JPH0416111B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Technical Field> The present invention relates to a device for exchanging developing units in a rotary developing device equipped with a plurality of developing units.

<Prior art and its drawbacks> When trying to make multiple monochrome copies,
Generally, it is necessary to replace the developer tank for each color.
In a typical image forming apparatus, a plurality of developer tanks containing developers of different colors are prepared.
The structure is such that the developer tank for the color to be used can be replaced by opening the front panel of the image forming apparatus. However, in this device, only one developing tank can be attached to the main body, so if you want to change the color of the copy, you must always replace the developing tank, which is very inconvenient.

Therefore, Japanese Patent Publication No. 55-3707 proposed a developing device in which a plurality of developing tanks are arranged around a photoreceptor drum and any developing tank can be used.

However, in this device, the developing tank occupies a large area around the photosensitive drum, which affects other image forming process means. Furthermore, since the distance from the exposure position to the development position differs for each corner developer tank, a problem may arise in that color tone, image contrast, etc. differ from developer tank to developer tank. Furthermore, since the developing angles of the developing tanks with respect to the surface of the photosensitive drum are different, it is necessary to change the shape of each developing tank, which inconveniently increases the manufacturing cost of the developing tanks as a whole.

Japanese Patent Publication No. 46-13478 proposes an image forming device in which a plurality of developer tanks are rotatably supported on the same axis. However, in this image forming apparatus, since each developer tank always faces the same direction, the drive mechanism is complicated and the space is large.

In Japanese Patent Publication No. 55-20579, a plurality of developer tanks are supported in rotation, and one of the developer tanks is selectively opposed to the photosensitive drum. In a rotary developing device with such a structure,
Although the disadvantages of the developing device disclosed in Japanese Patent Publication No. 46-13478 can be overcome, if you want to increase the number of developing colors that can be used, it is necessary to set up developing tanks corresponding to that number in advance, so it is difficult to use the developing device. The problem is that the larger the number of colors to be developed, the larger the entire developing device becomes.

<Objective of the Invention> An object of the invention is to support a plurality of developing units with a rotary developing device, and to enable a specific developing unit to be easily replaced when an opening/closing plate provided in the housing of the image forming apparatus is opened. Thus, it is an object of the present invention to provide a developing unit exchange device for a rotary developing device in which the size of the entire developing device does not increase even when the number of usable developing colors increases.

<Structure and effects of the invention> This invention is constructed as follows.

First, the developing unit is provided with a roller driving section and an engaging section that can be connected to its side.

Furthermore, the housing of the image forming apparatus is provided with an opening/closing plate. Furthermore, a connecting plate which can be freely connected to the roller driving section of the developing unit located on the photosensitive drum side among the plurality of rotatably supported developing units and is movable in the axial direction of the developing unit; A developing unit positioning means that positions the developing unit when moving toward the photoreceptor drum; and an engagement that engages the engaging portions of the plurality of developing units when positioned by the developing unit positioning means. A receiving portion is provided.

Further, the opening/closing plate is connected to the connecting plate and the developing unit positioning means, and when the opening/closing plate is closed, the connecting plate is moved in a direction in which it is connected to the roller driving section to connect them, and the developing unit is moved. a link mechanism that positions the developing unit by moving the positioning means toward the photosensitive drum, and releases the connected state and the positioned state when the opening/closing plate is opened to set the developing unit in a removable state; and is provided.

With the above structure, when the opening/closing plate is opened, the roller driving section is released from the connected state, and the positioning state is released to set the developing unit in a removable state. When the opening/closing plate is closed, the above-mentioned connected state and positioning state are established, and the developing unit is set in the mounted and positioned state.

With the above configuration, the present invention allows the developing unit to be set in a removable state with respect to the developing device or to be set in a positioned and mounted state simply by opening and closing the opening/closing plate. I can do it. Therefore, if you select multiple developing units of relatively widely used colors and install them in the developing device, you can normally use any developed color from among those colors by simply rotating the developing unit. At the same time, when development of another color becomes necessary, by opening the opening/closing plate and replacing the developing unit, development of the replaced color can be performed. In this case as well, the developing unit can be replaced by simply opening and closing the opening/closing plate, and the operation is extremely simple.

