JP2001134075A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the excessive transport phenomenon from occurring by preventing a controlling load from being applied on both end parts of a controlling member. SOLUTION: In this developing device provided with the controlling member 12 on the upstream side of the developing position of the developer carrier 10 on which a periphery sealing is disposed opposite to a smooth surface 10a formed on both end parts of the roughened developer transporting surface 10b, the control width of a controlling member is made wider than the width of the developer transporting face, a rising part T is formed on both end parts of the controlling member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for supplying a developer to an electrostatic latent image carrier to develop a visible image, and more particularly to a developing device in which the developer leaks or scatters outside the developing device. The present invention relates to a developing device provided with a developer sealing mechanism for preventing the development.

[0002]

2. Description of the Related Art Conventionally, in a developing device which supplies a developer to an electrostatic latent image carrier to visualize the developer, the developer holding ability of the developer carrier is unstable, When the dimensional accuracy of each mechanism varies, or when the developer carrier is rotated at a high speed, there is a problem that the developer is spilled or scattered especially from the end of the developing device. For this reason, various proposals have been made, but all of them have been complicated in structure or insufficient in sealing.

Therefore, the width of the regulating member for regulating the thickness of the developer is made larger than the width of the rough surface of the developing sleeve (developer conveying width), and the inner surface of the seal member fixed to the developing housing is smoothed. There has been proposed a device that presses against a surface (both ends of a developing sleeve) with an appropriate pressing force (Japanese Patent Application Laid-Open No.
2-192768). There has also been proposed a seal member that is attached to the inner surface of the housing and pressed against both ends of the developing roller so as to slightly overlap both ends of the regulating member (Japanese Patent Laid-Open No. 62-143073).

[0004]

However, in order to achieve both developer conveyance and sealing performance, as shown in FIG.
If the conveying surface of the developer carrying member is roughened and the end sealing area is a smooth surface, the regulating member comes into contact with the conveying surface over the smooth surface, so that the amount of wear on the smooth surface is small, and Wear amount increases, and as a result, as shown in FIG.
Both ends of the regulating member are sharp as shown by the symbol S, and the regulating load is concentrated here, and a prescribed regulating load is not applied to the transport surface, and an excessive transport phenomenon in which the developer transport amount becomes excessive occurs. There was a problem that it would.

An object of the present invention is to solve the above-mentioned problem, and an object of the present invention is to prevent a regulated load from being concentrated only at both ends of a regulating member and to prevent an over-conveyance phenomenon from occurring.

[0006]

According to a first aspect of the present invention, there is provided a developer carrying member provided with a peripheral surface seal opposed to a smooth surface formed at both ends of a roughened surface of a developer carrying surface. In a developing device in which a regulating member is provided upstream of the developing position and the regulating width of the regulating member is larger than the width of the developer conveying surface, both ends of the regulating member are cut up. The invention according to claim 2 is characterized in that the cut-up start position of the regulating member is located on the end side of the boundary between the conveying surface and the smooth surface of the developer carrier. The invention of claim 3 is characterized in that the cut-off amount of the regulating member increases from the inside toward the end.

The invention according to a fourth aspect is characterized in that an end face sealing member is inserted between the cut-up portion at the end of the regulating member and the developer carrying member.

[0008]

Embodiments of the present invention will be described below. The developing device of the present invention can be applied to any of a magnetic developing method and a non-magnetic developing method, and can be applied to both mono-color and full-color.
In the following, a description will be given of a pressure contact developing system and a full color example.

