JPH048440Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a paper peeling device for a fixing roller that is applied to an image forming apparatus that applies electrophotographic technology.

[Prior art and its problems]

In image forming apparatuses that apply electrophotographic technology, it is generally necessary to fix toner images formed on paper by heating or applying pressure, and for this fixing, a heating roller and a pressure roller are brought into contact with each other. Many roll fixing type fixing devices are used, in which the paper is rotated by two rollers and the paper is passed between both rollers. In such a fixing device, the surface in contact with the toner, that is, the outer peripheral surface of the heating roller, is made of a material with good releasability to prevent offset development caused by the adhesiveness of the toner or wrapping due to the inability to separate the paper. For example, heat-resistant mold release rubbers such as silicone rubber and fluorine rubber are used. However, even if these releasable materials are used, it is not possible to completely prevent paper from wrapping around.
Therefore, in order to more reliably prevent the paper from wrapping around the heating roller, conventionally, the method shown in FIG. 4 or 5 a
As shown in FIGS. and b, the peeling claw A is rotatably supported by a shaft A', and its tip is pressed against the heating roller C by a spring B. It peeled off from the heating roller C. In this case, the peeling claw A requires a shaft A' in order to press its tip against the heating roller C, which increases the number of parts and costs.In addition, as shown in FIG. 5, a small shaft engages with one end of the spring B. If there is E, there is a problem that when replacing or assembling a deformed or damaged item, the installation work of the peeling claw A itself and the spring B is not easy and becomes a large-scale work.

[Purpose of invention]

The present invention aims to reduce the number of parts by eliminating the mounting shaft of the peeling claw whose tip is pressed into contact with the fixing roller consisting of a heating roller and a pressure roller, and to provide a paper peeling device for the fixing roller that is easy to install. purpose.

[Key points of the idea]

According to the present invention, with respect to the fixing roller which is composed of a heating roller and a pressure roller that rotates while being in pressure contact with the heating roller and which pinches and conveys the paper, the peeling claw disposed on the downstream side in the paper conveyance direction is In a paper peeling device for a fixing roller that peels the conveyed paper from the outer circumferential surface of the fixing roller by contacting the fixing roller, a leading edge part that contacts the fixing roller, and a downstream part of the paper conveying direction from the leading edge part. a peeling claw having an end face parallel to the axis of the fixing roller and intersecting the paper conveying surface on the side, and a recess parallel to the axis in the middle part of the end face in the cross direction; an opening into which the end surface of the peeling claw can be inserted in a manner that intersects with the end surface of the peeling claw is provided on the opposite surface facing the paper transport surface at a position farther from the contact position of the leading edge portion with respect to the transport surface; A downstream edge in the paper conveyance direction parallel to the core is used as a hook part of the recess, and a part of the end surface projects in a direction away from the paper conveyance surface, so that the peeling claw can freely rotate through the hook part. a plate-shaped support member for supporting;
a spring member having one end connected to the peeling claw and the other end biased and supported in a direction in which the tip end portion contacts the outer circumferential surface of the fixing roller; The fixing roller is hooked on a support member and the spring member presses the leading edge portion against the outer circumferential surface of the fixing roller, thereby peeling the conveyed paper through the leading edge portion. This is achieved by providing a paper stripping device.

[Example of idea]

An embodiment of the present invention will be described with reference to the drawings, taking a recording device as an example.

FIG. 3 is a schematic configuration diagram showing the main parts of a recording apparatus 1 to which a paper peeling device for a fixing roller according to the present invention is applied.

The recording device 1 includes a recording section 3 that forms recorded information on a photosensitive drum 2, a paper feeding section 5 that sequentially feeds paper 4 in synchronization with the recorded information formed on the photosensitive drum 2, It is composed of a conveying section 6 and the like that conveys the paper 4, reverses it, and discharges it to a predetermined position.

The recording unit 3 includes a charger 7 that is disposed close to above the photoreceptor drum 2 and uniformly charges the photoreceptor drum 2, and a charger 7 that records recorded information on the photoreceptor 2 to form an electrostatic latent image. a printing head 8 for printing, a developing device 9 for developing the electrostatic latent image formed on the photosensitive drum 2, a transfer device 10 for transferring the developed recorded information onto the paper 4, and It is composed of a cleaner 11 and the like that removes residual toner on the photosensitive drum 2 that has not been transferred. The print head 8 uses, for example, a liquid crystal light shutter in which a large number of microshutters are assembled in the main scanning direction, and forms an electrostatic latent image on the photoreceptor drum 2 by light incident from a light source (not shown) through a light guide. let

The paper feed unit 5 includes a paper feed cassette 12 that stores sheets 4 of a predetermined size in a stacked manner, and a paper feed roller 13 that takes out and feeds the sheets 4 one by one from the top.
Turn guide 14 that guides the conveyance direction of paper 4
, a standby roll 15 for transporting the paper 4 along the turn guide 14 , and a stopper 16 for transporting the paper 4 in synchronization with the recorded information on the photosensitive drum 2 .

