Image forming apparatus
AssigneeKabushiki Kaisha Toshiba
InventorYasuhiro Iwata
Life of this patent
Estimating the term…
Abstract
An image forming apparatus comprises a main charger for charging the surface of a photosensitive drum, an exposure unit for illuminating an original and guiding light from the original onto the drum, thereby forming thereon an electrostatic latent image corresponding to an image of the original, a detector for detecting the size of the original, and an erase array for erasing an undesired electric charge on the photosensitive drum in accordance with the original size detected by the detector.
Claims27
An image forming apparatus comprising:
- means for carrying an original thereon;
- cover means movable between a first position in which cover means covers the original and the carrying means and a second position in which the cover means leaves exposed the original and the surrounding portion of the carrying means;
- image forming means for forming on an image carrier a first copy image corresponding to an image of the original on the carrying means and a second copy image corresponding to an image surrounding the original;
- and
- means for preventing the formation of the second copy image when the cover means is positioned in the second position.
An image forming apparatus comprising:
- an image carrier;
- charging means for charging the image carrier;
- illumination means for illuminating an original;
- optical means for guiding light reflected from the original onto the charged image carrier, thereby forming an electrostatic latent image thereon;
- detecting means for detecting an image region corresponding to an image of the original by detecting the light guided by the optical means;
- and
- erase means for erasing an electric charge on the image carrier corresponding to a no-image region outside the image region.
An image forming apparatus comprising:
- image forming means for forming on an image carrier a first copy image corresponding to an image of the original on the carrying means and a second copy image corresponding to an image of a region surrounding the original;
- means for detecting the size of the original;
- means for preventing the formation of the second copy image in accordance with the result of detection by the size detecting means;
- and
- means for moving the image forming means and size detecting means simultaneously against the original in the same direction two times in every copying cycle so that the size detecting means detects the size of the original while moving for the first time, and the image forming means forms the copy image on the carrier while moving for the second time.
An image forming apparatus comprising:
- an image carrier movable in one direction;
- image forming means for scanning the original in one direction to form a first copy image corresponding to an image of the original and a second copy image corresponding to an image of a region surrounding the original onto the image carrier during the movement of the image carrier;
- means for detecting the size of the original;
- and
- means for preventing the formation of the second copy image in accordance with the result of detection by the size detecting means, while the image forming means scans the original and the image carrier is moved in said direction.
Dependencies are inferred from the claim text.