JPS623272A - Heat roll device - Google Patents

Abstract

PURPOSE:To facilitate the separation of a developer and to prevent a system from being contaminated by feeding electricity to a plane type heat generating element which reaches a position right before a pressure application position through the rotation of a cylindrical roll body and cutting off the electricity right after the the element passes by the pressure application position and said position. CONSTITUTION:A heat roll 7 has its surface part heated up to set temperature from right before it contacts a pressure roll 8 and the electric feeding is stopped right after fixation to lower its temperature to cooling temperature. Thus, the temperature of the outer peripheral surface of the heat roll 7 is raised from right before to right after the contacting of the pressure roll 8. Further, the plane type heat generating element 12 is arranged on the outer peripheral surface of the heat roller 7, so this heat is utilized effectively and the improvement of heat efficiency is obtained. Specially, when fused toner sticks on the outer peripheral surface of the heat roll 7, the heat roll 7 is heated partially and the remaining part is in a cool state, so the toner is easily removed. Consequently, the need for a separation claw, silicone oil, etc., is eliminated and contamination originating from the use of them is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a heating roll device used for fixing, etc. in electrophotographic copying machines and the like.

[Conventional technology]

An electrophotographic copying apparatus is equipped with a photosensitive drum having a photoconductor surface layer, and the outer circumferential surface of the photosensitive drum is uniformly charged, and then the outer circumferential surface is exposed to light through the image of the object to be copied, thereby producing the above-mentioned image. Copying has come to be done by forming an electrostatic latent image on the outer peripheral surface, attaching toner to this electrostatic latent image to form a toner image, transferring this to copy paper, etc., and then fixing it. There are 3.1. The fixing of the above toner is usually done by transferring the toner image onto the copy paper between a heating roll and a fixing roll.
]・), 1 by heating and fixing.
;[-'' This type of conventional heating roll is shown in Figure 7.
, 1, "・2, 1 is a sealed cylindrical core metal, with both left and right ends
9. A hollow rotating shaft 2 is provided on one side. A heating tube body 4 having a nichrome wire 3 built therein is coaxially inserted into the hollow rotating shaft 2 . And the above cylinder
:1゜゛・,・: An elastic body 5 is provided on the outer peripheral surface of the core metal 1 in the circumferential direction.
.

I'm being kicked. The heating roll 6 having such a structure energizes the nichrome wire 3 in the heating tube 4 to generate heat, transmits this heat through the core metal 1 to the elastic body 5, and uses the heat to reduce the toner image transferred to the copy paper. has become established.

[Problem that the invention seeks to solve]

However, since this heating roll 6 heats the entire core metal 1 with the nichrome wire 3 inside the heating tube 4, it consumes a lot of power and also takes a long preheating time (warm-up time). It has its drawbacks. Furthermore, in the heating roll 6 having such a structure, only the central portion of the core metal 1 is heated efficiently (heating is not achieved at both left and right ends), so there is a tendency that the entire core metal 1 is not heated uniformly. In order to improve this, the thickness of the core metal 1 has been increased.However, when doing this,
Not only does the warm-up time mentioned above become longer,
There is a problem that the weight of the heating roll 6 becomes heavy. Moreover, during the fixing process, the toner image that has melted off adheres to the surface of the elastic body 5, but since the entire heating roll 6 is uniformly heated and is at a fairly high temperature, this molten toner does not peel off. Therefore, it is necessary to use peeling claws and silicone for mold release, and the surface of the heating roll 6 may be damaged by the peeling claws, and the entire system may be contaminated by the silicone oil for mold release. There are some drawbacks such as being exposed.

This invention was developed in view of these circumstances, and has good thermal efficiency and low power consumption.Moreover, the heating roll is lightweight, and the developer such as toner can be easily peeled off, so there is no contamination of the system. Its purpose is to provide a heating roll device.

[Means for solving problems]

In order to achieve the above object, the heating roll device of the present invention is a cylindrical roll whose outer peripheral surface is divided into a plurality of regions in the circumferential direction and which pressurizes a pressurized body at a predetermined position on the rotating circumference. A main body, a plurality of planar heating elements disposed along the circumference in the plurality of regions of the outer circumferential surface of the cylindrical roll main body, and a pressurizing position in front of the ・ by rotation of the cylindrical roll main body. The device is configured to include an energizing means that energizes the sheet heating element that has arrived at the position and cuts off the energization immediately after passing through the pressurized position or that position.

Next, this invention will be explained in detail.

