JP3080431B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine for forming a desired image on recording paper by a unitized process apparatus in accordance with an electrophotographic process.

[0002]

2. Description of the Related Art In a conventional image forming apparatus, for example, in a copying machine, an electrophotographic process apparatus such as a charging charger and a developing device surrounds the periphery of a rotating photoreceptor while considering the mutual distance according to the process order. Each was mounted on a frame or the like of the device body. While the number of the above-described process devices has been increased or increased in accordance with the demand for higher functionality of the copying machine, there has been a demand for a reduction in the size of the entire device, which has made the layout inside the device difficult. Further, in a copier, for example, daily maintenance work required in connection with the operation of the apparatus such as toner replenishment and toner discharge work accompanying toner consumption, paper jams in a paper transport path, and contamination of each process device. In the event of abnormal stop due to deterioration, etc., maintenance and inspection, repair work or periodic inspection is required. These operations are usually performed by separating and releasing the main parts of the main body of the device.
Such a device is convenient for removing jammed paper in the event of a paper jam, but is not always suitable for maintenance and inspection work of each process device. For example, Japanese Patent Application Laid-Open No. Sho 60-14
No. 0264 discloses an electrophotographic copying apparatus in which a process unit for integrally holding a photoconductor and a process device is provided, and this unit is detachable from the apparatus main body, and the photoconductor and the process device are mutually movable. Have been.

[0003]

However, in the above-mentioned prior art, since the mounting position of the process unit to the apparatus main body is fixed, the attaching / detaching operation becomes complicated, and for example, the maintenance and inspection when a paper jam occurs. In the case of work such as
In some cases, a worker's body and clothes are stained by toner attached to a process device or the like, or a worker accidentally touches and damages a photoconductor. Further, even a routine maintenance operation such as toner replenishment involves disassembling a part of the apparatus main body, so that it is necessary to rely on a business trip of a service person who has acquired specialized knowledge. Furthermore, when the copying machine is not used for a long time, the contact portion of the photoconductor and the process device that is in pressure contact with the photoconductor is deteriorated due to long-time pressurization, or the toner is solidified in those press contact portions, and the copying machine is not used At the time of restart, troubles such as the occurrence of a stripe pattern in the copy image occurred. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in the related art, and in particular, it is possible to perform a daily maintenance work such as toner replenishment extremely easily and without error, and to deal with a paper jam in a transfer paper transport path. An object of the present invention is to provide an image forming apparatus that does not accidentally damage or stain a photoconductor during operation.

[0004]

According to the present invention, there is provided an image forming apparatus comprising: a rotating image carrier; and a plurality of electrostatographic process means disposed around the image carrier. In the apparatus, a detecting unit for detecting a paper jam in the transfer path of the transfer sheet, a control unit for controlling an operation of the image forming apparatus, and at least a part of the plurality of electrophotographic processing units are formed in a divided manner. And at least two units that are rotatable integrally with the image carrier, and that are detachable from the image carrier, and partially cover the surface of the image carrier when mounted on the image carrier. When the detection unit detects a paper jam in the transfer path other than the transfer position of the toner image, the control unit rotates the unit together with the carrier to move the image carrier. Transfer of transfer paper to exposed part The control unit moves the unit away from the image carrier when performing control to move the unit to the retreat position separated from the road, or when the detection unit detects a paper jam at the transfer position of the toner image. The image carrier is moved to the separated position, and if necessary, the image carrier is fixed at the image forming operation position, and the transfer means and its accompanying device are moved to the retracted position separated from the position facing the image carrier. It is like that.

