JP2011009803A - Optical wireless communication apparatus, optical wireless communication portable terminal, transmitter, optical wireless communication method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that a conventional optical wireless communication apparatus cannot precisely receive information transmitted from a light source for optical wireless communication.SOLUTION: An optical wireless communication apparatus includes a photographing section 101 for acquiring images by photographing at least one light source including an optical wireless communication light source, a light source detection section 102 for detecting images of light sources within the photographed images obtained by the photographing section 101, a light source selection section 103 for acquiring the position information of the images of the optical wireless communication light source from images of the light sources detected by the light source detection section 102, an information acquisition section 104 for acquiring information on an incidence position, namely a position on which light output from the optical wireless communication light source impinges from the position information of images of the optical wireless communication light source obtained by the light source selection section 103, and acquiring information to be transmitted, namely information transmitted from the optical wireless communication light source by optical wireless communication at an incidence position indicated by information on the incidence position, and an output section 105 for outputting information obtained by the information acquisition section 104.

Description

  The present invention relates to an optical wireless communication apparatus that receives information transmitted by optical wireless communication using light such as visible light.

  Conventionally, an LED light source for illumination, a power line for supplying power to the LED light source, information modulation means for modulating and multiplexing a plurality of pieces of information on the power line and superimposing them on a power waveform, and on the power line Broadcasting system having filter means for selectively separating one or more from a plurality of modulated information and controlling the light quantity or blinking of the LED light source, and transmitting information by changing or blinking the light quantity of the LED light source (For example, refer to Patent Document 1).

  In this broadcasting system, information transmitted by visible light communication is received using a light receiving terminal.

Japanese Unexamined Patent Publication No. 2004-147063 (first page, FIG. 1 etc.)

  However, in a situation where a light source that performs optical wireless communication such as visible light communication, a light source that does not perform optical wireless communication, and ambient light such as indirect illumination and natural light, etc. are mixed, When the information transmitted from the light source is received by optical wireless communication, the light receiving terminal cannot selectively receive only the light emitted from the light source that performs optical wireless communication. The light emitted by other light sources that are not performed is also received. For this reason, light emitted from a light source that does not perform optical wireless communication is received in a mixed manner with light emitted from a light source that performs optical wireless communication, so that information transmitted by optical wireless communication can be received with high accuracy. There was a problem that it was not possible.

  An optical wireless communication apparatus of the present invention includes an imaging unit that acquires an image by capturing one or more light sources including an optical wireless communication light source that is a light source that performs optical wireless communication, and a captured image that is an image acquired by the imaging unit. A light source position detection unit that detects a position of the optical wireless communication light source and obtains position information that is position information of the optical wireless communication light source, and a position information of the optical wireless communication light source acquired by the light source position detection unit. Information transmitted from the optical wireless communication light source by optical wireless communication at the position indicated by the communication light incident position information is obtained by acquiring communication light incident position information that is information on a position where light output from the wireless communication light source is incident. An optical wireless communication apparatus including an information acquisition unit that acquires transmission target information and an output unit that outputs information acquired by the information acquisition unit.

  With this configuration, it is possible to accurately receive information transmitted from a light source that performs optical wireless communication.

  In addition, the position of the optical wireless communication light source is detected by using an imaging unit capable of detecting the light receiving position and the like, and substantially visible light communication such as content information transmitted from the optical wireless communication light source. The position of the optical wireless communication light source is detected using the imaging unit by enabling the information acquisition unit including a photo detector or the like having a response speed faster than that of the imaging device to selectively receive the information to be subjected to Reception of information transmitted by optical wireless communication can be performed by the information acquisition unit. As a result, the position detection of the visible light wireless light source and the reception of information modulated at a high frequency transmitted by optical wireless communication can be made compatible, and as a result, the data transfer speed can be improved. it can.

  In the optical wireless communication apparatus of the present invention, in the optical wireless communication apparatus, the light source position detecting unit detects a light source in a captured image that is an image acquired by the imaging unit, and the light source detection An optical wireless communication apparatus comprising: a light source selecting unit that selects an optical wireless communication light source in a captured image from light sources detected by the unit and acquires position information of the selected optical wireless communication light source.

  With this configuration, it is possible to selectively receive only the light output from the optical wireless communication light source using the position information of the optical wireless communication light source.

  In the optical wireless communication apparatus according to the present invention, in the optical wireless communication apparatus, the light source selection unit is a light that is an image of a light source whose light intensity changes among light source images detected by the light source detection unit. It is an optical wireless communication device that acquires position information of an image of a wireless communication light source.

  With this configuration, the position of the optical wireless communication light source can be detected with high accuracy, and only the light output from the optical wireless communication light source can be selectively received.

  The optical wireless communication apparatus according to the present invention is an optical wireless communication apparatus in which the imaging unit includes an image sensor that is an image sensor.

  With this configuration, the position of the optical wireless communication light source can be accurately detected from the distribution of the intensity of light received by the image sensor.

  In the optical wireless communication apparatus of the present invention, in the optical wireless communication apparatus, the information acquisition unit includes a light receiving unit that receives light incident on a position indicated by the communication light incident position information and converts the light into an electrical signal. And an optical wireless communication apparatus that obtains transmission target information transmitted by optical wireless communication from the optical wireless communication light source at the position indicated by the communication light incident position information.

  With this configuration, it is possible to accurately receive information transmitted from a light source that performs optical wireless communication.

  In the optical wireless communication apparatus according to the present invention, in the optical wireless communication apparatus, the information acquisition unit includes an incident position information acquisition unit that acquires the communication light incident position information, and a communication acquired by the incident position information acquisition unit. A selective transmission unit that selectively transmits only light incident on a position indicated by light incident position information; a light receiving unit that receives light transmitted by the selective transmission unit and converts the light into an electrical signal; and An optical wireless communication apparatus comprising information acquisition means for acquiring information transmitted by optical wireless communication from a converted electrical signal.

  With this configuration, only light output from the optical wireless communication light source can be selectively received.

  The optical wireless communication apparatus of the present invention is the optical wireless communication apparatus, wherein the selective transmission means is a liquid crystal panel capable of controlling a light blocking area, and an area of the liquid crystal panel, and an incident position information acquiring means The optical wireless communication apparatus further includes a light shielding control unit that controls the liquid crystal panel so that a region other than the position indicated by the communication light incident position information acquired by the device is a light shielding region.

  With this configuration, only light output from the optical wireless communication light source can be selectively received. In addition, it is possible to flexibly form a transmission region according to the position and size of light incident from the optical wireless communication light source. Further, the position of the light-shielding area can be changed simply by changing the light-shielding pattern of the liquid crystal, and the position of the transmission area can be changed easily and at high speed. In addition, failure due to wear or the like can be reduced by eliminating physical moving parts.

  The optical wireless communication apparatus of the present invention is the optical wireless communication apparatus, wherein the light receiving means is a photo detector.

  With such a configuration, it is possible to respond at high speed to a change in the intensity of light from a light source that performs optical wireless communication, and it is possible to receive information modulated at a high frequency. As a result, the data transmission speed can be improved.

  Further, in the optical wireless communication apparatus of the present invention, in the optical wireless communication apparatus, the light source position detection unit repeatedly acquires position information of an image of the optical wireless communication light source in the captured image, and the information acquisition unit Each time the light source position detection unit acquires the position information of the optical wireless communication light source, the communication light incident position information is acquired and transmitted from the optical wireless communication light source by optical wireless communication at the position indicated by the communication light incident position information. This is an optical wireless communication apparatus that acquires transmission target information that is information to be transmitted.

  With this configuration, it is possible to accurately receive the light transmitted from the optical wireless communication light source following the change in the position of the optical wireless communication light source.

  The optical wireless communication apparatus of the present invention is a selection instruction that is an instruction to select any one of the position information of the plurality of optical wireless communication light sources detected by the light source position detection unit in the optical wireless communication apparatus. The information acquisition unit acquires the communication light incident position information corresponding to the position information of the optical wireless communication light source specified by the selection instruction received by the selection instruction reception unit. An optical wireless communication apparatus that acquires transmission target information that is information transmitted by optical wireless communication from the optical wireless communication light source at a position indicated by the communication light incident position information.

  With this configuration, it is possible to selectively receive information transmitted from one of the plurality of optical wireless communication light sources.

  The transmission device of the present invention includes a transmission target information acquisition unit that acquires transmission target information that is information to be transmitted by optical wireless communication, and a modulation unit that modulates the transmission target information acquired by the transmission target information acquisition unit. Information that is used to detect the position of a light source that performs optical wireless communication, the marker signal output unit outputting a marker signal having a frequency different from the frequency at which the modulation unit performs modulation, and the modulation unit outputting Transmission comprising: a superimposing unit that superimposes transmission target information to be transmitted and a marker signal output from the marker signal output unit; and a transmission unit that transmits information including the transmission target information and the marker signal superimposed by the superimposing unit. Device.

  With this configuration, it is possible to determine whether the light source that performs optical wireless communication using transmitted information is a light source that performs optical communication by detecting a marker signal having a frequency different from that of the transmission target information. It can be easily determined whether or not the light source is a light source that performs optical wireless communication.

  According to the optical wireless communication apparatus and the like according to the present invention, it is possible to accurately receive information transmitted from a light source that performs optical wireless communication.

The figure for demonstrating the structure of the visible light communication apparatus in this Embodiment Flow chart for explaining the operation of the visible light communication apparatus Flow chart for explaining the operation of the visible light communication apparatus The figure for demonstrating the marker signal of the visible light communication apparatus Schematic diagram for explaining a specific example of the visible light communication device The figure which shows an example of the picked-up image for demonstrating operation | movement of the visible light communication apparatus The figure which shows the example which binarized the picked-up image for demonstrating operation | movement of the visible light communication apparatus The figure which shows an example of the light source coordinate management table | surface for demonstrating operation | movement of the visible light communication apparatus The figure which shows an example of the visible light communication light source management table | surface for demonstrating operation | movement of the visible light communication apparatus The figure which shows the permeation | transmission area | region of a liquid crystal panel for demonstrating operation | movement of the visible light communication apparatus The figure which shows the state in which the light which permeate | transmitted the liquid crystal panel is received for demonstrating operation | movement of the visible light communication apparatus The figure which shows an example of the basic information which the visible light communication apparatus received The figure which shows an example of a display of the visible light communication apparatus The figure which shows an example of a display of the visible light communication apparatus Block diagram showing the configuration of the transmitter Schematic diagram showing an example of the external appearance of the computer system The figure which shows an example of a structure of the computer system

  Hereinafter, embodiments of an optical wireless communication apparatus and the like will be described with reference to the drawings. In addition, since the component which attached | subjected the same code | symbol in embodiment performs the same operation | movement, description may be abbreviate | omitted again.

