Image output system including a plurality of units connected by communications with master-slave relation

Abstract

A printer periodically sends a request inquiry command “Interrupt In” to a digital camera at a high rate. The digital camera returns a printer status request, a print request, a print cancel request, etc., to the printer as a reply to “Interrupt In.” The camera operates as a usual storage class USB device for the printer except that the camera performs the described operation. Therefore, the printer makes a search for a directory in the camera and reads an image file, a print page layout file, etc., required for print on its own initiative.

1 . An image output system comprising:
 an image source unit;   an image output unit; and   a communication interface for connecting said image source unit and said image output unit, said image source unit having:   an operation unit for issuing an image output instruction;   request command generation means being responsive to the image output instruction for generating a request command for requesting said image output unit to perform image output operation based on predetermined output condition setting;   request command transmission means for transmitting the request command through said communication interface to said image output unit;   data storage for storing a resource file used for said image output unit to perform the image output operation; and   slave communication means for accessing the resource file in the data storage as controlled in a slave manner by said image output unit, and   said image output unit having:   request command reception means for receiving the request command through said communication interface from said image source unit;   resource file acquisition means for acquiring the resource file through said communication interface from said image source unit by controlling the slave communication means; and   control means for controlling the image output operation based on the received request file and the acquired resource file.