JP2002049208A - Image-forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent faulty drive and breakages due to increase in the rotational load and to prevent faulty development from occurring though plural developing devices having a feeding means for feeding toner toward a developing roller, are arranged around an image carrier, while changing their angles and a toner cartridge having a feeding means for feeding the toner to the developing device is provided detachably, even when the toner feeding means is a rotating body such as an agitator. SOLUTION: The developing devices 10(Y) and 10(M), having large inclination are constituted so that the supply port 44 of the toner cartridge 40 is not positioned on a 2nd line A2, linking the adjacent agitators 16 and 43 between the developing device and the toner cartridge by separating from the line A2, and the developing devices 10(M) and 10(K), having small inclination, are constituted so that the supply port is positioned on the line A2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus such as a printer, a facsimile, a copying machine, etc. for forming an image by using an electrophotographic technique. In particular, it relates to the developing device.

[0002]

2. Description of the Related Art Conventionally, as an image forming apparatus using an electrophotographic technique, for example, an image forming apparatus as shown in FIG. 11 is known (Japanese Patent Application Laid-Open No. 10-221951). The image forming apparatus includes a photosensitive member 1 as an image carrier having a photosensitive layer on an outer peripheral surface, a charging unit 2 for uniformly charging the outer peripheral surface of the photosensitive member 1, and a uniform charging by the charging unit 2. Exposure means 3 for selectively exposing the outer peripheral surface of the photoreceptor 1 to form an electrostatic latent image by applying exposure L, and applying a toner as a developer to the electrostatic latent image formed by the exposure means 3 (Four shown in the figure) developing devices 4 to make visible images (toner images)
(Y, C, M, K) and a transfer device 5 for transferring the toner image developed by the developing device 4 to a transfer medium such as paper. The developing device 4 includes a case 4 a containing the toner T, and a developing roller 4 c rotatably supported by the case 4 a on a shaft 4 b and applying toner to the photoconductor 1. An agitator chamber 4 is provided in a case 4a of the developing device 4.
d and a developing chamber 4e for storing the toner to be supplied to the developing roller 4c. In the agitator room 4d,
Agitator 4f as feeding means for feeding toner toward developing roller 4c (in this case, toward developing chamber 4e)
Is provided. A developing roller 4c is provided in the developing chamber 4e.
Is provided with a supply roller 4g for supplying toner to the surface. The developing roller 4c is provided with a blade 4h that comes into sliding contact with the surface of the developing roller 4c and regulates the amount of toner supplied toward the photoconductor 1. The toner in the case 4a is stirred by the agitator 4f while the developing roller 4c is stirred.
Sent to. Such a plurality of developing devices 4
(Y, C, M, K) are arranged radially around the photoreceptor 1 at different angles. Therefore, according to such an image forming apparatus, the photosensitive member 1 serving as an image carrier is
Can be reduced. The developing device 4
When all of the toner inside is consumed, the entire developing unit 4 is replaced.

[0003]

<Problem 1> In the conventional image forming apparatus described above, the developing device 4 is replaced together with the developing device 4 when all the toner contained therein is consumed. As a result, the components of the developing device may be wasted. Such a problem can be solved by providing a toner cartridge for supplying toner to the developing device so as to be detachable from the developing device. Also, the toner cartridge contains
To ensure that the toner is supplied to the developing device, it is desirable to provide a feeding means for feeding the toner to the developing device. However, in the image forming apparatus as described above, the plurality of developing devices 4 (Y, C, M, and K) are
Since it is arranged around the photoreceptor 1 at different angles, depending on the difference in the attitude of the developing device and the toner cartridge,
A difference occurs in the movement state of the toner due to gravity. For this reason,
Assuming that the toner cartridge for replenishing toner to the developing device is provided detachably with respect to the developing device without taking any measures, if the postures of the developing device and the toner cartridge are relatively close to the inverted state ( For example, in the developing devices 4Y and 4C), the toner is excessively supplied from the toner cartridge to the developing device, and the toner around the agitator 4f is present in an unnecessarily large amount.
If the rotational load of the agitator 4f increases, drive failure may occur, or in extreme cases, the agitator (including its drive system) may be damaged. On the other hand, when the attitudes of the developing device and the toner cartridge are nearly horizontal (for example, the developing devices 4M and 4K), a shortage of toner supply from the toner cartridge to the developing device occurs, and there is a possibility that defective development may occur. <Problem 2> Further, in the above-described image forming apparatus,
Since the plurality of developing devices 4 (Y, C, M, K) are arranged around the photoreceptor 1 at different angles, the moving state of the toner toward the developing roller 4c depends on the attitude of the developing devices. Differences occur. That is, in the magenta developing device 4M and the black developing device 4K, the toner is hardly moved by gravity in the magenta developing device 4M and the black developing device 4K, but the cyan developing device 4C and the yellow developing device 4Y have the same attitude. When the attitude gradually rises, the toner moves due to gravity. In the conventional image forming apparatus, the developing roller 4 can be used without considering the attitude of the developing device.
The agitator 4f, which is a feeding unit for feeding the toner toward c, has substantially the same idea (the idea that the toner only needs to be sent toward the developing roller 4c without considering the attitude of the developing device). Because of the configuration, the following problems have occurred. That is, in the developing devices 4C and 4Y in which the developing roller 4c is located below, a large amount of toner is unnecessarily present around the developing roller 4c and the agitator 4f. When the rotational load is increased, drive failure occurs, or in extreme cases, the agitator (including its drive system) may be damaged. (2) The toner pressure around the developing roller 4c increases, the contact force of the blade 4h on the developing roller 4c decreases, and excessive toner is supplied to the photoreceptor 1 and the image density becomes too high. In extreme cases, toner may leak from between the developing roller 4c and the blade 4h. If the contact pressure of the blade 4h against the developing roller 4c is increased to solve this problem, when the toner in the developing device is consumed and the amount of toner in the developing device decreases, the rotation of the developing roller 4c is reduced. (When the toner pressure becomes smaller), the amount of toner supplied to the photoreceptor 1 through the space between the developing roller 4c and the blade 4h is reduced, resulting in poor development. On the other hand, if the toner supply force of the agitator 4f, which is the toner supply means, is reduced to solve the above problems (1) and (2), the developing device 4 is substantially in a horizontal state.
At M and 4K, a shortage of toner supply to the developing roller 4c occurs, resulting in poor development.

