JPS5931985A - Image fixation device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

The present invention relates to an image fixing device for an electrophotographic image recording apparatus]6, and particularly to cleaning in an image fixing device using a roller. Currently, image fixing devices in electrophotographic image recording devices such as electronic copying machines pass a copy sheet between a pair of rollers and fix the toner image formed on the copy sheet using heat or pressure. It occupies the mainstream. This is because compared to a one-chamber type that fixes toner images using thermal radiation, it consumes less energy and is more energy efficient, provides quick and reliable fixing, and is superior in safety. In this method, since the toner image comes into direct contact with the roller surface, so-called offset, in which toner adheres to the roller surface, may occur. In this case, the toner that should originally be fixed on the image adheres to the roller surface, which then acts on the image on the copy sheet that passes between the rollers, causing the toner to fix in unexpected places on the sheet or on the surface of the copy sheet. Remove dirt. In order to prevent the above-mentioned disadvantages, it is common to apply a release agent such as silicone oil to the surfaces of the mouth and mouth, but even in this case, the above-mentioned disadvantages cannot be completely eliminated. Therefore, most roller-based fixing devices H are equipped with cleaning means in which a wiping part m for wiping off toner adhering to the roller comes into contact with the roller. The copying material (copying sheet) that is wiped off by the member and passes between the rollers from then onwards has no effect on the second image.
I try not to smell it. Conventionally, the above-mentioned cleaning means has a simple pressure contact method in which the wiping part side is pressed against and fixed to a roller using a leaf spring or the like, or a web-shaped wiping part is wound around (=J-digit feeding shaft and a feeding rod 1). A winding shaft is provided for winding up the wiping member υ, and a roller is positioned between the two shafts, and the wiping member 9 fed from the feeding shaft is pressed against the roller. Among these methods, the former instant pressure welding method is structurally simple, but since the wiping part H is fixed, the part of the wiping member that comes into contact with the roller is extremely limited. The same part of the wiping member always comes into contact with the roller.For this reason, the toner on the roller concentrates and adheres only to the part of the wiping member that is in contact with the roller. The contact area of the roller quickly becomes dirty and a layer of fused toner forms on its surface, which rapidly reduces the wiping effectiveness of the wiping area. If a wiping member is pressed against a 10-layer for a long period of time, deformation may occur over time due to pressure, and in this deformed area, the roller contact pressure decreases and the elasticity peculiar to nonwoven fabric decreases, making it difficult to utilize the elasticity of nonwoven fabric. This reduces the effect of wiping off the toner.Therefore, such a simple pressure welding method
The disadvantage is that the durability of the wiping part is very poor. On the other hand, is the latter web method one of the above? 11 It is more durable than a pure pressure welding type, but it requires at least a feed-out shaft and a take-up shaft, and a drive mechanism to rotate these shafts and a control mechanism to control the drive. Furthermore, the pressure contact mechanism that presses the wiping member against the roller is attached, resulting in a very crude structure, which not only increases the size of the device, but also requires maintenance for each mechanism, which is very troublesome. It is. The present invention does not have the drawbacks of both conventional cleaning methods, has excellent durability of the wiping member, and
It is an object of the present invention to provide an image fixing device "fr-+M" having one mechanism in the cylinder and a cleaning means that is easy to maintain. The one-image fixing device is provided with a wiping part for wiping off deposits on the surface of at least one roller of the fixing device, and this wiping part is held in a cylindrical shape on a holding body, and the holding body is It is characterized by comprising: a pressure contact driving means for intermittently pressing the wiping member against the roller through the holder, and a rotation driving means for intermittently rotating the wiping member by a predetermined distance M through the holder. Hereinafter, the present invention will be described in detail with reference to the drawings. Fig. 1 is a schematic sectional view of a main part of an embodiment of the present invention. Roller 1 and roller 3 are used to release toner from the toner. The rollers are coated with Teflon on the surface to improve their properties, and roller 2 is a roller whose surface layer is made of silicone rubber.Roller 1 and roller 3 are hollow, and a heater 4 is installed at the center of the shaft. . The roller 3Id is heated to a temperature range in which it becomes plastic and can be fused to the copy sheet 9. Furthermore, during the operation of the fixing device, the roller 3Id roller 1
A load is applied in the direction of rollers 1, 2 .
