JPH07319267A - Developing device for image forming device - Google Patents

Abstract

PURPOSE:To surely automatically retreat developing devices from an image carrier without requiring a special operation at the time of pulling out the image carrier. CONSTITUTION:This image forming device provided with the image carrier 14 capable of being loaded/unloaded in/from a device main body in the front, the developing devices 17a and 17b arranged so that they can be in contact/ uncontact with the image carrier 14 to obtain developing and nondeveloping states and contact/uncontact driving mechanisms 23a and 23b moving the developing devices 17a and 17b to obtain the developing or nondeveloping state is constituted to provide a driving mechanism for retreating moving the developing device in the developing state to the nondeveloping state linked with an operation accompanied with the loading/unloading operations of the image carrier 14 and a means actuated to retreat only with the first operation, even if the operation for actuating the driving mechanism for retreating is consecutively repeated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device in an electrophotographic image forming apparatus such as an electrophotographic copying machine or a printer.

[0002]

2. Description of the Related Art An electrophotographic image forming apparatus has a structure in which a charging device, an image exposing section, a developing device, a transfer device, a cleaner and the like are sequentially arranged around a photoconductor in the rotating direction thereof. , If this is a model for pulling out the photoconductor and the developing machine from the main body of the device for inspection, repair, etc., the developing machine can be moved toward and away from the photoconductor and pull out the photoconductor and the developing machine from the main body of the device At this time, the developing device is moved to a separated position so that the photosensitive member and the developing device do not come into contact with each other and the photosensitive member is not damaged.

By the way, as a contacting / separating mechanism of a conventional developing machine, (1) a knob for manual contacting / separating is provided on the main body of the apparatus, and the knob is manually rotated when the developing apparatus is contacted / separated. There is. (2) The developing device is separated in conjunction with the operation of rotating the toner box on the front side of the apparatus main body. (3) Due to the rotational moment generated in the developing device by opening and closing the upper machine frame, the developing device is separated by its own weight (for example, Japanese Patent Laid-Open No. 4-50
594). Etc. were taken.

[0004]

The above-mentioned conventional techniques have the following problems corresponding to them. (1) Since the operator operates manually, the photosensitive member (process unit) and the developing device are pulled out while the separation work is forgotten, and the surface of the photosensitive member is damaged. There is.

(2) The cost increases due to the drive transmission gear that is interlocked with the opening operation of the toner box, the solenoid for controlling the drive transmission with the drive shaft, and the spring clutch. (3) When the rotating shaft moves poorly due to the evacuation due to its own weight, the separation may be insufficient and the photoconductor may be damaged.

The present invention has been made in view of the above, and when the process unit photosensitive member is pulled out from the main body of the apparatus, no special operation is required, and all developing devices are automatically secured from the photosensitive member. It is an object of the present invention to provide a developing device in an electrophotographic image forming apparatus that can be operated in a state of being separated from each other, can operate the photoconductor without interfering with the developing device, and can realize the above-described function at low cost. To do.

[0007]

In order to achieve the above object, a developing device mounting apparatus of an electrophotographic image forming apparatus according to the present invention comprises an image carrier which is detachable on the front side of the apparatus body. A developing device arranged to be in contact with and separated from the image carrier in a developing state and a non-developing state, and a contacting / separating drive mechanism for moving the developing device between the developing state and the non-developing state. In the image forming apparatus having, in the contact / separation drive mechanism, an evacuation drive mechanism for moving the developing device in the developing state to the non-developing state in association with the operation accompanying the loading / unloading operation of the image carrier is provided. The evacuation drive mechanism has a structure for performing evacuation operation only by the first operation even when the operation for operating the evacuation drive mechanism is continuously repeated.

[0008]

[Operation] When, for example, the upper mechanism is opened like an alligator in order to pull out the image carrier, the evacuation drive mechanism operates in conjunction with this operation and the developing device is retracted from the image carrier. The developing device is retracted only by this first operation, and the retracting drive mechanism is not operated even if the alligator opening operation of this upper mechanism is repeatedly operated.

[0009]

EXAMPLES Examples of the present invention will be described with reference to the drawings. FIG. 1 shows an image forming apparatus 1 including an apparatus according to the present invention.
In one embodiment, reference numeral 1 in the drawing is an apparatus main body, and the apparatus main body 1 has a structure in which a lower mechanism 2 and an upper mechanism 3 are separated from each other. The pivot 4 located on the lower right side as viewed can be opened and closed like an alligator with respect to the lower mechanism 2 with respect to the pivot.