A first object of the present invention is to solve the above-mentioned problem 1 and provide a plurality of developing devices having a feeding means for feeding toner toward a developing roller, changing the angle around the image carrier. And a toner cartridge having a feeding means for feeding toner to the developing device is detachably provided, and the toner feeding means is a rotating body such as an agitator. Even in such a case, an object of the present invention is to provide an image forming apparatus which can prevent drive failure and breakage due to an increase in the rotational load, and does not cause development failure. A second object of the present invention is to solve the above-mentioned problem 2 in addition to the above-mentioned problem 1, and to provide an image forming apparatus in which the image density does not become too high or the development failure does not occur.

[0005]

According to a first aspect of the present invention, there is provided an image forming apparatus, comprising: a plurality of developing devices having a feeding unit for feeding a toner to a developing roller; A toner cartridge which is arranged around the image carrier at an angle and has a feeding means for feeding toner to the developing device is detachably provided, and this cartridge is mounted on the developing device. An image forming apparatus, wherein the toner supply port of the toner cartridge faces the toner receiving port provided in the developing device in a state in which
For a developing device having a large angle between a first line connecting the center of the developing roller and the feeding means adjacent to the developing roller and a horizontal line, a toner cartridge supply port and a toner receiving port of the developing device are provided. Is configured so as to be separated from a second line connecting adjacent feeding units between the developing device and the toner cartridge and not to be positioned on the second line, and that the first line and the horizontal line For the developing device having a small angle, the supply port of the toner cartridge and the toner receiving port of the developing device are located on the second line connecting the adjacent feeding means between the developing device and the toner cartridge. It is characterized by having such a configuration.

Here, "the developing device having a large angle" means that the supply port of the toner cartridge and the toner receiving port of the developing device are located on the second line. This means a developing device in which a driving failure of a rotating body such as the agitator described above occurs, and the meaning of "a developing device having a small angle" means that the toner cartridge supply port and the toner receiving device of the developing device are not used. If the entrance is not located on the second line,
This means a developing device in which the above-described development failure occurs.

[0007] The image forming apparatus according to the second aspect is the first aspect.
In the above image forming apparatus, the distance between the supply port and the toner receiving port from the second line increases as the angle between the first line and the horizontal line increases. .

[0008] In order to achieve the second object, a third aspect is provided.
The image forming apparatus according to claim 1 or 2, wherein the toner supply force of the supply unit in the developing device in which the angle between the first line and the horizontal line is large is:
The angle is smaller than that of a small developing device. According to a fourth aspect of the present invention, in the image forming apparatus according to the third aspect, a sum of a toner feeding force of a feeding unit and a toner feeding force by gravity in the developing device is the plurality of developing devices. It is characterized by being substantially the same for all vessels. According to a fifth aspect of the present invention, in the image forming apparatus according to the fourth aspect, when the angle is 90 °, the toner feeding force of the feeding unit in the developing device is 0%, and the toner is fed by gravity. When the supply force is 100% and the toner supply force of the supply unit is 100% and the toner supply force by gravity is 0% in the case where the angle is 0 °, the toner supply unit The sum of the feeding force and the toner feeding force due to gravity is 70% to 80% for all of the plurality of developing devices.
An image forming apparatus according to a sixth aspect is the image forming apparatus according to the third, fourth, or fifth aspect, wherein the feeding unit has a shaft and fins provided on the shaft.
The feeding force of the toner is changed by changing the number and / or the shape and / or the rigidity of the fins.

[0009]

