KR20050041155A - Developing apparatus and electrophotographic image forming apparatus adopting the same - Google Patents

Abstract

A developing apparatus and an electrophotographic image forming apparatus employing the same are disclosed. The disclosed developing apparatus includes: a developer conveying member for developing an electrostatic latent image formed on the counseling member while rotating and spaced apart from the counseling member at regular intervals; It is installed so as to be spaced apart from the counseling member so as to be rotatable, and by rotating the air in a direction opposite to the air flow direction generated by the rotation of the counseling member and the developer transporter in the developing region between the counseling member and the developer transporter. A rotating member for generating a flow; Equipped.

Description

Developing apparatus and electrophotographic image forming apparatus adopting the same

The present invention relates to a developing apparatus and an electrophotographic image forming apparatus employing the same, and more particularly, to prevent scattering of a developer during development in a non-contact developing method in which development occurs in a state in which a counseling member and a developer conveying body maintain a constant interval. A developer and an electrophotographic image forming apparatus employing the same may be used to prevent a developer from contaminating a developer and to improve image quality.

Electrophotographic image forming apparatuses such as laser printers, facsimile machines, digital copiers, etc., scan light into the consultation body to form an electrostatic latent image corresponding to a desired image, and supply a developer to the electrostatic latent image to toner images. After forming a, it is a device for printing on paper.

1 shows a conventional general electrophotographic image forming apparatus.

Referring to FIG. 1, the surface of the counseling member 21 is electrically uniformly charged by the discharge of the charger 22. Subsequently, the digital signal input from the computer or the scanner to the image forming apparatus is converted into an optical signal through an exposure apparatus such as a laser scanning unit (LSU) or a light-emitting diode (LED) array. The optical signal forms an electrostatic latent image of a predetermined shape on the consultation member 21. At this time, the developer 28 of the developing apparatus 24 is supplied to the developer conveyance body 25 by the supply roller 26, and the developer 28 supplied to this developer conveyance body 25 is developed. As the first conveying member 25 is rotated, it is conveyed to the developing region A between the consultation support body 21 and the developer conveying member 25. Here, the developer layer is regulated to a certain thickness on the surface of the developer carrier 25 by the developer layer regulating member 27 provided on the developer carrier 25. Next, when the consultation member 21 rotates to pass the developing region A, the developer 28 attached to the developer conveying member 25 is applied to the electrostatic latent image region formed on the consultation member 21 by electrostatic force. As a result, a visible toner image is formed on the consultation member 21. On the other hand, when the print medium 23 transferred from the paper feeder enters the transfer unit 29, the toner image formed on the consultation body 21 moves to the print medium 23 by the voltage applied to the transfer unit 29. Done. The toner image thus moved to the print medium 23 is fixed to the print medium 23 by the heat and pressure of the fixing unit 30. In FIG. 1, reference numeral 20 denotes a cleaning blade for cleaning the consultation member 21 after the toner image formed on the consultation member 21 is transferred to the print medium 23, and reference numeral 28 'denotes the cleaning. The waste developer removed by the blade 20 is shown. Reference numeral 31 denotes a stirrer for stirring the developer 28 inside the developing apparatus 24.

In the image forming apparatus for printing an image by the above process, the developer conveyance member 25 and the consultation support body 21 are rotated in the direction in which they engage with each other to face each other, and in the developing region A, the developer conveyance member. The gap between the 25 and the consultation delay 21 is kept constant. Then, the rotational speed of the developer delivery body 25 is set faster than the rotational speed of the consultation support body 21 so that the developer 28 can sufficiently move from the developer delivery body 25 to the consultation support body 21. In such a configuration, the developer 28 attached to the developer conveying member 25 passes through the developing region A and is caused by an electrostatic force according to the potential difference between the consultation support body 21 and the developer conveying member 25. It moves to the electrostatic latent image area formed in the consultation member 21.

On the other hand, since both the developer conveyance member 25 and the consultation support body 21 have a drum shape, the developing region A also has a nozzle shape. In this nozzle-shaped developing region A, when the consultation body 21 and the developer carrier 25 rotate in a direction in which they engage with each other, an air flow a in the direction of the arrow shown in FIG. 1 is formed. do. In addition, the air flow in the direction of the arrow shown in FIG. 1 between the developing device 24 and the print medium 23 in the process of entering the transfer means 29 by the print medium 23 transferred by the paper feeder. ) Is formed. Therefore, the fine developer 28 particles moving to the electrostatic latent image region by the electrostatic force in the developing region A are disturbed by the air flows a and b as described above. In particular, the developer 28 particles having insufficient charge amount are more affected by the air flow (a, b) than the electrostatic force, so that they adhere to the non-image area of the counseling member 21 without moving to the electrostatic latent image area, thereby improving image quality. It may degrade or be scattered into the image forming apparatus along the air flows a and b to contaminate the interior of the apparatus. In addition, there is a problem that the tip of the print medium 23 in contact with the paper guide 51 is contaminated by contaminating the paper guide 51 for guiding the print medium 23 from the transfer means 29 to the fixing means 30. Occurs.

