JP2007019935A - Visible light communication system and method, visible light signal transmission apparatus, method, and program, visible light signal receiving apparatus, method, and program, and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain a data communication faster than conventional visible light communication. <P>SOLUTION: When receiving desired communication data comprising a binary bit string via a bus line 142 from a main CPU 20 at first, a light emission control CPU 14 divides the received bit string by 3 bits each from the start bit (S1). Then the light emission control CPU 14 references a pattern table stored in a pattern table storage section 12 to set a high (H) or low (L) level of R, G, B pulses to an LED driver 19 by each division bit string (S2). The LED driver 19 allows an LED group 17 to emit light in a timing in response to the R, G, B pulse settings (S3). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to visible light communication, and more particularly to visible light communication applicable to an imaging apparatus.

Conventionally, various visible light communications using light emitting means and light receiving elements have been developed. For example, Patent Document 1 discloses on-off keying (OOK). This is based on the pulse generation rule that a pulse is generated when the bit of communication data is [1] and no pulse is generated when the bit of communication data is [0], and the light intensity output based on the data series This is a method for transmitting and receiving a pulse train corresponding to communication data by controlling. For example, if the bit string of communication data is 1101, the setting pulse is set according to the bit string such as high, high, low, high, and the like. This document exemplifies a video camera recorder having an illumination device and a display as visible light output means.
JP 2004-72365 A

  When data is transmitted by conventional on / off keying, only 1-bit data can be transmitted by one light emission, and high-speed communication cannot be expected. The present invention has been made in view of such problems, and an object of the present invention is to provide a technique that enables data communication at higher speed than conventional visible light communication.

  In order to solve the above-mentioned problems, a visible light communication system according to the present invention includes an LED group composed of LEDs that emit R, G, and B visible light, a light emission control unit that sets a light emission pattern of the LED group, and a light emission control unit. A visible light signal transmission device including an LED driver that controls the light emission of the LED group according to the light emission pattern set in the above, and a light emission pattern storage unit that stores a table that defines the light emission pattern of the LED group corresponding to desired octal data The light emission control unit transmits an R, G, B visible light signal from the LED group by setting the light emission pattern of octal data constituting the desired communication data in the LED driver according to the table of the light emission pattern storage unit. Visible light signal transmission device, receiving side clock generator for outputting a vertical synchronization signal at the first frequency f1, receiving R light signal and taking R, G, B images An image sensor that outputs R, G, and B image signals in synchronization with a vertical synchronization signal that is output from the receiving clock generation unit, and an R, G, and B image signals that are output from the image sensor A / D conversion unit for converting to R, G, B image data, a received light amount detection unit for detecting the received light amount for each color of visible light signals of R, G, B based on R, G, B image data A receiving light emission pattern storage unit for storing a table defining a light emission pattern of an LED group corresponding to desired octal data, and R, G, B detected by the received light amount detection unit A light emission pattern discriminating unit that discriminates the light emission pattern of the LED group according to the amount of received light for each color of the visible light signal, and specifies octal data corresponding to the light emission pattern discriminated by the light emission pattern discriminating unit according to the table of the receiving side light emission pattern storage To do And a visible light signal reception apparatus having a specific unit.

  According to the present invention, desired octal data, that is, 3-bit data corresponding to 3-digit binary data can be transmitted and received by one light emission of the LED group, and theoretically 3 bits compared with the conventional on-off keying. Double the communication speed.

  Preferably, the visible light signal transmission device further includes a transmission side clock generation unit that outputs a transmission drive signal, which is a clock signal for driving the light emission control unit, at the second frequency f2, and the light emission control unit includes the emission side clock. The light emission pattern of the LED group is set in synchronization with the transmission drive signal output at the second frequency f2 from the generation unit.

  Preferably, the second frequency f2 satisfies f2 ≦ f1 / 2.

  In this way, an image signal for at least two frames can be obtained from the same visible light signal, and the reliability and reliability of communication can be ensured.

  Preferably, the visible light signal receiving device further includes a synchronization start signal transmission unit that transmits a synchronization start signal that instructs the visible light signal transmission device to start synchronization with the vertical synchronization signal from the receiving side clock generation unit. The optical signal transmission device further includes a synchronization start signal reception unit that receives the synchronization start signal transmitted from the synchronization start signal transmission unit, and the originating clock generation unit transmits at the timing when the synchronization start signal reception unit receives the synchronization start signal. The output timing of the drive signal is synchronized.

  Here, the second frequency f2 satisfies f2 = f1.

  If it carries out like this, a visible light signal can be transmitted synchronizing with the drive timing of the image pick-up element of a visible light signal receiver, and communication can be speeded up as much as possible.

  The synchronization start signal transmitter may be configured with an infrared transmitter that transmits an infrared signal, or may be configured with an LED group.

  The synchronization start signal receiving unit may be configured by a transmission side image sensor that receives an infrared signal transmitted from the synchronization start signal transmission unit, converts the infrared signal into R, G, and B imaging signals and outputs the signals.

  In this case, the visible light signal transmission device includes an emission side A / D conversion unit that converts R, G, and B image signals output from the emission side image sensor into R, G, and B image data; , B on the basis of the image data of the infrared signal, and on the side of the exposure on the basis of the brightness of the infrared signal measured by the light metering unit. It is preferable to further include a control unit.

  In this way, infrared signals can be received more reliably.

  Preferably, the visible light signal receiving device is configured to measure the brightness of the visible light signal based on the R, G, B image data, and the brightness of the visible light signal measured by the receiving light metering unit. A receiving-side exposure control unit that determines an appropriate aperture value and shutter speed based on the exposure value.

  By doing so, the visible light signal can be received more reliably.

  Specifically, the light emission pattern discriminating unit discriminates the light emission pattern of the LED group according to whether or not the light reception amount for each color of the R, G, B visible light signals detected by the light reception amount detection unit exceeds a predetermined threshold value. To do.

  In order to solve the above-described problem, a visible light signal transmission device according to the present invention includes an LED group including LEDs that emit R, G, and B visible light, and a light emission control unit that sets a light emission pattern of the LED group. A visible light signal transmission device including an LED driver that controls light emission of the LED group according to a light emission pattern set by the light emission control unit, the table defining a light emission pattern of the LED group corresponding to desired octal data The light emission control unit sets the light emission pattern of octal data constituting the desired communication data in the LED driver according to the table of the light emission pattern storage unit, so that the LED group R , G, B visible light signals are transmitted.

  According to the present invention, desired octal data, that is, 3-bit data corresponding to 3-digit binary data can be transmitted by one light emission of the LED group, theoretically three times as compared with conventional on-off keying. The communication speed can be secured.

  The visible light signal transmission device preferably outputs a vertical synchronization signal at the first frequency f1 and outputs a transmission drive signal that is a clock signal for driving the light emission control unit at the second frequency f2. The light emission control unit further sets a light emission pattern of the LED group in synchronization with the transmission drive signal output at the second frequency f2.

  The second frequency f2 preferably satisfies f2 ≦ f1 / 2.

  This visible light signal transmission device preferably further includes an image sensor that receives an infrared signal, converts it into an R, G, B image signal and outputs it.

