Developer cartridge having a spirally-formed feeding member mounted in a cylindrical member and method of manufacturing the same

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a developing cartridge used in an image forming apparatus such as a printer apparatus, a copying machine, a facsimile machine or the like to which an electrophotographic system is applied, and more particularly to a developer cartridge having a spirally-formed feeding member mounted in a cylindrical member.

2. Description of the Related Art

In a conventional image forming apparatus, such as a full color printer apparatus or the like, to which an electrophotographic system is applied, normally three developers for developing electrostatic latent images with three primary color developers of Y (yellow), M (magenta) and C (cyan), preferably four developers containing the above three developers and a black color developer for developing an electrostatic latent image with black (K) developer are mounted so that one of these plural color developers is selectively disposed in the neighborhood of an electrostatic latent image carrier or each of these plural developers is disposed in the neighborhood of each of plural electrostatic latent image carriers corresponding to the respective color developers, and an electrostatic latent image formed on the single electrostatic latent image carrier or electrostatic latent images formed on the plural electrostatic latent image carrier are successively visualized by the corresponding color developers, thereby forming a full color image.

When attributing importance to the compact size of the apparatus or reduction of the cost of the apparatus in the above full color image forming apparatus, though an image forming speed slows down a little, the method of selectively disposing one of the plural developers in the neighborhood of the single electrostatic latent image carrier is adopted. The inventors of this application have tackled to implement such an image forming apparatus that a rotator having four developers disposed along the peripheral direction thereof is rotatably disposed, and when an electrostatic latent image formed on an electrostatic latent image carrier is developed by each developer, the rotator is rotated so that a desired color developer is disposed so as to confront the electrostatic latent image carrier.

In a full color image forming apparatus being considered by the inventors, a system using a toner cartridge is adopted to supplement toner to each developer. The toner cartridge is detachably mounted in the developer, and it is designed so that an operator of the image forming apparatus replaces a toner cartridge with a new one when all the toner in the toner cartridge concerned is consumed.

As the toner cartridge as described above is proposed a toner cartridge using a so-called “trickle developing system” which is called by the inventors of this application and in which developer containing at least toner is supplied from the toner cartridge concerned to the developer and deteriorated developer is withdrawn from the developer into the toner cartridge little by little. This type toner cartridge using the trickle developing system has been introduced into actual machines.

In the toner cartridge using the “trickle developing system”, a withdrawing unit for stocking old developer thus withdrawn is disposed at the end portion of the toner cartridge concerned. This toner cartridge is generally designed so that a rotational fixing portion of an agitator for supplying new developer is provided at a toner cap side in order to minimize the volume of the withdrawing portion for the old developer and increase the volume of the stock portion for the new developer.

However, the above conventional technique has the following problems. That is, in the case of the conventional toner cartridge as described above, the rotational fixing portion of the agitator for supplying new developer is provided at the toner cap side, and thus after developer containing at least toner is filled into the toner cartridge, the agitator which has been mounted in the toner cartridge must be fitted to the driving portion of the toner cap at the same time when the toner cap is mounted into the main body of the toner cartridge, so that it is very difficult to perform a toner cap mount work.

Furthermore, in the case of the above conventional toner cartridge, when toner is filled into the toner cartridge in such a state that the agitator is disposed in the toner cartridge, air is contaminated into toner to reduce the apparent density of the toner and thus reduce the substantial toner fill amount per unit time, so that the working efficiency of filling the toner into the toner cartridge is reduced.

Still furthermore, in the case of the above conventional toner cartridge, a so-called one-side supported type toner cartridge in which an agitator for feeding toner is supported only at the toner cap side is used. In this case, in connection with recent requirements of enhancing image quality and designing the apparatus in compact size, the toner particle size is reduced and toner containing wax which enables elimination of oil as separating agent in the fixer is used. In this case, there may occur such a problem that the toner particles aggregate together to form lumps of toner due to the slight rubbing between the agitator and the inner wall of the toner cartridge, and these lumps of toner are developed to induce degradation of image quality.

In addition, in the case of a toner cartridge using a so-called one-side supported type agitator, the rotational torque for rotating the agitator is increased due to the rubbing between the agitator and the inner wall of the toner cartridge, the eccentric rotation of the agitator or the like, so that a driving device for rotating the agitator must be designed in large size.

Therefore, in order to solve the above problems, it may be considered that a so-called double-side supported type agitator in which both the end portions of an agitator are supported is used in place of the so-called one-side supported type agitator.

However, even when the double-side supported type agitator is used, there is still such a problem that the center portion of the agitator may interfere in the inner wall of the toner cartridge due to warp caused by the agitator's own weight, warp caused by the press force of the toner particles, or warp caused by centrifugal force occurring during rotation or at acceleration occurring at the stop time of the rotation in the case of a rotational type developing apparatus.

Furthermore, in order to enhance the fill efficiency of the toner, it is necessary to mount an agitator in a toner cartridge after toner is filled in the toner cartridge. However, in this case, it is required that the agitator is mounted in the toner cartridge after the toner is filled in the toner cartridge, and also the tip portion of the agitator is fitted into the bearing portion. According, there is such a problem that the tip portion of the agitator may not be surely fitted into the bearing portion due to a failure of fitting, and thus a defective toner cartridge is liable to be produced.

In addition, when the agitator is mounted after the toner is filled in the toner cartridge, there occurs such a new problem that the toner is trapped at the bearing portion in the toner cartridge and thus the agitator cannot be inserted into the bearing portion.

