JPH05134542A - Toner supplying device of developing device - Google Patents

Abstract

PURPOSE:To maintain the specified distribution state of toners in a developing device even if copying is continuously executed by using paper of a small size with an electrophotographic copying device using paper of a large size. CONSTITUTION:A toner supplying device 15 provided with transporting screws 16, 17 is disposed between the toner replenishing part and toner cartridge of the developing device to carry the toner by a carrying screw. A perforated plate member 20 provided with many long holes 22 and a toner supplying roll 18 are disposed in the part of the toner supplying device 15 corresponding to the developing device. A means for dropping the toners stuck to the surface of the toner supplying roll 18 from a hole group 21 is used. The hole group 21 is constituted with such a mechanism as to supply a large amt. of the toners in the central part of the developing device and to drop the toners of the amts. smaller nearer both sides thereof so as to maintain the specified concn. of the toner in the developing device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for supplying toner to a developing device using a two-component developer in an image forming apparatus such as an electronic copying machine. The present invention relates to a toner supply device of a developing device configured to supply toner and not supply excess toner to side edges.

[0002]

2. Description of the Related Art In an image forming apparatus using an electrophotographic system such as an electronic copying machine, a toner image is formed on an image bearing member such as a photosensitive drum, and the paper on which the toner image is transferred is fixed through a fixing device. Uses such means as making a copy. In order to form the toner image, a developing device is arranged corresponding to the developing area of the image carrier. In the developing device, the contained developer is adhered to the surface of the developing roller as a thin layer, and the toner is transferred to the electrostatic latent image by rubbing the image bearing member to form a visible image as a toner image. It uses the means to make it.

As the developer, a one-component developer composed of only so-called toner components, a two-component developer in which a toner component and a carrier are mixed, and the like are used. In the developing device using the two-component developer, the two-component developer is sufficiently stirred by using a stirring member, and the toner component is electrostatically attached to the periphery of the carrier and supplied to the developing roller. The mechanism is used. Further, the toner is
Since the toner image is gradually consumed as the toner image is formed, it is necessary to sequentially supply the toner image according to the consumed amount. Then, as described above, the new toner supplied to the developing device is mixed with the developer already contained in the developing device and is supplied toward the developing roller.

As described above, in order to supply new toner to the developing device, for example, Japanese Utility Model Publication No. 63-422.
A device as disclosed in Japanese Patent No. 4 is used. In the apparatus shown in the above-mentioned conventional example, two screw devices are arranged so as to be conveyed in opposite directions, and a mechanism for stirring toner by the screw devices is used. A mechanism for feeding the toner from the accommodating device such as the toner hopper to the developing device using the screw and a mechanism for moving the toner in the opposite direction by another screw arranged along the developing roller are configured. ing. Therefore, the two screws that perform the conveying action in the opposite direction perform the operation of stirring the toner and the carrier in the developing device and the operation of supplying the developer to the developing roller.

In the case of using a mechanism for supplying toner from a toner containing member, for example, Japanese Patent Publication No. 63-569.
A device such as Japanese Patent No. 91 is known. In the device of the conventional example, when supplying the toner from the toner hopper to the developing device, using the foam roll and the plate member with holes,
A mechanism is used for dropping the toner little by little through the holes provided in the holed plate member. In the toner supply device using the perforated plate member, the toner consumption amount in the central portion of the developing device is large, and the toner consumption amount at both end portions is very small. A roll member that can rotate independently of each other is provided in the section, and means for rotating only the roll member in the central portion is configured as necessary. When the toner is supplied from the toner supply device to the developing device, the toner is supplied in advance corresponding to the amount of toner consumed in the developing device. Therefore, the state of the toner distribution in the developing device. Can be maintained satisfactorily.

However, in a developing device such as Japanese Utility Model Publication No. 63-4224, there is a problem that the performance of charging the toner is not sufficiently exhibited, and even if only the problem of supplying the toner to the developing device is solved, There arises a problem that the chargeability of the two-component developer cannot be exhibited well. Further, as a means for solving the problem that the toner consumption amount is different between the central portion and both end portions, for example, as shown in the conventional example of the above-mentioned publication, a developer shunting means is disposed inside the apparatus. Then, it is conceivable to use a means for adjusting the distribution of the toner density in the developing device. By providing a stirring mechanism in combination with the flow dividing means, it is considered that the distribution of the toner inside the developing device can be set well and the problem of toner charging due to stirring can be solved.

