JP2001134162A - Damper device for image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a damper device of an image forming device, by which the image forming device is made lightweight and compact, a half-shut state is evaded and a fault in a carrying state or image quality is prevented. SOLUTION: The image forming device provided with an image forming means, a fixing device and an opening/closing possible door is constituted in such a way that the damper device for generating an energizing force when the door is closed is arranged at the inner side of the door to evade the half- shut state by closing the door through the use of the damper device even unless the door is perfectly closed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine, when a door becomes a half-door, a manual response (closure) is performed by a user, and the door is turned on / off by a projection provided inside the door. Equipped with an open / close detection sensor that turns off, paper jams in the fixing device are generally performed by a type that shuts off the drive system to the fixing device by opening and closing the door or a type that releases the pressing force manually by the user. . In general, such a door is opened and closed using its own weight, and a torque-type damper device may be provided at the center of rotation. As a damper device for such an image forming apparatus, for example, in Japanese Patent Application Laid-Open No. 8-95417 and Japanese Patent Application Laid-Open No. 10-162684, a knob for removing a paper jam is pressed with the front door closed. Thus, there is described a mechanism (interlock mechanism) in which the interlocking device of the apparatus main body and the fixing device is released in conjunction with the pressing.

[0003]

Generally, a door provided in an image forming apparatus such as a copying machine is opened and closed for the purpose of paper jam or toner replenishment inside the apparatus. It functioned as a protective cover only to protect the user from gears and high-pressure parts. However, in recent years, the door itself tends to be heavy because an image forming member and a transfer sheet conveying member are provided inside the door in order to reduce the size and weight of the image forming apparatus. For this reason, if a mechanism that opens and closes the door slowly around the fulcrum is not provided, the door will open under its own weight unless it is manually held, or members in the opening and closing path of this door may be damaged. , The user may be injured. As a closing mechanism after the door is closed, a mechanism using a magnetized lock by a magnet, a lever, and a claw is used. However, when a plurality of magnets are used, even if one magnet is magnetized, if the other magnets are not magnetized well, the door may be closed in a "half door" state. On the other hand, even when the lever and the claw are used, the door may be half-open due to friction such as the above-described contact between the image forming unit and the paper conveying unit in the process of closing the door. When a copying operation is performed in such a half-door state, light may enter the image forming apparatus from the outside to cause an image abnormality, or the door may open during paper conveyance, causing a paper jam. Would.

As means for removing a paper jam in the fixing device, the driving of the fixing device is temporarily released, and at the same time, the pressing force between the fixing roller and the pressure roller is released to remove the paper jam. In this case, a mechanism that achieves the above-mentioned method with a wire or cam mechanism is provided in conjunction with opening and closing of the door, but in a copying machine etc. set at low price, cost reduction in addition to size and weight reduction More and more users manually perform these tasks in order to achieve this. Further, in the case of the above-mentioned conventional publication, the size of the device itself increases as the number of components increases, and thus it is not possible to cope with recent reductions in size and weight.

[0005]

In order to achieve the above object, the present invention is directed to an image forming apparatus having an image forming means, a fixing device, and a door which can be opened and closed. A damper device is provided inside the door to generate an urging force when the door is closed.

According to a second aspect of the present invention, in the first aspect of the present invention, a detection switch for detecting opening and closing of the door is provided, and the damper device operates in conjunction with the detection switch. .

According to a third aspect of the present invention, in the first aspect, a magnet is provided at a tip portion of the damper device.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the operation control device for controlling the operation of the damper device is attached to the damper device.

According to a fifth aspect of the present invention, in the first aspect of the present invention, an operating member for operating the damper device is provided, and the operating member controls the pressing force between the fixing roller and the pressure roller of the fixing device. Therefore, it is characterized in that it is interlocked with the pressure control lever.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the conventional damper device of the image forming apparatus, to reduce the size and weight, to avoid the half-door state, and to improve the transportation state and image quality. An object of the present invention is to provide a damper device for an image forming apparatus that can prevent quality defects.