The lower mechanism 2 includes a paper feed device 8 including a plurality of paper feed trays 5a, 5b, 5c, a paper feed roller 6, a pair of registration rollers 7, a transfer device 9, and a fixing device 1.
0, a paper discharge device 11 and the like are provided. Each paper feed tray 5a,
5b and 5c can be taken in and out on the front side of the lower mechanism 2 and the recording paper 13 can be replenished on the front side.

On the other hand, the upper mechanism 3 includes a photoconductor 14, a laser writing device 15 for writing an original image on the photoconductor 14 with a laser beam, and a uniform charging before writing on the photoconductor 14 by the laser writing device 15. The charging device 16 and a plurality of sets for developing the electrostatic latent image written by the laser writing device 15 into a toner image, for example, first and second developing devices 17a and 17b and a cleaner 18 are provided.

The photoconductor 14 faces the transfer device 9 and the paper feeding device 8 of the lower mechanism 2, and the recording paper 13 supplied from the paper feeding device 8 is transferred onto the photoconductor 14 by the transfer device 9. The toner image is transferred. The recording paper 13 on which the toner image is transferred is heated and fixed by the fixing device 10 and discharged from the paper discharging device 11 to the sorter 19 or the like.

The photoconductor 14 is formed as a process unit together with a charger 16 and a cleaner 18, and this process unit can be pulled out to the front side in a state where the upper mechanism 3 is opened with the pivot 4 as a fulcrum and can be detached. ing.

In the case of a color copying machine, the developing machines 17a and 17b are provided with only the types of toner colors. In this embodiment, the second developing machine 17b is for black, the first developing machine 1 is
7a is for color. And both developing machines 17
a and 17b are the first developing machine 17a when waiting for copying.
Is separated from the photoconductor 14 and the second developing device 17b is set to a so-called home position in which the second developing device 17b approaches the photoconductor 14 and is in a developing state.

As shown in FIGS. 2 to 4, each of the developing units 17a and 17b is movable in the contacting and separating directions with respect to the photoconductor 14 and is supported by the frame body side.
Are supported by the supporting members 21a and 21b, and the developing rollers 22 come into contact with and separate from the photoconductor 14 by the movement of the supporting members 21a and 21b.
Each of the developing machines 17a and 17b can be taken in and out from the front side of the main body device with respect to each of the supporting members 21a and 21b.

Contacting / separating drive devices 23a, 23a for moving each developing device in the contacting / separating direction are connected to the back portions of the supporting members 21a, 21b. Since the two contact / separation drive devices 23a and 23b have the same mechanism, the second developing device 17b will be described with reference to FIG. Note that FIG. 5 is a view seen from the back side of the main body device.

A pair of push rods 24 are provided on the back surface of the support member 21b.
A cylindrical body 25 is slidably fitted into each of the push rods 24, 24 while being biased by a spring 26 in a direction in which they are separated from each other. And this cylinder 2
5, an elongated hole 27 elongated in the direction perpendicular to the moving direction of the support member 21b is provided. The elongated hole 27 on the side of the first support member 21a has the first crankshaft 28a, and the elongated hole 27 on the side of the second support member 21b has the second crankshaft 28a.
The respective crank portions 29a, 29b of b are fitted respectively, and when the crank shafts 28a, 28b rotate, they are reciprocated along the front and rear guide members 30a, 30b.

The positions in the moving direction of the developing machines 17a and 17b with respect to the rotation angles of the crankshafts 28a and 28b are as shown in FIGS.
Details will be described in (a), (b), and (c). FIG. 6A shows the developing operation state in which the developing machines 17a and 17b are close to the photoconductor 14, and the crank portions 29a and 29b of the crankshafts 28a and 28b at this time are in the moving direction (death) of the developing machines 17a and 17b. It is designed to stop at a position that is θ ° ahead of the point). It is suitable that this θ ° is about 5 to 10 °.

FIG. 6B shows a state in which the crankshafts 28a and 28b have been rotated 120 ° clockwise from this state.
FIG. 6C shows a state further rotated by 120 ° in the clockwise direction, and both states are separated states.

