KR100754206B1 - Power control method and apparatus for heating roller - Google Patents

Abstract

Disclosed are a power control method and apparatus for a heating roller. A printing apparatus for fixing a toner image employing a heating roller and a pressure roller, the power control method for a heating roller according to the present invention for controlling roller power supplied to a heat generating resistance included in the heating roller is supplied from the outside. (A) gradually increasing the maximum level of source power to a predetermined maximum supply level and supplying the source power as the roller power to the heating resistance, measuring the surface temperature of the heating roller and measuring the surface temperature (B) supplying the source power having the maximum supply level as the maximum level to the heat generating resistor until the predetermined fixing target temperature and the toner image of the given print data on the print medium provided; (C) fixing by using a heating roller and the pressure roller, and (a) Immediately after the printing apparatus is turned on or immediately after the printing apparatus enters the printing mode from the standby mode, and the printing apparatus recognizes the pressure roller until the completion of the step (b). Preferably, the pressure roller is interlocked with the heating roller.

Description

Power control method and apparatus for heating rollers {Method and apparatus for controlling power for Heating Roller}

1 is a waveform diagram illustrating a power control principle for a conventional heating roller.

2 is a block diagram for explaining a power control device for a heating roller according to the present invention.

3 is a waveform diagram illustrating a power control principle for a heating roller according to the present invention.

4 is a flowchart for explaining a power control method for a heating roller according to the present invention.

FIG. 5 is a flowchart for explaining an exemplary embodiment of the present invention for step 410 illustrated in FIG. 4.

Each of (a) to (g) of FIG. 6 is a waveform diagram of an input source voltage having an alternating current form from an external source.

FIG. 7 is a flowchart for explaining an exemplary embodiment of the present invention with respect to step 420 illustrated in FIG. 4.

FIG. 8 is a flowchart for explaining an exemplary embodiment of the present invention with respect to step 430 illustrated in FIG. 4.

FIG. 9 is a flowchart performed to heat the surface of the pressure roller to a fixing target temperature before step 430 shown in FIG. 4 is performed.

FIG. 10 is a reference diagram for describing the flowchart illustrated in FIG. 9.

11A and 11B are waveform diagrams for describing the flowchart shown in FIG. 9.

<Description of Symbols for Main Parts of Drawings>

210: power supply unit 220: temperature measuring unit

230: toner fixing unit 240: first comparison unit

250: second comparison unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating roller (IHR: Heating Roller) used for toner image fixing, and more particularly, to a power control method and apparatus for a heating roller for supplying external source power to a heating resistance of the heating roller. .

A printing apparatus, such as a printer or a copying machine, which forms an image of a given print data on a print medium using a developer such as toner, fixes a toner image corresponding to the print data on the print medium, and prints the fixed print medium on the print medium. By discharging to the outside, the printed matter can be provided to the user.

Such a printing device may employ a heating roller including a heating resistance. In this case, in order for the fixing to take place, the surface temperature of the heating roller must be maintained at a fixing target temperature, for example, a temperature near 180 degrees Celsius.

The printing apparatus enters the print mode when it receives a print instruction for the first time after the power is turned on or receives a print instruction while operating in the standby mode. At this time, the time from when the print instruction is received to the time when the first printed matter is discharged is referred to as FPOT (First Print Out Time). As a result, in order to reduce the printing waiting time of the printing apparatus employing the heating roller, the surface temperature of the heating roller must be reached to the fixing target temperature more quickly.

1 is a waveform diagram illustrating a power control principle for a conventional heating roller. If the resistance value of the heating resistance is determined in proportion to the temperature of the heating resistance below the threshold temperature, when the voltage Vin 110 as shown in FIG. Current (Ir) 120 as shown in (b) flows.

As such, if the current Ir flowing through the heat generating resistor gradually decreases until the temperature of the heat generating resistor reaches a critical temperature, the conventional power control principle for the heating roller is to generate heat at the time when power is supplied to the heat generating resistor. Excessive current flows through the resistor, which causes a problem of breaking the circuit due to electric shock. In addition, in this case, a high current in the form of alternating current flows to the heating roller, thereby causing a problem of deeper flicker characteristics. Here, the flicker characteristic means a phenomenon of temporarily weakening the power supplied to the peripheral circuit.

On the other hand, the threshold resistance value, which is the resistance value of the heating resistance when the heating resistance is the critical temperature, is uniquely determined for each of the heating resistances. The more the heating resistance with the lower threshold resistance is used, the greater the amount of power can be supplied to the heating resistance. The surface temperature can be increased more quickly. However, as the heat generating resistor having a lower threshold resistance is used, a larger current flows in the heat generating resistor at the time when power is supplied to the heat generating resistor, thereby making the aforementioned problems stand out. As a result, the power control principle for the conventional heating roller has been forced to use a heat generating resistor having a moderately low threshold resistance value, thereby shortening the time required to increase the surface temperature of the heating roller to the fixing target temperature. There is a problem that there is a limit.

