JPH09274352A - Tandem color image forming device - Google Patents

Abstract

To provide a tandem type color image forming apparatus provided with an image forming unit that does not cause toner leakage without causing an inconvenient combination between sub units. A developing unit (11) has a receiving pipe (28) projecting from a casing (13) also serving as a toner container into a supporting frame (18) and a receiving port (28-1) provided on an upper surface of the developing unit (11). 31b (or 31c) is arranged so as to overlap and closes the receiving port 28-1. The sending section shutter 35b of the black image carrying unit 12 is fitted into either the black receiving section shutter 31b or the color receiving section shutter 31c, but the sending section shutter 35c of the color image carrying unit 12 is fitted. Fits only to the color receiving shutter 31c. Due to the rotation of the fixed lever 21, the groove 34b or 34c of the receiving portion shutter is moved to the protrusion 35- of the sending portion shutter.
1b or 35-1c is clamped and rotated, and the opening portions of both shutters move to the opposing portions of the delivery port and the receiving port of both pipes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses an image forming unit in which a sub-unit for discharging powder and a sub-unit for storing discharged powder are removably integrated with each other, and the image forming unit. The present invention relates to an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, there is an electrophotographic image forming apparatus used as a copying machine or a printer. This image forming apparatus forms a latent image on a photoconductor by optical writing, converts the latent image into a toner image (development), and transfers the developed toner image to a sheet to be fixed.

In order to perform such image formation, a photoconductor drum, an initialization charger, an exposure head, a developing roller, a toner feeder, a transfer charger, a cleaner, etc. are provided in the image forming unit in the image forming apparatus. Various devices are provided. Generally, an image forming apparatus used in an office or the like requires relatively frequent maintenance work, and the above-mentioned internal devices are often replaced with new ones. For this reason, in order to facilitate these operations, it is practical to integrate the above-mentioned internal device as an assembly device (unit) and attach it to the image forming apparatus of the main body in a detachable manner for practical use. Has been converted.

However, when the internal device is unitized in this way, when the unit is discarded as it is because the life of the unit is exhausted, the individual devices assembled in the unit have different lifespans, so that they can still be used. It is uneconomical if the mounting device is inside, and this is a waste of resources. Therefore, in recent years, a unit in which a unit is divided into a plurality of sub-units and these are integrated into one unit has been put into practical use.

FIGS. 12 (a), 12 (b) and 12 (c) are views showing an example of such a unit. FIG. 3A is a perspective view showing a state where the unit is separated into two sub units.
(b) is a perspective view in which two sub-units are integrated, and FIG. (c)
FIG. 6 is a cross-sectional view showing a state of the engaging portion. As shown in FIG. 1A, this unit is composed of two sub-units, a developing set 1 and a drum set 2, the developing set 1 includes a toner container 3 and a developing roller 4, and the drum set 2 includes
The photoconductor drum 5 and a cleaner (not shown) are provided. These are integrally engaged to form one unit as shown in FIG.

This unit is an apparatus main body (image forming apparatus)
When mounted on, the gear 5-1 of the photosensitive drum 5 is connected to the drive mechanism of the apparatus main body to drive the entire unit. This unit is configured to collect, in the developing set 1, the residual toner removed from the photosensitive drum 5 by the cleaner. For that purpose, a feed pipe 6 for feeding the removed toner is provided in the drum set 2, and a receiving pipe 7 for receiving the removed toner is provided in the developing set 1.

[0007] Cylindrical lid-shaped shutters 6-1 and 7-1 are attached to the tips of the sending pipe 6 and the receiving pipe 7, respectively. As shown in FIG. 2B, after the developing set 1 and the drum set 2 are integrally assembled, the shutters 6-1 and 7-1 are rotated, respectively, and on the other hand, the feeding port 6a of the feeding pipe 6 and the shutter 6 are rotated. -1 opening (not visible in the figure) is aligned, on the other hand, the receiving opening 7a of the receiving pipe 7 and the opening 7-1a of the shutter 7-1 are aligned, and these are engaged to form a passage for the removed toner. . Then, the conveyor 8 provided in each pipe is rotated to convey the removed toner from the drum set 2 to the developing set 1.

[0008]

By the way, in recent years, color image recording apparatuses (color printers) have been improved with the improvement of technology.
Is being put to practical use. Electrophotographic color printers typically have subtractive color combinations of Y (yellow: yellow), M (magenta: red dye), and C (cyan: greenish blue).
Printing is performed using the three primary colors, or four types of color toners in which Bk (black: black) dedicated to printing characters and the like is further added to these three colors. For this reason, a tandem type color printer is configured by including four image forming units as shown in FIG.

Generally, when a color printer is installed, only full-color printing is rarely performed, and in many cases, monochrome printing of texts is performed. Since the black toner is used not only for monochrome printing but also for full-color printing, the image forming unit in charge of black printing among the image forming units is most consumed. Among them, among the various types of assembled devices, the photoconductor drum is consumed most. Therefore, assuming that the life of the photoconductor drums incorporated in the three image forming units for color toner is, for example, 12000 sheets of A4 size paper, the photoconductor drums incorporated in the image forming unit for black toner are usually It is formed more robustly and more accurately than the photosensitive drums for the color toners so that its life is about 24,000 sheets of paper. Normally, these useful lives (printing use limit) are such that the number of times used for printing is counted and, for example, when a predetermined number of uses of 12000 sheets or 24000 sheets is reached, a device replacement message is displayed. There is.

In this case, as shown in FIG. 12, when the image forming unit is a composite unit consisting of two sub-units of a drum set holding a photosensitive drum and a toner set holding a developing unit, both units are inconvenient. Problems occur due to the various combinations. For example, when a drum set for color toner with a short life is mistakenly assembled to a toner set for black toner, the counter counts as a photoconductor drum for black toner, so the life of the drum set is reduced. Despite running out, do not issue a message to replace the device. As a result, a problem in image formation such as deterioration of image quality occurs. Conversely, if you accidentally assemble a long-life black toner drum set into a color toner toner set, you will have to replace the drum set with a new one in accordance with the device replacement message and discard it.
Costly loss occurs because the product that has a long life is discarded. However, in this case, no trouble occurs in image formation.

