CN1035791C

CN1035791C - Fixing apparatus

Info

Publication number: CN1035791C
Application number: CN90100611A
Authority: CN
Inventors: 安達信和; 磯田雄三; 宫本敏男; 友行洋二
Original assignee: Canon Inc
Current assignee: Canon Inc
Priority date: 1989-02-08
Filing date: 1990-02-08
Publication date: 1997-09-03
Anticipated expiration: 2005-02-08
Also published as: ES2070938T3; EP0382189A3; EP0382189B1; DE69019008D1; DE69019008T2; EP0382189A2; KR930008609B1; CN1044863A; KR900013357A

Abstract

An image fixing apparatus for fixing a toner image on an image supporting material. A guiding member for guiding the image supporting material is provided without contact to an image fixing rotatable member but with a predetermined small clearance. In order to maintain the predetermined clearance, spacers are provided at positions outside the maximum image forming region. The rotatable image fixing member is prevented from being damaged, and in addition, the image supporting material is prevented from being wrapped on the rotatable member.

Description

Fixing device

The present invention relates to a kind of can the use and in duplicating machine or electrofax printing machine, be used for fixing the visual fixing device of toner (toner).

Be contained at present in the imaging device all is the roller-type fixing device, wherein, compress mutually between the roll and form a roll gap, when the image-carrier that is loaded with loose toner image (imagesuPPorting member) passed through above-mentioned roll gap, toner image just had been fixed.

Figure 19 shows an example of this fixing device.This device comprises the fixing roller 10 of a built-in heater H and compresses a hold-down roller of this roller.

When the toner image carrier passed through roll gap, that face that is loaded with toner image contacted with fixing roller, like this, was promptly fixed by heat and pressure without fixing image.

Disengaging pawl 12 is used for preventing that image carrier from twisting on the fixing roller 1, and it is rotatably installed on the turning axle 13, and presses down tight fixing roller 10 in the effect of spring 14.

Reference number

15 and 16 indicated be the inlet saddle, numeral 17 refers to the outlet saddle.

Yet such device has following these several problems; The first, because the blade of disengaging pawl mouth is pressed on the fixing roller, so roll is easy to damage.In addition, the also separated pawl mouth of toner that remains on the fixing roller sweeps, and be accumulated in gradually on the blade of disengaging pawl 12 and in the above to solidify, thereby can pollute image carrier, nor can be image carrier correctly from roller separately.In case fixing roller is damaged, one or several undesirable striped can appear on the image.In addition, because the blade of disengaging pawl contacts with roll, be wound on when causing paperboard or similar fault on the roll in case image carrier takes place, cleaning work will be very difficult, and might damage disengaging pawl.

In view of the foregoing, people consider not adopt disengaging pawl and adopt the method for the overall diameter that dwindles fixing roller that image carrier is separated with roll, and the curvature that can increase roller surface like this is with static repulsion that increases carrier and the clinging power that makes it to surpass toner.But, making it to separate as the elastic force that only leans on carrier from roll, separating force is just too little, and (as basis weight is 60g/m when the thin elastic force of carrier is less ²) time, when perhaps toner adhesion power is strong (as big toner zone on the paper as black image continuously), perhaps during because of long-term use variation, image carrier tends to be wound on the roll fixing roller to the stalling characteristic of toner.

Above-described fixing device also is equipped with inlet saddle and outlet saddle navigational figure carrier.From preventing that the foothold of wrinkle and crimping from appearring in image carrier, the position relation between these saddles and the roll is very important.Therefore, these saddles must accurately be located.

Therefore, a fundamental purpose of the present invention provides a kind of roll that can prevent and damages, can safeguard well that fixing image also can prevent that image carrier is wound on the fixing device on the roll.

Another object of the present invention provides a kind of fixing device that comprises the guiding device that can guarantee that image carrier is correctly guided.

By reading the description of most preferred embodiment of the present invention being done below in conjunction with accompanying drawing, these and other some purpose of the present invention, feature and advantage will become more obvious.

Fig. 1. be the top plan view of fixing device according to an embodiment of the invention.

Fig. 2. be the side sectional view of the fixing device among Fig. 1.