In addition, if the printing apparatus is instructed to print immediately after the printing apparatus is turned on, a control unit (not shown) that generally controls operations performed in the printing apparatus, for example, a central processing unit (CPU) of the printing apparatus. ) Can instruct heating of the heating roller only after the initialization of the printing apparatus, in particular, after the initialization of the control unit is completed. As a result, the above-mentioned problem that there is a limit in shortening the print waiting time is more pronounced when the printing apparatus is instructed to print before the initialization of the controller (not shown) is completed.

The technical problem to be achieved by the present invention is that when the power of the printing device is turned on, the heating roller can be heated before the initialization of the printing device is completed, and a predetermined time has elapsed while gradually supplying power to the heating roller at the beginning. After that, it is possible to supply the maximum power that can be supplied, thereby providing a power control method for the heating roller, which improves the flicker characteristics and allows the surface temperature of the heating roller to reach the fixing target temperature in a short time. have.

Another object of the present invention is to provide a power control apparatus for a heating roller that performs the power control method.

Another object of the present invention is to provide a computer-readable recording medium storing at least one computer program for performing the power control method.

In order to achieve the above object, a printing apparatus for fixing a toner image employing a heating roller and a pressure roller, the power control method for a heating roller according to the present invention for controlling the roller power supplied to the heat generating resistance included in the heating roller (A) gradually increasing the maximum level of source power supplied from the outside to a predetermined maximum supply level and supplying the source power as the roller power to the heat generating resistor, and measuring the surface temperature of the heating roller; And (b) supplying the source power having the maximum supply level as the maximum level to the heat generating resistor as the roller power until the measured surface temperature reaches a predetermined fixing target temperature and the toner image of the given print data. (C) fixing to the printed media using the heating roller and the pressure roller. Step (a) is performed immediately after the printing apparatus is turned on or immediately after the printing apparatus enters the printing mode from the standby mode, and the printing apparatus recognizes the pressure roller from the printing apparatus (b). It is preferable that the pressure roller is interlocked with the heating roller until the performing of step) is completed.

In order to achieve the above object, the power control apparatus according to the present invention for performing the power control method for the heating roller, the maximum level of the source power input from the outside in response to the first or second warm-up command signal gradually Increase the source power to the heat generating resistor as the roller power, and output the source power having the maximum supply level as the maximum level to the heat generating resistor as the roller power in response to a third warm-up instruction signal, A power supply for outputting the source power having the temperature holding level as the maximum level to the heat generating resistor as the roller power in response to a fixing command signal, and measuring the surface temperature of the heating roller in response to the third warm-up command signal And a temperature measuring part outputting the measured surface temperature and a fourth warm-up instruction signal. A toner fixing unit for interlocking the heating roller and the pressure roller and fixing the toner image on the print medium using the heating roller and the pressure roller in response to the fixing instruction signal, and input from the power supply unit. Comparing the increased maximum level with the maximum supply level, and comparing the measured surface temperature with the fixing target temperature and a first comparator for generating the second and third warm-up instruction signals corresponding to the compared result. And a second comparing unit configured to generate the third warm-up instruction signal and the fixing instruction signal in response to the comparison result, wherein the first warm-up instruction signal is immediately after the printing apparatus is turned on or the printing apparatus is in standby. Is generated immediately after entering the printing mode from the mode, and the fourth warm-up instruction signal is generated immediately after the printing device recognizes the pressing roller. It is preferable to produce.

In order to achieve the above further object, a printing apparatus for fixing a toner image employing a heating roller, comprising: storing at least one computer program according to the present invention for controlling roller power supplied to a heating resistance included in the heating roller; The computer-readable recording medium includes the steps of: (a) supplying the source power as the roller power to the heat generating resistor gradually increasing the maximum level of source power supplied from the outside to a predetermined maximum supply level; (B) measuring the surface temperature of the heating roller and supplying the source power having the maximum supply level as the maximum level to the heat generating resistor until the measured surface temperature reaches a predetermined fixing target temperature; and The heating roller and the pressurization on a print medium provided with a toner image of a given print data. It is preferable to store a computer program for performing the step (c) of fixing using a roller.

In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings that illustrate preferred embodiments of the present invention and the accompanying drawings.

Hereinafter, a power control method and apparatus for a heating roller according to the present invention will be described with reference to the accompanying drawings.

Figure 2 is a block diagram of an embodiment for explaining a power control device for a heating roller according to the present invention, the power supply unit 210, temperature measuring unit 220, toner fixing unit 230, the first comparison unit ( 240 and the second comparator 250.

Both the power supply unit 210 to the second comparison unit 250 are provided in a printing apparatus for fixing a toner image, for example, a fixing system of a laser printer or a copying machine. To this end, on this specification, the printing apparatus has a heating roller including one or more lamps.

Here, each lamp has a heating resistance. In this case, the heating resistance is made of tungsten or the like, and may have a variable characteristic in which the resistance value is determined in proportion to (or inversely) the temperature of the heating resistance below the threshold temperature. When the resistance value is determined in proportion to the temperature of the heating resistance below the threshold temperature, the heating resistance may be expressed as having a positive temperature coefficient (P.T.C) characteristic. For convenience of explanation, hereinafter, it is assumed that the heating resistance has a proportional temperature characteristic.

On the other hand, a plurality of lamps included in the heating roller, that is, the plurality of heat generating resistors may be connected in parallel, and the roller power which is the power supplied to the heat generating resistor may be independently controlled for each of the heat generating resistors.