From the standpoint of selling products, the problem that occurs when the drum set for black toner is mistakenly assembled to the toner set for color toner is only the cost loss, but the drum set for color toner is wrong. A problem that occurs when the toner set is installed in a toner set for black toner is a problem related to product credibility, which is deterioration of image quality. This credit problem will be reflected in management as a large loss in the future, and will have a far greater adverse effect than in the case of the above-mentioned cost loss. Therefore, it is necessary to avoid this.

Further, since the cylindrical lid-shaped shutters 6-1 and 7-1 shown in FIG. 12 are simply covered on the sending pipe 6 and the receiving pipe 7, respectively, the developing set 1
When the drum set 2 and the drum set 2 are separated from each other, the shutter 6-1 or 7 can be shaken even if a large vibration is applied or they are accidentally touched
-1 easily rotates, and the feed port of the feed pipe 6 and the receiving port 7a of the receiving pipe 7 open. In both the feed pipe 6 and the receiving pipe 7, the removed toner reaches the delivery port during the transportation while the apparatus is in operation. Therefore, when the pipe port is opened as described above, the removed toner spills and scatters to the surroundings. There is an inconvenience that the clothes get dirty.

Further, the closing of the shutter at the time of set separation is
Since it must be done at the same time as the set separation, the operation is extremely cumbersome and therefore toner spillage is likely to occur. If the spilled toner scatters and contaminates the inside of the main body apparatus (image forming apparatus), the quality of the formed image remarkably deteriorates.

Further, since the delivery ports of the feed pipe 6 and the receiving pipe 7 are unstable in engagement and there is a gap, when transported from the factory in the state of a complete unit in which the set is assembled, the toner levitated by the vibration is spilled. There was also the problem of going out.

The object of the present invention is to solve the above-mentioned conventional problems.
A tandem type color image provided with an image forming unit that does not cause an inconvenient combination between sub-units when replacing one unit and does not cause toner leakage by recirculating removed toner cleaned between sub-units when in use A forming device is provided.

[0016]

The structure of the present invention will be described below. A tandem type color image forming apparatus of the present invention includes a first unit having an image carrier, a developing device for developing a latent image formed on the image carrier using a developer of a predetermined color, and the first unit. And a second unit having a supporting means for detachably supporting the unit, and an image forming unit which is configured to be separable, and which are engaged with each other via engaging means provided on the both units to form an integral image forming unit. Therefore, in the tandem-type color image forming apparatus in which a plurality of sets of the image forming units are detachably attached to the apparatus main body, the engaging means constitutes one of the plurality of sets of image forming units. It is configured so that it can be engaged only by a predetermined partner unit.

The engaging means comprises, for example, as described in claim 2, an engaging portion of one unit and an engaging portion of the other unit, and an engaging portion of one unit and an engaging portion of the other unit. The mating portion has two types of shapes, and the engaging portion that forms one shape of one unit selectively engages the engaging portion of the other unit, and the engaging shape that forms the other shape of one unit. The section is configured to non-selectively engage the engagement section of the other unit.

Further, for example, as described in claim 3, the first unit includes a cleaner for removing the developer remaining on the image carrier from the image carrier, and the developer removed by the cleaner. The second unit has a shutter member for opening and closing a discharge port, and the second unit receives the removed developer discharged from the discharge port when the first unit is mounted, and conveys it to the developing device. Means, a shutter member for opening and closing a receiving port for receiving the removed developer of the conveying means, and a lock lever for releasably locking the first unit to the supporting means. Is configured to lock and to simultaneously open the shutter member.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. 1A, 1B, and 1C are perspective views showing an assembled state showing an order in which a developing unit and an image carrying unit of an image forming unit in one embodiment are assembled.

FIG. 2 is a view showing the shape of the groove of the receiving portion shutter of the developing unit, the shape of the protrusion of the sending portion shutter of the image carrying unit, and their engagement and disengagement. 3 (a), (b), and (c) are side cross-sectional views showing the connection state of the powder transfer section between the developing unit and the image carrying unit of the image forming unit and the engagement mechanism between the fixed lever and the support member. It is a figure. 1 (a), (b), (c) and 3 (a), (b), (c) above
Shows a part of both units, that is, the structure in the vicinity of the engaging portion.

FIG. 4 is a perspective view of an image forming unit completed by combining the developing unit and the image carrying unit, and FIG. 5 is a perspective view looking down from the opposite side (upper right of FIG. 4). 6 and FIG.
2 is a side sectional view seen from the right side of FIG.

First, the overall construction of the image forming unit will be described with reference to FIGS. 1 (a), 1 (b) and 1 (c), the assembled state diagram, the completed perspective views of FIGS. 4 and 5, and the side sectional view of FIG. Explain. As shown in FIGS. 1 and 4 to 6, the image forming unit 10
Is composed of two sub-units, a developing unit 11 (second unit) and an image carrying unit 12 (first unit). The developing unit 11 (see FIG. 6) includes an enclosure 13 also serving as a toner container, an agitator 14 rotatably held in the enclosure 13, a supply roller 15, a developing roller 16 and a doctor blade 17. It is set up.
A frame 18 (see FIGS. 4 and 5) for assembling the image carrying unit 12 is provided under the housing 1.
3 in the arrangement direction downstream side (in FIG. 4, diagonally lower right direction, FIG.
Is formed diagonally to the lower left). A support shaft 16-1 of the developing roller 16 projects outward from the lower side surface of the casing 13.

A bearing hole 19a is formed in the upper left side wall of the frame 18 (see FIG. 4), and a bearing hole 19a is formed in the upper right side wall.
The bearing portion 19b is formed so as to be cut out obliquely from above.
(See FIGS. 1, 3 and 5). The bearing 19b is provided with a fixed lever 21 that closes the upper opening. The fixed lever 21 is attached to the engaging portion 32 of the frame 18, and as shown by an arrow A in FIG.
Rotate up and down approximately 90 degrees.