[0011]

FIG. 1 is a schematic front view of an image forming apparatus according to the present invention. Here, the present invention is characterized in that by providing a damper device inside the door, when the door is not completely closed, the door is pushed back. With this damper device, the half-door state can be avoided, and the above-described problems such as image and conveyance failure can be prevented. Hereinafter, the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, a photoreceptor 2 is provided inside an image forming apparatus 1, and a charging device 3 for performing a charging process on the photoreceptor 2 is provided around the photoreceptor 2. An exposure device 4 having a polygon mirror for reading a document image, a scanner unit, a CCD sensor, and the like, and irradiating image information by a laser beam onto the surface of the photoconductor 2, and an electrostatic latent image exposed on the surface of the photoconductor 2; A developing device 5 for visualizing, a transfer device 6 for transferring a toner image developed on the photoreceptor 2 to a sheet, and a cleaning device 7 for removing and collecting toner remaining on the surface of the photoreceptor 2 after transfer are arranged at respective predetermined positions. Have been. The transfer device 6 transfers the electrostatic latent image formed on the photoconductor 2 to transfer paper. Further, a fixing device 8 for fixing an unfixed toner image on the transfer sheet is disposed downstream of the transfer path of the transfer sheet. This fixing device 8
Has a fixing roller 17 having a heating heater 9 therein and a pressure roller 18. The pressure roller 18 is constantly pressed toward the fixing roller 17 by the elastic force of a pressure spring 20 provided on a pressure lever 19. ing. Therefore, the unfixed toner image is fixed by the heat generated by the heater 9 and the pressing force.

Reference numeral 11 denotes a paper feeder for feeding paper (transfer paper). The paper in the paper feeder 11 is lifted by a spring 16 provided below the bottom plate 11a, and its uppermost paper is moved. The transfer paper is separated by the separation means 12 and fed by the feed roller 13. The transfer paper fed in this way is abutted against the registration roller 14 and temporarily stopped.
The image is conveyed again by the rotation of the registration roller 14 in synchronization with the above image, and the electrostatic latent image on the photoconductor 2 is transferred by the transfer device 6. Next, the transfer paper is separated from the photoreceptor 2 by a separator (not shown), and then conveyed to a fixing device 8 via a conveyance path, where the copy image is fixed. Thereafter, the copy paper is discharged by the paper discharge device 15, and a series of copy operations is completed.

Reference numeral 22 denotes a door which can be opened and closed about a fulcrum 21. A magnet 23 is fixedly provided at the upper end of the door 22, and the magnet 23 is magnetized on the main body 1a side. The door 22 is closed by this magnetizing force. Further, as shown in FIG. 1, a damper device 24 is provided on the main body side of the image forming apparatus 1 and at a position facing the upper side of the door 22. The damper device 24 is constituted by a hollow housing cap 26, and a pressure spring 25 having an urging force is fitted therein. For this door
Immediately before the state in which the door 22 is completely closed, the urging force in the opening direction of the door 22 is applied by the damper device 24.
Here, even though the magnet 23 of the door 22 is magnetized on the main body side 1a, that is, the door 22 is completely closed, this urging force acts, but the magnetizing force of the magnet 23 itself is set relatively strong. This does not prevent the door 22 from closing completely. Further, even when a plurality of magnets 23 are provided to increase the magnetizing force, the holding state of the door 22 can be avoided only by the magnetizing force of only one magnet 23 by adjusting the operation stroke of the damper device 24. Become like As a result, the door 22 is completely closed by the magnetizing force of the magnet 23, so that the half-door state can be reliably avoided. In addition, this damper device 24
In addition to the pressure spring 25 of the present embodiment, a configuration in which the housing cap 26 is covered or a syringe-type configuration utilizing the compressive force of air may be used.

