JP2574804B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus such as a copying machine, a printing machine, or a laser beam printer, and more particularly, to a transfer unit and a transfer unit for an image forming unit. The present invention relates to a movable image forming apparatus.

2. Description of the Related Art Conventionally, an image forming apparatus including a plurality of pairs of conveying rollers for conveying a sheet fed from a storage device to an image forming unit from a fixing unit has been known. The forming apparatus has a conveyance guide between the conveyance roller pair,
The sheet is guided by the conveyance guide from the conveyance roller pair, and is clamped by the next conveyance roller pair. The apparatus has a drawback that the sheet is charged or paper dust is generated due to friction with the conveyance guide.

As a solution to this drawback, a transport belt is provided,
There is an image forming apparatus that conveys a sheet to a fixing device from immediately after sheet feeding by the conveyance belt.

(C) Problems to be Solved by the Invention However, in the image forming apparatus provided with the above-described transport belt, a jam or the like occurs during image formation, and the sheet is sandwiched between the photoconductor and the transport belt. When the image formation is stopped in the state, since the transport belt is always in contact with the photoconductor, it is difficult to remove the sheet from between the two and it is difficult to remove the sheet, which causes a problem that the jam processing becomes complicated,
Another problem is that the sheet is torn during the removal operation, and the fragments remain on the conveyor belt or the like. If image formation is restarted with the sheet fragments remaining, image failure may occur.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an image forming apparatus capable of speeding up and simplifying a jam process and ensuring the removal of a sheet.

(D) Means for Solving the Problems The present invention has been made in view of the above circumstances,
Inside the image forming apparatus main body, an image forming unit, conveying means for conveying a sheet through the image forming unit, and transferring an image of the image forming unit to the sheet conveyed to the image forming unit by the conveying means Transfer means, and an image forming apparatus comprising:
A driving unit disposed at a first position close to the image forming unit or at a second position separated from the image forming unit, and the conveying unit is supported by the image forming apparatus main body so as to be openable and closable and opened to expose the conveying unit. An opening / closing door to be opened, an opening / closing detection means for detecting opening / closing of the opening / closing door, and the driving means for arranging the transfer means and the transfer means at the second position based on an opening / closing detection signal of the opening / closing detection means. And control means for controlling.

Further, the control means may control the drive means based on a closing signal of the open / close detection means to arrange the transport means and the transfer means at the first position.

Further, the control device arranges the transport unit and the transfer unit at the second position in a normal state where image formation is not performed, while the transport unit and the transfer unit in an image formation state where image formation is performed. The transfer unit may be arranged at the first position.

(E) Operation Based on the above configuration, when the opening / closing door is opened, the conveying means inside the image forming apparatus main body is exposed, and the opening / closing detecting means generates an opening detection signal. The control unit controls the driving unit based on this signal, and arranges the conveying unit and the transfer unit at the second position separated from the image forming unit via the driving unit. Thereby, a gap is formed between the image forming unit and the transport unit. Therefore, for example, even when a sheet is sandwiched between the image forming unit and the conveying unit due to a jam or the like, simply opening the opening / closing cover automatically interlocks with the image forming unit in conjunction with the opening operation. Since a gap is provided between the sheet and the conveying means, a user or the like can simply remove the sheet and easily remove the sheet without damaging the sheet.

On the other hand, when the opening / closing door is closed after the sheet is removed, a closing detection signal is generated by the opening / closing detection unit, and the control unit controls the driving unit based on the signal, and the conveyance unit and the transfer unit via the driving unit. At a first position close to the image forming unit. The image forming apparatus in which the transfer unit and the transfer unit are arranged at the first position can restart image formation.

In the present invention, as described above, the transfer unit and the transfer unit are automatically moved to the second position and the first position in conjunction with the opening and closing operations of the opening and closing doors, respectively. Therefore, unlike the case where the conveyance unit and the transfer unit are moved manually, the sheet sandwiched between the image forming unit and the conveyance unit is forgotten or not known to be moved to the second position. There is no danger of forcibly pulling out and damaging it, or of removing the sheet and forgetting to move it to the first position and restarting image formation at all.

