CONTROL DEVICE CONTROLLING AMOUNT OF COLORANT BASED ON LINEAR CORRELATIONS BETWEEN DIFFERENCE RATIOS AND OFFSETS

• US 20140071504A1
• Filed: 08/28/2013
• Published: 03/13/2014
• Est. Priority Date: 09/07/2012
• Status: Active Grant

• Current Assignee: Brother Kogyo Kabushiki Kaisha
• Original Assignee: Brother Kogyo Kabushiki Kaisha
• Inventors: KUNO, Masashi
• Granted Patent: US 8,928,960 B2
• Time in Patent Office: Days
• US Class Current: 358/505
• CPC Class Codes: H04N 1/00015 Reproducing apparatus
• CPC Class Codes: H04N 1/00045 using a reference pattern designed for the purpose, e.g. a test chart
• CPC Class Codes: H04N 1/00087 Setting or calibrating picture signal circuits H04N1/40
• CPC Class Codes: H04N 1/2346 according to a detected condition or state of the reproducing device, e.g. temperature or ink quantity
• CPC Class Codes: H04N 2201/0006 details of the reference pattern (DM 1105)

Abstract

A control device performs: acquiring an optical measured scan value; setting a measured offset using the measured scan value by reference to predetermined correlations; and determining a control value using the measured offset amount. The control value is used for controlling an amount of colorant to be ejected during printing. In the predetermined correlations, a first pair of scan values is associated with a first pair of offsets. A second pair of scan values is associated with a second pair of offsets. The first and second pair has a first and second scan difference between the scan values, respectively. The first and second pair of offsets has a first and second offset difference between the offsets, respectively. The first scan difference is different from the second scan difference. The first offset difference is same as the second offset difference.

Claims

1. A control device comprising:

a processor; and

a memory storing computer-readable instructions therein, the computer-readable instructions, when executed by the processor, causing the control device to perform;

acquiring a measured scan value, the measured scan value being acquired by measuring optically a scan target image printed on a recording medium;

setting a measured offset amount using the measured scan value by reference to predetermined correlations between predetermined scan values and predetermined offset amounts, the measured offset amount indicating a difference between the measured scan value and a predetermined reference value, the predetermined scan values being optically acquired from test images that have been printed by using a predetermined colorant, the predetermined scan values including a first predetermined scan value, a second predetermined scan value, and a third predetermined scan value, the third predetermined scan value being different from the first predetermined scan value and the second predetermined scan value, the predetermined offset amounts including a first predetermined offset amount, a second predetermined offset amount, and a third predetermined offset amount, the third predetermined offset amount being different from the first predetermined offset amount and the second predetermined offset amount, the predetermined correlations being set such that;

a first predetermined scan value pair is associated with a first predetermined offset amount pair, the first predetermined scan value pair being a pair of the first predetermined scan value and the second predetermined scan value, the first predetermined offset amount pair being a pair of the first predetermined offset amount and the second predetermined offset amount, the first predetermined scan value pair has a first scan difference between the first predetermined scan value and the second predetermined scan value, the first predetermined offset amount pair has a first offset difference between the first predetermined offset amount and the second predetermined offset amount;

a second predetermined scan value pair is associated with a second predetermined offset amount pair, the second predetermined scan value pair being a pair of the third predetermined scan value and one of the predetermined scan values, the second predetermined offset amount pair being a pair of the third predetermined offset amount and one of the predetermined offset amounts, the second predetermined scan value pair has a second scan difference between the third predetermined scan value and the one of the predetermined scan values, the second predetermined offset amount pair has a second offset difference between the third predetermined offset amount and the one of the predetermined offset amounts;

the first scan difference is different from the second scan difference; and

the first offset difference is same as the second offset difference; and

determining a control value using the measured offset amount, the control value being used for controlling an amount of colorant to be ejected during printing.

2. The control device according to claim 1, wherein the scan target image is printed by a printing unit,

wherein the setting sets the measured offset amount using both the measured scan value and a temperature inside the printing unit that is measured when the scan target image is printed by the printing unit.

3. The control device according to claim 1, wherein the scan target image is printed by a printing unit,

wherein the determining determines the control value using both the measured offset amount and a temperature inside the printing unit that is measured when the scan target image is printed by the printing unit.

4. The control device according to claim 1, wherein the acquiring acquires N number of measured scan values from N number of scan target images, N being an integer greater than or equal to 2, each of the N number of scan target images being different from one another;

wherein the setting sets a single measured offset amount using the N number of measured scan values.

