JP2003323029A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of easily and surely stopping and holding the rotation of a turning type developing body without driving the driving means of the turning type developing body as an image forming apparatus where a supporting frame body supporting at least a turning type developing body can be pulled out from an apparatus main body. <P>SOLUTION: The image forming apparatus has the turning type developing body 104 having a developing device 20 for developing an electrostatic latent image formed on an image carrier 101 by using developer turnably around a turning shaft 104b, and the supporting frame body 11 supporting at least the developing body 104 and pulled out from the apparatus main body A. In the apparatus, a holding means 1 for holding the developing body 104 in a rotation stopping state is provided in the frame body 11. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic or electrostatic recording type image forming apparatus such as a copying machine, a printer or a facsimile, and more particularly to a color copying machine, a color facsimile or a color printer. Of the image forming apparatuses capable of forming a multicolor image, it is particularly suitable for use in an apparatus having a rotary developing member.

[0002]

2. Description of the Related Art Generally, in multicolor image formation, a plurality of color toner images are sequentially formed on, for example, an electrophotographic photoconductor (photoconductor) which is an image carrier, and the plurality of color toner images are formed on a recording sheet or the like. The method of superposing them on the transfer medium sequentially or collectively is used.

In such a multicolor image forming apparatus, it is necessary, for example, by mounting a developing device for each color of black, yellow, magenta and cyan on a rotary developing member and rotating the rotary developing member. A so-called rotary developing method has been proposed and put into practical use, in which a developing device is sequentially moved to a developing position facing a photoconductor as an image carrier to perform a developing operation.

Conventionally, as a supporting structure of a rotary developing member in a multicolor image forming apparatus of this type, a structure in which it is directly held by a frame of an image forming apparatus main body (apparatus main body) has been often seen. This is because the holding rigidity can be easily ensured and the structure can be simplified by holding the device main body frame.

The developing unit housed in such a rotary developing unit is constructed so that it can be pulled out in the direction of the rotation axis of the rotary developing unit, and is used from the front of the main body of the apparatus during maintenance and replacement of the developing unit. There were many configurations that achieved accessibility by accessing. On the other hand, since the photoconductor is also a regular replacement unit or a service maintenance unit, in many cases, the unit can be directly pulled out from the apparatus main body in order to improve the replacement / service maintenance property.

On the other hand, the gap between the developer carrying member (developing sleeve etc.) and the photosensitive member (photosensitive drum etc.) provided in the developing device housed in the rotary type developing member has a great influence on the image characteristics. In many multicolor image forming apparatuses using a rotary developing member, a so-called abutting roller type developing means that easily guarantees this gap directly is used.

In the rotary type developing body containing the developing device having the abutting roller type developing means, the developing device is abutted against the photoconductor after the development of the preceding color is completed in the continuous image forming operation ( It was necessary to perform a series of operations in which the rotation type developing body is started to rotate, the rotation is stopped for a predetermined angle, and then the rotation is stopped and the developing device is pressed against again. .

However, in recent years, the speed of multicolor image forming apparatuses has been increasing, and there is a demand for shortening the time required for rotating / stopping the rotary developing member during image formation and starting the developing process. In such a situation, there is no time for pressing and releasing pressure of the abutting roller method, so by adjusting the gap between the developer bearing member and the photosensitive member to a predetermined value in advance, There have been found many configurations in which the developing process can be started only by making the color developing device face the photoconductor.

Recently, in the rotary developing member, maintenance may be required not only in the developing device but also in other parts. Therefore, in order to improve service maintenance, the photosensitive member and the rotary developing member are combined into one frame. It is also becoming possible to see a device that is supported by the frame and is configured so that the frame body can be pulled out from the main body of the device.

As a merit of this structure, not only the service maintenance property is improved as described above, but also when the gap between the developer carrying member and the photosensitive member is adjusted and assembled, the positional accuracy is easily obtained. This gap value has the advantage of being stable.

In addition to the problems of the support structure of the rotary type developer described above, in the multicolor image forming apparatus having the rotary type developer, the rotation stop control of the rotary type developer is important. There are challenges.

Conventionally, there are many examples in which a stepping motor is used as the rotation driving means of the rotary developing member. In this rotation control, many controls are performed to count the number of pulses and stop the rotation of the rotary developing member at the developing position based on a predetermined sensor signal.

In the case of a multicolor image forming apparatus of the type in which a developer cartridge, which is a developer accommodating portion, is housed in a rotatable developing member, which is often found in the past, a rotation stopping method of simply rotating and stopping at a predetermined position. Using, when the user tries to replace the developer cartridge at the time of replacing the developer cartridge and applies an operation force to release the lock mechanism of the cartridge, the rotation type developing member rotates due to the rotation moment of the operation force, In some cases, the developer cartridge cannot be replaced because the operation feeling becomes poor or, in the worst case, the rotation angle becomes large.

Therefore, as for the method of stopping the rotation of the rotary developing member, there are many conventional ones that simply continue to excite the phase of the stepping motor at the developing position as seen in Japanese Patent Publication No. 10-260581. .

Further, as disclosed in Japanese Patent Publication No. 11-038754, the rotating force is suppressed by a knob extending from the central axis of the rotary type developing member to the front surface of the apparatus main body frame, and the developer cartridge is replaced. The composition was also seen.

On the other hand, the structure of the multicolor image forming apparatus is as follows.
Most often, a configuration is used in which only the black developing device is removed from the rotary developing member, and the black developing device is independently placed at a position facing the photosensitive member. The merit of this configuration is that, for example, when a black monochromatic image is continuously formed, the developer carrying member of the color developing device provided on the rotary developing member is stopped at a position apart from the photoconductor. By making it stand by, the durability around the color developing device can be improved. In such a configuration, if control is performed such that the phase of the stepping motor is continuously excited to keep the rotary developing member at the stop position, problems such as an increase in power consumption and an increase in temperature inside the machine occur.

In this case, even if the excitation of the stepping motor is stopped, the rotation can be suppressed to a certain extent by the rotation suppressing force of the stepping motor, so-called cogging. However, if the stepping motor rotates one step or two steps when the weight balance of the rotary developing member is lost, the subsequent operation may not be guaranteed.

The same can be said when replacing the developer cartridge, and if there is no reliable rotation-preventing mechanism for the rotation type developing body, it rotates during the replacement of the developer cartridge,
Not only the exchange operability is deteriorated, but also the operation cannot be guaranteed. Further, in consideration of energizing the rotary drive motor of the rotary type developer when replacing the developer cartridge operated by the user, in order to prevent runaway of the rotary drive motor control, a double triple It was necessary to adopt a configuration that added a heavy safety mechanism.

Therefore, Japanese Patent Publication No. 08-254874, Japanese Patent Publication No. 10-142886, and Japanese Patent Publication No. 11-31.
As disclosed in Japanese Patent No. 6479, an example in which another rotation blocking mechanism is provided instead of excitation of the rotary drive motor of the rotary developing member has been devised.

In addition to the rotary drive motor, these structures are
An engaging portion that engages with a rotation blocking mechanism provided outside the rotary developing body is provided in a part of the rotary developing body to suppress the rotational force and prevent the rotary developing body from rotating. It is composed.

