JP4133588B2 - Fixing device, image forming device, heater temperature control program - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fixing device that heats and fixes with a predetermined heater, and in particular, when the operation of the fixing device starts, the time until the temperature of the heater of the fixing device reaches a predetermined target temperature is shortened. It is what.
[0002]
[Prior art]
First, in a fixing device provided in an image forming apparatus configured as a copying machine, a printer, a facsimile, or a complex machine thereof, a process for raising the temperature of a heater to a predetermined target temperature (hereinafter referred to as Ready temperature) (hereinafter referred to as warm-up). Will be described with reference to the flowchart of FIG. Such processing is performed when the power is turned on by a control unit that performs full control of the image forming apparatus. Note that reference numerals S1, S2,... In FIG. In this process, the Ready temperature is set to 125 degrees.
S1: First, when the power of the image forming apparatus is turned on by a user, the CPU work area stored as backup data in the nonvolatile memory of the image forming apparatus, fixed data such as control parameters, and maintenance Read fluctuation data such as the number of prints used. Until the reading of the backup data is completed, the process of step S1 is performed. When the reading of the backup data is completed, the process proceeds to step S2.
S2: It is confirmed whether communication is synchronized between the image reading unit of the image forming apparatus and the control unit. Until the confirmation of communication synchronization is completed, the process of step S2 is performed. When the confirmation of communication synchronization is completed, the process proceeds to step S3.
S3: A process for confirming whether an error has occurred in the devices constituting the image forming apparatus is performed. The process of step S3 is performed until the error confirmation process in the devices constituting the image forming apparatus is completed. When the error confirmation process is completed, the process proceeds to step S4.
S4: Upon completion of steps S1 to S3, the ready temperature of the heater (125 degrees in the present process) is determined, and for the first time, temperature rise processing for the heater with the ready temperature as the target temperature is started. The
S5: It is confirmed whether an error has occurred in the fixing device during the temperature rise process. If an error has occurred in the fixing device, the process proceeds to step S7, and if not, the process proceeds to step S6.
S6: As a result of detection by the sensor, if the temperature of the heater has reached the Ready temperature (125 degrees), the process proceeds to step S7. If not, the process returns to step S5.
S7: If an error occurs in the fixing device in step S5, or if the temperature of the heater has reached 125 degrees in step S6, the temperature rise process of the heater is stopped.
Note that a series of processing from step S1 to step S7 is performed with respect to the image forming apparatus in a power saving mode (for the purpose of power saving, when the image forming apparatus is not operated within a predetermined time, the ready temperature is maintained. It may also be used for processing that is performed when the heater is turned off and then restarted.
Although not shown, an error occurs during the execution of the above steps S1 to S3 (data initialization associated with the occurrence of abnormality in backup data and communication synchronization between the image reading unit and the control unit cannot be established). If the error occurs, the process for increasing the temperature of the heater is of course stopped. In addition, regarding the stop of the processing to raise the temperature of the heater when the cover etc. of the part where the fixing device is accommodated is open, a safety device etc. has been installed as a safety measure on the hardware side. Is well known.
[0003]
As described above, conventionally, the backup data reading process relating to the image forming apparatus stored in the non-volatile memory, the image processing, and the image processing apparatus until the process of increasing the temperature of the heater is started after the image forming apparatus is turned on. A communication synchronization process between the reading unit and the control unit and an error confirmation process in the devices constituting the image forming apparatus are performed by the control unit. The above-mentioned data relating to the image forming apparatus (fixed data such as the CPU work area, control parameters, etc., and fluctuation data such as the number of printed sheets used during maintenance) can be accessed quickly and in a volatile memory. It is temporarily held in a certain RAM (Random Access Memory). The data stored in the RAM is stored in the nonvolatile memory as backup data so as not to be erased. For example, as described in Patent Document 1, the non-volatile memory is electrically such as an EEPROM (Electrically Erasable Programmable Read-Only Memory) that has excellent noise resistance and does not require a battery when data is stored. A ROM that can be erased and written is used.
[0004]
[Patent Document 1]
JP-A-5-249769
[Problems to be solved by the invention]
In recent years, it has been required to shorten the time required for warm-up processing (hereinafter referred to as warm-up time) in an image forming apparatus. However, in the above-described conventional technology, about 2 seconds are required for backup data reading processing, and communication synchronization is performed. It has already been found that the confirmation process takes about 1 second and the machine error confirmation process takes about 1 second. With the above-mentioned conventional technology, the heater is driven after such a waiting time, so it is limited to shortening the warm-up time. was there.
