Information communication device

1. An information communication method, comprising:

continuously capturing an image of a subject that transmits a signal by changing luminance, with an image sensor;

displaying a captured image that includes a box and a subject image for identifying the subject, while continuously updating a position of the subject image on the captured image, according to a positional relationship between the image sensor and the subject established when the image of the subject is captured;

determining whether the subject image is in the box; and

receiving the signal transmitted by the subject when it is determined that the subject image is in the box,

wherein in the receiving,

second image data is obtained by performing capturing with a second exposure time shorter than a first exposure time so that exposure starts sequentially for a plurality of exposure lines each at a different time and each of the plurality of exposure lines partially overlaps in exposure time an adjacent one of the plurality of exposure lines, and information is obtained by demodulating a bright line pattern that appears in the second image data and corresponds to the plurality of exposure lines, and

the bright line pattern is caused to appear in the second image data by setting the second exposure time to be less than or equal to 1/480 second.

2. The information communication method according to claim 1 , further comprising:

determining whether a terminal device that includes the image sensor has been shaken laterally,

wherein in the capturing, images of plural subjects each of which transmits a signal by changing luminance are captured with the image sensor,

in the displaying, a captured image is displayed, the captured image including the images of the plural subjects and being obtained in the capturing,

in the receiving, the signals transmitted by the plural subjects are received, and

in the displaying,

an information notification image generated according to a signal from one of the plural subjects among the signals transmitted by the plural subjects and received, and showing information regarding the subject is superimposed on the captured image in a state where the information notification image is associated with the image of the subject, and

when it is determined that the terminal device has been shaken laterally, another information notification image generated according to a signal from another one of the plural subjects that is in a direction in which the terminal device has been shaken, and showing information regarding the another one of the plural subjects is superimposed on the captured image in a state where the other information notification image is associated with the image of the another one of the plural subjects.

3. The information communication method according to claim 2 ,

wherein in the displaying, for an image of each of one or more remaining subjects other than the image of the one or the another one of the plural subjects that is associated with the information notification image or the another information notification image, an information-presentable notification image for notifying that information regarding a remaining subject is further presentable is superimposed on the captured image.

4. An information communication apparatus, comprising:

a processor; and

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

continuously capturing an image of a subject that transmits a signal by changing luminance, with an image sensor;

displaying a captured image that includes a box and a subject image for identifying the subject, while continuously updating a position of the subject image on the captured image, according to a positional relationship between the image sensor and the subject established when the image of the subject is captured;

determining whether the subject image is in the box; and

receiving the signal transmitted by the subject when it is determined that the subject image is in the box,

wherein in the receiving,

second image data is obtained by performing capturing with a second exposure time shorter than a first exposure time so that exposure starts sequentially for a plurality of exposure lines each at a different time and each of the plurality of exposure lines partially overlaps in exposure time an adjacent one of the plurality of exposure lines, and information is obtained by demodulating a bright line pattern that appears in the second image data and corresponds to the plurality of exposure lines, and

the bright line pattern is caused to appear in the second image data by setting the second exposure time to be less than or equal to 1/480 second.

5. A non-transitory computer-readable recording medium storing an information communication program for performing information communication, the information communication program causing a computer to execute:

continuously capturing an image of a subject that transmits a signal by changing luminance, with an image sensor;

displaying a captured image that includes a box and a subject image for identifying the subject, while continuously updating a position of the subject image on the captured image, according to a positional relationship between the image sensor and the subject established when the image of the subject is captured;

determining whether the subject image is in the box; and

receiving the signal transmitted by the subject when it is determined that the subject image is in the box,

wherein in the receiving,

second image data is obtained by performing capturing with a second exposure time shorter than a first exposure time so that exposure starts sequentially for a plurality of exposure lines each at a different time and each of the plurality of exposure lines partially overlaps in exposure time an adjacent one of the plurality of exposure lines, and information is obtained by demodulating a bright line pattern that appears in the second image data and corresponds to the plurality of exposure lines, and

the bright line pattern is caused to appear in the second image data by setting the second exposure time to be less than or equal to 1/480 second.