On the other hand, the image carrier unit 12 (see FIG. 6) internally holds a photoconductor drum 22 (image carrier) rotatably, and an initialization charger 23 and a cleaner 24 which are in contact with the peripheral surface thereof. I have it. A groove hole 25 is provided in parallel with the axial direction of the photoconductor drum 22 on the upper surface of the image bearing unit 12 (see FIGS. 4 and 5) which is directly above the photoconductor drum 22. After the image forming unit 10 is mounted on the apparatus main body (image forming apparatus) described later in detail, the writing head 26 (see FIG. 6) arranged on the upper lid member descends as shown by an arrow E in FIG. Then, the tip end thereof is fitted into the groove 25. This image carrying unit 12
From both side surfaces of the photosensitive drum shaft 2 of the photosensitive drum 22.
2a and 22b are projected to the outside.

After the protective cover 27 covering the lower peripheral surface of the photosensitive drum 22 is slid upward on the downstream side to expose the lower peripheral surface of the photosensitive drum 22 (see FIG. 3 (a)), One photosensitive drum shaft 22a of the image carrier unit 12 is penetrated through the bearing hole 19a of the frame 18 of the developing unit 11, and then the other photosensitive drum shaft 22b is connected to the bearing hole 19a of FIG.
As shown by the arrow B in (a), the image bearing unit 1 is fitted into the bearing portion 19b of the frame 18 of the developing unit 11.
2 is loaded into the developing unit 11 (FIG. 3 (b) and FIG. 1).
(b)). After loading, as shown in Fig. 3 (b),
The fixing lever 21 that has been opened in advance is closed as shown by an arrow A in the figure, and temporarily fixed so as not to deviate from the photosensitive drum shaft 22b. In this state, the photosensitive drum shaft 22a,
22b projects outward from the side surface of the image forming unit 10 (frame 18). The image forming unit 10 in which the developing unit 11 and the image carrying unit 12 are integrated is mounted at a predetermined position in the image forming apparatus.

The receiving pipe 28 of the developing unit 11 and the sending pipe 29 of the image carrying unit 12 are interlocked with the rotation of the fixing lever 21 for temporarily fixing the photosensitive drum shaft 22b (see FIG. 6). The toner transfer ports of are opened and connected. The image forming unit 10 connects the receiving pipe 28 of the developing unit 11 and the toner delivery port of the sending pipe 29 of the image carrying unit 12 to remove the removed toner generated on the image carrying unit 12 side.
It is designed to be refluxed to the 1 side.

Subsequently, the receiving pipe 28 of the developing unit 11 for circulating the above-mentioned toner and the image carrying unit 1
The configuration of the connecting portion of the second delivery pipe 29 will be described with reference to FIGS. 1, 2, and 3. First, as shown in FIG. 1 (c), the receiving pipe 28 of the developing unit 11 has its outer end portion protruding from the lower portion of the housing 13 into the frame 18, and slightly more than the bearing portion 19b of the frame 18. A receiving port 28-1 is provided in the upper part near the downstream side (in the diagonally lower right direction in the figure). On this, a fixed lever 21 vertically set to the reference position shown in FIG. 1 (a) and a receiver shutter 31 integrated with the fixed lever 21 are formed in a shape in which the peripheral half surface of the cylinder lid is cut out, and the cutout opening is formed. The support member 32 fixed to the frame 18 with its portion facing upward
Is rotatably supported by the receiving pipe 2 with its rotation axis direction perpendicular to the axial direction of the receiving pipe 28.
8-1 is abutted.

As shown in FIGS. 3 (a) and 1 (a), the two sub-units are separated (the drawing shows the state immediately before the developing unit 11 is connected to the image carrying unit 12). (2), the fixed lever 21 and the receiving portion shutter 31 are prohibited from rotating by the locking claw 30a of the rotating member 30 arranged between the support portion 32 and the bearing portion 19b.

In this state, FIG. 1 (c) and FIG. 3 (b)
Around the edge of the receiving port 28-1 of the receiving pipe 28 shown in
Although not clearly visible in the figure, a packing member having appropriate elasticity is disposed between the receiving portion shutter 31 and the contact surface. Therefore, the receiving unit shutter 31 and the receiving port 28-1
There is no gap between the two, so that the receiving port 28-1 shown in FIG. 1 (c) is sealed. Receiving unit shutter 31
An opening 31-1 is formed in the peripheral surface facing the upstream side (the diagonal upper left direction in FIG. 1 and the left side in FIG. 3) of the above, and the elastic packing member 33 is attached to the inner surface around the edge thereof. . As shown in FIG. 3 (c), when the fixing lever 21 is rotated 90 degrees to the upstream side to temporarily fix the photoconductor drum shaft 22b of the photoconductor drum 22, the opening 31-1 is received. The pipe 28 is moved to a position corresponding to the receiving port 28-1.

On the inner surface of the lid bottom of the receiving section shutter 31, FIG.
In the standard arrangement shown in (b), the groove 34 is formed by two protrusions whose cross section faces slightly obliquely upward (this groove 34
May be formed by piercing the bottom surface of the lid bottom instead of forming two projections). The inclination of the groove 34 in the diagonally upward direction is the bearing portion 19b formed so as to be obliquely cut out from above.
It is formed to have the same inclination as the inclination of. On the other hand, the end portion on the image carrying unit 12 side that engages with this is
As shown in (a) and (b), a delivery section shutter 35 is arranged near the downstream side of the photosensitive drum shaft 22b of the photosensitive drum 22.

FIGS. 7A and 7B show the image carrying unit 12
The structure of the side end part of FIG. As shown in Figure (a),
An end of the delivery pipe 29 extends from the side end of the image carrying unit 12, and a tubular lid-shaped delivery portion shutter 35 is externally fitted to the end of the delivery pipe 29. Sending unit shutter 35
A ridge 35-1 is vertically provided on the outer surface of the cylinder bottom. This ridge 35-1 is the groove 34 of the receiving portion shutter 31.
The image carrier unit 12 is engaged with the developing unit 11 by being guided by and fitted (see FIG. 1B). At this time, in order to easily receive the ridge 35-1, the upper portion of the groove 34 is formed wide as shown in FIGS. 3 (a), (b) and (c).

