JP3121133B2 - Fixing device for electrophotographic recording device - Google Patents

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 transfer paper. . For example, the present invention is applied to a facsimile, a printer, a copying machine, and the like.

[0002]

2. Description of the Related Art Known documents describing the prior art according to the present invention include, for example, Japanese Patent Application Laid-Open No. 3-196173,
There is one disclosed in Japanese Patent Application Laid-Open No. 3-19679. JP Hei 3
In the "fixing device" of JP-A-196173, in order to prevent dew condensation on the surface of the optical sensor, a light-emitting element and a light-receiving element of the optical sensor are attached with a film-shaped transparent plate having an effect of preventing water droplets from adhering. An "image forming apparatus" disclosed in Japanese Patent Application Laid-Open No. HEI 3-19679 detects the width of a transfer material in a sheet cassette in the width direction in order to control the temperature of a fixing device.

In general, an electrophotographic recording apparatus forms an electrostatic latent image by performing optical writing after precharging a photosensitive belt. After toner is applied to the electrostatic latent image and developed to form a toner image, the toner image is transferred to a separately supplied recording sheet. The recording paper onto which the toner image has been transferred is heated, fixed and discharged, while the toner remaining on the photoreceptor is scraped off with a cleaning blade and collected as waste toner. I do. The most common fixing device used in such an electrophotographic recording device is:
"Heat roller fixing". In this "heat roller fixing" method, a toner image is fixed on transfer paper by being sandwiched between a heat roller in which a heating element such as a halogen lamp or the like and a pressure roller coated on the surface with heat-resistant rubber and carried out. Suitable for high-speed specifications. As a drawback of this fixing method, it is pointed out that moisture contained in the transfer paper evaporates at the time of fixing and the top plate above the heat roller forms dew. There is no conventional technology for preventing condensation on the top plate.However, as a means for controlling the temperature of the fixing device, there is a device for detecting the size of the transfer material or providing a cooling device. Some of them are used to prevent condensation on the sensor.

[0004] Obstacles caused by condensation on the top plate include the following. The discharged transfer paper is wetted by water droplets generated by condensation on the top plate. In a device (full front operation device) in which keyboard operation, toner replenishment, paper replenishment and discharge are concentrated on the front surface, user's clothes and the like are wet when a jam is cleared. In order to prevent the above-mentioned trouble at the time of fixing, it is best to lower the temperature of the halogen lamp inside the heat roller. However, since this temperature is set in consideration of the fixability of each toner to the transfer paper, It cannot be lowered easily.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and prevents dew condensation on a top plate above a heat roller without lowering the temperature of a halogen lamp or the like, and prevents transfer paper from being wet by water droplets or a user's It is an object of the present invention to provide a fixing device for an electrophotographic recording apparatus capable of preventing clothes from getting wet.

[0006]

[Configuration] The present invention, in order to achieve the object, (1)
In a fixing device for fixing a toner image on a medium by heat and a fixing device of an electrophotographic recording apparatus formed by a medium conveyance path subsequent to the fixing apparatus, a water absorption member is provided on the conveyance path top plate, and the water absorption member is provided. A cleaning pad is attached to the absorbing member, or (2) the moisture absorbing member and the
The bending pad is formed by bending a flexible sheet member
It is obtained by forming, or (3) a fixing device which the toner image of the medium is fixed by heat, the fixing device of the electrophotographic recording apparatus which is formed by the conveying path of the subsequent medium fixing device, the transport moisture in the cases of the cassette-type to the road
An absorbent member and a cleaning pad are provided, and the moisture absorbing member and the cleaning pad are rewindable and replaceable. Hereinafter, a description will be given based on examples of the present invention.

