JP2003098900A - Thermal fixing device and image forming device - Google Patents

Abstract

(57) Abstract: A heat fixing device and a heat fixing device capable of quickly and surely generating heat from a heat source, preventing voltage fluctuation of a power supply and effectively preventing flicker caused by the fluctuation. Provided is an image forming apparatus including a fixing device. SOLUTION: In order to maintain the heating roller 26 at the fixing temperature, at the time of temperature adjustment control for turning on / off the first halogen lamp 33, when the first halogen lamp 33 is turned on, an AC power supply 36 supplies the first halogen lamp. When the first halogen lamp 33 is turned off, power is supplied to the battery 35 from the AC power supply 36. As a result, the power is always supplied from the AC power supply 36, the voltage fluctuation of the line of the AC power supply 36 is reduced, and flicker is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat fixing device and an image forming apparatus including the heat fixing device.

[0002]

2. Description of the Related Art An image forming apparatus such as a laser printer is usually provided with a heat fixing device having a heating roller and a pressure roller in order to heat-fix the toner image transferred onto the paper, and the paper is heated. While passing between the roller and the pressure roller, the toner image transferred onto the paper is thermally fixed.

The heating roller of such a heat fixing device includes:
Usually, a heater composed of a halogen lamp or the like is installed along the axial direction of the heater, and the heater generates heat when power is supplied from a power source, thereby heating the heating roller.

Such a heater is normally kept in an ON state in order to raise the temperature of the heating roller to the fixing temperature at the time of warming up immediately after the power supply of the laser printer is turned on. When the roller reaches the fixing temperature, the temperature of the heating roller is adjusted by the on / off control to maintain the heating roller at the fixing temperature.

Further, in such a heat fixing device,
If the thermal fixing operation is not performed even after a lapse of a predetermined time while the temperature is adjusted at the fixing temperature, the heating roller is set to a standby state in which it is maintained at a predetermined set temperature lower than the fixing temperature. On / off control of the heater is performed to save labor.

[0006]

In recent years, however, there has been a demand for shortening the warm-up time in order to achieve a quick image forming operation, and in response to this, the heat fixing device of the image forming apparatus is A heater having a large heat generation amount has been provided.

[0007] However, while it is necessary to supply a large amount of electric power to the heater that generates a large amount of heat, the 15A AC power supply installed in a normal home or office
There is a limit to the power supply. Therefore, for example, in Japanese Unexamined Patent Application Publication No. 10-282821, an auxiliary power source including a secondary battery is provided in addition to the main power source, and when the power supply amount to the fixing unit is small, the power source is supplied to the fixing unit. At the same time, the auxiliary power supply is charged, and at the time of warm-up when a large amount of power is required to be supplied to the fixing unit, power is supplied to the fixing unit by both the main power supply and the auxiliary power source, and the fixing unit is heated at high speed. It has been proposed to let.

However, for example, when the heater that requires such a large amount of power supply is on / off controlled to maintain the heating roller at the fixing temperature, the current flowing from the power source changes greatly, and As a result, the voltage of the power supply line fluctuates, and, for example, a phenomenon called flicker occurs in which the brightness of the illumination around the laser printer is changed according to on / off control. There is.

The present invention has been made in view of such a problem, and an object of the present invention is to reduce the voltage fluctuation of the power source while quickly and surely generating heat from the heat source, which results from that. An object of the present invention is to provide a thermal fixing device and an image forming apparatus including the thermal fixing device, which can effectively prevent flicker.

[0010]

To achieve the above object, the invention according to claim 1 heats the heating member for thermally fixing the toner image formed on the recording medium, and the heating member. In order to maintain the heating member at a fixing temperature, the thermal fixing device includes a heat source for supplying electric power to the heat source, and a power source capable of supplying electric power to the heat source and the electric power storing means. , Turn on the heat source
In the temperature control control for off control, when the heat source is off, a selective power supply means for supplying power from the power source to the power storage means is provided.

According to this structure, during temperature control control, when the heat source is off, electric power from the power source is supplied to the power storage means and the power storage means is charged. Therefore, the electric power supplied from the power source when the heat source is on can be directly supplied to the power storage means when the heat source is off.Therefore, the power source should always supply power regardless of the on / off control of the heat source. You can As a result, even when the heat source is turned on / off, the current flowing from the power source does not change significantly, the voltage fluctuation of the power source line can be reduced, and flicker can be effectively prevented.

The invention described in claim 2 is the same as claim 1.
In the invention described in (1), the selective power supply means selectively supplies power to the heat source from the power source when the heat source is on, and supplies power to the power storage means from the power source when the heat source is off. It is characterized by supplying.

According to this structure, during temperature control control, when the heat source is on, the power from the power source is selectively supplied to the heat source, while when the heat source is off, the power from the power source is selectively supplied to the storage means. Is supplied to. Therefore, when the heat source is on, the power that is being supplied from the power source to the heat source can be directly supplied to the power storage means when the heat source is off.Therefore, the power source always supplies power regardless of the on / off control of the heat source. I can continue. As a result, even when the heat source is turned on / off, the current flowing from the power source does not change significantly, the voltage fluctuation of the power source line can be reduced, and flicker can be effectively prevented.

The invention described in claim 3 is the same as claim 1
In the invention described in above, the selective power supply means supplies power from the power supply to the power storage means and power from the power storage means to the heat source when the heat source is on during temperature adjustment control. I am trying.

According to this structure, during temperature control control, when the heat source is on, power is supplied from the power supply to the power storage means, and from the power storage means to the heat source, while the heat source is off. Electric power from the power source is supplied to the power storage means. Therefore, during the temperature adjustment control, it is possible to constantly supply a predetermined electric power from the power supply to the power storage means and to control the heat source on / off by the electric power supplied from the power storage means. as a result,
Even if the heat source is turned on / off, the current flowing from the power source does not change significantly, the voltage fluctuation of the power source line can be reduced, and flicker can be effectively prevented.

The invention according to claim 4 is the same as claim 1
In the invention described in any one of (1) to (3), the selective power supply unit does not supply power from the power source to the heat source or the power storage unit when in a standby state where the temperature is lower than the fixing temperature. Is characterized by.

In the standby state, the heat source is controlled to be turned on and off so that the set temperature is lower than the fixing temperature, and in such temperature adjustment control with a small amount of power supply, power is supplied to the heat source. It is also possible to supply power to the power storage means to charge the power storage means. However, if such temperature adjustment control is performed in the standby state, power consumption also increases,
This causes a problem that energy saving, which is the purpose of the standby state, cannot be achieved.

However, according to such a structure, in the standby state, since neither the heat source nor the power storage means is supplied with electric power from the power source, it is possible to sufficiently save energy.

The invention described in claim 5 is the same as claim 1.
The invention according to any one of claims 1 to 4 is characterized in that the heat source includes a power source side heat source to which the power source is connected and a power storage means side heat source to which the power storage means is connected.

According to this structure, the heat source on the power source side is directly supplied with the power from the power source, and the heat source on the power storage means side is once charged with the power from the power source, and the charged power is supplied to the heat source. It is supplied from the power storage means. Therefore, the heat source on the power source side can be reliably operated by the power from the power source, and the heat source on the power storage unit side can be reliably operated by the power from the power storage unit, that is, the heat source on the power source side or the power storage unit side. The heat sources can be reliably and independently operated by the power supply from the power source or the power storage means.

The invention according to claim 6 is the same as claim 1.
In the invention described in any one of (1) to (4), both the power source and the power storage means are connected to the heat source.

According to this structure, since both the power source and the power storage means are connected to the heat source, the heat source can be reliably supplied by the selective power supply means or the selective power supply from the power storage means. Can be activated.

The invention described in claim 7 is the same as claim 6
In the invention described in above, the selective power supply means supplies power to the heat source only from the power storage means at least for a first predetermined period when the heat source is turned on at the start-up when the temperature is raised to the fixing temperature. It is characterized by doing.

When the heat source is turned on at the time of starting up to the fixing temperature, the temperature of the heat source is low and the resistance is small. Therefore, when power is supplied from the power source, a large current may flow.

However, according to such a configuration, when the heat source is turned on at the time of start-up, electric power is supplied to the heat source only from the power storage means for at least the first predetermined period, so that it is effective that a large current flows from the power source. Can be prevented.

The invention according to claim 8 is an image forming apparatus, which is characterized by including the heat fixing device according to any one of claims 1 to 7.

In such an image forming apparatus, the heat fixing device is provided with a heat source having a large amount of heat generation to quickly and surely generate heat, thereby making it possible to shorten the temperature rising time at startup. Also in the on / off control during the temperature adjustment control at the fixing temperature, it is possible to reduce the voltage fluctuation of the power supply and effectively prevent the flicker due to it.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a side sectional view of an essential part showing an embodiment of a laser printer as an image forming apparatus of the present invention. In FIG. 1, a laser printer 1 includes a feeder section 4 for feeding a sheet 3 as a recording medium in an inner casing 2, and an image forming section for forming a predetermined image on the fed sheet 3. 5 and so on.

The feeder unit 4 is detachably mounted on the bottom of the main body casing 2, a sheet pressing plate 7 provided in the sheet feeding tray 6, and one end of the sheet feeding tray 6. And a paper feed roller 8 provided above the paper feed roller 8 and a downstream side of the paper feed roller 8 in the conveyance direction of the paper 3 (hereinafter, an upstream side or a downstream side of the paper 3 in the conveyance direction is simply referred to as an upstream side or It may be referred to as a downstream side.) Conveying rollers 10 and 11 provided on the downstream side, and a registration roller 12 provided downstream of the conveying rollers 10 and 11 in the conveying direction of the sheet 3.

The sheet pressing plate 7 is capable of stacking the sheets 3 in a stacked manner, and is swingably supported at the end portion far from the sheet feeding roller 8 so that the near end portion is vertically moved. It is movable in any direction, and is biased upward from the back side by a spring (not shown). for that reason,
As the stacking amount of the sheets 3 increases, the sheet pressing plate 7 is swung downward against the biasing force of the spring with the end portion farther from the sheet feeding roller 8 as a fulcrum. The paper feed roller 8 and the paper feed pad 9 are arranged to face each other, and the paper feed pad 9 is pressed toward the paper feed roller 8 by a spring 13 provided on the back side of the paper feed pad 9. . The topmost sheet 3 on the sheet pressing plate 7 is pressed from the back side of the sheet pressing plate 7 toward the sheet feeding roller 8 by a spring (not shown), and the sheet feeding roller 8 is rotated by the sheet feeding roller 8 to rotate. After being sandwiched between the pad 9 and the pad 9, the sheets are fed one by one. The fed sheet 3 is sent to the registration roller 12 by the transport rollers 10 and 11. Registration roller 12
Is composed of a pair of rollers and is configured to send the sheet 3 to the image forming section 5 after a predetermined registration.

The feeder unit 4 further includes a multi-purpose tray 14, a multi-purpose paper feed roller 15 and a multi-purpose paper feed pad 15a for feeding the papers 3 stacked on the multi-purpose tray 14. The multi-purpose paper feed roller 15 and the multi-purpose paper feed pad 15a are arranged to face each other, and the multi-purpose paper feed roller 15 and the multi-purpose paper feed pad 15a are provided by a spring (not shown) provided on the back side of the multi-purpose paper feed pad 15a. The pad 15a is pressed against the multi-purpose paper feed roller 15. The sheets 3 stacked on the multi-purpose tray 14 are sandwiched between the multi-purpose sheet feeding roller 15 and the multi-purpose sheet feeding pad 15a by the rotation of the multi-purpose sheet feeding roller 15 and then fed one by one. .

The image forming section 5 includes a scanner unit 16,
A process cartridge 17, a transfer roller 24, a heat fixing device 18, and the like are provided.

The scanner unit 16 is provided in the upper part of the main body casing 2, and has a laser emitting portion (not shown),
A polygon mirror 19, which is driven to rotate, lenses 20 and 21, a reflecting mirror 22 and the like are provided, and a laser beam based on predetermined image data emitted from a laser emitting section is generated.
As shown by the chain line, the polygon mirror 19, the lens 20,
The reflecting mirror 22 and the lens 21 are passed or reflected in this order, and the photosensitive drum 2 of the process cartridge 17 to be described later is described.
The surface of No. 3 is irradiated with high-speed scanning.

The process cartridge 17 is arranged below the scanner unit 16 and is detachably attached to the main body casing 2. The process cartridge 17 includes the photosensitive drum 23, and also includes a scorotron charger, a developing roller, a toner accommodating portion, etc., which are not shown.

The toner accommodating portion is filled with a positively chargeable non-magnetic one-component polymerized toner as a developer, and the toner is carried on the developing roller as a thin layer having a constant thickness. On the other hand, the photosensitive drum 23 is rotatably disposed so as to face the developing roller, the drum body is grounded, and the surface thereof is formed of a positively chargeable photosensitive layer made of polycarbonate or the like. .

The surface of the photosensitive drum 23 is uniformly positively charged by a scorotron type charger as the photosensitive drum 23 rotates, and then exposed by high-speed scanning of the laser beam from the scanner unit 16. An electrostatic latent image is formed on the basis of predetermined image data, and when the electrostatic latent image is subsequently formed on the surface of the photosensitive drum 23, the toner carried on the developing roller and positively charged is formed when the electrostatic latent image is formed. The latent image, that is, the surface of the photosensitive drum 23 that is uniformly positively charged, is supplied to a portion of the surface of the photosensitive drum 23 that is exposed by a laser beam and has a reduced potential, and is selectively carried to be visualized. This achieves reversal development.

The transfer roller 24 is disposed below the photosensitive drum 23 so as to face the photosensitive drum 23 while being rotatably supported on the main body casing 2 side. The transfer roller 24 has a metal roller shaft covered with a roller made of a conductive rubber material, and a predetermined transfer bias is applied to the photosensitive drum 23. Therefore, the visible image formed of the toner image carried on the photosensitive drum 23 is transferred to the sheet 3 while the sheet 3 passes between the photosensitive drum 23 and the transfer roller 24.
The sheet 3 on which the visible image has been transferred is conveyed to the thermal fixing device 18 described below via the conveying belt 25.

The heat fixing device 18 is disposed on the downstream side of the process cartridge 17, and is disposed opposite to the heating roller 26 as a heating member, and the heating roller 26 and the sheet 3 conveyance path sandwiched therebetween. A pressing roller 27 that presses the heating roller 26 and a conveying roller 28 that is provided on the downstream side of the heating roller 26 and the pressing roller 27 are provided.

The heating roller 26 includes a cylindrical roller body 32 made of a metal tube such as aluminum, a first halogen lamp 33 as a heat source on the power source side, and a second halogen lamp 34 as a heat source on the power storage means side. There is.

The first halogen lamp 33 and the second halogen lamp 34 are provided in parallel in the roller body 32 along the axial direction, and the first halogen lamp 33 has an AC power source 36 (see FIG. 2) described later. ) Generates heat when supplied with electric power, and the second halogen lamp 34 is
Power is supplied from a battery 35 (see FIG. 2), which will be described later, to generate heat, thereby heating the roller body 32.

The pressing roller 27 has a metal roller shaft covered with a roller made of an elastic material, and the heating roller 26.
Is pressed with a predetermined pressure.

In the thermal fixing device 18, the toner image transferred onto the paper 3 in the process cartridge 17 is thermally fixed while the paper 3 passes between the heating roller 26 and the pressing roller 27. I have to.

Paper 3 fixed in heat fixing device 18
Is then transported to the transport roller 28 provided on the downstream side of the thermal fixing device 18, the transport roller 29 and the paper discharge roller 30 disposed on the downstream side of the transport roller 28,
The paper is discharged onto the paper discharge tray 31 by the paper discharge roller 30.

In the laser printer 1, the ROM of the CPU (not shown) provided in the main body casing 2 is shown.
The first halogen lamp 33 and the second halogen lamp 34 are controlled by a selected power supply program stored in the selected power supply means.

Next, the control of the first halogen lamp 33 and the second halogen lamp 34 by the selective power supply program will be described with reference to FIGS. 2 and 3.

FIG. 2 shows a circuit configuration diagram of the thermal fixing device 18. As shown in FIG. 2, the laser printer 1 includes an AC power source 36 as a power source in the main body casing 2.
A charging circuit 37 and a battery 35 as a power storage unit are provided, and the AC power supply 36 is the first halogen lamp 3
3 and the second halogen lamp 34 through the charging circuit 37 and the battery 35. That is, the power supply line is branched into two parts on the downstream side of the AC power source 36, one of which is directly connected to the first halogen lamp 33 and the other of which is connected to the charging circuit 37. The downstream side of the charging circuit 37 is connected to the battery 35, and the downstream side of the battery 35 is connected to the second halogen lamp 34.

In one power supply line, A
Between the C power supply 36 and the first halogen lamp 33, a first open / close switch 38 for supplying or shutting off power to the first halogen lamp 33 is provided, and the other power supply line is connected to the AC power supply 36. Between the charging circuit 37,
Second for supplying or shutting off power to the charging circuit 37
An open / close switch 39 and a third open / close switch 40 for supplying or shutting off power to the second halogen lamp 34 are provided between the battery 35 and the second halogen lamp 34.

In the heat fixing device 18, the first halogen lamp 33 is directly supplied with electric power from the AC power source 36 by opening / closing the first opening / closing switch 38, the second opening / closing switch 39 and the third opening / closing switch 40. Along with
The second halogen lamp 34 is once charged with electric power from the AC power supply 36 in the battery 35, and the charged electric power is supplied from the battery 35.

Next, a state in which each of these parts is controlled by the selective power supply program and the temperature of the heating roller 26 is controlled will be described with reference to FIG. 3, which is a timing chart of each part.

First, the laser printer 1 is turned on (AC
After the power supply 36 is turned on, the heating roller 26 is heated to the fixing temperature (T) during warming up (R
In 1), the first open / close switch 38 is closed, and the power from the AC power supply 36 is supplied to the first halogen lamp 33, whereby the first halogen lamp 33 is turned on and the third open / close switch 40 is provided. Is closed and the power from the battery 35 is supplied to the second halogen lamp 34, whereby the second halogen lamp 34 is turned on. As a result, the heating roller 26 moves the first halogen lamp 3
Heated from both the third and second halogen lamps 34,
During the warming up (R1), the temperature is rapidly raised to a predetermined fixing temperature (T) (in the laser printer 1, for example, set to 170 to 180 ° C.).

During the warm-up temperature rise (R1), the second open / close switch 39 is open, and the AC power supply 36 does not charge the battery 35 via the charging circuit 37.

Then, the heating roller 26 is set to the fixing temperature (T).
After reaching the temperature, the heating roller 26 is fixed at its fixing temperature (T).
The temperature adjustment control for maintaining the temperature is performed. That is, during the temperature adjustment control (C), the third opening / closing switch 40 is continuously opened, and the first opening / closing switch 38 and the second opening / closing switch 39 are alternately opened / closed (that is, the first opening / closing switch). The second opening / closing switch 39 is closed when the switch 38 is opened, and conversely, the first opening / closing switch 38 is closed when the second opening / closing switch 39 is opened.

Then, the fixing temperature (T) of the heating roller 26 is controlled by the on / off control of the first halogen lamp 33.
Is maintained. Then, at this time, the second opening / closing switch 39
Since the first open / close switch 38 is closed when is opened, the power from the AC power supply 36 is supplied only to the first halogen lamp 33. On the other hand, the first opening / closing switch 38
Since the second open / close switch 39 is closed when is opened, the power from the AC power supply 36 is supplied to the battery 35 via the charging circuit 37, and the battery 35 is charged.

As described above, during the temperature adjustment control (C) at the fixing temperature (T), the image forming section 5 performs the image forming operation to form the toner image on the sheet 3,
The paper 3 is sequentially conveyed to the heat fixing device 18 to perform the heat fixing operation. However, the paper 3 is conveyed from the image forming unit 5 even if a predetermined time has elapsed since the previous heat fixing operation. When the heat fixing operation is not performed, the control in the standby state (S) for lowering the temperature of the heating roller 26 below the fixing temperature (T) is performed by the selective power supply program.

That is, in the standby state (S), all of the first opening / closing switch 38, the second opening / closing switch 39, and the third opening / closing switch 40 are opened. Then, from the AC power source 36, the first halogen lamp 33
No electric power is supplied to neither the charging circuit 37 nor the charging circuit 37, and no electric power is supplied from the battery 35 to the second halogen lamp 34. Therefore, both the first halogen lamp 33 and the second halogen lamp 34 are turned off, and heating is performed. The temperature of the roller 26 gradually decreases as compared with the temperature adjustment control (C). At this time, the second open / close switch 39 is also open, so that the battery 35 is not charged via the charging circuit 37.

Then, when the image forming operation is performed again in the image forming section 5, the heating roller 26 is heated again and the temperature is raised to the fixing temperature (T). When the temperature is raised from the standby state (R2), the second open / close switch 39
Is continuously opened, and the first opening / closing switch 38
And the third opening / closing switch 40 is closed. Then, the heating roller 26 is heated by both the first halogen lamp 33 and the second halogen lamp 34 in the same manner as during the warm-up temperature rise (R1), and during the temperature rise from the standby state (R2), The temperature is rapidly raised to a predetermined fixing temperature (T). At this time, the second
Since the open / close switch 39 is opened, the charging circuit 37
The battery 35 is not charged via the.

Then, the heating roller 26 is set to the fixing temperature (T).
After the temperature reaches, the temperature adjustment control for maintaining the heating roller 26 at the fixing temperature (T) is performed as described above.

As described above, in the thermal fixing device 18 of the laser printer 1, the first power is supplied by the selective power supply program during the temperature adjustment control (C) at the fixing temperature (T).
When the halogen lamp 33 is turned on, the AC power source 36
The electric power from the AC power supply 36 is selectively supplied to the battery 35 when the electric power from the AC power supply 36 is selectively supplied to the first halogen lamp 33. Therefore, the power supplied from the AC power supply 36 to the first halogen lamp 33 when the first halogen lamp 33 is turned on can be directly supplied to the battery 35 when the first halogen lamp 33 is turned off. , The AC power supply 36 is the first halogen lamp 33.
Regardless of the on / off control of, the power can be continuously supplied. As a result, the first halogen lamp 33
Even when the ON / OFF control is performed, the current flowing from the AC power supply 36 does not significantly change, the voltage fluctuation of the AC power supply 36 line can be reduced, and flicker can be effectively prevented.

In the standby state, for example, the first halogen lamp 33 is controlled to be turned on / off so as to be a predetermined set temperature lower than the fixing temperature (T), and the temperature at which the power supply amount is small is set. In the control, while supplying power to the first halogen lamp 33,
It is also possible to supply power to the battery 35 to charge the battery 35, but if such temperature control is performed during standby, power consumption also increases, and energy saving, which is the purpose during standby, is achieved. I can't.

Therefore, in the thermal fixing device 18, no power is supplied from the AC power supply 36 to the first halogen lamp 33 and the battery 35 at the time of standby (S) by the selected power supply program, and By controlling the battery 35 not to supply power to the second halogen lamp 34, the energy saving in the standby state (S) is sufficiently achieved.

In the heat fixing device 18, the electric power from the AC power source 36 is directly supplied to the first halogen lamp 33, and the electric power from the AC power source 36 is once supplied to the battery 35 to the second halogen lamp 34. Since the battery 35 is charged and the charged power is supplied from the battery 35, the first halogen lamp 33 can be reliably operated by the power from the AC power supply 36 by the selective power supply by the selective power supply program. , Second halogen lamp 34
Can be reliably operated by the electric power from the battery 35, that is, the first halogen lamp 33 or the second halogen lamp 34 can be reliably and independently operated by the power supply from the AC power source 36 or the battery 35. The first halogen lamp 33 and the second halogen lamp 34 in the above control can be operated.
A reliable operation of can be achieved.

Further, for example, at the time of temperature adjustment control (C) at the fixing temperature (T), the first halogen lamp 33 is turned off, the AC power supply 36 supplies power to the battery 35, and the battery 35 is charged. While the battery 35 to the second
The temperature of the heating roller 26 may be controlled by supplying power to the halogen lamp 34 and controlling the on / off of the second halogen lamp 34.

FIG. 4 is a timing chart of each part where such temperature control is performed.

That is, as shown in FIG. 4, in this temperature control, during the warming-up temperature rise (R1) and during the temperature rise from the standby state (R2), the first halogen lamp 33 and While heating the heating roller 26 by both the second halogen lamps 34 to raise the temperature, the first opening / closing switch 38 is continuously opened during the temperature adjustment control (C) at the fixing temperature (T). At the same time, the second opening / closing switch 39 is continuously closed and the third opening / closing switch 40 is opened / closed. Then, AC power supply 3
From 6, the electric power is supplied only to the battery 35 via the charging circuit 37, and the electric power from the battery 35 controls the second halogen lamp 34 to be turned on and off. As a result, the fixing of the heating roller 26 is performed. The temperature (T) is maintained.

According to such control, the fixing temperature (T)
When the second halogen lamp 34 is turned on during the temperature adjustment control (C), the power is supplied from the AC power source 36 to the battery 35 via the charging circuit 37, and at the same time, the second halogen lamp is discharged from the battery 35. When the second halogen lamp 34 is turned off while the power is supplied to the battery 34, the power from the AC power supply 36 is supplied to the battery 35 via the charging circuit 37, and the battery 35 is charged. Therefore, during the temperature adjustment control (C) at the fixing temperature (T), the electric power from the AC power supply 36 is always supplied to the battery 35 at a constant electric power regardless of the on / off control of the second halogen lamp 34. Therefore, the second halogen lamp 34 can be controlled to be turned on / off by the electric power supplied from the battery 35 to maintain the fixing temperature (T) of the heating roller 26. As a result, even with such control, the current flowing from the AC power supply 36 does not change significantly, voltage fluctuations in the AC power supply 36 line can be reduced, and flicker can be effectively prevented.

Further, in the thermal fixing device 18 of the laser printer 1, one third halogen lamp 41 as a heat source may be connected to both the AC power source 36 and the battery 35. FIG. 5 shows a circuit configuration diagram of such a heat fixing device 18.

In FIG. 5, the AC power source 36 is directly connected to the third halogen lamp 41 via the rectifying circuit 42, and is also connected to the third halogen lamp 41 via the charging circuit 37 and the battery 35. That is, the power supply line is branched into two downstream of the AC power source 36, one of which is connected to the rectifier circuit 42, and the downstream of the rectifier circuit 42 is connected to the third halogen lamp 41. The other side is connected to the charging circuit 37, the downstream side of the charging circuit 37 is connected to the battery 35, and the downstream side of the battery 35 is connected to the third halogen lamp 41.

Further, in one of the power supply lines, between the rectifier circuit 42 and the third halogen lamp 41, a first open / close switch for supplying or shutting off the power from the AC power supply 36 to the third halogen lamp 41. 38 is provided,
In the other power supply line, between the AC power supply 36 and the charging circuit 37, a second opening / closing switch 39 for supplying or shutting off power to the charging circuit 37, and a battery 35.
A third open / close switch 40 for supplying or shutting off the electric power from the battery 35 to the third halogen lamp 41 is provided between the third halogen lamp 41 and the third halogen lamp 41.

In this heat fixing device 18, the opening / closing of the first opening / closing switch 38 causes the power from the AC power source 36 to be directly supplied to the third halogen lamp 41, and the second opening / closing switch 39 and the third opening / closing switch 40. By opening and closing,
The battery 35 is once charged with electric power from the AC power source 36, and the charged electric power is supplied from the battery 35 to the third halogen lamp 41.

Next, a state in which each of these parts is controlled by the selective power supply program and the temperature of the heating roller 26 is controlled will be described with reference to FIG. 6 which is a timing chart of each part.

In the following description, during the predetermined time (M), in the third halogen lamp 41 immediately after the temperature rise, such a large current flow is reduced from the low temperature at which the resistance is small and the large current flows. The time required to reach the temperature is set to, for example, 2 in this laser printer 1.
Although it is set to seconds, it is set appropriately according to the device configuration and the like.

First, after the power is turned on (the AC power source 36 is turned on), during the warming-up temperature rise (R1) for heating the heating roller 26 to the fixing temperature (T), first, for the first predetermined time (M), The first opening / closing switch 38 and the second opening / closing switch 39 are opened, the third opening / closing switch 40 is closed, and the power from the battery 35 is supplied to the third halogen lamp 41, whereby the third halogen lamp 41. Is turned on. As a result, the heating roller 2
6 is heated by the third halogen lamp 41, which is powered only by the battery 35. Then, after the elapse of the predetermined time (M), the opening of the second opening / closing switch 39 and the closing of the third opening / closing switch 40 are continued, and
The first open / close switch 38 is closed, and the electric power from the AC power supply 36 is supplied to the third halogen lamp 41 which is already supplied with electric power from the battery 35. by this,
The heating roller 26 is heated by the third halogen lamp 41 supplied with power from both the AC power source 36 and the battery 35, and at the time of warming up during this warm-up (R1).
In, the temperature is rapidly raised to a predetermined fixing temperature (T).