[0005]

When the detecting means detects a paper jam of the transfer paper and the paper jam position is in a transport path other than the transfer position of the toner image, the control means issues a control signal to move the unit together with the carrier. By rotating, the exposed portion of the image carrier is moved to a retracted position separated from the transfer path of the transfer sheet. If the paper jam position is the transfer position of the toner image, the control means issues a control signal to move the unit to a position separated from the image carrier, and, if necessary, forms the image carrier. It is fixed at the operating position, or the transfer unit and its associated device are moved to a retracted position separated from the position facing the image carrier.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing a configuration of a digital copying machine according to an embodiment of the present invention, and FIG. 2 is a perspective view thereof. FIG.
As shown in FIG. 1, a contact glass 2 is disposed on the upper surface of a case C of the copying machine main body, and an original O to be subjected to image formation is placed on the contact glass 2. A scanning unit S is provided below the contact glass 2. The scanning unit S includes a first scanning optical system 5 including a light source 3 for illuminating the original and a mirror 4 that moves with the reading scan, a second scanning optical system 8 including mirrors 6 and 7, and a fixed unit. Lens 9 and an image reading element 10. When a print switch on an operation panel (not shown) of the copying machine body is pressed, the first and second scanning optical systems 5 and 8 move in the directions of arrows, respectively, and scanning of the original O is performed. The scanned image of the document O is divided into first and second scanning optical systems 5 and 8,
The image is read by the image reading element 10 through the lens 9, converted into an electric signal of an image, further digitized, and subjected to image processing. An image forming unit D is provided below the scanning unit S. The image forming unit D is a laser diode (LD) 1
1, LD drive plate 12, polygon mirror 13, mirror 1
4, an electrophotographic process device such as a photoreceptor belt 1, a developing device 16, a cleaning device 23, a charging charger 15, a transfer charger 18, a separation charger 19, etc., a transport belt 21 and a fixing roller 22. Transfer paper is stored in a paper feed unit 17 disposed upstream of the transfer unit, and the transfer paper is taken out one by one by a transport roller.
It is conveyed toward a transfer section between the photoreceptor belt 1 and the transfer charger 18. On the other hand, a signal read by the image reading element 10 and subjected to image processing is input to the LD drive plate 12 as described above. A drive signal is applied to the LD 11 from the LD drive plate 12, and a modulated laser beam is emitted from the LD 11 according to the drive signal. The laser light is reflected by the polygon mirror 13 and the mirror 14 and reaches the exposed portion of the photoreceptor belt 1. The surface of the photoreceptor belt 1 is uniformly charged in advance by the charging charger 15, and when a laser beam is exposed, an electrostatic latent image is formed on the portion.
The electrostatic latent image is developed by the developing device 16 and becomes a visible image using toner. The obtained visible image is further conveyed as the photoreceptor belt 1 moves, and the transfer sent from the paper supply unit 17 by corona discharge of the transfer charger 18 at the exposed portion at the lower end where the photoreceptor belt 1 is turned upside down. Transferred to paper. The transfer paper on which the image has been transferred is discharged by the separation charger 19 and separated from the surface of the photoreceptor belt 1.
The transfer paper thus separated is fed to the fixing roller 22 by the conveyor belt 21, and after the transfer image is fixed by the fixing roller 22, the transfer paper on which copying has been completed is the case C.
It is discharged outside. On the other hand, the toner still remaining on the surface of the photoreceptor belt 1 after the transfer operation is removed by the cleaning device 23.

