JPH054171U - Recording paper separating device - Google Patents

Abstract

(57) [Abstract] [Purpose] A separation plate is used to smoothly separate recording paper from the peripheral surface of a soft fixing roll without damaging the surface of the fixing roll. [Structure] The front end contacts the peripheral surface of the fixing heating roll 1, and the base end moves parallel to the support shaft 12 in the upward and downward directions via the guides 11d, 11d and the projection 11f. The support shaft 12 is rotated, and both ends in the axial direction about the protrusion 11f are supported so as to be tiltable upward and downward, and the tip end is biased to the peripheral surface side of the fixing heating roll 1 in the middle part. A separation plate 11 provided with a tension spring 13 for

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a separating device that prevents a recording paper from being wound around a fixing roll in the process of fixing a toner image on the recording paper in electrophotography, electrostatic printing, and the like.

[0002]

[Prior Art]

 The toner image transferred onto the recording paper is fixed on the surface of the recording paper by heating the recording paper while pressing it through the fixing roll, but in this process, the toner is melted and the recording paper is fixed on the surface of the fixing roll. The recording paper will be caught in the fixing roll and cause troubles. For this reason, it is practiced to separate the recording paper from the surface of the fixing roll on the output side of the recording roll using a separating claw.

The separating claw is usually configured such that its base end is pivotally supported by a shaft, and the tip of the claw is brought into sliding contact with the surface of the fixing roll to peel off the recording paper from the surface of the fixing roll. By the way, as a fixing roll, a hard synthetic resin or metal fixing roll has been conventionally used, but in recent years, a rubber soft roll tends to be used for improving image quality.

However, in the case of a soft roll, the tip of the separating claw sometimes bites into the surface of the fixing roll and damages the surface of the fixing roll, and various countermeasures for this have been conventionally proposed.

FIG. 6 is a schematic side view showing a conventional separating device (No. Shokai 56-150947), and FIG. 7 is an enlarged sectional view taken along line VII-VII of FIG. 6, in which 21 and 22 are fixed. Roll and 25 are recording papers. The fixing rolls 21 and 22 are rotationally driven in the arrow direction by a driving unit (not shown), respectively, and the recording paper 25 having the toner image adhered thereto is fed from the arrow direction into both fixing rolls 21 and 22. After the toner image is fixed by heating and pressing, the toner images are peeled off from the surface of the fixing rolls 21 and 22 by the winding prevention claws 26 and 27 on the output side of both fixing rolls 21 and 22 and discharged (not shown). It is designed to be discharged onto the tray.

Each of the winding preventing claws 26, 27 has a base end pivotally supported by a support shaft 28, 29, and each tip end is slidably contacted with the peripheral surface of the fixing rolls 21, 22. The pivotal structure of the prevention claw 27 is specifically as shown in FIG. The winding prevention claw 27 is provided with a sleeve 30 having an annular protrusion 30a on the inner surface of the central portion in the axial direction at the base end thereof, and the annular protrusion 30a is attached to the support shaft 29 inserted into this sleeve 30. The coil spring 31 urges and holds the winding prevention claw 27 toward the peripheral surface of the fixing roll 22.

As a result, the anti-wrapping claw 27 is rotatable with respect to the support shaft 29, and within the range of the gap d between the support shaft 29 and the sleeve 30 about the annular projection 30a. It can be tilted in any of up, down, left, right, front, and rear directions with respect to 29. In such a conventional apparatus, a process of absorbing the dimensional error caused in the manufacturing process, the assembly error caused by vibration, etc., and sliding the tip end of the anti-wrapping claw 27 against the peripheral surface of the fixing roll 22. Even when the frictional force becomes uneven, the peripheral surface of the fixing roll 22 can be smoothly slid on and the recording paper 25 can be peeled off without damaging the surface of the fixing roll 22. There is.

[0008]

[Problems to be solved by the device]

 By the way, in such a conventional device, the anti-wrapping claw 27 as a whole is orthogonal to the support shaft 29, so that tilting is allowed in any of the directions of up, down, left, right, front, and rear. The degree of freedom of the anti-wrapping claw 27 with respect to the fixing roll 22 is too great, and the chances of damage to the peripheral surface of the fixing roll 22 increase. When the roller 25 is tilted with respect to the conveying direction, the toes of the winding prevention pawl 27 become non-parallel to the generatrix M of the fixing roll 22 as shown in FIG. When the recording paper 25 is conveyed, it may collide with the recording paper 25, damage the fixing roll 22, bite into the edge of the recording paper 25, dent the edge of the recording paper 25, and make a crease. There were difficulties such as causing trouble.

The present invention has been made in view of the above circumstances, and an object thereof is to reduce the degree of freedom of a separation plate for preventing wrapping around a supporting shaft so that a recording paper can be smoothly peeled off. The present invention provides a recording paper separating device.