5. The control device according to claim 4, wherein the setting sets the single measured offset amount by:

setting N number of measured offset amounts using the N number of measured scan values; and

calculating an average of the N number of measured offset amounts as the single measured offset amount.

6. The control device according to claim 1, wherein the scan target image includes a first color image printed with a first colorant and a second color image printed with a second colorant, the second colorant being different from the first colorant,

wherein the acquiring acquires a first measured scan value from the first color image and a second measured scan value from the second color image, respectively;

wherein the setting sets a first measured offset amount using the first measured scan value and the determining determines a first control value for the first colorant using the first measured offset amount,

wherein the setting sets a second measured offset amount using the second measured scan value and the determining determines a second control value for the second colorant using the second measured offset amount.

7. The control device according to claim 6, wherein the first colorant is pigment colorant;

wherein the second colorant is dye-based colorant.

8. The control device according to claim 1, wherein the scan target image is printed with magenta colorant;

wherein the measured scan value expresses an intensity of green color component that is acquired by measuring the scan target image.

9. The control device according to claim 1, wherein the scan target image includes a first-size dot image in which dots having a first dot size are formed and a second-size dot image in which dots having a second dot size are formed, the second dot size being different from the first size;

wherein the acquiring acquires a measured scan value for the first dot size from the first-size dot image and a measured scan value for the second dot size from the second-size dot image, respectively;

wherein the setting sets a measured offset amount for the first dot size using the measured scan value for the first dot size and the determining determines a target control value for the first dot size using the measured offset amount for the first dot size,

wherein the setting sets a measured offset amount for the second dot size using the measured scan value for the second-size and the determining determines a target control value for the second dot size using the measured offset amount for the second dot size.

10. The control device according to claim 1, wherein the target control value is used for correcting a value related to a halftone process.

11. The control device according to claim 1, wherein each of the predetermined scan values in the predetermined correlations is set to an actual measured value that has been measured from the corresponding test image with an actual usage amount of the predetermined colorant when the test image was printed using a target usage amount of the predetermined colorant, the predetermined offset amounts corresponding to a ratio of a calibration amount to the actual usage amount linearly, the calibration amount being a difference between the target usage amount and the actual usage amount.

12. The control device according to claim 1, further comprising a reading unit configured to optically read the scan target image and to generate the measured scan value.

13. The control device according to claim 1, further comprising a printing unit configured to print the scan target image.

14. The control device according to claim 13, further comprising a sensor configured to detect temperature in the printing unit when the printing unit prints the scan target image.

15. A non-transitory computer readable storage medium storing a set of program instructions installed on and executed by a computer, the program instructions comprising:

acquiring a measured scan value, the measured scan value being acquired by measuring optically a scan target image printed on a recording medium;

setting a measured offset amount using the measured scan value by reference to predetermined correlations between predetermined scan values and predetermined offset amounts, the measured offset amount indicating a difference between the measured scan value and a predetermined reference value, the predetermined scan values being optically acquired from test images that have been printed by using a predetermined colorant, the predetermined scan values including a first predetermined scan value, a second predetermined scan value, and a third predetermined scan value, the third predetermined scan value being different from the first predetermined scan value and the second predetermined scan value, the predetermined offset amounts including a first predetermined offset amount, a second predetermined offset amount, and a third predetermined offset amount, the third predetermined offset amount being different from the first predetermined offset amount and the second predetermined offset amount, the predetermined correlations being set such that;

a first predetermined scan value pair is associated with a first predetermined offset amount pair, the first predetermined scan value pair being a pair of the first predetermined scan value and the second predetermined scan value, the first predetermined offset amount pair being a pair of the first predetermined offset amount and the second predetermined offset amount, the first predetermined scan value pair has a first scan difference between the first predetermined scan value and the second predetermined scan value, the first predetermined offset amount pair has a first offset difference between the first predetermined offset amount and the second predetermined offset amount;

a second predetermined scan value pair is associated with a second predetermined offset amount pair, the second predetermined scan value pair being a pair of the third predetermined scan value and one of the predetermined scan values, the second predetermined offset amount pair being a pair of the third predetermined offset amount and one of the predetermined offset amounts, the second predetermined scan value pair has a second scan difference between the third predetermined scan value and the one of the predetermined scan values, the second predetermined offset amount pair has a second offset difference between the third predetermined offset amount and the one of the predetermined offset amounts;

the first scan difference is different from the second scan difference; and

the first offset difference is same as the second offset difference; and

determining a control value using the measured offset amount, the control value being used for controlling an amount of colorant to be ejected during printing.