In this embodiment, the photoreceptor belt 1 is constituted by an endless belt stretched between rollers separated by a predetermined distance so that the longitudinal section becomes a flat oblong shape. In addition, main electrostatographic process devices for forming an image, such as the developing device 16 and the cleaning device 23, which are arranged around the photoreceptor belt 1, are separately housed in two substantially semi-cylindrical units having substantially the same shape. ing. These two units (developing unit U1 and cleaning unit U2) are detachably mounted on a parallel flat portion of the photoreceptor belt 1 as described later. It has a cylindrical shape having a central axis in the direction, and can rotate integrally with the central axis as a rotation axis. These units U1 and U2 are rotated integrally with the photoreceptor belt 1 so as to be opposed to a substantially semicircular mounting opening 25 formed on the side surface of the case C shown in FIG. A unit for detachment and further maintenance and replacement can be attached to the apparatus main body. In this copying machine, at the time of image forming operation, the photoreceptor belt 1 is arranged vertically long in the vertical direction, and the opposing moving parts which are parallel to each other and move in the up and down directions are sandwiched between these units U1 and U2. However, since a curved surface that reverses the moving direction of the upper and lower ends is exposed to serve as a photosensitive portion and a transfer portion, there is no need to provide an opening for image formation in the units U1 and U2, and the photosensitive belt 1 is connected to the end portion. Can be completely covered by the housings of the units U1 and U2 having a substantially semi-cylindrical outer shape except for the curved surface portion. Further, when the copying machine is not operating or during maintenance work, the pressure contact state between the electrophotographic process apparatuses of the two units U1 and U2 and the photosensitive belt 1 is released. For example, when the toner in the developing device is almost consumed during the operation of the copying machine, or when the recovery tank of the cleaning device is full, the copying operation is interrupted to replenish the toner or discharge the discharged toner. Maintenance work must be performed. In such a case, in this embodiment, an alarm display and guidance are displayed on the operation / display unit of the copying machine main body, which will be described later.
1, or the cleaning unit U2 rotates and moves to a position facing the mounting opening 25. Therefore, the maintenance and replacement work can be completed simply by opening the mounting opening 25, pulling out the unit to be replaced and loading a new unit, so that anyone can easily perform the maintenance and replacement work. Further, since the developing unit U1 and the cleaning unit U2 are arranged rotationally symmetrically, when loading a new unit, the two units U1 and U2 can be removed from the mounting opening 25 of the copier body in any order without distinguishing the unit. The unit may be inserted and loaded, and even a user unfamiliar with the mechanical device can perform the loading operation of the unit without error. As described above, the replenishment of new toner and the discharge of discharged toner, which are required in association with the operation of the copying machine, can be performed without releasing the front panel of the case C as in the conventional example. Only the pulling out and loading of the two units U1 and U2 from the user, there is no need to request and wait for a service technician on-site maintenance work, and the user can perform the maintenance work with his or her own hands. The burden is small, and the work efficiency is improved because the time during which the operation of the copier is stopped and the copying machine is stopped is omitted.

Hereinafter, the configuration and operation of the main part of the embodiment will be described in detail. 3 and 4 are front views showing a fixed state and a fixed state of the electrostatographic process unit of the first embodiment. A photoreceptor belt 1 which is an image carrier made of an organic photoreceptor (OPC) is stretched between rollers 100 and 101 having the same diameter as a support driving body, and the rollers 100 and 101 are supported by rollers as shown by arrows. Orbital movement is achieved by clockwise rotation. As described above, the developing unit U1 and the cleaning unit U2 are disposed in close proximity to the opposing moving portions 1a, 1b running parallel and opposite to each other between the two rollers 100, 101 of the photoreceptor belt 1, and have a longitudinal section. Both shapes are semicircular and rotationally symmetric. Further, the photosensitive belt 1, the developing unit U1, and the cleaning unit U2 are
Are rotatable integrally with each other. Thereby, the loading operation to the apparatus main body irrespective of the order of the above-mentioned two units becomes possible. A curved portion of the photoreceptor belt 1 supported by the rollers 100 and 101 is exposed at a cylindrical gap defined by the outer circumferences of the developing unit U1 and the cleaning unit U2. It is a transfer section for a toner image. The developing device 16 is housed and supported in the housing 102 of the developing unit U1. The developing device 16 includes a developing roller 160 containing a magnet, a toner tank 167, an agitator 162 for stirring the toner, and the like. Toner tank 16
An opening 167a is formed in the vicinity of one end of the flat portion of the developing device 7, and a developing roller 160 is rotatably mounted with a part of the peripheral surface facing the outside from the opening 167a. Inside the toner tank 167, the opening 1 is in contact with the developing roller 160.
The neutralizing brush 163 and the agitator 1 are provided in the vicinity of 67a.
62 and a developing blade 161 are provided along the rotation direction of the developing roller 160, respectively. The space inside the toner tank 167 is filled with toner. In the developing device 16, the toner in the toner tank 167 is agitated by the rotation of the agitator 162, and
The developing blade 161 forms a toner layer having a constant thickness on the peripheral surface of the developing roller 160. This toner is supplied to the electrostatic latent image on the photosensitive belt 1 that is in contact with the developing roller 160 by the rotation of the developing roller 160, and is attracted to the charge on the surface of the photosensitive belt 1 to form a visible image. The toner not adsorbed on the photoreceptor belt 1 adheres to the developing roller 160 and is conveyed.
After the charge is removed by the charge removing brush 163, the toner tank 16
7 and is regulated by the developing blade 161. The entire developing device 16 is rotatable about a positioning pin 164 that supports one end of the developing device 16.
A spring 159 is stretched between the second hook 166 and the hook 167b at the free end of the toner tank 167. The developing device 16 is urged in the counterclockwise direction, that is, the direction in which the developing roller 160 is separated from the photosensitive belt 1 by the elastic force of the spring 159 about the positioning pin 164. In the image forming state, the developing device 16 is driven by a solenoid (not shown) to rotate the cam 165. Side, the free end of the toner tank 167 is
It is positioned in contact with the inner bent stopper piece 102a at one end of the second. As a result, the developing roller 160 presses and contacts the opposing moving portion 1a of the photosensitive belt 1 with a predetermined pressure. The developing unit U1 and the cleaning unit U2 are fixed by a fixing unit (not shown) so as not to rotate about the rotation axis.