[0010]

[Means for Solving the Problems]

 The recording paper separating device according to the present invention is such that the leading end of the recording paper is slidably contacted with the fixing roll surface in order to separate the recording paper having a toner image fixed on the surface thereof through a fixing roll. In a recording paper separating device having a separating plate supported by a supporting shaft arranged in parallel with the fixing roll, the separating plate supports the widthwise central part on the base end side at one point with respect to the supporting shaft. And a guide member that restrains the movement of the recording paper in the feeding direction with respect to the support shaft, and is supported by an elastic support member that biases and holds toward the peripheral surface of the fixing roll. It is characterized by

[0011]

[Action]

 According to the present invention, the separating plate is supported by the projection in such a state that the separating plate is restrained from moving in the front-back direction with respect to the supporting shaft by the guide member and is allowed to move in the direction orthogonal to the supporting shaft. Since it is supported at a single point on the shaft, various design errors or distortion due to vibration are absorbed, and damage to the fixing roll and recording paper is prevented.

[0012]

【Example】

 Hereinafter, the present invention will be specifically described with reference to the drawings showing an embodiment thereof. FIG. 1 is a side view showing a recording paper separating apparatus according to the present invention, in which 1 is a heating roller for fixing, 2 is a pressure roller for fixing, and 3 and 4 are discharges arranged in the upper and lower sides. Rolls 5 indicate recording paper.

The fixing heating roll 1, the fixing pressure roll 2, and the discharging rolls 3 and 4 are arranged in the transporting area of the recording paper 5 at predetermined intervals, respectively, and are conveyed in the arrow direction. The recording paper 5 is first passed through the fixing heating roll 1 and the fixing pressure roll 2 to fix the toner image on the surface, and then separated by the separating device 10 from the surface of the fixing heating roll 1. The sheet is discharged onto a tray (not shown) by the discharge rolls 3 and 4 after passing between the separating device 10 and the guide plate 9.

The fixing heating roll 1 is configured by forming a silicon rubber layer 1b having a thickness of 0.5 to 2 mm on the outer peripheral surface of a metal cylindrical body 1a, and a heater 1c is disposed inside. It can be driven to rotate in the opposite direction together with the fixing pressure roller 2 by a drive source not shown. 6 is a thermistor for adjusting the surface temperature of the fixing heating roll 1, 7 and 8 are oils for increasing the releasability of the recording paper 5 to the fixing heating roll 1 and the fixing pressure roll 2. It is an oil roller.

The guide plate 9 faces the conveyance area of the recording paper 5 between the heating roll 1 for fixing, the pressure roll 2 for fixing, and the discharging rolls 3 and 4 and is located below the guide plate 9, and the separating device 10 is located above. They are provided respectively.

FIG. 2 is an enlarged front view seen from the line II-II of FIG. 1, and FIG. 3 is an enlarged perspective view of the separation plate. The separating device 10 for the recording paper 5 is provided with a plurality of sets of separating plates 11, 11 ... Arranged in the axial direction of the fixing heating roll 1 and the fixing pressure roll 2. Each of the separating plates 11 and 11 has substantially the same configuration, and one separating plate 11 will be specifically described.

As shown in FIGS. 2 and 3, the separating plate 11 is made of stainless steel having a thickness of about 0.3 mm, or is made of heat-resistant resin and is formed into a rectangular plate shape, and has a single-edged knife edge taper surface at its tip. 11a is formed, and in order to maintain the flatness, the base end portion is bent to the upper surface side to form a standing piece 11b, and the ear portions 11c and 11c are further formed on both side portions slightly closer to the tip end side than the center portion The guide parts 11d, 11d each having a rectangular shape in a side view are activated slightly closer to the base end side than the center part, and the separation plate 11 is supported at the substantially central part of the surface between the guide parts 11d, 11d. Is provided with a protrusion 11f for supporting it at one point.

The projection 11f has a dimensional ratio of height 2 to diameter 1 thereof. The width of the separating plate 11 is not particularly limited, but if it is too small, it will bite into the fixing heating roll 1 and is preferably 20 mm or more. However, if it is too large, it warps itself, and deformation, thermal strain, etc. occur, resulting in lack of adhesion to the fixing heating roll 1.

The guide portions 11d, 11d are provided with a hole having a rectangular shape in a front view in a central portion, and a support shaft 12 provided in a frame (not shown) in parallel with the fixing heating roll 1 is inserted into the hole. The movement of the support shaft 12 in the axial direction is restricted by a snap ring 12a, and one end of each tension spring 13, 13 is connected to each of the two ears 11c, 11c, and the other end is It is fixed to a frame (not shown) so that the separation plate 11 is biased and held toward the peripheral surface of the fixing heating roll 1 and the projection 11f of the separation plate 11 is brought into contact with the peripheral surface of the support shaft 12. ..