In another conventional example, Japanese Patent Publication No. 07-3192.
As disclosed in Japanese Patent Publication No. 75 and Japanese Patent Publication No. 08-006467, the shape of the engaging portion that engages with the rotation preventing mechanism is devised, and the rotation direction of the rotation drive motor is normally and reversely reversed to firmly prevent rotation. There are also examples of realization of power.

[0022]

However, the conventional example has the following problems.

As described above, in the structure in which the rotary developing member is directly held by the main body of the apparatus, when trying to increase the speed,
Even if the gap between the developer carrying member and the photoconductor is adjusted and set, it is difficult to guarantee the gap value because the supporting frames are different.

Further, in the structure in which the rotary developing member is directly held by the apparatus main body, the service maintenance property when the rotary developing member is maintained deteriorates.

As for the method of stopping the rotation of the rotary developing body, only the black developing device can be used for the rotary developing body by relying on the rotation restraining force of the stepping motor that rotationally drives the rotary developing body. With the configuration arranged outside of, in the black monochromatic continuous image formation mode, it causes an increase in power consumption due to excitation,
This may cause the temperature inside the machine to rise.

Further, in the case where the developer cartridge is stored inside the rotary type developing member, if the developer cartridge is not excited at the time of exchanging it in order to avoid the above danger, the user If the unlocking operation of the developer cartridge is performed with a large force that exceeds the holding force due to the cogging of the stepping motor, the rotary developer rotates and the operation feeling deteriorates. The cartridge cannot be removed.

Further, even when the rotating body rotation inhibiting knob as disclosed in Japanese Examined Patent Publication No. 11-038754 is provided, if the user does not have the knob, it will still rotate and the operability will be improved. There are still challenges.

These problems are caused by the above-mentioned Japanese Patent Publication No. 08-
No. 254,874, Japanese Patent Publication No. 10-142886, Japanese Patent Publication No. 11-316479, and Japanese Patent Publication No. 0
The technique disclosed in Japanese Patent Publication No. 7-319275, Japanese Patent Publication No. 08-006467, etc. has been improved to some extent.

However, as described above, in order to make the service maintenance property and the gap assurance property between the developer carrying member and the photosensitive member dominant, the rotary developing member is held in the same frame as the photosensitive member. If the structure is such that it can be pulled out together with the main body of the apparatus, in the conventional techniques described in the above-mentioned publications, the engagement is released when the frame is pulled out, and the rotary developing body becomes free. For this reason, when the service person removes the developing devices one by one, the rotary developing member rotates, which may significantly impair the workability.

Conventionally, there are many examples in which these rotation restraining means are electrically driven. However, when maintenance is performed by a service person, the rotation restraining mechanism does not work because the main body of the apparatus is not energized. There is also.

In addition, by giving the main body a rotation restraining mechanism,
There are some cases in which a torque limiter or other rotational force restraining means is separately provided when the frame is pulled out to consider the safety of the service person when replacing the developing device, but this is not sufficient yet.

Therefore, an object of the present invention is to provide an image forming apparatus capable of at least pulling out a supporting frame for supporting a rotary developing member from the main body of the apparatus, without driving the driving means of the rotary developing member. An object of the present invention is to provide an image forming apparatus capable of stopping and holding the rotation of a rotary developing member simply and reliably.

Another object of the present invention is to function reliably and to easily release the holding even when the support frame for supporting at least the rotary developing member is pulled out from the main body of the apparatus. An image forming apparatus is provided.

[0034]

The above object can be achieved by an image forming apparatus according to the present invention. In summary, the present invention is
A rotary developing body having a developing device for developing an electrostatic latent image formed on an image carrier using a developer so as to be rotatable around a rotary shaft, and supporting at least the rotary developing body. In the image forming apparatus having a supporting frame body that can be pulled out from the apparatus main body, the supporting frame body is provided with a holding unit that holds the rotary developing member in a rotation stopped state. It is a device. The image forming apparatus may further include a drive unit for the rotary developing member on the apparatus main body side.

According to one embodiment of the present invention, the holding means engages with a holding receiving member which is interlocked with the rotation of the rotary developing body to hold the rotary developing body in a rotation stopped state. It has an engaging member. In one embodiment, the rotary developing member has a rotary gear that is rotationally driven, and the holding unit is a locking portion provided on at least one gear of a gear train that interlocks with the rotation of the rotary gear. And an engaging member that holds the rotary developing member in a rotation stopped state by engaging with the. In this case, normally, the rotation angle phase in which the rotation-type developer is kept in the rotation-stopped state is set at equal angular intervals. or,
In another embodiment, the holding unit has an engaging member that engages with a locking portion that is provided integrally with the rotary developing body to hold the rotary developing body in a rotation stopped state. . In the state where the support frame is housed in the apparatus main body, it is preferable that the engaging unit is moved to the non-engagement state by electrical control only when the rotary developing body rotates. It is also preferable that in the state where the support frame is pulled out from the apparatus main body, the engaging means can be manually moved to the engaged or non-engaged state.

In the present invention, the rotary developing member may have a plurality of the developing means. Also, the developing device is
The developing device may be removable from the support frame body pulled out from the apparatus main body, and the developing device may be removable from above or sideways of the support frame body. Further, the rotary developing body may have a developer accommodating portion, which is arranged in communication with the developing device and is detachable from the rotary developing body, independently. The accommodating portion may be removable from the rotary developing body in the rotation axis direction of the rotary developing body. Further, the developer accommodating portion has locking means for engaging with the rotary developing body, and the locking means is rotated about a central axis in the inserting direction of the developer accommodating portion, It may be one that engages with the rotatable developer.

According to an embodiment of the present invention, the rotary developing member includes a developing position when the electrostatic latent image is developed by the developing device, and the developer accommodating portion. And a developer accommodating portion attaching / detaching position at the time of attachment / detachment, and the holding means holds the rotation stopped state of the rotary developing member at both positions. You can

[0038]

BEST MODE FOR CARRYING OUT THE INVENTION An image forming apparatus according to the present invention will be described below in more detail with reference to the drawings.

Embodiment 1 FIG. 1 shows a schematic cross section of an embodiment of an image forming apparatus according to the present invention. The image forming apparatus 100 according to the present exemplary embodiment is a multicolor image forming apparatus (color copying machine) including a rotary developing member.

The image forming apparatus 100 of this embodiment has a rotary developing device 104 which is a rotary developing member, which is the most characteristic feature of this embodiment. The image forming apparatus main body (apparatus main body) A includes a document placing table 110, a light source 111, and a mirror system 1.
12, a reader unit R including a lens system 113, a CCD unit 114, and the like, a paper feeding unit V, an image forming unit I, and the like. The paper feeding unit V has a cassette 115 and a manual feed cassette 116 that accommodate a transfer material S such as a recording sheet and an OHP sheet and can be attached to and detached from the image forming apparatus main body 100. The transfer material S is transferred from the cassette 115 and the manual feed cassette 116.
Is supplied.