[0009] The cleaning unit U2 has a flat portion opposed to the opposing moving portion 1b on the opposite side of the photoreceptor belt 1, and
A cleaning device 23 having a charging charger 15 and an eraser 24 is accommodated and supported in a plane portion of the housing 103. The collection tank 236 of the cleaning device 23 has an opening 23 at a position facing the opposing moving portion 1b of the photosensitive belt 1 along with the charging charger 15 and the eraser 24.
In the vicinity of the opening 236a, a cleaning blade 230 which is in contact with the photosensitive belt 1 and a rotatable fur brush 231 are provided. Further, a flicker bar 234 formed integrally with the collection tank 236 is provided at the opening 236 a and is in contact with the fur brush 231. A toner peeling plate 233 extending from the case 236 at a position facing the flicker bar 234 in the opening 236a.
, A toner collecting rod 232 to which the tip is pressed is rotatably provided, and closes the opening 236a. A fullness detection sensor 239 is attached near the eraser 24 in the collection tank 236, and issues a warning signal when the collection tank 236 is filled with waste toner. In the cleaning device 23, one end of the collection tank 236 is rotatably supported by a positioning pin 164 of the developing device 16 and a positioning pin 235 provided at a position rotationally symmetric with respect to the rotation axis R <b> 1. A spring 237 is stretched between the hook 236b provided on the outer edge and the hook 158 of the housing 103. In the image forming operation state, the cam 238 rotates and its projection presses the back surface of the collection tank 236 toward the photosensitive belt 1 against the elastic force of the spring 237, and the free end of the collection tank 236 becomes the end of the housing 103. The cleaning device 23 is positioned and fixed in contact with the stopper piece 103a formed by the inner bending of the edge. As a result of this positioning and fixing, the cleaning blade 230 and the fur brush 231 are pressed against the opposing moving portion 1b of the photoreceptor belt 1 with a predetermined pressure. In the cleaning device 23, the fur brush 231 scrapes off the residual toner on the photoreceptor belt 1, and the flicker bar 234
The remaining toner scraped off from 31 is knocked down. Residual toner that could not be scraped off by the fur brush 231 is peeled off by the cleaning blade 230. The residual toner scraped off in this manner is transferred to a toner collection rod 232.
The rotation of the toner release plate 233 and the operation of suppressing the toner peeling plate 233 sequentially take in the collection tank 236. The charging charger 15 charges the photoreceptor belt 1 after the cleaning, and
The eraser 24 erases unnecessary portions of the charge so that an electrostatic latent image is formed only in a necessary image area, and prepares for a new exposure scan on the photosensitive belt 1 by light reflected from the mirror 14. Thus, the developing device 16, the cleaning device 23, the charging charger 15, and the eraser 2
The process of forming an electrostatic latent image on the photoreceptor belt 1 by the image forming apparatus 4 is performed.