  The image sensor receives a synchronization start signal that is an infrared signal that indicates the timing to start synchronization with the vertical synchronization signal from the visible light signal receiving device that is a communication partner, and the clock generator receives the synchronization start signal. The output timing of the transmission drive signal is synchronized with the timing.

  Here, the second frequency f2 satisfies f2 = f1.

  The visible light signal transmission device preferably includes an A / D conversion unit that converts R, G, and B image signals output from the image sensor into R, G, and B image data, and R, G, and B image signals. A photometric unit that measures the brightness of the infrared signal based on the image data, and an exposure control unit that determines an appropriate aperture value and shutter speed based on the brightness of the infrared signal measured by the photometric unit.

  In order to solve the above-described problem, a visible light signal receiving device according to the present invention includes a clock generation unit that outputs a vertical synchronization signal at a first frequency f1, and LEDs that emit R, G, and B visible light. R, G, and B visible light signals transmitted from the LED group are received and converted into R, G, and B imaging signals, and R, G, and B are synchronized with a vertical synchronization signal output from the clock generation unit. An image sensor that outputs an image signal of B, an A / D converter that converts an image signal of R, G, and B output from the image sensor into image data of R, G, and B, image data of R, G, and B Is a visible light signal receiving device including a received light amount detection unit that detects a received light amount for each color of R, G, B visible light signals based on the light emission pattern of the LED group corresponding to desired octal data Light emission pattern storage unit that stores a specified table and detection of received light amount The light emission pattern discriminating unit for discriminating the light emission pattern of the LED group according to the amount of light received for each color of the R, G, B visible light signals detected by the light source and the light emission pattern discriminated by the light emission pattern discriminating unit according to the table of the light emission pattern storage And a data specifying unit for specifying corresponding octal data.

  According to the present invention, desired octal data, that is, 3-bit data corresponding to 3-digit binary data can be received by one light emission of the LED group, theoretically three times as compared with conventional on-off keying. The communication speed can be secured.

  Preferably, the visible light signal receiving device transmits a synchronization start signal for instructing the visible light signal transmitting device as a communication partner to start synchronization with the vertical synchronization signal output from the clock generating unit. Is further provided.

  Preferably, the visible light signal receiving device includes a photometric unit that measures the brightness of a visible light signal based on R, G, and B image data, and an appropriate aperture based on the brightness of the visible light signal measured by the photometric unit. And an exposure control unit for determining a value and a shutter speed.

  Specifically, the light emission pattern discriminating unit discriminates the light emission pattern of the LED group according to whether or not the light reception amount for each color of the R, G, B visible light signals detected by the light reception amount detection unit exceeds a predetermined threshold value. To do.

  In order to solve the above-described problems, an imaging apparatus according to the present invention includes an LED group including LEDs that emit R, G, and B visible light, a light emission control unit that sets a light emission pattern of the LED group, and a light emission control unit. An imaging device comprising: an LED driver that controls the light emission of the LED group according to the light emission pattern set; and an imaging device that receives light, converts it into R, G, B imaging signals and outputs the signals, and outputs desired octal data The light emission pattern storage unit stores a table defining the light emission pattern of the LED group corresponding to the light emission pattern, and the light emission control unit sends the light emission pattern of octal data constituting the desired communication data to the LED driver according to the table of the light emission pattern storage unit. By setting, a visible light signal of R, G, B is transmitted from the LED group.

  In other words, the configuration of the imaging device according to the present invention is partly in common with the configuration of the visible light signal transmission device according to the present invention. Therefore, the number of additional parts and the cost required for transmitting a visible light signal in the imaging device can be reduced.

  In order to solve the above-described problem, an imaging apparatus according to the present invention includes an LED group including a clock generation unit that outputs a vertical synchronization signal at a first frequency f1, and LEDs that emit R, G, and B visible light. R, G, B visible light signals transmitted from the receiver are received and converted to R, G, B imaging signals, and R, G, B imaging is synchronized with the vertical synchronization signal output from the clock generator. An image sensor that outputs signals, an A / D converter that converts R, G, and B image signals output from the image sensor into R, G, and B image data, based on R, G, and B image data An imaging apparatus including a received light amount detection unit that detects a received light amount for each color of visible light signals of R, G, and B, and stores a table that defines a light emission pattern of an LED group corresponding to desired octal data R, G, detected by the light emission pattern storage unit and the received light amount detection unit A light emission pattern determination unit that determines the light emission pattern of the LED group according to the amount of received light for each color of the visible light signal, and octal data corresponding to the light emission pattern determined by the light emission pattern determination unit according to the table of the light emission pattern storage unit And a data specifying unit.

  That is, the configuration of the imaging apparatus according to the present invention is partially in common with the configuration of the visible light signal receiving apparatus according to the present invention. Therefore, the number of additional parts and the cost required for receiving the visible light signal in the imaging device can be reduced.

  In order to solve the above-described problem, a visible light signal transmission method according to the present invention is a visible light signal transmission method using a group of LEDs that emit R, G, B visible light, and a desired octal number. The step of storing a table defining the light emission pattern of the LED group corresponding to the data, and the light emission pattern of the octal data constituting the desired communication data are set in the LED driver according to the table, whereby the R, G, B from the LED group is set. Transmitting a visible light signal.

  In order to solve the above-described problem, a visible light signal receiving method according to the present invention receives R, G, B visible light signals transmitted from a group of LEDs that emit R, G, B visible light. A visible light signal receiving method, a step of storing a table defining a light emission pattern of an LED group corresponding to desired octal data, and receiving a visible light signal and converting it into R, G, B imaging signals. Outputting the R, G, B imaging signals to R, G, B image data, and R, G, B visible light signals based on the R, G, B image data. Corresponding to the step of detecting the amount of light received for each color, the step of determining the light emission pattern of the LED group according to the amount of light received for each color of the detected R, G, B visible light signals, and the light emission pattern determined according to the table Specify the octal data to be Tsu and a flop.

  In order to solve the above-described problem, a visible light signal communication method according to the present invention is a visible light communication method using a group of LEDs that emit R, G, and B visible light, and includes desired octal data. Storing a table defining the light emission pattern of the LED group corresponding to the LED group, and setting the light emission pattern of octal data constituting the desired communication data to the LED driver according to the table, so that R, G, B from the LED group A step of transmitting a visible light signal, a step of receiving a visible light signal transmitted from the LED group, converting it to an R, G, B imaging signal and outputting it, and an R, G, B imaging signal as R, G , B image data, converting the R, G, B visible light signals for each color based on the R, G, B image data, detecting the received R, G, B image data; For each color of B visible light signal Comprising the steps of: determining the emission pattern of the LED groups according to the received light amount, and identifying the octal data corresponding to the illumination pattern is determined according to the table.

