Nozzle drive control device and method

1. A nozzle drive control method comprising:

applying a drive voltage to a nozzle to eject an ink droplet;

sensing a size or an ejecting speed of the ejected ink droplet;

determining whether the sensed size or ejecting speed of the ink droplet is included within a predetermined range; and

calculating a second drive voltage as the drive voltage when the sensed size or ejecting speed of the ejected ink droplet is not included within the predetermined range, to apply the second drive voltage to the nozzles to eject a second ink droplet, to sense a second size or second ejecting speed of the second ink droplet as the size or ejecting speed, and to determine whether the size or ejection speed of the second ink droplet is included within the predetermined range,

wherein the determining of whether the sensed size or ejecting speed of the ink droplet is included within the predetermined range comprises using predetermined ranges corresponding to respective nozzles in an image forming apparatus having a plurality of nozzles.

2. The method of claim 1 , wherein the calculating of the second drive voltage comprises repeating the calculating the second drive voltage as the drive voltage until the sensed result is included within the predetermined range.

3. The method of claim 1 , wherein the calculating of the drive voltage comprises calculating the second drive voltage according to a determination that variation rates of the size and the ejecting speed of the ink droplet and the second size and ejection speed of the second ink droplet ejected from the nozzle are linear with respect to the applied drive voltage.

4. The method of claim 3 , wherein the calculating of the second drive voltage comprises calculating the second drive voltage using the following equation:

V new =V old +(Q target −Q sensed )/a, wherein V new is the new drive voltage to be calculated, is a V old is the previously applied drive voltage, Q target is a predetermined size or ejecting speed of the ink droplet, Q sensed is the sensed size or ejecting speed of the ink droplet, and a is a predetermined slope.

5. The method of claim 1 , wherein the calculating of the second drive voltage comprises calculating the second drive voltage using a Newton-Rhapson method, false-position method, or a bisection method.

6. The method of claim 1 , further comprising:

applying another drive voltage to another nozzle to eject another ink droplet;

sensing another size or ejecting speed of the another ink droplet ejected by the another nozzle;

determining whether the sensed size or ejecting speed of the another ink droplet ejected by the another nozzle is included within a different predetermined range; and

calculating a third drive voltage as the another drive voltage when the sensed size or ejecting speed of the another ink droplet ejected by the another nozzle is not included within the different predetermined range, to apply the third drive voltage to the another nozzle to eject a second another ink droplet, to sense a second another size or ejecting speed of the second another ink droplet ejected from the second nozzle as the another size or ejecting speed of the ink droplet ejected by the another nozzle, and to determine whether the size or ejection speed of the second another ink droplet ejected by the another nozzle is included within the different predetermined range.

7. The method of claim 1 , further comprising:

storing the applied drive voltage for the nozzle when it is determined that the sensed size or ejecting speed of the ink droplet ejected is included within the predetermined range.

8. The method of claim 7 , further comprising:

controlling the nozzle by the stored drive voltage when performing a print job.

9. A computer-readable recording medium having embodied thereon a computer program for executing a nozzle drive control method, the method comprising:

applying a drive voltage to a nozzle to eject an ink droplet;

sensing a size or an ejecting speed of the ejected ink droplet;

determining whether the sensed size or ejecting speed of the ink droplet is included within a predetermined range; and

calculating a second drive voltage as the drive voltage when the sensed size or ejecting speed of the ejected ink droplet is not included within the predetermined range, to apply the second drive voltage to the nozzles to eject a second ink droplet, to sense a second size or second ejecting speed of the second ink droplet as the size or ejecting speed, and to determine whether the size or ejection speed of the second ink droplet is included within the predetermined range,

wherein the determining of whether the sensed size or ejecting speed of the ink droplet is included within the predetermined range comprises using predetermined ranges corresponding to respective nozzles in an image forming apparatus having a plurality of nozzles.

10. A nozzle drive control device comprising:

a power supply to apply a drive voltage to a nozzle to eject an ink droplet;

an ink droplet sensor to sense a size or an ejecting speed of the ejected ink droplet;

a determiner to determine whether the sensed size or ejecting speed of the ejected ink droplet is included within a predetermined range; and

a controller to calculate a second drive voltage as the drive voltage when the determiner determines that the sensed size or ejecting speed of the ejected ink droplet is not included within the predetermined range and to control the power supply, the ink droplet sensor, and the determiner to apply the second drive voltage to the nozzle to eject a second ink droplet, to sense a second size or ejection speed of the second ink droplet, and to determiner whether the size or ejection speed of the second ink droplet is included within the predetermined range, respectively,

wherein the determiner comprises predetermined ranges corresponding to respective nozzles in an image forming apparatus having a plurality of nozzles.

11. The device of claim 10 , wherein the controller controls the power supply, the ink droplet sensor, and the determiner repeatedly until the determiner determines that the sensed size or ejecting speed of the ejected ink droplet is included within the predetermined range.

12. The device of claim 11 , wherein the controller comprises:

a voltage calculator to calculate the second drive voltage to be applied to the nozzle using the sensed size or ejecting speed of the ejected ink droplet; and

a repetition controller to repeatedly control the power supply, the ink droplet sensor, and the determiner in accordance with the calculated second drive voltage.

13. The device of claim 12 , wherein the voltage calculator calculates the second drive voltage according to a determination that variation rates of the size and the ejecting speed of the ink droplet and the second size and ejecting speed of the second ink droplet ejected from the nozzle are linear with respect to the applied drive voltage.

14. The device of claim 12 , wherein the voltage calculator calculates the second drive voltage using the following equation:

V new =V old +(Q target −Q sensed )/a, wherein V new is a new drive voltage to be calculated, V old is the previously applied drive voltage, Q target is a predetermined size or ejecting speed of the ink droplet, Q sensed is the sensed size or ejecting speed of the ink droplet, and a is a predetermined slope.

15. The device of claim 12 , wherein the voltage calculator calculates the second drive voltage using a Newton-Rhapson method, false-position method, or a bisection method.

16. The device of claim 11 , further comprising:

a drive voltage storage unit to store the applied drive voltage for the nozzle when the determiner determines that the sensed size or ejecting speed of the ejected ink droplet is within the predetermined range.

17. The device of claim 16 , further comprising:

a nozzle controller to control the nozzle by the stored drive voltage when performing a print job.

18. A method to control a nozzle, the method comprising:

applying a drive voltage to the nozzle to eject an ink droplet;

detecting a size or an ejecting speed of the ejected ink droplet;

determining whether the size or ejecting speed of the ejected ink droplet is within a predetermined range; and

calculating a new drive voltage as the drive voltage to apply to the nozzle when the determined size or ejecting speed of the ejected ink droplet is not within the predetermined range, and repeating the applying of the new drive voltage, the detecting a size or ejection speed, and the determining of whether the size or ejection speed of the ejected ink droplet is within the predetermined range until the detected size or ejection speed is within the predetermined range,

wherein the determining of whether the sensed size or ejecting speed of the ink droplet is included within the predetermined range comprises using predetermined ranges corresponding to respective nozzles in an image forming apparatus having a plurality of nozzles.