(Embodiment)
FIG. 1 is a diagram for explaining a configuration of a visible light communication apparatus according to the present embodiment.

  Visible light communication is an apparatus that transmits data by changing the intensity of light emitted from a light source in accordance with a signal obtained by modulating data to be transmitted. In other words, it is a technique for transmitting information by fluctuations in light intensity. Note that this variation in light intensity is a concept including blinking of light. However, the blinking of light here may be considered as a change in light intensity. Here, a light source that performs visible light communication is referred to as a visible light communication light source. In the present embodiment, the visible light communication light source is preferably an LED light source. In addition, in order to prevent a false detection in which a light source other than a visible light communication light source is erroneously detected as a visible light communication light source, a light source other than a visible light communication light source is also a light source with little flickering, for example, other than a fluorescent lamp. An LED light source or an incandescent lamp is preferred. Since the visible light communication technique such as a configuration for transmitting information via the visible light communication light source is a known technique, a detailed description thereof will be omitted.

  The visible light communication device 1 includes an imaging unit 101, a light source position detection unit 102, an information acquisition unit 103, an output unit 104, a selection instruction reception unit 105, a first lens 201, and a beam splitter 202. The visible light communication device 1 is a device that receives information transmitted from a light source that performs visible light communication.

  The imaging unit 101 includes an image sensor 1011 and image processing means 1012.

  The light source position detection unit 102 includes a light source detection unit 1021 and a light source selection unit 1022.

  The information acquisition unit 103 includes incident position information acquisition means 1031, selective transmission means 1032, light receiving means 1033, information acquisition means 1034, and the second lens 203.

  The selective transmission means 1032 includes a liquid crystal panel 10321 and a light shielding control means 10322.

  The first lens 201 is a condensing unit that condenses the light emitted from the subject and the light reflected from the subject and makes the light enter the visible light communication apparatus 1. Specifically, the light condensed by the first lens 201 is incident on the photographing unit 101. Instead of the first lens 201, other condensing means such as a concave mirror may be provided. The first lens 201 is preferably a lens having a wide angle of view in order to photograph a subject in a wide area at a time.

  The beam splitter 202 transmits the light incident through the first lens 201 to be incident on the photographing unit 101, and further reflects the incident light to be incident on the information acquisition unit 103 described later. Specifically, the beam splitter 202 causes the transmitted light to enter the image sensor 1011. The beam splitter 202 inputs the reflected light to the selective transmission means 1032 of the information acquisition unit 103 described later, more specifically, the liquid crystal panel 10321. Here, the half mirror is also considered as one of the beam splitters 202. In the present embodiment, a structure is provided that allows light incident through the first lens 201 to be incident on both the imaging unit 101 and the information acquisition unit 103 simultaneously or by switching. If so, a configuration other than the beam splitter 202 may be provided. For example, light that is incident through the first lens 201 is provided by providing a flip-up type mirror used for a so-called single-lens reflex camera or the like instead of the beam splitter 202 and controlling the timing of the mirror's flip-up. May be switched and made incident on both the imaging unit 101 and the information acquisition unit 103. In addition, the positional relationship among the imaging unit 101, the information acquisition unit 103, and the first lens 201 is relatively moved, and the imaging unit 101 and the information acquisition unit 103 are switched and arranged on the optical axis of the first lens 201. You may be able to do it.

  The imaging unit 101 captures one or more light sources including a visible light communication light source that is a light source that performs visible light communication, and acquires an image. Here, the acquired image captured by the imaging unit 101 is referred to as a captured image. The imaging unit 101 captures one or more light sources including a visible light communication light source via the first lens 201, and acquires information on an image obtained by capturing the one or more light sources. In addition, light sources other than a visible light communication light source are light sources, such as normal illumination in which information is not transmitted using light. The captured image may be a color image as long as the position of the light source that performs visible light communication can be detected by the light source position detection unit 102 described later, or an image having two or more gradations, for example, a grayscale image. Alternatively, it may be an image representing only the brightness of the image. The photographing unit 101 may photograph a still image or a photographed image that is a moving image composed of a plurality of frames. The moving image described here is a concept that includes a plurality of still images taken continuously in time series. In this embodiment, the configuration of the imaging unit 101 will be described by taking as an example a case where the imaging unit 101 includes the image sensor 1011 and the image processing unit 1012. The imaging unit 101 can usually be realized by an imaging device, a GPU (Graphics Processing Unit), an MPU, a memory, or the like. The processing procedure of the photographing unit 101 is usually realized by software, and the software is recorded on a recording medium such as a ROM. However, it may be realized by hardware (dedicated circuit).

  The image sensor 1011 outputs an electrical signal corresponding to the incident light. The imaging element 1011 is an element configured by arranging a plurality of light receiving elements (not shown). The image sensor is a so-called image sensor. The image sensor 1011 is, for example, a CCD or a CMOS. The image sensor 1011 converts incident light into an electric signal corresponding to the intensity of the light, and outputs an electric signal whose waveform changes according to a change in the intensity of the incident light. Specifically, each light receiving element constituting the image sensor 1011 outputs an electrical signal corresponding to the intensity of the incident light, and as a result, the image sensor 1011 is incident on the light receiving surface of the image sensor. An electrical signal corresponding to the distribution of the intensity of the emitted light is output. In general, the image sensor 1011 can extract only an electric signal obtained by a light receiving element in a desired region according to the received light. In the present embodiment, light emitted from the visible light communication light source is collected by the first lens 201 and is incident on the image sensor 1011. A color filter such as RGB is usually provided on the incident surface of the image sensor 1011, and the color image is finally selected by selecting the color of light incident on each light receiving element by the color filter. Is configurable. However, the color filter may be omitted as necessary in the structure of the image sensor 1011 and the light source detection. The color filter may be changed to a filter that transmits only light of a specific wavelength.

  The image processing unit 1012 receives an electrical signal output from the image sensor 1011 and configures a captured image. Specifically, the electrical signal output from the image sensor 1011 is demodulated and converted into a digital signal or the like to constitute information of the captured image. The image configured by the image processing unit 1012 is, for example, a moving image including one or more still images and a plurality of frames. The file format of the image that the image processing unit 1012 configures is not limited. The image processing unit 1012 temporarily stores information on the configured image in a storage medium such as a memory (not shown). The image processing unit 1012 can be realized by, for example, a DSP (Digital Signal Processor), a GPU, a memory, or the like. The processing procedure of the image processing means 1012 is usually realized by software, and the software is recorded on a recording medium such as a ROM. However, it may be realized by hardware (dedicated circuit).

  The light source position detection unit 102 detects a visible light communication light source in a captured image that is an image acquired by the imaging unit 101. And the positional information which is the information of the position of the detected visible light communication light source is acquired. The position of the visible light communication light source described here is the position of all or some of the pixels included in the image of the visible light communication light source in the captured image, or the region where the image of the visible light communication light source in the captured image exists. The position of the center point, the position of the outline of the area, the position representing the area such as each corner, and the like. The position information acquired by the light source position detection unit 102 is, for example, information on coordinates in the captured image indicating the position of the detected visible light communication light source. The unit of the coordinate information is, for example, a pixel unit or a relative value with respect to the vertical or horizontal length of the captured image. Further, information indicating the position in the image sensor 1011 corresponding to the coordinates in the photographed image, that is, the image sensor 1011 serving as the output source of the electrical signal used to obtain the pixel at the position indicated by the coordinates in the photographed image. Information indicating a position, for example, coordinate information may be used.

  For example, the light source position detection unit 102 detects the positions of all the light sources including the visible light communication light source in the captured image. Then, it is determined whether each detected light source is a light source whose light intensity varies. If the light intensity varies, the detected light source is determined as a visible light communication light source, and the detected light source Is obtained as position information of the visible light communication light source. The light source position detection unit 102 may detect the visible light communication light source by a method other than the above. For example, a visible light communication light source emits light of a predetermined color different from other light sources, and a region where pixels close to this color exist in a captured image is searched and searched. The position indicating the area may be detected as the position of the area of the visible light communication light source. The light of a predesignated color includes light from which a color of a specific wavelength is excluded. In addition, a marker indicating that the visible light communication light source has been specified in advance, on the surface of the visible light communication light source or in the vicinity thereof, is provided in advance, and the specified shape is obtained by pattern matching or the like. A process for detecting a matching shape may be executed in the captured image, and a matching image or a region where a pixel with high luminance in the vicinity thereof is present may be detected as a visible light communication light source. This marker is preferably a marker having a color that is easy to detect, such as a red LED. Alternatively, the shape or arrangement of the visible light communication light source is designated in advance, the shape matching the designated shape or arrangement is detected in the captured image by pattern matching or the like, and the region of the matching shape is You may judge that it is a visible light communication light source. In the case where the visible light communication light source performs visible light communication by turning on and off the light completely, when a moving image is used as a captured image used for detecting the position of the visible light communication light source, the captured image is not necessarily displayed. Since not all frames contain an image of a visible light communication light source, even if the above visible light communication light source is detected for one frame image, the visible light communication light source is not necessarily detected reliably. It is not always possible. Therefore, the visible light communication light source is detected with the color and shape as described above for each of the plurality of frames, and all the information on the position where the visible light communication light source is detected at least once is used as the position information of the visible light communication light source. It is preferable to obtain. That is, it is preferable to obtain the logical sum of the position information of the visible light communication light source acquired from each of the plurality of frame images. Alternatively, the position information of the visible light communication light source may be acquired from an image obtained by combining a plurality of frames of a moving image in advance. When a still image is used as a captured image, it is preferable to use a still image captured with an exposure time sufficiently longer than the on / off cycle of the light source for visible light communication. In addition, it is preferable that the light source position detection unit 102 continuously and repeatedly acquires the position information of the image of the visible light communication light source in the captured image, and constantly updates the position information to the latest information. By doing in this way, even if the position of the visible light communication device 1 is changed due to movement or the like, it is possible to always obtain accurate position information of the visible light communication light source. The light source position detection unit 102 can be usually realized by an MPU, a memory, or the like. The processing procedure of the light source position detection unit 102 is usually realized by software, and the software is recorded on a recording medium such as a ROM. However, it may be realized by hardware (dedicated circuit).

  In the present embodiment, the case where the position information of the visible light communication light source is acquired from the captured image using the light source detection unit 1021 and the light source selection unit 1022 included in the light source position detection unit 102 will be described as an example. To do.

  Here, the visible light communication light source superimposes transmission target information that is information to be transmitted by visible light communication and a marker signal that is a signal used to detect the position of the visible light communication light source. Information is sent. The marker signal is a signal having a predetermined frequency and a value whose value fluctuates in a predetermined pattern. The marker frequency is usually binary data in which a predetermined pattern is repeated at a predetermined cycle. Here, the frequency of the marker signal is referred to as a marker frequency. Assume that the marker frequency is a frequency at which the image sensor 1011 can also acquire information. On the other hand, the transmission target information transmitted by visible light communication may be information having a frequency higher than the frequency that can be received by the image sensor 1011 as long as the light receiving unit 1033 described below can receive light. In addition, here, the light output from the visible light communication light source transmits information due to fluctuations in the intensity of light, and is normally turned on when information is transmitted.

