The present invention is directed to modulators of indoleamine 2,3-dioxygenase, as well as compositions and pharmaceutical methods thereof. The tooth faces merge smoothly with the tooth gap bottom, the sprocket root diameter is smaller than the root diameter according to ISO standards, and the radius of the arcuate tooth gap bottom is greater than the radius of the chain roller. When disconnecting a voice communication line, mobile phone 100-1 produces a notification sound and displays the acquired image data, thereby notifying a user of mobile phone 100-1 of acquiring data by data communication during voice communication.