<Embodiment> (a) Main part structure of a copying machine FIG. 2 is a schematic diagram of the main part of a copying machine using a developing unit exchange device according to an embodiment of the present invention. In the figure, 1 is a photosensitive drum.
Around this photosensitive drum 1, there is a 1st charger 2, a focusing light transmitter 3, a rotary developing device 4, a transfer charger 5, a peeling roller 6, and a cleaner unit 7.
are arranged in this order. 1st charger 2
charges the surface of the photoreceptor drum 1 uniformly. The focusing light transmitter 3 forms an image of the original 8 on the surface of the photosensitive drum. Paper 10 is conveyed from a paper feed cassette (not shown) to a transfer section via a conveyance path 9.
The cleaner unit 7 includes a blade 70 whose tip is in contact with the surface of the photoreceptor drum and this blade 7.
A waste toner box is provided for storing the waste toner scraped off by the waste toner.

The rotary developing device 4 is composed of two developing units A and B. These developing units A and B can be rotated about the rotation axis O in either a clockwise direction (direction F) or a counterclockwise direction (direction E). Since a rotating lever 25 is attached to the tip of the rotating shaft O, the developing unit can be rotated by operating this rotating lever 25.

The developing unit A is composed of a developing tank 20 and a hopper 21. The developer tank 20 has an opening 20c
It is equipped with a developing roller 20a and a stirring roller 20b inside. Further, a toner supply roller 22 is provided between the developer tank 20 and the hopper 21. The hopper 21 is connected to the supply roller 22 when the developer 23 in the developer tank 20 becomes low.
The developer is replenished through the . The developing unit B is provided point-symmetrically to the developing unit A with respect to the rotation axis O. This developing unit B also has the same structure as the developing unit A described above.

(b) Structure of the developing unit exchange device Structure near the rotating support plate FIG. 1 is a diagram showing the structure of the developing unit exchange device of the rotary developing device.

The developing unit A is provided with an engaging protrusion 52, which constitutes an engaging portion, with connectable roller drive portions 50, 51 on the right side thereof as viewed in the figure. The developing unit A is also provided with an engaging protrusion 54 at a position symmetrical to the engaging protrusion 52 on the lower side of the left side. Further, in this embodiment, in addition to the roller drive units 50, 51 and the engagement protrusion 52, a connector 53 for electrical connection is provided. Furthermore, above both ends of the back surface of the developing unit A, there are arm engaging protrusions 5 that engage with positioning arms to be described later.
5 and 56 are provided. In addition, there is an arm engagement groove 5 on the bottom that engages with the positioning arm.
9 is provided. The roller drive section 51 is connected to the rotation shaft of the developing roller 20a (not shown), and the roller drive section 50 is connected to the rotation shaft of the stirring roller 20b. These roller drive units 50 and 51 are connected to a connecting device to be described later, and driving force is transmitted from the main body of the copying machine. Note that although only the developing unit A is shown in the figure, the developing unit B also has roller drive units 50, 5.
1 connector 53 and engagement protrusions 52, 54
It is equipped with

