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US 2003/0193698 A1Published application
Image reading apparatus
AssigneeCanon Kabushiki Kaisha
InventorToshio Hayashi
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AssigneeCanon Kabushiki Kaisha
InventorToshio Hayashi
Estimating the term…
A reader has a one-pass both-side reading function and comprises a selector which synthesizes in a dot sequential manner image signals from a CCD for reading a front face image and from a contact sensor for reading a rear face image, and transmits both-side image data in the same configuration as that of an I/F which transmits one-side image data. It transfers image information to a printer at high speed without being equipped with a high-capacity memory and without increasing the number of signal lines.
An image reading apparatus capable of reading a document sheet which has images recorded on both front and back sides thereof, having:
Dependencies are inferred from the claim text.
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From the US filing history. Foreign family members aren’t listed.
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Circuits or arrangements for the control thereof, e.g. using a programmed control device or according to a measured quantity: selecting or setting…
Scanning arrangements , i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing…:…
Simultaneous scanning of two or more separate pictures , e.g. two sides of the same sheet: of two pictures corresponding to two sides of a single…
Connection or combination of a still picture apparatus with another apparatus, e.g. for storage, processing or transmission of still picture…:…
Term end not estimated
1. Field of the Invention
The present invention relates to an image reading apparatus, and particularly to an image reading apparatus capable of reading a front side and a back side of a document sheet simultaneously or almost simultaneously.
2. Related Background Art
FIG. 1 is a schematic block diagram showing data flows from a CCD and a contact sensor;
FIG. 2 is a timing chart when the present invention is embodied;
FIG. 3 is a timing chart when a one-side document sheet is read;
Preferred embodiments of an image reading apparatus of the present invention will hereinafter be described in reference to the drawings.
FIG. 1 is a simple block diagram of an image copying apparatus in which the present invention is embodied. The same members as those in FIG. 6 are given the same numbers. A schematic operation of the block diagram shown in FIG. 1 will be described. When a front side of a both-side document sheet is read by a CCD 209, predetermined image processing including A/D conversion processing is applied to a front side image signal output from the CCD 209 in an image processing circuit 31, and a signal is input as 10-bit digital data 301 of the front side image for each pixel to a terminal A of a selector 33. On the other hand, when a back side image of the both-side document sheet is read by a contact sensor 250, the predetermined image processing including the A/D conversion processing is similarly applied to a back side image signal output from the contact sensor 250 in an image processing circuit 32, and a signal is input as 10-bit digital data 302 of the back side image for each pixel to a terminal B of the selector 33.
In the selector 33, a VCLK 304, which is a reference clock for driving the CCD 209 and the, contact sensor 250, is input to a terminal A*/B via a gate 35. When a signal input to the terminal A*/B is 0, the signal input to the terminal A is output from a terminal Y, and when a signal of the terminal A*/B is 1, the signal input to the terminal B is output from the terminal Y.