JPH08320625A - Fixing device - Google Patents

Abstract

PURPOSE: To provide a fixing device constituted so that printing quality is enhanced by uniformizing the temperature of a heating surface without giving vibration to a paper and the like and solving a problem such as the wrinkling of the paper caused by the vibration and the nonuniformity of the heating temperature. CONSTITUTION: A heat roller 18 is provided with a roller-like cylindrical main body 22, liquid 24 such as water or oil with which the inside of the main body 22 is filled, dampers 26 and 26 being as a vibration absorbing member hermetically sealing both ends of the main body 22 and a fine vibration generation member 30 fitted to one damper 26 in a state where the tip part thereof gets in the liquid 24. Then, the generation member 30 is constituted of an ultrasonic vibrator (or electromagnetic vibrator) and connected to an ultrasonic signal generator 34.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an electrophotographic printer,
The present invention relates to a fixing device in a printing device such as a facsimile or a copying machine.

[0002]

2. Description of the Related Art Conventionally, fixing of toner in a printing apparatus of this type has been carried out by a method of simultaneously applying heat and pressure. For example, as shown in FIG. The unfixed toner 64 is passed between a heat roller 68 having a built-in heater lamp 66 and a pressure roller 70 so as to be heated by the heat energy of the heater lamp 66 and pressed against each other.

Further, as shown in FIG. 6, the ultrasonic vibrator 7 is attached to either one of the pair of pressure rollers 72 and 74.
There is also proposed a so-called ultrasonic fixing method in which 6 is provided to apply ultrasonic vibration to one of the pressure rollers 72 to generate Joule heat due to the vibration in the pressure contact portion to fix the pressure roller 72.

Further, as shown in FIG. 7, the toner 80 placed on the photoconductor 60 by the developing device 78 is brought into pressure contact between the transfer fixing member 82 as an ultrasonic vibration generator and the photoconductor 60. An ultrasonic fixing method in which transfer and fixing are performed at the same time has also been proposed.

[0005]

However, in the above-mentioned heat roller system, since the heat transfer of the heater lamp is propagated in the solid, the temperature distribution on the surface of the heat roller is likely to be uneven, resulting in uneven heating. However, there are problems such as insufficient fixing strength and wrinkling and curling of the paper.

Further, the ultrasonic fixing method in which the toner is directly vibrated has problems such as toner scattering and deviation of the fixed image due to slight vibration of the paper. Further, in the ultrasonic fixing method in which transfer and fixing are performed at the same time, the vibration is exposed. Since it is transmitted to the body, there has always been a risk of causing a fatal defect such as distortion of the electrostatic latent image before transfer.

As described above, both the non-vibration fixing method and the ultrasonic fixing method using the heater heat in the conventional example have a disadvantage that side effects caused by their characteristics are caused.

[0008]

SUMMARY OF THE INVENTION According to the present invention, the disadvantages of the conventional example are improved, and in particular, stable fixing can be achieved by avoiding adverse effects due to uneven heating and vibration, and by this, the quality of an image fixed on a sheet or the like is improved. An object of the present invention is to provide a fixing device that can be improved.

[0009]

According to a first aspect of the present invention, there is provided a heat roller disposed downstream of the photoconductor along the paper path, and pressure contacting the heat roller via the paper. In a fixing device including a roller, a heat roller, a tubular body, dampers provided at both ends of the tubular body to seal the inside, and a liquid filled in the tubular body and heated by vibration. , A micro-vibration generating member supported by the damper and protrudingly provided in the liquid.

According to a second aspect of the invention, in the fixing device according to the first aspect, a stirring member for stirring the liquid is provided in the cylindrical body as the cylindrical body rotates.
The configuration is adopted.

According to the third aspect of the invention, the fixing is provided with a heat roller arranged on the downstream side of the photosensitive member along the sheet traveling path, and a pressure roller that comes into pressure contact with the heat roller via the sheet. In the device, the heat roller
A tubular body, a damper that is provided at both ends of the tubular body and seals the inside, a cylindrical hollow rigid member whose both ends are supported by the damper, the hollow rigid member, and the tubular body described above. And a liquid that is hermetically filled between them and heated by vibration, and a plurality of minute vibration generating members for heating the hollow rigid body member are provided on the inner surface of the hollow rigid body member. This aims to achieve the above-mentioned object.

[0012]

In the invention according to claim 1, when the minute vibration generating member is driven, the vibration energy propagates to the liquid, and the liquid is heated to a uniform temperature by free heat transfer. This uniform temperature is transmitted to the tubular body, and the surface of the tubular body is evenly and uniformly heated. The vibration of the minute vibration generating member is absorbed by the vibration absorbing member and the liquid, and is hardly transmitted to the cylindrical main body.

