JP2002031989A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device which, in case of a sheet jam for example, allows opening of a door and disposal of the jammed sheet, improves quality of a transfer image, and prevents erroneous operation during the disposal, thereby improving operability. SOLUTION: The image forming device has a drive member which rotates a fixing roller and a pressure roller, and an outer cover attached so as to be opened/closed. Energization of the drive member is stopped when the outer cover is opened. The device also has a control means which allows the drive member for the fixing member to normally rotate and stop or reversely rotate and stop, or to repeat normal and reverse rotation. The control means allows the drive member to normally or reversely rotate or repeat the normal or reverse rotation even in the case energization of the drive member is stopped during the opening of the outer cover.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus such as a copying machine, a printer, a facsimile and the like.

[0002]

2. Description of the Related Art An example of this type of conventional image forming apparatus will be described with reference to the embodiment of the present invention shown in FIGS.
Is a developing unit, 4 is a photoreceptor, 5 is a paper feeding unit, 6 is a transfer charger, 7 is a fixing unit, 9 is a paper discharging unit, 11 is a cleaning unit,
12 is a fixing roller, 13 is a fixing heater, 14 is a pressure roller, 16
Indicates a temperature sensor.

In the above-described image forming apparatus, the toner image formed on the surface of the photoconductor 4 is transferred onto a sheet fed from the sheet feeding unit 5, and a fixing roller 12 and a pressure roller are According to 14, the toner is fixed to the paper by pressing and heating the paper, and a desired transfer image is obtained. By the way, jam paper or the like may occur during such a transfer operation. In this case, the operation of the apparatus is stopped, and the door of the exterior cover (not shown) is opened to remove the jammed paper remaining in the apparatus main body. By the way, at this time, sudden operation of the apparatus is dangerous, so that the supply of power from the power supply to the drive system of the apparatus is stopped.

When the jammed paper is removed as described above, if jammed paper exists in the fixing roller 12 portion, the jammed paper is directly pulled by hand to remove the paper, or the fixing roller 12 is manually rotated. However, in this case, not only may the hand come into contact with the high-temperature fixing roller 12, but also, since the fixing roller 12 and the pressure roller 14 are in contact with each other at a high pressure, rotation is extremely difficult. There is a problem that is.

[0005]

In order to solve such a problem, a fixing device as disclosed in JP-A-59-19979 has been provided. When the operation of the recording apparatus is stopped, the fixing device drives the fixing motor and discharges the sheet existing between the fixing rollers in a state where the door is closed, so that the behavior of the sheet during that time can be grasped. If the paper cannot be removed and the paper is stuck, it may cause damage to the device or make it difficult to remove the paper, thereby reducing the advantage of stopping the operation of the device. There's a problem.

In addition, if the jammed paper is removed in a state where the fixing temperature is low, there is a problem that unfixed toner adheres to the fixing roller and stains subsequent copies.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the conventional image forming apparatus, and to open the door when jam paper or the like is generated so that the processing can be performed. It is another object of the present invention to provide an image forming apparatus capable of improving the quality of the image forming apparatus and preventing erroneous operations during the processing and improving operability.

[0008]

In order to achieve the above object, the present invention comprises a driving member for rotating a fixing roller or a pressure roller, and an exterior cover openably and closably mounted on the apparatus main body. The power supply to the drive member is stopped when the exterior cover is opened, and the power supply to the drive member is stopped when the exterior cover is opened. A control means capable of rotating / stopping the driving member even in the state is provided.

According to a second aspect of the present invention, the driving member is constituted by a rotary motor, and the control means controls the normal operation of the rotary motor even when power to the rotary motor is stopped when the outer cover is opened. It is characterized in that it can be rotated and stopped.

According to a third aspect of the present invention, the driving member is constituted by a forward / reverse rotating motor, and the control means is configured to stop the energization of the forward / reverse rotating motor when the outer cover is opened. However, it is characterized in that it is constituted by a forward / reverse rotation switch capable of performing reverse rotation / stop of a motor capable of forward / reverse rotation.

According to a fourth aspect of the present invention, when the energization to the forward / reverse rotatable motor is stopped when the exterior cover is opened, the control means controls the forward / reverse rotation of the forward / reverse rotatable motor. It is characterized by being constituted by a forward / reverse repetition switch capable of repeating stop and reverse rotation / stop.

According to a fifth aspect of the present invention, the forward switch and the reverse switch are turned on only when turned on, and the forward / reverse switch is kept on until turned off when turned on. It is characterized by having become.