A support portion for a rotary developing device is provided in the housing of the main body of the copying machine. This support section supports the developing units A and B on both left and right sides.
The support portion on the right side as viewed in the drawing includes a right-handed rotating support plate 60 having notches on both left and right sides, and a connecting plate 61 located in the notch on the rotating drum side of this rotating support plate 60. The connecting plate 61 is movable in the axial direction of the developing unit, and the roller drive parts 50, 51 of the developing unit A are connected inside the connecting plate 61.
Connecting portions 61a and 61b that can be respectively engaged with
A connector receiver 61c that can be engaged with the connector 53 is further provided. Inside the right rotation support plate 60, there is a guide groove 65 that is open at the top and extends vertically downward.
and a guide groove 66 which is open at the bottom and extends vertically upward in the same way as the guide groove 65 described above.
is provided. A slightly wider groove is formed at the lower end of the guide groove 65, and this becomes an engagement receiver 63 with which the engagement protrusion 52 of the developing unit A engages. Further, a wide portion is formed at the upper end of the guide groove 66, and this portion becomes an engagement receiving portion 64 that engages with an engagement protrusion of a developing unit B (not shown). The receiving rotation support plate 60 further has elongated holes 67 and 68 cut out in the upper part, and elongated holes 69 and 70 cut out in the lower part. Positioning arms 62a and 62b, which will be described later, are inserted into these long holes 67 and 68 from the outside of the clockwise rotation support plate 60 in the axial direction of the developing unit. Similarly, positioning arms 62c and 62d are inserted into the elongated holes 69 and 70 in the axial direction of the developing unit. As will be described later, these positioning arms 62a to 62d are connected to the elongated holes 6.
It is movable along lines 7 to 70 in the direction of the photoreceptor drum. With the developing units A and B installed, the positioning arms 62a to 62
When the developing unit 2d is moved toward the photosensitive drum, the engaging protrusions provided on the developing unit engage with the engaging receiving portions formed at the upper and lower ends of the guide groove, and the developing unit is aligned. A left-hand rotation support plate 80 is provided at a position opposite to the right-hand rotation support plate 60 and separated by the length of the development unit, and supports the left side surface of the development unit. A guide groove 81 of the same size as the guide groove 65 formed vertically on the right rotation support plate 60 is also provided inside the left rotation support plate 80, and a guide groove 81 of the same size is provided at the same position as the other guide groove 66. Another guide groove (not shown) is also formed in the guide groove. An engagement receiving portion 82 is provided at the lower end of the guide groove 81 . The engagement protrusion 54 of the developing unit A engages with this engagement receiving portion 82 . Furthermore, positioning arms 83a and 83b are provided at positions facing the positioning arms 62a and 62b so as to be movable toward the photosensitive drum, and similarly, a positioning arm 8 (not shown) is also provided on the lower side.
3c and 83d are positioning arms 62c,
It is provided so as to face 62d. FIG. 6 shows a state in which the developing units A and B are installed and the positioning arms 62a to 62d are engaged with the arm engaging protrusions and arm engaging grooves (see FIG. 1) of the developing units. . In the figure, 55 and 59 are arm engaging protrusions and arm engaging grooves of developing unit A, and 57 and 5 are arm engaging grooves.
Reference numeral 8 denotes an arm engaging protrusion and an arm engaging groove of the developing unit B.

Structure of Opening and Closing Plate An opening and closing plate 90 is rotatably provided above the rotary support plates 60 and 80, that is, in the housing above the developing device including the developing unit. The size of the opening 89 formed when the opening/closing plate 90 is opened is set to a size that allows just one developing unit to pass through. Furthermore, as will be described later, by means of a link mechanism connected to this opening/closing plate 90,
Positioning arms 62 (62a to 62d), 83 (83
a to 83d) move toward the photoreceptor drum,
Also, the connecting plate 61 moves in the axial direction of the developing unit. When the opening/closing plate 90 is opened, the positioning arms 62 and 83 move in the opposite direction to the photosensitive drum 1. Further, the connecting plate 61 moves in the direction of releasing the connected state. The connection plate 61 moves in the connection release direction, and the positioning arm 6
2 and 83 move in the opposite direction to the photoreceptor drum, the engaging protrusions 52 and 54 of the developing unit A located on the photoreceptor drum side are moved.
and a guide groove 6 located on the photoreceptor drum side.
5, 81 are disengaged from the engagement receiving portions 63, 82 provided at the lower ends, and the developing unit A becomes able to move upward along the guide grooves 65, 81. That is, the developing unit A can be removed from the developing device through the opening 89 formed by opening the opening/closing plate 90. In this case, the developing unit B will also come out downward, so
To prevent this, a support plate (not shown) is provided to prevent the developing unit B from falling downward.