Further, as shown in FIG. 1, when a door opening / closing detection sensor 27 is provided inside the image forming apparatus 1 in conjunction with the operation of the damper device 24, the image and the image can be displayed even when the door is in the half-door state. Inconveniences such as poor conveyance can be prevented. That is, a part of the housing cap 26 of the damper device 24 is used as a pressing portion 39 for turning on / off the door open / close detection sensor 27, and when the door 22 is closed in a completely closed state, the pressing portion 39 Door open / close detection sensor 27 is ON
It can be so. As a result, even when the door 22 is in a half-door state due to, for example, deformation of the door 22 or poor magnetization of the magnet, the power supply line is cut off in this half-door state because the door open / close detection sensor 27 remains OFF. Therefore, the copying operation cannot be started.
The door opening / closing detection sensor 27 is configured such that the door opening / closing detection sensor 27 is directly connected to the pressure spring 25, and the door opening / closing detection sensor 27 is activated (ON) when a predetermined or more urging force is applied to the pressure spring 25. You may make it.

FIG. 2 shows a second embodiment of the present invention. That is, as shown in FIG. 2, a magnet 28 is provided at a tip portion of the damper device 24a, and an iron plate 29 is provided inside the door 22 and at a position facing the magnet 28 when closed. With this configuration, the door open / close detection sensor 27
At "b point" which is open outward from "a point" to be flipped,
The door 22 can be once held by the magnetizing force of the magnet 28. As a result, when the door is closed, the door and the damper device 24a are magnetized by the magnetizing force of the magnet, and even if the user releases his hand when the door 22 is opened, the door 22 is once opened slightly. As a result, when the door 22 is opened again, it is possible to prevent the door 22 and nearby objects from being erroneously damaged. Here, the mounting positional relationship between the magnet 28 and the iron plate 29 may be opposite to that of the present embodiment, and furthermore, if it has a strong holding force to some extent such as Velcro (registered trademark), it is used as a substitute for the magnet 28 and the iron plate 29. It is also possible.

FIG. 3 shows a third embodiment of the present invention. In this embodiment, a torque damper device 30 is provided at a position adjacent to a damper device 24b.
b is a mechanism that operates relatively gently. That is, as shown in FIG. 3, the torque damper device 30 has a gear 31 that rotates under a certain load.
At the lower part of b, rack teeth 40 which can be engaged with the gear 31 are formed. Accordingly, the gear 31 is driven by the operation of the damper device 24b.
Is rotated, and a torque (load) is generated by the torque damper device 30, so that the urging force of the pressure spring 25 is absorbed and the sudden operation of the damper device 24b can be prevented. Here, the torque damper device 30 includes a device that generates torque only in one-side rotation and a device that generates torque in both-side rotation. For this reason, when the door 22 is suddenly closed and there is a component that may be damaged in the image forming apparatus 1, a torque damper device 30 that generates torque for both rotations.
When the door 22 is used, the damper device 24b can be operated with a slow operation both when the door 22 is closed and when it is opened. By slowly operating the damper device 24b in this manner, the operability by the user can be improved, and a sense of quality can be produced.

FIG. 4 shows a fourth embodiment of the present invention. That is, in the fourth embodiment, the damper device 24c has a pair of housing caps 26a and 26b, and the rear end of one housing cap 26b is slidably fitted into the other housing cap 26a. It has a closed structure. The inner diameter of the housing cap 26a and the outer dimensions of the housing cap 26b are substantially the same, and a small hole 32 for exhaust is formed in the lower part of the housing cap 26a. Therefore, when the damper device 24c is operated, the compressed air acts inside the damper device 24c as the housing cap 26b slides, so that the elasticity of the pressure spring 25 is absorbed. The operation will be relatively gentle. This eliminates the need to separately provide the torque damper device 30 in the damper device 24c, which can contribute to cost reduction by reducing parts.

