Patent Number: 8,576,463

Title: Automatic document feeder and image forming apparatus

Abstract: An automatic document feeder includes an original feed table that has a detection hole and on which a bundle composed of a plurality of originals is set; and an original detection sensor that detects the original on the original feed table. The original detection sensor is a reflective optical sensor having a light-emitting unit and a light-receiving unit, and disposed under or inside of the original feed table to detect the original though the detection hole. The detection hole includes a light-emitting side portion corresponding to the light-emitting unit of and a light-receiving side portion corresponding to the light-receiving unit of the original detection sensor, the light-emitting side portion and the light-receiving side portion having planar shapes different from each other. The original feed table includes a light-shielding portion that is provided above the light-receiving unit of the original detection sensor, and has a slanted surface overhanging the light-receiving unit.

Inventors: Yomogida; Matsuo (Miyagi, JP)

Assignee: Ricoh Company, Limited

International Classification: H04N 1/04 (20060101)

Expiration Date: 1/05/12017