Further, since the EPPROM in which the backup data is stored has a lower data access speed than the RAM, for example, when the data size of the backup data stored in the EPPROM is large, it takes more time to read the backup data. There's a problem. In addition, as described above, the Ready temperature is determined as a result of the process from when the power of the image forming apparatus is turned on by the user until the temperature of the heater starts to rise. When a retry occurs, there may be a problem that the warm-up time takes a long time.
Accordingly, the present invention has been made in view of the above circumstances, and the object of the present invention is to start the temperature rise of the heater simultaneously with the start of operation of the fixing device, and the temperature rise process in the heater is performed. During the process, the backup data reading process, the communication synchronization process between the image reading unit and the control unit, and the error checking process for the devices constituting the image forming apparatus are performed. The object is to shorten the warm-up time by providing a device for adjusting the temperature to the Ready temperature determined from the above three processes.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a fixing device in which a heater is driven and controlled to reach a target temperature, and the developer adhered to the sheet is heated and fixed on the sheet by the heater. if but the temperature of the heater when it is started has not reached the preset predetermined temperature, so that the temperature of the heater is increased by applying a current to the heater without a targeted temperature The first temperature control means for driving and controlling the heater, and the target temperature or the parameters related to the heater driving for obtaining the target temperature are read out from the nonvolatile memory during the control by the first temperature control means. and the target temperature and the like check means for checking Te, by the target temperature and the like check means, after the target temperature or the parameter has been confirmed, the target temperature or the para which is the confirmation Composed of a fixing device, characterized by comprising and a second temperature control means for controlling the temperature of the heater based on the over data.
For this reason, at the same time when the operation of the fixing device is started, the first temperature control means starts the process of increasing the temperature of the heater, so that the temperature of the heater is checked by the target temperature confirmation means. At the same time as the process up to the start of the ascent process (backup data reading process, synchronization confirmation process of communication between the image reading unit and the control unit, error checking process for the devices constituting the image forming apparatus) The process of increasing the temperature of the vessel is performed in parallel. Thereafter, the temperature of the heater is finally adjusted to the Ready temperature by the second temperature control means, so that the warm-up time can be shortened.
[0007]
In the above case, it is desirable to provide information writing means for writing the target temperature or the parameter to the nonvolatile memory . Further, it is determined whether or not to stop the heater based on information on the operation of the heater stored in the nonvolatile memory , or whether or not the temperature of the heater has risen within a predetermined heating time. It is even better if the fixing device determines whether or not to stop the heater.
[0008]
Further, the fixing device described above may be a means for a fixing process in the image forming apparatus.
[0009]
The present invention is a program for controlling the fixing device for controlling the driving of the heater so as to reach the target temperature, and for heating and fixing the developer attached to the sheet to the sheet by the heater. if but the temperature of the heater when it is started has not reached the preset predetermined temperature, so that the temperature of the heater is increased by applying a current to the heater without a targeted temperature The first temperature control means for driving and controlling the heater, and the target temperature or the parameters related to the heater driving for obtaining the target temperature are read out from the nonvolatile memory during the control by the first temperature control means. and the target temperature and the like check means for checking Te, by the target temperature and the like check means, after the target temperature or the parameter has been confirmed, the target temperature or the para which is the confirmation It can also be regarded as a heater temperature control program for realizing the function of controlling the second temperature control means for controlling the temperature of the heater based on the over data.
[0010]
In the above case, a heater temperature control program for realizing a function of determining whether or not to stop the heater based on information on the operation of the heater stored in the nonvolatile memory. It is desirable to be. Furthermore, any heater temperature control program for realizing a function of determining whether or not to stop the heater depending on whether or not the temperature of the heater has risen within a predetermined heating time may be used.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings so that the present invention can be understood. The following embodiment is an example embodying the present invention, and does not limit the technical scope of the present invention. FIG. 1 is a schematic cross-sectional view of an image forming apparatus A according to an embodiment of the present invention (hereinafter referred to as an embodiment), and FIG. 2 is a function representing a schematic configuration of the image forming apparatus A according to the embodiment. FIG. 3 is a flowchart showing the warm-up process of the image forming apparatus A according to the prior art, and FIG. 4 is a flowchart showing the warm-up process in the image forming apparatus A according to the embodiment.