A developing apparatus for solving the developer scattering problem as described above is illustrated in FIG. 2.

Referring to FIG. 2, after the air is forcedly convection in a direction opposite to the air flow generated in the developing region between the counseling member 1 and the developer conveying body 2a by using two fans fan5 and 15. When passing through the developing region through the intake and exhaust ducts 3 and 13, the developer is collected and moved to the filter 4 installed outside the developing apparatus 2 without being scattered elsewhere.

However, in the developing apparatus 2 of the above structure, the intake and exhaust ducts 3 and 13 and the two fans 5 and 15 should be installed, and the air volume should be controlled through the control apparatus 6. Therefore, the structure of the developing apparatus 2 becomes complicated, and there exists a problem that a price rises. In addition, the user is inconvenient to replace the filter 4 in which scattered developer is collected at an appropriate time. In addition, it is practically very difficult to control the behavior of the developer particles having a size of several microns by the amount of air of the fans 5 and 15. That is, when the air volume is excessive, the amount of the developer collected is increased, so that the replacement cycle of the filter 4 is faster, and conversely, when the air volume is small, the scattering prevention effect is inferior.

The present invention has been made in order to solve the above problems, in the non-contact developing method in which the development is maintained in a state in which the consultation delay and the developer carrier maintain a constant interval, thereby preventing the developer from scattering of the developer during development. It is an object of the present invention to provide a developing apparatus capable of preventing contamination, improving image quality, realizing miniaturization and low cost, and an electrophotographic image forming apparatus employing the same.

In order to achieve the above object,

The developing apparatus of the electrophotographic image forming apparatus according to the present invention,

A developer carrier for developing an electrostatic latent image formed on the counseling member while rotating and spaced apart from the counseling member at regular intervals;

It is installed so as to be spaced apart from the counseling member so as to be rotatable, and opposite to the air flow direction generated by rotation of the counseling member and the developer transporter in the developing region between the counseling member and the developer transporter by the rotation. Rotating member for generating an air flow in the direction; Equipped.

The rotating member is preferably installed below the developer carrier.

The rotating member is preferably rotated in the same direction as the rotation direction of the consultation delay.

In addition, the rotational linear speed of the rotating member is preferably equal to the rotational linear speed of the counseling member or greater than the rotational linear speed of the counseling member.

The rotating member may include a rotating shaft and at least one rotating blade provided on the rotating shaft. In addition, the rotating member may include a rotating shaft and a rotating roller provided on the rotating shaft.

The rotating member may further include a power transmission means for receiving power from the developer carrier. Here, the power transmission means are respectively provided at both ends of the rotating shaft, it is preferable to include a pair of rotating plate to rotate in engagement with the outer peripheral surface of the developer carrier to rotate.

On the other hand, the electrophotographic image forming apparatus according to the present invention,

Consultation delay;

A developer conveying body for developing an electrostatic latent image formed on the counseling member while rotating and spaced apart from the counseling member at a predetermined interval, and installed to be rotatable while being spaced apart from the counseling member. A developing device including a rotating member for generating air flow in a direction opposite to an air flow direction generated by the rotation of the consultation member and the developer conveying body in a developing region between the conveying bodies; Include.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals in the drawings denote like elements.

 3 is a view schematically showing main parts of an electrophotographic image forming apparatus according to an exemplary embodiment of the present invention.

Referring to FIG. 3, an electrophotographic image forming apparatus according to an exemplary embodiment of the present invention includes a counseling member 121, a charger 122 for charging the counseling member 121 to a predetermined potential, and the charged counseling service. An exposure apparatus (not shown) for scanning the body 121 to form an electrostatic latent image of a predetermined shape, a developing apparatus 124 for developing the electrostatic latent image as a toner image, and a toner formed in the counseling member 121 And a transfer unit 129 for transferring the image onto the print medium 123.

