JP2823738B2 - Electrophotographic fixing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises first to third fixing rollers, and fixes to the pressure contact portions of the first and second fixing rollers and the pressure contact portions of the second and third fixing rollers, respectively. The present invention relates to a fixing device of an electrophotographic apparatus in which a portion is formed.

[0002]

2. Description of the Related Art In a full-color copy in a full-color copying machine, an exposure operation on a photosensitive member for forming an electrostatic latent image corresponding to a document image and a developing operation on the electrostatic latent image with toner are performed in yellow and magenta. And cyan toner images are formed, and these toner images are transferred onto a sheet in a superimposed state. Then, the full-color image is obtained by heating and melting the three-layer toner image on the sheet between two heat rollers, which are fixing rollers of the fixing device, to fix the toner image on the sheet.

As described above, in full-color copying, it is necessary to fix a three-layer color toner image on a sheet between two heat rollers without causing separation between the color toner images. Therefore, the color toners of the above-described colors used for full-color copying have different physical properties from the black toner used for black-and-white copying, and generally have low releasability. In full-color copying, a sufficient amount of heat must be supplied from the heat roller in order to melt and mix the three layers of toner images in the fixing operation described above. For this reason, as the heat roller, a material having high releasability from the toner and a flexible material is used so that the fixing portion width formed between the heat rollers, that is, the nip width can be widened. There is a need to.

Therefore, in a copying machine capable of full-color copying and black-and-white copying, in order to completely satisfy the above-mentioned requirements in the fixing device, the heat roller becomes expensive and the life of the heat roller becomes long. The running cost is high since the running cost is short.
For this reason, in order to reduce the cost, it is necessary to compromise the performance of the fixing device to some extent.

In order to solve such a problem, it is conceivable to provide separate fixing devices for full-color copying and black-and-white copying. In such a scheme,
Optimal fixing operation can be performed in full-color copy and black-and-white copy, and copy cost in black-and-white copy can be reduced. However, if two independent fixing devices are provided, the mechanism becomes complicated, and the size of the device becomes large. This makes it difficult to adopt such a configuration.

On the other hand, Japanese Patent Application Laid-Open No. 51-98036 discloses three heat rollers, upper, middle and lower, in which a first fixing portion is formed between the upper and middle heat rollers, and a middle and lower heat roller is formed. A fixing device that forms a second fixing portion between heat rollers is disclosed. Therefore, using this structure, for example, the first fixing unit may be a fixing unit for full-color copying, and the second fixing unit may be a fixing unit for monochrome copying.

In this case, as shown in FIG. 16, the upper heat roller 501 is made of soft rubber, and the surface material is made to have a very good releasability. Oil is further applied to the upper heat roller 501 from the oil application roller 504 to further enhance the releasability. The middle heat roller 502 is formed of a hard material having good releasability from the black toner. Therefore, no oil needs to be applied, and the life is extended. The lower heat roller 503 is formed of a suitable durable material. In addition, the middle and lower heat rollers 5
02 and 503 are provided with peeling claws 505 and 505 for peeling the paper.

As described above, the three heat rollers 501
503, the optimal heat roller 50 for full-color copy and black-and-white copy
The best fixing operation can be performed by 1 to 503.
Also, as compared with the case where separate fixing devices for full-color copying and black-and-white copying are provided, it is easier to design the paper transport mechanism and the like, simplifying the structure, reducing costs and reducing the size of the device. Can be planned.

Further, as described above, in the case of a structure having three heat rollers 501 to 503, for example, the middle heat roller 502 is a driving roller, and the upper and lower heat rollers are driven rollers. . For manual paper jam processing around the upper fixing unit and the lower fixing unit, a manual rotation operation unit 509 is provided via a gear 506 provided on the middle heat roller 502 via an idle gear 507. Gear 508 is connected. Accordingly, when a paper jam occurs in the upper fixing unit or the lower fixing unit, the connection between the middle heat roller 502 and its driving mechanism is cut off, and the manual rotation operation unit 509 is rotated to execute the paper jam processing. It can be carried out.

[0010]

However, in the above structure, when the paper jam occurs in the upper fixing unit and when the paper jam occurs in the lower fixing unit, the jammed paper is discharged in the same direction. Is rotated in the opposite direction. For this reason, depending on whether the fixing unit used is the upper fixing unit side or the lower fixing unit side, the operator operates the manual rotation operation unit 5.
09 must be determined, and the operation of the manual rotation operation unit 509 is complicated. Further, the operator tends to make a mistake in the rotation direction of the manual rotation operation unit 509, and if the paper is discharged in the wrong direction, any one of the heat rollers 50
The paper is wound around 1 to 503 or the peeling claw 5
There is a problem in that the sheet is caught between the heat transfer rollers 05 and 505 and the heat rollers 502 and 503 and the leading ends of the peeling claws 505 and 505 are damaged.

[0011]

According to a first aspect of the present invention, there is provided a fixing device for an electrophotographic apparatus, wherein the first to third rotating fixing rollers are driven to solve the above-mentioned problems. , Middle and lower heat rollers, a first fixing portion is formed at a pressure contact portion between the first fixing roller and the second fixing roller,
A second fixing unit is formed at a pressure contact portion between the second fixing roller and the third fixing roller, and each of the first and second fixing units includes:
In a fixing device of an electrophotographic apparatus for fixing an image of a developer on a sheet to a sheet, the second fixing roller includes the first fixing unit.
A first fixing roller provided between the first fixing roller and the third fixing roller;
One of the third fixing roller is pressed against the second fixing roller.
So that they can move away from each other.
On the other hand, a manual rotation operation unit rotated by a manual operation and a paper discharge direction from the first fixing unit and the second fixing unit with respect to rotation of the manual rotation operation unit in a predetermined direction are in the same direction. The rotation of the manual rotation operation unit is transmitted to the first fixing roller and the third fixing roller, and
It is characterized by comprising a rotation transmitting means for Ru and over La is reversely rotating to each other.