(F) Example Hereinafter, an example of the present invention will be described with reference to the drawings.

The laser beam printer 1 as an image forming apparatus includes:
As shown in FIG. 1, three sets of image forming units 3, 5, and 6 are provided in a body (image forming apparatus main body) 2, and the image forming units 3, 5, and 6 are each configured to use different color toners. To form a color image. The machine body 2 includes a detachable cassette 7, and the cassette 7 is provided on the machine body 2 side.
A cassette detection switch 9 for detecting the mounting of the cassette is provided. Further, a paper feed roller 10 for feeding the sheets S stored in the cassette 7 is provided above the cassette 7, and a registration roller for synchronously transporting the sheets S is provided downstream of the roller 10. Pair 11 is provided. A sheet detection sensor 12 including a lamp 12a and a photodiode 12b is provided downstream of the roller pair 11, and a driving unit rotatably supported by a frame 13 downstream of the diode 12. A transport belt (transport means) 17 made of a resin material such as polyurethane is stretched over the roller 15 and the driven roller 16, and
The pressing roller 19 is configured to contact and rotate. Downstream of the roller 19, upper and lower suction chargers 20a and 20b are disposed with the transport belt 17 interposed therebetween.
A sheet detection sensor 21 including a lamp 21a and a photodiode 21b is provided downstream of the chargers 20a and 20b.
Further, the image forming unit 3 is provided downstream of the sensor 21, and the image forming unit 3 is configured to receive a laser signal from a laser scanner unit 22 via a mirror 23. The image forming section 3 has a cylindrical photosensitive drum 25, and a primary charger 26 around the drum 25.
A developing device 27 for developing with magenta toner, a transfer charger (transfer means) 29, and a cleaner 30 are provided. Further, a sheet detection sensor 31 is provided downstream of the image forming unit 3, and the sensor 31 is configured by a lamp 31a and a photodiode 31b. Further, the image forming unit 5 is provided downstream of the sensor 31, and the image forming unit 5 is configured to receive a laser signal from the laser scanner unit 32 via a mirror 33. The image forming section 5 has a cylindrical photosensitive drum 35,
Around the drum 35, a primary charger 36, a developing device 37 for developing with cyan toner, a transfer charger (transfer means) 39, and a cleaner 40 are provided. Further, a sheet detection sensor 41 is provided downstream of the image forming unit 5, and the sensor 41 is configured by a lamp 41a and a photodiode 41b. Further, downstream of the sensor 41, the image forming unit 6
The image forming unit 6 is configured to receive a laser signal from a laser scanner unit 42 via a mirror 43. The image forming section 6 has a cylindrical photosensitive drum 45, a primary charger 46, a developing device 47 for developing with yellow toner, a transfer charger (transfer means) 49 around the drum 45. A cleaner 50 is provided. Further, downstream of the image forming unit 6 and the transport belt 17
Downstream of the separation claw that separates the sheet S from the belt 17
The belt 17 is provided below the separation claw 51.
A conductive blade 52 is provided to remove dirt and remove electrostatic attraction. Further, a conveyance guide 53 is provided downstream of the separation claw 51, and the guide 53 includes a sheet detection sensor 55 including a lamp 55a and a photodiode 55b. A fixing device 56 is provided downstream of the guide 53, and the fixing device 56 includes a lamp.
A sheet discharge sensor 57 constituted by 57a and a photodiode 57b is provided. A fixing cover switch 60 that is turned on and off by opening and closing a cover 59 is provided above the setting clothing 56, and a paper output tray 61 is provided outside the body 2 downstream of the setting clothing 56. Has been established. Further, a discharge guide 62 is provided below the transport guide 53,
An openable / closable discharge cover 63 is provided downstream of the guide 62. A cam shaft 65 connected to a cam motor (drive source) 64 is rotatably supported below the body 2. A cam 66 is fixed to the shaft 65, and a lifter is provided by the cam 66. A frame 67 is supported so as to be able to move up and down, and rollers 69 are rotatably supported on the left and right sides of the lifter frame 67. Thus, an elevating unit U is configured, and a driving unit is constituted by the elevating unit U and the cam motor 64. It is configured. Further, the frame 13 is
Are supported so as to be movable in a substantially horizontal direction (see FIG. 1). The drive roller 15, the driven roller 16, the attraction charger 20b, and the photodiode 2 are supported by the frame 13.
1b, 31b, 41b, the transfer chargers 29, 39, 49, the separation claw 51, and the conductive blade 52 are attached, and a transport unit 70 is configured by these.

