IP Library Granted Patent US 8,018,479
Granted Patent B2
US 8,018,479 · App. 12/199,292 · Granted Sep 13, 2011

Method and system for correcting the linearity error in electrophotographic devices

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Quick Facts
Patent No.
US 8,018,479
App. No.
12/199,292
Granted
Sep 13, 2011
Kind
B2
Abstract

The invention describes a method and system for correcting linearity error of an electrophotographic device with a reduced number of lenses. The method and system insert additional time-slices in the data being processed by the electrophotographic device. The additional time-slices are inserted in the data in a predefined order based on a plurality of random numbers. The insertion of additional time-slices corrects the linearity error of the electrophotographic device.

Claims (34)

1. A method for correcting a linearity error in an electrophotographic device, the electrophotographic device being used for processing data comprising a plurality of pels, each of the plurality of pels comprising a plurality of time-slices, the method comprising:

computing one or more total time-slices corresponding to one or more regions of the data, each of the one or more regions of the data comprising a predefined number of pels, the computation being performed based on a first predefined criterion;

adding a plurality of random numbers from a generated matrix to the one or more total time-slices;

computing a plurality of scan insertion vectors based on the addition of the plurality of random numbers to the one or more total time-slices, each of the plurality of scan insertion vectors describing a single scan line of data and each of the plurality of scan insertion vectors comprising a plurality of tokens, wherein the plurality of tokens corresponds to the one or more regions of the data;

inserting one or more time-slices in the one or more regions of the data based on the plurality of tokens, the one or more time-slices being inserted in a predefined order, wherein the insertion of the one or more time-slices corrects the linearity error in the electrophotographic device; and

storing the plurality of scan insertion vectors in a memory;

wherein a predefined number of unique scan insertion vectors of the plurality of scan insertion vectors are stored in the memory.

2. The method according to claim 1 further comprising computing the one or more time-slices in each of the plurality of pels, the computation being performed based on a second predefined criterion.

3. The method according to claim 2 , wherein the second predefined criterion is based on one or more properties of the electrophotographic device and one or more properties of the data.

4. The method according to claim 1 , wherein the first predefined criterion is based on the one or more properties of the electrophotographic device.

5. The method according to claim 1 , wherein at least one of the plurality of random numbers is added to each of the one or more total time-slices.

6. The method according to claim 1 , wherein each of the plurality of scan insertion vectors corresponds to at least one of the one or more regions of the data.

7. The method according to claim 1 , wherein each of the one or more total time-slices comprises one or more time-slices in the predefined number of pels and one or more time-slices to be inserted in the corresponding one or more regions of the data.

8. The method according to claim 7 , wherein the plurality of random numbers are added to the one or more time-slices to be inserted in the one or more regions of the data.

9. The method according to claim 1 , wherein the predefined order of insertion is based on the plurality of random numbers.

10. The method according to claim 1 , wherein the one or more time-slices are inserted in between two pels in the one or more regions.

11. The method according to claim 1 further comprising storing the plurality of random numbers in a matrix, wherein a plurality of elements of the matrix is added to the one or more time-slices to be inserted in the one or more regions of the data, with only one element of the matrix being added to the one or more time-slices in a single region of the data.

12. The method according to claim 1 , wherein adding a plurality of random numbers to the one or more total time-slices varies across a plurality of scan lines of the data and within the single scan line of data.

13. The method according to claim 1 , wherein the computing the plurality of scan insertion vectors is based on computing a derivative of a scan position with respect to a change in scanner angle.

14. A method for correcting a linearity error in an electrophotographic device, the electrophotographic device being used for processing data comprising a plurality of pels, each of the plurality of pels comprising a plurality of time-slices, the method comprising:

computing one or more total time-slices corresponding to one or more regions of the data, each of the one or more regions of the data comprising a predefined number of pels, the computation being performed based on a first predefined criterion;

adding a plurality of random numbers from a generated matrix to the one or more total time-slices;

computing a plurality of scan insertion vectors based on the addition of the plurality of random numbers to the one or more total time-slices, each of the plurality of scan insertion vectors describing a single scan line of data and each of the plurality of scan insertion vectors comprising a plurality of tokens, wherein the plurality of tokens corresponds to the one or more regions of the data;

inserting one or more time-slices in the one or more regions of the data based on the plurality of tokens, the one or more time-slices being inserted in a predefined order, wherein the insertion of the one or more time-slices corrects the linearity error in the electrophotographic device;

storing the plurality of scan insertion vectors in a memory;

storing the plurality of random numbers in a matrix, wherein a plurality of elements of the matrix is added to the one or more time-slices to be inserted in the one or more regions of the data, with only one element of the matrix being added to the one or more time-slices in a single region of the data; and

selecting the plurality of elements in such a way that a sum of the plurality of random numbers across each row is zero.

15. A method for correcting a linearity error in an electrophotographic device, the electrophotographic device being used for processin data comprising a plurality of pels each of the plurality of pels comprising a plurality of time-slices, the method comprising:

computing one or more total time-slices corresponding to one or more regions of the data, each of the one or more regions of the data comprising a predefined number of pels, the computation being performed based on a first predefined criterion;

adding a plurality of random numbers from a generated matrix to the one or more total time-slices;

computing a plurality of scan insertion vectors based on the addition of the plurality of random numbers to the one or more total time-slices, each of the plurality of scan insertion vectors describing a single scan line of data and each of the plurality of scan insertion vectors comprising a plurality of tokens, wherein the plurality of tokens corresponds to the one or more regions of the data;

inserting one or more time-slices in the one or more regions of the data based on the plurality of tokens, the one or more time-slices being inserted in a predefined order, wherein the insertion of the one or more time-slices corrects the linearity error in the electrophotographic device; and

storing the plurality of scan insertion vectors in a memory;

wherein each of the plurality of scan insertion vectors is unique with respect to each other and accessed from the memory before scanning of the data begins.

Assignments (4)
RELEASE OF SECURITY INTEREST Recorded Jan 18, 2024
From: CHINA CITIC BANK CORPORATION LIMITED, GUANGZHOU BRANCH, AS COLLATERAL AGENT
To: LEXMARK INTERNATIONAL, INC.
Reel/Frame 066345/0026 →
CORRECTIVE ASSIGNMENT TO CORRECT THE INCORRECT U.S. PATENT NUMBER PREVIOUSLY RECORDED AT REEL: 046989 FRAME: 0396. ASSIGNOR(S) HEREBY CONFIRMS THE PATENT SECURITY AGREEMENT. Recorded Oct 24, 2018
From: LEXMARK INTERNATIONAL, INC.
To: CHINA CITIC BANK CORPORATION LIMITED, GUANGZHOU BRANCH, AS COLLATERAL AGENT
Reel/Frame 047760/0795 →
PATENT SECURITY AGREEMENT Recorded Aug 30, 2018
From: LEXMARK INTERNATIONAL, INC.
To: CHINA CITIC BANK CORPORATION LIMITED, GUANGZHOU BRANCH, AS COLLATERAL AGENT
Reel/Frame 046989/0396 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 27, 2008
From: HADADY, CRAIG ERIC; JONES, CHRISTOPHER DANE; LEMASTER, JOHN
To: LEXMARK INTERNATIONAL, INC.
Reel/Frame 021449/0538 →