JP2007147994A - Display device with data communication function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device with a data communication function which is capable of stable visible light communication and allows an image like a moving image to be displayed on a display face as desired even during visible light communication. <P>SOLUTION: A first digital camera 2 includes a LCD panel 43 capable of displaying an image and a LED 41 for radiating the LCD panel 43 with illuminating light and is configured so that an image to be displayed on the LCD panel 43 is processed in accordance with brightness of this image before display of the image on the LCD panel 43 and the LED 41 is blinked with the processed image on the LCD panel 43 to transmit an optical signal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a display device having a data communication function configured to display an image on a display unit and output an optical signal by blinking a light emitting unit.

  Conventionally, data communication methods such as wired communication, wireless communication, and infrared communication have been widely used as methods for communicating data between a plurality of devices. In wired communication, a transmitting device and a receiving device are connected using a cable, and data is transmitted and received via the cable. In wireless communication, the transmitting device and the receiving device are connected wirelessly using a wireless LAN or the like. Data is transmitted and received by using radio waves as a communication medium. In infrared communication, data is transmitted and received by using infrared as a communication medium.

  However, in wire communication, it is indispensable to connect a transmission device and a reception device with a cable prior to transmitting and receiving data. Therefore, the user is forced to perform troublesome work. In addition to the necessity of setting, it is necessary that both the transmission device and the reception device have a dedicated wireless communication unit. In addition, in infrared communication, as well as wireless communication, both the transmission device and the reception device need not only have a dedicated communication unit, but also transmit large amounts of data because the communication speed is slow. It was difficult to do.

  Therefore, in recent years, visible light communication using visible light such as illumination light as a communication medium has been proposed, and in order to improve the communication speed, visible light using a light-emitting element that can blink at high speed, such as an LED, as a transmission unit. Communication systems are being developed.

  In such a visible light communication system, as long as it has a light-emitting element that can blink at high speed, it can be used as a transmission device without a dedicated communication unit. In addition, a visible light communication system using an LED provided as a backlight for a transmission unit has been proposed.

For example, Patent Document 1 discloses a visible light communication system that transmits data by blinking an LED provided as a backlight at a high speed on a display device of a mobile phone, and Patent Document 2 discloses an output. There has been disclosed a visible light communication system that uses a display device of an audio device as a data transmission device by blinking an LED provided as a backlight of a level meter for displaying a sound level at high speed. Furthermore, Patent Document 3 discloses a visible light communication system that transmits data by displaying a white image on an LCD panel and blinking an LED provided as a backlight at a high speed in that state.
JP 2004-185492 A JP 2004-248128 A JP 2004-246274 A

  However, in the visible light communication system for transmitting data by blinking the LED provided as the backlight, there is a merit that an existing display device can be used, while the light emitted from the LED is Since the light is output to the outside after passing through the LCD panel, the intensity of light emitted from the display surface when the LED emits light is greatly affected by the light transmission state of the LCD panel.

  For this reason, in the display device of the visible light communication system disclosed in Patent Document 1, when an image with a large luminance variation such as a moving image is displayed during data communication, the display surface is displayed when the LED is emitted. There is a problem that the intensity of light emitted from the light source fluctuates and it becomes impossible to transmit and receive data stably.

  Also, when a dark image such as a night view is displayed on the LCD panel, the intensity of light emitted from the display surface when the LED emits light is greatly attenuated by the LCD panel. And when the light emission of the LED is stopped, the difference in intensity of the light emitted from the display surface is reduced, and as a result, it is difficult for the receiving device side to detect the light emission of the LED and the stop of the light emission. It was.

  On the other hand, in the display device of the visible light communication system disclosed in Patent Document 2, an image is displayed on the display device by using a display device that displays a specific image called a bar graph indicating the level of the audio signal. However, in such a case, there is a problem that the displayed image is limited to a specific image called a bar graph.

  On the other hand, in the display device of the visible light communication system disclosed in Patent Document 3, the LED provided as the backlight is blinked in a state where a white image is displayed on the display surface, and thus stable. However, since the image cannot be displayed on the display device while the data is being transmitted / received, the original function of the display device for displaying the image is impaired. There was a problem.

  As described above, in the display device of the conventional visible light communication system, it is impossible to stably output an optical signal while displaying a desired image on the display device. Therefore, stable visible light communication is performed. Further, it has been desired to develop a display device having a data communication function capable of displaying an image such as a moving image on a display surface as desired during visible light communication.

  Therefore, an object of the present invention is to enable stable visible light communication and to display an image such as a moving image on the display surface as desired during visible light communication. The object is to provide a display device having a data communication function.

  The object of the present invention includes a display panel capable of displaying an image, and a light emitting means for irradiating the display panel with illumination light, displaying an image on the display panel and blinking the light emitting means. In a display device having a data communication function configured to output an optical signal, prior to displaying an image on the display panel, the display panel according to the brightness of the image to be displayed on the display panel This is achieved by a display device having a data communication function, wherein an image to be displayed is processed, and the light emitting means is blinked in a state where the processed image is displayed on the display panel.

  The object of the present invention is also provided with a display panel capable of displaying an image and light emitting means for irradiating the display panel with illumination light, displaying an image on the display panel, and blinking the light emitting means. Switching between a first image to be displayed on the display panel and a second image brighter than the first image in a display device having a data communication function configured to output an optical signal This is achieved by a display device having a data communication function, characterized in that the light emitting means blinks while the second image is displayed.

  According to the present invention, stable visible light communication can be performed, and an image such as a moving image can be displayed on a display surface as desired even during visible light communication. .

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

  FIG. 1 is a schematic diagram showing a configuration of a visible light communication system according to a preferred embodiment of the present invention.

  As shown in FIG. 1, in the visible light communication system 1 according to the present embodiment, the display device 4 of the first electronic camera 2 functions as a transmission device, and the display device 7 of the second electronic camera 5 It functions as a receiving device, and is configured to receive data transmitted from the display device 4 of the first electronic camera 2 by the display device 7 of the second electronic camera 5.

  FIG. 2 is a schematic perspective view showing the configuration of the display device 4 of the first electronic camera 2.

  As shown in FIG. 2, the display device 4 includes a plurality of LEDs 41 functioning as a light source, a light guide plate 42 that spreads light emitted from the LEDs 41 in a planar shape, and an LCD panel 43 that controls a transmission amount of incident light. And. The LCD panel 43 has a plurality of display pixels arranged in a matrix, and is configured to be able to control the light transmission amount for each display pixel.

  In the display device 4 having such a configuration, light emitted from the LED 41 and incident on the light guide plate 42 is diffused by the light diffusion dots 44 provided in the light guide plate 42 and then enters the LCD panel 43. The light incident on the LCD panel 43 is partially transmitted through the LCD panel 43 or attenuated or blocked by the LCD panel 43. As a result, an image whose brightness is finely adjusted in units of display pixels is displayed on the display surface 43a of the LCD panel 43, and a specific image, character, or the like is displayed.