  Moreover, in order to solve the above-mentioned subject, the visible light signal transmission program which concerns on this invention is an arithmetic unit which sets the LED pattern which consists of LED which light-emits visible light of R, G, B, and the light emission pattern of LED group. A visible light emission control unit, an LED driver that controls light emission of the LED group according to the light emission pattern set by the light emission control unit, and a light emission pattern storage unit that stores a table that defines the light emission pattern of the LED group corresponding to desired octal data A visible light signal transmission program executed in an optical signal transmission device, wherein a step for setting a light emission pattern of octal data constituting desired communication data in an LED driver according to a table of a light emission pattern storage unit is executed in the light emission control unit Let

  In order to solve the above-described problem, the visible light signal transmission program according to the present invention includes a clock generation unit that outputs a vertical synchronization signal at a first frequency f1, and a group of LEDs that emit R, G, and B visible light. R, G, B visible light signals transmitted from the receiver are received and converted to R, G, B imaging signals, and R, G, B imaging is synchronized with the vertical synchronization signal output from the clock generator. An image sensor that outputs signals, an A / D converter that converts R, G, and B image signals output from the image sensor into R, G, and B image data, based on R, G, and B image data A received light amount detection unit for detecting the received light amount for each color of R, G, B visible light signals, a light emission pattern storage unit for storing a table defining a light emission pattern of an LED group corresponding to desired octal data, and an arithmetic unit Can be implemented in a visible light signal receiving device comprising A light signal reception program, the step of determining the light emission pattern of the LED group according to the amount of received light for each color of the detected R, G, B visible light signal, and the light emission pattern determined according to the table of the light emission pattern storage unit And the step of specifying octal number data corresponding to.

  According to the present invention, desired octal data, that is, 3-bit data corresponding to 3-digit binary data can be transmitted and received by one light emission of the LED group, and theoretically 3 bits compared with the conventional on-off keying. Double the communication speed.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

<First Embodiment>
FIG. 1 is a block diagram of a transmission side digital camera 100 (hereinafter abbreviated as a transmission side camera 100) which is a preferred embodiment of a visible light signal transmission device according to the present invention. The originating camera 100 is provided with an operation unit 120 for performing various operations when the user uses the originating camera 100. The operation unit 120 includes a power switch 121 for turning on the power for operating the originating camera 100, a switching lever 122 for freely switching between shooting and playback, and a shooting mode dial for selecting auto shooting, manual shooting, and the like. 123, a cross key 124 for setting, selecting or zooming various menus, a flashing switch 125, and an information position specifying key 126 for executing or canceling the menu selected with the cross key 124. It has been.

  Further, the originating camera 100 is provided with an image display LCD 102 for displaying a photographed image, a reproduced image, and the like, and an operation LCD display 103 for assisting the operation.

  The originating camera 100 is provided with a release switch 104. The release switch 104 transmits a shooting start instruction to the main CPU 20. In the originating camera 100, the shooting / playback switching lever 122 can be switched between shooting and playback. When shooting, the user switches the shooting / playback switching lever 122 to the shooting side, and when shooting, shooting is performed. The playback switching lever 122 is switched to the playback side. Further, the light emitting side camera 100 is provided with a flash light emitting device having a flash light emitting tube 105a that emits flash light.

  In addition, the source camera 100 includes a photographing lens 101, a diaphragm 131, and a CCD sensor 132 that is an image sensor that converts a subject image formed through the photographing lens 101 and the diaphragm 131 into an analog image signal. And are provided. More specifically, the CCD sensor 132 generates an image signal by accumulating charges generated by subject light irradiated to the CCD sensor 132 for a variable charge accumulation time (exposure period). The CCD 132 sequentially outputs image signals for each frame at a timing synchronized with the vertical synchronization signal VD output from the CG unit 136.

  As shown in FIG. 2, minute color filters of R, G, and B are arranged in a matrix on the light receiving surface of the CCD 132, and an image pickup signal including each color component of R, G, and B has a white balance / γ After being amplified to an appropriate level by the processing unit 133, the A / D unit 134 converts the image data into R, G, and B images. The pixel arrangement of the CCD 132 is illustrated by taking a Bayer type as an example, but various arrangement methods such as a honeycomb type can be adopted and are not limited to those illustrated.

  When the CCD sensor 132 is used as the image sensor, an optical low-pass filter 132a that removes unnecessary high-frequency components in the incident light is disposed in order to prevent generation of color false signals, moire fringes, and the like. . In addition, an infrared cut filter 132b that absorbs or reflects infrared light in incident light and corrects a sensitivity characteristic unique to the CCD sensor 132 having high sensitivity in a long wavelength region is provided. There are various specific arrangement modes of the optical low-pass filter 132a and the infrared cut filter 132b. For example, the arrangement can be as described in paragraphs 0003 to 0004 of Japanese Patent Publication No. 2000-114502 by the present applicant. However, in order to perform infrared light communication as will be described later, the infrared cut filter 132b is disposed so as not to cover the invalid pixel region (region not used for image generation) of the CCD sensor 132, and the infrared light is invalidated. It is preferable that light can be received in the pixel region.

  Further, the source camera 100 adjusts the white balance of the subject image represented by the analog image signal from the CCD sensor 132 and adjusts the slope (γ) of the straight line in the gradation characteristic of the subject image, and further receives the analog image signal. A white balance / γ processing unit 133 including an amplification variable amplifier for amplification is provided.

  Further, the originating camera 100 includes an A / D unit 134 for A / D converting an analog signal from the white balance / γ processing unit 133 into digital R, G, B image data, and the A / D unit 134. A buffer memory 135 for storing R, G, B image data is provided.

  In this embodiment, the A / D unit 134 has an 8-bit quantization resolution, and outputs analog R, G, B image signals output from the white balance / γ processing unit 133 to R, G of levels 0 to 255. , B are converted into digital image data and output. However, this quantization resolution is merely an example and is not an essential value for the present invention.

  The originating camera 100 also includes a CG (clock generator) unit 136, a photometry / ranging CPU 137, a charge / emission control unit 138, a communication control unit 139, a YC processing unit 140, and a power battery 68. Is provided.

  The CG unit 136 includes a vertical synchronization signal VD for driving the CCD sensor 132, a drive signal including a high-speed sweep pulse P, a control signal for controlling the white balance / γ processing unit 133, the A / D unit 134, and a communication control unit. A control signal for controlling 139 is output. Further, a control signal from the photometry / ranging CPU 137 is input to the CG unit 136.

  The photometry / ranging CPU 137 measures the distance by driving the photographing lens 101 and the diaphragm 131 by a driving means (not shown) such as a motor driver, and controls the CG unit 136 and the charge / light emission control unit 138. When the release switch 104 is half-pressed, the photometry / ranging CPU 137 measures the brightness of the subject (EV) based on the image data periodically (every 1/30 seconds to 1/60 seconds) obtained by the CCD 132. Value calculation). Then, based on the obtained EV value, an exposure value including an aperture value (F value) of the aperture 131 and an electronic shutter (shutter speed) of the CCD 132 is determined according to a predetermined program diagram.

  When the release switch 104 is fully pressed, the photometry / ranging CPU 137 drives the aperture 131 based on the determined aperture value, controls the aperture diameter of the aperture 131, and controls the CG 136 based on the determined shutter speed. The charge accumulation time in the CCD 132 is controlled via (automatic exposure mechanism).

