JPH09230721A - Image fixing device with shutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image fixing device which prevents a paper jam due to a malfunction of a shutter opening/closing mechanism and also permits a copying operation when a shutter is opened even in case the opening/closing mechanism is out of order. SOLUTION: This device is composed of a shutter opening/closing means 8 and a sensor 12 for detecting the status of the opening/closing of the shutter. Here, in the case a status signal from a sensor 12 is closed when a shutter opening signal is applied to the shutter opening/closing means 8, the copying operation is interrupted or inhibited. On the other hand, in the case the status signal from the sensor is opened when a shutter closing signal is applied to the shutter opening/closing means 8, the copying operation is permitted even if the shutter mechanism is out of order.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image fixing device used in copying machines, printers, facsimiles and the like.

[0002]

2. Description of the Related Art In recent years, there has been a strong demand for energy saving of products, and copying machines, printers, facsimiles, etc. (hereinafter collectively referred to as copying machines etc.)
Energy saving is also emphasized in the market. Among them, about 80% of the energy consumed by a copying machine or the like during standby is lost energy by the image fixing device, and this lost energy is wasted energy.

[0003] Conventionally, about 40% of the energy lost by such an image fixing device is the dissipation of heat to the outside of the image fixing device due to convection.
In Japanese Patent Laid-Open No. 4-49073, the entire image fixing device is covered with a cover, and a shutter is provided at an opening (recording paper entrance / exit) through which recording paper passes, and the shutter is opened when the paper is passed and the shutter is closed when the paper is not passed. In this way, an image fixing device has been proposed in which the dissipation of heat to the outside of the image fixing device is prevented as much as possible.

[0004]

However, when the shutter is provided at the recording paper entrance / exit through which the recording paper passes, if the shutter opening / closing mechanism fails and the recording paper entrance / exit of the image fixing device is blocked, When the recording paper is conveyed to the image fixing device by copying or printing operation of a copying machine,
Paper jam problem occurs. Even if the shutter opening / closing mechanism is out of order, the fixing operation itself is possible if the recording paper entrance / exit of the image fixing device is open.In such a case, copying or printing operation of a copying machine is prohibited. If you do,
In reality, there is a problem that the opportunity for copying is missed even though copying is possible.

Therefore, an object of the present invention is to prevent paper jams due to a failure of the shutter opening / closing mechanism, and to execute the operation of the image fixing device while the shutter is open even if the shutter opening / closing mechanism has a failure. An object of the present invention is to provide an image fixing device having a shutter that enables image forming operations such as copying and printing in a copying machine.

[0006]

In order to achieve the above object, the present invention according to claim 1 is an image fixing device for fixing the unfixed toner on a recording sheet on which an unfixed toner image is formed. A shutter provided at an opening through which the paper passes, a drive unit for opening and closing the shutter, an open / closed state detection unit for detecting the open / closed state of the shutter, and the shutter drive unit are operated to open / close the shutter. The opening / closing control means for controlling is compared with the signal from the opening / closing control means and the signal from the opening / closing state detecting means, and when the opening / closing control means outputs a shutter opening signal, the opening / closing state detecting means causes the shutter closed state. If the opening / closing state detecting means outputs a shutter close signal, the opening / closing state detecting means shuts off the fixing operation of the image fixing device. When detecting the Potter opened is an image fixing apparatus characterized by having a fixing operation control means for performing a fixing operation of said image fixing apparatus.

Further, claim 2 for achieving the above object.
The present invention described is used in an image forming apparatus for forming an image on a recording paper by an electrophotographic method, and an image fixing device having a shutter at an opening through which the recording paper passes, a driving means for opening and closing the shutter. An opening / closing state detecting means for detecting the opening / closing state of the shutter; an opening / closing control means for operating the shutter driving means to control opening / closing of the shutter; and a signal from the opening / closing control means and the opening / closing state detecting means. When the open / close control means outputs a shutter open signal and the open / close state detecting means detects a shutter closed state, the operation of the image forming apparatus is prohibited and the open / close control means closes the shutter. Control for permitting the operation of the image forming apparatus when the opening / closing state detecting means detects the shutter open state when the signal is output. An image fixing apparatus characterized by comprising: a stage, a.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
An embodiment of the present invention will be described.

