Image forming apparatus and image forming method with synchronous and asynchronous control for continuous operation

Abstract

An image forming method reads a document by a scanner that is a device, provides image data corresponding to a document image, forms an image corresponding to the image data provided from the scanner by a printer that is a device, and detects operating errors of the scanner and the printer. Further, when any operating error is detected, the image forming method stops the operation of the device generating the error and operates the device not generating the error.

1 . An image forming apparatus comprising:
 a scanner to read documents and provide image data corresponding to a document image;   a printer to form an image corresponding to the image data provided from the scanner;   an error detector to detect an operating error of the scanner and the printer that are devices;   a controller to stop an operation of the device that cause the error and operate the device only that did not cause the error when the error detector detects the operating error;   a first memory to store image data;   compression/expansion means for compressing or expanding the image data;   a second memory to store the image data compressed by the compression/expansion means;   means for setting an image forming condition;   means for deciding whether a first control for operating the scanner and the printer in parallel is used with each other or a second control for operating the printer after whole image data of all documents are stored in the second memory by the scanner when forming an image based on the image forming conditions that are set by the means for setting;   wherein the image forming apparatus is controlled based on the control decided by the means for deciding, and   wherein in the case of the first control, the document image data read by the scanner is stored in the first memory and then, provided to the printer and also compressed by the compression/expansion means and stored in the second memory, in the case of the second control, the document image data read by the scanner is stored in the first memory, compressed by the compression/expansion means, stored in the second memory, expanded by the compression/expansion circuit, stored in the first memory and then, provided to the printer; and   means for switching the first control to the second control when the first control is decided by the means for deciding and an error is generated during the image forming operation.   
     
     
         2 . An image forming method comprising:
 reading documents by a scanner that is a device to provide image data corresponding to a document image;   forming an image corresponding to the image data provided from the scanner by a printer that is a device;   detecting operating errors of the scanner and the printer;   suspending the operation of the device generating an error and operating the device not generating an error when the operating error is detected;   setting the image forming conditions;   deciding whether a first control for operating the scanner and the printer in parallel is used with each other or a second control for operating the printer after whole image data of all documents are stored in the second memory by the user when executing the image formation;   executing control based on the decided control including:   firstly storing image data,   compressing/expanding the image data, and   secondly storing the image data compressed in the compressing/expanding step,   wherein in the case of the first control, the document image data read by the scanner is stored in the firstly storing step and then provided to the printer, and the document image data is also compressed in the compression/expansion step and stored in the secondly storing step, and in the case of the second control, the document image data read by the scanner is stored in the firstly storing step and then, compressed in the compression/expansion step and stored in the secondly storing step or expanded in the compression/expansion step and stored in the firstly storing step, and then provided to the printer; and   switching the first control to the second control when the first control is decided in the deciding step and an error is generated during the image forming operation.