JPH10222006A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device to dispensed with the operation of removing fixtures in pulling out a fixing means by adopting such a constitution that power supply to a heater of the fixing means is automatically stopped when the fixing means is pulled out from the image forming device, even if a front door opening/closing detecting mechanism recognizes that a front door is closed by attaching the jig. SOLUTION: This image forming device is provided with a fixing means 56 which is drawably provided to an image forming device body and for fixing a toner transferred on a transfer material by using a heater and a heater control means for controlling the power supply to the heater 8 of the fixing means 56. In this case, a position detecting means 7 for detecting the position of a releasing means 6 is provided and the heater control means is set so as to stop the power supply to the heater with a signal from the position detecting means 7 of which a lock of the fixing means 56 is released.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, and more particularly, to an image forming apparatus provided with a fixing means so as to be able to be pulled out of a main body.

[0002]

2. Description of the Related Art FIG. 4 shows an example of a conventional image forming apparatus.
The image forming operation of the copying machine will be described.

The image forming apparatus generally includes an image forming apparatus main body 51, an automatic document feeder 52 disposed on the image forming apparatus main body 51, and an image forming apparatus provided inside the image forming apparatus main body 51. Optical system 53, photosensitive drum 5
4, a developing unit 55, a fixing unit 56, and the like.

Here, the optical system 53 includes the original illumination lamp 5.
The scanner 7 illuminates and scans the original on the original platen glass 58, and forms reflected light from the original on the photosensitive drum 54 by the scanning mirror 59 and the lens 60.

A photosensitive drum 54 is provided with a primary charger 61, a developing device 55, a transfer charger 62, and a separation charger 63 around the photosensitive drum 54. The photosensitive drum 54 is
After being rotated, the reflected light of the document from the optical system 53 forms an image to form an electrostatic latent image, and then the electrostatic latent image is visualized as a toner image by the developing device 55.

The image forming apparatus main body 51 has a transfer material 6 at the bottom.
A paper feed cassette 65 for stacking and housing the sheets 4 is provided. The transfer material 64 is separated one by one by a pickup roller 66, and is conveyed by a conveyance roller 67 to a vertical path conveyance path 68.
To the photosensitive drum 54.

Then, the toner image on the photosensitive drum 54 is transferred to the transfer material 64 by the charging action of the transfer charger 62. After the transfer, the transfer material 64 is separated from the photosensitive drum 54 by the charging action of the separation charger 63,
9 leads to the fixing device 56. And the heating roller 7
0, and the toner image is heated and fixed between the pressure roller 71 and the image forming apparatus main body 5 by the discharge roller 72.
It is discharged out of 1. The heating roller 70 has a built-in heater (not shown).

When a paper jam (jam) occurs during the above-described series of copying operations, the user looks at the message indicating the location of the jam displayed on the operation display panel on the upper part of the main body 51 of the image forming apparatus. The jam processing for removing the jammed paper by opening the door or the like of the image forming apparatus main body 51 is performed.

FIGS. 5 to 8 show a state in which the door and the like of the image forming apparatus main body 51 are opened during the jam clearance.

In the image forming apparatus main body 51, as a door,
A front door 73, a right door 74, a discharge door 75, and the like are provided. Further, in the image forming apparatus main body 51, a paper feed cassette 65 is disposed so as to be able to be pulled out.

There are usually four places where jams occur. 1
The third is a jam caused by the operation of the pickup roller 66. When this jam occurs, as shown in FIG. 5, the paper feed cassette 65 is pulled out and the vertical path
Then, the right door 74 facing 8 is opened to perform jam processing.

The second is when the transport roller 67 cannot transport the transfer material 64 at a predetermined speed in the vertical path transport path 68 from the paper feed to the photosensitive drum 54. The right door 74 facing the vertical path conveyance path 68 is opened as shown in FIG.