According to the image forming apparatus of the first aspect, a plurality of developing devices having a feeding means for feeding the toner toward the developing roller are arranged around the image carrier at different angles. Therefore, it is possible to reduce the radius of the image carrier even though a plurality of developing devices are arranged on the image carrier. Further, since the toner cartridge having a feeding unit for feeding the toner to the developing device is detachably provided, when the toner in the developing device is consumed and becomes low, the toner can be replaced without replacing the developing device. Since the toner can be supplied by replacing only the cartridge, the components of the developing device are not wasted. Further, since the toner cartridge is provided with a feeding unit for feeding the toner to the developing device, the toner is reliably fed. A developing device having a large angle between the first line connecting the center of the developing roller and the feeding means adjacent to the developing roller and the horizontal line (therefore, usually, the attitude of the developing device and the toner cartridge is relatively small) In the case where the toner cartridge is close to an inverted state), the supply port of the toner cartridge and the toner receiving port of the developing device are separated from the second line connecting adjacent feeding means between the developing device and the toner cartridge. Since the toner cartridge is configured not to be located on the second line, it is possible to prevent the toner cartridge from being excessively supplied to the developing device from the toner cartridge. For this reason,
Even when the toner supply means in the developing device is a rotating body such as an agitator, it is possible to prevent drive failure and breakage due to an increase in the rotational load. On the other hand, for a developing device in which the angle between the first line and the horizontal line is small (therefore, usually, when the attitude of the developing device and the toner cartridge is close to a horizontal state), the toner cartridge supply port and the toner receiving portion of the developing device Since the inlet is located on the second line connecting the adjacent feeding means between the developing device and the toner cartridge, the toner is smoothly supplied from the toner cartridge to the developing device. Will be done. For this reason, toner shortage in the developing device hardly occurs, and poor development hardly occurs. That is, according to the image forming apparatus of the first aspect, a plurality of developing devices having a feeding unit for feeding the toner toward the developing roller are arranged around the image carrier at different angles. Even if a toner cartridge having a feeding means for feeding toner to the developing device is detachably provided, and even if the toner feeding means is a rotating body such as an agitator, Driving failure or breakage due to an increase in rotational load can be prevented, and development failure hardly occurs. According to the image forming apparatus of the second aspect, in the image forming apparatus of the first aspect, as the angle between the first line and the horizontal line increases, the postures of the developing device and the toner cartridge are generally increased. (The closer to the inverted state, the larger the distance between the supply port and the toner receiving port from the second line, so that it is ensured that the toner is excessively supplied from the toner cartridge to the developing device. Therefore, even when the toner feeding means in the developing device is a rotating body such as an agitator, it is possible to reliably prevent a driving failure or breakage due to an increase in the rotating load. According to the image forming apparatus of the third aspect, the first or second aspect is provided.
In the image forming apparatus described above, the toner supply force by the supply unit in the developing device having a large angle between the first line and the horizontal line is smaller than that in the developing device having the small angle. The following operational effects can be obtained. That is, the toner formed by the feeding unit in the developing device having a large angle between the first line connecting the center of the developing roller and the feeding device and the horizontal line (therefore, usually, the developing device in which the developing roller is located below). Since the feeding force is smaller than that of the developing device having the small angle, the developing device in which the toner is easily moved toward the developing roller by gravity has a relatively small toner feeding force due to gravity. In a developing device in which the toner is hardly moved toward the developing roller by gravity, the toner is mainly fed toward the developing roller by a relatively large toner feeding force by the feeding means. Will be sent. Therefore, it is possible to prevent the image density from becoming too high or the development failure from occurring even though a plurality of developing devices are arranged at different angles around the image carrier. Become.
Therefore, when the developing roller has a blade for the developing roller, it is possible to prevent toner from leaking between the developing roller and the blade. According to the image forming apparatus of the fourth aspect, in the image forming apparatus of the third aspect, the sum of the toner feeding force by the feeding unit and the toner feeding force by gravity is equal to all of the plurality of developing devices. Are substantially the same, it is possible to reliably prevent the image density from becoming too high or the development failure from occurring. Therefore, it is also possible to reliably prevent the toner leakage. According to the image forming apparatus of the fifth aspect, in the image forming apparatus of the fourth aspect, when the angle is 90 °, the toner feeding force by the feeding unit is 0%, and the toner feeding force by gravity is reduced. Assuming that the toner feeding force by the feeding means when the angle is 0 ° is 100% and the toner feeding force by gravity is 0% when the angle is 0 °, the toner feeding force by the feeding means and the gravity Since the sum with the toner supply force is 70% to 80% for all of the plurality of developing devices, it is possible to more reliably prevent the image density from becoming too high or the development failure from occurring. It becomes possible. That is, if the sum of the toner feeding force of the feeding unit and the toner feeding force due to gravity is less than 70%, there is a possibility that the toner is insufficiently supplied to the developing roller and development failure occurs. Conversely, if it exceeds 80%, the toner is excessively supplied around the developing roller,
Although there is a possibility that the image density becomes too high, according to the image forming apparatus of the fifth aspect, the sum of the toner feeding force by the feeding unit and the toner feeding force by gravity is:
Since it is 70% to 80% for all of the plurality of developing devices, it is possible to more reliably prevent the image density from becoming excessively high and the occurrence of defective development. Therefore, the toner leakage can be more reliably prevented. According to the image forming apparatus of the sixth aspect, in the image forming apparatus of the third, fourth or fifth aspect, the feeding means has a shaft and a fin provided on the shaft. Since the toner feeding force is changed by changing the number and / or shape and / or rigidity of the fins, the toner feeding force by the feeding means can be easily changed. Therefore, the above-mentioned drive failure and breakage of the feeding means can be more reliably and easily prevented.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic front sectional view showing a main part of an embodiment of an image forming apparatus according to the present invention.

The overall basic structure of this image forming apparatus other than the toner cartridge is the same as that of the above-described conventional image forming apparatus (FIG. 11), and the photosensitive member 1 as an image carrier having a photosensitive layer on the outer peripheral surface. A charging unit (not shown) for uniformly charging the outer peripheral surface of the photoreceptor 1, and selectively exposing the outer peripheral surface of the photoreceptor 1 uniformly charged by the charging unit to an electrostatic latent image Exposure means (not shown) for forming
A plurality of (four in the illustration) developing units 10 (Y, C, M) which apply toner as a developer to the electrostatic latent image formed by the exposing means to form a visible image (toner image). , K).

Each of the developing devices 10 is mounted on a mounting table 30 and is swingably attached to the main body of the image forming apparatus, and only the developing device corresponding to the color of an image to be formed is the photosensitive member 1. Can be abutted. 40 (Y, C, M,
K) is a toner cartridge for replenishing the developing device 10 with toner, and is detachably attached to the developing device 10.

Since the basic construction of each developing unit 10 is the same, the developing unit 10C for cyan will be described as a representative with reference to FIG. The developing device 10 includes a case 11, and a developing roller 12 rotatably supported by a shaft 12b on side plates 11a, 11a (only one is shown in FIG. 2) of the case 11 and applying toner to the photoreceptor 1. I have. Case 1
Reference numeral 1 includes a lower case 11e and an upper case 11f. The developing roller 12 is driven by driving means (not shown).
For example, it is driven to rotate at a peripheral speed of about 360 mm / s in the direction of the arrow in FIG. The case 11 has first and second agitator chambers 13 and 14 and a developing chamber 15 for storing toner to be supplied to the developing roller 12. First
In the second agitator chambers 13 and 14, first and second rotationally driven in directions indicated by arrows in FIG.
Agitators 16 and 17 are provided.
The second agitator faces the developing roller 12 (the developing chamber 1
(Toward 5) constitutes a feeding means for feeding toner. In the developing chamber 15, a supply roller 18 for supplying toner to the surface 12a of the developing roller 12 is provided. The supply roller 18 is driven to rotate in a direction indicated by an arrow in FIG. 2 by a driving unit (not shown) at a peripheral speed of, for example, about 240 mm / s.

