JPH0635360A - Fixing device for electrophotographic recorder - Google Patents

Abstract

PURPOSE:To prevent dew condensation on a top board on the upper part of a heating roller by providing a moisture absorbing member on a carrying path. CONSTITUTION:A transferring paper is pinched and fed between the heating roller 17 as a heat source and a pressuring roller 11 whose surface is coated with rubber, so that a toner image on a surface is thermally fixed on the transferring paper. Since the transferring paper is stuck to the heating roller 17, it is peeled by a separation pawl 20. The transferring paper on which the toner image is fixed obtains stiffness through a roller 23 and is fed to the external part of the device. When the paper is thermally fixed, moisture included becomes vapor to be condensed into dew on the top board of the carrying path 19, so that an absorptive the flexible sheet member (moisture absorbing member 21) is stuck to the top board of the carrying path, and the transferring paper is prevented from being wet by the drop of water by means of the dew condensation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device for an electrophotographic recording device, and more particularly to a fixing device for preventing dew condensation on a conveying path in an electrophotographic recording device for thermally fixing a toner image on a transfer paper. . For example, it is applied to a facsimile, a printer, a copying machine and the like.

[0002]

2. Description of the Related Art Known publications describing the prior art relating to the present invention include, for example, JP-A-3-196173 and
There is one disclosed in Japanese Patent Laid-Open No. 3-196079. JP-A-3
The "fixing device" of Japanese Patent Laid-Open No. 196173 is a device in which a film-shaped transparent plate having a water drop adhesion preventing effect is attached to the light emitting element and the light receiving element of the optical sensor in order to prevent dew condensation on the surface of the optical sensor. The "image forming apparatus" disclosed in Japanese Patent Laid-Open No. 3-196079 detects the widthwise size of the transfer material in the paper feed cassette in order to control the temperature of the fixing device.

Generally, an electrophotographic recording apparatus pre-charges a photosensitive belt and then performs optical writing to form an electrostatic latent image. Toner is applied to the electrostatic latent image to develop the latent image, and then the toner image is formed, and then the toner image is transferred to a separately supplied recording paper. The recording paper on which the toner image has been transferred is heated and fixed and discharged, while the toner remaining on the photoconductor is scraped off by a cleaning blade and collected as waste toner. To do. The most common fixing device used in such an electrophotographic recording device is
It is "heat roller fixing". This "heat roller fixing" method fixes the toner image on the transfer paper by sandwiching it between a heat roller with a heating element such as a halogen lamp and a pressure roller whose surface is covered with heat-resistant rubber, and then carrying it out. This method is suitable for high-speed specifications. A drawback of this fixing method is that the water contained in the transfer paper evaporates at the time of fixing and the top plate above the heat roller condenses. Although there is no conventional technique for preventing the top plate from dew condensation, there is a means for detecting the size of the transfer material or providing a cooling means as a means for controlling the temperature of the fixing device. Some of them are used to prevent dew condensation on the sensor.

The following problems are caused by the dew condensation on the top plate. The discharged transfer paper gets wet with water droplets generated by dew condensation on the top plate. In a device (full front operation device) in which keyboard operations, toner replenishment, paper replenishment and discharge are concentrated on the front (full front operation device), the user's clothes and the like will be wet when the jam is removed. In order to prevent the above troubles during fixing, it is best to lower the temperature of the halogen lamp inside the heat roller, but this temperature is set in consideration of the fixability of each toner to the transfer paper, It cannot be lowered easily.

[0005]

[Purpose] The present invention has been made in view of the above circumstances, prevents condensation on the top plate of a heat roller without lowering the temperature of a halogen lamp or the like, and prevents the transfer paper from getting wet with water droplets or from the user. It is an object of the present invention to provide a fixing device for an electrophotographic recording device capable of preventing the clothes from getting wet.

[0006]

In order to achieve the above object, the present invention provides (1)
A fixing device for fixing a toner image on a medium by heat, and a fixing device of an electrophotographic recording device formed by a medium conveying path after the fixing device, wherein a water absorbing member is provided in the conveying path, or (2) A fixing device for fixing a toner image on a medium by heat, and a fixing device of an electrophotographic recording device formed by a medium conveying path at a stage subsequent to the fixing device,
A water absorbing member is provided on the conveying path, and a cleaning pad is attached to the water absorbing member, or (3) a fixing device for fixing the toner image on the medium by heat, and a medium conveying path after the fixing device. In the fixing device of the electrophotographic recording apparatus formed by the above, a water absorbing member is provided in the conveying path, and the water absorbing member can be replaced by a winding type, or (4) the toner image on the medium is heated. In a fixing device of an electrophotographic recording apparatus, which is formed by a fixing device for fixing and a medium conveying path downstream of the fixing device, a water absorbing member is provided in the conveying path, and a cleaning pad is attached to the water absorbing member. The water absorbing member and the cleaning pad are rollable and replaceable. Hereinafter, description will be given based on examples of the present invention.