This roller power is supplied to the heat generating resistor in the alternating form because the roller voltage and the roller current are in the alternating form. Here, the roller voltage means a voltage applied to the heat generating resistance, and the roller current means a current flowing through the heat generating resistance.

In response to the first or second warm-up command signal, the power supply unit 210 gradually increases the maximum level of the source power input from the outside and outputs the source power as a roller power to the heat generating resistor. On the other hand, in response to the third warm-up command signal or the fixing command signal, the power supply unit 210 outputs source power input from the outside as a roller power to the heat generating resistor without changing the maximum level. In the present specification, the outside means an outside of the heat generating resistor, in particular, the outside of the power supply 210, the source power means power input to the power supply 210, and the roller power generates heat through the power supply 210. The power supplied to the resistor. Here, the source power is input through the input terminal IN6.

The temperature measuring unit 220 measures the surface temperature of the heating roller in response to the third warm-up command signal, and outputs the measured surface temperature.

The toner fixing unit 230 links the heating roller and the pressure roller (PR: Pressure Roller) in response to the fourth warm-up instruction signal, and prints the printed medium in response to the fixing instruction signal for the toner image of the print data given to the printing apparatus. Fixing is carried out using a heating roller and a pressure roller. Here, the interlock means that when the heating roller (or pressure roller) rotates, the pressure roller (or heating roller) also rotates together with the heating roller (or pressure roller). Further, the print data is composed of one or more pages, and the toner image is fixed to each page on the print medium.

Specifically, the toner fixing unit 230 includes a heating roller and a pressure roller, and the pressure roller is interlocked with the heating roller in response to the fourth warm-up instruction signal, and as a result, both the surface temperature of the pressure roller and the surface temperature of the heating roller are obtained. Reaches the fixing target temperature which will be described later. On the other hand, the print medium is supplied in response to the fixing instruction signal between the heating roller and the pressure roller which are engaged with each other to rotate. In this case, not only the supply of the print medium, but also the rotational movements of the heating roller and the pressure roller are performed in response to the fixing instruction signal. In this way, the heating roller and the pressure roller are rotated to fix the toner image on the supplied print medium, and the print medium on which the toner image is fixed is discharged to the outside of the printing apparatus as a print.

Hereinafter, the first, second, third and fourth warm-up instruction signals and the fixing instruction signals will be described in detail.

The first warm-up command signal is input through the input terminal IN 1, and the power supply 210 increases the maximum level of the input source power and supplies the source power with the maximum level increased to the heat generating resistor as the roller power. Means 'signal'. The first warm-up command signal is generated immediately after the power of the printing apparatus is turned on or immediately after the printing apparatus enters the printing mode from the stand-by mode. To this end, the printing apparatus includes a control unit (not shown) for controlling heating-related tasks of the printing apparatus (hereinafter referred to as a 'heating control unit') and a task other than heating-related tasks among all tasks that can be performed in the printing apparatus ( Hereinafter, a control unit (not shown) (hereinafter, referred to as a 'non-heating control unit') for controlling a 'non-heating operation' is provided to be distinguished from each other. Here, the heating-related work means a work having a degree of relevance more than a predetermined relevance to the heating work. At this time, the higher the predetermined relation is, the better.

For example, a heating control part (not shown) recognizes a heating roller as a heating roller, or controls heating of a heating roller. The first warm-up command signal is preferably generated by such a heating control unit (not shown). Meanwhile, the non-heating control unit (not shown) recognizes the pressure roller as the pressure roller, controls the rotational driving of the heating roller and the pressure roller, or controls the laser scanning unit (LSU: Laser Scanning Unit) provided in the printing apparatus.

On the other hand, the non-heating control unit (not shown) preferably corresponds to a central processing unit (CPU) of the printing device. At this time, the central processing unit controls all operations that the printing apparatus can perform except for heating related tasks.

As such, the control unit for controlling the tasks that the printing apparatus can perform is provided separately from the heating control unit (not shown) and the non-heating control unit (not shown) in the printing device, so that when the power of the printing device is turned on, In contrast to the conventional power control principle in which heating related operations could be performed only after the initialization of the central processing unit was completed, the printing apparatus may start heating the heating roller even before the initialization of the central processing unit is completed.

The heating control unit and the non-heating control unit may be distinguished in hardware or in software.

The second warm-up command signal is input through the input terminal IN 2, and the power supply unit 210 increases the maximum level of the input source power and supplies the source power of which the maximum level is increased to the heat generating resistor as the roller power. 'Means a signal, and is generated through the first comparator 240.

The third warm-up command signal is input through the input terminal IN 3, and means a signal that causes the power supply unit 210 to supply the source power having the maximum supply level as the maximum level to the heat generating resistor as the roller power. It is generated through the comparator 240 or the second comparator 250.

The fourth warm-up instruction signal is input through the input terminal IN 4, and means a signal that causes the heating roller and the pressure roller to interlock, and the non-heating control unit (not shown) of the printing apparatus recognizes the pressure roller as the pressure roller. After the non-heating control is generated. In particular, the fourth warm-up instruction signal is preferably generated immediately after the non-heating control unit (not shown) recognizes the pressure roller as the pressure roller.

