Communication method

1. A communication method used in a terminal that includes a front camera and a back camera, the communication method comprising:

switching between the front camera and the back camera according to an orientation of the terminal; and

performing visible light communication by using the front camera or the back camera, which is selected in the switching,

wherein the performing of visible light communication includes:

capturing a first subject that is changing in luminance by using the front camera and obtaining a first image when the front camera is used;

capturing a second subject by using the back camera and obtaining a second image when the back camera is used; and

obtaining specified information that is related to the first subject or the second subject.

2. The communication method according to claim 1 ,

wherein when the orientation of the terminal is substantially parallel to ground, the performing of visible light communication includes performing, by using the front camera selected in the switching, visible light communication with the second subject which is located above the user and emits visible light.

3. The communication method according to claim 2 ,

wherein when the orientation of the terminal is substantially perpendicular to ground, the performing of visible light communication includes performing, by using the back camera selected in the switching, visible light communication with the first subject which is located in front of a user and emits visible light.

4. The communication method according to claim 1 ,

wherein the terminal is included in a watch,

the front camera is provided on a front surface of the watch, and the back camera is provided on a side surface of the watch, the front surface having a display that displays a time of the watch, and

when the display of the watch is substantially parallel to ground, the performing of visible light communication includes:

performing, by using the front camera, visible light communication with the second subject which is located above the user and emits visible light; and

performing, by using the back camera, visible light communication with the first subject which is located in front of the user and emits visible light.

5. The communication method according to claim 1 ,

wherein the performing of visible light communication includes inquiring a server about the specified information, thereby obtaining information related to the first subject or the second subject corresponding to the specified information, and

when no information corresponds to the specified information as a result of the inquiring the server, the performing of visible light communication further includes displaying, on a display of the terminal, an error notification indicating that no information is related to the first subject or the second subject.

6. The communication method according to claim 2 , further comprising:

performing, by using the front camera selected in the switching, visible light communication with the second subject which is located above the user and emits visible light, thereby obtaining information of the first subject; and displaying the information on a display of the terminal, and

changing the information displayed on the display of the terminal, wherein in the changing, the information to be displayed on the display is changed by user's flicking on the display.

7. A communication apparatus, comprising:

a front camera;

a back camera;

a processor; and

a memory having therein a program, the program causing the processor to execute operations including:

switching between the front camera and the back camera according to an orientation of the terminal; and

performing visible light communication by using the front camera or the back camera, which is selected in the switching,

wherein the performing of visible light communication includes:

capturing a first subject that is changing in luminance by using the front camera and obtaining a first image when the front camera is used;

capturing a second subject by using the back camera and obtaining a second image when the back camera is used; and

obtaining specified information that is related to the first subject or the second subject.

8. A non-transitory computer-readable recording medium storing a program for performing visible light communication, the visible light communication program causing a computer to execute:

switching between the front camera and the back camera according to an orientation of the terminal; and

performing visible light communication by using the front camera or the back camera, which is selected in the switching,

wherein the performing of visible light communication includes:

capturing a first subject that is changing in luminance by using the front camera and obtaining a first image when the front camera is used;

capturing a second subject by using the back camera and obtaining a second image when the back camera is used; and

obtaining specified information that is related to the first subject or the second subject.