The first and second agitator chambers 13 and 14 communicate with each other through a toner flow path (communication opening) 13a, and the second agitator chamber 14 and the developing chamber 15 communicate with each other through a toner flow path (communication opening) 14a.
In communication.

A blade 19 for regulating the amount of toner supplied to the surface 12a of the developing roller 12 is in contact with the surface. The blade 19 is attached to the case 11 via the support plate 20. On the opposite side of the blade 19, between the surface 12 a of the developing roller 12 and the case 11, there is provided a seal member 23 made of a thin sheet that slides on the developing roller surface 12 a. Seal member 2
3 is fixed to the case 11.

The toner cartridge 40 includes a case 41 in which a toner (not shown) is stored, agitators 42 and 43 provided in the case 41, and a toner supply port 44 provided in the case 41. In addition, the agitators 42 and 43 that are rotationally driven in the direction of the arrow in FIG. 2 by a driving unit (not shown) constitute a feeding unit that feeds the toner toward the developing device 10. Such a toner cartridge 40 is attached to the side plate rear portions 11b, 11b of the developing device 10 (FIG. 2).
, Only one of them is shown).
4 is a toner receiving port 10a provided in the developing device 10.
The toner in the toner cartridge 40 is supplied to the developing device 10 through the supply port 44 and the toner receiving port 10a by its own weight and the rotation of the agitators 42 and 43.

Therefore, the toner in the toner cartridge 40 is supplied to the toner receiving port 10 as shown by the arrow t1.
a into the first agitator chamber 13 of the developing device 10 from
The developer flows into the second agitator chamber 14 through the communication port 13a as shown by the arrow t2 while being agitated by the first agitator 16, and flows through the communication port 14a as shown by the arrow t3 while being agitated by the second agitator 17. 15, is rubbed against the surface 12 a of the developing roller 12 at a contact portion 18 a with the developing roller 12 by the supplying roller 18 while flowing along the rotation of the supplying roller 18 as indicated by an arrow t 4, and The amount of adhesion to the surface of the developing roller is regulated and applied to the surface of the photoconductor 1 from the developing roller surface 12a. The toner that has not been rubbed against the surface 12a of the developing roller 12 by the supply roller 18 flows along the rotation of the developing roller 12 as shown by an arrow t5, and further, the blade 19 as shown by arrows t6, t7 and t8. It circulates along the inner surface and the inner surface of the developing chamber. Further, of the toner adhered to the developing roller surface 12a, the remaining toner that has not been transferred to the photoreceptor 1 passes through the seal member 23, returns to the inside of the developing chamber 15, and moves in the rotation direction of the developing roller 12 and the supply roller 18. Along the flow, as indicated by arrows t10 and t11.

The developing device 10 (Y, C, M,
K) and toner cartridge 40 (Y, C, M, K)
As shown in FIG. 1, are arranged around the photoreceptor 1 at different angles so as to be substantially radial. The attitude of the developing device 10 (the degree of inversion and the inclination angle) can be defined by the angle between a line (first line) connecting the center of the developing roller and the feeding means and a horizontal line. In the embodiment, as shown in FIG. 1, the angle θ is defined by a first line A1 connecting the center 12c of the developing roller 12 and the center 17c of the second agitator 17 serving as a feeding means, and a horizontal line H. It is. In FIG. 1, the counterclockwise direction in FIG. 1 is "+", the angle θ1 of the developing device 10Y is about 50 °, and the angle
Is about 20 °, the angle θ3 of the developing unit 10M is about 5 °, and the angle θ4 of the developing unit 10K is about −16 °. As shown in FIG. 7, the attitude of the toner cartridge 40 (the degree of inversion and the inclination angle) is different from that of the toner cartridge 40 and the developing device 10.
Can be defined by an angle between a horizontal line H and a line (second line) A2 connecting the adjacent agitators 43 and 16 at their centers.
The angle θY of 0Y is about 56.5 ° and the toner cartridge 4
The angle θC of 0C is about 57.3 °, and the toner cartridge 4
The angle θM of 0M is about 41.6 °, and the toner cartridge 4
The angle θK at 0K is about 24.5 °. As shown in FIG. 10, the attitude of the toner cartridge 40 includes a line A3 connecting the agitator 43 closest to the developing device 10 and the agitator 42 adjacent to the agitator 42 in the toner cartridge 40 at their centers, and a horizontal line H In this case, the angle θY1 of the toner cartridge 40Y is about 56 °, and the angle θY of the toner cartridge 40C is
C1 is about 36 °, the angle θM of the toner cartridge 40M
1 is about 9 °, and the angle θK1 of the toner cartridge 40K is about 11 °.

In the above-described image forming apparatus, considering the easiness of toner supply from the toner cartridge 40 to the developing device 10, the toner is more easily supplied as the posture of the toner cartridge 40 becomes closer to the inverted state. A supply port 44 of the toner cartridge 40 and a toner receiving port of the developing device 10 are located on a second line A2 connecting the agitators 43 and 16 adjacent to each other between the toner cartridge 40 and the developing device 10 at their centers. When 10a is located, it is most easily supplied. In such a situation, if no measures are taken (for example, with respect to all the developing devices 10 and the toner cartridges 40, the supply port 44 and the toner receiving port 10a are located on the second line A2). ), The developing units 10Y and 10C and the toner cartridges 40Y and 40C whose postures are relatively in an inverted state Is supplied too much, and the toner is present in an unnecessarily large amount around the agitators 16 and 17, and its rotational load is increased to cause driving failure and breakage.
As described above, with respect to the 10K and the toner cartridges 40M and 40K, insufficient toner may be supplied from the toner cartridge 40 to the developing device 10 to cause development failure, as described above.

