JP3172806B2 - Printer fixing 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 printer having a pair of fixing rollers for sandwiching recording paper.

[0002]

2. Description of the Related Art In general, in a printer using an electrophotographic system, writing (exposure) of image information is performed by a LED head on a photosensitive drum charged by a main charger to form an electrostatic latent image. Further, toner is applied to the electrostatic latent image from a developer, and a visible image is formed by the adhesion of the toner. Then, toner is transferred from the photosensitive drum to the recording paper by the transfer charger, and the toner on the recording paper is fixed by a fixing device having a pair of fixing rollers (heat rollers) sandwiching the recording paper.

By the way, since the fixing device has a fixing roller for sandwiching the recording paper, if a paper jam occurs,
In order to remove the jammed recording paper, it is necessary to separate one of the fixing rollers from the other, and if the life of the fixing roller has expired due to a failure such as a broken lamp or abrasion, it is necessary to replace the fixing roller. The fixing device has a structure that satisfies such requirements.

FIG. 5 shows a conventional fixing device 40. Reference numeral 42 denotes a lower frame of the printer main body 41.
An upper frame 44 is attached to the rear upper end via a hinge 43 so as to be openable and closable. Further, a pair of fixing rollers 45,
46, one fixing roller 45 is supported by the lower frame 42, and the other fixing roller 46 is supported by a support unit 47. One end of the support unit 47 is rotatably attached to the lower frame 42 via a support shaft 48, and the other end is fixed to the lower frame 42 via a fixing screw 49. Thus, the fixing device 40 in which the fixing roller 45 is located on the lower side and the fixing roller 46 is located on the upper side is configured. In the drawing, Lo is a recording paper,
Mo indicates a displacement mechanism of the fixing roller 45.

Therefore, when a paper jam occurs, if the fixing screw 49 is loosened and removed from the lower frame 42, the support unit 47 can be pivotally displaced upward with the support shaft 48 as a fulcrum. The recording paper Lo can be removed. When the fixing roller 46 is replaced, in addition to the above operation, the support shaft 47 can be disassembled and the support unit 47 can be removed.

[0006]

However, the above-described conventional fixing device 40 has the following problems.

First, every time a paper jam is processed or the fixing roller is replaced, a turning operation of the fixing screw 49 and a disassembly or assembly of the support shaft portion 48 are required, so that the operation becomes complicated and one-touch replacement cannot be performed.

Second, the relative positional accuracy between the fixing rollers 45 and 46 is low, and it is difficult to realize stable recording paper running and fixing processing.

The present invention solves the above-mentioned problems in the prior art, and can easily perform paper jam processing and replacement of a fixing roller with a single touch, and dramatically improves the positional accuracy of the fixing roller. It is an object of the present invention to provide a fixing device for a printer that can realize stable recording paper running and fixing processing.

[0010]

The present invention comprises a printer main body 5 having a lower frame 3 and an upper frame 4 which are openably and closably connected via a hinge portion 2, and a pair of fixing rollers 6, 7 sandwiching the recording paper L. The fixing device 1 of the printer using an electrophotographic method, in which one fixing roller 6 is supported by one frame 3 and the other fixing roller 7 is supported by a support unit 8 separate from the printer main body 5 in FIG. In particular, the positioning between the lower frame 3 and the support unit 8 is performed between the lower frame 3 and the support unit 8, the engagement mechanism 9 in which the end of the support unit 8 is rotatably engaged with the lower frame 3. The engaging mechanism 10 is provided.
Is formed by an engaging shaft portion 12 provided in the lower frame 3 and an engaging concave portion 13 formed by notching the supporting unit 8 engaging with the engaging shaft portion 12 in a horizontal U shape. Is formed by a fitting shape portion 14 formed in the lower frame 3 by being depressed in an arc shape, and a bearing 15 provided in the support unit 8 fitted in the fitting shape portion 14. Further, the upper frame 4 and the support unit 8 A pressure mechanism 11 for pressing the support unit 8 toward the lower frame 3 when the frame is closed is provided therebetween.

