JPH06258884A - Image forming device - Google Patents

Abstract

PURPOSE:To provide the image forming device capable of reducing interference on the tips of teeth of gears with each other caused in the case of rotating a body such as a developing cartridge with respect to a device main body and in the case of transmitting driving force thereto from the device main body side through a gear driving device, capable of preventing the tips of teeth from being deformed, and evading causing noise and lowering image quality. CONSTITUTION:The gear 10 is fixed to the supporting shaft 14 of a the developing cartridge D, and the gear 9 is arranged on a developing device driving supporting member 7. A bar pressing member 45 successively approaches a gear phase matching bar 43 first, then a gear phase matching bar 44 in the case of vertically falling from an upper part to a lower part. The phases of the bars 43 and 44 are lined up in the vertical direction by making the bars 43 and 44 pass through the inside of a groove 47 formed on the lower end of the bar pressuring member 45. Consequently, the phase of the gear 10 and that of the gear 9 coincide with each other, so that the gears 10 and 9 can be meshed without causing the interference on the tips of teeth.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus using an electrophotographic system, and more particularly to an image forming apparatus having a unit such as a developing cartridge detachably attached to an apparatus main body. It can be preferably embodied in an image forming apparatus that forms a multicolor image such as a full-color image.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus provided with a unit such as a developing cartridge, a gear is used to transmit a rotational movement to a rotating body such as a developer carrying member included in the developing cartridge. However, when exchanging the developing cartridge, this developing cartridge is mounted at a predetermined position of the main body of the apparatus, the drive gear on the main body of the apparatus and the gear on the side of the developing cartridge are pressed against each other, and thereby the play of the gear is used It is configured to mesh.

To explain further, FIG. 1 shows an example of a color image forming apparatus provided with a plurality of developing cartridges. In the image forming apparatus of this example, an image carrier 1 such as a photosensitive drum is charged. The member 2 and the cleaner 3 are integrally assembled into a cartridge, and the drum cartridge C is detachably attached to the main body of the apparatus, the developing chamber having the developer carrier and the toner containing chamber containing the toner are integrally formed into a cartridge. The developing cartridges D of respective colors (that is, the yellow developing cartridges Dy, which can be independently attached to and detached from the main body of the apparatus)
Development for developing the latent image on the image carrier 1 by sequentially moving the magenta developing cartridge Dm, the cyan developing cartridge Dc, the black developing cartridge Db) and the developing cartridge D of each color to a developing position facing the image carrier 1. It is characterized in that a developing cartridge switching mechanism for switching the cartridge D is provided.

According to this image forming apparatus, a latent image for each color is formed on the image carrier 1 of the drum cartridge C by image exposure from the optical unit 107, and a color changing mechanism develops a latent image corresponding to the latent image. The cartridge D is switched to develop the latent image.

The toner images of the respective colors obtained by the development for the respective colors in this manner are sequentially superposed and transferred onto the paper 102 held on the transfer drum 103. Paper 10
The sheet 2 is fed from the sheet feeding unit 101, the front end thereof is gripped by the gripper 103f of the transfer drum 103, and is held on the outer periphery thereof by the rotation of the transfer drum 103. The sheet 102 on which the toner image has been transferred is separated from the transfer drum 103 and sent to the fixing unit 104, where it is fixed to mix and fix the toner images, and then passes through the sheet discharge section 105 and onto the sheet discharge tray 106. Is discharged to.

FIG. 2 shows the drum cartridge C described above.
~ It demonstrates with reference to FIG. The drum cartridge C is
As shown in FIG. 2, a pair of side plates 1 in the main body of the image forming apparatus.
00 (only the front side is shown) on the mounting opening 100a,
One of the front side plates 100 is mounted between the side plates 100 by inserting the front side plate 100 from the outside in the thrust direction (perpendicular to the surface of the side plate 100). Thus, the drum cartridge C is attached to the apparatus main body in the thrust direction. It is detachably installed. The waste toner container 4 is attached to one side of the drum cartridge C exposed from the side plate 100. At a corresponding position of an outer plate (not shown) on the front side of the apparatus main body (front side of the paper surface of FIG. 1), a not-shown entrance / exit for allowing the drum cartridge C and the waste toner container 4 to be put in and out of the apparatus main body is provided.

As shown in FIGS. 3 and 5, the drum cartridge C has plate-like frame portions 21 at both ends thereof, and the cylindrical image carrier 1 is provided between the lower portions of the frame portions 21. It is rotatably attached.

The drum cartridge C is protected by a protection member 6 covering a lower half portion of the image carrier 1 which is exposed to the outside of the drum cartridge C before being mounted on the apparatus body. The protection member 6 has a substantially semi-cylindrical shape with an open upper surface, and the projections 6a extending from both ends of the open end of the semi-cylindrical body are provided in the vicinity of the center of both ends of the frame portion 21 of the drum cartridge C. By being inserted into the notch groove 21a, it is attached to the drum cartridge C in its longitudinal direction. Side plate 10
When the drum cartridge C is inserted into the mounting opening 100a of the side plate 100 when the drum cartridge C is mounted on the side plate 0, the frame portion 6b provided at the front end portion of the protective member 6 in the insertion direction is attached to the side plate 100 as shown in FIG. Then, the protective member 6 is removed from the drum cartridge C.

