Image reading apparatus and color erasing apparatus

摘要

An image reading apparatus includes a first illumination section configured to obliquely illuminate a surface of a sheet in an image reading area, a second illumination section arranged upstream of the first image reading area and configured to obliquely illuminate the surface of the sheet in the image reading area, and a reading section configured to read the surface of the sheet illuminated in the image reading area. The apparatus can switch between a two-side illumination mode in which the image reading area is illuminated by both illumination sections, and a single-side illumination mode in which the image reading area is illuminated by only one illumination section. The apparatus further includes a determination section configured to determine the state of the surface of the sheet (e.g., rip or creases) based on image data corresponding to the surface read in the single-side illumination mode.

主权项

1. An image reading apparatus comprising:
a first illumination section arranged at a downstream side of a first image reading area in a sheet conveyance direction and configured to obliquely illuminate a first surface of a sheet in the first image reading area; a second illumination section arranged at an upstream side of the first image reading area in the sheet conveyance direction and configured to obliquely illuminate the first surface of the sheet in the first image reading area; a first reading section configured to read the first surface of the sheet illuminated in the first image reading area; an illumination switching section configured to switch between: a first two-side illumination mode in which the first image reading area is illuminated by the first illumination section and the second illumination section when the sheet is subjected to image reading in the first image reading area, and a first single-side illumination mode in which the first image reading area is illuminated by only one of the first illumination section and the second illumination section when the sheet is subjected to image reading in the first image reading area; and a determination section configured to acquire image data corresponding to the first surface of the sheet read by the first reading section in the first single-side illumination mode, identify noise relative to a background color of the sheet in the acquired image data, and determine the state of the first surface of the sheet based on the noise.