Link Mechanism and Other Structures FIG. 3A shows a rear view of the link mechanism and the right rotation support plate 60, and FIG. 3B shows a side view thereof.

The opening/closing plate 90 can be rotated about a fulcrum 91 within a range of 90 degrees between a position shown by a solid line and a position shown by a two-dot chain line in the figure. An opening/closing plate angle 92 attached to the side of the opening/closing plate 90 has a long hole 93 cut out diagonally. One end of a connecting rod 94 is locked in this elongated hole 93. The connecting rod 94 is arranged horizontally, and the other end is locked to a short piece 95a of an inverted L-shaped lever 95 that is rotatable about a rotating shaft 96 as a fulcrum. This short piece 95a is located in a substantially horizontal state, and the long piece 95b is arranged so as to face downward. One end of a wire 96 is locked to the tip of this long piece 95b. The wire 96 is arranged horizontally, and the other end passes through a hole 98 formed in the housing 97 and is locked to the connecting plate 61, as shown in FIG. 3B. The wire 96 is bent at a right angle at the position of the hole 98.

The connecting plate 61 is connected to the connecting portion 6 as shown in FIG.
1a and 61b, and a connector receiver 61c. As described above, this connecting plate 61 is movable in the axial direction of the developing unit, and the shaft 99 can slide within the bearing portion 100 during movement.

The tip of the vertical piece 95b of the lever 95 is further engaged with the left end of the L-shaped slide plate 101. This L-shaped slide plate 101 has a long hole 101a slightly to the right of its horizontal piece, and the right rotation support plate 6 is inserted into this long hole 101a.
A rotating shaft 102, one end of which is fixed at 0, passes through it. Further, a key portion 101b is formed at the right end portion of this L-shaped slide plate 101.
This key portion 101b is fitted into a fitting portion 105 of an arm connecting member, which will be described later.

The positioning arms 62a and 62c (see FIG. 1) are connected by an arm connecting member 103 on the outside of the right rotation support plate 60. Also, positioning arms 62b and 62d
means another arm connecting member 1 disposed approximately parallel to the arm connecting member 103.
04. A fitting portion 105 is provided approximately at the center of the arm connecting member 103, and the key portion 101b of the L-shaped slide plate 101 is fitted into this fitting portion 105 as described above. Arm connecting members 103 and 104
There are springs 106, 107 on the top and bottom between
is being built.

FIG. 4 shows the vicinity of both ends of a rotating shaft 96 that rotatably supports the lever 95. As shown in FIG. As shown in the figure, the lever 1 is attached to the left end of the rotating shaft 96.
10 is attached. This lever 11
0 has the same shape as the vertical piece 95b of the lever 95 provided at the right end of the rotating shaft 96,
Its tip is locked to an L-shaped slide plate 105. The L-shaped slide plate 105 is connected to the positioning arm 8 on the left rotation support plate 80.
3 (83a to 83d) toward the photoreceptor drum. Although the arm connecting members 103 and 104 as shown in FIG. 3A are not shown on the left rotation support plate 80 in FIG. An arm connecting member is provided to connect the upper and lower positioning arms. FIG. 5 shows a view (rear view) of the left rotation support plate 80 from the outside. In the figure, reference numerals 110 and 111 indicate arm connection members corresponding to the arm connection members 103 and 104 of the right rotation support plate 60, respectively. Left rotation support member 80
has elongated holes 112, 113 above and elongated holes 114, 115 below. Further, a rotation shaft 116 whose one end is fixed to the left rotation support plate 80 is provided at the center thereof. Furthermore, a key portion 105 is provided at the left end of the L-shaped slide plate 105.
b is provided, and a fitting portion 117 into which this key portion 105b fits is provided approximately at the center of the arm connecting member 110. Further, springs 118 and 119 are installed vertically between the arm connecting members 110 and 111. The arm connecting member 110 has the long holes 112 and 114.
The positioning arm 83a is connected to a positioning arm 83c (not shown) (provided at a position opposite to the positioning arm 62c) via the positioning arm 83a. Also, arm connecting member 1
Reference numeral 11 denotes a positioning arm 83b and a positioning arm 83d (not shown) (provided at a position opposite to the positioning arm 62d).
Connect with.

