KR101235218B1 - A image fixing device of image forming apparatus - Google Patents

Abstract

Disclosed is a fixing apparatus of an image forming apparatus in which paper jam is easily removed. The disclosed invention comprises a pair of fixing rollers for fixing a toner image transferred onto a sheet; And a sensor lever rotatably installed downstream of the fixing roller to detect a conveyance state of the paper, wherein the sensor lever rotates to remove the first rotation angle and paper jam which are rotated by the feed force of the paper. It is characterized in that the rotatable at a second rotation angle greater than the first rotation angle. According to this, since the sensor lever and the paper do not interfere when the paper jam is removed, the paper jam is easily removed.

Fusing, sensing, jam, broken, print media, paper, cover, angle of rotation, multi-stage, lever.

Description

A fixing device of an image forming apparatus

1 is a view schematically showing a fixing apparatus of a general image forming apparatus;

2 is a view schematically showing an image forming apparatus employing a fixing apparatus of the present invention;

3 and 4 is a view showing the structure and operation of the fixing device according to an embodiment of the present invention, and

5 is a view showing the structure and operation of the fixing device according to another embodiment of the present invention.

Description of the Related Art

10: paper feed unit 20: image forming unit

30: transfer unit 50: fixing device

51: first fixing roller 52: second fixing roller

53: sensor lever 54: 1-stage hinge

55: two-stage hinge 60: rear cover

The present invention relates to an image forming apparatus, and more particularly, to a fixing apparatus for fixing a toner image transferred to a sheet.

As is well known, an image forming apparatus such as a printer or a copier includes a fixing apparatus for fixing a toner image transferred on a sheet so as not to drop by applying heat and pressure.

1 is a view schematically showing an example of a fixing apparatus provided in a general image forming apparatus. As shown in the drawing, the fixing roller is provided with the heating roller 1 and the pressing roller 2 facing each other with a predetermined nip, and the toner image is transferred between the two rollers 1 and 2 that rotate relative to each other. When the paper P passes, heat and pressure are applied to the toner image, causing the toner image to stick to the paper P.

On the discharge path behind the rollers (1) and (2), the sensor lever (3) is installed to rotate at a predetermined angle about the hinge (4). The sensor lever 3 rotates within an angular range given by the conveying force of the conveyed paper. That is, the sensor lever 3 is in the solid line position of FIG. 1 and rotates to the dotted line position when the paper P is in contact, and returns to the solid line position when the paper P is completely removed. Therefore, if the sensor is provided on / off operation according to the position of the sensor lever (3), by checking the time to turn on / off, it is possible to check whether the paper is normally discharged or jam occurred during discharge.

If a jam occurs in the paper discharge, the jammed paper is grasped and pulled in the direction of the arrow shown by the dashed line in FIG. However, since the sensor lever 3 blocks the jam removing path, it is difficult to remove the jam. That is, the sensor lever 3 is set to rotate at an angle of approximately 90 ° in consideration of its function and the relationship with the peripheral parts.

Therefore, when the paper jam is removed, a problem such as paper tearing occurs due to the interference of the sensor lever 3. This tearing of the paper not only prevents smooth jam removal, but is also bad because the debris may act as another bad factor inside the fixing device.

The present invention has been made in view of the above, and an object thereof is to provide a fixing apparatus of an image forming apparatus that is easy to remove paper jams.

The fixing apparatus of the image forming apparatus according to the present invention for achieving the above object comprises a pair of fixing rollers for fixing a toner image transferred on a sheet; And a sensor lever rotatably installed downstream of the fixing roller to sense a conveyance state of the paper, wherein the sensor lever is rotated to remove the first rotation angle and paper jam which are rotated by the feed force of the paper. It is characterized in that the rotatable at a second rotation angle greater than the first rotation angle.

According to a preferred embodiment of the present invention, the first rotation angle is set to about 90 degrees, and the second rotation angle is preferably set to about 180 degrees.

According to another preferred embodiment of the present invention, the sensor lever can be rotatably supported by a multi-stage hinge, wherein the first stage hinge is rotated at the first rotation angle, the second stage hinge is the second It is preferable to rotate at a rotation angle.

In addition, the first and second stage hinges may be interposed with the first and second torsion springs for returning the sensor lever to the initial position, wherein the elasticity of the second torsion spring is elasticity of the first torsion spring. It is preferable to set larger.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 schematically shows an image forming apparatus employing a fixing apparatus of the present invention, wherein reference numeral 10 denotes a paper feeding unit, 20 an image forming unit, 30 a transfer unit, 50 a fixing unit, and 60 a rear. It is a cover.

The fixing device 50 fixes the toner image transferred to the paper P through the transfer unit 30 by applying heat and pressure. 3 and 4, the fixing device 50 includes first and second fixing rollers 51 and 52, a sensor lever 53, and the like.

The first and second fixing rollers 51 and 52 are opposed to each other with a predetermined nip, and the toner images are transferred between the first and second fixing rollers 51 and 52 which are rotated relative to each other. (P) passes.