When the toner in the toner tank 167 is exhausted, a toner end sensor (not shown) which detects a decrease in the rotational load of the agitator 162 and outputs a signal, detects this, and issues a toner end signal. In addition, when the recovery tank 236 is full of discharged toner as described above, the full tank sensor 239 detects this and issues a toner full detection signal to display an alarm on the operation / display unit. The user can perform maintenance replacement of the developing unit U1 or the cleaning unit U2 based on this information. When the user himself performs the maintenance replacement work, when the user presses a replacement switch on an operation panel (not shown), the fixing of the photoreceptor belt 1, the developing unit U1, and the cleaning unit U2 is released, and the rotation is performed about the rotation axis R1. The unit to be replaced rotates to a position facing the mounting opening 25. That is, when the driving of the solenoid (not shown) is released, the cam 165 or the cam 238 is rotated and unlocked, and the supporting and fixing of the developing device 16 to the housing 102 is released as shown in FIG. Cleaning device 23
Is released, and the toner tank 167 or the recovery tank 236 is rotated around the positioning pin 164 or 235 in a direction away from the photoreceptor belt 1 by the tension of the springs 159 and 237, and the toner tank 167 or the recovery tank 236 is rotated. The collection tank 236 can be taken out from the mounting opening 25. The exchanged toner tank 167 or the recovery tank 236 is configured as a one-touch detachable cartridge (hereinafter referred to as a process pack).
7 or the recovery tank 236 is inserted into the case C from the mounting opening 25, and mounted on the housing 102 or the housing 103, and the mounting end button on the operation panel is pressed. As a result, the cam 165 or the cam 238 rotates to lock the process pack, and the developing unit U1 and the cleaning unit U2 rotate about the rotation axis R1 to orient in a predetermined vertical direction, thereby causing the process pack to rotate. The maintenance and replacement work is completed, and the copying machine becomes operable. Unit U1,
Since the casing 102 and the casing 103 of U2 are formed in the same shape, in the process of loading the process pack,
The two types of process packs can be attached to either of the opposing moving portions 1a and 1b of the photoreceptor belt 1. As described above, in the present embodiment, the toner tank 167 and the recovery tank 236 have the same and symmetrical substantially semi-cylindrical shapes and are configured to be integrally rotatable. At the time of maintenance and replacement work of the process pack when the toner is full at 167, only the simple work of mounting and dismounting the process pack from the mounting opening 25 on the front of the case C suffices. Can be processed. The main part of the photoreceptor belt 1 and the main electrostatographic process apparatus are always provided with housings 102 and 103.
For example, during inspection of a paper jam in the apparatus main body or removal of paper, an operator can accidentally touch the photoreceptor belt 1 or the like, thereby soiling or damaging the apparatus. Further, since the electrophotographic process unit can be unlocked and the contact between the electrophotographic process apparatus and the photoreceptor belt 1 can be released except during the image forming operation, for example, the photoreceptor belt 1 and the cleaning blade 2 can be released.
30 does not deteriorate due to pressurization for a long time, or the toner solidifies at the contact portion thereof, and does not adversely affect the formed image.