In FIG. 7 (a) above, the delivery pipe 29
Although not visible in the figure, a delivery port is formed in the lower portion of the peripheral surface of the end portion. In addition, an opening is formed in the peripheral surface of the delivery section shutter 35, which is also invisible in the figure (upper right direction in FIG. 7A). In the state of FIG. 7A, the delivery pipe 2
The delivery port 9 and the opening of the delivery shutter 35 are displaced by 90 degrees. Then, when the delivery shutter 35 rotates 90 degrees in the clockwise direction in the figure, the opening of the delivery shutter 35 moves to a position corresponding to the delivery port of the delivery pipe 29.

A projection 35-2 is formed on the upper surface of the delivery shutter 35. A protective cover 36 is disposed on the end surface of the image carrying unit 12 so as to cover the protrusion 35-2 in the lower opening. One end of the key-type lever 37 is rotatably supported by the side surface of the image carrying unit 12 in the protective cover 36, and its free end is biased downward by a biasing member (not shown). The end is brought into contact with the projection 35-2 of the delivery portion shutter 35. Since the contact portion of the projection 35-2 is in the rotation direction of the delivery portion shutter 35, the delivery portion shutter 35 is prevented from rotating by the contact of the key-type lever 37. As a result, when the image carrier unit 12 is detached from the image forming unit 10 and is in a single state, the rotation of the delivery shutter 35 is prohibited and the delivery port of the delivery pipe 29 is kept sealed. .

The vicinity of the engaging portion of the developing unit 11 with which the image carrying unit 12 is united (see FIGS. 1 (a) and 1 (c))
A release lever 38 is provided upright. When the image carrying unit 12 is mounted at a predetermined position in the frame 18 as shown in FIGS. 3 (b) and 1 (b) so as to engage with the developing unit 11, as shown in FIG. 7 (b). In addition, the tip of the release lever 38 presses the free end side of the key-type lever 37 to rotate the key-type lever 37 upward against the urging force of the urging member, so that the key-type lever 37 and the protrusion 35- Release the contact with 2. As a result, the delivery portion shutter 35 of the delivery pipe 29 engages with the receiving portion shutter 31 in a rotatable state. Further, in this state (the state shown in FIG. 3 (b), FIG. 1 (b) and FIG. 7 (b)), the opening portion of the sending portion shutter 35 is joined to the opening portion 31-1 of the receiving portion shutter 31. . Then, the sending unit shutter 35
Since the ridge 35-1 is fitted in the groove 34 of the receiving portion shutter 31, if the receiving portion shutter 31 rotates (that is, the fixed lever 21 rotates), the rotation (rotation).
Follows and rotates in the same direction.

As described above, the receiving portion shutter 31 (that is, the fixed lever 21) includes the support portion 32 and the bearing portion 19b.
Rotation is prohibited by a rotation member 30 arranged between them. The engagement mechanism between the fixed lever 21 (that is, the receiving portion shutter 31) and the support portion 32 is shown below, and the rotation prohibition of the fixed lever 21 and its release will be described below.

The rotating member 30, as shown in FIG.
It is provided with a locking claw 30a that extends upward and bends to the right, and a release protrusion 30b that extends to the left and bends upward, and is rotatably provided with the middle thereof as a fulcrum. The rotating member 30 is biased in the clockwise direction in the figure by a torsion spring 30-1, and when the two sub units are separated as shown in FIG. The tip of 30b projects upward from the bottom of the bearing portion 19b, and on the other hand, the tip of the locking claw 30a opens the opening 31 of the receiving portion shutter 31.
-1 and abut against the upper edge of the opening 31-1, so that the fixed lever 21 (reception part shutter 31) is moved from the retracted position shown in FIG. 3 (a) to that shown in FIG. 3 (c). Rotation to the locked position is prohibited. Therefore, the fixed lever 21
Does not move with some vibration while being set in the vertical position shown in FIG. 3 (a) or FIG. 1 (a). Thereby, when the developing unit 11 is alone, the receiving port 28-1 of the receiving pipe 28 is kept sealed. In this way, the stopper mechanism that prevents the operation of moving the fixed lever 21 from the retracted position to the locked position is formed.

The image carrying unit 12 is shown in FIG.
As shown in FIGS. 1 (b) and 7 (b), when engaged with the developing unit 11, the photosensitive drum shaft 22b pushes the tip of the release projection 30b of the rotating member 30 downward to rotate it. The moving member 30 is rotated counterclockwise. As a result, the tip of the locking claw 30a of the rotating member 30 retracts from the inside of the opening 31-1 of the receiving portion shutter 31, and the opening 31-1.
The contact between the upper edge and the locking claw 30a is released. That is, the rotation prohibition of the receiving portion shutter 31, that is, the fixed lever 21 is released.

As described above, the fixed lever 21 whose rotation inhibition is released by the engagement with the image carrying unit 12 is shown in FIG.
3B, the photosensitive drum shaft 22b of the photosensitive drum 22 is temporarily fixed as shown in FIG. 3C. As a result, the receiving portion shutter 31 integrated with the fixed lever 21 rotates 90 degrees counterclockwise in the figure, and the opening 31-1 shown in FIGS. 3 (a) and 3 (b) moves downward by 90 degrees. It rotates and moves to coincide with the receiving port 28-1 of the receiving pipe 28. The delivery shutter 35 is also rotated by 90 degrees in accordance with the rotation of the receiving shutter 31, so that the opening of the delivery shutter 35 and the delivery port of the delivery pipe 29 coincide with each other.

FIG. 8 shows a sending pipe 29 and a receiving pipe 28.
A cross-sectional view showing a connected state with. It is to be noted that FIG. 5 is a cross-sectional view taken along the arrow J of the connecting portion of the sending pipe 29 and the receiving pipe 28 which are hidden and hidden in the frame 18 of the image forming unit 10 shown in FIG. In FIG. 8, the ridge 35-1 fitted in the groove 34 of the receiving section shutter 31 as described above causes the sending section shutter 35 to rotate 90 degrees following the rotation of the receiving section shutter 31. Due to the above rotation, the opening portion 35-3 of the sending portion shutter 35, which is already joined to the opening portion 31-1 of the receiving portion shutter 31 when the two shutters are engaged,
On the other hand, the receiving port 28- of the receiving pipe 28 via the opening 31-1 of the receiving unit shutter 31 and the packing member 39.
1 and, on the other hand, the outlet 29-of the outlet pipe 29
Connect with 1. As a result, the sending pipe 29 and the receiving pipe 28 communicate with each other.

