Power control method and apparatus to control a heating roller

Abstract

A power control method and apparatus to control a heating roller, the power control method including gradually increasing a maximum level of a source power supplied from an external source up to a specific maximum supply level, and supplying the source power to the heating resistor as the roller power, measuring a surface temperature of the heating roller, and supplying the source power having a maximum level equal to the maximum supply level to the heating resistor as the roller power until the measured surface temperature reaches a specific fixing target temperature, supplying the source power having an upper limit of the maximum level equal to a specific fixing property improving level to the heating resistor as the roller power until a printing medium is first fed, and fixing a toner image of print data onto the fed printing medium by using the heating roller.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the present general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIGS. 1A-1C illustrate a power control principle of a conventional heating roller;

FIG. 2 is a block diagram illustrating a power control apparatus used to control a heating roller according to an embodiment of the present general inventive concept;

FIGS. 3A, 3B, and 4 are waveform diagrams illustrating a power control principle to control a heating roller according to an embodiment of the present general inventive concept;

FIG. 5 is a flowchart illustrating a power control method to control a heating roller according to an embodiment of the present general inventive concept;

FIG. 6 is a flowchart illustrating operation 510 of the power control method of FIG. 5 according to an embodiment of the present general inventive concept;

FIG. 7 is a flowchart illustrating operation 520 of the power control method of FIG. 5 according to an embodiment of the present general inventive concept;

FIG. 8 is a flowchart illustrating operation 540 of the power control method of FIG. 5 according to an embodiment of the present general inventive concept; and

FIG. 9 is a waveform diagram illustrating a roller power supplied to a heating roller of an image forming apparatus in a standby mode according to an embodiment of the present general inventive concept.

Claims

1. A power control method to control a heating roller, in which a roller power being supplied to a heating resistor included in the heating roller is controlled in an image forming apparatus using the heating roller to fix a toner image, the power control method comprising: supplying a source power supplied from an external source to the heating resistor as the roller power while gradually increasing a maximum level of the source power up to a specific maximum supply level;measuring a surface temperature of the heating roller, and supplying the source power having a maximum level at the maximum supply level to the heating resistor as the roller power until the measured surface temperature reaches a specific fixing target temperature;supplying the source power having an upper limit of the maximum level at a specific fixing property improving level to the heating resistor as the roller power until a printing medium is first fed; andfixing a toner image of print data onto the fed printing medium by using the heating roller.

2. The power control method of claim 1, wherein, in the supplying of the source power having the upper limit of the maximum level at the specific fixing property improving level, the source power is supplied to the heating resistor as the roller power while the maximum level of the source power having an upper limit at the fixing property improving level is gradually increased until the printing medium is first fed.

3. The power control method of claim 1, wherein the supplying of the source power supplied from the external source to the heating resistor as the roller power begins to be performed right after the image forming apparatus is turned on, or right after the image forming apparatus is switched from a standby mode to a print mode.

4. The power control method of claim 1, wherein: a first control unit to control the supplying of the source power supplied from the external source to the heating resistor, the measuring of the surface temperature of the heating roller and supplying the source power having the maximum level at the maximum supply level to the heating resistor, and the supplying of the source power having the upper limit of the maximum level at the specific fixing property improving level to the heating resistor, and a second control unit to control of the fixing of the toner image of print data onto the fed printing medium by using the heating roller, are separate control units in the image forming apparatus.

5. The power control method of claim 1, wherein the image forming apparatus includes the heating roller and a pressure roller, the toner image is fixed by using the heating roller and the pressure roller in the control of the fixing of the toner image of print data onto the fed printing medium by using the heating roller, and the pressure roller co-rotates with the heating roller after the image forming apparatus recognizes the pressure roller until the measuring of the surface temperature of the heating roller, and supplying the source power having the maximum level at the maximum supply level to the heating resistor is ended.

6. The power control method of claim 1, wherein the roller power is not supplied to the heating resistor of the image forming apparatus in a standby mode.

7. The power control method of claim 1, wherein the maximum supply level is the largest maximum level of the roller power that can be supplied to the heating resistor.

8. The power control method of claim 1, wherein, in the control of the fixing of the toner image of print data onto the fed printing medium by using the heating roller, the source power having a maximum level equal to a thermostat level that is lower than the maximum supply level is supplied to the heating resistor as the roller power, and the toner image is fixed by using the heating roller to which the roller power having a maximum level equal to the thermostat level is supplied, and the surface temperature of the heating roller to which the roller power is supplied has a specific similarity with respect to the fixing target temperature.

9. The power control method of claim 8, wherein the control of the fixing of the toner image of print data onto the fed printing medium by using the heating roller comprises: selecting at least one heating resistors among a plurality of heating resistors;supplying the source power having a maximum level equal to the thermostat level to each of the selected heating resistors as the roller power; andfixing the toner image onto the printing medium by using the heating roller and the pressure roller, andwherein the roller power is not supplied to the heating resistors not selected.