According to a sixth aspect of the present invention, there is provided a fixing roller temperature sensor, and the temperature sensor detects that the fixing roller is below a predetermined temperature even when the forward / reverse rotation of the forward / reverse rotation motor is repeated. In this case, the forward / reverse rotation repetition switch does not drive the forward / reverse rotation motor.

[0014]

Embodiments of the present invention will be described in detail with reference to the drawings. In this embodiment, the same parts as those of the related art are denoted by the same reference numerals, and the description thereof will be omitted. The different parts will be mainly described.

FIG. 2 shows a main part of the fixing means 7 of this embodiment. Reference numeral 17 denotes a fixing motor constituting a driving member provided separately from a main motor 26 and a developing motor 27 described below. The fixing motor 17 can drive only the fixing means 7 so as to avoid damaging other units even when driven in a jam.

FIG. 3 is a block diagram of a control unit of the image forming apparatus according to the present invention.
21 has a temperature sensor 16, a ROM 22, a RAM 23, a nonvolatile RA
M24, the main motor 2 via one I / O port 25
6. A developing motor 27, auxiliary members 28 such as various clutches and solenoids, and a driver 29 of the fixing motor 17 which can rotate forward and backward are connected. A display unit 32 for displaying the status of each unit via the other I / O port 31, a temperature sensor 16 for the fixing roller 12, a door sensor 33, a jam detection sensor 34 in the paper transport path, other various sensors 35, a fixing motor 17 forward switch 36, reverse switch 37 and forward / reverse repeat switch 38,
Various inputs such as a rotary encoder of the fixing motor 17 not shown are connected.

In such a case, information that should be retained even when the power is turned off is stored in the nonvolatile RAM 24. The output to the fixing motor 17 is
The on / off signal, the rotation direction instruction, the rotation speed instruction, the power down, and the like are performed via a driver (not shown). When the temperature detected by the temperature sensor 16 is equal to or lower than the temperature at which the toner can be fixed, the apparatus does not operate even when the forward rotation switch 36 and the reverse rotation switch 37 are turned on. After the jammed paper is removed, the door is closed once, the fixing roller 12 is heated, and then the door is opened. As a result, the toner adhered to the fixing roller 12 is fixed to the sheet, and the stain on the fixing roller 12 is removed.

When it is desired to stop the driving of the fixing means 7, the normal rotation switch 36 and the reverse rotation switch 37 are turned off to cut off the power supply. Also door switch and forward switch
The state of the reverse switch 37 and the reverse switch 37 can be monitored by the CPU 21 in conjunction with the supply and disconnection of power to the reverse switch 37. Further, when the reverse switch 37 is turned on and the door is closed, the driving is stopped. On the contrary, when the door is opened while the reverse switch 37 is turned on, the CPU 21 controls so as not to drive.

FIG. 4 is a block diagram showing a power supply / cutoff means for driving the driving system such as the fixing motor 17. When a door of the apparatus main body is opened, a door switch 30 is turned off to supply power of the driving system. The supply is cut off to prevent the drive train from operating. Therefore, in this case, the drive system cannot be operated.However, if the user wants to operate the drive system with the door opened for jam clearance or the like, the user turns on the forward rotation switch 36,
Alternatively, when the reverse switch 37 is turned on, a power source is connected to the drive system, power is supplied, and the drive system becomes operable. Here, the normal rotation switch 36 and the reverse rotation switch 37 are turned on only when turned on.

FIG. 5 shows a flow chart of the above-mentioned operation. When the door is open, (1) the forward rotation switch 3
When the switch 6 is turned on, the CPU 21 outputs a signal to the fixing motor driver 29 for forward rotation ON (forward rotation OFF for reverse rotation) and ON signal ON (OFF for OFF).

(2) Contrary to the above, when the normal rotation switch 36 is turned off, the power supply is cut off and the driving is forcibly stopped.
Output stop signal to (3) When the door is open,
When the forward / reverse repetition switch 38 is turned on, the operation of performing forward rotation for a certain period of time and then temporarily stopping to perform reverse rotation driving to temporarily stop is repeated.

When the switch is turned off during the operation and when the door is closed, the operation is immediately stopped.
In this case, the timing of starting the forward / reverse rotation is limited to the case where the switch is turned on from the off state while the door is open, thereby preventing the occurrence of a malfunction. When the reverse switch 37 is on, the forward switch 36 is ignored. By setting the cycle of repeating the normal rotation and the reverse rotation to be longer than the time required for the fixing roller 12 and the pressure roller 14 to make one rotation, it is possible to remove dirt on the entire surface of the fixing roller 12 and the pressure roller 14. Become.

