CN108490751A - Fixing device and image forming apparatus - Google Patents

Abstract

The present invention provides the fixing device for the contact area that can larger obtain fixing belt and heating element with structure as easy as possible in mode of heating.The pressure roller (63) for being configured at band outside around the path is pressed to the fixing roller (62) for being configured at the band of cricoid fixing belt (61) inside around the path across fixing belt (61), so that pressure roller (63) is contacted with the surface of fixing belt (61) and formed in the fixing device of fusing nip (69), is had：Heating roller (64) is configured at band outside around the path；With bearing part (66), it is configured at band inside around the path, fixing belt (61) is set to be crimped on heating roller (64), the face contacted with band part (61a) in bearing part (66) becomes the curved shape of the peripheral surface (64a) along heating roller (64).

Description

Fixing device and image forming apparatus

Technical field

The present invention relates to fixing devices and image forming apparatus that the unfixed image made on recording sheet is fixed.

Background technology

For image forming apparatuses such as printers, exists and have the so-called fixing dress with mode of heating for having used fixing belt The image forming apparatus set.

As the fixing device with mode of heating, Patent Document 1 discloses such as lower structures, that is, as shown in figure 24, tool It is standby：Fixing belt 901；Fixing roller 902, be configured at for fixing belt 901 around advance (hereinafter referred to as " band detours in path Diameter ".) inside；Heating roller 903；Two jockey pulleys 904,905；Jockey pulley 906 is configured at the outside of band around the path；With And pressure roller 907, it is configured at the outside of band around the path, and fixing roller 902 is pressed via fixing belt 901.

901 tenter of fixing belt passes through pressurization in fixing roller 902, heating roller 903, jockey pulley 904~906, in recording sheet S When roller 907 and the contact area that is, fusing nip 910 on the surface of fixing belt 901, pass through the heat of the fixing belt 901 after being heated The pressurization of amount and pressure roller 907, to be fixed the unfixed image on recording sheet S.

Being configured at the jockey pulley 906 in the outside of band around the path makes the pressing force in arrow α direction act in fixing belt 901 Heating roller 903 and jockey pulley 905 between part, thus fixing belt 901 be wound in the spooling length 911 of heating roller 903 and prolong Long, i.e. fixing belt 901 and the contact area of heating roller 903 further increases, from heating compared with the smaller structure of contact area Roller 903 supplies more heats to fixing belt 901.

In addition, Patent Document 2 discloses the fixing devices of such as lower structure, that is, in the band of cylindric fixing belt Outside around the path configures pressure roller, and the surface of fixing belt is made to be contacted with pressure roller and form fusing nip, and is surround in band The inside in path configures planar heater, and the pressing roller for being configured at the outside of band around the path is being configured via fixing belt pressing Planar heater in the inside of band around the path, by the heat transfer of planar heater to fixing belt.

It is this with mode of heating compared with pressure roller directly to be pressed to the mode in fixing roller, can larger obtain fixing The surface of band and the contact area (the sheet material carry direction length of fusing nip) of pressure roller, therefore realize the raising of fixation performance.

Patent document 1：Japanese Unexamined Patent Publication 2016-177206 bulletins

Patent document 2：Japanese Unexamined Patent Publication 2015-84082 bulletins

In the structure of above-mentioned patent document 1, in order to significantly obtain the contact surface of fixing belt 901 and heating roller 903 Product, needs more jockey pulley, to which structure member increases and the size of fixing device also increases.

In addition, in the structure of patent document 2, though pressing roller presses fixing belt in planar heater, fixing belt The part for being tightly attached to planar heater be only the part that is contacted with the surface of pressing roller, contact area is minimum.Therefore, it is fixed Slave planar heater of the band in a period of the traveling is reduced to the supply amount of the heat per unit time of fixing belt.In order to To the heat of fixing belt supply amount it is less in the state of make to heat up in the fixing belt short time, consider that fixing belt is further thinned Thickness and reduce thermal capacity, but become smaller correspondingly with thermal capacity, the heat that can be supplied to the recording sheet by fusing nip Also it reduces, fixing unevenness is generated to become easy.In addition, fixing belt is thinned, has and generated with broken when band crawls The misgivings of damage.

Invention content

The present invention puts and generates in view of the above-mentioned problems, and its purpose is to provide can be in band mode of heating with to the greatest extent Possible easy structure larger obtains the fixing device and image forming apparatus of the contact area of fixing belt and heating element.

To achieve the goals above, fixing device of the invention will be configured at the ring of the fixing belt across cricoid fixing belt The pressing member in outside makes above-mentioned add towards the pressurized component pressing being configured on the inside of the circular path of the fixing belt around the path Splenium part contacts with above-mentioned fixing belt surface and forms fusing nip, and recording sheet is made to be fixed the note by above-mentioned fusing nip The unfixed image on sheet material is recorded, which is characterized in that having：Outer roller is configured at the ring of above-mentioned fixing belt Outside around the path；Bearing part is configured on the inside of the circular path of above-mentioned fixing belt, so that above-mentioned fixing belt is crimped on above-mentioned outer Portion's roller；And heater, said external roller or above-mentioned bearing part are heated, with above-mentioned outer in above-mentioned fixing belt Portion's roller becomes the mode of the curved shape of the peripheral surface along said external roller with the band part folded by above-mentioned bearing part, determines The shape in the face contacted with above-mentioned band part in above-mentioned bearing part.

It is the periphery along said external roller alternatively, it is also possible to the face contacted with above-mentioned band part in above-mentioned bearing part The curved shape in face.

Also, can also said external roller be configured at across above-mentioned fixing belt and with above-mentioned pressing member opposite side.

It is pressure roller alternatively, it is also possible to above-mentioned pressing member, above-mentioned pressurized component is the fixing pad of pulvilliform shape.

Herein, have the support member for supporting above-mentioned pressurized component, rotation of the above-mentioned bearing part along said external roller Axis is long size, and above-mentioned support member is long size along the rotary shaft of said external roller, and is had：Base plate, with it is above-mentioned The fixing pad is fixed in the face that opposed side is padded in fixing；With the first, second side plate, their short side directions two from above-mentioned base plate It holds to the side bending present in above-mentioned bearing part, the front end of above-mentioned first side plate and the front end of above-mentioned second side plate The interval of short side direction is more than the width of above-mentioned bearing part or the diameter of said external roller.

It is longer than the perimeter of above-mentioned fixing belt alternatively, it is also possible to the perimeter of said external roller.

Also, can also above-mentioned bearing part along said external roller rotary shaft be long size, connection said external roller Rotary shaft and above-mentioned fusing nip sheet material carry direction center position imaginary line on by the width in above-mentioned bearing part Position present in degree direction central portion is when being set as reference position, the width direction central portion in above-mentioned bearing part be present in from The position that said reference position is deviateed centered on the rotary shaft of above-mentioned outer roller to the direction of rotation upstream side of the outer roller In the case of structure, the face contacted with above-mentioned band part in above-mentioned bearing part, said external roller direction of rotation upstream The corner of the end of side is formed as R shapes.

Alternatively, it is also possible to above-mentioned bearing part along said external roller rotary shaft be long size, connection said external roller Rotary shaft and above-mentioned fusing nip sheet material carry direction center position imaginary line on by the width in above-mentioned bearing part Position present in degree direction central portion is when being set as reference position, the width direction central portion in above-mentioned bearing part be present in from The position that said reference position is deviateed centered on the rotary shaft of above-mentioned outer roller to the direction of rotation downstream side of the outer roller In the case of structure, the face contacted with above-mentioned band part in above-mentioned bearing part, said external roller direction of rotation downstream The corner of the end of side is formed as R shapes.

Also, can also at least one party of above-mentioned pressurized component and above-mentioned pressing member be roller, fixing device has：The Any of above-mentioned roller is carried out rotation driving by one driving unit as driven roller；Second driving unit, rotation driving Said external roller；Detection unit, to contacted with above-mentioned pressing member in above-mentioned fusing nip in above-mentioned fixing belt The difference of the peripheral speed of second part folded by the peripheral speed and said external roller of a part and above-mentioned bearing part is detected；And Control unit controls above-mentioned first driving unit and above-mentioned second driving unit, and above-mentioned control unit executes：First Control adjusts above-mentioned drive in such a way that the peripheral speed of above-mentioned driven roller is stablized in the fixing speed for being equivalent to recording sheet transporting velocity The rotary speed of dynamic roller；It is controlled with second, according to the testing result of above-mentioned detection unit, in a manner of eliminating the difference of above-mentioned peripheral speed Adjust the rotary speed of said external roller.

Alternatively, it is also possible to by the direction of rotation in the region that the peripheral surface of said external roller is contacted with above-mentioned fixing belt most When the tangent line in the position of upstream is set as imaginary tangent line, above-mentioned fixing belt enters the peripheral surface of said external roller and above-mentioned supporting part Entry angle γ when between part relative to above-mentioned imaginary tangent line is 90 ° or less.

Also, can also be further equipped with 1 group or more by said external roller, above-mentioned bearing part and above-mentioned heater The group of composition, in 2 or more groups, outer roller in the axial heating region and second group of outer roller in first group Axial heating region is different.

Said external roller is heated alternatively, it is also possible to above-mentioned heater, the pyroconductivity of above-mentioned bearing part is less than above-mentioned fixed The pyroconductivity of shadow bands.

Also, can also above-mentioned heater heat said external roller, being contacted with above-mentioned band part in above-mentioned bearing part Face be mesh configuration.

Alternatively, it is also possible to have：First movement unit enables said external roller across above-mentioned fixing belt and to close The direction of above-mentioned bearing part and the direction of separate above-mentioned bearing part are moved；With first movement control unit, control above-mentioned First movement unit so that in the circular traveling process of above-mentioned fixing belt, make said external roller to close to above-mentioned bearing part Direction movement, so that above-mentioned fixing belt is crimped on said external roller using above-mentioned bearing part, in the stopping of above-mentioned fixing belt Cheng Zhong makes said external roller be moved to the direction far from above-mentioned bearing part, and above-mentioned crimping is made to release.

Also, can also have：First movement unit enables said external roller to be leaned on to opposite with above-mentioned bearing part Close direction and the direction movement being relatively distant from；With first movement control unit, above-mentioned first movement unit is controlled, it is above-mentioned fixed Shadow bands can be surround around the first fixing pattern advanced with the second speed slower than above-mentioned First Speed with First Speed Advance the second fixing pattern between switch over, above-mentioned first movement control unit execute it is above-mentioned second fixing pattern when, Compared with when executing above-mentioned first fixing pattern, above-mentioned bearing part is made to be moved to the direction being relatively distant from said external roller, Reduce the contact area of said external roller and above-mentioned fixing belt.

