JPH07199648A - Developing device - Google Patents

Abstract

PURPOSE:To prevent the gap between a developing roller and a regulating member for regulating the quantity of developer supplied to the developing roller from changing even in the case of moving the developing roller, in a developing device adjusting the gap between the developing roller and an image carrier to the constant by energizing the developing roller toward the image carrier side with an energizing means and moving the developing roller along the guiding part. CONSTITUTION:In adjusting the gap Ds from the image carrier 2 to the constant by the adjusting means 15 by energizing the developing roller 12 toward the image carrier 2 side with the energizing means 17 and moving the developing roller 12 along the guide part 16, the device is constituted so that the developing roller 12 is moved in the direction other than the direction X orthogonally crossing the moving direction Y of the image carrier 2 in the position opposing to the developing roller 12, and so that the end face 14a of the regulating member 14 is provided in parallel to the moving direction of the developing roller 12 through the gap Db from the developing roller 12.

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 in an image forming apparatus such as a copying machine or a printer,
The developing roller that conveys the developer to the image carrier is biased toward the image carrier, and this developing roller is moved along the guide portion,
The distance between the developing roller and the image carrier is adjusted to be constant, and the amount of the developer conveyed to the image carrier by the developing roller is regulated by a regulating member provided so as to be spaced from the developing roller by a required distance. The present invention relates to the developing device.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine or a printer, a developing device supplies a developer to an image carrier to perform development. As one of such developing devices. As shown in FIG. 1, a developing device 1 in which a developing roller 12 is provided so as to face the image carrier 2 with a certain distance from the cylindrical image carrier 2.
Existed.

Here, in such a developing device 1, as shown in FIG. 1, the developer 3 contained in the device main body 10 is agitated and conveyed by the agitating / conveying members 13a provided in the device main body 11. The developer 3 is supplied to the rotating developing roller 12 while being agitated and conveyed by 13b, and the amount of the developer 3 thus supplied is regulated by a regulating member 14 provided with the developing roller 12 at a required interval. After that, the developer 3 is applied to the image carrier 2 by the developing roller 12.
It was designed to be conveyed to a position facing.

Then, the developer 3 conveyed by the developing roller 12 as described above is transferred from the developing roller 12 to the image carrier 2 which rotates at a position opposed to the developing roller 12 with a required gap. It is arranged that the image is supplied to the image carrier 2 to be developed.

When the developer 3 is supplied from the developing roller 12 to the image carrier 2 as described above, the runout of the image carrier 2 at the time of rotation and the image carrier 2 formed in a cylindrical shape. The distance between the developing roller 12 and the image carrier 2 may change due to the low circularity or the like, which changes the amount of the developer 3 supplied from the developing roller 12 to the image carrier 2. However, there are cases where stable development cannot be performed.

For this reason, in the prior art, FIG. 1 and FIG.
As shown in FIG. 2, a gap adjusting roller 1 having a diameter larger than that of the developing roller 12 is provided on both sides of the developing roller 12.
5, the developing device 1 as a whole is biased toward the image carrier 2 by a biasing means 4 such as a spring, thereby pressing the roller 15 against the image carrier 2, and the developing roller 12 and the image carrier 2 are pressed. The distance Ds between and was kept constant.

However, when the developing device 1 as a whole is urged to the image carrier 2 by the urging means 4 such as a spring, the size of the apparatus is increased and the urging means 4 is used.
It is necessary to increase the urging force of the roller 15, which increases the frictional resistance between the roller 15 and the image carrier 2.
If the rotation of the image carrier 2 and the developing roller 12 is hindered,
There is a problem that the roller 15 and the image carrier 1 that come into contact with each other are worn, and the distance Ds between the developing roller 12 and the image carrier 2 is changed. In the case where the above are unitized together, there is also a problem that the entire developing device 1 cannot be moved as described above.

Therefore, in recent years, as shown in FIGS. 3 and 4, the side wall 1 of the main body 11 of the developing device 1 is shown.
1a is provided with a guide hole 16 directed toward the image carrier 1, and a bearing 12a for rotatably supporting the developing roller 12 is arranged in the guide hole 16 so that the developing roller 12 can move along the guide hole 16. At the same time, the bearing 12a is urged toward the image carrier 2 by the urging means 17 such as a spring, whereby the rollers 15 provided on both sides of the developing roller 12 are pressed against the image carrier 2, and the developing roller 12 A device in which the distance Ds between the image carrier and the image carrier 2 is adjusted has been developed.

Here, in the developing device 1 as described above, the purpose is simply to urge the developing roller 12 toward the image carrier 2 side by the urging means 17 to move it to the image carrier 2 side. The regulating member 1 for regulating the direction in which the developing roller 12 is moved along the guide hole 16 and the moving direction of the developing roller 12 and the amount of the developer 3 supplied to the developing roller 12.
The relationship with 4, etc. was not considered at all.

Therefore, in the developing device 1 as described above, generally, as shown in FIGS. 3 and 4, the moving direction (Y) of the image carrier 2 at the position where the guide hole 16 faces the developing roller 12. ), And the developing roller 12 is moved along the guide hole 16, while the regulating member 14 is similar to the developing device 1 shown in FIG. Generally, the developing roller 12
And, it was provided so as to be inclined so as to pass through the required space.

However, as described above, the regulating member 14 is provided so as to be inclined with respect to the developing roller 12 with a required space therebetween, and the image carrier 2 at a position facing the developing roller 12.
When the developing roller 12 is moved along the guide hole 16 extending in the direction (X) orthogonal to the moving direction (Y), the developing roller 12 may be moved slightly along the guide hole 16.
The distance Db between the developing roller 12 and the regulating member 14 changes greatly, which changes the amount of the developer 3 conveyed to the image carrier 2 by the developing roller 12 greatly, and stable development can be performed. The problem of disappearing occurred.

That is, as shown in FIG. 4, when the angle formed by the direction of the end surface 14a of the regulating member 14 facing the developing roller 12 and the moving direction of the developing roller 12 is θ, the developing roller 12 has a guide hole. 16 along with the distance Δx, the distance Db between the end surface 14a of the regulating member 14 and the developing roller 12 becomes Δxsi as shown in FIG.
By changing by nθ, for example, when the distance Db between the end surface 14a of the regulating member 14 and the developing roller 12 is set to 0.5 mm and the angle θ is 30 degrees, the developing roller 12 is guided by the guide hole 16 When moved 0.5 mm along the edge, the end surface 14a of the regulating member 14 set to 0.5 mm
The distance Db between the developing roller 12 and the developing roller 12 is changed by 0.25 mm, and the amount of the developer 3 conveyed to the image carrier 2 by the developing roller 12 is largely changed, so that stable development cannot be performed.

Therefore, the inventors of the present invention reduce the change in the distance Db between the developing roller 12 and the regulating member 14 when the developing roller 12 moves along the guide hole 16 as described above. As shown in FIG. 6, the regulating member 1
4 in the direction orthogonal to the moving direction of the developing roller 12,
It was conceived that the end surface 14a of the regulating member 14 facing the developing roller 12 should be in the same direction as the moving direction of the developing roller 12.

In this way, since the regulating member 14 has a certain thickness, even if the developing roller 12 moves along the guide hole 16 as described above, the end surface 1 of the regulating member 14 is not changed.
The change in the distance Db between the 4a and the developing roller 12 was reduced.

However, also in such a developing device 1, when the bearing 12a for rotatably supporting the developing roller 12 is movably provided in the guide hole 16 provided in the side wall 11a of the apparatus main body 11, the bearing 12a is provided. When the guide hole 16 is made larger than the diameter of the bearing 12a in order to smoothly move in the guide hole 16, the bearing 12a rattles in the guide hole 16, and the developing roller 12 and the regulating member 14 Db between the end surface 14a of the
There was a problem that changed.

That is, in the developing device 1 as described above, the bearing 12a is urged toward the image carrier 2 by the urging means 17 to move the developing roller 12 along the guide hole 16 and the image carrier. Since the direction of the reaction force from the 2 side is linear, the bearing 12a is not regulated in the direction orthogonal to the direction of the guide hole 16, and the bearing 12a contacts the upper edge of the guide hole 16, The lower edge of the guide hole 16 is contacted, and the distance Db between the developing roller 12 and the end surface 14a of the regulating member 14 is changed.

By changing the distance Db between the developing roller 12 and the end surface 14a of the regulating member 14 in this manner, the developer 3 conveyed to the image carrier 2 by the developing roller 12 is transferred as described above. There was a problem in that the amount changed greatly and stable development could not be performed.

When the regulating member 14 is provided vertically above the developing roller 12 as in the developing device 1 shown in FIG. 6, the developer 3 removed from the developing roller 12 by the regulating member 14 is developed. There is also a problem in that the developer 3 is not properly dropped from the roller 12 and accumulates in the vicinity of the regulation member 14, and the developer 3 accumulated in this way is clogged between the regulation member 14 and the development roller 12.

[0019]

SUMMARY OF THE INVENTION The present invention is a developing device used in an image forming apparatus such as a copying machine or a printer, and in particular, a developing roller for conveying a developer to the image carrier is provided on the image carrier side. The developing roller is urged to move along the guide portion so that the gap between the developing roller and the image carrier is adjusted to be constant, and the amount of the developer conveyed by the developing roller to the image carrier is adjusted. An object of the present invention is to solve the above problems in a developing device that is regulated by a regulation member provided so as to be spaced from a developing roller by a required distance.

That is, according to the present invention, in the developing device as described above, the developing roller is urged toward the image carrier by the urging means, and the developing roller is moved along the guide portion so that the developing roller and the image are formed. Even when the gap between the carrier and the carrier is adjusted to be constant, the gap between the developing roller and the regulating member that regulates the amount of the developer supplied to the developing roller may change greatly. It is another object of the present invention to make the amount of the developer conveyed to the image carrier by the developing roller constant and to enable stable development.

[0021]

According to the present invention, in order to solve the above problems, a developing roller that conveys a developer to an image carrier and a biasing force that biases the developing roller toward the image carrier. Unit, a guide unit that regulates the moving direction of the developing roller urged by the urging unit, and a gap adjustment that adjusts the gap between the developing roller and the image carrier moving along the guide unit to a constant value. In the developing device, the developing roller has a guide portion, and a developing device having a means and a regulating member that is provided at a required distance from the developing roller so as to regulate the amount of the developer conveyed to the image carrier by the developing roller. The moving direction is set to be a direction other than the direction orthogonal to the moving direction of the image carrier at the position facing the developing roller, and the end of the regulating member facing the developing roller. There is had to be parallel to the moving direction of the developing roller which moves along the guide portion.

[0022]

In the developing device according to the present invention, the developing roller that conveys the developer to the image carrier is urged toward the image carrier by the urging means such as a spring, and the developing roller is moved along the guide portion. The gap between the developing roller and the image carrier is adjusted to be constant by the gap adjusting means.

Here, in the developing device of the present invention, the end surface of the regulating member facing the developing roller is parallel to the moving direction of the developing roller moving along the guide portion as described above. In the range of the thickness of the end surface of the regulating member, even if the developing roller moves along the guide hole, the distance between the end surface of the regulating member and the developing roller rarely changes. The amount of the regulated developer becomes stable, and the amount of the developer conveyed to the image carrier by the developing roller becomes constant.

Further, in the developing device according to the present invention, the developing roller is urged toward the image carrier by the urging means as described above, and the developing roller is moved along the guide portion so that the developing roller and the image carrier are carried. In adjusting the distance between the body and the body constant, the moving direction of the developing roller moved along the guide portion is a direction other than the direction orthogonal to the moving direction of the image carrier at a position facing the developing roller. Therefore, although depending on the direction of the guide portion and the direction in which the developing roller is biased by the biasing means, the developing roller is always positioned at either the upper edge or the lower edge of the guide portion by the biasing means. The developing roller is prevented from rattling in the direction orthogonal to the direction of the guide portion, and the gap between the developing roller and the end surface of the regulating member is stable, and the developing roller is stable. The amount of the developer conveyed to the image bearing member further stabilized by chromatography la.