First, the structure of the electrophotographic recording apparatus will be described with reference to FIG. In the figure, 1 is a photoconductor, 2 is a precharger, 3 is an exposure unit, 4 is a developing unit, 5 is a transfer unit, and 6
Is a fixing device, 7 is a static eliminator, 8 is a CTM (cleaner toner magazine), 9 is a toner replenishing tank part, 10 is a spiral, 11 is a pressure roller, 12 is a waste toner tank part, 1
3 is a holder, 14 is a cleaning blade, 15 is a transfer paper, 16 is a halogen lamp, and 17 is a heat roller.
A process unit including the photoconductor 1, the precharger 2, the exposure unit 3, the developing unit 4, the transfer unit 5, the fixing unit 6 and the static eliminator 7, and C as a cleaning unit and a toner replenishing unit.
TM8 is installed. To supply toner to the developing device 4,
The removal of the residual toner on the photoconductor after the transfer is performed by the spiral 10 inside the toner supply tank unit 9 through the drop duct by the contact of the cleaning blade 14 held by the holder 13 of the waste toner tank unit 12. The waste toner tank portion 12 is housed inside. on the other hand,
The transfer paper 15 on which the toner image is transferred by the transfer device 5 is
It is fixed by a fixing device 6 which is composed of a heat roller 17 having a halogen lamp 16 charged therein and a pressure roller 11 whose surface is covered with rubber, and is discharged to the outside of the apparatus.

FIG. 1 is a block diagram for explaining an embodiment (claim 1) of the fixing device according to the present invention. In the figure, 19 is a conveying path top plate, 20 is a separation claw, and 21 is a moisture absorbing member. , 22
Is a cleaning pad, 23 is a waist-rolling roller, and other parts having the same functions as those in FIG. As a heat source, a heat roller 17 having a halogen lamp 16 inside a hollow is pressed against a pressure roller 11 whose surface is covered with rubber with a slight nip.
The transfer paper is conveyed while being sandwiched between the transfer paper and the toner image on the surface of the transfer paper is thermally fixed on the transfer paper. At that time, the transfer paper adheres to the heat roller 17 and is peeled off by the separation claw 20. In order to improve the releasability of the surface of the heat roller 17, the cleaning pad 22 soaked with lubricating oil is pressed against the heat roller 17. The transfer paper on which the toner image has been fixed is stiffened by the stiffening roller 23 and is sent out of the apparatus. When the paper is heat-fixed, the moisture contained therein turns into water vapor, and the conveyance path top plate 1
Since 9 is condensed, a water-absorbing flexible sheet member (water absorbing member 21) is attached to the top plate of the transport path to prevent water drops from condensing and wet the transfer paper.

FIG. 2 is a view showing another embodiment (claim 2) of the fixing device according to the present invention, and the reference numerals in the drawing are the same as those in FIG. 1 is different from the embodiment of FIG. 1 in that a water-absorbent flexible sheet member is bent in a V shape so that a folding portion serves as a boundary, and one is used as a water absorbing member 21 and the other is used as a cleaning pad. 22 is that the water absorbing member 21 side is attached to the conveyance path top plate 19 and the cleaning pad 22 side is brought into contact with the heat roller 17.

FIG. 3 is a view showing still another embodiment (claim 3) of the fixing device according to the present invention. The difference from the embodiment of FIG. As shown in FIG. 5, the sheet member is formed into a belt to support roller 25.
It is possible to rotate by a driving device by supporting it with. By doing so, it is possible to improve the water absorption rate when a larger amount of water vapor than usual is generated as in the case of continuous copying. Further, since the belt and the supporting roller are contained in the case 24, they can be easily replaced when the water absorption becomes poor.

FIG. 4 is a diagram showing still another embodiment (claim 4) of the fixing device according to the present invention. The basic construction is as shown in FIG.
Same as the above example, but half of the belt-shaped water-absorbent flexible sheet member is located at the position of the transfer paper conveyance path top plate 19 as the moisture absorbing member 21, and the other half is soaked with lubricating oil. The heating pad 17 has become a cleaning pad 22.
Touches. As shown in FIG. 6, the belt is rotated by a driving device. The belt and support roller are
Since it is housed in the case 24, it can be easily replaced when the water absorption becomes poor.

