JP2001083788A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To almost perfectly prevent a leakage of toner, at the attaching/ detaching time of the toner cartridge to/from a developing device. SOLUTION: This developing device, is provided with a development housing 4a, the toner injecting mouse 4c formed on the development housing 4c, a shutter 25 for opening/closing the toner injecting mouse, and a guide rail 24 holding both side ends of the shutter in free sliding, and moreover a step part 24b formed on an inside surface of the guide rail so that a gap between the inside surface of the guide rail and the developing housing becomes narrower at the toner injection side, and furthermore, an elastic member 27 being tightly fixed to the inside surface of the above guide rail.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile or the like using an electrophotographic method, and more particularly to a developing device for supplying a replacement toner to a developing device.

[0002]

2. Description of the Related Art In an image forming apparatus of the above-mentioned type, an image carrier such as a photoreceptor which is driven to rotate, a latent image forming means for sequentially forming an electrostatic latent image on the photoreceptor, The image forming apparatus includes developing means for developing the image into a toner image, and a transfer device for transferring the toner images of a plurality of colors on the photoreceptor to a recording medium.

Conventionally, the above-mentioned developing device includes a developing device having a developing roller in contact with a photoreceptor and a toner cartridge detachably mounted on the developing device and supplying toner to the developing device. For example, JP-A-2-28
No. 7476 proposes providing a movable shutter on a toner cartridge and opening and closing the movable shutter to prevent leakage of toner when the toner cartridge is attached to or detached from a developing device.

[0004]

However, in the above-mentioned conventional developing device, since the toner supply port on the developing device side is always open, toner leaks when the toner cartridge is attached to or detached from the developing device, so that the user's hand may be damaged. And the clothes are stained, and the user's finger enters the toner supply port, and the toner is stained. Further, when the developing unit is replaced during its life, the developing unit is transported for recycling, but there is a problem that the toner leaks due to vibration during transportation.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a developing device capable of almost completely preventing leakage of toner when a toner cartridge is attached to or detached from a developing device. And

[0006]

For this purpose, a developing device according to the present invention comprises a developing housing, a toner inlet formed in the developing housing, a shutter for opening and closing the toner inlet, and both ends of the shutter. A guide rail that is slidably held, a step formed on the inner surface of the guide rail so that the distance between the inner surface of the guide rail and the developing housing becomes smaller on the toner injection port side, and fixed to the inner surface of the guide rail. And an elastic member provided.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram showing an example of an image forming apparatus to which the present invention is applied. Although this image forming apparatus is a color electrophotographic printer capable of forming a full-color image with four color toners, the present invention is not limited to this, and a toner image is formed on an image carrier such as a photoconductor. The present invention can be applied to all image forming apparatuses of a forming method.

The photoreceptor 1 has a thin cylindrical conductive substrate and a photosensitive layer formed on the surface thereof, and is driven to rotate in a direction indicated by an arrow by a driving means (not shown). Around the photosensitive member 1, along a rotating direction thereof, a charging roller 2 as a charging unit, an exposure unit 3 for forming an electrostatic latent image on the photosensitive member 1, and a developing unit for developing the electrostatic latent image. Developing unit 4, an intermediate transfer device 5 for transferring the toner image formed on the photoconductor 1 onto the intermediate transfer belt 7,
A photoreceptor cleaning device 6 for removing the toner remaining on the top is disposed.

The developing unit 4 includes a developing unit 4 for yellow.
The developing unit includes a developing unit 4C for Y, cyan, a developing unit 4M for magenta, and a developing unit 4K for black. Each developing unit includes a developing roller 4b disposed in a developing housing 4a. These developing units 4Y, 4C, 4M, and 4K are arranged so as to be swingable with respect to the photoconductor 1, and each of the developing units 4Y, 4C, 4M, and 4K is selectively rotated by one rotation of the photoconductor 1.
Only the photosensitive member 1 can be contacted.

The intermediate transfer device 5 comprises a drive roller 9 for running the intermediate transfer belt 7, a backup roller 10 for primary transfer, a backup roller 11 for secondary transfer, and the like. An intermediate transfer belt 7 is stretched. The intermediate transfer belt 7 is urged toward the photoconductor 1 by a primary transfer backup roller 10, where a primary transfer portion T1 is formed. Further, a secondary transfer roller 12 is opposed to the secondary transfer backup roller 11 with the intermediate transfer belt 7 interposed therebetween.
Here, a secondary transfer portion T2 is formed.