FIG. 5 is a front view showing a locked state of the electrophotographic process unit of the second embodiment. In the following description, portions that are the same as or deemed to be the same as in the first embodiment are given the same reference numerals, and descriptions thereof are omitted. The mechanical feature of this embodiment is that, in the first embodiment, the charging charger 15 and the eraser 24 are mounted outside the electrostatographic process unit, and the cleaning blade 230 and the fur brush 231 are separated from the developing roller 160 to collect the tank. 236 is disposed near the free end, and the electrophotographic process apparatus with little deterioration over time is removed from the process pack to reduce the cost and waste of the process pack, and to improve the function of collecting the discharged toner and perform cleaning. This is to increase the moving distance of the blade 230 and the fur brush 231 during rotation. In this embodiment, the charging charger 15, the eraser 24, and the transfer charger 18 are arranged outside the circumference of the rotation of the electrostatographic process unit, so that the rotation of the electrostatographic process unit at the time of maintenance replacement or mounting of the process pack is not hindered. Is being done. Also in the second embodiment, since the developing unit U1 and the cleaning unit U2 have the same cross-sectional shape, the process packs of these units U1 and U2 can be moved to any of the opposed moving portions 1a and 1b of the photosensitive belt 1. Can also be attached to Also in this embodiment, the developing unit U1, the cleaning unit U2, and the photoreceptor belt 1 are integrally rotated so that the developing unit U1 or the cleaning unit U2 is attached to the mounting opening 25.
, A desired process pack can be taken out, and a new process pack can be fitted and mounted in each of the housings 102 and 103. Further, the portion of the photoreceptor belt 1 sandwiched between the units U1 and U2 is covered, and the supporting portions of the rollers 100 and 101 at both ends are exposed, and exposure or transfer is performed at the exposed portion. The configuration, operation and effect of the other parts of the present embodiment are the same as those of the first embodiment already described.

In a copying machine, toner and paper dust are scattered due to long-term operation, and the toner or paper dust adheres to a mechanical device to cause an abnormal operation or to cause a paper jam to stop the operation due to the protection device. is there. As described above, in this embodiment, the photosensitive belt 1 has the casings 102 and 103 of the two process packs in which the opposing moving portions 1a and 1b are sandwiched.
Are covered and protected by rollers 100 and 101
The portion that goes around the area becomes an exposed portion and a transfer portion, and therefore cannot be covered with the protective member. Therefore, for example, when a paper jam occurs and the jammed paper is removed, the operator or the jammed paper may come into contact with the exposed portion of the photosensitive belt 1 and contaminate the photosensitive belt 1 with oil, dust, or the like. There is a risk of causing damage. In such a case, a streak pattern or a shadow is formed in the obtained image, and a clear image cannot be obtained. FIGS. 6 and 7 are explanatory views showing a state in which a paper jam has occurred in the transfer paper transport system. FIG. 6 shows a transfer section, and FIG. 7 shows a case where a paper jam occurs in a transport system other than the transfer section. Paper feed unit 1 in the transport system of the copier
Optical sensors s1, s2, and s3 for detecting the leading or trailing edge of the transfer paper are provided near the feed roller 26, upstream of the registration roller 27 in front of the transfer unit, and downstream of the fixing roller 22, respectively. Each sensor detects its position or the timing at which the transfer paper passes between each other, and the controller compares the time with a reference value, and issues an abnormal signal such as a paper jam to control the operation of the copying machine. Perform an error handling process such as stopping. As shown in FIG. 6, when the transfer section causes a paper jam, for example, when the transfer paper is separated and fails, the cams 165 and 238 are rotated without rotating the two units U1 and U2. Release the energizing solenoid. As the cams 165 and 238 rotate counterclockwise, the developing tank 167 and the recovery tank 236 also rotate counterclockwise around the positioning pins 164 and 235 by the elastic force of the springs 159 and 237, and the developing roller 160, the fur brush 231 and the cleaning blade 230 are released from the state of contact with the photosensitive belt 1 and are separated from each other by a predetermined distance. In parallel with the separating operation between the units U1 and U2 and the photoreceptor belt 1, a transfer charger 18 and a separation charger 19 are provided, and two rollers 28 and 29 which support and rotate the transport belt 21 are supported. The substructure T rotates clockwise about the rotation axis of the roller 28 and moves to a retracted position separated from the transfer unit, and a space convenient for a paper jam clearing operation by an operator manually is provided near the transfer unit. Form. Due to the separating operation of the developing tank 167 and the collecting tank 236 from the photoreceptor belt 1 and the retracting operation of the transfer unit structure T from the transfer unit, a sufficient space for paper jam processing is formed near the transfer unit. When the operator touches the photoreceptor belt 1 and soils it, or pulls the paper jammed in the vicinity of the photoreceptor belt 1 forcibly, the jammed paper damages the surface of the photoreceptor belt 1 or the jammed paper breaks on the way. The inconvenience of being impossible to remove is not caused.

