JPH03125166A - Developing device - Google Patents

Abstract

PURPOSE:To bring a required developing unit to a developing position at a high speed and to smoothly transmit driving force to the developing unit arriving at the developing position, without producing noise by providing a supporting body with a driving shaft for each of the developing units and with a drive-transmitting coupling which can be engaged with and separated from the drive-coupling of each of the developing units. CONSTITUTION:In the position where the supporting body 6b faces each of the developing units, the driving shaft 80 is pivotally supported on a line extended from the developing roller shaft 71 of corresponding developing unit, so that it can freely rotate and also move in the prescribed range in the axial direction shown by an arrow N; the drive-transmitting coupling 81, which can be engaged with and separated from a developing unit driving coupling 75, is fixed at the front end of the driving shaft 80. Therefore, the required developing unit is speedily brought to the developing position without being interruped by anything, by rotating the supporting body, and the driving shaft which corresponds with the developing unit can be pushed out by a driving member. Since the coupling engage with each other, and the driving shaft is rotated and driven, the developing unit can be surely and smoothly switched and operated without any impact.

Description

Detailed Description of the Invention W fat conversion to 11L 1 The present invention has a plurality of developing devices supported on a support that rotates around one axis, and selectively rotates to a developing position to perform development. This relates to the developing device of the image forming apparatus.

4.1 A developing device for an image forming apparatus such as a full-color copying machine, a multicolor copying machine, or a multicolor printer is capable of rotating multiple developing devices around a single shaft fixed to the main body of the image forming apparatus. The photoreceptor was supported on a support, and the support was rotated around its axis to selectively bring each developer to a development position where its developing roller contacted the photoreceptor, so that development was performed in each required color in sequence. A so-called revolver type developing device is known.

FIG. 5 is a diagram showing the overall general configuration of an example of a full-color copying machine equipped with this type of developing device.

In the figure, 1 is an original table, 2 is a lamp for illuminating the original, 3 is an aperture system, and 4 is a photosensitive drum.

Around the photosensitive drum 4, in the order of rotational direction indicated by the arrow, there are a charger 5, an exposure position by the exposure optical system 3, and four color developing units 6Y, magenta, cyan, and black, 6Y, 6M, and 6C.

68K on a support 6b rotatable around an axis 6a,
A working device 6, a transfer charger 7, a separation charger 8, a cleaning device 9, and a static elimination lamp 10 are provided, which are capable of switching the color of each ring in a revolver manner. Also, in the exposure optical path, blue,
Green and red color separation filters 11B, 11G, IIR
and an ND filter 11N are provided so as to be switchable and insertable. The color separation filter 11 and the above developer 6 are
When the blue filter IIB is inserted into the optical path, the yellow developing unit 6Y is brought to the operating position in contact with the photoreceptor, when the green filter LIG is inserted, the magenta developing unit 6M is inserted, and the red filter IIR is inserted. When the cyan developing unit 6C is
When the black developing unit 68K is inserted, the black developing unit 68K is switched to the operating position.

Transfer charger 7, separation charger 8 and photosensitive drum 4
Transfer paper 15 is fed from a paper feed cassette 12 through a pickup roller 13 and a registration roller 14 to a transfer section between the two.

A gripper 1 that grips the leading edge of the transfer paper so as to be capable of reciprocating linear movement in the tangential direction of the photosensitive drum 4 from the transfer section to the discharge side thereof.
A transfer paper transport member 17 having a diameter of 6 is provided. The transfer paper conveyance member 17 is formed, for example, as a sliding member guided by a guide member extending in the tangential direction of the photoreceptor drum 4 at the transfer position, and moves the rack fixed to the member 17 to the photoreceptor drum 4. By meshing with a gear that is provided coaxially and rotates at least integrally with the photoreceptor drum 4 during transfer, the movement stroke to move in the transfer paper ejection direction at the same linear speed as the photoreceptor during transfer is the length of the transfer paper. is roughly equal to In FIG. 3, 17° indicates the position of the transfer paper conveying member 17 that is furthest forward. When the transfer paper retreats, the guide member from the registration rollers retreats downward so that the retreat path of the transfer paper is not blocked by the registration rollers 14.

