Two-side image forming apparatus

A two-side image forming apparatus comprising:

• a first sheet-transferring path, for use in one-side image formation, for transferring, to a printed sheet storage section via an image transcribing section, a sheet supplied from an unprinted sheet storage section;
• a second sheet-transferring path, connected to the first sheet-transferring path, for supplying a turned-over one-side printed sheet to the image transcribing section,
• an intermediate roller provided along the second sheet-transferring path;
• a resist roller for synchronizing a timing at which a sheet is transferred onto the first sheet-transferring path, and a controller controlling the concurrent transfer of a plurality of sheets in an overall sheet-transferring path when performing two-side image forming operation, the overall sheet-transferring path including the first sheet-transferring path and the second sheet-transferring path,
• wherein the controller resumes a rotation of the intermediate roller and a rotation of the resist roller so that the intermediate roller and the resist roller start at the same time to transfer the sheets to the second sheet-transferring path and the first sheet-transferring path, respectively, and
• wherein the first sheet-transferring path includes switch-back means, located at an immediate upstream of the printed sheet storage section, the switch-back means transferring the one-side printed sheet to the second sheet-transferring path, wherein the resist roller is located at a crossing point between the second sheet-transferring path and that part of the first sheet-transferring path which is between the unprinted sheet storage section and the image transcribing section, wherein the controller adjusts a resuming timing for resuming the transfer of the sheet to the image transcribing section in order to adjust on which part of the sheet an image is to be transcribed by the image transcribing section.

A two-side image forming apparatus comprising:

• a first sheet-transferring path, for use in one-side image formation, for transferring, to a printed sheet storage section via an image transcribing section, a sheet supplied from an unprinted sheet storage section;
• a second sheet-transferring path, connected to the first sheet-transferring path, for supplying a turned-over one-side printed sheet to the image transcribing section,
• an intermediate roller provided along the second sheet-transferring path;
• a resist roller for synchronizing a timing at which a sheet is transferred onto the first sheet-transferring path, and
• a controller controlling concurrent transfer of a plurality of sheets in an overall sheet-transferring path when performing two-side image forming operation, the overall sheet-transferring path including the first sheet-transferring path and the second sheet-transferring path,
• wherein the controller resumes a rotation of the intermediate roller and a rotation of the resist roller so that the intermediate roller and the resist roller start at the same time to transfer the sheets to the second sheet-transferring path and the first sheet-transferring path, respectively,
• wherein the first sheet-transferring path includes switch-back means, located at an immediate upstream of the printed sheet storage section, the switch-back means transferring the one-side printed sheet to the second sheet-transferring path,
• wherein the first sheet-transferring path, the second sheet-transferring path, and the switch-back means respectively include sheet transfer driving sections, which are independently driven by different driving sources and controlled by the controller.

A two-side image forming apparatus comprising:

• a first sheet-transferring path, for use in one-side image formation, for transferring, to a printed sheet storage section via an image transcribing section, a sheet supplied from an unprinted sheet storage section;
• a second sheet-transferring path, connected to the first sheet-transferring path, for supplying a turned-over one-side printed sheet to the image transcribing section,
• an intermediate roller provided along the second sheet-transferring path;
• a resist roller for synchronizing a timing at which a sheet is transferred onto the first sheet-transferring path,
• a controller controlling concurrent transfer of a plurality of sheets in an overall sheet-transferring path when performing two-side image forming operation, the overall sheet-transferring path including the first sheet-transferring path and the second sheet-transferring path, the controller resuming a rotation of the intermediate roller and a rotation of the resist roller so that the intermediate roller and the resist roller start at the same time to transfer the sheets to the second sheet-transferring path and the first sheet-transferring path, respectively;
• and
• second sheet detection means in the second sheet-transferring path, the second sheet detection means for detecting the one-side printed sheet transferred into the second sheet-transferring path,
• wherein the controller (i) stops the one-side printed sheet that is detected, when the second sheet detection means detects the one-side printed sheet, and (ii) resumes transfer of the one-side printed sheet in a predetermined timing.