Sheet feeding apparatus, image forming apparatus having the same and image reading apparatus having the same

An image forming apparatus comprising:

• movable sheet supporting means for supporting a sheet;
• a sheet feeding roller for urging against the sheet supported by said sheet supporting means and rotating in a sheet feeding direction to feed the sheet;
• a separating roller opposed to said sheet feeding roller and rotatable in a sheet restoring direction to separate the sheet fed from said sheet feeding roller, wherein said separating roller urges against said sheet feeding roller;
• conveying means disposed downstream of a separating portion, in which said sheet feeding roller is in pressure contact with said separating roller, in the sheet feeding direction for conveying the sheet fed from said sheet feeding roller;
• image forming means for forming an image on the sheet conveyed by said conveying means;
• and
• pressing and retracting means for moving said sheet supporting means to place the sheet supported by said sheet supporting means into pressure contact with said sheet feeding roller and to release the pressure contact between said sheet feeding roller and the sheet,
• wherein said pressing and retracting means moves said sheet supporting means to separate the sheet, which has been in pressure contact with said sheet feeding roller, from said sheet feeding roller to release the pressure contact between said sheet feeding roller and the sheet after a leading end of the sheet reaches said separating portion and before the leading end of the sheet reaches said conveying means.

An image reading apparatus comprising:

• movable sheet supporting means for supporting a sheet;
• a sheet feeding roller for urging against the sheet supported by said sheet supporting means and rotating in a sheet feeding direction to feed the sheet;
• a separating roller opposed to said sheet feeding roller and rotatable in a sheet restoring direction to separate the sheet fed from said sheet feeding roller, wherein said separating roller urges against said sheet feeding roller;
• conveying means disposed downstream of a separating portion, in which said sheet feeding roller is in pressure contact with said separating roller, in the sheet feeding direction for conveying the sheet fed from said sheet feeding roller;
• image reading means for reading image information on the sheet conveyed by said conveying means;
• and
• pressing and retracting means for moving said sheet supporting means to place the sheet supported by said sheet supporting means into pressure contact with said sheet feeding roller and to release the pressure contact between said sheet feeding roller and the sheet,
• wherein said pressing and retracting means moves said sheet supporting means to separate the sheet, which has been in pressure contact with said sheet feeding roller, from said sheet feeding roller to release the pressure contact between said sheet feeding roller and the sheet after a leading end of the sheet reaches said separating portion and before the leading end of the sheet reaches said conveying means.