JP3868367B2 - Fixing device control apparatus and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for a fixing device used in an image forming apparatus such as a printer, a copying machine, and a facsimile, and an image forming apparatus including the control device, and more particularly, to reduce power consumption and return from a standby state. The present invention relates to a fixing device control device that can substantially achieve smoothing and an image forming apparatus including the control device.
[0002]
[Prior art]
Conventionally, the temperature of the heat roller during printing is different from the temperature of the heat roller during standby waiting for the print button to be pressed or waiting for a print command. For example, Patent Document 1 discloses a fixing device temperature control device that suppresses power consumption during standby by controlling the heat roller to a temperature lower than the fixing temperature at the time.
[0003]
[Patent Document 1]
Japanese Examined Patent Publication No. 7-40161 [0004]
[Problems to be solved by the invention]
The conventional techniques described above have the following problems.
That is, when the ambient temperature is low as in winter, there is a problem that wasteful power is consumed to compensate for this and maintain the temperature of the heat roller at a predetermined standby temperature.
In order to solve this problem, if the heat roller temperature during standby is set to a low value, it takes a very long time to raise the temperature to a predetermined printing temperature.
The present invention aims to solve the above-mentioned problems.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides:
A fixing device comprising a heater, a heat roller heated by the heater, and a temperature sensor for detecting the temperature of the heat roller; and a temperature suitable for printing based on a detection signal of the temperature sensor. In a fixing device control device comprising a first control means for controlling to a temperature of 1,
First standby mode control means for maintaining the output power to the heater at a constant power during standby ;
Second standby mode control means for controlling the heat roller to a predetermined second temperature lower than the first temperature during standby;
Control switching means for switching between control by the first standby mode control means and control by the second standby mode control means in accordance with the temperature of the heat roller detected by the temperature sensor;
It is comprised as a control apparatus of the fixing device characterized by comprising.
Since the is the supply power in the standby mode can be controlled to be constant, it is possible to efficiently can set the power consumption barely had regulations boss is a good temperature control, especially as winter Even when the ambient temperature is low, there is no loss due to wasteful heating of the heat roller during the standby time, which is economical .
Further, since the control switching means is provided, it is possible to perform appropriate fixing device control in accordance with the temperature when the ambient temperature is greatly different in summer and winter. For example, in winter when the ambient temperature is low, if the second standby mode control with constant temperature is performed, the power consumption during standby time becomes enormous, so the first standby mode control with constant power is automatically adopted. In summer, when the ambient temperature is high, the second standby mode control with a constant temperature is automatically adopted to reduce both power consumption and the return time to the temperature required for printing. By achieving this, it will be possible to achieve power savings throughout the year .
In addition, when the temperature sensor detects a predetermined temperature higher than the first temperature during the control by the first standby mode control means, it further comprises power supply stop means for forcibly stopping the supply power. In this case, the power supply can be stopped before the heater reaches a dangerous temperature, and a safe fixing device can be provided.
As a method of power control by the first standby mode control means, duty ratio control by repeating ON / OFF of supplied power periodically is simple.
In this case, it can be easily achieved by adopting a method of synchronizing the ON / OFF timing of the supplied power with the zero cross in an appropriate waveform.
Any of the above fixing device control devices is suitable for use in an image forming apparatus.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Subsequently, an embodiment in which the present invention is embodied will be described for understanding of the present invention.
Here hardware block diagram of a control device of a fixing device according to the embodiment of Figure 1 the present invention, FIGS. 2-3 is a flowchart showing the control procedure of the fixing apparatus in the control device, FIG. 4, the fixing device FIG. 2 is a conceptual diagram of a full-color copying machine as an example of an image forming apparatus to which the control device can be applied.
First, a full-color copying machine as an example of an image forming apparatus including the above-described fixing device (fixing device) control device will be described.
The image forming apparatus X includes a conveyance belt 1 stretched between a pair of rollers, and the recording paper 2 is configured to be conveyed on the conveyance belt 1 in a direction indicated by an arrow in the drawing. In addition, a monochrome (black) image forming area B, a cyan image forming area C, a magenta image forming area M, and a yellow image forming area Y are provided on the transport belt 1 in order from the right. A photosensitive drum 5 is disposed on each of the two, and a transfer roller 6 is disposed on the lower side of the conveying belt 1 so as to face the respective photosensitive drums. (The arrangement order of the image forming regions B, C, M, and Y is not particularly limited, and this arrangement can be changed as appropriate.)