3 is in a pressurized state, and the silicone rubber layer of the row 22 is deformed under pressure and is in surface contact between the rollers 1 and 2 and between the rollers 2 and 3, respectively.
and a nip portion 7 is formed. On the other hand, the nonwoven fabric 11 is held in a cylindrical shape on the roll cylinder 10, and the roll cylinder 10
is movable to the roll 3 side, and the roll cylinder IO
The upper nonwoven fabric 11 can be pressed against the roller 3. FIG. 2 is a perspective view showing in detail the mechanism related to the roll cylinder 10 used in the embodiment of FIG. 1. A gear 13 is fixed to the shaft 12 of the roll cylinder 10, and the end of the Ih1I12 is inserted into the inner ring 15 of the IJ song 4 and is rotatable. page 1 ring 1
The outer ring 16 of No. 4 is fitted into the circular hole 18 of the swing-y'-m 17 and remains fixed. In addition, the outer ring 16 of the per ring 14
i/i, rock! 11IJ-1-m 19 arc-shaped opening [1 part 20 also>'fl Isj",
It is possible to print 1bl+j for ++20. (
111 moving arm 17 is +p! It is rotatably supported on the 1 support 21, and on the other hand, the swing arm, 1.9 (:i rotation support 41
It is also fixed at +21. Oscillation AJ, ], 7
The upper i/i 2 of and 19 is the notch 22 and 2
3, a tension spring 24 is applied thereto, and the swinging arm 17 and the swinging arm 19 are pulled together. A pressure arm 1125 is fixed to the shaft 21, and a dowel 26 is fixed to the end of the nucleus pressure arm 25. A bottle 27 is fixed near the dowel 26 of the pressure arm 25, and a tension spring 28 is attached to the bottle 27.
Since the other end is supported by a pin 29 fixed to the main body of the device, the rotational force of the pressurizing arm 25 in the direction of arrow A -\ is (
:J is given. An 11i single-core cam 31 is fixed to the support 30 so as to engage with the dowel 26, and the pressurizing arm 25 is rotated by the rotation of the eccentric cam 31. A gear 33 is supported. iil j+113n 34 of the spring clutch 32 is the control arm 3
When the rotation is restrained by the claw 35a of No. 5, the gear 33 and the control ring 34 become free to rotate relative to the 111113 (l), and when the restriction is released, the gear 33 and the control ring 34 It rotates as a body with the shaft 30.The control ring 340 circumference -LK has a protrusion 34PL.34b, and both protrusions are I?1II30=i+
, and 'f' at the left and right ends of the control ring.
:i1]], and both engage with the claw 35a iiJ
It's in Noh. The control arm 35 is rotatable around a pin 36'5, and the tension bar 37, which is hung on a cutout 351) at the other end of the control arm 35, has the other end connected to the device S'? It is supported by a bottle 38 fixed to the main body, and applies rotational force to the control arm 35 in the direction of the raw egg B. However, the control arm 35 is rotated 1. f, full limited. Further, in the control arm 35, an L-type bottle 40 is fixed between the notch S5b and the bottle 36, and the bottle 4o is fixed to the arm 41.
Connected to Granger 42 via Q. A gear 44 that meshes with the gear 33 is fixed to 'il+43. The support 43 is connected to a drive source (not shown) and transmits a force of jh<1. Further, the rotary barley crop 121 is rotatable and meshes with the gear 13 (one gear 45 is supported). Furthermore, the gear 46 meshing with the gear 45 is il+
47, and the shaft 47iJ is connected to a rotating shaft 49 of a low-speed motor 48. Low-speed motor 48&J: The low-speed motor 48&J: is configured to rotate a predetermined number of times at predetermined time intervals, i.e., in this embodiment, for example, before and after the copy sheet passes between the rollers. , ?ν It is controlled by the sequence control device of the main body of the copying machine or the device for detecting the passage of the copy sheet between the rollers. The directions are set to be opposite to each other at the contact portion.Furthermore, the granger 42 is energized when the image foot fixing device starts operation, and when the operation of the tooth gap fixing device is finished. The current is cut off. Figure 2 shows a cylindrical non-woven fabric 11

[1 - The mechanism near one end of the cylinder 10]>f is shown, but the mechanism near the other end is symmetrical with the above mechanism, and everything else is the same except for that point. A mechanism is in place. Next, the operation will be explained. Before the fixing device is activated, the control arm 5 is rotated in the direction of arrow B by the tension spring 37 and comes into contact with the striker 4'39, and the claw 35
a engages with the protrusion 348 of the control ring 34 to restrain the control ring 34, and the spring ring 32 kl: is in a released state. At this time, as shown in FIG. 3, the eccentric cam 31r11 is in a position such that the lowest part 31a from the center of rotation is in contact with the dowel 26, and the angle of the pressure arm 25 at this time is fixed to the rotation support 11ft+21. Swinging Arno 1
9, located further away from roller 3. Therefore, one end of the arc-shaped neighbor 20 of the swinging arm I9 is attached to the swinging arm.