Therefore, in this embodiment, as shown in FIG. 7, the supply port 44Y and the toner receiving port are provided for the developing device 10Y and the toner cartridge 40Y and the developing device 10C and the toner cartridge 40C having the large inclination angles. 10aY, and 44C and 10aC are configured so as to be separated from the second line A2 and not positioned on the second line A2. Further, the developing device 10Y having a larger inclination angle
About the developing unit 10C having a smaller inclination angle
The separation distance E (see FIG. 8) of the supply port 44Y and the toner receiving port 10aY from the second line A2 is larger than that of FIG. Note that the repose angle of the toner used in this type of image forming apparatus is usually 20 ° to 30 °. Therefore, in relation to the repose angle of the toner, the inclination angle (see FIG. For the toner cartridges 40Y and 40C that are larger than the corners,
4Y and toner receiving port 10aY, and 44C and 10aC
However, the developing device 10Y having a larger inclination angle is configured so as not to be positioned on the second line A2 apart from the second line A2. 10C, the distance E between the supply port 44Y and the toner receiving port 10aY from the second line A2.
(See FIG. 8). With the above configuration, the developing device 10Y and the toner cartridge 40 are shown in FIG.
As shown in the example of Y, the toner supplied from the toner cartridge 40 to the developing device 10 is moved from the toner cartridge 40 to the first developing device 10 as indicated by an arrow t1Y.
Without directly going to the agitator 16, it is supplied in a state where the supply force is reduced by being put on one cushion so as to hit the wall surface 11i of the case 11. Although not shown, the developing device 10C and the toner cartridge 4
The same applies to 0C. On the other hand, as shown in FIG.
For the developing device 10M and the toner cartridge 40M having a relatively small inclination angle, and for the developing device 10K and the toner cartridge 40K, the supply port 44M and the toner receiving port 10aM, and 44K and 10aK correspond to the second line A.
2. In relation to the rest of the toner, the inclination angle (see FIG. 10) of the toner cartridge 40 is smaller than the rest angle of the toner.
Regarding M and 40K, the supply port 44M and the toner receiving port 10aM, and 44K and 10aK are configured to be located on the second line A2. With the above configuration, as shown in FIG. 9 by taking the developing device 10M and the toner cartridge 40M as an example, the toner supplied from the toner cartridge 40 to the developing device 10 is changed to an arrow t1M.
As shown in FIG.
Is supplied directly to the first agitator 16. Although not shown, the same applies to the developing device 10K and the toner cartridge 40K.

In such an image forming apparatus,
If no measures are taken, the developing roller 1
2, the developing units 10Y and 10C,
In particular, in the developing device 10Y having a large inclination angle (θ1), a large amount of toner around the developing roller 12 and the second agitator 17 is present in an unnecessarily large amount. As described above, problems such as leakage of toner and toner may occur.

Therefore, in this embodiment, the angle θ
Is configured such that the toner feeding force by the second agitator 17 which is a feeding unit in a large developing device is smaller than that in a developing device having a small angle. That is, the toner feeding force by the second agitator 17 in the developing device 10Y is smaller than that in the developing device 10C, the toner feeding force by the second agitator 17 in the developing device 10C is smaller than that in the developing device 10M,
The toner feeding force of the second agitator 17 in the developing device 10M is configured to be smaller than that in the developing device 10K. In order to change the toner feeding force by the second agitator 17, means such as changing the number of rotations may be used, but in this embodiment, the second agitator 17 is used.
The toner feeding force is changed by changing the number of fins provided on the shaft.

FIG. 3 is a perspective view showing the second agitator 17 (Y) in the developing unit 10Y for yellow. The second agitator 17 (Y) includes a shaft 17b and one frame-shaped stirring arm 17a integrally formed therewith (see FIG. 1).

FIG. 4 is a perspective view showing the second agitator 17 (C) in the developing unit 10C for cyan. This second
The agitator 17 (C) includes a shaft 17b, one stirring arm 17a integrally formed with the shaft 17b,
a and fins 17d attached to a (see FIG. 1). The length L1 of the fin 17d is such that the tip edge 17e does not slide on the inner wall surface 14b of the second agitator chamber 14 (see FIG. 2). In FIG. 4, the imaginary line 17f indicates a fin having a length L whose leading edge is in sliding contact with the inner wall surface of the agitator chamber. The fin of the second agitator 17 (C) in the developing device 10C for cyan is used. The length L1 of 17d is such that the leading edge 17e does not slide on the inner wall surface 14b of the second agitator chamber 14 (see FIG. 2). Such a developing device 10 for cyan
According to the second agitator 17 (C) in C, compared to the second agitator 17 (Y) in the developing device 10Y for yellow shown in FIG. Increase.

The second agitator 17 (M) in the magenta developing device 10M shown in FIG. 1 is the same as the second agitator 17 (M) in the cyan developing device 10C shown in FIG.
(C), another fin 17d is provided symmetrically with respect to the axis. According to the second agitator 17 (M) in the magenta developing device 10M, the number of the fins 17d is two compared to the second agitator 17 (C) in the cyan developing device 10C shown in FIG. As a result, the toner feeding force is increased, and the toner feeding force approximately twice as large as that of the second agitator 17 (C) is obtained.

