JPH09265231A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cope with large quantities of copies and prints while maintaining the proper sizes of a developing device and device main body, which can meet the need of compactness. SOLUTION: Toner is supplied from a toner storage/supply means 18, existing independently from the device main body, to the developing device 16 via a toner conveying pipe 22 and a toner lead-in means 20. The toner lead-in means 20 is attached and detached with the aid of the mount structure of a built-in type toner supply device using an ordinary toner-cartridge.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus, and more particularly to an image forming apparatus such as a printer, a facsimile, a copying machine, etc., which uses a two-component developer or a one-component developer.

[0002]

2. Description of the Related Art The following is a technique relating to a toner supply device for supplying toner to a developing unit of a developing unit from a toner storage unit (toner storage unit) provided separately from the developing unit. In a developing device using a two-component developer, a toner storage unit is connected to the developing unit by a pipe, and a coil screw provided inside the pipe transfers the toner to the developing unit to supply the toner (for example, JP-A-61-188564). A technology in which a toner storage container is provided close to the developing unit, and toner is mainly supplied from the toner storage container to the developing unit by gravity.

Further, there is the following technique for supplying and circulating the developer to the developing section of the developing device from a developer storing part provided separately from the developing device. In a developing device using a two-component developer, a technique in which a developer storage unit and a developing unit are connected by a pipe, and a coil screw provided inside the pipe transfers the developer to the developing unit and circulates it ( For example, JP-A-4-198966). A technology that uses a screw pump (commonly called a mono pump) capable of powder transfer without using the coil screw in the above configuration.

[0004]

By the way, in the prior art as described above, although there is a difference in structure, the toner supply device for supplying the toner to the developing device is wholly housed in the image forming apparatus main body. Because of the construction, there is a demand for a compact device, and the toner storage amount is small. For this reason, when a large number of copies and prints are to be made, the toner container such as the toner cartridge must be frequently replaced, so that the so-called machine downtime increases and the copy / print cost increases. . In order to deal with a large number of copies and prints, the capacity of the toner container must inevitably be increased. However, in this case, the size of the device is increased, the installation area of the device is increased, the cost of the device is increased, etc. Unavoidable problem of. In addition, since the entire toner supply device is built in the device, there are problems such as a complicated structure and reduced maintainability.

Therefore, the present invention can cope with a large number of copies and prints while maintaining the appropriate size of the developing device and the main body of the device which can meet the demand for compactness, reduce machine downtime, and copy / print. It is an object of the present invention to provide an image forming apparatus that can reduce costs.

[0006]

SUMMARY OF THE INVENTION The present invention makes it possible to use both a normal toner supply form by a built-in toner cartridge and a toner supply form in the case of large-volume copying and printing. In this case, it is based on the idea that the toner accommodating body is an external system independently existing outside the apparatus so that the installation area is increased only during use. This makes it possible to arbitrarily add a large capacity function when necessary while maintaining the suitability of the size of the device. Specifically, in the invention according to claim 1, in an image forming apparatus including a developing device and a toner supplying device for supplying toner to the developing device, the toner supplying device is built in a main body of the image forming device. The toner from the toner storage / supply means that is separate from the image forming apparatus main body and the built-in toner supply device that supplies the toner from the toner cartridge to the developing device through the toner introduction means is introduced. The external toner supplying device supplies the toner to the developing device via the means, and both the internal toner supplying device and the external toner supplying device can be used.

According to a second aspect of the present invention, in the structure according to the first aspect, the toner storing / supplying means of the external toner supplying device and the corresponding toner introducing means are connected by a toner transfer pipe. The toner storage / supply means is provided with a screw pump for sending toner to the toner transfer pipe, and is capable of promoting the flow of the toner sent by the screw pump and independently transferring and discharging the toner in the toner transfer pipe. An air supply means is provided. According to a third aspect of the present invention, in the configuration according to the first or second aspect, the engagement shapes of the toner introduction units of the built-in toner supply device and the external toner supply device with the image forming apparatus main body are common. It has a composition called eggplant. According to a fourth aspect of the present invention, in the configuration according to the second aspect, the toner introduction unit of the external toner supply device includes an air vent member.