  The light source detection unit 1021 detects a light source in a captured image that is an image acquired by the imaging unit 101. The light source to be detected here is a light source including a visible light communication light source and a light source other than the visible light communication light source. Specifically, an area with high luminance is detected from a captured image captured by the image sensor 1011. When the captured image is a color image, the luminance described here may be a luminance for a specific color, for example, a blue luminance. Further, a color region in a specific range may be detected. The areas detected in this way are areas determined as all light sources including the visible light communication light source in the captured image. For example, the light source detection unit 1021 determines that an area in which a high-luminance pixel in the captured image, for example, a pixel having a luminance value equal to or higher than the threshold exists adjacent to the number of pixels specified in advance is a light source. You may do it. The light source detection unit 1021 may detect the position of the light source by other methods. For example, when the area of a color specified in advance, for example, the color of light emitted from the light source is known in advance, by specifying this color, the area where pixels close to this color in the photographed image exist can be used as the light source. It can be determined that there is. Alternatively, when the shape of the light source can be specified, the light source may be detected from the captured image by pattern matching of the shape of the light source. The light source detection unit 1021 can be usually realized by an MPU, a memory, or the like. The processing procedure of the light source detection means 1021 is usually realized by software, and the software is recorded on a recording medium such as a ROM. However, it may be realized by hardware (dedicated circuit).

  The light source selection unit 1022 selects a visible light communication light source in the photographed image from among the light sources detected by the light source detection unit 1021, and acquires position information of the selected visible light communication light source. Normally, the visible light communication light source changes the light intensity in a short time to perform visible light communication, but other light sources often have almost no light intensity fluctuation. Accordingly, if the light source other than the visible light communication light source is a light source such as an LED light source whose light intensity does not vary with time, the light intensity of the light source captured in the captured image varies. The light source is a visible light communication light source. For this reason, the light source selection unit 1022 acquires the position information of the image of the visible light communication light source, which is the image of the light source whose light intensity varies with time, among the light source images detected by the light source detection unit 1021. Good.

  Here, the response speed of the image sensor 1011 which is an image sensor such as a CCD or CMOS is slower than that of a photodetector or the like, and the frequency of the electric signal detectable from the electric signal output from the image sensor 1011 is currently about 100 KHz. Thus, it is not possible to detect fluctuations in the electrical signal having a frequency of about 100 MHz as in the case of using a photodetector with a high response speed. Therefore, in the case where transmission target information modulated at a high frequency is transmitted by visible light communication in order to increase the bandwidth of visible light communication, the image processing means 1012 is used to transmit only the transmission target information. It is difficult to detect fluctuations in light intensity from light of optical communication. For this reason, the marker signal described above having a relatively low frequency is superimposed on information to be transmitted by visible light communication and transmitted from the visible light communication light source. This marker signal can also be detected from an electrical signal output from the image sensor 1011 having a slow response speed. For this reason, a marker frequency signal, that is, a signal having the same frequency as the marker signal is separated and extracted from the electrical signal output from the image sensor 1011 according to the light transmitted from each light source, and the value of this signal varies. By determining whether or not the signal is a marker signal, it is possible to determine whether or not the light source is a visible light communication light source that transmits information superimposed with the marker signal by visible light communication.

  Specifically, the light source selection unit 1022 includes a light receiving element (not shown) included in an area in the image sensor 1011 corresponding to one of the areas that the light source detection unit 1021 determines to be a light source. An electric signal output in response to the incidence of light is continuously acquired for a predetermined time. The electric signal output from the light receiving element included in the region corresponding to the light source in the imaging element 1011 may be a value obtained by adding the electric signal output from one or more light receiving elements included in the region, The average value of the electrical signals output by the light receiving elements may be used. At this time, if one region is a visible light communication region, the obtained electrical signal is a signal of information obtained by superimposing transmission target information and a marker signal as described above. Then, the light source selection unit 1022 extracts marker frequency information from the electrical signal continuously acquired from one region.

  The light source selection unit 1022 acquires a predetermined number of voltage values at a predetermined sampling period from the extracted marker frequency information, and determines whether or not the acquired voltage values have changed. For example, it is determined whether the difference between the maximum value and the minimum value of the acquired voltage is equal to or greater than a threshold value. If the difference is equal to or greater than the threshold value, it is determined that fluctuation has occurred. Judge. When it is determined that fluctuation has occurred, for example, when the difference between the maximum value and the minimum value is greater than or equal to the threshold value, it can be considered that the electrical signal acquired from one region includes a marker signal. , It is determined that one region is a light source for visible light communication. Conversely, if no fluctuation occurs, it is determined that the light source is another light source whose light intensity does not change. Then, by performing the same processing for other regions that the light source detection unit 1021 determines to be light sources, it is possible to determine whether each light source captured in the captured image is a visible light communication light source. it can. Then, the light source selection unit 1022 acquires information indicating the position of the light source determined to be the visible light communication light source in the captured image as the position information of the visible light communication light source. In addition, instead of acquiring information indicating the position of the light source determined to be the visible light communication light source in the captured image as the position information of the visible light communication light source, the image sensor 1011 is the visible light communication light source. You may make it acquire the information which shows the position of the area | region which receives the light which injects from the determined light source as positional information on a visible light communication light source.

  In order to reliably detect the marker signal by a predetermined number of times of sampling, the frequency and pattern of the marker signal may be determined based on the relationship between the marker signal and the sampling period as described below, for example.

  FIG. 4 is a schematic diagram showing the relationship between the marker signal and the sampling period. In the figure, a sampling period 41 indicates the timing for sampling. Here, sampling is performed at regular time intervals. The marker signals 42a to 42j are signals having binary values “H” and “L”, respectively. Here, “H” is indicated by diagonal lines, and “L” is indicated by plain color. Here, the sampling period 41 is set to “1”, and the ratio of the period of the marker signals 42 a to 42 j and the period in which the binary value that is the pattern of the marker signals 42 a to 42 j appears is represented. For example, the marker signal 42a is a signal whose frequency is 1/3 of the sampling period 41, the period of “H” is 1/3, and the period of “L” is 2/3. The marker signal 42b is a signal whose frequency is 1/3 of the sampling period 41, the period of “H” is 1/3, and the period of “L” is 1/3. The marker signal 42c is a signal whose frequency is ½ of the sampling period 41, the “H” period is ½, and the “L” period is 1.

  For example, in the marker signal 42a, when sampling is performed at the sampling period 41, only one data is always detected, for example, “H” only. For this reason, when the marker signal 42a is used, it is not possible to detect a marker signal that is a signal whose value varies. On the contrary, in the marker signal 42b, when sampling is performed at the sampling period 41, signals of “H” and “L” are detected alternately. For this reason, when the marker signal 42a is used, if the signal extracted at the marker frequency is a signal whose value fluctuates, the marker signal is detected. Therefore, the light source position detection unit 102 can determine whether the light source is a visible light communication light source. In order to reliably detect the marker signal by sampling a predetermined number of times, the sampling period may be changed. The light source selection unit 1022 can usually be realized by an MPU, a memory, or the like. The processing procedure of the light source selection unit 1022 is usually realized by software, and the software is recorded on a recording medium such as a ROM. However, it may be realized by hardware (dedicated circuit).

  When the image captured by the imaging unit 101 is a moving image composed of a plurality of frame images, the light source position detection unit 102 uses the marker information as described above to perform visible light communication as follows. The position of the light source may be detected.

  First, the light source detection unit 1021 detects a region with high luminance from one frame image of a captured image captured by the image sensor 1011.

  Next, the light source selection unit 1022 sequentially acquires the luminance value for each of the detected high luminance regions for the subsequent plurality of frame images. And it is judged whether the fluctuation | variation beyond the threshold value designated beforehand has arisen in the acquired luminance value. For example, it is determined whether the difference between the maximum value and the minimum value of the acquired luminance values is greater than or equal to a threshold value. And when the fluctuation | variation has arisen, it determines that one area | region is a light source of visible light communication from which the intensity | strength of light changes. Conversely, if no fluctuation occurs, it is determined that the light source is other. And the information which shows the position of the light source determined to be the visible light communication light source in the picked-up image is acquired as the position information of the visible light communication light source.

  In the case of detecting the position of the visible light communication light source from the frame image in this way, the marker is used so that the change in the luminance of the visible light communication light source can be reliably detected using a plurality of frame images, as described above. The pattern and frequency at which the signal value changes must be set in accordance with the frame rate of the captured image. In this case, it may be considered that the frame rate is the sampling rate described above.

  The information acquisition unit 103 acquires communication light incident position information, which is information on a position where light output from the visible light communication light source is incident, from the position information of the visible light communication light source acquired by the light source position detection unit 102. Transmission target information, which is information transmitted by visible light communication from the visible light communication light source at the position indicated by the communication light incident position information, is acquired. Specifically, the information acquisition unit 103 indicates a correspondence relationship between a region where light having passed through the first lens 201 is incident on the information acquisition unit 103 and a captured image obtained by photographing the light having passed through the first lens 201. Information is stored in a storage medium or the like in advance, and the information acquisition unit 103 corresponding to the position information of the visible light communication light source in the captured image acquired by the light source position detection unit 102 using the information indicating the correspondence relationship. Information on a position on an area where light having passed through the first lens 201 is incident is acquired. Then, only light incident on the acquired position is selectively received, and transmission target information is acquired from the received light. Specifically, the region where light having passed through the first lens 201 of the information acquisition unit 103 is incident is a region where light of a liquid crystal panel 10321 described later is incident. In addition, the information acquisition unit 103 receives light output from the visible light communication light source every time the light source position detection unit 102 acquires the position information of the visible light communication light source or the position information changes, for example. Communication light incident position information, which is information indicating the position, is acquired, and transmission target information transmitted from the visible light communication light source is acquired at the position indicated by the communication light incident position information.

  When the light source position detection unit 102 acquires communication light incident position information corresponding to two or more visible light communication light sources, the information acquisition unit 103 receives two or more selection instruction reception units 105 described later. Communication light incident position information corresponding to the position information of the visible light communication light source specified by the selection instruction, which is an instruction to select any one of the position information of the visible light communication light source, is obtained. What is necessary is just to acquire the transmission object information transmitted by visible light communication from the visible light communication light source at the position indicated by the information. Alternatively, the transmission target information may be alternately acquired at a specific timing or an unspecified predetermined timing at two or more positions indicated by communication light incident positions corresponding to two or more visible light communication light sources.