  In the present embodiment, the LCD panel 43 has the lowest light transmittance when a power supply voltage is applied to the display pixels, and the highest light transmittance when a ground voltage is applied to the display pixels. It is comprised by the normally white type | mold LCD panel which becomes.

  FIG. 3 is a block diagram showing the configuration of the first electronic camera 2.

  As shown in FIG. 3, the first electronic camera 2 includes a CCD 21 that captures an image and generates image data, a signal processing unit 22 that performs predetermined signal processing on the image data output from the CCD 21, A frame memory 23 that has a recording capacity capable of recording image data for frames, records image-processed image data in units of frames, an LCD panel 43, and an LCD controller 24 that controls the operation of the LCD panel 43. The LED 41, the LED controller 25 that controls the operation of the LED 41, the VRAM (Video RAM) 26 that records the image data of the image displayed on the LCD panel 43, and the data that is transmitted by visible light communication is modulated into a predetermined format The average brightness (average luminance) of the image displayed on the data modulation unit 27 and the LCD panel 43 is calculated. A luminance calculator 28; a CPU 29 that controls the operation of the entire first electronic camera 2; a ROM 30 that records a control program for the first electronic camera 2; a RAM 31 that functions as a buffer memory for various image processing; An operation unit in which operation buttons such as a setting button for setting various setting conditions in addition to a shutter button for taking an image and a mode switching button for switching the operation mode of the first electronic camera 2 are arranged. 32.

  In the present embodiment, the first electronic camera 2 has a “shooting mode” for shooting an image, a “playback mode” for playing back the shot image, and data for the second electronic camera 5. Three operation modes, “data transmission mode” for transmission, can be selectively switched.

  The LCD controller 24 is a circuit for controlling a voltage applied to each display pixel of the LCD panel 43 in accordance with image data of an image displayed on the LCD panel 43, and the operation mode of the first electronic camera 2 is “ Regardless of the mode set to “shooting mode”, “reproduction mode”, or “data transmission mode”, a predetermined image is applied to the LCD panel 43 without fixing the voltage applied to the LCD panel 43 to the ground voltage. Is displayed.

  The LED controller 25 is a circuit for controlling the light emission of the LED 41 and the stop of the light emission. When the operation mode of the first electronic camera 2 is set to “shooting mode” or “playback mode”, While the LED 41 is caused to emit light and function as a backlight for illumination, when the operation mode of the first electronic camera 2 is set to the “data transmission mode”, the content of data output from the data modulation unit 27 is changed. In response, the LED 41 blinks, and the LED 41 functions as a transmission unit for data transmission using visible light. Specifically, the data value “1” of the data output from the data modulation unit 27 is associated with the light emission of the LED 41, and the data value “0” is associated with the stop of the light emission of the LED 41, and the predetermined transmission cycle is set. Synchronously, the light emission time and light emission stop time of the LED 41 are controlled.

  As described above, in the present embodiment, when the operation mode of the first electronic camera 2 is set to the “data transmission mode”, the LED 41 displays the data while the predetermined image is displayed on the LCD panel 43. It is controlled to function as a transmission unit, and an optical signal is output.

  The data modulation unit 27 is a circuit for pulse-coding data to be transmitted by visible light communication. As the pulse encoding method, various modulation methods by PWM (Pulse Width Modulation) can be used, but in order to prevent the occurrence of bias in the number of “0” or “1” in the encoded data, It is preferable to use a modulation method by Manchester encoding.

  Here, as shown in FIG. 4, when the data to be encoded is “1”, the first half of the 1-bit period of the data is set to “1” and the second half is the modulation method by Manchester encoding. In this encoding method, when data is modulated to “0” and the data to be encoded is “0”, the first half of the 1-bit period of data is modulated to “0” and the second half to “1”. In such a modulation method by Manchester encoding, both “0” and “1” correspond to encoded data regardless of whether the data to be encoded is “1” or “0”. Therefore, it is possible to prevent a bias from occurring in the number of “0” or “1” in the encoded data.

  Based on the image data recorded in the frame memory 23, the luminance calculation unit 28 calculates an average luminance level when an image corresponding to the image data is displayed on the LCD panel 43. As described above, the frame memory 23 has a recording capacity capable of recording image data for a plurality of frames. Since the image data for a plurality of frames is recorded in the frame memory 23, the luminance calculation unit 28 An average luminance level is calculated for each of a plurality of frames of image data.

  The CPU 29 functions as a control unit that controls the overall operation of the first electronic camera 2, and when the operation mode of the first electronic camera 2 is set to “data transmission mode”, the display surface of the LCD panel 43. In order to adjust the average luminance level of the entire 43a to a luminance level at which an optical signal can be transmitted and received, the image data recorded in the frame memory 23 is compressed and the display size is reduced as shown in FIG. The image data of the image 35 and the image data of the brightness adjustment image 36 for adjusting the average brightness of the entire display surface 43a are generated.

  Further, the CPU 29 determines whether or not the average luminance level of the image calculated by the luminance calculation unit 28 is included between the upper limit value Yru and the lower limit value Yrl of the preset reference luminance level, and the determination result Accordingly, the level of the image data of the brightness adjustment image 36 and the size of the brightness adjustment image 36 are set.

  Here, the upper limit value Yru and the lower limit value Yrl of the reference brightness level are a brightness level Y1 that is too bright to transmit and receive optical signals, a brightness level Y2 that does not adversely affect the transmission and reception of optical signals, and the optical signal transmission and reception. Therefore, the brightness level is set according to three brightness levels Y3 which are too dark. That is, as shown in FIG. 6, the upper limit value Yru of the reference luminance level is set at the boundary between the luminance level Y1 and the luminance level Y2, and the lower limit value Yrl of the reference luminance level is the boundary between the luminance level Y2 and the luminance level Y3. Set to

  Further, the reference level and the reference size are determined in advance for the level of the image data of the brightness adjustment image 36 and the size of the brightness adjustment image 36, and the reference level of the image data of the brightness adjustment image 36 and the reference size of the brightness adjustment image 36. Is a luminance level when an image whose average luminance level is included between the upper limit value Yru and the lower limit value Yrl of the reference luminance level is displayed, that is, the average luminance level of the image does not interfere with transmission / reception of an optical signal. If the brightness adjustment image 36 is displayed, the level and size are set so as not to affect the average brightness level of the entire display surface 43a.

  In particular, the reference size of the brightness adjustment image 36 is such that as the size of the brightness adjustment image 36 increases, the size of the reduced image 35 decreases and the reduced image 35 may become difficult to see. The area occupied by the brightness adjustment image 36 in 43a is set to be smaller than the area occupied by the reduced image 35. Specifically, the reference size of the brightness adjustment image 36 is such that the vertical and horizontal lengths are about 0.2 times the vertical length of the display surface 43a of the LCD panel 43 and the horizontal length, respectively. It is preferable to set the length to about 0.2 times the length.