According to the invention of claim 5, claim 2 or 3
Alternatively, the developing device has a toner receiving port for receiving the toner supplied from the toner introducing device of the external toner supplying device, and the toner introducing device faces the toner receiving port. It has a toner supply port,
The area of the toner supply port is larger than the sectional area of the toner transfer pipe. According to a sixth aspect of the present invention, in the structure according to the fifth aspect, the toner introduction unit of the external toner supply device has a shutter member that prevents the toner from falling off from the toner supply port. The composition is adopted. According to a seventh aspect of the present invention, in the structure according to the sixth aspect, the toner supply port and the shutter member can be integrally mounted to the toner introducing means of the built-in toner supply device, and the toner having the single structure can be attached. The supply port and the shutter member can be commonly attached to the toner introducing means of the external toner supply device. According to an eighth aspect of the invention, in the configuration of the first aspect, the toner introducing means of the built-in toner supplying device and the toner introducing means of the external toner supplying device are the same member. According to a ninth aspect of the present invention, in the configuration according to the eighth aspect, the toner introducing unit as the same member has a toner cartridge attaching / detaching member and a toner transfer pipe attaching / detaching member. .

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. First, the specifications for mass copying will be described. As shown in FIG. 1, the image forming apparatus 2 includes a process cartridge 4, an external toner supply device 6, a transfer unit 8, a fixing unit 10, a paper feed cassette 12,
13, 14, etc. are provided. The process cartridge 4 is provided with an image forming device such as the photoconductor 15 and is integrally provided with a developing device 16. The sheet selected from the desired sheet feeding cassette is sent to the registration roller pair 17 by a carrying unit such as a carrying roller, and is carried to the transfer unit 8 in time with the toner image formed on the photoconductor 15. , The toner image is transferred. The sheet on which the unfixed toner image is placed is conveyed to the fixing unit 10 and discharged after fixing.

The external toner supplying device 6 is a toner storing / supplying device 18 which exists independently outside the device and has a function of accelerating the toner flow by air, and a toner introducing device 20 built in the device which engages with the developing device 16. And a toner transfer pipe 22 connecting them. As the toner transfer pipe 22, it is desirable to use a material that is flexible and has excellent toner resistance (for example, soft vinyl chloride, nylon, Teflon (trade name)). Due to the flexibility of the toner transfer pipe 22, the device body and toner storage
The degree of freedom of arrangement with the supply means 18 is increased, effective use of the installation place can be achieved, and maintenance is facilitated.

As shown in FIG. 2, the process cartridge 4 is positioned and held between the rear plate 58 of the apparatus main body and the front side plate 59 of the apparatus main body by positioning pins (not shown) provided on them. It is prevented from coming off by a stopper 113 formed integrally with 41. A guide plate 108 for mounting a normal built-in toner supply device described later is fixed to the side of the process cartridge 4. A positioning pin 109 for positioning the toner introduction unit of the built-in toner supply device is provided at the tip of the guide plate 108, and the positioning pin 109 is provided.
Positioning is performed by another positioning pin (not shown) formed on the front plate 59 of the apparatus main body. The toner introducing means 20 of the external toner supply device 6 also uses this engagement shape as it is (Claim 3), and the positioning hole 201 that engages with the positioning pin 109.
And a positioning hole 202 corresponding to the positioning pin of the apparatus main body front side plate 59. The mounting direction of the toner introducing means 20 is in the direction of arrow S as in the built-in toner supply device. The toner transfer pipe 22 is drawn in from the rear side plate 58 side of the apparatus main body, and the attachment / detachment section 203 of the toner introducing means 20.
Connected to. In FIG. 2, reference numeral 60 indicates a drive unit of the toner cartridge of the built-in toner supply device.