  The automatic exposure mechanism (AE mechanism) includes an aperture priority AE, a shutter speed priority AE, a program AE, and the like. In any case, an object brightness is measured, and an exposure value determined based on a photometric value of the object brightness. In other words, by taking a picture with a combination of the aperture value and the shutter speed, control is performed so that an image is taken with an appropriate exposure amount, and it is possible to save troublesome exposure determination.

  The photometry / ranging CPU 137 performs data communication with the main CPU 20.

  The charge / light emission control unit 138 is supplied with power from the power supply battery 68 to emit light from the flash light emission tube 105a, charges a flash light emission capacitor (not shown), and controls light emission from the flash light emission tube 105a. .

  The communication control unit 139 includes a communication port 107, and the communication control unit 139 outputs an image signal of a subject photographed by the originating camera 100 to an external device such as a personal computer equipped with a USB terminal. In addition, by inputting an image signal from such an external device to the originating camera 100, data communication with the external device is performed. The originating camera 100 has a function that simulates the ISO sensitivity 100, 200, 400, 1600, etc. of a normal camera that takes a photograph in a roll-shaped photographic film, and has an ISO sensitivity of 400 or more. When switched, the high-sensitivity mode is set in which the amplification factor of the amplifier of the white balance / γ processing unit 133 is set to a high amplification factor exceeding a predetermined amplification factor. The communication control unit 139 stops communication with the external device during shooting in the high sensitivity mode.

  Further, the originating camera 100 includes a compression / decompression & ID extraction unit 143 and an I / F unit 144. The compression / decompression & ID extraction unit 143 reads and compresses the image data stored in the buffer memory 135 via the bus line 142 and stores the image data in the memory card 200 via the I / F unit 144. In addition, the compression / decompression & ID extraction unit 143 extracts an identification number (ID) unique to the memory card 200 and reads the image data stored in the memory card 200 when reading the image data stored in the memory card 200. Are decompressed and stored in the buffer memory 135.

  In addition, the originating camera 100 includes a main CPU 20, an EEPROM 146, a YC / RGB conversion unit 147, and a display driver 148. The main CPU 20 controls the entire originating camera 100. The EEPROM 146 stores solid data and programs unique to the originating camera 100. The YC / RGB conversion unit 147 converts the color video signal YC generated by the YC processing unit 140 into RGB signals of three colors, and outputs them to the image display LCD 102 via the display driver 148.

  In addition, the originating camera 100 has a configuration in which an AC adapter 48 for obtaining power from an AC power supply and a power supply battery 68 are detachable. The power supply battery 68 is composed of a rechargeable secondary battery such as a nickel-cadmium battery, a nickel metal hydride battery, or a lithium ion battery. The power supply battery 68 may be a single-use primary battery such as a lithium battery or an alkaline battery. The power supply battery 68 is electrically connected to each circuit of the source camera 100 by being loaded into a battery storage chamber (not shown).

  The case where the AC adapter 48 is loaded in the originating camera 100 and power is supplied from the AC power source to the originating camera 100 via the AC adapter 48 is when the power battery 68 is loaded in the battery storage chamber. In addition, the power output from the AC adapter 48 is preferentially supplied to each part of the source camera 100 as driving power. In addition, when the AC adapter 48 is not loaded and the power battery 68 is loaded in the battery storage chamber, the power output from the power battery 68 is used as driving power for each part of the source camera 100. Supplied as

  Although not shown, the originating camera 100 is provided with a backup battery separately from the power supply battery 68 housed in the battery housing chamber. For example, a dedicated secondary battery is used as the built-in backup battery and is charged by the power supply battery 68. The backup battery supplies power to the basic function of the source camera 100 when the power battery 68 is not loaded in the battery storage chamber, such as when the power battery 68 is replaced or removed.

  That is, when the power supply from the power supply battery 68 or the AC adapter 48 is stopped, the backup battery is connected to the RTC 15 or the like by a switching circuit (not shown) and supplies power to these circuits. As a result, as long as the backup battery 29 does not reach the end of its life, power supply continues to the basic functions such as the RTC 15 without interruption.

  An RTC (Real Time Clock) 15 is a chip dedicated to timekeeping, and continuously operates by receiving power supply from the backup battery even when power supply from the power supply battery 68 or the AC adapter 48 is turned off.

  FIG. 3 is a block diagram of the communication light emitting device 16. The communication light emitting unit 16 includes a pattern table storage unit 12, a light emission control CPU 14, an LED group 17 (R, G, B LEDs 17R, 17G, 17B), a light control sensor 18, and an LED driver 19.

  The LED driver 19 takes in a light emission control signal indicating a light emission pattern, a light emission timing, a light emission time, a light emission amount, and the like from the light emission control CPU 14. The light emission pattern of the LED group 17 is stored in advance in the pattern table storage unit 12 including various storage media such as a nonvolatile memory.

  The light emission timing set in the LED driver 19 by the light emission control CPU 14 is synchronized with a transmission drive signal that is a clock signal output from the CG 136.

  The LED driver 19 controls the LED group 17 in accordance with a control signal from the light emission control CPU 14, and controls the light emission pattern, light emission timing, light emission time, and light emission amount of the R, G, B LEDs 17R, 17G, 17B. The electrical energy of the R, G, B LEDs 17R, 17G, 17B is supplied from the power supply battery 68 or the AC adapter 48.

  When the LED group 17 emits light, the light emission control CPU 14 detects the light emission amount via the light control sensor 18. When the detected light emission amount matches the reference value for adjusting the light emission amount, a light emission stop signal is output to the LED driver 19 in order to stop the light emission. When the light emission stop signal is input from the light emission control CPU 14, the LED driver 19 controls to stop the light emission of the LED group 17. Thereby, the electric current which flows into the LED group 17 from the power supply battery 68 is interrupted | blocked, and light emission of the LED group 17 stops.

  Although not shown, the configuration of the communication light emitting unit 16 may be made common to all or part of the configuration of the flash light emitting device or the conventional tally lamp and its light emission control device. For example, the light emission control CPU 14 and the photometry / ranging CPU 137 may be the same CPU. Alternatively, all or part of the LEDs 17R, 17G, and 17B may be configured in common with the tally lamp. In this way, the visible light transmitter according to the present invention can be realized without providing a special device in the conventional digital camera.

  FIG. 4 is a block diagram of a receiving digital camera 300 (hereinafter abbreviated as receiving camera 300) which is a preferred embodiment of the visible light signal receiving apparatus according to the present invention. In this figure, the same blocks as those of the originating camera 100 are denoted by the same reference numerals, and the configuration and function thereof are basically the same as described above, and the description thereof is omitted.

  The CCD 132 of the receiving camera 300 receives R, G, B visible light emitted from the communication light emitting device 16 of the emitting camera 100. Visible light received by the CCD 132 is converted into R, G, B image signals and output to the white balance / γ processing unit 133, subjected to predetermined processing, and then subjected to R, G, B in the A / D conversion unit 134. The conversion to the B image data is as described above.