A carrier coil 41 is arranged in the delivery pipe 29, and the carrier coil 41 is used as the image carrier unit 1.
It rotates with the driving of 2. The transport coil 41 transports the removed toner accumulated in the image carrying unit 12 along the delivery pipe 29 to the connecting end. On the other hand, another transfer coil 42 is also disposed in the receiving pipe 28, and rotates with the driving of the developing unit 11. The carrying coil 42 is received from the delivery port 29-1 of the delivery pipe 29 through the opening 35-3 of the delivery shutter 35, the opening 31-1 of the receiving shutter 31 and the packing member 39, and the receiving port 28-. The toner that has flowed into the No. 1 is received, and this toner is carried into the developing unit 11.

As described above, when the image carrying unit 12 and the developing unit 11 are in a single state, the toner delivery port is sealed by the shutter immovable by an external impact or the like, and the two units are engaged. , The movement prohibition of the shutter is released, and in conjunction with the rotation of the temporarily fixed lever,
The delivery ports of both units are connected.

The delivery pipe 29, delivery portion shutter 35, receiving pipe 28, and receiving portion shutter 31 shown in FIG.
Is formed by using a transparent resin, once the unit is used, the delivery pipe 29, the delivery portion shutter 35,
The recirculation toner attached to the inside of the receiving pipe 28 and the receiving unit shutter 31 can be visually recognized from the outside. In this way, the color of the toner can be confirmed at the engaging portions of both units, so that it is convenient to prevent errors when handling a plurality of image forming units 10 as in the case of color printing. Further, when a see-through window is provided at an appropriate position on the upper surface or the side surface of the portion where the receiving pipe 28 of the developing unit 11 shown in FIG. 5 is arranged, the image forming unit after the developing unit 11 and the image carrying unit 12 are assembled. Even in the state of 10, the color of the toner can be confirmed from the outside, so that when the toner is mounted in the main body of the apparatus, the toner can be immediately mounted in the correct arrangement, and the work becomes easy.

Next, an image forming apparatus equipped with such an image forming unit 10 will be described. FIG. 9 is an external perspective view of an image forming apparatus provided with the image forming unit detachably. As shown in the figure, the image forming apparatus 45 is a small-sized image forming apparatus that can be mounted on a desktop type rack for a personal computer. The image forming apparatus 45 includes an opening / closing tray 46 on the front surface (on the right side in the drawing) and a paper cassette 47 detachably attached to the lower portion.
Further, a paper discharge tray 49 is formed on the upper surface of the upper lid member 48, and the image-formed paper discharged from the upper paper discharge port 51 is stacked therein. A power switch 52, a liquid crystal display device 53, a plurality of input keys 54 and the like are arranged on the front side of the upper lid member 48.

FIG. 10 is a sectional view schematically showing the internal structure of the image forming apparatus. Inside the image forming apparatus, as shown in FIG.
A belt 57 for conveying the paper, which is held by the driven rotation roller 56 and moves in a circulating manner, is disposed. Above the belt 57, the plurality of image forming units 10 (10-
1, 10-2, 10-3, 10-4) are arranged side by side in a multi-stage manner in the sheet conveying direction. Each of the photoconductor drums 22 (22-1, 22-2, 22-3, of the image forming unit 10)
22-4) directly above, the write heads 26 (26-1, 26-2, 26-3, disposed on the back surface of the upper lid member 48).
26-4) is inserted and arranged by closing the upper lid member 48. The writing head 26 is composed of an LED head. The upper lid member 48 opens and closes around a support shaft 58 behind the device body 45. The photoconductor drum 22 is in contact with the sheet conveying surface of the belt 57, and is arranged to face the photoconductor drum 22 from the back surface of the belt 57, and the transfer brush 59 (only one is numbered in the figure). Is shown).

A standby roll pair 61 and a sheet detection sensor 62 are provided on the upstream side (right side in the drawing) of the belt 57 in the sheet conveyance direction. The upstream side is branched laterally (front of the apparatus) and downward, A paper feed roller 63, a separating member 64, and the open / close tray 46 described above are arranged in the lateral direction. In addition, a conveyance path 65 formed of two guide plates is disposed below,
Upstream of that, the above-mentioned paper cassette 47 has a large number of papers P.
Is housed inside and the end of the paper is seen. A paper feed roller 66 is disposed above the paper feed end. A separation claw 67, a fixing device 68, a paper discharge roller 69, and a switching lever 71 are provided downstream of the belt 57 in the paper conveyance direction. Fixer 6
Reference numeral 8 is composed of a pressure contact roller, a heat generating roller, a peripheral surface cleaner, an oil applying roller, a thermistor, etc. which are assembled in a heat insulating casing, and heat-fixes the toner image transferred onto the paper on the paper. The switching lever 71 guides the sheet to the upper discharge path 72 when it is in the lower position as shown in the figure, and to the sheet discharge port 73 which opens the sheet on the rear surface of the apparatus when it is rotated upward. invite. The downstream side of the discharge path 72 communicates with the upper discharge port 51 via a discharge roll pair 74.

A cleaner bottle 75 is detachably arranged between the belt 57 and the paper cassette 47. this,
A blade scraper 76 is provided on the top of the cleaner bottle 75.
Is attached, and its tip is in contact with the surface of the lower circulation portion of the transfer transfer belt 57. Blade scraper 76
Cleans the transfer transfer belt 57 by scraping off the toner remaining on the surface of the transfer transfer belt 57, and stores the scraped off toner in the cleaner bottle 75.

The belt 57 is used for the image forming unit 1
The fixed support roll 77 and the movable support roll 78 support between 0-1 and 10-3. Fixed support roll 77
Is rotatably fixed to the frame of the main body of the apparatus, and the movable roll 78 is held at the other end of a support member 79 that swings around a support shaft of the fixed roll 77. Support member 7
A cam 81 is engaged with the lower portion of 9 to selectively pivot left and right between the position shown in the figure and the position rotated 90 degrees clockwise.