According to a second aspect of the present invention, there is provided a fixing device for an electrophotographic apparatus, wherein the first device is rotatably driven to solve the above-mentioned problem.
A third fixing roller, a first fixing portion is formed at a pressure contact portion between the first fixing roller and the second fixing roller,
A second fixing unit is formed at a pressure contact portion between the second fixing roller and the third fixing roller, and each of the first and second fixing units includes:
In a fixing device of an electrophotographic apparatus for fixing an image of a developer on a sheet to a sheet, a manual rotation operation section for rotating by manual operation and one fixing roller for rotating the manual rotation operation section to form a first fixing section And a rotation transmitting means for transmitting to one of the fixing rollers forming the second fixing section, a rotation direction instructing means for instructing a rotation direction of the manual rotation operation section, and a rotation direction generated near the first and second fixing sections. The paper jam detecting means for detecting the paper jam and its position, and the direction indicated by the rotation direction indicating means are used in the detection result by the paper jam detecting means and among the first fixing unit and the second fixing unit. And a control unit for controlling the operation of the rotation direction instruction unit so that the rotation direction is the rotation direction of the manual rotation operation unit for discharging the sheet in the direction corresponding to the fixing unit.

[0013]

According to the first aspect of the present invention, when a paper jam occurs in the first fixing section between the first fixing roller and the second fixing roller, and between the second fixing roller and the third fixing roller. In any of the cases where the paper jam occurs in the second fixing unit, the paper can be discharged in the same direction with respect to the rotation of the manual rotation operation unit in the predetermined direction. Therefore, when operating the manual rotation operation unit for paper jam processing, the operator performs the manual rotation operation without considering whether the used fixing unit is the first fixing unit or the second fixing unit. The part can be rotated and the operation is facilitated.

According to the configuration of the second aspect, the first or the second
When a paper jam occurs in the vicinity of the fixing unit, occurrence of a paper jam at a position where the paper jam occurs, for example, a paper entry side position with respect to the first or second fixing unit, occurrence of a paper jam at a paper ejection side position,
The rotation direction of the manual rotation operation unit for discharging the jammed paper in an appropriate direction according to the used fixing unit of the first fixing unit and the second fixing unit is changed by the rotation direction instruction unit. Be instructed. Therefore, when a paper jam occurs, the operator does not need to determine the rotation direction of the manual rotation operation unit based on the position where the paper jam has occurred and the fixing unit used, and the manual rotation for the paper jam processing is not required. The operation of the operation unit is easy.

[0015]

【Example】

Embodiment 1 An embodiment of the present invention will be described below with reference to FIGS. A full-color copying machine as an electrophotographic apparatus in the present embodiment (hereinafter simply referred to as a copying machine)
As shown in FIG. 3, a document table 3 made of hard transparent glass is provided on the upper surface, and an exposure optical system 4 is provided below the document table 3. The exposure optical system section 4 includes a lamp unit 5 that scans a document (not shown) placed on the document table 3 while irradiating the document with light, and a plurality of light guides that guide reflected light from the document to the photoconductor 8. And a lens unit 7 arranged in the optical path of the reflected light.

A charging charger 9 for charging the surface of the photoconductor 8 to a predetermined potential is provided on the outer periphery of the photoconductor 8, and an inter-image eraser (from the charging charger 9 in the rotation direction of the photoconductor 8) is provided. (Not shown), black developing tank 1
0, yellow developing tank 11, magenta developing tank 12, cyan developing tank 13, intermediate transfer device 14, cleaning device 15
And the static eliminator 16 are arranged in this order.

The above-mentioned intermediate transfer device 14 is used to transfer the transfer belt 1
7, rollers 18 and 19 for supporting the transfer belt 17
20, the transfer belt 17 is brought into pressure contact with the photoconductor 8,
A first transfer roller 21 for transferring the toner image formed on the surface to the transfer belt 17 is pressed against the roller 20 via the transfer belt 17 when the toner image is transferred to the sheet, and the toner image on the surface of the transfer belt 17 is transferred onto the sheet. And a cleaning device 23 for removing residual toner on the surface of the transfer belt 17.

A registration roller 24, a paper feed cassette 25, and a paper feed tray 26 for supplying paper to the intermediate transfer device 14 at a predetermined timing are provided on the paper feed side of the intermediate transfer device 14. In the vicinity of the paper feed tray 25 and the paper feed tray 26, paper feed rollers 27, a transport roller 28 and the like are provided. Intermediate transfer device 14
A suction unit 100 that conveys a sheet, a fixing device 200, a sheet discharge roller 30, and a sheet discharge tray 31 are provided in the sheet output direction.

The suction unit 100 is provided with a conveyor belt (not shown), and the conveyor belt is driven by a belt drive motor (not shown) to make an orbital movement.
The sheet on which the unfixed toner image has been transferred is conveyed to the fixing device 200 while being attracted to the belt.
Further, the suction unit 100 is driven by, for example, a cam mechanism using the above-described belt drive motor as a drive source,
It is adapted to rotate to an upper position and a lower position. Note that the above upper position is a position where a sheet can be transported to an upper fixing unit of the fixing device 200 described below, and the lower position is
This is the position where the paper can be transported to the lower fixing unit.