The swing arm 17 comes into contact with the outer ring 16 of the bridge 14 and pushes it to the right in the figure.
The one who got 1 F from 1'll jiJ is rotating,
Since the roll cylinder support 12 is supported by a bearing 14 mounted on this swing arm 17, the non-woven material
is away from roller 3. When the fixing device starts operating, first, the roller l. 2.3 is driven, the heaters 4, 5 are energized, and the rollers 1, 2.3 are heated. Still, the support 43d receives a driving force from the driving source and starts rotating, causing the gear 44 to rotate, and the gear 33 meshing with the gear 44 to rotate. At this point, Pushinger 42 is energized and excited by a signal from the copying machine main body, and draws arm 41 to the left. As a result, the control arm 35&j rotates in the force direction of arrow B' via the pin 40f, and the pawl 3!5g disengages from the protrusion 34a on the control ring 34, releasing the restraint of the control ring 34. [
7, the spring clutch 32 becomes engaged, and the rotation of the gear 33 is transmitted to the shaft 30, thereby causing the eccentric cam 31 to rotate. When the eccentric cam 31 rotates to a position where the highest part 3tb from the center of rotation contacts the dowel 26, the control ring 34, which rotates together with the gear 33, moves its protrusion 34b upward and engages the claw. 35a. Therefore, the rotation of the control ring 34 is restricted, and the spring clutch 3
2 is released, the rotation of the gear 33 is not transmitted to the shaft 30, and the rotation of the eccentric cam 31 is correct. At this point, each component assumes the position shown in FIG. That is, the pressure arm 25 is rotated in the direction of arrow A' by the eccentric cam 31, and the swing arm 19, which is fully fixed to the shaft 21, assumes a rotation position where it approaches the roller 3. Then, the swinging arm 19 is rotated by the tension of the tension spring 24 in the same direction to approach the roller 3. Roll cylinder 10
Since the bearing 14 is supported by the swing arm 17, the roll cylinder 10 moves toward the row 23 and presses the nonwoven fabric 11 against the roller 3. Therefore,
The contact pressure between the nonwoven fabric 11 and the roller 3 is adjusted by the tension of the tension spring 24. In this state, when the rollers 1, 2.3 are heated to an appropriate temperature range by the heater 4.5, the toner image on the copy sheet 8 can be fixed. The copy sheet 8 on which the toner image 9 has been formed passes through the error section 6 between the rollers 1 and 2, but when an offset occurs, the toner 9 on the copy sheet 8
The iJ surface layer adheres to the silicone rubber roller 2. Then, as the roller 2 rotates, I'! on the roller 2! Toner is transferred to roller 2) Roller 3 whose two surfaces are fully coated with Teflon
σ) reaches the error section 7. At this time, since silicone rubber has better releasability than Teflon and lower affinity for toner, the toner is transferred to the roller 3 whose surface is coated with DEFLON. As the roller 3 rotates, the toner adhering to the gorge 3) reaches the contact area of the non-woven fabric 1 and adheres to the non-woven fabric 11. All the toner adhering to the roller is pressed against the +7-ra; -7 is wiped off by the non-woven fabric 1, which then passes between the rollers and does not affect the swirling image of the WM photo sheet. In this embodiment, while the copy sheet is passing between the rollers,

[
Since iVl/-1 rotates at a predetermined rotation rate before and after that, the portion of the nonwoven fabric 11 that contacts the row 23 changes sequentially. In the case of this embodiment, the rotational direction of the nonwoven fabric 11 is opposite to the rotational direction of the roller 3 at the contact portion, and the relative speed at the contact portion is increased by -1. When the operation of the fixing device is completed, the power supply to the heater 4.5, the rotational drive source of the rollers 1, 2.3, and the pusher 42 is cut off. Therefore, the control arm 35
7, it rotates in the direction of arrow B until it abuts against the stopper 39. Therefore, the pawl 35a is disengaged from the protrusion 34b on the control ring 34, and the spring clutch 32 becomes engaged. The drive source connected to the shaft 43 is de-energized, but rotates for a while due to inertia, and l1lII43. gear 4