The second agitator 17 (K) in the black developing device 10K shown in FIG. 1 is the same as the second agitator 17 (C) in the cyan developing device 10C shown in FIG.
As shown in FIG. 1, the fin 17 d of FIG. 1C has a length L such that the leading edge of the fin 17 d slides on the inner wall surface 14 d (see FIG. 1) of the second agitator chamber. Are provided symmetrically with respect to. The second agitator 17 (K) in such a black developing device 10K.
According to the above, the second magenta developing device 10M
As compared with the agitator 17 (M), the toner feeding force is increased by the length of the fin 17f. As shown in FIG. 1, the black developing unit 10K has a negative inclination angle θ4, so that the second agitator 1K
There is a possibility that toner is not sufficiently supplied to the developing roller 12 (developing chamber) only by increasing the toner feeding force by 7 (K). Therefore, in this embodiment, as shown in FIG. 1, for the black developing device 10K, a guide positioned between the second agitator chamber 14 and the developing chamber 15 in the rotation path of the fin 17f. The plate 11h is provided, and the toner scraped up by the fins 17f is
It is configured to be guided by the guide plate 11h and surely fed to the developing chamber 15.

Further, in this embodiment, the sum of the toner feeding force by the second agitator 17 and the toner feeding force by gravity is substantially the same for all of the plurality of developing devices 10 (Y, C, M, K). It is configured to be. In this embodiment, the second tilt angle θ is 90 °.
The toner feeding force by the agitator 17 is 0%, the toner feeding force by gravity is 100%, and the toner feeding force by the second agitator 17 when the inclination angle θ is 0 ° is 10%.
0% (a state in which a feeding force equivalent to the toner feeding force by gravity when the inclination angle θ is 90 ° is obtained), and assuming that the toner feeding force by gravity is 0%, the second
The sum of the toner supply force by the agitator 17 and the toner supply force by gravity is determined by the three developing units 10Y, 10C, 1
It is configured to be 70% to 80% with respect to 0M. The black developing device 10K is configured to be 70% to 80% including the action of the guide plate 11h.

This will be described in detail with reference to FIGS. As shown in FIGS. 5 (a1) and 5 (a2), one rotation of the agitator A having the paddle P causes the agitator chamber B to rotate.
When all the toner T in the inside is scraped out (supplied),
The toner feeding force by the agitator A is defined as 100%. Further, as shown in FIGS. 5 (b1) and 5 (b2), the agitator A1 is composed of the shaft b and the frame-shaped arm a and has no fin. Therefore, such an agitator A1 rotates. However, since the toner T in the agitator chamber B is not scraped off at all, the toner feeding force by the agitator is specified to be 0% in such a case. Further, as shown in FIGS. 5 (c1) and 5 (c2), half of the toner T in the agitator chamber B is scraped off by one rotation of the agitator A2 including the shaft b, the frame-shaped arm a and the fin F (feeding). Is supplied), the toner supply force by the agitator A2 is specified to be 50%. Therefore, FIG.
As shown in (d1) and (d2), the toner feeding force by the agitator A3 in which two frame-shaped arms a and two fins F are provided symmetrically with respect to the axis b is 100%. The toner feeding force by the agitator as described above can be appropriately set by changing the number and / or shape and / or rigidity of the fins. For example, as shown in FIG. 6A, by providing a notch F1 in the fin F, the toner feeding force can be reduced by 33%.
It can also be about. 6 (b1) (b2) (b
3) shows a toner feeding state by such an agitator A4, and the toner T in the agitator chamber B is rotated by three rotations.
Is almost all scraped out. Further, as shown in FIG. 4, the toner feeding force can be changed by changing the length L of the fin, or the toner feeding force can be changed by changing the rigidity of the fin.

On the other hand, the toner feeding force (feeding force toward the developing roller 12) due to gravity in each developing device of this embodiment is about 75 in the yellow developing device 10Y having the inclination angle θ1 of about 50 °. % (Substantially Sin component, the same applies hereinafter),
Approximately 35% for the developing device 10C for cyan having the inclination angle θ2 of about 20 °, about 10% for the developing device 10M for magenta having the inclination angle θ3 of about 5 °, and for black having the inclination angle θ4 of about -16 °. In the developing device 10K, it is about -20%.

Therefore, in this embodiment, the second agitator 17 of the developing unit 10Y for yellow is used.
(Y), as shown in FIGS. 3 and 1, a shaft 17b and one frame-shaped stirring arm 17a integrally formed therewith.
The toner feeding force by the second agitator 17 (Y) is set to 0%, the toner feeding force (0%) by the second agitator 17 (Y), and the toner feeding force by gravity (about 75%). Is set to be about 75%. Regarding the developing device 10C for cyan, the second agitator 17 (C) is provided with a shaft 17b and one stirring arm 17a integrally formed with the shaft 17b, as shown in FIGS. The fins 17d attached to the stirring arm 17a constitute a second agitator 17 (C).
The toner supply force of the second agitator 1
The sum of the toner feeding force (about 40%) by 7 (C) and the toner feeding force by gravity (about 35%) is about 75%. In the developing device 10M for magenta, the second agitator 17 (M) is connected to a shaft 17b and two stirring arms 17a formed symmetrically with the shaft 17b.
And the fins 17d, the second agitator 17
(M), the toner feeding force by the second agitator 17 (M) and the toner feeding force by gravity (about 10%) are about 80%.
%. Developing device 10 for black
As for K, as described above, the second agitator 17 (K) is formed by rotating the shaft 17b, the two agitating arms 17a formed symmetrically with the shaft 17b, and the distal end edge of the inner wall surface 14d of the second agitator chamber (see FIG. 1) Length L to be in sliding contact with
And the second agitator 1
7 (K) is set to about 100% (see FIGS. 5 (d1) and 5 (d2)), and the above-described guide plate 11h is provided to supply the toner by the second agitator 17 (K) (about 100%). %) And the toner feeding force due to gravity (about -20%) is configured to be about 80%. That is, in this embodiment, the sum of the toner feeding force by the second agitator 17 as the feeding means and the toner feeding force by gravity is equal to the plurality of developing devices 10.
(Y, C, M, K) are configured to be substantially the same for all (so as to be 70% to 80%).

The functions and effects of the above embodiment are summarized as follows. (A) Since a plurality of developing devices 10 having a feeding means for feeding toner toward the developing roller 12 are arranged around the image carrier 1 at different angles, Although a plurality of developing devices 10 are arranged,
The radius of the image carrier 1 can be reduced. Further, since the toner cartridge 40 having a feeding unit for feeding toner to the developing device 10 is detachably provided, when the toner in the developing device 10 is consumed and becomes small, the developing device 10 is removed. Since the toner can be supplied by replacing only the toner cartridge 40 without replacement, the components of the developing device 10 are not wasted. Further, the toner cartridge 4
0 indicates feeding means 42 for feeding toner to the developing device,
Since the toner cartridge 43 is provided, the toner is reliably fed. The developing device 10Y (10C) having a large angle between the first line A1 connecting the center of the developing roller 12 and the second agitator 17 which is a feeding means adjacent to the developing roller and the horizontal line H is large. The supply port 44Y (44C) of the toner cartridge 40Y (40C) and the toner receiving port 10aY of the developing device 10Y (10C).
(10aC) connects the adjacent agitators 43Y (43C) and 16Y (16C) as the feeding means between the developing device 10 and the toner cartridge 40.
And is not positioned on the second line A2 apart from the line A2 of the toner cartridge 40Y.
(40C), the toner is not excessively supplied to the developing device 10Y (10C). For this reason, even if the toner supply means in the developing device 10Y (10C) is a rotating body such as an agitator, it is possible to prevent drive failure or damage due to an increase in the rotational load. On the other hand, the developing device 10 has a small angle between the first line A1 and the horizontal line H.
For M (10K), the toner cartridge 40
M (40K) supply port 44M (44K) and developing unit 1
0M (10K) toner inlet 10aM (10aK)
Are arranged on a second line A2 connecting adjacent feeding means between the developing device and the toner cartridge, so that the toner cartridge 40M
(40K), the toner is smoothly supplied to the developing unit 10M (10K). Therefore, the developing device 10
Insufficient toner in M (10K) is less likely to occur, and poor development is less likely to occur. That is, according to the image forming apparatus of this embodiment, a plurality of developing devices 10 each having a feeding unit for feeding the toner toward the developing roller 12 are provided.
, The toner cartridge 40 having a feeding unit for feeding toner to the developing device 10 is detachably provided. Is a rotating body such as an agitator, it is possible to prevent a drive failure or breakage due to an increase in the rotational load, and it is difficult for a development failure to occur. (B) As the angle between the first line A1 and the horizontal line H increases, the supply port 44 and the toner receiving port 10a
The distance E from the second line A2 is large, so that it is ensured that the toner is not excessively supplied from the toner cartridge 40 to the developing device 10, so that the toner feeding in the developing device is prevented. Even if the means is a rotating body such as an agitator, it is possible to reliably prevent drive failure and breakage due to an increase in the rotational load. (C) A developing device having a large angle θ between the first line A1 connecting the center of the developing roller 12 and the feeding means 17 and the horizontal line H (therefore, a developing device in which the developing roller 12 is normally located below) In the developing devices 10Y and 10C in which the toner easily moves toward the developing roller 12 due to gravity, the toner feeding force of the feeding unit 17 in the developing device 10Y is smaller than that in the developing device having the small angle. In the developing device 10M in which the toner is fed toward the developing roller by a relatively small toner feeding force of the feeding unit and the toner hardly moves toward the developing roller due to gravity, the feeding unit mainly uses the feeding unit. The toner is fed toward the developing roller with a relatively large toner feeding force. Therefore, although a plurality of developing units are arranged at different angles around the image carrier,
It is possible to prevent the image density from becoming too high or from causing a development defect. Therefore, drive failure or breakage due to an increase in the rotational load of the agitator 17 as the toner feeding means can be prevented, and toner leakage from between the developing roller 12 and the blade 19 can be prevented. Become. (D) Since the sum of the toner feeding force by the feeding means and the toner feeding force by gravity is substantially the same for all of the plurality of developing devices, the image density becomes too high, This can be reliably prevented from occurring. Therefore, it is possible to prevent the above-described drive failure and breakage, and it is also possible to reliably prevent the toner leakage. (E) When the angle is 90 °, the toner feeding force by the feeding means 17 is 0%, and the toner feeding force by gravity is 1
Feeding means 17 when the angle is 0 ° and the angle is 0 °.
Is assumed to be 100% and the toner feeding force due to gravity is assumed to be 0%, the sum of the toner feeding force due to the feeding means 17 and the toner feeding force due to gravity is the sum of all of the developing devices. Is 70% to 80%, it is possible to more reliably prevent the image density from becoming too high or the occurrence of defective development. That is, if the sum of the toner feeding force of the feeding unit 17 and the toner feeding force due to gravity is less than 70%, a shortage of toner supply to the developing roller 12 may occur, resulting in poor development. Yes, conversely 80%
Is exceeded, toner may be excessively supplied around the developing roller 12 and the image density may become excessively high. However, according to the image forming apparatus of this embodiment, the toner The sum of the supply force and the toner supply force due to gravity is 70% for all of the plurality of developing devices.
% To 80%, it is possible to more reliably prevent the image density from becoming excessively high or developing defects. Therefore, it is possible to prevent the above-described drive failure and breakage, and it is also possible to reliably prevent the toner leakage. (F) The feeding means 17 includes a shaft 17b and fins provided on the shaft, and the number and / or shape and / or rigidity of the fins is changed to change the toner feeding force. Therefore, the toner feeding force of the feeding unit 17 can be easily changed. In addition, the above-described drive failure and breakage of the feeding means 17 can be more reliably and easily prevented. (G) For the developing unit 10Y and the toner cartridge 40Y having a large inclination angle, and for the developing unit 10C and the toner cartridge 40C, the supply port 44Y and the toner receiving port 10Y are provided.
aY, 44C and 10aC are configured so as to be separated from the line A2 and not to be positioned on the line A2.
0M, developing unit 10K and toner cartridge 40
For K, supply port 44M and toner receiving port 10aM,
And 44K and 10aK are located on the line A2, so that the image density becomes too high,
It is possible to more reliably prevent the occurrence of defective development. Therefore, the drive failure and breakage can be more reliably prevented, and the toner leakage can be more reliably prevented.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be appropriately modified within the scope of the present invention.