Furthermore, in order to avoid the trap of the toner at the bearing portion, it is considered that a toner escaping hole is provided to the bearing portion. However, if the position of the toner escaping hole is improper, the toner rather invades into the bearing portion, and lumps of toner are formed in the bearing portion by rotation of the agitator shaft. The lumps of toner thus formed in the bearing portion leak from the escaping hole, and induce defects in image quality.

Still furthermore, in the case of the so-called double-side supported type agitator, when the agitator is mounted after the toner is filled in the toner cartridge, there occurs such a new problem that it cannot be judged by a visual check or the like whether the shaft portion of the agitator is normally fitted into the bearing portion in the toner cartridge.

SUMMARY OF THE INVENTION

In view of the above circumstances, the present invention aims to provide a developer cartridge in which developer containing at least toner can be efficiently filled.

The present invention also aims to provide a developer cartridge which enables a mount work of a cap member to be easily performed even when the developer cartridge is designed so that a feeding member is mounted in the developer cartridge after developer containing at least toner is filled in the developer cartridge.

The present invention also aims to provide a developer cartridge which can surely prevent a feeding member and the inner wall of a developer cartridge from being rubbed against each other even when the particle diameter of toner is reduced or toner containing wax is used, thereby preventing the image quality from being degraded due to agglomerated toner.

The present invention also aims to provide a developer cartridge which can avoid a driving device for rotating a feeding member from being designed in large size.

The present invention also aims to provide a developer cartridge which can surely prevent the interference between a feeding member and the inner wall of the developer cartridge even when the feeding member is designed as a so-called double-side supported type.

The present invention also aims to provide a developer cartridge which can surely pivotally support the tip of the feeding member even when the feeding member is designed as a so-called double-side supported type.

The present invention also aims to provide a developer cartridge which can surely prevent toner particles from being newly agglomerated at the bearing portion of the feeding member even when the feeding member is designed as a so-called double-side supported type.

The present invention also aims to provide a developer cartridge which can easily check whether a feeding member is normally pivotally supported even when the feeding member is designed as a so-called double-side supported type.

That is, according to a first aspect of the present invention, there is provided a developer cartridge having a cylindrical member in which developer containing at least toner is stocked, a supply port opened in one end side of the cylindrical member and a spiral feeding member which is freely rotatably disposed in the cylindrical member, the feeding member being rotated to feed the developer stocked in the cylindrical member to the support port, characterized in that the feeding member is mounted in the cylindrical member after developer is filled in the cylindrical member.

According to a second aspect of the present invention, in the developer cartridge of the first aspect, one end portion of the feeding member is freely rotatably attached to a cap member for sealing the open end portion of the cylindrical member through which the developer is filled, and the feeding member is mounted in the cylindrical member while being attached to the cap member.

According to a third aspect of the present invention, in the developer cartridge of the first aspect, when the feeding member is mounted in the cylindrical member, the feeding member is inserted into the cylindrical member filled with the developer while being rotated.

According to a fourth aspect of the present invention, in the developer cartridge of the third aspect, the rotational direction of the feeding member is the same direction as the winding direction of the spiral of the feeding member.

According to a fifth aspect of the present invention, in the developer cartridge of the first aspect, the end portion of the feeding member located at the opposite side to the cap member is pivotally supported in the cylindrical member through a shaft member and a bearing member.

According to a sixth aspect of the present invention, in the developer cartridge of the fifth aspect, the tip portion of the shaft member fixed to the end portion of the feeding member is designed in a tapered shape, and the tip portion of the shaft member is designed to have an acute angle less than 90 degrees.

According to a seventh aspect of the present invention, in the developer cartridge of the fifth or sixth aspect, a developer discharging portion for discharging developer trapped in the bearing member when the shaft member is fitted into the bearing member is provided at the tip portion of the shaft member.

According to an eighth aspect of the present invention, in the developer cartridge of the fifth or sixth aspect of the present invention, a guide portion for guiding the shaft member into the bearing member is provided to the tip portion of the bearing member.

According to a ninth aspect of the present invention, in the developer cartridge of the fifth or sixth aspect of the present invention, a developer discharging portion for discharging developer trapped in the bearing member is provided to the bearing member when the shaft member is fitted into the bearing member.

According to a tenth aspect of the present invention, in the developer cartridge of the ninth aspect of the present invention, the developer discharging portion provided to the bearing member comprises plural opening portions formed along the axial direction on the inner surface of the bearing member.

According to an eleventh aspect of the present invention, in the developer cartridge of the tenth aspect of the present invention, the opening portions are not opened in the radial direction of the bearing member.

According to a twelfth aspect of the present invention, in the developer cartridge of the fifth aspect of the present invention, the feeding member is supported at both the end portions by a shaft, and is not brought into contact with the inner wall of the cylindrical member even when it is most warped.

According to a thirteenth aspect of the present invention, in the developer cartridge of the twelfth aspect of the present invention, the center portion of the feeding member in the axial direction is set to be smaller in diameter than both the end portions thereof.

According to a fourteenth aspect of the present invention, in the developer cartridge of the twelfth aspect of the present invention, the feeding member comprises a linear portion extending in the axial direction of the cylindrical member and a spiral portion which is provided spirally around the outer periphery of the linear portion, and the spiral portion is fixed to the linear portion at the center portion of the feeding member to prevent the spiral portion from being deformed.

According to a fifteenth aspect of the present invention, in the developer cartridge of the fifth aspect of the present invention, a shaft member is fixed to the tip of the feeding member, and the fixing force of the shaft member is set to such a level that the shaft member does not fall off the feeding member even when the shaft member is not fitted into the bearing member at the cylindrical member side and the feeding member is deformed.