As shown in FIGS. 3 and 4, the toner introducing means 20 includes a main body 204 mountable on the guide plate 108,
A detachable toner introduction cover 52 is provided on one side surface of the main body 204, and an air vent hole 20 formed in the upper portion of the main body 204.
6 and an air filter 207 as an air vent member provided so as to cover the air vent hole 206. A horizontal toner supply port 54 is formed on the bottom surface of the toner introducing cover 52. A shutter member 88 for vertically moving and opening / closing the toner supply port 54 is integrally incorporated. Shutter member 88
Is a bendable elastic member 90 as a shutter body.
And a supporting member 92 for supporting this, and this supporting member 92
The support member 92 has a spring member 96 for urging the shutter member 88 so as to always close the shutter member 88. Elastic member 9
0 is formed of a polyester film such as Mylar (trade name) and is attached to the supporting member 92 with a double-sided tape or the like. The toner introduction cover 52 is formed with a moving hole 52a for moving the protrusion 94.

As shown in FIG. 5, the toner introducing cover 52 is integrally formed with arc-shaped guide portions 98, 98 for guiding the elastic member 90 of the shutter member 88. Is an elastic seal member 10 for preventing the toner leakage by biting the tip of the elastic member 90.
0 is provided. The moving hole 52a includes a circular hole 52b formed in the center and a narrow hole 52c extending vertically from the circular hole 52b.
And a neck portion of the protrusion 94 is formed in a plate shape. This suppresses the shake of the vertical movement of the shutter member 88. As shown in FIG. 6, in the upper case 43 of the developing device 16, a guide rib 1 that engages with the protrusion 94 and drives the shutter member 88 to open and close when the toner introducing unit 20 is attached or detached.
14 are formed integrally. This guide rib 114 is
It has a trapezoidal shape that protrudes in the vertical direction, and has an inclined surface 1.
It has 14a, 114b and a flat top 114c.

On the other hand, the developing device 16 has a toner receiving port 56.
7, a shutter member 115 for opening and closing the toner receiving port 56 is provided below the guide rib 114 substantially in parallel with the toner receiving port 56. The shutter member 115 is composed of a flat plate-shaped shutter body 116 and a spring member 117 for urging the shutter body 116 so as to always close the shutter body 116. The shutter body 116 has a guide formed on the toner introducing means 20. The shutter member 1 is engaged with the ribs 208 and 209.
A cylindrical protrusion 118 for driving the opening / closing of 15 in the horizontal direction is integrally formed. Further, slide pieces 116a are formed on both sides of the shutter body 116, and correspondingly, a guide portion 41a with which the slide piece 116a is engaged is formed on the upper case 41.
6 slides horizontally on the upper case 41. A boss 116 b that supports one end of the spring member 117 is integrally formed on the lower surface of the shutter body 116.
The other end of 7 is a U-shaped rib 41 formed on the upper case 41.
b.

FIG. 3A shows a state before the toner introducing means 20 is mounted, and the shutter member 88 is the spring member 9.
The toner supply port 54 is closed by being closed by the urging force of 6.
In this case, as shown in FIG. 4A, the shutter member 1
The protrusion 118 of the guide rib 2 of the toner introducing means 20 is also included.
Since the action of 08 is not received, the toner receiving port 56 is closed. When the predetermined mounting position is reached, as shown in FIG. 3B, the shutter member 88 rises and the toner supply port 54 opens. As shown in FIG. 4B, at the same time, the shutter member 115 retracts and the toner receiving port 56 opens, so that the developing device 16 and the toner introducing means 20 are in communication with each other, and the toner transferred from the toner storing / supplying means 18 is transferred. Is the developing device 1
6. The toner supply port 54 is provided in the toner passage portion 2.
The opening area of the toner transfer pipe 22 is set to be larger than the inner cross-sectional area of the toner transfer pipe 22 so that the toner does not accumulate on the toner. The reason is that, when the toner is accumulated and remains in the toner passage portion 210, the next supplied toner is further accumulated on the remaining toner, and the toner passage portion 210 is eventually closed. .

Since the capacity of the toner storing / supplying means 18 is large, a large amount of copying and printing operations can be continuously performed. Since the toner supplied by the toner storing / supplying means 18 contains air, it is necessary to remove air, but when the toner is supplied to the toner introducing means 20,
Only air flows from the air vent hole 206 to the air filter 20.
You can get out through 7. This prevents the atmospheric pressure in the developing device 16 from rising and the toner from blowing out from the gap due to this.