[0007]

As described above, arranging the toner shunting means inside the developing device makes it possible to set the toner distribution state in a relatively small developing device, and to provide a stirring mechanism. By combining the above, the toner can be uniformly adhered to the developing roll to perform the developing action. However, in a large-sized image forming apparatus that uses a large-sized sheet, even if the flow dividing unit is used, the width of the developing device is very wide.
It is difficult to uniformly set the toner distribution state inside the developing device. For example, in an image forming apparatus having a maximum image forming width of 920 mm, when the work of making a copy using a sheet having a width of 420 mm is continuously performed, the toner density in the central portion of the developing device is rapidly lowered. Problem has occurred.

The above-mentioned problems are caused by the Japanese Patent Publication No. 63-63.
Even when various mechanisms of the above-mentioned conventional example except for JP-A-56991 are used, it appears that the problem of toner density distribution has a great influence on copy quality. Further, in order to eliminate the deviation of the toner in the developing device, the problem can be solved by interrupting the operation of the device and performing idle operation for a relatively long time. However, when the image forming apparatus is actually used, such idling cannot be performed.

In the case where the roll member is divided and independently rotatable as shown in Japanese Patent Publication No. 63-56991, in addition to the complicated structure of the developing device. However, there is a problem that the device becomes large.
When a problem of uneven toner density occurs inside the developing device, unevenness occurs in the density of the copy image, white spots in the image, etc. occur, which greatly affects the copy quality. Become. However, when a drawing or the like is copied using a large size paper, there are many cases where the defect cannot be easily confirmed at the time of copying. However, if there is a defect in the drawing or the like, it causes a serious problem in actually using the drawing. Therefore, in a developing device provided in a device that continuously performs copying work using a wide paper, it is desired to develop a device capable of simultaneously solving two problems of toner bias and chargeability. It is the current situation.

[0010]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problem of uneven toner density inside the developing device, and it is possible to determine the toner distribution inside the developing device for large-sized paper. It is an object of the present invention to provide a device that can be set satisfactorily and that can simplify the mechanism therefor.

[0011]

SUMMARY OF THE INVENTION According to the present invention, a developing device is arranged corresponding to an image bearing member such as a photosensitive drum, and a toner for a two-component developer is supplied to the developing device. And a means for charging the toner using a stirring mechanism inside the developing device. In the developing device of the present invention, as the first invention, the toner supply amount on the central side in the direction perpendicular to the feeding direction of image formation is 0.70 to 0 in the adjacent outer region. .9
At a ratio of 5, the supply amount is set so that the supply amount decreases in sequence, and the toner supply amount is set to 0 in the regions at both ends. As a result, in the image forming apparatus, the reference position for image formation can correspond to the toner consumption amount distribution when the center position of the apparatus is set.

As a second aspect of the present invention, in a region perpendicular to the feeding direction of image formation, the toner supply amount on the side of the edge where the side of the image is regulated is adjacent to the toner supply amount. , 0.70 to 0.95, the supply amount is set so that the supply amount decreases in sequence, and the toner supply amount is set to 0 in the side end region. As a result, in the image forming apparatus, the reference position for image formation is
It is possible to correspond to the distribution of the toner consumption amount when it is set at the side end portion of the apparatus.

Further, in the present invention, the toner supply means is composed of at least a roll-shaped member and a plate-shaped member, and the toner attached around the roll-shaped member is dropped from an opening provided in the plate-shaped member. The toner is supplied, and the toner supply amount can be adjusted by sequentially reducing the length of the openings or by sequentially changing the arrangement pitch of the openings. Further, the roll member arranged corresponding to the plate member with holes is constituted by a urethane roll, and the toner holding ability is changed by changing the degree of foaming of the urethane roll, or the plate member The toner supply amount can also be adjusted by changing the toner drop amount from the hole and changing the toner supply amount to the developing device.