According to a sixteenth aspect of the present invention, in the developer cartridge of the fifth aspect of the present invention, a shaft member is fixed to the tip of the feeding member, and there is provided a rotation stopping member for stopping the rotation of the feeding member when the shaft member is not fitted into the bearing member at the cylindrical member side.

According to a seventeenth aspect of the present invention, in the developer cartridge of the sixteenth aspect of the present invention, the bearing member is fixed to the tip of the feeding member and a through hole is formed inside the bearing member.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the present invention will be described in detail based on the following figures, wherein:

FIGS. 1A and 1B

show a developer cartridge according to a first embodiment of the present invention, wherein

FIG. 1B

is a side view of the developer cartridge and

FIG. 1A

is a longitudinal-sectional view taken along A—A line of

FIG. 1B

;

FIG. 2

is a diagram showing a full color printer apparatus to which the developer cartridge of the first embodiment is applied;

FIG. 3

is a diagram showing the construction of a rotary type developing apparatus to which the developer cartridge of the first embodiment is applied;

FIG. 4

is a perspective view showing the outlook of the developer cartridge of the first embodiment;

FIG. 5

is an exploded perspective view showing the developer cartridge of the first embodiment;

FIG. 6

is a front view showing the tip portion of a spiral agitator;

FIG. 7

is a front view showing the tip portion of the spiral agitator;

FIGS. 8A

to

8

C are front view, plan view and side view showing a shaft member which is attached to the spiral agitator;

FIG. 9

is a diagram showing an experiment condition and a graph showing experiment results;

FIG. 10

is a diagram showing a shaft member and a bearing member attached to the tip portion of a spiral auger;

FIG. 11

is a perspective view showing the shaft member and the bearing member attached to the tip portion of the spiral auger;

FIG. 12

is a longitudinally sectional view showing the construction of the developer cartridge and the spiral auger;

FIG. 13

is a diagram showing the state that the spiral auger is mounted after developer is filled in the developer cartridge;

FIG. 14

is a graph showing experiment results; and

FIG. 15

is a graph showing experiment results.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A preferred embodiment according to the present invention will be described hereunder with reference to the accompanying drawings.

[First Embodiment]

FIG. 2

shows a full color printer apparatus as an image forming apparatus to which a developer cartridge according to a first embodiment of the present invention is applied.

In

FIG. 2

, reference numeral

1

represents a photosensitive drum as an image carrier, and the photosensitive drum

1

is rotated at a predetermined speed along the direction indicated by an arrow

2

by a driving unit (not shown). The surface of the photosensitive drum is uniformly charged so as to be kept to a predetermined potential by a charging roll

3

, and then four color images of yellow (Y), magenta (M), cyan (C) and black (K) are successively exposed to light by an exposure device

4

formed of ROS (Raster Output Scanner) or the like to form electrostatic latent images corresponding to the respective colors if a full color image is formed. The predetermined color electrostatic latent images formed on the surface of the photosensitive drum

1

are respectively developed by corresponding developers

5

Y,

5

M,

5

C,

5

K of a rotary type developing apparatus

5

to form predetermined color toner images.

The rotary type developing apparatus

5

has the four color developers

5

Y,

5

M,

5

C,

5

K of yellow (Y), magenta (M), cyan (C), black (Y) to perform a full color developing operation, and the respective developers

5

Y,

5

M,

5

C,

5

K develop the latent images on the photosensitive drum

1

with yellow, magenta, cyan and black toner materials. When each color toner image is developed, the rotary type developing apparatus

5

is rotated in the direction indicated by an arrow R by a motor (not shown), and the corresponding one of the developers

5

Y,

5

M,

5

C and

5

K is located at a developing position at which the developer concerned confronts the photosensitive drum

1

. In a process control mode, a test chart is formed on the photosensitive drum

1

, and the density of the test chart is detected by a sensor

6

. Each color toner image developed on the photosensitive drum

1

is successively transferred onto an intermediate transfer belt

9

as an intermediate transfer medium by a primary transfer roll

7

, and finally four color toner images are transferred onto the intermediate transfer belt

9

while being superposed on one another.

The intermediate transfer belt

9

is rotatably suspended under tension by a driving roll

10

, an idle roll

11

, a backup roll

12

and an idle roll

13

. The driving roll

10

is driven by a driving motor having an excellent constant-speed driving performance (not shown), and it serves to rotate the intermediate transfer belt

9

at a predetermined speed.

The four color toner images which are superimposed on the intermediate transfer belt

9

are collectively transferred onto a recording sheet P as a recording medium by a secondary transfer roll

14

which is pressed against the recording sheet P through the backup roll

12

and the intermediate transfer belt

9

. The recording sheet P is supplied from any one of two sheet supply cassettes

16

,

17

provided at the lower portion of the printer apparatus by a sheet supply roll

18

or

19

, fed through plural feeding roll pairs

20

,

21

to a registration roll pair

22

and then temporarily stopped there. Thereafter, the registration roll pair

22

which starts its rotation in synchronism with the toner image transferred onto the intermediate transfer belt

9

feeds the recording sheet P to a secondary transfer position at which the backup roll

12

and the secondary transfer roll

14

are pressed against each other through the intermediate transfer belt

9

. After the four color toner images are collectively transferred from the surface of the intermediate transfer belt

9

onto the recording sheet at the secondary transfer position, the recording sheet P is subjected to a fixing treatment using heat and pressure in a fixer

23

, and discharged to a discharge tray

24

at the side surface of the main body of the apparatus or a discharge tray

25

at the upper portion of the main body of the apparatus by a switching operation of a switching gate (not shown).

