JP2005017737A - Image forming apparatus and its power control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of securing stable fixation processing even when an optional device is added, and to provide its power control method. <P>SOLUTION: In the image forming apparatus on which the optional device 21 can be mounted, it is provided with a fixing device 16 which fixes a developer image transferred on transfer paper and a control circuit 12 which decides presence/no presence of the setting of power to be supplied to the fixing device 16 and mounting of the optional device 21. The control circuit 12 decides the presence/no presence of the mounted optional device 21, sets power to supply to the fixing device 16 to the first power when it decides that the optional device 21 is not mounted, sets the power to the second power lower than the first power when it decides that the optional device 21 is mounted, sets the temperature of the fixing device 16 at the time of copy halt of prescribed transfer paper to the first temperature when it decides that the optional device 21 is not mounted and sets the temperature to the second temperature higher than the first temperature when it decides that the optional device is mounted. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus and a power control method thereof.
[0002]
[Prior art]
The image forming apparatus can be configured as a system by adding various optional devices such as a finisher, an LCF (Large Capacity Feeder), and an inserter to the image forming apparatus main body.
[0003]
However, when such an optional device is attached to the image forming apparatus, the power consumption of the entire system increases accordingly. For this reason, in some cases, the power consumption of the entire system may exceed the standard power.
[0004]
On the other hand, if the power supplied to the fixing device with high power consumption is reduced among the image forming apparatuses so that the power consumption of the entire system does not exceed the standard power, stable fixing processing may not be ensured. there were.
[0005]
[Problems to be solved by the invention]
As described above, the conventional image forming apparatus has a problem that when the optional apparatus is mounted, the power consumption of the entire system does not exceed the standard power and stable fixing processing cannot be performed.
[0006]
SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide an image forming apparatus capable of ensuring stable fixing processing even when an optional device is added, and a power control method therefor.
[0007]
[Means for Solving the Problems]
The image forming apparatus according to the present invention can be equipped with an optional device,
A fixing device for fixing the developer image transferred to the transfer paper;
A setting circuit for supplying power to the fixing device, and a control circuit for determining whether the optional device is installed,
The control circuit includes:
Determine whether the optional device is installed,
The power supplied to the fixing device is set to the first power when it is determined that the optional device is not installed, and from the first power when it is determined that the optional device is installed. Set to a low second power,
When it is determined that the optional device is not installed, the temperature of the fixing device when copying of a predetermined transfer paper is stopped is set to the first temperature, and when it is determined that the optional device is installed. And a second temperature higher than the first temperature.
[0008]
The image forming apparatus of the present invention can be equipped with a plurality of optional devices,
A fixing device for fixing the developer image transferred to the transfer paper;
A setting circuit for supplying power to the fixing device, and a control circuit for determining whether the optional device is installed,
The option devices include n-th (n is an integer of 2 or more) option devices as a combination according to the type and number, and the power consumption of each is n-1th option device <nth option. Equipment,
The control circuit includes:
Determine whether the optional device is installed,
If it is determined that the optional device is installed, determine which of the plurality of optional devices is,
The power supplied to the fixing device is set to the first power when it is determined that the optional device is not installed, and the nth power when it is determined that the nth optional device is installed. Set to a lower n + 1th power,
When it is determined that the optional device is not installed, the temperature of the fixing device when copying of a predetermined transfer paper is stopped is set to the first temperature, and it is determined that the nth optional device is installed. The time is set to the (n + 1) th temperature lower than the nth temperature.
[0009]
The power control method of the image forming apparatus to which the optional device of the present invention can be attached is
A fixing device that fixes the developer image transferred onto the transfer paper;
A setting circuit for supplying power to the fixing device, and a control circuit for determining whether the optional device is installed,
The control circuit determines whether the optional device is installed,
The power supplied to the fixing device is set to the first power when it is determined that the optional device is not installed, and from the first power when it is determined that the optional device is installed. Set to a low second power,
When it is determined that the optional device is not installed, the temperature of the fixing device when copying of a predetermined transfer paper is stopped is set to the first temperature, and when it is determined that the optional device is installed. And a second temperature higher than the first temperature.
