JPH07319280A - Developing device for image forming device - Google Patents

Abstract

PURPOSE:To improve vibration-proofing and impact resistance without increasing load torque imposed on a driving motor by providing a positional deviation preventing mechanism for preventing a developing device shifted to a developing state from getting out of a specified position in the middle of a motive power transmitting means. CONSTITUTION:In a developing actuation state where a developing machine approaches to a photoreceptor, the crank parts 29a and 29b of crank shafts 28a and 28b are stopped at a position by theta deg. before the moving direction (dead point) of the developing machine (a). It is proper to set theta deg. to 5-10 deg.. A state where the crank shafts 28a and 28b are rotated clockwise by 120 deg. from the above state (b) and a state where they are rotated clockwise by 120 deg. further (c) are a separation state, respectively. The positional deviation preventing mechanism is provided in the driving transmitting means. Therefore, even when the developing device gets out of the specified position and the driving transmitting means is idly rotated, the positional deviation preventing mechanism is actuated and the deviation in a position of the developing device is prevented. Especially, the driving transmitting means is prevented from being idly rotated to a reverse rotating side.

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 which is movable toward and away from an image carrier (photoreceptor).

[0002]

2. Description of the Related Art An electrophotographic image forming apparatus in which a developing device moves between a developing operation position and a non-developing operation position with respect to an image carrier, and a copying operation is performed when the developing device is in the developing operation position. If the developing device comes out of the developing operation position during this time, a miscopy of image loss will be output, or if the developing device is unfixed during the transfer of the image forming device body, it will be affected by vibration or shock. The developer may spill out and cause problems such as paper stains and stains inside the machine.

Conventionally, as means for moving a developing device between a developing operation position and a non-developing operation position and stopping it at a predetermined position, (1) When a plurality of developing devices are moved, each developing device is equipped with By controlling the solenoid ON-OFF, the spring clutch controls the transmission of the drive for the movement of the developing device,
The developing device is moved to a predetermined position. After the developing device is moved, the solenoid and the spring clutch are in a fixed state, so that each developing device is also fixed (for example, Japanese Patent Laid-Open No. 63-97968).

(2) By detecting that the developing device is in either the developing operating position or the non-developing operating position, the developing device is selectively controlled to drive the movement stopping pressurizing means. (For example, JP-A-2-42464).

(3) Each developing device is provided with a lock mechanism that serves as a resistance against the rotation of the crankshaft that moves and pressurizes the developing device at the moment when it starts moving from a predetermined position.

[0006]

The above-mentioned conventional techniques have the following problems corresponding to them. (1) Since one set of solenoid and spring clutch is required for each developing device, the structure becomes complicated and the cost becomes high. Further, due to the structure of the spring clutch, the inner surface angle and the outer arm angle depend on the accuracy of the hook angle of the coil spring, so that the adjustment is necessary individually and the reliability is poor.

(2) The movement stop pressurizing means of the developing device is driven by a cam, and the control method is by a solenoid and a spring clutch, which has the same problem as (1). (3) The holding force is such that the developing device is held at a predetermined position and is easily released without interfering with the rotation of the crankshaft that drives the moving pressurization, and the vibration and the image during the copying operation. It is very difficult to design the balance of the holding force of the lock mechanism, because a sufficient holding force is required to withstand the vibration and shock that accompany the transfer of the forming apparatus body.

Further, since the phase angle of the crankshaft corresponding to the developing operation position of the developing device is 0 ° in the horizontal direction with respect to the image carrier, the developing device is held at the peak value of the rotational torque of the crankshaft. Become. For this reason, the developing device is in an unstable state in which it can rotate both in the forward rotation direction and in the reverse rotation direction, and the position of the developing device can easily be disengaged due to disturbance such as vibration and shock.

The present invention has been conceived in view of the above, and when any of the developing devices is in the developing operation position, the internal vibration and image during the copying operation can be performed without increasing the load torque to the drive motor. It can withstand vibration and shock when transferring the forming device body.
An object of the present invention is to provide a developing device in an image forming apparatus in which a mechanism for moving the developing device can be simplified.

[0010]

In order to achieve the above object, a developing device in an image forming apparatus according to the present invention is provided with a plurality of developing devices for an image bearing member in a developing state and a non-developing state. In the developing device in the electrophotographic image forming apparatus, which is arranged so as to be able to come into contact with and separate from each other, and which is provided with a moving means connected to a driving source driven by electric means such as a motor via a power transmission means, in each developing device, In the middle of the power transmission means, there is provided a position deviation prevention mechanism for preventing the developing device moved to the developing state from coming off from a predetermined position.

In the above structure, a one-way clutch for limiting the rotation of the power transmission means in the idling direction is provided in the middle of the power transmission means, and the phase angle corresponding to the developing position is located before the peak value of the rotational torque. The configuration is set to.

As a means for holding and fixing the developing device at a predetermined position, a lock mechanism for locking a drive transmission system for moving the developing device by turning on and off a solenoid is used.