The left rotation support plate 80 has a substantially disk shape, but has notches 80 at two opposing points around its periphery.
a and 80b are provided. Furthermore, the notch 80a or 80b of this left rotation support plate 80
A rotation regulating elastic body 120 that engages with is provided. This rotation regulating elastic body 120 is
It is fixed to the main body of the copying machine. In the state shown in FIG.
It is in a state where it is engaged with a.

In FIG. 4, levers 95 and 110
At the front end of the rotating shaft 96 for rotating the
A positioning release lever 120 is attached. This positioning release lever 120 is provided with a positioning hole 121 in the center thereof, and can be rotated in the direction of arrow E until this hole 121 fits into a convex portion (not shown). This positioning release lever 120 has the same function as the connecting rod 94 of the opening/closing plate. That is, by rotating the positioning release lever 120 in the direction of arrow E without opening the opening/closing plate 90, the wire 96 and the slide plates 101, 1 can be removed.
05 toward the front in the D direction, the connecting state of the connecting plate 61 is released, and the positioning arm is moved in the direction opposite to the photoreceptor drum, so that the engaging protrusion of the developing unit is aligned with the engaging receiving part. (63, 67, 82, etc.) can be released from the engaged state. Therefore, by rotating the positioning release lever 120 to release the above-mentioned connected state and positioned state, the opening/closing plate 90 is rotated by rotating the rotary lever 25 (see FIG. 2).
The developing unit can be rotated with the door closed.

(c) Function of developing unit exchange device Next, the effect will be explained.

Replacement operation 1 Open the opening/closing plate 90. At this time, if the original table of the copying machine main body is located above the opening/closing plate 90, the original placing table is moved before opening/closing plate 90 is opened. Opening/closing plate 9
0, the connecting rod 94 moves in the C direction (see Figures 3 and 4), and the lever 95 moves to the E position.
direction (rotate approximately 30°). At this time, the wire 96 whose one end is stopped by the long piece 95b of the lever 95 is pulled. The other end of the wire 96 passes through a hole 98 in the housing 97, is bent at a right angle, and is locked to the connecting plate 61, so that when the wire 96 is pulled, the connecting plate 61 moves in the direction of arrow G. (Figure 3B
reference). By moving the connecting plate 61 in the direction of arrow G, the connecting state between the connecting portions 61a and 61b and the drive rollers 50 and 51 of the developing unit A on the photosensitive drum side is released, and the connector 53 and the connector receiver 60c are also disconnected. The state of connection with is also canceled.

Furthermore, as the lever 95 rotates in the direction of the arrow E, the slide plate 101 is moved in the direction of the arrow D.
move in the direction. Then this slide plate 10
The key part 101b provided at the end of the arm pulls the arm connecting member 103 in the direction of arrow D. Furthermore, the arm connecting member 104 is pulled in the direction of arrow D via the springs 106 and 107. As a result, the positioning arm 62 is pulled in the direction opposite to the photoreceptor drum, that is, in the D direction. As a result, the entire developing unit is also pulled in the direction of arrow D, and in the image unit A, the engaging protrusion 52,
54 is released from its engaged state with respect to the engagement receiving portions 63 and 82. Note that, as shown in FIG. 4, when the opening/closing plate 90 is opened, the slide plate 1
Since 01 and 105 also move in the direction of arrow D, the positioning arm 83 on the left rotation support plate 80 side is also pulled in the opposite direction to the photoreceptor drum. Therefore, in this state, the developing unit A can be pulled out through the opening 89.

Replacement operation 2: Take out the developing unit A through the opening 91 and insert a new developing unit A'.
At this time, the engaging projections of the new developing unit A' are inserted along the respective guide grooves 65 and 81 of the right rotation support plate 60 and the left rotation support plate 80.