In the image forming section I, a cylindrical electrophotographic photosensitive member as an image bearing member, that is, a photosensitive drum 101, a primary charger 102 as a charging means for charging the photosensitive drum 101, is independently configured. Black developing device (developing means) 30,
A rotary developing device 104 (FIG. 2) having a plurality of color developing devices (developing means) 20 integrated with the developer cartridge 6 mounted therein, a post charger 117 for adjusting the image quality after development, for example, four color developing devices. After transfer images are formed by superimposing toner images, an endless annular transfer belt 105, which is an intermediate transfer member that transfers a multicolor image to a transfer material, and toner (transfer residual toner) remaining on the photosensitive drum 101 after transfer are cleaned. 2 to transfer the toner image from the transfer belt 105 to the transfer material S at the secondary cleaner N2.
A secondary transfer roller 107 as a secondary transfer means, a belt cleaner 118 for cleaning transfer residual toner on the transfer belt 105, and the like are provided. The transfer belt 105 is looped over a plurality of rollers and moves endlessly. A primary transfer roller 106, which is a primary transfer unit for transferring a toner image from the photosensitive drum 101 to the transfer belt 105, is arranged at a position facing the photosensitive drum 105 via the transfer belt 105, and a primary transfer portion N1 is provided. Is formed.

As described above, in the present embodiment, the image forming section I is provided with the black developing device 30 and the rotary developing device 104, and the rotary developing device 104 is as shown in FIG. , Yellow developing device 20Y, magenta developing device 2
It has a color developing device for three colors of 0M and a cyan developing device 20C. In the present embodiment, a configuration of a three-color rotary is shown as an example of the rotary developing device 104, but it goes without saying that the number of developing devices mounted on the rotary is not limited to this in view of the gist of the present invention. Yes.

In this embodiment, the black developing device 30,
The photosensitive drum 101, the primary charger 102, the rotary developing device 104, the post charger 117, the transfer belt 105, the drum cleaner 108, the belt cleaner 118, and the like can be pulled out from the main assembly A of the apparatus as an integrated support frame (drawing frame body). ) 11 (discussed below) are supporting at the same time.

On the upstream side of the image forming section I in the conveying path of the transfer material S, in the paper feeding section V from the cassette 115 or the manual cassette 116 to the pickup roller 11
9, the posture and position accuracy of the transfer material S supplied through the transfer roller 120, the transfer path 121, etc.
A registration roller 122 is provided that sends out the transfer material S at a timely timing in accordance with the upper toner image. Further, on the downstream side, a conveying device 123 that conveys the transfer material S on which the toner image is transferred, a fixing device 109 that fixes an unfixed image on the transfer material S, and a transfer material S on which the image is fixed are formed into a multicolor image. A discharge roller 124 and the like for discharging outside the device are arranged.

Next, the operation of the image forming apparatus 100 of this embodiment will be described. When a paper feed signal is output from a controller (not shown) that is a control device that controls the operation of the image forming apparatus 100 provided in the apparatus main body A, the transfer material S is removed from the cassette 115 or the manual feed cassette 116. Supplied. On the other hand, the light reflected by the reader unit R from the light source 111 to the document D placed on the document placing table 110 is once read by the CCD unit 114 and then converted into an electric signal. This signal is transmitted to the image forming unit I.
The laser beam L from the laser scanner unit 103 as an exposure unit included in the unit is irradiated onto the photosensitive drum 101 rotating counterclockwise as indicated by an arrow R1 in the figure. The photosensitive drum 101 is previously charged by the primary charging device 102, an electrostatic latent image is formed by irradiating light, and then a plurality of color developing devices arranged in the black developing device 30 and the rotary developing device 104. The container 20 forms the toner image of the selected color.

The potential of the black toner image formed on the photosensitive drum 101 is adjusted by the post charger 117, and eventually the primary transfer bias voltage applied to the primary transfer roller 106 at the primary transfer portion N1 is applied. Transfer belt 1 by action
05 is transcribed on. In the color mode, the toner image transferred to the transfer belt 105 moves toward the primary transfer portion N1 by further rotating the transfer belt 105 once so that the next toner image is formed and transferred. During this period, the rotary developing device 104 rotates the developing device for the next designated color in the counterclockwise direction of the arrow a so as to face the photosensitive drum 101, and prepares to develop the next electrostatic latent image.

Thus, in the full-color mode, the steps of electrostatic latent image formation, development, and transfer are repeated until the toner images of the predetermined number of images (colors) are sequentially transferred to the transfer belt 105.

On the other hand, the transfer material S fed from the paper feeding section V is corrected for skew by the registration roller 122, and further fed to the image forming section I at a timed timing. Then, the toner image is transferred from the transfer belt 105 to the transfer material S by the action of the secondary transfer bias voltage applied to the secondary transfer roller 107.

Then, the transfer material S separated from the transfer belt 105 is conveyed to the fixing device 109 by the conveying device 123, where the unfixed transfer image is permanently fixed on the transfer material S by heat and pressure. The transfer material S on which the image is fixed is discharged from the apparatus main body A by the discharge roller 124.

In this way, an image is formed on the transfer material S fed from the paper feeding section V and discharged. Transfer residual toner remaining on the photosensitive drum 101 after transferring the toner image is removed and cleaned by the drum cleaner 108, and transfer residual toner remaining on the transfer belt 105 is removed and cleaned by the belt cleaner 118. Photosensitive drum 10
1. The transfer belt 105 is repeatedly used for image formation.

Next, the rotary developing device 1 in this embodiment
04 will be further described. In this embodiment, the rotary developing device 104 includes a yellow developing device 20Y and a magenta developing device 20 on a rotary 104a which is a rotatable developing device support.
M, cyan developing device 20C, rotary developing device 104
Can be freely rotated around a rotary shaft (cylindrical shaft) 104b by a rotary drive motor (stepping motor) (not shown) as a drive means provided in the apparatus main body A.

Here, a color developing device mounted inside the rotary developing device 104, that is, a yellow developing device 20Y,
The magenta developing device 20M and the cyan developing device 20C have substantially the same configuration except the color of the developer. Therefore, in the following description, when it is not necessary to distinguish the developing devices of the respective colors,
The subscripts Y, M, and C given to indicate that the elements belong to the developing device for each color are omitted.

The developing device 20 contains a two-component developer (developer) mainly containing a non-magnetic toner (toner) and a magnetic carrier (carrier). Further, the developing device 20 has an opening in a developing region facing the photosensitive drum 101, and a developing sleeve 21 as a developer carrying member is rotatably arranged so as to be partially exposed in the opening. Developing sleeve 2 containing a fixed magnet which is a magnetic field generating means
1 is composed of a non-magnetic material, and the arrow R in the figure at the time of developing operation
2 rotates in the counterclockwise direction to hold and convey the developer in the developing device 20 in layers. And the developing sleeve 2
1 supplies a developer to a developing area facing the photosensitive drum 101 to develop the electrostatic latent image on the photosensitive drum 101.
The developer on the developing sleeve 21 after developing the electrostatic latent image is conveyed as the developing sleeve 21 rotates and is collected in the developing device 20. Further, the developer in the developing device 20 is collected by the first developer circulating screw 22a (the side closer to the developing sleeve 21) and the second developer circulating screw 22b (the side farther from the developing sleeve 21) which are the developer stirring and conveying members. It circulates in the developing device 20, and is mixed and stirred. Further, when the developing device 20 performs the developing operation at the developing position P1, the developer containing the toner consumed by the image formation is connected to the developer replenishing container (developer containing portion).
The developer cartridge 6 is replenished by the replenishing means 23.

