Patent ID: 8599395

Claim:
A printing device that executes a print job based on print data supplied from electronic equipment connected via a network, and permits interruption by another print job during execution of the supplied print job, the printing device comprising: a receiver which receives the print data which includes a series of PDL commands from the electronic equipment; a PDL command registration unit which registers the series of PDL commands included in the received print data into a PDL command memory unit; a print job control unit which, when the print data is received, registers print job specifying information that specifies the print job represented by the received print data to the end of an input job queue; and a command execution unit which executes the print job by successively executing the series of PDL commands stored in the PDL command memory unit from the head; wherein each of the series of PDL commands can be classified as either (a) a re-execution necessary command that is necessary to execute again when a print job halted by the interruption process is restarted, or (b) a re-execution unnecessary command that is unnecessary to execute again when a print job halted by the interruption process is restarted; wherein the command execution unit (a) judges whether the executed PDL command is a re-execution unnecessary command when each of the PDL commands is executed, and (b) overwrites the executed PDL command stored in the PDL command memory unit with a NOP command indicating no processing to be done if the executed PDL command is determined to be a re-execution unnecessary command; wherein the print job control unit controls the command execution unit to start execution of a print job specified by the print job specifying information at the head of the input job queue when the end of execution of a print job by the command execution unit is detected; and wherein, when an instruction for the interruption process is detected, the print job control unit (a) registers the print job specifying information which specifies the print job for the interruption process into the head of the input job queue, and (b) controls the command execution unit to halt the print job being executed and start execution of the print job for the interruption process.