As shown in FIG. 4, the suction unit 100 is provided with a paper detection switch 226 as paper jam detection means, and the upper paper guide 228 near the paper ejection roller 30 is similarly provided with paper jam detection means. A paper detection switch 227 is provided.

As shown in FIG. 4, the fixing device 200 includes an upper heat roller 201 as a first fixing roller, a middle heat roller 202 as a second fixing roller, and a lower heat roller 203 as a third fixing roller. Are provided in parallel in the vertical direction. In the present embodiment, the fixing at the time of full-color copying is performed by the upper fixing portion as the first fixing portion formed at the pressure contact portion between the upper heat roller 201 and the middle heat roller 202.
2 formed at the pressure contact portion between the second heat roller 203 and the lower heat roller 203.
The fixing at the time of black-and-white copying is performed by a lower fixing unit as a fixing unit. Therefore, for example, the upper heat roller 201 is provided with a 2 mm thick silicon rubber layer having high releasability around a cored bar, and the middle heat roller 202 is provided with a 20 μm thick Teflon around the cored bar. Coated, lower heat roller 203
Has a 4 mm-thick silicon rubber layer provided around a cored bar.

Each of the heat rollers 201 to 203 has a hollow shape, and a heater lamp 20 for heating is provided in the hollow portion.
4 are provided. Around the upper and lower heat rollers 201 to 203, a thermistor 205 for detecting the surface temperature thereof, a thermostat (not shown) for preventing overheating incorporated in a circuit of the heater lamp 204, and a surface of the heat rollers 201 to 203 A cleaning roller 206 for removing toner and the like adhered to the sheet is provided. Further, around the middle and lower heat rollers 202 and 203, peeling claws 207 for peeling the paper from the roller surface are provided.
Is provided. On the other hand, an oil application roller 208 and a release plate 229 are provided around the upper heat roller 201. The oil application roller 208 has a structure in which fibers are wound around a tank containing silicon oil, and the fibers are impregnated with the silicon oil through small holes formed in the tank. Then, by applying silicone oil to the surface of the upper heat roller 201 with the oil application roller 208, adhesion of the color toner to the roller surface,
That is, the offset is prevented to ensure the releasability of the color toner image, and that the full-color copy image is given gloss. The peeling plate 229 is located on the upper heat roller 2
01, and the roller 230 provided on the peeling plate 229 is in sliding contact with the upper heat roller 201 so that the leading end of the peeling plate 229 and the upper heat roller 201 A gap having a predetermined width is secured between them.

In order to form the upper fixing section and the lower fixing section, in the present embodiment, the position of the middle heat roller 202 is fixed, and the upper and lower heat rollers 201 and 20 are fixed.
A mechanism for moving the upper and lower heat rollers 201 and 203 toward and away from the middle heat roller 202 by vertically moving the roller 3 is adopted. This is because the middle heat roller 202 is driven and the upper and lower heat rollers 201 and 203 are driven in order to simplify the drive mechanism of the heat rollers 201 to 203 as described later. Next, this heat roller separation / contact mechanism will be described with reference to FIGS.

The middle heat roller 202 is rotatably held by a holding member (not shown) in a fixed position. A swing member 210 is rotatably connected to both ends of the middle heat roller 202 via bearings (not shown). Also, the upper and lower heat rollers 201 and 20
Numeral 3 is rotatably held by upper and lower holders 209 and 211 provided at both ends of each of the heat rollers 201 and 203 via bearings (not shown).
The swing member 210 and the upper and lower holders 209 and 21
1, the cleaning roller 206
Are rotatably mounted in a state of being constantly in contact with the corresponding heat rollers 201 to 203. Swing member 21
0 and the upper and lower holders 209 and 211 are respectively
The end on the paper output side is connected to the roller support base 21 by the connection shaft 212.
3 and the upper and lower holders 209 and 211 are swingable with respect to the roller support base 213. On the other hand, the roller support base 213 is supported to be vertically movable. Ends of the upper and lower holders 209 and 211 on the paper input side are pulled downward and upward by a tension spring 214, respectively. Further, engaging portions 209 are provided at ends of the upper and lower holders 209 and 211 on the paper input side.
a. 211a is formed, while the roller support base 213 is formed.
The engagement portion 213a engages with the engagement portion 209a and restricts the rotation of the upper holder 209 downward, and the engagement portion engages with the engagement portion 211a and rotates the lower holder 211 upward. Is formed.

The oil application roller 208 is a roller holder 2
15 is rotatably held at one end thereof. The roller holder 215 is pivotally connected to a roller support base 213 in the vicinity of the center by a connection shaft 215a. The other end of the roller holder 215 has a compression spring 216 and an eccentric cam 2.
17 are provided. The compression spring 216 urges the roller holder 215 to rotate in a direction to separate the oil application roller 208 from the upper heat roller 201. On the other hand, the eccentric cam 217 is driven and rotated by the oil application roller cam drive mechanism 292 shown in FIG.
5, the oil application roller 208 is brought into pressure contact with the upper heat roller 201.

An opening-like cam disposition portion 210a is formed at the end portion of the rocking member 210 on the paper input side.
An eccentric cam 219 formed on the camshaft 218 is disposed at 0a. The cam shaft 218 is supported by a support member (not shown) and rotates at a fixed position. The above-described eccentric cam 219 and the upper edge portion 210 of the cam disposition portion 210a
b, an interposing plate 220 is provided.
Reference numeral 0 denotes a paper output side end that is swingably connected to the roller support base 213 by a connection shaft 221. A screw 222 is screwed to an end portion of the interposing plate 220 on the paper input side through the upper edge portion 210b of the cam disposition portion 210a. This screw 222
Of the compression spring 22 between the head of the
Three are arranged. Accordingly, the rotation of the cam shaft 218, that is, the eccentric cam 219, causes the swinging member 210 to swing up and down around the middle heat roller 202, and the roller support base 213 moves up and down with this. Lower heat rollers 201 and 203 are middle heat rollers 20
2 to and away from it. In this case, the sliding contact between the eccentric cam 219 and the swing member 210 is determined by the screw 22
2 can be adjusted by rotating it.