Next, as shown in FIG. 7, when a paper jam occurs in a portion other than the transfer portion, the image forming operation is immediately stopped and the drive of the solenoid for urging the rotation of the cams 165 and 238 is released. Then, the developing unit 167 and the collecting tank 236 are separated from the photosensitive belt 1, and the two units U1 and U2 are further moved counterclockwise by about 90 degrees.
To move the transfer section of the photoreceptor belt 1 to a retracted position separated from the transfer paper transport path. In this case, it is known that there is no paper jam near the transfer section.
The retreat operation of the transfer unit structure T is not performed. As described above, when a paper jam occurs, the two units U1 and U2 are rotated by about 90 ° when the paper jam is cleared by a manual operation of the operator in the transfer paper transport path other than the transfer section. This is to prevent the operator from touching the photoreceptor belt 1 or to prevent the jammed paper from entering the photoreceptor belt 1 to damage the photoreceptor belt 1. Also, at that time, to rotate in the counterclockwise direction, the units U1 and U2 are rotated in the opposite direction to move the collection tank 236 upward,
This is because, when the opening 236a is oriented downward, the uncharged discharged toner is prevented from dropping from the opening 236a. On the other hand, as in the embodiment, the toner contained in the developing tank 167 moved to the upper retreat position is sufficiently charged, and therefore does not fall from the opening 167a of the developing tank 167.
Note that the angle at which the two units U1 and U2 are rotated does not necessarily need to be 90 °, and can be moved to a position where there is no possibility that the operator will accidentally touch the photoreceptor belt 1 in consideration of the internal layout of the copying machine. Any angle is acceptable.

In any of the above-described embodiments, when a new process pack is loaded in the copying machine body,
An automatic forming operation for adapting to the photoreceptor belt is performed. In the embodiment, the one using a one-component developing device has been described. However, the one using a two-component or multi-component developing device can be similarly configured. In the embodiment, when the toner in the toner tank 167 runs out, or when the waste toner is full in the collection tank 236, the toner end sensor or the full sensor 239 is used.
Has described a method of detecting this and issuing a detection signal to display an alarm on the operation / display unit. However, when each sensor issues a detection signal, the developing unit U1 or the cleaning unit U2 is not unlocked. Alternatively, the unit may be automatically rotated so that the corresponding unit moves to a position facing the mounting opening 25 and waits. In the above embodiment, the developing unit U1 or the cleaning unit U2
The operation of taking out a replaceable process pack housed in the apparatus main body from the casing C of the apparatus main body, performing a maintenance exchange operation on the process pack including the electrostatographic process apparatus, and remounting the process pack in the housing C is performed by a process housed in each unit. There is no restriction on the order in which the packs are taken out, the order in which they are mounted, and their positions, and the operation can be performed by a semi-automated one-touch operation. Can be performed very simply and quickly.