The fixing instruction signal is input through the input terminal IN 5, and means a signal that causes the power supply unit 210 to supply the source power having the temperature holding level as the maximum level to the heat generating resistor as the roller power, and the second comparator. Generated through 250 or generated by a non-heating control unit (not shown) while the fixing is performed.

Hereinafter, the principle of generating the second and third warm-up command signals and the fixing command signal will be described together with the operation of the first comparator 240 and the second comparator 250.

The first comparison unit 240 compares the increased maximum level input from the power supply unit 210 with a predetermined maximum supply level, and generates a second warm-up command signal and a third warm-up command signal according to the compared result. . Here, the maximum supply level is preferably the maximum level of the roller power that can be supplied to the heating resistance to the maximum.

Specifically, when the increased maximum level input from the power supply 210 is smaller than the maximum supply level, the first comparator 240 generates a second warm-up command signal. In contrast, when the increased maximum level input from the power supply unit 210 has reached the maximum supply level, the first comparison unit 240 generates a third warm-up command signal.

Meanwhile, the second comparison unit 250 compares the surface temperature measured by the temperature measuring unit 220 with a fixing target temperature, for example, 180 degrees Celsius, and provides a third warm-up command signal and a fixing command signal according to the comparison result. Create Here, the fixing target temperature means the surface temperature of the heating roller on which the toner image can be stably fixed. At this time, the surface temperature of the heating roller on which the toner image can be stably fixed may be any temperature above the minimum fixable minimum temperature or below the maximum fixable maximum temperature, and the fixing target temperature is between the minimum fixable minimum temperature and the maximum fixable temperature. It is preferable to set in advance.

In detail, when the surface temperature measured by the temperature measuring unit 220 is smaller than the fixing target temperature, the second comparing unit 250 generates a third warm-up command signal. On the contrary, when the surface temperature measured by the temperature measuring unit 220 has reached the fixing target temperature, the second comparing unit 250 generates the fixing command signal.

The operations of the power supply unit 210, the temperature measuring unit 220, the first comparator 240, and the second comparator 250 mentioned above are controlled by a heating controller (not shown), and the toner fixing unit ( The operation of 230 is preferably controlled by a non-heating controller (not shown).

3 is a waveform diagram illustrating a power control principle for a heating roller according to the present invention. As shown, a part or all of the sinusoidal source voltage Vin 300 generated by the source voltage generator (not shown) is applied as a roller voltage to a heat generating resistor having a proportional temperature characteristic, thereby generating heat. In the resistance, a roller current Ir 320 as shown in the drawing flows. To this end, the power supply unit 210 inputs part or all of the source voltage 300 from the source voltage generator (not shown), and outputs the input source voltage 300 as a roller voltage to the heat generating resistor.

Here, the source voltage 300, the roller voltage and the roller current 320 all have an alternating waveform. As a result, both the source power and the roller power have an alternating waveform as described above. Specifically, the envelope of the source power and the roller power has the same form as the positive envelope 332 of the envelopes 332 and 334 of the roller current 320.

As illustrated, the waveform diagram of the roller current 320 flowing through the heat generating resistance may be divided into three sections, the flicker characteristic improvement section 310, the maximum power supply section 312, and the fixing section 314.

Here, the flicker characteristic improvement section 310 refers to a section in which the power supply unit 210 operates in response to the first or second warm-up command signal. More specifically, in the flicker characteristic improvement section 310, the power supply unit 210 gradually increases the maximum level of the source power to the maximum supply level and supplies the source power to the heat generating resistor as the roller power. On the other hand, the roller voltage applied to the heat generating resistor is part of the source voltage 300 until the maximum level of the source power reaches the maximum supply level.

The maximum power supply section 312 refers to a section in which the power supply unit 210 operates in response to the third warm-up command signal. More specifically, in the maximum power supply section 312, the power supply unit 210 supplies the source power having the maximum supply level as the maximum level as the roller power to the heat generating resistor. On the other hand, in the maximum power supply section 312, the source voltage 300 is all applied to the heat generating resistance as a roller voltage.

The fixing section 314 refers to a section in which the power supply unit 210 and the toner fixing unit 230 operate in response to the fixing command signal. More specifically, in the fixing section 314, the power supply unit 210 supplies the source power having the temperature holding level as the maximum level to the heat generating resistor as the roller power, and the toner fixing unit 230 sets the temperature holding level to the maximum. The toner image is fixed onto the print medium using a heating roller supplied with the roller power as the source power having the level. On the other hand, in the fixing section 314, the roller voltage applied to the heat generating resistor is part of the source voltage.

The surface temperature of the heating roller supplied with the source power having the temperature holding level as the maximum level has a predetermined approximation with the fixing target temperature. For example, the surface temperature of the heating roller supplied with the source power having the temperature holding level as the maximum level is in the range of 95% to 105% of the fixing target temperature. At this time, the surface temperature of the heating roller supplied with the source power having the temperature holding level as the maximum level should be a temperature between the minimum settable temperature and the maximum settable temperature.