As shown in FIG. 2, the laser beam printer 1 is provided with doors (opening / closing doors) 71, 71 which can be opened and closed on the front side of the machine body 2. It is configured such that the unit 70 can be pulled out to the near side. Door switches (open / close detecting means) 72, 72 which are turned ON / OFF by opening and closing the doors 71, 71 are provided on the front side of the body 2 and further provided with the transfer unit 70 on the back side of the body 2. A position switch 73 that is turned ON / OFF by attachment / detachment is provided. In the figure, reference numeral 75 denotes a reset switch.

The laser beam printer 1 includes a microcomputer (control means) 76 as shown in FIG.
The input port of the microcomputer 76 includes the cassette detection switch 9, the sheet detection sensors 12, 21, 31, 41, and 5
5, the sheet discharge sensor 57, the fixing cover switch 60, the door switch 72, the position switch 73 and the reset switch 75 are connected.
64, a transportation failure warning display 77, a weight display 79, a lifting / lowering unit operation warning display 80, a transportation unit mounting failure warning display 81, and a buzzer 82 are connected.

In addition, these indications 77, 79, 80, 81 and buzzer 82
As shown in the figure, the operation unit 84 of the laser beam printer 1
The operation unit 84 includes a start key 85, a numeric keypad 86, a density key 87, and the like.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG.

When an image signal is input from an external device to the laser beam printer 1 (S1), an image signal of a green component is input to a laser scanner unit 22, and the laser scanner unit 22 receives a built-in laser based on the image signal of the green component. A laser beam modulated and emitted by a diode (not shown) is irradiated to a photosensitive drum 25 which is uniformly charged by a primary charger 26 via a mirror 23 in a parallel operation state by a polygon mirror (not shown). As a result, a latent image of a green component is formed on the photosensitive drum 25, and the latent image is developed by a magenta toner contained in the developing device 27 to become a visible image. Similarly, the image forming unit 5 forms an image visualized by the cyan toner on the photosensitive drum 35 based on the image signal of the red component, and the image forming unit 6 further uses the yellow toner based on the image signal of the blue component. The visualized image is formed on the photosensitive drum 45. Then, the sheet S stored in the cassette 7 is fed to the registration roller pair 11 by the paper feed roller 10, and is nipped and conveyed by the registration roller pair 11. Then, if the leading end of the sheet S is detected by the sheet detecting sensor 12 within the set time a after the rotation of the sheet feeding roller 10 and the signal output value from the photodiode 12b changes (S2),
The microcomputer 76 stops the pair of registration rollers 11 (S3), and moves the transport unit 70 located at the standby position (see FIG. 5) by rotating the cam motor 64 to the cam 66.
With the lifter frame 67, it is pushed up to the transport position (first position, see FIG. 1). Furthermore, microcomputers
76 restarts the registration roller pair 11 at a predetermined timing (S4), and the sheet S is conveyed by the registration roller pair 11 in synchronization with the image on the photosensitive drum 25. Then, the sheet S is nipped and conveyed by a driven roller 16 and a pressing roller 19, and further adsorbed by a conveying belt 17 having an electrostatic attraction force by attraction chargers 20 a and 20 b to the image forming section 3. Conveyed. At this time, if the sheet S is detected by the sheet detection sensor 21 within the set time b after the registration roller pair 11 is restarted and the signal output value from the photodiode 2b changes (S5), the signal from the sensor 21 is detected. Based on the detection signal, the microcomputer 76 determines that the sheet S has passed. Then, the sheet S is printed with an image formed by the magenta toner on the photosensitive drum 25 by the transfer charger 29, and is conveyed to the image forming unit 5. At this time, if the sheet S is detected by the sheet detection sensor 31 within the set time c, that is, within a predetermined time after being detected by the sheet detection sensor 21, and there is a change in the signal output value from the photodiode 31b (S6), The microcomputer 76 determines that the sheet S has passed based on the detection signal of the sensor 31. The sheet S is printed with an image formed by the cyan toner on the photosensitive drum 35 by the transfer charger 39,
The sheet is conveyed to the image forming section 6. At this time, if the sheet S is detected by the sheet detection sensor 41 within a set time, that is, within a predetermined time after being detected by the sheet detection sensor 31, and the signal output value from the photodiode 41b changes (S
7) Based on the detection signal of the sensor 41, the microcomputer 76 determines that the sheet S has passed. Then, the sheet S is printed with an image formed by yellow toner on the photosensitive drum 45 by the transfer charger 49,
It is separated from the conveyor belt 17 by 51. Then, when the sheet S is guided to the fixing device 56 by the conveyance guide 53, the leading end thereof is detected within a predetermined time d by the sheet detection sensor 55, that is, within a predetermined time after being detected by the sheet detection sensor 41, and the photodiode is detected. When there is a change in the signal output value from 55b (S8), the image is fixed by the fixing device 56. At this time, the sheet S is heated and pressurized in the fixing device 56, and the respective color toners on the sheet S fuse and perform subtractive color mixing to form a full-color image. When the rear end of the sheet S is detected by the sheet detection sensor 55 within the set time e, that is, within a predetermined time after the front end of the sheet S is detected, and the signal output value from the photodiode 55b changes (S9), The sheet S on which the full-color image is fixed is discharged to the discharge tray 61. At this time, if the sheet S is detected within a set time f by the sheet discharge sensor 57, that is, within a predetermined time after the sheet rear end is detected by the sheet detection sensor 55, and the signal output value from the photodiode 57b changes. (S10) Based on the detection signal of the sensor 57, the microcomputer 76 rotates the cam 66 by the cam motor 64 to lower the transport unit 70 together with the lifter frame 67 to the standby position (see FIG. 5). And the photosensitive drums 25, 35,
The transport belt 17 separated from the roller 45 continues to rotate, and the conductive blade 52 cleans the toner and paper powder attached to the surface and removes electricity.