After the toner image transfer step is completed, residual toner is removed from the photosensitive drum

1

by a cleaning device

8

formed of a blade or the like, and the photosensitive drum

1

is on standby for a next image forming step or the like. Further, after the toner image transfer step is completed, residual toner is removed from the intermediate transfer belt

9

by a belt cleaner

15

located so as to confront the idle roll

13

, and the intermediate transfer belt

9

is on standby for a next image forming step.

The wasted toner scraped off the photosensitive drum

1

or the intermediate transfer belt

9

by the cleaning device

8

and the belt cleaner

15

is withdrawn into a waste toner withdrawing tank

26

. Particularly, the waste toner withdrawn from the belt cleaner

15

is fed to the waste toner withdrawing tank

26

through a transport pipe

27

by a feeding unit constructed by an auger, a feeding screw, etc.

FIG. 3

is a cross-sectional view showing an embodiment of the rotary type developing apparatus

5

.

As shown in

FIG. 3

, the rotary type developing apparatus

5

has a rotor

30

which rotates in a clockwise direction around a rotational shaft

32

located at the center thereof. The rotor

30

has a center portion

33

designed in a substantially square form, and four arms

31

which extend substantially in the radial direction from the center portion

33

so as to intersect to one another at 90 degrees. The four developers

5

Y,

5

M,

5

C,

5

K of yellow (Y), magenta (M), cyan (C), black (K) are mounted to the arms

31

of the rotor

30

by a mounting unit (not shown).

All the developers

5

Y,

5

M,

5

C,

5

K are constructed in the same structure, and the developer

5

Y of yellow (Y) will be representatively described. The developer

5

Y of yellow (Y) is mainly divided into a developer main body

40

and a developer cartridge

50

.

In the developer main body

40

are provided an elongated developing roll

41

extending in the vertical direction to the surface of the drawing, and two spiral augers

42

,

43

which are located at the back surface side of the developing roll

41

and extend in parallel to the developing roll

41

. Here, when the developing roll

41

is rotated, the spiral auger

42

feeds developer

44

stocked in the developer main body

40

while stirring the developer

44

in one direction perpendicular to the surface of the drawing. On the other hand, the other spiral auger

43

feeds the developer

44

while stirring the developer

44

in the opposite direction to the feeding direction of the spiral auger

42

, and uniformly supplies the developer

44

to the developing roll

41

.

The developing roll

41

magnetically absorbs carriers contained in the developer

44

by a magnet roll (not shown) disposed therein, forms a magnetic brush of developer

44

on the surface thereof and feeds the toner absorbed to the carriers to a developing area confronting the photosensitive drum

1

. The electrostatic latent image formed on the photosensitive drum

1

is visualized by the magnetic brush of the developer

44

which is formed of the carriers and the toner on the surface of the developing roll

41

.

The developing cartridge

50

is formed of an elongated cylindrical container extending in the vertical direction to the surface of the drawing, and the inside of the developer cartridge

50

is divided into a stock chamber for new developer and a withdrawing chamber for deteriorated developer. The stock chamber for the new developer is provided with a supply port (not shown), and the supply port intercommunicates with a substantially cylindrical casing

51

for guiding the new developer to the developer main body

40

. The cylindrical casing

51

is provided at the upper portion of the back surface side of the developer main body

40

. A spiral auger

52

is disposed in the casing

51

, and the developer

44

supplemented from the developer cartridge

50

is guided by the spiral auger

52

to the supply port

53

provided on the upper surface of the back surface side of the developer main body

40

and supplemented into the developer main body

40

. A flap

54

is provided at the outlet port located at the lower end portion of the supply port

53

of the developer main body

40

so as to be freely opened/closed, and it is opened when the developer

5

Y is located at a developing position D of FIG.

3

. On the other hand, the flap

54

is closed by its own weight when the developer

5

Y is located at a position F or position G of FIG.

3

.

A circulating withdrawing passage

56

is provided to the deteriorated developer withdrawing chamber

55

of the developer cartridge

50

, and a discharge pipe

57

which is bent in a substantially L-shaped form is connected to the withdrawing passage

56

. The discharge pipe

57

is disposed at the upper portion of the substantially center portion of the developer main body

40

, and a withdrawing port

58

located at the tip (lower end in

FIG. 3

) of the discharge pipe

57

is located in the developer main body

40

. The withdrawing port

58

is located at the front side of the supply port

53

for the new developer, and also it is opened to the ceiling wall portion of the developer main body

40

. The new developer

44

supplied from the supply port

53

is stirred/fed by the spiral augers

42

,

43

, and it is supplied to the developing roll

41

while it is circulated in the developer main body

40

, thereby contributing to the development. The old developer

44

contributing to the developing step while circulating in the developer main body

40

is withdrawn through the withdrawing passage

56

into the deteriorated developer withdrawing chamber

55

of the developer cartridge

50

by the withdrawing port

58

when the developer main body

40

is located at a position E or F in FIG.

3

.