The operation of the image forming apparatus having the above configuration will be described. When an image forming signal is input from a computer (not shown), the photosensitive member 1, the developing rollers 4b of the developing unit 4, and the intermediate transfer belt 7 are driven to rotate. First, the outer peripheral surface of the photoconductor 1 is uniformly charged by the charging roller 2, and the outer peripheral surface of the uniformly charged photoconductor 1 is
The exposure unit 3 performs selective exposure L in accordance with the image information of the first color (for example, yellow) to form a yellow electrostatic latent image.

Only the developing roller 4b of the yellow developing unit 4Y comes into contact with the photoconductor 1, whereby a toner image of a yellow electrostatic latent image is formed on the photoconductor 1. A primary transfer voltage having a polarity opposite to the charge polarity of the toner is applied to the intermediate transfer belt 7, and the toner image formed on the photoconductor 1 is
The image is transferred onto the intermediate transfer belt 7 in the primary transfer section T1. After the toner remaining on the photoreceptor 1 is removed by the photoreceptor cleaning device 6, the outer peripheral surface of the photoreceptor 1 is discharged by a discharger (not shown).

The above operation is repeated for the second, third, and fourth colors of the image forming signal, and the latent image formation and development by one rotation of the photosensitive member 1 and the intermediate transfer belt 7 are repeated. Four color toner images corresponding to the contents of the formation signal are superimposed and transferred on the intermediate transfer belt 7. Then, at the timing when this full-color image reaches the secondary transfer portion T2, the sheet S is supplied to the secondary transfer portion T2 from the direction of the arrow, and at this time, the transfer roller 12
And a secondary transfer voltage is applied to transfer the full-color toner image on the intermediate transfer belt 7 onto the recording medium S.

The toner cartridge 13 according to the present invention can be detachably mounted on the developing housing 4a of the developing device 4Y. The other developing units 4C, 4C
The same applies to M and 4K. Toner cartridge 1
3 includes a case body 13a and a toner outlet 13b formed in the case body 13a.
When the toner cartridge 3 is mounted on the developing housing 4a, the toner is supplied from the toner outlet 13b to the toner supply port 4c of the developing housing 4a. In the case main body 13a, the rotary transport member 14 is disposed on the upstream side, and the rotary compression member 15 is disposed on the downstream side.

FIG. 2A is a horizontal sectional view of the toner cartridge of FIG. 1, FIG. 2B is a view of the rotary compression member of FIG. 2A viewed from the direction B, and FIG. CC of 2 (A)
It is sectional drawing which follows a line.

FIG. 2 shows the case body 13 described with reference to FIG.
a, a toner discharge port 13b, a rotary transport member 14, and a rotary compression member 15 provided at the center of the case body 13a. A projection 13c is provided at the bottom of the case body 13a.
The case body 13 a is designed such that the cross-sectional area on the side of the rotary conveying member 14 is larger than the cross-sectional area of the rotary compression member 15.

The rotary transport member 14 includes a rotary shaft 14a rotatably supported by the case body 13a, and a plurality of plate-shaped transport plates 14b fixed to the rotary shaft 14a. The rotary compression member 15 is rotatably supported by the case body 13a, a delivery member 15b fixed to the rotation shaft 15a so as to face the toner discharge port 13b, and rotates on both sides of the delivery plate 15b. The shaft 15a is provided with a compression blade 15c integrally formed of resin.

The delivery member 15b includes a rotating shaft 15a.
, The horizontal plate 15d is supported at intervals of 90 ° by rods 15e, and the compression blades 15c are structured such that semi-circular plates are alternately inclined and connected to the rotating shaft 15a. . Rotary transport member 14 and rotary compression member 1
A spherical portion 16 is formed at one end of each of the rotary shafts 14a and 15a, and the spherical portion 16 is pivotally supported by a bearing 1d formed on the case body 13a. A driven gear (see FIG. 3) is connected. Since the spherical portion 16 contacts the bearing portion 1d at a point, the torque acting on the rotating shafts 14a and 15a can be reduced.