Alternatively, it is also possible to have：Second mobile unit, enable above-mentioned pressurized component and above-mentioned pressing member across Above-mentioned fixing belt and moved to relatively close direction and the direction that is relatively distant from；With the second mobile control unit, in control State the second mobile unit, in the circular traveling process of above-mentioned fixing belt, make above-mentioned pressurized component and above-mentioned pressing member to Relatively close direction movement, above-mentioned pressing member is pressed formed above-mentioned in above-mentioned pressurized component across above-mentioned fixing belt Fusing nip makes above-mentioned pressurized material and above-mentioned pressing member to the side being relatively distant from the stopped process of above-mentioned fixing belt To movement, above-mentioned pressing is made to release.

Alternatively, it is also possible to above-mentioned bearing part have substrate and low friction plate, the low friction plate be located in the substrate with it is upper It states between band part and for reducing the friction with above-mentioned band part.

Also, it can also be to being contacted with above-mentioned band part in the inner surface and above-mentioned bearing part of above-mentioned fixing belt Face coats lubricant.

Alternatively, it is also possible in the inner surface of above-mentioned fixing belt, be provided with for reducing the friction with above-mentioned bearing part Low friction layer.

Also, can also have cleaning member, which contacts with the surface of said external roller, and removing is attached to State the foreign matter on the surface of outer roller.

Alternatively, it is also possible to be provided with release layer on the surface of said external roller.

The present invention image forming apparatus have make to be formed in the unfixed image on carried recording sheet fixing Fixing section, the image forming apparatus are characterized in that, as above-mentioned fixing section, having above-mentioned fixing device.

As described above, become along the outer of outer roller with the outer roller in fixing belt and the band part folded by bearing part The mode of the curved shape of circumferential surface determines the shape in the face contacted with band part in bearing part, and thus, it is possible to easy Structure significantly obtains the contact area of the outer roller or bearing part and fixing belt that are heated by heater, so as to higher Effect ground supplies the heat of outer roller or bearing part to fixing belt.

Description of the drawings

Fig. 1 is the integrally-built brief diagram for the printer for indicating embodiment 1.

Fig. 2 is the block diagram of the structure for the control unit for indicating printer.

Fig. 3 is the figure of the structure for the fixing section for indicating printer.

Fig. 4 is so that the figure that the state that bearing part, fixing belt and heating roller are separated from each other is indicated.

(a) of Fig. 5~(c) is periodically to indicate to make heating roller utilize close to bearing part from state shown in Fig. 4 Bearing part and heating roller clamp the schematic diagram of the action of fixing belt.

Fig. 6 is the figure for the structure for indicating comparative example.

Fig. 7 is the figure for indicating to be provided with the example with guiding mechanism in bearing part.

Fig. 8 is the figure of the structure for the fixing section for indicating embodiment 2.

Fig. 9 is the figure of the variation for the fixing section for indicating embodiment 2.

Figure 10 is the figure of other variations of the fixing section for indicating embodiment 2.

Figure 11 is the figure of the structure for the fixing section for indicating embodiment 3.

Figure 12 is the enlarged drawing that the band of bearing part surround the end of direction upstream side.

Figure 13 is the figure of the variation for the fixing section for indicating embodiment 3.

Figure 14 is the figure of the structure for the fixing section for indicating embodiment 4.

Figure 15 is the figure for the flow chart for indicating the second control.

Figure 16 is to show schematically in embodiment 5 to act on heating from fixing belt in the circular traveling process of fixing belt The figure of the power P of roller.

Figure 17 is the figure of the part around path of the fixing belt in the fixing section for indicate embodiment 5.

Figure 18 is the figure of the variation for the fixing section for indicating embodiment 5.

(a) and (b) of Figure 19 is the figure of the structure for the fixing section for indicating embodiment 6.

Figure 20 is the flow chart of the content of the control of the position switching for the carrying and heating roller for indicating plain paper and ground paper.

Figure 21 is the control for indicating to switch over heating roller between disengaged position and contact position in embodiment 7 The flow chart of content.

Figure 22 is the figure for the variation for indicating fixing section.

Figure 23 is the side view of heating roller in fixing section shown in Figure 22, heater and fixing belt.

Figure 24 is the figure for the configuration example for indicating the existing fixing device with mode of heating.

Symbol description：

1 ... printer；6 ... fixing sections；7 ... control units；11 ... belt sag detection sensors；61 ... fixing belts；61a ... bands Part；62 ... fixing rollers；63 ... pressure rollers；64,264 ... heating rollers (outer roller)；64b ... descalers；65,265 ... heaters； 66,266 ... bearing parts；The corner of 66p, 66q, 661,662 ...；67,67a ... drive motors；69 ... fusing nips；71 ... bases Bottom；73 ... slip sheets；162 ... fixing pads；170 ... support members；171 ... base plates；172,173 ... side plates；615 ... is false Think tangent line；616 ... imaginary lines；The direction of rotation most upstream in the region contacted with fixing belt in the peripheral surface of 649 ... heating rollers Position；Qa, Qb ... heat nip length (the contact area length of heating roller and fixing belt)；S ... recording sheets.

Specific implementation mode

Hereinafter, the embodiment of the fixing device of the present invention and image forming apparatus to be applied to the colour of tandem type Printer (hreinafter referred to as " printer ".) in case of illustrate.

(embodiment 1)

(1) structure of printer

Fig. 1 is the brief front view for the structure for indicating printer 1.

As shown in the drawing, printer 1 has：Image forming part 3, intermediate transfer portion 4, supply delivery section 5, fixing section 6, control Portion 7 processed and operation panel 8 etc..

Printer 1 is with network (for example, LAN：LAN it) connects, is receiving printing from external terminal installation (not shown) When executing instruction of task forms colored toner image based on the instruction, and will be formed by toner image to recording Sheet material transfers and forms coloured image.

Image forming part 3 has imaging section 3Y, 3M, 3C, 3K and exposure portion 10.

Imaging section 3K have the photoconductor drum 31 that the direction shown in the arrow A rotates, be disposed in surrounding electro-mechanical part 32, Development section 33 and descaler 34 etc. for cleaning photoconductor drum 31, are imaged the toner of black (K) color on photoconductor drum 31 Picture.

Imaging section 3Y, 3M, 3C have with imaging section 3K basically same structures, symbol is omitted in the figure.Imaging section The toner image of yellow (Y) color of 3Y imagings, imaging section 3M are imaged the toner image of dark red (M) color, green (C) color of imaging section 3C imagings Toner image.It should be noted that among the above, though being configured to use photoconductor drum 31 as picture carrying body, but not limited to this, Such as photoreceptor band etc. can also be used.

Intermediate transfer portion 4 also has other than being configured at and comparing imaging section 3Y~3K intermediate transfer belts 41 closer to the top There are driven roller 42, driven voller 43, primary transfer roller 44 and secondary transfer roller 45 etc..

41 tenter of intermediate transfer belt in driven roller 42, driven voller 43, for imaging section 3Y~3K each correspondingly The primary transfer roller 44 of configuration, and the direction shown in the arrow B is surround by driving.

Primary transfer roller 44 is matched for each imaging section 3Y~3K and across intermediate transfer belt 41 is opposed with photoconductor drum 31 It sets.Secondary transfer roller 45 is arranged opposite across intermediate transfer belt 41 and driven roller 42.

Exposure portion 10 is configured at compared to imaging section 3Y~3K more on the lower, is directed to according to the drive signal from control unit 7 The transmitting of photoconductor drum 31 that each of imaging section 3Y~3K is charged directed through the electro-mechanical part 32 of the imaging section is used for Y~K Light beam Ly, Lm, Lc, Lk that the image of color is formed irradiate the photoconductor drum 31 to be exposed scanning.By the exposure scan Electrostatic latent image is formed on each photoconductor drum 31 of imaging section 3Y~3K.

For each of imaging section 3Y~3K, the electrostatic latent image being formed on the photoconductor drum 31 of the imaging section is developed The developer in portion 33, to which the toner image of color corresponding with the imaging section to be formed on photoconductor drum 31.

For each imaging section 3Y~3K, the toner image being formed on photoconductor drum 31 is once turned by primary transfer roller 44 It is printed on intermediate transfer belt 41.At this point, in a manner of the same position that the toner image is overlappingly needed on intermediate transfer belt 41 Execute assorted imaging action with opportunity being staggered.

For each imaging section 3Y~3K, in primary transfer, not being transferred in the toner image on photoconductor drum 31 It is removed from photoconductor drum 31 by descaler 34 in the remaining toner that intermediate transfer belt 41 remains on photoconductor drum 31.

Supply delivery section 5 has：Store the paper feeding cassette 51 of recording sheet material S；By the sheet material S a piece of one in paper feeding cassette 51 Piece is exported to the outlet roller 52 in transport road 53；And turn with intermediate sheet material S derived from institute is delivered to secondary transfer roller 45 The opportunity for printing the secondary transfer position 46 that band 41 contacts carries the timing roller 54 etc. of sheet material S.

Timing roller 54 is carried to secondary transfer printing with the toner image of the Chong Die Y~K colors being needed on intermediate transfer belt 41 Sheet material S is cooperatively carried to secondary transfer position 46 by the opportunity of position 46.Moreover, passing through secondary transfer position in sheet material S When 46, using secondary transfer roller 45 by the toner image secondary transfer printing on intermediate transfer belt 41 on sheet material S.

The sheet material S that toner image has been secondary transferred in secondary transfer position 46 is carried to fixing section 6.

Fixing section 6 be configured at it is closer to the top compared to secondary transfer position 46, by heating, pressurizeing to being secondary transferred roller 45 The toner image (unfixed image) carried on the sheet material S come is thermally fixed.The sheet material S for having passed through fixing section 6 is discharged roller 55 are expelled to outside machine, and are incorporated in discharge tray 56.

Operation panel 8 is configured at the maneuverable position when subscriber station is in 1 front of printer, is herein apparatus main body 2 Upper surface device face side position, have and receive the key of various tasks from the user executed instruction, receive to hold Capable task selects selection input of the type of sheet material used in the selection key indicated, receiving such as plain paper, ground paper Key etc..The information received on operation panel 8 is sent to control unit 7.

(2) structure of control unit

Fig. 2 is the block diagram for the structure for indicating control unit 7.

As shown in the drawing, control unit 7 has：The portion communication interface (I/F) 7a, CPU7b, ROM7c, RAM7d etc., each other can It communicates with each other.

Communication I/F portion 7a are the interfaces for LAN card, lan board etc with network such as LAN connection, with The terminal installation of the outside connected via network is communicated.

Control imaging section 3Y~3K, CPU7b exposure portion 10, intermediate transfer portion 4, is supplied based on the information from operation panel 8 To delivery section 5 and fixing section 6, print out task is made to be smoothly performed.The control in each portion such as imaging section 3Y~3K is stored in ROM7c Program needed for system, the program are read by CPU7b.RAM7d is used as the working region of CPU7b.

(3) structure of fixing section 6

Fig. 3 is the figure for the structure for indicating fixing section 6.