The developer used in the color developing device 20 is not particularly limited to the above two-component developer,
For example, a non-magnetic one-component developer (toner) may be used. Also, with respect to the black developing device 30, the configuration of the developing device itself can be the same as that of the color developing device 20. The black developing device 20 has a separately provided developer supply container (not shown).
To replenish the developer. The black developing device 30 can use, as a developer, a magnetic or non-magnetic one-component developer or a two-component developer including a toner and a carrier, like the color developing device 20.

In this embodiment, at the time of forming a full-color image, the rotary developing device 104 held at a predetermined phase (home position) makes an arrow so that the developing sleeve 21 of the color developing device 20 faces the photosensitive drum 101. Rotate in the a direction to start forming a multicolor image. In the present exemplary embodiment, the rotary developing device 104 is arranged at the developing position P1 facing the photosensitive drum 101 during full color image formation.
First, the yellow developing device 20Y, the magenta developing device 20M, and the cyan developing device 20C are arranged in FIG. 2 and development is performed in this order. In this embodiment, the rotary developing device 104 is rotated counterclockwise when the main assembly A of the apparatus is viewed from the front.
It is clear that the direction of rotation is determined by the developing conditions and the like, and the rotation direction is not limited for the purpose of the present invention.

Further, in this embodiment, the developer cartridge 6 is housed inside the rotary developing device 104 integrally with the developing device 20, and the rotary developing device 104 is operated during the image forming operation.
Rotates with the rotation of. The developer cartridge 6 is a substantially cylindrical bottle type, and has a so-called cartridge type bottle configuration that can be easily replaced during the suspension of the operation when the developer remaining in the developer cartridge 6 runs out. . In the present embodiment, the developer cartridge 6 can be replaced by pulling it out from the front surface of the apparatus main assembly A (the front side in FIG. 1). Further, the developer cartridge 6 is provided with a lock knob (described later) so that the developer cartridge 6 can be fixed and released inside the rotary developing device 104, so that the user can easily recognize the set state of the developer cartridge 6. ing.

Now, the rotary developing device 104 of the present embodiment.
When the image forming apparatus 100 is powered on, first,
Rotation is stopped by detecting a standby position (so-called home position) different from the developing position. In the present embodiment, the home position is set to an angular position where the first developing station (yellow developing device 20Y) is located 60 degrees before the developing position P1 (direction opposite to arrow a in the figure). This is the developing sleeve 21 of the yellow developing device 20Y and the developing sleeve 21 of the third developing station (cyan developing device 20C).
Are positions farthest from the position facing the photosensitive drum 101, and the developing sleeve 21 of the first station (yellow developing device 20Y) can be moved to the developing position P1 earliest in the next rotation. .

Needless to say, the home position is not limited to this position for the purpose of the present invention. Further, the rotary developing device 104 has at least two rotation stops, that is, a development stop position at which development is performed by each of the development devices 20 and a developer accommodating section attachment / detachment position when the developer cartridge 6 is attached / detached (exchanged). Have a position. The developer accommodating portion attaching / detaching position may be the same as the home position, or may be a different stop position. Here, in order to avoid complexity, the developer containing portion exchange position will be described as being the same as the home position.

Next, when an image output request is issued from a controller (not shown) which is a control means for controlling the operation of the image forming apparatus 100, the controller causes the laser beam output from the laser scanner unit 103 to move the image onto the photosensitive drum 101. An electrostatic latent image is formed, and development by the black developing device 30 is started. During this period, the controller rotationally controls the rotary drive motor (not shown) of the rotary developing device 104,
A developing position P where the developing sleeve 21 of the first developing station (yellow developing device 20Y) faces the photosensitive drum 101.
The rotary developing device 104 is rotationally driven so as to be arranged at 1. When the development in the first station is completed, the controller then rotates the rotary developing device 104 by 120 degrees and shifts to the developing process in the next developing station. When the developing process for each color is completed, the controller controls the rotary developing device 104 to rotate to the home position and returns to the standby state. In this embodiment, the order of development is black (K), yellow (Y), magenta (M), and cyan (C), but the order is not limited from the point of the present invention. Needless to say, other development orders may be used.

In the present embodiment, the black developing device 30 is not mounted on the rotary developing device 104 but is independently supported by the drawer frame 11. Therefore, when the output image request from the controller is a black monochromatic image, the rotary developing device 104 does not rotate while the black developing device 30 is developing. As a result, the longevity of the color developing device has been significantly extended and the longevity has been realized.

Next, referring also to FIG. 3, the drawer frame 11
Will be further described.

FIG. 3 shows the rotary developing device 1 as described above.
04, the photosensitive drum 101, and a drawer frame 11 that integrally supports some units that are not necessary for image formation.
Indicates. In the figure, a rotation stop holding unit 1 which is a rotation stop holding means of the rotary developing device 104, which is the most characteristic of the present embodiment and will be described later in detail, is also shown.
In order to avoid complexity, the black developing device 30, the primary charging device 102, the post charging device 117, the transfer belt 105, the drum cleaner 108, the belt cleaner 118, etc. are omitted from FIG.

In this embodiment, as shown in FIG. 3, the drawer frame 11 is constructed so that it can be pulled out from the front surface of the main assembly A of the apparatus. As a result, service maintainability is significantly improved. In this embodiment, the developing sleeve 2 of the color developing device 20 mounted on the rotary developing device 104 is also used.
The gap between the photosensitive drum 101 and the photosensitive drum 101 (hereinafter, referred to as "SD gap") is not an abutting roller system, but an adjustment assembly configuration at the time of assembly. This enables high-speed switching of the rotary developing device 104. As described above, the configuration in which the photosensitive drum 101 and the rotary developing device 104 are simultaneously held in the drawer frame 11 is very advantageous from the viewpoint of guaranteeing and varying the SD gap, and can guarantee excellent image characteristics. it can.

In this embodiment, the black developing device 30 is used when the drawer frame 11 is drawn out as shown in FIG.
By removing, the upper part of the rotary developing device 104 is exposed, and the color developing device 20 can be easily removed from the inside of the rotary developing device 104 from above. In addition, since various units related to development are simultaneously mounted on the drawer frame 11, it is possible to easily access other defective units or units that require regular maintenance. It is very excellent in sex. In this embodiment, the color developing device 20 is accessed from above as an example, but the access direction may be lateral as long as the rotary developing device 104 is on the drawer frame 11. Needless to say.

Now, with reference to FIGS. 4 and 5, the rotation stop holding mechanism, which is the most characteristic feature of this embodiment, will be described.

The rotation stop holding mechanism is provided in the drawer frame 11 and holds the rotation of the rotary developing device 104 in the stopped state in the apparatus main body A and in the state of being pulled out from the apparatus main body A from the drawer frame 11. It has a holding means and a rotation stop holding receiving member that is supported by the drawer frame 11 together with the rotary developing device 104 and is interlocked with the rotation of the rotary developing device 104.

In this embodiment, the rotation stop holding mechanism has the rotation stop holding unit 1 as the rotation stop holding means on the drawer frame 11. Further, a rotary gear 3 (FIG. 5) that receives a rotational drive force from a rotational drive motor provided on the apparatus main assembly A side is integrally provided at one longitudinal end of the rotary developing device 104. Further, a rotation stop holding gear 2 that meshes with the rotary gear 3 and transmits the rotational drive of the rotary developing device 104 is provided on the drawer frame 11. In this embodiment, the rotation stop holding gear 2 which is one of the gear trains interlocking with the rotary gear 3 that receives the rotary drive of the rotary developing device 104 constitutes a rotation stop holding receiver.