The fixing device 22 is located above the reciprocating path of the transfer paper conveying member 17 so as not to interfere with the reciprocating movement of the transfer paper conveying member 17. Transfer paper 1 on which the predetermined number of transfers have been completed
5 to the fixing device 22, a transfer section side support roller 2 is installed between the downstream side of the transfer section and the upstream side of the fixing device 22.
A transfer paper conveyance belt 23 is provided to be swingable about 3-1 as an axis. The transfer paper conveyance belt 23 has a suction housing 2 inside.
4, when the transfer paper enters the fixing process after the transfer is completed, when the leading edge of the transfer paper moves to the suction part of the transfer paper conveyance belt 23, the two grip release members release the gripper of the transfer paper conveyance member 17. 16, the leading edge of the transfer paper 15 is attracted to the conveyance belt 23, and the transfer paper conveyance member 17 is moved to the position 17.
', and raise the front end of the conveyor belt 23 so that the conveyance direction faces the fixing device 22, and then
conveys the transfer paper toward the fixing device.

Note that the reference numeral 30 in the figure is a stopper that fixes the leading edge of the transferred transfer material 15 in a fixed position.

By the way, conventionally, in a revolver-type developing device capable of switching developed colors, an input gear provided in each developing device meshes with a single developing device driving gear on the main body side when a certain developing device comes to the developing position. Usually, a method is adopted in which the developing device is driven by In this case, the support is rotated around its axis to move the developer and the input gear on the developer side meshes with the drive gear on the main body, so a mechanical shock is generated when the input gear is engaged, causing impact noise. Also, wear of the gears is unavoidable, resulting in problems such as whistling noise and reduced durability of the device.

Furthermore, it is difficult to increase the rotation speed of the support for moving the developing device toward the developing position in order to increase the image forming speed.

SUMMARY OF THE INVENTION The present invention addresses the above-mentioned drawbacks of the conventional structure of a developing device having a plurality of revolver-type developing devices, and brings required developing devices to a developing position at high speed.

It is an object of the present invention to provide a highly reliable revolver type developing device capable of transmitting a driving force to a developing device smoothly brought to a developing position without making a loud noise.

In order to solve the above-mentioned problems, the present invention has been made for each of a plurality of developing devices supported on a support member fixed to an image forming apparatus main body and rotatable around one axis. In a developing device of an image forming apparatus that performs development by selectively moving a body to a developing position by rotating the developing device, each of the developing devices has a developing device drive coupling for driving the developing device, The support body is characterized in that it has a drive shaft for each developing device and a drive transmission coupling that is provided on each of the drive shafts and is detachable from the drive coupling of each of the developing devices.

Color-1 With the above configuration, the developer drive coupling attached to each developer and the drive shaft and drive force transmission coupling for each developer provided on the support can be used to connect the support to the support. If you rotate it around the axis, it will rotate as a unit, so
Smooth engagement and disengagement can be achieved by simply moving the driving force transmission force on the support side in the axial direction. There is no impact or gear wear, and it is possible to prevent noise generation and a decrease in durability. .

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram showing the configuration of one developing device of a developing device according to an embodiment of the present invention. FIG. 2 is a diagram showing a support supporting four developer holders and a drive engagement means for the developer (only 6M is shown in the figure).

The developing device of this embodiment includes four developing units 6Y, 6M, and 6C that use -component nonmagnetic toner.

68K is supported on a support 6b which is rotatably supported as shown by the arrow on a shaft 6a fixed to the main body of the image forming apparatus.

As shown in FIG.
Inside, there is a developing roller 62 that contacts the photosensitive drum 4 through the opening, a toner supply roller 63 that contacts the developing roller at eight points and supplies the toner 31, and a V4 press on the toner 31 in the housing 61 to prevent blocking. , an agitator 64 that supplies toner to the toner supply roller 63, and a toner layer thickness regulating member 6 that regulates the toner layer thickness on the developing roller 62.
6. A charge eliminating member 65 is provided to eliminate charge from the residual toner and the developing roller 62 returned by the developing roller from the developing section where the developing roller 62 and the photoreceptor drum 4 come into contact.

Since the developing action of these members is well known, the explanation thereof will be omitted.

The shaft 71 of the developing roller 62 of each developing device passes through the housing 61 and extends toward the support 6b, and a gear 74 meshes with a gear 73 provided at the shaft end of the shaft 72 of the toner supply roller 63. A developer drive coupling 75 is fixed to the end of the shaft 71. Note that the drive gear of the agitator is omitted in the figure.