As shown in FIGS. 8 and 9, the toner accommodating / supplying means 18 includes a casing 182 having moving wheels 180 and stays 181, a toner accommodating container 184 provided in the casing 182, and a toner accommodating container. Container 1
An agitator 185 that agitates the toner in 84, a conveying screw 186, a screw pump 187 connected to the front end of the conveying screw 186, and an air pump serving as an air supply unit that is installed so as to join the screw pump 187. 188 and agitator 185
And a drive motor 18 for driving the conveying screw 186 and the like
9 and 9.

The toner container 184 includes a plurality of mounting pieces 3.
01-shaped container body 300, side plates 304 and 305 fixed to both sides of the container body 300 via seal members 302, and a top plate 306 having a circular opening 306a and a rectangular opening 306b. The toner loading member 307 with a lid is attached to the circular opening 306a of the top plate 306, and the window member 308 is attached to the rectangular opening 306b.

A gear 30 is provided at the rear end of the conveying screw 186.
9 is fixed, and this gear 309 is the drive motor 18
9 worm gear 310 is engaged. A gear 311 is fixed to the rear end of the agitator 185, and is driven by the power of a drive motor 189 via an intermediate gear 312 meshing with the gear 311. Toner storage container 18
The toner inside 4 is the weight of the toner itself and the agitator 18
5 and the conveying screw 186 are rotated so that the screw is reliably fed to the screw pump 187. Screw pump 187
Is generally called a mono pump, and is composed of a rotor 313 engaged with the front end of the conveying screw 186, an elastic stator 314 surrounding the rotor 313, and a holder 315 holding the stator 314. The toner transfer pipe 2 is provided at one end of the holder 315.
The joint part 315a for 2 is formed. There is a gap of about 1 mm between the side surface of the stator 314 and the inner side surface of the holder 315, which communicates with the toner passage. An air supply port 316 is formed on the outer surface of the holder 315 so as to blow into the toner passage through the gap. The air supply port 316 and the air discharge port 188a of the air pump 188 are connected by an air hose 317, and an air detector 318 is provided in the middle of the air hose 317.
Is installed. The air detector 318 is the container body 31.
9 and a sensor 320.

When the air pump 188 operates, it blows air through the air supply port 316 into the toner passage of the screw pump 187 at a blowing rate of about 0.5 to 1 liter / minute. As a result, fluidization of the toner discharged from the screw pump 187 is promoted, and the toner transfer by the powder pump is ensured.

The toner supply control in the external toner supply device 6 is based on the output result of the toner density sensor in the developing device 16, and when it is judged that the toner in the developing device 16 is low, the toner storing / supplying means 18 is provided. By issuing an activation signal to. When controlling the screw pump 187 and the air pump 188 at the start of operation, only the air pump 188 is turned on, and after 0.5 to 1 second, the screw pump 187 (driving motor 189) is turned on.
At the time of stop, after turning off the drive motor 189, only the air pump 188 is operated for 1 to 3 seconds. The reason for performing such operation control is shown below.

While the screw pump 187 is operating, the toner almost uniformly mixed with air fills almost the entire area of the toner transfer pipe 22, but the entire apparatus is stopped at once, that is, the screw pump 187. When both the air pump 188 and the air pump 188 are stopped at the same time, only the air escapes from the air-mixed toner filled in the toner transfer pipe 22, and the toner sinks downward due to its own weight, which increases the bulk density of the toner. Then, when the toner is sent to restart the external toner supply device 6, the remaining toner blocks the transfer of the toner, and the toner is clogged. As a result, the screw pump 187 may be locked or burned (toner sticks to the rotor 313 due to excessive temperature rise, and the stuck toner scrapes the stator 314, causing pump damage). is there. However, as described above, by operating only the air pump 188 at the start of the operation of the toner supply device, the residual toner in the toner transfer pipe 22 can be discharged only by air. Alternatively, by operating only the air pump 188 after the operation is stopped,
The inside of the toner transfer pipe 22 can be made almost empty.
As described above, the toner clogging can be eliminated and the toner can be transferred more reliably.

As described above, in the toner supply device using the powder pump (screw pump 187), it is very important to transfer the toner together with the air in order to secure the reliability of the device.

