Image forming apparatus having a memory and two operating modes, and method of using same

An image forming apparatus which comprises:

• image reading means for reading an image of a document and for outputting image data descriptive of the image of the document;
• image forming means for performing an image formation based on the image data;
• storage means for storing the image data;
• and
• switching means for switching between a first and a second image forming mode depending on an image forming condition, wherein the image data output by the image reading means is directly transmitted to the image forming means by bypassing the storage means so that a reading operation of the reading means and an image forming operation of the image forming means are simultaneously performed in the first image forming mode, and the image data output by the image reading means is transmitted to the image forming means through the storage means so that the image forming operation is performed after completion of the image reading operation in the second image forming mode, wherein said image forming condition includes a document size, an image forming mode and the number of copies desired to be made.

An image forming apparatus which comprises:

• image reading means for reading an image of a document and for outputting image data descriptive of the image of the document;
• image forming means for performing an image formation based on the image data;
• storage means for storing the image data;
• and
• switching means for switching between a first and a second image forming mode each time a predetermined number of copies has been made, said predetermined number being determined depending on an image forming condition, wherein the image data output by the image reading means is directly transmitted to the image forming means by bypassing the storage means so that a reading operation of the reading means and an image forming operation of the image forming means are simultaneously performed in the first image forming mode, and the image data output by the image reading means is transmitted to the image forming means through the storage means so that the image forming operation is performed after completion of the image reading operation in the second image forming mode.

A digital copying apparatus which comprises:

• an image reader for reading an image of a document and outputting image data descriptive of the image of the document;
• an operation panel for setting an image condition by a manual input;
• a printer for performing an image formation based on the image data;
• image memory for storing the image data;
• switching means for switching between a first image forming mode and a second image forming mode, wherein the image data output by the image reader is directly transmitted to the printer by bypassing the image memory so that a reading operation of the image reader and an image forming operation of the printer are simultaneously performed in the first image forming mode, and the image data read by the image reader is transmitted to the printer through the image memory so that the image forming operation is performed after completion of the image reading operation in the second image forming mode;
• and
• control means for controlling said switching means in order to select one of the first image forming mode and the second image forming mode according to the image forming condition set by manual input.

An image forming apparatus which comprises:

• image reading means for reading an image of a document and for outputting image data descriptive of the image of the document;
• detecting means for detecting a size of the document;
• image forming means for performing an image formation based on the image data;
• storage means for storing the image data;
• switching means for switching between a first image forming mode and a second image forming mode, wherein the image data output by the image reading means is directly transmitted to the image forming means by bypassing the storage means so that a reading operation of the reading means and an image forming operation of the image forming means are simultaneously performed in the first image forming mode, and the image data read by the image reading means is transmitted to the image forming means through the storage means so that the image forming operation is performed after completion of the image reading operation in the second image forming mode;
• and
• control means for controlling said switching means in order to select one of the first image forming mode and the second image forming mode according to the document size detected by said detecting means.

An image forming apparatus which comprises:

• image reading means for reading an image of a document and for outputting image data descriptive of the image of the document;
• image forming means for performing an image formation based on the image data;
• storage means for storing the image data;
• an auto document feeder for successively feeding a plurality of documents one by one to the image reading means, and for reversing the document after one side of the document is read by the image reading means;
• switching means for switching between a first image forming mode and a second image forming mode depending on a reversing operation of the auto document feeder, wherein the image data output by the image reading means is directly transmitted to the image forming means by bypassing the storage means so that a reading operation of the reading means and an image forming operation of the image forming means are simultaneously performed in the first image forming mode, and the image data read by the image reading means is transmitted to the image forming means through the storage means so that the image forming operation is performed after completion of the image reading operation in the second image forming mode.