Image reading apparatus and method

• US 7,551,328 B2
• Filed: 01/08/2003
• Issued: 06/23/2009
• Est. Priority Date: 01/09/2002
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Sawao, Takashi, Ishibashi, Junichi, Kondo, Tetsujiro, Nagano, Takahiro, Wada, Seiji, Miyake, Toru, Fujiwara, Naoki
• Primary Examiner(s): Worku; Negussie
• Application Number:
  US10/471,344
• Publication Number:
  US 20040263920A1
• Time in Patent Office: 2,358 Days
• Field of Search: 358/474, 358/482, 358/494, 358/497, 358/486, 358/513, 382/164, 382/167, 382/118, 382/274, 348/135, 348/174, 348/17, 348/208.4, 340/937, 340/938, 340/936
• US Class Current: 358/474
• CPC Class Codes: H04N 1/028 for picture information pick-up
• CPC Class Codes: H04N 1/1013 with sub-scanning by translatory movement of at least a part of the main-scanning components H04N1/107 takes precedence
• CPC Class Codes: H04N 1/191 the array comprising a one-dimensional array , or a combination of one-dimensional arrays, or a substantially one-dimensional array, e.g. an array of staggered elements

Abstract

The present invention enables image data with good S/N and high resolution to be obtained reliably in a short reading time. A CCD 102 is formed by arranging line sensors, in which detecting elements having a time integration effect are arranged in a direction orthogonal to a relative movement direction in which the CCD 102 moves relative to an original, in a plurality of columns in the relative movement direction. A signal processing unit 107 detects pixel components on the basis of a model for separating first pixel values obtained in a processing unit time by the CCD 102 into a plurality of the pixel components corresponding to detection positions of the object being detected, and generates second pixel values corresponding to the detection positions of the object being detected on the basis of the detected pixel components. The present invention is applicable to scanners.

Claims

1. An image reading apparatus comprising:

a reading device formed by arranging line sensors, in which detecting elements having a time integration effect are arranged in a direction orthogonal to a relative movement direction in which the reading means moves relative to an object being detected, in a plurality of columns in said relative movement direction;

a pixel component detecting device configured to detect pixel components on the basis of a model for separating first pixel values obtained in a processing unit time by said detecting elements into a plurality of said pixel components corresponding to detection positions of said object being detected; and

a pixel value generating device configured to generate second pixel values corresponding to said detection positions of said object being detected on the basis of said pixel components detected by said pixel component detecting means,

wherein, said pixel component detecting device includes a model generating device for generating said model that represents a relation between said first pixel values and a plurality of said pixel components corresponding to said detection positions, said pixel components being accumulated in each divided unit time obtained by dividing said processing unit time by a number of columns of said line sensors; and

wherein said pixel component detecting device is configured to detect said pixel components on the basis of said model generated by said model generating device.

2. An image reading apparatus as claimed in claim 1, further comprising a speed detecting device configured to detect relative speed between said detecting elements and said object being detected,

wherein said model generating device is configured to generate said model that represents a relation between said first pixel values obtained from a part of said detecting elements of said line sensors arranged in said reading device and said pixel components in correspondence with said relative speed detected by said speed detecting device.

3. An image reading apparatus as claimed in claim 1, further comprising a speed detecting device configured to detect relative speed between said detecting elements and said object being detected,

wherein said model generating device is configured to generate said model that represents a relation between third pixel values obtained by adding together said first pixel values obtained from adjacent said detecting elements of a plurality of said detecting elements arranged in columns in said relative movement direction of said reading device and said pixel components in correspondence with said relative speed detected by said speed detecting device.

4. An image reading apparatus as claimed in claim 1, further comprising a control device configured to control said reading means such that when said reading device is positioned at an initial position, said reading device configured to pick up an image of said object being detected and output said first pixel values corresponding to said detecting elements in a state of standing still with respect to said object being detected during said processing unit time,

wherein said pixel component detecting device is configured to detect other said pixel components by substituting said pixel components generated on the basis of said first pixel values resulting from image pickup by said reading device in the state of standing still with respect to said object being detected under control of said control device into said model that represents a relation between said first pixel values and a plurality of said pixel components corresponding to said detection positions.

5. An image reading apparatus as claimed in claim 4, characterized in that:

said control device is configured to control said reading means such that said reading device is configured to pick up an image of said object being detected and outputs said first pixel values corresponding to said detecting elements in the state of standing still with respect to said object being detected during said processing unit time at predetermined time intervals.

