JP2521666B2 - Development device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a developing device, and more particularly to a developing device having a developer recovery section.

(Prior Art) As is well known, the electrostatic latent image formed on an image bearing member such as a photoconductor is subjected to visible image processing by a developing device.

A magnetic brush developing device is one of the developing devices used for such visible image processing.
A developing roller for forming a magnetic brush that faces the photoconductor in the casing, and a paddle wheel located below the developing roller and agitating the developer in the casing while drawing up the charged developer to the developing roller. A doctor that regulates the layer thickness of the developer adhering to the surface of the developing sleeve that is drawn up by the paddle wheel, and a collecting blade that scrapes off the developer remaining on the developing roller after the visualization process. I have it.

By the way, the developer used in such a developing device undergoes a change with time during use, and the characteristics required in the developing process such as electric resistance, polarity, charge amount, dielectric constant and magnetic characteristic of toner particles are not obtained. In such a case, the developer is collected because it deteriorates.

Therefore, conventionally, for example, a shutter for opening and closing the opening is provided in the opening formed in the bottom of the casing,
At the time of collecting the developer, a structure is provided in which a tray for the developer is arranged below the opening, the shutter is opened, and the paddle wheel for stirring is rotated to drop the developer on the tray (for example, JP-A-57-94764). Gazette) or a reservoir for collecting the collected developer is formed at the bottom of the casing, a conveying screw rotating in the container is provided, and a dedicated collecting bottle is attached to the developer discharging side of the storing part. A structure has been used in which the transport screw is manually rotated to transport the developer in the storage section toward the recovery bottle.

However, in such a structure, the developer is naturally dropped or collected by manual operation, so it takes time to collect the developer, and when the developer is dropped, the peripheral portion of the developing device is contaminated due to scattering of the developer. Further, since a dedicated tray or a collection bottle is required, there is a problem that the developing device becomes large because a space for installing these is required.

(Purpose) In view of the problems of the conventional developing device, the purpose of the present invention is to be able to finish the recovery of the developer in a relatively short time, to prevent the scattering of the developer at the time of recovery, and to use a dedicated tray or recovery. There is a need for a developing device in which a space for installing a bottle is unnecessary and the device itself can be downsized.

(Structure) In order to achieve the above object, the present invention provides a developer carrier for forming a magnetic brush that faces a latent image carrier, and a developer carrier that is positioned below the developer carrier and is driven to rotate. In a developing device including a stirring member that stirs a developer, and a casing that can accommodate the developer carrying member and the stirring member, a collecting space formed at the lowest position in the casing, and the collecting space. A developer that can be conveyed along the axial direction of the stirring member in the working space and rotatably and axially movably supported to the discharge side of the developer in the collecting space; A lid body is provided at an axially non-end portion corresponding to the developer discharge side in the recovery space, the lid being capable of opening and closing the developer discharge side in the recovery space in association with the movement in the axial direction. Present A developer collecting device mainly including an image agent conveying member is provided, and the developer conveying member keeps the installation state of the developing device, and the collecting space according to the moving position in the axial direction. Is set to rotate so as to convey the developer toward the discharge side of the collecting space, and the driving position that opens the lid from the discharge side of the collecting space, and convey the developer toward the discharging side of the collecting space. Instead, the discharge side of the recovery space can be selected as a non-driving position in which the cover is closed.

According to the present invention, the developer discharging side of the collecting space can be opened and closed by the lid according to the axial movement position of the developer transport member, and the developing device is set to the copying machine at the time when the drive position is set. The developer transport member can be discharged on the developer discharge side in the recovery space while being installed in the main body.

Hereinafter, details of the embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a sectional view of a developing device according to the present invention. In FIG. 1, a casing 1 is opened at a position facing the photosensitive drum D, and a partition wall 2 provided inside the casing 1 develops a developing tank.
It is divided into 1A and replenishment tank 1B.

Then, in the developing tank 1A, a magnetic brush developing roller 3 which is a developer carrying member for carrying the developer facing the photoconductor drum D inside the opening, and a developer stirring member located under the developing roller 3 Paddle wheel 4 which is a developer stirring member, a doctor 5 which is located on the upstream side of the photosensitive drum D in the rotation direction of the developing roller 3 in the rotation direction of the developing roller 3 and regulates the layer thickness of the developer, although not shown. Equipped with a density sensor that detects the developer density.