  The R, G, B image data obtained by the A / D unit 134 is also input to the integrating circuit 150. The integration circuit 150 averages the R, G, B image data for each predetermined divided area of the screen and for each same color component, and further calculates the average of the R, G, B image data of all areas for each frame. Values Ir, Ig, and Ib are calculated. The integrated average values Ir, Ig, and Ib are used as the amounts of R, G, and B visible light received.

  However, the R, G, and B visible light receiving amounts Ir, Ig, and Ib can be detected by a light receiving sensor (not shown) other than the CCD 132 that has sensitivity to the R, G, and B visible lights, respectively. is there.

  As shown in FIG. 5, a communication system 500 according to the present invention includes an originating camera 100 and a receiving camera 300. Optical data transmission by visible light emission from the originating camera 100 and optical data reception by the receiving camera 300 are performed by the following communication operation.

Referring to FIG. 6, first, when the light emission control CPU 14 receives desired communication data including a binary bit string from the main CPU 20 via the bus line 142, the light emission control CPU 14 sets the received bit string to 3 bits from the start bit. Divide every time (S1). This 3-bit string is called a divided bit string. The divided bit string is a three-digit binary number, and is equivalent to an octal number representing 2 ³ = 8 patterns. When a bit string less than 3 bits is generated from the end of the communication data, “0” is added to the missing bit to forcibly form a divided bit string of 3 bits.

  Next, the light emission control CPU 14 refers to the pattern table (see FIG. 7) stored in the pattern table storage unit 12 and sets the high (H) or low (L) of the R, G, B pulse for each divided bit string. The LED driver 19 is set (S2).

  The light emission amount and the light emission time are also set, but the values are arbitrary. Further, the contents of the pattern table are not limited to those shown in FIG.

  Here, the pulse setting period of the light emission control CPU 14, that is, the generation period of the transmission drive signal by the CG unit 136 is synchronized with the charge accumulation period (exposure period) of the CCD 132 of the receiving camera 300. Although the specific aspect is demonstrated by below-mentioned embodiment, it is not specifically limited to this.

  The LED driver 19 causes the LED group 17 to emit light at a timing according to the R, G, and B pulse settings (S3).

  For example, if the bit string of communication data is 110001, first, the bit string is divided into “110” and “001” every three bits from the start bit (S1). Next, according to the pattern table, for the divided bit string “110”, the R pulse is set high, the G pulse is set high, and the B pulse is set low (S2, see FIG. 8). In this case, the LED 17R and the LED 17B emit light with the set light emission amount and light emission time, but the LED 17G does not emit light (S3).

  Hereinafter, communication data optically transmitted by the light emission of the LED group 17 is referred to as a visible light signal.

  Referring to FIG. 6 again, the receiving camera 300 receives the visible light signal transmitted from the communication light emitting device 16 by the CCD 132 (S4).

  The main CPU 20 of the receiving camera 300 determines the light emission pattern of the received visible light signal (S5). That is, the main CPU 20 inputs the received light amounts Ir, Ig, and Ib calculated by the integrating unit 150 or detected by a light receiving sensor (not shown) for the visible light received by the CCD 132, and the received light amounts Ir, Ig, and Ib are set to a predetermined threshold value. It is determined for each received light amount whether X is above or below X. If the received light amount Ir, Ig, Ib of a certain color exceeds the threshold value X, it is determined that the color is light emission (H), and if it is below the threshold value X, the color is determined to be non-light emission (L) ( (See FIG. 9).

  If the bit resolution of the A / D converter 134 is level 0 to 255 and the maximum level of received light amount of image data obtained by full light emission of the LED 17R, LED 17B, and LED 17G is 150, the predetermined threshold value X is 150. One example is to set X = 75.

  Then, in accordance with a pattern table stored in advance in the EEPROM 146 (the same as that stored in the originating camera 100), a divided bit string corresponding to the H, L emission pattern of R, G, B is specified (S6). . For example, when RGB visible light as shown in FIG. 9 is received, the divided bit string “110” is restored.

  This process is repeated in synchronization with the light emission period of RGB visible light. This repetition period is a period in which an image signal of one frame is read out if the light emission period of RGB is synchronized with the charge accumulation period of the CCD 132. Theoretically, the maximum communication speed is obtained.

  Then, a bit string in which the divided bit strings specified from the visible light signals sequentially received according to the light emission period are arranged in the light receiving order is restored as communication data (S7).

  As described above, in the communication system according to the present invention, 3-bit binary data (equivalent to octal) can be expressed by one light emission of the LED group 17, which is 1 in comparison with the conventional optical communication by on-off keying. Three times as much data can be transmitted per light emission.

  A program that causes the light emission control CPU 14 to execute the above-described communication operations S1 to S2 is stored in the pattern table storage unit 68 or other computer-readable storage medium. A program for causing the main CPU 20 to execute the above-described communication operations S5 to S7 is stored in an EEPROM 146 or other computer-readable storage medium.

Second Embodiment
In the communication system of the first embodiment, the light emission period of the communication light emitting device 16 can be considered variously. However, in order to ensure the reliability and reliability of communication, the following is preferable.

  That is, the CG 136 sets the frequency f2 of the transmission drive signal output to the light emission control CPU 14 to be ½ or less of the output frequency f1 of the vertical synchronization signal VD (that is, less than the Nyquist frequency of the output frequency f1). The light emission control CPU 14 sets the light emission pattern of the LED group 17 in synchronization with the transmission drive signal. For this reason, the light emission frequency of the LED group 17 becomes 1/2 or less of the output frequency f1 of the vertical synchronizing signal VD.

  FIG. 10 is a timing chart showing the relationship between the vertical synchronization signal VD of the receiving camera 300 and the generation cycle of the transmission drive signal of the originating camera 100 when f2 = f1 / 2, for example.

  The CCD 132 sequentially outputs image signals for each frame at a timing synchronized with the vertical synchronization signal VD. In this case, the period excluding the period in which the overflow drain signal OFD indicating the timing of discarding excess charge by the overflow drain (Overflow Drain) provided in the CCD 132 is input to the CCD 132 is substantially equal to the exposure period (charge accumulation period) of the CCD 132. Become.

  Here, since the frequency f1 of the transmission drive signal is ½ or less of the output frequency f1 of the vertical synchronization signal VD, the CCD 132 uses the same light emission pattern at least twice from the communication light emitting device 16 within the period. Upon exposure, an image signal for at least two frames can be obtained from the same visible light signal. For this reason, the communication data obtained based on the image signal obtained from the CCD 132 has a time redundancy of 50% or more. The receiving camera 300 can ensure the reliability and reliability of communication by performing error check and error correction using the redundancy of communication data.

<Third Embodiment>
In the communication system of the first embodiment, in order to increase the communication speed between the originating camera 100 and the receiving camera 300 as compared with the second embodiment, the following may be performed.

  That is, the CG 136 of the source camera 100 outputs the vertical synchronization signal VD as a transmission drive signal. In this way, the light emission cycle is simply doubled compared to the second embodiment, but if this light emission cycle does not match the exposure period of the receiver camera 300, the receiver camera 300 cannot receive a visible light signal.