If the print data is composed of fewer pages, for example, two pages, fixing is completed for all of the toner images of the print data even if the roller power is no longer supplied to the heating roller whose surface temperature reaches the fixing target temperature. The surface temperature may not drop below the settable minimum temperature. In this case, unlike the above, the power supply unit 210 may not supply the source power having the temperature maintenance level as the maximum level to the heat generating resistor as the roller power, and thus, roller power is not additionally supplied in the fixing section 314. Even if not, the toner fixing unit 230 can stably fix the toner image.

However, if the print data is made up of many pages, for example, tens of pages, when the roller power is no longer supplied to the heating roller whose surface temperature has reached the fixing target temperature, it is fixed to all the toner images of the print data. The surface temperature may drop below the settable minimum temperature before this is completed. In this case, as described above, the power supply unit 210 must supply source power having the temperature holding level as the maximum level to the heat generating resistor as the roller power.

On the other hand, in the flicker characteristic improvement section 310 and the maximum power supply section 312, the roller power is supplied to each of all the heating resistances included in the heating roller, but in the fixing section 314, selected ones of all the heating resistances are selected. It is preferable that the roller power is supplied only to the heating resistance.

At this time, the selection is performed by a non-heating control unit (not shown), and the heating control unit periodically or aperiodically changes the selected heating resistance. That is, in the fixing section 314, the time region in which the roller current 320 flows refers to the time region in which the heating resistance itself is selected by the non-heating controller (not shown).

4 is a flow chart for explaining a power control method for a heating roller according to the present invention, the appearance of the roller power is supplied to the heat resistance resistance flicker characteristics improvement section 310, the maximum power supply section 312 and the fixing section By controlling differently for each, the steps (steps 410 to 430) are performed so that the surface temperature of the heating roller can reach the fixing target temperature in a short time while improving flicker characteristics.

The power supply unit 210 gradually increases the maximum level of the source power to a predetermined maximum supply level, and supplies the source power to the heat generating resistor as roller power (step 410). In this case, step 410 may be performed immediately after the power of the printing apparatus is turned on, or may be performed immediately after the printing apparatus enters the printing mode from the standby mode.

After operation 410, the temperature measuring unit 220 measures the surface temperature of the heating roller, and the power supply unit 210 supplies the maximum supply level to the maximum level until the measured surface temperature reaches a predetermined fixing target temperature. Source power, which is provided as a second source, is supplied to the heat generating resistor as roller power (step 420).

After step 420, the power supply unit 210 supplies source power having the temperature holding level as the maximum level to the heat generating resistor as the roller power, and the toner fixing unit 230 heats the toner image of the given print data on the print medium. Fixing using a roller and a pressure roller (step 430).

It is preferable that the above-described operations of steps 410 and 420 are controlled by a heating controller (not shown), and the execution of step 430 is controlled by a non-heating controller (not shown). Each of the steps 410, 420, and 430 corresponds to the flicker characteristic improvement section 310, the maximum power supply section 312, and the fixing section 314, respectively.

On the other hand, after step 430, the non-heating control unit (not shown) determines whether the print data is given while the predetermined standby mode entry determination time has elapsed after step 430, and after the step 430, the standby mode entry determination time has elapsed. If it is determined that no print data is given in the middle, the printing apparatus is put into the standby mode.

In this case, the non-heating control unit (not shown) determines whether print data has been given after the printing apparatus enters the standby mode, and if it is determined that print data has been given after the printing apparatus enters the standby mode, prints the printing apparatus. Enter the mode, and the power supply 210 instructs to perform step 410.

FIG. 5 is a flowchart for describing an embodiment 410A according to the present invention for the step 410 shown in FIG. 4. The source power is gradually increased to a predetermined maximum supply level, and the source power is gradually increased. Is supplied to the heat generating resistor as roller power (steps 510 to 530).

The power supply unit 210 supplies the source power to the heat generating resistor as roller power for a second predetermined time at a first predetermined time interval (operation 510). At this time, it is preferable that the first predetermined time is equal to or greater than the second predetermined time and is not variable unlike the second predetermined time which is variable.

After operation 510, the first comparator 240 determines whether the maximum level of the source power supplied in operation 510 is smaller than the maximum supply level (operation 520).

If it is determined in step 520, the first comparator 240 increases the second predetermined time, increases the maximum level of the source power, and requests the power supply 210 to perform step 510 again. In operation 530, the process is instructed.

In contrast, if it is determined in step 520 that it is not small, the flow proceeds to step 420.

As such, the second predetermined time is increased as the maximum level of source power approaches the maximum supply level. This alleviates the flicker characteristic caused by excessive roller power supplied to the heat generating resistor at the time when the power of the printing device is turned on or when the printing device enters the printing mode from the standby mode and power is supplied to the heat generating resistor.

6A to 6G are shaded sources in which 10%, 20%, 25%, 33%, 50%, 67% and 100% of the source voltage 300 is applied to the heating resistance as the roller voltage. As waveform diagrams of the voltage, the second predetermined time is gradually increased.

The shaded portions (hereinafter, referred to as full on intervals) shown in each waveform diagram represent the time when the source voltage 300 is supplied to the heating resistor. Hereinafter, the unshaded part is called a full off period.

The second predetermined time means a time occupied by the pull-on period among the first predetermined time A. FIG. In the flicker characteristic improvement section 310, as proceeds from Fig. 6A to Fig. 6G, the second predetermined time is gradually increased.