2, FIG. 3 and FIG. 4, in FIG. 2, the second developing device 17b is in the developing position and the first developing device 17b is in the developing position.
FIG. 3 shows a state in which a is separated from each other, that is, a so-called home position (2nd developing device position).
7b shows a retracted position state in which the first developing device 17a is in the developing position.
The respective developing machine position states are shown.

Next, a rotary drive mechanism 31 for rotationally driving both crankshafts 28a and 28b will be described with reference to FIGS. 7, 8 and 9. The rotary drive mechanism 31 is located on the inner side of the machine body, and first and second crankshaft gears 32a and 32b are fixed to the ends of the crankshafts 28a and 28b, respectively. The two gears 32 a and 32 are connected via an intermediate gear 33. These gears 32a, 32b, 33
Have the same number of teeth. The intermediate gear 33 is rotatably supported by the intermediate shaft 34. Note that FIG. 8 shows a state in which the upper mechanism 3 is opened like an alligator.

The second crankshaft gear 32b is connected to a tooth drive gear 37 driven by a position converting drive motor through a driven gear 35 concentric with the pivot 4 and another driven gear 36. However, the first and second crankshaft gears 32a and 32b respectively rotate clockwise in FIG.

A cylindrical hole 38 is provided inside the intermediate gear 33 with the same axis, and locking teeth 39 are provided on the inner surface of the cylindrical hole 38. The intermediate shaft 34 is rotatably supported with respect to the machine frame.
The locking claw 40 that engages with 9 is fixed.

The relationship between the locking tooth 39 and the locking claw 40 is as follows.
The intermediate shaft 34 is counterclockwise in FIG. 8 (direction of opening the alligator).
When it rotates, the intermediate gear 33 is integrally rotated counterclockwise.

A retracting gear 41 is fixed to the intermediate shaft 34, and the retracting gear 41 is mounted on the machine frame of the lower mechanism 2 around the axis of the pivot 4, which is the pivot point of the upper mechanism 3. It is meshed with the fixed fan gear 42, and when the upper mechanism 3 is opened in the form of an alligator about the pivot 4, the retracting gear 41 meshes with the fan gear 42 and rotates by a predetermined angle. , The locking claw 40 is integrally formed with the intermediate gear 3
It is designed to rotate within 3.

The positional relationship between the locking teeth 39 and the locking claws 40 in the rotational direction, and the first and second crankshafts 28a, 28
The relative relationship between the rotational orientations of b will be described below. Figure 1
0 (a) and (b) indicate the home position state in which the upper mechanism 3 is closed and the first and second crankshafts 28
a and 28b are 240 ° out of phase. In this state, the locking claw 40 is slightly inclined, for example, the rotation angle of the locking claw 40 is θ °.
₁ , for example, to face the locking teeth 39 with a margin of about 5 to 10 °.

When the upper mechanism 3 is opened like an alligator in the above state, as shown in FIGS. 11 (a) and 11 (b), it interlocks with the fan gear 42 to engage with the evacuation gear 41. Is rotated, whereby the locking claw 40 engages with the locking tooth 39 to rotate the intermediate gear 33 over 120 °. That is, the gear ratio of the retracting gear 41 and the fan gear 42 is set to 120 for the intermediate gear 33 depending on the opening angle of the alligator.
° It is in a rotating relationship. In this state, both developing machines 17
a and 17b are in the retracted state.

When the alligator is closed from the above state, the retracting gear 41 reverses by the same rotation angle as the above operation, but the intermediate gear 33 rotates only a slight angle corresponding to the rotation angle of the alligator, so that it is locked. The claw 40 is not opposed to the locking tooth 39. Therefore, after the alligator opening operation is performed once, the first and second crankshaft gears 32a and 32b do not rotate no matter how many times they are opened and closed, and both developing machines 17a and 17b maintain the retracted state. ing.

A fan-shaped dog plate 45 is attached to the side surface of the first crankshaft gear 32a, and a sensor 46 for reading the position of the dog plate 45 is provided on the bracket side. The dog plate 45 has an angle size of 120 °.

The positional relationship between the dog plate 45 and the sensor 46 is shown in FIG. 12 at the home position (black development).
As shown in FIG. 12A, the dog plate 45 has passed the sensor 46 and the sensor 46 is turned OFF. As shown in FIG. 12B in the retracted position, the dog plate 45 has the sensor 46.
12C, the OFF state is maintained, the dog plate 45 begins to cross the sensor 46, and the sensor 46 is turned ON. There is.

