An optical reading device, a control method for an optical reading device, and a program for directing execution of the method each enables efficient and quick transmission of digital image data obtained from reading a document to a host computer or other control device. A dot impact printer having an optical reading device that optically reads documents and stores the resulting digitized image data, sets target reading areas, and transmits digital image data stored in a scan buffer rendered in a RAM to the host computer. When multiple target areas are set, the transmission order of the target areas is determined according to specific conditions, and the target areas are transmitted according to this transmission sequence.