[0013] The third is a jam that occurs during transfer to the transfer material 64 at the position of the photoreceptor drum 54 or after transfer, resulting in defective conveyance to the fixing device 56. When this jam occurs, as shown in FIG. 7, the front door 73 is mainly opened to perform the jam processing. Depending on the detection location, the right door 74
Open.

Fourth, the transfer material 6 is fixed within a predetermined time after fixing.
4 is a jam caused by not being discharged. When this jam occurs, as shown in FIG.
Open 5

Regarding the first, second and fourth jams, the remaining transfer material 64 can be confirmed by pulling out the paper feed cassette 65 and opening the doors 74 and 75, so that the jam can be easily removed. it can.

On the other hand, in the third jam processing,
Normally, since this is the most complicated portion inside the image forming apparatus main body 51, even after the instruction to open the front door 73 in FIG. Desired. In particular, when there is the transfer material 64 that has reached the fixing device 56, it is difficult to perform the jam processing operation according to only the third procedure, and the fourth processing procedure may be required. 64 may be torn.

In order to improve the operability of the jam processing, a copying machine of recent years uses a unit in which the fixing device 56 and the conveying belt 69 are individually provided or a unit in which the fixing device 56 and the conveying belt 69 are integrated. The mainstream one is configured to be movable so that it can be pulled out from the main body 51 toward the user. FIG. 9 shows, as an example of such a movable configuration, a fixing / conveying unit 76 on which the fixing device 56 and the conveying belt 69 are mounted and integrated. In this figure,
The state where the fixing and conveying unit 76 is pulled out is shown. In this figure, a release lever 78 is provided to lock the fixing and conveying unit 76 to the image forming apparatus main body 51 and to release the locked state. In order to pull out the fixing and conveying unit 76, it is necessary to open the front door 73 and then operate the release lever 78 to release the state in which the fixing and conveying unit 76 is locked to the image forming apparatus main body 51.

Since a considerable amount of current flows through the heater of the fixing unit 56, if the fixing / conveying unit 76 is pulled out while the heater is energized and the contact of the connector (not shown) for energizing the heater is separated, a leak will occur. And the life of the connector is shortened. Therefore, when the fixing and conveying unit 76 is pulled out (that is, when the contact point of the connector is separated), the power supply to the heater must be cut off. Therefore, conventionally, when the front door 73 is opened,
A front door 73 is detected by a front door open / close detection mechanism (not shown).
The heater is turned off in synchronization with the opening of the heater.

However, when repairing an assembly line or a serviceman at a manufacturing factory, it is required to operate the image forming apparatus with the front door 73 opened to confirm the operation state inside the image forming apparatus main body 51. May be done.

At the time of such a line process or repair,
A jig (not shown) is used to make the front door opening / closing detection mechanism recognize that the front door 73 is closed even when it is open. According to this, even when the front door 73 is kept open, the heater is energized and the image forming apparatus main body 51 can be operated.

[0021]

In the above-mentioned conventional example,
In order to pull out the fixing and conveying unit 76 when the jig is used at the time of a line process or at the time of repair by a service person, the jig must be removed. If the jig is not removed, since the heater of the fixing device 56 is energized, when the fixing and transporting unit 76 is pulled out and the contact of the connector is separated, a leak occurs and the life of the connector is shortened. .

However, the operation of removing the jig when pulling out the fixing / conveying unit 76 is troublesome. Therefore, conventionally, the efficiency of the image forming apparatus has been inevitably reduced in terms of its productivity and workability at the time of service.

In the above, the fixing / conveying unit 76 in which the fixing unit 56 and the conveying belt 69 are integrally mounted and which is movable has been described. The same problem occurs.

An object of the present invention is to provide a fixing device which can be used when the fixing means is pulled out of the image forming apparatus even when the front door opening / closing detecting mechanism recognizes that the front door is closed by attaching a jig. By automatically stopping the power supply to the heater of the fixing unit, it is unnecessary to remove the jig when pulling out the fixing unit, thereby improving the productivity and the efficiency of the service operation. An object of the present invention is to provide a forming apparatus.