The drum cartridge C is, as shown in FIG. 6 (in FIG. 6, the frame portion 21 on the front side is peeled off and shown), and the image carrier 1 and its charging member 2 and the image carrier. 1 cleaner 3, that is, the cleaning member 3a,
An agitating member 3b for the cleaned toner and a toner feeding screw 3c to the waste toner container 4 are provided.
Further, on the frame portion 21 on the waste toner container 4 side (front side),
Positioning members 5, 5'for the side plate 100 of the drum cartridge C are provided.

As shown in FIG. 1, the above-mentioned developing cartridge switching mechanism has a rotating shaft 110 parallel to the shaft of the image carrier 1.
A pair of plate-shaped developing cartridge holding members 108 rotatable around the center, and an arc-shaped guide member 112 fixed to the apparatus main body, which surrounds the periphery of the developing cartridge holding members 108 excluding the portions of the drum cartridge C and the transfer drum 103. I have it.

The holding member 108 has four portions along the circumferential direction.
An accommodating hole 108b having a substantially semicircular cutout for accommodating the developing cartridge D is provided at the location.
The developing cartridges D of the respective colors are accommodated in the accommodation holes 108b of the pair of holding members 108 at a position other than the developing position facing the image carrier 1 while being guided by the guide member 112, as shown in FIG. Are installed between the holding members 108 and vice versa.
Removed from. Thus, the developing cartridge D for each color
Are independently provided in the thrust direction so as to be attachable to and detachable from the apparatus body. An inlet / outlet (not shown) of each developing cartridge D is provided at a predetermined position on an outer plate (not shown) on the front side of the apparatus main body (front side of the paper surface of FIG. 1).

As shown in FIGS. 8 and 9, the developing cartridge D is a cylindrical support container in which the developing device 12 is rotatably accommodated via a developing device 12 and rotary support shafts 14 fixed to both ends thereof. The rotary support shaft 14 on the back side of the apparatus penetrates the end face of the developing device 12 and is attached to the control mechanism of the developing cartridge switching mechanism described later.

The developing device 12 is roughly divided into a toner accommodating chamber 19 and a developing chamber 20 adjacent to the toner accommodating chamber 19. In the toner accommodating chamber 19, an agitating / conveying member 18 for agitating toner and conveying it to the developing chamber 20 is provided. The developer carrier 15 is provided in the developing chamber 20, a supply / stripping member 17 for supplying the toner to the developer carrier 15 and stripping the undeveloped toner thereon, and the developer carrier 15. A regulation member 16 that regulates the layer thickness of the toner and imparts an electric charge is provided.

At both ends of the support container 13, leg portions 13a corresponding to the step portion 108a provided in the storage hole 108b of the holding member 108 shown in FIG. 1 are provided, and the leg portions 13a are provided. Of the developing cartridge D housed in the housing hole 108b by fitting into the housing 108b.
The supporting container 13 is held non-rotatably with respect to the holding member 108. When the developing cartridge D is positioned at the developing position, the leg portion 13a moves the developing cartridge D to the image carrier 1
It also serves as a guide for moving in the direction. When the developing cartridge D is moved to the developing position, the surface of the support container 13 on the side opposite to the leg portion 13a side has the support container 13
An opening 13b is provided so that the developer carrier 15 of the inner developing device 12 faces the image carrier 1.

Each developing cartridge D has the developing device 12 in a predetermined posture, in this embodiment, the toner storage chamber 19 and the developing chamber 20.
Are horizontally adjacent to each other (the wall 12a partitioning the toner storage chamber 19 and the developing chamber 20 is vertical), that is, the parallel portion 14a of the rotary support shaft 14 is horizontal, and the support container 13 is moved to the horizontal position. The storage hole 1 of the holding member 108 is formed such that the opening 13b is oriented in the radial direction outward of the holding member 108.
It is accommodated in 08b and attached to the holding member 108.

The developing cartridge switching mechanism is shown in FIG.
As shown in FIG. 5, the holding member 108 is rotated to sequentially move each developing cartridge D to the developing position, and at the same time, the developing mechanism 12 in the developing cartridge D is moved to the developing position with a control mechanism that maintains the developing device 12 in a horizontal posture. Pressurizing means 11 for pressing and positioning the developing cartridge D in the direction of the image carrier 1.
1 is further provided.

The control mechanism of the switching mechanism is shown in FIGS.
As shown in FIG. 3, a disc-shaped developing device drive mechanism support member 7 provided integrally with the holding member 108 or provided so as to rotate integrally with the rotation shaft 110 of the holding member 108 is provided. Then, inside the support member 7, a gear 9 is arranged corresponding to the gear 10 fixed to the rotation support shaft 14 of each developing device 12, and both gears 9 and 10 mesh with each other to develop the developing device drive mechanism. Make up. Further, a gear 8 meshing with each gear 9 is attached to the rotary shaft 110, and the gears 8, 9 and 10 constitute a planetary gear mechanism.

According to the above control mechanism, when the supporting member 7 is driven to rotate the holding member 108 toward the developing position in order to move the developing cartridge D, the supporting member 7 and the supporting member 7 revolve around the gear 8. The gear 9 and the gear 10 perform a planetary gear movement, and the developing device 12 is always maintained in the horizontal posture regardless of the movement of the developing cartridge D. or,
The support container 13 is held in a posture in which the opening 13b is directed outward in the radial direction of the holding member 108. As a result, at the developing position, the opening 13b of the support container 13 and the developer carrier 15 of the developing device 12 face the image carrier 1.