The rotation stop / hold unit 1 is a solenoid 4 as a rotation stop / hold selection means that is controlled to select whether to hold or release the rotation stop state of the rotary developing device 104.
And a state in which the rotation of the rotary developing device is stopped via the rotation stop holding gear 2 and the rotary gear 3 by being fixed to the solenoid 4 and engaging with the groove portion 2a as the locking means provided in the rotation stop holding gear 2. And a pin member 5 as an engaging means to be held by. The pin member 5 is fixed by penetrating the solenoid plunger 4a of the solenoid 4. FIG. 5 shows a state in which the rotary gear 3 and the rotation stop holding gear 2 are engaged with each other to operate.

As shown in FIG. 3, the rotation stop holding unit 1 is provided in the drawer frame 11 together with the above-mentioned other units including the rotary developing device 104. Then, when the drawer frame 11 is pulled out from the apparatus main body A, the rotation stop holding gear 2 and the rotary gear 3 are pulled out in a state in which they mesh with each other.

In the normal standby state of the image forming apparatus 100,
The solenoid 4 of the rotation stop holding unit 1 is not energized,
It is in a state of being pulled in the direction of arrow c in FIG. 4 by the force of a spring (not shown). At this time, solenoid 4
The pin member 5 that is press-fitted into is engaged with the groove portion 2a of the rotation stop holding gear 2, and the rotation stop holding gear 2 cannot rotate.
This state is the standby state.

When the controller instructs the rotation of the rotary developing device 104, the controller first instructs the solenoid 4 of the rotation stop holding unit 1 to be energized and then the solenoid 4 is rotated.
Sucks the solenoid plunger 4a in the direction of arrow d in FIG. Thereby, the pin member 5 and the rotation stop holding gear 2
The engagement with the groove 2a is released, and the rotary gear 3 becomes rotatable. In the present embodiment, the winding direction and the energizing direction are determined so that the solenoid plunger 4a is attracted in the arrow d direction in the drawing in the energized state.

Here, as will be described in detail later, after the controller has instructed to energize the solenoid 4 and a predetermined time (suction time + margin) has elapsed, the rotary developing device 1
Driving of the No. 04 drive motor (rotary drive motor) is instructed. When the rotary drive motor rotates for a predetermined number of steps, the controller turns off the power supply to the solenoid 4 after a lapse of a margin time after the rotary drive motor is stopped. As a result, the pin member 5 is again pulled in the direction of arrow c in FIG. 4 by the spring, and engages with the groove portion 2 a of the rotation stop holding gear 2.

The rotation stop holding unit 1 of the present embodiment is installed in a position where the rotation stop mechanism of the rotary developing device 104 is effective, at a location easily accessible even when the drawer frame 11 is pulled out. By doing so, for example, when an operator such as a service person performs maintenance while pulling out the drawer frame 11 with the power of the apparatus main body A turned off, the rotary developing device 104 rotates. The operator's safety can be secured without In other words, in this embodiment, the groove portion 2a of the rotation stop holding gear 2 and the pin member 5 are engaged with each other in a state where the energization of the solenoid 4 is turned off, and the rotation of the rotary developing device 104 is prevented.

Furthermore, if necessary, the solenoid 4 of the rotation stop holding unit 1 can be easily accessed, and the pin member 5 can be easily accessed.
Can be released from the groove portion 2a of the rotation stop holding gear 2 to release the hold. As a result, the rotation of the rotary developing device 104 can be stopped and held at an arbitrary position, so that it is possible to obtain a very excellent service maintainability.

Here, the number of steps of the rotary drive motor will be further described. In this embodiment, since the rotary developing device 104 is a so-called three-color rotary device having the three-color developing devices 20, from the home position until the first developing station (yellow developing device 20Y) is located at the developing position P1. Rotation angle is 60 degrees, the rotation angle required to move between development stations is 120 degrees, and at the end of development, 60 degrees when the development station moves from the development stop position located at development position P1 to the home position. , The number of rotation angle steps is determined. Needless to say, such a rotation angle step number is not limited to the above rotation angle for the purpose of the present invention.

In this way, the rotation stop holding unit 1 is
The solenoid 4 is energized only when the rotary drive motor rotates, and is not energized when it does not rotate. This is very advantageous in power consumption and temperature rise during development. Further, since the standby current when the home position is set is unnecessary, the image forming apparatus 100
It is also very advantageous for power consumption or temperature rise in the normal standby state or in the power saving mode in which the power source in the apparatus main body A is turned off except for a part.

Next, the relationship between the rotation angle of the rotary developing device 104 and the groove portion 2a of the rotation stop holding gear 2 in the rotation stop holding unit 1 will be described.

In this embodiment, the gear ratio between the rotary gear 3 and the rotation stop holding gear 2 is set to 6: 1. By doing so, the pin member 5 and the groove portion 2a of the rotation stop holding gear 2 are engaged with each other at the home position 60 degrees before the developing position of the first developing station where the yellow developing device 20Y is arranged at the developing position P1. , The rotary stop holding gear rotates 360 degrees in the direction of the arrow b in the figure even at the first developing station developing position where the rotary gear rotates 60 degrees in the direction of the arrow a in the figure. 5 and the groove portion 2a of the rotation stop holding gear 2 are engaged with each other. Of course, even at the second developing station developing position and the third developing station developing position in which the rotary developing device 104 is rotated by 120 degrees, the rotation stop holding gear 2 is rotated by 720 degrees each, so that the pin member 5 and The groove portion 2a of the rotation stop holding gear 2 is engaged. Here, when the condition of the gear ratio between the rotary gear 3 and the rotation stop holding gear 2 is expressed by a mathematical expression, (rotary gear) :( rotation stop holding gear) = N: A (1) N: rotary development It is understood that it is sufficient to satisfy the relational expression of the number of phases A fixed in one round of the device: the number of grooves in one round of the rotation stop holding gear.

In this embodiment, the rotary developing device 104 is set to 1
The phase for fixing the rotation during the circumference is 6 at each developing position and the home position rotated by 60 degrees from that position.
Since the number of the groove portions 2a in one rotation of the rotation stop holding gear 2 was set to one, the gear ratio between the rotary gear 3 and the rotation stop holding gear 2 was set to 6: 1.

That is, as shown in FIG. 6, when the number of the groove portions 2a of the rotation stop holding gear 2 is set to 2, A in the conditional expression (1) becomes 2. At this time, if the number of phases fixed in one rotation of the rotary developing device 104 is 6 as in the above case, the gear ratio between the rotary gear 3 and the rotation stop holding gear 2 may be 3: 1. . in this case,
When the rotary developing device 104 rotates 60 degrees from the home position to the first developing station developing position, the rotation stop holding gear 2 rotates 180 degrees, so that it is engaged with the first groove portion 2a1 of the rotating gear 2 in FIG. Pin member 5
Will then engage the second groove 2a2. In this way, at the second developing station developing position and the third developing station developing position which rotate by 120 degrees, the rotation stop holding gear 2 rotates by 360 degrees, so that the pin member 5 sequentially engages with the second groove portion 2a2 of the rotary gear 2. Will be done.

Here, the number of grooves of the rotation stop holding gear 2 is 1
Two cases and two cases have been described. However, if the conditional expression (1) is satisfied, the number of developing devices mounted on the rotary developing device 104 and the number of grooves of the rotation stop holding gear 2 are not limited to this. It goes without saying that it is not something.