Further, each of the above-mentioned developing devices is
In addition to having one or more developing positions, it has two or more non-developing positions.

Then, a reference position setting function for drive control is provided to a part of the driving means for moving the plurality of developing devices, and the position of each developing device is predicted from the reference position as a starting point and driving is stopped. The timing is controlled to move and stop the selected developing device.

In the construction showing the above means, the developing device comprises a developing machine and a supporting member for supporting the developing machine.
The moving means may be connected to either the developing machine or the supporting member.

[0016]

[Operation] Each of the above developing devices is removed from the specified position,
Even if the drive transmission means tries to rotate idly, the positional deviation prevention mechanism operates and the positional deviation of each developing device is prevented. In particular, idling of the drive transmission means to the reverse side is prevented.

[0017]

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 sheet feeding device 8 including a plurality of sheet feeding trays 5a, 5b and 5c, a sheet feeding 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 a developed 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 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 made into a process unit together with the charger 16 and the 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. There is.

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 devices 17a and 17b is movable in the contacting / separating direction 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 backs 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, 28b will be described with reference to FIGS. 7, 8 and 9. The rotary drive mechanism 31 is located on the back side of the machine body, and the 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 via a driven gear 35 concentric with the pivot 4 and another driven gear 36 to a tooth drive gear 37 driven by a position converting drive motor. The first and second crankshaft gears 32a and 32b rotate clockwise in FIG. 8, respectively.

A cylindrical hole 38 is provided on the inner side of the intermediate gear 33 with the same axis, and a locking tooth 39 is 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 about the axis of the pivot 4 which is the pivot point of the upper mechanism 2. It is meshed with a fixed fan gear 42, and when the upper mechanism 3 is opened around the pivot 4 in an alligator shape, 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 tooth 39 and the locking claw 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 moved, for example, the rotation angle θ of the locking claw 40.
The locking teeth 39 with a margin of ₁ , for example 5 to 10 degrees.
To face.

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 this and meshes with the fan gear 42 so that the retracting 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 opening and closing the alligator 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 ON / OFF of the sensor 46 controls the ON / OFF control of the drive motor for position conversion. 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 of the two positions, namely, the home position, the retracted position, and the first developing device position (color copy position),
48c are provided at 120 ° intervals. A positioning arm 49 is in contact with the cam plate 47 by a spring 50 as shown in FIG. 14A or by a solenoid 51 as shown in FIG. 14B. Protrusions 52 are provided which engage with the cutouts 48a, 48b, 48c in a disengageable manner, and the protrusions 52 engage with the cutouts 48a, 48b, 48c at the above-mentioned positions, and the positions are set and set. It is like this.

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 arm 49 operates in response to the signal from the sensor 46 or the stop signal of the drive motor. The assisting fixing of the cam plate 47 can prevent the developing machine from being displaced due to vibration during transportation of the apparatus main body, operation of the apparatus, and the like.

A stepping motor is used as the drive motor, but the drive motor is used to drive 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. The first and second developing machines 17a and 17b are stopped, and as shown in FIG.
The first developing device 17a is in a non-developing state in which it is separated from the photoconductor 14, and the second developing device 17b is in a developing state in which it approaches the photoconductor 14.

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, 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, the process shown in FIG.
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 crank shaft 28a engaged with the developing machine 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 reverse 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 17b 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 sandwiched between the peak value of the rotational torque of the crankshaft and the engagement position of the one-way clutch composed of the locking teeth 39 and the locking claws 40. It

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 marginal angle 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 17
a and 17b are capable of stably forming an image during the copying operation at the respective developing operation positions,
Further, even when vibration or impact is applied from the outside due to transfer of the main body of the image forming apparatus or the like, the developing machines 17a and 17b are fixed without deviating from the predetermined positions.
The developer does not spill over from 17b and the inside of the machine is not polluted.

In the above operation, as shown in FIG.
The first crankshaft 28a in each state shown in (b) and (c) has a cam plate 47 as shown in FIGS. 14 (a) and (b).
And the protrusion 52 of the arm 49 are engaged with each other for positioning. This enhances the positioning function described above.

Next, the operation when the upper mechanism 3 is opened in an alligator shape with the drive motor stopped and the home position is described. In the home position, the locking claw 4 of the one-way clutch provided in the intermediate gear 33
0 faces the locking tooth 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, by setting the rotation angle of the retracting gear 41 to 120 °, both gears 32a and 32b rotate 120 ° from the home position, and therefore both developing machines 17a and 17b. Changes from the state shown in FIG. 15 to the state shown in FIG.

In the above embodiment, an example in which two sets of developing machines are provided has been shown, but the number of sets may be three or more (N). In this case, 360 ° in the rotation direction of the crankshaft is equally divided into (N + 1) to be the stop position of the crankshaft. In this case, if the number of N increases, it becomes impossible to obtain a sufficient retract distance. Therefore, in the case of four developing machines, there is a tradeoff with the apparatus main body, but it is more space to use the two developing machines described above. It may be advantageous in terms of torque, etc., and should be selected according to the situation.