Next, the action at the time of sheet conveyance failure will be described with reference to FIGS.
Description will be given along the flowcharts up to the figure.

In the aforementioned S2, the photodiode 12
When the microcomputer 76 determines that there is no change in the signal output value from b, the computer 76 determines that a transport failure has occurred in the cassette 7 and activates the transport failure removal sequence (see FIG. 9). Then, the microcomputer 76 determines whether or not the sheet S in which the transport failure has occurred is the first transported sheet S (S11). If it is determined that the first sheet is transported, the microcomputer 76 performs the image forming operation of the laser beam printer 1. Stop and turn on the transport failure warning display 77 (S1
2). When the microcomputer 76 determines that the sheet S is not the first sheet but the sheet S of the continuous image formation, the computer 76 stops the rotation of the sheet feed roller 10 and the registration roller pair 11. (S13) and sheet S
After the time (g seconds) required from the time when is fed into the laser beam printer 1 to the time when it is discharged, the image forming operation of the laser beam printer 1 is stopped, and the conveyance failure warning display 77 is turned on (S14). Then, upon confirming the warning display 77, the operator pulls out the cassette 7 from the machine body 2 and removes the jam sheet S. At this time, the microcomputer 76 detects the removal of the cassette 7 by the cassette detection switch 9 which is turned off by the removal of the cassette 7 (S1).
Five). Then, when the operator mounts the cassette 7 from which the jam sheet S has been removed to the machine body 2 again, the cassette detection switch 9 is turned ON (S16), and the microcomputer 76 receiving the ON signal of the switch 9 displays the conveyance failure warning display 77.
It turns off and restarts the image forming operation (S17). Then, when the laser beam printer 1 repeats the operation from S1 described above, if the microcomputer 76 determines NO in S5, S6, S7, S8 or S9, the computer 76 determines whether or not the continuous image forming operation is being performed. (S18), if it is determined that the continuous image forming operation is being performed, it is determined whether or not the jammed sheet S is the first sheet (S19). If it is determined that the jammed sheet S is the first sheet, the image forming operation is stopped and transported. The failure warning display 77 is turned on (S20). If it is determined that the sheet is not the first sheet, the microcomputer 76 stops the image forming operation and fixes the sheet S that has already been transferred from the conveyor belt 17 after the transfer of the three color toner images. Enough time (h
Second) The fixing device 56 is operated (S21), and then the operation of S20 is performed.