[0025]

SUMMARY OF THE INVENTION According to the invention of the present application, the above-mentioned object is to provide a fixing unit which is provided in a main body of an image forming apparatus so as to be drawn out and fixes a toner transferred onto a transfer material using a heater. And detecting the position of the release unit in an image forming apparatus having a heater control unit for controlling energization of the heater of the fixing unit and a release unit for releasing a state in which the fixing unit is locked to the image forming apparatus main body. A position detecting unit is provided, and the heater control unit is achieved by setting so as to stop energizing the heater by a signal from the position detecting unit that the fixing unit is unlocked.

That is, in the invention according to the present application,
When the position detecting unit detects that the fixing unit is unlocked from the image forming apparatus body when the fixing unit is pulled out of the image forming apparatus, the heater control unit stops energizing the heater. That is, although the front door open / close detection mechanism is actually recognized as being closed even when the front door is open by the action of the jig, when the fixing unit is pulled out from the image forming apparatus, the fixing The energization of the means is automatically stopped. Therefore, even if the contact of the connector for energizing the heater is separated, no leak occurs,
Shortening the life of the connector is prevented. Therefore, when the jig is used at the time of a line process or at the time of repair by a service person, it is not necessary to remove the jig when pulling out the fixing unit.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to FIGS. Here, the same components as those in the above-described conventional example are denoted by the same reference numerals.

FIG. 1 shows the fixing and conveying unit 3 in which the fixing device 56 and the conveying belt 69 are integrated. This fixing and conveying unit 3 corresponds to the fixing and conveying unit 76 of the conventional example shown in FIG. That is, the fixing / conveying unit 3 is slidably provided so that it can be pulled out from the image forming apparatus main body 51 toward the front with the front door 73 of the image forming apparatus main body 51 opened (see FIG. 9). The fixing and transporting unit 3 includes a slide table 4, a fixing device 56 as a fixing unit and a transport belt 69 as a horizontal transport unit provided on the upper surface of the slide table 4.
And a position detecting sensor 7 as position detecting means.

Here, the release lever 6 is provided to release the state in which the fixing and conveying unit 3 is locked to the image forming apparatus main body 51. The release lever 6 has a lever main body 6A and a detection flag 6B protruding from a side of the lever main body 6A on the falling side. When the lever main body 6A is tilted, the detection flag 6B enters the U-shaped position detection sensor 67.
The release lever 6 of the present embodiment is provided on the upper surface of the slide base 4,
The locked position raised as shown in FIG.
As shown in (B), it is rotatably supported between the unlocked position and the folded position. The release lever 6 is manually rotated. Release lever 6 is shown in FIG.
As shown in (B), when the fixing and transporting unit 3 is mechanically locked to the image forming apparatus main body 51 when it is tilted to the locked position, it cannot be pulled out from the image forming apparatus main body 51. On the other hand, the release lever 6 is
As shown in (A), when the locker is in the raised unlocked position, the fixing and conveying unit 3 can be pulled out.

The position detecting sensor 7 is formed in a U-shape, and a light beam passes through between the U-shapes. When the light beam is cut off, the switch is turned on or off. It has become. Release lever 6 is shown in FIG.
(A), the position detecting sensor 7 detects that the light is
Outputs a signal that detects that is locked. On the other hand, when the release lever 6 is tilted, the position detection sensor 7 outputs a signal indicating that the light is blocked by the detection flag 6B and the lock is released.

Next, a heater power supply control system of the fixing device 56 including the release lever 6 and the position detection sensor 7 will be described with reference to FIG.

This heater energization control system is composed of two systems. One is composed of a front door open / close detection mechanism 9 connected to a heater 8. The other is composed of a release lever 6 and a position detection sensor 7, a CPU 10 to which the position detection sensor 7 is connected, and a heater driving device 11 connected to the CPU 10 and connected to the heater 8. is there. The CPU 10 and the heater driving device 11 constitute a heater control unit.