As shown in the drawing, fixing section 6 has：Cricoid fixing belt 61, fixing roller 62 (fixing member), pressure roller 63 (add Splenium part), heating roller 64 (outer roller), heater 65 and bearing part 66 etc..

Fixing belt 61 becomes the tubular that outer diameter is, for example, 40mm, the pressure roller 63 rotated in the direction of arrow E is driven in, along arrow Head F is directed around traveling.The circular direction of fixing belt 61 is known as band around direction, by the fixing belt orthogonal with direction is surround 61 width direction (being equivalent to Y direction) is known as bandwidth direction.

Fixing belt 61 is made of elastic layer and surface layer are laminated in that order on base.For the material of base, Such as using PI (polyimides) resin, the thickness of base is for example as 80 μm.For the material of elastic layer, such as use Si (silicon) rubber, the thickness of elastic layer is for example as 200 μm.For the material on surface layer, such as use PFA (perfluoroalkoxyalkanes) Pipe, the thickness on surface layer is for example as 30 μm.Base becomes inner surface (back side) side of fixing belt 61, and surface layer becomes fixing belt 61 Surface side.It should be noted that it's not limited to that for the material of each layer, thickness etc..In addition, the number of plies is not limited to 3 layers, it can also structure As having the layer of 1 layer or 2 or more.Material, thickness, the number of plies are not limited equally for each component such as aftermentioned fixing roller 62 Deng.

Fixing roller 62 is configured at the circular path of fixing belt 61, and (band is around the path：It is equivalent to row shown in the thick line of the figure Inbound path) inside.Such as outer diameter of fixing roller 62 is 30mm, is by the elastic layer 62b of silicon rubber etc. and spongy layer 62c by this Sequence is laminated in made of the surface of solid metal core 62a made of iron.The diameter of metal core 62a is, for example, 18mm, elastic layer The thickness of 62b is, for example, 4mm, and the thickness of spongy layer 62c is, for example, 2mm.Axial direction (the paper vertical direction of fixing roller 62：Quite In the direction orthogonal with the carry direction D of sheet material S) length be slightly longer than the width (direction orthogonal with carry direction D of sheet material S Length).For this axially be long size for, for fixing belt 61, pressure roller 63, heating roller 64, heater 65 and Bearing part 66 is identical.

The axial both ends free rotary ground supporting of the metal core 62a of fixing roller 62 in the frame (not shown) of fixing section 6, Fixing belt 61 can be driven in and rotated along the directions arrow C.

Pressure roller 63 is configured at band outside around the path and determines across fixing belt 61 and the inside with band around the path The position of 62 opposite side of shadow roller.Such as outer diameter of pressure roller 63 is 30mm, is by elastic layer 63b and the PFA pipe of silicon rubber etc. Deng surface layer 63c be laminated in that order made of the surface of solid metal core 63a made of iron.The diameter example of metal core 63a It is such as 26mm, the thickness of elastic layer 63b is, for example, 2mm, and the thickness of surface layer 63c is, for example, 20 μm.

Pressure roller 63 is to rotate freely and in the direction (arrow Ha) close to fixing roller 62 and the direction far from fixing roller 62 (arrow Hb) freely movably by its axial direction both ends be supported on fixing section 6 frame and normality under applied by spring etc. Power component (not shown) exerts a force to close to the direction (arrow Ha) of fixing roller 62.

By the active force, pressure roller 63 presses fixing roller 62 across fixing belt 61.In the figure, show by this by Pressure, the spongy layer 62c of fixing roller 62 become the example for the shape being recessed inwardly.By the pressing, to ensure that pressure roller 63 is pressed It is connected to the region (fusing nip) 69 on the surface of fixing belt 61.The crimp force (nip loads) can for example be formed as 100N~ 400N.In addition, the sheet material carry direction length (roll-gap width) of fusing nip 69 can for example be formed as 7mm.Pressure roller 63 is logical Come over drive motor 67 rotary driving force and by the direction of arrow E rotation drive.

Heating roller 64 be configured at band outside around the path and across fixing belt 61 and with 63 opposite side of pressure roller.

For heating roller 64 for example in the cylindrical shape for the aluminum that outer diameter is 20mm, thickness is 0.5mm, being will be (poly- by PTFE Tetrafluoroethene) thickness that constitutes is that 40 μm of surface layer is laminated in made of surface.The axial both ends of heating roller 64 rotate freely Ground is supported on the frame of fixing section 6, and can be rotated along the directions arrow G.

The halogen heater for such as 1000W that heater 65 is bar-like inside inserts in the heating roller 64 of cylindrical shape.From heating The heat transfer that device 65 generates is to heating roller 64.

Bearing part 66 is the plate-shaped member that cross section is circular shape, is configured at band inside around the path and across fixed Shadow bands 61 and with the position for 64 opposite side of heating roller for being configured at the outside of band around the path.

Fig. 4 is for ease of explaining the structure of bearing part 66, and so that bearing part 66, fixing belt 61 and heating roller The figure that 64 states being separated from each other are indicated.The shape that fixing belt 61 is not contacted with the both sides of bearing part 66 and heating roller 64 State is known as nature.In its natural state, become in fixing belt 61 should be folded by heating roller 64 and bearing part 66 Band part 61a does not act on the state of external force, when from the end on observation band part 61a of heating roller 64, the shape of band part 61a As the circular shape being bent towards the direction opposite direction with the bending of the peripheral surface 64a of opposed heating roller 64.

Bearing part 66 has substrate 71, pressing rubber 72 and slider 73 etc..

Substrate 71 is that (polyamides is sub- along the plate-shaped member of the curved shape of the peripheral surface 64a of heating roller 64, such as by PI Amine) resin composition, thickness 2mm.

Pressing rubber 72 is installed on the flexure plane 71a of the inside of substrate 71, is the plate made of flexure plane 71a bendings The silicon rubber of shape, such as thickness are 2mm.

Slider 73 is the sheet material being made of mesh configuration etc. for being impregnated with glass cloth of fluororesin etc, is deposited by surface Bumps and make with the contact area of fixing belt 61 reduce, to make and the frictional resistance of fixing belt 61 reduce.

The flexure plane 71b, another side 73b that the one end 73a of slider 73 is fixed on the outside of substrate 71 are free end, Another side 73b with positioned at the inner surface of fixing belt 61 and press rubber 72 inside flexure plane 72a between state from It hangs down the upper end of substrate 71.

Fig. 5 is periodically to indicate to make heating roller 64 and heater 65 integrally close to supporting part from state shown in Fig. 4 Part 66 and the schematic diagram that the action of fixing belt 61 is clamped using bearing part 66 and heating roller 64, in addition to fixing belt 61 plus Component omission other than hot-rolling 64, heater 65, bearing part 66 diagram.

(a) of Fig. 5 indicates the identical state of nature as shown in fig. 4.(b) of Fig. 5 indicates the band portion of fixing belt 61 Point 61a is pressed the side present in bearing part 66 by heating roller 64, from nature to one present in bearing part 66 Side is slightly concave and is deformed into the appearance of the shape of peripheral surface 64a along heating roller 64.The deformed shape is equivalent to court The back-flexing shape being bent to direction ((a) of Fig. 5) opposite direction of the bending with band part 61a under natural conditions.

(c) of Fig. 5 indicates further to make heating roller 64 close to bearing part 66 from (b) of Fig. 5 and incite somebody to action via fixing belt 61 Heating roller 64 presses the state in bearing part 66.The state is equivalent to state shown in Fig. 3, becomes the band of back-flexing shape Part 61a is crimped on pressing rubber 72 across slider 73 and heating roller 64 is also crimped on the state for pressing rubber 72.It is sliding The face contacted with fixing belt 61 in movable plate 73 becomes the face 66b (Fig. 3) contacted with fixing belt 61 in bearing part 66.

It is being deformed into the band part 61a with the bending of nature opposite direction, effect, which has, eliminates its back-flexing shape And it is intended to restore the direction (direction of expansion of the cylinder posture of original nature：The directions arrow J of (b) of Fig. 5) self Restoring force.Band part 61a is set to become by the effect of the restoring force of the self-recovery power and pressing rubber 72 of band part 61a It must be easy to be tightly attached to the peripheral surface 64a of heating roller 64, along the bearing part 66 of the curved shape of the peripheral surface 64a of heating roller 64 Also become easy the peripheral surface 64a for being tightly attached to heating roller 64, so as to larger obtain the heating roller 64 as heating source with The contact area of fixing belt 61.

In contrast, fixing belt 61 is simply being wound in heating roller 64 and fixing assuming that using as shown in Figure 6 In the case of the structure (comparative example) of roller 62, as described below.

That is, in comparative example shown in Fig. 6, the band part 61b contacted with heating roller 64 in fixing belt 61 passes through self Restoring force and be intended to along the directions arrow Ja (direction far from heating roller 64) expansion, therefore can not significantly obtain and heating roller 64 Contact area.

In the structure of comparative example shown in Fig. 6, in order to significantly obtain the contact area, consider configuration dotted line 68a, The circular route diversion of fixing belt 61 is path shown in dotted line 61d, to take longerly by such jockey pulley shown in 68b Obtain structure of the fixing belt 61 to the spooling length of heating roller 64.However, the structure is substantially identical as example shown in Figure 24, knot Structure component increases.In addition, in the case where configuring jockey pulley, due to being necessary to ensure that its installation space, so actually having to The interval for further expanding heating roller 64 and fixing roller 62, also increases to the size of fixing device.

On the other hand, in the structure of embodiment shown in Fig. 3, the self-recovery power of the band part 61a of fixing belt 61 Make band part 61a itself heating rollers 64 to be tightly attached to close to the effect of the direction of heating roller 64, bearing is utilized to not improve Band part 61a pressings in the pressing force of heating roller 64, also can significantly be obtained the contact area with heating roller 64 by component 66. In addition, by significantly obtaining contact area, heating is transferred to which the driving force around direction of fixing belt 61 becomes easy Roller 64, to the swimmingly driven rotation of heating roller 64.As a result, compared with generating the uneven situation of rotation in heating roller 64, inhibit The heat for being transferred to band part 61a via heating roller 64 from heater 65 surround a certain position and the other positions in direction in band It is inconsistent, it can be in band around the heat of the further equilibrium supply in direction to fixing belt 61, so as to further decrease fixing The temperature variation of roll gap 69.

The case where above-mentioned Fig. 5 in the actual assembled of fixing section 6 to making heating roller 64 be positioned close to bearing part 66 Example be illustrated, but can also instead of use for example into exercise bearing part 66 close to heating roller 64 and position operation Structure.

Specifically, bearing part 66 by can relative to heating roller 64 along far from direction of closing move in a manner of be supported on The frame of fixing section 6 makes bearing part 66 move closer to add via the band part 61a of fixing belt 61 when assembling fixing section 6 Hot-rolling 64, if becoming from the both sides of heating roller 64 and bearing part 66 have crimped band part 61a as shown in (c) of Fig. 5 State, then positioning terminate, and can carry out the operation that bearing part 66 is fixed on to the frame of fixing section 6 using screw etc..