Then, the operator confirming the transport failure warning display 77 opens the left and right doors 71, 71 on the front side of the machine body 2 (see FIG. 2). As a result, the left and right door switches 72, 72 are turned off (S2
2) The microcomputer 76 determines that the doors 71, 71 have been opened based on the OFF signals (open signals) of the switches 72, 72. Then, the computer 76 rotates the cam shaft 65 by the cam motor 64 to lower the lifting unit U,
The elevating unit operation warning indicator 80 lights and the buzzer
Ring 82 (S23 in FIG. 10). Further, the microcomputer 76 determines whether or not the elevating unit U has been lowered to the position (second position) shown in FIG. 6 based on a signal from a detecting means (not shown) for detecting the rotation angle of the cam shaft 65. (S2
4) If it is determined that the vehicle has descended, the cam motor 64 is stopped to stop the descending operation of the elevating unit U, the elevating unit operation warning display 80 is turned off, and the buzzer 82 is stopped (S25). When the operator confirms that the buzzer 82 has stopped, the operator pulls out the transport unit 70 to the near side to remove the jam sheet S (see FIG. 2), turns on the reset switch 75 (S26), and displays a transport failure warning display 77. Turns off (S27). At this time, the position switch 73 is turned off by pulling out the transfer unit 70 (S28).
The microcomputer receiving the OFF signal of 73 turns on the transport unit mounting failure warning display 81 (S29).

As described above, according to the image forming apparatus 1 of the present invention, in conjunction with the opening of the doors 71, 71, the transport unit 70 having the transport belt 17, and the transfer chargers 29, 39, 49 is automatically driven by the driving unit. 6, and a gap is formed between the image forming units 3, 5, 6 and the conveyor belt 17, so that the image forming units 3, 5, 6 and the conveyor belt 17 When removing the sheet sandwiched between the sheets, the user can easily remove the sheet S simply by pulling out the sheet S.

Note that, unlike the present invention, a configuration in which the transport unit 70 is manually arranged at the second position is also conceivable, but in this case, the manual operation is not only complicated, but also Or, without knowing, the image forming units 3, 5,
In order to pull out the sheet S that is still sandwiched between the transfer belt 6 and the transfer belt 17, the sheet S may be damaged,
May be damaged, and the photosensitive drums 25, 35, 45 and the transport belt 17 may be damaged. In the present invention, there is no such fear at all.