  FIG. 7 is a schematic perspective view showing the configuration of the display device 7 of the second electronic camera 5.

  As shown in FIG. 7, the display device 7 of the second electronic camera 5 includes a plurality of LEDs 71, a light guide plate 72 having a plurality of light diffusion dots 74, an LCD panel 73 having a display surface 73a, and a photodiode. 75. The display device 7 of the second electronic camera 5 has the same configuration as that of the display device 4 of the first electronic camera 2 except that the display device 7 includes a photodiode 75.

  The photodiode 75 is disposed so that its light receiving surface faces the light guide plate 72, and receives light incident on the light guide plate 72 from the outside of the second electronic camera 5 via the LCD panel 73. To function.

  Similarly to the LCD panel 43 shown in FIG. 2, the LCD panel 73 is a normally white type LCD panel.

  FIG. 8 is a block diagram showing the configuration of the second electronic camera 5.

  As shown in FIG. 8, the second electronic camera 5 includes a CCD 51, a signal processing unit 52, a frame memory 53, an LCD panel 73, an LCD controller 54, an LED 71, an LED controller 55, and a VRAM 56. , A photodiode 75, a data reproducing unit 57, a CPU 59, a ROM 60, a RAM 61, and an operation unit 62, and a “photographing mode” for photographing an image and a “reproduction” for reproducing the photographed image. Three operation modes, “mode” and “data reception mode” for receiving data transmitted from the first electronic camera 2, can be selectively switched.

  In the second electronic camera 5 according to the present embodiment, the CCD 51, the signal processing unit 52, the frame memory 53, the ROM 60, the RAM 61, and the operation unit 62 are the CCD 21, the signal processing unit 22, and the frame memory 23 shown in FIG. The ROM 30, the RAM 31, and the operation unit 32 have the same configuration.

  When the operation mode of the second electronic camera 5 is set to “shooting mode” or “reproduction mode”, the LCD controller 54 applies a voltage to be applied to the LCD panel 73 according to an image to be displayed on the display surface 73a. However, when the operation mode of the second electronic camera 5 is set to “data reception mode”, the voltage applied to the LCD panel 73 is fixed to the ground voltage, and the light transmittance of the LCD panel 73 is increased. Make it the highest.

  Further, when the operation mode of the second electronic camera 5 is set to “shooting mode” or “reproduction mode”, the LED controller 55 causes the LED 71 to emit light and function as a backlight for illumination. When the operation mode of the electronic camera is set to “data reception mode”, the light emission of the LED 71 is stopped so that light is not incident on the LCD panel 73 from the LED 71 and the light guide plate 72 side.

  As described above, in the present embodiment, when the operation mode of the second electronic camera 5 is set to the “data reception mode”, no light is emitted from the inside of the display device 7. The light incident on the LCD panel 7 from outside 5 is efficiently transmitted through the LCD panel 73 and guided to the light receiving surface of the photodiode 75 through the light guide plate 72.

  The data reproduction unit 57 samples the data output from the photodiode 75 in synchronization with the transmission cycle of the optical signal, and decodes the encoded data to reproduce the data transmitted from the first electronic camera 2. To do.

  The CPU 59 functions as a control unit that controls the overall operation of the second electronic camera 5 and also operates in the operation mode of the second electronic camera 5 in order to prevent the photodiode 75 from receiving light emitted from the LED 71. Is set to “shooting mode” or “playback mode”, the photodiode 75 is turned off, and only when the operation mode of the second electronic camera 5 is set to “data reception mode”. Start up.

  The visible light communication system 1 according to the present embodiment having the above-described configuration transmits data from the first electronic camera 2 to the second electronic camera 5 as follows.

  FIG. 9 is a time chart illustrating a procedure of data transmission / reception processing executed by the visible light communication system 1. Here, after the moving image of the subject is captured by the first electronic camera 2, the captured moving image image data is displayed in a state where the captured moving image is displayed on the LCD panel 43 of the first electronic camera 2. A case will be described as an example of transmission to the second electronic camera 5 by an optical signal.

  In photographing a subject with the first electronic camera 2, as shown in FIG. 8, first, the operation mode of the first electronic camera 2 is set to "photographing mode" (step S1-1).

  Next, a moving image of the subject is taken by the first electronic camera 2, and image data is generated by the CCD 21 and the signal processing unit 22 of the first electronic camera 2 (step S1-2). The image data generated in this way is recorded in the frame memory 23 of the first electronic camera 2.

  Next, in order to transmit the image data recorded in the first electronic camera 2 to the second electronic camera 5, the operation unit 32 is operated by the user, and the operation mode of the first electronic camera 2 is set to “data transmission”. The mode is switched to “mode”, and image data of the captured moving image is selected as image data to be transmitted to the second electronic camera 5 (step S1-3).

  On the second electronic camera 5 side, in order to receive the image data transmitted from the first electronic camera 2, the operation unit 62 is operated by the user, and the operation mode of the second electronic camera 5 is “ The mode is switched to “data reception mode” (step S2-1).

  Thereafter, the first electronic camera 2 and the second electronic camera 5 are arranged so that the LCD panel 43 of the first electronic camera 2 faces the LCD panel 73 of the second electronic camera 5.

  When the operation mode of the second electronic camera 5 is switched to the “data reception mode”, the voltage applied to the LCD panel 73 is set to the ground voltage by the LCD controller 54 (step S2-2). At the same time, the light emission of the LED 71 is stopped and the photodiode 75 is activated by the CPU 59 (steps S2-3 and S2-4).

  On the other hand, on the first electronic camera 2 side, when the operation mode is switched to the “data transmission mode”, the image data of the image recorded in the frame memory 23 is output to the data modulation unit 27 and modulated by the data modulation unit 27. Processing is performed (step S1-4). The image data subjected to the modulation process is recorded in the RAM 31 or an internal memory (not shown) provided in the LED controller 25.

  Next, image data of an image to be displayed on the LCD panel 43 while the image data is transmitted as an optical signal from the first electronic camera 2 (hereinafter may be referred to as “image to be displayed”). Then, it is read from the frame memory 23, and the average luminance level of the image data is calculated by the luminance calculation unit 28 (step S1-5).

  Here, since the moving image corresponding to the image data transmitted by the optical signal and the moving image displayed on the LCD panel 43 during the transmission of the optical signal are the same, from the frame memory 23, The image data obtained by the processing of step S1-1 and step S1-2 is read, and the average luminance level is calculated by the luminance calculation unit 28.

  When the average luminance level of the image to be displayed on the LCD panel 43 is calculated, the calculated average luminance level is output to the CPU 29. The CPU 29 calculates the calculated average luminance level as the upper limit value Yru and the lower limit value of the reference luminance level. It is determined whether or not included in Yrl (step S1-6).