The position conversion drive motor is controlled to be turned on and off by turning the sensor 46 on and off. 13 (a) and 13 (b) show the sequence, and FIG. 13 (a) shows the control when making a black copy from the retracted position to the home position. When a certain time elapses after the drive motor is started, the dog plate 45 crosses the sensor 46 so that the sensor 46 is turned off.
It becomes N, and then the home position is reached by passing by. As a result, the drive motor is stopped after Tsec and the home position state is maintained. And during this time a black copy is taken.

FIG. 13B shows the first position from the retracted position.
The control when making a color copy at the developing machine position is shown. After a certain time has passed since the start of the drive motor,
The dog plate 45 crosses the sensor 46, and the sensor 46 is turned on. Then, after Tsec has elapsed, the drive motor is turned off, and a color copy is taken during this period. Then, the driving motor is turned on at the same time when the color copying is completed, the dog plate 45 is disengaged from the sensor 46, and then the driving motor is turned off after Tsec. The Tsec can be set arbitrarily and may be zero.

As shown in FIG.
As shown in (a), the cam plate 47 is fixed. Then, on the peripheral surface of the cam plate 47, the 3 of the crankshaft 28a
Notches 48a, 48b corresponding to one position, that is, a home position, an avoidance position, and a first developing device position (color copy position), respectively.
48c are provided at 120 ° intervals. A positioning arm 49 is urged into contact with the cam plate 47 by a spring 50 as shown in FIG. 14 (a) or a solenoid 51 as shown in FIG. 14 (b). Protrusions 52 are provided to engage with the cutouts 48a, 48b, 48c in a disengageable manner, and the protrusions 52 engage with the cutouts 48a, 48b, 48c at the respective positions to position and set the respective positions. It has become so.

Notches 48a, 48b of the cam plate 47,
48c shape, projection 52 shape of arm 49 and spring 5
The biasing force of 0 is sufficient to assist the fixing when the developing machine 17a is set to each position, and
It is designed so that it can be easily released when moving a.

As shown in FIG. 14 (b), when the solenoid 51 is attached to the arm 49, the operation is performed at a timing from the signal from the sensor 46 or the drive motor stop signal. By the assisting fixation of the cam plate 49, it is possible to prevent the displacement of the developing machine due to the vibration of the apparatus body during transportation, the operation of the apparatus, and the like.

A stepping motor is used as the drive motor, but the drive motor drives the second crankshaft gear 32.
The transmission of power of the drive motor may be controlled by interposing a clutch such as an electromagnetic clutch up to the point b. Further, as a means (sensor) for detecting the reference position, a transmission type optical sensor, a reflection type optical sensor, a contact type magnetic sensor, a non-contact type magnetic sensor, a micro switch, a pressure sensitive load cell or the like can be used.

The operation of the above configuration will be described below.
By driving the drive motor, the second crankshaft gear 32b, the intermediate gear 33, and the first gear 35 are driven via the driven gear 35.
The crankshaft gear 32a is driven to rotate.

At this time, when the command to stop at the home position is issued, in the state shown in FIG. 12A, that is, in the state where the dog plate 45 passes the sensor 46 and the sensor 46 is turned off. Stopped, first
As shown in FIG. 2, the second developing machines 17a and 17b are in a non-development state in which the first developing machine 17a is separated from the photoconductor 14 and the second developing machine 17b is in a development state in which the second development machine 17b is close to the photoconductor 14. Becomes

At this time, the rotational posture of the second crank shaft 28b engaged with the developing device 17b in the developing state is shown in FIG.
As shown in (a), the crank portion 29b is located at a position θ ° before the dead point. The rotation posture of the first crank shaft 28a engaged with the first developing machine 17a is shown in FIG.
As shown in (b), the second crankshaft 28 is rotated by 120 ° from the crank portion 29b of the second crankshaft 28.

On the other hand, when a command is issued to stop at the retreat position, it is stopped in the state shown in FIG. 12 (b), and the first and second developing machines 17a and 17b are set as shown in FIG. Both the first and second developing machines 17a and 17b are separated from the photoconductor 14.

Further, when a command to stop at the 1st developing device position (color developing) is issued,
2 (c) is stopped in the state shown in FIG.
Is in a developing state, and the second developing machine 17b is in a non-developing state.