FIG. 1 is a schematic diagram illustrating a developing device of the present invention. In addition, since it is a full-color developing device, Y, M,
Although there are C and Bk developing devices, only one developing device is shown in the figure for convenience. Reference numeral 1 denotes a photosensitive drum as an electrostatic latent image carrier, and a developing device 2 is provided to face the photosensitive drum.
The developing device 2 has a developing device housing 4 fixed to the base 3, an agitator mechanism 14 for stirring and conveying the toner, an elastic supply roller 11 for supplying the toner conveyed from the agitator mechanism 14, and a supply roller 11. A developing roller 10 as a toner carrier for transferring the toner supplied to the surface thereof to the photosensitive drum by elastic contact; a regulating blade 12 in which urethane rubber is adhered to a metal for regulating the thickness of the toner layer on the surface of the developing roller; A lower seal 13 made of a PET film, which is in pressure contact with the roller and prevents the toner at the bottom of the housing from leaking to the outside, is provided. The developing roller 10 and the supply roller 11 elastically contact and rotate in the same direction with a difference in peripheral speed,
At the contact portion (nip), a toner layer having a predetermined thickness (for example, several hundred μm) is formed on the surface of the developing roller by moving and rubbing in opposite directions. At this time, the toner is charged with a predetermined polarity by friction with the developing roller and the supply roller, is further regulated to a layer thickness of about 10 μm by the regulating blade 12, and is charged to the same polarity by friction with the blade. The developing roller and the photoreceptor drum rotate in opposite directions and move in the same direction at the contact portion, and the electrostatic latent image on the photoreceptor is developed by toner while being pressed against each other while slipping with each other. In the drawing, the developing roller and the photosensitive drum are separated from each other, but during development, the developing roller is brought into contact with the photosensitive drum by swinging the base 3 by a drive mechanism (not shown) to perform pressure contact development.

FIG. 2 is a sectional view of an end of the developing device of the present invention.
FIG. 4 is a diagram illustrating a toner leakage prevention mechanism. Developing roller 1
Reference numeral 0 denotes the photosensitive drum, the front surface of which is exposed, but the upper and lower portions of the developing roller are provided with a regulating blade 12 and a lower seal 13 along the axial direction of the developing roller, so that toner leaks. Never. However, at the end portion of the developing roller, toner leakage is likely to occur particularly from the joint between the lower seal and the peripheral seal. Accordingly, in the present embodiment, the lower seal 13 is sandwiched between the both ends of the developing roller by the peripheral seal 16 adhered to the peripheral seal member 15 and the developing roller 10 so that the toner at the joint between the lower seal and the peripheral seal is formed. We are trying to prevent leakage.

The peripheral seal member 15 is made of, for example, plastic, and the surface to which the peripheral seal 16 is adhered has a shape substantially following the curved surface of the developing roller, and is attached to the developing device housing 4. Of course, a part of the housing is used as a peripheral seal member without providing a dedicated peripheral seal member, and the peripheral seal 16 is used.
May be attached. Peripheral seals 16 are provided at both ends of the developing roller, and are composed of, for example, a two-layer structure in which Teflon felt is adhered to an elastic body.
The felt surface is pressed against the surface of the developing roller over the gap between the lower seal and the lower seal, and the lower seal 13 is sandwiched between the developing roller and the developing roller by the elastic pressing force. Conventionally, depending on the accuracy of the parts, a gap was formed between the seals at the ends, causing toner leakage. However, as shown in FIG. 2, the peripheral seal was elastically compressed, and both ends of the lower seal were sandwiched and pressed against the developing roller. Therefore, there is no gap even when the developing device is operated or when the toner is vibrated. Further, it is possible to easily secure the contact of the lower seal, which is difficult to position, with the developing roller.

In order to secure the sealing property at the end of the developing roller by the peripheral surface seal, it is necessary to press the developing roller against the developing roller with a predetermined pressing force. By the way, if the lower seal is thick, the spring constant becomes large, and a slight displacement causes a strong force to be applied to the developing roller, which causes filming in which the toner is crushed and adhered.
A thin PET film is used. As shown in FIG. 2, when the end portion of the lower seal 13 is sandwiched between the developing roller and the peripheral surface seal, if the pressing force at the sandwiched portion is too large, the frictional force becomes excessive, and the thin lower seal is worn. There is a possibility that a hole is formed, and the torque accompanying the rotation of the developing roller increases, which may cause the lower seal to be involved.

Therefore, the peripheral seal is configured to reduce the pressing force on the developing roller at the lower seal portion. For example, the gap between the developing roller and the peripheral surface sealing member is discontinuously or continuously increased toward the lower seal portion, so that the compression ratio of the peripheral seal at the lower seal portion is made smaller than other portions. Alternatively, the thickness of the peripheral seal is discontinuously or continuously reduced toward the lower seal portion so that the compression ratio of the peripheral seal at the lower seal portion is smaller than that of the other portions. With such a configuration, the pressing force on the developing roller by the peripheral surface seal in the lower seal portion can be reduced. As a result, it is possible to prevent the lower seal from being worn and forming a hole, and at the same time, to prevent the lower seal from being caught by the rotation of the developing roller.