Hereinafter, the structure of an image fixing device to which the present invention is applied and the structure of a copying machine using the image fixing device will be described, and then two modes of specific control and operation of the copying machine will be described. To do.

FIG. 1 is a schematic view of an image fixing apparatus to which the present invention is applied, and FIG. 2 is a schematic view showing an image forming apparatus portion which is a main configuration of a copying machine using the image fixing apparatus. 3 is a drawing showing an example of an operation panel provided on the upper surface of this copying machine.

In the image fixing device 18 shown in FIG. 1, the heating roller 1 and the pressure roller 2 are covered with an upper cover 3 and a lower cover 4, and an opening for recording paper to pass between the covers 3 and 4. Parts (exit and entrance) are provided. And
In this opening, shutters 5a and 5 interlocking with each other are provided.
b is provided. The shutters 5a and 5b are connected to a moving member 7 installed at a position lower than the conveyance path of the recording paper, and the moving member 7 is operated by one solenoid 8 to open and close the shutters 5a and 5b. Be seen. As a result, when the shutter is open, the shutter 5
The opening a opens to the inside of the image fixing device 18, and the shutter 5b opens to the outside, and also serves as a conveyance guide for the recording paper.
The direction indicated by A in the figure is the recording paper conveyance direction.

The moving member 7 and the solenoid 8 are driving means for opening and closing the shutters 5a and 5b as described above. One end of the moving member 7 is connected to the solenoid 8 and the other end is a frame of a copying machine or the like. It is connected to the spring member 11 fixed to the. The moving member 7 is made of a spring material 11.
The shutters 5a and 5b are closed while being pulled by
The shutters 5a and 5b are opened by being pulled leftward in the figure by the solenoid 8.

The open / closed state of the shutter is detected by a shutter open / close sensor 12 which is an open / closed state detecting means.
The shutter opening / closing sensor 12 uses, for example, a limit switch or a photo interrupter. Since the shutters 5a and 5b are interlocked with each other in this device, a limit switch is provided on the lower outside of the shutter 5b to detect opening / closing of the shutter. I decided to do it.

The heating roller 1 inside the image fixing device is heated by a heat source (not shown), and is rotated by a motor and a rotation mechanism (not shown), and is pressed by the heating roller 1 and is driven by a pressure roller 2. The unfixed toner is fixed by the recording paper passing through the gap (nip portion). A temperature sensor 31 for detecting the fixing temperature is provided around the heating roller 1 and is controlled to a temperature required for fixing. Further, a claw member 32 for peeling the recording paper from the heating roller 1 is provided, and a paper ejection sensor 6 and a paper ejection roller 19 are provided downstream of the image fixing device 18 in the recording paper conveyance direction.

Here, the covers 3 and 4 and the shutter 5
The a and 5b are made of, for example, stainless steel, and are preferably covered with a heat insulating material so that the heat in the inside does not easily escape.

The copying machine shown in FIG. 2 has a general image forming apparatus, and its basic operation is to push the copy start switch 20 on the operation panel 25 shown in FIG. 3 (O).
Then, the copy execution operation is started. As a result, the recording paper is supplied from the cassette 28 by the rotation of the pickup roller 13, passes through the separating roller 14, and is blocked by the timing roller 15 and temporarily stands by. During this time, an original to be copied is read by an image reading device provided on the upper part of the copying machine (not shown), and an electrostatic latent image is formed on the photoconductor 16. Then, the electrostatic latent image formed on the photoconductor 16 is transferred as an unfixed toner image on the recording paper supplied in synchronization with the transfer timing from the timing roller 15. After the transfer, the recording paper is sent to the image fixing device 18 by the suction belt 17, and the unfixed toner image is fixed on the recording paper. The recording paper on which the image has been fixed is discharged by the discharge roller 19 and the copy operation is completed.