Fig. 3 is returned to, if drive motor 67 is driven in rotation, rotary driving force is transferred to pressure roller 63, pressure roller 63 It rotates in the direction of arrow E, so, the rotation driving of pressure roller 63 is transferred to the fixing belt 61 being crimped in fusing nip 69 With fixing roller 62, fixing belt 61 along the directions arrow F it is driven around advance and fixing roller 62 also along the driven rotation in the directions arrow C Turn.Moreover, the driving force around direction around the fixing belt 61 advanced is transferred to heating roller 64, to which heating roller 64 is along arrow The driven rotation in the directions G.

In structure as described above, if being powered to heater 65 during the rotation of pressure roller 63 driving, from adding The heat that hot device 65 is sent out is transferred to the band part of heating roller 64 and the fixing belt 61 folded by bearing part 66 from heating roller 64 61a, band part 61a reach fusing nip 69 by the circular traveling of fixing belt 61.Heat as a result, from heater 65 It is supplied to fusing nip 69.

In the present embodiment, although not shown, it but detects the surface temperature of fixing belt 61 and is sent to its testing result The sensor of control unit 7 is configured at fixing section 6.7 sensor-based detection temperature of control unit is into trip temperature adjusting control, that is, Switch the point of heater 65 in a manner of the fixing temperature (such as 170 DEG C) needed for the temperature of fusing nip 69 is maintained at fixing Bright and extinguishing.

By the temperature adjusting control, the temperature of fusing nip 69 is stablized in fixing temperature, in 53 upper edge arrow D of transport road When sheet material S after the secondary transfer printing that direction is carried is by fusing nip 69, the unfixed toner image on sheet material S is molten by heating Melt and is pressurized and is fixed on sheet material S.

It should be noted that in structure shown in Fig. 3, the band part of heating roller 64 and the fixing belt 61 folded by bearing part 66 The band of 61a becomes identical direction around direction and the direction of rotation (roller direction of rotation) of heating roller 64.In fixing belt 61, volume The band being around in bearing part 66 becomes curvature one around the part 61f of the end 66f of direction (roller direction of rotation) upstream side The portion of the end 66g in the roller direction of rotation downstream side determined curved shape larger in degree, and be wound in bearing part 66 Point 61g also becomes curvature larger curved shape to a certain extent.

But band part 61a is only to be pressed against heating by the restoring force of the pressing rubber 72 of bearing part 66 The restoring force of roller 64, pressing rubber 72 is not so strong, since slider 73 presses the friction between rubber 72 and band part 61a It is greatly reduced.The bending (deformation) of the end 61g of the end 61f and downstream side of the upstream side of fixing belt 61 is not up to as a result, The degree of great load is applied to fixing belt 61, will not shorten the service life of fixing belt 61.

As described above, in the present embodiment, the bending of heating roller 64 and the peripheral surface 64a along heating roller 64 The band part 61a of fixing belt 61 folded by the bearing part 66 of shape is deformed into the bending of the peripheral surface 64a along heating roller 64 Shape, that is, the back-flexing shape (concave shape) in the direction being bent and nature opposite direction.

The self-recovery power for being deformed into the band part 61a after back-flexing shape is acted on to close to the direction of heating roller 64 And so that band part 61a itself is become easy and be tightly attached to heating roller 64, to significantly obtain the contact area with heating roller 64, by This does not configure the components such as jockey pulley, can effectively supply the heat of heating roller 64 to fixing belt 61 yet.In addition, due to larger Ground obtains the contact area with heating roller 64, even if so there is fixing belt 61 thickness also can fully be heated.

It should be noted that among the above, though bearing part 66 is constituted using substrate 71, pressing rubber 72 and slider 73, But not limited to this.It can also be like that arranged using schematic diagram for example shown in Fig. 7 from the band of the substrate 71 of arc-shaped and be surround Direction upstream end 71d extends the band guiding mechanism 77 of curved shape outstanding towards upstream side and is arranged from downstream 71e courts Downstream extend the structure with guiding mechanism 78 of curved shape outstanding.

It is guided in the band guiding mechanism 77,78 as guide portion around the fixing belt 61 advanced, to become easy Inhibit the swing around the fixing belt 61 when advancing, fixing belt 61 can be made more stably around traveling.

(embodiment 2)

In the above embodiment 1, to having as across the fixing member arranged opposite with pressure roller 63 of fixing belt 61 The configuration example of standby fixing roller 62 is illustrated, but in present embodiment 2, and pad, this point and embodiment 1 are used instead of roller It is different.Hereinafter, in order to avoid repeated explanation, for content same as embodiment 1, the description thereof will be omitted, for identical structure Element marks the same symbol.

Fig. 8 is the figure of the structure for the fixing section 6 for indicating embodiment 2.

As shown in the drawing, it is provided with fixing pad as across fixing belt 61 and the fixing member arranged opposite of pressure roller 63 162 and support the fixing pad 162 support member 170.By using fixing pad 162, can be minimized than fixing roller and low Thermal capacitance quantifies.

As the material of fixing pad 162, such as rubber can be used, more specifically silicon rubber etc., in addition, for example can Using resin, more specifically LCP (liquid crystal polymer), PPS (polyphenylene sulfide) etc..

Same as embodiment 1, pressure roller 63 presses fixing pad 162 across fixing belt 61, therefore ensures that fusing nip 69 Nip loads (nip pressure), but fusing nip 69 as described above become suitable top load.In order to ensure the top load, absolutely In most cases only configuration fixing pad 162 is inadequate, therefore in the present embodiment, the branch of configuration support fixing pad 162 The material that support part part 170 and support member 170 also use rigidity high.

Support member 170 is that flat board member is bent to as shown in the figure made of the U-shaped of cross section Part, the axial direction along pressure roller 63 is long size, and long side direction both ends are fixed on the frame of fixing section 6.

Support member 170 has：It is fixed with the base plate 171 of fixing pad 162 and the short side direction two from base plate 171 Hold the first, second side plate 172,173 to the side bending present in bearing part 66.By being formed as section U-shaped, To compared with simply using the structure of tablet, improve to the curved of the pressing direction (directions arrow Ha) based on pressure roller 63 Stiffness, so as to make the nip pressure of top load act on fusing nip 69.

Moreover, by the front end of the front end 172a and the second side plate 173 of the first side plate 172 of support member 170 When the interval of the short side direction (Z-direction) of 173a is set as Wa, the width of the short side direction of bearing part 66 is set as Wb, become The structure of relationship with Wa ＞ Wb.With this configuration, can support member 170 the first, second side plate 172,173 it Between space 179, store in bearing part 66 roller direction of rotation central portion (in bearing part 66 closest to support member The part of 170 base plate 171) 66a, therefore the interval of heating roller 64 and pressure roller 63 can be reduced in the X-axis direction, it can The size for further decreasing the X-direction of fixing section 6, so as to realize the miniaturization of fixing section 6 in X-direction.

Using the structure of the figure, though in the miniaturization of X-direction realization fixing section 6, in fixing belt 61 More lean on band more to lean on band around direction upstream side around direction downstream side and compared to bearing part 66 compared to fusing nip 69 Band part 61p more leans on band more to lean on band around direction around direction downstream side and compared to fusing nip 69 with bearing part 66 is compared The respective curvature around path of band part 61q of upstream side increases compared with the structure of embodiment 1.

The situation means that the deformation of fixing belt 61 becomes much larger, and increases the burden of fixing belt 61.In fixing belt 61 Burden increases and assumes in the case of being affected to the service life, can also use such as lower structure, that is, as shown in Figure 9 in X-axis Direction make heating roller 64 compared with the interval of pressure roller 63 structure of Fig. 8 and slightly expand, reduce fixing belt 61 band part Thus the curvature around path of 61p, 61q reduce the bending of band part 61p, 61q, to reduce the burden to fixing belt 61.

It should be noted that in Fig. 8, structure shown in Fig. 9, in the circular traveling process of fixing belt 61, there is support member The feelings of 170 the first side plate 172 and 173 respective front end of the second side plate and the back side 61z of fixing belt 61 misgivings contacted Under condition, it can also use and the structure shown in Fig. 7 with guiding mechanism 77,78 is set.

In addition, according to apparatus structure difference, it is possible to form the roller of fusing nip 69 with the value lower than above-mentioned top load Gap load, in this configuration, the bending stiffness of support member 170 is relatively low just enough sometimes.In this case, by such as Shorten the extension of the first side plate 172 of support member 170 and the slave base plate 171 of the second side plate 173 as shown in Figure 10 Prominent length 17a, 17b, can reduce the size of side plate 172,173.In this configuration, sometimes above-mentioned as shown in the figure Interval Wa and width Wb become Wa ＜ Wb relationship.Since support member 170 becomes smaller in itself, so correspondingly realizing low heat capacity Quantization.

In addition, if the perimeter for for example meeting heating roller 64 (outer roller) as the structure of Figure 10 is longer than the week of fixing belt 61 Long relationship, then the area of heated side becomes than 1 week size bigger of band, therefore can inhibit the heating in the circumferential direction of fixing belt 61 It is uneven.

In addition, when the outer diameter of heating roller 64 is set as Wh, the structure for the relationship for meeting Wa ＞ Wb ＞ Wh can also be used Or meet the structure of the relationship of Wa ＞ Wh ＞ Wb.

(embodiment 3)

In the above embodiment 1, to heating roller 64, bearing part 66, fixing roller 62 and pressure roller 63 to be arranged in The configuration example that mode on straight line configures is illustrated, but in present embodiment 3, is formed as the position of bearing part 66 Set be configured at from the straight line along heating roller 64 it is circumferential slightly offset from position structure, this puts different from embodiment 1.

Figure 11 is the figure of the structure for the fixing section 6 for indicating embodiment 3.

The rotary shaft of heating roller 64 is being set as 64e as shown in the drawing, by the sheet material carry direction center of fusing nip 69 Position be set as 69e, the bending direction central portion (being equivalent to width direction central portion) in bearing part 66 is set as 66a, will Link imaginary line (the first vacation of the rotary shaft 64e of the heating roller 64 and position 69e in the sheet material carry direction center of fusing nip 69 Think line) 301 are set as, the structures being present on imaginary line 301 of the width direction central portion 66a in bearing part 66 (are equivalent to Embodiment 1) the position of the bearing part 66 when being set as reference position, become in bearing part 66 in embodiment 3 Width direction central portion 66a is present in from the reference position centered on the rotary shaft 64e of heating roller 64 and to heating roller 64 Direction of rotation upstream side deviates from the structure of the position of angle, θ a.

In the case where pressure roller 63 is driving side, in the structure that bearing part 66 is located at the reference position, fixing belt 61 Band part 61q has easy stretching trend, and band part 61p, which has, is easy relaxation trend.If the relaxation of band part 61p increases (with reference to figure 13 61u), then pass through angle θ b formed by the recording sheet S of fusing nip 69 and the surface of fixing belt 61 and has reduced, recording sheet S is easily reduced from the separation property of fixing belt 61.