  As a result of the determination, if the calculated average luminance level is included between the upper limit value Yru and the lower limit value Yrl of the reference luminance level, the image for which the average luminance level is calculated is displayed on the LCD panel 43. In this state, since the optical signal can be transmitted and received even if the LED 41 is blinked, the level of the image data of the brightness adjustment image 36 and the size of the brightness adjustment image 36 are set to the reference level and the reference size, respectively. . At the same time, the image data of the image to be displayed on the LCD panel 43 is read from the frame memory 23 while the optical signal is being transmitted, and the display size of the image is reduced according to the size of the brightness adjustment image 36. Therefore, the image data is compressed.

  On the other hand, when the calculated average luminance level of the image is lower than the lower limit value Yrl of the reference luminance level, the display surface is displayed when the image for which the average luminance level is calculated is displayed on the LCD panel 43. Since the average luminance level of 43a does not reach a luminance level sufficient for transmitting and receiving an optical signal, the CPU 29 sets the level of the image data of the luminance adjustment image 36 to a level higher than the reference level, and the luminance adjustment image. The size of 36 is set to a size larger than the reference size.

  In the present embodiment, the image data level of the brightness adjustment image 36 and the size of the brightness adjustment image 36 are changed by first setting the image of the brightness adjustment image 36 in a state where the size of the brightness adjustment image 36 is set to the reference level. Only when the data level is increased and the image data level is increased, the size of the brightness adjustment image 36 is increased only when the average brightness level of the entire display surface 43a does not reach the lower limit value Yrl of the reference brightness level. Is done.

  On the other hand, when the calculated average luminance level of the image is higher than the upper limit value Yru of the reference luminance level, the average of the display surface 43 a is displayed when the image for which the average luminance level is calculated is displayed on the LCD panel 43. Since the brightness level becomes excessive, the CPU 29 sets the level of the image data of the brightness adjustment image 36 to a level lower than the reference level, and sets the size of the brightness adjustment image 36 to a size smaller than the reference size. .

  Even when the level of the image data of the brightness adjustment image 36 is set to a level lower than the reference level and the size of the brightness adjustment image 36 is made smaller than the reference size, first, the level of the image data of the brightness adjustment image 36 is reduced. Nevertheless, the size of the brightness adjustment image 36 is reduced only when the average brightness level of the entire display surface 43a is not less than or equal to the upper limit value Yru of the reference brightness level.

  Thus, when the size of the reduced image 35, the level of the image data of the brightness adjustment image 36, and the size of the brightness adjustment image 36 are set, the image data of the reduced image 35 and the image data of the brightness adjustment image 36 are generated. It is recorded in the frame memory 23 (step S1-7).

  A series of processes including the above-described calculation process of the average brightness level (step S1-5), the comparison process with the reference brightness level (step S1-6), and the setting process of the brightness adjustment image 36 (step S1-7) are performed by the LED 41. When a moving image is displayed on the LCD panel 43 while the light signal is transmitted by blinking, the image data of a plurality of frames scheduled to be displayed is executed in units of frames. Therefore, for example, when an image of 30 frames is displayed while the light signal is transmitted by blinking the LED 41, these processes are repeatedly executed 30 times.

  On the other hand, when a still image is displayed on the LCD panel 43 while the LED 41 is blinked and an optical signal is transmitted, the average luminance level calculation process (step S1-5) is not performed because the average luminance of the display surface 43a does not fluctuate. ), The process of comparing with the reference brightness level (step S1-6) and the process of setting the brightness adjusted image 36 (step S1-7) are executed only once before the still image is displayed.

  Next, the image data of the brightness adjustment image 36 is read from the frame memory 23 together with the image data of the reduced image 35, and the CPU 29 compresses the image data according to the number of display pixels of the LCD panel 43 and the compression. The recorded image data is recorded in the VRAM 26.

  The image data recorded in the VRAM 26 is output to the LCD controller 24, and a voltage corresponding to the image data is applied from the LCD controller 24 to the LCD panel 43 in synchronization with a predetermined display cycle. In this way, as shown in FIG. 5, the reduced image 35 whose display size has been changed and the brightness adjustment image 36 provided around the reduced image 35 are displayed on the LCD panel 43 (step S1-8).

  At the same time, the modulated image data recorded in the RAM 31 or the like is output to the LED controller 25, the LED controller 25 controls the light emission timing of the LED 71, and the LED 71 blinks (step S1-9). Thus, an optical signal is transmitted from the LCD panel 43 of the first electronic camera 2 toward the LCD panel 73 of the second electronic camera 5.

  The optical signal transmitted toward the LCD panel 73 of the second electronic camera 5 passes through the LCD panel 73 and is received by the photodiode 75 via the light guide plate 72 (step S2-4). Thereafter, the output signal of the photodiode 75 is output to the data reproducing unit 57, and the image reproducing unit 57 reproduces the image data transmitted from the first electronic camera 2 (step S2-5). In this way, image data is transmitted from the first electronic camera 2 to the second electronic camera 5.

  As described above, in the present embodiment, while the LED 41 is blinked and the optical signal is transmitted, the reduced image 35 with the reduced display size and the reduced image 35 are displayed on the LCD panel 43 of the first electronic camera 2. The brightness adjustment image 36 is displayed so as to surround the periphery, and by adjusting the image data level of the brightness adjustment image 36 and the size of the brightness adjustment image 36, the average brightness of the entire display surface 43a transmits and receives an optical signal. It has been adjusted to be at a sufficient level. For this reason, even if an optical signal is transmitted in a state where an image is displayed on the LCD panel 43, the difference in intensity of light emitted from the display surface 43a between when the LED 41 emits light and when the LED 41 stops emitting light, Receiving the optical signal can be kept large enough. Therefore, stable visible light communication can be performed even if the LED 41 is blinked in a state where an image with a large luminance variation such as a moving image is displayed on the LCD panel 43.

  Further, in the present embodiment, the image to be displayed on the LCD panel 43 is reduced according to the size of the brightness adjustment image 36 to generate the reduced image 35. A part of the image is not displayed, and the entire image to be displayed can be displayed even while the optical signal is transmitted.

  Further, in the present embodiment, even when the average luminance level of the image is included between the upper limit value Yru and the lower limit value Yrl of the reference luminance level, the image data of the luminance adjustment image 36 is generated and the luminance adjustment is performed. Since the image 36 is displayed, the display size of the reduced image 35 is frequently enlarged or reduced, and it is possible to suppress annoyance when viewing the image.

  In the present embodiment, when changing the image data level of the brightness adjustment image 36 and the size of the brightness adjustment image 36, the image data level of the brightness adjustment image 36 is preferentially changed. It can be further suppressed that the display size of the reduced image 35 is frequently enlarged or reduced to feel annoying when viewing the image.

  FIG. 10 is a block diagram showing the configuration of the first electronic camera used in the visible light communication system 1 according to another preferred embodiment of the present invention, which is the same as the first electronic camera 2 shown in FIG. The same reference numerals are assigned to the configurations.