10. The power control method of claim 1, further comprising: determining whether print data is received while a specific standby mode determining time elapses after the control of the fixing of the toner image of print data onto the fed printing medium by using the heating roller is performed, and switching the image forming apparatus to a standby mode if the print data is not received when the standby mode determining time elapses after the control of the fixing of the toner image of print data onto the fed printing medium by using the heating roller is performed; and(f) determining whether print data is received after the image forming apparatus is switched to the standby mode in the determining of whether the print data is received while the specific standby mode determining time elapses, and switching the image forming apparatus to a print mode and proceed to the supplying of the source power supplied from the external source to the heating resistor if the print data is received after the image forming apparatus is switched to the standby mode in the determining of whether the print data is received while the specific standby mode determining time elapses.

11. The power control method of claim 1, wherein the heating resistor has a variable characteristic in which resistance thereof is determined in proportion to the heating resistor's temperature equal to or less than a threshold temperature.

12. A power control apparatus to control a heating roller, in which a roller power being supplied to a heating resistor included in the heating roller is controlled in an image forming apparatus using the heating roller and to fix a toner image, the power control apparatus comprising: a power supply unit which gradually increases a maximum level of a source power supplied from an external source in response to a first or second warm-up indication signal, outputs the source power to the heating resistor as the roller power, outputs the source power having a maximum level equal to a specific maximum supply level to the heating resistor as the roller power in response to a third warm-up indication signal, and outputs the source power having an upper limit of a maximum level equal to a specific fixing property improving level to the heating resistor as the roller power in response to a fifth warm-up indicating signal;a temperature measuring unit which measures a surface temperature of the heating roller in response to the third warm-up indication signal;a toner fixing unit to feed a printing medium and to fix a toner image of given print data onto the fed printing medium by using the heating roller in response to a fixing indication signal;a first comparing unit which compares the increased maximum level with the maximum supply level, and generates the second or third warm-up indication signal according to the comparison result;a second comparing unit which compares the measured surface temperature with a specific fixing target temperature, and generates one of the third warm-up indication signal and the fixing indication signal according to the comparison result obtained by the second comparing unit; anda paper feed detecting unit which checks whether the printing medium is fed in response to the fixing indication signal, and generates the fifth warm-up indication signal in response to the check result,wherein the first warm-up indication signal is generated right after the image forming apparatus is turned on, or right after the image forming apparatus is switched from a standby mode to a print mode.

13. The power control apparatus of claim 12, wherein the image forming apparatus includes the heating roller and a pressure roller, the toner fixing unit allows the heating roller to co-rotate with the pressure roller in response to a fourth warm-up indication signal, and fixes the toner image onto the printing medium by using the heating roller and the pressure roller in response to the fixing indication signal, andthe fourth warm-up indication signal is generated right after the image forming apparatus recognizes the pressure roller.

14. The power control apparatus of claim 12, wherein the power supply unit supplies no power to the heating roller as the roller power in response to a power supply interruption signal, and the power supply interruption signal is generated while the image forming apparatus is in the standby mode.

15. The power control apparatus of claim 12, further comprising: a first unit to control the power supply unit; anda second unit to control the toner fixing,wherein the first and second units are separate units in the image forming apparatus.

16. The power control apparatus of claim 12, wherein the fixing indication signal is generated according to one of a comparison result obtained by the second comparing unit and while the toner fixing unit operates.

17. An image forming apparatus including a heating roller, in which a roller power being supplied to a heating resistor included in the heating roller is controlled in the image forming apparatus to fix a toner image, the image forming apparatus comprising: a power supply unit which gradually increases a maximum level of a source power supplied from an external source in response to a first or second warm-up indication signal, outputs the source power to the heating resistor as the roller power, outputs the source power having a maximum level equal to a specific maximum supply level to the heating resistor as the roller power in response to a third warm-up indication signal, and outputs the source power having an upper limit of a maximum level equal to a specific fixing property improving level to the heating resistor as the roller power in response to a fifth warm-up indicating signal;a temperature measuring unit which measures a surface temperature of the heating roller in response to the third warm-up indication signal;a toner fixing unit to feed a printing medium and to fix a toner image of given print data onto the fed printing medium by using the heating roller in response to a fixing indication signal;a first comparing unit which compares the increased maximum level with the maximum supply level, and generates the second or third warm-up indication signal according to the comparison result obtained by the first comparing unit;a second comparing unit which compares the measured surface temperature with a specific fixing target temperature, and generates the third warm-up indication signal or the fixing indication signal according to the comparison result obtained by the second comparing unit; anda paper feed detecting unit which checks whether a printing medium is fed in response to the fixing indication signal, and generates the fifth warm-up indication signal in response to the check result,wherein the first warm-up indication signal is generated right after the image forming apparatus is turned on, or right after the image forming apparatus is switched from a standby mode to a print mode.