The instruction of such a copy operation is given from the operation panel 25 as shown in FIG.
5 has a start button 20 for instructing execution of copying.
And a copy permission status display lamp 21 for indicating whether or not copying is possible. When the copying machine is in a copy prohibition mode in which a copying operation cannot be accepted due to a copying operation or a mechanical failure, a copy permission status display is displayed. The lamp 21 displays the copy prohibition mode, and even if the copy start button 20 is pressed, the copy operation is not executed. When the copy permission status display lamp 21 displays the copy permission mode and the copy start button 20 is pressed, the copy operation is performed as described above. In addition, the operation panel 25,
In addition to the start button 20 and the copy permission status display lamp 21, there are provided a display panel 22 for displaying various messages, a ten key 23 for setting the number of copies, and the like.

FIG. 4 is a block diagram of a control system for controlling the entire copying machine. A CPU (central control unit) 40 controls the entire copying machine, and is connected to a RAM 42 that stores control information and a ROM 41 that stores control programs and control data. Further, the CPU 40 has detection signals from the paper discharge sensor 6 and the shutter opening / closing detection sensor 12 installed in the copying machine, and other sensors 30 (for example, the temperature sensor 31), input keys on the operation panel 25 (for example, copy start). Key 20 and numeric keypad 23)
The input signal from is input through an input interface (not shown). On the other hand, from the CPU 40, the solenoid 8 for opening and closing the shutter and the control load 50 in the copying machine
(For example, the image fixing device, the image reading device, the photoconductor 16 and the rollers of the conveying path, and other parts related to the image forming operation)
A signal for controlling the signal is output via an output interface (not shown). Therefore, the CPU 40 functions as an opening / closing control unit and a fixing operation control unit in a first mode described later, and functions as an opening / closing control unit and a control unit in a second mode described later.

A first mode of control of this copying machine will be described below. In the following description, the ON edge means a change in the state of the switch, sensor, signal, etc. when the state is switched from OFF to ON. Similarly OFF
An edge means a change in state when a state of a switch, a sensor, a signal, etc. is switched from ON to OFF.

FIG. 5 is a flow chart of the main routine for controlling the copying machine. When the main switch (not shown) is pressed and the power is turned on, the copy permission flag is set to "0" (copy permitted state) in step (S1), and various other copying machines are set in step (S2). Initialize control contents. At step (S3), the internal timer is started in the CPU 40, and the control after step (S4) is executed within the time set by this internal timer.

In step (S4), the information keyed in from the operation panel 25 is accepted, and necessary information is displayed on the display panel 22 and the copy permission status display lamp 21 on the operation panel. In step (S5), the copy operation is controlled according to the control content set in step (S4). In step (S6), other than the control executed in step (S5), for example, control such as temperature adjustment of the image fixing device is executed.

Then, in step (S7), it is determined whether or not the internal timer has ended. If the internal timer has ended here, the process returns to step (S3) and the internal timer is restarted.

FIG. 6 is a flowchart showing the control procedure of the copy operation subroutine. First, step (S1
In 1), the state of the copy permission flag is determined, and if the state is "0", that is, the state of copy permission, the steps after step (S12) are executed, and the copy permission flag is "1", that is, copy. If it is prohibited, it returns to the main routine.

In step (S12), the print key 20
If it is confirmed that the ON edge is detected, the copy start flag is set to "1" in step (S13). If the detection of the on-edge is not confirmed, the step (S13) is not executed and the step (S
Proceed to 14).

In step (S14), it is determined whether or not the copy start flag is "1". If the copy start flag is "1", the steps after step (S15) are executed and the copy start flag is "1". If not, it returns to the main routine.

In step (S15), the control of the paper feed / conveyance system is executed, and in step (S16), other controls such as the image reading device and the photoconductor are executed. When the copy operation is executed in step (S17),
The copy number cumulative counter CT is counted up, and the cumulative number of copies is stored in the RAM 42 connected to the CPU 40.
To memorize.

In step (S18), the total number of copies counted by the copy number integration counter CT is compared with the number set on the operation panel to determine whether or not the copy operation is completed, and the copy operation is completed. If not, step (S19) and step (S20) are not executed and the process proceeds to step (S21). On the other hand, if the copy operation has been completed, the process proceeds to step (S19) to set the copy start flag to "0", then the copy number integration counter CT is reset at step (S20), and the process proceeds to step (S21). .