[0007]
In each of the image forming areas, a main charger 7, an optical system 8 for image exposure, and a developing unit for toner of a color corresponding to each image forming area are arranged in this order around the photosensitive drum 5. Has been. That is, in the monochrome image forming area B, the monochrome developing unit 9B filled with black toner, in the cyan image forming area C, the cyan developing unit 9C filled with cyan toner, and in the magenta image forming area M, filled with magenta toner. In the magenta developing unit 9M and the yellow image forming area Y, a yellow developing unit 9Y filled with yellow toner is provided. Further, between the area where the transfer roller 6 is provided and the main charger 7, a static eliminator (not shown) and a cleaning device 10 are arranged.
The image forming apparatus X includes devices included in a general quadruple tandem image forming apparatus other than that shown in FIG. 1, but the description thereof is omitted here because it is not particularly characteristic. .
[0008]
The image forming cycle in each of the image forming areas will be described by taking the monochrome image forming area B as an example.
First, the photosensitive drum 5 is uniformly charged to a predetermined polarity by the main charger 7 including a corona charger or a contact charging roller. Next, image exposure is performed by light irradiation from an optical system 8 such as an LED, and an electrostatic latent image is formed on the surface of the photosensitive drum 5. This electrostatic latent image is developed by toner transfer by the monochrome developing device 9B filled with black toner, and a toner image is formed on the surface of the photosensitive drum 5. The charging polarity of the toner image is the same as the charging polarity of the photosensitive drum 5 charged by the main charger 7 when developing by so-called reversal development, and when developing by so-called regular development. , The polarity is opposite to the charging polarity of the photosensitive drum 5.
The toner image formed on the surface of the photosensitive drum 5 in this manner is transferred onto the transfer paper 2 that has been transported on the transport belt 1 in a region facing the transfer roller 6 (transfer region). This transfer is performed by applying a bias voltage having a polarity opposite to that of the toner image to the transfer roller 6. Further, instead of using the transfer roller 6, it is possible to transfer by using a corona charger and charging the back surface of the transfer paper 2 with a polarity opposite to that of the toner image. After the transfer is completed, the static eliminator and the cleaning device 10 (not shown) remove the static electricity on the photosensitive drum 5 and clean the toner remaining on the surface of the drum 5 to perform the next image forming cycle.
[0009]
As described above, in the monochrome image forming area B, a monochrome image made of black toner is formed on the transfer paper 2, and in the same manner, in the cyan image forming area C, cyan made of cyan toner is formed. In the color image and magenta image forming area M, a magenta color image made of magenta toner and a yellow image made of yellow toner are formed in the yellow image forming area Y. That is, when a monochrome image is formed, the above-described image formation cycle is executed only in the monochrome image formation region B, and a monochrome image is formed on the transfer paper 2. When a full-color image is formed, the above-described image forming cycle is executed in each of the image forming regions B, C, M, and Y, and the single color toner images of the respective colors are superimposed to form a full color on the transfer paper 2. An image is formed. The transfer paper 2 on which the image is formed in this manner is discharged from the transport belt 1 and introduced into a fixing device (fixing device) 11 where the image is fixed and discharged.
The control device of the fixing device 11 according to the present invention can be used for the heat roller control of the fixing device 11.
[0010]
Next, the control device 17 of the fixing device 11 will be described with reference to FIG.
As shown in FIG. 1, the controller 17 of the fixing device 11 used in the image forming apparatus includes a heater 13 that heats the heat roller 12 and a temperature sensor 14 that detects the ambient temperature around the heat roller 12. is doing. The power to the heater 13 is transmitted to the heater 13 through a control unit 15 that controls power from the power source 16. The control unit 15 also controls an image forming process of the image forming apparatus itself described later.
[0011]
Next, the processing procedure by the control unit 15 will be described with reference to the flowchart in FIG.
FIG. 2 is a main routine of the control device 17. Here, S1, S2,... Are processing procedure (step) numbers.
As shown in FIG. 2, when the power is turned on, the control unit 15 determines whether or not the current standby mode is set (S1). The standby mode is set when a predetermined time has elapsed without the print button instructing execution of the image processing being pressed, and the output power from the control unit 15 to the heater 13 is suppressed to be lower than that during the printing process. This mode suppresses power consumption when not in use. Accordingly, the setting to the standby mode is determined by whether or not a predetermined time has passed without the print button being pressed.
If it is determined in S1 that the current mode is the standby mode, the standby mode process shown in FIG. 3 is executed (S2). Details of the process will be described later .
If it is determined that the standby mode is not set in S1, it is determined in S3 whether or not the print button has been pressed, that is, whether or not an image forming process has been instructed. If the print button has not been pressed (NO in S3), the process returns to S1.
If it is determined in S3 that the print button has been pressed, the printing process is executed until the set number of sheets is printed (S4, S5). When the set number of sheets is printed, the process returns to S1.