That is, the heater 8 is connected to the front door opening / closing detecting mechanism 9 and the heater driving device 11, and is turned on / off by the components.

The front door opening / closing detecting mechanism 9 is provided between the AC power supply 12 for supplying AC power to the heater 8 and the heater 8, and stops the power supply to the heater 8 when the front door 73 is open. It has a switch function. The front door opening / closing detection mechanism 9 detects whether the front door 73 is open or closed, and outputs a detection signal (DC signal) to the CPU 10.
The reason why the front door opening / closing detection mechanism 9 notifies the CPU 10 that the front door 7 has been opened in this way is that the power supply to the heater 8 is stopped because the front door 7 is opened, and that the AC power supply 12 This is for causing the CPU 10 to distinguish and recognize the case where power is no longer supplied to the heater 8 (error) as a result of disconnection or the like between the heater 8 and the like.

On the other hand, as described above, the position detecting sensor 7 detects the position (standing or falling) of the release lever 6 provided on the fixing / conveying unit 3 so that the fixing / conveying unit 3 moves the image forming apparatus main body 51. To detect whether it is locked or unlocked,
The detection signal is output to the CPU 10. CPU1
In the case of 0, when a signal indicating that the lock is released is input from the position detection sensor 7, a signal for instructing the heater driving device 11 to stop (OFF) the power supply is output. The heater driving device 11
It has a function of outputting a signal (power OFF signal) for turning off the power supply from the AC power supply 12 to the heater 8 based on a command signal from the PU 10.

Even if the CPU 10 receives a signal from the front door opening / closing detection mechanism 9 that detects that the front door 73 is open, it sends a signal from the position detection sensor 7 that the lock of the fixing and conveying unit 3 has been released. When it is obtained, an energization OFF signal is output to the heater driving device 11, and the energization to the heater 8 is stopped by giving priority to the energization OFF signal.

In the image forming apparatus configured as described above, the power supply to the heater 8 is stopped when the fixing and conveying unit 3 is pulled out as follows.

When the front door 73 is closed, the power supply from the AC power supply 12 to the heater 8 is stopped by the front door open / close detection mechanism 9.

Now, assuming that the front door 73 is opened in order to pull out the fixing and conveying unit 3 from the image forming apparatus main body 51, the power supply from the AC power supply 12 to the heater 8 is stopped by the front door open / close detection mechanism 9. . Thereby, the front door 7
Safety when opening the work 3 is ensured. At the same time, the front door opening / closing detection mechanism 9 switches the front door 7
Is sent to the CPU 10 when it is detected that the is opened.

By the way, for example, when the service person operates the front door 7
It is necessary to be able to repair the inside of the image forming apparatus main body 51 while operating the image forming apparatus main body 51 with the 3 opened. For this reason, even if the front door 73 is kept open, a jig (not shown) is used to make the front door open / close detection mechanism 9 recognize that the front door 73 is closed.
In this case, even if the front door 73 is actually open, the front door open / close detection mechanism 9 is made to recognize that the front door 73 is closed by the jig. However, in the present invention, even if the front door opening / closing detecting mechanism 9 recognizes that the front door 73 is closed and outputs a signal indicating that the front door 73 is closed to the CPU 10, the fixing and conveying unit 3 is moved to the image forming apparatus main body 5.
When the battery is pulled out from the position 1, the power supply to the heater 8 is automatically stopped as described below.

The fixing and conveying unit 3 is connected to the image forming apparatus main body 5.
Before pulling out from the position 1, the release lever 6 is tilted to release the state in which the fixing and conveying unit 3 is locked to the image forming apparatus main body 51. Then, the detection flag 6B of the released release lever 6 enters the U-shaped position detection sensor 7 as shown in FIG. Accordingly, the position detection sensor 7 detects that the lock of the fixing and conveying unit 3 has been released, and outputs a signal indicating that the lock has been released. The CPU 10 that has received the lock release detection signal from the position detection sensor 7 outputs a signal for instructing the heater driving device 11 to stop supplying power to the heater 8. The heater driving device 11 outputs an energization OFF signal to the heater 8 based on the command signal from the CPU 10. The energization OFF signal from the heater driving device 11 is
, The power supply to the heater 8 is stopped.