The above and below heat rollers 201 and 2
03, the middle heat roller 202 is driven, and the upper and lower heat rollers 201 and 203 are driven. The middle heat roller 202 is driven to rotate by a heat roller driving mechanism 250 shown in FIG. It is driven to rotate by a cam drive mechanism 293 shown in FIG.

In the above-described heat roller driving mechanism 250, as shown in FIG. 1, during black-and-white copying, the driving force is transmitted to the middle heat roller 202 in the counterclockwise direction by the heat roller driving motor 251 shown in FIG. Gear 252 to be rotated, gears 253 and 254, belt 255, black-and-white copy clutch 256, black-and-white copy clutch 256
Is performed through a gear 256a, gears 257 and 258, and a gear 259 provided on the middle heat roller 202, so that the middle heat roller 202 rotates clockwise. At this time, the clutch 26 for full color copying is used.
1 is OFF. Then, as shown in FIG. 5, the lower heat roller 203 pressed against the middle heat roller 202 rotates counterclockwise with the rotation of the middle heat roller 202. On the other hand, at the time of full-color copying, as shown in FIG. 2, transmission of the driving force to the middle heat roller 202 is performed by the gears 252 and 253, the belt 260, the full-color copying clutch 261, and the gear 261a provided on the full-color copying clutch 261. , Gear 257
258 and the gear 259, and the middle heat roller 202 rotates counterclockwise. At this time, the monochrome copying clutch 256 is off. Then, as shown in FIG.
The upper heat roller 201 pressed in contact with 2 rotates clockwise with the rotation of the middle heat roller 202.

Further, as shown in FIG. 1, the fixing device 200 comprises a knob 283 as a manual rotation operation unit and a rotation transmission mechanism 280 as rotation transmission means. To 203 are provided. The rotation transmission mechanism 280 includes a gear 281 provided on the upper heat roller 201,
81, a gear pulley 282 on which a belt 287 is hung, a lower heat roller 203
Pulley 284, belt guide roller 285
To transmit the rotation of the pulley 286 and the geared pulley 282 to the pulley 284, that is, the lower heat roller 203,
Belt 2 hung between pulley 282 with gear and pulley 284 via belt guide rollers 285 and 286
87. The knob 283 is connected to the geared pulley 282, and the geared pulley 28
2 is rotated manually. Therefore, as shown in FIG. 1, the lower heat roller 203 is pressed against the middle heat roller 202 to form a lower fixing portion during black-and-white copying, and as shown in FIG. In both cases of full color copying in which the upper fixing portion is formed by pressing the upper portion 201, the paper jammed in the upper or lower fixing portion and the knob 28
When the knob 3 is rotated in the counterclockwise direction, the sheet is discharged in the direction of the paper discharge roller 30, and when the knob 283 is rotated in the clockwise direction, the sheet is discharged in the direction of the suction unit 100.

Further, as shown in FIG. 7, the fixing device 200 includes a control device 29 comprising a microcomputer, for example.
1 is provided. The control device 291 is provided with the above-described paper detection switches 226 and 22 which are turned on when the paper passes.
7, a door switch 295, and a heat roller drive motor 251, a black-and-white copy clutch 256, a full-color copy clutch 261 and a cam drive mechanism 29, as described later, based on inputs from various input keys and the like.
3. Paper jam display unit 294 provided on the display panel, oil application roller cam drive mechanism 292, and heater lamp 2
04 and the like are controlled.

The above-mentioned door switch 295 is for detecting the opening / closing of a door provided in a cabinet of a copying machine which is opened at the time of paper jam, and the control device 291 controls the door switch 295 when the door is opened. When turned off,
Black and white copy clutch 2 of heat roller drive mechanism 250
56 and full color copy clutch 261 are turned off.
To interrupt the transmission of drive, and then the door switch 2
When 95 is turned on, both clutches 256 and 261 are returned to the original state. Also, the control device 2
Reference numeral 91 denotes a sheet detection switch 226 and a sheet detection switch 2
27, the paper passage time during this time is monitored, and each paper detection switch 226/22 is monitored.
7 is monitored, and the paper detection switch 226 is monitored.
-When the passage time of the sheet between the sheets 227 exceeds a predetermined time or when the ON time of the sheet detection switches 226 and 227 exceeds the predetermined time, it is determined that the sheet is jammed, and the paper jam has occurred. And the position thereof is indicated by a paper jam display section 294.
Is displayed.

In the above configuration, first, a full-color copying operation in the copying machine will be described. When the full color copy is selected, the suction unit 100
Is arranged in an upper position. Also, as shown in FIG. 6, the eccentric cam 219 is disposed so that the maximum eccentric portion faces upward, whereby the swinging member 210 rotates counterclockwise around the middle heat roller 202, and the roller support base is rotated. 213
Move downward, and the upper heat roller 201 is pressed against the middle heat roller 202. The oil application roller 208 is pressed against the upper heat roller 201 by the eccentric cam 217. In the heat roller driving mechanism 250 shown in FIG. 2, the full color copy clutch 261 is turned on, while the black and white copy clutch 256 is turned off. Therefore, the middle heat roller 202 rotates counterclockwise, and the upper heat roller 201 rotates clockwise.