  For this reason, as shown in FIG. 11, the synchronization start signal transmitter 30 is provided in the receiving camera 300 of the first embodiment. The synchronization start signal transmitter 30 optically transmits a synchronization start signal to the source camera 100, and includes, for example, the communication light emitting device 16 of the first embodiment. In this case, the synchronization start signal is transmitted by light emission of R, G, and B.

  The communication synchronization operation for synchronizing the light emission timing of the communication light emitting device 16 of the receiving camera 300 with the vertical synchronization signal VD of the receiving camera 300 will be described below with reference to FIG.

  First, the synchronization start signal transmission unit 30 transmits a synchronization start signal in synchronization with the output timing of the vertical synchronization signal VD output from the CG unit 136 of the receiving camera 300 (S101).

  When the originating camera 100 receives the synchronization start signal from the synchronization start signal transmitter 30 by the CCD 132 (S102), the main CPU 20 outputs the vertical synchronization signal VD of the CG unit 136 at the timing when the synchronization start signal is received. Are controlled to be synchronized (S103).

  The light emission control CPU 14 synchronizes the output of the light emission timing signal to the LED driver 19 with the vertical synchronization signal VD output from the CG unit 136. Accordingly, the LED group 17 emits a visible light signal in synchronization with the vertical synchronization signal VD of the receiving camera 300 (S104), and the CCD 132 of the receiving camera 300 receives the visible light signal in synchronization with the exposure period ( S105).

  The program for causing the main CPU 20 to execute the above-described communication synchronization operation S102 is stored in an EEPROM 146 or other computer-readable storage medium.

  FIG. 13 shows a source VD that is a vertical synchronization signal output from the CG unit 136 of the source camera 100 and a receiver VD that is a vertical synchronization signal output from the CG unit 136 of the receiver camera 300 in the communication synchronization operation. The relationship between the light reception timing of a start signal and the light emission timing of the communication light-emitting device 16 is shown. As shown in this figure, since the synchronization start signal is synchronized with the receiving side VD, the output timing of the originating side VD is also synchronized with the receiving side VD. Since the light emission timing is synchronized with the transmission side VD, the light emission timing is eventually synchronized with the reception side VD. Therefore, the receiving camera 300 can obtain 3-bit data from the image signal of each frame.

  As described above, the light emission timing of the communication light-emitting device 16 is synchronized with the light-emitting side VD by this operation, and theoretically, a communication speed at least twice that of the communication system of the second embodiment can be secured.

<Fourth embodiment>
In the first to third embodiments, the intensity of light received from the communication light emitting device 16 increases or decreases depending on the usage environment of the communication light emitting device 16 (installation position, distance, etc.). In this case, the amount of light incident on the CCD 132 may be over or under, which may hinder communication.

  Therefore, the photometry / ranging CPU 137 performs the following exposure control operation. That is, as shown in FIG. 14, the brightness of visible light from the communication light emitting device 16 incident on the CCD 132 is measured (S51), and an exposure value suitable for communication is determined according to the measured brightness (S52). The exposure value suitable for communication includes an aperture value suitable for communication (communication aperture value) and a shutter speed suitable for communication (communication shutter speed). The photometry / ranging CPU 137 drives the aperture 131 according to the determined aperture value for communication, and controls the aperture diameter of the aperture 131. The photometry / ranging CPU 137 controls the charge accumulation time in the CCD 132 via the CG 136 based on the determined communication shutter speed (S53).

  For example, when the photometry / ranging CPU 137 measures the brightness below a predetermined first threshold, the maximum aperture value on the open side (the limit value that does not work for larger aperture diameters) is set accordingly. Decide on a value. Further, for example, when the photometry / ranging CPU 137 measures the brightness above a predetermined second threshold value, the minimum aperture value on the small aperture side (the limit value that does not operate to a smaller aperture diameter) is set accordingly. Determine the communication aperture value. By doing this, it is possible to prevent over / under of the amount of received visible light signal.

<Fifth Embodiment>
The synchronization start signal transmitter 30 of the third embodiment may be configured with an infrared light transmitter for infrared communication. In this case, as shown in FIG. 15, an infrared light receiving circuit 63 is provided in the outgoing camera 100. Then, as shown in FIG. 16, the source camera 100 receives a synchronization start signal and other various infrared signals from the synchronization start signal transmitter 30 of the receiver camera 300. The infrared light receiving circuit 63 converts the incident infrared signal into a digital signal and outputs the digital signal to the main CPU 20.

  The receiving camera 300 can also receive an infrared signal by the CCD 132. That is, if infrared light passes through the optical low-pass filter 132a and reaches the light receiving surface of the CCD 132, the infrared light received by the CCD 132 is used as white light, and the infrared light receiving circuit 63 is used as a substitute. . Thereby, the CCD 132 can detect not only visible light but also an infrared signal emitted from the synchronization start signal transmitting unit 30, and a special configuration such as the infrared light receiving circuit 63 can be omitted.

  The CCD 132 converts the infrared light incident from the synchronization start signal transmission unit 30 (representing the synchronization start signal and other various control signals) into R, G, and B image signals and outputs them to the white balance / γ processing unit 133. The white balance / γ processing unit 133 amplifies the image signal, and the A / D conversion unit 134 digitally converts the image signal into R, G, B image data and outputs the image data to the main CPU 20. The main CPU 20 controls various operations such as an operation of the communication light emitting device 16 and an imaging operation in accordance with the image data input from the A / D conversion unit 134.

  With such a configuration, the source camera 100 can receive data by receiving infrared light from the receiver camera 300 with the CCD 132. Communication using R, G, B visible light signals corresponds to the downlink, and communication using infrared rays corresponds to the uplink.

  Here, when receiving data by receiving infrared light with the CCD 132, the same problem as in the fifth embodiment also occurs. That is, if the intensity of the infrared light received from the synchronization start signal transmission unit 30 configured by the infrared light transmission device increases or decreases, the amount of light incident on the CCD 132 becomes over or under, which hinders communication. there is a possibility.

  Therefore, the photometry / ranging CPU 137 measures the brightness of infrared light from the communication light emitting device 16 incident on the CCD 132, and determines an exposure value suitable for communication according to the measured brightness. The exposure value suitable for communication includes an aperture value suitable for communication (communication aperture value) and a shutter speed suitable for communication (communication shutter speed). The photometry / ranging CPU 137 drives the diaphragm 131 according to the determined communication diaphragm value, and controls the aperture diameter of the diaphragm 131. The photometry / ranging CPU 137 controls the charge accumulation time in the CCD 132 via the CG 136 based on the determined communication shutter speed. This operation is the same as the exposure control operation (see FIG. 14) of the fourth embodiment.

  By so doing, information optically transmitted from the communication light emitting device 16 can be received more reliably.

<Sixth Embodiment>
In the first to fifth embodiments, the configurations of the originating camera 100 and the receiving camera 300 are not necessarily distinguished. That is, as shown in FIG. 17, a digital camera 400 having both configurations may be provided. However, in order to simplify the configuration, the configuration of the synchronization start signal transmitter 30 is made common with the communication light emitting device 16. In this way, as shown in FIG. 18, bidirectional communication is possible between the cameras 400-A and B having the same configuration by emitting and receiving RGB visible light.