First, a configuration of the electrophotographic recording apparatus will be described with reference to FIG. In the figure, 1 is a photoreceptor, 2 is a precharger, 3 is an exposure unit, 4 is a developing device, 5 is a transfer device, 6
Denotes a fixing unit, 7 denotes a static eliminator, 8 denotes a CTM (cleaner / toner magazine), 9 denotes a toner supply tank unit, 10 denotes a spiral, 11 denotes a pressure roller, and 12 denotes a waste toner tank unit.
Reference numeral 3 denotes a holder, 14 denotes a cleaning blade, 15 denotes transfer paper, 16 denotes a halogen lamp, and 17 denotes a heat roller.
Process means including photoreceptor 1, precharger 2, exposure unit 3, developing unit 4, transfer unit 5, fixing unit 6, static eliminator 7, etc., and C as cleaning unit and toner replenishing unit
TM8 is mounted. Toner supply to the developing device 4
Removal is performed through a drop duct by a spiral 10 inside the toner supply tank unit 9, and removal of residual toner on the photoreceptor after transfer is performed by contact of a cleaning blade 14 held by a holder 13 of a waste toner tank unit 12. Are stored in the waste toner tank unit 12. on the other hand,
The transfer paper 15 to which the toner image has been transferred by the transfer device 5 is
The fixing is performed by a fixing device 6 composed of a heat roller 17 in which a halogen lamp 16 is charged and a pressure roller 11 whose surface is covered with rubber, and is discharged to the outside of the apparatus.

[0008] Figure 1 is a block diagram for explaining a fixing equipment according to the present invention, in the figure, 19 is conveying path top plate, 20 is the separation claw 21 is moisture absorbent member, 22 is a cleaning pad,
Reference numeral 23 denotes a stiffening roller, and the other portions having the same functions as those in FIG. 7 are denoted by the same reference numerals. As a heat source, a heat roller 17 containing a halogen lamp 16 inside a hollow is
A pressure roller 11 whose surface is covered with rubber is pressed with a slight nip. Since the transfer paper is conveyed while being sandwiched therebetween, the toner image on the surface is thermally fixed on the transfer paper. At this time, the transfer paper is
And is peeled off by the separation claw 20. In order to make the surface of the heat roller 17 peelable, the cleaning pad 22 impregnated with lubricating oil is placed on the heat roller 1.
7 is pressed. The transfer paper on which the toner image has been fixed is crimped by a crimping roller 23 and sent out of the apparatus. When the paper is heat-fixed, the moisture contained therein becomes water vapor and condenses on the transport path top plate 19, so that the transport path top plate has a water-absorbing flexible sheet member (moisture absorbing member 21).
Is attached to prevent the transfer paper from wetting the water droplets due to condensation.

[0009] Figure 2 is a diagram showing the real施例the fixing device according to the present invention (claim 1), reference numbers in the figure is similar to FIG. The difference from the fixing device shown in FIG. 1 is that the absorbent flexible sheet member is bent in a U-shape so that the folded portion is used as a boundary, one of which is absorbed by the moisture absorbing member 21 and the other is impregnated with a lubricant. As the pad 22, the moisture absorbing member 2
One side is attached to the transport path top plate 19, and the cleaning pad 22 side is brought into contact with the heat roller 17.

[0010] Figure 3, illustrating another fixing equipment according to the present invention
A configuration diagram for a fixing apparatus differs from that shown in Figure 1, the flexible sheet member of absorbent is water absorbing member 21, as shown in FIG. 5, is supported by the support roller 25 in the belt This is a point that it is made rotatable by the driving device. By doing so, it is possible to improve the water absorption when a larger amount of water vapor is generated than usual, such as when continuous copying is performed. Also, the belt and the support roller are
Since it is contained in the case 24, it can be easily replaced when the water absorption becomes poor.

[0011] Figure 4 is a view showing another embodiment of a fixing device according to the present invention (claim 3), the basic configuration, a constant of 3
The cleaning device is the same as the fixing device , except that half of the belt-shaped water-absorbing flexible sheet member is located on the transfer sheet top plate 19 as the moisture absorbing member 21 and the other half is impregnated with lubricating oil. The pad 22 is in contact with the heat roller 17. As shown in FIG. 6, the rotation of the belt is performed by a driving device. Further, since the belt and the support roller are housed in the case 24, the belt and the support roller can be easily replaced when the water absorption becomes poor.