[0012]
First, the overall configuration of the image forming apparatus A according to the embodiment of the present invention will be described with reference to FIG.
The image forming apparatus A is a multifunction machine having a copying function and a printer function. The image forming apparatus A includes a sheet feeding unit for mounting a plurality of cassettes 31 below, a duplex unit 32 disposed above the sheet feeding unit, and an image forming unit 33 and a fixing device X disposed above the sheet unit. Further, a scanner 35 for reading an image and an automatic document feeder (hereinafter referred to as ADF) 36 are attached to the upper part. Further, a display operation unit 3 such as a liquid crystal touch panel is disposed on the upper surface of the main body of the image forming apparatus A, and the user can select one of the image quality mode and the plurality of cassettes 31 by operating the display operation unit 3. Various operations such as selection of use or start operation of image reading are performed. The image forming unit 33 is provided with an image forming unit 44 in which a charging device 41, a developing device 42, and a cleaning device 43 are disposed around the photosensitive drum 40. A transfer device 45 is arranged. The photosensitive drum 40 has a photosensitive layer formed on the surface of an aluminum cylinder having a diameter of 84 mm, for example, and is driven to rotate clockwise in FIG. The charging device 41 charges the surface of the rotating photosensitive drum 40 to several hundred volts by corona discharge. On the downstream side of the charging device 41 on the surface of the photosensitive drum 40 in the rotation direction, an exposure device 50 including an LED array head and a Selfoc lens is exposed to form an electrostatic latent image. Image data used for controlling the light emission output of the exposure apparatus 50 is input from the image processing unit 30.
That is, the original image light guided by the mirror from the scanner 35 is incident on a CCD (Charge-Coupled Device) 37, where it is A / D converted to digital image data (original Image data) is input to the image processing unit 30. Further, the document image data is subjected to predetermined image processing in the image processing unit 30, and the image data after image processing is input to the exposure device control unit 60, and the image processing unit 60 performs image processing after the image processing. The exposure apparatus 50 is controlled so that exposure according to the data is performed.
[0013]
In the developing device 42, the developing roller rotates so that the magnetic brush formed on the surface of the developing roller comes into contact with the surface of the photosensitive drum 40, and a charged toner is attached to the electrostatic latent image to form a toner image. The toner image is conveyed in the transfer device 45 in a state where the transfer paper conveyed from any of the cassettes 31 is sandwiched between the photosensitive drum 40 and the transfer belt 46 moving at the same speed as the peripheral speed. While being charged, the toner image is transferred onto the transfer paper. Further, a cleaning device 43 is disposed on the downstream side of the transfer device 45, and toner and other deposits remaining on the surface of the photosensitive drum 40 are removed. The transfer device 45 of the image forming apparatus A employs a transfer belt, but it can be replaced by a transfer roller.
The transfer paper onto which the toner image has been transferred by the transfer device 45 is conveyed to a fixing device X provided on the downstream side in the conveying direction, and passes between the fixing roller 1 of the fixing device X and the pressure roller 2 facing the fixing device X. As described above, the toner on the transfer paper is melted and fixed by the heat of the fixing roller 1 provided with a heater inside.
In the present invention, at the same time as the power of the image forming apparatus A is turned on, a process for increasing the temperature of the heater is started by the control unit. Finally, the process performed by the control unit (reading process of backup data) The temperature of the heater is adjusted to the ready temperature determined based on the results of the communication synchronization confirmation processing between the image reading unit and the control unit and the error confirmation processing for the devices constituting the image forming apparatus.
The pressure roller 2 presses the transfer paper against the fixing roller 1 to ensure toner fixing. The transfer paper on which the toner image is fixed by the fixing device X is sent to the transfer paper processing device B side.
[0014]
Next, the configuration of the main part relating to the driving of the fixing device X of the image forming apparatus A according to this embodiment will be described with reference to FIG.
The entire image forming apparatus A is controlled by a control unit 70 including a CPU 71, a program ROM 72, a data storage ROM (EPPROM) 73, a RAM 74, and the like. The control unit 70 performs various controls and arithmetic processes when a predetermined program stored in the program ROM 72 is executed by the CPU 71. In the present invention, a heater temperature control program is listed as a program stored in the program ROM 72 and executed by the CPU. Further, data relating to the image forming apparatus A (fixed data such as the work area of the CPU 71 and control parameters, and variation data such as the number of printed sheets used during maintenance) are temporarily held in the RAM 74 which is a volatile memory. Thereafter, the data is stored as backup data in a data storage ROM (EPPROM) 73 which is a nonvolatile memory.