  As shown in FIG. 10, the first electronic camera 80 includes a CCD 21, a signal processing unit 22, a frame memory 23, an LCD panel 43, an LCD controller 24, an LED 41, an LED controller 25, and a VRAM 26. A data modulation unit 27, a luminance calculation unit 28, a CPU 81, a ROM 30, a RAM 31, and an operation unit 32. As will be described later, the function of the CPU 81 is different from the function of the CPU 29 shown in FIG. Except for this point, it has the same configuration as the first electronic camera 2 shown in FIG.

  The CPU 81 functions as a control unit that controls the overall operation of the first electronic camera 80. When the operation mode of the first electronic camera 80 is set to the “data transmission mode”, the display surface of the LCD panel 43 is displayed. In order to adjust the average luminance of the entire 43a to a luminance level at which an optical signal can be transmitted and received, as shown in FIG. 11, an image of a normal size scheduled to be displayed on the LCD panel 43 (hereinafter, referred to as “normal image”). .) The image data of the brightness adjustment image 96 displayed superimposed on 95 is generated.

  The level of the brightness adjustment image 96 and the size of the brightness adjustment image 96 are set in advance in the same manner as the level of the brightness adjustment image 36 and the size of the brightness adjustment image 36 shown in FIG. It has been established. The reference level of the image data of the brightness adjustment image 96 and the reference size of the brightness adjustment image 96 are displayed when an image whose average brightness level is included between the upper limit value Yru and the lower limit value Yrl of the reference brightness level is displayed. When the average luminance level of the image is a luminance level sufficient for transmitting an optical signal, the level and size are set so as not to affect the average luminance level of the entire display surface 43a even when the luminance adjustment image 96 is displayed. Has been.

  In addition, the reference size of the brightness adjustment image 96 is larger as the size of the brightness adjustment image 96 is larger, so that the area superimposed on the normal image 95 is larger and the area of the LCD panel 43 that can display the normal image 95 is smaller. The area occupied by the brightness adjustment image 96 in the displayable area of the LCD panel 43 is set to be smaller than the area occupied by the normal image 95. Specifically, the reference size of the brightness adjustment image 96 is set so that the area occupied by the brightness adjustment image 96 in the displayable area of the LCD panel 43 is about 1/10 or less of the area occupied by the normal image 95. It is preferred that

  On the other hand, the position where the brightness adjustment image 96 is displayed is not set as a reference position, and is set within the area displaying the background in the normal image 95, and the area displaying the background. When is large, it is set to a portion of the area where the luminance level is low.

  Further, the shape of the brightness adjustment image 96 is preferably set to a shape indicating a direction such as a triangle or an arrow in order to inform the user that an optical signal is being transmitted, but does not necessarily indicate the direction. The shape need not be set, and may be other shapes such as a circle or a rectangle.

  When the optical signal is transmitted to the second electronic camera 5 using the first electronic camera 80 having the above-described configuration, the optical signal is transmitted in the same manner as the first electronic camera 2 shown in FIG. Prior to transmitting the signal, first, the image data of the image to be displayed on the LCD panel 43 is read from the frame memory 23 while the image data is transmitted as an optical signal from the first electronic camera 80, The average luminance level is calculated by the luminance calculation unit 28.

  Next, the CPU 81 determines whether or not the calculated average luminance level is included between the upper limit value Yru and the lower limit value Yrl of the reference luminance level, and the calculated average luminance level is the upper limit value Yru of the reference luminance level. And the lower limit value Yrl, the image data level of the brightness adjustment image 96 and the size of the brightness adjustment image 96 are set to the reference level and the reference size, respectively.

  On the other hand, when the calculated average brightness level of the image is lower than the lower limit value Yrl of the reference brightness level, the average brightness level of the display surface 43a of the LCD panel 43 is equal to or higher than the lower limit value Yrl of the reference brightness level. As described above, the level of the image data of the brightness adjustment image 96 is set to a level higher than the reference level, and the size of the brightness adjustment image 96 is set to a size larger than the reference size.

  On the other hand, when the calculated average brightness level of the image is higher than the upper limit value Yru of the reference brightness level, the average brightness level of the display surface 43a of the LCD panel 43 is equal to or lower than the upper limit value Yru of the reference brightness level. The level of the image data of the brightness adjustment image 96 is set to a level lower than the reference level, and the size of the brightness adjustment image 96 is set to a size smaller than the reference size.

  Also in the present embodiment, when adjusting the level of the image data of the brightness adjustment image 96 and the size of the brightness adjustment image 96, first, similarly to the first electronic camera 2 shown in FIG. In the state where the size of the image is set to the reference level, only the level of the image data of the brightness adjustment image 96 is changed, and even if the level of the image data is changed, the average brightness level of the entire display surface 43a remains Only when the lower limit value Yrl is not reached or when the lower limit value Yru is not reached, the size of the brightness adjustment image 96 is changed.

  Thus, when the level of the image data of the brightness adjustment image 96 and the size of the brightness adjustment image 96 are set, image data of the brightness adjustment image 96 is generated, and an image obtained by superimposing the brightness adjustment image 96 on the normal image 95 is generated. Image data is generated and recorded in the frame memory 23.

  Thereafter, in a state where an image obtained by superimposing the brightness adjustment image 96 on the normal image 95 is displayed on the LCD panel 43, the LED 41 blinks in accordance with data to be transmitted to the second camera 5, and the second camera The optical signal is transmitted toward the LCD panel 73 of No. 5.

  As described above, in this embodiment, while the LED 41 is blinked and an optical signal is transmitted, an image in which the brightness adjustment image 96 is superimposed on the normal image 95 is displayed on the LCD panel 43 of the first electronic camera 80. By adjusting the level of the image data of the brightness adjustment image 96 and the size of the brightness adjustment image 96, the average brightness of the entire display surface 43a is adjusted to a level sufficient to transmit / receive optical signals. Yes. Therefore, similarly to the first electronic camera 2 shown in FIG. 3, even if the LED 41 blinks in a state where an image with a large luminance variation such as a moving image is displayed on the LCD panel 43, stable visible light communication is possible. It becomes possible to do.

  FIG. 12 is a block diagram showing a configuration of a first electronic camera used in the visible light communication system 1 according to still another preferred embodiment of the present invention. The first electronic camera 2 shown in FIG. The same code | symbol is attached | subjected about the same structure.

  As shown in FIG. 12, the first electronic camera 100 includes a CCD 21, a signal processing unit 22, a frame memory 23, an LCD panel 43, an LCD controller 24, an LED 41, an LED controller 25, and a VRAM 26. A data modulation unit 27, a luminance calculation unit 28, a CPU 101, a ROM 30, a RAM 31, and an operation unit 32. As will be described later, the function of the CPU 101 is different from the function of the CPU 29 shown in FIG. Except for this point, it has the same configuration as the first electronic camera 2 shown in FIG.