  Here, the information acquisition unit 103 selectively uses the incident position information acquisition unit 1031, the selective transmission unit 1032, the second lens 203, the light receiving unit 1033, and the information acquisition unit 1034 to selectively transmit light transmitted from the visible light communication light source. The process of receiving light and acquiring the transmission target information transmitted from the visible light communication light source will be described below.

  The incident position information acquisition unit 1031 is a visible light communication light source in a region where light output from the visible light communication light source of the information acquisition unit 103 is incident based on the position information of the visible light communication light source acquired by the light source position detection unit 102. The communication light incident position information, which is information on the position where the light output from is incident, is acquired. Specifically, the photographed image photographed by the photographing unit 101 and the shape of the region where the light that has passed through the first lens 201 in the information acquisition unit 103 is similar have a similar relationship, and the coordinate axes of both are the first lens. If it is set to be in the same direction with respect to an image incident through 201, the coordinate information of the visible light communication light source of the photographed image is used by using the similarity ratio between the photographed image and the light incident region. Communication light incident position information, which is coordinate information of a position where light from a visible light communication light source is incident in a region where light having passed through the first lens 201 in the information acquisition unit 103 is incident, is acquired from the position information. . For example, when the position information is coordinate information, when the similarity ratio is 1: 1, the incident position information acquisition unit 1031 uses the coordinate information of the visible light communication light source in the captured image acquired by the light source position detection unit 102. As it is, the information acquisition unit 103 acquires the information as the coordinate information which is the information on the incident position in the region where the light is incident. In addition, when the similarity ratio between the captured image and the light incident area is 2 to 1, the values of the x-axis and y-axis of the coordinate information of the visible light communication light source in the captured image are each halved. The coordinate information is acquired as coordinate information that is information on an incident position in the region where light is incident in the information acquisition unit 103. That is, when the similarity ratio between the captured image and the light incident area is n (n is an arbitrary positive number) to 1, the x-axis and y-axis of the coordinate information of the visible light communication light source in the captured image The coordinate information whose value is 1 / n is acquired as coordinate information that is information on the incident position in the region where light is incident in the information acquisition unit 103. In addition, information that associates one or more pixels in the captured image with information indicating the position of a region where light is incident in the information acquisition unit 103, for example, coordinate information, is managed in advance. From the information, information indicating the position in the region where the light is incident in the information acquisition unit 103 corresponding to the pixel in which the visible light communication light source is detected in the captured image may be acquired as the communication light incident position information. . In the present embodiment, as will be described later, a case where the region where light that has passed through the first lens 201 of the information acquisition unit 103 is incident is a liquid crystal panel 10321 will be described as an example. For this reason, instead of using the coordinate information in the liquid crystal panel 10321 as the communication light incident position information, information specifying a pixel (not shown) in the liquid crystal panel 10321, for example, an ID or a number of the pixel may be used. . For example, information in which one or more pixels in the captured image are associated with one or more pixels in the liquid crystal panel 10321 is managed in advance, and the visible light communication light source in the captured image is determined based on the associated information. Information specifying the pixel of the liquid crystal panel 10321 corresponding to the detected pixel may be acquired. In addition, when the captured image captured by the imaging unit 101 and the shape of the region where the light that has passed through the first lens 201 in the information acquisition unit 103 is not completely similar, acquisition is performed according to the difference in shape. What is necessary is just to correct | amend position information. Note that the position information of the visible light communication light source acquired by the light source position detection unit 102 is position information of a part of the visible light communication light source such as the position information of the center position of the visible light communication light source in the captured image. In this case, the incident position information acquisition unit 1031 sets the area including the area around the position corresponding to the position information in the area where the light is incident in the information acquisition unit 103 as the communication light incident position. May be. Here, when the light source position detection unit 102 acquires the position information of two or more visible light communication light sources, the position information of one visible light communication light source corresponding to the selection instruction received by the selection instruction reception unit 105 described later. Communication light incident position information corresponding to may be acquired. Thereby, it is possible to acquire visible light communication information only from the visible light communication light source designated in the selection instruction. Alternatively, communication light incident position information corresponding to position information of two or more visible light communication light sources may be alternately configured at specific or unspecified predetermined timing. Thereby, information from two or more visible light communication light sources can be acquired alternately. The incident position information acquisition unit 1031 can be usually realized by an MPU, a memory, or the like. The processing procedure of the incident position information acquisition unit 1031 is usually realized by software, and the software is recorded on a recording medium such as a ROM. However, it may be realized by hardware (dedicated circuit).

  The selective transmission means 1032 selectively transmits only the light incident on the position indicated by the communication light incident position information acquired by the incident position information acquisition means 1031 among the light incident through the first lens 201. Specifically, the selective transmission means 1032 includes a filter, a diaphragm, or the like that can form a region that can transmit light only in an arbitrary region within the region where the light having passed through the first lens 201 is incident. By controlling the filter and the diaphragm, an area where light can be transmitted is formed only at the position indicated by the incident position information acquired by the incident position information acquiring unit 1031. Here, a case where the selective transmission means 1032 includes the liquid crystal panel 10321 and the light shielding control means 10322 and the above processing is performed using these will be described.

  The liquid crystal panel 10321 changes the orientation of the liquid crystal by applying a voltage to the liquid crystal with a plurality of arranged electrodes, and controls whether to transmit light for each segment provided with the electrode, thereby transmitting light. The shape of the area to be controlled can be controlled. Here, for example, a liquid crystal panel in which segments are arranged in a lattice shape is used. This segment is called a pixel here. The liquid crystal panel 10321 may be a color liquid crystal panel such as an RGB color, or a binary or gray scale liquid crystal panel such as black and white. The liquid crystal panel 10321 only needs to be able to display two colors, a color that allows light to pass through and a color that does not allow light to pass, and the number of gradations that can be displayed only needs to be two or more. By using a color liquid crystal panel as the liquid crystal panel 10321, the color of the region through which light is transmitted can be set to an arbitrary color, for example, blue. By doing in this way, it becomes possible to permeate | transmit only the arbitrary colors of the light from a visible light communication light source, for example, only blue. The liquid crystal panel 10321 is disposed at a position where light having passed through the first lens 201 is incident.

  The light blocking control unit 10322 controls the liquid crystal panel 10321 so that a region other than the incident position indicated by the incident position information acquired by the incident position information acquiring unit 1031 of the liquid crystal panel 10321 is a region that blocks light. In this case, the incident position information acquired by the incident position information acquiring unit 1031 is preferably information that can specify one or more pixels of the liquid crystal panel 10321. Specifically, a control signal for controlling each pixel of the liquid crystal panel 10321 is output to the liquid crystal panel 10321, and the pixel of the liquid crystal panel 10321 corresponding to the communication light incident position acquired by the incident position information acquisition unit 1031 transmits light. The liquid crystal panel 10321 is controlled so as to be a possible pixel and pixels in other regions to be pixels that block light. As a result, only the light input to the communication light incident position out of the light incident on the liquid crystal panel 10321 through the first lens 201, that is, only the light from the visible light communication light source is transmitted through the liquid crystal panel 10321. Become. A transmissive pixel is a pixel that can transmit light from visible light communication. The transmissive pixel may be, for example, a pixel that is transparent or translucent, or may be a pixel that transmits only a specific color of light. For example, when the liquid crystal panel 10321 is a color liquid crystal panel such as an RGB liquid crystal panel, the pixel corresponding to the communication light incident position acquired by the incident position information acquiring unit 1031 of the liquid crystal panel 10321 is a blue pixel, and other regions By making the color black or the like, only blue light can be selectively transmitted from the pixel position corresponding to the communication light incident position. The shading control means 10322 can be usually realized by an MPU, a memory, or the like. The processing procedure of the shading control means 10322 is usually realized by software, and the software is recorded on a recording medium such as a ROM. However, it may be realized by hardware (dedicated circuit).

  The second lens 203 is a condensing unit that condenses the light transmitted through the selective transmission unit 1032, specifically, the liquid crystal panel 10321 and makes it incident on the light receiving unit 1033. The second lens 203 needs to be installed so that light transmitted through any position of the selective transmission means 1032, specifically, the liquid crystal panel 10321 is incident on the light receiving means 1033. Instead of the second lens 203, other condensing means such as a concave mirror may be provided. Further, when the light transmitted through the selective transmission unit 1032 can be incident on the light receiving unit 1033 without being condensed, such as when the size of the light receiving unit 1033 is sufficiently large, the second lens 203 can be omitted. is there.

  The light receiving means 1033 receives light incident on the incident position indicated by the incident position information and converts it into an electrical signal. Specifically, light selectively extracted by the selective transmission unit 1032, specifically, the liquid crystal panel 10321 is collected by the second lens 203 and is incident on the light receiving unit 1033. The light receiving means 1033 converts the intensity of the incident light in this way into an electric signal. The light receiving means 1033 is a light receiving element having a high response speed, specifically a photodetector. The light receiving means 1033 may be composed of a plurality of photodetectors as long as it functions as a single photodetector. By using one photodetector as the light receiving means 1033, light can be converted into an electrical signal at high speed, and visible light communication light that fluctuates at high speed can be received with high accuracy.

  The information acquisition unit 1034 acquires information transmitted by visible light communication from the electrical signal converted by the light receiving unit 1033. For example, the information acquisition unit 1034 demodulates the electrical signal converted by the light receiving unit 1033 at a predetermined frequency specified in advance, and extracts information. Further, AD conversion or the like may be appropriately performed on the extracted information. The configuration and the like of the information acquisition unit 1034 are the same as the information acquisition unit and the like used in a receiving terminal of a normal visible light communication system, and thus detailed description thereof is omitted. The information acquisition unit 1034 can usually be realized by an MPU, a memory, or the like. The processing procedure of the information acquisition unit 1034 is usually realized by software, and the software is recorded on a recording medium such as a ROM. However, it may be realized by hardware (dedicated circuit).

  The output unit 104 outputs the information acquired by the information acquisition unit 103. Output described here includes display on a display, printing on a printer, sound output, transmission to an external device, storage in a recording medium, delivery of processing results to another processing device or other program, etc. It is a concept that includes. The output unit 104 may or may not include an output device such as a display or a printer. The output unit 104 can be implemented by output device driver software, or output device driver software and an output device.

  The selection instruction receiving unit 105 receives a selection instruction that is an instruction to select any one of the position information of the plurality of visible light communication light sources detected by the light source position detection unit 102. In particular, the selection instruction may be received only when the light source position detection unit 102 acquires position information of a plurality of visible light communication light sources. The selection instruction described here may be an instruction that can select one position of the visible light communication light source as a result. For example, an instruction for designating the visible light communication light source or each visible light communication light source is transmitted. When the information is different, it may be an instruction to select information transmitted by the visible light communication light source. The reception described here is, for example, reception from an input unit, reception of an input signal transmitted from another device, reading of information from a recording medium, or the like. The selection instruction input means may be anything such as a numeric keypad, a keyboard, a mouse, or a menu screen. The selection instruction receiving unit 105 can be realized by a device driver for input means such as a numeric keypad or a keyboard, control software for a menu screen, or the like.

