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US 6,288,802 B1Granted
Image scanner
AssigneeNEC Corporation
InventorsMasami Hoshina, Shintaro Komuro
Life of this patent
Estimating the term…
Abstract
An image scanner capable of detecting the center of a valid image reading range is disclosed. To accurately detect the center position of a mirror, a center mark is positioned outside of the valid image reading range in parallel to the axis of rotation of the mirror. The center mark is input together with an image.
Claims3
An image scanner capable of detecting a center of an image of a document in a subscanning direction, comprising:
- a reading section including a linear CCD image sensor, a lens, a mirror for scanning the document in the subscanning direction, and a mechanism for rotating said mirror;
- a post supporting said reading section such that said reading section is positioned at a predetermined distance above the document;
- a base supporting said post;
- and
- a center mark positioned outside of a valid image reading range in parallel to an axis of rotation of said mirror for accurately detecting when said mirror has scanned a center position of the valid image reading range in the subscanning direction, said center mark being input together with the image of the document.
2 more elements
A method of detecting a center of an image of a document in a subscanning direction by use of an image scanner, comprising the steps of:
- returning, after power-up of said image scanner, a mirror included in a reading section to a physical read start position;
- causing a linear CCD image sensor to read one line for thereby starting a detection of a center mark positioned outside of a valid image reading range in parallel to an axis of rotation of said mirror;
- determining whether or not said center mark is present on the one line incident to said linear CCD image sensor;
- calculating, when said center mark is detected, a reading range in a subscanning direction by using said center mark as a center;
- and
- returning said mirror toward the read start position by a number of lines between said read start position and a position where said center mark is detected, whereby said read start position is determined.
3 more elements
Dependencies are inferred from the claim text.