition, by adding a header to the beginning of each data, the content of the header can be grasped. In addition, when adding dummy data to the transmitted data, the mobile terminal 30B removes unnecessary dummy data by including information on the dummy data in the header so that the original transmission data is included. Can be restored.
  • Display unit 42 simultaneously displays the contents of the reception information associated by association unit 47 and the image of the area representing the transmission source of the reception information on the screen.
  • the display unit 42 for example, a liquid crystal display can be used.
  • the data selection unit 45 is used to select data corresponding to one of a plurality of displays displayed on the display unit 42.
  • the data selection unit 45 for example, an input key that can be operated by the user can be used.
  • the display unit 42 and the data selection unit 45 can be omitted. If the display unit 42 is not provided, an output unit is provided that outputs the content of the reception information associated by the association unit 47, an image of an area representing the transmission source of the reception information, and at least a part thereof to the outside. It should be configured as follows. In addition, a voice output unit that converts the content of the received information into voice and outputs it may be provided instead of the display unit 42 or additionally.
  • the transmission device and the reception device, the transmission method, and the reception method of the present invention when a plurality of signals having different transmission powers are transmitted by visible light, the receiving station distinguishes the plurality of visible light signals. It is useful for electronic bulletin boards that can receive data and transmit data by visible light communication, and portable terminals that can receive data by visible light communication.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Optical Communication System (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

Cette invention a pour objet un appareil émetteur (10) comprenant une partie de commande des instants de transmission (14) qui module conformément à des informations de transport mutuellement indépendantes, les contenus d'affichage respectifs d'une pluralité de parties d'affichage et qui émet les informations de transport à des instants différents. Un terminal récepteur (30) comprend une partie de réception de lumière visible (32) qui reçoit des lumières visibles (21) provenant des parties d'affichage de l'appareil émetteur pour détecter les informations de transport; une partie de capture d'image (31) qui reçoit les lumières visibles sous la forme d'images bidimensionnelles; et une partie de commande de réception d'informations (36) qui sépare, sur la base de changements dans les lumières visibles reçues, les informations de transport détectées par la partie de réception de lumière visible (32) en une pluralité de composants d'informations et qui associe une pluralité de zones sur l'image capturée par la partie de capture d'image (31) aux composants d'informations respectifs de la pluralité de composants d'informations.
PCT/JP2006/313604 2006-07-07 2006-07-07 Appareil émetteur, appareil récepteur, procédé de transmission et procédé de réception WO2008004309A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/JP2006/313604 WO2008004309A1 (fr) 2006-07-07 2006-07-07 Appareil émetteur, appareil récepteur, procédé de transmission et procédé de réception

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2006/313604 WO2008004309A1 (fr) 2006-07-07 2006-07-07 Appareil émetteur, appareil récepteur, procédé de transmission et procédé de réception

Publications (1)

Publication Number Publication Date
WO2008004309A1 true WO2008004309A1 (fr) 2008-01-10

Family

ID=38894287

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2006/313604 WO2008004309A1 (fr) 2006-07-07 2006-07-07 Appareil émetteur, appareil récepteur, procédé de transmission et procédé de réception

Country Status (1)

Country Link
WO (1) WO2008004309A1 (fr)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003179556A (ja) * 2001-09-21 2003-06-27 Casio Comput Co Ltd 情報伝送方式、情報伝送システム、撮像装置、および、情報伝送方法
JP2005218066A (ja) * 2004-02-02 2005-08-11 Nakagawa Kenkyusho:Kk 位置情報通信装置
JP2005301519A (ja) * 2004-04-08 2005-10-27 Toyota Motor Corp 信号機検出装置および信号機検出方法
JP2005301518A (ja) * 2004-04-08 2005-10-27 Toyota Motor Corp 信号機検出装置および信号機検出方法
JP2006020294A (ja) * 2004-05-31 2006-01-19 Casio Comput Co Ltd 情報受信装置、情報伝送システム及び情報受信方法
JP2006092486A (ja) * 2004-09-27 2006-04-06 Nippon Signal Co Ltd:The Ｌｅｄ信号灯器
JP2006174149A (ja) * 2004-12-16 2006-06-29 Victor Co Of Japan Ltd 親機側光無線伝送装置

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003179556A (ja) * 2001-09-21 2003-06-27 Casio Comput Co Ltd 情報伝送方式、情報伝送システム、撮像装置、および、情報伝送方法
JP2005218066A (ja) * 2004-02-02 2005-08-11 Nakagawa Kenkyusho:Kk 位置情報通信装置
JP2005301519A (ja) * 2004-04-08 2005-10-27 Toyota Motor Corp 信号機検出装置および信号機検出方法
JP2005301518A (ja) * 2004-04-08 2005-10-27 Toyota Motor Corp 信号機検出装置および信号機検出方法
JP2006020294A (ja) * 2004-05-31 2006-01-19 Casio Comput Co Ltd 情報受信装置、情報伝送システム及び情報受信方法
JP2006092486A (ja) * 2004-09-27 2006-04-06 Nippon Signal Co Ltd:The Ｌｅｄ信号灯器
JP2006174149A (ja) * 2004-12-16 2006-06-29 Victor Co Of Japan Ltd 親機側光無線伝送装置

Similar Documents

Publication Publication Date Title
JP4739914B2 (ja) 通信装置、通信システム及び通信方法
CN104871452B (zh) 可视光通信方法及可视光通信装置
EP2940895B1 (fr) Procédé d'affichage vidéo
JP4939024B2 (ja) 光通信装置、及び光通信方法
JP4610511B2 (ja) 可視光受信装置および可視光受信方法
US20100054748A1 (en) Receiver and system for visible light communication
EP2795533B1 (fr) Appareil permettant de recevoir et de transmettre des informations optiques
US20120320262A1 (en) Device, system, and method for controlling light source to capture image
CN104081753B (zh) 不闪式可见光通信系统、发送装置、接收装置及通信方法
US11197064B2 (en) Display device, display control method, and program
JP6434724B2 (ja) 情報通信方法
Aoyama et al. Line scan sampling for visible light communication: Theory and practice
US20150028746A1 (en) Augmented reality graphical user interface for network controlled lighting systems
AU2010239556A1 (en) Lighting techniques for wirelessly controlling lighting elements
US9479723B2 (en) Display device, display control method, and program
WO2015137313A1 (fr) Procédé de réception de lumière visible
US20140361968A1 (en) Display device, display control method, and program
WO2014117557A1 (fr) Procédé et appareil de transmission d'un signal synchrone 3d et téléviseur 3d
CN107420826B (zh) 一种带有监控报警功能的照明系统
CN105187124B (zh) 一种基于背光调制的信息传输方法和装置
JP2011009803A (ja) 光無線通信装置、光無線通信携帯端末、送信装置、光無線通信方法、およびプログラム
JP2011009805A (ja) 光無線通信端末装置、光無線通信システム、光無線通信方法、およびプログラム
JP2007156170A (ja) 画像撮影システム
WO2008004309A1 (fr) Appareil émetteur, appareil récepteur, procédé de transmission et procédé de réception
US10511819B2 (en) Image projection system, projector, and method for controlling image projection system

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 06780879

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

NENP Non-entry into the national phase

Ref country code: RU

122 Ep: pct application non-entry in european phase

Ref document number: 06780879

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP