JP2003255687A - Developing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably supply tone to a toner carrier by restraining a large load from being imposed on a toner supplying member for supplying the toner to the toner carrier. <P>SOLUTION: A device main body 10 is devided into a tone storage part 14 in which the toner (t) is stored and a toner supply part 15 supplying the toner to the toner carrier 11 for carrying the toner to an image carrier P with a partitioning member 12 having an aperture part 13, and an opening/closing member 16 for opening the aperture part only when the toner is guided from the toner storage part to the toner supply part is provided to guide the toner to the toner supply part through the aperture part by a toner feeding member 17 in the toner storage part, and supplied to the toner carrier by the toner supply member 18 in the developing device. In the device, the upper end of the opening/closing member is fixed on the upper side of the aperture part and also a projection 16a projecting to a toner supply part side is provided at the lower part of the opening/closing member which is not fixed. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device used for developing an electrostatic latent image formed on an image carrier in an image forming apparatus such as a copying machine or a printer, and more particularly, to a developing device inside the main body of the apparatus. By providing a partition member having an opening in
In the case where the inside of the apparatus main body is separated into a toner accommodating portion that accommodates toner and a toner supply portion that conveys toner to the image carrier and that supplies toner to the toner carrier, and the toner is guided from the toner accommodating portion to the toner supply unit. An opening / closing member for opening the opening is provided so that the toner in the toner storage unit is guided to the toner supply unit through the opening by the toner feeding member and the toner supplied to the toner supply unit is supplied to the toner carrier by the toner supply member. The developing device configured as described above is characterized in that the clogging of the toner in the toner supply unit is suppressed.

[0002]

2. Description of the Related Art Conventionally, a developing device used in an image forming apparatus such as a copying machine or a printer does not use a carrier in addition to a two-component developing system using a toner and a carrier as a developer. There is known a one-component developing system using only toner.

Here, in the one-component developing system using only toner as the developer as described above, generally, as shown in FIG. 1, the toner t accommodated in the main body 1 of the apparatus is fed. The member 2 sends the toner to the roller-shaped toner supply member 3, the toner supply member 3 is rotated to supply the toner t to the roller-shaped toner carrier 4, and the toner t thus supplied is supplied. The toner carrier 4 is conveyed by rotation, and a regulating member 5 is brought into pressure contact with the surface of the toner carrier 4 to regulate the amount of the toner t conveyed by the toner carrier 4 by the regulating member 5 and the toner. t was triboelectrically charged.

Then, the toner t thus regulated and charged is guided by the toner carrier 4 to the developing area facing the image carrier P, and the electrostatic latent image formed on the image carrier P is developed. Was doing.

After developing in this way, the toner t remaining on the surface of the toner carrier 4 is returned to the inside of the apparatus main body 1, and the toner t is carried by the toner supply member 3. The toner 4 is separated from the surface of the body 4 and new toner t is supplied to the toner carrier 4.

However, when the regulating member 5 is pressed against the surface of the toner carrier 4 as described above to regulate the amount of the toner t conveyed by the toner carrier 4, the toner t having a large particle size is used. Is released from the toner carrier 4,
The toner t having a small particle diameter is used for the development first, and the toner t remaining on the toner carrier 4 after the development is used.
Even when the toner is removed, the toner t having a large particle diameter comes to be removed from the toner carrier 4, and the proportion of the toner t having a large particle diameter gradually increases in the apparatus main body 1 to improve the image quality of the image formed. There was a problem that it decreased.

Therefore, in recent years, as shown in FIG. 2, the partition member 6 having an opening 6a in the main body 1 of the apparatus.
Is provided to separate the inside of the apparatus main body 1 into a toner storage portion 1a for storing the toner t and a toner supply portion 1b for supplying the toner t to the toner carrier 4, and the toner carrier 4 as described above.
The toner t having a large particle diameter separated from the toner storage unit 1
A developing device that suppresses the return to a has come to be used.

On the other hand, in recent years, a color image forming apparatus has come to be used in which a plurality of developing devices store toners of different colors to form a color image.

As one of such color image forming apparatuses, as shown in FIG. 3, four developing devices 1A to 1D accommodating toners of different colors are held on a rotary support 7 and are rotated. The one in which the support 7 is rotated so that each of the developing devices 1A to 1D is sequentially guided to a position facing the image carrier P for development is used.

Here, when the developing device shown in FIG. 2 is used for each of the developing devices 1A to 1D in such a color image forming apparatus, the rotary support 10 holding the developing devices 1A to 1D is used. When the toner rotates, the toner supply unit 1b
The toner t having a large particle diameter is returned to the toner containing portion 1a, the effect of providing the partition member 6 having the opening 6a is lost, and only the toner t having a small particle diameter is used for the development first, However, there still remains a problem that the image quality of the image formed gradually deteriorates due to the large toner t remaining.

Therefore, the applicant of the present invention has filed in Japanese Patent Application Laid-Open No. 2001-2001.
As disclosed in JP 331028 A and JP 2001-3331038 A, an opening / closing member for opening / closing the opening is attached to the partition member, and the opening is opened only when the toner is guided from the toner storage unit to the toner supply unit. In this way, a developing device has been developed which prevents the toner having a large particle diameter in the toner supply portion from returning to the toner storage portion.

