JPH0619305A - Developing device - Google Patents

Abstract

PURPOSE:To carry supplied developer to a part along a developer carrier in a developer carrying path as soon as the developer is supplied to a hopper, and to perform development immediately after the developer is supplied. CONSTITUTION:This device is provided with the hopper 21 storing the developer so that it can be supplied and furnishing it, the developer carrying path 22 for carrying the developer from the hopper 21, and the developer carrying body 24 carrying the developer through the path 22 and furnishing the developer to the developer carrier 1 at a part along the carrier 1 in the developer carrying path. When the developer is supplied to the hopper 21, the carrying body 24 is driven so that the developer in the hopper 21 may at least reach the part along the developer carrier 1 in the path 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device, and more particularly to a developing device used in a copying machine or a laser beam printer for forming an image by an electrophotographic method and an image forming apparatus having the developing device. .

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 3-28248 discloses a developing device of this type. In this product, a circulation conveyance path for circulating and conveying the developer is provided behind the developing sleeve. One of the forward path and the return path of the circulation conveyance path is along the developing sleeve, and the toner replenishment path from the hopper provided at the back is connected to a part of the other path.

A two-component developer containing a carrier and a toner is circulated and conveyed while being agitated in the circulation conveyance path, and is supplied to the intermediate development sleeve at a portion facing the development sleeve. The developing sleeve conveys the carried developer to a portion facing the photosensitive drum and supplies toner to the developing sleeve to perform development.

In short, since the developer is circulated and fed to the developer carrying member, the supply of the developer is stable.

Further, the toner concentration of the developer is detected on the circulation conveyance path, and when the toner concentration falls below a predetermined concentration, the toner is supplied from the hopper and the predetermined toner concentration is maintained, so that the developing performance is stabilized.

By the way, in the developing device, when the developer such as toner is exhausted in the hopper, it is usual to replenish the developer so that the developer can be used continuously.

For this replenishment, the developer replenishing container is attached to the hopper, or the mouth of the developer container is applied to the developer replenishing port of the hopper to transfer the developer from the developer replenishing container to the hopper. Done by.

In this case, in the developing device described in the above publication,
As described above, while the stable supply of the developer is possible, the replenished developer is sequentially conveyed through the developer conveying path and reaches the entire length area of the portion along the developer carrying body equally,
The developer is stably supplied to the carrier.

Conventionally, for this stable supply, an initializing operation for operating the developing device for a predetermined time is performed after the developer is replenished.

[0010]

However, in the above-mentioned conventional method, since the time for the initialization operation is specially required, it is necessary to wait for the image forming operation for a predetermined time after the replenishment of the developer. Further, since it also takes some time to transfer the developer from the developer supply container to the hopper for supplying the developer, there is a waiting time for this.
Therefore, it is inconvenient to use because the image formation must be waited for a relatively long time or the image formation must be interrupted.

Further, at the time of replenishing the developer, the replenishment developer does not reach the developer conveying path, so that the rate of filling the developer into the developing device at the time of replenishing the developer is low and the replenishment efficiency of the developer is poor. .

Therefore, an object of the present invention is to provide a developing device capable of solving the above-mentioned problems by driving the developer transport body in parallel with the replenishment of the developer.

[0013]

In order to achieve the above object, the present invention provides a hopper capable of replenishing and supplying a developer, a developer conveying path for conveying the developer from the hopper, The developer transport path is provided with a developer transport body that transports the developer and supplies the developer to the developer transport body at a portion along the developer transport body of the developer transport path. At this time, the developer transport body is driven so that the developer in the hopper reaches at least a portion along the developer transport body of the developer transport path.

In this case, it is advantageous that the hopper has a stirring member for stirring the developer, and the stirring member and the developer carrier are interlocked.

Further, a replenishing port for attaching and detaching the developer replenishing container is provided in the hopper, and means for detecting that the developer replenishing container is attached to the replenishing port, and the developer conveying body by a detection signal from the detecting means. It is preferable to provide a control means for driving the developer for a predetermined time so that the developer in the hopper reaches at least the developer supply position on the developer carrying path to the developer carrier.

Further, the developer replenishing container has an agitating member therein, and the developer replenishing container has a rotating shaft of the agitating member and a rotating shaft of the agitating member in the hopper. It is preferable to provide a joint portion that is connected to and disconnected from each other by being attached and detached.

The developer transport path is a circulation path for circulating the developer from the hopper via the supply position to the developer carrier, and the developer in the hopper is driven for a predetermined time for driving the developer transport body. It is preferable to set the time required to complete at least one round of the developer transport path.

Further, it is preferable that the developer carrying path comprises a forward path for carrying the developer along the developer carrying member and a backward path for carrying the developer through the forward path in the opposite direction and returning it.

[0019]

According to the above-mentioned structure of the present invention, the developer stored in the hopper is sent to the developer transport path and is transported by the developer transport body, and the developer is transported at a portion along the developer carrying body of the developer transport path. However, when replenishing the developer to the hopper, the developer transporting body is driven so that the developer in the hopper reaches at least the portion along the developer carrying body of the developer transporting path. Since the developer is replenished, the replenished developer is transported to at least the supply position to the developer carrier, and after the developer is replenished, there is no special initializing operation or waiting time due to this. The agent can be stably supplied to the development carrier to be used for development.

Further, at the developer replenishing stage, the developer to be replenished into the hopper can be conveyed and filled up to a portion along the developer carrier of the developer conveying path, so that a large amount of developer is replenished. be able to.

In each of the above cases, a stirring member for stirring the developer is provided in the hopper, and the stirring member and the developer transport body are made to interlock with each other. To drive, the stirring member in the hopper is also driven without any special drive source or operation to promote the transfer of the developer from the hopper to the developer transfer path and to smoothly transfer the developer along the developer carrier. It can be performed stably.

Further, the hopper is provided with a replenishing port for attaching and detaching the developer replenishing container, means for detecting that the developer replenishing container is attached to the replenishing port, and the developer conveying body by a detection signal from the detecting means. Is provided for a predetermined time so that the developer in the hopper reaches at least the developer supply position to the developer carrier in the developer transport path, the developer supply container supplies the developer to the hopper. When the developer is replenished by being attached to the mouth, the detection means detects this and the control means drives the developer transport body for a predetermined time. Simultaneously with the replenishment of the developer by transfer, the developer replenished in the hopper can be automatically and reliably delivered to at least the developer conveying path and conveyed to a portion along the developer carrier.

Further, the developer replenishing container has an agitating member inside thereof, and the agitating member of the developer replenishing container and the rotating shaft of the agitating member in the hopper are connected to the replenishing port of the hopper of the developer replenishing container. By providing a joint that connects and disconnects each other by attachment and detachment, when the developer supply container is installed in the supply port of the hopper and the developer is supplied, the developer supply is performed without any special drive source or operation. The stirring member in the container is also driven at the same time, so that the transfer of the developer from the developer supply container to the hopper can be smoothly performed.

The developer transport path is a circulation path for circulating the developer from the hopper via the supply position to the developer carrier, and the developer in the hopper is developed for a predetermined time for driving the developer transport body. When the time required to complete at least one circulation of the developer transport path is set, the replenishment developer in the hopper is transported at least until it completes one circulation of the circulation path when the developer is replenished, and the entire developer transport path is set to the normal developer amount. Can be kept.

Further, when the developer transport path is composed of a forward path for transporting the developer along the developer carrier and a return path for transporting the developer which has passed through the forward path in the opposite direction, replenishment development in the hopper It is possible to achieve the early conveyance of the agent to the portion along the developer carrier of the developer conveying path.

[0026]

EXAMPLE A first example of the present invention shown in FIGS. 1 to 9 will be described below.

1 to 5 show a developing device, and FIG. 6 shows an image forming device equipped with the developing device. FIG. 7 shows in detail the structure around the photosensitive drum of the image forming apparatus. 8 shows the internal structure of the developer supply container, and FIG.
FIG. 3 is a block diagram of a drive control circuit of the developing device.

This embodiment is a simple, small-sized and inexpensive image forming apparatus particularly suitable for personal use such as being connected to a personal computer. As shown in FIG. The case of a printer having 1 and a print head 2 for performing image exposure on the printer 1 is illustrated.

The print head 2 employs a so-called solid scanning system in which light emitting elements such as LEDs and a liquid crystal shutter are arranged to perform image exposure. Larger models can also employ a printhead that deflects the laser beam to perform scanning.

As shown in FIG.
As shown in FIG. 3, the charging charger 3, the print head 2, the developing device 4, the transfer roller 5, and the cleaning device 6 are sequentially arranged in the rotation direction of the photosensitive drum 1 as indicated by the arrow.

Returning to FIG. 6, in front of the transfer portion between the photosensitive drum 1 and the transfer roller 5, a paper feed path 13 is provided which is connected to a manual paper feed port 12 on the outer surface of the main body 11, Behind the transfer section, a fixing device 18 provided in the main body 11
A transport path 15 to is provided.