In the above state, as shown in FIG.
The surface of the photoconductor 8 rotating in the B direction is uniformly charged by the charging charger 9, and the first scanning of the document on the document table 3 is performed by the exposure optical system unit 4. Light reflected from the original is exposed to the surface of the photoconductor 8 between the charging charger 9 and the inter-image eraser (not shown) via a blue color separation filter (not shown) and a slit (not shown). The point is irradiated to expose the photoreceptor 8 to form an electrostatic latent image. Next, the potential of the non-image area on the photoreceptor 8 is removed by the inter-image eraser. Thereafter, the electrostatic latent image is developed by the yellow developing tank 11 to form a yellow toner image.

Next, the yellow toner image on the surface of the photoreceptor 8 is transferred to the transfer belt 17 circulating in the direction C by the first transfer roller 21 to which a negative high voltage is applied. The residual toner on the surface of the photoconductor 8 is removed by the cleaning device 15, and the residual potential on the surface of the photoconductor 8 is removed by the charge removing device 16.

When the above-described series of operations is completed, the photosensitive member 8 is charged again by the charging charger 9, and the original is scanned by the exposure optical system 4 for the second time. In this case, a green color separation filter is used, and the electrostatic latent image formed on the photoconductor 8 is developed with magenta toner in the magenta developing tank 12. The magenta toner image formed on the surface of the photoconductor 8 is transferred by the first transfer roller 21 so as to be superimposed on the previous yellow toner image on the transfer belt 17. Thereafter, similarly, the third scanning by the exposure optical system unit 4 using the red color separation filter is performed, and the cyan toner image is developed on the photoconductor 8 by the development with the cyan toner in the cyan developing tank 13. It is formed. This cyan toner image is transferred onto the magenta toner image on the transfer belt 17.

Next, the second transfer roller 22, which has been separated from the transfer belt 17 in the operation so far, is
7, and a negative voltage higher than the surface potential of the transfer belt 17 is applied to the second transfer roller 22, so that the second transfer roller 22 is conveyed from the sheet cassette 25 or the sheet tray 26 via the registration roller 24. The three-layer toner image on the transfer belt 17 is transferred to the paper.

The sheet on which the toner image has been transferred is conveyed to the fixing device 200 by the suction unit 100. At this time, since the suction unit 100 is held at the upper position, the sheet is conveyed to the upper fixing section between the upper and middle heat rollers 201 and 202. In the upper fixing section, the three-layer color toner image on the paper is heated and melted by the upper and middle heat rollers 201 and 202, and is fixed on the paper. At this time, the upper heat roller 2
Since 01 is supplied with silicone oil from the oil application roller 208, offset of the toner image to the upper heat roller 201 is prevented, and gloss is given to the full-color toner image on the paper.

The sheet discharged from the fixing device 200 is discharged onto a discharge tray 31 by a discharge roller 30.

After the copying operation is completed, the copying machine enters a standby state, and the lower heat roller 203 is pressed against the middle heat roller 202. This is because it is possible to promptly start a frequently used black-and-white copy, and to extend the life of the heat roller by pressing the heat roller in a combination with a small permanent distortion due to the pressure contact.

Next, the black-and-white copying operation of the copying machine will be described. When the monochrome copy is selected, the suction unit 100 is arranged at the lower position. FIG.
As shown in FIG. 7, the eccentric cam 219 is arranged so that the maximum eccentric portion faces downward, whereby the swinging member 210 rotates clockwise around the middle heat roller 202, and the roller support base 213 moves upward. And lower heat roller 20
3 is pressed against the middle heat roller 202. Further, the eccentric cam 217 rotates 180 ° from the state shown in FIG.
The urging force of 16 causes the oil application roller 208 to separate from the upper heat roller 201. In the heat roller driving mechanism 250 shown in FIG.
56 turns ON, while clutch 2 for full-color copying
61 turns OFF. Therefore, while the middle heat roller 202 rotates clockwise, the lower heat roller 20
3 rotates counterclockwise.

In the above state, the photosensitive member 8 shown in FIG.
Is uniformly charged by the charging charger 9, and the exposure optical system 4 scans the original on the original placing table 3. The reflected light from the document is guided to the exposure optical system 4 and irradiated on the photoconductor 8 without passing through the color separation filter and the slit, and an electrostatic latent image is formed on the photoconductor 8. Thereafter, the above-described electrostatic latent image is developed by the black developing tank 10, and the black toner image thus formed is transferred to the transfer belt 17 and further transferred to paper.

The above-described paper on which the toner image has been transferred is supplied to the middle and lower heat rollers 2 by the suction unit 100.
The toner image is conveyed to the lower fixing section between 02 and 203 and the toner image is fixed on the sheet. The sheet discharged from the fixing device 200 is discharged onto a discharge tray 31 by a discharge roller 30.

If a paper jam is detected by the paper detection switches 226 and 227 during full-color copying or black-and-white copying, the control device 291 turns off the heater lamp 204 and the heat roller driving motor 2
At the same time as the control such as the stop of 51 is performed, the state is displayed on the paper jam display section 294. When the operator opens the cabinet door for paper jam processing, the monochrome copying clutch 256 and the full-color copying clutch 261 are turned off. Thereafter, when the operator rotates the knob 283 by manual operation, the paper jammed in the upper fixing unit or the lower fixing unit is discharged to the suction unit 100 side or the discharge roller 30 side depending on the rotation direction. That is, when the knob 283 is rotated clockwise, the paper is discharged to the suction unit 100 side, and when the knob 283 is rotated counterclockwise, the paper is discharged to the paper discharge roller 30 side. In this case, since the paper discharge direction when the knob 283 is rotated in one direction is the same between the black-and-white copy and the full-color copy, the operator needs to consider only the paper discharge direction when turning the knob 283. It is not necessary to determine the rotation direction of the knob 283 in consideration of black-and-white copying or full-color copying, and the operation of the knob 283 for paper jam processing is not necessary. Easy.