Then, the heating roller 26 is set to the fixing temperature (T).
After the temperature reaches, the temperature adjustment control for maintaining the heating roller 26 at the fixing temperature (T) is performed as described above. That is, during the temperature adjustment control (C), the third
The open / close switch 40 is continuously opened, and the first
The open / close switch 38 and the second open / close switch 39 are alternately opened / closed. Then, the heating roller 26 is fixed at the fixing temperature (T) by the on / off control of the third halogen lamp 41.
And the electric power is constantly supplied from the AC power supply 36 to the third halogen lamp 41 or the battery 35 by the selective opening / closing of the first opening / closing switch 38 and the second opening / closing switch 39.

Also in the standby state (S), similarly to the above, all of the first opening / closing switch 38, the second opening / closing switch 39, and the third opening / closing switch 40 are opened, and the third halogen lamp 41 is turned off. Therefore, the temperature of the heating roller 26 is gradually lowered as compared with the temperature adjustment control (C).

When the temperature rises from the standby state (R
In 2), first, the first opening / closing switch 38 and the second opening / closing switch 39 are continuously opened and the third opening / closing switch 40 is closed for the first predetermined time (M).
Then, the heating roller 26 is heated by the third halogen lamp 41, which is supplied with power only from the battery 35, as in the warming-up time (R1).
Then, after the elapse of the predetermined time (M), the opening of the second opening / closing switch 39 and the closing of the third opening / closing switch 40 are continued, and the first opening / closing switch 38 is closed,
Electric power from the AC power supply 36 is supplied to the third halogen lamp 41 which is already supplied with power from the battery 35. As a result, the heating roller 26 is heated by the third halogen lamp 41 that is supplied with power from both the AC power source 36 and the battery 35, and the heating roller 26 is quickly heated to the predetermined fixing temperature even when the temperature rises from the standby state (R2). The temperature is raised to (T).

In the heat fixing device 18 having the circuit structure shown in FIG. 5, the third halogen lamp 41 is connected to the AC line.
Since both the power supply 36 and the battery 35 are connected, the third halogen lamp 41 can be reliably operated by the power supply from the AC power supply 36 or the battery 35 according to the selected power supply program.

At the time of warming up the temperature (R
Immediately before the start-up when the temperature is raised to the fixing temperature such as 1) or the temperature rise from the standby state (R2), the temperature of the third halogen lamp 41 is usually low and the resistance is small. Immediately after that, when power is supplied from the AC power supply 36, a large current may flow. However, in the temperature control of the power supply control program shown in FIG. 6, during warming up (R1) and during rising from the standby state. During the warm time (R2), the third halogen lamp 41 again
When the power is turned on, the third halogen lamp 41 is controlled to be supplied with electric power only from the battery 35 for the first predetermined time (M), so that it is effective that such a large current flows from the AC power supply 36. Can be prevented.

In such control, during the warming-up temperature rise (R1) and during the temperature rise from the standby state (R2), the first open / close switch 38 and the third open / close switch 38 and the third switch are operated after a predetermined time (M) has elapsed. Both the open / close switches 40 are closed so that the third halogen lamp 41 is turned on by both the electric power from the AC power supply 36 and the electric power from the battery 35. However, for example, after a predetermined time (M) has passed, While closing the first open / close switch 38,
The third open / close switch 40 may be opened to control the third halogen lamp 41 to be turned on only by the power supply from the AC power supply 36. In that case, the rectifier circuit 42 is not always necessary.

Further, in the above description, in the standby state (S), all of the first opening / closing switch 38, the second opening / closing switch 39 and the third opening / closing switch 40 are opened,
Although all the halogen lamps (the first halogen lamp 33 and the second halogen lamp 34 in FIG. 2, or the third halogen lamp 41 in FIG. 5) are controlled to be turned off, even during standby (S), The heating roller 26 may be controlled at a predetermined set temperature lower than the fixing temperature (T) by controlling ON / OFF of any halogen lamp.

Further, in the thermal fixing device 18, the battery is used as the power storage means, but the power storage means is not limited to the battery and may be, for example, a capacitor. A battery is preferably used for the capacitor because the charged state is not maintained when the AC power supply 36 is turned off.

In the laser printer 1 described above, the heat fixing device 18 is provided with a halogen lamp (first halogen lamp 33 and second halogen lamp 34 in FIG. 2 or a third halogen lamp 34 in FIG. 5) which generates a large amount of heat. AC power supply 36 and battery 3 with halogen lamp 41)
Power is supplied from 5 to quickly and surely generate heat during warm-up temperature rise (R1) and during standby temperature rise (R2), thereby shortening the temperature rise time at startup. In addition, the ON / OFF control during the temperature adjustment control (C) at the fixing temperature (T) is performed by the selective power supply program.
It is possible to reduce the voltage fluctuation of the power supply line 36 and effectively prevent flicker due to the fluctuation.

