IMAGE READING DEVICE, IMAGE FORMING APPARATUS, AND SHADING DATA PROCESSING METHOD

• US 20170111549A1
• Filed: 09/27/2016
• Published: 04/20/2017
• Est. Priority Date: 10/19/2015
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: MIYAZAKI, Susumu, YOSHIDA, Tomoyuki, INUI, Tetsuo, IMOTO, Shigefumi
• Granted Patent: US 10,063,744 B2
• Time in Patent Office: Days
• CPC Class Codes: H02N 1/12 in the form of a conveyor belt, e.g. van de Graaff machine
• CPC Class Codes: H04N 1/0313 Direct contact pick-up heads, i.e. heads having no array of elements to project the scanned image elements onto the photodectors
• CPC Class Codes: H04N 1/12 using the sheet-feed movement or the medium-advance or the drum-rotation movement as the slow scanning component, e.g. arrangements for the main-scanningsheet-feed movement by translatory movement of a flat picture-bearing surface H04N1/1008; main-scanning using oscillating or rotating mirrors H04N1/113; using multi-element arrays H04N1/19
• CPC Class Codes: H04N 1/2034 at identical corresponding positions, i.e. without time delay between the two image signals
• CPC Class Codes: H04N 1/407 Control or modification of tonal gradation or of extreme levels, e.g. background level
• CPC Class Codes: H04N 1/4095 Correction of errors due to scanning a two-sided document, i.e. show-through correction
• CPC Class Codes: H04N 2201/0081 Image reader H04N2201/0091 - H04N2201/0094 take precedence

Abstract

An image reading device includes a first unit to read one surface of a document in a first area facing a document path, a second unit disposed in the first area to read the other surface of the document, a first reference member facing the first unit at a first distance therefrom at a second position in a second area not facing the path, a second reference member facing the first unit at a second distance therefrom at a first position in the first area, a third reference member facing the second unit at the second distance therefrom, and a correction unit to correct, based on a difference between first data generated through reading of the first member by the first unit and second data generated through reading of the second member by the first unit, third data generated through reading of the third member by the second unit.

Claims

1. An image reading device comprising:

a first image reading unit movable between a first area facing a document transport path and a second area not facing the document transport path, and capable of reading, in the first area, a first surface of a document transported on the document transport path;

a second image reading unit disposed in the first area and capable of reading a second surface of the document;

a first shading reference member facing the first image reading unit at a first distance therefrom when the first image reading unit is located at a second position in the second area;

a second shading reference member facing the first image reading unit at a second distance therefrom across the document transport path when the first image reading unit is located at a first position in the first area;

a third shading reference member facing the second image reading unit at the second distance therefrom across the document transport path; and

a correction unit to correct third shading data based on a difference between first shading data and second shading data, the first shading data generated through reading of the first shading reference member by the first image reading unit, the second shading data generated through reading of the second shading reference member by the first image reading unit, and the third shading data generated through reading of the third shading reference member by the second image reading unit.

2. The image reading device of claim 1, wherein the first distance corresponds to a distance from the first image reading unit located at the first position in the first area to a part of the document transport path facing the first image reading unit.

3. The image reading device of claim 1, further comprising a document table on which a document is placed to be read by the first image reading unit moving in the second area.

4. The image reading device of claim 1, wherein the correction unit standardizes the corrected third shading data.

5. The image reading device of claim 4, wherein the second image reading unit includes a light source, and the correction unit standardizes the corrected third shading data based on adjustment of a light amount of the light source of the second image reading unit.

6. The image reading device of claim 4, wherein the correction unit standardizes the corrected third shading data based on calculation performed on the third shading data.

7. The image reading device of claim 4, wherein the correction unit corrects misalignment between main scanning pixels of data read by the first image reading unit and main scanning pixels of data read by the second image reading unit.

8. An image forming apparatus comprising the image reading device of claim 1.

9. A shading data processing method performed by an image reading device including a first image reading unit and a second image reading unit, the first image reading unit being movable between a first area facing a document transport path and a second area not facing the document transport path, and capable of reading, in the first area, a first surface of a document transported on the document transport path, and the second image reading unit disposed in the first area and capable of reading a second surface of the document, the shading data processing method comprising:

acquiring first shading data through reading, with the first image reading unit and at a second position in the second area, a first shading reference member facing the first image reading unit as at a first distance therefrom;

acquiring second shading data through reading, with the first image reading unit and at a first position in the first area, a second shading reference member facing the first image reading unit at a second distance therefrom across the document transport path;

acquiring third shading data through reading, with the second image reading unit, a third shading reference member facing the second image reading unit at the second distance therefrom across the document transport path; and

correcting the third shading data based on a difference between the first shading data and the second shading data.