In step (S21), a shutter opening / closing control subroutine, which will be described later, is executed to execute step (S21).
Proceed to 22). In step (S22), a shutter security control subroutine described later is executed, and the process returns to the main routine.

FIG. 7 is a flowchart showing the control procedure of the shutter opening / closing control subroutine. First, in step (S81), it is determined whether or not the copy start flag is "0". If the copy start flag is "0", that is, if the copy operation is not executed, the process proceeds to step (S82) and the solenoid is operated. If 8 is in operation, stop it and close the shutter. On the other hand, when the copy start flag is "1", that is, when the copy operation is executed, the process proceeds to step (S83), the solenoid 8 is operated, and the shutter is opened. The shutter opening / closing operation is performed in steps S15 and S16 described above such as the sheet feeding and the process operation around the photosensitive member, that is, until the unfixed toner image is formed on the recording sheet.

FIG. 8 is a flowchart showing the control procedure of the shutter security control subroutine. In this subroutine, the failure state of the shutter during the copy operation is detected, and the suspension or prohibition of the copy operation is controlled according to the detected failure state.

First, in step (S31), a control signal (shutter open / close signal) issued to the solenoid 8 for opening / closing the shutter is detected, and as a control, the shutter is opened or closed. Determine if it has become. If the shutter opening / closing signal is closed, step (S32) and step (S33) are executed, and if the shutter opening / closing signal is open, step (S34) and the subsequent steps are executed.

If the shutter open / close signal is closed in step (S31), it is then determined in step (S32) based on the signal from the shutter open / close sensor 12 whether the shutter is actually closed. If the shutter is closed, it is not a malfunction and the process returns to the copy operation subroutine. On the other hand, if the shutter is open, there is a contradiction between the shutter open / close signal and the actual shutter status, so it is determined that there is a failure, and the failure is displayed on the display panel 22 in step (S33), but the shutter is open. Then, since the normal copy operation can be performed, the process returns to the copy operation subroutine without stopping or prohibiting the copy operation.

In the step (S31), if the shutter open / close signal is open, the next step (S3)
In 4), it is determined from the signal from the shutter opening / closing sensor 12 whether the shutter is actually open. If the shutter is open, it is not a malfunction and the process returns to the copy operation subroutine. On the other hand, if the shutter is closed, there is a contradiction between the shutter open / close signal and the actual shutter condition, so it is determined that there is a failure, and step (S35) and subsequent steps are executed. In step (S35), the failure is displayed on the display panel 22, and in step (S36)
Then, all the operations of the image fixing device, the image reading device, the conveying device, etc. are stopped. Next, in step (S37), the copy permission flag is set to "1", that is, copy prohibition is set, and the process returns to the copy operation subroutine. By setting the copy permission flag to "1", the copy permission status display lamp 21 displays the copy prohibition, and the copy operation cannot be performed thereafter and the copy prohibition state is set. The copy permission flag is set to "0" in the initial setting (step S1) by restarting the power supply after repairing the shutter.

The above is the detection of the shutter failure in the first mode and the control contents when the failure occurs.
If a failure is detected in the copy operation state and the shutter is closed at the time of the shutter open signal, the copy operation is stopped, the failure is notified, and the subsequent copy operation is also prohibited. And if the shutter is open even in the case of failure,
Although the failure is displayed, the copy operation is maintained.

In this embodiment, since the failure is detected during the copy operation, it is possible to reliably detect and cope with the failure occurring during the copy operation. Since it is left behind in the transport path, the user has to remove the leftover paper. Therefore, an example in which the security control of the shutter is performed before starting the copying operation for the purpose of solving the problem of paper removal will be described below as a second mode. The configuration of the device used in the second mode is the same as that in the first mode and the description thereof is omitted.

FIG. 9 is a flowchart of the main routine in the second mode. First, when the main switch (not shown) is pressed to turn on the power, step (S4)
In 1) and step (S42), machine failure diagnosis and initial setting are performed.