[Embodiment 2] Another embodiment of the present invention will be described below with reference to FIGS. For the sake of convenience, members having the same functions as those shown in the drawings of the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 8, the fixing device 3 of this embodiment
00 indicates that the middle heat roller 202 is
And a heat roller separation / contact mechanism that performs a separation / contact operation with respect to the lower heat roller 203. In the figure, an upper heat roller 201 as a first fixing roller is provided on a roller support base 301, a middle heat roller 202 as a second fixing roller is provided on a middle holder 302, and a lower heat roller as a third fixing roller. 203 is provided on the lower holder 303. Upper heat roller 201
Is attached to a roller support base 301 provided in a fixed state, and a thermistor 205, a cleaning roller 206, and an oil application roller 20 supported by the roller support base 301 are provided therearound. On the other hand, around the middle and lower heat rollers 202 and 203, a thermistor 205, a cleaning roller 206, and a peeling claw 207 are provided, supported by the middle and lower holders 302 and 303, respectively.

Each of the middle and lower holders 302 and 303 has an end on the paper output side swingably connected to the roller support base 301 by a connection shaft 304, and an end on the paper input side by tension springs 305 and 306. Both are pulled upward. The rotation of the lower holder 302 in the counterclockwise direction about the connection shaft 304 due to this is regulated by the engagement portion 303a engaging with the engagement portion 301a of the roller support base 301.

An eccentric cam 219 provided on a cam shaft 218 is arranged at the upper edge of the middle holder 302 at the paper input side end. Then, as shown in FIG.
9 is disposed with the maximum eccentric portion facing downward, the eccentric cam 219 drives the middle holder 302 downward,
The middle heat roller 202 is pressed against the lower heat roller 203 to form a lower fixing portion for monochrome copying. On the other hand, FIG.
When the eccentric cam 219 is disposed with the maximum eccentric portion facing upward, the middle holder 302 is driven upward by the tension spring 305, and the middle heat roller 202 is pressed against the upper heat roller 201 to perform full-color copying. An upper fixing portion is formed.

Further, the upper or lower heat rollers 201-2
As for the rotation of 03, as in the fixing device 200 shown in the first embodiment, the middle heat roller 202 is driven, and the upper and lower heat rollers 201 and 203 are driven. Then, the middle heat roller 202 is driven by the heat roller driving mechanism 250 shown in FIG.

As shown in FIG. 10, the fixing device 300 includes a knob 315 as a manual rotation operation unit and a rotation transmission mechanism 310 as rotation transmission means. The rotation transmission mechanism 310 is provided at one end of the middle heat roller 202, an idle gear 312 meshing with the gear 311, a knob shaft 313, and one end of the knob shaft 313 and meshes with the idle gear 312. A gear 314 is provided. The idle gear 312 and the knob shaft 313 are rotatably attached to the middle holder 302. The knob 315 is provided at the other end of the knob shaft 313, and rotates the knob shaft 313. Therefore, by manually rotating the knob 315, the middle heat roller 202 can be rotated clockwise and counterclockwise.

A display plate 316 supported by the middle holder 302 is provided in the vicinity of the knob 315. The display plate 316 is made of, for example, a light emitting diode, and is used to indicate the rotation direction of the knob 315. Rotation direction display units 317 and 318 as rotation direction instruction means are provided.
The rotation direction display section 317 has a knob 315 in a counterclockwise direction.
, And the rotation direction display section 318 instructs the rotation of the knob 315 in the clockwise direction. The lighting operation of these rotation direction display sections 317 and 318 is controlled by the control device 321 described below.

The fixing device 300 includes a control device 321 as control means shown in FIG.
Reference numeral 21 denotes the paper detection switches 226 and 22 shown in FIG.
7, a door switch 295, and a heat roller drive motor 251, a black-and-white copy clutch 256, a full-color copy clutch 261 and a cam drive mechanism 29, as described later, based on inputs from various input keys and the like.
3. The operation of the paper jam display unit 294, the heater lamp 204, the rotation direction display units 317 and 318, and the like is controlled.

The controller 321 controls the paper jam display unit 2
In the control of the sheet detection unit 94, the ON / OFF of the sheet detection switch 226 and the sheet detection switch 227 monitors the passage time of the sheet during this period, and also monitors the ON time of each of the sheet detection switches 226 and 227. When the passage time of the sheet between the switches 226 and 227 exceeds a predetermined time,
If the ON time of 227 exceeds a predetermined time, it is determined that a paper jam has occurred, and the occurrence and location of the paper jam are displayed on the paper jam display unit 294. In the control of the rotation direction display units 317 and 318, the control unit 321 determines whether a black-and-white copy or a full-color copy is being performed and whether the position of the paper jammed in the upper or lower fixing unit is a suction relative to the fixing unit. An appropriate rotation direction of the knob 315 for discharging the jammed paper is indicated by the rotation direction display unit 3 depending on whether the unit 100 is on the paper discharge roller 30 side.
Instructions are provided at 17.318. Other configurations are the same as those of the fixing device 200 shown in the first embodiment.