FIG. 1 illustrates the principle of the invention. In the figure, 7
8 is a heating roll, and 8 is a pressure roll. The heating roll 7 and the pressure roll 8 rotate as shown by the arrows, so that the copy paper (not shown) onto which the toner image has been transferred passes between the heating roll 7 and the pressure roll 8 to fix the toner image. It has become. The outer peripheral surface of the heating roll 7 is divided into a plurality of regions in the circumferential direction, and planar heating elements are independently arranged in each region. The area in contact with the pressure roll 8 in these divided areas is N, and the counterclockwise direction from that area is N-1, N-2.
, N-3, and clockwise around N is N+1.
Assuming that N+2, for the planar heating elements disposed in the above region, the voltage .sup.2 is applied to the elements N-2 to N-1 and N in front of the contact point N between the heating roll 7 and the pressure roll 8. is applied, the planar heating element generates heat, and a voltage ■ is applied at the position N+1 immediately after passing through the contact N. The application of is cut off. FIG. 2 shows the temperature distribution on the outer circumferential surface of the heating roll 7 due to the heat generated by the planar heating element in each of the divided regions. ,.

In other words, the heating roll 7 has a voltage of ■ from the point N-2 before the point N where it comes into contact with the pressure roll 8 to the point N mentioned above. The temperature was raised by applying N, and N was applied.

Immediately after the passage, a temperature drop occurs in the N+1 area, and a temperature drop also occurs in N+2.

That is, according to the present invention, the outer circumferential surface of the heating roll 7 is heated to the temperature required for fixing immediately before fixing, and immediately after fixing, electricity is cut off and cooled down, thereby significantly reducing power consumption. It becomes wet. Moreover, because the planar heating element is arranged on the outer peripheral surface of the roll, it has extremely high thermal efficiency compared to the conventional example in which the heating element is arranged in the center of the roll, and evenly heats the entire heating group. , you will be able to achieve your goals. Moreover, the developer such as toner that has fallen off can be removed in a cooled position, thereby making it easier to remove.

Next, the present invention will be explained in detail based on examples.

〔Example〕

FIG. 3 is a vertical cross-sectional view of one embodiment of the present invention, and FIG.
The right side view of the figure is shown. In these figures, reference numeral 9 denotes a hollow cylindrical core bar whose left and right ends are formed into a hollow rotary shaft 1o, and whose outer peripheral surface is divided into four regions in the circumferential direction. A planar heating element 12 is formed along the circumference with a first insulating layer 11 in between. A second insulating layer 13 is formed over the entire circumferential surface of the four planar heating elements 12 thus formed.

Both left and right end surfaces of the core bar 9 and the surfaces of the left and right rotating shafts 10 are covered with an insulating coating layer 14, and the insulating coating layer 14 covering the rotating shaft 10 has four conductive element pieces 15 arranged around the circumference. They are arranged at appropriate intervals in the direction. This conductive element piece 15
lead wires 1 from corresponding planar heating elements 12 to
6 extends and is in electrical continuity with the planar heating element 12. In this case, as shown in FIG.
7 to the conductive element piece 15. Then, a brush (not shown) comes into contact with the four conductive element pieces 15 provided on the left and right rotating shafts 10, and sheet heating is generated just before the heating roll 7 rotates and reaches the pressurizing position. The element 12 is energized to heat it up, and then immediately after passing the pressurized position, the energization is cut off to cool it down. This will be explained with reference to FIG. FIG. 6(a) shows the rotational state of each planar heating element 12, and shows the rotation state of each sheet heating element 12.
N[L2. The 31st floor 4 indicates the area to which the first to fourth sheet heating elements 12 are attached. N1
1 liter of Ml is the contact point with the pressure roll 8:, “
shall be. Further, arrow A indicates the rotation direction of the heating roll 7.
' is shown. In this case, the brush roll is N[L
[,: Contacting the corresponding conductive element piece 15 to heat the planar heating element 12.

This contact starting point is indicated by N8. Then, set the contact release point to N
2, the surface temperature distribution state of the outer circumferential surface of the heating roll 7 at M1 to N8 is as shown in FIG. 6(b).

That is, the temperature of the surface portion of the heating roll 7 is raised to the set temperature immediately before it comes into contact with the pressure roll 8, and immediately after the fixing is completed, the current is turned off and the temperature is lowered to the cooling temperature. In this case, the number of rotations of the pressure roll 8 is 60 times/
It is set to minutes.