[0010]
Alternatively, an image forming apparatus power control method capable of mounting a plurality of optional apparatuses according to the present invention includes:
A fixing device that fixes the developer image transferred onto the transfer paper;
A setting circuit for supplying power to the fixing device, and a control circuit for determining whether the optional device is installed,
The option devices include n-th (n is an integer of 2 or more) option devices as a combination according to the type and number, and the power consumption of each is n-1th option device <nth option. Equipment,
The control circuit determines whether the optional device is installed,
If it is determined that the optional device is installed, determine which of the plurality of optional devices is,
The power supplied to the fixing device is set to the first power when it is determined that the optional device is not installed, and the nth power when it is determined that the nth optional device is installed. Set to a lower n + 1th power,
When it is determined that the optional device is not installed, the temperature of the fixing device when copying of a predetermined transfer paper is stopped is set to the first temperature, and it is determined that the nth optional device is installed. The time is set to the (n + 1) th temperature lower than the nth temperature.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an image forming apparatus and a power control method thereof according to embodiments of the present invention will be described with reference to the drawings.
[0012]
FIG. 1 shows the configuration of an image forming apparatus according to an embodiment of the present invention.
[0013]
The image forming apparatus 11 includes a control circuit 12, a fixing device 16, and a motor 17 in a stand-alone state. Further, the image forming apparatus 11 includes, as elements necessary for performing image formation (not shown), a scanner, a photosensitive drum, a charging device disposed around the photosensitive drum, an exposure device, a developing device, a transfer device, and the like. It has.
[0014]
The scanner reads the document and generates an image signal, the charging device charges the surface of the photosensitive drum, and the exposure unit exposes the surface of the photosensitive drum according to the image signal to form an electrostatic latent image, and develops it. The developer supplies a developer containing toner to form a developer image on the photosensitive drum, and the transfer device transfers the developer image onto a transfer sheet.
[0015]
The fixing device 16 presses and heats the developer image transferred to the transfer paper to fix it, and includes a heat roller HR, a press roller PR, a heat roller HR, and a heat roller HR arranged to face the heat roller HR. The motor 17 that rotates the press roller PR and the heater HT such as a lamp that heats the heat roller HR and induction heating means are provided.
[0016]
The control circuit 12 controls the operation of each element included in the image forming apparatus 11, and includes a CPU (Central Processing Unit) 13, a ROM (Read Only Memory) 14, and an NVRAM (Non-Volatile RAM) 15. Have.
[0017]
An optional device 21 can be connected to the image forming apparatus 11.
[0018]
The optional device 21 includes, for example, a finisher that finishes printing sheets that have been printed in a desired number and order, an LCF that stores a large amount of specific transfer sheets and supplies them to the image forming apparatus 11, a cover sheet between the transfer sheets, and the like There are various types such as an inserter for inserting the same type, and a plurality of the same type may be connected.
[0019]
When the option device 21 is connected to the image forming apparatus 11, the CPU 13 recognizes how many types of option devices 21 are connected.
[0020]
Incidentally, as described above, there are various types of option devices 21 that can be mounted on the image forming apparatus 11, and there are many combinations. Some optional devices 21 have a high mounting rate and some have a low mounting rate, and the power consumption varies from one device to another.
[0021]
Therefore, the power consumption of the entire system after the optional device 21 is connected varies.
[0022]
If the power of the entire system is kept below the standard value after mounting the optional device 21 as in the prior art, the power consumption is the highest in the stand-alone state by the amount of power increased by the installed optional device 21. The power supplied to the large fixing device 16 is lowered.
[0023]
For example, in stand-alone mode, it is conceivable to supply power of 1000 W to the fixing device 16 and to control the power supplied to the fixing device 16 to 900 W when any of the optional devices 21 is installed.
[0024]
However, when such power control is performed, the power supplied to the fixing device 16 is insufficient, and the temperature drop during copying becomes steep, so that a fixing failure occurs or copying stops due to standby is likely to occur.
[0025]
Therefore, in the present embodiment, even when the optional device 21 is installed, the power shown in the flowchart of FIG. 2 is used so that stable fixing processing can be secured by avoiding as much as possible fixing failure and copy stoppage due to standby. Take control.
[0026]
First, the image forming apparatus 11 is turned on.
[0027]
As step S10, the CPU 13 determines whether or not the optional device 21 is installed. If the optional device 21 is not installed, the process proceeds to step S12. If the optional device 21 is installed, the process proceeds to step S14.
[0028]
In step S12, the power supplied to the fixing device 16 at the stand-alone time is set to 1000 W, for example, and the process proceeds to step S16.
[0029]
In step S14, the power supplied to the fixing device 16 when the optional device 21 is mounted is set to 900 W, for example, and the process proceeds to step S18.