Driving of the support member 7 and the holding member 108 is
As shown in FIG. 12, the drive source 3 provided on the apparatus main body side
Performed by two. That is, the holding member 108 is attached with the pulley 29 that rotates around the rotating shaft 110, and the pulley 3 engaged with the pulley 29 and the drive source 32.
The belt 30 that transmits the driving force of the driving source 32 to the rotating shaft 110 is wound around the rotating shaft 110.

The gap between the image carrier 1 of the drum cartridge C and the developing cartridge D is adjusted for one developing cartridge D as an initial setting. As shown in FIG. 11 (FIG. 11 shows the frame portion 21 on the front side by peeling off the frame portion 21 on the front side), the concave developing device positioning member 27 is provided on the frame portions 21 at both ends of the drum cartridge C. Correspondingly, the developing device 12 of the developing cartridge D is provided with a protrusion 28. The frame portion 21 located on the inner side of the drum cartridge C is notched at a portion of the image carrier 1, and an eccentric member 23 is attached to a central shaft 22 of the image carrier 1 protruding from the notched portion 21a. ing. The notch portion 21a corresponding to the positioning portion at the end portion of the developer carrying member 15 provided in the developing device 12 is the recess 21.
An abutting member 26 of the developer carrying member 15 is inserted into the recess 21b.

When the developing cartridge D located at the developing position is pressed in the direction of the image bearing member 1 by the pressing means 111 shown in FIG. 1, the developing cartridge D moves in the direction of the image bearing member 1 and the supporting container 13 thereof. The drum cartridge C enters into the opening 13a of the developing device 12, the protrusion 28 of the developing device 12 abuts on the positioning member 27 of the drum cartridge C inside the opening 13a, and the abutting member 26 of the developer carrier 15 attaches to the eccentric member 23. bump into. By rotating the eccentric member 23 in this state, the gap (development gap) between the developer carrier 15 and the image carrier 1 is adjusted.

The eccentric member 23 is provided with an elongated hole 24, and the protruding member 25 provided on the frame portion 21 of the drum cartridge C is fitted in the elongated hole 24. After adjusting the gap between the developer bearing member 15 and the image bearing member 1, the protrusion member 25 is deformed to fix the eccentric member 23, whereby the gap is fixed, and the initial setting of the developing gap is completed.
After that, at the time of development, by pressing the developing cartridge D of each color located at the developing position by the pressing means 110, the protrusion 28 of the developing device 12 abuts the positioning member 27 of the drum cartridge C, and the image carrier 1 is supported. The developing cartridge D is positioned and the developer carrier 15
A predetermined developing gap can be obtained between the image carrier 1 and the image carrier 1.

When the developing cartridge D of each color is moved to the developing position and positioned, the developer carrying member 15 in the developing device 12 rotates to perform the developing operation. Therefore, as shown in FIG. 12, the gear 34 engaged with the drive source 35 on the apparatus main body side is connected to the gear 33 provided on the developer carrying member 15.

[0024]

As described above, in the image forming apparatus having the above-described structure, for example, in order to control each developing cartridge D to a fixed posture, each developing device 12
Corresponding to the gear 10 fixed to the rotary support shaft 14 of
And each holding member 1 for holding each developing cartridge D.
Every time it is attached to the developing device 08, the gear 9 on the developing device side is meshed with the device main body side, that is, the gear 10 attached to the support member 7 in this example, and the drive from the device main body side to the developing device side is performed. Although transmitted, the two gears have a problem that their tooth tips interfere with each other when they mesh with each other.

That is, such interference between the tooth tips may damage the gears to each other, or may cause the teeth to be deformed by scraping each other's teeth, resulting in noise or development. In some cases, accurate position control of the cartridge could not be performed.

In particular, even in the drum cartridge C which can be attached to and detached from the main body of the apparatus, the photosensitive drum which can be freely rotated is driven from the main body of the apparatus by a gear drive mechanism similar to that of the developing cartridge. Is transmitted, unevenness occurs in the transmission drive to the photosensitive drum, which greatly affects the image.

Therefore, an object of the present invention is to provide a unit having a rotating body, which is detachably attached to the apparatus main body such as a developing cartridge and a drum cartridge, via a gear drive to the apparatus main body. An image forming apparatus capable of reducing the interference at the tooth tips of gears generated when transmitting driving force from the side, thereby preventing the tooth tips from being deformed, and avoiding noise generation and image quality deterioration. Is to provide.

[0028]

The above object can be achieved by an image forming apparatus according to the present invention. In summary, the present invention is
An image forming unit that constitutes an image forming unit, is configured to be detachable from the apparatus body side, and has a unit to which a driving force is transmitted from the apparatus body side when mounted on the apparatus body side. In a device, a phase of a gear transmission mechanism for transmitting a driving force from the device body side to the unit and a gear of a connecting portion in the gear transmission mechanism is controlled, and interference between mutual tooth tips of the gears is reduced. And an image forming apparatus.

According to the second aspect of the present invention, the developing device switching mechanism is provided with a plurality of developing devices, and each developing device is sequentially moved to the developing position facing the image carrier so that images of a plurality of colors are formed on the image carrier. In each of the developing devices, a drive transmission path is formed between the developing device and a drive source common to each developing device at the developing position to drive a driven member in the developing device, and In the image forming apparatus, a pulse motor is used as the driving source.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An image forming apparatus according to the present invention will be described below in more detail with reference to the drawings.

(First Invention) First to Third Embodiments
Will be described. In the embodiments described below, the image forming apparatus of the present invention is embodied in the color image forming apparatus described above. Therefore, the overall configuration and operation description of the color image forming apparatus will be omitted, and the present invention will be described. Only the main characteristic part of will be described.

