JP3778261B2 - Development device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
According to the present invention, a developing roller and a regulating member that presses the tip of the developing roller to regulate the toner amount to form a toner thin film are disposed in a housing, and an electrostatic latent image formed on an image carrier is disposed. The present invention relates to a developing device that visualizes an image into a toner image.
[0002]
[Prior art]
In an image forming apparatus using an electrophotographic method, an electrostatic latent image is formed by a latent image forming apparatus on an image carrier such as a photosensitive member that is driven to rotate, and toner conveyed by a developing device is applied to electrostatically form the image. The latent image is developed and visualized as a toner image. In this case, in the developing device, it is required to stably form a uniform toner thin film on the developing roller that conveys the toner, and for that purpose, a member (regulating member, regulating blade) that regulates the amount of toner is used. The applicant of the present invention has proposed a developing device in which the height adjustment and skew adjustment of the regulating member can be easily performed and pressed against the developing roller with a constant spring load (see, for example, Japanese Patent Application No. 11-266404). The outline will be described below.
[0003]
FIG. 4 is a view for explaining the outline of the proposed developing device. 1 is a regulating member, 2 is a housing, 3 is a blade supporting member, 4 is a developing roller, 5 is a supporting portion, 6 is a skew adjusting portion, Reference numeral 7 denotes a blade pressing spring portion, and 8 denotes a blade pressing spring.
[0004]
In the developing device shown in FIG. 4, the developing roller 4 is pivotally supported on the housing 2, the regulating member 1 is attached to the upper surface, the ridge line a at the tip is pressed against the developing roller 4, and the opposite side of the ridge line a is set at two points. It is supported by the support part 5. The blade support member 3 is disposed so as to support the regulating member 1 on its back surface, and the support portion 5 has two projections between the back surface of the regulating member 1 and the upper surface of the blade support member 3. Touch and support in the height direction. The blade pressing spring portion 7 has a plurality of, for example, five, blade pressing springs 8 disposed therein to cause the developing roller 4 to press the ridge line a at the tip of the regulating member 1. As shown, a blade pressing spring 8 is stretched between the spring mounting hook of the regulating member 1 and the spring mounting hook of the blade support member 3. The skew adjustment unit 6 is provided with two long holes in the vicinity of both ends of the support line parallel to the ridge line at the tip of the regulating member 1, and pins are provided at positions of the blade support member 3 corresponding to the two long holes, Each pin fits into the two long holes to support the regulating member 1 freely in the longitudinal direction, and an eccentric cam is used to adjust twisting in the left-right direction in the drawing, that is, skew adjustment.
[0005]
Of the two support portions 5 that support the regulating member 1, one supports the protrusion provided on the blade supporting member 3 on the back surface of the regulating member 1 and supports it at a certain height, and the other The mounting height (Y) of the regulating member 1 is adjusted by supporting the tip of a screw screwed to the regulating member 1 so that the height can be adjusted by contacting the blade on the blade support member 3. On the other hand, the skew (X) adjustment is performed by fitting a skew adjustment eccentric cam into one of the long holes in the skew adjustment unit 6. These adjustments cause the regulating member 1 to be parallel without causing a left-right difference in the interference force to the regulating member 1 and without causing a twist between the ridge line at the tip of the regulating member 1 and the developing roller 4. Can be supported.
[0006]
[Problems to be solved by the invention]
As described above, the regulating member is configured to press the developing roller with a constant load in order to stably form a thin film of toner on the developing roller. A slight gap is formed and toner leakage is likely to occur. Therefore, conventionally, for example, as a seal between the regulation member 1 and the blade support member 3, a cushioning member such as a sponge is sandwiched between them, or a sheet such as PET is attached to the blade support member 3. It is configured to be applied to the base part.
[0007]
However, in the conventional configuration as described above, a reaction force is applied to the regulating member from the blade support member by the seal member, and therefore, when the regulating member is pressed against the developing roller with a constant load, an adverse effect is exerted.
[0008]
[Means for Solving the Problems]
The present invention solves the above-described problems, and makes it possible to reliably perform sealing without adversely affecting the regulating member when pressing the developing roller with a constant load.
[0009]
To this end, the present invention supports the developing roller in the housing, attaches a restricting member to the upper surface of the developing roller, disposes a pressing spring between the restricting member and the support portion, and the restricting member by the pressing spring. The ridge line at the tip of the restricting member is pressed against the developing roller by pressing it toward the support part side, and the back surface of the restricting member on the opposite side of the ridge line is supported by the support part, and the toner amount of the developing roller In a developing device that forms a toner thin film and visualizes the electrostatic latent image formed on the image carrier as a toner image, the back surface of the regulating member is disposed on the developing chamber side of the support portion. A sealing member bent at an angle parallel to the surface is affixed to the back surface of the restricting member, and is arranged so as to seal a gap between the back surface of the restricting member and the support portion.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view for explaining an embodiment of the developing device according to the present invention. FIG. 2 is a top view for explaining the embodiment of the developing device according to the present invention. Restriction member, 2 is a housing, 3 is a blade support member, 4 is a developing roller, 5 is a support portion, 6 is a skew adjustment portion, 7 is a blade pressing spring portion, 8 is a blade pressing spring, 9, 10a, and 10b are seal members Indicates.
[0011]
1 and 2, the developing roller 4 is pivotally supported by the housing 2, the regulating member 1 is attached to the upper surface, the ridge line at the tip thereof is pressed against the developing roller 4, and the regulating member 1 has a blade on the opposite side of the ridge line. It is supported by the support member 3. The blade support member 3 is disposed so as to support the regulating member 1 on its back surface. For example, two blades are brought into contact with each other between the back surface of the regulating member 1 and the upper surface of the blade support member 3 to increase the height. Support in the vertical direction. The blade pressing spring portion 7 has a plurality of, for example, five blade pressing springs 8 disposed therein so that the developing roller 4 presses the ridge line at the tip of the regulating member 1. A blade pressing spring 8 is stretched between the spring mounting hook of the blade support member 3.
[0012]
The seal member 9 seals the gap between the back surface of the regulating member 1 and the blade support member 3 and prevents the regulating member 1 from adversely affecting the load pressed against the developing roller 4 by having toner sandwiched in the gap. For example, a PET film is attached to the back surface of the regulating member 1 as shown in the figure to seal the gap at the contact portion with the blade support member 3. The seal member 9 is bent at an angle parallel to the surface of the blade support member 3 on the developing chamber side from the back surface of the restriction member 1, and the surface of the blade support member 3 is in a direction in which a load is applied to the restriction member 1. It is parallel to. Therefore, almost no force is applied in the direction that impedes the movement of the regulating member 1 that presses against the developing roller 4, and the gap between the back surface of the regulating member 1 and the blade support member 3 is maintained while maintaining a smooth movement of the regulating member 1. Can be sealed.
[0013]
The sealing members 10a and 10b are made of urethane sheet, and are disposed in the downstream portion of the developing roller 4 so as to be shifted in position and angle so that the contact with the developing roller 4 has a low load. Is to hold down. In addition, each seal member is angled to some extent, so that each of the seal members strikes the developing roller at a different angle with respect to the warp and impact of the housing, and an effective seal is realized.
[0014]
FIG. 4 is a diagram showing a configuration example in which the developing device according to the present invention is used in a full-color image forming apparatus, in which 31 denotes a photosensitive member, 32Y, 32C, 32M, and 32K denote developing devices, 33 denotes a housing, and 34 developing. A roller, 35 is a regulating member, 36 is a blade support member, 37 is a blade pressing spring, 38 is a developing cover, 39 is a stirring shaft, and 40 is a toner cartridge.
[0015]
As a full-color image forming apparatus equipped with the developing device according to the present invention, as shown in FIG. 4, for yellow and cyan for developing an electrostatic latent image around the photosensitive member 31 along the rotation direction. Developer units 32Y, 32C, 32M, and 32K including four color developer units of C, M for magenta, and K for black are arranged. Further, a charging roller as a charging means, an exposure unit for forming an electrostatic latent image on the photosensitive member 31, an intermediate transfer device for transferring a toner image formed on the photosensitive member 31 onto an intermediate transfer belt, and a photosensitive member Photoreceptor cleaning devices for removing the toner remaining on the body 31 are arranged. However, these are already well-known structures in the color image forming apparatus and are not directly related to the present invention. Is omitted.
[0016]
The operation of the full-color image forming apparatus will be briefly described. The photoreceptor 31 has a thin cylindrical conductive substrate and a photosensitive layer formed on the surface thereof, and is rotated by a driving unit (not shown). The developing device units 32Y, 32C, 32M, and 32K are arranged so as to be swingable with respect to the photosensitive member 31, and only the developing roller of one developing device is selectively provided for each rotation of the photosensitive member 31. It is made possible to contact. When image formation is performed, for example, when an image formation signal from a computer (not shown) is input, the photosensitive member 31, the developing rollers of the developing unit 32, and the intermediate transfer belt are driven to rotate.