In order to eliminate fixing belt 61 band part 61p relaxation, as long as to band part 61p working tensions, in order to make Tension force effect is in band part 61p, as long as another band part 61q dare to be made to have relaxation trend.As making band part 61q Structure with relaxation trend uses and bearing part 66 is configured at from reference position to heating roller in present embodiment 3 64 direction of rotation upstream side deviates from the structure of the position of angle, θ a.

Due to significantly obtaining angle, θ b with this configuration, so the separation property of recording sheet S can be improved.It should say It is bright, if tension force effect in band part 61p, heating roller 64 in the band part 61a of the fixing belt 61 folded by bearing part 66 Band around direction upstream side end 61f, with and the abutting pressure increasings of the end 66f of bearing part 66 that contact of end 61f Greatly, the load of the band part 61f of bending is also increased.

It is therefore preferable that the roller direction of rotation G in bearing part 66, (band is around direction like that as best seen in the enlarged view of figure 12 F) corner 66p, 66q of the end 66f of upstream side applies R shapes, to reduce the load to the band part 61f of bending.

If it should be noted that being nearly free from reductions of the recording sheet S from the separation property of fixing belt 61, figure can also be used Such structure shown in 13.

Specifically, the bending direction central portion 66a being configured in bearing part 66 is present in from above-mentioned reference position The position of angle, θ c is deviated to the direction of rotation downstream side of heating roller 64 centered on the rotary shaft 64e of heating roller 64.

For the structure, as described above preferably to the roller direction of rotation of bearing part 66 (band is around direction) The corner 661,662 (referring to Fig.1 2) of the end 66g in downstream side applies R shapes.

It should be noted that among the above, though in the case of the structure that bearing part 66 is not located at the reference position, in supporting part R shapes are arranged in the corner of the end 66f of the roller direction of rotation upstream side of part 66 or the end 66g in downstream side, but do not limit In this.For example, the structure for the embodiment 1 that even bearing part 66 is located at the reference position, it can also be in bearing part 66 R shapes are respectively set in the corner of the one side or both sides of the end 66f of roller direction of rotation upstream side and the end 66g in downstream side.

(embodiment 4)

It is driving side, fixing belt 61, fixing roller 62 and heating roller 64 to pressure roller 63 in the above embodiment 1~3 It is illustrated for the configuration example of slave end, but in present embodiment 4, is configured to pressure roller 63 and heating roller 64 respectively becomes Independent driving side, this puts different from Embodiments 1 to 3.

Figure 14 is the figure of the structure for the fixing section 6 for indicating embodiment 4.

As shown in the drawing, with make 67 phase of drive motor of the rotation driving of pressure roller 63 independently, configured with making heating roller 64 The drive motor 67a of driving is rotated, drive motor 67,67a can rotate driving respectively.It should be noted that in present embodiment 4 In, as across fixing belt 61 and the pressurized component arranged opposite with pressure roller 63, configured with identical with embodiment 2 fixed Shadow pad 162.

The band part 61m (part for constituting fusing nip 69) contacted with pressure roller 63 into fixing belt 61, which is transmitted, to be come from The rotary driving force of pressure roller 63 is transmitted to the band part 61a folded by heating roller 64 and bearing part 66 from heating roller 64 Rotary driving force.

In the structure for only transmitting the rotary driving force from pressure roller 63 to band part 61m as Embodiments 1 to 33 In, it is easy due to the resistance to sliding with bearing part 66 when between heating roller 64 and bearing part 66 in band part 61a The peripheral speed of band part 61a is set to generate variation.If the constant situation of peripheral speed relative to band part 61m and generate variation, become The case where easy ting produce side relaxation, another party's stretching of band part 61p, 61q, to be become easy in traveling process Generate the deformation of fixing belt 61.

For this purpose, in present embodiment 4, in order to inhibit the deformation of the fixing belt 61 generated because the peripheral speed changes, and structure Rotary driving force is separately transmitted as to band part 61m, 61a, is used not generate the peripheral speed of band part 61m, 61a The mode of difference separately controls the structure of the peripheral speed of band part 61m, 61a.

Specifically, configured with first detection units such as the encoders of rotary speed of rotary shaft for detecting pressure roller 63, So as to detect the peripheral speed of pressure roller 63.

In addition, in the inside around path of fixing belt 61, configured with the inner surface with the band part 61q of fixing belt 61 The bar 11a of 611 contacts.Bar 11a is contacted when dead weight is normal with the inner surface 611 of band part 61q, follows band part 61q's Upper and lower variation (solid line, dotted line and single dotted broken line respectively shown in position) and upper and lower displacement.Herein, it is with the position of solid line Benchmark, the position expression of dotted line produce the state of stretching, and the position of single dotted broken line indicates to produce loose state.

In the case where making the peripheral speed of band part 61m be formed as constant (a reference value), if the peripheral speed of band part 61a becomes small In a reference value, then band part 61q has stretching trend (dotted line), the position of bar 11a to rise.At this point, band part 61p has relaxation to become Gesture.

On the other hand, if the peripheral speed of band part 61a becomes larger than a reference value, band part 61q has loose trend, and (single-point is drawn Line), the position of bar 11a declines.At this point, band part 61p has stretching trend.

It is configured with belt sag detection sensor 11 (Fig. 2) as the sensor for the upper and lower position for detecting bar 11a, it can Based on the testing result of belt sag detection sensor 11, the upper and lower variation to band part 61q, i.e. band part 61q have relaxation to become Gesture still has stretching trend to be detected.Belt sag detection sensor 11 is properly termed as to the fixing belt 61 in traveling process In band part 61m (first part) and band part 61a (second part) peripheral speed the second detection unit that is detected of difference.

Moreover, control unit 7 executes the first control and the second control, wherein first control is control rotation driving pressurization The drive motor 67 (the first driving unit) of roller 63 is being equivalent to recording sheet transporting velocity with the peripheral speed stabilization of pressure roller 63 The mode of fixing speed adjusts the rotary speed of pressure roller 63, which is the driving horse of control rotation driving heating roller 64 Up to 67a (the second driving unit), according to the testing result of belt sag detection sensor 11, to eliminate the week of band part 61m, 61a The mode of the difference of speed adjusts the rotary speed of heating roller 64.

Figure 15 is the flow chart of the second control performed by control unit 7, anti-when calling (not shown) by main program every time It is multiple to execute.It should be noted that premised on following condition, i.e., the second control is：It is controlled the peripheral speed of pressure roller 63 by first It is maintained constant with fixing speed.

As shown in the drawing, control unit 7 obtains the testing result (step S1) of belt sag detection sensor 11.Based on belt sag The testing result of detection sensor 11 is judged (step S2) whether the upper and lower position of band part 61q is located at the reference position.

If being judged as, the upper and lower position of band part 61q is located at the reference position (being in step s 2 "Yes"), returns.At this In the case of, all speed differences are not present in band part 61m, 61a.

If being judged as being not located at reference position (being in step s 2 "No"), to whether produce relaxation judge (step S3).If being judged as producing relaxation, i.e. the peripheral speed of all speed ratio band part 61m of band part 61a it is fast (in step s3 for "Yes"), then slow down specified amount into the peripheral speed for being about to heating roller 64, such as the peripheral speed (constant) relative to pressure roller 63 slows down 2% The control (step S4) of size, and return.

On the other hand, if being judged as not generating relaxation and producing stretching, i.e. all speed ratio band part 61m of band part 61a Peripheral speed it is slow (being in step s3 "No"), then accelerate specified amount into the peripheral speed for being about to heating roller 64, such as relative to pressure roller 63 peripheral speed accelerates the control (step 5) of 2% size, and returns.

If the peripheral speed of band part 61m is maintained fixing speed as a result, prevent band part 61p, 61q from generating relaxation, drawing It stretches, so as to make fixing belt 61 more stably advance.

(embodiment 5)

In the above-described embodiment, to the band part 61f of the end 66f for being wound in bearing part 66 in fixing belt 61 Larger configuration example is illustrated the curvature of (Fig. 3, Figure 12) to a certain extent, but in present embodiment 5, is configured to this Curvature is smaller (the degree of bending is smaller), this puts different from above-mentioned embodiment.

Figure 16 is in the sizable structure of curvature for the band part 61f for being schematically illustrated at fixing belt 61, in fixing belt 61 Circular traveling process in the figure of which kind of power P has been acted on from band part 61f to heating roller 64.In the figure for ease of explaining It is bright and the mutual band part 61f contacted originally is made to be shown in the figure with the state detached with heating roller 64, and for nothing It should be noted that the component omission such as bearing part 66 illustrate.

The power P acted on from band part 61f to heating roller 64 become along tangent line 614 direction power, that is, along with fixing With the band in the region contacted with heating roller 64 in 61 around the part 619 of direction most upstream side in band around direction upstream side The power in the direction (along the direction of the direction of travel of band part 618) of the tangent line 614 of the plane tangent of adjacent band part 618.

The position 649 contacted with the end 619 of fixing belt 61 on the peripheral surface 64a of heating roller 64 is equivalent to heating roller 64 The position of the direction of rotation most upstream in the region contacted with fixing belt 61 on peripheral surface 64a, the line tangent with position 649 is set as Imaginary tangent line 615 (though detach but actually contact in the figure) will link the rotary shaft 64e at the position 649 and heating roller 64 Imaginary line be set as 616, if by power P points for along the component Pa in the direction of imaginary tangent line 615 and along with imaginary tangent line 615 just The component Pb of the imaginary line 616 of friendship, then the direction of component Pa is as the direction of rotation opposite direction with heating roller 64.

Heating roller 64 relative to around advance 61 driven rotation of fixing belt structure in, the heating roller in fixing belt 61 64 mainly become the drive of the driven rotation of heating roller 64 with the frictional force of band part 61a and heating roller 64 folded by bearing part 66 Power, if but power P includes the ingredient Pa become with the direction of rotation opposite direction of heating roller 64, the driving force phase of driven rotation Reduce and become to be not easy driven with answering.If for example heating roller 64 is alternately produced the rotation that can be driven in fixing belt 61, nothing as a result, Method is driven in the case where rotation of fixing belt 61 and generates rotation unevenness in heating roller 64, then has from heating roller 64 to fixing belt 61 Heating amount per unit time change and generate the uneven misgivings of heating.

For the heating unevenness, the sizable structure of curvature of the band part 61f of fixing belt 61 is specifically fixed With 61 to heating roller 64 entry angle γ, more specifically fixing belt 61 enter heating roller 64 peripheral surface 64a and supporting part It is larger as larger factor relative to the entry angle of the imagination tangent line 615 when between part 66.It should be noted that angle γ is equal to 180 ° subtract fixing belt 61 to obtained by 615 angulation of the approach axis (direction of power P) of heating roller 64 and imaginary tangent line Angle.