Next, referring to FIG. 7, a method of inserting, locking and releasing the developer cartridge 6 in the rotary developing device 104 in this embodiment will be described.

As shown in FIG. 7, the developer cartridge (toner bottle) 6 has a bottle knob 6a at one end in the longitudinal direction (end on the front side in the insertion direction), and the bottle knob 6
A bottle locking collar 6b, which is locking means, is provided on the rear side in the insertion direction of the developer cartridge 6 from a. The bottle knob 6a and the bottle locking collar 6b integrally form a lock knob that holds the developer cartridge 6 in the rotary developing device 104 in an engaged state as an end cap at one longitudinal end of the developer cartridge 6. To do.

A front side plate 7 constituting a frame body (rotary) 104a as a developing device support is provided at one side portion in the longitudinal direction corresponding to the front side face of the rotary developing device 104 in the inserting direction of the developer cartridge 6. Has been. The front side plate 7 is formed with a groove 7a for attracting the bottle locking collar 6b of the developer cartridge 6.

In the direction of arrow e in FIG. 7 (rotary developing device 10
When the developer cartridge 6 is inserted in a direction substantially parallel to the axial direction of 4), the bottle locking collar 6b provided on the bottle knob 6a is attached to the front side plate 7 of the rotary developing device 104.
Is called into the groove portion 7a provided in the front side plate 7 and is inserted deeper than the front side plate 7. Here, a click feeling of a click mechanism (not shown) notifies the operator that the developer cartridge 6 has been fully inserted.

The operator, who has recognized that the developer cartridge 6 has been inserted all the way, rotates the bottle knob 6a 90 degrees clockwise in the arrow f in FIG. 7 to set the developer cartridge 6. At this time, since the bottle locking collar 6b has already been inserted deeper than the front side plate 7, the bottle locking flange 6b is extended to the back side of the front side plate 7 by the operator rotating the bottle knob 6. With the entry of, the developer cartridge 6 is prevented from coming off from the rotary developing device 104.

The lock click mechanism (not shown) allows the operator to easily recognize that the bottle knob 6 has rotated 90 degrees and the rotary developing device 104.
In order to prevent the lock from being released by the rotational vibration of the lock click mechanism, the lock click mechanism is usually provided with a suitable device. Since such a lock click mechanism is not related to the gist of the present invention, further detailed description will be omitted.

According to the rotation stop and hold unit 1 of this embodiment, when such a method of fixing the developer cartridge 6 is adopted, the rotary developing operation is performed by the lock / unlock operation of the developer cartridge 6 by the operator. Bowl 104
The developer cartridge 6 can be safely replaced without rotating. Of course, it is not necessary to energize the rotary drive motor or the solenoid 4 of the rotation stop holding unit 1 in a state where the front door of the apparatus main body A is opened in order to replace the developer cartridge 6. For this reason, there is no risk of malfunction of the rotary drive motor, and since it is not necessary to energize the operator while waiting for the operator to replace the developer cartridge 6, power consumption increases and temperature rises inside the machine. Nothing.

Here, for the sake of explanation, the bottle knob 6 is used.
The method of fixing the developer cartridge 6 between the front plate 7 and the front plate 7 has been shown as an example, but the present invention is not limited to application to an image forming apparatus adopting such a developing cartridge fixing method. Is clear. The present invention preferably works even if the developer cartridge 6 is fixed to the rotary developing device 104 by any method in which the operator may apply some force, and the same effects as described above are obtained. Obtainable.

As described above, according to the configuration of the present embodiment, S when the high speed switching of the rotary developing device 104 is performed is performed.
The stability of the -D gap is excellent, and while the excellent image characteristics are realized, the image forming unit including the rotary developing device 104 can be integrally pulled out from the apparatus main body A, which is excellent in service maintenance. Further, as is conventionally done, it is not necessary to continue to excite the rotary drive motor in order to prevent the rotation of the rotary developing device 104 in the black monochromatic continuous image forming mode, which causes an increase in power consumption due to the excitation. It does not cause the temperature rise in the machine. Further, even when the operator operates the developer cartridge 6 with a large force when replacing the developer cartridge 6,
The rotation of the rotary developing device 104 is prevented, and the operability is not significantly impaired.

As described above, according to the present invention, in particular, the black developing device 30 is provided outside the rotary developing device 104, and the developer cartridge 6 is housed inside the rotary developing device 104. Device 104 and photosensitive drum 101
The image forming apparatus is configured so as to be held in the same frame body 11 and can be pulled out at the same time.

That is, according to the present embodiment, the rotary developing device 104 has the same drawer frame 11 as the photosensitive drum 101.
The excellent image characteristics can be realized by adopting the SD gap adjusting assembly system which is held at the position and realizes the high speed switching of the rotary developing device 104 without using the abutting roller.
Moreover, since the drawer frame 11 can be integrally drawn from the apparatus main body A, service maintenance is excellent. Further, even when only the black developing device 30 is arranged outside the rotary developing device 104 to perform black monochromatic continuous image formation,
Since it is not necessary to continue to excite the rotary drive motor of the rotary developing device 104 as in the conventional case, neither the increase in power consumption due to the excitation nor the in-machine temperature rise is caused.

Further, according to the present embodiment, in the structure in which the developer cartridge 6 is stored inside the rotary developing device 104, the operator releases the lock of the developer cartridge with a great force when replacing the developer cartridge. Even in such a case, the rotation stop and hold unit 1 does not cause the rotary developing device 104 to rotate, which makes the operation feeling uncomfortable and prevents the developer cartridge from coming off.
Further, when the pull-out frame body 11 that can pull out the rotary developing device 104 and the photosensitive drum 101 together is pulled out, the rotation restraining mechanism is not disengaged and becomes free as in the conventional case. Therefore, for example, when the service person removes the developing devices 20 one by one, the rotary developing device 104 does not rotate and workability is not significantly impaired.

Further, since the rotation stop holding unit 1 can be moved manually in addition to being electrically driven, even when the apparatus main body A is not energized, for example, during maintenance by a service person, Use the rotation restraint mechanism,
Alternatively, it can be released. In addition, according to the rotation stop holding unit 1 of the present embodiment arranged on the drawer frame 11, the rotation stop of the rotary developing device 104 is the same mechanism when the apparatus main body is housed and when it is pulled out from the apparatus main body. It is a simple and reliable mechanism because it can be completed with.

Embodiment 2 Next, another embodiment of the present invention will be described. The basic structure and operation of the present embodiment are the same as those of the first embodiment except the rotation stop and hold mechanism of the rotary developing device which is a rotary type developing member, so here, the elements having the same structure and action will be described. Are denoted by the same reference numerals, and detailed description will be omitted.

FIG. 8 shows the drawer frame 11 of this embodiment. The drawer frame body 11 according to the present embodiment has substantially the same configuration as the drawer frame body 11 according to the first embodiment,
The configuration of the rotation stop holding mechanism of the rotary developing device 104 is different from that of the first embodiment.

With reference to FIG. 9, the rotation stop holding mechanism of the rotary developing device 104 in this embodiment will be described.
Here, only the characteristic points of this embodiment will be described.