FIG. 7 is a flowchart for explaining an embodiment 420A according to the present invention for the step 420 shown in FIG. 4, in which the surface temperature of the heating roller is measured and the measured surface temperature becomes the fixing target temperature. Until the maximum supply level to the maximum level of the source power as a roller power supply to the heat generating resistor (steps 710 ~ 730).

The temperature measuring unit 220 measures the surface temperature of the heating roller (operation 710), and the second comparator 250 determines whether the surface temperature measured in operation 710 is a fixing target temperature (operation 720).

If it is determined that the surface temperature measured in operation 710 is not the fixing target temperature (operation 720), the power supply unit 210 supplies the source power having the maximum supply level as the maximum level to the heat generating resistor (roller power 730). step).

In contrast, if it is determined that the surface temperature measured in operation 710 is a fixing target temperature (operation 720), the operation proceeds to operation 430.

FIG. 8 is a flowchart for explaining an embodiment 430A according to the present invention for the step 430 shown in FIG. 4, in which source power having a temperature maintenance level as a maximum level is supplied to the heating resistor as roller power. Fixing the toner image is performed (steps 810 to 830).

The non-heating control unit (not shown) selects one or more heating resistors among the plurality of heating resistors included in the heating roller (operation 810).

After operation 810, the power supply unit 210 supplies, as roller power, source power having a temperature maintenance level as a maximum level to the heat generating resistor selected in operation 810 (operation 820).

After operation 820, the toner fixing unit 230 fixes the toner image on the print medium by using a heating roller and a pressure roller (operation 830).

FIG. 9 is a flowchart performed to heat the surface of the pressure roller to a fixing target temperature before step 430 shown in FIG. 4 is performed, and immediately after the non-heating control unit (not shown) of the printing apparatus recognizes the pressure roller. Until the completion of the step 420 shown in Figure 4, the step of heating the surface of the pressure roller (steps 910 ~ 970).

On the other hand, Figure 10 is a reference diagram for explaining the flow chart shown in Figure 9, Figure 11 (a) is a timing diagram 1110 of the surface temperature of the heating roller in accordance with the conventional power control principle, 11B is a timing diagram 1120 of the surface temperature of the heating roller in accordance with the power control principle according to the present invention. Hereinafter, FIG. 9 will be described in detail with reference to FIGS. 10 and 11.

When only the surface temperature of the heating roller 1010 is the fixing target temperature, and the surface temperature of the pressure roller 1020 is a temperature lower than the minimum fixing temperature, when the print medium 1030 is supplied for fixing, the heating roller 1010 is supplied. ) Is deprived of the heat it had to the pressure roller 1020, so that the surface temperature of the heating roller 1010 may drop below the minimum settable temperature. In this case, the toner image 1040 cannot be stably fixed to the print medium 1030, and thus the print state of the printed matter 1050 is not good.

As a result, in order for the toner image 1040 to be stably fixed to the print medium 1030, both the surface temperature of the heating roller 1010 and the surface temperature of the pressure roller 1020 should be the fixing target temperature STt. That is, before the step 430 shown in FIG. 4 is performed, both the surface temperature of the heating roller 1010 and the surface temperature of the pressure roller 1020 must reach the fixing target temperature STt.

As such, in order for the surface temperature of the pressure roller 1020 to rise, the pressure roller 1020 needs to take away the heat of the heating roller 1010 while interlocking with the heating roller 1010. This is due to the pressure roller 1020, unlike the heating roller 1010, does not have a heat generating resistance.

In view of this point, how the surface temperature of the heating roller 1010 changes in the flicker characteristic improvement section 310 and the maximum power supply section 312 will be described below.

According to the conventional power control principle, both the heating-related work and the non-heating work are controlled by the same control unit (not shown). In this case, when the printing device is turned on or the printing device enters the printing mode from the standby mode (t (hereinafter, means 'time') = 0), the control unit (not shown) of the printing device has a time T1 (t = 0 ~ t1). Here, the control unit (not shown) is preferably a central processing unit (CPU) of the printing device.

Portions other than the control unit (not shown) of the printing apparatus are initialized for a time T2 (t = t1 to t3) from the time point at which initialization of the control unit is completed (t = t1). That is, the control unit (not shown) starts to recognize the pressure roller 1010 of the printing apparatus as the pressure roller from one time point in this section T2, and also starts to recognize the heating roller 1020 as the heating roller. do.

In addition, power is supplied to the heat generating resistor from the time when the controller (not shown) recognizes the heating roller 1020. For example, if the controller (not shown) recognizes the heating roller 1020 from t = t2, the surface temperature of the heating roller 1010 will rise from t = t2 as shown.

On the other hand, the surface temperature of the heating roller 1010 is at a predetermined ready temperature STr at a time point t = t4 at which time T4 has elapsed from t = t3, for example, at 160 degrees Celsius [??]. And the pressure roller 1020 is interlocked with the heating roller 1010 from that time point t = t4. Although the pressure roller 1020 may be interlocked with the heating roller 1010 immediately after it is recognized, in this case, the surface temperature of the heating roller 1010 is equal to 't = 4 + -5 inclination at t'. Since it rises from t3, it cannot rise quickly, and the heating roller 1010 and the pressure roller 1020 are interlocked from the time point t = t4.