6. An image reading apparatus as claimed in claim 1, further comprising a control device is configured to control exposure time for each of said detecting elements of said reading device such that each of said first pixel values includes said pixel component corresponding to a different position in the relative-movement direction of said object being detected,

wherein said pixel component detecting device is configured to detect said pixel components on the basis of said model that represents a relation between said first pixel values each including said pixel component corresponding to a different position in the relative movement direction of said object being detected and a plurality of said pixel components corresponding to said detection positions.

7. An image reading apparatus as claimed in claim 6, characterized in that:

said control device is configured to control the exposure time for each of said detecting elements of said reading device such that each of said first pixel values includes said pixel component corresponding to a different position in the relative movement direction of said object being detected at predetermined time intervals.

8. An image reading apparatus as claimed in claim 1, further comprising a moving device configured to move one of said object being detected and said reading device to change a relative position between said object being detected and said reading device.

9. An image reading apparatus as claimed in claim 1, characterized in that:

said pixel component detecting device includes a normal equation generating device configured to generate a normal equation on the basis of a model for separating first pixel values obtained by said detecting elements into a plurality of pixel components corresponding to detection positions of said object being detected; and

said pixel component detecting device is configured to detect said pixel components on the basis of said normal equation generated by said normal equation generating device.

10. An image reading apparatus as claimed in claim 9, further comprising:

a first control device configured to control image pickup of said reading device such that each of said detecting elements arranged in a plurality of columns in said relative movement direction begins exposure at an identical first position of said detection positions of said object being detected and ends exposure at an identical second position different from said first position; and

a second control device configured to control the image pickup of said reading device such that said detecting elements begin exposure after ending exposure at a third time between a first time when all of said detecting elements arranged in the plurality of columns have reached said first position and have begun exposure and a second time when one of said detecting elements arranged in the plurality of columns has reached said second position and has ended exposure;

wherein said normal equation generating device is configured to generate said normal equation by setting said first pixel values obtained by said detecting elements in said normal equation representing a relation between a plurality of said pixel components including said pixel component corresponding to one of said first position, said second position, and a third position as said detection position at said third time and said first pixel values.

11. An image reading apparatus as claimed in claim 9, characterized in that:

said normal equation generating device is configured to generate said normal equation for calculating said pixel components by applying a method of least squares.

12. An image reading apparatus as claimed in claim 9, characterized in that:

said normal equation generating device is configured to generate said normal equation weighted in correspondence with lengths of exposure times for obtaining said first pixel values.

13. An image reading method of an image reading apparatus, said image reading apparatus including a reading device formed by arranging line sensors, in which detecting elements having a time integration effect are arranged in a direction orthogonal to a relative movement direction in which the reading apparatus moves relative to an object being detected, in a plurality of columns in said relative movement direction, said image reading method comprising the steps of:

detecting pixel components on the basis of a model for separating first pixel values obtained in a processing unit time by said detecting elements into a plurality of said pixel components corresponding to detection positions of said object being detected; and

generating second pixel values corresponding to said detection positions of said object being detected on the basis of said pixel components detected by processing of said pixel component detecting step.

14. A computer-readable medium encoded with a computer program, said program being for image reading processing of an image reading apparatus, said image reading apparatus including a reading apparatus formed by arranging line sensors, in which detecting elements having a time integration effect are arranged in a direction orthogonal to a relative movement direction in which the reading apparatus moves relative to an object being detected, in a plurality of columns in said relative movement direction, said program comprising the steps of:

detecting pixel components on the basis of a model for separating first pixel values obtained in a processing unit time by said detecting elements into a plurality of said pixel components corresponding to detection positions of said object being detected; and

generating second pixel values corresponding to said detection positions of said object being detected on the basis of said pixel components detected by processing of said pixel component detecting step.

15. A computer-readable medium encoded with a computer program executable by a computer, said computer controlling an image reading apparatus, said image reading apparatus including a reading apparatus formed by arranging line sensors, in which detecting elements having a time integration effect are arranged in a direction orthogonal to a relative movement direction in which the reading apparatus moves relative to an object being detected, in a plurality of columns in said relative movement direction, said program comprising the steps of:

detecting pixel components on the basis of a model for separating first pixel values obtained in a processing unit time by said detecting elements into a plurality of said pixel components corresponding to detection positions of said object being detected; and

generating second pixel values corresponding to said detection positions of said object being detected on the basis of said pixel components detected by processing of said pixel component detecting step.