Behind the fixing device 18, there is provided a paper discharge path 17 communicating with a paper discharge port 16 on the outer surface of the main body 11.

The main body 11 has rectangular side surfaces on the front and rear sides as viewed in a direction perpendicular to the plane of the paper, has two installation surfaces 11a and 11b along one long side and one short side thereof, and the other side of the paper feeding side. A mouth 12 and a paper exit 16 are provided. Therefore, installation surface 11
Paper can be fed and discharged regardless of whether the main body 11 is installed by either a or 11b.

Further, with respect to the photosensitive drum 1, the cleaning device 6 is located on the side opposite to the installation surface 11a, and the developing device 4 is located on the installation surface 11a side. The transfer roller 5 is located on the side facing the opening 16.

The paper feed port 12 is provided near the installation surface 11a of the outer surface of the main body 11, and the paper ejection port 16 is provided on the installation surface 11a.
It is provided near the end on the side far from a.

A fixing device 18 is provided at a position apart from the photosensitive drum 1 near the sheet discharge port 16 side between the sheet discharge port 16 and the transfer portion.

As a result, the recording sheet fed from the sheet feeding port 12 is sent to the transfer portion, and after the transfer, the fixing device 18
The sheet can be discharged to the sheet discharge port 16 through the short path using a very small space in the main body 11.

The fixing device 18 is located on the photosensitive drum 1 regardless of which of the installation surfaces 11a and 11b the main body 11 is installed on. Therefore, it is possible to prevent the heat of the fixing device 18 from adversely affecting the image forming mechanism portion around the photosensitive drum 1.

Further, the developing device 4 is installed on the installation surface 11 due to the above arrangement.
Whether the main body 11 is installed by either a or 11b,
It will be located on the side or below the photosensitive drum 1. For this reason, it is possible to prevent the developer from being excessively supplied due to the gravitational action and clogging the respective parts when the developer is supplied to the photosensitive drum 1 as a developer carrying body to which the developer is directly supplied from the developing device 4. Can be, especially the photosensitive drum 1
This is effective for the developing method of the present embodiment in which the developer is brought into contact with a wide area of the above to temporarily develop the entire surface and then the developer in the non-image area is removed and collected.

Further, even if the developer leaks from the developing device 4, it is avoided that the developer adheres to the photosensitive drum 1 and stains it.

The paper passage path and the transfer portion of the main body 11 can be opened and closed for jam clearance, repair, and the like. In this case
So that the right side portion of the developing device 4 in is opened,
The developing device 4 and the photosensitive drum 1 which are unitized can be attached and detached through the opening in the direction indicated by an arrow 31 in the figure.

The attachment / detachment direction can be freely set according to the arrangement of other devices and the opening / closing structure of each part of the main body 11.

The developing device 4 itself is shown in detail in FIGS. This will be described. A hopper 21 that stores and supplies the developer, a developer transport path 22 that transports the developer from the hopper 21, and a developer that transports the developer on the developer transport path 22 along the developer transport path 22. Developer carrier 2 that supplies developer to the photosensitive drum 1 as a carrier
4 is provided so that development can be performed in the developing field 23 around the photosensitive drum 1.

In the developer transport path 22, a forward path 22a for sending the developer from the hopper and a backward path 22b for returning the developer sent to the forward path 22a to the hopper 21 are a continuous developer including a part of the hopper 21. It forms a circuit. A part of the outward route 22a and the return route 22b, that is, the outward route 22a in this embodiment.
A wide developer supply port 61 is provided at a, which is in contact with the photosensitive drum 1 as the developer carrying member and supplies a sufficient amount of the developer to the entire surface development.

As a result, it is stored in the hopper 21,
The developer stirred by the stirring blade 20 is sent to the forward path 22a of the developer transport path 22, and then the return path 22 is continued.
Since the returning to the inside of the hopper 21 through b is repeated, a fixed amount of the developer is constantly circulated and conveyed in the circulation path formed by the forward path 22a and the return path 22b of the hopper 21 and the developer conveyance path 22 while the developer is in the hopper 21. It is possible to stably supply the developer to the photosensitive drum 1 as the developer carrying member through the developer supply port 61 during the circulation and conveyance so that proper development can be performed.

In the development of the system in the present embodiment, the developer is supplied to a relatively wide area of the photosensitive drum 1 through the wide developer supply port 61, and the image area and the non-image area on the photosensitive drum 1 are The entire surface development in which both the image areas are developed by the developer suction force to the photosensitive drum 1 side due to the potential difference or the magnetic action is once performed. When utilizing the magnetic force, a magnetic developer is used.

Next, when the full-scale developing portion on the photosensitive drum 1 reaches the developing field 23, it is adsorbed to the non-image portion on the photosensitive drum 1 by the developer suction force to the developing sleeve 25 side due to the potential difference and the magnetic action. The developing agent is sucked onto the developing sleeve 25 and removed to complete the development.

When the developer in the non-image area is removed by suction, when an alternating suction force due to an AC potential is applied between the photosensitive drum 1 and the developing sleeve 25, the developer is adsorbed particularly on the surface of the non-image area. Even a stable developer, the relatively free or free enough developer particles in the upper layer of the non-image area are vibrated first to collide with the stable developer. , The developing sleeve 25 can be effectively sucked and removed.

The developer on the developing sleeve 25 removed from the non-image portion is returned to the developer conveying path 22 by the rotation of the developing sleeve 25 and is collected. Reference numeral 52 denotes a blade for this recovery, and also serves as a seal for preventing the developer from leaking between the developer supply port 61 and the developing sleeve 25.

Further, the developer circulated and conveyed returns to the inside of the hopper 21 every time it is circulated, and is renewed and mixed with the developer inside the hopper 21, so that the entire development including the developer inside the hopper 21 is performed. The developer can be supplied while being kept homogeneous, and stable development can be guaranteed without sudden deterioration due to abnormal consumption of some components or uneven distribution of the developer with a long history of use.

Since the forward path 22a and the return path 22b are closed spaces containing the developer transport body 24, the developing device 4 can be used in a stand-alone state in which the developing device 4 is pulled out from the main body 11 or with the main body 11 in which the developing device 4 is mounted. Even if the installation direction is changed, the developer in each part in the developer transport path 22 is held in place against the gravity effect between the developer transport body 24 and the developer transport body 24. Also, it is possible to avoid biasing to one side of the return path.

Further, the developer supply port 61, which is in contact with the developer carrying member such as the photosensitive drum 1 of the developer transport path 22, has the forward path 22a.
In the developing system, the developer carrying path 22 can be installed along the photosensitive drum 1 and the developing sleeve 25 with a small bulk because the developing method is partially in contact with the developing sleeve 25.

Further, in this case, if the developer conveying path 22 forms the closed space together with the photosensitive drum 1 and the developing sleeve 25, the closed space required for supplying the developer to the developing field 23 is narrow. Therefore, the developer can be held more reliably.

The developing sleeve 25 is installed in a developing field cover 30a integrally formed with a part of the developing casing 30 forming the hopper 21 and the developer transport path 22.

Further, within the closed space, the developer transport body 24 in the forward path 22a, the photosensitive drum 1 and the developing sleeve 2 are provided.
5 side, the developer play space 55, which does not reach the carrying force of the developer carrying body 24, and does not carry the photosensitive drum 1 and the developing sleeve 25, is provided in the developing sleeve 25 and the photosensitive drum 1. It is set so as to be positioned in a magnetic field 54 which is formed between the magnetic poles of the cylindrical magnet 53 and the sector magnet 81 provided inside and which has a strength capable of holding the developer against gravity.

Therefore, the developer in the developer play space 55 is hard to be caught on the spot without receiving the carrying force of the developer carrying body 24 and the carrying force of the photosensitive drum 1 and the developing sleeve 25, but it has a magnetism. If so, the magnetic field 54 holds it against gravity, so that the bias of the developer can be prevented more reliably.

The developer carrying capacity in the developer carrying path 22 is
By increasing the lead of the screw blade 24a of the developer carrier 24, which is a screw, the size is appropriately increased toward the downstream side from the outlet 21a of the hopper 21 to the inlet 21b of the hopper 21 via the forward path 22a and the return path 22b. Is set to.

As a result, a greater conveying force is exerted on the developer sent from the hopper 21 toward the downstream side, and the developer forward path 22a and developer backward path 22b.
The margin in the inside is gradually increased, and finally, it is sent into the hopper 21 having a large capacity to be released, so that the developer may be clogged during circulatory transfer, and the density becomes close to this, and the development is performed. It is possible to prevent the agent from being strongly fatigued.

When the lead of the developer transport body 24 becomes large, the gripping force of the developer becomes weak, and the developer cannot be sufficiently held in each part, and the bias may not be prevented.

In this case, it is possible to take measures by forming the screw blade 24a in multiple lines.

Further, the passage width of the connecting path 22c from the outward path 22a to the returning path 22b is made larger than that of the outward path 22a, and the developer being circulated and conveyed is loosened in this portion, so that the transition to the next path in the bending path is performed. And transportation becomes smooth.

Further, since the developer carrier 24 in the outward path 22a is a screw and faces the hopper 21, the free developer in the hopper 21 can be well captured and reliably delivered.

The developer carrying capacity of the developer carrying body 24 can be appropriately set by the diameter of the other developer carrying body, the driving speed, and the like.

Further, the developer carrying capacity of the hopper outlet 21a is set to be larger than that of the developing sleeve 25 of the developer carrying member 24. Therefore, it is possible to prevent the supply amount of the developer from being insufficient to be supplied to the developing field 23 while being circulated and conveyed.

In this embodiment, the lead of the portion of the developer carrying body 24 facing the photosensitive drum 1 is constant.
As a result, the developer supplied to the photoconductor drum 1 while being circulated and conveyed is different from the photoconductor drum 1 due to the difference in the conveyance speed.
It is possible to prevent the supply amount to the non-uniformity.

When the developer carrier 24 on the return path 22b side has largely entered into the hopper 21 as in the present embodiment, the developer is transferred from the return path 22b into the hopper 21 to return the developer to the inside of the hopper 21. It is possible to positively agitate and mix with the developer in the hopper 21 while surely feeding the developer into the inner part of the hopper 21.

Each developer transport body 24 is driven to rotate in the opposite direction by the drive mechanism 82 by the lead of the same direction, and the developer is transported by the meshing of the gears 27 and 28 directly connected to each other. Can be achieved, and the structure of the drive mechanism 82 can be simplified.

Further, this gear connection is performed via the torque limiter 57. Therefore, in the unlikely event of the outward route 22a or the return route 2
Even if excessive addition occurs due to clogging of the developer or high density in 2b, it can be dealt with by the slip of the torque limiter 57,
Avoid excessive driving.

Replenishing port 21 for replenishing the developer of hopper 21
A cover 58 is provided on c, and the developer supply container 43 is attached to remove the cover 58 so that the developer can be supplied.

Since the hopper 21 is located outside one end in the longitudinal direction of the photosensitive drum 1 and the forward path 22a and the return path 22b extend from the hopper 21 in parallel to the photosensitive drum 1, the hopper 21 is located outside the photosensitive drum 1. Not located around the radial surface,
Since only the outward path 22a and the inward path 22b of the developer are located around the outer diameter surface of the photosensitive drum 1 and in parallel with it, the developer can be supplied to the developing sleeve 25. The space occupying can be halved.

Therefore, it is advantageous for further downsizing of the image forming section, and there is a space in image exposure and installation of the charging means and the like, and the degree of freedom in installation of the image forming device increases. Further, the developing device 4 itself can be installed in any orientation.

Further, when the developing device 4 is unitized with the photosensitive drum 1 and the like and is attached to and detached from the main body 11 as indicated by an arrow 31 in FIGS. 1 and 6, the hopper is located behind the developer carrying path 22 as in the conventional case. In the case of the above type, the hopper 21 interferes with the print head 2 so that the attachment and detachment cannot be performed.

Therefore, it is conceivable to handle the print head 2 as a unit together with the developing device 4 and the photosensitive drum 1 and simultaneously attach and detach it. However, the print head 2 is expensive and there is a problem in treating it as a consumable item as a part of the detachable unit.

When the hopper 21 is located outside one end in the longitudinal direction of the photosensitive drum 1 as in this embodiment, it does not interfere with the print head 2 in the attachment / detachment. Therefore, the print head 2 is used as an element on the main body 11 side. There is an advantage that it can be fixed.

The cleaning device 6 has a cleaning blade 32 in contact with the surface of the photosensitive drum 1, and the cleaning blade 32 removes the residual developer after the transfer from the surface of the photosensitive drum 1.

The cleaning blade 32 is provided at one edge of the developer receiving port 34 of the developer returning passage 33 for returning the removed residual developer to the hopper 21, and the removed residual developer is passed through the developer returning passage 33. It is designed to be scooped into. Reference numeral 56 is a seal piece provided on the other edge of the developer receiving port 34.

A developer transporting body 35, which is a screw, is provided in the developer returning passage 33, and the residual developer received in the developer returning passage 33 is returned into the hopper 21.
A special device for storing and discarding the residual developer removed by this is unnecessary.

If the image forming apparatus of the present embodiment is of a small size suitable for personal use, the residual developer is recovered and used again, but the amount is small and a large amount in the hopper 21. Since it is used by being mixed with the developer of No. 1 by stirring, it is difficult to exert any influence and it does not cause any particular problem.

In this embodiment, the forward path 22a and the backward path 22b of the developer transport path 22 are the forward path 22a facing the photosensitive drum 1 in the installation direction of the main body 11 installed on the installation surface 11a shown in FIG. Is located slightly higher than the return path 22b.

As a result, even when the main body 11 is installed on the installation surface 11b, the positional relationship between the forward path 22a and the return path 22b becomes constant. Therefore, the supply state of the developer is unlikely to change regardless of whether the main body 11 is installed on the installation surfaces 11a and 11b, and in both cases, the developer is supplied to the photosensitive drum 1 from below. It is advantageous to prevent excessive supply due to gravity.

Therefore, it is possible to prevent the developer from being strongly stressed due to a high density state or clogging due to excessive supply.

It should be noted that the forward path 22a and the return path 22b may be arranged in a different positional relationship. As a result, the outward path 22a is on the lower side, so that the developer at the lowest position in the hopper 21 can be sent out and used for development.

The developer transport body 35 is the developer transport path 22.
Are located in parallel to the developer transport body 24 and close to each other with the photosensitive drum 1 sandwiched therebetween, and can be easily driven by gear-linking and interlocking with them, which contributes to simplification and downsizing of the apparatus. Contribute.

The stirring blade 20 is interlocked with the developer carrier 24 via gears 41 and 42 to rotate.

As a result, without any special drive source or operation,
The developer hopper 21 can be smoothly transferred to the developer transport path 22.

Further, the developer supply container 43 is shown in FIG.
As shown in (B), it has a stirring blade 91 inside and the developer discharge ports 93 at two circumferential positions are closed by caps 92 rotatable about the rotation shaft 44 of the stirring blade 91. . The cap 92 has a developer discharge port 94 facing the developer discharge port 93, and this has the rotary shaft 44.
The developer in the developer supply container 43 can be discharged when it coincides with the developer discharge port 93 by the rotation around the center.

The developer replenishing container 43 is attached by fitting the cap 92 to the replenishing port 21c of the hopper 21, and the fitting at this time prevents the developer from scattering to the outside.

When the mounted developer supply container 43 is rotated with respect to the cap 92 fitted in the supply port 21c, the developer discharge ports 93, 94 of both the cap 92 and the developer supply container 43 are aligned. Since it is opened toward the inside of the hopper 21, the developer in the developer supply container 43 is transferred into the hopper 21 by its own weight.

At this time, the rotating shaft 44 of the stirring blade 91
Is coupled to the rotating shaft 20a of the stirring blade 20 by the couplings 45, 4
6, the stirring blades 91 in the developer supply bottle 43 are driven in association with the rotation of the stirring blades 20.

A sensor for detecting the mounting of the developer supply container 43 on the side of the hopper 21 for automatically driving the developer transport body 24 when the developer supply container 43 is mounted and the developer is supplied. 95 is provided. Various sensors such as a photo sensor and a limit switch can be applied to the sensor 95, and the mounting of the developer supply container 43 can be performed optically,
Detects electrically or mechanically.

As shown in FIG. 9, a CPU 101 is provided on the main body 11 side (or the developing device 4 side), and a sensor 94 is provided.
When the mounting of the developer supply container 43 is detected by the drive mechanism 8
2 is allowed to work for a predetermined time.

Accordingly, when the developer replenishing container 43 is mounted on the hopper 21 to replenish the developer, the driving mechanism 82 is operated at the same time as the mounting of the developer replenishing container 43 to drive the developer transport body 24. Stirring blade 20 in hopper 21
And the stirring blade 91 in the developer supply container 43 is interlockedly rotated.

At this time, the developer in the developer supply container 43 is easily dropped into the hopper 21 due to the stirring of the stirring blades 91, and the transfer to the hopper 21 proceeds smoothly. Further, the developer replenished in the hopper 21 is smoothly sent to the developer carrying path 22 by the stirring of the stirring blade 20 and can be stably carried by the developer carrying body 24.

During the predetermined time, the developer in the hopper 21 is
It is set to such an extent that at least it contacts the photosensitive drum 1, which is the developer carrier in the developer transport path 22, and reaches the position where the developer is supplied to the photosensitive drum 1, which is relatively short due to the smooth delivery and stable transport. This can be achieved in a short time, and the developer replenishment and conveyance can be completed in a short time in parallel with the smooth developer replenishment.

In short, when the developer is supplied to the hopper 21, the developer transport body 24 is driven so that the developer in the hopper 21 extends along at least the photosensitive drum 1 which is the developer carrier of the developer transport path 22. If you try to reach the part,
Since the replenished developer is conveyed at least to the supply position to the photoconductor drum 1 which is the developer carrier, the replenishment of the developer can be performed without any special initialization operation or waiting time after the replenishment of the developer. The developer can be stably supplied to the photosensitive drum 1, which is a developing carrier, and can be used for development, and special operations and operations such as an initialization operation are not required after the developer is replenished, and immediate image formation can be started or restarted. Also, the waiting time itself due to the replenishment of the developer can be shortened.

Further, at the developer replenishing stage, the developer to be replenished into the hopper 21 can be conveyed and filled up to the portion along the photosensitive drum 1 which is the developer carrying member of the developer conveying path 22. A large amount of the developer can be replenished, and the developer replenishment efficiency is improved.

The driving of the developer transporting body 24 accompanying the replenishment of the developer can be started by the switch operation of the operator.

Further, the developer transport path 22 is a circulation path for circulating the developer from the hopper 21 via the supply position to the photosensitive drum 1 which is the developer carrier, and the developer transport body 24
If a predetermined time for driving the developer is set to a time required for the developer in the hopper 21 to make at least one round in the developer transport path 22, at least the replenished developer in the hopper 21 is supplied to the developer transport path 22 at the time of replenishing the developer. It is possible to convey the developer until the entire circulation path is completed and keep the entire amount of the developer conveyance path 22 at a normal developer amount, and supply the developer to the photosensitive drum 1 when image formation is started or restarted. Can be further stabilized.

The developer carrying path 22 is a forward path 22 for carrying the developer along the photosensitive drum 1 which is a developer carrying member.
a and a return path 22b that conveys and returns the developer that has passed through the outward path 22a in the opposite direction. The outward path 22a is in contact with the photosensitive drum 1 to supply the developer to the inside of the hopper 21. The replenishment of the replenishment developer to the portion along the photosensitive drum 1 which is the developer carrying member of the developer conveyance path 22 is achieved at an early stage, which also enables the start or restart of the image formation by the replenishment of the developer. The waiting time can be shortened.

As the developer carrying members 24 and 35, various known ones such as those having a carrying blade can be adopted other than the screw.

In particular, as the developer transport body 35, since the developer transport amount is extremely small, a simple one such as a coil spring can be adopted.

FIG. 9 shows a second embodiment of the present invention, in which the developer supply port 61 provided in the outward path 22a of the developer transport path 22 is formed with a narrow width to develop on the developing sleeve 25 which is a developer carrier. It is of a conventional type in which a developing agent is supplied to supply the agent.

The layer thickness of the developer supplied to the developing sleeve 25 is regulated by the elastic blade 51, and when the developer is charged by the friction at this time and conveyed to the developing field 23, the image portion on the photosensitive drum 1 is imaged. It is sucked into and developed.

The developer in the developer play space 55 can be held against gravity by the magnetic field 54 formed between the magnetic poles of the cylindrical magnet 53 in the developing sleeve 25.
Reference numeral 50 is a seal piece that seals between the developing field cover 30a and the developing sleeve 25.

Since the other structure is the same as that of the first embodiment, the description thereof will be omitted.

[0106]

According to the present invention, the developer stored in the hopper is sent to the developer transport path and is transported by the developer transport body, and the developer is transported to the developer transport path along the developer carrier. The developer is supplied for development, but when the developer is replenished to the hopper, the developer carrier is driven so that the developer in the hopper reaches the portion along the developer carrier of the developer carrier path. At the end of the replenishment of the developer, the replenished developer is conveyed to the position where it is supplied to the developer carrier, and the developer is developed without any special initialization operation or waiting time after the replenishment of the developer. Since the carrier is stably supplied for development, image formation can be started or restarted immediately after the developer is replenished, which is convenient for use.

At the developer replenishing stage, the developer to be replenished into the hopper can be conveyed and filled up to the portion along the developer carrier of the developer conveying path, so that a large amount of developer is replenished. Therefore, the developer replenishment interval in the developing device having the same capacity can be lengthened.

In each of the above cases, if a stirring member for stirring the developer is provided in the hopper and the stirring member and the developer transport body are interlocked with each other, the developer transport body can be operated at the stage of replenishing the developer. For driving, the stirring member in the hopper is also driven without any special drive source or operation to promote the transfer of the developer from the hopper to the developer transfer path and stabilize the transfer to the part along the developer carrier. In addition, the developing performance at the start or restart of image formation can be made sufficient. It is also possible to shorten the time required to convey the developer to the above-mentioned position and shorten the waiting time for image formation.

Further, the hopper is provided with a mounting port for mounting and demounting the developer replenishing container, means for detecting that the developer replenishing container has been mounted in the mounting port, and the developer transport body by the detection signal from the detecting means. Is provided for a predetermined time so that the developer in the hopper reaches the developer supply position to the developer carrier in the developer transport path, and the developer supply container is installed in the hopper. When the developer is replenished by being attached to the developer, the detection means detects this and the control means drives the developer transport body, so that the developer is transferred from the developer replenishing container to the hopper. Simultaneously with the replenishment of the developer, the developer replenished in the hopper is automatically sent out to the developer conveyance path and conveyed to the part along the developer carrier, no special operation is required and operation is forgotten. Or operation mistake It is possible to avoid a failure due.

Further, the developer replenishing container has an agitating member inside, and the rotating shaft of the agitating member of the developer replenishing container and the rotating shaft of the agitating member in the hopper are connected to the mounting opening of the hopper of the developer replenishing container. By providing a joint part that connects and disconnects each other by attachment and detachment, when the developer replenishment container is installed in the mounting opening of the hopper and the developer is replenished, the developer replenishment is performed without any special drive source or operation. The stirring member in the container is also driven at the same time, so that the transfer of the developer from the developer supply container to the hopper can be performed smoothly, and the developer supply time is shortened to shorten the waiting time for image formation. can do.

Further, the developer transport path is a circulation path for circulating the developer from the hopper via the supply position to the developer carrier, and the developer in the hopper is developed for a predetermined time for driving the developer transport body. When the time required to complete at least one round of the developer transport path is set, the replenishment developer in the hopper is transported until one round of the circulation path at the time of replenishment of the developer, and the entire developer transport path is set to the normal developer amount. Therefore, the developing performance can be further stabilized when the image formation is started or restarted.

In the case where the developer transport path is composed of a forward path for transporting the developer along the developer carrying member and a return path for transporting the developer which has passed through the forward path in the opposite direction, replenishment development in the hopper. Since it is possible to early convey the developer to the portion along the developer carrying member of the developer conveying path, it is possible to further shorten the waiting time for starting or resuming image formation.

[Brief description of drawings]

FIG. 1 is a perspective view of a developing device to which the present invention is applied.

FIG. 2 is a plan view of the developing device of FIG. 1 as seen in a horizontal cross section.

FIG. 3 is a plan view showing a part of the developing device of FIG. 1 on a hopper side.

FIG. 4 is a sectional view of a hopper portion of the developing device of FIG.

5 is a cross-sectional view of a part of the developing device of FIG. 1 on the hopper side as viewed in a vertical direction.

FIG. 6 is an overall schematic configuration diagram of an image forming apparatus having the developing device of FIG.

7 is a cross-sectional view showing an image forming unit of the image forming apparatus in FIG.

8 is a cross-sectional view showing an internal structure of a developer supply container used in the developing device of FIG.

9 is a block diagram of a drive control circuit of a developer transport body of the developing device of FIG.

FIG. 10 is a cross-sectional view showing an image forming unit of the image forming apparatus showing the second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor drum 4 Developing device 11 Main body 20 Stirring blade 20a Rotating shaft 21 Hopper 21c Replenishing port 22 Developer transport path 22a Forward path 22b Return path 23 Development field 24 Developer transport body 25 Development sleeve 41, 42 Gear 43 Developer supply container 44 Rotating shaft 61 Developer supply port 82 Drive mechanism 91 Stirring blade 95 Sensor 101 CPU

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[Procedure amendment]

[Submission date] January 18, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction content]

[Document name] Statement

Title of the invention Developing device

[Claims]

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device, and more particularly to a developing device used in a copying machine or a laser beam printer for forming an image by an electrophotographic method and an image forming apparatus having the developing device. .

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 3-28248 discloses a developing device of this type. In this product, a circulation conveyance path for circulating and conveying the developer is provided behind the developing sleeve. One of the forward path and the return path of the circulation conveyance path is along the developing sleeve, and the toner replenishment path from the hopper provided at the back is connected to a part of the other path.

A two-component developer containing a carrier and a toner is circulated and conveyed while being agitated in the circulation conveyance path, and is supplied to the intermediate development sleeve at a portion facing the development sleeve. The developing sleeve conveys the carried developer to a portion facing the photosensitive drum and supplies toner to the developing sleeve to perform development.

In short, since the developer is circulated and fed to the developer carrying member, the supply of the developer is stable.

Further, the toner concentration of the developer is detected in the circulation conveyance path, and when the toner concentration falls below a predetermined concentration, the toner is supplied from the hopper and the predetermined toner concentration is maintained, so that the developing performance is stabilized.

By the way, in the developing device, when the developer such as toner is exhausted in the hopper, it is usual to replenish the developer so that the developer can be used continuously.

For this replenishment, the developer replenishing container is attached to the hopper, or the mouth of the developer container is applied to the developer replenishing port of the hopper to transfer the developer from the developer replenishing container to the hopper. Done by.

In this case, in the developing device described in the above publication,
As described above, while the stable supply of the developer is possible, the replenished developer is sequentially conveyed through the developer conveying path and reaches the entire length area of the portion along the developer carrying body equally,
The developer is stably supplied to the carrier.

Conventionally, for this stable supply, an initializing operation for operating the developing device for a predetermined time is performed after the developer is replenished.

[0010]

However, in the above-mentioned conventional method, since the time for the initialization operation is specially required, it is necessary to wait for the image forming operation for a predetermined time after the replenishment of the developer. Further, since it also takes some time to transfer the developer from the developer supply container to the hopper for supplying the developer, there is a waiting time for this.
Therefore, it is inconvenient to use because the image formation must be waited for a relatively long time or the image formation must be interrupted.

Further, at the time of replenishing the developer, the replenishment developer does not reach the developer conveying path, so that the rate of filling the developer into the developing device at the time of replenishing the developer is low and the replenishment efficiency of the developer is poor. .

Therefore, an object of the present invention is to provide a developing device capable of solving the above-mentioned problems by driving the developer transport body in parallel with the replenishment of the developer.

[0013]

In order to achieve the above object, the present invention provides a hopper capable of replenishing and supplying a developer, a developer conveying path for conveying the developer from the hopper, The developer transport path is provided with a developer transport body that transports the developer and supplies the developer to the developer transport body at a portion along the developer transport body of the developer transport path. At this time, the developer transport body is driven so that the developer in the hopper reaches at least a portion along the developer transport body of the developer transport path.

In this case, it is advantageous that the hopper has a stirring member for stirring the developer, and the stirring member and the developer carrier are interlocked.

Further, a replenishing port for attaching and detaching the developer replenishing container is provided in the hopper, and means for detecting that the developer replenishing container is attached to the replenishing port, and the developer conveying body by a detection signal from the detecting means. It is preferable to provide a control means for driving the developer for a predetermined time so that the developer in the hopper reaches at least the developer supply position on the developer carrying path to the developer carrier.

Further, the developer replenishing container has an agitating member therein, and the developer replenishing container has a rotating shaft of the agitating member and a rotating shaft of the agitating member in the hopper. It is preferable to provide a joint portion that is connected to and disconnected from each other by being attached and detached.

The developer transport path is a circulation path for circulating the developer from the hopper via the supply position to the developer carrier, and the developer in the hopper is driven for a predetermined time for driving the developer transport body. It is preferable to set the time required to complete at least one round of the developer transport path.

Further, it is preferable that the developer carrying path comprises a forward path for carrying the developer along the developer carrying member and a backward path for carrying the developer through the forward path in the opposite direction and returning it.

[0019]

According to the above-mentioned structure of the present invention, the developer stored in the hopper is sent to the developer transport path and is transported by the developer transport body, and the developer is transported at a portion along the developer carrying body of the developer transport path. However, when replenishing the developer to the hopper, the developer transporting body is driven so that the developer in the hopper reaches at least the portion along the developer carrying body of the developer transporting path. Since the developer is replenished, the replenished developer is transported to at least the supply position to the developer carrier, and after the developer is replenished, there is no special initializing operation or waiting time due to this. The agent can be stably supplied to the development carrier to be used for development.

Further, at the developer replenishing stage, the developer to be replenished into the hopper can be conveyed and filled up to a portion along the developer carrier of the developer conveying path, so that a large amount of developer is replenished. be able to.

In each of the above cases, a stirring member for stirring the developer is provided in the hopper, and the stirring member and the developer transport body are made to interlock with each other. To drive, the stirring member in the hopper is also driven without any special drive source or operation to promote the transfer of the developer from the hopper to the developer transfer path and to smoothly transfer the developer along the developer carrier. It can be performed stably.

Further, the hopper is provided with a replenishing port for attaching and detaching the developer replenishing container, means for detecting that the developer replenishing container is attached to the replenishing port, and the developer conveying body by a detection signal from the detecting means. Is provided for a predetermined time so that the developer in the hopper reaches at least the developer supply position to the developer carrier in the developer transport path, the developer supply container supplies the developer to the hopper. When the developer is replenished by being attached to the mouth, the detection means detects this and the control means drives the developer transport body for a predetermined time. Simultaneously with the replenishment of the developer by transfer, the developer replenished in the hopper can be automatically and reliably delivered to at least the developer conveying path and conveyed to a portion along the developer carrier.

Further, the developer replenishing container has an agitating member inside thereof, and the agitating member of the developer replenishing container and the rotating shaft of the agitating member in the hopper are connected to the replenishing port of the hopper of the developer replenishing container. By providing a joint that connects and disconnects each other by attachment and detachment, when the developer supply container is installed in the supply port of the hopper and the developer is supplied, the developer supply is performed without any special drive source or operation. The stirring member in the container is also driven at the same time, so that the transfer of the developer from the developer supply container to the hopper can be smoothly performed.

The developer transport path is a circulation path for circulating the developer from the hopper via the supply position to the developer carrier, and the developer in the hopper is developed for a predetermined time for driving the developer transport body. When the time required to complete at least one circulation of the developer transport path is set, the replenishment developer in the hopper is transported at least until it completes one circulation of the circulation path when the developer is replenished, and the entire developer transport path is set to the normal developer amount. Can be kept.

Further, when the developer transport path is composed of a forward path for transporting the developer along the developer carrier and a return path for transporting the developer which has passed through the forward path in the opposite direction, replenishment development in the hopper It is possible to achieve the early conveyance of the agent to the portion along the developer carrier of the developer conveying path.

[0026]

EXAMPLE A first example of the present invention shown in FIGS. 1 to 9 will be described below.

1 to 5 show a developing device, and FIG. 6 shows an image forming device equipped with the developing device. FIG. 7 shows in detail the structure around the photosensitive drum of the image forming apparatus. 8 shows the internal structure of the developer supply container, and FIG.
FIG. 3 is a block diagram of a drive control circuit of the developing device.

This embodiment is a simple, small-sized and inexpensive image forming apparatus particularly suitable for personal use such as being connected to a personal computer. As shown in FIG. The case of a printer having 1 and a print head 2 for performing image exposure on the printer 1 is illustrated.

The print head 2 employs a so-called solid scanning system in which light emitting elements such as LEDs and a liquid crystal shutter are arranged to perform image exposure. Larger models can also employ a printhead that deflects the laser beam to perform scanning.

As shown in FIG.
As shown in FIG. 3, the charging charger 3, the print head 2, the developing device 4, the transfer roller 5, and the cleaning device 6 are sequentially arranged in the rotation direction of the photosensitive drum 1 as indicated by the arrow.

Returning to FIG. 6, in front of the transfer portion between the photosensitive drum 1 and the transfer roller 5, a paper feed path 13 is provided which is connected to a manual paper feed port 12 on the outer surface of the main body 11, Behind the transfer section, a fixing device 18 provided in the main body 11
A transport path 15 to is provided.

Behind the fixing device 18, there is provided a paper discharge path 17 communicating with a paper discharge port 16 on the outer surface of the main body 11.

The main body 11 has rectangular side surfaces on the front and rear sides as viewed in a direction perpendicular to the plane of the paper, has two installation surfaces 11a and 11b along one long side and one short side thereof, and the other side of the paper feeding side. A mouth 12 and a paper exit 16 are provided. Therefore, installation surface 11
Paper can be fed and discharged regardless of whether the main body 11 is installed by either a or 11b.

Further, with respect to the photosensitive drum 1, the cleaning device 6 is located on the side opposite to the installation surface 11a, and the developing device 4 is located on the installation surface 11a side. The transfer roller 5 is located on the side facing the opening 16.

The paper feed port 12 is provided near the installation surface 11a of the outer surface of the main body 11, and the paper ejection port 16 is provided on the installation surface 11a.
It is provided near the end on the side far from a.

A fixing device 18 is provided at a position apart from the photosensitive drum 1 near the sheet discharge port 16 side between the sheet discharge port 16 and the transfer portion.

As a result, the recording sheet fed from the sheet feeding port 12 is sent to the transfer portion, and after the transfer, the fixing device 18
The sheet can be discharged to the sheet discharge port 16 through the short path using a very small space in the main body 11.

The fixing device 18 is located on the photosensitive drum 1 regardless of which of the installation surfaces 11a and 11b the main body 11 is installed on. Therefore, it is possible to prevent the heat of the fixing device 18 from adversely affecting the image forming mechanism portion around the photosensitive drum 1.

Further, the developing device 4 is installed on the installation surface 11 due to the above arrangement.
Whether the main body 11 is installed by either a or 11b,
It will be located on the side or below the photosensitive drum 1. For this reason, it is possible to prevent the developer from being excessively supplied due to the gravitational action and clogging the respective parts when the developer is supplied to the photosensitive drum 1 as a developer carrying body to which the developer is directly supplied from the developing device 4. Can be, especially the photosensitive drum 1
It is effective for the developing method of the present embodiment in which the developer is uniformly supplied and adhered to the entire wide area, and then the developer in the non-image area is removed and collected.

In this embodiment, the developer is magnetic.
Although the component developer is used, even if the developer leaks from the developing device 4, it is avoided that the developer adheres to the photosensitive drum 1 and stains it.

The paper passage path and the transfer portion of the main body 11 can be opened and closed for jam clearance, repair, and the like. In this case
So that the right side portion of the developing device 4 in is opened,
The developing device 4 and the photosensitive drum 1 which are unitized can be attached and detached through the opening in the direction indicated by an arrow 31 in the figure.

The attachment / detachment direction can be freely set according to the arrangement of other devices and the opening / closing structure of each part of the main body 11.

The developing device 4 itself is shown in detail in FIGS. This will be described. A hopper 21 that stores and supplies the developer, a developer transport path 22 that transports the developer from the hopper 21, and a developer that transports the developer on the developer transport path 22 along the developer transport path 22. Developer carrier 2 that supplies developer to the photosensitive drum 1 as a carrier
4 is provided so that development can be performed in the developing field 23 around the photosensitive drum 1.

In the developer transport path 22, a forward path 22a for sending the developer from the hopper and a backward path 22b for returning the developer sent to the forward path 22a to the hopper 21 are a continuous developer including a part of the hopper 21. It forms a circuit. A part of the outward route 22a and the return route 22b, that is, the outward route 22a in this embodiment.
A wide developer supply port 61 is provided at a, which is in contact with the photosensitive drum 1 as the developer carrying member and supplies a sufficient amount of the developer to the entire surface development.

As a result, it is stored in the hopper 21,
The developer stirred by the stirring blade 20 is sent to the forward path 22a of the developer transport path 22, and then the return path 22 is continued.
Since the returning to the inside of the hopper 21 through b is repeated, a fixed amount of the developer is constantly circulated and conveyed in the circulation path formed by the forward path 22a and the return path 22b of the hopper 21 and the developer conveyance path 22 while the developer is in the hopper 21. It is possible to stably supply the developer to the photosensitive drum 1 as the developer carrying member through the developer supply port 61 during the circulation and conveyance so that proper development can be performed.

In the development of the system in the present embodiment, the developer is supplied to a relatively wide area of the photosensitive drum 1 through the wide developer supply port 61, and the image area and the non-image area on the photosensitive drum 1 are Indiscriminately supplying and attaching the developer to both image parts
It

Next, when the photoconductor drum 1 having the developer adhered to the entire surface reaches the developing field 23, it is detected as the collecting roller 25.
Electric field force and magnetic force due to the potential difference between the photoconductor drum 1 and
The developer adsorbed on the non-image portion on the photosensitive drum 1 is sucked and removed onto the collecting roller 25 by the interaction of the above to complete the development.

When the developer in the non-image area is removed by suction, a DC electric field is applied between the photosensitive drum 1 and the collecting roller 25.
When an alternating electric field is applied to the non-image area, even if the developer is adsorbed on the surface of the non-image area and is stable, the developer particles in the upper layer of the non-image area are relatively free or free and sufficiently free. It is possible to vibrate first to collide it with the stable developer, and effectively suck and remove it toward the collecting roller 25 side.

The developer on the collecting roller 25 removed from the non-image portion is rotated by the collecting roller 25 and the developer conveying path 2
Return to 2 and collect. Reference numeral 52 denotes a blade for collecting the developer, but the developer is supplied to the developer supply port 61 and the collecting roller 2.
It also serves as a seal to prevent leakage from the space between the five.

Further, the developer circulated and conveyed returns to the inside of the hopper 21 every time it is circulated, and is renewed and mixed with the developer inside the hopper 21, so that the entire development including the developer inside the hopper 21 is performed. The developer can be supplied while being kept homogeneous, and stable development can be guaranteed without sudden deterioration due to abnormal consumption of some components or uneven distribution of the developer with a long history of use.

Since the forward path 22a and the return path 22b are closed spaces containing the developer transport body 24, the developing device 4 can be used in a stand-alone state in which the developing device 4 is pulled out from the main body 11 or with the main body 11 in which the developing device 4 is mounted. Even if the installation direction is changed, the developer in each part in the developer transport path 22 is held in place against the gravity effect between the developer transport body 24 and the developer transport body 24. Also, it is possible to avoid biasing to one side of the return path.

Further, the developer supply port 61, which is in contact with the developer carrying member such as the photosensitive drum 1 of the developer transport path 22, has the forward path 22a.
It is also provided on the photoconductor drum 1 and the collecting roller 25 .
It can be reduced to install bulky along the over La 25.

Further, in this case, if the developer transport path 22 forms the closed space together with the photosensitive drum 1 and the collecting roller 25, the closed space required for supplying the developer to the developing field 23 is narrow. Therefore, the developer can be held more reliably.

The collecting roller 25 is installed in a developing field cover 30a formed integrally with a part of the developing casing 30 forming the hopper 21 and the developer transport path 22.

Further, within the closed space, the developer transport body 24 in the forward path 22a, the photosensitive drum 1 and the collecting roller 25.
The developer play space 55, which is not supported by the conveying force of the developer conveying body 24 and is not supported by the photosensitive drum 1 and the collecting roller 25, is formed in the collecting roller 25 and the photosensitive drum 1. Cylindrical magnet 53 provided in
The magnetic field is formed between the magnetic poles of the sector-shaped magnet 81 and the sector-shaped magnet 81, and is set so as to be located in the magnetic field 54 having a strength capable of holding the developer against gravity.

Therefore, the developer in the developer play space 55 is hard to be caught on the spot without receiving the carrying force of the developer carrying body 24 and the carrying force of the photosensitive drum 1 and the collecting roller 25, but it is magnetized. If so, the magnetic field 54 holds it against gravity, so that the bias of the developer can be prevented more reliably.

The developer carrying capacity in the developer carrying path 22 is
By increasing the lead of the screw blade 24a of the developer carrier 24, which is a screw, the size is appropriately increased toward the downstream side from the outlet 21a of the hopper 21 to the inlet 21b of the hopper 21 via the forward path 22a and the return path 22b. Is set to.

As a result, a greater conveying force is exerted on the developer sent from the hopper 21 toward the downstream side, and the developer forward path 22a and developer backward path 22b.
The margin in the inside is gradually increased, and finally, it is sent into the hopper 21 having a large capacity to be released, so that the developer may be clogged during circulatory transfer, and the density becomes close to this, and the development is performed. It is possible to prevent the agent from being strongly fatigued.

When the lead of the developer transport body 24 becomes large, the gripping force of the developer becomes weak, and the developer cannot be sufficiently held in each part, and the bias may not be prevented.

In this case, it is possible to take measures by forming the screw blade 24a in multiple lines.

Further, the passage width of the connecting path 22c from the outward path 22a to the returning path 22b is made larger than that of the outward path 22a, and the developer being circulated and conveyed is loosened in this portion, so that the transition to the next path in the bending path is performed. And transportation becomes smooth.

Further, since the developer carrier 24 in the outward path 22a is a screw and faces the hopper 21, the free developer in the hopper 21 can be well captured and reliably delivered.

The developer carrying capacity of the developer carrying body 24 can be appropriately set by the diameter of the other developer carrying body, the driving speed, and the like.

Further, the developer carrying capacity of the hopper outlet 21a is set to be larger than the carrying capacity of the photosensitive drum 1 which is a developer carrying member. Therefore, it is possible to prevent the supply amount of the developer from being insufficient to be supplied to the developing field 23 while being circulated and conveyed.

In this embodiment, the lead of the portion of the developer carrying body 24 facing the photosensitive drum 1 is constant.
As a result, the developer supplied to the photoconductor drum 1 while being circulated and conveyed is different from the photoconductor drum 1 due to the difference in the conveyance speed.
It is possible to prevent the supply amount to the non-uniformity.

When the developer carrier 24 on the return path 22b side has largely entered into the hopper 21 as in the present embodiment, the developer is transferred from the return path 22b into the hopper 21 to return the developer to the inside of the hopper 21. It is possible to positively agitate and mix with the developer in the hopper 21 while surely feeding the developer into the inner part of the hopper 21.

Each developer transport body 24 is driven to rotate in the opposite direction by the drive mechanism 82 by the lead of the same direction, and the developer is transported by the meshing of the gears 27 and 28 directly connected to each other. Can be achieved, and the structure of the drive mechanism 82 can be simplified.

Further, this gear connection is performed via the torque limiter 57. Therefore, in the unlikely event of the outward route 22a or the return route 2
Even if excessive addition occurs due to clogging of the developer or high density in 2b, it can be dealt with by the slip of the torque limiter 57,
Avoid excessive driving.

Replenishing port 21 for replenishing the developer of hopper 21
A cover 58 is provided on c, and the developer supply container 43 is attached to remove the cover 58 so that the developer can be supplied.

Since the hopper 21 is located outside one end in the longitudinal direction of the photosensitive drum 1 and the forward path 22a and the return path 22b extend from the hopper 21 in parallel to the photosensitive drum 1, the hopper 21 is located outside the photosensitive drum 1. Not located around the radial surface,
Only forward 22a and return 22b of the developer is positioned in parallel with this outer surface around the photosensitive drum 1 photoreceptor Dora
It is possible to supply the developer to the beam 1, the developing device 4
It is possible to halve the space occupied around the photosensitive drum 1.

Therefore, it is advantageous for further downsizing of the image forming section, and there is a space in image exposure and installation of the charging means and the like, and the degree of freedom in installation of the image forming device increases. Further, the developing device 4 itself can be installed in any orientation.

Further, when the developing device 4 is unitized with the photosensitive drum 1 and the like and is attached to and detached from the main body 11 as indicated by an arrow 31 in FIGS. 1 and 6, the hopper is located behind the developer carrying path 22 as in the conventional case. In the case of the above type, the hopper 21 interferes with the print head 2 so that the attachment and detachment cannot be performed.

Therefore, it is conceivable to handle the print head 2 as a unit together with the developing device 4 and the photosensitive drum 1 and simultaneously attach and detach it. However, the print head 2 is expensive and there is a problem in treating it as a consumable item as a part of the detachable unit.

When the hopper 21 is located outside one end in the longitudinal direction of the photosensitive drum 1 as in this embodiment, it does not interfere with the print head 2 in the attachment / detachment. Therefore, the print head 2 is used as an element on the main body 11 side. There is an advantage that it can be fixed.

The cleaning device 6 has a cleaning blade 32 in contact with the surface of the photosensitive drum 1, and the cleaning blade 32 removes the residual developer after the transfer from the surface of the photosensitive drum 1.

The cleaning blade 32 is provided at one edge of the developer receiving port 34 of the developer returning passage 33 for returning the removed residual developer to the hopper 21, and the removed residual developer is passed through the developer returning passage 33. It is designed to be scooped into. Reference numeral 56 is a seal piece provided on the other edge of the developer receiving port 34.

A developer transporting body 35, which is a screw, is provided in the developer returning passage 33, and the residual developer received in the developer returning passage 33 is returned into the hopper 21.
A special device for storing and discarding the residual developer removed by this is unnecessary.

If the image forming apparatus of the present embodiment is of a small size suitable for personal use, the residual developer is recovered and used again, but the amount is small and a large amount in the hopper 21. Since it is used by being mixed with the developer of No. 1 by stirring, it is difficult to exert any influence and it does not cause any particular problem.

In this embodiment, the forward path 22a and the backward path 22b of the developer transport path 22 are the forward path 22a facing the photosensitive drum 1 in the installation direction of the main body 11 installed on the installation surface 11a shown in FIG. Is located slightly higher than the return path 22b.

As a result, even when the main body 11 is installed on the installation surface 11b, the positional relationship between the forward path 22a and the return path 22b becomes constant. Therefore, the supply state of the developer is unlikely to change regardless of whether the main body 11 is installed on the installation surfaces 11a and 11b, and in both cases, the developer is supplied to the photosensitive drum 1 from below. It is advantageous to prevent excessive supply due to gravity.

Therefore, it is possible to prevent the developer from being strongly stressed due to a high density state or clogging due to excessive supply.

It should be noted that the forward path 22a and the return path 22b may be arranged in a different positional relationship. As a result, the outward path 22a is on the lower side, so that the developer at the lowest position in the hopper 21 can be sent out and used for development.

The developer transport body 35 is the developer transport path 22.
Are located in parallel to the developer transport body 24 and close to each other with the photosensitive drum 1 sandwiched therebetween, and can be easily driven by gear-linking and interlocking with them, which contributes to simplification and downsizing of the apparatus. Contribute.

The stirring blade 20 is interlocked with the developer carrier 24 via gears 41 and 42 to rotate.

As a result, without any special drive source or operation,
The developer hopper 21 can be smoothly transferred to the developer transport path 22.

Further, the developer supply container 43 is shown in FIG.
As shown in (B), it has a stirring blade 91 inside and the developer discharge ports 93 at two circumferential positions are closed by caps 92 rotatable about the rotation shaft 44 of the stirring blade 91. . The cap 92 has a developer discharge port 94 facing the developer discharge port 93, and this has the rotary shaft 44.
The developer in the developer supply container 43 can be discharged when it coincides with the developer discharge port 93 by the rotation around the center.

The developer replenishing container 43 is attached by fitting the cap 92 to the replenishing port 21c of the hopper 21, and the fitting at this time prevents the developer from scattering to the outside.

When the mounted developer supply container 43 is rotated with respect to the cap 92 fitted in the supply port 21c, the developer discharge ports 93, 94 of both the cap 92 and the developer supply container 43 are aligned. Since it is opened toward the inside of the hopper 21, the developer in the developer supply container 43 is transferred into the hopper 21 by its own weight.

At this time, the rotating shaft 44 of the stirring blade 91
Is coupled to the rotating shaft 20a of the stirring blade 20 by the couplings 45, 4
6, the stirring blades 91 in the developer supply bottle 43 are driven in association with the rotation of the stirring blades 20.

A sensor for detecting the mounting of the developer supply container 43 on the side of the hopper 21 for automatically driving the developer transport body 24 when the developer supply container 43 is mounted and the developer is supplied. 95 is provided. Various sensors such as a photo sensor and a limit switch can be applied to the sensor 95, and the mounting of the developer supply container 43 can be performed optically,
Detects electrically or mechanically.

As shown in FIG. 9, a CPU 101 is provided on the main body 11 side (or the developing device 4 side), and a sensor 94 is provided.
When the mounting of the developer supply container 43 is detected by the drive mechanism 8
2 is allowed to work for a predetermined time.

Accordingly, when the developer replenishing container 43 is mounted on the hopper 21 to replenish the developer, the driving mechanism 82 is operated at the same time as the mounting of the developer replenishing container 43 to drive the developer transport body 24. Stirring blade 20 in hopper 21
And the stirring blade 91 in the developer supply container 43 is interlockedly rotated.

At this time, the developer in the developer supply container 43 is easily dropped into the hopper 21 due to the stirring of the stirring blades 91, and the transfer to the hopper 21 proceeds smoothly. Further, the developer replenished in the hopper 21 is smoothly sent to the developer carrying path 22 by the stirring of the stirring blade 20 and can be stably carried by the developer carrying body 24.

During the predetermined time, the developer in the hopper 21 is
It is set to such an extent that at least it contacts the photosensitive drum 1, which is the developer carrier in the developer transport path 22, and reaches the position where the developer is supplied to the photosensitive drum 1, which is relatively short due to the smooth delivery and stable transport. This can be achieved in a short time, and the developer replenishment and conveyance can be completed in a short time in parallel with the smooth developer replenishment.

In short, when the developer is supplied to the hopper 21, the developer transport body 24 is driven so that the developer in the hopper 21 extends along at least the photosensitive drum 1 which is the developer carrier of the developer transport path 22. If you try to reach the part,
Since the replenished developer is conveyed at least to the supply position to the photoconductor drum 1 which is the developer carrier, the replenishment of the developer can be performed without any special initialization operation or waiting time after the replenishment of the developer. The developer can be stably supplied to the photosensitive drum 1, which is a developing carrier, and can be used for development, and special operations and operations such as an initialization operation are not required after the developer is replenished, and immediate image formation can be started or restarted. Also, the waiting time itself due to the replenishment of the developer can be shortened.

Further, at the developer replenishing stage, the developer to be replenished into the hopper 21 can be conveyed and filled up to the portion along the photosensitive drum 1 which is the developer carrying member of the developer conveying path 22. A large amount of the developer can be replenished, and the developer replenishment efficiency is improved.

The driving of the developer transporting body 24 accompanying the replenishment of the developer can be started by the switch operation of the operator.

Further, the developer transport path 22 is a circulation path for circulating the developer from the hopper 21 via the supply position to the photosensitive drum 1 which is the developer carrier, and the developer transport body 24
If a predetermined time for driving the developer is set to a time required for the developer in the hopper 21 to make at least one round in the developer transport path 22, at least the replenished developer in the hopper 21 is supplied to the developer transport path 22 at the time of replenishing the developer. It is possible to convey the developer until the entire circulation path is completed and keep the entire amount of the developer conveyance path 22 at a normal developer amount, and supply the developer to the photosensitive drum 1 when image formation is started or restarted. Can be further stabilized.

The developer carrying path 22 is a forward path 22 for carrying the developer along the photosensitive drum 1 which is a developer carrying member.
a and a return path 22b that conveys and returns the developer that has passed through the outward path 22a in the opposite direction. The outward path 22a is in contact with the photosensitive drum 1 to supply the developer to the inside of the hopper 21. The replenishment of the replenishment developer to the portion along the photosensitive drum 1 which is the developer carrying member of the developer conveyance path 22 is achieved at an early stage, which also enables the start or restart of the image formation by the replenishment of the developer. The waiting time can be shortened.

As the developer carrying members 24 and 35, various known ones such as those having a carrying blade can be adopted other than the screw.

In particular, as the developer transport body 35, since the developer transport amount is extremely small, a simple one such as a coil spring can be adopted.

FIG. 10 shows a second embodiment of the present invention, in which a developer supply port 61 provided on the outward path 22a of the developer carrying path 22.
Of the developing sleeve 71, which is a developer bearing member
It is of a normal type in which a developer is supplied to develop the toner.

The layer thickness of the developer supplied to the developing sleeve 71 is regulated by the elastic blade 51. When the developer is charged by the friction at this time and conveyed to the developing field 23, the image portion on the photosensitive drum 1 is imaged. It is sucked into and developed.

The developer in the developer play space 55 can be held against gravity by the magnetic field 54 formed between the magnetic poles of the cylindrical magnet 53 in the developing sleeve 71 .
Reference numeral 50 denotes a seal piece that seals between the developing field cover 30a and the developing sleeve 71 .

Since the other structure is the same as that of the first embodiment, the description thereof will be omitted.

[0106]

According to the present invention, the developer stored in the hopper is sent to the developer transport path and is transported by the developer transport body, and the developer is transported to the developer transport path along the developer carrier. The developer is supplied for development, but when the developer is replenished to the hopper, the developer carrier is driven so that the developer in the hopper reaches the portion along the developer carrier of the developer carrier path. At the end of the replenishment of the developer, the replenished developer is conveyed to the position where it is supplied to the developer carrier, and the developer is developed without any special initialization operation or waiting time after the replenishment of the developer. Since the carrier is stably supplied for development, image formation can be started or restarted immediately after the developer is replenished, which is convenient for use.

At the developer replenishing stage, the developer to be replenished into the hopper can be conveyed and filled up to the portion along the developer carrier of the developer conveying path, so that a large amount of developer is replenished. Therefore, the developer replenishment interval in the developing device having the same capacity can be lengthened.

In each of the above cases, if a stirring member for stirring the developer is provided in the hopper and the stirring member and the developer transport body are interlocked with each other, the developer transport body can be operated at the stage of replenishing the developer. For driving, the stirring member in the hopper is also driven without any special drive source or operation to promote the transfer of the developer from the hopper to the developer transfer path and stabilize the transfer to the part along the developer carrier. In addition, the developing performance at the start or restart of image formation can be made sufficient. It is also possible to shorten the time required to convey the developer to the above-mentioned position and shorten the waiting time for image formation.

Further, the hopper is provided with a mounting port for mounting and demounting the developer replenishing container, means for detecting that the developer replenishing container has been mounted in the mounting port, and the developer transport body by the detection signal from the detecting means. Is provided for a predetermined time so that the developer in the hopper reaches the developer supply position to the developer carrier in the developer transport path, and the developer supply container is installed in the hopper. When the developer is replenished by being attached to the developer, the detection means detects this and the control means drives the developer transport body, so that the developer is transferred from the developer replenishing container to the hopper. Simultaneously with the replenishment of the developer, the developer replenished in the hopper is automatically sent out to the developer conveyance path and conveyed to the part along the developer carrier, no special operation is required and operation is forgotten. Or operation mistake It is possible to avoid a failure due.

Further, the developer replenishing container has an agitating member inside, and the rotating shaft of the agitating member of the developer replenishing container and the rotating shaft of the agitating member in the hopper are connected to the mounting opening of the hopper of the developer replenishing container. By providing a joint part that connects and disconnects each other by attachment and detachment, when the developer replenishment container is installed in the mounting opening of the hopper and the developer is replenished, the developer replenishment is performed without any special drive source or operation. The stirring member in the container is also driven at the same time, so that the transfer of the developer from the developer supply container to the hopper can be performed smoothly, and the developer supply time is shortened to shorten the waiting time for image formation. can do.

Further, the developer transport path is a circulation path for circulating the developer from the hopper via the supply position to the developer carrier, and the developer in the hopper is developed for a predetermined time for driving the developer transport body. When the time required to complete at least one round of the developer transport path is set, the replenishment developer in the hopper is transported until one round of the circulation path at the time of replenishment of the developer, and the entire developer transport path is set to the normal developer amount. Therefore, the developing performance can be further stabilized when the image formation is started or restarted.

In the case where the developer transport path is composed of a forward path for transporting the developer along the developer carrying member and a return path for transporting the developer which has passed through the forward path in the opposite direction, replenishment development in the hopper. Since it is possible to early convey the developer to the portion along the developer carrying member of the developer conveying path, it is possible to further shorten the waiting time for starting or resuming image formation.

[Brief description of drawings]

FIG. 1 is a perspective view of a developing device to which the present invention is applied.

FIG. 2 is a plan view of the developing device of FIG. 1 as seen in a horizontal cross section.

FIG. 3 is a plan view showing a part of the developing device of FIG. 1 on a hopper side.

FIG. 4 is a sectional view of a hopper portion of the developing device of FIG.

5 is a cross-sectional view of a part of the developing device of FIG. 1 on the hopper side as viewed in a vertical direction.

FIG. 6 is an overall schematic configuration diagram of an image forming apparatus having the developing device of FIG.

7 is a cross-sectional view showing an image forming unit of the image forming apparatus in FIG.

8 is a cross-sectional view showing an internal structure of a developer supply container used in the developing device of FIG.

9 is a block diagram of a drive control circuit of a developer transport body of the developing device of FIG.

FIG. 10 is a cross-sectional view showing an image forming unit of the image forming apparatus showing the second embodiment of the present invention.

[Explanation of reference numerals] 1 photoconductor drum 4 developing device 11 main body 20 stirring blade 20a rotating shaft 21 hopper 21c replenishing port 22 developer transport path 22a forward path 22b return path 23 developing field 24 developer transport body 25 collecting roller 41, 42 gear 43 Developer supply container 44 Rotating shaft 61 Developer supply port 71 Development sleeve 82 Drive mechanism 91 Stirring blade 95 Sensor 101 CPU

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

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[Figure 1]

[Procedure 3]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 6

[Correction method] Change

[Correction content]

[Figure 6]

[Procedure amendment 4]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 7

[Correction method] Change

[Correction content]

[Figure 7]

[Procedure Amendment 5]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 10

[Correction method] Change

[Correction content]

[Figure 10]

Claims (6)

[Claims] 1. A hopper for storing and supplying the developer so that the developer can be replenished, a developer transport path for transporting the developer from the hopper, and a developer transport path for transporting the developer on the developer transport path. A developer carrier for supplying the developer to the developer carrier is provided at a portion along the developer carrier, and when the developer is replenished to the hopper, the developer carrier is driven to remove the developer in the hopper. A developing device characterized in that it reaches at least a portion along a developer carrying member of a developer carrying path. 2. The developing device according to claim 1, wherein the hopper has a stirring member for stirring the developer, and the stirring member and the developer transport body are interlocked with each other. 3. A hopper is provided with a replenishing port for attaching and detaching the developer replenishing container, means for detecting that the developer replenishing container is attached to this replenishing port, and the developer transport by a detection signal from this detecting means. 3. A control means for driving the body for a predetermined time so that the developer in the hopper reaches at least a developer supply position of the developer carrying path to the developer carrying body. The developing device according to 1. 4. The developer replenishing container has an agitating member inside, and is provided on the revolving shaft of the agitating member of the developer replenishing container and the revolving shaft of the agitating member in the hopper to the replenishing port of the hopper of the developer replenishing container. The developing device according to any one of claims 1 to 3, further comprising a joint portion that is connected to and disconnected from each other by attaching and detaching. 5. The developer carrying path is a circulating path for circulating the developer from the hopper via a supply position to the developer carrying member, and the developer in the hopper is driven for a predetermined time for driving the developer carrying member. 5. The developing device according to claim 1, wherein is set to a time required to make at least one round of the developer transport path. 6. The developer carrying path according to claim 1, wherein the developer carrying path comprises a forward path for carrying the developer along the developer carrying member, and a backward path for carrying the developer in the opposite direction and returning the developer in the opposite direction. The developing device as described in 1.