Accordingly, the surface temperature of the pressure roller 1020 rises from t = t4, whereby the surface temperature of the heating roller 1010 is less in t = 4 + ~ 5 sections, compared to t = 0 ~ t4- sections. Ascend quickly. In addition, both the surface temperature of the heating roller 1010 and the surface temperature of the pressure roller 1020 reach the fixing target temperature STt at the time point t = t5 after time T5 has elapsed from t = t4.

As a result, according to the conventional power control principle, when the printing apparatus is instructed to print immediately after the power is turned on (t = 0 +), or when the printing apparatus in the standby mode is instructed to print (t = 0), the print waiting time It cannot be less than T3 + T4.

On the other hand, according to the present invention, immediately after the printing apparatus is turned on or immediately after the printing apparatus enters the printing mode from the standby mode (t = 0 +), the heating control unit (not shown) uses the heating roller 1010 as the heating roller. Recognize and instruct the power supply 210 to start supplying power to the heat generating resistor. Therefore, according to the present invention, the time corresponding to T3 described above is not included in the print wait time.

In addition, according to the present invention, the pressure roller 1020 is immediately after being recognized by a non-heating control unit (not shown) regardless of whether or not the surface temperature of the heating roller 1010 reaches the fixing standby temperature STr. It is preferable to interlock with the heating roller 1010 from (t = t6 +). Accordingly, the surface temperature of the pressure roller 1020 rises from t = t6, whereby the surface temperature of the heating roller 1010 is less in t = 6 + ~ 7 sections than in t = 0 ~ t6- sections. Ascend quickly. Here, t6 has the same value as t1 and is included in the flicker characteristic improvement section 310 or the maximum power supply section 312. On the other hand, both the surface temperature of the heating roller 1010 and the surface temperature of the pressure roller 1020 reach the fixing target temperature STt at t = t7.

As a result, according to the present invention, the following steps are performed before the step 430 shown in FIG. 4 is performed.

First, the printing apparatus is turned on or the printing apparatus enters the printing mode from the standby mode (step 910). After operation 910, the non-heating controller (not shown) is initialized (operation 920).

After operation 920, the pressure roller 1020 interlocks with the heating roller 1010 immediately after the non-heating control unit (not shown) recognizes the pressure roller 1020 as the pressure roller 1020 (steps 930 to 960). ).

That is, after operation 920, the non-heating controller (not shown) recognizes one or more portions of each portion of the printing apparatus except for self (operation 930), and the pressure roller 1020 recognizes the pressure roller 1020. In operation 940, it is determined whether the answer is correct.

If it is determined in step 940 that it has not been recognized, the non-heating controller (not shown) recognizes one or more parts of each of the parts that are not yet recognized, and proceeds to step 940.

On the contrary, if it is determined in step 940, the toner fixing unit 230 links the pressure roller 1020 and the heating roller 1010 (step 960), and the second comparator 250 is heated. It is determined whether the surface temperature of the roller 1010 has reached the fixing target temperature STt (step 970).

If it is determined in step 970 that the process proceeds to step 430, in step 970, if it is determined that it has not arrived in step 960.

The invention can also be embodied as computer readable code on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disks, optical data storage devices, and the like, and may also be implemented in the form of a carrier wave (for example, transmission over the Internet). Include. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

The best embodiments have been disclosed in the drawings and specification above. Although specific terms have been used herein, they are used only for the purpose of describing the present invention and are not used to limit the scope of the present invention as defined in the meaning or claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

As described above, the power control method and apparatus for a heating roller according to the present invention, when the power of the printing apparatus is turned on, can heat the heating roller before the initialization of the printing apparatus is completed, Increasing the power gradually and supplying the maximum power that can be supplied after a certain time has elapsed, thereby improving the flicker characteristics and allowing the surface temperature of the heating roller to reach the fixing target temperature in a short time. Has an effect.

Claims (15)

