Sheet feeder and image forming apparatus

摘要

A sheet feeder includes a feed roller for feeding a sheet and a lifting plate for lifting the sheet to be fed to a feeding height of the feed roller. This sheet feeder further includes a wire for raising the lifting plate and a winding member formed with a winding configuration section for winding the wire. This winding configuration section is provided with a high-position winding section for a high-position side in a lifting height of the lifting plate and a low-position winding section for a low-position side. The high-position winding section is larger in winding radius than the low-position winding section. Accordingly, a sheet feeder having a simple structure capable of rapidly moving down the lifting plate and preventing impact of the lifting plate and an image forming apparatus incorporating the sheet feeder can be provided.

主权项

1. A sheet feeder including a feed roller for feeding a sheet and a lifting plate for lifting the sheet to be fed up to a feeding height for the feed roller, the device including:
a wire for raising the lifting plate; and a winding member formed with a winding configuration section for winding up the wire to raise the lifting plate, wherein the winding configuration section includes: a high-position winding section for winding the wire while the lifting plate is located on a high-position side in a lifting height; a low-position winding section for winding the wire while the lifting plate is located on a low-position side in the lifting height, the high-position winding section having a larger radius than a radius of the low-position winding section; and a middle-position winding section for winding the wire while the lifting plate is located in a middle region between the high-position side and the low-position side in the lifting height, the middle-position winding section being between the high-position winding section and the low-position winding section, and the middle-position winding section has a winding radius decreasing from a high-position winding section side toward a low-position winding section side.