In the above-described configuration, when the paper P is jammed at the initial stage of entering the upper fixing section during full-color copying, as shown in FIG. 12, the paper detection switch 226 is kept ON while the paper detection switch is maintained. Reference numeral 227 maintains the OFF state. Thereby, the control device 321 detects a paper jam on the suction unit 100 side in the upper fixing unit. In this case, the sheet P is on the suction unit 100 side, and may be wrapped around the upper heat roller 201 when discharged on the discharge roller 30 side. Therefore, it is safer to discharge on the suction unit 100 side. Then, the sheet P can be discharged to the suction unit 100 side by rotating the knob 315 in the clockwise direction. Therefore, the control device 321 displays the rotation direction display unit 318 for instructing the rotation of the knob 315 in the clockwise direction. Turn on. Therefore, when the operator opens the cabinet door and the black-and-white copy clutch 256 and the full-color copy clutch 261 are turned off, the rotation direction display section 318 is displayed.
When the knob 315 is rotated clockwise in accordance with the instruction, the sheet P is discharged from the upper fixing unit to the suction unit 100 side.

Further, as shown in FIG. 13, during full color copying, if the paper P is jammed in the late stage of entering the upper fixing unit, the paper detection switch 226 is OFF and the paper detection switch 227 is kept ON. I do. As a result, the control device 321 detects a paper jam on the discharge roller 30 side in the upper fixing unit. In this case, the paper P is
It is better to discharge the paper to the paper discharge roller 30 side. Then, the sheet P can be discharged to the sheet discharge roller 30 by rotating the knob 315 in the counterclockwise direction, so that the control device 321 controls the knob 31 in the counterclockwise direction.
The rotation direction display unit 317 for instructing the rotation of No. 5 is turned on. Therefore, when the operator rotates the knob 315 in the counterclockwise direction according to the instruction of the rotation direction display unit 317, the paper P is discharged from the upper fixing unit to the paper discharge roller 30 side.

On the other hand, when the paper P is jammed at the initial stage of the paper entering the lower fixing section during black-and-white copying as shown in FIG. 14, the paper detection switch 226 is kept on while the paper detection switch 227 is off. Maintain state. Thereby, the control device 321 detects a paper jam on the suction unit 100 side in the lower fixing unit. In this case, the paper P
Can be discharged to the suction unit 100 side by rotating the knob 315 in the counterclockwise direction, so that the control device 321 turns on the rotation direction display section 317.

Further, as shown in FIG. 15, when the paper P is jammed in the latter half of the paper feeding to the lower fixing unit at the time of monochrome copying, the paper detection switch 226 is turned off and the paper detection switch 227 is kept on. I do. Thereby, the control device 321 detects a paper jam on the discharge roller 30 side in the lower fixing unit. In this case, the sheet P can be discharged to the sheet discharge roller 30 by rotating the knob 315 in the clockwise direction, so that the control device 321 turns on the rotation direction display section 318.

As described above, in the present fixing device 300, when a paper jam occurs, the rotation direction of the knob 315 for clearing the paper jam is indicated by the rotation direction display sections 317 and 318. It is not necessary to judge the rotation direction of the knob 315 based on whether the paper P is being discharged or full color copy, and whether the appropriate discharge direction of the paper P is the suction unit 100 side or the paper discharge roller 30. Operation of the knob 315 is easy.

[0058]

According to the first aspect of the present invention, there is provided a fixing device for an electrophotographic apparatus, wherein the second fixing roller is a first fixing roller.
Between the first and third fixing rollers.
One of the receiving rollers is pressed against the second fixing roller and the other is
Are provided so that they can move away from each other
On the other hand, a manual rotation operation unit that rotates by manual operation,
As the discharge direction of the sheet from the first fixing portion of the relative rotation in a predetermined direction and a second fixing portion of the manual rotary operation unit are the same direction, a first fixing roller the rotation of the manual rotation operation portion To both the third fixing roller and these two rollers.
A structure that a rotary transmission means Ru is reversely rotating to each other.

Accordingly, the case where a paper jam occurs in the first fixing section between the first fixing roller and the second fixing roller,
Either in the case where a paper jam occurs in the second fixing unit between the fixing roller and the third fixing roller, and in the case where the paper is ejected in the same direction with respect to the rotation of the manual rotation operation unit in the predetermined direction. Can be. Therefore, when operating the manual rotation operation unit for paper jam processing, the operator performs the manual rotation operation without considering whether the used fixing unit is the first fixing unit or the second fixing unit. There is an effect that the part can be rotated and the operation is facilitated.

As described above, the fixing device of the electrophotographic apparatus according to the second aspect of the present invention is configured such that the manual rotating operation unit is rotated by manual operation, and the rotation of the manual rotating operation unit is used to form one of the first fixing units. A rotation transmitting unit for transmitting the fixing roller and one of the fixing rollers forming the second fixing unit, a rotation direction instructing unit for instructing a rotation direction of the manual rotation operation unit, and a rotation direction instructing unit near the first and second fixing units. The paper jam detecting means for detecting the generated paper jam and its position, the direction indicated by the rotation direction indicating means is used for the detection result by the paper jam detecting means, and for the use of the first fixing unit and the second fixing unit. Control means for controlling the operation of the rotation direction instructing means so that the rotation direction becomes the rotation direction of the manual rotation operation unit for discharging the paper in the direction corresponding to the fixing unit.

Accordingly, when operating the manual rotation operation unit for paper jam processing, the operator needs to determine the rotation direction of the manual rotation operation unit based on the position where the paper jam has occurred and the fixing unit used. Therefore, there is an effect that the operation of the manual rotation operation unit for paper jam processing becomes easy.

[Brief description of the drawings]

FIG. 1, showing an embodiment of the present invention, is an explanatory view of a rotation transmitting mechanism and a heat roller driving mechanism of a fixing device during black and white copying.