FIG. 11 shows the image forming units 10 (10-1, 10-2, 10-3, 10 arranged side by side in the multistage structure).
-4) is shown enlarged. Since the configuration of the image forming unit 10 has been described with reference to FIG. 6, the function will be described here. The image forming unit 10-
Nos. 1, 10-2, 10-3, and 10-4 have the same configuration except that the colors of the toners contained therein are different. Further, as described above, the image forming unit 10-4 is
Developing unit 11 for taking charge of image formation of black toner
The black toner is stored in the other image forming unit 10
(10-1, 10-2, 10-3) contains Y (yellow), M (magenta) and C (cyan) color toners, respectively.

The agitator 14 in the interior of the developing unit 11 of the image forming unit 10 rotates as shown by the chain double-dashed line in the figure to send the toner 82 to the lower supply roller 15 while agitating the toner 82. . Supply roller 15
Is made of a sponge member, is pressed against the developing roller 16,
The toner 82 sent from the stirrer 14 is rubbed and supplied to the peripheral surface of the developing roller 16. A leaf-spring-shaped doctor blade 17 abuts on the circumferential surface of the developing roller 16 in the rotating direction to give a frictional charge to the toner 82, thereby enhancing the adhesiveness to the developing roller 16 and keeping the toner layer attached to a constant thickness. Suppress.

Between the charger 23 and the developing roller 16,
The writing head 26 draws an arcuate locus as shown by the chain double-dashed line 84 in FIG. 11 with the closing of the upper lid member 48 shown in FIG. When the upper lid member 48 is opened and the writing head 26 is pulled up, the image forming unit 10 can be individually taken out of the apparatus in a straight line direction that is obliquely inclined to the upper right as indicated by a chain double-dashed line 85 in the figure. In this way, when the image forming unit 10 is taken out, the protective lid 27 rotates counterclockwise to cover the exposed surface of the photosensitive drum 22 and protect it.

When the transparent window or the like is provided as described above, when the toner is taken out to the outside and then mounted again, the color of the toner can be confirmed so that the mounting position (arrangement) is correct. In addition, when assembling in a factory or when replacing the image carrying unit for maintenance work, even if the image carrying unit 12 for black toner having a long life is mistakenly attached to the developing unit 11 for color toner As a result, care must be taken not to mount the image carrier unit 12 for color toner, which has a short life even if it is wrong, to the developing unit 11 for black toner. In the present embodiment, the mounting of the image carrier unit 12 for color toner to the developing unit 11 for black toner is automatically prohibited.

The prohibition mode will be described below with reference to the corresponding diagram of FIG. The correspondence diagram of FIG.
5 (black sending unit shutter 35b and color sending unit shutter 35c), and the receiving unit shutter 31 (black receiving unit shutter 31b and color receiving unit shutter 31c) of the developing unit on the left. . The corresponding frames of the sending unit shutter 35 and the receiving unit shutter 31 are the corresponding frames of the black sending unit shutter 35b and the black receiving unit shutter 31b, and the corresponding frames of the color receiving unit shutter 31c. In each of the figures, a “◯” mark indicating permission of engagement is shown.
On the other hand, an "X" mark indicating prohibition of engagement is shown in the corresponding frame of the color sending portion shutter 35c and the black receiving portion shutter 31b, and the corresponding frame of the color receiving portion shutter 31c is engaged. A "○" mark indicating permission is shown. That is, the black sending portion shutter 35b (the photosensitive drum 22 for black toner)
Shutter of the image carrying unit 12 which holds -4)
Is formed so that it can be engaged with the black receiving portion shutter 31b (developing unit 11 for black toner) and the color receiving portion shutter 31c.
On the other hand, the color delivery shutter 35c (the delivery shutter of the image carrier unit 12 holding the photoconductor drums 22-1 to 22-3 for color toner) is only related to the color receiving shutter 31c. And the engagement with the black receiving portion shutter 31b is prohibited.

These relationships are related to the black sending portion shutter projections 35-1b and the color sending portion shutter projections 35-1c, and the black receiving portion shutter grooves 34b formed on the respective shutters in FIG. Color receiving section shutter groove 34c
It is constituted by. As shown in the figure, the protrusions (black protrusion shutter protrusions) 3 of the black transmitter shutter 35b
In 5-1b, the upper width H is wide and the lower width S is smaller than that.
Is narrowly formed. On the other hand, the ridges of the color delivery section shutter 35c (color delivery section shutter ridges) 35-1
c is formed with a wide width H which is the same in the upper and lower sides.

On the other hand, the black receiving portion shutter 31b
The groove (black receiving portion shutter groove) 34b has a narrow width S at the lower portion and a wide width H at the upper portion. This shape is a shape in which the black delivery shutter ridges 35-1b are fitted without excess or deficiency. The color sending portion shutter projection 35-1c having the same wide width H at the top and bottom is formed.
Cannot fit into and engage with it. That is, engagement is prohibited.

On the other hand, the groove (color receiving portion shutter groove) 34c of the color receiving portion shutter 31c is formed to have the same wide width H in the upper and lower sides. This shape is a shape in which the color delivery portion shutter protrusions 35-1c are fitted without excess or deficiency, and the black delivery portion shutter protrusions 35-1b are easily fitted to engage with each other at the upper wide portion H. It is a shape that fits.

As a result, the black transmitting portion shutter projection 35
-1b non-selectively engages with either the black receiving portion shutter groove 34b or the color receiving portion shutter groove 34c,
The color delivery section shutter protrusion 35-1c selectively engages only with the color receiving section shutter groove 34c. In other words, the black receiving section shutter groove 34b selectively engages only with the black sending section shutter projection 35-1b, and the color receiving section shutter groove 34c receives the black sending section shutter projection. 35
-1b or non-selectively engages with either of the color delivery portion shutter protrusions 35-1c.

As a result, it is possible to prevent the color image bearing unit having a short life from being mistakenly assembled to the black developing unit, which deteriorates the image quality over time and deteriorates the credibility of the product. can do.

Next, the operation of the image forming process in this image forming apparatus will be described with reference to FIGS. 10 and 11 again. First, the image forming apparatus 45 (see FIG. 9) is powered on, the number of sheets and other designations are keyed in,
When full-color printing (image formation) is specified,
The cam 81 is driven by a drive mechanism (not shown) to rotate 90 degrees in the counterclockwise direction, which causes the support member 79 to rotate upward, whereby the movable support roll 78 moves upward, and the belt 57 moves. All four photosensitive drums 22 (2
2-1, 22-2, 22-3, 22-4).