Fig. 3. be a skeleton view that separates saddle.

Fig. 4 and Fig. 5. be the cutting of motion of the image carrier in the fixing device in the presentation graphs 1

Face figure.

Fig. 6. be the part skeleton view of fixing device according to another embodiment of the invention.

Fig. 7. be the top cross-sectional view of fixing device according to still another embodiment of the invention.

Fig. 8. be the central sectional view of the embodiment shown in Fig. 7.

Fig. 9. be side cutaway view embodiment illustrated in fig. 7.

Figure 10-14. shows the embodiment of other several fixing devices.

Figure 15 A and 15B. are the perspectives of the fixing device that constitutes according to another embodiment

Figure and sectional view.

Figure 16. be the top plan view of an image on the recording materials among the top embodiment

Figure.

Figure 17 and 18. is the skeleton views according to the fixing device of another embodiment.

Figure 19. be the sectional view of the fixing device of routine.

Below in conjunction with accompanying drawing embodiments of the invention are described.In the accompanying drawings, the unit with correlation function will be endowed similar reference number.

Fig. 1 is according to one embodiment of present invention and the top plan view of a fixing device that constitutes that Fig. 2 is its side cutaway view.This device comprises a warm-up mill (fixing roller) 1 with fluoride resin surface of good separating property, the image carrier material p (as paper) that is used to prevent to carry toner image is wound on the separation saddle (guiding device) 2 on the fixing roller 1, flexiblely supports the screw 3 that separates saddle 2 and is arranged on warm-up mill 1 and separates between the adjacent top of saddle 2, be used for stably providing the pad 4 of a little gap g.In the present embodiment, pad 4 is fixed on and separates on the saddle 2, is made by the heat resistance material that sliding properties is good.This device also comprises a projection 5 as the pivot of the pivot motion that separates saddle 2, be used for flexibly supporting the spring 6 that separates saddle 2, a bearing 8 that is used for to warm-up mill, and the gear 9 that is driven, is used to drive warm-up mill 1 by a non-driving mechanism that draws.The effect of baffle plate 7 is the motions on its length direction of restriction warm-up mill 1.Hold-down roller 20 is pushed down warm-up mill 1, and hold-down roller 20 is provided with a silica gel and makes elastic layer.Hold-down roller 20 rotates with warm-up mill 1.Hot-rolling 1, hold-down roller 20 are provided with a silica gel and make elastic layer.Hold-down roller 20 rotates with warm-up mill 1.

Warm-up mill 1 and hold-down roller 20 are the fixing rotatable fixing members of toner image that are used for making on the image carrier.In these two rolls, warm-up mill 1 contacts with a side of image carrier material carrying pigment image.

This device also comprises and is used for the inlet saddle that enters by roll guiding toner image carrier, is used to guide the outlet saddle 17 of carrier output, and the

framework

18 and 19 of fixing device.

Fig. 3 is the skeleton view that separates saddle 2.From as can be seen following, the projection 5 that separates on the saddle 2 is supported on the framework 19 of fixing device, and the support pad 4 that separation saddle 2 is heated the horizontal place, two ends of roller 1 simultaneously again supports; Like this, separating saddle 2 is supported on three points by a spring 6 by screw.

Support pad 4 is arranged on the two ends on the length direction of warm-up mill 1.Have above outside the maximum image information area on the carrier of loose toner image, its position is equivalent near the side of the maximum sized image-carrier that this device can use.

In the present embodiment, pad 4 is arranged on the side of maximum sized carrier, can improve the separation function of pad like this.

If too small, might cause remaining the accumulation of toner so by the finedraw g that pad 4 constitutes.On the contrary, if excessive, separation function is just poor.

Therefore, finedraw g is preferably between the 0.1-0.6mm.The length direction that preferably makes finedraw g edge be parallel to warm-up mill when separating saddle is installed, and promptly the generatrix direction of roller 1 stretches.