FIG. 2 is an explanatory diagram of a rotation transmission mechanism and a heat roller driving mechanism during full color copying in the fixing device.

FIG. 3 is an overall configuration diagram of a copying machine provided with the above fixing device.

FIG. 4 is an enlarged view illustrating a configuration near a fixing device illustrated in FIG. 3;

FIG. 5 is a schematic front view showing a state in which a heat roller separation / attachment mechanism included in the fixing device shown in FIG.

FIG. 6 is a schematic front view showing a state of the heat roller separation / contact mechanism at the time of full-color copying, partially cut away.

FIG. 7 is a block diagram illustrating a configuration of a main part of a control system included in the fixing device illustrated in FIG. 4;

FIG. 8 is a schematic front view showing another embodiment of the present invention, in which a heat roller separating mechanism provided in the fixing device is partially broken in a black and white copying state.

FIG. 9 is a schematic front view showing a state of the heat roller separation / attachment mechanism at the time of full color copying, partially cut away.

FIG. 10 is a perspective view showing a knob for manual rotation and a rotation transmission mechanism provided in the fixing device.

FIG. 11 is a block diagram illustrating a configuration of a main part of a control system provided in the fixing device.

FIG. 12 is a diagram illustrating a paper discharge direction when a paper jam occurs in the initial stage of paper input to the upper fixing unit and a rotation direction indicating operation of a knob by a rotation direction display unit during full-color copying in the fixing device. FIG.

FIG. 13 shows a paper discharge direction when a paper jam occurs in a later stage of paper input to the upper fixing unit and a rotation direction indicating operation of a knob by a rotation direction display unit in the above fixing device during full color copying. FIG.

FIG. 14 is a view showing a fixing device according to the first embodiment;
FIG. 8 is an explanatory diagram illustrating a paper discharge direction when a paper jam occurs in the initial stage of paper input to a lower fixing unit and a rotation direction indication operation of a knob by a rotation direction display unit.

FIG. 15 is a diagram illustrating a discharge direction of paper when a paper jam occurs in a later stage of paper input to the upper fixing unit and a rotation direction indicating operation of a knob by a rotation direction display unit in the above-described fixing device during black-and-white copying. FIG.

FIG. 16 is an explanatory diagram of a mechanism for manually rotating a heat roller in a conventional fixing device.

[Explanation of symbols]

 200 fixing device 201 upper heat roller (first fixing roller) 202 middle heat roller (second fixing roller) 203 lower heat roller (third fixing roller) 226 paper detection switch (paper jam detection means) 227 paper detection switch (paper jam) 280 Rotation transmission mechanism (rotation transmission means) 283 Knob (manual rotation operation unit) 300 Fixing device 310 Rotation transmission mechanism (rotation transmission means) 315 Knob (manual rotation operation unit) 317 Rotation direction display unit (rotation direction instruction means) ) 318 Rotation direction display unit (rotation direction instruction means) 321 Control device (control means)

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Nobuyuki Ueda 22-22, Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Yasutoshi Kawai 22-22, Nagaikecho, Abeno-ku, Osaka-shi, Osaka Sharp shares Inside the company (72) Inventor Yasuhiro Ono 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Shuichi Yoshinaka 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Toshiki Ogita 22-22, Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (56) References JP-A-3-267975 (JP, A) Full-scale 1979-139948 (JP, U) (58) Survey Field (Int.Cl. ⁶ , DB name) G03G 13/20 G03G 15/00 526 G03G 15/20

Claims (2)

(57) [Claims] A first fixing portion formed at a pressure contact portion between the first fixing roller and the second fixing roller; a first fixing portion formed at a pressure contact portion between the first fixing roller and the second fixing roller; Third
In a fixing device of an electrophotographic apparatus, a second fixing portion is formed at a pressure contact portion with a fixing roller, and the first and second fixing portions fix an image of a developer on a sheet to a sheet . The second fixing roller includes the first fixing roller and the third fixing roller.
Roller, the first and third fixing rollers,
One is pressed against the second fixing roller and the other is separated
A manual rotation operation unit which is provided so as to be capable of separating and contacting each other, and is rotated by a manual operation; and a sheet from the first fixing unit and the second fixing unit with respect to rotation of the manual rotation operation unit in a predetermined direction. as the discharge direction of the same direction, both of these rollers to transmit the rotation of the manual rotation operation portion into a first fixing roller and the third fixing roller
The fixing device of an electrophotographic apparatus, wherein a and a rotation transmitting means Ru is reversely rotating to each other. A first fixing section formed at a pressure contact portion between the first fixing roller and the second fixing roller; a first fixing section formed at a pressure contact portion between the first fixing roller and the second fixing roller; Third
In a fixing device of an electrophotographic apparatus, a second fixing portion is formed at a pressure contact portion with a fixing roller, and the first and second fixing portions fix a developer image on a sheet to a sheet. A manual rotation operation unit for rotating the manual rotation operation unit, a rotation transmission unit for transmitting rotation of the manual rotation operation unit to one fixing roller forming the first fixing unit, and one fixing roller forming the second fixing unit; Rotation direction instructing means for instructing the rotation direction of the rotation operation unit; paper jam detecting means for detecting the paper jam occurring near the first and second fixing units and the position thereof; Is the rotation direction of the manual rotation operation unit for discharging the paper in the direction according to the detection result by the paper jam detection unit and the used fixing unit of the first fixing unit and the second fixing unit. So times The fixing device of an electrophotographic apparatus, characterized in that a control means for controlling operation of the direction instructing means.