A method is provided for obtaining information from a transmission device using an image sensor that includes a plurality of exposure lines. The method includes obtaining image data by starting exposure sequentially for the plurality of exposure lines each at a different time, starting exposure of a next exposure line before exposure of one exposure line ends, and imaging for a predetermined exposure time. The method also includes obtaining the information by demodulating data specified by a pattern of bright lines that appear in the image data, the bright lines corresponding to the plurality of exposure lines. The method further includes setting the predetermined exposure time so that a relation of tE>tHT is satisfied, where the predetermined exposure time is tE μs, and a period of high frequency noise of a light source included in the transmission device is tHT μs.