The motion of image carrier in the fixing device in the present embodiment is described below with reference to Fig. 4 and Fig. 5.As shown in Figure 4, the toner image without fixing on the carrier p is heated and compresses by the slit that forms between the roll, thereby toner image is fixed.In this process, carrier p and warm-up mill 1 fit tightly, but its front end leaves warm-up mill 1 slightly, separate from warm-up mill 1 under the effect of the blade that separates saddle 2, are sent to (among a Fig. 5) unshowned output then.

Present embodiment is effective especially under the situation of minor diameter warm-up mill (being not more than 30mm as roller diameter).

In the present embodiment, support pad 4 is in sliding contact with heated roll.After long-term the use, warm-up mill also may be touched the place and damage.But because the contact position is positioned at outside the maximum image area, even occur damaging, Gu Ding image is also unaffected.

But when roll wear arrived to a certain degree, slit g can change.

For avoiding this situation, be preferably on warm-up mill 1 and the part that pad 4 contacts and form the superficial layer that separating property is good, as the fluoride resin layer.

In addition, the surface of the pad 4 that contacts with warm-up mill 1 also is covered with fluoride resin.

Fig. 6 shows another embodiment of the present invention.What in the present embodiment, the pad of the top ends of separation saddle adopted is the roller 40 that rotates with warm-up mill.There is not wear problems among this embodiment.

If separate saddle is to make with the resin of usually easy temperature distortion, so preferably guarantees the maintenance of the finedraw that pad causes.And preferably the structure of separating saddle and certain guide member (as the inlet saddle) are combined.

Show an embodiment among Fig. 7-9 again, wherein separate saddle 2 and under 6 effects of a tension spring, press to warm-up mill 1.Separating saddle 2 can be pivotable around a pivot 25, and is provided with many ribs 21 at least on contiguous warm-up mill that part of, separates image carriers by these ribs 21.Can reduce separation saddle and the contacted part of toner image by the method that rib is set.

A device according to another embodiment has been shown among Figure 10, and its Intermediate gasket 41 is set on the warm-up mill.

A device according to another embodiment has been shown among Figure 11, and pad 42 wherein is with to separate saddle 2 and warm-up mill 1 independent mutually.

A device according to another embodiment has been shown among Figure 12, and finedraw is wherein realized near bearing 8 by separating saddle 2.

A device according to another embodiment has been shown among Figure 13, and wherein the sub-fraction superficial layer of warm-up mill is done thicklyer (1a), and this contacts with separating saddle 2 than thickness portion 1a, thereby guarantees the existence of slit.

A device according to another embodiment has been shown among Figure 14, and split-frame is wherein made by molding process by resin material, and the pad part also forms when injection molding is operated.Pad among each embodiment shown in Fig. 7-14 is similar to the pad among that embodiment shown in Fig. 1, and the maximum image that also is positioned on the image carrier forms outside the zone, and also can resemble and be provided with the surface isolation layer the pad shown in Fig. 1.The pad that uses among these embodiment of the present invention separates the saddle except being used to, and can also be used on other guide member of bootstrap image carrier.

Fixing device according to another embodiment has been shown among Figure 15 A and the 15B.Heat fixing roll comprises that a thickness is the hollow aluminum barrel of 18mm for the 2mm overall diameter, and it is one deck resin bed of being made by pFA or similar material of tens microns that aluminum barrel is covered with thickness.A halogen heater is equipped with in fixing roller 1 inside.This well heater heats fixing roller, and uses a unillustrated temperature detecting unit (as thermistor) to keep temperature constant.

Hold-down roller 20 comprises that a stainless steel metal core body and a layer thickness that a diameter is 9mm are the layer of silica gel of 3.5mm, and this layer of silica gel has good heat resistanceheat resistant performance and separating property.

The effect that separates saddle 2 is leader record material p (an image carrier material).Separating saddle 2 does not contact with fixing roller 1.Separate saddle 2 and prevent that recording materials are wound on the fixing roller.Between its blade 2a and fixing roller 1, has a finedraw g.Finedraw g stretches along the length direction of fixing roller 1.

The blade 2a of guide member the center with fixing roller of being positioned at be the summit from the center O of center O that connects fixing roller and hold-down roller ' line to place with respect to the downstream direction 55 ° (θ angles) of the sense of rotation of fixing roller.