In step (41), shutter failure diagnosis, which will be described later, and control for the diagnosis result (shutter maintenance)
In step S42, various control contents of other copying machines are initialized.

Next, at step (S43), the internal timer is started, and the control after step (S44) is executed within the time set by this internal timer. In step (S44), the input key of the operation panel 25 is accepted,
Also, necessary information is displayed on the display panel 22 of the operation panel 25. In step (S45), the step (S4)
The copy operation is controlled according to the control contents set in 4). In step (S46), other than the control executed in step (S45), for example, control such as temperature adjustment of the image fixing device is executed. Then, step (S47)
Then, it is determined whether the internal timer has ended. If the internal timer has ended here, the process returns to the repeat step (S43) to restart the internal timer.

FIG. 10 is a flow chart showing the control procedure of the shutter maintenance subroutine of the step (S41). In this subroutine, the prohibition of the copy operation is controlled according to the failure diagnosis of the shutter and the failure status before the copy operation.

First, in step (S51), a shutter open signal is sent to the solenoid 8, and then in step (S51).
In 52), it is determined whether or not the shutter is actually opened based on the signal from the shutter opening / closing sensor 12 in response to the opening signal in step (S51). If the shutter is actually open, it is determined that there is no failure in response to the shutter open signal in step (S51), and the steps after step (S55) are executed. on the other hand,
If the shutter is actually closed, there is a malfunction in the shutter, and since the shutter is closed, the copy operation cannot be performed, so step (S53).
In step S5, the failure is displayed on the display panel 22.
In 4), the copy permission flag is set to "1", that is, the copy prohibited state, and the process returns to the main routine. By setting the copy permission flag to “1”, the copy permission status display lamp 21 displays the copy prohibition, and the copy operation is prohibited thereafter.

After step (S55), a failure diagnosis for the operation of closing the shutter is performed. Here, in step (S55), a shutter close signal is first sent to the solenoid 8, and then in step (S56), the shutter open / close sensor 12 actually outputs the shutter close signal in response to the shutter close signal in step (S55). Determine if the shutter is closed. If the shutter is closed, there is no contradiction to the closing operation, so it is determined that there is no malfunction, and in step (S58) a shutter open signal is sent to the solenoid 8 to open the shutter in preparation for the subsequent copying operation. . On the other hand, when the shutter is open, the shutter close signal and the actual state are inconsistent, so it is determined that the shutter has a failure, and the failure is displayed on the display panel 22 in step (S57), but the copy operation is prohibited. Does not.

Next, at step (S58), since the machine is in a copy ready state, that is, the shutter is actually open even if a shutter close signal is output, or a normal state, The copy permission flag is set to "0" and the process returns to the main routine.

FIG. 11 is a flowchart showing the control procedure of the copy operation subroutine. First, step (S6
In 1), the state of the copy permission flag is determined, and if the state is "0", that is, the state of copy permission, the steps after step (S62) are executed, and the copy permission flag is "1", that is, copy. If it is prohibited, it returns to the main routine.

Next, in step (S62), it is judged whether or not the print key 20 is turned on, and when the detection of the ON edge is confirmed, the copy start flag is set to "1" in step (S63). . When the detection of the on-edge is not confirmed, the process proceeds to step (S64) without executing step (S63).

In step (S64), it is determined whether or not the copy start flag is "1". If the copy start flag is "1", the steps after step (S65) are executed and the copy start flag is "1". If not, it returns to the main routine.

In step (S65), the control of the paper feed / conveyance system is executed, and in step (S66), other control such as the control of the image reading device and the photoconductor is executed.

Next, in step (S67), when the copying operation is executed, the copy number cumulative counter CT is incremented and the cumulative number of copied sheets is stored in the RAM 42 connected to the CPU 40.

Next, at step (S68), the total number of copies counted by the copy number integration CT counter is compared with the number set on the operation panel to determine whether or not the copy operation is completed. If not completed, step (S69) and step (S70)
The shutter opening / closing control of step (S71) is performed without executing the above step and the process returns to the main routine. On the other hand, if the copy operation is completed, the process proceeds to step (S69) to reset the copy number cumulative CT counter, and then the copy start flag is set to "0" in step (S70).

