Sheet feeder and image forming apparatus

Abstract

A sheet feeder comprising a sheet receiving section (P20) having an elevating / lowering plate (960), a member (920) for regulating the sides of sheets, an air blowing section (986) for blowing air toward the sides of sheets at upper levels out of the sheets received in the sheet receiving section, a sheet suction-conveyance section (VT20) installed above the sheet receiving section with a gap kept from the uppermost sheet of the sheets received in the sheet receiving section, a reflective sensor (970) for detecting the upper limit position of stacked sheets received in the sheet receiving section, and a control section for performing control to elevate the elevating / lowering plate when an output from the reflective sensor indicates an intermediate state provided between a sheet brought into a floating state by an air flow which is blown from the air blowing section, and a sheet maintaining the stacked state. As a result, stabilized sheet-feeding can be ensured even if a thick sheet of a small size is used, and the upper limit position of sheets can be controlled by a simple constitution.

Description

technical field [0001] The present invention relates to a paper feeding device that sucks and feeds thin sheets of paper from above a stack of paper stacked and stored in a paper storage unit through a paper suction and conveying unit, and relates to a copier, a printer, a facsimile having the paper feeding device machine and other image forming devices. Background technique [0002] By performing charging, exposure, and development processes, a toner image based on originals or image data is formed on an image carrier, and the toner image is directly transferred to paper or the toner image is transferred through an intermediate transfer body. An image forming apparatus that performs a fixing process after an image is transferred to a sheet is widely known. [0003] Such an image forming apparatus includes: a paper storage unit capable of stacking and storing sheets of paper; and a paper feeding device having a paper feeding unit that feeds the paper in the paper storage un...

AI Technical Summary

Problems solved by technology

[0023] Also, if the blown air is strengthened in order to float the paper, there is a possibility that the rear end of the paper and the height detection sensor lever will also float.

[0024] If so, it is impossible to make the height detection sensor lever move according to the height position of the paper top surface, and as a result, it brings obstacles to the control of the top surface position of the paper on the condition that the height detection sensor lever operates according to the height position of the paper top surface.

Images