The difference of the separating effect that the difference of finedraw g causes has been shown in the table one.There is shown after handling 100 carriers with all black picture as shown in figure 16 the relation between finedraw g, leading space and the paperboard frequency.Here be fixed on 55 °.

Table 1

Slit g (mm)
Slit g (mm)								1.0	0.8	0.7	0.6	0.5	0.4	0.2	0.1
Leading space (mm)	0 1 2 3 4 5 6 7	100 95 90 90 85 85 80 80	60 50 40 40 35 30 30 30	30 20 15 10 4 2 2 1	15 2 0 0 0 0 0 0	8 1 0 0 0 0 0 0	4 1 0 0 0 0 0 0	1.0	0.8	0.7	0.6	0.5	0.4	0.2	0.1	0 0 0 0 0 0 0 0	0 0 0 0 0 0 0 0

As can be seen from the table, leading space surpasses 2mm gradually, and if finedraw greater than 0 but be not more than 0.6mm, paperboard (being recording materials) is reeled just rare.

Table 2 shows the difference of the separating effect that the difference of angle θ causes.Illustrate 100 in the table and had after complete black image carrier shown in Figure 16 finish the photographic fixing processing relation between angle θ leading space and the paperboard frequency.

Table 2

Angle θ
Angle θ											10 °	20 °	30°	40°	50°	60°	70°	80°	90°	100°	110°
Leading space (mm)	0 1 2 3 4 5 6 7	100 95 90 90 85 85 80 80	60 50 40 40 35 30 30 30	30 20 15 10 4 2 2 1	15 2 0 0 0 0 0 0	8 1 0 0 0 0 0 0	4 1 0 0 0 0 0 0	0 0 0 0 0 0 0 0	0 0 0 0 0 0 0 0	0 0 0 0 0 0 0 0	10 °	20 °	30°	40°	50°	60°	70°	80°	90°	100°	110°	4 1 4 0 0 0 0 0	8 2 1 0 0 0 0 0

Leading space is not less than 2mm gradually among the figure, and therefore, the θ angle preferably is not less than 40 °.If the θ angle is greater than 90 °, then the burble point of recording materials and fixing roller will be shifted to outside the upstream guide member with respect to the sense of rotation of roller, and the result makes paper not send smoothly, causes the paper generation paperboard of some quantity.Therefore, the θ angle preferably is not less than 40 °, is not more than 90 °.

The stickability of the toner on the recording materials can cause recording materials to be wound on the fixing roller.The present invention has used the trend of the repulsive force of recording materials to resist the stickability of toner.Moment when utilizing the leading space of recording materials to leave fixing roller slightly makes recording materials separate with fixing roller by means of separating saddle 2.Therefore, if a separation saddle is positioned at the position of the repulsive force that can produce recording materials, lock out operation will stably carry out.

Figure 17 shows a routine guide member, and it is made into the form of the disengaging pawl that do not contact with fixing roller.In this embodiment, the slit between the movable end of disengaging pawl 22 and the fixing roller 1 is 0.6mm, and θ is 55 °.Use contactless disengaging pawl, just can resemble among several embodiment of front just recording materials separate with fixing roller, be the leading space of recording materials when leaving fixing roller slightly under its repulsion effect, disengaging pawl 22 promptly is inserted between recording materials and the fixing roller.

The effect of this example is identical with the effect of describing with table 1 and table 2 of the several embodiment in front.

Figure 18 shows an embodiment again, and guide member wherein is made into, not with contacted blade 23 shapes of fixing roller.The movable end of blade 23 and the slit between the fixing roller are fixed on 0.6mm, and the θ angle is 55 °.For strengthening separating effect, the movable end of blade is cut into an acute angle.Present embodiment also can reach with table 1 and 2 in identical effect.

In sum, by keeping finedraw g between guide member and the fixing roller and being independent of an angle θ of the structure and material of guide member, just can realize stable lock out operation.

The front said that slit g must correctly adjust.In order to satisfy this requirement, preferably the contacted pad device of use and guide member and fixing roller is being guaranteed this gap.