Embodiment 1 FIG. 13 and FIG. 14 are views showing the main characteristic part of the present invention best. In this embodiment, the developing cartridge D is
The holding member 108 is elastically supported by an elastic member, for example, a coil spring 41 in the opening 108b (not shown in FIGS. 13 and 14).

Developing device rotary support shaft 14 of developing cartridge D
A gear 10 is fixed to the tip of the gear 10, and a gear 9 is arranged corresponding to the gear 10 on the apparatus main body side, that is, in the developing device drive support member 7 in this embodiment.

According to this embodiment, the developing cartridges D of the respective colors are guided by the guide members 112 as shown in FIG.
As shown in FIG. 13, the gear 10 of the developing cartridge D does not mesh with the gear 9 on the apparatus main body side even if it is accommodated in the inside 8b and inserted between the holding members 108.

According to the present invention, the developing device rotation support shaft 14 provided with the gear 10 and the rotation support shaft 42 provided with the gear 9.
Gear phase matching bars 43 and 44 are formed on the respective gears. In the present embodiment, the rotation support shafts 14, 42 have the same diameter, and the gear phasing bars 43 and 44 have an elongated shape having the same width as the diameter of the rotation support shafts 14, 42, in this embodiment. It is formed in an oval shape. A bar pushing member 45 is arranged above the gear phase matching bars 43 and 44 in alignment with the gear phase matching bars 43 and 44.

FIG. 13 shows a state in which the developing cartridge D is inserted into the opening 108b of the holding member 108, and the gear 10 has not meshed with the gear 9 on the apparatus main body side. On the other hand, FIG. 14 shows the developing cartridge D by the action of the gear phase adjusting bars 43 and 44 and the bar pushing member 45.
The gear 10 and the gear 9 on the apparatus body side are in mesh with each other.

Referring to FIG. 15, gear phase adjusting bar 4
The operation of 3 and 44 and the bar pushing member 45 will be described.

As described above, in the state immediately after the developing cartridge D is inserted into the opening 108b of the holding member 108, the gear 10 and the gear 9 are not meshed, and the gear phase adjusting bars 43 and 44 are respectively. It is set to an arbitrary phase (FIG. 15 (a)). Next, the bar pushing member 45 vertically descends from the upper side to the lower side in the present embodiment, and first approaches the gear phase adjusting bar 43. The bar pushing member 45 is formed with an elongated ring-shaped 46 at the bar tip portion, and a groove 47 having the same width as the width of the gear phase adjusting bars 43 and 44 is formed at the lower end portion thereof. Therefore, when the bar pushing member 45 is pressed against the gear phasing bar 43, the gear phasing bar 43 is pushed into the groove 47 of the bar pushing member 45, whereby the gear phasing bar 43 is vertically aligned. The phase is set (FIG. 15B).

Further, when the bar pushing member 45 vertically descends downward, the bar pushing member 45 approaches the gear phasing bar 44. When the bar pushing member 45 is pressed against the gear phasing bar 44, the gear phasing bar 44 is pushed into the groove 47 of the bar pushing member 45, whereby the gear phasing bar 44 is aligned with the vertically aligned phase. (Fig. 15
(C)). In this way, the gear phasing bars 43 and 4
4 are in the same vertical phase so that gear 10
And 9 are also in phase and both gears 10, 9
Can engage with each other without interfering with the tooth tips (FIG. 15 (d)).

Embodiment 2 FIGS. 16 and 17 show a second embodiment of the present invention. According to this embodiment, similarly to the previous embodiment, the gear 10 is fixed to the tip of the developing device rotation support shaft 14 of the developing cartridge D, and the gear body 10 corresponding to the gear 10 is That is, the gear 9 is arranged on the support member 7. However, according to this embodiment, the gear 10 is provided with an auxiliary gear 10A having a tip circle diameter larger than that of the gear 10 and having the same number of teeth, which are positively displaced, than the gear 10, and the gear 9 is also provided. An auxiliary gear 9A having a tip circle diameter larger than that of the gear 9 and having the same number of positively displaced teeth is provided at the tip portion thereof.

Therefore, as shown in FIG. 7, the developing cartridges D of the respective colors are guided by the guide members 112, housed in the housing holes 108b of the pair of holding members 108, and inserted between the holding members 108. Then, as shown in FIG. 16, the gear 10 of the developing cartridge D does not immediately mesh with the gear 9 on the apparatus main body side.

According to the present embodiment, first, the gears 10A and 9A mesh with each other because they are dislocation gears and therefore have sharp tips and relatively easy meshing. As a result, the phases of the gear 10 and the gear 9 are matched.

Further, the developing cartridge D is attached to the holding member 10.
When the gear 10 and the gear 9 are inserted to the predetermined position inside the gear 8, the gear 10 and the gear 9 face each other. In this state, when the developing cartridge is pushed up by the push-up member 50 or the pressing means 111 in order to set the developing cartridge at an appropriate position in the holding member 108, the gears 10 and 9 in phase are
It can be easily engaged.

According to this embodiment, even if the auxiliary gears 10A and 9A for phase matching are scratched, it is possible to prevent the actual driving gear part from being scratched and the image quality is improved. It avoids the occurrence of problems that affect the.