The upper and lower lengths l ₁ (see FIG. 3) of the holes of each guide portion 11d, 11d are larger than the diameter of the support shaft 12, and the left and right widths l ₂ of the holes are supported. The diameter is set to be approximately equal to the diameter of the shaft 12, and when the guide parts 11d and 11d are fitted onto the support shaft 12, the guide parts 11d and 11d cannot move in the front and rear directions with respect to the support shaft 12. Restrained, but movement in the up and down directions and rotation around the support shaft 12 is allowed, as well as tilting of the separation plate 11 to the left and right in the width direction around the protrusion 11f is allowed. It is in a state.

FIG. 4 is an enlarged view showing the structure of the tip portion of the separating plate 11. The tip portion of the separating plate 11 has a taper surface 11a on the side facing the fixing heating roll 1 over a predetermined width. The entire surface is coated with a toner offset prevention material such as Teflon. The gap S between the base of the taper surface 11a and the peripheral surface of the fixing heating roll 1 should be 0.1 mm or less, and the tip end should be in sliding contact with the peripheral surface of the fixing heating roll 1 at a predetermined pressure (about 20 g). Is set to.

In the apparatus of the present invention as described above, the recording paper 5 is carried between the fixing heating roll 1 and the fixing pressure roll 2 in the arrow direction as shown in FIG. While being heated between the roll 1 and the fixing pressure roll 2, the toner image is fixed to the surface of the recording paper 5 by pressure bonding. The recording paper 5 on which the toner image is fixed between the fixing heating roll 1 and the fixing pressure roll 2 is separated from the fixing heating roll 1 by the separating plate 11 and is discharged to the discharging rolls 3 and 4 not shown. Delivered to the tray.

The separation plate 11 has coil springs 13 and 13 with the tapered surface 1a at the tip thereof slidably contacting the peripheral surface of the fixing heating roll 1 at a predetermined pressure, and the base end portion thereof has guide portions 11d and 11d is restrained by the support shaft 12 in the front-back direction (moving direction of the recording paper 5), but is moved upward and downward with respect to the support shaft 12, the rotation around the support shaft 12, and the protrusion 11f. By tilting in the left and right directions around the center, variations in sliding friction between the tip of the separating plate 11 and the peripheral surface of the fixing heating roll 1 are absorbed.

FIG. 5 is an explanatory view showing a manner of sliding contact of each separating plate 11 with the peripheral surface of the fixing heating roll 1. In the device of the present invention, the tip of the separating plate 11 is as shown in FIG. 5 (a). The portion of the heating roller for fixing 1 is kept parallel to the generatrix of the heating roller 1 for fixing, absorbs the variation in sliding friction, and does not damage the surface of the heating roller 1 for fixing. It is possible to make smooth sliding contact.

On the other hand, in the conventional device, since the anti-wrapping claw 27 is allowed to move in the front and rear directions, in this structure, as shown in FIG. The leading edge tilts (θ) and the corner bites into the fixing roll surface, and even if this is applied to the separating plate, damage to the fixing roll surface is unavoidable as shown in FIG. 5 (b).

[0026]

[Effect of the device]

 As described above, in the apparatus of the present invention, the base end of the separation plate is rotatable and tiltable with the forward and rearward movements of the support shaft being restrained. Since it is always maintained parallel to the busbar of the recording paper, it can collide with the edge of the recording paper at the same time and peel it off without damaging it. It plays.

[Brief description of drawings]

FIG. 1 is a schematic side view of a recording paper separating device according to the present invention.

FIG. 2 is an enlarged schematic diagram along line II-II in FIG.

FIG. 3 is an enlarged perspective view of one separation plate.

FIG. 4 is an enlarged view showing the configuration of the tip portion of the separation plate in the device of the present invention.

FIG. 5 is an explanatory view showing the relationship between the separating plate in the device of the present invention, the separating plate of the conventional device, and the busbar of the fixing roll.

FIG. 6 is a schematic side view showing a conventional device.

FIG. 7 is an enlarged sectional view taken along line VII-VII of FIG.

FIG. 8 is an explanatory diagram showing a sliding contact posture of a separation plate with respect to a generatrix of a fixing roll.

[Explanation of symbols]

 1 Fixing heating roll 2 Fixing pressure roll 3,4 Discharging roll 5 Recording paper 9 Guide plate 10 Separation device 11 Separation plate 11a Tapered surface 11c Ear 11d Guide 11f Projection 12 Support shaft 13 Tension spring

Claims (1)

[Claims for utility model registration] [Claim 1] The front end is slidably contacted with the surface of the fixing roll in order to separate the recording paper having the toner image fixed on the surface thereof through the fixing roll from the fixing roll surface. In a separation device for recording paper, which comprises a separating plate supported by a supporting shaft arranged in parallel with the fixing roll, the separating plate supports a central portion in the width direction on the base end side at one point with respect to the supporting shaft. And a guide member for restraining the movement of the recording paper in the feeding direction with respect to the support shaft, and is supported by an elastic support member that biases and holds toward the peripheral surface of the fixing roll. A recording paper separating device characterized by the above.