The toner filled in the toner cartridge 13 is transported to the rotary compression member 15 by the transport plate 14b of the rotary transport member 14, and the toner is transferred to both members 14, 1
5, the toner is compressed and moved toward the center by the action of the compression blades 15c on both sides of the rotary compression member 15, and is discharged from the toner discharge port 13b by the delivery member 15b to the developing device 4Y side. Is supplied to the toner injection port 4c. As a result, the amount of toner scraped off by one rotation of the rotary compression member 15 increases, and since the toner is compressed, the contact area with air decreases, and the toner is not affected by humidity, and a stable toner discharge amount can be obtained. Can be

FIG. 3 is a side view of the developing device 4Y and the toner cartridge 13 shown in FIG. Driven gears 17 and 18 are connected to the ends of the rotating shafts 14a and 15a of the rotary transport member 14 and the rotary compression member 15, respectively. The driven gears 17 and 18 are meshed with a drive gear 19, and the toner cartridge 13 Is mounted on the developing device 4Y, the driven gear 18 is meshed with the driving gear 20 on the developing device 4Y side, whereby the rotation of the driving gear 19 is transmitted to the gears 17, 18, and 20. . The drive gear 20 on the side of the developing device 4Y rotates a conveying member that conveys the toner in the developing device. Rotary shaft 1 of rotary compression member 15
Since the toner cartridge 5a is formed of a flexible resin, when the toner cartridge 13 is mounted on the developing device 4Y, the driven gear 18
When the drive gear 20 and the drive gear 20 do not mesh with each other, the rotation shaft 15a escapes to facilitate the meshing of the two gears.

Next, an embodiment of the developing device of the present invention will be described with reference to FIGS. In the following description, the same components are denoted by the same reference numerals in each drawing, and the description may be omitted.

FIG. 4A is a sectional view of the toner cartridge, and FIG. 4B is a front view. A toner outlet 13b is formed on the front surface of the case body 13a, and guide rails 21 are provided on both left and right sides of the toner outlet 13b. A shutter 22 on the cartridge side is slidable between the guide rails 21. It is arranged in. Further, a pair of shutter engaging pieces 23 is formed below the shutter 22 on the cartridge side.

FIG. 5A is a sectional view of the developing device, and FIG.
5 is a front view, and FIG. 5C is a cross-sectional view taken along line CC of FIG. 5B and viewed in the direction of the arrow. A toner inlet 4c is formed on the rear surface of the developing housing 4a, and guide rails 24 are provided on both left and right sides of the toner inlet 4c.
5 is slidably disposed. A pair of shutter engagement pieces 26 is formed above the developing device side shutter 25. In FIG. 5C, the guide rail 24 includes:
Mounting pieces 24 a are formed on the upper and lower sides and are mounted on the developing housing 4. Further, a step portion 24b is formed on the inner surface of the guide rail 24, so that the distance between the inner surface of the guide rail 24 and the developing housing 4a is reduced by the toner injection port 4c.
It is formed so as to be narrow on the side. An elastic member 27 is adhered to the inner surface of the guide rail 24.

FIG. 6 is a diagram for explaining the operation of attaching and detaching the toner cartridge having the above-mentioned structure to and from the developing device.
FIG. 6A shows a state in which the toner cartridge 13 shown in FIG. 4A is attached to the developing device 4Y shown in FIG. 5A. In this state, the toner discharge port on the cartridge side is shown. 13b is closed by a shutter 22 on the cartridge side, and the toner injection port 4c on the developing unit side is closed by a shutter 25 on the developing unit side. The toner outlet 13b is located above the toner inlet 4c.
b and the toner injection port 4c are configured not to overlap. The shutter 22 on the cartridge side
Are engaged with a shutter engaging piece 26 on the developing device side, and upper and lower portions of the shutter 25 on the developing device are engaged with the shutter engaging piece 23 on the cartridge side.