Embodiment 3 FIGS. 18 and 19 show a third embodiment of the present invention. According to this embodiment, similarly to the previous embodiment, the gear 10 is fixed to the tip of the developing device rotation support shaft 14 of the developing cartridge D, and the supporting member on the apparatus main body side corresponding to the gear 10. A gear 9 is arranged at 7. However, according to this embodiment, both the gear 10 and the gear 9 are spur gears, but the gear 9 has the tapered member 9 at the tip of the spur gear.
A is provided, and the same number of grooves as the spur gears are formed in this tapered member 9A.

Therefore, as shown in FIG. 7, the developing cartridges D of the respective colors are guided by the guide members 112 and are accommodated in the accommodating holes 108b of the pair of retaining members 108, and are inserted between the retaining members 108. Then, as shown in FIG. 18, the gear 10 of the developing cartridge D does not immediately mesh with the gear 9 on the apparatus main body side, but first abuts against the slope of the taper member 9A. Furthermore, as the developing cartridge D is inserted into the holding member 108 to a predetermined position, the gear 10 meshes with the tooth groove of the tapered member, and the phases of the gear 10 and the gear 9 match.

Therefore, the developing cartridge D is held by the holding member 1.
When installed in the proper position within 08, the gear 10 and the gear 9 can be meshed with each other without causing interference of the tooth tips.

According to this embodiment, the gear 10 and the gear 9 can be aligned in phase simply by providing the gear 9 with the tapered member 9A having a tooth groove, so that the phase control means is extremely simple. Achieved by composition.

In each of the above-described embodiments, the developing cartridge D has been described, but other units having a rotating body, such as the drum cartridge C having a photosensitive drum, can have the same structure and can obtain the same effects. it can.

That is, according to the first aspect of the invention, the gear drive device is provided for the unit including the rotating body, which is detachably attached to the main body of the apparatus such as the developing cartridge D and the drum cartridge C. It is possible to reduce the interference at the tooth tips of the gears that occur when the driving force is transmitted from the device body side via the, thereby preventing the tooth tips from being deformed, and avoiding noise and image quality deterioration. it can.

(Second Invention) As described with reference to FIGS. 1 to 12, the developing device having the developer of each color is moved with respect to the image carrier and the images of the respective colors are superposed to form a full-color image. In the image forming apparatus for forming a multicolor image such as, each developing device, that is, the developing cartridge D (the yellow developing cartridge Dy, the magenta developing cartridge Dm, the cyan developing cartridge Dc, the black developing cartridge Db) in the above-described embodiment, The developing cartridge D, which is held by a holding member 108 of a developing cartridge switching mechanism as a developing device moving mechanism, is moved to a developing position where the developing cartridge D having a developer of a predetermined color faces the image carrier 1.

At this time, in the image forming apparatus having such a configuration, the developer carrying member 15 and the stirring / conveying member 18 provided in each developing cartridge D are provided, and the developing chamber 2 is provided.
0, the developer carrying member 15, the supply / peeling member 17,
Each developing cartridge D such as the stirring / conveying member 18
A driven member provided inside is connected to a drive source for driving these members.

According to the structure of this embodiment, the gears 33 on the side of the developing cartridges and the gears 34 on the side of the drive source mesh with each other at the developing position.

However, in this structure, the tooth tips of the gears interfere with each other during drive connection in the gear drive transmission portion,
There is a problem that the connection is not performed well.

In order to solve such a problem, the driving force from the driving source is always applied to each developing cartridge D at the same time.
The drive transmission system for driving only the developing cartridge positioned at the developing position can be configured. However, in this case, it is necessary to further provide an electromagnetic clutch for each developing cartridge, which complicates the structure and inevitably increases the size, and further, the drive transmission system becomes long and the transmission efficiency decreases. I have a problem.

Next, the second invention will be described with reference to Examples 4 to 6. In the embodiments described below, the image forming apparatus of the present invention is embodied in a color image forming apparatus similar to the color image forming apparatus described above with reference to FIGS. 1 to 12. Therefore, different components of both image forming apparatuses will be described, members having the same configurations and functions will be denoted by the same reference numerals, and detailed description thereof will be omitted.

Embodiment 4 According to Embodiment 4, the developing cartridge D and the developing cartridge switching mechanism are different from those of the previous embodiment.

In this embodiment, the control mechanism of the switching mechanism is
As shown in FIGS. 20 to 22, a disc-shaped developing device drive mechanism supporting member 7 that rotates around a rotating shaft 110 together with the holding member 108 is provided, and a driving mechanism for the developing device 12 is formed inside thereof. Gears 9 and 10 that mesh with each other are provided corresponding to each developing cartridge D, and a gear 8 that meshes with each gear 10 is attached to the rotary shaft 110. The planetary gear mechanism is configured by these gears 8, 9 and 10. Is configured.

A concave member 11 having a horizontal groove 11a having one end opened is attached to the developing cartridge D side of each of the above gears 10. The holding member 108 is mounted in the groove 11a of the concave member 11. The rotary support shaft 14 of the developing device 12 housed in the developed developing cartridge D is fitted with its parallel portion 14a horizontal.

Also in this embodiment, the developing device 1 shown in FIG.
A developing device having the same configuration as that of No. 2 is used, and is composed of a toner storage chamber 19 and a development chamber 20. The toner storage chamber 19 is provided with an agitating / transporting member 18 that agitates toner and transports it to the developing chamber 20. In the developing chamber 20, a developer carrier 15, a supply / peel member 17 for supplying toner to the developer and stripping undeveloped toner thereon, and a layer of toner carried on the developer carrier 15. A regulation member 16 that regulates the thickness and applies an electric charge is provided.