4. Gear 33. The eccentric cam 31 is rotated via the shaft 30. At the same time, the control ring 34 also rotates. Then, a rotational force is applied to the pressure arm 25 in the input direction by the tension of the tension spring 28 (it bends), so the eccentric cam 31
During the rotation, the dowel 26 slides on the circumference of the eccentric cam 31, and the pressure arm 25 rotates in the direction of arrow A in FIG. When the eccentric cam 31 rotates to the position where its lowest part contacts the dowel 26, the control ring 34 similarly rotates until the protrusion 341k engages with the pawl 35a of the control arm 35, at which point the pawl 3
5a is constrained to rotate at the same speed 34 as 1i: m. ijl'
:D, &″I: The connection U of Neclap 32 is released,
The gear 330 rotation is no longer transmitted to the shaft 30, and (Ifi
The rotation of i, Q, and 31 is also stopped to maintain the rotating can height, and return to the state before the start of operation of the device. The deformation caused by the contact pressure can be reduced by pressing the old (nonwoven fabric 11 in this example) against the -D-ji, and the wiping part 4J is intermittently rotated at 5" to improve the wiping effect. Next, as another example, just before the resheet passes between the rollers of the fixing device, the "°C wiping section A" is applied to at least one of the plurality of "colas" of the fixing device. An embodiment will be described in which the sheet is pressed against one 11-roller and the pressure is released after the returning sheet passes between the rollers.The mechanical structure of the embodiment is as described above. This embodiment is the same as the first embodiment, but the timing at which the wiping portion comes into pressure contact with the roller is different.
Explanation using Figure 4191: The plunger 12 is activated by the Silkens control signal of the main body of the copying machine or the detection of copying I≠sheet passage 11':'a provided near the copy sheet inlet of the fixing device. Immediately before or during passing between the rollers of the device Pt, the copy sheet is fixed by a signal from the copying machine body, and a sequence control signal from the main body of the copying machine or fixing is applied to the trowel through which the copy sheet passed between the rollers. The energization is canceled by a signal from a copy sheet passage detection means provided near the copy sheet exit of the device.During the operation of the fixing device, the rollers 1, 2 and 3 are turned off.
is driven to rotate, and the L roller is heated by heaters 4 and 5 to a temperature capable of fixing the toner on the copy sheet onto the copy sheet. ! F. In addition, the shaft 43 is rotated by a drive source (not shown), and the gear 3 meshes with the gear 44 fixed to the puller 43.
3 is constantly rotating. In this state, the control arms 3 and 5 are normally rotated in the direction of arrow B by the tension spring 37, and the pawl 3511 engages with the protrusion 34a of the control ring 34 to restrain the control ring 34, and the spring clutch 32 is in a released state. At this time, the eccentric cam 31 is in a position such that the lowest part 31a from the center of rotation is in contact with the dowel 26, as in the state shown in FIG. The swinging arm 19 fixed to 21 is in a pivoting position away from the rollers 3. Therefore, due to the tension of the tension spring 24, the swinging arm 17
Since the bearing 14 of the shaft 12 of the roll cylinder is supported by the swinging arm 17 of the nonwoven fabric 11 kJ: a-ra 3, the nonwoven fabric 11 is separated from the roller 3. From the above state, the image copying operation is performed, and just before the copy sheet passes between the rollers, or during the passage, the plunge... The arm 41 is energized and energized by a signal from a copy sheet passage detecting means provided near the sheet entrance, thereby drawing the arm 41 to the left. by this,
The control arm 351d is rotated in the direction of arrow B' via the pin 40, and the pawl 35a is disengaged from the protrusion 341k on the control ring 34, releasing the control ring 34 from its restraint. Therefore, the spring clutch 32 is in the engaged state, and the rotation of the gear 33 is caused by the rotation of the shaft 30.