In this case, the pressing mechanism 11 includes an elastically supported pressing section 16 provided on the upper frame 4 and the pressing section 1.
6 can be constituted by a pressurized portion 17 provided on a support unit 8 which can be pressed.

[0012]

According to the fixing device 1 of the printer according to the present invention,
The printer body 5 includes a lower frame 3 and an upper frame 4,
The upper frame 4 opens and closes with respect to the lower frame 3 using the hinge 2 as a pivot point.

On the other hand, the fixing device 1 includes a lower fixing roller 6 and an upper fixing roller 7. The lower fixing roller 6 is supported by the lower frame 3, and the upper fixing roller 7 has a bearing 15. It is supported by the support unit 8. In this case, since the support unit 8 is configured separately from the printer main body 5, the support unit 8 can be attached to and detached from the printer main body 5.

Thus, when the support unit 8 is mounted on the printer main body 5, the upper frame 4 is opened, the engaging recess 13 of the support unit 8 is engaged with the engaging shaft portion 12, and the support unit 8 is When the outer peripheral portion of the provided bearing 15 is fitted to the fitting shape portion 14 of the lower frame 3, and then the upper frame 4 is closed, the elastically supported pressurizing portion 16 provided on the upper frame 4 makes the supporting unit 8. Pressed part 1 of
7, the support unit 8 is pressed toward the lower frame 3 side. Therefore, the support unit 8 is fixed in an accurately positioned state by the fitting of the fitting shape portion 14 and the bearing 15.

On the other hand, when performing a paper jam process or replacing the fixing roller, opening the upper frame 4 releases the pressurization of the pressurized portion 17 by the pressurizing portion 16 and the pressurizing portion 15 It separates from the pressure part 17. Thereby, the support unit 8 can be rotationally displaced about the engagement shaft portion 12 as a fulcrum. Further, the support unit 8 can be removed as it is. In this way, the running path can be released or the fixing roller 7 can be replaced by one-touch operation.

[0016]

Next, preferred embodiments according to the present invention will be described in detail with reference to the drawings.

First, in order to clarify the present invention, an overall schematic configuration of a label printer using an electrophotographic system will be described.
This will be described with reference to FIG.

The label printer P shown in FIG. 1 includes a printer main body 5, and a photosensitive drum D is arranged in the middle of the printer main body 5. On the other hand, a continuous recording paper L fed out from a supply reel (not shown) is a traveling path formed by a paper guide 51, a plurality of roller mechanisms 52 including a pair of drive rollers and driven rollers, a plurality of guide plates 53, and the like. It is wound on a winding reel (not shown) through F. Then, the recording paper L contacts the outer peripheral surface of the photosensitive drum D.

On the other hand, around the photosensitive drum D,
A cleaner (toner recovery unit) 54, an eraser 55 for erasing charges on the photosensitive drum D, a main charger 56 for giving charges to the photosensitive drum D, and writing (exposure) of image information to be recorded on the photosensitive drum D (exposure). L forming
An ED head 57, a developer 58 for forming a visible image by attaching toner to the electrostatic latent image on the photosensitive drum D, and a transfer charger 59 for transferring toner to the recording paper L are sequentially arranged. The transfer charger 59 is supported by the displacement mechanism 60 and moves forward and backward with respect to the photosensitive drum D, whereby the recording paper L comes into contact with or separates from the photosensitive drum D. Further, the fixing device 1 according to the present invention is disposed on the traveling path F. The fixing device 1 has a function of fixing toner adhered to the recording paper L, and includes a pair of fixing rollers 6 and 7 using a heat roller.

Next, the configuration of the fixing device 1 will be described with reference to FIGS.
This will be described more specifically with reference to FIG.