[0015]

As described above, according to the first aspect of the present invention, when the detecting means for detecting the paper jam of the transfer paper of the image forming apparatus detects the paper jam at the transfer position of the toner image, the static state is reduced. Since the plurality of units accommodating the electrophotographic process means are moved to the separated position separated from the image carrier, the operator can easily remove the jammed paper in the transfer unit, and the jammed paper is The paper jam can be handled extremely easily and quickly without damaging the body or breaking the body in the middle. According to the second aspect of the present invention, when the detecting means detects a paper jam in a transport path other than the transfer position of the toner image, the plurality of units are rotated together with the image carrier to expose the exposed portion of the image carrier. Is moved to the retreat position separated from the transfer paper transport path, so that there is no risk of an operator accidentally damaging or soiling the image carrier during a paper jam handling operation. Can be performed easily and without error. According to the third aspect of the present invention, since the image carrier is fixed at the image forming operation position, there is no possibility that the jammed paper in the transfer section is further cut in the image carrier direction.
According to the fourth aspect of the present invention, the transfer unit and the accompanying device are moved to the retracted position separated from the position facing the image carrier, so that the operation of removing the jammed paper in the transfer unit by the operator can be further improved. It can be done easily and quickly.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of a digital copying machine according to an embodiment of the present invention.

FIG. 2 is a perspective view of the digital copying machine.

FIG. 3 is a front view showing a fixed state of the electrophotographic process unit of the first embodiment.

FIG. 4 is a front view showing an unlocked state of the electrophotographic process unit.

FIG. 5 is a front view showing a fixed state of the electrostatographic process unit of the second embodiment.

FIG. 6 is an explanatory diagram illustrating a state in which transfer paper has been jammed in a transfer unit.

FIG. 7 is an explanatory diagram illustrating a state in which transfer paper has been jammed in a transport path other than a transfer unit.

[Explanation of symbols]

 Reference Signs List 1 photoreceptor belt 15 charging charger 16 developing device 18 transfer charger 19 separation charger 22 fixing roller 23 cleaning device 24 eraser 25 mounting opening 160 developing roller 164,235 positioning pin 167 toner tank 230 cleaning blade 231 fur brush 236 collection tank

──────────────────────────────────────────────────続 き Continued from the front page (72) Inventor Masaaki Nagano 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (56) References JP-A-62-31865 (JP, A) JP-A-62-35383 (JP, A) JP-A-61-103175 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 15/00 550 G03G 21/16-21/18 G03G 15/00 526 B65H 5/02 B65H 5/06

Claims (4)

(57) [Claims] 1. An image forming apparatus comprising an orbiting image carrier and a plurality of electrostatic photographic processing means disposed around the image carrier, detects a paper jam in a transfer path of a transfer sheet. Detection means, control means for controlling the operation of the image forming apparatus, and at least a part of the plurality of electrophotographic processing means are formed separately and rotatable integrally with the image carrier. And at least two units that are detachable from the image carrier and partially cover the surface of the image carrier when the image carrier is mounted on the image carrier. The image forming apparatus according to claim 1, wherein when a paper jam of the transfer paper is detected, the control unit performs control to move the unit to a separated position separated from the image carrier. 2. An image forming apparatus comprising an orbiting image carrier and a plurality of electrostatic photographic processing means disposed around the image carrier, detects a paper jam in a transfer paper transport path. Detection means, control means for controlling the operation of the image forming apparatus, and at least a part of the plurality of electrophotographic processing means are formed separately and rotatable integrally with the image carrier. And at least two units that are detachable from the image carrier and partially cover the surface of the image carrier when the image carrier is mounted on the image carrier. When detecting a paper jam of the transfer paper in the transport path, the control means rotates the unit together with the carrier to move the exposed portion of the image carrier to a retracted position separated from the transport path of the transfer paper. Control An image forming apparatus comprising: 3. The image forming apparatus according to claim 1, wherein when the detecting unit detects a paper jam at the transfer position of the toner image, the control unit performs control to fix the image carrier at the image forming operation position. An image forming apparatus comprising: 4. The control device according to claim 1, wherein when the detection unit detects a paper jam at the transfer position of the toner image, the control unit moves the transfer unit and its accompanying device from the position facing the image carrier. An image forming apparatus that performs control for moving to a separated evacuation position.