In the rotary type developing apparatus

5

having the developers

5

M,

5

C,

5

K which are designed in the same construction as the developer

5

Y thus constructed, when the developer main body

40

arrives at the developing position (D position) confronting the photosensitive drum

1

, the flap

54

opens the supply port

53

by its own weight, and the new developer

44

is supplemented into the developer main body

40

by rotating the spiral auger

52

if necessary. When the development of the electrostatic latent image on the photosensitive drum

1

is completed by the developer main body

40

, the rotor

30

is clockwise rotated and the developer is shifted from the D position to the lower and right E position, the flap

54

is semi-opened as shown in the drawing, the withdrawing port

58

is placed face up, the old developer fed through the discharge pipe

57

flows to the withdrawing passage

56

without flowing backward into the developer main body

40

. This deteriorated developer C is passed through the withdrawing passage

56

and withdrawn to the deteriorated developer withdrawing chamber

55

until the developer main body

40

is shifted from the lower and left F position to the upper and left G position. As described above, by providing the circulating withdrawing passage

56

, the developer C to be withdrawn can be prevented from flowing backward into the developer main body

40

.

Further, during the shift of the developer main body

40

from the upper and left G position to the upper and right D position (developing position), the new developer

44

is fed to the casing

51

by an action of an agitator (not shown) provided in the developer cartridge

50

, and guided to the supply port

53

by the spiral auger

52

in the casing

51

. At this time, the flap

54

opens the supply port

53

again, and thus the new developer

44

is supplemented into the developer main body

40

through the supply port

53

.

Next, the construction of the developer cartridge

50

will be described with reference to a perspective view of FIG.

4

and an exploded perspective view of FIG.

5

.

The developer cartridge has a developer stock unit in which at least toner is stocked, and a developer withdrawing box mounted at one end of the developer stock unit. The detection unit is disposed so as to confront the developer withdrawing box, and it serves to detect the presence or absence of the developer withdrawn in the developer withdrawing box to identify whether the developer cartridge is new or old.

That is, as shown in

FIGS. 4 and 5

, the developer cartridge

50

has a stock case

61

as an elongated cylindrical developer stock unit (cylindrical member) for stocking new developer, a cap

62

as a cap member which is detachably mounted on the stock case

61

to close one end of the stock case

61

, a supply port

63

as an inlet port for a passage through which the new developer is supplied from the stock case

61

to the developer main body

40

of the developing apparatus, a take-in port for taking in the deteriorated developer withdrawn from the developer, a cylindrical short withdrawing case

71

for stocking the deteriorated developer withdrawn through the take-in port

72

, and a withdrawing box

75

as a developer withdrawing box fitted into the withdrawing case

71

. As shown in

FIG. 5

, a tag piece

76

is formed on the withdrawing box

75

, and an opening

77

formed in the tag piece

76

intercommunicates with the take-in port

72

when the withdrawing box is fitted into the withdrawing case

71

. Further, a cap

79

having a handle

78

is press-fitted into the withdrawing box

75

.

A recess portion is formed along the peripheral direction on the periphery of the supply port

63

and the take-in port

72

to form a guide groove. A shutter

73

which is bent in an arcuate form along the outer surface of the developer cartridge

50

is attached to the guide groove so as to be slidable in the peripheral direction. Further, a cylindrical slide cover

81

is slidably mounted so as to surround parts of the withdrawing box

75

and the withdrawing case

71

. The slide cover

81

is urged by a spring

82

so as to cover the shutter

73

as shown in FIG.

5

.

Therefore, when the developer cartridge

50

is not mounted on the developer cartridge mount portion of the rotor

30

, the shutter

73

closes the supply port

63

and the take-in port

72

by the elastic force of an urging unit (not shown), and further the slider cover

81

covers the shutter

73

.

On the other hand, when the developer cartridge

50

is inserted into the developer cartridge mount portion of the rotor

30

, a long groove

74

formed in the width direction of the shutter

73

is engaged with a projection formed on the developer cartridge mount portion and the handle

78

is nipped and rotated by fingers, the developer cartridge

50

is rotated to move the shutter

73

, so that the supply port

63

and the take-in port

72

are opened together. The slant open end of the slide cover

81

abuts against a stopper (not shown) at the apparatus side to expose the shutter

73

.

FIG. 4

shows such a state that the developer cartridge

50

is mounted on the developer cartridge mount portion, and it is shown in

FIG. 4

that the supply port

63

and the take-in port

72

are opened.

In

FIG. 5

, reference numeral

91

represents a transparent window for detecting the old developer, reference numeral

92

represents a white sheet for detecting the old developer, and reference numeral

93

represents an opening portion for detecting the old developer.

In this embodiment, in the developer cartridge which is equipped with a cylindrical member for stocking developer containing at least toner, a supply port opened at one end side of the cylindrical member, and a spiral feeding member which is freely rotatably disposed in the cylindrical member, and serves to feed the developer stocked in the cylindrical member to the supply port by rotating the feeding member, the feeding member is mounted in the cylindrical member after the developer is filled in the cylindrical member.

In this embodiment, one end portion of the feeding member is freely rotatably attached to a cap member for sealing a developer filling open end portion of the cylindrical member, and the feeding member is mounted into the cylindrical member under the state that the cap member is attached to the feeding member.

Further, in this embodiment, when the feeding member is mounted in the cylindrical member, the feeding member is inserted into the cylindrical member filled with the developer while being rotated, and the rotational direction of the feeding member is set to the same section as the winding direction of the spiral of the feeding member.

That is, as shown in

FIGS. 1A

,

1

B and

4

, the developer cartridge

50

to this embodiment has a stock case

61

serving as the cylindrical elongated developer stock unit (cylindrical member) for stocking new developer

44

obtained by mixing toner and carriers in a predetermined mixing ratio, a cap

62

serving as the cap member which is detachably on the stock case

61

so as to close one end of the stock case

61

, a supply port

63

serving as the inlet port for a passage through which new developer

44

is supplied from the stock case

61

to the developer main body

40

of the developing apparatus, a take-in port

72

for taking in deteriorated developer C withdrawn from the developer main body

40

, a cylindrical short withdrawing case

71

for stocking the deteriorated developer C withdrawn through the take-in port

72

, and a withdrawing box

75

serving as the developer withdrawing box which is fitted into the withdrawing case

71

. In

FIG. 5

, the stock case

61

, the withdrawing case

71

and the withdrawing box

75

are constructed separated from each other, however, these members may be integrally constructed.