[0017]
First, the outer peripheral surface of the photoreceptor 31 is uniformly charged by the charging roller, and the outer peripheral surface is selectively exposed according to image information of the first color (for example, yellow) by the exposure unit, so that the electrostatic A latent image is formed. At this time, only the developing roller of the yellow developing unit contacts the photoconductor 31, whereby a yellow electrostatic latent image toner image is formed on the photoconductor 31. This toner image is transferred onto an intermediate transfer belt to which a primary transfer voltage having a polarity opposite to that of the toner is applied, and the toner remaining on the photoconductor 31 is removed by a photoconductor cleaning device, and then the photoconductor. The outer peripheral surface of the body 31 is neutralized by the neutralizing means.
[0018]
In response to the second, third, and fourth colors of the image forming signal, the above operation is repeated to form and develop a latent image by one rotation of the photoreceptor 31 and the intermediate transfer belt, and the contents of the image forming signal The four color toner images corresponding to the toner image are superimposed and transferred on the intermediate transfer belt. Then, this full-color image is transferred onto a recording medium.
[0019]
When the developing device according to the present invention is used in the full-color image forming apparatus as described above, the blade pressing spring 37 is disposed under the regulating member 35, that is, in the developing chamber. Thus, it is possible to save the space of 32, which is extremely effective especially in downsizing of a full-color device.
[0020]
In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible. For example, in the above-described embodiment, the present invention has been applied to the developing device already proposed by the applicant, but the present invention is a developing device that presses the regulating member against the developing roller with a constant load by a spring or the like. If the seal member is folded at an angle that is parallel to the direction in which the load is applied to the regulating member at a site where a gap is formed between the regulating member and the back surface of the developing chamber, the sticking member is attached to the back surface of the regulating member. Good. Accordingly, it goes without saying that the present invention can be applied not only to a developing device mounted on a full-color image forming apparatus, but also to a developing device mounted on a monocolor or monochrome image forming apparatus, or a developing device mounted on another image forming apparatus.
[0021]
【The invention's effect】
As is apparent from the above description, according to the present invention, a developing roller and a regulating member that presses the tip against the developing roller to regulate the amount of toner and form a toner thin film are disposed in the housing, In a developing device that visualizes an electrostatic latent image formed on an image carrier into a toner image, a seal member that is bent from the back surface of the restricting member to an angle parallel to the surface of the support on the developing chamber side is regulated. Since it is affixed to the back surface of the member and arranged so as to seal the gap between the back surface of the restricting member and the support portion, the restricting member is bent by an angle parallel to the direction in which the load is applied to the restricting member. In the direction of obstructing the movement of the can almost no force. Therefore, it is possible to seal the gap between the developing chambers generated on the back surface of the regulating member while maintaining smooth movement of the regulating member.
[Brief description of the drawings]
FIG. 1 is a transverse sectional view for explaining an embodiment of a developing device according to the present invention.
FIG. 2 is a top view for explaining an embodiment of the developing device according to the present invention.
FIG. 3 is a diagram illustrating a configuration example in which a developing device according to the present invention is used in a full-color image forming apparatus.
FIG. 4 is a diagram for explaining an outline of a proposed developing device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Restriction member, 2 ... Housing, 3 ... Blade support member, 4 ... Developing roller, 5 ... Support part, 6 ... Skew adjustment part, 7 ... Blade press spring part, 8 ... Blade press spring, 9, 10a, 10b ... Seal member

Claims (1)

  A developing roller is pivotally supported in the housing, a regulating member is attached to the upper surface of the developing roller, a pressing spring is disposed between the regulating member and the supporting portion, and the regulating member is moved to the supporting portion side by the pressing spring. The ridge line at the tip of the regulating member is pressed against the developing roller by pressing, and the back surface of the regulating member on the opposite side of the ridge line is supported by a support portion to regulate the toner amount of the developing roller and to form a toner thin film In the developing device that visualizes the electrostatic latent image formed on the image carrier into a toner image, an angle that is parallel to the developing chamber side surface of the support portion from the back surface of the regulating member A developing device comprising: a sealing member bent in affixed to a back surface of the regulating member, and arranged to seal a gap between the back surface of the regulating member and the support portion.

Images