According to the above control mechanism, when the holding member 108 is rotated toward the developing portion to move the developing cartridge D, the concave shape of the support member 7 is formed by the planetary gear mechanism including the gears 8, 9, and 10. The member 11 has its groove 11
a is kept horizontal. Therefore, regardless of the movement of the developing cartridge D, the developing device 12 is always maintained in the horizontal posture,
The support container 13 is held in a posture in which the opening 13b is directed outward in the radial direction of the holding member 108. As a result, at the developing position, the opening 13b of the support container 13 and the developer carrier 15 of the developing device 12 face the image carrier 1.

Driving of the holding member 108 is performed with reference to FIGS.
As shown in FIG. 2, this is performed by rotationally driving the gear 36 integrally provided on the developing device drive mechanism support member 7 from the drive source 32 provided on the apparatus main body side through the gear 31. Further, according to the present embodiment, as shown in FIG. 24, the gear 51 fixed to the central rotation shaft 110 of the holding member 108.
Drive force from a drive source 54 provided on the apparatus main body side is transmitted via a gear mechanism, whereby the rotating shaft 11
The attitude of each developing cartridge D can be controlled through a planetary gear mechanism such as 0 and gears 8, 9, and 10.

Referring to FIG. 23, the developer carrying member 15 of the developing cartridge D which has been selectively positioned and has reached the developing position.
A drive mechanism for a driven part such as is shown. The developer carrier 15 has a gear 33 provided on the developer carrier 15 and an opening 13 b of the developer cartridge support container 13.
A gear 34 provided on the apparatus main body side is meshed with and is driven by a drive source 35.

On the holding member 108, the revolution position flag 38
Is provided, and a revolution position sensor 39 is provided on the apparatus main body side in correspondence with the flag 38. Therefore, when selecting or replacing the developing cartridge D,
Based on the position where the revolution position sensor 39 shuts off the revolution position sensor 38, the predetermined developing cartridge D is moved to the developing position facing the image carrier 1 or the developing cartridge replacement position 5
Move to 0.

Referring to FIGS. 25 and 26, the developer carrier driving gear 3 of the developing cartridge D located at the developing position.
3 and a gear 34 provided on the apparatus body side will be described.

Developing cartridge D located at the developing position
As shown in FIG. 25, the pressing means 111 presses the image bearing member 1 toward the image bearing member 1 and positions the developer bearing member 15 at a predetermined proper position with respect to the image bearing member 1. At the same time, the developer carrier driving gear 33 meshes with the gear 34 provided on the apparatus main body side through the opening 13 b of the developing cartridge supporting container 13 and is driven by the driving source 35.

The pressurizing means 111, as shown in FIG.
According to this embodiment, a support member 60 fixed to the apparatus main body side and a pressure cam member 62 swingably provided around a pin 61 planted in the support member 60 are provided.
The pressure cam member 62 is biased in the direction of the arrow by spring means (not shown) to support the developing container D in the support container 13.
And the developing cartridge D is pressed toward the image carrier 15 side.

An eccentric cam 63 is attached to the central rotating shaft 110 of the holding member 108, and the holding member 10
24, that is, at the time when the developing cartridge D is located at the developing position, the rotary shaft 110 is driven by the drive source, that is, the pressurization control motor 54 through the gear 51 as shown in FIG. The eccentric cam 63 also rotates. Due to the rotation of the eccentric cam 63, the eccentric cam 63 is
As shown in FIG. 26, the pin 64 abuts on the pressure cam member 62, and the pressure cam member 62 is swung in the direction of the arrow against the spring means, whereby the pressure cam member 62 is rotated. The member 62 is separated from the support container 13 of the developing cartridge D, and the developing cartridge D is also separated from the image carrier 15. The rotation control of the eccentric cam 63 is performed as shown in FIG.
This can be done by detecting the flag 52 of the gear 51 fixed to the rotating shaft 110 with the cam sensor 53.

As can be seen in FIGS. 25 and 26,
By the action of the pressure cam member 62, the developing cartridge D
Is pressed toward the image carrier 1, and at the same time, the gear 33 of the developing cartridge D meshes with the drive transmission gear 34 provided on the apparatus main body side and is driven by the drive source 35. When the developing cartridge D is separated from the image carrier 1, the gear 33 of the developing cartridge and the drive transmission gear 34 are disengaged from each other.

According to the present invention, the drive source 35 for driving the gear 34 on the apparatus main body side is a stepping motor. Then, after driving the developer carrier 15 of the developing cartridge D, the stop position of the stepping motor 35 is controlled in a state that the developing cartridges 15 have the same phase relationship. Therefore, according to the present invention, the drive transmission gear 34 and the gear 33 of each developing cartridge D are brought into contact with and separated from each other in the same relationship, that is, the engagement and the disengagement of both gears 34 and 33 are achieved.

Further, according to the present embodiment, the drive transmission gear 34
S is the integer (N), where T is the number of teeth of S and S is the number of steps of one rotation of the stepping motor 35. Further, by configuring the number of development driving steps of each developing cartridge D as follows, both gears 3
The phases of 4 and 33 at the time of connection can be made the same. Dy for the yellow developing cartridge, Dm for the magenta developing cartridge, Dc for the cyan developing cartridge,
When the black developing cartridge is expressed as Db, the number of development driving steps of Dy = a1 · N + K1 Dm, the number of developing driving steps of Dc = a2 · N + K2, the number of developing driving steps of Dc = a3 · N + K3, the number of developing driving steps of Db = a4 · N + K4 And a1, a2, a3, a4 are integers, and K
1 = K2 = K3 = K4 and is an integer.