This causes the eccentric cam 31 to rotate. Then, the eccentric cam 31 is located at the highest part 31b from the center of rotation.
When the gear rotates to the f~2 position where the dowel 26 and the dowel 26 touch, the gear 3
The protrusion 34b of the control roller 34, which rotates together with the control roller 3, moves upward and engages with the pawl 3511. Therefore, the control ring 34
The rotation of the gear 33 is restricted, the coupling between the spring clutch and the gear 32 is released, and the rotation of the gear 33 is not transmitted to the ll1l130.
The eccentric cam 31 stops rotating. At this point, the positional relationship of each groove element is the same as that shown in FIG. That is, the pressure arm 25 is rotated in the direction of arrow A' by the eccentric cam 31, and assumes a rotational position l in which the swing arm 19 fixed to the shaft 21 approaches the roller 3. And the swing arm 19
Due to the tension of the tension spring 24, the swing arm 17 is also rotated in the direction toward the roller 3. Since the bearing 14 of the shaft 12 of the roll cylinder 10 is supported by the swing arm 17, the roll cylinder 1O moves toward the roller 3 and presses the nonwoven fabric 11 against the row 23. Therefore, the contact pressure between the nonwoven fabric 11 and the roller 3 is adjusted by the tension of the tension spring 24. l The formed repetition′q sheet of the ner music symbol () 8ζ
The length of the nig part 6 between loan l and 17-ra 2 is 7m1.
I apologize for the inconvenience, but in this case, the surface layer of the toner 9 on the copy sheet 8 is made of silicon (7) and the roller 2' is attached. Then, as the roller 2 rotates, the toner that has landed on the roller 2- reaches the rough part 7 between the roller 2 and the roller 3 whose entire surface is coated with Teflon. At this time, since silicone has better releasability than Teflon, but is inferior to Teflon, the toner and Teflon are transferred to the roller 3, which has a strong force on its surface. −
t, and as the roller 3 rotates, the first toner of n-ra3hi reaches the contact portion of the non-woven fabric 11 and adheres to the non-woven fabric 11. In this way, all the toner that has landed on the rollers is wiped off by the nonwoven fabric 11 that is in contact with the rollers 3, thereby preventing the toner from affecting the image on the copy sheet that passes between the rollers. 48 rotates intermittently, for example, in one example, the copy sheet rotates by a predetermined rotation bar during or before and after passing between the rollers, so that the portion of the nonwoven fabric 11 that contacts the roller 3 sequentially rotates. Change. In addition, the shaft 12f of the roll cylinder 10
: The pivot axis of the supporting swing arm 17, and '11] ],
The rotation center axes of the gears 45 that transmit the rotational drive force to the gear 13 on the gear 2 are all the same rotation support shaft 21, and the rotation drive force to the gear 13 is 1m"JbAh17 rotation. After the copy sheet has passed between the rollers, the sequence control from the copying machine main body (installed near the copy sheet delivery [S] or fixed 9 machine) The power supply to the planter 42 is cut off in response to a signal from the reverse sheet passage detection means.Therefore, the control arm 35 is rotated in the direction of arrow 13 by the tension of the tension spring 37 until it comes into contact with the swivel collar 39. , the pawl 35a is removed from the protrusion 34b on the control element 34, and the spring clutch 32 becomes engaged.The drive source connected to the shaft 43 is the shaft 43.Gear 44.Gear 33.Shaft 3
0 to rotate the eccentric cam 31. At the same time, the control ring 34 also rotates. Since the pressure arm 25 is rotated in the input direction by the tension of the tension spring 28, while the eccentric cam 31 is rotating, the dowel 26t''
The pressurizing arm 25G is rotated in the direction of the arrow in FIG. 3. Until the position where the cam 31 touches the dowel 26: 1→l! When Tu+L, the control ring 34 similarly reaches a point where the protrusion 34a engages with the pawl 35a of the control arm 35 lff-! Move ri-i1 with l,
Here, the pawl 35^ restricts the rotation of the control ring 340. Therefore, the coupling tilt of the gene clutch 32! fr divided,・
The rotation t of the roller 33 is no longer transmitted to the shaft 3o, and the eccentric cam 31 also stops rotating and maintains its rotational position.