At this time, the rotation posture of the first crankshaft 28a engaged with the developing device 17a in the developing state is shown in FIG.
As shown in (a), the crank portion 29a is at the position of θ ° in front of the dead point.

During the above position conversion, the intermediate gear 33
Is freely rotated counterclockwise. When either one of the developing machines is in the developing state, as shown in FIG.
As shown in (c), the locking claw 40 faces the locking tooth 39 with a margin of rotation angle of 5 to 10 °. Therefore, when the intermediate gear 33 is reversed by the rotation angle of 5 to 10 °, the locking claw 40 engages with the locking tooth 39 and does not rotate in the opposite direction any more, and the one-way clutch action is achieved.
At this time, the locking claw 40 is connected to the intermediate shaft 34, the retracting gear 41,
It is fixed via a fan gear 42.

When one of the developing machines 17a and 147b is in the developing state and the crankshafts 28a and 28b idle in the reverse rotation direction, the locking claw 40 and the locking teeth 39 are rotated in the reverse rotation of about 5 to 10 °. Is locked and this reverse rotation is stopped. On the other hand, idling in the forward rotation direction is substantially not performed because the crankshaft rotates in the dead center direction. Therefore, the idle rotation of the crankshafts 28a and 28b is limited to a narrow range between the peak value of the rotational torque of the crankshaft and the position where the one-way clutch composed of the locking teeth 39 and the locking claws 40 is engaged. .

At this time, the phase angle of the crankshafts 28a, 28b is shifted to the front side from the dead center by 10 to 20 ° which is the sum of the angle θ ° from the dead center and the margin of the one-way clutch. However, the displacement in the moving direction of the developing machines 17a and 17b is about a stroke reduction of 0.9 mm even when the displacement angle of the crankshaft is 20 °.
Since it is within the absorption range of the spring biasing the spring from the rear of the developing device toward the photoconductor 14, the developing devices 17a and 17b are not displaced from the developing operation position, and the image formation is not affected.

Therefore, according to this embodiment, each developing machine 1
7a and 17b can stably form an image during the copying operation when they are in their respective developing operation positions, and even when vibration or shock is applied from the outside due to the transfer of the image forming apparatus main body, Each developing machine 17a, 17
b is fixed without being disengaged from the predetermined position, and
The developer does not spill over from 7a and 17b and stains the inside of the machine.

Next, the operation when the upper mechanism 3 is opened like an alligator while the drive motor is stopped and at the home position will be described. In the home position, the locking claw 4 of the one-way clutch provided in the intermediate gear 33
0 is opposed to 39 with a slight margin (5 to 10 °).

In this state, when the upper mechanism 3 is opened like a crocodile with the pivot 4 serving as a pivot point, the state shown in FIG. 10 changes to the state shown in FIG. 11, and the evacuation gear 41 meshed with the fan gear 42. Rotates by an angle corresponding to the opening angle of the upper mechanism 3, and the rotation is transmitted to the intermediate gear 33 via the locking claw 40 and the locking tooth 39, whereby the first and second crankshaft gears 32a, 32b are respectively provided. Rotates in the operating direction (clockwise).

At this time, the number of teeth of the retreat gear 41 with respect to the fan gear 42 is set so that the retreat gear 41 rotates by 120 ° according to the rotation angle of the upper mechanism 3, so that the intermediate gear 33 as well. The crankshaft gears 32a, 32b are rotated by 120 ° from the home position, respectively, by 120 °, so that both developing machines 17a, 17b are rotated.
As for b, as shown in FIG. 3, from the state shown in FIG. This state is shown in FIG. 15 and FIG. 16 in relation to the upper mechanism 3, and both developing machines 17a and 17b are in the retracted state by performing the opening operation from the closed state shown in FIG. 15 to the one shown in FIG. Becomes

When the upper mechanism 3 is closed from the above state, the retracting gear 41 is moved by the closing gear angle by the closing gear angle 4.
Rotate in the opposite direction along 2. As a result, the locking claw 40 also reversely rotates via the intermediate shaft 34, but the locking claw 40 idles inside the intermediate gear 33. Therefore, the rotational force due to the closing operation of the upper mechanism 3 is not transmitted to the crankshaft gears 32a and 32b, and the developing devices 17a and 17b are kept in the retracted state.

Further, in the above state, that is, in the state where the upper mechanism 3 is opened once and then closed again, the locking claw 40 has not returned to the position facing the locking tooth 41, and therefore, again and again. Both developing machines 1 even if the upper mechanism 3 is opened once
7a and 17b are kept in the retracted state. The above state is released by returning to the home position by turning on / off the interlock.