According to the second aspect of the present invention, the liquid is stirred by the operation of the stirring member, and the temperature of the entire liquid is made uniform quickly.

In the invention according to claim 3, when the minute vibration generating member is driven, the rigid member vibrates and the vibration energy heats the cylindrical body. The vibration of the rigid member is absorbed by the vibration absorbing member and the liquid, and is hardly transmitted to the tubular body.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.

First, as shown in FIG. 2, an electrophotographic printer has a recording medium layer on which a latent image is recorded and rotates at a constant rotation speed, and a recording medium layer of this photosensitive body 2. A latent image forming unit 4 for forming an electrostatic latent image, a developing unit 8 for adhering the toner layer 6 to the formed electrostatic latent image to develop the latent image, a transfer unit 10 and a fixing device 12. The toner layer 6 is transferred as a toner image 14 onto the sheet 16 at the transfer section 10 and then sent to the fixing device 12 to be fixed.

The fixing device 12 includes a heating body 18 for fixing toner.
And a pressure roller 20 pressed against the heat roller 18.

The heat roller 18 is, as shown in FIG.
A roller-shaped tubular main body 22, a liquid 24 such as water or oil filled in the tubular main body 22, and dampers 26, 26 as vibration absorbing members for sealing both ends of the tubular main body 22 are provided. ing. Further, the damper 26 on one side is equipped with a minute vibration generating member 30 in a state of entering the liquid 24 via a bearing 28, and the cylindrical main body 22 is provided with a main frame of the fixing device 12 not shown. Both ends are supported by bearings 32. The distance between the bearings 32 is set to be larger than the width of the paper 16.

The microvibration generating member 30 is composed of a piezoelectric ultrasonic oscillator (or an electromagnetic oscillator), and can be operated by being urged by the ultrasonic signal transmitter 34.

When an AC voltage is applied by the ultrasonic signal transmitter 34, the minute vibration generating member 30 causes ultrasonic vibration, and this vibration energy is transmitted to the liquid 24 to heat the liquid 24. Here, the ultrasonic signal transmitter 3
The optimum frequency and amplitude of 4 are the toner type and liquid 2
It depends on the 4 types.

Since the degree of freedom of heat transfer in the liquid is greater than that in the solid, the temperature of the liquid 24 is quickly equalized in combination with the stirring action by vibration. As a result, the surface temperature of the cylindrical main body 22 also becomes a uniform state without unevenness.

Further, since the vibration of the minute vibration generating member 30 is absorbed by the damper 26 and the liquid 24, it is hardly transmitted to the cylindrical main body 22 and the main frame of the fixing device (not shown).

Therefore, when the sheet 16 on which the toner image 14 has been transferred is carried into the fixing device 12, the sheet 16 is uniformly heated and pressed against in a vibration-free state, whereby the conventional fixing strength is insufficient. Further, the fixing is carried out smoothly and surely without any inconvenience such as wrinkling or curling of the paper, scattering of toner due to slight vibration of the paper, and deviation of the fixed image.

Also, when applied to a structure in which transfer fixing is performed by pressing against the photoconductor 2, the problem of electrostatic latent image distortion does not occur because there is no vibration.

Next, a second embodiment of the present invention will be described with reference to FIG.

The other embodiment shown in FIG. 3 shows another example of the heating member for fixing toner in the fixing device.
In addition to the embodiment shown in FIG. 2, the heat roller 36 shown in FIG. 3 is equipped with a stirring member 38 for forcibly circulating the liquid 24 inside the cylindrical main body 22. The stirring member 38 is configured to include a cylinder 40 fixed inside the tubular main body 22 via a leg portion 40a, and a spiral blade portion 42 fixedly mounted inside the cylinder 40.

Then, for example, when the cylindrical body 22 is rotated by being urged by a drive motor and a drive transmission gear (not shown), the liquid 24 inside the cylindrical body 22 is affected by the stirring member 38 and the gravity of the liquid 24. It is forced to circulate like an arrow. Then, the circulation direction of the liquid 24 is such that the liquid 24 heated by the micro-vibration generating member 30 is in the cylinder 40 immediately after heating.
The direction of the spiral blade portion 42 is determined so that the spiral blade flows in the direction of the arrow. The other structure is the same as that of the first embodiment shown in FIGS.

According to the second embodiment, the forced circulation of the liquid 24 has the advantage that the temperature of the entire liquid 24 can be uniformized more reliably and quickly.