[0023]

As described above, the present invention has a driving member for rotating a fixing roller or a pressure roller, and an outer cover which is openably and closably mounted. According to the first to third aspects of the present invention, when the energization to the driving member is stopped when the exterior cover is opened, the power supply to the member is stopped. By operating the reversing or reversing switch, the driving member can be rotated forward / stop or reversely / stopped in a desired forward or reverse direction, so that unfixed toner adheres to the fixing roller or jam paper occurs. In the case where the control member is operated by simply operating the control member while observing the inside from the door opening portion of the outer cover, the toner or the jammed paper can be removed, And it can be processed quickly with preventing the operation there is an effect that it is possible to improve operability.

According to a fourth aspect of the present invention, when the energization to the forward / reverse rotatable motor is stopped when the outer cover is opened, the control means controls the forward / reverse rotation of the forward / reverse rotatable motor. It consists of a forward / reverse repeat switch that can repeat rotation / stop and reverse rotation / stop, and this forward / reverse repeat switch remains on until turned off when turned on. Since the switch is used, the operator does not have to bother to keep the switch on by himself during the work, and the motor rotates forward and backward only when the switch is on. Therefore, even if the user forgets to turn off the switch, it is possible to prevent a malfunction of the apparatus from occurring and to improve operability.

According to a sixth aspect of the present invention, there is provided a temperature sensor for the fixing roller, and the temperature sensor keeps the temperature of the fixing roller at or below a predetermined temperature even when the forward / reverse rotation of the forward / reverse rotating motor is repeated. When it is detected, the forward / reverse rotation repetition switch does not drive the forward / reverse rotation motor, thus preventing erroneous operation of forward / reverse rotation for jam paper processing and improving operability. There is.

[Brief description of the drawings]

FIG. 1 is a front view of an example of a conventional typical image forming apparatus.

FIG. 2 is a perspective view of a main part of a fixing unit of the embodiment.

FIG. 3 is a block diagram of a control unit according to the first embodiment.

FIG. 4 is a block diagram of a power supply circuit of the same.

FIG. 5 is an operation flowchart of the above.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 laser optical system 2 charging charger 3 developing unit 4 photoreceptor 5 paper feeding unit 6 transfer charger 7 fixing means 9 paper discharging unit 11 cleaning unit 12 fixing roller 13 fixing heater 14 pressure roller 16 temperature sensor 17 fixing motor 21 CPU 22 ROM 23 RAM 24 Non-volatile RAM 25 I / 0 port 26 Main motor 27 Developing motor 28 Auxiliary member 29 Fixing motor driver 31 I / 0 port 32 Display section 33 Door sensor 34 Jam detection sensor 35 Various sensors 36 Forward switch 37 Reverse switch 38 Repeat Feed switch

Claims (6)

[Claims] A fixing device having a fixing roller and a pressure roller; a driving member for rotating the fixing roller or the pressure roller; and an exterior cover openably and closably mounted on the apparatus body. In the image forming apparatus in which the power supply to the drive member is stopped when the door is opened, the drive member rotates and stops even when the power supply to the drive member is stopped when the exterior cover is opened. An image forming apparatus, comprising: a control unit that can perform the control. The driving member is constituted by a motor, and the control means is capable of performing normal rotation / stopping of the motor when the exterior cover is opened, even when power to the motor is stopped. The image forming apparatus according to claim 1, wherein the image forming apparatus includes a switch. 3. The driving member is constituted by a forward / reverse rotating motor, and the control means controls the forward / reverse rotation even when the power to the forward / reverse rotating motor is stopped when the outer cover is opened. 2. The image forming apparatus according to claim 1, further comprising a reverse switch capable of performing a reverse rotation / stop of a possible motor. 4. The control means, when the enclosing cover is opened, in a state in which the power supply to the forward / reverse rotatable motor is stopped, the forward / reverse rotation of the forward / reverse rotatable motor and the reverse rotation / stop. 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is configured by a forward / reverse switching switch capable of repeating the following. 5. The forward rotation switch and the reverse rotation switch are turned on only when turned on, and the forward / reverse repetition switch is turned on until turned off when turned on. The image forming apparatus according to claim 4. 6. A fixing roller having a temperature sensor, wherein, even when the forward / reverse rotation of the forward / reverse rotation motor is repeated, when the temperature sensor detects that the temperature of the fixing roller is lower than a predetermined temperature, the forward / reverse rotation is performed. The image forming apparatus according to claim 4, wherein the repetition switch does not drive the forward / reverse rotation motor.