Further, the control unit 70, a heater of the fixing device X, a main body driving unit 75 for driving the fixing roller 1, the pressure roller 2, and the like, a sensor for detecting the temperature of the heater, and an image reading unit 77 Image processing unit for performing image processing on a print job received from an external device such as a main body sensor unit 76 for detecting opening and closing of the cover, the scanner 35, the ADF 36, the CCD 37, and a personal computer, and an image read by the scanner 35 The image reading unit 77 composed of 30 and the communication unit 78 that controls communication with the external device are connected by a bus.
[0015]
Next, the warm-up process performed by the control unit 70 in the image forming apparatus A according to the present embodiment will be described with reference to the flowchart of FIG. Further, reference numerals S20, S21,... In FIG. In this embodiment, the Ready temperature is set to 125 degrees.
S20: First, when the operation of the image forming apparatus A is started by the user, the temperature of the heater is detected by the main body sensor unit 76. As a result, when the temperature of the heater has already reached a predetermined temperature that is not much different from the Ready temperature (110 degrees in this embodiment), the process of starting the temperature rise of the heater is performed. First, the process proceeds to step S22 in order to directly adjust the temperature of the heater to the ready temperature determined in steps S22 to S24 described later. If it has not reached 110 degrees, the process proceeds to step S21.
The predetermined temperature may be set artificially in advance or may be set by a program executed by the CPU 71.
S21: The temperature increase process for the heater is started. At this time, the heater may be driven toward an appropriate temporary target temperature, or a process of simply passing a current without setting the target temperature may be used. Here, this step S21 is the first temperature control means in the present invention.
S22: The control unit 70 performs the backup data reading process similar to step S1 in the prior art. If processing is completed, it will progress to Step S23.
Note that a non-volatile memory such as an EPPROM included in the image forming apparatus in step S22 is a storage unit in the present invention. When the nonvolatile memory is a writable nonvolatile memory such as EPPROM or a flash memory improved from EPPROM, the backup data can be changed artificially. The means for executing the process of writing to the nonvolatile memory (that is, the backup data is variable) is the information writing means in the present invention.
S23: The communication synchronization process with the image reading unit 77 similar to step S2 in the prior art is performed by the control unit 70. If the process is completed, the process proceeds to step S24.
S24: The device error checking process similar to that in step S3 in the prior art is performed by the control unit 70. If the process is completed, the process proceeds to step S25.
As described above, in the present embodiment, the processing such as reading of the backup data is performed after the heater starts to be driven in S21, so that the temperature in the heater is increased even during the execution of steps S22 to S24. Since it is implemented, there is no useless waiting time, and a rapid temperature rise of the heater is achieved.
Incidentally, although not shown, the Ready temperature that is a determination criterion in Step S27 described later is determined by the control unit 70 according to the execution results of Step S22 to Step S24. A series of these processes corresponds to the target temperature confirmation means in the present invention.
Although not shown in the figure, during the processing of steps S22 to S24, an error (initialization of data accompanying the occurrence of an abnormality in backup data and communication between the image reading unit A and the control unit 70). If an error such as failure to synchronize occurs, of course, the process of increasing the temperature of the heater is stopped.
S25: It is determined whether or not an error has occurred in the control process while raising the temperature of the heater. If it has occurred, the process proceeds to step S28, and if not, the process proceeds to step S26.
S26: The temperature of the heater is detected by the main body sensor unit 76. As a result, if the temperature rise does not change even after the predetermined time (10 seconds in the present embodiment) is exceeded even though the temperature of the heater is raised, The controller 70 determines that an error has occurred during the temperature rise process, and proceeds to step S28.
S27: The temperature of the heater is detected by the main body sensor unit 76. As a result, when the temperature of the heater has reached the Ready temperature, the process proceeds to step S28, and when the temperature of the heater has not reached the Ready temperature, the process returns to step S25.
S28: If an error occurs in the control process while raising the temperature of the heater in step S25, or if the temperature of the heater has not changed for more than 10 seconds in step S26, In any case where the temperature of the heater has reached the Ready temperature in S27, the temperature rise of the heater is stopped because an abnormality has occurred in the fixing device X.
Note that the processing from step S25 to step S27 is the second temperature control means in the present invention.