Next, referring to FIG. 27, the developing cartridge D and the holding member 108 (and the supporting member 7) of this embodiment.
The operation of will be described.

First, when the drive source 32, that is, the revolution switching motor 32 is started and the flag 39 provided on the holding member 108 is detected by the sensor 38, the motor 32 is stopped and the revolution initial position of the holding member 108. Is set.

Then, the revolution switching motor 32 is started by the image formation start signal, and the predetermined developing cartridge D is positioned at the developing position, so that the motor 32 is stopped.
Subsequently, the developing cartridge D is pressed toward the image carrier 1 by the pressing means 111, and at the same time, the gear 33 of the developing cartridge D meshes with the drive transmission gear 34 provided on the apparatus main body side. Then, the stepping motor 35
Is started, the motor rotates for a predetermined number of steps, and stops when the developing operation is completed. Upon completion of the developing operation, the pressing means 111 operates to separate the developing cartridge D from the image carrier 1, that is, retract it.

Subsequently, the revolution switching motor 32 is started to move the next developing cartridge D to the developing position,
The same operating process as above is repeated. In this way
When each developing cartridge completes the developing operation, the image forming process ends.

FIG. 30 shows an example of a control block diagram of the developing cartridge drive motor 35. That is, the drive motor 35 of the developing cartridge D is controlled by the CPU according to the signal from the revolution position sensor.

Fifth Embodiment According to the fifth embodiment, a metal magnetizing gear is used as the drive transmission gear 34, and the magnetic sensor 70 is arranged in the vicinity thereof, which is different from the fourth embodiment. .

Therefore, the development of each developing cartridge D is stopped at the position where the stepping motor 35 is rotated by the same number of steps based on the signal of the magnetic sensor 70.
As a result, the same operational effects as those of the above-mentioned fourth embodiment can be achieved.

FIG. 29 is an operation flow chart of the developing cartridge D and the holding member 108 (and the supporting member 7) according to this embodiment. The contents thereof are the same as those described with reference to FIG. 27 of the fourth embodiment, and detailed description thereof will be omitted. Further, FIG. 30 shows an example of a control block diagram of the developing cartridge drive motor 35. That is, the drive motor 35 of the developing cartridge D is controlled by the CPU by the signals from the revolution position sensor and the magnetic sensor.

As described above, as another method for detecting the phase position of the developing drive transmission gear 34, a flag is provided on the drive transmission gear 34, and the flag is continuously adjusted by the photo interrupter according to the phase of the gear. Alternatively, a flag for cutting the photo interrupter may be provided on the circumference of the drive transmission gear 34, and the stepping motor 35 may be stopped with a predetermined pulse after the flag is cut.

Embodiment 6 FIGS. 31 and 32 show another embodiment of the present invention. According to the sixth embodiment, the drive connection coupling member 71 having the convex portion 71a is provided on the apparatus main body side, and the similar convex portion 72a is also formed on the developer carrying member 15 of the developing cartridge D. A drive coupling member 72 is provided.

At the time of drive connection, as shown in FIG. 31, the developing cartridge D is pressed toward the image carrier by the pressing means 111, whereby the convex portion 72a of the drive connection coupling member 72 drives the stepping motor. The protrusion 71a of the coupling coupling member 71 is brought into contact with the protrusion 71a, whereby the driving force from the apparatus main body side is transmitted to the developing cartridge side.

As shown in FIG. 32, when the pressing means 111 releases the pressing of the developing cartridge D toward the image carrier, the convex portion 72a of the drive connection coupling member 72 and the stepping motor drive connection are thereby released. The contact engagement state with the convex portion 71a of the coupling member 71 is also released, and the transmission of the driving force from the apparatus main body side to the developing cartridge side is stopped. Further, in this state, the convex portion 71 of the stepping motor drive coupling coupling member 71 is
a shows that the developing cartridge D is the holding member 1 in the direction of the arrow.
It does not interfere with being moved by 08.

According to the present invention, in the stepping motor 35, the stop phase of the drive coupling coupling members 72 and 71 is always the same as in the previous embodiment.
It is controlled so that the state shown in FIG.

[0085]

As described above, according to the image forming apparatus of the first invention, for example, the developing cartridge, the drum cartridge, and the like, which are detachably attached to the apparatus main body, are provided. When mounted on the main body of the device, the drive unit transmits the driving force from the main body of the device via the gear transmission mechanism, and at that time, it is configured to control the phase of the gears in the connecting portion, so Interference at the tips is reduced, which prevents deformation of the tip of the gear,
It is possible to avoid generation of noise and deterioration of image quality.

According to the second invention, when the drive is transmitted from the main assembly of the apparatus to the developing cartridge or the like by using the gear transmission mechanism or the like, the pulse motor is used as the drive source,
In addition, since the rotation stop position of the pulse motor is controlled and the stop phases of the connecting members such as the drive transmission gears of the respective developing cartridges are all made the same, the gears do not interfere with each other at the time of meshing, and common A drive connection between the drive source and each developing device can be achieved, noise and gear damage due to connection errors can be prevented, and a reliable and high-quality image can be obtained.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of an image forming apparatus of the present invention.

2 is a perspective view showing a mounting method of a drum cartridge and a waste toner container provided in the image forming apparatus of FIG.