In FIG. 1, reference numeral 5 denotes the printer main body, which includes a lower frame 3 and an upper frame 4 and a rear lower end of the upper frame 4 is attached to a rear upper end of the lower frame 3 via a hinge 2 so as to be openable and closable. Can be

Reference numeral 6 denotes a lower fixing roller, and the fixing roller 6 is supported by the lower frame 3. in this case,
The lower frame 3 is provided with a displacement mechanism 21, and the fixing roller 6 is displaceably supported by the displacement mechanism 21. That is, the displacement mechanism 21 includes a base plate 23 whose rear end is rotatably supported by a rotation shaft 22, and an eccentric cam 24 that engages with the front end of the base plate 23, and the fixing roller 6 is provided at an intermediate portion of the base plate 23. Supported. Thereby, the fixing roller 6 (base plate 23) is displaced to the set position or the release position according to the rotation angle of the eccentric cam 24. Since the eccentric cam 24 engages with the base plate 23 via a spring, the fixing roller 6 functions as a pressure roller and is urged in a direction to press the upper fixing roller 7 described later. A pair of such displacement mechanisms 21 are provided on both left and right sides of the lower frame 3, and both ends of the fixing roller 6 are supported. In this case, the eccentric cam 24 may be provided only on one of the right and left.

Further, the lower frame 3 has an engaging shaft 1
2 are formed, and the fitting shape part 14 is formed. The fitting shape portion 14 is formed in the upper end side of the lower frame 3 by being recessed downward in an arc shape (see FIG. 2).

On the other hand, a support unit 8 is formed separately from the printer main body 5. The support unit 8 includes a bearing 15 and a support plate 2 that supports the bearing 15.
The upper fixing roller 7 is rotatably supported by a bearing 15. In this case, the bearing 15 and the fitting shape part 14 constitute the fitting mechanism part 10, and the bearing 1
The outer periphery of 5 is fitted to the fitting shape portion 14. As shown in FIG. 3, the bearing 15 integrally has a large-diameter flange portion 27 on the outer peripheral portion, and the flange portion 27 is engaged with a side surface of the lower frame 3. At the rear end of the support plate 26, an engaging concave portion 13 cut out in a horizontal U shape is formed. The engagement shaft 12 and the engagement recess 13 constitute the engagement mechanism 9, and the engagement recess 13 can be engaged with the engagement shaft 12. Further, a pressurized portion 17 that is formed to be horizontally bent is integrally provided at the front end of the support plate 26.

On the other hand, a pressing portion 16 is provided on the upper frame 4. The pressing portion 16 has a pusher 31, which is urged downward by a spring 30. In this case, the pressurizing section 16 and the pressurized section 17 constitute the pressurizing mechanism section 11, and the pressurizing section 16 can press (press) the pressurized section 17. Therefore, the relationship between the urging force Fu of the fixing roller 7 by the spring 30 and the urging force Fd of the fixing roller 6 by the spring 24s is set so that Fu> Fd.

The support unit 8, the engagement mechanism 9, the fitting mechanism 10, and the pressure mechanism 11 are all provided in a pair so as to be symmetrical on both left and right sides.

Next, the functions of the fixing device 1 will be described with reference to FIGS.
This will be described with reference to FIG.

First, in the printer main body 5, the upper frame 4 rotates about the hinge portion 2 as a fulcrum.
Can be opened and closed.

Therefore, when the support unit 8 is mounted on the printer main body 5, the upper frame 4 is opened, the engagement recess 13 of the support unit 8 is engaged with the engagement shaft portion 12, and the bearing unit 8 The outer peripheral portion of the lower frame 15 is fitted to the concave fitting portion 14 provided on the lower frame 3. Then, when the upper frame 4 is closed, the elastically supported pressing portion 16 provided on the upper frame 4 presses the pressed portion 17 provided on the support unit 8. As a result, the bearing 15 is pressed against and fitted to the fitting shape portion 14, so that the support unit 8 is fixed in a state where it is accurately positioned with respect to the lower frame 3. In this case, since the bearing 15 that supports the shaft of the fixing roller 7 is directly positioned,
If the positional accuracy of the lower frame 3 is ensured, high positioning accuracy of each of the fixing rollers 6 and 7 is ensured.

Therefore, at the time of recording, the recording paper L is sandwiched between the fixing rollers 6 and 7, and the toner on the recording paper L is subjected to a fixing process by heating and pressing.