Next, in step (S71), the shutter is opened / closed by using the copy start flag for determination as in the first embodiment (see FIG. 7), and the process returns to the main routine.

The above is the detection of the shutter failure and the control contents in the case of the failure in the second embodiment. With this, when the shutter failure is detected before the copying operation and the shutter is closed at the shutter open signal, If the copy operation is prohibited to notify the failure and the shutter is open at the time of the shutter close signal, the failure is displayed but the copy operation is held in a possible state.

In both of the above-described two modes, when a failure is detected while the shutter is open, the temperature control of the image fixing device is set to a temperature control different from that of the failure-free condition. May be performed.

[0052]

According to the present invention described above, the operation of the image fixing device is stopped or prohibited if the shutter is closed when the shutter is open, and if the shutter is open when the shutter is open, the shutter opening / closing mechanism is broken. Prevents paper jams caused by the problem, and enables the operation of the image fixing device when the shutter is open even if the opening / closing mechanism is broken, so that the operation efficiency of the image fixing device is improved without stopping as much as possible. Can be increased.

Further, according to the present invention, the operation of the image forming apparatus is stopped or prohibited when the shutter is closed when the shutter is open, and the image forming apparatus is operable when the shutter is open when the shutter is closed. Since the paper jam due to the failure is prevented and the operation can be performed as the image forming apparatus when the shutter is open even if the opening / closing mechanism is out of order, the utilization efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a schematic view of an image fixing device having a shutter.

FIG. 2 is a schematic diagram showing a configuration of a copying machine.

FIG. 3 is a view showing an operation panel of a copying machine.

FIG. 4 is a block diagram of a control system of the copying machine.

FIG. 5 is a flowchart of a main routine for explaining the control of the first mode.

FIG. 6 is a flowchart of a copy operation subroutine shown in FIG.

7 is a flowchart of a shutter opening / closing control subroutine shown in FIG.

8 is a flowchart of a shutter maintenance subroutine shown in FIG.

FIG. 9 is a flowchart of a main routine for explaining the control of the second mode.

10 is a flowchart of a shutter maintenance subroutine shown in FIG. 9 above.

11 is a flowchart of the copy operation subroutine shown in FIG.

[Explanation of Codes] 1 ... Heating roller, 2 ... Pressure roller, 3 ... Top cover, 4 ... Bottom cover, 5a, 5b ... Shutter, 7 ... Moving member, 8 ... Solenoid, 11 ... Spring material, 12 ... Open / closed state Detection sensor, 18 ... Image fixing device, 40 ... CPU.

Claims (2)

[Claims] 1. An image fixing device for fixing an unfixed toner on a recording paper on which an unfixed toner image is formed, a shutter provided at an opening through which the recording paper passes, and a shutter for opening and closing the shutter. Drive means, open / closed state detection means for detecting the open / closed state of the shutter, open / close control means for operating the shutter drive means to control opening / closing of the shutter, signals from the open / close control means and the open / closed state detection means When the opening / closing control means outputs a shutter open signal and the opening / closing state detecting means detects a shutter closed state, the fixing operation of the image fixing device is prohibited and the opening / closing control is performed. When the opening / closing state detecting means detects the shutter open state when the means outputs the shutter close signal, the fixing operation of the image fixing device is performed. Image fixing apparatus, comprising: the fixing operation control means for, the. 2. An image fixing apparatus used in an image forming apparatus for forming an image on a recording sheet by an electrophotographic method and having a shutter at an opening through which the recording sheet passes, and a driving unit for opening and closing the shutter. An open / closed state detecting means for detecting an open / closed state of the shutter; an open / close control means for operating the shutter driving means to control opening / closing of the shutter; a signal from the open / close control means and a signal from the open / close state detecting means When the opening / closing control unit outputs a shutter open signal, the opening / closing state detection unit detects the shutter closed state, the operation of the image forming apparatus is prohibited, and the opening / closing control unit outputs the shutter close signal. Control for permitting the operation of the image forming apparatus when the open / close state detecting means detects the shutter open state when Image fixing apparatus characterized by comprising: a stage, a.