Patent ID: 6711626
Filing Date: 2004-03-23
Classification: H04N

Abstract:
A composite device, comprising:an interface unit and a plurality of devices, including a printing device, an image scanning device, and a control device; the interface unit being divided into a plurality of physically identical logical channels, and obtaining predetermined commands; each of the plurality of devices being interconnected to respective ones of the plurality of logical channels, and being operated on the basis of the predetermined commands; the control device controlling the operation of the other devices of the plurality of devices to perform the commands obtained by the interface unit; the control device comprising a command holding unit and a priority setting unit; the commanding holding unit holding one of the commands obtained by the interface unit; and the priority setting unit setting a priority for a given command; wherein, when a competition occurs, between one device of the plurality of devices attempting to perform one command and another device of the plurality of devices attempting to perform another command, the control device: causes the one device to be operated according to the one command, causes the command holding unit to hold the other command, and upon completion of the operation by the one device, causes the other device to be operated on the basis of the other command held by the command holding unit; wherein, when a given command for operating one device of the plurality of devices is inputted at a time when another device of the plurality of devices is being operated on the basis of another command, and the given command has a respective priority higher than the respective priority of the other command, the control device: interrupts operation of the other device, and causes the operation of the one device until completion of the operation indicated by the given command.