The first fixing roller 51 is a heating roller in which a heat source 51a is embedded to heat the printing medium, and the second fixing roller 52 pressurizes the printing medium by pressing means not shown. It is a pressure roller. However, the present invention is not necessarily limited thereto, and both the first and second fixing rollers 51 and 5 may be provided with heating and pressing functions at the same time.

The sensor lever 53 is rotatably installed downstream of the first and second fixing rollers 51 and 52 in order to detect the conveying state of the paper P. Here, the sensor lever 53 is rotatably supported by the first and second stage hinges 54 and 55.

The first stage hinge 54 rotates at the first rotation angle R1 by the conveying force of the paper P, and the second stage hinge 55 has the first rotation angle R1 to remove the jammed paper P. It rotates at the 2nd rotation angle R2 larger than (). Here, the first rotation angle R1 is set to about 90 degrees, and the second rotation angle R2 is set to about 180 degrees.

In addition, the first and second stage hinges 54 and 55 are provided with first and second torsion springs 54a and 55a for returning the sensor lever 53 to an initial position. At this time, the elasticity of the second torsion spring 55a is set larger than the first torsion spring 54a. This takes into account the different first and second rotation angles R1 and R2 of the first and second stage hinges 54 and 55.

The change in position due to the rotation of the sensor lever 53 is sensed by a sensor not shown on and off, and the sensor checks the normal discharge or jam generation of the paper P by checking the on / off time. .

Meanwhile, in the present exemplary embodiment, although the sensor lever 53 is configured as the first and second stage hinges 54 and 55, the sensor lever 53 is not limited thereto, and the sensor lever 53 may include the first and second rotation angles R1 ( Naturally, it can be supported by one or three or more hinges provided it can be rotated to R2).

That is, as shown in FIG. 5, it is obvious that the sensor lever 153 may be supported by one hinge 154 to be rotatable with the first and second rotation angles R1 and R2. Do. At this time, the sensor lever 153 is also returned to the initial position by the torsion spring 154a interposed in the hinge 154.

On the other hand, since the sensor lever 153 of FIG. 5 requires a larger rotation radius in comparison with a sensor lever having a multi-stage hinge, the sensor lever 153 of FIG.

An operation relationship of the fixing device 50 of the image forming apparatus having the above configuration will be described with reference to FIGS. 2 to 4.

As shown in Fig. 2, the paper P on which the toner image is transferred by the image forming unit 20 and the transfer unit 30 is transferred between the first and second fixing rollers 51 and 52. The first and second fixing rollers 51 and 52 fix the toner image to the paper P by heating and pressing the paper P. FIG.

The paper P on which the toner image is fixed is continuously conveyed and discharged to the outside, and the sensor lever 53 is centered on the first hinge 54 by contact with the paper P, as shown in FIG. 3. To rotate within the range of the first rotation angle R1.

In detail, the sensor lever 53 is positioned at the dotted line position, rotates to the solid line position by the contact of the paper P, and when the paper P is completely removed, the sensor lever 53 is moved back to the dotted line position by the first torsion spring 54a. To return.

If the paper P is not normally transferred and jam occurs as shown in FIG. 4, a sensor interfering with the sensor lever 53 checks this and notifies the user through a separate notification means.

Then, the user opens the rear cover 60 to remove the jammed paper P from the fixing device 50. At this time, the sensor lever 53 is rotated at the second rotation angle R2 by the two-stage hinge 55, so as not to interfere with the jam paper P to be removed.

Thereafter, when the jammed paper P is completely removed, the sensor lever 53 is formed by the first and second torsion springs 54a and 55a interposed in the first and second stage hinges 54 and 55. It returns to the initial position again.

According to the present invention as described above, the sensor lever is rotatable by the first rotation angle rotated by the conveying force of the paper and the second rotation angle rotated to remove the jam, thereby the jammed paper from which the sensor lever is removed It will not interfere. This enables easy paper jam removal without existing problems such as tearing of the paper.

While the invention has been shown and described in connection with the preferred embodiments for illustrating the principles of the invention, the invention is not limited to the construction and operation as shown and described. Rather, those skilled in the art will appreciate that many modifications and variations of the present invention are possible without departing from the spirit and scope of the appended claims. And all such modifications and changes as fall within the scope of the present invention are therefore to be regarded as being within the scope of the present invention.

Claims (4)

A pair of fixing rollers for fixing the toner image transferred onto the paper; And And a sensor lever rotatably installed downstream of the fixing roller to detect a conveyance state of the paper. The sensor lever is rotatably supported by a multi-stage hinge, the first-stage hinge of the multi-stage hinge rotates at a first rotational angle rotated by a conveying force of paper, and the two-stage hinge of the multistage hinge removes paper jam. And a second rotation angle greater than the first rotation angle to rotate. The method of claim 1, And the first rotation angle is set to about 90 degrees, and the second rotation angle is set to about 180 degrees. delete The method of claim 1, The first and second stage hinges are interposed with first and second torsion springs for returning the sensor lever to an initial position, and the elasticity of the second torsion spring is set larger than that of the first torsion spring. Fixing apparatus of the image forming apparatus.

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