In this embodiment, the rotation stop holding mechanism is
The rotation stop holding unit 1 as the rotation stop holding means is provided on the drawer frame 11. In addition, the rotary developing device 104
A rotation stop rotary rotation stop plate 53 as a rotation stop holding receiving member is integrally provided at one end in the longitudinal direction of the.

The rotation stop holding unit 51 electrically drives the solenoid arm 52 and the solenoid arm 52 as the engaging means for holding the rotation of the rotary developing device 104 in a stopped state, and holds the rotation developing state of the rotary developing device 104.
It has a solenoid 54 as a rotation stop holding selection means which is controlled so as to select release. The rotary rotation stop plate 53 is provided with a concave portion 53a as a locking means for engaging with the convex portion 52a of the solenoid arm 52 and stopping / holding the rotation of the rotary developing device 104 at a predetermined position.

In this embodiment, the rotary developing device 104 has three
Since it is a color rotary, three rotation stop holding positions corresponding to the development stop position are determined, and the concave portion 53a of the rotary rotation stop plate 53 is set at a position where the convex portions 52a of the solenoid arm 52 face each other at the phase. Good. Also, the home position may be set to an arbitrary position, and the concave portion 53a of the rotary rotation stop plate 53 may be set to a position where the convex portion 52a of the solenoid arm 52 at that phase faces.

In this way, unlike the first embodiment,
Even the rotary developing device 104 in which the phases of the developing stations are set to be non-uniform can be reliably stopped and held. Further, the home position is also advantageous in that it can be set to an arbitrary angular position from the developing position.

The operation of the rotation stop / hold unit 51 of this embodiment will be described. In the present embodiment, when the image forming apparatus 100 is in the normal standby state, the solenoid 54 of the rotation stop holding unit 51 is not energized, and the force of a spring (not shown) causes the solenoid 54 to rotate.
It is in a state of being pulled in the direction of the middle arrow g.
The solenoid 54 of the present embodiment is different from the solenoid 4 used in the first embodiment in that the winding direction and the energizing direction are determined so that the solenoid plunger 54a is pushed out in the energized state.

That is, at this time, the solenoid plunger 54a
Is pulled toward the solenoid 54 in the direction of the arrow g in the figure, so that the solenoid arm 52 is attached to the rotation support shaft 52.
It is in a state of being rotated in the direction of the arrow h in the figure around b. As a result, the convex portion 52a of the solenoid arm 52 is engaged with the corresponding concave portion of the plurality of concave portions 53a provided on the rotary rotation stop plate 53, and the rotary developing device 104 integrated with the rotary rotation stop plate 53 is formed. Cannot rotate. This state is the normal standby state.

Then, the controller is the developing rotary 10
4 is instructed to rotate, the controller first instructs the solenoid 54 of the rotation stop holding unit 51 to be energized,
The solenoid pushes out the solenoid plunger 54a.
As a result, the solenoid arm 52 moves to the rotation support shaft 52b.
Is rotated in the direction of the arrow i in the figure, and the convex portion 52a of the solenoid arm 52 and the concave portion 53 of the rotary rotation stop plate 53 are rotated.
The engagement with a is released, and the rotary developing device 104 integrated with the rotary rotation stop plate 53 becomes rotatable.

Here, as in the first embodiment, the controller instructs driving of the rotary drive motor after a predetermined time (suction time + margin) has elapsed after instructing energization of the solenoid 54. Eventually, when the rotary drive motor rotates a predetermined number of steps, after stopping the rotary drive motor,
After the time for the margin has passed, the controller turns off the power supply to the solenoid 54. As a result, the solenoid plunger 54a is again pulled in the direction of the arrow g in the drawing by the spring, and the convex portion 52a of the solenoid arm 52 and the concave portion 53a of the rotary rotation stop plate 53 come into engagement.

Also in the present embodiment, the rotation stop holding unit 51 is in a state where the drawer frame 11 is pulled out from the apparatus main assembly A, and the rotation stop mechanism of the rotary developing device 104 is in an effective state in an easily accessible place. is set up. By doing so, even when an operator such as a service person performs maintenance, even when the drawer frame 11 is pulled out and the work is performed with the power source of the apparatus main body A turned off, the rotary developing device 104 rotates. It is possible to ensure the safety of the operator without causing it. That is, in the present embodiment, the concave portion 53a of the rotary rotation stop plate 53 and the convex portion 52 of the solenoid arm 52 are engaged with each other in a state where the energization of the solenoid 54 is off, and the rotary developing device 1
Prevents 04 rotation.

Further, since the solenoid arm 52 of the rotation stop holding unit 51 can be easily accessed if necessary, the engagement state between the convex portion 52a of the solenoid arm 52 and the concave portion 53a of the rotary rotation stop plate 53 is released. be able to. As a result, the rotary developing device 1 can be placed at any position.
Since the rotation of 04 can be stopped / held, it is possible to obtain a very excellent service maintainability.

As described above, also in this embodiment, the rotation stop holding unit 51 energizes the solenoid 54 only when the rotary drive motor rotates, and does not energize it when it does not rotate. This allows
It is very advantageous in terms of power consumption and temperature rise during development.
Further, as in the first embodiment, the standby current when in the home position is not required, so that the image forming apparatus 100 is in a normal standby state or when the power source in the apparatus main body A is partially removed.
F is also very advantageous for power consumption in the power saving mode or for temperature rise.

Further, for example, when the same developer cartridge 6 fixing method as that described in the first embodiment is adopted, the rotary developing device 104 is locked by the operator's lock / unlock operation of the developer cartridge 6. The developer cartridge 6 can be safely replaced without rotating. Moreover, since it is not necessary to energize the rotary drive motor and the solenoid 54 of the rotation stop holding unit 51 with the front door of the apparatus main body A opened, the risk of malfunction of the rotary drive motor and the like is eliminated. Further, it is similar to the first embodiment in that it is possible to prevent an increase in power consumption during the waiting time for the operator to replace the developer cartridge 6 and an increase in temperature inside the machine.

As described above, according to this embodiment, the same effect as that of the first embodiment can be obtained, and the phase of the developing station,
This has the advantage that the home position can be set to an arbitrary angular position.

Here, with reference to FIG. 10, the solenoid 4 or 54 which can be commonly applied to the first and second embodiments.
An example of the power supply timing to the power supply will be described.

The diagram shown in FIG. 10 shows the drive timing of the rotary motor, the energization timings of the solenoids 4 and 54, and the image writing timing in order from the top. The application timing of the developing bias is shown respectively. In each of the diagrams, the upper line basically shows the energized state and the lower line shows the non-energized state.

As shown in the figure, the controller instructs the solenoid 4 or 54 to be energized a predetermined time j before rotating the rotary developing device 104. This time j
Becomes, as described above, the suction time + the margin. Here, the suction time refers to the time until the solenoid 4 or 54 electrically reacts and the solenoid plunger 4a or 54a ends mechanically, and the margin is
Specifically, it is considered including the time when the control software reacts. As an example, in the case of each of the above-described embodiments, this time j is set to 100 ms, and reliable rotation stop /
Hold operation is realized.