The air detector 318 is an air pump 18
8 detects whether air is being supplied to the screw pump 187, and serves as a safety device for minimizing the system down of the external toner supply device 6. As shown in FIG. 10, both ends are air hoses 3
A spherical float 321 is enclosed in a transparent container body 319 connected to 17. When the float 321 is mixed with air, it is lifted from the position A to the position B by the air. The sensor 320 is provided at a position corresponding to the position B and detects the presence or absence of the float 321. If the presence of the float 321 is detected, it can be seen that the air is cleanly supplied to the screw pump 187. When it is detected that the float 321 is not in the fixed position, the control unit (not shown) stops the driving of the external toner supply device 6 and displays a failure on the display unit of the main body (image forming apparatus main body). In addition, the image forming operation of the main body is stopped. The float 321 can be made of various materials such as resin and metal such as stainless steel, and the shape thereof is not limited to the spherical shape. Also, the sensor 320 is not limited to the reflected light detection method, but various types such as a transmitted light detection method and a magnetic detection method can be adopted.

Next, FIGS. 11 and 12 show the image forming apparatus 2.
It shows the normal specifications of. In this case, the toner introducing unit 20 is removed and the built-in toner supply device 500 is attached. The toner transfer pipe 22 is arranged inside the apparatus main body so as not to interfere with the built-in toner supply apparatus 500. The built-in toner supply device 500 includes a drive unit 60, a guide plate 108, a receiving table 42 that is detachably attached to the guide plate 108, and a toner introducing unit 40 that is integrally formed with the receiving table 42. The toner introducing unit 40 is roughly configured by a toner cartridge 38 having a tip end attached thereto and placed on a pedestal 42.

The toner introducing means 40 is provided with the toner introducing cover 52 integrally provided with the shutter member 88 and the toner supplying port 54 in the same manner as described above. The toner introducing cover 52 is the toner in the external toner supplying device 6. It can be shared with the introduction means 20. The positioning with respect to the main body of the apparatus is the same, and the toner introducing means 40 has positioning holes 42b and 42c. Further, guide ribs 102 and 104 are formed on the toner introducing unit 40, and the function of opening and closing the shutter member 115 of the developing device 16 is the same as that described above. The shutter member 88 of the toner introducing unit 40 is opened and closed by the guide rib 114 of the developing device 16 as in the above. In FIG. 12, reference numeral 84 indicates a handle for opening the tip cap of the toner cartridge 38.

In the above embodiment, the external toner supply device 6 is used.
An example (so-called retrofitting) of removing a main part when switching the built-in toner supply device 500 is shown, but an example in which this removal is unnecessary is shown in FIGS. 13 and 14. The toner introduction unit 600 shown in this example is shared by the external toner supply device and the built-in toner supply device, and includes a toner introduction unit 602 corresponding to the external toner supply device,
A toner introducing unit 604 corresponding to the built-in toner supply device is integrally provided. In FIG. 13, reference numeral 605 indicates an attaching / detaching portion of the toner transfer pipe 22, and reference numeral 606 indicates an air filter. Further, in FIG. 14, reference numeral 46 indicates a pushing member, and reference numeral 48 indicates an opening. In the case of the common configuration as described above, it is possible to omit the replacement work within the apparatus main body and the attachment / detachment work of the toner introduction cover 52 when switching the specifications, and it is possible to simplify the configuration.

[0028]

According to the present invention, it is possible to cope with a large number of copies and prints while maintaining the appropriate size of the developing device and the main body of the device, reducing the downtime of the machine, and reducing the copy / printing time.
The printing cost can be reduced. In addition, since either the conventional built-in toner cartridge or the external type large capacity type can be arbitrarily selected, the usability can be improved. In particular, according to the second aspect of the invention, since air is supplied to the toner passage of the screw pump to promote fluidization of the toner, it is possible to reliably transfer the toner from the outside. Particularly, according to the fifth aspect of the invention, since the area of the toner supply port is made larger than the inner cross-sectional area of the toner transfer pipe, it is possible to avoid toner clogging due to toner accumulation in the toner introducing means. In particular, according to the invention described in claim 8, since the toner introducing means of the built-in type toner supplying device and the external type toner supplying device are the same member, it is possible to facilitate the work and simplification of the configuration switching operation. it can.

[Brief description of drawings]

FIG. 1 is an overall schematic diagram of a mass copy specification of an image forming apparatus showing an embodiment of the present invention.

FIG. 2 is a perspective view of a toner introduction unit of the external toner supply device.

3A and 3B are vertical cross-sectional views of a toner introduction unit of the external toner supply device, FIG. 3A being a state before mounting and FIG. 3B being a state after mounting.

4A and 4B are horizontal cross-sectional views of a toner introduction unit of the external toner supply device, FIG. 4A being a state before mounting and FIG. 4B being a state after mounting.

FIG. 5 is a back side perspective view of the toner introducing cover.

FIG. 6 is a perspective view showing a guide rib on the developing device side that opens and closes a shutter member of the toner introducing unit.

FIG. 7 is an exploded perspective view showing a shutter member on the developing device side.

FIG. 8 is a schematic vertical cross-sectional view of toner storage / supply means of the external toner supply device.

FIG. 9 is an exploded perspective view of toner storage / supply means.

FIG. 10 is a sectional view of an air detector.

FIG. 11 is an overall schematic diagram of an image forming apparatus with a built-in toner supply device specification using a toner cartridge.

FIG. 12 is an exploded perspective view of a built-in toner supply device.

FIG. 13 is a perspective view of a toner introduction unit commonly used by the built-in toner supply device and the external toner supply device.

FIG. 14 is a vertical cross-sectional view of a toner introducing unit having a common structure.

[Explanation of symbols]

 6 External Type Toner Supplying Device 16 Developing Device 18 Toner Storage / Supplying Means 22 Toner Transfer Pipe 38 Toner Cartridge 40 Toner Introducing Means 54 Toner Supplying Port 56 Toner Receiving Port 88 Shutter Member 187 Screw Pump 188 Air Pump as Air Supplying Means 207 , 606 Air filter as air vent member 500 Built-in toner supply device

Claims (9)

[Claims] 1. An image forming apparatus comprising a developing device and a toner supplying device for supplying toner to the developing device, wherein the toner supplying device uses toner from a toner cartridge incorporated in a main body of the image forming device. Built-in toner supply device that supplies the toner to the developing device through the introduction unit, and toner storage that exists separately from the image forming apparatus main body.
An external toner supplying device for supplying toner from the supplying device to the developing device through the toner introducing device. Both the internal toner supplying device and the external toner supplying device can be used. A characteristic image forming apparatus. 2. A toner storage device for the external toner supply device.
The supply means and the corresponding toner introduction means are connected by a toner transfer pipe, and the toner storage / supply means is provided with a screw pump for supplying the toner to the toner transfer pipe and a toner pumped by the screw pump. The image forming apparatus according to claim 1, further comprising: an air supply unit that facilitates the flow of the toner and that can independently transfer and discharge the toner in the toner transfer pipe. 3. The built-in type toner supply device and the external type toner supply device respectively have a common shape for engaging the toner introducing means with the main body of the image forming apparatus. Image forming apparatus. 4. The image forming apparatus according to claim 2, wherein the toner introduction means of the external toner supply device is provided with an air vent member. 5. The developing device has a toner receiving port for receiving the toner supplied from the toner introducing device of the external toner supplying device, and the toner introducing device supplies the toner opposite to the toner receiving port. The image forming apparatus according to claim 2, further comprising an opening, wherein an area of the toner supply opening is larger than a cross-sectional area of the toner transfer pipe. 6. The toner introducing means of the external toner supply device has a shutter member for preventing the toner from falling out of the toner supply port.
The image forming apparatus as described in the above. 7. The toner supply port and the shutter member can be integrally mounted to the toner introducing means of the built-in toner supply device, and the toner supply port and the shutter member of the integrated structure are the external toner. 7. The image forming apparatus according to claim 6, wherein the image forming apparatus can be commonly attached to the toner introducing means of the supply device. 8. The image forming apparatus according to claim 1, wherein the toner introducing means of the built-in toner supplying device and the toner introducing means of the external toner supplying device are the same member. 9. The toner introducing means as the same member,
9. The image forming apparatus according to claim 8, further comprising a detachable member for the toner cartridge and a detachable member for the toner transfer pipe.