However, when the opening / closing member for opening and closing the opening is attached to the partition member and the opening is opened only when the toner is guided from the toner accommodating portion to the toner supplying portion, the toner supplying portion is opened. A large amount of toner is supplied, or the toner stays in the toner supply unit without being circulated well, the toner is clogged in the toner supply unit, and a large load is applied to the rotation of the toner supply member that supplies the toner to the toner carrier. Problems arise such that the toner cannot be stably supplied to the toner carrier, or the toner is used for development in a state where the toner is not sufficiently charged, and fogging occurs in an image formed.

[0013]

SUMMARY OF THE INVENTION According to the present invention, a partition member having an opening is provided in a main body of an apparatus, a toner storage section for storing toner in the main body of the apparatus, and a toner carrying unit for carrying the toner to an image carrier. An opening / closing member that separates the toner supply unit that supplies toner to the body and opens the opening only when the toner is guided from the toner storage unit to the toner supply unit is provided, and the toner in the toner storage unit is opened by the toner feeding member. It is an object of the present invention to solve the above problems in a developing device in which the toner in the toner supply unit is supplied to the toner carrier by the toner supply member while being guided to the toner supply unit through the unit.

That is, according to the present invention, in the developing device as described above, it is possible to prevent a large amount of toner from being supplied from the toner storage portion to the toner supply portion and to prevent the toner from staying in the toner supply portion. An object of the present invention is to prevent the toner supply unit from being clogged, prevent a large load from being applied to the toner supply member, and stably supply the toner to the toner carrier.

[0015]

In the first developing device of the present invention, in order to solve the above problems, a partitioning member having an opening is provided in the main body of the device,
In the case where the inside of the apparatus main body is separated into a toner accommodating portion that accommodates toner and a toner supply portion that conveys toner to the image carrier and that supplies toner to the toner carrier, and the toner is guided from the toner accommodating portion to the toner supply unit. An opening / closing member for opening the above-mentioned opening is provided only for the above, and a toner feeding member for guiding the toner in the above-mentioned toner storage section to the toner supply section through the above-mentioned opening is provided, and the toner in the toner supply section is supplied to the toner carrier. In a developing device provided with a toner supply member, the upper end of the opening / closing member is fixed to the upper side of the opening, and a protrusion protruding toward the toner supply unit is provided below the opening / closing member that is not fixed. I did it.

As in the first developing device of the present invention, the upper end of the opening / closing member for opening the opening is fixed to the upper side of the opening only when the toner is introduced from the toner containing portion to the toner supply portion. In addition, if a protrusion protruding toward the toner supply unit is provided in the lower portion of the open / close member that is not fixed, when the toner is supplied from the toner storage unit to the toner supply unit to some extent, the toner in the toner supply unit causes the open / close member and the lower portion thereof. While the protrusion provided on the protrusion is pushed toward the partition member, the pressure of the toner is applied from above the protrusion.

Therefore, when the toner is accumulated to some extent in the toner supply portion, the opening / closing member is strongly pushed toward the partition member side, and even if the toner in the toner containing portion is guided to the opening portion by the toner feeding member. The opening / closing member keeps the opening in a closed state, the toner is prevented from being excessively supplied to the toner supply unit, and the toner is prevented from clogging the toner supply unit, and a large load is applied to the toner supply member. Therefore, the toner can be stably supplied to the toner carrier.

In the first developing device, a rotating toner supply roller is used as the toner supply member, and the toner supply roller is provided at the upper end side where the open / close member is fixed at a portion facing the open / close member. When you rotate it from the bottom to the side where the protrusion is provided,
Along with the rotation of the toner supply roller, the toner is conveyed from the fixed upper end of the opening / closing member to the lower side where the protrusion is provided at the portion facing the opening / closing member, and the force of the toner thus conveyed. In addition to the above-mentioned protrusion, the opening / closing member is further strongly pushed toward the partition member.

Further, in the second developing device of the present invention, in order to solve the above problems, a partition member having an opening is provided in the main body of the apparatus to store toner in the main body of the apparatus. And a toner supply unit that supplies toner to the toner carrier that conveys toner to the image carrier, and opens and closes the opening only when guiding the toner from the toner storage unit to the toner supply unit. A member is provided, and a toner feeding member that guides the toner in the toner storage unit to the toner supply unit through the opening is provided, and the toner in the toner supply unit is rotated by being rotated while being pressed against the toner carrier. In a developing device provided with a toner supply roller for supplying the carrier, the toner supply roller is rotated by the rotation of the toner supply roller. When the toner is conveyed in the direction of gravity in between the partition member, the above-mentioned toner supply roller and the toner carrying member are in contact with the circumferential direction of the nip width x
(Mm) and the length y (mm) of the closest portion between the partition member side and the toner supply roller are 1.1xy.
The condition of> 0.5 is satisfied.