  The CPU 101 functions as a control unit that controls the overall operation of the first electronic camera 100, and is calculated by the luminance calculation unit 28 when the operation mode of the first electronic camera 100 is set to “data transmission mode”. The average luminance level of the image to be compared is compared with the reference luminance level, and the calculated average luminance level of the image is lower than the lower limit value Yrl of the reference luminance level or higher than the upper limit value Yru of the reference luminance level As shown in FIG. 13, the image data of the brightness adjustment image 105 in which the average brightness level of the image scheduled to be displayed on the LCD panel 43 is increased or decreased is generated.

  In the present embodiment, the CPU 101 has a conversion table for converting the level of the image data, and changes the level of the image data using the conversion table to generate the brightness adjustment image 105.

  FIG. 14 is a schematic diagram illustrating a conversion table. In FIG. 14, the horizontal axis of the conversion table indicates the input level of the image data, and the vertical axis indicates the output level of the image data.

  When the average luminance level of the image scheduled to be displayed on the LCD panel 43 is increased, as shown by the curve A in FIG. 14, the conversion table 110 has a maximum or minimum level of image data to be subjected to table conversion. The closer the level is, the lower the amplification factor is set. The closer the level of the image data subject to table conversion is to the intermediate level, the higher the amplification factor is set.

  On the other hand, when the average luminance level of the image to be displayed on the LCD panel 43 is reduced, as shown by the curve B in FIG. 14, the conversion table 110 has the maximum level of the image data to be converted. Alternatively, the reduction rate is set to be lower as the level is closer to the minimum level, and the reduction rate is set to be higher as the level of image data to be subjected to table conversion is closer to the intermediate level. .

  The patterns of curves A and B in the conversion table 110 are set according to the magnitude of the difference between the average luminance level of the image calculated by the luminance calculation unit 28 and the upper limit value Yru or the lower limit value Yrl of the reference luminance level. The For example, when the difference between the average luminance level of the image subject to table conversion and the lower limit value Yrl is small, the conversion is performed so that the amplification factor at the intermediate level is low as shown in FIG. The pattern of the curve A of the table 110 is set. On the other hand, when the difference between the average level of the image subject to table conversion and the lower limit Yrl is large, the conversion is performed so that the amplification factor at the intermediate level is large as shown in FIG. The pattern of the curve A of the table 110 is set.

  When the optical signal is transmitted to the second electronic camera 5 using the first electronic camera 100 having the above configuration, the optical signal is transmitted in the same manner as the first electronic camera 2 shown in FIG. Prior to transmitting a signal, first, image data of an image to be displayed is read from the frame memory 23 during transmission of an optical signal, and an average luminance level is calculated by a luminance calculation unit 28.

  Next, the CPU 101 determines whether or not the calculated average brightness level is included between the upper limit value Yru and the lower limit value Yrl of the reference brightness level, and the calculated average brightness level is the upper limit value Yru of the reference brightness level. And the lower limit value Yrl, the image data of the image for which the average luminance level is to be calculated is directly converted into the image of the luminance adjusted image 105 without converting the level of the image data. It is recorded in the frame memory 23 as data.

  In contrast, when the calculated average luminance level of the image is lower than the lower limit value Yrl of the reference luminance level, the difference between the calculated average luminance level of the image and the lower limit value Yrl of the reference luminance level is set. Accordingly, the curve A pattern of the conversion table 110 is set, and the level of the image data of the image for which the average luminance level is calculated is increased by using the conversion table 110 in which the curve A pattern is set. Image data of the adjusted image 106 is generated.

  Further, even when the calculated average luminance level of the image is higher than the upper limit value Yru of the reference luminance level, according to the magnitude of the difference between the calculated average luminance level of the image and the upper limit value Yru of the reference luminance level, The curve B pattern of the conversion table 110 is set, and using the conversion table 110 in which the curve B pattern is set, the level of the image data of the image for which the average luminance level is calculated is reduced, and the luminance adjusted image 106 is set. Image data is generated.

  The brightness adjustment image 106 generated in this way is recorded in the frame memory 23, and thereafter, the brightness adjustment image 106 is displayed on the LCD panel 43. In this state, the LED 41 blinks, and the LCD panel of the second camera 5 is displayed. An optical signal is transmitted to the terminal 73.

  As described above, in the present embodiment, while the light signal is transmitted by blinking the LED 41, the brightness adjustment image 106 whose average brightness level is increased or decreased is used instead of the image originally scheduled to be displayed on the LCD panel 43. As in the first electronic camera 2 shown in FIG. 3, even if the LED 41 is blinked in a state where an image with a large luminance variation such as a moving image is displayed on the LCD panel 43, as in the first electronic camera 2 shown in FIG. It becomes possible to perform stable visible light communication.

  In the present embodiment, the patterns of the curves A and B in the conversion table 110 are obtained by calculating the difference between the average luminance level of the image calculated by the luminance calculating unit 28 and the upper limit value Yru or the lower limit value Yrl of the reference luminance level. By setting according to the size, the increase / decrease rate of the brightness level is set according to the average brightness level of the image scheduled to be displayed on the LCD panel 43. Therefore, regardless of the average brightness level of the image to be displayed, the average brightness level of the image is converted to ensure that it is sufficient to perform visible light communication. can do.

  FIG. 16 is a block diagram showing a configuration of a first electronic camera used in the visible light communication system 1 according to still another preferred embodiment of the present invention. The first electronic camera 2 shown in FIG. The same code | symbol is attached | subjected about the same structure.

  As shown in FIG. 16, the first electronic camera 200 according to the present embodiment includes a CCD 21, a signal processing unit 22, a frame memory 23, an LCD panel 43, an LCD controller 24, an LED 41, and an LED controller. 201, a VRAM 26, a data modulation unit 27, a CPU 202, a ROM 30, a RAM 31, and an operation unit 32. As will be described later, the functions of the LED controller 201 and the CPU 202 are shown in FIG. The configuration is the same as that of the first electronic camera 2 shown in FIG. 3 except that the functions of the LED controller 25 and the CPU 29 are different, and that the luminance calculation unit 28 is not provided.

  The CPU 202 functions as a control unit that controls the overall operation of the first electronic camera 200, and when the operation mode of the first electronic camera 200 is set to the “data transmission mode”, as shown in FIG. In addition, the image data of the white image 206 is generated separately from the normal image 205 scheduled to be displayed on the LCD panel 43.

  Thus, the generated image data of the white image 206 is recorded in the frame memory 23 so as to be inserted by one frame after the image data of the normal image 205 for four frames. Therefore, in the present embodiment, when the operation mode of the first electronic camera 200 is set to “data transmission mode”, the normal image 205 for four frames is displayed on the LCD panel 43, and then 1 A white image 206 for a frame is displayed.

  Further, the CPU 202 outputs to the LED controller 201 a frame timing signal FT indicating the timing at which the display content of the LCD panel 43 is switched from the normal image 205 to the white image 206 or from the white image 206 to the normal image 205. The frame timing signal FT is set to L level during the period when the normal image 205 is displayed, and is set to H level during the period when the white image 206 is displayed.