Further, in the replenishment tank 1B, a replenishment developer falling from the replenishment tank T mounted on the replenishment tank 1B, in this case, a bridge phenomenon of powder toner is prevented, and an agitator 6 for charging by agitation and replenishment It is equipped with a rotatable replenishing roller 7 located at the communicating portion between the tank 1B and the developing layer 1A.

On the other hand, in the lowermost part of the casing 1 on the side of the developing tank 1A, at a position corresponding to the lower part of the paddle wheel 4, a developer collecting chamber 8 having a space constituted by a peripheral wall 8a forming a cylinder and communicating with the developing tank 1A. Is provided.

As shown in FIG. 2, the peripheral wall 8a forming the recovery chamber 8 has both longitudinal ends fixed to the end wall 1A1 of the casing 1, and one end of the peripheral wall 8a communicates with the recovery chamber 8. The end pipe 1A1 corresponds to the recovery pipe 9 having a space. The recovery pipe 9 is located on the developer discharge side in the recovery chamber 8, one end in the longitudinal direction is fixed to the end wall 1A1 of the casing 1, and the introduction pipe 11 is connected to the other end in the longitudinal direction via an elbow 10. Has been done. As shown in FIG. 5, the introduction pipe 11 is connected to a waste developer tank 12 corresponding to a developer accommodating member that accommodates the recovered developer. The elbow 10 in this case is configured as a guide member for guiding the developer collected between the recovery pipe 9 and the waste developer tank 12.

By the way, inside the recovery chamber 8 described above, a developer recovery device 13 whose longitudinal direction is the axial direction is provided.

That is, the developer collecting device 13 is, as shown in FIG.
The casing 1 is provided with a shaft 13A penetrating one of the end walls 1A1 and parallel to the axial direction of the paddle wheel 4, and the shaft 13A is cantilevered by being inserted into a sealing material 14 mounted on the end wall 1A1. And, it is rotatably supported.

The shaft 13A is movable in the axial direction, and a driven gear 15 capable of meshing with the drive gear 4A of the paddle wheel 4 is fixed at a position projecting leftward from the end wall 1A1 in the figure. The driven gear 15 and the end wall 1A1 The driven gear 15 is normally biased via the driven gear 15 so as not to mesh with the drive gear 4A by the compression spring 17 located between the driven gear 15 and the retainer 16 therein.

A downward L-shaped operation handle 18 is fitted and screwed at the end of the shaft 13A on the side having the driven gear 15. The shaft 13A is fixed with a spiral blade 19 as a developer carrying member on the peripheral surface of the recovery chamber 8 and the end of the recovery pipe 9, and the end corresponding to the axial end of the recovery pipe 9. Further, a lid 20 having a size capable of closing the recovery pipe 9 is screwed.

Therefore, this shaft 13A is normally driven by the compression spring 17 to drive the drive gear 4A of the paddle wheel 4 as shown in FIG.
And the driven gear 15 do not mesh with each other and the lid 20
Is set to a position in which the opening of the recovery pipe 9 is closed and closed (hereinafter, this position is referred to as a non-driving position).

On the other hand, the operation handle 18 has the shaft 13 as shown in FIG. 4 in which the driven gear 15 meshes with the drive gear 4A.
It has an angular shaft 18a into which A is inserted, and a gripping part 18b that hangs down at the end of the angular shaft. A position control member 21 laterally corresponds to the angular shaft 18a.

That is, as shown in FIG. 4, the position control member 21 includes a stud 21A fixed upright to the end wall 1A1 (see FIG. 2) and a collar 21B formed on the stud 21A.
And a side wall 1A1 and a control plate 21C sandwiched between the side wall 1A1 and slidably supported in a direction crossing the angular axis 18a, and hung on the stud 21A and a bent piece of the control plate 21C. The tension spring 21D urges the forked portion formed at the tip to enter the upper and lower surfaces of the square shaft 18a.

The square shaft 18a surface on which the forked portion of the control plate 21C enters the control board 21C is Yes and slit 18a1 to be fitted is formed, the slits 18a ₁ is against the bias of the compression spring 17 The shaft 13A is held in a drive state in which the driven gear 15 meshes with the drive gear 4A (hereinafter, this state is referred to as a drive state).

Then, in the movement path of the grip portion 18b of the operation handle 18,
Sensor S for detecting that the control plate 21C is engaged with respect to the slit 18a ₁ Yes and is provided, the sensor S is connected to a drive circuit for driving the gear 4A paddle wheel 4 (not shown).

In FIG. 4, reference numeral 22 is a guide plate fixed to the end wall 1A1 at a position opposed to the control plate 21C.

Since the present embodiment has the above-described structure, when the developer is not collected, the shaft 13A disengages the driven gear 15 and the drive gear 4A from each other by the biasing force of the compression spring 17, as shown in the second illustration. Since it moves in the direction, the developer collecting device 13 from the drive gear 4A
The drive is not transmitted to the spiral blade 19, and the end of the recovery pipe 9 is closed by the lid 20 provided on the shaft 13A to set the non-drive state. Therefore, the developer in the developing tank 1A is stored in the recovery chamber 8 but is not recovered.

On the other hand, at the time of the developer collection, the operating handle 18, the control plate 21C of the position control member 21 against the bias of the compression spring 17 is engaged with the slit 18a ₁ of the square shaft 18a by pushing up and latched.

Then, as shown in FIG. 3, the lid 20 having the shaft 13A is provided.
By projecting into the elbow 10, the axial end of the recovery pipe 9 is opened, and the driven gear 15 meshes with the drive gear 4A to set the drive position. A drive transmission path is formed here from the paddle wheel side to the developer collecting device 13. At this time, the grip 18b of the operating handle 18
Corresponds to the sensor S, the rotation start control of the drive gear 4A is performed via this sensor S. Therefore, the spiral blade 19 of the developer recovery device 13 rotates to transfer the developer in the recovery chamber 8 toward the end of the recovery pipe 9,
Here, the developer is supplied to the waste developer tank through the introduction pipe 11.
Recovered to 12.

Further, when it is desired to stop the developer collecting state or when the state is finished, the control plate 21C (see FIG. 4) of the position control member 21 is pulled against the bias of the tension spring 21D. The shaft 13A to the second position by the biasing of the compression spring 17.
Return to the position shown.

(Effect) As is apparent from the above description, according to the present invention, the developer discharge side of the recovery space can be opened and closed by the lid according to the moving position of the developer transport member in the axial direction, When the drive position is set, the developer transport member can be discharged on the developer discharge side in the recovery space with the developing device installed in the main body of the copying machine. Since the developer can be discharged on the developer discharge side of the recovery space corresponding to the axially non-end portion of the developer carrying member, the developer is relatively short without being scattered during the carrying process. The developer can be collected in a time, and the installation space for the tray, the collection bottle, and the like can be eliminated, so that the apparatus itself can be downsized.

Further, since the operator can directly perform the operation for driving the recovery device at the time of recovery and at the time of non-recovery, erroneous operations can be reduced and the device can be downsized by the amount that no special clutch is required.

[Brief description of drawings]

FIG. 1 is a sectional view of a developing device according to the present invention, FIGS. 2 and 3 are sectional views of essential parts of the developing device according to the present invention, FIG. 4 is a perspective view of essential parts of the developing device according to the present invention, and FIG. FIG. 3 is an explanatory diagram of a developing device according to the invention. 1 ... Casing, 3 ... Development roller, 4 ... Paddle wheel, 4A ... Drive gear, 8 ... Collection chamber, 13 ... Developer collection device, 13A ... Shaft, 15 ... Driven gear, 17 ... … Compression spring, 18 …… Operating handle, 19 …… Spiral blade, 20
...... Lid, 21 ...... Position control member.

Claims (1)

(57) [Claims] 1. A developer carrying member for forming a magnetic brush, which faces the latent image carrying member, a stirring member located below the developer carrying member and stirring the developer by being rotationally driven, In a developing device including a developer carrier and a casing capable of accommodating the stirring member, a collecting space formed at a lowermost position of the casing, and an axial direction of the stirring member in the collecting space. Along which the developer can be conveyed toward the developer discharge side in the recovery space and is supported rotatably and axially movable, and discharge of the developer in the recovery space. And a developer conveying member provided with a lid body capable of opening and closing the discharge side of the developer in the collecting space in conjunction with the axial movement at the axially non-end portion corresponding to the side. Present The developer transporting device includes a developer transporting member, and the developer transporting member is configured to rotate the developer transporting member to transport the developer toward the discharge side of the recovery space according to the axial movement position while maintaining the installed state of the developing device. And a drive position for opening the lid from the discharge side of the recovery space, and the discharge side of the recovery space without conveying the developer toward the discharge side of the recovery space. A developing device, which can be selected from a non-driving position in which the body is closed.