As described above, when the fixing / conveying unit 3 is pulled out, the power supply to the heater 8 is automatically stopped.
Leakage does not occur even if the contacts of the heater energizing connector (not shown) are separated, and the life of the connector is not shortened.

According to the present invention, when the contact of the connector for energizing the heater is released, the energization of the heater 8 is reliably stopped. Door open / close detection mechanism 9
Can be simplified to a sensor that simply detects opening and closing of the front door 73. In this case, the cost can be reduced.

In the above-described embodiment, the fixing device 56 is an example of a movable type in which the fixing means can be pulled out.
Although the fixing and conveying unit 3 in which the fixing belt 56 and the conveying belt 69 are integrally mounted is shown, the present invention is not limited thereto, and the present invention can be applied to a case where only the fixing device 56 as a fixing unit can be pulled out. .

[0045]

According to the image forming apparatus of the present invention described above, when the fixing means is pulled out of the image forming apparatus main body, the lock of the fixing means to the image forming apparatus main body is released. Is detected, the heater control means stops supplying power to the heater. That is, despite the fact that the front door opening / closing detection mechanism recognizes that the front door is closed by the action of the jig, the heater is energized in accordance with the operation of the release unit when the fixing unit is pulled out. Is automatically stopped. Therefore, when pulling out the fixing means,
Even if the contacts of the connector for energizing the heater are separated, no leakage occurs, and the life of the connector is not shortened. Therefore, when the jig is used at the time of a line process or at the time of repair by a service person, it is not necessary to remove the jig when pulling out the fixing means,
It is possible to improve efficiency in terms of productivity of the image forming apparatus and workability during service.

Even if the user forgets to remove the jig when pulling out the fixing means, the power supply to the heater is automatically stopped, so that the life of the connector can be reliably prevented from being shortened, and the reliability of the connector can be improved. Can be realized.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an example of a fixing and conveying unit provided in an image forming apparatus of the present invention.

2A and 2B show a releasing unit and a position detecting unit provided in the fixing and conveying unit of FIG. 1; FIG. 2A shows a case where the fixing and conveying unit is in a locked state, and FIG. This shows a case where the fixing and conveying unit is in an unlocked state.

FIG. 3 is a block diagram illustrating a heater of a fixing unit of the fixing and conveying unit of FIG.

FIG. 4 is an overall schematic diagram of an image forming apparatus for explaining the present invention and a conventional example.

FIG. 5 is a perspective view of an image forming apparatus for explaining an example of a conventional jam processing.

FIG. 6 is a perspective view of an image forming apparatus for explaining another example of the conventional jam processing.

FIG. 7 is a perspective view of an image forming apparatus for explaining still another example of the conventional jam processing.

FIG. 8 is a perspective view of an image forming apparatus for explaining still another example of the conventional jam processing.

FIG. 9 is an operation state diagram showing a state in which the fixing and conveying unit of the conventional example is pulled out.

[Explanation of symbols]

 Reference Signs List 3 Fixing / conveying unit 6 Release lever (release means) 7 Position detection sensor (position detection means) 8 Heater 9 Front door open / close detection mechanism 10 CPU (heater control means) 11 Heater driving device (heater control means) 51 Image forming apparatus main body 56 Fixing device (fixing means) 69 Conveyor belt 73 Front door

Claims (1)

[Claims] A fixing means for fixing the toner transferred onto the transfer material using a heater, which is provided in the main body of the image forming apparatus, and a heater control means for controlling power supply to the heater of the fixing means. An image forming apparatus having a fixing means for releasing a state in which the fixing means is locked to the image forming apparatus main body, wherein a position detecting means for detecting a position of the releasing means is provided; An image forming apparatus, wherein the power supply to the heater is stopped by a signal indicating that the lock of the fixing unit is released.