A spiral agitator

95

as the spiral feeding member is freely rotatably disposed in the stock case

61

, and the developer

44

stocked in the stock case

61

is fed to the supply port

63

by rotating the spiral agitator

95

. The base end portion of the spiral agitator

95

is fixedly fitted to the shaft portion

97

of a rotating member

96

which is freely rotatably attached to the cap

62

as shown in FIG.

1

. Plural pawl portions

98

which are to be engaged with a driving member (not shown) at the developer main body

40

are provided on the outside end surface of the rotating member

96

.

The spiral agitator

95

is formed of a wire rod of stainless, iron or the like, and it has a linear portion

95

a

extending in the axial direction at the center of the stock case

61

, and spiral portions

95

b

which are spirally provided at the outer periphery of the linear portion

95

a.

In this embodiment, the feeding member is pivotally supported at the end portion thereof opposite to the cap member in the cylindrical member through a shaft member and a bearing member.

In this embodiment, the shaft member is fixed to the end portion of the feeding member, the tip portion of the shaft member is tapered and the point angle of the tip portion of the shaft member is set to be more acute than 90 degrees.

Further, in this embodiment, the tip portion of the shaft member is provided with a developer discharging portion for discharging developer trapped in the bearing member when the shaft member is fitted into the bearing member.

Still further, in this embodiment, the shaft member is fixed to the tip of the feeding member, and the fixing force of the shaft member is set to such a level that the shaft member does not fall off the feeding member even when the shaft member is not fitted to the bearing member at the cylindrical member side and thus the feeding member is deformed.

That is, the spiral agitator

95

is designed as a so-called double-side supported type, and it is freely rotatably attached to the cap

62

at the base end portion thereof. In addition, the tip portion thereof is freely rotatably pivotally supported on a partition wall

99

which is obliquely provided at the end portion of the back side in the stock case

61

. Therefore, the shaft member

100

is firmly fixedly fitted to the tip portion of the spiral agitator

95

as shown in

FIGS. 6 and 7

. As shown in

FIG. 8

, the shaft member

100

is formed of synthetic resin of POM or the like, and a recess groove

101

is provided along the longitudinal direction at the base end portion side in the longitudinal direction thereof so as to be snap-fitted to the tip portion of the linear portion

95

a of the spiral agitator

95

. The sectional and planar shapes of the recess groove

101

are designed to be slightly broadened like a taper shape at the inlet side thereof and to be circular with the upper portion being opened at the back (deep) side thereof so as to snap-fit the tip portion of the linear portion

95

a

of the spiral agitator

95

. The recess groove

101

is designed so that the tip portion of the linear portion

95

a

of the spiral agitator

95

can be firmly snap-fitted over the overall length in the longitudinal direction of the recess groove

101

, and the fixing force of the shaft member

100

is set to such a level that the shaft member

100

does not fall off the agitator

95

even when the shaft member

100

is not fitted to the bearing member at the stock case

61

described later and the agitator

95

is deformed. The shaft member

100

may be formed integrally with the tip portion of the agitator

95

by an outsert molding.

As shown in

FIGS. 8A and 8B

, the tip portion

100

a

of the shaft member

100

is designed to be tapered, and the point angle of the tip portion

100

a

of the shaft member

100

is set to be more acute (for example, 60 degrees) then 90 degrees.

The inventors of this application have tested to check whether the shaft member

100

can be inserted into the bearing member in which toner exists while varying the point angle of the tip portion

100

a

of the shaft member

100

as shown in FIG.

9

. As a result, it is apparent from

FIG. 9

that if the point angle of the tip portion of the shaft member is more acute than 90 degrees, the shaft member can be excellently inserted into the bearing member in which the toner exists. Replace

Further, the shaft member

100

is provided, at both the surfaces of the tip portion

100

a

thereof, with a recess groove

102

as the developer discharging portion for discharging the developer trapped in the bearing member when the shaft member

100

is fitted to the bearing member.

In this embodiment, a guide portion for guiding the shaft member into the bearing member is provided to the tip portion of the bearing member.

Further, in this embodiment, the bearing member is provided with the developer discharging portion for discharging the developer trapped in the bearing member when the shaft member is fitted into the bearing member, and the developer discharging portion provided to the bearing member is constructed by plural opening portions which are provided along the axial direction on the inner surface of the bearing member. The opening portions are not opened to the radial direction of the bearing member.

As shown in

FIGS. 1

,

10

and

11

, a bearing member

103

which supports the shaft member

100

of the spiral agitator

95

while they are engaged with each other and freely rotatably supports the tip portion of the spiral agitator

95

is provided to the partition wall at the back side in the stock case

61

. As shown in

FIGS. 10 and 11

, the tip portion of the bearing member

103

is provided with a taper portion

104

serving as the guide portion for guiding the shaft member

100

into the bearing member

103

.

The bearing member

103

is provided with a developer discharging portion

105

for discharging the developer

44

trapped in the bearing member

103

when the shaft member

100

is fitted into the bearing member

103

. The developer discharging portion

105

provided to the bearing member

103

is constructed by plural (in this embodiment, three) opening portions having a recess-groove shape which are provided along the axial direction on the inner surface

103

a

of the bearing member

103

. The opening portions

105

are not opened to the radial direction of the bearing member

103

, thereby preventing the toner from invading from the outside into the bearing member

103

.