Subsequently, the paper feed roller 66 is replaced by the paper cassette 47.
The sheet P placed and accommodated in the sheet is fed to the standby roll pair 61 via the conveyance path 65. Alternatively, the paper feed roller 63 feeds the paper placed on the open / close tray 46 to the standby roll pair 61. The sheet detection sensor 62 detects the fed sheet P.
Is detected. The standby roll pair 61 stops rotating and the paper P
The tip of the abutment is brought into contact with the sandwiching part and made to stand by.

The drive rotation roller 55 starts to rotate in the counterclockwise direction, and the driven rotation roller 56 is driven to start to rotate in the counterclockwise direction as well. This allows the belt 57
The upper circulation portion contacts the four photoconductor drums 22 and
The whole moves circularly in the direction indicated by the arrow H 1 from right to left.

At the same time, the image forming units 10-1 to 10-1
10-4 are sequentially driven according to the print timing,
In response to the drive, the photosensitive drums 22-1 to 22-4 are
It is sequentially driven to rotate in the clockwise direction. Then, the write heads 26 corresponding to the respective image forming units 10 are sequentially driven. By this driving, the initialization charger 23 applies uniform electric charge to the peripheral surface of the photoconductor drum 22, and the writing head 26 performs writing by exposure on the peripheral surface of the photoconductor drum according to an image signal to expose it. An electrostatic latent image is formed on the peripheral surface of the body drum. The developing roller 16 transfers the toner 82 to the low potential portion of the electrostatic latent image to form (develop) a toner image on the peripheral surface of the photosensitive drum.

At the timing when the leading edge of the toner image on the peripheral surface of the uppermost photosensitive drum 22-1 is rotatably conveyed to a point facing the belt 57, the print start position of the paper P coincides with the point. In this way, the standby roll pair 61 starts rotating and feeds the paper P to the paper carry-in entrance of the image forming unit. The press roller 86 and the driven rotation roller 56 sandwich the fed paper P together with the belt 57, and the press roller 86 presses the front end of the paper P into the belt 57 to press the paper P.
Is transported. The leading edge of the paper P is sequentially sent out by nipping by the driven rotation roller 56 and the pressing roller 86, and even after leaving the nipping portion, it is stably adsorbed by the belt 57 and the photosensitive drum 22-1 and the transfer brush 59. It is conveyed to the most upstream transfer unit formed by. After that, electrostatic attraction occurs between the belt 57 and the paper P due to the electric field of the transfer portion, so that the paper P is sequentially conveyed along the belt 57 to the next transfer portion.

While being conveyed in this manner, the paper P is applied to each photosensitive drum 22 by applying a voltage from each transfer brush 59.
An electric field formed between the photosensitive drums 22 and
The toner image on the peripheral surface is sequentially transferred onto the paper surface.

The sheet P on which the four color toner images have been transferred is separated from the belt 57 by the separating claw 67, and the fixing device 68 is provided.
Be delivered to. After the toner image is heat-fixed on the sheet P by the fixing device 68, the sheet P is ejected by the sheet ejection roller 69.
The toner image is discharged from the upper side of the apparatus 3 or from the upper sheet discharge port 51 with the toner image of the lower side.

In conjunction with such image forming processing, FIG.
The transfer coils 41 and 42 shown in FIG. The cleaner 24 scrapes off and removes the toner 82 remaining on the peripheral surface of the photosensitive drum 22, and the transport coils 41 and 42 cause the removed toner 82 remaining in the image carrying unit 12 to flow back to the developing unit 11 by the above removal. .

The image forming apparatus 45 can easily print only black. For black only printing,
The cam 81 rotates 90 degrees clockwise from the position shown in FIG. At this time, the contact point of the cam 81 with the support member 79 is the closest point from the fulcrum of the cam 81, so that the support member 79 rotates downward. As a result, the moving support roll 78 moves downward and is separated from the position supporting the belt 57.

Due to the movement of the movable support roll 78, the belt 57 is directly supported on the upstream side of the fixed support roll 77 by the fixed support roll 77 and the driven rotary roller 56, and is inclined obliquely downward to the upstream side, so that the photosensitive member Except for the drum 22-4, the photosensitive drums 22-3, 22-2, and 22-1 are moved to the non-transferable position apart from the contact with the photosensitive drums 22-3, 22-2, 22-1.

The belt 57 does not move up and down between the drive rotation roller 55 and the fixed support roll 77, and therefore maintains the contact state with the photoconductor drum 22-4, thereby making it possible to print only black. Become. The image formation and the transportation of the removed toner are the same as in the case of the color printing.

[0069]

As described above, according to the present invention,
The black image carrying side unit is allowed to engage with both the black and color developing side units, while the color image carrying side unit is selectively allowed to engage with the color developing side unit only, and the black developing side unit is allowed. Since the mutual engaging portions are formed in the unit so that they are not engaged with each other, it is possible to prevent the color image carrier unit having a short life from being mistakenly assembled in the black developing unit. It is possible to prevent the deterioration of the image quality due to the oversight, and thus prevent the deterioration of the credit of the product and the deterioration of the corporate credit due to the wrong assembly of the units.

When the unit is a single unit, both the image carrier side unit and the developing side unit are provided with a lock mechanism for inhibiting the rotation of the shutter of the toner transfer port, so that the toner transfer is performed even during the operation for combining both units. The mouth does not open accidentally, and therefore, toner contamination can be prevented and a comfortable working environment can be maintained. Further, since the shutter lock mechanism is mutually released by both units when they are united, there is no need to worry about performing an erroneous operation because of less trouble, and therefore the work efficiency of assembling both units is improved. Also, since the release of the sealing of the shutter is interlocked with the temporary fixing lever of the image carrier, not only is it troublesome, but also the timing and operation of the release of sealing can be set correctly, so you can rest assured without worrying about toner leakage. You can do the work. In addition, since the image forming unit in which the toner does not leak is attached to the image forming apparatus and used, the inside of the apparatus is not contaminated with the leaked toner, and therefore a high-quality image can always be printed out. Improves the working environment.