At a position on the support body 6b facing each developing device, a drive shaft 80 is rotatably mounted on an extension line of the developing roller shaft 71 of each developing device as shown in FIG. It is movable in the axial direction within a predetermined range, and at its tip,
A drive transmission coupling ring 81 that can be engaged with and disengaged from the developer drive coupling 75 described above is fixed.

FIG. 3 is a diagram showing a state in which the developer drive coupling 75 and the drive transmission coupling 81 are engaged. Both couplings 75, 81 each have a pair of projections 75a at both ends of one diameter that engage with those of the other coupling.
, 81a are provided in a protruding manner, and when the drive shaft 80 retreats in the axial direction, both the protrusions 75a and 81a are removed.

FIG. 4 is a diagram showing the axial movement and rotation drive mechanism of the drive shaft 80. The drive shaft 80 has a bearing 82 on the support 6b.
It is rotatably and slidably supported in the axial direction by a sleeve-shaped rotating shaft 83 which is pivotally supported through the sleeve. An annular recess 83a is provided in a part of the inner surface of the rotating shaft 83, and a stopper 84 protruding from the drive shaft 80 comes into contact with both end surfaces of the recess 83a, thereby regulating the axial movement range of the drive shaft 80. It looks like this. A coupling 85 having a hemispherical tip is fixed to the right end of the drive shaft 80 in FIG. 4, and a compression spring 86 is interposed between the left end of the coupling 85 and the right end of the rotating shaft 83. When the driving member 87 provided on the machine frame of the main body of the apparatus opposite to the right end of the coupling 85 is moved as shown by the double-headed arrow by a driving member (not shown), the coupling 85 follows this and moves left and right. . Engaging protrusions 85a and 83b are provided on the left end of the force coupling 85 and the right end of the rotating shaft 83, respectively, and when the coupling 85 moves to the left side, these engage, and the driving shaft 80 and the rotating shaft 83 are integrally formed. Rotate to . A drive gear 88 is fixed to a position on the right side of the support body 6b of the rotating shaft 83, and is driven to mesh with a gear (not shown) that rotates about the rotation center of the support body by a drive source (not shown).

The drive member 87 described above is provided only at a position corresponding to the drive shaft of the developing device at the developing position.

Therefore, the drive shaft 80 of the developing device that is not in the developing position does not engage with the drive coupling 75 on the developing device side.
The rotating shaft 83 and the coupling 85 also do not engage with each other.
Even if the rotating shaft 83 is rotationally driven through the gear 88, the drive shaft 80 does not rotate, and the drive coupling 75 of the developing unit is not rotationally driven. According to the invention, by rotating a support, a desired developing device can be quickly brought to a developing position without being obstructed by anything, and by pushing out a drive shaft corresponding to the developing device with a driving member, a coupling can be achieved. Since the developing device is engaged and rotated, it is possible to switch and operate the developing device smoothly and reliably without impact, which is effective in reducing bright noise and improving reliability.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the configuration of one developing device of a developing device according to an embodiment of the present invention, and FIG. 2 is a driving engagement means for connecting a support of the developing device and one of the developing devices according to an embodiment of the present invention. FIG. 3 is a side view showing the state of engagement between the developer drive coupling and the drive transmission coupling, FIG. 4 is a sectional view showing the axial movement and rotational drive mechanism of the drive shaft, and FIG. FIG. 5 is a sectional view showing the overall configuration of an example of an image forming apparatus to which the present invention is applied. 6... Developing device, 6a... Rotating shaft of support, 6b... Developing device support, 6Y, 6M, 6C, 6BK... Developing device, 71... Developing roller shaft, 75...・Developer drive coupling, 80... Drive shaft, 81... Drive transmission coupling, 83... Rotating shaft, 87... Drive member, 88... Rotating gear 1, 2nd blade M

Claims (1)

[Scope of Claims] Each of a plurality of developing devices supported on a support fixed to an image forming apparatus main body and rotatable around one axis is selectively moved to a developing position by rotating the support. In the developing device of the image forming apparatus, each of the developing devices has a developing device drive coupling for driving the developing device, and the support body includes a drive shaft for each developing device and a coupling for driving the developing device. A developing device comprising a drive transmission coupling which is provided in each of the developing devices and is detachable from the drive coupling of each of the above-mentioned developing devices.