[0033]

According to any one of the first to sixth aspects of the present invention, there are provided a plurality of developing devices each having a feeding means for feeding toner toward a developing roller. In spite of the fact that a toner cartridge having a feeding means for feeding toner to the developing device is detachably provided and the toner feeding means is a rotating body such as an agitator, Even in some cases, drive failure or breakage due to an increase in the rotational load can be prevented, and development failure is less likely to occur. Further, claim 2
According to the image forming apparatus described above, even when the toner feeding means in the developing device is a rotating body such as an agitator, it is possible to reliably prevent a driving failure or breakage due to an increase in the rotating load. According to the image forming apparatus of the third aspect, it is possible to prevent the image density from becoming excessively high and the occurrence of poor development. When a blade is provided for the developing roller, toner leakage from between the developing roller and the blade can be prevented. According to the image forming apparatus of the fourth aspect, it is possible to reliably prevent the image density from becoming too high or to cause a development defect, and also to reliably prevent the drive failure or damage. Can also
The toner leakage can be reliably prevented. According to the image forming apparatus of the fifth aspect, it is possible to more reliably prevent the image density from becoming too high or to cause a development defect, and to reliably prevent the above-described drive failure or damage. In addition, the toner leakage can be reliably prevented. According to the image forming apparatus of the sixth aspect, it is possible to easily change the toner feeding force of the feeding unit, and to more reliably and easily prevent the above-described driving failure and breakage of the feeding unit. Can be.

[0034]

[Brief description of the drawings]

FIG. 1 is a schematic front sectional view showing a main part of an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a partially enlarged view of FIG. 1;

FIG. 3 is a perspective view showing a second agitator 17 (Y) in a developing device 10Y for yellow.

FIG. 4 is a perspective view showing a second agitator 17 (C) in a developing device 10C for cyan.

FIGS. 5A to 5D are explanatory diagrams of a toner feeding force by an agitator.

FIG. 6A is a perspective view showing an example of an agitator, and FIG.
1) to (b3) are explanatory diagrams of a toner feeding force by the agitator.

FIG. 7 is a diagram showing an inclined state of the toner cartridge 40.

FIG. 8 is an operation explanatory view in a partially enlarged view of FIG. 7;

FIG. 9 is a partially enlarged view of FIG. 7 for explaining the operation.

FIG. 10 is a diagram illustrating an inclined state of the toner cartridge.

FIG. 11 is an explanatory view of a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoreceptor (image carrier) 10 Developing device 10a Toner receiving port 12 Developing roller 16, 17 Agitator (feeding means) 17b Shaft 17d, 17f Fin A1 First line connecting center of developing roller and feeding means H Horizontal line θ angle 40 Toner cartridge 42, 43 Agitator (feeding means) 44 Supply port A2 Second line E Separation distance

Claims (6)

[Claims] A plurality of developing devices each having a feeding unit for feeding toner toward a developing roller, the developing devices being arranged at different angles around an image carrier; A toner cartridge having a feeding means for feeding the toner is provided detachably, and in a state where the cartridge is mounted on the developing device, the toner supply port of the toner cartridge is connected to a toner receiving port provided in the developing device. A developing device in which the angle between a first line connecting the center of the developing roller and the feeding means adjacent to the developing roller and a horizontal line is large, the toner cartridge And the toner receiving port of the developing device are separated from the second line connecting the adjacent feeding means between the developing device and the toner cartridge, and are positioned on the second line. For a developing device in which the angle between the first line and the horizontal line is small, the supply port of the toner cartridge and the toner receiving port of the developing device are adjacent to each other between the developing device and the toner cartridge. An image forming apparatus configured to be located on a second line connecting the feeding means to be connected to each other. 2. The separation distance between the supply port and the toner receiving port from the second line increases as the angle between the first line and the horizontal line increases. 2. The image forming apparatus according to 1. 3. The developing device according to claim 1, wherein an angle between the first line and the horizontal line is large, and a toner feeding force of the feeding unit in the developing device is smaller than that in a developing device having the small angle. Item 3. The image forming apparatus according to Item 1 or 2. 4. The developing device according to claim 1, wherein the sum of the toner feeding force of the feeding means and the toner feeding force by gravity is substantially the same for all of the plurality of developing devices. Item 4. The image forming apparatus according to Item 3. 5. When the angle is 90 °, the toner feeding force of the feeding unit in the developing device is 0%, the toner feeding force by gravity is 100%, and the angle is 0 °.
In the developing device, the toner feeding force by the feeding means is 100%, and the toner feeding force by gravity is 0%.
Assuming that, the toner feeding force by the feeding means,
The image forming apparatus according to claim 4, wherein the sum of the toner supply force due to gravity is 70% to 80% for all of the plurality of developing devices. 6. The feeding means has a shaft and fins provided on the shaft, and the number and / or the shape and / or the rigidity of the fins are changed to increase the toner feeding force. 6. The image forming apparatus according to claim 3, wherein the image forming apparatus is changed.