The above description has been made with respect to the case where the stop position in the rotation direction of the crankshaft is equally divided into 360 ° (N + 1).
As an anomalous example, FIG. 17 shows the position of the (2nd) developing machine in the case of three developing machines. When the second developing device is in the developing state, the first (1st) developing device and the third developing device
In the developing machine of (3rd), it is sufficient that the developing device is at a distance at which the ears do not come into contact with the photosensitive member, and the retracting distance may be short.

This is the same when the first and third developing machines are in the developing state. Then, by setting the retreat distance as much as possible when retreating all the developing machines that require the most retracted distance, the case of a plurality of developing machines can be established.

[0062]

According to the present invention, even when any of the developing devices is in the developing operation position, vibration during the copying operation and transfer of the main body of the image forming apparatus can be performed without increasing the load torque to the drive motor. Can withstand vibrations and shocks such as time.

Further, according to the present invention, the mechanism for moving another developing device to the non-developing position when one developing device is in the developing state becomes simple, and high reliability and low cost can be realized. It was

Further, by adding the reference position setting function, it becomes possible to perform feedforward control for setting the stop of the driving of the drive motor after an arbitrary time from the signal of the sensor, and the optimum setting can be made for each developing device. Even with variations in position control due to changes over time such as wear of parts, it is possible to easily respond by changing the signal (time to stop position) by using the diagnostic.

[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 the 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.

5A, 5B, and 5C are explanatory diagrams showing stop positions of a crank portion of a crank shaft at respective positions of a developing machine.

FIG. 6 is an exploded perspective view showing a supporting structure of the 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 unit of the developing device contact / separation drive unit 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 portion 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 showing a power transmission portion 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 means 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 the positional relationship of the developing machine when the upper mechanism is opened.

FIG. 17 is an operation explanatory view showing the positional relationship between the developing machines when three developing machines are used.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Device main body, 2 ... Lower mechanism, 3 ... Upper mechanism, 4 ... Pivot, 5a, 5b, 5c ... Paper feed tray, 6 ... Paper feed roller, 7 ... Registration roller, 8 ... Paper feed device, 9 ... Transfer device 10 ... Fixing device, 11 ... Paper discharging device, 13 ... Recording paper,
14 ... Photoconductor, 15 ... Laser writing device, 16 ... Charging device, 17a, 17b ... Developing device, 18 ... Cleaner, 19 ...
Sorters, 21a, 21b ... Support members, 22 ... Developing rollers, 23a, 23b ... Contact / separation drive device, 24 ... Push rod, 2
5 ... Cylindrical body, 26, 50 ... Spring, 27 ... Oblong hole, 28a, 2
8b ... Crank shaft, 29a, 29b ... Crank part, 30
a, 30b ... Guide member, 31 ... Rotational drive mechanism, 32a,
32b ... crankshaft gear, 33 ... intermediate gear, 34 ... intermediate shaft, 35, 36 ... driven gear, 37 ... drive gear, 38 ... cylindrical hole, 39 ... locking tooth, 40 ... locking claw, 41 ... retracting gear , 42 ... fan gear, 45 ... dog plate, 46 ... sensor, 47
... Cam plates, 48a, 48b, 48c ... Notches, 49 ... Arms, 51 ... Solenoids, 52 ... Protrusions.

Claims (5)

[Claims] 1. A plurality of developing devices for the image carrier,
It is arranged so that it can come into contact with and separate from the developed state and the non-developed state,
In a developing device in an electrophotographic image forming apparatus in which each developing device is provided with a moving means connected to a drive source powered by electric means such as a motor through a power transmitting means, in the middle of the power transmitting means, A developing device in an image forming apparatus, which is provided with a positional deviation prevention mechanism for preventing the developing device moved to a developing state from being displaced from a predetermined position. 2. A one-way clutch for limiting the rotation of the power transmission means in the idling direction is provided in the middle of the power transmission means, and the phase angle corresponding to the developing position is set before the peak value of the rotational torque. The developing device in the image forming apparatus according to claim 1, wherein. 3. A lock mechanism that locks a drive transmission system for moving the developing device by turning a solenoid on and off as means for holding and fixing the developing device at a predetermined position. A developing device in the image forming apparatus described. 4. A plurality of sets of developing devices for the image carrier,
It is arranged so that it can come into contact with and separate from the developed state and the non-developed state,
In a developing device in an electrophotographic image forming apparatus, in which each developing device is provided with a moving means connected to a drive source powered by an electric means such as a motor through a power transmitting means, the developing devices are arranged in a moving direction. In the image forming apparatus, the developing device has one or more developing positions and two or more non-developing positions. 5. A reference position setting function for drive control is provided to a part of drive means for moving a plurality of developing devices, and the position of each developing device is predicted and driven with the reference position as a starting point. 5. The developing device in an image forming apparatus according to claim 4, wherein the timing of stop is controlled to move and stop the selected developing device.