A printing apparatus for fixing a toner image employing a heating roller and a pressure roller, the power control method for a heating roller for controlling roller power supplied to a heat generating resistor included in the heating roller, (a) gradually increasing the maximum level of source power supplied from the outside to a predetermined maximum supply level and supplying the source power as the roller power to the heat generating resistor; (b) measuring the surface temperature of the heating roller and supplying the source power having the maximum supply level as a maximum level to the heat generating resistor until the measured surface temperature reaches a predetermined fixing target temperature; ; And (c) fixing a toner image of a given print data on the provided print medium by using the heating roller and the pressure roller, The step (a) is performed immediately after the printing apparatus is turned on or immediately after the printing apparatus enters the printing mode from the standby mode, and the printing apparatus recognizes the pressing roller from the step (b). The pressure control method for the heating roller, characterized in that the pressure roller is interlocked with the heating roller until the execution is completed. According to claim 1, wherein the place instructing the performance of the heating-related operation including the performance of the steps (a) and (b) and the place instructing the performance of the non-heat-related operation including the performance of the step (c) is A power control method for a heating roller, characterized in that it is provided separately in the printing device. The method of claim 1, wherein the step (a) supplies the source power to the heat generating resistor as the roller power for a second predetermined time at a first predetermined time interval, and the second predetermined time is less than the first predetermined time. And the maximum level of the source power is increased as the maximum supply level approaches the maximum supply level. The power control method for a heating roller according to claim 1, wherein the maximum supply level is a maximum level of the roller power that can be supplied to the heat generating resistor at a maximum. The method of claim 1, wherein the step (c) supplies the source power having the temperature holding level smaller than the maximum supply level as the maximum level to the heat generating resistor as the roller power, and having the temperature holding level as the maximum level. Fixing the toner image of the print data consisting of one or more pages onto the print medium for each page by using the heating roller supplied with the source power, And a surface temperature of the heating roller to which the source power is supplied having the temperature holding level as a maximum level has a predetermined approximation to the fixing target temperature. The method of claim 5, wherein step (c) (c1) selecting one or more of the heating resistors among the plurality of heating resistors; (c2) supplying the source power having the temperature holding level as the maximum level to the selected heat generating resistor as the roller power; And (c3) fixing the toner image onto the print medium by page using the heating roller and the pressure roller, And the roller power is not supplied to the heat generating resistor not selected in the step (c1). The method of claim 1, wherein the power control method for the heating roller (d) it is determined whether the print data has been given after the predetermined standby mode entry decision time has elapsed after the step (c); If determined, putting the printing device into a standby mode; And (e) step (d) determines whether print data has been given after entering the printing apparatus into the standby mode, and step (d) determines that print data has been given after entering the printing apparatus into the standby mode. And entering the printing device into a printing mode and proceeding to step (a). The power control method of claim 1, wherein the heat generating resistor has a variable characteristic in which a resistance value is determined in proportion to a temperature of the heat generating resistor below a threshold temperature. A printing apparatus for fixing a toner image employing a heating roller and a pressure roller, said printing apparatus comprising: a power control apparatus for a heating roller for controlling roller power supplied to a heat generating resistance included in said heating roller, The source having a maximum level of source power input from the outside gradually increasing in response to a first or second warm-up instruction signal and outputting the source power as the roller power to the heat generating resistor, and having a maximum supply level as the maximum level. A power source that outputs power to the heat generating resistor as the roller power in response to a third warm-up command signal and outputs the source power having a temperature holding level as the maximum level to the heat generating resistor as the roller power in response to a fixing command signal Supply unit; A temperature measuring unit measuring the surface temperature of the heating roller in response to the third warm-up instruction signal; A toner for interlocking the heating roller and the pressure roller in response to a fourth warm-up instruction signal and fixing a toner image of a given print data onto a print medium using the heating roller and the pressure roller in response to the fixing instruction signal. Fixing unit; A first comparing unit comparing the increased maximum level with the maximum supply level and generating the second or third warm-up instruction signal in response to the compared result; And A second comparison unit comparing the measured surface temperature with a fixing target temperature and generating the third warm-up instruction signal or the fixing instruction signal according to the compared result; The first warm-up instruction signal is generated immediately after the power of the printing apparatus is turned on or immediately after the printing apparatus enters the print mode from the standby mode, and the fourth warm-up instruction signal is immediately after the printing apparatus recognizes the pressure roller. Power control device for a heating roller, characterized in that generated. 10. The method of claim 9, wherein the place instructing the performance of the heating-related operation including the operation of the power supply unit and the place instructing the performance of the non-heat-related operation including the operation of the toner fixing unit are separately provided in the printing apparatus. An electric power control device for a heating roller characterized by the above-mentioned. The method of claim 9, wherein the power supply unit In response to the first or second warm-up instruction signal, the source power is output to the heat generating resistor as the roller power for a second predetermined time at a first predetermined time interval, and the second predetermined time is the first predetermined time. Less than a predetermined time and the maximum level of the source power is increased as it approaches the maximum supply level. The power control apparatus for a heating roller according to claim 9, wherein the maximum supply level is a maximum level of the roller power that can be supplied to the heat generating resistor at a maximum. 10. The power control apparatus for a heating roller according to claim 9, wherein the fixing instruction signal is generated corresponding to a result compared in the second comparing unit or generated while the toner fixing unit is in operation. The power control apparatus of claim 9, wherein the heat generating resistor has a variable characteristic in which a resistance value is determined in proportion to a temperature of the heat generating resistor below a threshold temperature. A printing apparatus for fixing a toner image employing a heating roller and a pressure roller, the power control method for a heating roller for controlling roller power supplied to a heat generating resistor included in the heating roller, (a) gradually increasing the maximum level of source power supplied from the outside to a predetermined maximum supply level and supplying the source power as the roller power to the heat generating resistor; (b) measuring the surface temperature of the heating roller and supplying the source power having the maximum supply level as a maximum level to the heat generating resistor until the measured surface temperature reaches a predetermined fixing target temperature; ; And (c) fixing a toner image of a given print data on the provided print medium by using the heating roller and the pressure roller, The step (a) is performed immediately after the printing apparatus is turned on or immediately after the printing apparatus enters the printing mode from the standby mode, and the printing apparatus recognizes the pressing roller from the step (b). And a pressurizing roller interlocks with the heating roller until the completion of the execution. The computer readable recording medium storing a computer program for performing a power control method for the heating roller.

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