T12 part I]ll is roller 3K. Return to the initial state without pressure contact. The above action causes the copy sheet to turn green each time it passes between the rollers. In this embodiment, compared to the embodiment described above in which the wiping member IJ is pressed against the roller 3 during operation of the fixing device, the time for pressing the wiping member 11 against the roller can be minimized. Deformation of the wiping member can also be minimized. In addition, in the above two embodiments, the low speed motor 48 is
Each time the copying sheet) passes between the rollers, it rotates for a certain amount of time, and the wiping section All rotates for a predetermined amount. This operation may be performed each time it passes.The effects of the present invention will be described below.In general, when a wiping material such as a non-woven fabric is pressed against a roller for a long period of time (■), Deformation may occur over time,
In this deformed portion, the roller contact pressure is reduced, the elasticity peculiar to the nonwoven fabric is reduced, and the toner wiping effect using the elasticity of the nonwoven fabric is reduced. However, according to the present invention, the wiping member contacts the roller only intermittently, for example, only while the fixing device is operating (first embodiment) or only when the copy sheet passes through the fixing device (second embodiment). Since the wiping member is pressed into contact with the wiping member, a decrease in deformation and elasticity of the wiping member can be minimized. Further, at predetermined time intervals, for example, each time a copy sheet passes between the rollers in the embodiment, the wiping member rotates with the rotation of the roll cylinder that holds it, and the portion in contact with the roller is constantly changing. . Therefore, in the fixing device of the present invention, even when the wiping member is constantly in contact with the roller during the constant 14-spraying operation, the portion of the wiping member that contacts the roller 11 times is concentrated for a long period of time. Instead of being exposed to pressure, the contact area is constantly renewed -C, and deformation over time due to pressure is kept to a minimum. 1. As with the conventional simple pressure welding method described above, the toner that is wiped off concentrates on the same part of the wiping member and accumulates in a layer, deteriorating the wiping effect, which is disadvantageous, and the present invention improves the durability of the wiping member. can be significantly increased. Furthermore, when the wiping part is rotated by a predetermined distance each time a copy sheet passes between the rollers, the area of the wiping part used for wiping is minimized by one rotational drive. It is possible to minimize the consumption of parts, extend the life of the wiping part, and further improve durability. Furthermore, compared to the above-mentioned conventional fixing device equipped with a web-type cleaning means, the fixing device according to the present invention not only has the advantage that the structural mechanism can be made smaller with only one piece, but also has the advantage that it is easy to maintain the fixing device. When replacing the wiping member, remove the wiping member's holding member from the fixing device,
It is only necessary to replace the wiping member on the holding member and then reincorporate the holding member into the fixing device, which has the advantage of being extremely simple and requiring only a short time. Furthermore, in the present invention, by making the rotation direction of the wiping member opposite to the rotation direction of the contacting roller at the contact portion, the relative speed of the contact portion can be increased, thereby increasing the wiping speed. The accompanying wiping effect can be utilized to the fullest.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing a roller arrangement in an embodiment of the present invention, FIG. 2 is a perspective view illustrating a pressure contact mechanism and a drive mechanism of a wiping member in an embodiment of the present invention, and FIGS. FIG. 4 is an explanatory diagram of the operation of the mechanism shown in FIG. 2. 1.2.3... Roller of fixing device, 8... Roll cylinder, 1]... Wiping member, 17.19... Swinging arm, 25... Pressure arm, 31...(1,11
Center cam, 32... Spring clutch, 34... Control ring,
35... Control arm, 42... Electromagnetic plant gear, 48... Low speed motor. Figure 1

Claims (1)

[Claims] "In an image fixing device of an electrophotographic image recording apparatus in which a toner image is passed through a sheet carrying a toner image between collages and the toner image is fixed to the sheet, a wiping device for wiping off deposits on the surface of at least one of the rollers. l (a V-shaped part; a holder for holding the wiping member; a rotational drive means for intermittently rotating the wiping member through the holder; An image fixing device comprising: a pressure contact drive means for intermittently bringing the surface of at least one roller into pressure contact.