Thus, for example as shown in Figure 17, it can be so as to more lean on band around direction compared to band part 619 in fixing belt 61 The band part 618 of upstream side is located at more leans on the mode of the direction of rotation upstream side of heating roller 64 to set fixing compared to imaginary line 616 With 61 circular path.The peripheral surface 64a of the curvature and heating roller 64 around path in band part 618 is shown in FIG. 17 The identical example of curvature.

So, entry angle γ reduces, and the component Pa of power P also becomes side identical with the direction of rotation of heating roller 64 To, thus heating roller 64 become easy it is driven, it is uneven to become to be not likely to produce above-mentioned heating.Component Pa becomes and heating roller The 64 identical direction in direction of rotation be entry angle γ be less than 90 ° when, therefore be preferably configured as entry angle γ become 90 ° Below.

Alternatively, it is also possible to be formed as structure shown in such as Figure 18.

Figure 18 is to indicate that heating roller 64 is configured at the figure of the configuration example of upside relative to fixing belt 61.If will be such as embodiment party 1 such heating roller 64 of formula relative to 61 landscape configuration of fixing belt structure as landscape configuration, then structure shown in Figure 18 can be with Referred to as longitudinal configuration.

In longitudinally configuring, as shown in Figure 18, in the circular path of fixing belt 61, bearing part 66 is fairly close Support is fixed the support member 170 of pad 162, therefore the size of bearing part 66, and specifically width direction length (is equivalent to and adds The circumferential lengths of hot-rolling 64) it is easy to be restricted.In contrast, it is disposed transversely in the circular path of fixing belt 61 and significantly takes Bearing part 66 configuration space, therefore longer the width direction length for obtaining bearing part 66 is easy significantly to obtain The contact area of heating roller 64 and fixing belt 61, i.e. heating region.

On the other hand, in longitudinally being configured shown in Figure 18, in fixing belt 61 just have left fusing nip 69 after Band part 61p, there is the pressure roller 63 based on driving side and the feed speed that generates, relative to slave end heating roller 64 with Band part 61a folded by bearing part 66, which generates curvature, becomes fairly small expansion.Entry angle γ and 90 ° by the expansion Compared to becoming fairly small.The structure longitudinally configured in this way can be such that heating roller 64 is easy driven.

Compare the round and smooth driven rotation etc. for considering to make the heating region of fixing belt 61 to increase with heating roller 64, such as can It is enough using being suitable for structure shown in Figure 11, Figure 13, be configured at the centre of longitudinal configuration and landscape configuration specifically relative to fixed The configuration of shadow bands 61 and the apparatus structures such as structure for being configured at left oblique upper etc..

(embodiment 6)

Among the above, though the sheet material type of recording sheet S is (for example, plain paper and ground paper used in not specifically mentioned Deng), but print conditions are changed according to sheet material type in present embodiment 6, are to change sheet material transporting velocity herein, this point with it is real It is different to apply mode 1~5.

For ground paper, correspondingly, the thermal capacity of sheet material itself increases the degree gone out than common thickness of paper with thickness, Therefore in order to maintain fixing temperature identical with plain paper, the needs of heat of the supply more than plain paper are generated.In this embodiment party In formula, the transporting velocity during making ground paper pass through fusing nip 69, i.e., the rotary speed of the pressure roller 63 of driving side is than common Paper is slow (such as Half Speed).The fixing belt 61 of slave end, the peripheral speed of heating roller 64 are also slower than plain paper as a result, such as Half Speed, Ground paper becomes longer than plain paper by the time (roll gap time) needed for fusing nip 69, fusing nip 69 per unit time It supplies to the heat of ground paper and increases compared with plain paper.

If transporting velocity control is applied to ground paper, become the confession for no longer needing to make heater 65 according to sheet material type To electrically variable.If however, by the size for remaining and being selected for plain paper that supplies electric power of heater 65, with fixing belt Correspondingly, heating roller 64 extends the slack-off degree of 61 peripheral speed compared with the case where time of contact of fixing belt 61 is with plain paper, Heat from the supply of heating roller 64 to fixing belt 61 increases, to there is supply to the heat with Half Speed by the ground paper of fusing nip 69 Measure the misgivings become over.

For this purpose, in present embodiment 6, it is configured to the sheet material type according to used recording sheet S, changes heating roller 64 with the circumferential contact length (hereinafter referred to as " heating nip length Q " of fixing belt 61.), thus adjust from heating roller 64 It supplies to the heat per unit time of fixing belt 61.

Specifically, as shown in Figure 19, heating roller 64 is configured to close relative to bearing part 66 Direction (directions arrow Hb) and the direction separate relative to bearing part 66 (directions arrow Ha) are mobile, are become according to sheet material type More distance of the heating roller 64 relative to bearing part 66.The moving direction of heating roller 64 is known as far from direction of closing.

(a) of Figure 19 indicates that heating nip length Q becomes the first state of Qa, and (b) of Figure 19 indicates heating nip length Q As the second state of Qb (＜ Qa).It is, for example, 15mm to heat nip length Qa, and heating nip length Qb is, for example, 7.5mm. Band part 61a is set to be contacted with the peripheral surface 64a of heating roller 64 also by the restoring force of fixing belt 61 under second state, to be formed Heat nip length Qb.

First state shown in (a) of second state relative to Figure 19 shown in (b) of Figure 19, and as heating roller 64 with Heater 65 integrally moves the state of distance δ from bearing part 66 to separate direction.Hereinafter, by the heating of first state The position of the separate direction of closing (being equivalent to X-direction) of roller 64 is known as first position, by the remote of the heating roller 64 of the second state Position from direction of closing is known as the second position.

In the present embodiment, heating roller 64 and 65 respective both ends of heater are supported in the frame with fixing section 6 Different subframes (not shown), the subframe are supported to freely move along far from direction of closing relative to the frame of fixing section 6 It is dynamic.Subframe engaging be useful for determine heating roller 64 far from close to position (first position and the second position) cam (not shown).Cam is set to rotate by the driving force of the actuator 12 (Fig. 2) of motor etc., thus subframe is along far from direction of closing It is mobile, thus become heating roller 64 with heater 65 integrally relative to bearing part 66 along the knot moved far from direction of closing Structure.

When the rotation angle and heating roller 64 of cam when pre-determined heating roller 64 is located at first position are located at the second position Cam rotation angle, and so that cam is rotated with the rotation angle of the decision, thus, it is possible between the first location and the second location Switch the position of heating roller 64.Actuator 12, cam become the mobile unit for making heating roller 64 move.

The longer words of nip length Q are heated, heating roller 64 and the contact area of fixing belt 61 expand, supplied from heating roller 64 Heat to fixing belt 61 increases, conversely, if heating nip length Q is shorter, the contact area of heating roller 64 and fixing belt 61 It reduces, the heat from the supply of heating roller 64 to fixing belt 61 is reduced.

Therefore, if first state shown in (a) of Figure 19 is applied to plain paper, by shown in (b) of Figure 19 second State be applied to ground paper mode switching control heating roller 64 position, then either be directed to plain paper, or for it is common The paper ground paper slower compared to transporting velocity, can supply the heat suitable for being thermally fixed in fusing nip 69.

Figure 20 is the flow of the content of the control of the position switching for the carrying and heating roller 64 for indicating plain paper and ground paper Figure is all performed when carrying a piece of recording sheet S using control unit 7 every time.It should be noted that herein, to selectively using The first fixing pattern of plain paper has been used as recording sheet S and the second of the ground paper example for being fixed pattern has been used to carry out Explanation.

The sheet material type (step S11) of carried recording sheet S is obtained as shown in the figure.The acquirement is, for example, logical It crosses the information for obtaining the sheet material type that user inputs from the setting of operation panel 8 and carries out.In addition, in the data packet of print out task In the case of the information of the type containing sheet material, it can also be obtained by reading the information.

If it is ground paper, as plain paper (being in step s 12 "No") to be judged as carried recording sheet S not, then select The first fixing pattern is selected, control actuator 12 makes heating roller 64 be moved to first position ((a) of Figure 19) (step S13).Then, Control drive motor 67 makes pressure roller 63 (be predetermined speed for plain paper with reference speed：For example, 166mm/ seconds) It rotates (step S14), and terminates the processing.Fixing belt 61 is surround with reference speed (First Speed) and is advanced as a result,.

On the other hand, if being judged as, carried recording sheet S is ground paper (being in step s 12 "Yes"), selects Two fixing patterns, control actuator 12 make heating roller 64 be moved to the second position ((b) of Figure 19) (step S15).As a result, with it is general The case where logical paper, is compared, and heating roller 64 and the contact area of fixing belt 61 are reduced.

Then, control drive motor 67 makes pressure roller 63 (be predetermined and be used for ground paper with the low speed slower than reference speed Speed：For example, 83mm/ seconds)) rotation (step S16), and terminate the processing.Fixing belt 61 is with than reference speed (as a result, One speed) slow second speed is around advancing.

It is not only the heating roller 64 in the fixing belt 61 as shown in (a) of Figure 19 and the band part folded by bearing part 66 The substantially the entirety of curved shape and and heating roller become along the peripheral surface 64a of heating roller 64 in the circular direction length of 61a The case where 64 contact, and the part in the circular direction length of such band part 61a shown in (b) of Figure 19 is as along adding The curved shape of the peripheral surface 64a of hot-rolling 64 and the case where being contacted, which are also contained in band part 61a, to be become along heating The structure of the curved shape of the peripheral surface 64a of roller 64.

Among the above, plain paper and ground paper both paper are illustrated as sheet material type, but can also include it His type is such as thin paper, coated paper, postcard.Make the carrying speed by the sheet material of fusing nip 69 according to sheet material type It spends in (peripheral speed for being equivalent to fixing belt 61) different structure, can carry out heating roll gap with slack-off along with the transporting velocity The mode that length Q shortens extends control of the heating roller 64 relative to the distance of the separate direction of closing of bearing part 66.

In addition, as the condition for keeping the transporting velocity (peripheral speed of fixing belt 61) of sheet material different and to the example of sheet material type It illustrates, but not limited to this.Such as can be applied to such as lower structure, i.e.,：In the pattern that the monochrome image of only K colors is formed In, using the pattern as the first fixing pattern, using the transporting velocity of sheet material as reference speed (First Speed), in Y~K colors In the pattern that full-color image is formed, using the pattern as the second fixing pattern, the transporting velocity of sheet material is switched to and compares benchmark Slow low speed (second speed).

Though also, bearing part 66 is fixed, and heating roller 64 is enable to be connect along separate relative to bearing part 66 Nearly direction movement, but not limited to this.Bearing part 66 can be enable to be connect along separate relative to the heating roller 64 after fixation Nearly direction is mobile or both sides is enable to be moved along far from direction of closing.That is, can use heating roller 64 and bearing part 66 can Relatively along the structure moved far from direction of closing.