As mentioned above, the toner image carrier is as separating from fixing roller with the saddle that separates that rotatable fixing member (as fixing roller or photographic fixing band) is close to setting with a little gap by guide member according to the present invention.Can get rid of necessity that disengaging pawl must be fitted with rotary part like this, thereby can avoid the problem that exists in the conventional equipment, as because the effect of disengaging pawl makes fixing roller produce mechanical damage, thereby cause image to worsen.

In addition, pad is supported on outside the maximum information zone on the rotary part to guarantee little gap, and high-precision accurate oil seam can be provided like this.And even when rotary part damages because of contacting with pad, toner image is unaffected.

Contactless guide member can make the crayon image carrier separate from rotary part when using with minor diameter rotation fixing member especially effectively.

The present invention is applicable to that one of them roll or two rolls are all thickeied or cut thin occasion, is applicable to also that minimum, maximum slit are maintained to be not less than 0.1 micron, is not more than 0.6 micron occasion.

Though the present invention describes in conjunction with shown structure, the details during it is not limited to describe.The present invention should be considered as comprising improvement and the variation in improvement purpose or the following claim book scope.

Claims

1. fixing device comprises:

The rotatable fixing member (1) that is used for fixing the toner image on the image carrier (P),

Be used for tripping device (2) that above-mentioned image carrier (P) is separated from above-mentioned rotatable fixing member, this tripping device is arranged on the generatrix direction of above-mentioned rotatable fixing member (1), surface apart from above-mentioned rotatable fixing member has a predetermined spacing (g)

It is characterized in that:

Above-mentioned tripping device comprises a surperficial contacted support pad (4) with above-mentioned rotatable fixing member, this support pad (4) and the current zone of the image carrier with maximum size used become the overlapping relation setting and contact with the surface of above-mentioned rotatable fixing member, thereby maintain above-mentioned spacing, and can be separated maximum sized image carrier (P).

2. according to the device of claim 1, it is characterized in that: described support pad (4) is arranged on each head portion on the length direction of above-mentioned tripping device (2).

3. according to the device of claim 1, it is characterized in that: described support pad (4) has a superficial layer with good stalling characteristic.

4. according to the device of claim 3, it is characterized in that: described separating table surface layer is made by fluoride resin.

5. according to the device of claim 1, it is characterized in that: above-mentioned support pad is in outside the maximum image region.

6. according to the device of claim 1, it is characterized in that: described rotatable fixing member (1) contacts with loose toner image.

7. according to the device of claim 6, it is characterized in that described rotatable fixing member (1) is heated by heating arrangement.

8. according to the device of claim 1, it is characterized in that: predetermined spacing (g) is between 0.1-0.6mm.

9. according to the device of claim 1, it is characterized in that: above-mentioned tripping device (2) has a parallel end portion of bus with above-mentioned rotatable fixing member (1).

10. according to the device of claim 1, it is characterized in that: also comprise a compacting part (20) that is used to compress above-mentioned rotatable fixing member (1), the head portion of wherein said tripping device is arranged in the scope with respect to 40 °-90 ° of the downstream directions of the sense of rotation of above-mentioned rotatable part between the line at the center of center that connects above-mentioned rotatable part and above-mentioned compacting part.

11. the device according to claim 1 is characterized in that: the little 30mm of diameter of described rotatable fixing member (1).

12. the device according to claim 1 is characterized in that: above-mentioned tripping device (2) is made by the resin injection molding.

13. a fixing device comprises:

Along the excircle setting of above-mentioned rotatable fixing member and contact, that be used for rotatably carrying above-mentioned rotatable fixing member with it bogey (8),

Be used for tripping device (2) that above-mentioned image carrier (P) is separated from above-mentioned rotatable fixing member, this tripping device is arranged on the generatrix direction of above-mentioned rotatable fixing member, and the surface of the rotatable fixing member that distance is above-mentioned has a predetermined spacing (g) and it is characterized in that:

Above-mentioned tripping device has a support pad (4) to contact with above-mentioned bogey, thereby keeps above-mentioned spacing.

14. device as claimed in claim 13 is characterized in that: above-mentioned tripping device (2) is set on the above-mentioned bogey (8), and above-mentioned bogey (8) then is provided with near the relative in the longitudinal direction top.