Next, a third embodiment of the present invention will be described with reference to FIG.

The heat roller 44 shown in the third embodiment.
Is a roller-shaped tubular body 46, and the tubular body 4
A liquid 47 such as water or oil filled in 6 and a tubular body 46
Dampers 48, 4 as vibration absorbing members for sealing both ends of the
8 and a cylindrical hollow rigid member 52 provided in the liquid 47 while being supported by both dampers 48 via a bearing 50.
(For example, metals). This hollow rigid member 5
A plurality of micro-vibration generating members 54 are installed in the unit 2 at intervals in the longitudinal direction. Each of the minute vibration generating members 54 is connected to the ultrasonic signal transmitter 56.

When an AC voltage is applied to each of the minute vibration generating members 54 by the ultrasonic signal transmitter 56, the hollow rigid member 52 is heated by the vibration energy. Then, the heat of the heated hollow rigid member 52 is transferred to the liquid 47.
At the same time, the liquid 47 is heated.

The optimum frequency and amplitude of the ultrasonic signal transmitter 56 differ depending on the type of hollow rigid member 52, the type of liquid 47, the type of toner, and the like. The other structure is the same as that of the second embodiment shown in FIG.

Also in the third embodiment, as in the above-mentioned respective examples, a good heat fixing function can be exhibited with uniform heating and no vibration.

Further, each constituent element is not limited to the illustrated one, and the design can be changed as appropriate within the range where the fixing function by uniform heating and no vibration is satisfied.

[0035]

As described above, according to the present invention, the temperature of the heating surface of the heat roller can be made uniform without direct vibration of the heating surface, so that the fixing strength is insufficient, and the paper is wrinkled or curled. It is possible to more effectively avoid the problems such as the occurrence of the toner, the scattering of the toner due to the slight vibration of the paper, and the deviation of the fixed image, and thus it is possible to provide an excellent fixing device which has not been available in the past and can improve the print quality. .

Further, in the invention according to claim 2, since the liquid is forcibly circulated by the action of the stirring member, the temperature of the heating surface can be more uniformly and quickly achieved.

Further, in the invention according to claim 3, since the surrounding liquid is heated by the hollow rigid member heated by the vibration of the minute vibration generating member, and the cylindrical main body is heated via the liquid, The temperature of the heating surface can be made uniform more reliably and quickly.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view in which a heat roller that is a part of a fixing device according to a first embodiment of the present invention is partially omitted.

FIG. 2 is an explanatory diagram showing a usage state of the fixing device in the first embodiment of the invention.

FIG. 3 is an enlarged cross-sectional view with a part of a heat roller portion omitted in a second embodiment.

FIG. 4 is an enlarged cross-sectional view with a part of a heat roller portion omitted in a third embodiment.

FIG. 5 is an explanatory diagram showing an example of a fixing device in a conventional example.

FIG. 6 is an explanatory diagram showing an example of another fixing device in the conventional example.

FIG. 7 is an explanatory diagram showing an example of still another fixing device in the conventional example.

[Explanation of symbols]

 2 Photoconductor 12 Fixing Device 16 Paper 18 Heat Roller 20 Pressure Roller 22,46 Cylindrical Main Body 26,48 Damper (Vibration Absorbing Member) 24,47 Liquid 30,54 Micro Vibration Generating Member 38 Stirring Member 52 Hollow Rigid Member

Claims (3)

[Claims] 1. A fixing device comprising a heat roller arranged downstream of a photoconductor along a paper path, and a pressure roller which is pressed against the heat roller via a paper sheet. A tubular body, dampers provided at both ends of the tubular body to seal the inside, a liquid filled in the tubular body and heated by vibration, and a liquid supported by the damper and contained in the liquid. A fixing device comprising a minute vibration generating member protruding from the fixing device. 2. The fixing device according to claim 1,
A fixing device, wherein a stirring member that stirs the liquid as the cylindrical body rotates is provided inside the cylindrical body. 3. A fixing device comprising: a heat roller disposed downstream of a photoconductor along a paper traveling path; and a pressure roller that comes into pressure contact with the heat roller via a paper. A tubular body, a damper provided at both ends of the tubular body to seal the inside, a cylindrical hollow rigid member having both ends supported by the damper, the hollow rigid member and the tubular shape described above. And a liquid that is hermetically filled between the main body and a liquid that is heated by vibration, and the hollow rigid member is provided with a plurality of minute vibration generating members for heating the hollow rigid member on its inner surface. Fixing device.