FIG. 5 shows a fifth embodiment of the present invention. The feature of the fifth embodiment is that the pressure of the fixing device is released by using a damper device that operates by opening a door without using a wire, a cam mechanism, or the like, which has been conventionally used. That is, the support shaft is provided at the lower part of the damper device 24d.
An extension 35 having a support 35a is provided at the upper end of the pressure lever 19 which is rotatable about the support 32.
a is provided, and a connecting link 33 is rotatably interposed between the support shafts 19a and 35a. The connecting link 33 is rotatable about a support shaft 34. Therefore, when the damper device 24d is not operated, the connecting link 33 remains deviated in the X direction, so that the pressing roller 18 is constantly applied to the fixing roller 17 by the elastic force of the pressing spring 20 provided on the pressing lever 19. It is under pressure. On the other hand, when the door 22 is opened, the connecting link is
Since 33 is biased in the Y direction, the pressure lever 19 is also biased counterclockwise against the elasticity of the pressure spring 20, and as a result,
The pressing of the fixing roller 17 by the pressing roller 18 is released. As a result, it is possible to easily remove the jammed paper in the fixing device 8 or the conveyance path.

[0020]

The present invention is as described above. According to the first aspect of the present invention, there is provided an image forming apparatus having an image forming means, a fixing device, and a door which can be opened and closed. Since a damper device that generates a biasing force when the door is closed is provided, even if the door is not completely closed, the door can be pushed back by the damper device, thereby avoiding a half-door state, so that images and conveyance can be avoided. There is an effect that defects such as defects can be prevented.

According to a second aspect of the present invention, in the first aspect of the present invention, a door detection switch for detecting opening and closing of the door is provided, and the damper device operates in conjunction with the detection switch. Even in the case of the state, since the detection switch is not turned ON, the image forming operation cannot be started, and as a result, it is possible to reliably prevent problems such as image and conveyance failure.

According to a third aspect of the present invention, in the first aspect of the present invention, since a magnet is provided at a tip portion of the damper device, even if the user releases his hand when opening the door, once the door is opened, The door can be held in a slightly opened state, and there is an effect that it is possible to prevent a problem that the door or a nearby object is accidentally damaged when the door is opened.

According to a fourth aspect of the present invention, since the operation control device for controlling the operation of the damper device is attached to the damper device in the first aspect of the invention, the operation of the damper device can be performed slowly. Therefore, there is an effect that the operability is further improved, and a sense of quality can be provided.

According to a fifth aspect of the present invention, in the first aspect of the present invention, an operating member for operating the damper device is provided, and the operating member controls the pressing force between the fixing roller and the pressure roller of the fixing device. Because it is interlocked with the pressure control lever, the function of the damper device is exhibited, and the pressure of the fixing device is released by opening the door, so that paper jam in the fixing device can be performed without bothering the user. There is an effect that it can be easily removed.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view showing a first embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of a damper device according to a second embodiment.

FIG. 3 is an enlarged view of a main part of a damper device according to a third embodiment.

FIG. 4 is an enlarged view of a main part of a damper device according to a fourth embodiment.

FIG. 5 is an enlarged view of a main part of a damper device and a fixing device according to a fifth embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 image forming device 2 photoreceptor 3 charging device 4 exposure device 5 developing device 8 fixing device 17 fixing roller 18 pressure roller 19 pressure lever 20 pressure spring 21 fulcrum 22 door 23, 28 magnet 24, 24a, 24b, 24c damper Device 25 Pressure spring 26, 26a, 26b Housing cap 27 Door open / close detection sensor 29 Iron plate 30 Torque damper device 33 Connecting link

Claims (5)

[Claims] 1. An image forming apparatus comprising an image forming means, a fixing device and an openable / closable door, wherein a damper device for generating an urging force when the door is closed is provided inside the door. Damper device. 2. The damper device for an image forming apparatus according to claim 1, further comprising a detection switch for detecting opening and closing of the door, wherein the damper device operates in conjunction with the detection switch. 3. The damper device for an image forming apparatus according to claim 1, wherein a magnet is provided at a tip portion of the damper device. 4. The damper device for an image forming apparatus according to claim 1, wherein an operation control device for controlling the operation of the damper device is attached to the damper device. 5. An operation member for operating a damper device, wherein the operation member is interlocked with a pressure control lever for controlling a pressing force between a fixing roller and a pressure roller of the fixing device. A damper device for the image forming apparatus according to claim 1.