[0082]

As described above, according to the first aspect of the present invention, the electric power supplied from the power source when the heat source is on can be supplied to the power storage means as it is when the heat source is off. Can always supply power regardless of on / off control of the heat source. Therefore, the current flowing from the power supply does not change significantly,
Flicker can be effectively prevented by reducing the voltage fluctuation of the power supply line.

According to the second aspect of the present invention, the electric power supplied from the power source to the heat source when the heat source is on can be directly supplied to the storage means when the heat source is off.
The power supply can always supply power regardless of the on / off control of the heat source. Therefore, the current flowing from the power supply does not change significantly, the voltage fluctuation of the power supply line can be reduced, and flicker can be effectively prevented.

According to the third aspect of the present invention, during the temperature adjustment control, the power source can always supply a predetermined amount of power to the power storage means, and the heat source is turned on by the power supplied from the power storage means. It can be controlled off. Therefore, even if the heat source is turned on / off, the current flowing from the power source does not change significantly, the voltage fluctuation of the power source line can be reduced, and flicker can be effectively prevented.

According to the invention described in claim 4, in the standby state, both of the heat source and the electricity storage means are
By not supplying electric power from the power source, energy saving can be sufficiently achieved.

According to the fifth aspect of the present invention, the heat source on the power source side or the heat source on the power storage means can be independently and reliably operated by the power supply from the power source or the power storage means.

According to the invention of claim 6, the heat source is:
It can be operated reliably by the selective power supply from the power source or the power storage means by the selective power supply means.

According to the invention described in claim 7, it is possible to effectively prevent a large current from flowing from the power supply at the time of startup.

According to the invention described in claim 8, while the warm-up time can be shortened, the voltage fluctuation of the power source can be reduced even in the on / off control during the temperature adjustment control at the fixing temperature. As a result, flicker due to it can be effectively prevented.

[Brief description of drawings]

FIG. 1 is a side sectional view of an essential part showing an embodiment of a laser printer as an image forming apparatus of the present invention.

FIG. 2 is a circuit configuration diagram of a heat fixing device of the laser printer shown in FIG.

FIG. 3 shows a state in which the temperature of the heating roller is controlled in the laser printer shown in FIG.
FIG. 3 is a timing chart of each part of (on / off control of halogen lamp).

FIG. 4 is a timing chart of each part of the thermal fixing device shown in FIG. 2 in a state where the temperature of the heating roller is controlled (the second halogen lamp is on / off controlled during temperature adjustment control).

5 is a circuit configuration diagram of a heat fixing device (a mode in which a third halogen lamp is connected to both an AC power source and a battery) of another embodiment of the laser printer shown in FIG.

FIG. 6 is a timing chart of each part in a state where the temperature of the heating roller is controlled in the thermal fixing device shown in FIG. 5 (power is supplied only from the battery for the first predetermined time during temperature increase).

[Explanation of symbols]

1 laser printer 3 sheets 18 Heat fixing device 26 heating roller 33 First halogen lamp 34 Second halogen lamp 35 battery 36 AC power supply 41 Third halogen lamp

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H033 AA20 AA30 AA32 AA41 BA25                       BA30 BB18 CA03 CA04 CA05                       CA07 CA20 CA26 CA30 CA45                 3K058 AA46 AA81 BA18 CA01 CA12                       CA31 CB01 DA00

Claims (8)

[Claims] 1. A thermal fixing device comprising a heating member for thermally fixing a toner image formed on a recording medium, and a heat source for heating the heating member, wherein a power storage unit capable of supplying power to the heat source. And a power source capable of supplying electric power to the heat source and the power storage means, in order to maintain the heating member at a fixing temperature, during temperature adjustment control for controlling the heat source on / off, when the heat source is off, A thermal fixing device comprising: a selected power supply unit that supplies power from a power source to the power storage unit. 2. The selective power supply means selectively supplies power to the heat source from the power source when the heat source is on, and supplies power to the power storage means from the power source when the heat source is off, during temperature adjustment control. The heat fixing device according to claim 1, wherein the heat fixing device is supplied. 3. The power selection means supplies power from the power source to the power storage means and power from the power storage means to the heat source when the heat source is on during temperature adjustment control. The heat fixing device according to claim 1. 4. The selective power supply means does not supply power from the power source to either the heat source or the power storage means when in a standby state where the temperature is lower than the fixing temperature. Item 5. A thermal fixing device according to any one of items 1 to 3. 5. The heat source comprises a power source side heat source to which the power source is connected and a power storage means side heat source to which the power storage means is connected. The heat fixing device described in 1. 6. The heat fixing device according to claim 1, wherein both the power source and the power storage unit are connected to the heat source. 7. The selective power supply means supplies power to the heat source only from the power storage means during at least the first predetermined period when the heat source is turned on at the start-up when the temperature is raised to the fixing temperature. The heat fixing device according to claim 6, wherein 8. An image forming apparatus comprising the heat fixing device according to claim 1. Description: