JPS63178262A - Developing device - Google Patents

Abstract

PURPOSE:To reduce to the minimum a moment which works at every driving time of a developing device unit, by transferring driving force to the developing device unit by clutching a power transfer member of a necessary developing device unit which has been moved to a developing position opposed to a body to be developed. CONSTITUTION:The titled device is provided with a hollow shaft 310 of nonrotation functioning as a rotation center shaft of a rotation supporting body 300, a driving member 115 which is placed in the hollow shaft 310 and driven by an external driving source, and a power transfer member 116 which is placed at the rotation supporting body side and relays the driving force to a developing device unit 101. In this state, when the developing device unit 101 has moved to a prescribed developing position opposed to a body to be developed, by rotation of the rotation supporting body 300, the power transfer member 116 is connected to the driving member 115 and the driving force of the external driving force is set to a transfer state or a transferable state with respect to the developing device unit 101. In such a way, the distance between the rotation center axis of the rotation supporting body, and a connecting part of the driving member and the power transfer member can be reduced remarkably,and a moment which works on the rotation supporting body at the time of driving of the developing device unit is reduced remarkably.

Description

Detailed Description of the Invention A. Purpose of the Invention [Field of Industrial Application] The present invention is applicable to multicolor (monochromatic color of two or three or more colors, multicolor) or full color electrophotographic copying machine, computer facsimile, etc. The present invention relates to a developing device that is incorporated into an image forming apparatus such as a color recording device that constitutes an output section of the present invention.

More specifically, a plurality of developing units containing different color developers are supported on a rotating support, and by controlling the rotation of the rotating support, a single developing object such as a rotating photosensitive drum is connected to a required developing unit. The present invention relates to a rotary developing device that is moved to a predetermined developing position opposite to a WIa' carrier to perform development using the required developing device unit.

[Conventional technology]

This rotary developing device sequentially arranges a plurality of developing units so as to face the member to be developed, and selectively controls the operation of these developing units to create a required developing unit. In the case of a 0-rotation type developing device, which is used in practical use along with a side-by-side type developing device that performs development, only one developing unit is always facing the object to be developed, so the circumference of the object to be developed must be kept as small as possible. This has the advantage of being advantageous in downsizing and simplifying the image forming apparatus.

A rotary developing device includes a rotary support member supporting a plurality of developer units, and a rotary drive mechanism that moves the rotary support member to a predetermined developing position facing the object to be developed by controlling the rotation of the rotary support member. The developing device unit includes a developing device driving mechanism for driving the developing roller layer, developer stirring means, etc. of the developing device unit.

The developing device drive mechanism transmits the driving force of the driving source to the required developing device unit that is moved to the developing position by controlling the rotation of the rotary support, and after the developing device unit finishes performing the phenomenon, the driving force is transmitted. This is a mechanism that transmits driving force to the developing unit that is then moved to the developing position.

FIG. 5 shows an example of the developing device drive mechanism. In FIG. It is assumed that the developing unit is one of a plurality of developing units, and is currently located at a predetermined developing position where a developing roller 130 faces an object to be developed (not shown).

221 is the drive input gear on the 101 side (43)
0 is a main drive device that drives the gear, and when the developer unit 101 is located at a predetermined development position facing the object to be developed, the drive input gear 221 on the side of the developer unit 101 is and the drive gear 461 on the main drive device R430 side are in mesh with each other.

This drive device M430 includes both side plates 460a and 460b and a connecting plate 4soc that connects the both side plates 460a@460b.
The housing 460 has a generally U-shaped cross section. The housing 460 is.

It is swingably mounted around a pivot shaft 456 fixed to the main body of the copying machine (not shown). A gear 457 is rotatably provided on the pivot shaft 456.

A shaft 458 is rotatably provided in the housing 460 at a position spaced apart from the pivot shaft 456 . A gear 459 and the aforementioned driving gear 461 are fixed to the shaft 458, and the gear 459 is connected to the aforementioned gear 457, and the gear 461 is connected to the driving input gear 221 of the developer unit 101 as described above.
is engaged with. Therefore, gear 459 and gear 457 are in the relationship of a planetary gear and a sun gear.

The housing 460 drives the drive gear 461 by the action of a spring 463.
is urged to move toward the input gear 221, but when the developer unit 101 is not at the developing position, the side plate 460a collides with the pin 462, so that the amount of rocking of the housing 460 is restricted. In other words, the developing device 2) 1 is moved to the developing position by the rotation of the rotating support.
Before the input gear 221 on the 01 side and the drive gear 461 on the main drive unit M430 mesh with each other, the side plate 460a contacts the pin 462, and the housing 460 remains stationary in this state. Also, when the drive gear 461 and the input gear 221 are engaged, the side plate 460b of the housing is connected to the human power gear 22.
It comes into contact with a roller 223 rotatably provided on the shaft 224 of 1,
The distance between the centers of both gears 461 and 221 is maintained at an appropriate amount.

Furthermore, wooden drive equipment! 1430 includes a gear 455 rotatably provided on a shaft 453 fixed to the main body of the copying machine, and a belt pulley 454 is integrally connected to the gear 455. A timing belt 452 is stretched between the belt pulley 454 and a belt pulley 451b attached to the output shaft 451a of the drive motor M2, and the output rotation of the drive motor M2 is transmitted via the timing belt 452 to the pulley 4514→ The signal is transmitted from the gear 455 to the gear 457 to the gears 459 and 461, and then to the drive input gear 221 of the developing unit IO1. The rotational force of the drive input gear 221 is transmitted to the developing roller 130, a developer stirring screw shaft (not shown), etc. via gears 222, 225, and 226, thereby driving the developing unit lot.

In addition, the output shaft 451a of the drive motor M2 and the belt pulley 4
A one-way clutch 451c is interposed between the clutch 51b and the clutch 51b. The one-way clutch 451c is connected to the output shaft 4
When 51a rotates in the direction of arrow A, the output shaft 451
a and belt pulley 451b rotate together, and work so that they can freely rotate in the opposite direction.

As mentioned above, the rotation center of the rotary support supporting a plurality of developing device units is located at the axis 0-O, and each developing device unit rotates around the rotation center axis 0-O of the rotary support in the direction indicated by the arrow. The zero drive unit 430, which is rotated and sequentially moved to the developing position, is connected to the developing unit 101 as described above.
moves to the developing position and the input gear 22 on the unit/to side moves to the developing position.
1, the housing 460 is positioned in contact with the stopper bin 462, so that the position of the drive gear 461 is slightly closer to the axis 0-O than when it is engaged with the developing unit 462. . developer unit)
When 101 rotates in the direction of the arrow, first the input gear 221
comes into contact with the waiting drive gear 461 from the lower left side and enters the developing position while rotating the drive gear 461 in the direction of arrow B. At this time, since the one-way clutch 451c is present, the rotor and gear head of the motor M2 are not rotated, and the belt pulley 451b rotates around the motor output shaft 451a, so the drive gear 461 rotates as the input gear 181 of the developer unit approaches. can do.

When one developing process is completed, the rotating support of the rotary developing device is rotated in the direction of the arrow in order to perform another developing process.

As a result, the developing unit 101 rotates from the developing position in the direction indicated by the arrow, and the gear 221 is disengaged from the drive gear 461. In other words, the connection between the developer unit lot and the main drive device 430 is severed.

When the next developing unit (/ ) moves to the developing position, the input gear (22L) on that unit side and the main drive unit fi
The 430-coupled driving gear 461 is in mesh with the developing unit, and the driving force can be transmitted to the developing unit.

[Problem that the invention seeks to solve]

In the developing device drive mechanism configured as described above, the input gear 221 of the developing device unit to be driven at the developing position is located at a radius r from the rotation center axis O-0 of the rotating support of the developing device unit.
, and at that position the present drive device I
It meshes with the drive gear 461 of 430 and receives the driving force.

Therefore, when the driving force is input from the drive gear 461 to the input gear 221, the rotary support of the developing unit has a moment) M about the axis O-O.

works.

If f is the tangential force (torque) at the input gear 221 required to drive the developer unit 101 in a predetermined direction, then the above moment M O is M o = f X r, and f is, for example, 2 kg, When r is 10 cm, the moment acting on the rotating support when the developing unit is driven is M o
= 20Kgc, which is quite large, and this force applies a large load to the positioning means of the rotating support each time the developing unit is driven.

The repetitive large load on the positioning means of the rotary support caused by the above moment) causes wear of the means over time, a decrease in positioning accuracy of rotation angle control of the rotary support due to the wear, and a biting force acting on the means. This causes problems such as a decline in the smooth operation of the device and disturbances in the formed image due to vibrations.

An object of the present invention is to solve the above-mentioned problems by devising a method to minimize the moment acting on the above-mentioned rotating support each time the developing unit is driven.

Summary: Structure of the Invention [Means for Solving the Problems] The present invention has a plurality of developing device units supported on a rotating support, and controlling the rotation of the rotating support to move a required developing device unit to the object to be developed. The rotary developing device is moved to a predetermined opposing developing position to perform development using the required developing device unit.

and a non-rotating hollow shaft as the central axis of rotation of the rotating support.

a drive member disposed within the hollow shaft and driven by an external drive source; and a power transmission member disposed on the side of the rotary support and relaying the driving force to the developing device unit/), and the rotary support When the developer unit is moved to a predetermined development position facing the object to be developed by the rotation of the developer unit, the power transmission member is connected to the drive member, and the driving force of the external drive source is transmitted to the developer unit. The gist of the present invention is a developing device characterized by: being in a transmittable state or in a transmittable state.

[For production]

That is, the central axis of rotation of the rotary support body that supports each developing device unit is made into a non-rotating hollow shaft, and a driving member driven by an external drive source is disposed within the hollow shaft. The power transmission member of the required developing device unit moved to the developing position facing the object to be developed by controlling the rotation of the support body is connected (clutching), and the driving force of the external drive source is applied to the required developing device unit. Since the power is transmitted to the operating state, the distance between the center axis of rotation of the rotary support and the connecting portion of the drive member and the power transmission member can be significantly reduced, and the developing unit The moment acting on the rotating support during driving is significantly reduced. As a result, all of the above-mentioned problems that arise when the acting moment is large are successfully eliminated.

〔Example〕

An embodiment of the developing device according to the present invention will be described in detail with reference to the drawings.

In this embodiment, the developing device is embodied as a dry rotary developing device of a full-color electronic copying machine, but the present invention is not limited to this embodiment.

A full-color electrophotographic copying machine includes various electrostatic latent image forming processes, such as the tRNP process, which includes the steps of primary charging, secondary charging/color separation exposure, and full-surface exposure, and the steps of primary charging and color separation exposure. Although the so-called Carlson process including the above may be used, in this embodiment, an electrophotographic copying machine to which the Carlson process is applied will be described.

A. Overall schematic structure of the copying machine (Fig. 4) Fig. 4 is a sectional view showing the overall schematic structure of a full-color electrophotographic copying machine. A photosensitive drum 1 having a photosensitive drum 1 is arranged and rotated in the direction of arrow X (counterclockwise).

A primary charge is applied to a position approximately directly above the photosensitive drum 1. photosensitive drum l
On the left side is a rotary developing device 100. A transfer device (transfer drum) 5 is disposed substantially directly below the photosensitive drum l, and a cleaning device 6 is disposed on the right side of the photosensitive drum l.

Further, an optical system 10 is disposed in the upper part of the electrophotographic copying machine, and an optical system 10 is arranged to transfer the image of the document 0 on a transparent platen 7 such as a glass plate between the primary charger 2 and the rotary developing device 100. The exposure unit 3 is configured to project (slit exposure) onto the photosensitive drum l. Although any optical system can be used as the optical system 1O, in this embodiment, a first scanning mirror 11, and second and third scanning mirrors that move in the same direction at half the speed with respect to the first scanning mirror 11 are used. Mirrors 12 and 13. Imaging lens 1
4, a fourth fixed mirror 15. Since the optical system 10 is a well-known slit exposure type optical system, detailed explanation will be omitted. The original illumination light source 16 is configured to move together with the first scanning mirror 11, and the color separation filter 1
7 is disposed between the fourth fixed mirror 15 and the exposure section 8 .

The reflected light image of the document 0 scanned by the first, second, and third scanning mirrors 11 and 12φ13 passes through the lens 14 and then
The light is color-separated by a color separation filter 17 via a fixed mirror 15, and an image is formed on the photosensitive drum 1 at an exposure section.

There is a fuser 2120 on the right side inside the full color electrophotographic copying machine.
and a paper feeding device 30 are arranged, and the transfer device 5 and the fixing device! Transfer paper transport systems 25 and 35 are provided between the i20 and the paper feeder 30, respectively.

In the above configuration, the photosensitive drum 1 performs the charging-exposure, development, transfer, and cleaning steps for each color separated by the color separation filter 17, including the primary charger 2, the optical system 10, the rotary developing device 100, and the transfer device. 5 and a cleaning device 6.

As will be described in more detail later, the rotary developing device 100 includes a rotary support 300 and four developing device units 1OIY (yellow), each of which is removably held at an angular interval of approximately 9 G'. developer unit), 101M (
Magenta ift! ! 1OIC (cyan developing unit), and 101B (black developing unit) Ru. That is, by controlling the rotation angle of the rotary support by approximately 9Q', a required developing unit is moved to a predetermined developing position facing the photosensitive drum 1, and development is performed by the developing unit. FIG. 4 shows a state in which a black developing unit 10IB is positioned opposite to the photosensitive drum 1.

The transfer device 5 typically includes a transfer drum 5b equipped with a gripper 5a for gripping a transfer material, that is, a transfer paper P, on its circumferential surface. The transfer device 5 receives the transfer paper P fed from the transfer paper cassette 31 or 32 of the paper feed device 3o via the transfer paper conveyance system 35.
The tip of the photosensitive drum 1 is gripped by a gripper 5a and rotated to transfer a visible image of each color on the photosensitive drum 1. A transfer charger 5c is arranged inside the transfer drum 5 in the transfer area.

The transfer paper P on which the developed image of each color, that is, the toner image has been sequentially transferred, is released from the gripper 5a and is peeled off from the transfer drum 5b by the separation claw 8.The transfer paper P-transfer paper conveyance system 2
5 to the fixing device 2o. The toner image on the transfer paper P is fixed onto the transfer paper by the fixing device 20,
The transfer paper is then discharged onto the tray 23.

B. Rotary developing device (FIGS. 1 to 3) As described above, the rotary developing device ioo basically includes a plurality of developing device units 101 (in this embodiment, a yellow developing device unit) 101Y, magenta developing device Units) IO
It consists of four developer units, IM, cyan developer unit 101C, and black developer unit 10IB, and a rotating support 300 on which the developer units are detachably attached and held at angular intervals of approximately 30°.

Reference numeral 310 denotes a hollow shaft serving as the central axis of rotation of the rotary support body 300, and the hollow shaft 310 is supported non-rotatably with both ends fixed between front and rear side plates (not shown) of the image forming apparatus.
The rotary support body 300 is rotatably supported around this fixed hollow shaft ♀10 via a bearing 50 (FIG. 2).

This rotating support 300 is driven to rotate clockwise as indicated by the upper arrow in FIG. When the developing device is moved to a predetermined developing position, it is positioned at that rotation angle position by a positioning mechanism (not shown) and is stably locked and held. And the developer unit)
When the development by 101 is completed, the locking by the positioning mechanism is released, and the rotary support is rotated again in order to move the next developing unit to the developing position.

FIG. 1 shows a state in which one developer unit 101 of a plurality of developer units supported by a rotary support 300 is moved to and held at a predetermined developing position facing the photosensitive drum l. ing. FIG. 3 shows the state before the developing device 22 and the developing device 101 reach the developing position.

(The developing unit was moved to the developing position and held there)
The lot receives a driving force from an external driving source through the gear train mechanism shown in FIGS. 1 and 2, and mechanically drives a developing roller, a developer stirring screw shaft, etc.

That is, M is a motor as an external drive source, 110 is an output shaft of the motor, and 111 is a motor gear 114 that is integrally fixed to the output shaft. A drive shaft 112 inserted into the central hollow shaft 310 is a gear attached to the rear end of the shaft via a one-way clutch 113, and is constantly meshed with the motor gear 111. The reference numeral 115 is a drive gear that is inserted into the hollow shaft 310 and is integrally fixed to the distal end side of the drive shaft 114. A part of the gear 115 is connected to the outside of the hollow shaft through a through hole 310a provided in the wall surface of the hollow shaft 310. is slightly exposed.

Reference numeral 123 designates an idler shaft installed on the inner surface of the side plate on the side of the rotation support 300, on which the second idler gear 117 is rotatably supported, and a swing plate 124 is provided on the same axis to freely swing. Reference numeral 116 denotes a first idler gear rotatably supported around a shaft 125 installed in the rocking plate 124, and the first idler gear 116 and the second idler gear 117 are always in mesh with each other. There is.

127 denotes the swing plate 124 as its support shaft 123 in FIG.
It is a tension spring that is always biased to rotate counterclockwise around , and its biasing force causes the first idler gear 116 in the state shown in FIG. The meshing state with respect to the drive gear 115 is stably maintained by contacting the exposed portion, and the swing plate 124
The rear end portion 124a is in contact with the outer surface of the hollow shaft 310 to ensure backlash of both the gears 115 and 116.

118 is the shaft 1 installed on the inner surface of the steel plate of the rotating support 300 pairs.
This third idler gear is rotatably supported around 26, and is always in mesh with the second idler gear 117.

Reference numerals 119 to 122 denote driving gear trains on the side of the developing unit IO1, and when the developing unit 101 is mounted and set on the rotating support 300, the driving human gear 119 (fifth (corresponding to the input gear 221 in the figure) and the third idler gear 117 on the rotation support 300 side are always maintained in a meshed state.

In the state shown in Figures 1-2, that is, in the state in which the required developer unit 101 is moved to and held at the developing position,
When the motor M, which is an external drive source, is driven, its driving force is transmitted to the developing unit lO through gear trains 111 to 118.
The driving force is transmitted to the input gear 119 on the 1 side, and as the input gear 119 is rotationally driven, the driving force is transmitted to the gears 120 to 1.
22 to rotate the developing roller, developer stirring screw shaft, etc.

The developing unit 10 is rotated by the rotating support 300.
1 reaches the developing position, the swing plate 124 moves along the outer periphery of the hollow shaft 310 with its rear end side 124 a in contact with and received by the outer periphery of the hollow shaft 310 as shown in the third figure. The first idler gear 116 (clutch gear) rotates together with the rotating support 300 and is therefore supported by the rocking plate 124.
It moves on a circle a concentric with 0 as a movement trajectory.

During the rotation process of the rotary support 300, the first idler gear 116, which is the clutch gear, is not in contact with the drive gear 115 (clutch-off), and therefore, the transmission of driving force to the developing unit 101 is cut off. There is no rotational drive of the developing roller, etc.

When the rotation of the rotary support 300 progresses and the developing unit 101 reaches a predetermined developing position, it is positioned at that rotational angular position by the positioning mechanism (not shown) and stably held in place, as described above.

At this point, the first idler gear 116, which is a clutch gear, comes into regular contact with the drive gear 115, resulting in a meshed state (clutch-on).

As a result, the developing roller and the like of the developing device unit IO1 are activated or become operable by the driving force of the external driving source M.

In the above, when the first idler gear 116 meshes with the drive gear 115, even if so-called gear riding occurs due to a collision between the teeth of both gears l15 and 116,
The first idler gear 116 is supported by a rocking plate 124
swings clockwise in FIG. 1 about the support shaft 123 against the spring 127, allowing the first idler gear 116 to escape, thereby preventing the gear from running over.

The one-way clutch 113 interposed between the drive shaft l14 and the gear 112 is connected to the shaft 114 in FIG.
When viewed from the direction of arrow A, the gear 112 is the motor gear 11.
When the gear 112 is rotated clockwise (developing unit driving direction), the rotational force is transmitted to the gear 7) 114, but not in the opposite direction, and the gear 112 is rotated clockwise (developing unit driving direction).
This is in the direction of the clutch, which is idling against the force of 4.