In the apparatus of the present invention, the toner can be supplied in accordance with the distribution of the toner consumption amount in the developing device, and the holes are provided in accordance with the reference position of the sheet conveyance in the image forming apparatus. An array of openings in the plate member, or the length of the openings,
The toner supply performance can be set according to the degree of foaming of the roll member. When a developing device having a wide width is used, a means for distributing the toner in a good state to each area in the width direction can be realized by a simple toner supply mechanism. Therefore, even when an image forming apparatus corresponding to a wide paper is continuously copied to a narrow image, the toner density in the developing device does not deviate, and the copy quality is improved. Can be maintained in a good state.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A toner supply device of a developing device of the present invention will be described with reference to the illustrated example. In the developing device 2 shown in FIG. 1, the developing roll 3 is arranged corresponding to the photosensitive drum 1, and a mechanism for supplying a two-component developer to the developing roll 3 is provided. Inside the housing of the developing device, the layer thickness regulating member 4 is arranged corresponding to the developing roll 3 to form a thin layer of the developer, and the excessively attached developer is removed from the toner returning plate member 6. The blender 7 is caused to perform a returning action.

Further, a blender 7 and a paddle member 5 are arranged inside the housing, and the developer inside the housing, newly supplied toner, and the developing returned through the return plate member 6 are carried out. Stir the agent. In addition to that, after being used for development by the developing roll,
The developer peeled from the developing roll is mixed and stirred, and the stirring action causes the pad to be charged.
The developer is supplied to the developing roll 3 via the.

In the developing device 2, the toner supplying device 15 is arranged above the blender 7, and the toner cartridge 10 is arranged to the toner supplying device 15 via the toner replenishing portion 12. .. The toner cartridge 10 may be of any structure. An auger member 11 is provided inside a container for storing a two-component developer, and the stored toner is agitated while being agitated. A mechanism for dropping from the outlet toward the toner replenishing unit 12 is used. Further, the toner replenishing section 12 uses a mechanism for supplying the toner to the toner supply device 15 while stirring the toner using the stirring bar 13. The toner supply device 15 disposed between the toner replenishing unit 12 and the developing device 2 is configured so that two conveying screws 16 and 17 arranged in parallel are used to perform the toner conveying operation inside the housing. is doing.

The toner supply device 15 is constructed as shown in FIGS. 2 and 3, and has a housing 19
The two conveying screws 16 and 17 are arranged in parallel to the upper part of the above, and the conveying screws are driven in the conveying direction by flight, so that the toner circulating action is performed above the toner supply roll 18. In the toner supply device 15, when the position where the toner cartridge is mounted and the developing device 2 are separated,
It is possible to extend the housing of the portion for accommodating the conveying screw so that the conveying screw can perform a long-distance conveying action.

In the toner supply device 15,
In a portion corresponding to the developing device 2, a toner supply roll 18 is arranged below the conveying screw, and a plate member 20 with a hole is provided below the toner supply roll 18. The toner supply roll 18 can be configured by a conventionally used foam roll, and for example, a urethane foam roll can be used. And with respect to the plate member 20 with holes provided with a large number of long holes 22 ...
The surface of the toner supply roll 18 is slid so that the toner attached to the surface of the toner supply roll 18 is supplied from the hole group 21 toward the developing device 2.

As described above, in the apparatus for supplying the toner by combining the toner supply roll 18 and the plate member 20 with holes, the plate member 20 with holes is as follows.
A plate member having a structure as shown in FIG. 4 can be used. In the plate member 20 with holes shown in FIG. 4,
A large number of long holes 22a, 22b, 22c, ... Are provided in one row, and the toner supply roll 18 is slid with respect to the hole group 21 constituted by the large number of long holes, whereby the surface of the roll is rolled. The toner adhered to is dropped from the hole group 21 toward the developing device. Hereinafter, a case where the image forming standard is set in the central portion of the apparatus will be described. In the hole group 21, with respect to the central region M,
Areas L, K, ... On both sides of the area are set, and the long holes 22a, 22b, 22c in each area are configured such that the lengths of the openings are gradually reduced.

That is, the length of the long hole in the region L is set such that the toner supply amount in the region L is 0.70 to 0.95 with respect to the toner supply amount in the central region M. ..
The length of the opening provided in the region K outside the region L is such that the supply amount is 0.70 to 0.
Set to have a ratio of 95. As described above, in the outermost region N, a portion having no opening is formed to have a predetermined width. Then, the toner supply amount from the opening in each of the regions is gradually reduced at the same ratio so that the toner is supplied from the plate member 20 with holes toward the developing device, and the toner is supplied to both end portions. On the other hand, do not supply toner. In the present invention, apart from the toner supply method by adjusting the length of the opening, the length of the opening is set to be the same, but the toner supply amount is also adjusted by changing the arrangement pitch of the openings. It can be performed. In that case, it is possible to use means such as sequentially setting the arrangement interval of the openings to be large corresponding to the amount of toner consumed in each region.

In the apparatus in which the holed plate member having the above-mentioned structure and the urethane roll are combined, a large amount of toner drops in the central area M as shown in the graph of FIG. In L and K, the amount of toner corresponding to the ratio of the length of the opening is dropped.
Further, the toner is not supplied to the end portions on both sides of the developing device at all, and when the toner is agitated by the paddle member or the blender inside the developing device, only the toner that rotates to the outside is developed. It is equipped with a mechanism for supplying the powder to the.

In the above-mentioned toner supply device, the paper conveyance mode in the image forming apparatus is shown in the case where the paper is conveyed in alignment with the central portion of the conveyance path, and the central portion of the developing device shown in FIG. 5 is shown. The position C is set so as to match the position of the central portion of the paper. On the other hand, when the paper transport mode on the transport path is set to the so-called side registration system, the size of the opening provided in the plate member shown in FIGS. 4 and 5 and the toner supply amount Is set so that only one side is used with respect to the position C of the central portion.

That is, in the side-registration type apparatus, a small non-supplying region is arranged between the reference line of the paper and the line indicated by the reference numeral C, and the half openings on the right side of the drawing are respectively arranged. It will be arranged corresponding to the area. This small area where toner is not supplied is added because toner dust is likely to be generated when the toner concentration is high at the end of the developing device, and in order to prevent it, the toner concentration in the area is slightly lowered. This is because I want to set it. Also,
If the area where toner is not supplied is small, even if toner is not supplied to that area, the toner wraps around due to stirring of the developer. Does not lead to a decrease in

As described above, in the device provided with the mechanism for supplying the toner from the toner supplying device 15 to the developing device 2, for example, the developing device in a large electronic copying machine for handling an image of A0 width. It is possible to configure a device that supplies toner to the. With respect to the developing device 2, the perforated plate member 20 of the toner supply device 15 and the toner supply roll 1
8 and 8 are arranged corresponding to the width of the developing device, and the toner conveyed by the conveying screw is supplied into the developing device through the supply member. At that time, the degree of foaming of each region of the roll member or the plate member 2 with holes
The length of each area of the hole group 21 arranged at 0 or the arrangement pitch is set based on the data of the toner consumption amount of each area in the developing device and the like, and the toner supply amount in each area is predetermined. It can be changed at the ratio of. Then, even when a large number of copies of a relatively small size image are made, it is possible to prevent deviation of the toner density inside the developing device and maintain the image density uniform.

In the developing device shown in FIG. 1,
Inside the housing, paddle member 6 and blender 7
The developer agitating member is disposed by means of, and the action of improving the toner distribution state is performed even inside the developing device. Further, by providing a developer flow dividing means on the return plate, stirring can be promoted. However, when copying a very wide image, as described above,
Unless the mechanism for supplying the toner is particularly taken into consideration, the deviation of the toner concentration cannot be eliminated only by the stirring means inside. Then, as described above, by using the stirring member arranged inside the developing device and the toner supplying mechanism from the toner supplying device, it is possible to make the toner density uniform inside the developing device.

Further, as mentioned above, the plate member 20 with holes is provided.
In addition to setting the length of the opening provided in the above, in the present invention, the adhesion performance of the toner to the toner supply roll 18 can be formed corresponding to each area. For example, when the toner supply roll 18 is formed of a foaming roll such as urethane, the surface roughness of the urethane roll is changed corresponding to the area of the plate member with holes, and the toner supply performance is adjusted corresponding to each area. Can be configured to have That is, in the toner supply roll 18, in the central region M, a large amount of toner can be attached to the surface of the roll, and the regions L and K are arranged.
Then, the toner holding performance corresponding to the toner supply amount in the area is sequentially provided.

In order to change the toner holding performance of the roll, it is possible to separately manufacture the toner corresponding to each area and combine the roll members to form one toner supply roll. Further, when the toner supply roll as described above is used, it is possible to combine it with one in which the openings provided in the perforated plate member are set for each area. In this case, it is possible to finely adjust the toner supply amount for each area, and it is possible to obtain a better result.

[0029]

As described above, in the apparatus of the present invention, it is possible to supply the toner in accordance with the distribution of the toner consumption amount in the developing device, and the reference of the sheet conveyance in the image forming apparatus. Depending on the position, the arrangement of the openings of the plate member with holes, or the length of the openings, the degree of foaming of the roll member,
The toner supply performance can be set. When a developing device having a wide width is used, the toner can be distributed in a good state to each area in the width direction with a simple toner supply mechanism. Therefore,
The image quality of a wide paper is good, and even if you make a continuous copy of a narrow image, the toner density inside the developing device does not become uneven and the copy quality is good. Can be maintained in a good state.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of a developing device of the present invention.

FIG. 2 is a perspective view showing a configuration of a toner supply device of the present invention.

FIG. 3 is an explanatory diagram showing a relationship between a toner supply device and a plate member with holes.

FIG. 4 is a plan view showing an arrangement of hole groups provided in a plate member with holes.

FIG. 5 is a graph showing the amount of toner supplied from the perforated plate member of the present invention.

FIG. 6 is an explanatory diagram of a state of toner falling from a general opening.

[Explanation of symbols]

1 photoconductor drum, 2 developing device, 3 developing roll, 5 paddle member, 7 blender, 1
0 toner cartridge, 12 toner supply section,
15 toner supply device, 16/17 conveying screw, 18 toner supply roll, 20 plate member with holes, 21 hole group, 22 long holes.

Claims (5)

[Claims] 1. A developing device using a two-component developer containing at least a carrier and a toner is arranged corresponding to an image bearing member such as a photosensitive drum, and means for supplying the toner to the developing device is provided. In a device provided with a means for charging a developer by using a stirring mechanism inside the developing device, the toner supply means is provided with respect to the toner supply amount at the central portion side in the direction perpendicular to the image feeding direction. In the adjacent outer regions, the toner supply amount is set such that the supply amount is gradually reduced at a ratio of 0.70 to 0.95, and the toner supply amount is set to 0 in the both end regions in the vertical direction.
The toner supply device for a developing device according to claim 1, wherein the toner supply device is set to. 2. The toner supply means is arranged in a region perpendicular to an image feeding direction, in an area on the side opposite to the opposite end with respect to a supply amount on an end side where a side part of the image is regulated. , 0.
The toner supply amount is set so that the supply amount is gradually reduced at a ratio of 70 to 0.95, and the toner supply amount is set to 0 in the regions at both ends in the vertical direction.
The toner supply device for a developing device according to claim 1, wherein the toner supply device is set to. 3. The toner supply unit is composed of at least a roll-shaped member and a plate-shaped member, and supplies toner by dropping toner attached to the periphery of the roll-shaped member from an opening provided in the plate-shaped member. The toner supply device according to claim 1, wherein the toner supply amount is adjusted by sequentially reducing the length of the opening. 4. The toner supply unit is composed of at least a roll-shaped member and a plate member, and supplies toner by dropping the toner attached to the periphery of the roll-shaped member from an opening provided in the plate-shaped member. The toner supply device according to claim 1, wherein the toner supply amount is adjusted by changing the arrangement pitch of the openings. 5. The toner supply unit is composed of at least a roll-shaped member and a plate member, and supplies toner by dropping toner attached to the periphery of the roll-shaped member from an opening provided in the plate-shaped member. Along with the adjustment of the toner supply amount, the roll member is composed of a urethane roll,
3. The method according to claim 1, wherein the amount of toner dropped from the opening of the plate member is changed by changing the degree of foaming of the roll so as to change the toner holding capacity. A toner supply device of the developing device described.