18. The image forming apparatus of claim 17, further comprising a pressure roller, wherein the toner fixing unit allows the heating roller to co-rotate with the pressure roller in response to a fourth warm-up indication signal, and fixes the toner image onto the printing medium by using the heating roller and the pressure roller in response to the fixing indication signal, and the fourth warm-up indication signal is generated right after the image forming apparatus recognizes the pressure roller.

19. The image forming apparatus of claim 17, wherein the power supply unit supplies no power to the heating roller as the roller power in response to a power supply interruption signal, and the power supply interruption signal is generated while the image forming apparatus is in the standby mode.

20. The image forming apparatus of claim 17, wherein a first unit to control the operations of the power supply unit and a second unit to control the operations of the toner fixing unit are separate units in the image forming apparatus.

21. The image forming apparatus of claim 17, wherein the fixing indication signal is generated according to one of a comparison result obtained by the second comparing unit and while the toner fixing unit operates.

22. A computer-readable medium having embodied thereon a computer program to execute a power control method to control a heating roller, in which a roller power supplied to a heating resistor included in the heating roller is controlled in an image forming apparatus using the heating roller to fix a toner image, the power control method comprising: gradually increasing a maximum level of a source power supplied from an external source up to a specific maximum supply level, and supplying the source power to the heating resistor as the roller power;measuring a surface temperature of the heating roller, and supplying the source power having a maximum level equal to the maximum supply level to the heating resistor as the roller power until the measured surface temperature reaches a specific fixing target temperature;supplying the source power having an upper limit of the maximum level equal to a specific fixing property improving level to the heating resistor as the roller power until a printing medium is first fed; andfixing a toner image of print data onto the fed printing medium by using the heating roller.

23. A power control apparatus usable in an image forming apparatus, to control heating resistors of a heating roller to fix a toner image, the power control apparatus comprising: a power supply unit to receive an external power source and supply a roller power to the heating resistors;a temperature measuring unit to measure a surface temperature of the heating roller;a first comparing unit to compare the roller power supplied to the heating resistors to a maximum supply level and to generate one of a second warm-up indication signal and a third warm-up indication signal, the second warm-up indication signal being generated if the roller power supplied is below the maximum supply level, and the third warm-up indication signal being generated if the roller power supplied is at the maximum supply level; anda second comparing unit to compare the measured surface temperature of the heating roller to a predetermined target fixing temperature, and to generate one of the third warm-up indication signal and a fixing indication signal, the third warm-up indication signal being generated, if the measured surface temperature of the heating roller is less than the target fixing temperature, and the fixing indication signal being generated if the measured surface temperature of the heating roller is at the target fixing temperature,wherein the power supply unit:gradually increases a maximum level of the source power supplied as the roller power in response to one of a first warm-up indication signal and the second warm-up indication signal, the first warm-up indication signal being generated after one of a first power on of the image forming apparatus and a switch of the image forming apparatus from a standby mode to a print mode,supplies the roller power at a current maximum level of the source power in response to one of the third warm-up indication signal and the fixing indication signal, anddoes not supply roller power to the heating resistors in response to a power interruption indication signal, the power interruption indication signal being generated when the image forming apparatus is in standby mode.

24. The power control apparatus of claim 23, further comprising: a toner fixing unit, comprising the heat roller and a pressure roller, to co-rotate the heat and pressure rollers in response to a fourth indication signal, and to feed a printing medium and to fix the toner image on the printing medium in response to the fixing indication signal, wherein the fourth indication signal is generated after the image forming apparatus recognizes the pressure roller, and the toner fixing unit does not respond to the fixing indication signal if the image forming apparatus has not received a printing order.

25. The power control apparatus of claim 24, further comprising: a paper feed detecting unit to detect whether [the printing medium is fed and to generate a fifth warm-up indication signal if the printing medium is not fed in response to the fixing indication signal,wherein the power supply unit supplies the source power as the roller power at a fixing property improving level to the heat resistors in response to the fifth warm-up indication signal.

26. The power control apparatus of claim 25, wherein the power supply unit is controlled by a first unit separate from one or more second control units to control the paper feed detecting unit and the toner fixing unit in the image forming apparatus.

27. The power control apparatus of claim 26, wherein the power supply unit supplies the roller power in response to one of the first, second, and third warm-up indication signals, the fixing indication signal, and the power interruption indication signal before the one or more second control units are initialized.

28. The power control apparatus of claim 23, wherein the image forming apparatus switches from the standby mode to the print mode after receiving a printing order.

29. A power control apparatus usable in an image forming apparatus, to control a heating roller to fix a toner image, the power control apparatus comprising: a power supply unit to receive an external power source and supply a roller power to the heating roller; anda temperature measuring unit to measure a surface temperature of the heating roller,wherein the power supply until performs one of gradually increasing a maximum level of the source power supplied as the roller power, supplying the roller power at a current maximum level of the source power, and not supplying roller power to the heating roller according to a measured level of the roller power supplied and a surface temperature of the heating roller.

30. The power control apparatus of claim 29, wherein the power supply unit is controlled by a first control unit separate from one or more second control units to initialize the image forming apparatus.