[0030]
In step S16, as temperature control in the fixing device 16,
The fixing temperature when the copy operation of plain paper is stopped is 160 ° C,
Fixing temperature is 173 ° C when the copy operation of cardboard is stopped,
The motor 17 of the fixing device 16 in the ready state is turned on at 70 ° C., off at 100 ° C.,
The temperature of the fixing device 16 during the remaining heat is set to 70 ° C.
And
[0031]
On the other hand, in step S18, as temperature control in the fixing device 16,
When the plain paper copy operation is stopped, the fixing temperature is 163 ° C.
Fixing temperature is 177 ° C when copying of thick paper is stopped
The motor 17 of the fixing device 16 in the ready state is turned on at 85 ° C., off at 115 ° C.,
The temperature of the fixing device 16 during the residual heat is 155 ° C.
Furthermore, the copy speed was changed from 65 cpm to 55 cpm at 170 ° C.
And
[0032]
Here, when the optional device 21 is installed and the power supply to the fixing device 16 is changed to 900 W, the temperature setting is changed as in step S18 for the following reason.
[0033]
(1) When the optional device 21 is installed, the power supplied to the fixing device 16 decreases. For this reason, the fixing temperature drops rapidly, and the time to decrease to a temperature at which fixing becomes impossible becomes faster.
[0034]
That is, at the stand-alone time, the power supplied to the fixing device 16 is sufficiently high at 1000 W, so there is no problem in controlling the copying operation to be stopped at the lowest fixing temperature. However, if the power is reduced to 900 W, the power is insufficient in the fixing device 16, so that the temperature is further drastically decreased until the temperature is detected and the copy operation is stopped. For this reason, fixing failure may occur in the paper copied in the meantime.
[0035]
As a countermeasure, the fixing temperature (fixing temperature during standby) when stopping the copying operation when the optional device 21 is installed is changed to a higher temperature to secure the fixing rate. (For example, stand-alone: 160 ° C, with optional device installed: 163 ° C)
[0036]
(2) The above (1) relates to copying of plain paper. However, since the fixing temperature drops more rapidly with thick paper, the fixing temperature when stopping the copying operation is changed to be higher than with plain paper. (For example, 173 ° C when stand-alone, 177 ° C when an optional device is installed)
[0037]
(3) During the ready, the CPU 13 controls the temperature so that the fixing temperature of the fixing device 16 does not decrease too much. That is, the heat roller is heated by a heater provided therein. However, during the ready, the rotation of the heat roller is stopped. For this reason, only the contact surface with the heat roller is heated in the press roller that is disposed to face the heat roller and is not provided with a heater.
[0038]
When copying is started in this state and the heat roller and the press roller rotate, the heat of the heat roller is rapidly taken away by the surface of the press roller that is not in contact with the heat roller. For this reason, the problem described in the above (1) is likely to occur, or temperature unevenness may occur on the surfaces of the heat roller and the press roller, causing a fixing failure.
[0039]
As a countermeasure, when the temperature of the press roller (temperature on the surface not in contact with the heat roller) decreases during the ready, the motor 17 of the fixing device 16 is rotated at a low speed.
[0040]
Here, since the power supplied to the fixing device 16 is insufficient when the optional device 21 is installed as compared with the stand-alone case, the problem described in (1) is likely to occur. Therefore, it is necessary to make the phenomenon (1) difficult to occur by warming the temperature of the fixing device 16 as much as possible, that is, the temperature around the heat roller, the press roller, and the fixing device even during the ready.
[0041]
As a countermeasure, the temperature at which low-speed rotation of the motor 17 of the fixing device 16 during ready is started is increased when the optional device 21 is mounted, so that the temperature of the entire image forming apparatus 11 is increased.
[0042]
For example, in the stand-alone mode, the rotation of the motor 17 is turned on at 70 ° C. and turned off at 100 ° C., whereas when the optional device 21 is installed, the motor 17 is turned on at 85 ° C. and turned off at 115 ° C.
[0043]
The rotation of the motor 17 is not limited to a low speed but is not limited to the rotation speed.
[0044]
(4) The temperature of the fixing device 16 during preheating is also changed so as not to cause the problem described in (1) above.
[0045]
For example, the temperature of the fixing device 16 is controlled to be maintained at 70 ° C. at the time of stand-alone, whereas it is controlled to be maintained at 155 ° C. when the optional device 21 is mounted. When the temperature in each preheat is exceeded, the preheat is stopped and the temperature is controlled to be maintained.
[0046]
(5) When the optional device 21 is installed, the problem described in (1) is likely to occur. Therefore, when the temperature of the fixing device 16 is lowered to a certain temperature, control is performed so as to reduce the copying speed and suppress the lowering of the fixing temperature.