Then, after the jam processing is completed, the operator returns the transport unit 70 to the inside of the machine body 2. As a result, the position switch 73 is turned ON (S30), and the microcomputer 76 receiving the ON signal from the switch 73 turns off the transport unit mounting failure warning display 81 (S31). Then, when the operator closes the left and right doors 71, 71, the left and right door switches 72, 72 are switched.
Is turned on (S32), and the ON signals (close signals) of the switches 72, 72 are turned on.
Microcomputer 76 that receives the light turns on a weight display 79 indicating that the operation is being prepared (S33). Further, the computer 76 determines whether or not the jammed sheet S has been jammed during the continuous image forming operation (S34).
Is operated at least for a time (i seconds) sufficient for the transport belt 17 to move half the circumference, and the sheet S adsorbed on the transport belt 17 is peeled off by the separation claw 51 and transported to the discharge guide 62. (See FIG. 7). At this time, the transport belt 17 is cleaned of the toner and the like adhered by the conductive blade 52 and is discharged (S35). Then, after elapse of i seconds, the microcomputer 76 sets each of the sensors 12, 21, 31, 41
The lamps 12a, 21a, 31a and 41a are turned on, and it is determined whether or not the signal output values from the respective photodiodes 12, 21b, 31b and 41b are normal (S36). The failure warning display 77 is turned on (S37), and the operation from S26 is repeated. If the microcomputer 76 determines that the output value is normal, the microcomputer 76 rotates the photosensitive drums 25, 35, and 45 at least once, and the cleaners 30, 40, and 50 rotate the drums.
The surface cleaning of 25, 35, 45 is performed (S38). On the other hand, if it is determined in S34 that the continuous image forming operation is not being performed, the microcomputer 76 sets each of the photodiodes 12b, 21b, 31
It is determined whether the signal output values from b and 41b are normal (S39). If it is determined that the signal output value is not normal, the conveyance failure warning display 77 is turned on (S40), and the operation from S26 is repeated. When the microcomputer 76 determines that the signal output value is normal, the microcomputer 76 rotates the photosensitive drums 25, 35, and 45 at least one time to clean the surface, and further moves the transport unit 70 at least with the transport belt 17 around. The belt 17 is operated for a sufficient time (i seconds) to move half of the length, and the surface of the belt 17 is cleaned and static electricity is removed (S41). Then, after elapse of i seconds, the microcomputer 76 rotates the cam shaft 65 by the cam motor 64,
The transport unit 70 is pushed up via the lifter frame 67 by 66, and furthermore, the elevating unit operation warning display 80 is turned on and the buzzer 82 emits a warning sound. Then, based on the signal from the detecting means, the computer 76 determines whether or not the transport unit 70 has risen to a position where image forming work can be performed (S43). Stop and elevating unit operation warning display 80
Is turned on, and the buzzer 82 is stopped (S44). And
The microcomputer 76 turns off the weight display 79 (S4
5) The operation from S1 is performed.

As described above, according to the image forming apparatus 1 of the present invention, in conjunction with the closing of the doors 71, 71, the transport unit 70 having the transport belt 17, and the transfer chargers 29, 39, 49 is finally automatically operated. It is arranged at the first position shown in FIG. 1 and the image formation can be resumed.

Note that, unlike the present invention, a configuration in which the transport unit 70 is manually arranged at the first position can be considered. In this case, however, the manual operation is complicated, and
Before closing 1,71, one may forget to move the transport unit 70 to the first position.

If it is determined in S10 that the signal output value from the photodiode 57b has not changed within the set time f, the microcomputer 76 stops the image forming operation of the laser beam printer 1 and displays a conveyance failure warning display. Light 77 is turned on (S46). Then, when the operator detecting the display 77 opens the cover 59 of the fixing device 56, the fixing cover switch 60 is turned off (S47), and the microcomputer 76 receiving the OFF signal of the switch 60 informs the microcomputer 76 that the cover 59 has been opened. to decide. Then, when the operator removes the jam sheet S and closes the cover 59, the fixing cover switch 60
Is turned on (S48), and the microcomputer 76 receiving the ON signal of the switch 60 determines whether or not the signal output value of the photodiode 57b is normal (S49). Repeat the operation. If it is determined that the output value is normal, the microcomputer 76
Turns off the conveyance failure warning display 77 and turns on the weight display 79 (S50). Then the computer 76
Operates the temperature adjustment circuit to increase the temperature of the heat roller in the fixing device 56 until the temperature of the heat roller in the fixing device 56 reaches a temperature at which the fixing operation is possible (S51). When the temperature of the heat roller rises to a temperature at which the fixing operation can be performed, the microcomputer 76 causes each photosensitive drum to operate.
25, 35, 45, the conveying unit 70 and the fixing device 56 are operated for i seconds to fix the sheet S in the middle of the image forming operation adsorbed on the conveying belt 17 by the fixing device 56 and discharge it out of the machine body 2 ( S52). At this time, the photosensitive drums 25, 35, 45 and the transport belt 17 are cleaned by the respective cleaners 3, 40, 50 or the conductive blades 52. Then, after elapse of i seconds, the microcomputer 76 sets the respective photodiodes 12b, 21b, 31b,
It is determined whether the signal output values of 41b and 55b are normal (S53), and when it is determined that the signal output values are not normal, the operation from S23 is repeated. If the microcomputer 76 determines that the signal output value is normal, the microcomputer 76 turns off the weight display 79 (S54) and resumes the image forming operation from S1.