(embodiment 7)

In the above-described embodiment, the configuration example contacted when fixing belt 61 and normal heating roller 64 is illustrated, but In present embodiment 7, it is configured to make heating roller 64 detach from fixing belt 61 if fixing belt 61 is in stopped process, this point is not Together.

Make heating roller 64 from the deformation that the separation of fixing belt 61 is fixing belt 61 in order to prevent.That is, this is because：If long-term Between during long holidays completely without printing while placing (long-term), then default shadow bands 61 are completely motionless during the length, To which the band part 61a being bent round about along the circumferential surface of heating roller 64 in fixing belt 61 remains the curved of the opposite direction Curved shape has the misgivings for the deformation for leading to fixing belt 61.If heating roller 64 is made to detach from fixing belt 61 when fixing belt 61 stops, Then fixing belt 61 returns to original natural posture (Fig. 4) because of the restoring force of itself, so as to prevent relative to original Natural gesture distortion is the curved shape of opposite direction.

Make heating roller 64 relative to fixing belt 61 detach or contact structure, can by with enable 64 phase of heating roller For bearing part 66 along the 6 identical structure of embodiment that moves of contact separation direction, i.e., according to the rotation angle of cam and Enable heating roller 64 in the position (disengaged position) detached from fixing belt 61 and the position contacted with fixing belt 61 (contact position Set) between the structure that moves realize.

Figure 21 is the stream of the content for the control for indicating to switch over heating roller 64 between disengaged position and contact position Cheng Tu is performed when executing a print out task using control unit 7 every time.

It should be noted that being carved at the beginning of print out task, pressure roller 63 is in halted state, and heating roller 64 is located at separation position It sets (subsequent steps S25, S26).

As shown in the drawing, if being judged as, print out task starts (being in the step s 21 "Yes"), and controlling actuator 12 makes to add Hot-rolling 64 is migrated from disengaged position to contact position (Fig. 3) (step S22).Fixing belt 61 is pressed as supported portion part 66 as a result, It is connected to the common state of heating roller 64.Then, control drive motor 67 makes pressure roller 63 start to rotate (step S23), goes forward side by side Enter step S24.Fixing belt 61 starts to surround traveling as a result,.

In step 24, whether print out task is terminated to judge.If being judged as, print out task terminates (in step S24 In be "Yes"), then controlling drive motor 67 makes pressure roller 63 stop rotating (step S25).Fixing belt 61 stops as a result,.

Later, control actuator 12 makes heating roller 64 be migrated from contact position to disengaged position (step S26), and terminating should Processing.Fixing belt 61 becomes the natural state detached from heating roller 64 as a result,.It should be noted that if heating roller 64 is not from fixing The degree of line contact is kept completely separate and is with 61, then fixing belt 61 is also indeformable, therefore can also be formed as the line contact condition. It is known as releasing crimping including separation and line contact shape.

It can crimp in traveling process into fixing belt 61 is exercised, released in the stopped process of fixing belt 61 in this way The switching control of crimping.

It should be noted that in the present embodiment, also same as embodiment 6, can use makes heating roller 64 and supporting part Part 66 can be relatively along the structure moved far from direction of closing.

In addition, in figure 21, though after heating roller 64 is moved to contact position, pressure roller 63 is made to start to rotate (step S22, S23), but this can also be made sequentially to become reverse order.Equally, though after the rotation of pressure roller 63 stops, heating roller 64 (step S25, S26) is moved to disengaged position, but this can also be made sequentially to become reverse order.This is for shown in such as Figure 20 Step S13, S14 and step S15, S16 are also identical, and respective sequence can also be made to become reverse order.

Among the above, to making heating roller 64 be contacted relative to fixing belt 61, the control of separation is illustrated, but same, Fixing roller 62 and pressure roller 63 can also be enable across fixing belt 61 and relatively moved to close direction and separate direction It is dynamic.

In this case, it can also carry out control as follows：In the circular traveling process of fixing belt 61, make 62 He of fixing roller Pressure roller 63 is relatively moved to close direction, is pressed pressure roller 63 via fixing belt 61 and is formed and be fixed in fixing roller 62 Roll gap 69 (Fig. 3) makes fixing roller 62 and pressure roller 63 relatively be moved to separate direction in the stopped process of fixing belt 61 It is dynamic, release the pressing.

This is because：Fixing belt 61 receives strong pressing force, edge in fusing nip 69 from pressure roller 63 as shown in Figure 3 The circumferential surface of pressure roller 63 is bent round about relative to natural posture, and the opposite direction is remained in long-term place to have Curved shape misgivings.

(variation)

More than, based on embodiment, the present invention is described, but the present invention is not limited to above-mentioned implementation certainly Mode, it may be considered that following variation.

(1) in the above-described embodiment, though being configured with each heating roller 64, heater 65 and bearing part 66, It's not limited to that.For example, it is also possible to using having heating roller 64 relative to a fixing belt 61 like that as shown in figure 22, adding First group of hot device 65 and bearing part 66；With with a different set of heating roller 264, heater 265 and the supporting part Second group of structure of part 266.

Using the structure, the heating region by making the heating roller 64 in first group can be further obtained Heating region with the heating roller 64 in second group is in heating region that is axially distinct, and making the bandwidth direction in fixing belt 61 Different structures.

Figure 23 is the heating roller 64 shown in the arrow X-direction observation chart 22,264, heater 65,265 and fixing belt 61 When figure, it is different to schematically illustrate heating roller 64, the heating region in 264 medium-band width directions.

It is only inserted into the rodlike heater 65 of the heating roller 64 of tubular and is present in bandwidth direction middle section Part becomes heating part, from the heat transfer that the heating part is sent out to the heating region 271 of heating roller 64, and from the heating region 271 are transferred to the heating region 261 of fixing belt 61.

Equally, be only inserted into the rodlike heater 265 of the heating roller 264 of tubular across bandwidth direction central area Domain and be present in two outside region part become heating part, from the heat transfer that each heating part is sent out to heating roller 64 Heating region 272,273, and the heating region 262,263 of fixing belt 61 is transferred to from heating region 272,273 respectively.

The region 261 in bandwidth direction center is logical in the so-called small size paper such as B5 sizes or A4 sizes in fixing belt 61 The region in the bandwidth direction contacted with the small size paper when crossing fusing nip 69.On the other hand, the area on the outside of bandwidth direction Domain 262,263 be in fixing belt 61 when the so-called large scale paper of only B4 sizes or A3 sizes etc. is by fusing nip 69 and this is big The region in the bandwidth direction of size paper contact.

Therefore, it in the case where having used small size paper, can only be heated if only heater 65 is energized and small size The corresponding small size width of paper, the so-called end excessive temperature rise on the outside of two so as to prevent bandwidth direction, is using In the case of large scale paper, heating big ruler corresponding with large scale paper is become able to if the both sides of heater 65,265 are energized Very little width correspondingly heats the region suitable for each width so as to the size (width) with recording sheet.

It should be noted that above-mentioned 2 groups can also be replaced, and use the structure for the group for having 3 or more.

In addition, instead of having multigroup structure, and only have in 1 group of structure as Embodiment 1, it can also use By the heating roller 64 with the insertion tubular of multiple heaters 65 in the different heating region in bandwidth direction, and according to documentary film The size of material switches the structure of be powered heater 65.

(2) in the above-described embodiment, though face 66b (Fig. 3 contacted with band part 61a in bearing part 66：Hereinafter, Referred to as " electrolysis ".) the curved shape for being shaped so as to the peripheral surface 64a along heating roller 64, but not limited to this.

As long as can with fixing belt 61 by self-recovery power become along heating roller 64 peripheral surface 64a bending The mode ((a) of Figure 19, (b) etc.) of shape, from across fixing belt 61 and with 64 opposite side of heating roller (band around the path interior Side) make fixing belt 61 be crimped on the heating roller 64 for being present in the outside of band around the path peripheral surface 64a shape.

Can make the shape of the electrolysis 66b of bearing part 66 for example formed as with centered on the rotary shaft of heating roller 64 The circular shape of the identical curvature of concentric circles, the curvature circular shape more slightly smaller than the circular shape etc. curved shape.In addition, Such as it is also contemplated that be formed as from the end on observation of heating roller 64 when the sides band part 61a V-shaped, " く " font etc. for opening.

(3) in the above-described embodiment, though bearing part 66 has substrate 71, pressing rubber 72 and slider 73, It's not limited to that.For example, the structure being made of substrate 71 and pressing rubber 72 can be used, by 73 structure of substrate 71 and slider At structure, only with substrate 71 structure etc..Though for slider 73 in the slider for having used glass cloth among the above, simultaneously It is not limited to this, the sheet material of heat resistance and low friction can be used.In addition, only to have the structure of substrate 71, The flexure plane contacted with band part 61a in substrate 71 can be used to be provided with the structure of low friction layer.

In addition, in order to reduce the frictional force of the inner surface 61z of fixing belt 61 and the electrolysis 66b of bearing part 66, also may be used With using the structure for the two being respectively coated in advance lubricant.As lubricant, such as silicone oil, fluorocarbon oil fat etc. can be used.And And the inner surface 61z in fixing belt 61 can also be used to apply low friction layer, such as apply the structure of fluorine coating.It can use By the structure of either one or two of above-mentioned or multiple combinations.

(4) in the above-described embodiment, though the material of the base of fixing belt 61 and the substrate 71 of bearing part 66 is formed For PI resins, but it's not limited to that certainly.It is fixing in the case that heat source bearing part 66 is not heat source in heating roller 64 It is easy to be transferred to bearing part 66 (being easy supported portion part 66 to absorb) with 61 heat, the heat of fixing belt 61 is escaped De- bearing part 66 and heat loss increases, therefore be preferably formed into and meet the pyroconductivity of bearing part 66 and be less than fixing belt 61 The structure of the relationship of pyroconductivity.It is waited in the smaller range that can fully allow in design in the degree of heat loss In the case of, opposite relationship can also be formed as.

In addition, among the above, though it is configured to the inside that rodlike heater 65 is inserted into the heating roller 64 of tubular, not It is defined in this.As long as being configured to heating roller 64 to be heated by heater 65, such as the heater using plate can also be used Heat the structure etc. of the outer surface of the heating roller of solid shape.

Also, though heating roller 64 is heated by heater 65, and but not limited to this.For example, it is also possible to be configured to supporting part Part 66 is heated by the heaters, and heating roller 64 is not heated by the heaters.Using the structure, it can be configured to be fixed Both sides with the inside configuration bearing part 66 of 61 band around the path and the heater for heating the bearing part 66.

(5) in the above-described embodiment, though the peripheral surface 64a of not specifically mentioned cleaning heating roller 64, such as be easy The part for generating the toner particle when recording sheet S is by fusing nip 69 on recording sheet S is used as so-called offset Toner (Offset toner) is transferred to the surface of fixing belt 61, is further shifted from fixing belt 61 and is attached to heating roller 64 Peripheral surface 64a this problem structure in, can use to be arranged from the peripheral surface 64a of heating roller 64 and remove the offset toner Descaler structure.