[0047]
For example, such control is not performed in the stand-alone mode, and when the fixing device temperature is lowered to 170 ° C. when the optional device 21 is mounted, the copy speed up to that point is changed from 65 cpm to 55 cpm.
[0048]
As described above, the change in the fixing temperature setting has been described for the stand-alone mode and when the optional device 21 is mounted. However, more detailed control may be performed according to the type and number of the optional devices 21.
[0049]
That is, when the optional device 21 is mounted, there are finishers, LCFs, inserters, and the like, and the number of the devices to be mounted is different, and various forms are possible.
[0050]
Therefore, n (n is an integer greater than or equal to 2) types, such as mounting one optional device, mounting two optional devices of the same type, mounting two optional devices one by one, etc. (Optional device (1), optional device (2), optional device (3),... Optional device (n)).
[0051]
Here, the power consumption is as follows: Stand-alone <Option device (1) installed <Option device (2) installed <Option device (3) installed <, ..., <Option device (n) installed To do.
[0052]
That is, when the optional device (1) is mounted, the optional device (2) is mounted, the optional device (3) is mounted, and so on, the power supplied to the fixing device 16 decreases, and fixing failure is likely to occur. Thus, when the optional device (n) is installed, the power is lowest and a fixing failure is likely to occur.
[0053]
The control procedure in this case is as shown in FIG. 3, for example.
[0054]
In step S100, it is determined whether or not the optional device is installed. If the optional device is not installed, the process proceeds to step S200.
[0055]
In step S200, the set power of the fixing device at the stand-alone time is set to X (W).
[0056]
In step S300, the fixing device temperature is set as follows.
The fixing temperature when the copy operation of plain paper is stopped is A ° C.
The fixing temperature when the thick paper copy operation is stopped is B ° C.
Regarding the on / off control of the motor 17 of the fixing device 16 during the ready, it is controlled so as to be on at C ° C. and off at D ° C.
The temperature of the fixing device 16 during the remaining heat is E ° C.
And
[0057]
If it is determined in step S100 that the optional device is installed, the process proceeds to step S101, and it is determined whether the optional device is (1). If it is the optional device (1), the process proceeds to step S201.
[0058]
In step S201, the setting power of the fixing device when the optional device (1) is mounted is (X−x1) W.
[0059]
In step S301, the fixing device temperature is set.
The fixing temperature when the copying operation of plain paper is stopped is (A + a1) ° C.
The fixing temperature when the copying operation of thick paper is stopped is (B + b1) ° C.
The on / off control of the motor 17 of the fixing device 16 during the ready is controlled so as to be turned on at (C + c1) ° C. and turned off at (D + d1) ° C.
The temperature of the fixing device 16 during the remaining heat is (E + e1) ° C.
Change the copy speed from Gcpm to (G-g1) cpm at F ° C.
And
[0060]
If it is not the optional device (1) in step S101, the process proceeds to step S102, and it is determined whether it is the optional device (2). If it is the optional device (2), the process proceeds to step S202.
[0061]
In step S202, the set power of the fixing device when the optional device (2) is mounted is (X−x2) W.
[0062]
In step S302, the temperature setting of the fixing device is
The fixing temperature when the copy operation of plain paper is stopped is (A + a2) ° C.
The fixing temperature when the thick paper copy operation is stopped is (B + b2) ° C.
Regarding the on / off control of the motor 17 of the fixing device 16 during the ready, control is performed so that it is on at (C + c2) ° C. and off at (D + d2) ° C.
The temperature of the fixing device 16 during the remaining heat is (E + e2) ° C.
The copy speed was changed from Gcpm to (G-g2) cpm at F ° C.
And
……
[0063]
In step S10 (n-1) not shown, it is determined whether or not the device is an optional device (n-1). If it is not an optional device (n-1), the process proceeds to step S10n and whether or not it is an optional device (n). Judging. If it is an optional device (n), the process proceeds to step S20n.
[0064]
In step S20n, the set power of the fixing device when the optional device (n) is mounted is (X-xn) W.
[0065]
In step S30n, the temperature setting of the fixing device is
The fixing temperature when the copy operation of plain paper is stopped is (A + an) ° C.
The fixing temperature when the copying operation of thick paper is stopped is (B + bn) ° C.
Regarding on / off control of the motor 17 of the fixing device 16 during the ready, control is performed so as to be turned on at (C + cn) ° C. and turned off at (D + dn) ° C.