The transport section 6 is located above the paper feed cassette 12,
A separating roller 17 separates the paper 4 on which the recorded information on the photosensitive drum 2 has been transferred by the transfer device 10 from the photosensitive drum 2, a guide plate 18 that receives and guides the paper, and heats the recorded information after transfer. and a fixing roller 19 for fixing by pressure;
a peeling claw 21 attached to the conveyance guide plate 20 in close proximity to the paper, and a guide plate 22 that guides the paper upward.
22, transport rolls 23a and 23b that transport the paper upward along the guide plates 22 and 22, and a paper discharge roll 24 that discharges the paper to a paper discharge section 1b provided on the top surface of the housing 1a. There is.

The fixing roller 19 is an upper heating roller 19.
a and a lower pressure roller 19b, and a peeling claw 2
1 has its tip pressed against the heating roller 19a,
The paper is sent out from between the heating roller 19a and the pressure roller 19b, and is peeled off from the heating roller 19a by the peeling claw 21.

FIG. 1 is a partially enlarged perspective view showing a state in which the peeling claw 21 is attached to the conveyance guide plate 20 by a spring 25, and FIG. 2 is a partially enlarged side sectional view of the same.

The conveyance guide plate 20 has a horizontal part 20a bent and formed from a flat plate-like material and an upwardly inclined part 20b, and a rectangular opening 20c through which the peeling claw 21 passes through and an inclined part are provided at predetermined positions of the horizontal part 20a. Part 20b
Rectangular openings 20d, 20d corresponding to the conveyance roll 23a are opened from the horizontal portion 20a to the horizontal portion 20a.
The rear end surface is disposed close to the outer circumferential surface of the heating roller 19a, and guides the paper that has passed through the heating roller 19a as it is transported by the transport rolls 23a and 23b. The above conveyance roll 23
a is the lower transport roll 2 through the opening 20d.
3b.

The peeling claw 21 is made of a heat-resistant synthetic resin such as polyamide or polyimide, or a metal material, and has a substantially triangular cross section with an acute-angled edge portion 21a at the lower end, an oblique side, an opposite side, and a base. Slanted surface 21b and opening 2 corresponding to the opposite side
It has a forward end surface 21c opposite to the front end surface 21c, and an upward end surface and a rearward end surface 21d substantially parallel to the forward end surface 21c are formed at the upper end. Further, the peeling claw 21 has a recess 21e having an arcuate cross section partially formed in the middle part of the forward end surface, and a recess 21f having a similar arcuate cross section formed at the connection part between the inclined surface 21b and the rearward end surface 21d. , the recess 21e is hooked to one end of the opening 20c of the conveyance guide plate 20.

The spring 25 has a long part 25a and a short part 25b formed by folding an elastic band-shaped material in half into an inverted U shape, and has a curved end 25c with a rearward concave surface at the tip of each of the long part 25a and the short part 25b. 25d, and the curved end 25c on the side of the long portion 25a is connected to the opening 2 of the conveyance guide plate 20.
0c, and the curved end 25d on the short portion 25b side is fitted into and latched into the recess 21f of the peeling claw 21, and supports the peeling claw 21 by a biasing force in the direction indicated by the arrow X. It serves to bias the edge portion 21a in the direction indicated by Y and press the edge portion 21a against the heating roller 19a.

When attaching the peeling claw 21, the cover 26 on the fixing roller 19 is moved by an unillustrated opening mechanism, the recess 21e is hooked to one end of the opening 20c of the conveyance guide plate 20, and the long part 25a of the spring 25 is attached.
While compressing the spring 25 by placing a hand on the short portion 25b, insert the curved ends 25c and 25d into the other end of the opening 20c and the concave portion 21f at the other end opposite to the edge portion 21a of the peeling claw 21, respectively. When you release your hand after latching, the peeling claw 21 is supported by the conveyance guide plate 20 by the biasing force of the spring 25, and
It is rotatable around the concave portion 21e, and the edge portion 21a is pressed against the heating roller 19a, and the paper 4
can be reliably peeled off from the heating roller 19a.

When removing the peeling claw 21, hold the long part 25a and the short part 25b to compress the spring 25, and hook the curved ends 25c and 25d from the other end of the opening 20c and the recess of the peeling claw 21, respectively. By releasing the peeling claw 21, the peeling claw 21 can be easily removed from the conveyance guide plate 20.