  Next, the operation of the visible light communication apparatus will be described using the flowchart of FIG. Here, a case where information in which a marker signal having a different frequency and information to be subjected to visible light communication are superimposed is transmitted from the visible light communication light source by visible light communication will be described as an example.

  (Step S201) The imaging unit 101 captures an image and acquires a captured image. The captured image may be a still image or a moving image composed of a plurality of frame images.

  (Step S202) The light source position detection unit 102 acquires the position information of the visible light communication light source in the captured image acquired in step S201. Details of this processing will be described later.

  (Step S203) The incident position information acquisition unit 1031 determines whether or not the position information of a plurality of visible light communication light sources has been acquired in Step S202. If position information of a plurality of visible light communication light sources is acquired, the process proceeds to step S209, and if not, the process proceeds to step S204.

  (Step S204) The incident position information acquisition unit 1031 acquires communication light incident position information corresponding to the position information of the visible light communication light source acquired in Step S202. Specifically, using information indicating the correspondence between the captured image and the liquid crystal panel, the position information on the liquid crystal panel 10321 corresponding to the position of the visible light communication light source in the captured image is obtained from the position information of the visible light communication light source. get.

  (Step S205) The light shielding control unit 10322 controls the liquid crystal panel 10321 using the communication light incident position information acquired in step S204, and light is transmitted only through the pixel at the position indicated by the communication light incident position information of the liquid crystal panel 10321. As a possible state, pixels in other regions are made to block light. For example, the liquid crystal panel 10321 displays an image in which only the region indicated by the communication light incident position information is a transmissive region and the other regions are black that does not transmit light. As a result, only the light output from the visible light communication light source is transmitted through the region constituted by the pixel at the position indicated by the communication light incident position information of the liquid crystal panel 10321, and the other light is blocked by the liquid crystal panel 10321.

  (Step S206) The information acquisition unit 1034 acquires information transmitted by visible light communication from the electrical signal output by the light receiving unit 1033 that has received the light transmitted through the liquid crystal panel 10321.

  (Step S207) The output unit 104 outputs information acquired by the information acquisition unit 1034 through visible light communication. For example, it is displayed on a display (not shown).

  (Step S208) The information acquisition unit 103 determines whether or not to stop receiving information transmitted by visible light communication. It may be determined to stop the output in response to any trigger. For example, when an instruction to stop reception is received from a reception unit (not shown) or the like, it may be determined to stop reception. If the reception is to be canceled, the process is terminated. If the reception is not to be canceled, the process returns to step S201.

  (Step S209) The incident position information acquisition unit 1031 determines whether the selection instruction receiving unit 105 has received a selection instruction. If it has been received, the process proceeds to step S210. If it has not been received, the process proceeds to step S211.

  (Step S210) The incident position information acquisition unit 1031 selects the position information of the visible light communication light source specified by the selection instruction, and acquires the communication light incident position information corresponding to the selected position information. Then, the process proceeds to step S205.

  (Step S211) The output unit 104 performs an output requesting selection of any one of position information of a plurality of visible light communication light sources, for example, display. Prior to this process, using the position information of the plurality of visible light communication light sources, respectively, a plurality of pieces of communication light incident position information are acquired and the liquid crystal panel 10321 is controlled in the same manner as in step S204. Information transmitted by visible light communication is sequentially acquired from the position indicated by the communication light incident position information for each predetermined time, and the acquired information is displayed as so-called preview information at the time of the display requesting the selection described above. You may do it.

  (Step S212) The incident position information acquisition unit 1031 determines whether or not the selection instruction receiving unit 105 has received a selection instruction in response to an output requesting selection in step S211. If accepted, the process proceeds to step S210. If not received, the process proceeds to step S213.

  (Step S213) The information acquisition unit 103 determines whether to stop the reception of visible light communication. If the reception is to be canceled, the process is terminated. If the reception is not to be canceled, the process returns to step S212.

  In the flowchart shown in FIG. 2, if it is determined in step S208 that the reception is not stopped until the time specified in advance after the process of step S205, the process returns to step S206 to return the transmission target information. May be repeatedly performed at the position indicated by the same communication light incident position information, and when a predetermined time has elapsed, the process may return to step S201 to detect a change in the position of the visible light source.

  If it is determined in step S208 that the reception is not stopped, the process returns to step S201. However, the processes in step S206 and step S207 are repeated in parallel during the subsequent processes after step S201. You may make it do.

  Further, when position information of a plurality of visible light communication light sources is detected, any one position information may be selected according to a rule specified in advance. This rule may be any rule, for example, position information may be selected at random, or position information closer to the center of the captured image may be selected. Moreover, you may make it select the one where the intensity | strength of the light obtained from each positional information is higher.

  Next, details of processing for acquiring position information of the visible light communication light source using the above-described captured image will be described using the flowchart of FIG. This process is a process corresponding to the process of step S202.

  (Step S301) The light source detection unit 1021 detects a light source in the captured image acquired in step S201 described above. As a specific example, a light source is usually composed of pixels with a high luminance value in a photographed image, and therefore, for each pixel constituting the photographed image, a light value and a pixel constituting the light source are discriminated. The threshold is sequentially compared. Then, a pixel having a luminance value equal to or higher than the threshold is determined to be a light source pixel. A region in which pixels determined to be light source pixels continuously exist is sequentially detected as one light source. Then, the coordinate information of each pixel constituting the light source is stored in a storage medium (not shown) in association with identification information for identifying the light source, for example. Here, a set of coordinate information of one or more pixels constituting one light source is set as position information indicating the position of the one light source. It should be noted that the center coordinates, the barycentric coordinates, the coordinates defining the contour, and the like of the area constituting one light source may be used as the light source position information. The position of the light source may be detected by other methods. For example, when the shape of the light source is determined in advance, it may be detected by performing pattern matching on the shape of the light source. Note that the captured image used here may be a still image or an image of one frame in a moving image, or may be an image obtained by combining a plurality of moving image images. Although the brightness value of the captured image is used here, the light source may be detected based on the color or the like in the captured image, or the value of a specific channel in the captured image, for example, R channel or G The light source may be detected using the channel and B channel values.

  (Step S302) The light source selection unit 1022 substitutes 1 for the counter q.

  (Step S303) The light source selection unit 1022 determines whether or not the qth light source is present in the light sources detected in step S301. If there is, the process proceeds to step S304. If not, the acquired information on the position of the visible light communication light source is returned to the higher-level process.

  (Step S304) The light source selection unit 1022 acquires an electrical signal obtained at a position corresponding to the q-th light source of the image sensor 1011. Specifically, the light source selection unit 1022 acquires an electrical signal output from one or more light receiving elements arranged at a position corresponding to the position of the qth light source in the captured image of the imaging element 1011. In addition, since the captured image is created from the electrical signal output from each light receiving element of the image sensor 1011, the position of each pixel in the captured image and one or more electrical signals that are used to create the pixel are output. Since the correspondence relationship with the position of the light receiving element is designated in advance, it is possible to acquire the position of the light receiving element corresponding to the pixel constituting the qth light source by using information indicating this correspondence relationship. is there. Here, unlike the case of shooting, the electric signal output from the image sensor 1011 is continuously acquired without scanning the image sensor 1011. Thereby, the light output from the q-th light source can be converted into a continuous electric signal.

  (Step S305) The light source selection unit 1022 acquires a marker frequency signal, which is the frequency of the marker signal, from the electrical signal acquired from Step S303. In addition, since the technique which takes out the signal of a predetermined frequency from an electrical signal is a well-known technique, description is abbreviate | omitted here.

  (Step S306) The light source selection unit 1023 samples, or digitizes, the electrical signal acquired in step S305 at a predetermined cycle specified in advance.

  (Step S307) The light source selection unit 1022 determines whether or not a predetermined time has elapsed from the start of the process of step S304 for the qth light source. Specifically, the predetermined time is information that specifies a period during which a signal for detecting a marker signal is received from one light source. If the predetermined time has elapsed, the process proceeds to step S308. If not, the process returns to step S303. Note that after the electrical signal output from the image sensor 1011 is received for a predetermined time, the received electrical signal may be sampled.

  (Step S308) The light source selection unit 1022 detects whether or not the signal acquired at the marker frequency is a marker signal. The detection of the marker signal here may be considered as detecting the detection of a signal whose signal magnitude is characteristic of the marker signal. Specifically, in step S306, the light source selection unit 1022 determines whether or not the intensity value of the electrical signal acquired by sampling within the predetermined time described above has fluctuated. It is determined that the signal is a marker signal, and if it is not changed, it is determined that the signal is not a marker signal. Whether or not it fluctuates may be determined in any way. For example, it fluctuates when the difference between the maximum value and the minimum value of values sampled within a predetermined time is larger than a preset threshold value. You may judge that Alternatively, it may be determined that the sampled value fluctuates when at least one value greater than a preset maximum value and one less than a preset minimum value are included. When the marker signal is detected, the process proceeds to step S309, and when the marker signal is not detected, the process proceeds to step S310.

  (Step S309) The light source detection unit 1021 acquires information on the position of the q-th light source among the light sources detected in Step S301 as position information of the visible light communication light source. For example, the coordinate information of one or more pixels constituting the qth light source is acquired as the position information of the visible light communication light source. Then, the acquired position information is temporarily stored in a storage medium (not shown) or the like in association with, for example, information for identifying the visible light communication light source. The temporarily stored position information of the visible light communication light source is the position information of the visible light communication light source acquired by the light source position detection unit 102.

(Step S311) The light source selection unit 1022 increments the value of the counter q by 1. Then, the process returns to step 303.
In the flowchart described with reference to FIG. 2, once the position of the visible light communication light source is detected, the second image capturing unit 201 repeatedly repeats the image capturing by the second image capturing unit 201 as illustrated in step S <b> 201 to obtain a newly acquired second captured image. The position of the light source is newly detected from the brightness of the pixel or the like in the same manner as the processing in step S301 described above, and the newly detected light source has a high correlation with the visible light communication light source detected immediately before, or You may make it detect the light source etc. with the shortest distance with the visible light communication light source detected immediately before as a position of the visible light communication light source in the newly image | photographed image. The visible light communication information may be received using the detected position information of the visible light communication light source. As a result, even when the position of the visible light communication light source changes, it is possible to detect the position after the change at high speed and to receive information communicated by visible light following the change in position.

  Hereinafter, a specific operation of the visible light communication apparatus according to the present embodiment will be described.