In this embodiment, with the above configuration, the temperature of the outer circumferential surface of the heating roll 7 can be increased only from immediately before to immediately after contact with the pressure roll 8, thereby significantly reducing power consumption. This is what happens. Further, since the planar heating element 12 is arranged on the outer circumferential surface of the heating roll 7 instead of in the center, the heat can be effectively utilized, and the effect of improving thermal efficiency can also be realized. In particular, if molten toner adheres to the outer circumferential surface of the heating roll 7, it is not easy to remove it in the conventional case because the entire circumference of the heating roll 7 is always heated. According to the heating roll 7, the heating roll 7 is heated only in public, and the other parts are in a cooled state.
・b=′2. ? , : h・88°, :)-)
-at"th,=hh<-'es, :,ru.

Therefore, conventional toner peeling is not possible.
5: There is no need to provide a special peeling claw, and there is no need to use silicone oil for peeling, so it is possible to prevent contamination caused by the use of silicone oil. become. In addition, according to the conventional example, there is a tendency for the temperature to become low on both end sides, and in order to improve this by heating only the central portion of the heating roll 7 well, the thickness of the core bar 9 of the heating roll 7 is increased. This made the core metal 9 thicker.
The drawback was that it took a long time to warm up the entire system. Also the weight
□91,) also had the disadvantage of being heavy.
However, according to the example product, the entire sheet heating element 12 is
1. It is possible to realize weight reduction without
It is also said that warm-up time can be significantly reduced.
2. 'Effects can also be obtained.
゛; As the constituent material of the planar heating element 12, known materials can be used. For example, carbon black graft polymer, metal foil, metal vapor deposited film (coated on a resin base), ceramics (
It is possible to use powders coated on a resin base to form a planar structure.

In addition, although the above embodiment describes a heating roll device of an electrophotographic copying machine, the present invention is not limited to this, but can also be applied to a printing machine.

It can be applied to word processors, printers, and other rolls. Further, the inside of the core metal of the heating roll may be left hollow or may be filled with liquid. In particular, the effects of the present invention can be better achieved by injecting a heat transfer inhibitor.

〔Effect of the invention〕

Since the heating roll device of the present invention is configured as described above, it has extremely high thermal efficiency and can significantly reduce power consumption. Moreover, unlike conventional methods, it is not necessary to set the core metal inside the heating goal to be thick, so there is no need for warm-up time required for heating the core metal, significantly increasing the start-up speed, and at the same time reducing the overall weight of the device. It will also be possible to achieve In addition, the heating roll is designed to prevent mold release when toner or other developer adheres to the heating roll surface.
゛Since it can be performed in the cooling area, there is no need for a special peeling claw like in the past, and at the same time, there is no need for silicone oil for peeling, which prevents damage to the heating roll surface caused by the use of a peeling claw and the use of silicone oil. This has the excellent effect of preventing contamination of the entire system.

[Brief explanation of drawings]

1 and 2 are explanatory diagrams explaining the principle of an embodiment of this invention, and FIG. 3 is a longitudinal sectional view of an embodiment of this invention.
FIG. 4 is a right side view thereof, FIG. 5 is a plan view of parts used in FIG. 4, and FIG. 6 is an explanatory view of the use of FIG. 3. 8... Heating roll 12... Planar heating element 15.
...Conductive element piece 16...Lead wire 17...Wire connection part. Ittsuke/Cessation procedure amendment method January 1985! 7th, 1985, Atonement Sacrificial Freeze No. 143235 No. 2, Name of the invention Heating roll device 3, Relationship with the case of the person making the amendment Patent applicant address 3600 Kitatoyama, Sakizu, Komaki City, Aichi Prefecture Name Tokai Rubber Industries Co., Ltd. Publisher: Morimasa Shibasaki5, Date of amendment order: September 4, 1985 (formerly sent: September 24, 1985) 6, Subject of amendment: 7゜ Contents of amendment (1) Specification, page 12, line 17 , ``This is an explanatory diagram for use.'' should be corrected to ``Explanatory diagram for use, FIG. 7 is a vertical cross-sectional view of a conventional example.'''.

Claims (2)

[Claims] (1) A cylindrical roll body whose outer circumferential surface is divided into a plurality of regions in the circumferential direction and which pressurizes a pressurized body at predetermined positions on the rotating circumference; Electricity is applied to a plurality of planar heating elements disposed along the circumference in a plurality of regions, and the planar heating elements that come to a position in front of the pressurizing position due to the rotation of the cylindrical roll body to apply pressure. A heating roll device characterized in that it is equipped with an energizing means that cuts off energization immediately after passing through a position or that position. (2) The energizing means includes a plurality of conductive element pieces provided along the circumference at appropriate intervals on the outer periphery of the rotating shaft of the cylindrical roll body and electrically conductive with the corresponding sheet heating elements, and the conductive element pieces. and a brush in contact with the first claim.
The heating roll device described in Section 1.