Image reading apparatus
AssigneeCanon Kabushiki Kaisha
InventorYasuyuki Shinada
Life of this patent
Estimating the term…
Abstract
An image reading apparatus includes a carrying unit for carrying a sheet original and a book original to a reading position, an original urging member including a reference member, closed when a sheet original is carried by the carrying unit and opened when a book original is carried by the carrying member, a reading unit for reading an image of an original carried to the reading position and the reference member of the original urging member in a closed state, and a correcting unit for correcting nonuniformity of an image signal obtained by reading an original image on the basis of a reference signal obtained by reading the reference number. When the original urging member is open, the correcting unit corrects nonuniformity of an image signal on the basis of the reference signal used upon reading of a previous original image.
Claims13
An image reading apparatus comprising:
- an original guide member including a reference member, for guiding a sheet original to a reading position, said original guide member being capable of being opened;
- first carrying means for carrying the sheet original to the reading position when said original guide member is in a closed state;
- second carrying means for carrying a book original to the reading position when said original guide member is in an open state;
- reading means for (a) reading an image of the original carried to the reading position by said first or second carrying means, and (b) reading said reference member of said original guide member when said original guide member is in a closed state;
- and
- correcting means for correcting nonuniformity of a image signal obtained by reading the image of the original on the basis of a reference signal obtained by reading said reference member, when said original guide member is in an open state and said reading means cannot read said reference member said correcting means corrects nonuniformity of the image signal based on the reference signal which was used at the time of reading of an image of a previous original.
An image reading apparatus comprising:
- an original guide member including a white plate, for guiding a sheet original to a reading position, said original guide member being capable of being opened;
- first carrying means for carrying the sheet original to the reading position when said original guide member is in a closed state;
- second carrying means for carrying a book original to the reading position when said original guide member is in an open state;
- reading means for (a) reading an image of the original carried to the reading position by said first or second carrying means to generate an image signal representing the image, and (b) reading said white plate of said original guide member in a closed state to generate a white signal;
- and
- converting means for converting a black signal from said reading means to a white signal, when said original guide member is in an open state and said reading means cannot read said white plate, said converting means converts an output signal from said reading means, except the image signal representing the image of the book original, into a white signal.
Dependencies are inferred from the claim text.