As a result, the rotational support 300 reaches the rotational angle state shown in FIG. 1 from FIG. 3, and the first idler gear 116, which is a clutch gear,
In the process of contacting the drive gear 115 and turning on the clutch, the first idler gear 116
5 and shirt) 114, but as mentioned above, the one-way clutch 113 is in a relationship that allows the shaft 114 to rotate freely in that direction.
The rotor of the motor M does not receive inertia and the drive gear 11
5 and the first idler gear 116 can be smoothly engaged.

Although omitted from the figure, the above-mentioned first idler gear 116 to third
A mechanism similar to the gear train mechanism corresponding to the idler gear 118 is provided on the inner side of the side plate of the rotary support 300 for each developing unit in a number corresponding to the number of other individual developer units installed and set on the rotary support 300. 7 are arranged at substantially equal intervals at positions corresponding to the mounting positions of the rotary supports 300, and each time a required developing unit is moved to the developing position by controlling the rotation of the rotary support 300, the above-mentioned developing unit corresponding to that developing unit is moved. Gear train mechanism 11
The first idler gears 116 of 6 to 118 are clutch geared to the drive gear 115 in the hollow shaft 310, and the driving force for driving the developing roller and the like to the developing device unit can be transmitted from the external drive source M to the transmission section. state.

Thus, according to the above-mentioned developing device drive mechanism, one rotation of the support member 3
Since the distance between the rotation center axis of 00 (the axis of the fixed hollow shaft 310) and the connecting portion of the drive gear 115, which is a drive member, and the first idler gear 116 (clutch gear), which is a power transmission member, is small, the developing device The moment acting on the rotating support 300 when the unit 101 is driven is significantly reduced.

As a result, all of the aforementioned problems that occur when the acting moment is large are all satisfactorily eliminated.

By applying an appropriate frictional torque T to the rotary support member 300 in advance, and establishing a relationship of approximately M=T or MAT with respect to the moment M acting on the rotary support member 300 when the developing device unit is driven, development can be performed. It is possible to eliminate the influence of the moment applied to the rotating support when the device driving force is input.

C. Effects of the Invention As described above, according to the present invention, regarding the rotary developing device,
By minimizing the moment acting on the rotary support each time the developing unit is driven, problems such as wear of the rotary support positioning means over time, decrease in positioning accuracy, deterioration in smooth device operation, and device vibration can be avoided. It is something that can be resolved,
The intended purpose is well achieved.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of main parts of the embodiment mechanism, FIG. 2 is a developed sectional view of its gear train, and FIG. 3 is a diagram showing the state of the mechanism before the rotating support reaches the rotation angle position shown in FIG. 1. FIG. 4 is a sectional view schematically showing an example of a full-color electrophotographic copying machine incorporating a rotary developing device, and FIG. 5 is a perspective view of an example of a developing device drive mechanism. 100 is a rotary developing device, 101 (YΦM@C/B) is a developing device unit, 300 is a rotating support, 310 is a hollow shaft as its rotation center, 112 to 122 is a gear train as a developing device driving mechanism, 115 is a gear as a driving member, 1
16 is a first idler gear (clutch gear) as a power transmission member, and M is a motor as an external drive source.

Claims (1)

[Claims] (1) A plurality of developer units are supported by a rotating support,
A rotary developing device that moves a required developing device unit to a predetermined developing position facing the object to be developed by controlling the rotation of the rotating support member, and executes development using the required developing device unit, the rotary supporting member a non-rotating hollow shaft serving as the central axis of rotation of the body; a driving member disposed within the hollow shaft and driven by an external drive source; and a driving member disposed on the rotating support side and relaying driving force to the developing unit. and a power transmission member that connects the power transmission member to the drive member when the developing device unit is moved to a predetermined development position facing the object to be developed by rotation of the rotating support, and the developing device A developing device characterized in that a driving force from an external driving source is transmitted or can be transmitted to the unit.