When both ends of the lower seal are sandwiched between the peripheral seal and the developing roller and pressed, the end of the lower seal is pulled by the rotation of the developing roller, so that the lower seal is liable to be involved.
As a countermeasure, as described above, it is effective to reduce the pressing force of the peripheral seal in the lower seal portion against the developing roller. However, the lower seal portion where the entrainment easily occurs (the portion pressed by the peripheral seal). It is effective to increase the bonding strength of the sheet.

The point of increasing the bonding strength of the lower seal will be described with reference to FIG. In order to increase the bonding strength of the lower seal at the peripheral seal,
The area of attachment of the lower seal to the developing device housing 4 is increased, and the lower seal is folded back on the rear surface side of the housing to be attached to the housing. Reference numeral 13a in FIG. 2 indicates a folded portion of the lower seal 13. As shown in FIG. 3, at the end of the developing roller of the lower seal 13 provided along the axial direction of the developing roller 10, a portion 13 b extending to the tip of the developing device housing 4 is provided.
Is formed and affixed, and the folded back portion 13a is further affixed to the rear surface of the developing device housing 4 to increase the affixed area of this portion as a whole. Therefore, even if a force that is pulled by the portion pressed by the peripheral seal 16 acts on the lower seal 13, there is no need to worry that the lower seal 13 is wound because of the high bonding strength. It is also conceivable to extend the lower seal 13 to the front end of the developing device housing 4 over the entire axial direction of the developing roller, and then to turn the lower seal 13 on the rear surface of the housing and apply the whole to increase the bonding strength. However, in this case, the contact of the lower seal with the developing roller becomes unstable due to the bending of the seal (the direction of receiving the force at the folded portion changes, so that a waving phenomenon occurs in the axial direction of the developing roller), and the toner leaks. May cause. Therefore,
In the present embodiment, the portion that increases the area to be attached is limited to the peripheral surface sealing portion. That is, since the position of the peripheral seal is determined by sandwiching the lower seal, even if the seal is turned back, no waving occurs, and the linearity of the contact portion with the developing roller required for the lower seal is ensured. No leakage occurs. In FIG. 3, reference numeral 19 denotes a bearing of the developing roller.

In FIG. 4, the lower seal 13 is made longer than the developing roller, extended to at least the end of the blast-free portion (smooth surface) 10a at the end of the developing roller, and pressed and supported by the peripheral seal 16. This is because if a lower seal end is present in the peripheral seal, the lower seal end is discontinuous (stepped) and toner leakage is likely to occur, and the lower seal end is set outward with respect to the rotating body of the developing roller. This is because the winding of the lower seal due to rotation can be reduced. In the part without the lower seal, the peripheral seal 16 is directly smoothed 10a.
Is pressed against.

The developing roller 10 and the supply roller 1
If there is a space at the boundary portion with No. 7, dead toner that is not used in that portion tends to be generated. Therefore, in FIG.
A curved portion C in which a bottom surface of the developing device housing 4 facing the boundary between the developing device roller 10 and the supply roller 17 is raised inward.
As a result, the space is reduced as much as possible so that dead toner is not produced as much as possible. In addition, since the developing device housing 4 is fixed to the base 3, the bottom surface of the developing device housing is flattened outward in the developing roller axial direction from a portion corresponding to a lower portion of the peripheral seal member, and a folded portion 13 a of the lower seal 13 is formed.
Should be attached to this flat part.

Next, an embodiment of the present invention for preventing the regulation load by the regulation blade from being concentrated on the end will be described. FIG. 5 is a diagram illustrating the relationship between the transport width and the regulation width. The developing roller includes a roughened conveying surface 10b for conveying the toner and smooth surfaces 10a at both ends. The regulating blade 12 has a structure in which a urethane rubber 12b is attached to a metal member 12a, and the urethane rubber 12b abuts on the developing roller on the upstream side from the developing position to apply a predetermined regulating load to regulate the thickness of the toner layer. . The regulating blade is made larger than the conveying width in order to regulate the toner thickness, and is made smaller than the developing roller length in relation to a member for sealing the end face. Further, in this embodiment, both ends of the regulating blade are cut up.