[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.

As shown in FIGS. 7 and 8, also in the developing device 10 of this embodiment, the image carrier 2 is fixed at the opening portion of the apparatus main body 11 facing the image carrier 2 formed in a cylindrical shape. The developing roller 12 that conveys the developer 3 is provided on the image carrier 2 so as to face each other with the space Ds therebetween.

Here, when the developing roller 12 is provided so as to face the image carrier 2 with a certain distance Ds, the guide portion 16 for regulating the moving direction of the developing roller 12 is used as shown in FIG. Further, as shown in FIG. 8, on the side wall 11a of the apparatus main body 11, from the direction (X) orthogonal to the moving direction (Y) of the image carrier 2 at the position facing the developing roller 12 toward the image carrier 2 side. A guide hole 16 inclined upward by a required angle is provided, and a bearing 12a for rotatably supporting the developing roller 12 is arranged in the guide hole 16, and the developing roller 12 is guided along the guide hole 16 via the bearing 12a. In addition to being movable, a biasing means 17 such as a spring is provided in the guide hole 16, and the biasing means 17 pushes the bearing 12a toward the image carrier 2 side to move the developing roller 12 toward the image carrier 2 side. Attached to It was way.

The developing roller 12 thus biased by the biasing means 17 toward the image carrier 2 faces the image carrier 2 at a constant distance Ds. As the gap adjusting means 15 for adjusting the distance Ds between the image carrier 12 and the image carrier 2, rollers 15 having a radius larger than the radius of the developing roller 12 by the distance Ds are arranged on both sides of the developing roller 12. The roller 15 is pressed against the image carrier 2 by the urging means 17 so that the distance Ds between the developing roller 12 and the image carrier 2 is kept constant.

Further, in the developing device 10 of this embodiment, the regulating member 14 for regulating the amount of the developer 3 conveyed to the image carrier 2 by the developing roller 12 is provided on the upper side of the developing roller 12. It is arranged in the main body 11 so as to be orthogonal to the moving direction of the developing roller 12, the end surface 14a of the regulating member 14 faces the developing roller 12 with a required distance Db, and the end surface 14a extends along the guide hole 16. It is arranged to be parallel to the moving direction of the moving developing roller 12.

When developing with the developing device 10 of this embodiment, the image bearing member 2 and the developing roller 12 are rotated, respectively, and the developer 3 in the apparatus main body 11 is rotated. 12 and the amount of the developer 3 thus supplied to the developing roller 12 is regulated by the regulating member 14 provided between the developing roller 12 and the developing roller 12 via a required distance Db, and then the developing roller 12 develops The developer 3 is conveyed to a position facing the image carrier 2, and the developer 3 supplies the developer 3 to the image carrier 2.

In the case where the developer 3 is supplied from the developing roller 12 to the image carrier 2 in this way, when the roundness of the image carrier 2 is low or the image carrier 2 has a rotational shake. The developing roller 12 moves along the guide hole 16 via the bearing 12a while the bearing 12a is pressed by the urging means 17, and the developing roller 12 and the image carrier 2 are moved by the roller 15 described above. The distance Ds was always kept constant.

Here, in the case where the developing roller 12 moves along the guide hole 16 in this way, in the developing device 10 of this embodiment, the end surface 14a of the regulating member 14 facing the developing roller 12 as described above. Is parallel to the moving direction of the developing roller 12 moving along the guide hole 16, the developing roller 12 moves along the guide hole 16 within the range of the thickness of the end surface 14a of the regulating member 14. However, the distance Db between the end surface 14a of the regulation member 14 and the developing roller 12 rarely changes, and the amount of the developer 3 regulated by the regulation member 14 is constant. The developer 3 was conveyed to the image carrier 2 by the developing roller 12, and stable development was possible.

Further, in the developing device 10 in this embodiment, the guide hole 16 for restricting the moving direction of the developing roller 12 is orthogonal to the moving direction (Y) of the image carrier 2 at the position facing the developing roller 12. Not the direction (X)
Since the bearing 12a of the developing roller 12 is biased by the biasing means 17 as described above, the bearing 12a is provided so as to be inclined slightly upward from the orthogonal direction (X) toward the image carrier 2 side. Is urged by the biasing means 17 in a direction slightly inclined upwards, whereby the bearing 12a always comes into contact with the upper edge of the guide hole 16, and thus the bearing 12a comes into contact with the upper edge of the guide hole 16. In this state, the developing roller 12 moves along the guide hole 16 and is maintained at a certain distance Ds from the image carrier 2.

Therefore, even if the size of the guide hole 16 is larger than the diameter of the bearing 12a, the bearing 12a
a does not rattle in the guide hole 16, and the distance Db between the developing roller 12 and the end surface 14a of the regulating member 14 is kept constant, whereby the developer 3 regulated by the regulating member 14 is maintained. The amount of the developer 3 was also constant, and a constant amount of the developer 3 was conveyed to the image carrier 2 by the developing roller 12, and stable development was possible.

Further, the developing device 10 in this embodiment
In the above, since the regulating member 14 is provided so as to be orthogonal to the guide hole 16 on the upper side of the developing roller 12, the developer 3 removed from the developing roller 12 by the regulating member 14 falls well from the developing roller 12. However, the removed developer 3 did not accumulate in the vicinity of the regulation member 14 and jam between the regulation member 14 and the developing roller 12.

In the developing device 10 of this embodiment, when the end surface 14a of the regulating member 14 facing the developing roller 12 is provided in parallel with the moving direction of the developing roller 12, the regulating member 14 is moved in the moving direction. The end surface 14a is arranged in a direction orthogonal to the direction of movement of the developing roller 12, and the end surface 14a is parallel to the direction of movement of the developing roller 12. Only the end surface 14a of the member 14 needs to be parallel to the moving direction of the developing roller 12. For example, as shown in FIG.
The end surface 14a of the regulating member 14 may be inclined so that the end surface 14a is parallel to the moving direction of the developing roller 12.

Further, in the developing device 10 in this embodiment, the regulating member 14 is provided on the upper side of the developing roller 12, but the position where the regulating member 14 is provided is not particularly limited to such a position. For example, as shown in FIG. 10, the developing roller 12 and the image carrier 2 are rotated in the opposite direction to the case of the above-described embodiment, and the regulating member 1 is used.
4 may be provided on the lower side of the developing roller 12 so that its end surface 14a is parallel to the moving direction of the image carrier 2.

Further, in the developing device 10 of this embodiment, the guide hole 16 for regulating the moving direction of the developing roller 12 is provided.
The image carrier 2 at a position facing the developing roller 12.
Image carrier 2 from a direction (X) orthogonal to the moving direction (Y) of
Although it is provided so as to incline upward by a required angle toward the side, the direction in which the guide hole 16 is inclined is not particularly limited, and although not shown, the moving direction of the image carrier 2 at the position facing the developing roller 12 The guide hole 16 may be provided so as to be inclined downward from the direction (X) orthogonal to (Y) toward the image carrier 2 side. In this case, the guide hole 16 may be provided in correspondence with the direction of the guide hole 16. The end surface 14a of the regulating member 14 is also inclined downward so that it is parallel to the guide hole 16.

[0039]

As described above in detail, in the developing device of the present invention, the developing roller for conveying the developer to the image bearing member is urged toward the image bearing member by the urging means such as a spring, and the developing roller is urged. Is moved along the guide portion, the gap between the developing roller and the image bearing member is adjusted to be constant by the gap adjusting means, and the amount of the developer conveyed to the image bearing member by the developing roller is adjusted to the developing roller. When regulating by the regulating member provided so as to have a required space, the regulating member is arranged such that the end surface of the regulating member facing the developing roller is parallel to the moving direction of the developing roller moving along the guide portion. In the range of the thickness at the end surface of the above, even if the developing roller moves along the guide hole, the distance between the end surface of the regulating member and the developing roller is less likely to change.

As a result, in the developing device according to the present invention, when the image carrier has a low circularity or when the image carrier has a rotational shake, the distance between the developing roller and the image carrier is reduced. Even if the developing roller is moved along the guide hole for constant adjustment, the amount of the developer regulated by the regulating member hardly changes, and the amount of the developer conveyed to the image carrier by the developing roller is not changed. The amount became constant, and stable development became possible.

Further, in the developing device according to the present invention, the developing roller is urged toward the image carrier by the urging means, and the developing roller is moved along the guide portion so that the developing roller and the image carrier are separated from each other. In adjusting the interval of the constant, the moving direction of the developing roller moved along the guide portion is set to a direction other than the direction orthogonal to the moving direction of the image carrier at the position facing the developing roller.
Depending on the direction of the guide portion and the direction in which the developing roller is urged by the urging means, the developing roller is restricted to either the upper edge or the lower edge of the guide portion, and the developing roller moves to the guide portion. No more rattling in the direction orthogonal to the direction.

As a result, in the developing device of the present invention, the developing roller does not rattle in the direction perpendicular to the direction of the guide portion, and the gap between the developing roller and the end surface of the regulating member does not change. The amount of the developer conveyed to the image carrier by the developing roller becomes constant, and more stable development can be performed.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view of a conventional developing device in which the entire developing device is biased toward an image carrier.

FIG. 2 is a plan view in which a part of a conventional developing device in which the entire developing device is biased toward the image carrier is cut away.

FIG. 3 is a side view in which a part of a conventional developing device in which only the developing roller is urged and moved toward the image carrier is cut away.

FIG. 4 is a partial explanatory view showing a state in which only the developing roller is urged and moved toward the image carrier in the conventional developing device shown in FIG.

FIG. 5 is an explanatory diagram showing a change in a gap between the developing roller and the regulating member when the developing roller is moved in the conventional developing device shown in FIG.

FIG. 6 is a partial explanatory view of a developing device in which a change in a gap between the developing roller and the regulating member is reduced when the developing roller is moved.

FIG. 7 shows a developing device according to an embodiment of the present invention.
It is the side view which notched one part.

FIG. 8 shows a developing device according to an embodiment of the present invention.
FIG. 6 is a partial explanatory view showing a state in which only the developing roller is urged and moved toward the image carrier.

FIG. 9 shows a developing device according to an embodiment of the present invention.
It is a partial explanatory view of a modification in which only the restricting member is modified.

FIG. 10 is a partial explanatory diagram of a modified example in which the rotation directions of the image carrier and the developing roller are changed and the position where the regulating member is provided is changed in the developing device according to the embodiment of the present invention.

[Explanation of symbols]

2 image carrier 3 developer 10 developing device 12 developing roller 14 regulating member 14a end face of regulating member 15 gap adjusting means (roller) 16 guide part (guide hole) 17 biasing means Ds distance between developing roller and image carrier 2 Db Distance between developing roller and end face of regulating member Y Movement direction of image carrier at position facing developing roller X Direction orthogonal to moving direction of image carrier at position facing developing roller

Claims (1)

[Claims] 1. A developing roller that conveys a developer to an image carrier, a biasing unit that biases the developing roller toward the image carrier, and a moving direction of the developing roller that is biased by the biasing unit. Guide portion, gap adjusting means for adjusting the distance between the developing roller and the image carrier, which is moved along the guiding portion, to a constant distance, and the developing roller is provided so as to be spaced apart from the image by the developing roller. In a developing device having a regulating member for regulating the amount of the developer conveyed to the carrier, the moving direction of the image carrier at a position where the direction in which the developing roller is moved along the guide portion faces the developing roller. And a direction other than the direction orthogonal to the direction, and the end surface of the regulating member facing the developing roller is parallel to the moving direction of the developing roller moving along the guide portion. .