Replacement operation 3 After inserting a new developing unit A', close the opening/closing plate 90. Then, due to an action opposite to the above-described action, the connecting plate 61 becomes connected, and the positioning arms 62 and 83 move toward the photosensitive drum to become attached.
At this time, the alignment of the new developing unit A' is completed.

Switching the developing unit To switch the developing unit, press the opening/closing plate 9.
0 with the positioning release lever 120 closed.
(See Figure 4) in the direction of arrow E.
21 is rotated until it is locked onto a convex portion (not shown). Then, since the rotating shaft 96 also rotates in the same E direction, the wire 96 and the slide plate 10
1,105 is pulled in the direction of arrow D. Due to these actions, the connection state by the connection plate 61 is released in the same way as when the opening/closing plate 90 is opened. At this time, the connecting plate 61 moves to the position indicated by the two-dot chain line as shown in FIG. Therefore, the clockwise rotation support plate 60 becomes rotatable. Also, the positioning arms 62, 8
3 is also in the opposite direction to the photoreceptor drum, that is, D
The alignment state is canceled because the object moves in the direction. At this time, when the rotation shaft O is rotated by the rotation lever 25 (see FIG. 2), the right rotation support plate 60 and the left rotation support plate 80 are rotated, and the two developing units are also rotated accordingly. If the rotation is stopped at the position where the rotation regulating elastic body 120 engages with the notch 80b, the developing unit B is replaced with the developing unit A.
reaches a position facing the photoreceptor drum. In this state, move the positioning release lever 120 by arrow F.
Rotate it in the direction and return it to its original position. Then, the connecting plate 61 becomes connected to the developing unit B, and the alignment arms 62, 83
moves toward the photoreceptor drum, that is, in the direction of arrow C, and becomes aligned.

With the above-described operation, the developing unit can be easily replaced by simply opening the opening/closing plate 90, and any one of the two developing units in the developing device can be positioned on the photosensitive drum side.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the structure of a developing unit exchange device of a rotary developing device according to an embodiment of the present invention;
FIG. 2 is a block diagram of the main parts of a copying machine using the rotary developing device, and FIGS. 3A and 3B are a rear view and a left side view of the right rotary support plate. 4 is a perspective view showing a part of the link mechanism, FIG. 5 is a rear view of the left rotation support plate, and FIG. 6 is a diagram showing the positional relationship between the positioning arm and the developing unit. 1...Photosensitive drum, 50, 51...Roller drive unit, 53...Connector, 52, 54...Engaging protrusion, 55, 56...Arm engaging protrusion, 60...
...Right rotation support plate, 61... Connection plate, 63, 64...
...Engagement receiving portion, 62a-62d...Arm for positioning, 90...Opening/closing plate, 94...Connection rod, 9
5... Lever, 96... Rotating shaft, 101... L-shaped slide plate.

Claims (1)

[Scope of Claims] 1. In a rotary developing device that is disposed on the side of a photosensitive drum and rotatably supports a plurality of developing units so that one of the developing units is selectively opposed to the photosensitive drum. , the developing unit includes a roller driving section and an engaging section that can be connected to the side thereof, an opening/closing plate provided in a housing of an image forming apparatus in which the rotary developing device is housed, and the plurality of developing devices. A connecting plate that is movable in the axial direction of the developing unit and that can be freely connected to the roller driving section of the developing unit located on the photosensitive drum side of the unit; A developing unit positioning means for positioning the developing unit during movement; an engagement receiving part that engages with the engaging part of the plurality of developing units when positioned by the developing unit positioning means; and the opening/closing plate. The connecting plate and the developing unit positioning means are connected, and when the opening/closing plate is closed, the connecting plate is moved in the direction of connecting to the roller driving section to connect them, and the developing unit positioning means is connected to the photoreceptor. a link mechanism that positions the developing unit by moving it toward the drum, and releases the connected state and the positioned state when the opening/closing plate is opened to set the current unit in a removable state. A developing unit exchange device for a rotary developing device.