On the other hand, when the paper jam is to be cleared or the fixing roller is to be replaced, the upper frame 4 is opened to release the pressurization of the pressurized portion 17 by the pressurizing portion 16 and the pressurizing portion 1.
6 is separated from the support unit 8. Therefore, the support unit 8 can be displaced upward with the engagement shaft portion 12 as a fulcrum, and the traveling path L can be released by one-touch operation.
Further, when replacing the fixing roller 7, the fixing roller 7 can be removed as it is.

The embodiment has been described in detail above.
The present invention is not limited to such an embodiment,
In the configuration, shape, etc. of the support unit, the pressure mechanism, etc.
It can be arbitrarily changed without departing from the gist of the present invention.

[0033]

As described above, the present invention provides an electrophotographic printer in which one fixing roller is supported by a lower frame and the other fixing roller is supported by a support unit separate from the printer body. In the fixing device of the first aspect, an engagement mechanism for rotatably engaging the end of the support unit with the lower frame and a fitting mechanism for positioning the lower frame and the support unit are provided between the lower frame and the support unit. ,
The engaging mechanism is configured by an engaging shaft portion provided on the lower frame and an engaging concave portion formed by cutting the supporting unit engaging with the engaging shaft portion into a horizontal U shape, and the fitting mechanism portion is
The lower frame is formed by a fitting portion formed by being concaved in an arc shape on the lower frame, and a bearing provided on a support unit fitted to the fitting shape portion. Further, the support unit is provided between the upper frame and the support unit when the frame is closed. Is provided on the lower frame side, so that the following remarkable effects can be obtained.

The paper jam processing and the fixing roller replacement work can be performed very easily by one-touch operation.

Since the positioning is performed by fitting to a support unit (particularly, a bearing) that supports the fixing roller, the positional accuracy of the fixing roller can be dramatically increased, and stable recording paper traveling and fixing processing can be realized.

[Brief description of the drawings]

FIG. 1 is a side view showing a mounting state of a fixing roller in a fixing device according to the present invention.

FIG. 2 is a side view showing a state in which a fixing roller is removed from the identification attaching device.

FIG. 3 is a partial plan view of the identification landing device,

FIG. 4 is a schematic configuration diagram of a label printer including an identification attaching device,

FIG. 5 is a side view of a fixing device according to the related art;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixing device 2 Hinge part 3 One frame (lower frame) 4 The other frame (upper frame) 5 Printer main body 6 Fixing roller 7 Fixing roller 8 Support unit 9 Engaging mechanism 10 Fitting mechanism 11 Pressure mechanism 12 Engagement shaft part 13 Engagement concave part 14 Fitted shape part 15 Bearing 16 Pressurizing part 17 Pressurized part L Recording paper

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G03G 13/20 G03G 15/00 550 G03G 15/20 G03G 21/16-21/18

Claims (2)

(57) [Claims] 1. A printer body having a lower frame and an upper frame that are openably and closably connected via a hinge portion, wherein one of a pair of fixing rollers sandwiching recording paper is supported by the lower frame, and the other is fixed. In a fixing device of an electrophotographic printer in which a roller is supported by a support unit separate from a printer body, an end of the support unit is rotatably connected to the lower frame between the lower frame and the support unit. An engaging mechanism and a fitting mechanism for positioning between the lower frame and the support unit are provided. The engaging mechanism is engaged with the engaging shaft provided on the lower frame and the engaging shaft. A fitting shape portion formed by notching the support unit with a horizontal U-shaped notch and forming the fitting mechanism portion by depressing the fitting mechanism portion in an arc shape in a lower frame, and the fitting shape portion A support unit provided in the support unit fitted to the portion, and further comprising a pressurizing mechanism for pressing the support unit toward the lower frame when the frame is closed between the upper frame and the support unit. Printer fixing device. 2. The pressurizing mechanism comprises an elastically supported pressurizing portion provided on an upper frame and a pressurized portion provided on a support unit which can be pressed by the pressurizing portion. Item 2. A fixing device for a printer according to Item 1.