[Brief description of drawings]

FIG. 1A, FIG. 1B, and FIG. 1C are perspective views of an assembled state showing an order of assembling a developing unit and an image carrying unit of an image forming unit according to an embodiment.

FIG. 2 shows the shape of the groove of the receiving section shutter of the developing unit of the image forming unit, the shape of the projection of the sending section shutter of the image carrying unit, and the relationship between their engagement and non-engagement in one embodiment. It is a figure.

3A, 3B, and 3C are connection states of a powder transfer unit between a developing unit and an image carrying unit of an image forming unit and engagement of a fixed lever and a supporting member in one embodiment. It is a side sectional view showing a mechanism.

FIG. 4 is a perspective view of an image forming unit completed by combining a developing unit and an image carrying unit.

5 is a perspective view of the image forming unit of FIG. 4 as viewed from the upper right.

6 is a side sectional view of the image forming unit of FIG. 5 viewed from the right side.

7A and 7B are diagrams showing a configuration of a side end portion of an image carrying unit.

FIG. 8 is a cross-sectional view showing a connected state of a sending pipe and a receiving pipe.

FIG. 9 is an external perspective view of an image forming apparatus that includes an image forming unit detachably.

FIG. 10 is a cross-sectional view schematically showing the internal configuration of the image forming apparatus.

FIG. 11 is an enlarged view showing an arrangement of image forming units arranged in a multi-stage manner.

FIG. 12 is a view showing an example of a conventional unit, (a) is a perspective view showing a state in which the unit is separated into two sub units, (b) is a perspective view in which the two sub units are integrated, c)
FIG. 6 is a cross-sectional view showing a state of the engaging portion.

[Explanation of symbols]

1 Developing Device Set 2 Drum Set 3 Toner Container 4 Developing Roller 5 Photosensitive Drum 5-1 Gear 6 Feed Pipe 6a Feeding Port 6-1 Cylindrical Lid Shutter 7 Receiving Pipe 7a Receiving Port 7-1 Cylindrical Lid Shutter 7-1a Shutter Opening 10 (10-1, 10-2, 10-3, 10-4) Image forming unit 11 Developing unit (second unit) 12 Image carrying unit (first unit) 13 Casing body 14 Stirrer 15 Supply roller 16 developing roller 16-1 support shaft 17 doctor blade 18 frame 19a bearing hole 19b bearing portion 21 fixed lever 22 (22-1, 22-2, 22-3, 22-4) photoconductor drum 22a, 22b photoconductor drum shaft 23 Initializing Charger 24 Cleaner 25 Slot 26 (26-1, 26-2, 26-3, 26-4) Writing Head 27 Protective Lid 28 Receiving Pipe 28-1 Receiving Port 29 Outlet Pipe 29-1 Outlet 30 Rotating Member 30a Locking Claw 30b Release Protrusion 30-1 Torsion Spring 31 Receiving Portion Shutter 31b Black Receiving Portion Shutter 31c Color receiving part shutter 31-1 Opening part 32 Support part 33 Elastic packing member 34 Groove 34b Black receiving part shutter groove 34c Color receiving part shutter groove 35 Sending part shutter 35b Black sending part shutter 35c Color sending out Part shutter 35-1 Convex strip 35-1b Delivery unit shutter convex strip for black 35-1c Delivery unit shutter convex strip for color 35-2 Protrusion 35-3 Opening 36 Protection cover 37 Key type lever 38 Release lever 39 Packing member 41 , 42 Conveyor coil 45 Image forming apparatus (apparatus main body) 46 Open / close tray 47 Paper cassette 48 Member 49 Paper ejection tray 51 Upper paper ejection port 52 Power switch 53 Liquid crystal display device 54 Input key 55 Drive rotation roller 56 Driven rotation roller 57 Paper transport belt 58 Spindle 59 Transfer brush 61 Standby roll pair 62 Paper detection sensor 63 Paper feed roller 64 Separation member 65 Conveyance path 66 Paper feeding roller 67 Separation claw 68 Fixing device 69 Paper ejection roller 71 Switching lever 72 Ejection path 73 Paper ejection port 74 Paper ejection roll pair 75 Cleaner bottle 76 Blade scraper 77 Fixed support roll 78 Moving support roll 79 Support member 81 Cam 82 Toner 84 Head locus 85 Image unit pull-out direction 86 Presser roller

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Kuniki Ono 2-229, Sakuragaoka, Higashiyamato-shi, Tokyo Inside Casio Electronics Co., Ltd. (72) Morika Takaga 2-229, Sakuragaoka, Higashiyamato-shi, Tokyo Casio Electronics Co., Ltd.

Claims (3)

[Claims] 1. A first unit having an image carrier, a developing device for developing a latent image formed on the image carrier using a developer of a predetermined color, and the first unit are detachable. And a second unit having a supporting means for supporting the image forming means, which is separable from each other, and which are engaged with each other through engaging means provided on the both units to form an integral image forming unit. A tandem type color image forming apparatus in which a plurality of sets of units are detachably attached to an apparatus main body, wherein the engaging means is a predetermined partner for forming one of the plurality of sets of image forming units. A tandem-type color image forming apparatus, characterized in that it is configured so that it can be engaged only with a unit. 2. The engaging means comprises an engaging portion of one unit and an engaging portion of the other unit, and the engaging portion of one unit and the engaging portion of the other unit have two types of shapes. And an engaging portion having one shape of one unit selectively engages with an engaging portion of the other unit, and an engaging portion having the other shape of one unit is engaged with the other unit. The tandem color image forming apparatus according to claim 1, wherein the tandem color image forming apparatus is non-selectively engaged with the joint portion. 3. The first unit includes a cleaner for removing the developer remaining on the image carrier from the image carrier, and a shutter for opening and closing a discharge port for discharging the developer removed by the cleaner. The second unit is provided with a member, and the second unit receives the removed developer discharged from the discharge port when the first unit is mounted, and conveys the developer to the developing unit; The shutter member includes a shutter member that opens and closes a receiving port for receiving the developer, and a lock lever that releasably locks the first unit with respect to the supporting unit. The shutter member is locked at the same time when the lock lever is locked. The tandem color image forming apparatus according to claim 1, wherein the tandem color image forming apparatus is configured to open.