When the case body 13a is rotated from the above state in the direction of arrow B in the figure, as shown in FIG. 6B, the shutter 22 on the cartridge side is held by the shutter engaging piece 26 on the developing device side. The toner discharge port 13b moves downward from above and moves below the shutter 22 on the cartridge side, and the shutter 25 on the developing device is moved below the toner injection port 4c by the shutter engaging piece 23 on the cartridge side. To move, the toner outlet 13b and the toner inlet 4
c is opened and communicated.

When the case body 13a is rotated from the state shown in FIG.
As shown in (A), the toner outlet 13b moves toward the shutter 22 on the cartridge side, and the shutter 25 on the developing device moves in the direction to close the toner inlet 4c with the shutter engaging piece 23 on the cartridge side. Because of the movement, the toner outlet 13b and the toner inlet 4c are closed. At this time, as shown in FIG. 5C, a step portion 24b is formed on the inner surface of the guide rail 24, and thereby the guide rail 2 is formed.
The gap between the inner surface of the developing unit 4 and the developing housing 4a is formed to be narrower on the side of the toner inlet 4c, and the elastic member 27 is adhered to the inner surface of the guide rail 24. When closing the toner injection port 4c,
The compressibility of the elastic member 27 changes and the shutter 25 is strongly pressed, so that toner leakage can be prevented. Further, when the shutter 25 is opened, the compressibility of the elastic member 27 is weakened, and the opening operation can be easily performed.

Although the embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made. For example, in the above embodiment, a step is provided on the guide rail on the developing device side, but a step may be provided on the guide rail on the toner cartridge side.

[0028]

As is apparent from the above description, according to the present invention, since the shutter can be strongly pressed by the elastic member, the toner does not spill out from the developing device, and the user's hands become dirty and the inside of the machine becomes dirty. Toner scattering is reduced, and leakage of toner can be almost completely prevented when the toner cartridge is attached to or detached from the developing device. Further, when the shutter is closed, the compressibility of the elastic member is strong, and when the shutter is opened, the compressibility is weak.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram illustrating an example of an image forming apparatus to which the present invention is applied.

2 (A) is a horizontal sectional view of the toner cartridge of FIG. 1, FIG. 2 (B) is a view of the rotary compression member of FIG. 2 (A) viewed from a direction B, and FIG. It is sectional drawing which follows CC line of 2 (A).

FIG. 3 is a side view of the developing device 4Y and the toner cartridge 13 of FIG.

FIG. 4 shows an embodiment of the developing device of the present invention, and FIG.
4A is a sectional view of the toner cartridge, and FIG. 4B is a front view.

5 shows an embodiment of the developing device of the present invention, and FIG.
5A is a cross-sectional view of the developing device, FIG. 5B is a front view, and FIG.
FIG. 5C is a sectional view taken along line CC of FIG. 5B and viewed in the direction of the arrow.

FIG. 6 is a view for explaining an attaching / detaching operation of the toner cartridge according to the present invention.

[Explanation of symbols]

 4Y: developing unit 4a: developing housing 4c: toner inlet 13: toner cartridge 13b: toner outlet 22, 25: shutter 21, 24: guide rail 23, 26: shutter engaging piece 27: elastic member

Claims (2)

[Claims] 1. A developing housing, a toner inlet formed in the developing housing, a shutter for opening and closing the toner inlet, a guide rail slidably holding both ends of the shutter, and the guide rail. A step formed on the inner surface of the guide rail so that the distance between the inner surface of the developing rail and the developing housing becomes smaller on the side of the toner injection port; and an elastic member fixed to the inner surface of the guide rail. Developing device. 2. A toner injection port provided on a developing device side, a shutter for opening and closing the toner injection port, and a shutter engaging piece;
A toner outlet provided on the toner cartridge side, a shutter for opening and closing the toner outlet, and a shutter engaging piece; the shutter on the developing device side and the shutter on the cartridge side are respectively connected to the shutter engaging piece on the cartridge side and the developing device side; A guide rail that slidably holds both ends of the shutter, wherein the developing device holds the shutter engaging piece and opens and closes a toner outlet and a toner inlet by rotating the toner cartridge. A step formed on the inner surface of the guide rail so that the distance between the inner surface of the guide rail and the developing housing becomes smaller on the toner injection port side; and an elastic member fixed to the inner surface of the guide rail. Characteristic developing device.