By repeating the processes of S1 to S5, the printing process and the standby mode when the printing process is not performed are repeated, so that the power consumption is reduced and the quick return to the printing state is achieved.
[0012]
Next, the standby mode 1 shown in FIG. 3 will be described as an example of the standby mode indicated by S2 in FIG.
In the standby mode 1 according to this embodiment, a first standby mode (executed by the first standby mode control means) that keeps the output power to the heater at a constant power lower than the output power at the time of printing during standby. is performed by a second standby mode (second standby mode control means for controlling to maintain at the heat roller 12 from the lower have a predetermined constant temperature the first temperature is a set temperature during printing in the standby ) In accordance with the temperature of the heat roller 12 detected by the temperature sensor 14 (control switching means).
That is, when the standby mode is entered, it is determined whether or not the temperature detected by the temperature sensor 14 (configured by a thermistor or the like) is higher than a predetermined temperature T1 (S10). The predetermined temperature is a temperature at which the atmosphere is judged to be quite hot. When the temperature detected by the temperature sensor 14 is higher than the predetermined temperature T1 , a second standby mode is set in which the heat roller 12 is maintained at a predetermined constant temperature lower than the first temperature, which is a set temperature during printing. It is (S11).
On the other hand, when the temperature detected by the temperature sensor 14 is lower than the predetermined temperature T1, the first standby mode is maintained in which the output power to the heater is kept at a constant power lower than the output power at the time of printing ( S12).
In such a standby mode 1, the ambient temperature around the heating preparative roller 1 2, a first standby mode power constant, second standby mode temperature constant is switched. For example, in winter when the ambient temperature is low, if the second standby mode control with a constant temperature is performed, the power consumption during the standby time becomes enormous, so the first standby mode control with a constant power is automatically performed. In the summertime when the ambient temperature is high, the second standby mode control with a constant temperature is automatically adopted to save power consumption and shorten the return time to the temperature required for printing. By making it possible to achieve both, power savings can be achieved throughout the year.
The power control in the first standby mode can be realized by duty ratio control by periodically turning ON / OFF the supplied power . In this case, the ON / OFF timing of the supplied power can be used as an example of control that periodically repeats ON / OFF of the power by synchronizing with the zero cross of an appropriate waveform.
[001 3 ]
【The invention's effect】
As is apparent from the above description, according to the present invention, when the ambient temperature is greatly different, such as in summer and winter, it is possible to appropriately control the fixing device according to the temperature. For example, in winter when the ambient temperature is low, if the second standby mode control with constant temperature is performed, the power consumption during standby time becomes enormous, so the first standby mode control with constant power is automatically adopted. In summer, when the ambient temperature is high, the second standby mode control with a constant temperature is automatically adopted to reduce both power consumption and the return time to the temperature required for printing. By achieving this, it will be possible to achieve power savings throughout the year.
[Brief description of the drawings]
FIG. 1 is a hardware block diagram of a control device of a fixing device according to an embodiment of the present invention.
FIG. 2 is a flowchart showing a main routine of a control device of the fixing device.
FIG. 3 is a flowchart showing a processing procedure in standby mode 1 of the control device of the fixing device.
FIG. 4 is a conceptual diagram of a full-color copying machine as an example of an image forming apparatus to which the present invention can be applied.
[Explanation of symbols]
11 Fixing device (fixing device)
12 Heat roller 13 Heater 14 Temperature sensor 15 Control unit 16 Power source 17 Control device

Claims (5)

A fixing device comprising a heater, a heat roller heated by the heater, and a temperature sensor for detecting the temperature of the heat roller; and a temperature suitable for printing based on a detection signal of the temperature sensor. In a fixing device control device comprising a first control means for controlling to a temperature of 1,
First standby mode control means for maintaining the output power to the heater at a constant power during standby ;
Second standby mode control means for controlling the heat roller to a predetermined second temperature lower than the first temperature during standby;
Control switching means for switching between control by the first standby mode control means and control by the second standby mode control means in accordance with the temperature of the heat roller detected by the temperature sensor;
And a fixing device control device. The power supply stop means for forcibly stopping the supply power when the temperature sensor detects a predetermined temperature higher than the first temperature during the control by the first standby mode control means. Item 4. The fixing device control device according to Item 1 . 3. The fixing device control device according to claim 1, wherein the power control by the first standby mode control means is performed by periodically repeating ON / OFF of the supplied power. 4. 4. The fixing device control device according to claim 1, wherein power control is performed by the first standby mode control unit by synchronizing ON / OFF timing of supplied power with zero crossing. 5. Image forming apparatus having a control device of the fixing device according to any one of claims 1-4.

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