The series of processing from step S20 to step S28 may be performed when the image forming apparatus A is restarted from the power saving mode.
[0016]
In addition, the process of said step S20-said step S28 is also what the heater 71 temperature control program previously stored in the said program ROM72 which the said control part 70 has was performed in the said CPU71. Therefore, it can be said that the above series of processing is a series of functions executed by this program.
[0017]
【The invention's effect】
As described above, according to the present invention, in the fixing device in which the heater is driven and controlled to reach the target temperature, and the developer attached to the sheet is heated and fixed on the sheet by the heater, Simultaneously with the start of operation, the temperature rise of the heater is started by the first temperature control means, and while the temperature rise process is being performed in the heater, the backup data reading process and the image reading unit described above are performed. The communication synchronization processing between the control unit and the error forming process for the devices constituting the image forming apparatus is performed (the three processes are target temperature confirmation means), and the temperature of the heater is finally set to the target temperature etc. By providing a device that adjusts the target temperature determined by the confirmation means by the second temperature control means, the warm-up time can be shortened.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of an image forming apparatus A according to an embodiment (hereinafter referred to as an embodiment) of the present invention.
FIG. 2 is a functional block diagram illustrating a schematic configuration of an image forming apparatus A according to an exemplary embodiment.
FIG. 3 is a flowchart showing a warm-up process of the image forming apparatus A according to the prior art.
FIG. 4 is a flowchart illustrating a warm-up process in the image forming apparatus A according to the exemplary embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Fixing roller 2 ... Pressure roller 3 ... Display operation part 30 ... Image processing part 31 ... Cassette 32 ... Duplex unit 33 ... Image forming part 35 ... Scanner 36 ... Automatic document feeder (ADF)
37 ... CCD
40 ... photosensitive drum 41 ... charging device 42 ... developing device 43 ... cleaning device 44 ... image forming unit 45 ... transfer device 46 ... transfer belt 50 ... exposure device 60 ... exposure device control means 70 ... control unit 71 ... CPU
72 ... Program ROM
73 ... ROM for data storage (EPPROM)
74 ... RAM
75 ... Main body drive unit 76 ... Main unit sensor input unit 77 ... Image reading unit 78 ... Communication unit

Claims (8)

In the fixing device that controls the driving of the heater so as to reach the target temperature and heats and fixes the developer adhered to the sheet to the sheet by the heater.
If the temperature of the heater does not reach a predetermined temperature that is set in advance when the operation of the fixing device is started , a current is passed through the heater without setting a target temperature. A first temperature control means for driving and controlling the heater so that the temperature rises, and a parameter relating to the heater driving for obtaining the target temperature or the target temperature during the control by the first temperature control means. After the target temperature or the parameter is confirmed by the target temperature or the like confirmation unit that is read from the nonvolatile memory and confirmed, and the target temperature or the like confirmation unit, the heater is based on the confirmed target temperature or the parameter. And a second temperature control means for controlling the temperature of the fixing device. The fixing device according to claim 1, further comprising an information writing unit that writes the target temperature or the parameter to the nonvolatile memory . The fixing device according to claim 1, wherein the fixing device determines whether or not to stop the heater based on information on the operation of the heater stored in the nonvolatile memory . The fixing device according to claim 1, wherein whether or not to stop the heater is determined based on whether or not the temperature of the heater has risen within a predetermined heating time. An image forming apparatus comprising the fixing device according to claim 1. The heater drive control so that the target temperature, the developer adhered to the sheet by the heater is a program for controlling a fixing device for heating and fixing to the seat, when the operation of the fixing device is started When the temperature of the heater does not reach a predetermined temperature set in advance, the heater is driven and controlled so that a current is passed through the heater without setting a target temperature to increase the temperature of the heater. A target temperature for reading out and confirming the target temperature or a parameter related to the heater driving for obtaining the target temperature during the control by the first temperature control means. After the target temperature or the parameter is confirmed by the confirmation means and the target temperature confirmation means, etc., based on the confirmed target temperature or the parameter. Heater temperature control program for realizing the function of controlling the second temperature control means for controlling the temperature of the serial heater. The heater temperature control program according to claim 6, for realizing a function of determining whether or not to stop the heater based on information on the operation of the heater acquired from the nonvolatile memory . The heater temperature control program according to claim 6 or 7, for realizing a function of determining whether or not to stop the heater depending on whether or not the temperature of the heater has risen within a predetermined heating time.

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