In this embodiment, the feeding member is supported at both the end portions by the shaft, and it is designed so that it is not brought into contact with the inner wall of the cylindrical member even when it is most warped. At this time, the center portion in the axial direction of the feeding member is formed to be smaller in diameter than both the end portions of the feeding member.

That is, as described above, as shown in

FIG. 1

, the spiral agitator

95

is formed of the wire rod of stainless, iron or the like, and it is constructed by the linear portion

95

a

extending in the axial direction at the center of the stock case

61

, and the spiral portion

95

b

which are spirally provided at about seven to eight turns on the outer periphery of the linear portion

95

a

. The spiral portion

95

b

of the spiral agitator

95

is formed in the spiral shape having a predetermined outer diameter and a predetermined pitch. As shown in

FIG. 12

, the spiral portion

95

b

of the spiral agitator

95

is designed so that the outer diameter of the 1.5 turn portion of each of both the end portions

95

b

′ is relatively large (for example, the outer diameter is set to 38 mm) and that of the center portion

95

b

″ excluding both the end portions is relatively small (for example, the outer diameter is set to 36 mm). In

FIG. 12

, it is illustrated that the outer diameter of the back side (the left side in

FIG. 12

) of the stock case

61

seems to be smaller, however, this is not relevant to the subject matter of the present invention.

As described above, the spiral portion

95

b

of the spiral agitator

95

is designed so that the center portion

95

b

″ thereof is set to be relatively small in outer diameter. The degree of reducing the outer diameter of the center portion

95

b

″ is set so that the center portion of the agitator is not brought into contact with the inner wall of the developer cartridge

50

even when the spiral agitator

95

is warped even in consideration of the factors such as its own weight, the press force of the developer, or the centrifugal force at the rotation time or the acceleration at the stop time of the rotation in the case of the rotary type developing apparatus

5

. In this case, the probability that the center portion of the agitator is brought into contact with the inner wall of the developer cartridge

50

can be reduced more as the outer diameter of the center portion

95

b

″ of the spiral agitator

95

is smaller. However, as the outer diameter of the agitator is reduced, the feeding performance of the developer by the spiral agitator

95

is reduced, and finally the amount of the developer trapped in the developer cartridge is increased. Therefore, the outer diameter of the center portion

95

b

″ of the spiral agitator

95

is preferably set to the maximum value in such a range that the center portion

95

b

″ of the spiral agitator

95

is not brought into contact with the inner wall of the developer cartridge

50

even when the spiral agitator

95

is warped even in consideration of factors such as its own weight, the press force of the developer, or the centrifugal force at the rotation time or the acceleration at the stop time of the rotation in the case of the rotary type developing apparatus

5

.

In this embodiment, the shaft member is fixed to the tip of the feeding member, and there is provided a rotation stop member for stopping the rotation of the feeding member when the shaft member is not fitted into the bearing member at the cylindrical member side.

That is, as shown in

FIGS. 1 and 11

, the bearing member

103

for pivotally supporting the tip portion of the spiral agitator

95

so that the spiral agitator is freely rotatable is provided on the partition wall

99

at the back side in the stock case

61

, and a flange portion

106

serving as the rotation stop member for stopping the rotation of the spiral agitator

95

when the shaft member

100

provided to the tip portion of the spiral agitator

95

is not fitted to the bearing member

103

is projectively provided on the outer periphery of the bearing member

103

as shown in FIG.

11

. That is, when the tip portion of the spiral agitator

95

is not fitted into the bearing member

103

, the tip portion of the spiral agitator

95

abuts against the outer peripheral surface of the bearing member

103

due to its own elastic force and is rotated. At this time, the tip portion of the spiral agitator

95

abuts against the flange portion

106

of the bearing member

103

, and thus the spiral agitator

95

cannot be further rotated.

According to the developer cartridge according to this embodiment thus constructed, the developer containing at least toner can be efficiently filled into the developer cartridge as follows.

Further, in this embodiment, even when the feeding member is mounted in the developer cartridge after the developer containing at least the toner is filled into the developer cartridge, the mount work of the cap member can be easily performed.

Still further, in this embodiment, even when the toner particles are designed in small size or toner containing wax is used, the feeding member and the inner wall of the developer cartridge can be surely prevented from being rubbed against each other, thereby preventing occurrence of image quality deterioration due to agglomerated toner.

In this embodiment, the driving apparatus for rotating the feeding member can be avoided from being designed in large size.

In this embodiment, even when the so-called double-side supported type feeding member is used, the feeding member and the inner wall of the developer cartridge can be surely prevented from interfering in each other.

In this embodiment, even when the so-called double-side supported type feeding member is used, the tip of the feeding member can be surely pivotally supported.

In addition, in this embodiment, even when the so-called double-side supported type feeding member is used, agglomerated toner can be surely prevented from being newly generated at the portion where the feeding member is pivotally supported.

Further, in this embodiment, even when the so-called double-side supported type feeding member is used, it can be easily checked whether the feeding member is normally pivotally supported.

That is, in the developer cartridge

50

according to this embodiment, after the developer

44

is filled into the stock case

61

of the developer cartridge

50

, as shown in

FIG. 13

, the cap

62

to which the spiral agitator

95

is attached is mounted in the stock case

61

having the developer

44

filled therein while the spiral agitator

95

is rotated by a driving unit (not shown). At this time, the rotational direction of the spiral agitator

95

is set to the same direction as the spiral direction of the spiral agitator

95

concerned.