[0052]

According to the present invention, when the process unitized image carrier is pulled out from the apparatus main body, no special operation is required, and the developing device is automatically and reliably retracted from the image carrier. Can be a process unit,
It can be operated without interfering with the developing device. In addition, the above function was realized at low cost.

[Brief description of drawings]

FIG. 1 is a schematic configuration explanatory view showing an electrophotographic copying machine which is an example of a machine for implementing an apparatus of the present invention.

FIG. 2 is an explanatory diagram showing a home position state.

FIG. 3 is an explanatory diagram showing a retracted state.

FIG. 4 is an explanatory diagram showing a 1st developing device position state.

FIG. 5 is an exploded perspective view showing a support structure portion of the developing machine.

6A, 6B, and 6C are explanatory diagrams showing stop positions of a crank portion of a crankshaft that can be placed at various positions of a developing machine.

FIG. 7 is a rear view showing a contact / separation drive device of the developing machine.

FIG. 8 is a structural explanatory view showing a power transmission portion of the developing device contact / separation drive device with a part thereof cut away.

FIG. 9 is a cross-sectional view showing a power transmission unit of a developing device contact / separation drive device.

10A and 10B are operation explanatory views showing a power transmission unit of the developing device contacting / separating drive device in a state where the upper mechanism is closed.

11A and 11B are operation explanatory views showing a power transmission unit of the developing device contacting / separating drive device in a state where the upper mechanism is opened.

12 (a), (b), and (c) are operation explanatory views of a power transmission unit of a developing device contact / separation drive device.

13A and 13B are operation sequence diagrams in the developing device contacting / separating operation.

14 (a) and 14 (b) are configuration explanatory views showing a positioning unit in the rotation direction of the crankshaft.

FIG. 15 is an operation explanatory view showing a positional relationship of the developing machine in a state where the upper mechanism is closed.

FIG. 16 is an operation explanatory view showing a positional relationship of the developing device in a state where the upper mechanism is opened.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Device main body, 2 ... Lower mechanism, 3 ... Upper mechanism, 4 ... Pivot, 5a, 5b, 5c ... Paper feeder, 6 ... Paper feed roller,
7 ... Registration roller, 8 ... Paper feeding device, 9 ... Transfer device, 1
0 ... Fixing device, 11 ... Paper discharging device, 13 ... Recording paper, 14 ...
Photoreceptor, 15 ... Laser writing device, 16 ... Charger, 1
7a, 17b ... Developing machine, 18 ... Cleaner, 19 ... Sorter, 21a, 21b ... Supporting member, 22 ... Developing roller, 2
3a, 23b ... Contact / separation drive device, 24 ... Push rod, 25 ... Cylindrical body, 26, 50 ... Spring, 27 ... Oblong hole, 28a, 28b ...
Crankshaft, 29a, 29b ... Crank part, 30a, 3
0b ... Guide member, 31 ... Rotation drive mechanism, 32a, 32b
... Crankshaft gears, 33 ... Intermediate gears, 34 ... Intermediate shafts, 3
5, 36 ... driven gear, 37 ... drive gear, 38 ... cylindrical hole,
39 ... Locking teeth, 40 ... Locking claws, 41 ... Retraction gears, 42
... fan gear, 45 ... dog plate, 46 ... sensor, 47 ... cam plate, 48a, 48b, 48c ... notch, 49 ... arm,
51 ... Solenoid, 52 ... Protrusion.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Enkazu Takahashi 2274 Hongo, Ebina City, Kanagawa Prefecture Fuji Xerox Co., Ltd.

Claims (1)

[Claims] 1. An image carrier which is detachable from the main body of the apparatus on the front side, and a developing device which is arranged so as to come into contact with and separate from a developing state and a non-developing state of the image carrier. In an image forming apparatus having a contacting / separating drive mechanism that moves the developing device between the developing state and the non-developing state, the contacting / separating drive mechanism is interlocked with the operation accompanying the mounting / dismounting operation of the image carrier. Then, a retracting drive mechanism for moving the developing device in the developing state to the non-developing state is provided.
A developing device in an image forming apparatus, which has means for performing a retracting operation only by a first operation even when an operation for operating the retracting drive mechanism is continuously repeated.