Next, the controller instructs the rotary drive motor to rotate, rotates by a predetermined angle and rotates for the number of steps required for the desired developing station (developing device) to reach the developing position P1, and then the rotary drive motor rotates. To stop.
Next, after a lapse of a predetermined time k, the controller releases the energization of the solenoid 4 or 54 and returns the solenoid plunger 4a or 54a to the standby position. The waiting time k at this time is a value that takes into consideration variations in the control soft margin. As an example, in each of the above-described embodiments, this time k is set to 50 ms in consideration of safety. Although this value theoretically depends on the soft structure, it is usually sufficient to take 5 to 10 ms.

Further, the controller is the rotary developing device 1
After the rotation of 04 is stopped for a predetermined time l, a developing bias is applied to the developing device to start the development. In this embodiment, the waiting time 1 is set to 100 ms in consideration of the vibration convergence time when the rotary developing device 104 stops rotating, the rising time of the developing bias, the rotating rising time of the developing sleeve 21, and the like.

Next, the controller cuts off the application of the developing bias after the developing for a predetermined length is completed. After that, time m
After that, preparation is started toward the start of rotation of the rotary developing device 104. Specifically, before the start of rotation j, the energization of the solenoid 4 or 54 is instructed. Since the description of the continuous operation thereafter is repeated, the description thereof will be omitted.

By controlling the energization of the solenoid 4 or 54 as described above, the operation of the rotation stop holding unit and the image forming operation in the state where the drawer frame 11 is housed in the apparatus main body A can be ensured. .

The structure of the multicolor image forming apparatus described in each of the above embodiments is an example for explaining the present invention, and the present invention is not limited to this, and the scope of the present invention. It is to be understood that various changes can be made within.
For example, in each of the above embodiments, the image forming apparatus employs an intermediate transfer system, but the present invention does not limit the transfer system at all, and a recording material supported on a transfer material carrier well known to those skilled in the art. Alternatively, a method of sequentially superimposing toner images on each other may be used.

[0119]

As described above, according to the present invention,
In an image forming apparatus capable of pulling out at least a supporting frame supporting a rotary developing body from the main body of the apparatus, rotation of the rotary developing body can be performed easily and surely without driving a driving means of the rotary developing body. Can be stopped and held.
Further, according to the present invention, even when the support frame body that supports at least the rotary developing body is pulled out from the apparatus main body, the function can be surely performed and the holding release can be easily performed.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a schematic sectional front view of a rotary developing device included in the image forming apparatus of FIG.

FIG. 3 is a schematic perspective view of a main portion showing a state where a drawer frame of the image forming apparatus of FIG. 1 is drawn out.

FIG. 4 is a schematic perspective view of a main part of an embodiment of a rotation stop holding mechanism.

FIG. 5 is a schematic front view of the main parts for explaining the operation of an embodiment of the rotation stop and hold mechanism.

FIG. 6 is a front view showing another example of the rotation stop holding gear of the rotation stop holding mechanism.

FIG. 7 is a schematic perspective view of a main part for explaining an example of a replacement operation of a developer cartridge.

FIG. 8 is a schematic perspective view of a main part of another example of the drawer frame.

FIG. 9 is a schematic front view of main parts for explaining the operation of another embodiment of the rotation stop and hold mechanism.

FIG. 10 is a timing chart diagram for explaining an example of control timing of the rotation stop / hold mechanism.

[Explanation of symbols]

1 Rotation stop holding mechanism 2 Rotation stop holding gear 3 rotary gear 4 solenoid 5 pin member 6 developer cartridge 51 Rotation stop holding mechanism 52 Solenoid arm 53 Rotation stop holding plate 54 solenoid 11 Drawer frame 20 Developer (color developer) 30 Developing device (black developing device) 101 photosensitive drum (image bearing member, electrophotographic photosensitive member) 102 primary charger (charging means) 103 Laser scanner unit (exposure means) 104 rotary developing device (rotary developing member) 105 transfer belt (intermediate transfer member) 106 primary transfer roller (primary transfer means) 107 secondary transfer roller (secondary transfer means) 108 Drum cleaner (cleaning means) 109 fixing device S transfer material

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H077 AA03 AB02 AB15 AC02 AD00                       AD02 AD06 AE04 AE06 BA01                       BA10 DB25 EA03 EA14 GA04                       GA13                 2H300 EA06 EA07 EA08 EB08 EB12                       EC05 EF03 EF08 EH01 EH16                       EJ09 EJ15 EJ22 EJ25 EJ45                       EJ51 EK03 GG01 GG02 GG03                       GG33 HH02 HH03 HH23 HH29                       HH32 HH33 QQ13 TT06

Claims (15)

[Claims] 1. A rotary developing member having a developing device for developing an electrostatic latent image formed on an image bearing member using a developer, the rotatable developing member being rotatable about a rotation axis, and at least the rotating device. In an image forming apparatus having a support frame body that supports the mold developing body and can be pulled out from the apparatus main body, holding means for holding the rotary developing body in a rotation stopped state is provided on the support frame body. A characteristic image forming apparatus. 2. The image forming apparatus according to claim 1, further comprising drive means for driving the rotary developing member on the apparatus main body side. 3. The holding means has an engaging member that engages with a holding receiving member that is interlocked with the rotation of the rotary developing body to hold the rotary developing body in a rotation stopped state. The image forming apparatus according to claim 1, wherein the image forming apparatus is the image forming apparatus. 4. The rotary developing member has a rotary gear that is rotationally driven, and the holding means is a locking portion provided on at least one gear of a gear train that interlocks with the rotation of the rotary gear. 3. The image forming apparatus according to claim 1, further comprising an engaging member that engages with the rotary developing member to hold the rotary developing member in a rotation stopped state. 5. The image forming apparatus according to claim 4, wherein the rotation angle phase in which the rotation stop state of the rotary developing member is held is set at equal angular intervals. 6. The holding means has an engaging member that engages with a locking portion provided integrally with the rotary developing body to hold the rotary developing body in a rotation stopped state. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. 7. In the state where the support frame is housed in the apparatus main body, only when the rotary developing body rotates,
7. The image forming apparatus according to claim 3, wherein the engagement unit is moved to a non-engagement state by electric control. 8. The engagement means can be manually moved selectively to an engaged or non-engaged state in a state where the support frame is pulled out from the apparatus main body. The image forming apparatus according to any one of 3 to 7. 9. The image forming apparatus according to claim 1, wherein the rotary developing member has a plurality of the developing units. 10. The image forming apparatus according to claim 1, wherein the developing device is removable from the support frame body pulled out from the apparatus main body. 11. The image forming apparatus according to claim 10, wherein the developing device is removable from above or laterally of the support frame. 12. The rotatable developing member has a developer accommodating portion arranged in communication with the developing device so as to be independently removable from the rotating developer. The image forming apparatus according to any one of claims 1 to 11, which is characterized. 13. The image forming apparatus according to claim 12, wherein the developer accommodating portion is removable from the rotary developing body in a rotation axis direction of the rotary developing body. 14. The developer accommodating portion has locking means for engaging with the rotary developing body, and the locking means rotates about a central axis in the inserting direction of the developer accommodating portion. Has been
2. The engaging member engages with the rotary developing member.
3. The image forming apparatus of 3. 15. The rotation type developing member has a developing position when the electrostatic latent image is developed by the developing device, and a developer accommodating portion when the developer accommodating portion is attached to and detached from the rotation type developing member. At least two rotation stop positions, that is, a part attachment / detachment position, are provided, and the holding means can hold the rotation stop state of the rotary developing member at both positions. 12, 13 or 14 image forming apparatuses.