In the above-described embodiment, the sheet detection sensor is constituted by the lamp and the photodiode. However, the invention is not limited to this, and the sheet detection sensor may be constituted by a micro switch or a device utilizing capacitance.

Further, in the above-described embodiment, the conductive blade 52 has been described as an example of a cleaning device for the transport belt 17, but the present invention is not limited to this, and a brush, a method using electrostatic attraction, a method using airflow, a method using adhesive force, and the like. May be used.

Further, in the above embodiment, the cam mechanism is described as an example of the lifting unit U. However, the present invention is not limited to this, and a pantograph mechanism, a rack and a pinion gear, or the like may be used.

In the above-described embodiment, the transport unit 70 is configured to move up and down in parallel, but is not limited thereto.
As shown in FIGS. 12 and 13, the same effect can be obtained by supporting only one side of the transport unit 70 'and rotatably supporting the one side around the one side.

(G) Effects of the Invention As described above, according to the present invention, the control means for controlling the drive means to arrange the transport means and the transfer means at the second position based on the open detection signal of the open / close detection means, When the opening / closing door is opened, the conveying means inside the image forming apparatus main body is exposed, and the conveying means and the transfer means are arranged at the second position separated from the image forming unit, and the image is formed. A gap is formed between the forming section and the conveying means. Therefore, for example, even when a sheet is sandwiched between the image forming unit and the conveying unit due to a jam or the like, simply opening the opening / closing cover automatically interlocks with the image forming unit in conjunction with the opening operation. Since a gap is provided between the sheet and the conveying means, a user or the like can simply remove the sheet and easily remove the sheet without damaging the sheet.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing an image forming apparatus according to the present invention, FIG. 2 is a plan view showing the operation thereof, and FIG.
FIG. 4 is a block diagram showing the control unit, and FIG. 4 is a plan view showing the operation unit. 5 to 7 are front sectional views showing the operation of the present invention. Also,
8 to 11 are flowcharts showing the operation of the present invention. FIGS. 12 and 13 are perspective views showing different embodiments of the present invention. DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 2 ... Image forming apparatus main body (body), 3, 5, 6 ... Image forming part, 17 ... Conveying means (conveying belt), 29, 39, 49 ... Transfer means (Transfer) Charger), 66 ……
Driving means (cam), 71: open / close door (door), 72: open / close detection means (door switch), 76: control means (microcomputer), S: seat, U: drive means (elevating unit) .

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kazuki Kanekura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Yoshihiko Hirose 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (72) Inventor Yasushi Murayama 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kunihiko Matsuzawa 3-30-2, Shimomaruko 3-chome, Ota-ku, Tokyo Canon Inc. ( 56) References JP-A-57-151954 (JP, A) JP-A-58-105268 (JP, A) JP-B-7-78666 (JP, B2)

Claims (3)

(57) [Claims] An image forming section on an inner surface of a main body of the image forming apparatus; conveying means for conveying a sheet through the image forming section; and image forming on a sheet conveyed to the image forming section by the conveying means. And a transfer unit for transferring an image of the image forming unit, wherein the transfer unit and the transfer unit are moved to a first position close to the image forming unit or a first position separated from the image forming unit. Drive means disposed at position 2, an opening / closing door supported by the image forming apparatus main body so as to be openable and closable, and exposing the transport means by opening; an opening / closing detecting means for detecting opening / closing of the opening / closing door; An image forming apparatus comprising: a control unit that controls the driving unit to arrange the transport unit and the transfer unit at the second position based on an open / close detection signal of a detection unit. 2. The control means according to claim 1, wherein said control means controls said transport means and said transfer means based on a closing signal of said open / close detection means.
The image forming apparatus according to claim 1, wherein the driving unit is controlled so as to be arranged at a position. 3. The image forming apparatus according to claim 1, wherein the control unit arranges the transporting unit and the transferring unit at the second position in a normal state where image formation is not performed, and the control unit controls the image forming state where image formation is performed. The image forming apparatus according to claim 1, wherein a transport unit and a transfer unit are arranged at the first position.