  FIG. 5 is a schematic diagram for explaining a specific example of the visible light communication apparatus. Here, the visible light communication device 1 is assumed to constitute at least a part of the visible light communication portable terminal 1a which is a portable portable terminal. As an example, it is assumed that the visible light communication apparatus 1 includes a display device 1051 that is an output device. It is assumed that LED light sources 51 to 54 are installed on the ceiling of the room where the visible light communication device 1 exists. Here, in particular, it is assumed that the LED light source 51 is a visible light communication light source that modulates information transmitted from a transmission device (not shown) by power line communication (PLC) or the like into visible light and transmits the visible light communication. Here, it is assumed that the user holds the first lens 201 facing the ceiling.

  Here, information on a television program of a plurality of channels by visible light communication, basic information indicating which channel is assigned to which frequency, a marker signal used to detect the position of the visible light communication light source, and A case will be described where, are transmitted with being superimposed. Information other than the marker signal in the information transmitted by visible light communication is referred to as content information here. The content information is information composed of images, sounds, texts, and the like, for example. Here, in the content information, information on different programs and basic information are assigned to different frequencies. That is, the content information is information obtained by frequency division for each program. In this case, the frequency of the marker signal is 28.8 KHz, the frequency of the basic information is 40 MHz, the frequency at which 1 channel information of the TV program is transmitted is 80 MHz, and the frequency at which 2 channel information is transmitted is 86 MHz. To do. Here, it is assumed that a signal on which these pieces of information are superimposed is transmitted from the LED light source 51 by visible light communication.

  The imaging unit 101 of the visible light communication device 1 captures an image of the ceiling via the first lens 201. Here, the number of pixels of the image captured by the image capturing unit 101 is assumed to be 320 × 240 pixels as an example for the sake of explanation. Note that the greater the number of pixels, the more accurately the light source is detected, but the processing is slowed accordingly.

  FIG. 6 is a diagram illustrating a captured image captured by the capturing unit 101. In this captured image, all LED light sources that are lit are photographed. In the figure, the same reference numerals as those in FIG. 5 indicate images of the same light source. In the image of FIG. 6, the upper left is the coordinate (0, 0), the right direction of the coordinate is the x-axis direction, and the lower direction of the coordinate is the y-axis direction. The unit of coordinates is assumed to be pixels.

  Next, the light source detection unit 1021 acquires a captured image, and detects a light source in the captured image. Here, the luminance value of each pixel of the photographed image is compared with a threshold value of a luminance value specified in advance, and a pixel having a luminance value equal to or higher than the threshold value is determined as a light source pixel. Here, it is assumed that the luminance is higher as the luminance value is larger. Then, it is determined that a region where luminance values equal to or greater than the threshold value are continuous is one light source.

  For example, if the acquired captured image is a still image as shown in FIG. 6, an area where pixels having a luminance value equal to or higher than the threshold value of this image are white, and an area where pixels having a luminance value less than the threshold value are present. FIG. 7 shows an oblique line, that is, this image binarized by the threshold value of the luminance value. By the process of detecting the light source as described above, it is determined that the four independent areas 51a to 51d shown in white in FIG. 7 are the light sources. The areas 51a to 54a are areas corresponding to the light sources 51 to 54, respectively.

  The detected coordinate information of the pixels constituting each light source is temporarily stored in a storage medium such as a memory (not shown) together with identification information given to each light source.

  FIG. 8 is a light source coordinate management table for managing the light source and the coordinate information of the pixels constituting the light source. The light source coordinate management table has an item “light source ID” which is identification information given to the light source and an item “coordinate” which is the coordinates of the pixels constituting the light source. Here, it is assumed that “001” to “004” are associated as “area IDs” with the pixels constituting the areas 51a to 54a, respectively.

  Next, the light source selection unit 1022 first receives an electric signal output by the light receiving element in the area in the imaging element 1011 corresponding to the area where the “light source ID” of the captured image is “001”, that is, the area 51a. . For example, when the imaging element 1011 and the captured image have a similar relationship, the light receiving element in the region on the imaging device 1011 that has a similar relationship to the region where the “light source ID” of the captured image is “001” Only the electrical signal output according to the intensity of the received light is continuously received.

  The light source selection unit 1022 separates the frequency of the marker signal, here a signal of 28.8 KHz, from the received electrical signal. Then, the separated signal is sampled at a predetermined sampling period. In this specific example, the relationship between the sampling period and the marker signal is such that when the marker signal is included, the marker signal can be reliably detected as described with reference to FIG. Keep it.

  The light source selection unit 1022 ends the reception and sampling of the electrical signal when a predetermined time, for example, 1/10 to 1/30 second, has elapsed from the start of the reception of the electrical signal, and the marker signal is received from the electrical signal. It is determined whether or not it is detected, that is, whether or not the signal separated from the electrical signal at the frequency of the marker signal is a marker signal whose value varies. For example, it is determined whether or not two values “H” and “L” are included in a value obtained by binarizing a plurality of values obtained by sampling with a predetermined threshold value. Here, if binary values are included, the light source selection unit 1022 determines that a marker signal has been detected. Then, the light source selection unit 1022 uses the information indicating the position of the region where the “light source ID” of the captured image is “001”, here the coordinate information of the pixels included in the region 51a as an example, and the position information of the visible light communication light source. And stored in a memory or the like (not shown).

  Next, similarly, an electric signal output by the light receiving element in the area in the image sensor 1011 corresponding to the area where the “light source ID” of the captured image is “002”, that is, the area 52a is received. And the signal of the frequency of a marker signal is isolate | separated from this electric signal, and it samples. Then, similarly to the above, it is determined whether or not the sampled value is a marker signal. Here, it is assumed that the sampled value does not include binary values. The light source selection unit 1022 determines that the marker signal is not detected, and does not acquire the position information of the region where the “light source ID” of the captured image is “002” as the position information of the visible light communication light source.

  Hereinafter, the same processing is performed for the areas with “003” and “004” as the “light source ID”. As a result of these processes, it is assumed that only the coordinate information of the pixels constituting one light source 51 whose “light source ID” is “001” is acquired as the position information of the visible light communication light source.

  FIG. 9 is a visible light communication light source management table for managing the position information of the visible light communication light source. The visible light communication light source management table has an item “light source ID” that is identification information of a visible light communication light source and an item “position information” that is coordinate information of each pixel constituting the visible light communication light source. . Here, “light source ID” corresponds to “light source ID” in the light source coordinate management table of FIG. 7, and light sources having the same value are assumed to be the same light source.

  Next, using the position information of the visible light communication light source shown in FIG. 9, the incident position information acquisition unit 1031 is information on the position on the liquid crystal panel 10321 where the light transmitted from the visible light communication light source is incident. Acquire communication light incident position information. Here, as an example, assuming that the number of pixels of the liquid crystal panel 10321 is 320 × 240 pixels, which is the same as the number of pixels of the captured image, the optical path length until the light passing through the first lens 201 reaches the image sensor 1011, and the first lens It is assumed that the light path length after the light passing through 201 is reflected by the beam splitter 202 and reaches the liquid crystal panel is the same. Then, it is assumed that an image in the same photographing range as the photographed image shown in FIG. That is, the coordinate information of the liquid crystal panel 10321 and the coordinate information of the captured image have a one-to-one correspondence. Therefore, the incident position information acquisition unit 1031 acquires the position information of the visible light communication light source as it is as the communication light incident position information. With such a configuration, the process of calculating the communication light incident position information from the position information of the visible light communication light source detected by the light source position detection unit 102 can be omitted, and the processing speed can be increased. Therefore, the communication light incident position information acquired here is the same as that shown in FIG. Note that in the case where the number of pixels of the captured image 1011 and the number of pixels of the liquid crystal panel 10321 are different, each pixel in the captured image 1011 and one of the liquid crystal panels 10321 at positions where the same image as the image indicated by this pixel is projected in advance. A correspondence table showing the correspondence relationship with the above pixels is prepared in a storage medium (not shown), and the communication light incident position information is obtained from the position information of the visible light communication light source using this correspondence table. Also good. Alternatively, coordinate conversion or the like may be performed.

  Next, the light shielding control unit 10322 controls the liquid crystal panel 10321 so that a region other than the position indicated by the acquired communication light incident position information among the pixels of the liquid crystal panel 10321 is a region that shields light. . Specifically, the liquid crystal panel 10321 is controlled such that only the pixel having the coordinates indicated by the communication light incident position information is a pixel that transmits light. As a result, as shown in FIG. 10, only the position indicated by the communication light incident position information 10321 of the liquid crystal panel becomes the light transmission region 1010. This region is a position where light emitted from the light source 51 that is a visible light communication light source is incident on the liquid crystal panel 10321.

  As a result, as shown in FIG. 11, the liquid crystal panel selectively receives only light emitted from the light source 51, which is a visible light communication light source, through the transmission region 1010, which is the region indicated by the communication light incident position information 10321. Is input. The light receiving means 1033 continuously outputs an electrical signal corresponding to the input light.

  Unlike the image sensor 1011, the light receiving unit 1033 such as a photodetector simply outputs an electrical signal corresponding to the intensity of light, and thus can perform high-speed processing. Therefore, information having a higher frequency than that of the image sensor 1011 can be extracted from the electrical signal output by the light receiving unit 1033 according to the incident light.

  Here, first, in order to extract the basic information, the information acquisition unit 1034 separates and extracts the 40 MHz signal, which is the frequency of the basic information, for about 20 milliseconds from the electric signal output from the light receiving element 1033. Further, the basic information is extracted by demodulating the separated signal. Here, for example, it is assumed that the basic information includes information on the channel of a television program transmitted as content information. It is assumed here that the process of extracting such basic information first is performed in advance. The basic information is stored in a storage medium or the like (not shown).

  FIG. 12 is a diagram illustrating an example of basic information acquired by the information acquisition unit 1034. The basic information includes items of “channel”, “broadcast station”, “preview”, and “frequency”. “Channel” is the number of the channel through which the television program is transmitted. “Broadcast station” is the name of a broadcast station of a television program to be transmitted. “Preview” is a preview image of a television program to be transmitted. “Frequency” is the frequency at which the television program is modulated.

  The output unit 104 displays the channel information indicated by the basic information as shown in FIG. 12 acquired by the information acquisition unit 1034, such as a preview image, for example, on the display device 1051, and prompts the user to select a channel, for example, , “Please select a channel”, etc. are displayed. A display example of the output unit 104 is shown in FIG.

  Next, when the user operates a button, a touch panel, or the like (not shown) to select channel 2, a reception unit (not shown) of the information processing apparatus 1 receives a channel 2 selection instruction. When the reception unit receives a channel 1 selection instruction, the information acquisition unit 1034 acquires “86 MHz” that is an attribute value of “frequency” of the record whose “channel” of the basic information illustrated in FIG. To do. Then, the information acquisition unit 1034 separates the acquired signal having the frequency of “86 MHz” from the electrical signal output from the light receiving unit 1033. Then, the separated signal is demodulated to obtain information on the TV program of channel 2. Then, the output unit 104 displays the television program acquired by the information acquisition unit 1034 on the display device 1051.