  Similar to the LED controller 25 shown in FIG. 3, the LED controller 201 causes the LED 41 to emit light for illumination when the operation mode of the first electronic camera 200 is set to “shooting mode” or “playback mode”. However, when the operation mode of the first electronic camera 200 is set to “data transmission mode”, the frame timing signal output from the CPU 202 is different from the LED controller 25 shown in FIG. In synchronization with FT, the LED 41 emits light and the LED 41 blinks. Specifically, when the frame timing signal FT is set to the L level, the LED 41 is caused to emit light to function as a backlight for illumination, while when the frame timing signal FT is set to the H level, the data The LED 41 blinks in accordance with the content of data output from the modulation unit 27, and the LED 41 functions as a transmission unit for data transmission using visible light.

  The first electronic camera 200 having the above configuration transmits an optical signal to the second electronic camera 5 as follows.

  FIG. 18 is a timing chart showing optical signal transmission processing executed using the first electronic camera 200.

  In the case of transmitting an optical signal using the first electronic camera 200, first, the operation mode of the first electronic camera 200 is switched to the “data transmission mode”, and then the CPU 202 displays an image of the white image 206. Data is generated. As described above, the generated white image data 206 is recorded in the frame memory 23 so as to be inserted by one frame after the image data of the image 205 for four frames.

  Thus, when the image data of the white image 206 is recorded in the frame memory 23, the CPU 202 reads out the image data recorded in the frame memory 23, and the read image data is the number of display pixels on the LCD panel 43. Are compressed and recorded in the VRAM 26.

  In the present embodiment, as described above, the frame memory 23 stores the image data of the white image 206 for every other frame, so that the LCD panel 43 has an image data as shown in FIG. First, a normal image 205 for four frames is displayed.

  Since the frame timing signal FT is set to the L level while the normal image 205 for four frames is displayed on the LCD panel 43, the LED 41 does not repeat the light emission and the light emission stop, and does not repeat the light emission. Function as.

  Next, when the image displayed on the LCD panel 43 is switched from the normal image 205 to the white image 206, the frame timing signal FT is set to the H level, and the LED controller 201 causes the LED 41 to blink. Are switched and an optical signal is output.

  The optical signal thus output is received by the photodiode 75 of the second electronic camera 5, and then the output signal of the photodiode 75 is output to the data reproducing unit 57, and the data reproducing unit 57 performs the first electronic operation. Data transmitted from the camera 200 is reproduced.

  Next, when the display period of the white image 206 ends and the image displayed on the LCD panel 43 is switched from the white image 206 to the normal image 205, the CPU 202 sets the frame timing signal FT to the L level, and the LED controller. 201 stops the blinking of the LED 41 and switches the operation of the LED 41 so that the LED 41 functions as a light source for illumination.

  As described above, in the present embodiment, the white image 206 is displayed on the LCD panel 43 while the light signal is transmitted by blinking the LED 41, so that stable visible light communication can be performed. .

  On the other hand, since the normal image 205 for four frames is displayed while the optical signal is not transmitted, the normal mode 205 is displayed while the operation mode of the first electronic camera 200 is set to the “data transmission mode”. The image 205 and the white image 206 are displayed alternately. However, in general, the frame rate when displaying a moving image is 1/30 sec, and the white image 206 is displayed for a very short time. Therefore, the normal image 205 and the white image 206 are alternately displayed. However, the white image 206 is not visually recognized. Therefore, it is possible to perform optical communication while displaying the normal image 205 on the LCD panel 43 without feeling unnatural.

  The present invention is not limited to the above embodiments, and various modifications are possible within the scope of the invention described in the claims, and these are also included in the scope of the present invention. Needless to say.

  For example, in the visible light communication system 1 according to the embodiment, the first electronic cameras 2, 80, 100, and 200 have only a function of transmitting an optical signal and do not have a function of receiving an optical signal. However, the first electronic camera 2, 80, 100, 200 further includes a light receiving unit and a data reproducing unit having the same configuration as the photodiode 75 and the data reproducing unit 57 of the second electronic camera 2, and an optical signal May be configured to be capable of receiving. Further, the second electronic camera 5 further includes a data modulation unit and a luminance calculation unit having the same configuration as the data modulation unit 27 and the luminance calculation unit 28 of the first electronic cameras 2, 80, 100, or A data modulation unit having the same configuration as that of the data modulation unit 27 of the first electronic camera 200 may be provided and configured to be able to transmit an optical signal.

  In the visible light communication system 1 according to the embodiment, the first electronic cameras 2, 80, 100, and 200 include a display panel configured by an LCD panel. Other display panels such as a panel may be provided.

  Furthermore, in the visible light communication system 1 according to the embodiment, the first electronic cameras 2, 80, 100, and 200 include the normally white type LCD panel 43, but the normally white type LCD panel. Alternatively, a normally black LCD panel may be provided. In such a case, the power supply voltage may be applied instead of the ground voltage when the light transmittance of the LCD panel is maximized.

  Moreover, in the said embodiment, although the description was added about the case where the image corresponding to the image data transmitted by the optical signal and the image scheduled to be displayed on the LCD panel 43 are the same image, the optical signal is used. The transmitted image data may be image data of an image different from the image scheduled to be displayed on the LCD panel 43. Furthermore, the data transmitted by the optical signal is not necessarily image data, and may be data other than image data such as file name data and URL data.

  Further, in the visible light communication system 1 according to the embodiment shown in FIGS. 1 to 15, the first electronic cameras 2, 80, and 100 transmit moving images to the LCD panel 43 while data is transmitted by optical signals. In the case of displaying an image, the calculation process of the average brightness level, the comparison process with the reference brightness level, and the setting process of the brightness adjustment image are executed for every frame to be displayed one frame at a time. However, the above-described processing can be configured to be executed only once for several frames of image data, or just once as in the case of displaying a still image.

  Furthermore, in the visible light communication system 1 according to the embodiment shown in FIG. 1 to FIG. 15, the first electronic cameras 2, 80, 100 transmit an optical signal as an image to be displayed on the LCD panel 43. It is configured to adjust the average luminance level of the entire display surface 43a both when it is higher and lower than the luminance level suitable for the image, but it is not necessarily suitable for the image to be displayed to transmit the optical signal. It is not necessary to adjust the average luminance level of the entire display surface 43a until the luminance level is higher than the average luminance level, and the image to be displayed on the LCD panel 43 is lower than the average luminance level suitable for transmitting an optical signal. Only in this case, the average luminance level of the entire display surface 43a can be adjusted.

  Further, in the visible light communication system 1 according to the embodiment shown in FIGS. 12 to 15, the first electronic camera 100 is scheduled to display the patterns of the curves A and B of the conversion table 110 on the LCD panel 43. Although it is configured to change according to the average luminance level of the image, it may be configured to fix the patterns of the curves A and B of the conversion table 110.