The temperature of the fixing device 16 during the remaining heat is (E + en) ° C.
The copy speed was changed from Gcpm to (G-gn) cpm at F ° C.
And
[0066]
Where a1 <a2 <... <an,
b1 <b2 <... <bn,
c1 <c2 <... <cn,
d1 <d2 <... <dn,
e1 <e2 <... <en,
g1 <g2 <... <gn,
And
[0067]
The above-described embodiment is merely an example, and does not limit the present invention. Various modifications can be made without departing from the technical scope of the present invention. For example, the type and number of optional devices are not limited.
[0068]
【The invention's effect】
As described above, the image forming apparatus and the power control method thereof according to the present invention can prevent a fixing failure even when an optional device is added, and can realize a stable fixing process.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of an image forming apparatus according to an embodiment of the present invention.
FIG. 2 is a flowchart showing a procedure of a power control method in the image forming apparatus.
FIG. 3 is a flowchart showing a procedure of another power control method in the image forming apparatus.
[Explanation of symbols]
11 Image forming apparatus 12 Control circuit 13 CPU
14 ROM
15 NVRAM
16 Fixing device 17 Motor 21 Optional device HR Heat roller PR Press roller

Claims (4)

In an image forming apparatus in which an optional device can be attached,
A fixing device for fixing the developer image transferred to the transfer paper;
A setting circuit for supplying power to the fixing device, and a control circuit for determining whether the optional device is installed,
The control circuit includes:
Determine whether the optional device is installed,
The power supplied to the fixing device is set to the first power when it is determined that the optional device is not installed, and from the first power when it is determined that the optional device is installed. Set to a low second power,
When it is determined that the optional device is not installed, the temperature of the fixing device when copying of a predetermined transfer paper is stopped is set to the first temperature, and when it is determined that the optional device is installed. The image forming apparatus is set to a second temperature higher than the first temperature. In an image forming apparatus capable of mounting a plurality of optional devices,
A fixing device for fixing the developer image transferred to the transfer paper;
A setting circuit for supplying power to the fixing device, and a control circuit for determining whether the optional device is installed,
The option devices include n-th (n is an integer of 2 or more) option devices as a combination according to the type and number, and the power consumption of each is n-1th option device <nth option. Equipment,
The control circuit includes:
Determine whether the optional device is installed,
If it is determined that the optional device is installed, determine which of the plurality of optional devices is,
The power supplied to the fixing device is set to the first power when it is determined that the optional device is not installed, and the nth power when it is determined that the nth optional device is installed. Set to a lower n + 1th power,
When it is determined that the optional device is not installed, the temperature of the fixing device when copying of a predetermined transfer paper is stopped is set to the first temperature, and it is determined that the nth optional device is installed. The image forming apparatus is characterized in that the temperature is set to an (n + 1) th temperature lower than the nth temperature. In the power control method of the image forming apparatus in which the optional device can be mounted,
The image forming apparatus includes a fixing device that fixes the developer image transferred to the transfer paper;
A setting circuit for supplying power to the fixing device, and a control circuit for determining whether the optional device is installed,
The control circuit determines whether the optional device is installed,
The power supplied to the fixing device is set to the first power when it is determined that the optional device is not installed, and from the first power when it is determined that the optional device is installed. Set to a low second power,
When it is determined that the optional device is not installed, the temperature of the fixing device when copying of a predetermined transfer paper is stopped is set to the first temperature, and when it is determined that the optional device is installed. A power control method for an image forming apparatus, wherein the second temperature is set higher than the first temperature. In an image forming apparatus power control method capable of mounting a plurality of optional devices,
The image forming apparatus includes a fixing device that fixes the developer image transferred to the transfer paper;
A setting circuit for supplying power to the fixing device, and a control circuit for determining whether the optional device is installed,
The option devices include n-th (n is an integer of 2 or more) option devices as a combination according to the type and number, and the power consumption of each is n-1th option device <nth option. Equipment,
The control circuit determines whether the optional device is installed,
If it is determined that the optional device is installed, determine which of the plurality of optional devices is,
The power supplied to the fixing device is set to the first power when it is determined that the optional device is not installed, and the nth power when it is determined that the nth optional device is installed. Set to a lower n + 1th power,
When it is determined that the optional device is not installed, the temperature of the fixing device when copying of a predetermined transfer paper is stopped is set to the first temperature, and it is determined that the nth optional device is installed. And a power control method for an image forming apparatus, wherein the temperature is set to an (n + 1) th temperature lower than an nth temperature.

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