  When the user selects channel 1, the information acquisition unit 1034 separates the signal having the frequency of “80 MHz” acquired from the basic information from the electrical signal output from the light receiving unit 1033 in the same manner as described above. The received signal is demodulated to obtain information on the channel 1 television program. Then, the TV program of channel 1 is displayed on the display device 1051 by the output unit 104.

  The light source position detection unit 102 repeatedly performs processing for acquiring the position information of the visible light communication light source from the captured images sequentially captured by the image capturing unit 101, and the relative position of the visible light communication light source with respect to the visible light communication device 1. Even if the position changes, the position information of the visible light communication light source is newly acquired at the changed position. Then, communication light incident position information is acquired from the newly acquired position information, and the position of the transmission region of the liquid crystal panel 10321 is adjusted. As a result, it is possible to reliably receive the light output from the visible light communication light source. For example, even if the position information of the visible light communication light source changes during reception of continuous information, it is possible to receive subsequent information by acquiring the communication light incident position information corresponding to the changed position information. . Thus, even if the relative position of the visible light communication light source with respect to the visible light communication apparatus 1 changes, it is possible to reliably acquire information output from the visible light communication light source following the change in the position. Is possible. In particular, in this embodiment, since the position of the transmissive region is adjusted using the liquid crystal panel 10321, no physical operation is necessary, so that the position adjustment can be performed quickly. In addition, mechanical failure is unlikely to occur. Further, even if the shape of the light source is diversified, the transmissive region can be freely changed in accordance with the shape of the light source and the like, so that there is an advantage of high adaptability.

  Here, it is assumed that the light source selection unit 1022 detects the position information of the two visible light communication light sources when the position information of the visible light communication light source is acquired. For example, it is assumed that in addition to the light source 51, the light source 52 also transmits a television program of a channel different from that of the light source 51 by visible light communication.

  In this case, the output unit 104 uses the display device 1051 to display that two visible light communication light sources are detected. A display example is shown in FIG. In FIG. 14, the visible light communication light source is referred to as a source as an example, and it is assumed that the light source 51 is associated with the source 1 and the light source 52 is associated with the source 2. When the user selects a visible light communication light source that wants to receive information from the visible light communication light source selection screen displayed in this way, here, source 2 by operating the touch panel or the like, the selection instruction receiving unit 105 Of the position information of the two visible light communication light sources detected by the light source selection unit 1022, a selection instruction for selecting the position information of the light source 52 that is the visible light communication light source selected by the user is received. The incident position information acquisition unit 1031 acquires communication light incident position information corresponding to the position information of the visible light communication light source selected by the selection instruction, and uses the communication light incident position information, similarly to the above, Only the information transmitted by visible light communication is received from the visible light communication light source selected by. Thereby, it becomes possible to selectively receive only one of information output from a plurality of visible light communication light sources.

  When the position information of the two visible light communication light sources is detected, the basic information transmitted from each visible light communication light source is acquired using the respective position information in the same manner as described above. Part of the information included in the display, for example, preview information, etc., may be displayed on the screen for selecting one of the plurality of visible light communication light sources as part of the information transmitted from each visible light communication light source. good. In this way, the user can easily determine what information is transmitted from each visible light communication light source.

  In the above-described specific example, the case where information on a plurality of channels is transmitted at different frequencies has been described. However, in the present invention, information obtained by time-dividing information on a plurality of channels is modulated to one frequency, and visible light communication is performed. You may make it transmit. In other words, in the present embodiment, a plurality of pieces of content information may be transmitted by frequency division, may be transmitted by time division, or may be transmitted in combination.

  In the above specific example, when basic information is unnecessary, transmission and reception of basic information may be omitted.

  As described above, according to the present embodiment, the position information of the visible light communication light source is acquired from the captured image, and the communication light that is the position information on which the light output from the visible light communication light source is incident using the position information. By acquiring incident position information and acquiring transmission target information that is information transmitted by visible light communication from the visible light communication light source at the position indicated by the communication light incident position information, there is another light source. Transmitted from a single light source that performs visible light communication even when light output from a light source other than the photographed light source, such as light from ambient light, indirect illumination, or the like is incident. Information can be received with high accuracy.

  In particular, the position of the visible light communication light source is detected by using the image sensor 1011 that can detect the light receiving position, and the substantial visible light such as content information transmitted from the visible light communication light source. By enabling the light receiving means 1033 such as a photodetector capable of high-speed response to selectively receive information to be communicated, high-frequency information is extracted from information transmitted by being superimposed by visible light communication. It becomes possible. This makes it possible to transmit information modulated at a high frequency by visible light communication, and improve the data transfer rate.

  In this embodiment, a liquid crystal panel 10321 is particularly provided as means for selectively receiving light transmitted from the visible light communication light source. Then, a transmission region is formed in the liquid crystal panel 10321 in accordance with the position of the visible light communication light source, so that light transmitted from the visible light communication light source is selectively received. In such a configuration, the display image of the liquid crystal panel 10321 may be controlled so that the transmission region is formed at a position corresponding to the position where the visible light communication light source is detected in the captured image of the liquid crystal panel 10321. Therefore, calculations such as the direction of the visible light communication light source and the shape and size of the light from the light source are unnecessary. As a result, the processing speed can be increased. In addition, since a physical mechanism for selectively receiving light can be omitted, it is possible to make it difficult for a malfunction to occur due to wear or the like.

  In the present invention, the liquid crystal panel 10321 may be arranged at a position where the light having passed through the first lens 201 is incident, and the arrangement is not limited. For example, as in the above embodiment, it may be disposed between the beam splitter 202 and the second lens 201, or may be disposed between the second lens 203 and the light receiving means 1033. Further, the liquid crystal panel 10321 may be disposed on the light receiving means 1033. Even when the liquid crystal panel 10321 is arranged at any position, similarly to the above embodiment, areas other than the incident position indicated by the incident position information acquired by the incident position information acquiring means 1031 by the light shielding control means 10322 block light. By controlling the liquid crystal panel 10321 so as to be in the region, the same effect as in the above embodiment can be obtained. In particular, by arranging the liquid crystal panel 10321 between the second lens 203 and the light receiving means 1033, it is only necessary to control the transmission of the light converged by the second lens 203. Therefore, the size of the liquid crystal panel 10321 is reduced. Thus, the cost can be reduced.

  In the following, the configuration and operation of an example of a transmission device that transmits information used for visible light communication in the above embodiment to a light source will be briefly described.

  FIG. 15 is a block diagram for explaining a configuration of a transmission device used for visible light communication.

  The transmission device 3 is connected to the light source 50 via a power communication line, a network, or the like.

  The transmission device 3 includes a transmission target information acquisition unit 301, a modulation unit 302, a marker signal output unit 303, a superimposition unit 304, and a transmission unit 305.

  The transmission target information acquisition unit 301 acquires transmission target information that is information to be transmitted by visible light communication. The transmission target information is, for example, a plurality of content information described above. The acquisition described here is a concept including reading of transmission target information stored in a recording medium or the like, reception of transmission target information from the outside, and the like. The transmission target information acquisition unit 301 is realized by a communication unit, a reading unit from a recording medium, an MPU, a memory, or the like. The processing procedure of the transmission target information acquisition unit 301 is usually realized by software, and the software is recorded on a recording medium such as a ROM. However, it may be realized by hardware (dedicated circuit).

  The modulation unit 302 modulates the transmission target information acquired by the transmission target information acquisition unit 301 with a predetermined frequency. The modulation unit 302 may modulate different transmission target information, for example, information on programs on different channels, at different frequencies. The frequency to be modulated here is a frequency that can be processed by the light receiving means 1033 such as the above-described photodetector, and is preferably a frequency at which a sufficient data transfer rate can be obtained. For example, the frequency to be modulated is a frequency of several tens to 100 MHz.

  The marker signal output unit 303 outputs a marker signal that is information used to detect the position of the visible light communication light source. The marker signal is a signal having a frequency that can be received by the image sensor as described above. This frequency is, for example, about several tens KHz to several hundred KHz. The marker signal is information that changes the magnitude of the signal in, for example, a certain pattern. The marker signal output unit 303 may generate a marker signal having a predetermined frequency, or may read out a digital marker signal stored in advance in a storage medium (not shown), modulate it at a predetermined frequency, and output it. May be.

  The superimposing unit 304 superimposes one or more modulated transmission target information output from the modulation unit 302 and the marker signal output from the marker signal output unit 303. In addition, when the transmission apparatus 3 transmits these information by power line communication, you may superimpose such information on the electric power carrier wave. Note that the superimposing unit 304 may be omitted when the marker signal and the transmission target information are switched according to time or the like.

  The transmitting unit 305 transmits information including the transmission target information and the marker signal superimposed by the superimposing unit 304 to the light source 50 via a power communication line, a network, or the like. The transmission unit 305 is realized by communication means or the like.

  The light source 50 includes a light emitter (not shown) such as an LED, an incandescent lamp, or a fluorescent lamp. As the illumination light source 50 for performing optical wireless communication, for example, an LED (Light Emitting Diode) capable of blinking at high speed is preferably used. The luminous intensity of the light source 50 is adjusted by adjusting the voltage supplied to the light source 50. By changing the intensity of light emitted from the light source 50 according to the information transmitted from the transmission unit 305, for example, by blinking, the information transmitted from the transmission unit 305 can be transmitted by visible light communication. . The intensity of light generated by the light source 50 may be directly controlled by information transmitted from the transmission unit 305. Alternatively, the light source 50 receives a information (not shown) that receives information transmitted from the transmission unit 305, a control unit (not shown) that controls the emission intensity according to a signal received by the receiving unit, and the like. You may have.

  The transmission apparatus 3 modulates the transmission target information acquired by the transmission target information acquisition unit 301 by the modulation unit 302, and superimposes the modulated transmission target information and the marker signal output by the marker signal output unit 303. The information superimposed is transmitted from the transmission unit 305 to the light source 50. As a result, information obtained by superimposing the marker signal and the information to be transmitted can be transmitted from the light source 50 by visible light communication.

  In the above-described embodiment, the case of receiving visible light communication has been described. However, the present invention can also be applied to optical wireless communication that can use light other than visible light, for example, infrared light and ultraviolet light. Even in such a case, the same effects as those of the above embodiment can be obtained. The optical wireless communication described here refers to communication using light waves having a very high frequency compared to radio waves, such as visible light, infrared light, and ultraviolet light. In this case, for example, an optical wireless communication light source is used instead of the visible light communication light source.

  In the above embodiment, each process (each function) may be realized by centralized processing by a single device (system), or by distributed processing by a plurality of devices. May be.

  In the above embodiment, it goes without saying that two or more communication means (such as an information transmission unit) existing in one apparatus may be physically realized by one medium.

  In the above embodiment, information related to processing executed by each component, for example, information received, acquired, selected, generated, transmitted, and received by each component. In addition, information such as threshold values, mathematical formulas, addresses, etc. used by each component in processing is retained temporarily or over a long period of time on a recording medium (not shown) even when not explicitly stated in the above description. It may be. Further, the storage of information in the recording medium (not shown) may be performed by each component or a storage unit (not shown). Further, reading of information from the recording medium (not shown) may be performed by each component or a reading unit (not shown).

  In the above-described embodiment, the case where the visible light communication device is a stand-alone has been described. However, the visible light communication device may be a stand-alone device or a server device in a server / client system. In the latter case, the output unit or the reception unit receives an input or outputs a screen via a communication line.

  In the above embodiment, each component may be configured by dedicated hardware, or a component that can be realized by software may be realized by executing a program. For example, each component can be realized by a program execution unit such as a CPU reading and executing a software program recorded on a recording medium such as a hard disk or a semiconductor memory.

  In addition, the software which implement | achieves the visible light communication apparatus in the said embodiment is the following programs. In other words, this program causes a computer to capture one or more light sources including an optical wireless communication light source that is a light source that performs optical wireless communication, and to acquire an image, and a captured image that is an image acquired by the imaging unit. A light source position detection unit that detects a position of the optical wireless communication light source and obtains position information that is position information of the optical wireless communication light source, and a position information of the optical wireless communication light source acquired by the light source position detection unit. Information transmitted from the optical wireless communication light source by optical wireless communication at the position indicated by the communication light incident position information is obtained by acquiring communication light incident position information that is information on a position where light output from the wireless communication light source is incident. It is a program for functioning as an information acquisition unit that acquires transmission target information, and an output unit that outputs information acquired by the information acquisition unit.

  In the program, the functions realized by the program do not include functions that can be realized only by hardware. For example, a function that can be realized only by hardware such as a modem or an interface card in an acquisition unit that acquires information or an output unit that outputs information is not included in the function realized by the program.

  Further, the computer that executes this program may be singular or plural. That is, centralized processing may be performed, or distributed processing may be performed.

  FIG. 16 is a schematic diagram illustrating an example of an external appearance of a computer that executes the program and realizes the visible light communication apparatus according to the embodiment. The above-described embodiment can be realized by computer hardware and a computer program executed on the computer hardware.

  In FIG. 16, a computer system 900 includes a computer 901 including a CD-ROM (Compact Disk Read Only Memory) drive 905 and an FD (Floppy (registered trademark) Disk) drive 906, a keyboard 902, a mouse 903, a monitor 904, and the like. Is provided.

  FIG. 17 is a diagram showing an internal configuration of the computer system 900. In FIG. 17, in addition to the CD-ROM drive 905 and the FD drive 906, a computer 901 is connected to an MPU (Micro Processing Unit) 911, a ROM 912 for storing a program such as a bootup program, and the MPU 911. A RAM (Random Access Memory) 913 that temporarily stores program instructions and provides a temporary storage space, a hard disk 914 that stores application programs, system programs, and data, and an MPU 911 and a ROM 912 are interconnected. And a bus 915. The computer 901 may include a network card (not shown) that provides connection to the LAN.

  A program for causing the computer system 900 to execute the functions of the visible light communication apparatus according to the above-described embodiment is stored in the CD-ROM 921 or the FD 922, inserted into the CD-ROM drive 905 or the FD drive 906, and stored in the hard disk 914. May be forwarded. Instead, the program may be transmitted to the computer 901 via a network (not shown) and stored in the hard disk 914. The program is loaded into the RAM 913 when executed. The program may be loaded directly from the CD-ROM 921, the FD 922, or the network.

  The program does not necessarily include an operating system (OS) or a third-party program that causes the computer 901 to execute the functions of the visible light communication apparatus according to the above-described embodiment. The program may include only a part of an instruction that calls an appropriate function (module) in a controlled manner and obtains a desired result. How the computer system 900 operates is well known and will not be described in detail.

  The present invention is not limited to the above-described embodiments, and various modifications are possible, and it goes without saying that these are also included in the scope of the present invention.

  As described above, the visible light communication device and the like according to the present invention are suitable as a device for receiving visible light communication, and in particular, a portable type whose relative position with respect to a light source emitting visible light communication is not fixed. It is useful as a visible light communication device.

DESCRIPTION OF SYMBOLS 1 Visible light communication apparatus 1a Visible light communication portable terminal 2 Transmission apparatus 101 Image pick-up part 102 Light source position detection part 103 Information acquisition part 104 Output part 105 Selection instruction | indication reception part 201 1st lens 202 Beam splitter 203 2nd lens 301 Acquisition of transmission object information Unit 302 modulation unit 303 marker signal output unit 304 superimposition unit 305 transmission unit 1011 image sensor 1012 image processing unit 1021 light source detection unit 1022 light source selection unit 1031 incident position information acquisition unit 1032 selection transmission unit 1033 light reception unit 1034 information acquisition unit 1041 display device 10321 Liquid crystal panel 10322 Shading control means

Claims (14)

A photographing unit that photographs one or more light sources including an optical wireless communication light source that is a light source that performs optical wireless communication;
A light source position detection unit that detects an optical wireless communication light source in a captured image that is an image acquired by the imaging unit, and acquires position information that is information on a position of the optical wireless communication light source;
From the position information of the optical wireless communication light source acquired by the light source position detection unit, communication light incident position information, which is information on a position where light output from the optical wireless communication light source is incident, is acquired, and the communication light incident position information An information acquisition unit that acquires transmission target information that is information transmitted by optical wireless communication from the optical wireless communication light source at the position indicated by:
An optical wireless communication apparatus comprising: an output unit that outputs information acquired by the information acquisition unit. The light source position detector
Light source detection means for detecting a light source in a captured image that is an image acquired by the imaging unit;
The light source selection means which selects the optical wireless communication light source in the picked-up image among the light sources which the said light source detection part detected, and acquires the positional information on the selected optical wireless communication light source. Optical wireless communication device. 3. The optical wireless communication device according to claim 2, wherein the light source selection unit acquires position information of an image of an optical wireless communication light source that is an image of a light source in which light intensity changes among images of the light source detected by the light source detection unit. Communication device. The optical wireless communication apparatus according to claim 1, wherein the photographing unit includes an image sensor that is an image sensor. The information acquisition unit
Comprising light receiving means for receiving light incident on a position indicated by the communication light incident position information and converting it into an electrical signal;
5. The optical wireless communication apparatus according to claim 1, wherein the light receiving unit acquires transmission target information transmitted by optical wireless communication from the optical wireless communication light source at a position indicated by the communication light incident position information. The information acquisition unit
Incident position information acquisition means for acquiring the communication light incident position information;
Selective transmission means for selectively transmitting only the light incident on the position indicated by the communication light incident position information acquired by the incident position information acquisition means;
A light receiving means for receiving the light transmitted by the selective transmission means and converting it into an electrical signal;
Information acquiring means for acquiring information transmitted by optical wireless communication from the electrical signal converted by the light receiving means;
The optical wireless communication apparatus according to claim 1, further comprising: The selective transmission means includes a liquid crystal panel capable of controlling a light blocking area;
Light shielding control means for controlling the liquid crystal panel so that an area of the liquid crystal panel other than the position indicated by the communication light incident position information acquired by the incident position information acquiring means is a light blocking area; The optical wireless communication apparatus according to claim 6 provided. The optical wireless communication apparatus according to claim 5, wherein the light receiving means is a photodetector. The light source position detection unit repeatedly acquires the position information of the image of the optical wireless communication light source in the captured image,
The information acquisition unit acquires the communication light incident position information every time the light source position detection unit acquires position information of the optical wireless communication light source, and the optical wireless communication light source at a position indicated by the communication light incident position information. The optical wireless communication apparatus according to claim 1, wherein transmission target information that is information transmitted by optical wireless communication is acquired from the optical wireless communication apparatus. A selection instruction receiving unit that receives a selection instruction that is an instruction to select any one of the position information of the plurality of optical wireless communication light sources detected by the light source position detection unit;
The information acquisition unit acquires the communication light incident position information corresponding to the position information of the optical wireless communication light source specified by the selection instruction received by the selection instruction receiving unit, and at the position indicated by the communication light incident position information The optical wireless communication apparatus according to claim 1, wherein transmission target information that is information transmitted from the optical wireless communication light source by optical wireless communication is acquired. An optical wireless communication portable terminal comprising the optical wireless communication device according to claim 1. A transmission target information acquisition unit that acquires transmission target information that is information to be transmitted by optical wireless communication;
A modulation unit that modulates the transmission target information acquired by the transmission target information acquisition unit;
A marker signal output unit that is information used to detect a position of a light source that performs optical wireless communication, and outputs a marker signal having a frequency different from a frequency at which the modulation unit performs modulation.
A superimposing unit that superimposes transmission target information output from the modulation unit and a marker signal output from the marker signal output unit;
A transmission apparatus comprising: a transmission unit that transmits information including transmission target information and a marker signal superimposed by the superimposition unit. An optical wireless communication method performed using an imaging unit, a light source position detection unit, an information acquisition unit, and an output unit,
A photographing step in which the photographing unit photographs one or more light sources including an optical wireless communication light source that is a light source that performs optical wireless communication;
A light source position detecting unit that detects an optical wireless communication light source in a captured image that is an image acquired in the imaging step, and acquires position information that is position information of the optical wireless communication light source; and
The information acquisition unit acquires communication light incident position information, which is information of a position where light output from the optical wireless communication light source is incident, from the position information of the optical wireless communication light source acquired in the light source position detection step, An information acquisition step of acquiring transmission target information that is information transmitted by optical wireless communication from the optical wireless communication light source at the position indicated by the communication light incident position information;
An optical wireless communication method, comprising: an output step in which the output unit outputs the information acquired in the information acquisition step. Computer
A photographing unit that photographs one or more light sources including an optical wireless communication light source that is a light source that performs optical wireless communication;
A light source position detection unit that detects an optical wireless communication light source in a captured image that is an image acquired by the imaging unit, and acquires position information that is information on a position of the optical wireless communication light source;
From the position information of the optical wireless communication light source acquired by the light source position detection unit, communication light incident position information, which is information on a position where light output from the optical wireless communication light source is incident, is acquired, and the communication light incident position information An information acquisition unit that acquires transmission target information that is information transmitted by optical wireless communication from the optical wireless communication light source at the position indicated by:
The program for functioning as an output part which outputs the information which the said information acquisition part acquired.

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