FIG. 3 is a perspective view showing a state before mounting the drum cartridge.

FIG. 4 is a perspective view showing that the protective member is removed when the drum cartridge is mounted.

FIG. 5 is a front view of the state before mounting the drum cartridge as viewed in the axial direction.

FIG. 6 is a cross-sectional view showing a state where an eccentric member is provided on a central axis of an image carrier installed in a drum cartridge.

FIG. 7 is a partially cutaway side view showing a mounting method of the developing cartridge provided in the image forming apparatus of FIG.

FIG. 8 is a cross-sectional view of the developing cartridge of FIG.

FIG. 9 is a perspective view of the developing cartridge of FIG.

10 is a front view showing a developing device driving mechanism of a developing cartridge switching mechanism provided in the image forming apparatus of FIG. 1 and a supporting member thereof.

FIG. 11 is a cross-sectional view showing a positioning portion of the image carrier and the developing cartridge.

FIG. 12 is a front view showing a driving method of a developing cartridge switching mechanism and a driven portion of the developing cartridge.

FIG. 13 is a perspective view illustrating a method of aligning the phase of the developing cartridge gear drive mechanism with the gear phase alignment bar.

14 is a perspective view illustrating a method of aligning a phase of a developing cartridge gear drive mechanism using the gear phase alignment bar of FIG.

FIG. 15 is a diagram for explaining in detail a phase alignment method of the developing cartridge gear drive mechanism by the gear phase alignment bar.

FIG. 16 is a front view for explaining a phase aligning method of the developing cartridge gear drive mechanism by another gear phase aligning means.

FIG. 17 is a front view for explaining a method of phasing the developing cartridge gear drive mechanism by the gear phasing means of FIG.

FIG. 18 is a front view for explaining a phase aligning method of the developing cartridge gear drive mechanism by another gear phase aligning means.

FIG. 19 is a front view for explaining a method of phasing the developing cartridge gear drive mechanism by the gear phasing means of FIG.

FIG. 20 is a perspective view of another embodiment of the developing cartridge.

FIG. 21 is a partially cutaway side view showing a mounting method of the developing cartridge of FIG. 20.

22 is a front view showing a developing device drive mechanism of a switching mechanism for the developing cartridge shown in FIG. 20 provided in the image forming apparatus of FIG. 1 and a supporting member thereof.

FIG. 23 is a front view showing the positioning portions of the image carrier and the developing cartridge.

FIG. 24 is a sectional view of the developing cartridge.

FIG. 25 is an operation of a pressurizing unit for the developing cartridge;
FIG. 7 is a front view illustrating a gear transmission mechanism for developing and a developing cartridge.

FIG. 26 is a front view for explaining the operation of the pressing means for the developing cartridge and the gear transmission mechanism for the developing cartridge of FIG. 25.

FIG. 27 is a flowchart illustrating the operation of the developing cartridge and the holding member.

FIG. 28 is a front view illustrating the operation of the pressurizing unit for the developing cartridge and the gear transmission mechanism for the developing cartridge according to another embodiment.

FIG. 29 is a flowchart illustrating the operation of the developing cartridge and the holding member.

FIG. 30 shows an example of a control block diagram of a developing cartridge drive motor and a developing cartridge revolution switching motor.

FIG. 31 is a front view for explaining the operation of the pressing means for the developing cartridge and the drive transmission mechanism for the developing cartridge according to another embodiment.

FIG. 32 is a front view for explaining the operation of the pressing means for the developing cartridge of FIG. 31 and the drive transmission mechanism for the developing cartridge.

[Explanation of symbols]

 1 Image Carrier (Photosensitive Drum) 7 Developer Driving Mechanism Support Member 13 Support Container 15 Developer Carrier 32 Developer Cartridge Holding Member Drive Source 35 Developer Carrier Drive Source 108 Developer Cartridge Holding Member 108b Developer Cartridge Storage Hole 110 Rotation Shaft C Drum cartridge D Development cartridge

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location G03G 21/00 118

Claims (4)

[Claims] 1. A unit that constitutes an image forming unit, is configured to be detachable from the apparatus main body side, and
In an image forming apparatus having a unit to which driving force is transmitted from the apparatus body side when mounted on the apparatus body side, a gear transmission mechanism for transmitting the driving force from the apparatus body side to the unit, and the gear. An image forming apparatus, comprising: a means for controlling a phase of gears of a connecting portion in a transmission mechanism, and reducing interference between tooth tips of the gears. 2. An image forming apparatus which comprises a plurality of developing devices in a developing device switching mechanism, sequentially moves each developing device to a developing position facing the image carrier, and forms images of a plurality of colors on the image carrier. In each of the developing devices, a drive transmission path is formed between the developing device and a driving source common to each developing device at the developing position to drive a driven member in the developing device, and the driving source is a pulse. An image forming apparatus characterized by using a motor. 3. A drive transmission member on the drive source side, which constitutes a connecting portion between the drive source and a developing device driven member in the drive transmission path, and a drive transmission member on the developing device driven member side. 3. The image forming apparatus according to claim 2, wherein the rotation stop position of the pulse motor is controlled so that the rotation stop phase becomes the same in each developing device. 4. A means for detecting the rotation stop phase of the drive transmission member on the drive source side in the connecting portion, wherein the rotation stop phase of the drive transmission member is set to each developing device based on the signal of the detection means. 4. The image forming apparatus according to claim 2, wherein the rotation stop position of the pulse motor is controlled so that the pulse motor has the same specific phase.