As described above, the spiral agitator

95

is mounted in the stock case

61

of the developer cartridge

50

after the developer

44

is filled in the stock case

61

of the developing cartridge

50

, so that the developer

44

containing at least the toner can be efficiently filled into the developer cartridge

50

.

In this embodiment, the spiral agitator

95

is mounted into the stock case

61

filled with the developer

44

while being rotated. Therefore, the spiral agitator

95

advances forwardly while screwed into the developer

44

by the screw portion thereof, and the shaft member

100

attached to the tip portion of the spiral agitator

95

is fitted into the bearing member

103

provided to the stock case

61

as shown in FIG.

1

. Further, since the spiral agitator

95

is freely rotatably attached to the cap

62

, the mount work of the cap

62

can be easily performed even when the agitator

95

is mounted into the developer cartridge

50

after the developer

44

containing at least the toner is filled in the developer cartridge

50

.

In the developer cartridge

50

, the spiral agitator

95

is supported at both the ends thereof by the cap

62

and the partition wall

99

of the stock case

61

, that is, the spiral agitator

95

is designed as the so-called double-side supported type. Accordingly, the spiral agitator

95

is basically different from the so-called one-side supported type agitator, and it is hardly brought contact with the inner wall of the stock case

61

, so that the driving device for rotating the spiral agitator

95

is not required to be designed in large size.

In addition, in this embodiment, the outer diameter of the center portion

95

b

″ of the spiral agitator

95

is set to a relatively small value, and thus it can be surely prevented from coming into contact with the inner wall of the stock case

61

. Further, even when the toner particle diameter is reduced or toner containing wax is used, the occurrence of image quality deterioration due to agglomerated toner can be substantially perfectly prevented as shown in

FIGS. 14 and 15

.

Further, in this embodiment, the recess groove

102

as the developer discharging portion is provided to the shaft member

100

attached to the tip portion of the spiral agitator

95

, and also the opening portion

105

as the developer discharging portion is provided to the bearing member

103

. Therefore, the developer

44

is hardly trapped in the bearing member

103

, and thus the shaft member

100

of the spiral agitator

95

can be surely fitted into the bearing member

103

. Even when the so-called double-side supported type agitator

95

is used, agglomerated toner can be surely prevented from be newly generated at the portion at which the agitator

95

is pivotally supported.

In this embodiment, the guide portion

104

is provided to the tip portion of the bearing member

103

, so that the shaft member

100

of the spiral agitator

95

can be more surely fitted into the bearing member

103

.

Further, in this embodiment, the flange portion

106

as the rotation stop member for stopping the rotation of the spiral agitator

95

when the shaft member provided to the tip portion of the spiral agitator

95

is not fitted into the bearing member

103

is provided on the outer periphery of the bearing member

103

as shown in FIG.

11

. Therefore, when the shaft member

100

provided to the tip portion of the spiral agitator

95

is not fitted into the bearing member

103

, the spiral agitator

95

is prevented from being rotated. Accordingly, even when the torque of the electric motor for rotating the spiral agitator

95

is sharply increased and the so-called double-side supported type agitator is used, it can be easily checked whether the agitator is normally pivotally supported.

In this embodiment, the shaft member is provided to the feeding member side, and the bearing member is provided to the cartridge side. However, the present invention is not limited to this embodiment, and it may be modified so that the bearing member is provided to the feeding member side and the shaft member is provided to the cartridge side. In such a case, the bearing member is fixed to the tip of the feeding member and a through hole is formed inside the bearing member, so that the developer in the cartridge can be discharged through the through hole inside the bearing member when the shaft member is fitted into the bearing member of the feeding member. Therefore, there can be achieved a remarkable effect that the developer can be easily discharged.

As described above, according to the developer cartridge of the present invention, the developer containing at least toner can be efficiently filled.

According to the developer cartridge of present invention, even when the developer cartridge is designed so that the feeding member is mounted into the developer cartridge after the developer containing at least the toner is filled into the developer cartridge, the mount work of the cap member can be easily performed.

According to the developer cartridge of the present invention, even when the toner particle size is reduced or toner containing wax is used, the feeding member and the inner wall of the developer cartridge can be surely prevented from being rubbed against each other, and the image quality deterioration due to the agglomerated toner can be prevented.

According to the developer cartridge of the present invention, the driving device for rotating the feeding member can be prevented from being designed in large size.

According to the developer cartridge of the present invention, even when the so-called double-side supported type feeding member is used, the feeding member and the inner wall of the developer cartridge can be surely prevented from interfering in each other.

According to the developer cartridge of the present invention, even when the so-called double-side supported type feeding member is used, the tip of the feeding member can be surely pivotally supported.

Accordingly to the developer cartridge of the present invention, even when the so-called double-side supported type feeding member is used, new agglomerated toner can be surely prevented from being generated at the portion at which the feeding member is pivotally supported.

According to the developer cartridge of the present invention, even when the so-called double-side supported type feeding member is used, it can be easily checked whether the feeding member can be normally pivotally supported.

Developer cartridge having a spirally-formed feeding member mounted in a cylindrical member and method of manufacturing the same

Information

Patent Number

Date Filed

Date Issued

Inventors

Original Assignees

Examiners

Agents

CPC

US Classifications

Field of Search

US

International Classifications

Abstract

Description

Claims

Priority Claims (1)

US Referenced Citations (1)

Foreign Referenced Citations (1)