Block diagram of the sending digital camera Arrangement of R, G, B minute color filters on the CCD light receiving surface Block diagram of light emitting device for communication Block diagram of the receiving digital camera Configuration diagram of communication system Flow chart showing the flow of communication operation Conceptual illustration of pattern table The figure which shows an example of the setting pulse of R, G, B The figure which shows an example of received light quantity Ir, Ig, and Ib which the integrating | accumulating part calculated Timing chart showing the relationship between vertical sync signal and transmission drive signal generation period Block diagram of the receiving digital camera provided with a synchronization start signal transmitter Flow chart showing flow of communication synchronization operation Timing chart showing the relationship between the emitting side VD, the receiving side VD, the light receiving timing of the synchronization start signal, and the light emitting timing of the communication light emitting device Flow chart showing flow of exposure control operation Block diagram of the sending digital camera with infrared light receiving circuit Diagram showing the state of infrared communication in a communication system Block diagram of a digital camera with the configuration of the originating camera and receiving camera Diagram showing the state of bidirectional communication between digital cameras using RGB visible light

Explanation of symbols

14: Light emission control CPU, 17: LED group, 19: LED driver, 16: Communication light emitting device, 20: Main CPU, 30: Synchronization signal transmitter, 63: Infrared light receiving circuit, 131: Aperture, 132: CCD, 134 : A / D converter, 150: Integration circuit

Claims (29)