[0012]

As is apparent from the above description, the present invention has the following effects. (1) Effect corresponding to claim 1: Since the moisture absorbing member is set on the top plate of the paper transport path for transfer, dew condensation on the top plate due to evaporation of water inside the transfer paper that occurs during heat fixing is prevented. it can. Therefore, when you want to prevent jamming of paper in a device (full front operation device) that prevents rusting of the machine due to condensation and concentrates keyboard operation, toner supply, paper supply and discharge on the front side. In addition, it is possible to prevent the user's clothes from getting wet. (2) Effect corresponding to claim 2: Half of one member is soaked with a lubrication pad and brought into contact with the heat roller, and the other side is set at the position of the transfer paper conveyance path top plate, so that a separate heat roller is used. Since it is not necessary to attach a cleaning pad, the number of parts can be reduced, cost can be reduced, and keyboard operation, toner replenishment, paper replenishment and discharge can be concentrated on the front (full front operation device). In (), it is possible to prevent the user's clothes from getting wet and prevent the machine from being rusted due to dew condensation when the jam is removed. (3) Effect corresponding to claim 3: The water-absorbent flexible sheet member is covered with a belt to cover it with a case, and it is set on the transfer sheet conveyance path top plate so that it can be easily detached from the front surface of the apparatus as a cassette type. Therefore, it is possible to prevent jamming etc. in a device (full front operation device) that prevents rusting of the machine due to condensation and concentrates keyboard operation, toner supply, paper supply and discharge on the front side. If you want to
The user's clothes can be prevented from getting wet, and the water absorbing member can be easily replaced by the user's hand. (4) Effect corresponding to claim 4: Half of one belt-shaped member is soaked with lubricating oil and brought into contact with a heat roller, and the other side is used as a moisture absorbing member at the top of the transfer paper transport path in a case. Since it is covered and cassette type and can be replaced from the front, rusting of the machine due to condensation due to rotation of the belt-shaped member can be prevented for a long time, and keyboard operation, toner supply, paper supply and discharge In a device that concentrates the front surface (full front operation device), it is possible to prevent the user's clothes from getting wet when jamming etc., and there is no need to provide a separate cleaning pad. The heat roller can be cleaned over a long period of time. Moreover, this cassette can be easily replaced by the user.

[Brief description of drawings]

FIG. 1 is a configuration diagram for explaining an embodiment of a fixing device of an electrophotographic recording apparatus according to the present invention.

FIG. 2 is a diagram showing another embodiment of the fixing device of the electrophotographic recording apparatus according to the present invention.

FIG. 3 is a view showing still another embodiment of the fixing device of the electrophotographic recording apparatus according to the present invention.

FIG. 4 is a view showing still another embodiment of the fixing device of the electrophotographic recording apparatus according to the present invention.

5 is a diagram showing a moisture absorbing member in the embodiment of FIG.

FIG. 6 is a diagram showing a water absorbing member and a cleaning pad in the embodiment of FIG.

FIG. 7 is a diagram showing an overall configuration diagram of an electrophotographic recording apparatus to which the present invention is applied.

[Explanation of symbols]

19 ... Conveying path top plate, 20 ... Separation claw, 21 ... Moisture absorbing member, 22 ... Cleaning pad, 23 ... Waisting roller,
24 ... Case, 25 ... Support roller.

Claims (4)

[Claims] 1. A fixing device for fixing a toner image on a medium by heat, and a fixing device of an electrophotographic recording apparatus, which is formed by a medium conveying path after the fixing device, wherein a water absorbing member is provided in the conveying path. A fixing device for an electrophotographic recording device, which is characterized in that 2. A fixing device for fixing a toner image on a medium by heat, and a fixing device of an electrophotographic recording apparatus, which is formed by a medium conveying path after the fixing device, wherein a water absorbing member is provided in the conveying path. A fixing device for an electrophotographic recording apparatus, wherein a cleaning pad is attached to the moisture absorbing member. 3. A fixing device for fixing a toner image on a medium by heat, and a fixing device for an electrophotographic recording apparatus, which is formed by a medium conveying path after the fixing device, wherein a water absorbing member is provided in the conveying path. A fixing device for an electrophotographic recording apparatus, wherein the water absorbing member is a roll-up type and replaceable. 4. A fixing device for fixing a toner image on a medium by heat, and a fixing device of an electrophotographic recording apparatus, which is formed by a medium conveying path after the fixing device, wherein a water absorbing member is provided in the conveying path. A fixing device for an electrophotographic recording apparatus, wherein a cleaning pad is attached to the water absorbing member, and the water absorbing member and the cleaning pad can be exchanged in a winding type.