[0012]

As apparent from the above description, the present invention has the following effects. (1) Effect corresponding to the first aspect: Since the moisture absorbing member is set on the top plate of the transfer paper transport path, dew condensation on the top plate due to evaporation of water inside the transfer paper generated during heating and fixing is prevented. it can. Therefore, when processing jam paper in a device that prevents rusting of the machine due to condensation and concentrates keyboard operation, toner supply, paper supply and discharge over the entire surface (full front operation device) Furthermore, it is possible to prevent the user's clothes from getting wet. In addition, the lubricating oil stain write or not a half of the one member in contact with the heat roller, for setting the other side to the position of the transport path the top plate of the transfer sheet, is not necessary to attach the cleaning pad to separate the heat roller Therefore, the number of parts can be reduced, the cost can be reduced, and jam handling etc. can be performed in a device (full front operation device) that concentrates keyboard operation, toner supply, paper supply and discharge on the front. In this case, it is possible to prevent the user's clothes from getting wet and prevent the machine from rusting due to dew condensation. (2) Effect corresponding to claim 2: moisture absorbing member and cream
The bending pad is formed by bending a flexible sheet member
Therefore, its manufacture and assembly are easy. (3) Effect corresponding to claim 3: A water-absorbing flexible sheet member is covered with a case in the form of a belt, and is set in a cassette type so that it can be easily detached from the front of the apparatus and set on a transfer sheet top plate. Prevents rusting of the machine due to dew condensation, and uses a device (full front operation device) that concentrates keyboard operation, toner supply, paper supply and discharge on the front (full front operation device). If you do
It is possible to prevent the user's clothes from getting wet, and furthermore, the water supply member can be easily replaced by the user's hand. Also, half of one belt-shaped member is soaked with lubricating oil and brought into contact with the heat roller, and the other is covered with a case at the top of the transfer path of the transfer paper as a moisture absorbing member, and is replaced from the front with a cassette type Since the belt-shaped member rotates, rusting of the machine due to dew condensation can be prevented for a long period of time, and a device that concentrates keyboard operation, toner supply, paper supply and discharge on the front side (full In a front operation device), when performing a jam clearance or the like, it is possible to prevent the user's clothes from getting wet, and furthermore, it is not necessary to provide a separate cleaning pad, and the heat roller is cleaned for a longer period of time than the conventional one. be able to. Further, this cassette can be easily replaced by the user.

[Brief description of the drawings]

FIG. 1 shows a fixing device of an electrophotographic recording apparatus according to the present invention.
It is a diagram for explaining the actual施例.

FIG. 2 shows a fixing device of an electrophotographic recording apparatus according to the present invention.
It is a diagram showing the real施例.

FIG. 3 shows a fixing device of the electrophotographic recording apparatus according to the present invention.
It is a figure for explaining other examples.

FIG. 4 shows a fixing device of the electrophotographic recording apparatus according to the present invention.
It is a figure showing other examples.

FIG. 5 is a diagram illustrating a moisture absorbing member in the fixing device of FIG. 3;

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: conveyance path top plate, 20: separation claw, 21: moisture absorbing member, 22: cleaning pad, 23: stiffening roller,
24 ... case, 25 ... support roller.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03G 13/20 G03G 15/20

Claims (3)

(57) [Claims] 1. A fixing device for an electrophotographic recording apparatus, comprising: a fixing device for fixing a toner image on a medium by heat; and a fixing device of an electrophotographic recording apparatus formed by a medium conveyance path subsequent to the fixing apparatus. And a cleaning pad attached to the moisture absorbing member. 2. A fixing device for an electrophotographic recording apparatus according to claim 1.
The moisture absorbing member and the cleaning package.
Is formed by bending a flexible sheet member into a U-shape
The fixing device of an electrophotographic recording apparatus, characterized in that the. 3. A fixing device a toner image of the medium fusing by heat, the fixing device of the electrophotographic recording apparatus which is formed by the conveying path of the subsequent medium fixing device, cases of cassette type to the conveying path Inside the moisture absorbing member and cleaning pad
A fixing pad for the electrophotographic recording apparatus , wherein the water absorbing member and the cleaning pad are wound and exchangeable.