FIG. 6 is a view for explaining the cut-up of the end of the regulating blade. As shown, a cut-up portion T is formed at the end of the regulating blade. With such a configuration, it is possible to avoid as much as possible that excessive wear occurs on the transfer surface and sharp ends due to less wear on the smooth surface, and the regulated load is concentrated on the ends to cause excessive transfer. . If the start-up position is on the transport surface, the regulating blade is in an area where the regulating blade does not contact the developing roller despite the transport area, resulting in excessive transport. On the other hand, too far from the boundary line, a sharp portion is formed on the boundary line side from the start position of the cut-up, and the regulated load is applied to that portion, and the portion is also excessively conveyed. 2 from the border
mm. The cut-up portion T
May be rectangular with a step, but if the amount of cut-up is suddenly large from the cut-up start position, toner leakage may occur. On the other hand, the wear of the end of the regulating blade is smaller at the end, and a load is applied to the end, and the end is likely to float. Therefore, by increasing the cut-up amount toward the end, it is possible to avoid the occurrence of floating due to small wear of the regulating end.

In the case where the cut-up portion is formed at the end of the regulating blade, if the cut-off amount is small, the end portion is less worn, so that a sharp portion is formed and a floating is caused. No lifting occurs. Further, by setting the thickness to 50 μm or more, as shown in FIG. 7, the elastic member 30 such as an acrylic moquette is inserted into the cut-up portion to seal the end portion, thereby preventing the restriction member from floating. On the other hand, if the cut-off amount is too large, toner leakage may occur. Therefore, the cut-off amount is 300
μm or less. With such an interval, an elastic member such as an acrylic moquette can be easily provided as an end seal. In this case, since the end seal applies a force to the regulating blade from the lateral direction, no force is applied to the regulating blade in the vertical direction.

[0021]

As described above, according to the present invention, by forming the cut-out portion at the end of the regulating member, it is possible to minimize the occurrence of excessive conveyance due to the regulation load being concentrated on the end. it can. Further, by setting the start position of the cut-up on the end side of the boundary between the transport surface and the smooth surface, it is possible to avoid occurrence of excessive transport. In addition, by increasing the cut-up amount toward the end, it is possible to prevent the restriction member from floating. In addition, by setting the cut-up amount to a size that allows the end face sealing member to enter, similarly, it is possible to prevent floating and prevent toner leakage.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a developing device of the present invention.

FIG. 2 is a sectional view of an end portion of the developing device according to the present invention.

FIG. 3 is a diagram illustrating attachment of a peripheral sealing member to a developing device housing.

FIG. 4 is a diagram illustrating a positional relationship between a developing roller and a peripheral surface seal.

FIG. 5 is a diagram illustrating a relationship between a conveyance width and a regulation width.

FIG. 6 is a diagram illustrating the cut-up of the end of the regulating blade.

FIG. 7 is a diagram showing a state where an end face seal is inserted into a cut-up portion.

FIG. 8 is a diagram illustrating a state in which both ends of the regulating member are sharp.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Photoreceptor drum, 2 ... Developing device, 3 ... stand, 4 ... Developing device housing, 10 ... Developing roller, 11 ... Supply roller, 12 ... Regulator blade, 13 ... Lower seal, 14 ... Agitator mechanism,
15: peripheral seal member, 16: peripheral seal, 19: bearing, 30: acrylic moquette.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Atsushi Takei 3-3-5 Yamato, Suwa-shi, Nagano Prefecture Seiko Epson Corporation F-term (reference) 2H077 AB04 AC04 AD02 AD06 AD13 AE03 CA12 EA15 FA22 GA13

Claims (4)

[Claims] A regulating member is provided upstream of a developing position of a developer carrying member provided with a peripheral surface seal opposed to a smooth surface formed at both ends of a developer conveying surface subjected to a surface roughening process. In a developing device in which the regulation width by the regulation member is larger than the width of the developer conveying surface, both ends of the regulation member are cut up. 2. The developing device according to claim 1, wherein the cut-off start position of the regulating member is located at an end side of a boundary between the conveying surface and the smooth surface of the developer carrier. 3. The developing device according to claim 1, wherein the amount of cut-up of the regulating member increases from the inside toward the end. 4. The developing device according to claim 1, wherein an end face sealing member is inserted between the cut-up portion at the end of the regulating member and the developer carrier.