LED group composed of LEDs that emit visible light of R, G, and B, a light emission control unit that sets a light emission pattern of the LED group, and an LED driver that controls light emission of the LED group according to the light emission pattern set by the light emission control unit A light emission pattern storage unit that stores a table that defines a light emission pattern of the LED group corresponding to desired octal data, and the light emission control unit configures desired communication data A visible light signal transmission device for transmitting R, G, B visible light signals from the LED group by setting a light emission pattern of octal data to the LED driver according to a table of the light emission pattern storage unit;
A receiving-side clock generating unit that outputs a vertical synchronizing signal at a first frequency f1, a vertical synchronizing signal that receives the visible light signal, converts it into R, G, and B imaging signals, and is output from the receiving-side clock generating unit An image sensor that outputs the R, G, and B image signals in synchronization with the signal, and an A / D that converts the R, G, and B image signals output from the image sensor into R, G, and B image data A visible light signal receiving apparatus including a conversion unit, a received light amount detection unit that detects a received light amount for each color of the R, G, and B visible light signals based on the R, G, and B image data, Receiving side light emission pattern storage unit for storing a table defining the light emission pattern of the LED group corresponding to the octal number data, and the received light amount for each color of the R, G, B visible light signals detected by the received light amount detection unit To determine the light emission pattern of the LED group according to Over emissions determination unit, a visible light signal receiving apparatus comprising data identifying unit for identifying the discriminated octal data corresponding to the light emission pattern of the light emission pattern determination unit in accordance with the table of the receiving-side emission pattern storage unit,
A visible light communication system. The visible light signal transmission device is:
An emission side clock generation unit that outputs a transmission drive signal, which is a clock signal for driving the light emission control unit, at a second frequency f2,
2. The visible light communication system according to claim 1, wherein the light emission control unit sets a light emission pattern of the LED group in synchronization with a transmission drive signal output at the second frequency f <b> 2 from the emission side clock generation unit. The second frequency f2 is
f2 ≦ f1 / 2
The visible light communication system according to claim 2, wherein: The visible light signal receiving device further includes a synchronization start signal transmitting unit that transmits a synchronization start signal that instructs the visible light signal transmitting device to start synchronization with the vertical synchronization signal from the receiving clock generation unit,
The visible light signal transmission device further includes a synchronization start signal receiving unit that receives a synchronization start signal transmitted from the synchronization start signal transmission unit,
The visible light communication system according to claim 2, wherein the source-side clock generation unit synchronizes the output timing of the transmission drive signal with the timing at which the synchronization start signal reception unit receives the synchronization start signal. The second frequency f2 is
f2 = f1
The visible light communication system according to claim 4, wherein:   The visible light communication system according to claim 4 or 5, wherein the synchronization start signal transmitter is configured by an infrared transmitter that transmits an infrared signal.   The said synchronization start signal receiving part is comprised by the transmission side image sensor which light-receives the infrared signal transmitted from the said synchronization start signal transmission part, converts into the imaging signal of R, G, B, and outputs it. Visible light communication system. The visible light signal transmission device is:
An originating A / D converter that converts R, G, B imaging signals output from the originating image sensor into R, G, B image data;
A light emitting side photometric unit that measures the brightness of the infrared signal based on the image data of R, G, B;
An emission side exposure control unit for determining an appropriate aperture value and shutter speed based on the brightness of the infrared signal measured by the emission side photometry unit;
The visible light communication system according to claim 7, further comprising: The visible light signal receiving device includes:
A receiving-side photometry unit that measures the brightness of the visible light signal based on the R, G, and B image data;
A receiving side exposure control unit that determines an appropriate aperture value and shutter speed based on the brightness of the visible light signal measured by the receiving side photometry unit;
The visible light communication system according to claim 1, further comprising:   The light emission pattern discriminating unit discriminates a light emission pattern of the LED group according to whether or not the light reception amount for each color of the R, G, B visible light signals detected by the light reception amount detection unit exceeds a predetermined threshold value. The visible light communication system in any one of 1-9.   The visible light communication system according to claim 1, wherein the octal data includes a three-digit binary data string. LED group composed of LEDs that emit visible light of R, G, and B, a light emission control unit that sets a light emission pattern of the LED group, and an LED driver that controls light emission of the LED group according to the light emission pattern set by the light emission control unit A visible light signal transmission device comprising:
A light emission pattern storage unit for storing a table defining a light emission pattern of the LED group corresponding to desired octal data;
The light emission control unit transmits visible light signals of R, G, and B from the LED group by setting a light emission pattern of octal data constituting desired communication data in the LED driver according to the table of the light emission pattern storage unit. Visible light signal transmitter. An emission-side clock generation unit that outputs a vertical synchronization signal at a first frequency f1 and outputs a transmission drive signal that is a clock signal for driving the light emission control unit at a second frequency f2.
The visible light signal transmission device according to claim 12, wherein the light emission control unit sets a light emission pattern of the LED group in synchronization with a transmission drive signal output at the second frequency f2. The second frequency f2 is
f2 ≦ f1 / 2
The visible light signal transmission device according to claim 13, wherein:   The visible light signal transmission device according to claim 13, further comprising an image sensor that receives an infrared signal, converts the image signal into an R, G, and B image signal and outputs the image signal. The imaging device receives a synchronization start signal that is an infrared signal that indicates the timing to start synchronization with a vertical synchronization signal from a visible light signal receiving device that is a counterpart of communication,
The visible light signal transmission device according to claim 15, wherein the clock generation unit synchronizes an output timing of the transmission drive signal with a timing at which the imaging element receives the synchronization start signal. The second frequency f2 is
f2 = f1
The visible light signal transmission device according to claim 16 satisfying An A / D converter that converts R, G, and B image signals output from the image sensor into R, G, and B image data;
A photometric unit that measures the brightness of the infrared signal based on the R, G, B image data;
An exposure controller that determines an appropriate aperture value and shutter speed based on the brightness of the infrared signal measured by the photometer; and
The visible light signal transmission device according to claim 15, further comprising: A clock generator that outputs a vertical synchronization signal at the first frequency f1, and receives R, G, and B visible light signals transmitted from a group of LEDs that emit R, G, and B visible light and receives R , G, and B image signals that are converted into an image signal that outputs the R, G, and B image signals in synchronization with a vertical synchronizing signal that is output from the clock generator, and R and G signals that are output from the image sensor. An A / D converter that converts G and B imaging signals into R, G, and B image data, and for each color of the R, G, and B visible light signals based on the R, G, and B image data A visible light signal receiving device including a received light amount detection unit for detecting a received light amount,
A light emission pattern storage unit for storing a table defining a light emission pattern of the LED group corresponding to desired octal data;
A light emission pattern discriminating unit for discriminating a light emission pattern of the LED group according to the amount of light received for each color of the R, G, B visible light signals detected by the light reception amount detection unit;
A data specifying unit for specifying octal data corresponding to the light emission pattern determined by the light emission pattern determination unit according to the table of the light emission pattern storage unit;
A visible light signal receiving device.   The synchronization start signal transmission part which transmits the synchronization start signal which instruct | indicates the timing which starts a synchronization with the vertical synchronizing signal which the said clock generation part outputs to the visible light signal transmission apparatus used as the other party of communication is further provided. Visible light signal receiver. A photometric unit that measures the brightness of the visible light signal based on the R, G, and B image data;
An exposure control unit that determines an appropriate aperture value and shutter speed based on the brightness of a visible light signal measured by the photometry unit;
The visible light signal receiving device according to claim 19 or 20, further comprising:   The light emission pattern discriminating unit discriminates a light emission pattern of the LED group according to whether or not the light reception amount for each color of the R, G, B visible light signals detected by the light reception amount detection unit exceeds a predetermined threshold value. The visible light signal receiving device according to any one of 19 to 21. LED group composed of LEDs that emit visible light of R, G, and B, a light emission control unit that sets a light emission pattern of the LED group, and an LED driver that controls light emission of the LED group according to the light emission pattern set by the light emission control unit An imaging device including an imaging device that receives light, converts it into R, G, and B imaging signals and outputs the signals;
A light emission pattern storage unit for storing a table defining a light emission pattern of the LED group corresponding to desired octal data;
The light emission control unit transmits visible light signals of R, G, and B from the LED group by setting a light emission pattern of octal data constituting desired communication data in the LED driver according to the table of the light emission pattern storage unit. An imaging device. A clock generator that outputs a vertical synchronization signal at the first frequency f1, and receives R, G, and B visible light signals transmitted from a group of LEDs that emit R, G, and B visible light and receives R , G, and B image signals that are converted into an image signal that outputs the R, G, and B image signals in synchronization with a vertical synchronizing signal that is output from the clock generator, and R and G signals that are output from the image sensor. An A / D converter that converts G and B imaging signals into R, G, and B image data, and for each color of the R, G, and B visible light signals based on the R, G, and B image data An imaging apparatus including a received light amount detection unit that detects a received light amount,
A light emission pattern storage unit for storing a table defining a light emission pattern of the LED group corresponding to desired octal data;
A light emission pattern discriminating unit for discriminating a light emission pattern of the LED group according to the amount of light received for each color of the R, G, B visible light signals detected by the light reception amount detection unit;
A data specifying unit for specifying octal data corresponding to the light emission pattern determined by the light emission pattern determination unit according to the table of the light emission pattern storage unit;
An imaging apparatus comprising: A visible light signal transmission method using a group of LEDs that emit R, G, B visible light,
Storing a table defining a light emission pattern of the LED group corresponding to desired octal data;
Transmitting an R, G, B visible light signal from the LED group by setting a light emission pattern of octal data constituting desired communication data in the LED driver according to the table;
A visible light signal transmission method including: A visible light signal receiving method for receiving R, G, B visible light signals transmitted from an LED group emitting visible light of R, G, B,
Storing a table defining a light emission pattern of the LED group corresponding to desired octal data;
Receiving the visible light signal, converting it into R, G, B imaging signals and outputting them;
Converting the R, G, B imaging signals into R, G, B image data;
Detecting the amount of received light for each color of the visible light signals of R, G, B based on the R, G, B image data;
Discriminating the light emission pattern of the LED group according to the amount of received light for each color of the detected R, G, B visible light signals;
Specifying octal data corresponding to the determined light emission pattern according to the table;
A visible light signal receiving method. A visible light communication method using a group of LEDs that emit R, G, B visible light,
Storing a table defining a light emission pattern of the LED group corresponding to desired octal data;
Transmitting visible light signals of R, G, B from the LED group by setting a light emission pattern of octal data constituting desired communication data in the LED driver according to the table;
Receiving a visible light signal transmitted from the LED group, converting the received visible light signal into an R, G, and B imaging signal;
Converting the R, G, B imaging signals into R, G, B image data;
Detecting the amount of received light for each color of the visible light signals of R, G, B based on the R, G, B image data;
Discriminating the light emission pattern of the LED group according to the amount of received light for each color of the detected R, G, B visible light signals;
Specifying octal data corresponding to the determined light emission pattern according to the table;
A visible light communication method. An LED group composed of LEDs that emit visible light of R, G, and B, a light emission control unit that is an arithmetic unit for setting a light emission pattern of the LED group, and light emission of the LED group according to the light emission pattern set by the light emission control unit A visible light signal transmission program that is executed in a visible light signal transmission device including an LED driver to be controlled and a light emission pattern storage unit that stores a table that defines a light emission pattern of the LED group corresponding to desired octal data,
A visible light signal transmission program for causing the light emission control unit to execute a step of setting a light emission pattern of octal data constituting desired communication data in the LED driver according to a table of the light emission pattern storage unit. A clock generation unit that outputs a vertical synchronization signal at a first frequency f1, R, G, and B visible light signals transmitted from a group of LEDs that emit R, G, and B visible light; An image pickup device that converts the image pickup signal of B into an image signal and outputs the image pickup signal of R, G, B in synchronization with a vertical synchronization signal output from the clock generation unit, and an output device of R, G, B output from the image pickup device An A / D converter that converts the image pickup signal into R, G, and B image data, and the received light amount for each color of the R, G, and B visible light signals based on the R, G, and B image data Visible light signal reception executed in a visible light signal receiving device including a received light amount detection unit to detect, a light emission pattern storage unit that stores a table that defines a light emission pattern of the LED group corresponding to desired octal data, and an arithmetic unit A program,
Discriminating the light emission pattern of the LED group according to the amount of received light for each color of the detected R, G, B visible light signals;
Specifying octal data corresponding to the determined light emission pattern according to the table of the light emission pattern storage unit;
Visible light signal receiving program for causing the arithmetic unit to execute.

Images