In addition, the material of the peeling claw 21 may be polyamideimide, polyphenylene sulfide, polyester, tetrafluoroethylene resin, etc. in addition to the above materials, and the number of peeling claws 21 is not limited to one, but may be multiple at a predetermined interval. You can also set it up. Further, the spring 25 is not limited to the case where the curved end 25c on the long portion 25a side is hooked to the other end of the opening 20c of the conveyance guide plate 20; It may be latched in a suitable position to urge it into pressure contact.

Further, the spring 25 is not limited to a leaf spring, but any compression spring, tension spring, or the like can be used as long as it has one end connected to the peeling claw 21 and urges the edge portion 21a in a direction to press against the heating roller 19a.

[Effect of idea]

According to the present invention, the peeling claw passes through the opening for inserting the peeling claw in the conveyance guide plate that guides the conveyance of the paper that has passed the fixing roller consisting of the heating roller and the pressure roller, and the end face facing the opening. is hooked to one end of the opening of the conveyance guide plate in a recess formed in an intermediate portion of the fixing roller, and the leading edge portion is urged by a biasing means in a direction in which the fixing roller is pressed against the outer circumferential surface of the fixing roller; The spring used as the biasing means is
One end is hooked to, for example, the conveyance guide plate, and the other end is hooked to the opposite end of the peeling claw, so that the mounting shaft of the peeling claw can be eliminated, reducing the number of parts and reducing costs. Therefore, it is possible to provide a paper peeling device for a fixing roller that can be easily installed.

[Brief explanation of drawings]

Fig. 1 is a partially enlarged perspective view showing a separating claw according to the present invention attached to a conveyance guide by a spring, Fig. 2 is a cross-sectional view from the upper side of the same, and Fig. 3 is a record to which the present invention is applied. FIG. 4 is a side view showing a conventional fixing roller paper peeling device, and FIGS. 5 a and 5 b are a side view and a perspective view, respectively, showing another conventional example. . 1...recording device, 2...photosensitive drum, 3...
Recording section, 4... Paper, 5... Paper feeding section, 6... Conveyance section, 7... Charger, 8... Print head, 9... Developer, 10... Transfer device, 11... Cleaner, 12
...Paper feed cassette, 13...Paper feed roller, 14...
Turn guide, 15...standby roll, 16...stopper, 17...separation roller, 18...guide plate,
19...Fixing roller, 19a...Heating roller, 1
9b... Pressure roller, 20... Conveyance guide plate, 2
0a...Horizontal part, 20b...Slope part, 20c, 2
0d...Opening, 21...Peeling claw, 21a...Edge, 21b...Slope, 21c...Front-facing end surface, 21d...Backward-facing end surface, 21e, 21f...
Recessed portion, 22... Guide plate, 23a, 23b... Conveyance roll, 24... Paper ejection roll, 25... Spring,
25a...Long part, 25b...Short part, 25c, 25
d...Curved end, 26...Cover.

Claims (1)

[Claims for Utility Model Registration] The fixing roller, which is composed of a heating roller and a pressure roller that rotates while being in pressure contact with the heating roller, pinches and conveys the paper, and a peeling claw disposed on the downstream side in the paper conveyance direction is connected to the fixing roller. A paper peeling device for a fixing roller that peels a conveyed paper from an outer circumferential surface of the fixing roller by contacting the fixing roller, a leading edge part making contact with the fixing roller;
an end face parallel to the axis of the fixing roller and in a direction intersecting the paper conveyance surface on the downstream side of the leading edge in the paper conveyance direction, and a recess parallel to the axis in the intermediate part of the end face in the cross direction; a peeling claw formed thereon; and the end surface of the peeling claw can be inserted into an opposing surface facing the paper transport surface at a position farther from the paper transport surface than the contact position of the leading edge portion, with the end surface of the peeling claw intersecting with the opposing surface facing the paper transport surface. an opening, and a downstream edge of the opening in the paper conveyance direction parallel to the axis is used as a hook part of the recess, and a part of the end surface protrudes in a direction away from the paper conveyance surface, and the peeling claw is a plate-shaped support member rotatably supported via the hook portion; one end connected to the peeling claw, and the other end biased and supported in a direction in which the tip end portion contacts the outer circumferential surface of the fixing roller; and a spring member, the peeling claw is hooked to the plate-like support member in the recess, and the spring member presses the leading edge portion against the outer circumferential surface of the fixing roller, thereby removing the sheet to be conveyed. A paper peeling device for a fixing roller, characterized in that the sheet is peeled off through the leading edge portion.