This is because：The offset toner of the peripheral surface 64a of heating roller 64 is attached to due to the rotation of heating roller 64 again The surface of fixing belt 61 is returned to from heating roller 64, and when reaching fusing nip 69, is transferred at the moment and is passed through fusing nip Recording sheet S during 69, to generate the misgivings for polluting recording sheet S.

As descaler, such as the scraper 64b described in Fig. 9 can be formed as.Can use makes the front end of scraper 64b support It is connected to the structure of the peripheral surface 64a of heating roller 64.Scraper 64b is long size along the axial direction of heating roller 64, such as by silicon rubber structure At, and be configured to be contacted throughout its axial direction with the peripheral surface 64a of heating roller 64.It wipes off to be attached to using scraper 64b and add The attachments such as offset toner, the dust of peripheral surface 64a of hot-rolling 64 clean the peripheral surface 64a of heating roller 64.

In addition, applying release layer by the peripheral surface 64a to heating roller 64, such as apply the structure of the fluorine coating of PTFE, It is also possible to prevent attachment and is attached to possible trouble to the peripheral surface 64a of heating roller 64.

(6) in the above-described embodiment, to across fixing belt 61 and in the inside configuration of band around the path as pressurized The fixing roller 62 or fixing pad 162 of component, and configure the pressure roller 63 as pressing member in the outside of band around the path Configuration example be illustrated, but as long as fusing nip 69 can be formed, be just not limited to this.For example, being in pressurized component In the case of fixing roller 62, the structure that pressing member is formed as into pressure pad and replaces pressure roller 63 can be used.In the situation Under, fixing roller 62 becomes driving side.In addition, in the above embodiment 1, it can also use and driving side is formed as into fixing roller 62 And replace the structure of pressure roller 63.Either one or two of fixing roller 62 and pressure roller 63 become driven roller.

(7) in the above-described embodiment, to the image forming apparatus of the present invention is applied to tandem type color printer The example of situation is illustrated, and but not limited to this.It can be applied to the fixing device with fixing belt and have this The image forming apparatus of fixing device.As image forming apparatus, the printing for being able to carry out coloured image formation can be applied to Machine or the printer for being only able to carry out monochrome image formation, and are not limited to printer, for example, can be applied to duplicator, Picture unit, MFP (all-in-one multifunctional machines：Multiple Function Peripheral) etc. image forming apparatuses.

Though in addition, control unit 7 is mutually separately constructed with fixing section 6, in mobile etc. the control for executing heating roller 64 Structure in, control unit 7 and fixing section 6 can be extracted and constitute fixing device.

Also, each numerical value of the material of each component, above-mentioned temperature, the size of component, electric power etc. is an example, can be with Suitable material, temperature, size etc. are predetermined according to apparatus structure.

Alternatively, it is also possible to which the content of the above embodiment and above-mentioned variation is combined as much as possible each other.It can also Can obtain the present invention effect in the range of, by the mechanism in each portion such as fixing section, each component be replaced by other mechanisms, other The component of shape is applied.

Industrial utilization feasibility

The present invention can be widely applied for the fixing device with fixing belt.

Claims (22)

1. a kind of fixing device will be configured at the pressing member on the outside of the circular path of cricoid fixing belt across the fixing belt court To the pressurized component pressing being configured on the inside of the circular path of the fixing belt, make the pressing member and the fixing belt surface It contacts and forms fusing nip, and so that recording sheet is passed through the fusing nip to be fixed the unfixed figure on the recording sheet Picture,

The fixing device is characterized in that having：

Outer roller is configured on the outside of the circular path of the fixing belt；

Bearing part is configured on the inside of the circular path of the fixing belt, the fixing belt is made to be connected to the outer roller；With And

Heater heats the outer roller or the bearing part,

The fixing device becomes edge with the band part clipped by the outer roller and the bearing part in the fixing belt The mode for the curved shape of the peripheral surface of the outer roller determines the face contacted with the band part in the bearing part Shape.

2. fixing device according to claim 1, which is characterized in that

The face contacted with the band part in the bearing part is the curved shape along the peripheral surface of the outer roller.

3. fixing device according to claim 1 or 2, which is characterized in that

The outer roller is configured at and the pressing member opposite side across the fixing belt.

4. the fixing device according to any one of claims 1 to 3, which is characterized in that

The pressing member is pressure roller, and the pressurized component is the fixing pad of pulvilliform shape.

5. fixing device according to claim 4, which is characterized in that

Have the support member for supporting the pressurized component,

The bearing part is long size along the rotary shaft of the outer roller,

The support member is long size along the rotary shaft of the outer roller, and with the face in side opposed with the fixing pad The base plate of the fixing pad and short side direction both ends from the base plate are fixed to the bearing part side bending First, second side plate,

The front end of first side plate and the interval of the short side direction of the front end of second side plate are more than the supporting part The diameter of the width of part or the outer roller.

6. the fixing device according to any one of Claims 1 to 5, which is characterized in that

The perimeter of the outer roller is longer than the perimeter of the fixing belt.

7. the fixing device according to any one of claim 1~6, which is characterized in that

The bearing part is long size along the rotary shaft of the outer roller,

It is being configured to when the position in the sheet material carry direction center for the rotary shaft and the fusing nip for linking the outer roller Imaginary line on when the position present in the width direction central portion in the bearing part is set as reference position, the bearing Width direction central portion in component is present in from the reference position centered on the rotary shaft of the outer roller to the outside of this In the case of the position that the direction of rotation upstream side of roller is deviateed,

The end of the direction of rotation upstream side of the face contacted with the band part in the bearing part, described outer roller Corner is formed as R shapes.

8. the fixing device according to any one of claim 1~6, which is characterized in that

The bearing part is long size along the rotary shaft of the outer roller,

It is being configured to when the position in the sheet material carry direction center for the rotary shaft and the fusing nip for linking the outer roller Imaginary line on when the position present in the width direction central portion in the bearing part is set as reference position, the bearing Width direction central portion in component is present in from the reference position centered on the rotary shaft of the outer roller to the outside of this In the case of the position that the direction of rotation downstream side of roller is deviateed,

The end in the direction of rotation downstream side of the face contacted with the band part in the bearing part, described outer roller Corner is formed as R shapes.

9. the fixing device according to any one of claim 1~8, which is characterized in that

At least one party of the pressurized component and the pressing member is roller,

The fixing device has：

Any of described roller is carried out rotation driving by the first driving unit as driven roller；

Second driving unit, rotation drive the outer roller；

Detection unit, to the first part contacted with the pressing member in the fusing nip in the fixing belt The difference of the peripheral speed of second part folded by peripheral speed and the outer roller and the bearing part is detected；And

Control unit controls first driving unit and second driving unit,

Described control unit executes：

First control, the tune in such a way that the peripheral speed of the driven roller is stablized in the fixing speed for being equivalent to recording sheet transporting velocity The rotary speed of the whole driven roller；With

Second control, according to the testing result of the detection unit, the outside is adjusted in a manner of eliminating the difference of the peripheral speed The rotary speed of roller.

10. the fixing device according to any one of claim 1~9, which is characterized in that

By on the peripheral surface of the outer roller and the position of the direction of rotation most upstream in region that the fixing belt contacts When tangent line is set as imaginary tangent line,

Relative to the imaginary tangent line when fixing belt is between the peripheral surface and the bearing part of the outer roller Entry angle γ is 90 ° or less.

11. the fixing device according to any one of claim 1~10, which is characterized in that

It is also equipped with 1 group or more of the group being made of the outer roller, the bearing part and the heater,

In 2 or more groups, the axial direction of the outer roller in the axial heating region and second group of the outer roller in first group Heating region it is different.

12. the fixing device according to any one of claim 1~11, which is characterized in that

The heater heats the outer roller,

The pyroconductivity of the bearing part is less than the pyroconductivity of the fixing belt.

13. the fixing device according to any one of claim 1~12, which is characterized in that

The heater heats the outer roller,

The face contacted with the band part in the bearing part is mesh configuration.

14. the fixing device according to any one of claim 1~13, which is characterized in that have：

First movement unit, enable the outer roller across the fixing belt and to close to the bearing part direction and It moves in direction far from the bearing part；With

First movement control unit controls the first movement unit so that in the circular traveling process of the fixing belt, The outer roller is set to be moved to close to the direction of the bearing part, to make the fixing belt crimp using the bearing part In the outer roller, in the stopped process of the fixing belt, the outer roller is made to be moved to the direction far from the bearing part It is dynamic, to make the crimping release.

15. the fixing device according to any one of claim 1~13, which is characterized in that have：

First movement unit enables the outer roller and the bearing part to relatively close direction and is relatively distant from It moves in direction；With

First movement control unit controls the first movement unit,

The fixing belt can with First Speed around the first fixing pattern advanced with slower than the First Speed the Two speed rings switch between the second fixing pattern of traveling,

The first movement control unit is fixed pattern phase when executing the second fixing pattern, with executing described first Than, so that the bearing part and the outer roller is moved to the direction being relatively distant from, to reduce the outer roller with it is described fixed The contact area of shadow bands.

16. the fixing device according to any one of claim 1~15, which is characterized in that have：

Second mobile unit enables the pressurized component to be leaned on to opposite across the fixing belt with the pressing member Close direction and the direction movement being relatively distant from；With

Second mobile control unit controls second mobile unit so that in the circular traveling process of the fixing belt, The pressurized component and the pressing member is set to be moved to relatively close direction, to described add across the fixing belt Splenium part presses on the pressurized component and forms the fusing nip, in the stopped process of the fixing belt, makes described Pressurized component is moved with the pressing member to the direction being relatively distant from, to make the pressing release.

17. the fixing device according to any one of claim 1~16, which is characterized in that

There is the bearing part substrate and low friction plate, the low friction plate to divide it with the band portion for being located in the substrate Between reduce the friction with the band part.

18. the fixing device according to any one of claim 1~16, which is characterized in that

The face coating lubricant contacted with the band part in inner surface and the bearing part to the fixing belt.

19. the fixing device according to any one of claim 1~16, which is characterized in that

In the inner surface of the fixing belt, it is provided with the low friction layer for reducing the friction with the bearing part.

20. the fixing device according to any one of claim 1~19, which is characterized in that

Has cleaning member, which contacts with the surface of the outer roller, removes the surface for being attached to the outer roller Foreign matter.

21. the fixing device according to any one of claim 1~20, which is characterized in that

The surface of the outer roller is provided with release layer.

22. a kind of image forming apparatus is that have to make to be formed in determining for the fixing of the unfixed image on carried recording sheet The image forming apparatus in shadow portion, which is characterized in that

As the fixing section, has the fixing device described in any one of claim 1~21.