As in the second developing device of the present invention, when the toner supply roller is rotated so that the toner is conveyed in the direction of gravity between the toner supply roller and the partition member, Toner is guided below the partition member through a space between the toner supply roller and the partition member, and this toner is supplied to the toner carrier by a rotating toner supply roller to a nip portion in contact with the toner carrier. Along with this toner supply roller, the toner not supplied to the toner carrier is further guided to the downstream side in the rotation direction of the toner supply roller, and is guided to the portion where the partition member and the toner supply roller face each other.
The toner thus guided to the portion where the partition member and the toner supply roller face each other is conveyed in the direction of gravity between the toner supply roller and the partition member by the rotation of the toner supply roller as described above, and inside the toner supply unit. The toner is circulated at.

As in the second developing device of the present invention, the circumferential nip width x (mm) at which the toner supply roller and the toner carrier contact each other, and between the partition member side and the toner supply roller. The length y (m
and m) satisfy the condition of 1.1x-y> 0.5, the toner is appropriately circulated in the toner supply unit as described above and the toner is prevented from clogging the toner supply unit. As a result, a large load is not applied to the toner supply roller, and the toner is stably supplied to the toner carrier. Further, in order to more properly circulate the toner in the toner supply unit, the nip width x (mm) and the length y (mm) of the closest portion are 1.1x−. It is preferable to satisfy the condition of y> 2.

In the third developing device of the present invention, in order to solve the above problems, a partition member having an opening is provided in the main body of the apparatus to store toner in the main body of the apparatus. And a toner supply unit that supplies toner to the toner carrier that conveys toner to the image carrier, and opens and closes the opening only when guiding the toner from the toner storage unit to the toner supply unit. A member is provided, and a toner feeding member that guides the toner in the toner storage unit to the toner supply unit through the opening is provided, and the toner in the toner supply unit is rotated by being rotated while being pressed against the toner carrier. In a developing device provided with a toner supply roller for supplying the carrier, the toner supply roller is rotated by the rotation of the toner supply roller. When toner is conveyed between the partition member and the direction opposite to the direction of gravity, the nip width x (mm) in the circumferential direction where the toner supply roller and the toner carrier contact each other, and the partition member side. The length y (mm) of the closest portion to the toner supply roller is 0.
The condition of 8x-y <1.5 was satisfied.

Here, like the third developing device in the present invention, the rotation of the toner supply roller causes the toner to be conveyed between the toner supply roller and the partition member in the direction opposite to the direction of gravity. With this setting, the toner below the toner supply roller is conveyed to the partition member side, the toner is guided upward through the space between the partition member and the toner supply roller, and this toner is separated between the toner supply roller and the toner carrier. The toner not supplied to the toner carrier is supplied to the lower part of the toner supply roller as it is supplied to the toner carrier at the contacting nip portion. The toner guided to the partition member is conveyed to the partition member side as described above, and this toner passes between the partition member and the toner supply roller. Guided upwards Te, so the toner is circulated in the toner supply unit.

As in the third developing device of the present invention, the circumferential nip width x (mm) at which the toner supply roller and the toner carrier contact each other, and between the partition member side and the toner supply roller. The length y (m
and m) satisfy the condition of 0.8x−y <1.5, the toner is appropriately circulated in the toner supply unit as described above, and the toner is prevented from clogging the toner supply unit. As a result, a large load is not applied to the toner supply roller, and the toner is stably supplied to the toner carrier. Further, in order to more properly circulate the toner in the toner supply unit, the nip width x (mm) and the length y (mm) of the closest portion are 0.8x−. It is preferable to satisfy the condition of y <0.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A developing device according to an embodiment of the present invention will be specifically described below with reference to the accompanying drawings.

(Embodiment 1) In the developing device in this embodiment, as shown in FIG. 4, the toner carrier 11 which holds the toner t on its surface and guides it to the developing area facing the image carrier P is imaged. The support member P is provided so as to face the support member P at a required interval, and the opening 13 is provided in the apparatus main body 10.
The partitioning member 12 having the above is provided to separate the toner storage unit 14 that stores the toner t and the toner supply unit 15 that supplies the toner t to the toner carrier 11.

Then, the upper end of a sheet-like opening / closing member 16 for opening / closing the opening 13 is fixed to the upper side of the opening 13 on the toner supply unit 15 side of the partition member 12, and A protrusion 16a protruding toward the toner supply unit 15 is provided at the lower end of the opening / closing member 16, and the lower end of the opening / closing member 16 provided with the protrusion 16a is rotated to open / close the opening 13. Has become.

A toner feeding member 17 having a flexible blade member 17a at its tip is rotatably provided in the toner containing portion 14, and the toner feeding member 17 is provided.
Is rotated to guide the toner t accommodated in the toner accommodating portion 14 by the blade member 17a to the opening portion 13 closed by the opening / closing member 16.

Here, when the amount of the toner t in the toner supply unit 15 is small, as shown in FIG. 4, the opening / closing member is opened by the toner t guided to the opening 13 by the toner feeding member 17 as described above. 16 is pressed, the lower end of the opening / closing member 16 is bent toward the toner supply unit 15 side to open the opening 13, and the toner t is supplied to the toner supply unit 15 through the opening 13 thus opened. become.

Further, in the toner supply section 15 to which the toner t has been supplied in this way, a toner supply roller 18 is provided so as to come into contact with the toner carrier 11, and this toner supply roller 18 is used as toner. The toner supply roller 18 is rotated in the same direction as the carrier 11, and at the portion where the toner supply roller 18 and the toner carrier 11 are in contact with each other, the toner supply roller 18 moves from the lower side to the upper side in the opposite direction to the toner carrier 11. In this way, the toner t is supplied from the toner supply roller 18 to the surface of the toner carrier 11.

Then, the toner carrier 11 thus supplied with the toner t is rotated, and the toner carrier 11 is rotated.
The toner t is conveyed by means of, and the respective end portions of the V-shaped regulating member 19 are brought into pressure contact with the surface of the toner carrying member 11 so that the amount of the toner t carried by the toner carrying member 11 is regulated by this regulating member. In addition to being regulated by 19, the toner t is charged by the regulating member 19.

Then, the toner t thus regulated and charged by the regulating member 19 is conveyed by the toner carrier 11 to the developing area facing the image carrier P, and the toner biasing power source (see FIG. A developing bias voltage is applied from not shown) to supply the toner t from the toner carrier 11 to the electrostatic latent image portion formed on the image carrier P for developing.

Here, in the developing device of this embodiment, the toner t accommodated in the toner accommodating portion 14 as described above is supplied to the toner supplying portion 15 through the opening portion 13, and as shown in FIG. When a certain amount of toner t is accumulated in the toner supply unit 15, the accumulated toner t pushes the opening / closing member 16 and the protrusion 16a provided under the opening / closing member 16 toward the partition member 12 side, and In accordance with the rotation of the toner supply roller 18 that rotates, the toner t is conveyed from the fixed upper end side of the opening / closing member 16 to the lower side where the protrusion 16a is provided in a portion facing the opening / closing member 16. The force of the toner t thus conveyed is applied to the protrusion 16a, and the opening / closing member 16 is strongly pushed toward the partition member 12 side.

Therefore, even when the toner t is guided to the opening 13 by the rotating toner feeding member 17 and the opening / closing member 16 is pushed, the opening 13 is blocked by the opening / closing member 16. This prevents the toner t from being excessively supplied to the toner supply unit 15 and clogging of the toner supply unit 15 with the toner t, thereby preventing a large load from being applied to the rotation of the toner supply roller 18. The toner supply roller 18 appropriately rotates and the toner is stably supplied to the toner carrier 11.

Here, in the developing device in this embodiment, the opening 13 in the partition member 12 is
As shown in FIG. 6, a rectangular small opening 13 is formed.
A plurality of such openings 13 are provided at a required interval, and a plurality of such openings 13 are formed into a sheet-like opening / closing member 16
However, it is also possible to provide the partition member 12 with one long rectangular opening 13.

Further, as shown in FIG. 7, a plurality of small opening / closing members 16 may be provided so as to correspond to the small opening 13 having a rectangular shape, or as shown in FIG.
It is also possible to provide the small opening 13 having the rectangular shape only on both sides of the partition member 12 and provide the small opening / closing member 16 for each opening 13. As shown in FIG. 8, if the rectangular small openings 13 are provided only on both sides of the partition member 12, the toner t is supplied from the toner storage section 14 to the toner supply section 15 only on both sides of the partition member 12. The toner t supplied to both sides of the toner supply unit 15 is sequentially sent to the central portion of the toner supply unit 15, and the amount of the toner t in the toner supply unit 15 becomes uniform. To be done.

In the developing device of this embodiment, the opening / closing member 16 is linearly attached to the partition member 12, but the force for pressing the opening / closing member 16 toward the partition member 12 is increased. As shown in FIG. 9, a partition member 1 for fixing the upper end of the opening / closing member 16
2 is provided with an inclined convex portion 12a so that the upper end portion of the opening / closing member 16 is bent, or as shown in FIG. 10, the holding member 16 is provided on the toner supply unit 15 side of the opening / closing member 16.
It is also possible to attach b.

(Experiment 1) In this experiment, the protrusion 1 is formed on the opening / closing member 16 as in the developing device shown in the first embodiment.
6A was provided, and a developing device of a comparative example in which the projection 16a was not provided on the opening / closing member 16 was examined for changes in drive torque applied to the drive system of the entire developing device.

Here, in this experiment, the partition member 12 has an opening 13 having a height of 6 mm and a width of 5 mm.
Six small openings 13 having a size of 5 mm are provided at intervals of 2 mm, while the opening / closing member 16 has a height of 12 mm.
mm, the width is 342 mm, and the thickness is 50 μm. One piece of polyethylene terephthalate film is used, and the partition member 12 on the upper side of the opening 13 is fixed to a portion 6 mm from the upper end of the opening / closing member 16. The lower end of the opening / closing member 16 is located 1 m below the lower end of the opening 13.
It was made to project. The opening / closing member 16 made of polyethylene terephthalate film has a Young's modulus of 4
It was Mpa.

In the developing device of the embodiment, the protrusion 1 made of ABS resin having a thickness of 1 mm, a height of 2 mm and a width of 342 mm is provided along the lower end of the opening / closing member 16.
6a was attached, and the lower end of the protrusion 16a was positioned 1 mm below the lower end of the opening 13. On the other hand, in the developing device of the comparative example, such a protrusion 16a is not attached.

In this experiment, the toner feeding member 17 was set to 60 rpm in the developing device as described above.
The toner t is guided to the opening 13 and the toner carrier 11 having a diameter of 14 mm is rotated by 200 r.
The toner supply roller 18 is rotated at 300 rpm in the same direction as the toner carrier 11 at the same time as the toner carrier 11 is rotated at pm.
The toner t is fed from the toner supply roller 18 so as to move upward from the lower side in the opposite direction.
To supply to the surface of.

Then, in a state where the toner t is not present in the toner supply unit 15, each developing device of the above-described embodiment and comparative example is driven for 9 minutes under the above conditions, and is added to the drive system of each developing device as a whole. The change in driving torque (N · m) was examined, and the results are shown in Table 1 below.

[0043]

[Table 1]

As is clear from these results, in the developing device of the embodiment using the opening / closing member 16 having the protrusion 16a attached to the lower end, the developing device of the comparative example using the opening / closing member 16 not attached with the protrusion 16a. Unlike the device, the drive torque did not gradually increase.

(Experiment 2) In this experiment, the height of the opening / closing member 16 used in the above Experiment 1 was extended by 2 mm, and the lower end of the opening / closing member 16 was projected 3 mm below the lower end of the opening 13. .

Then, the position of the protrusion 16a attached to the opening / closing member 16 is changed as shown in Table 2 below, and the toner t is not present in the toner supply unit 15 in the same manner as in the above case. , And each of them is driven for 9 minutes to obtain the amount of the toner t existing in the toner supply unit 15,
The results are shown in the table.

The protrusion 16 attached to the opening / closing member 16
Regarding the position of a, the difference in height between the lower end of the protrusion 16a and the lower end of the opening 13 is indicated by-when the lower end of the protrusion 16a is located below the lower end of the opening 13. Also,
In the toner supply unit 15 described above, the amount of toner t is 2
It was full with 8g.

[0048]

[Table 2]

As a result, the lower end of the protrusion 16a is located at the opening 13
When it is located 3 mm below the lower end of the toner, the toner t is almost not supplied to the toner supply portion 15, while the protrusion 1
When the lower end of 6a is located 1.5 mm above the lower end of the opening 13, the toner supply unit 15 is in a state where the toner t is excessively filled.

Therefore, when the protrusion 16a is attached to the opening / closing member 16, it is preferable that the lower end of the protrusion 16a is located at a position of -2 mm to 1 mm with respect to the lower end of the opening 13, and further -1 mm to 0 mm. It was more preferable to attach so that the position would be.

(Experiment 3) In this experiment, the thickness of the opening / closing member 16 and the projection 16a used in the above Experiment 1 were used.
The thickness of the toner supply unit 1 was changed as shown in Table 3 below, and otherwise the same as in Experiment 1 above.
5 was driven for 9 minutes in the absence of the toner t, and the amount of the toner t existing in the toner supply unit 15 was obtained. The results are shown in the same table.

[0052]

[Table 3]

As a result, the thickness of the opening / closing member 16 and the protrusion 16
As the thickness of “a” increases, the amount of toner t existing in the toner supply unit 15 decreases.

Although not shown in this experiment, as the Young's modulus of the opening / closing member 16 becomes higher, the opening / closing member 16 becomes less likely to be deformed, and the amount of the toner t existing in the toner supply unit 15 decreases.

Then, in this experiment, when the amount of the toner t existing in the toner supply unit 15 becomes 9 g or less,
The toner t is not properly supplied to the toner carrier 11, and the thickness of the opening / closing member 16 having a Young's modulus of 4 MPa is 100 μm.
m, when the thickness of the protrusion 16a is 2 mm,
The amount of the toner t existing in the toner supply unit 15 was 5 g, and the toner t was not sufficiently supplied to the toner carrier 11.

As a result, the Young's modulus A (p
a), the thickness B (m) of the opening / closing member 16 and the thickness C (m) of the protrusion 16a are considered to satisfy the relationship of A × B × C <0.8 (Pa · m ² ). To be

(Embodiment 2) As shown in FIG. 11, the developing device of this embodiment has substantially the same structure as that of the developing device of Embodiment 1 described above, and is therefore the same as the developing device of Embodiment 1. The description of the components will be omitted, and the features of the developing device in this embodiment will be described.

Here, in the developing device of this embodiment, as shown in FIGS. 11 and 12, the opening / closing member 16 for opening / closing the opening 13 provided in the partition member 12 is opened.
The protrusion 16a is not provided at the lower end of the toner supply roller 18, and the toner supply roller 18 is pressed against the surface of the toner carrier 11 so that the toner supply roller 18 and the toner carrier 11 have an appropriate nip width x (in the circumferential direction). mm).

In the developing device of this embodiment, the toner supply roller 18 is rotated in the same direction as the toner carrier 11 as in the developing device of the first embodiment, and the toner supply roller 18 is rotated. Due to the rotation, the toner t passes between the toner supply roller 18 and the partition 12 material.
Are transported in the direction of gravity.

Here, in the developing device of this embodiment, the nip width x (mm) in the circumferential direction in which the toner supply roller 18 and the toner carrier 11 contact each other, the partition member 12 side and the toner supply roller 18 are formed. By adjusting the length y (mm) of the closest portion through which the toner t passes, the nip width x (mm) and the length y (mm) of the closest portion are 1.1x-y> 0. The condition of .5 is satisfied.

When the above conditions are satisfied, the toner supply roller 18 rotates and
The toner t between the toner supply roller 18 and the partition member 12 is appropriately conveyed in the gravity direction, and the toner t is guided below the partition member 12. In addition, the toner t guided below the partition member 12 is guided to the nip portion in contact with the toner carrier 11 by the rotating toner supply roller 18, and the toner t is supplied to the toner carrier 11 at this nip portion. Meanwhile,
The toner t that has not been supplied to the toner carrier 11 is further conveyed by the rotation of the toner supply roller 18, and is guided to a portion where the partition member 12 and the toner supply roller 18 face each other. The toner t guided to the portion facing the toner supply roller 18 is conveyed in the gravity direction between the toner supply roller 18 and the partition member 12 by the rotation of the toner supply roller 18 as described above, and the toner supply unit 15 The toner t is properly circulated inside.

As a result, the toner t is prevented from staying and clogging in the toner supply unit 15, and the toner supply roller 18 is prevented.
Does not add a heavy load to.

(Experiment 4) In this experiment, a urethane foam roller was used as the toner supply roller 18 in the developing device shown in Embodiment 2 and the following Table 4 was used.
As shown in FIG. 13, the outer diameter of the toner supply roller 18 and the like are changed so that the nip width x (mm) in the circumferential direction in which the toner supply roller 18 and the toner carrier 11 are in contact with each other,
The length y (mm) of the closest portion where the toner t passes between the partition member 12 side and the toner supply roller 18 was changed, and the value of 1.1x-y is shown in Table 4.

Then, the developing device is driven under each condition shown in Table 4 and FIG. 13, the change of the drive torque applied to the drive system of the entire developing device is examined, and the case where the drive torque is average and there is almost no change is indicated by ○. Table 4 and FIG. 13 show Δ when the driving torque fluctuates cyclically, and x when the driving torque increased and the initial 1.4 times or more continued.

[0065]

[Table 4]

As a result, the circumferential nip width x (mm) at which the toner supply roller 18 and the toner carrier 11 contact each other.
And the length y (mm) of the closest portion between the partition member 12 side and the toner supply roller 18 is 1.1x-y>.
When the conditions of 0.5 and y <1.1x-05 are satisfied,
The drive torque did not continue to increase greatly, and when the conditions of 1.1x-y> 2 and y <1.1x-2 were satisfied, the change in drive torque was very small.

(Embodiment 3) The developing device in this embodiment is also configured in substantially the same manner as the developing device in the first embodiment, as shown in FIG. 14, and is therefore the same as the developing device in the first embodiment. The description of the components will be omitted, and the features of the developing device in this embodiment will be described.

Here, in the developing device of this embodiment, as shown in FIG. 14 and FIG.
Similarly to the developing device of the above, the projection 16a is provided on the lower end of the opening / closing member 16 for opening and closing the opening 13 provided in the partition member 12.
The toner supply roller 18 described above.
Is pressed against the surface of the toner carrier 11 so that the toner supply roller 18 and the toner carrier 11 are in contact with each other with an appropriate nip width x (mm) in the circumferential direction.

In the developing device of this embodiment, unlike the developing devices of Embodiments 1 and 2, the toner supply roller 18 is rotated in the opposite direction,
By the rotation of the toner supply roller 18, the toner t is conveyed between the toner supply roller 18 and the partition 12 material in the direction opposite to the direction of gravity.

In the developing device of this embodiment, the nip width x (mm) in the circumferential direction in which the toner supply roller 18 and the toner carrier 11 are in contact with each other, and between the partition member 12 side and the toner supply roller 18. The length y (mm) of the closest portion through which the toner t passes is adjusted so that the nip width x (mm) and the length y (mm) of the closest portion are 0.8x-y <1. The condition of 5 is satisfied.

When the above conditions are satisfied, the toner supply roller 18 rotates and
The toner t between the toner supply roller 18 and the partition member 12 is appropriately conveyed in the direction opposite to the direction of gravity, and this toner t is further rotated with the rotation of the toner supply roller 18 and the toner carrier 11. The toner t is supplied to the toner carrier 11 in this nip part where the toner t is not supplied to the toner carrier 11 while the toner t is further conveyed by the rotation of the toner supply roller 18. Then, the toner is fed between the toner supply roller 18 and the partition member 12,
The toner t is properly circulated in the toner supply unit 15.

As a result, the toner t is prevented from staying and clogging in the toner supply unit 15, and the toner supply roller 18 is prevented.
Does not add a heavy load to.

(Experiment 5) In this experiment, a urethane foam roller was used as the toner supply roller 18 in the developing device shown in the third embodiment, and the following Table 5 was used.
As shown in FIG. 16, by changing the outer diameter of the toner supply roller 18 and the like, the nip width x (mm) in the circumferential direction in which the toner supply roller 18 and the toner carrier 11 are in contact with each other,
The length y (mm) of the closest portion where the toner t passes between the partition member 12 side and the toner supply roller 18 was changed, and the value of 0.8xy was shown in Table 5.

Then, the developing device is driven under each condition shown in Table 5 and FIG. 16, and the change of the drive torque applied to the drive system of the entire developing device is examined. When the drive torque is average and there is almost no change, Table 5 and FIG. 16 show Δ when the drive torque fluctuates periodically, and x when the drive torque increased and the initial state was 1.4 times or more.

[0075]

[Table 5]

As a result, the nip width x (mm) in the circumferential direction where the toner supply roller 18 and the toner carrier 11 are in contact with each other.
And the length y (mm) of the closest portion between the partition member 12 side and the toner supply roller 18 is 0.8x−y <
When the conditions of 1.5 and y> 0.8x-1.5 are satisfied, the driving torque does not continue to be greatly increased, and particularly when 0.8x-y <0 and y> 0.8x are satisfied. When the condition was satisfied, the change in drive torque was very small.

In the developing devices of Embodiments 2 and 3 described above, the projection 16a is not provided at the lower end of the opening / closing member 16, but the opening / closing member 16 is the same as in the developing device of Embodiment 1 above. It is also possible to provide a protrusion 16a at the lower end of the partition member 12, and in this case, the partition member 12
The length y (mm) of the closest portion between the side and the toner supply roller 18 is the toner supply roller 18 and the protrusion 16a.
Can be between

[0078]

As described in detail above, in the first developing device according to the present invention, the upper end portion of the opening / closing member that opens the opening only when the toner is guided from the toner storage portion to the toner supply portion is opened. When the toner is accumulated in the toner supply part to some extent, the toner inside the toner supply part opens and closes when the toner is accumulated to some extent. The member and the protrusion provided on the lower portion thereof are pushed toward the partition member side, and the pressure of the toner is applied from above the protrusion, so that the opening / closing member is strongly pushed toward the partition member side.

As a result, in the first developing device of the present invention, when the toner is accumulated in the toner supply portion to some extent, the toner in the toner storage portion is guided to the opening portion by the toner feeding member. The opening / closing member keeps the opening in a closed state, prevents toner from being excessively supplied to the toner supply unit and clogging in the toner supply unit, and prevents a large load from being applied to the toner supply member. The toner is now stably supplied to the carrier.

In the first developing device, a rotating toner supply roller is used as the toner supply member, and the toner supply roller is projected from the upper end side where the opening / closing member is fixed in a portion facing the opening / closing member. When the toner supply roller is rotated toward the lower side, the toner flows along with the rotation of the toner supply roller from the upper end side where the opening and closing member is fixed to the lower side where the protrusion is provided. Then, the force of the toner thus conveyed is applied to the protrusions, so that the opening / closing member is further strongly pushed toward the partition member.

Further, in the second developing device of the present invention, when the toner supply roller is rotated to convey the toner in the gravity direction between the toner supply roller and the partition member, the toner supply roller and the toner A circumferential nip width x (mm) in contact with the carrier,
Since the length y (mm) of the closest portion between the partition member side and the toner supply roller satisfies the condition of 1.1x−y> 0.5, the toner appropriately circulates in the toner supply unit. Came to be.

As a result, in the second developing device according to the present invention, the toner is prevented from staying in the toner supply portion and clogging, and the toner is not applied to the toner supply member, and the toner is not applied to the toner carrier. Has become a stable supply.

Further, in the third developing device of the present invention, when the toner is fed between the toner feeding roller and the partition member by the rotation of the toner feeding roller in the direction opposite to the direction of gravity, the toner is fed. The circumferential nip width x (m in which the roller and the toner carrier contact)
m) and the length y (mm) of the closest portion between the partition member side and the toner supply roller are 0.8xy-
Since the condition of 1.5 is satisfied, the toner is properly circulated in the toner supply unit.

As a result, in the third developing device according to the present invention, the toner is prevented from staying and clogging in the toner supply portion, the toner supply member is not subjected to a large load, and the toner is carried on the toner carrier. Has become a stable supply.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a conventional developing device.

FIG. 2 is a schematic explanatory diagram of a conventional developing device in which a partition member having an opening is provided in the main body of the device.

FIG. 3 is a drawing in which four developing devices accommodating toners of different colors are held on a rotary support, and the rotary supports are rotated so that each developing device is sequentially guided to a position facing the image carrier. FIG. 3 is a schematic explanatory diagram of a color image forming apparatus that is configured to perform development.

FIG. 4 is a schematic explanatory diagram showing a state in which toner is supplied into the toner supply unit in the developing device according to the first embodiment of the present invention.

FIG. 5 is a schematic explanatory view showing a state in which the toner is accumulated in the toner supply unit to some extent and the toner is not supplied to the toner supply unit in the developing device of the first embodiment.

FIG. 6 is a partial explanatory view showing a state in which the opening / closing member for opening / closing the opening is attached to the partition member in the developing device of the first embodiment.

FIG. 7 is a partial explanatory view showing a first modified example in which the opening / closing member for opening / closing the opening is attached to the partition member in the developing device of the first embodiment.

FIG. 8 is a partial explanatory view showing a second modified example in which the opening / closing member for opening / closing the opening is attached to the partition member in the developing device of the first embodiment.

FIG. 9 is a partial explanatory view showing a third modified example in which the opening / closing member that opens and closes the opening is attached to the partition member in the developing device of the first embodiment.

FIG. 10 is a view showing the developing device according to the first embodiment, in which an opening / closing member for opening / closing the opening is attached to the partition member;
It is a partial explanatory view showing an example of change.

FIG. 11 is a schematic explanatory diagram of a developing device according to a second embodiment of the present invention.

FIG. 12 is a schematic explanatory view showing a toner supply portion of the developing device according to the second embodiment.

FIG. 13 is an experiment 4 using the developing device according to the second embodiment.
It is a figure showing the result of.

FIG. 14 is a schematic explanatory diagram of a developing device according to a third embodiment of the present invention.

FIG. 15 is a schematic explanatory view showing a toner supply portion of the developing device according to the third embodiment.

FIG. 16 is an experiment 5 using the developing device according to the third embodiment.
It is a figure showing the result of.

[Explanation of symbols]

Reference Signs List 10 device main body 11 toner carrier 12 partition member 13 opening 14 toner container 15 toner supply unit 16 opening / closing member 16a protrusion 17 toner feed member 18 toner supply member (toner supply roller) 19 regulating member P image carrier t toner x toner Nip width y in the circumferential direction in which the supply roller and the toner carrier contact each other The length of the closest portion between the partition member side and the toner supply roller

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Nobumi Mizumoto, Inventor             2-3-3 Azuchi-cho, Chuo-ku, Osaka             Kokusai Building Minolta Co., Ltd. (72) Inventor Takashi Miyazaki             2-3-3 Azuchi-cho, Chuo-ku, Osaka             Kokusai Building Minolta Co., Ltd. (72) Inventor Akihiro Kawasaki             2-3-3 Azuchi-cho, Chuo-ku, Osaka             Kokusai Building Minolta Co., Ltd. F-term (reference) 2H077 AA12 AA18 AA26 AA27 AB04                       AB13 AC04 AD06 AD13 AD17                       AD23 BA01 BA08

Claims (4)

[Claims] 1. A toner supply unit configured to provide a partition member having an opening in the apparatus main body to store toner in the apparatus main body, and to supply toner to a toner carrier that conveys toner to an image carrier. And an opening / closing member that opens the above-mentioned opening only when the toner is guided from the toner storage section to the toner supply section, and the toner in the toner storage section is transferred to the toner supply section through the opening. In a developing device provided with a toner feeding member for guiding and for supplying the toner in the toner supply unit to the toner carrier, the upper end of the opening / closing member is fixed to the upper side of the opening. At the same time, the developing device is characterized in that a protrusion protruding toward the toner supply portion is provided at the bottom of the opening / closing member that is not fixed. 2. The developing device according to claim 1, wherein:
The toner supply member is composed of a rotating toner supply roller, and at the portion facing the opening / closing member, the toner supply roller rotates from the upper end side where the opening / closing member is fixed to the lower side where the protrusion is provided. Developing device. 3. A toner supply unit for supplying a toner to a toner storage unit for storing toner in the main body of the apparatus by providing a partition member having an opening in the main body of the apparatus, and for supplying the toner to a toner support for conveying the toner to the image support And an opening / closing member that opens the above-mentioned opening only when the toner is guided from the toner storage section to the toner supply section, and the toner in the toner storage section is transferred to the toner supply section through the opening. In the developing device, which is provided with a toner feeding member that guides the toner, the toner feeding roller that rotates in a state of being pressed against the toner carrying member to feed the toner in the toner feeding unit to the toner carrying member is provided. When the toner is conveyed in the direction of gravity between the toner supply roller and the partition member by the rotation, the toner The circumferential nip width x (mm) where the supply roller and the toner carrier contact each other, and the length y (m) of the closest portion between the partition member side and the toner supply roller.
and m) satisfy the condition of 1.1x-y> 0.5. 4. A toner supply unit for supplying a toner to a toner storage unit for storing toner in the main body of the apparatus, which is provided with a partition member having an opening in the main body of the apparatus, and for supplying the toner to the toner carrier for conveying the toner to the image carrier. And an opening / closing member that opens the above-mentioned opening only when the toner is guided from the toner storage section to the toner supply section, and the toner in the toner storage section is transferred to the toner supply section through the opening. In the developing device, which is provided with a toner feeding member for guiding the toner, a toner supply roller is provided, which rotates in a state of being pressed against the toner carrier and supplies the toner supplied into the toner supply unit to the toner carrier. When the toner is conveyed between the toner supply roller and the partition member by the rotation of the supply roller in the direction opposite to the direction of gravity, The circumferential nip width x (mm) at which the toner supply roller and the toner carrier contact each other and the length y (mm) of the closest portion between the partition member side and the toner supply roller are: A developing device satisfying the condition of 8x-y <1.5.