  Further, in the visible light communication system 1 according to the embodiment shown in FIGS. 16 to 18, the first electronic camera 200 displays the white image 206 on the LCD panel 43 while transmitting data by an optical signal. However, instead of the white image 206, an image in which the average luminance level of the normal image 205 is increased may be displayed.

  Further, in the visible light communication system 1 according to the embodiment shown in FIGS. 16 to 18, the case where the number of frames for displaying the normal image 205 is set to “4” has been described. The number of frames for displaying 205 may be less than “4” or greater than “4”. Further, the number of frames for displaying the white image 206 is not necessarily “1”, and is “2” or more as long as the user viewing the image displayed on the LCD panel 43 does not feel unnaturalness. It may be.

  Furthermore, in the visible light communication system 1 according to the embodiment, the second electronic camera 5 includes a photodiode 75 in the display device 7 and is emitted from the first electronic camera 2 via the LCD panel 73. The photodiode is arranged outside the display device 7 such as the front surface or the side surface of the second electronic camera 5, and the photodiode is connected to the photodiode from the first electronic camera 2. You may be comprised so that the emitted light may inject directly. In addition, the light receiving means for receiving the light emitted from the first electronic camera 2 is not necessarily a photodiode, and may be another light receiving element such as a CCD.

  Moreover, in the said embodiment, the visible light communication which transmits data with the optical signal from the 1st electronic camera 2, 80, 100 provided with the display apparatus 4 to the 2nd electronic camera 5 which has the photodiode 75. Although a description is added to the system, the visible light communication system to which the present invention is applied is a method in which data is transmitted by an optical signal between a data transmission device having a display device and a data reception device having a light receiving means. The visible light communication system for transmitting and receiving is not particularly limited. For example, a visible light communication system including a display device and an electronic camera including a display device and a printer including a photodiode is provided. The present invention can also be applied to a visible light communication system including a mobile phone and an audio device provided with a photodiode.

It is a schematic diagram which shows the structure of the visible light communication system concerning preferable embodiment of this invention. It is a schematic perspective view which shows the structure of the display apparatus of the 1st electronic camera shown by FIG. It is a block diagram which shows the structure of the 1st electronic camera shown by FIG. It is a schematic diagram which shows the modulation method by Manchester encoding. It is a schematic diagram which shows a brightness adjustment process. It is a schematic diagram which shows a reference | standard luminance level. It is a schematic perspective view which shows the structure of the display apparatus of the 2nd electronic camera shown by FIG. It is a block diagram which shows the structure of the 2nd electronic camera shown by FIG. It is a time chart which shows the procedure of the transmission / reception process of the data performed by the visible light communication system concerning preferable embodiment of this invention. It is a block diagram which shows the structure of the 1st electronic camera used with the visible light communication system concerning other preferable embodiment of this invention. It is a schematic diagram which shows a brightness adjustment process. It is a block diagram which shows the structure of the 1st electronic camera used with the visible light communication system concerning further another preferable embodiment of this invention. It is a schematic diagram which shows a brightness adjustment process. It is a schematic diagram which shows the conversion table used for a brightness | luminance adjustment process. It is a schematic diagram which shows the conversion table used for a brightness | luminance adjustment process. It is a block diagram which shows the structure of the 1st electronic camera used with the visible light communication system concerning further another preferable embodiment of this invention. It is a top view which shows a normal image and a white image. It is a timing chart which shows the transmission process of the optical signal performed using a 1st electronic camera.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Visible light communication system 2, 80, 100, 200 1st electronic camera 4 Display apparatus 5 2nd electronic camera 21, 51 CCD
22, 52 Signal processor 23, 53 Frame memory 24, 54 LCD controller 25, 55, 201 LED controller 26, 56 VRAM
27 Data modulator 28 Luminance calculator 29, 59, 81, 101, 202 CPU
30, 60 ROM
31, 61 RAM
32, 62 Operation unit 35 Reduced image 36, 96, 105 Brightness adjustment image 41, 71 LED
42, 72 Light guide plate 43, 73 LCD panel 44 Light diffusion dot 57 Data reproduction unit 75 Photo diode 95, 205 Normal image 110 Conversion table 206 White image

Claims (15)

A display panel capable of displaying an image; and a light emitting means for irradiating the display panel with illumination light, displaying an image on the display panel, and causing the light emitting means to blink to output an optical signal. In a display device having a configured data communication function,
Prior to displaying an image on the display panel, the image to be displayed on the display panel is processed according to the brightness of the image to be displayed on the display panel, and the processed image is displayed on the display panel. A display device having a data communication function, wherein the light emitting means blinks in the state displayed on the screen. Generating a first image corresponding to an image to be displayed on the display panel and a second image for adjusting the brightness of the entire display panel according to the brightness of the first image; ,
2. The display having a data communication function according to claim 1, wherein the light emitting unit is caused to blink in a state in which the first image and the second image are displayed in a displayable area of the display panel. apparatus. The display device having a data communication function according to claim 2, wherein the second image is displayed so as to surround the first image. 4. The data communication function according to claim 3, wherein the first image is generated by reducing an image to be displayed on the display panel in accordance with a display size of the second image. Display device. The display device having a data communication function according to claim 2, wherein the second image is displayed so as to be superimposed on the first image. 3. The image data level of the second image and / or the size of the second image are changed according to the brightness of the image to be displayed on the display panel. 6. A display device having a data communication function according to any one of items 5 to 5. The display device having a data communication function according to claim 6, wherein the level of the image data of the second image is preferentially changed. Even when the brightness of an image to be displayed on the display panel is such that the optical signal can be transmitted, at least the brightness of the second image affects the brightness of the entire display panel. The display device having a data communication function according to any one of claims 2 to 7, wherein the second image is displayed at a brightness that is not given. Prior to displaying an image on the display panel, the brightness of the image to be displayed on the display panel is changed,
The display device having a data communication function according to claim 1, wherein the light emitting unit is caused to blink in a state where the image whose brightness has been changed is displayed on the display panel. The data communication function according to claim 9, wherein an increase / decrease rate of the brightness of the image to be displayed on the display panel is set according to the brightness of the image to be displayed on the display panel. Display device. A display panel capable of displaying an image; and a light emitting means for irradiating the display panel with illumination light, displaying an image on the display panel, and causing the light emitting means to blink to output an optical signal. In a display device having a configured data communication function,
While the first image to be displayed on the display panel and the second image brighter than the first image are switched and displayed, and the second image is displayed, the light emitting means A display device having a data communication function. 11. The data according to claim 10, wherein after displaying the first image having a predetermined number of frames, the second image having a number of frames smaller than the number of frames for displaying the first image is displayed. A display device having a communication function. The display device having a data communication function according to claim 11, wherein the second image is a white image. The display device having a data communication function according to claim 11 or 12, wherein the second image is an image brighter than the first image. The display device having a data communication function according to claim 1, further comprising light receiving means for receiving an optical signal.

Images