In addition, the developing apparatus 124 rotates spaced apart from the counseling member 121 at regular intervals while developing the developer conveying member 125 for developing an electrostatic latent image formed on the counseling member 121, and the developer conveying body ( A supply roller 126 for supplying the developer 128 to the developer conveying member 125 while rotating in the same direction as 125, and is provided on an upper portion of the developer conveying member 125 to supply the developer roller 126. The developer layer regulating member 127 for regulating the developer layer adhered to the surface of the developer conveying member 125 to have a constant thickness, and the counseling member 121 and the lower portion of the developer conveying member 125. It is provided with a rotating member 150 spaced apart.

In FIG. 3, reference numeral 120 denotes a cleaning blade for cleaning the consultation body 121 after the toner image formed on the consultation body 121 is transferred to the print medium 123, and reference numeral 128 'denotes the cleaning. The waste developer removed by the blade 120 is shown. Reference numeral 131 denotes a stirrer for stirring the developer 128 inside the developing apparatus 124, and reference numeral 160 denotes a housing that forms an outer wall of the developing apparatus 124.

The charger 122 applies a voltage to the counseling body 121 so that the surface potential thereof is maintained at a constant value in the range of approximately -600 to -700V. The charger 122 is made of a conductive rubber roller in contact with the consultation body 121. The exposure apparatus (not shown) may be a laser scanning unit (LSU) or a light emitting diode (LED) array, and the like, and the digital apparatus input to the image forming apparatus from a computer or a scanner is converted into an optical signal by the exposure apparatus. . Then, such an optical signal forms an electrostatic latent image of a predetermined shape on the consultation body 121. The transfer unit 129 is formed of a conductive sponge roller in contact with the consultation body 121. The transfer unit 129 has a high voltage to transfer the toner image formed on the consultation body 121 to the print medium 123. Is approved.

The developer conveying member 125 is installed in the developing area A so as to have a constant value within a range of about 150 to 300 µm. To this end, disc-shaped spacing members (not shown) are provided at both ends of the developer conveying member 125. The developer carrier 125 may be a conductive rubber roller or a roller coated with nickel (Ni) after sandblasting (Sand Blast) of cylindrical aluminum.

The developer layer regulating member 127 is manufactured by bending an stainless steel sheet (thickness of approximately 0.06 to 1.0 mm) having an elastic force to an L shape, and the developer layer regulating member 127 is formed of a steel sheet by laser welding. It is mounted to the housing 160 of the developing device 124 made. When the developer layer regulating subsidiary agent 127 is mounted, deformation occurs in the stainless steel sheet by the developer carrier 125, and thus an elastic force having a constant line force acts on the developer carrier 125. do. In addition, the developer 128 may be a one-component nonmagnetic developer using a polyester resin as a binder resin.

A voltage is applied from the power supply unit (not shown) to the developer conveying member 125, the supply roller 126, and the developer layer regulating member 127, and the power supply unit has a rectangular AC shape with a DC voltage. A power source with overlapping voltage is applied. The power supply unit can be controlled in accordance with the use environment and conditions.

The rotating member 150 is installed inside the developing apparatus 124 to be rotatable under the developer conveying member 125. In addition, the rotating member 150 is spaced apart from the counseling member 121 at regular intervals. The rotation member 150 is generated by the rotation of the consultation body 121 and the developer delivery body 125 in the developing region A between the consultation body 121 and the developer delivery body 125 by the rotation thereof. The air flow is generated in a direction opposite to the air flow direction. The perspective view of the rotating member 150 is shown in FIG.

Referring to FIG. 4, the rotating member 150 has a rotating shaft 151 having both ends mounted on the housing 160 of the developing apparatus 124, and at least one rotating blade 152 provided on the rotating shaft 151. ). Here, the shape or number of the rotary blades 152 may vary depending on the use conditions.

The rotating member 150 is shown in FIG. 3 to generate air flow in a direction opposite to the air flow direction generated by the rotation of the consultation body 121 and the developer carrier 125 in the developing region A. FIG. As described above, the rotation direction of the counseling member 121 is rotated in the same direction as the rotation direction of the developer carrier 125. At this time, the rotational linear speed of the rotary blade 152 is preferably the same as the rotational linear speed of the consultation body 121 or greater than the rotational linear speed of the consultation body 121. Here, the rotation member 150 may receive the rotational driving force from the drive gear assembled to one end of the developer transfer member 125 through the connecting gear. However, the rotating member 150 may also receive rotational driving force by independent driving means or other various methods.

5 shows another rotating member that can be applied to the developing apparatus 124 according to the present embodiment. Referring to FIG. 5, the rotating member 250 has a rotating shaft 251 having both ends mounted on the housing 160 of the developing apparatus 124, and a drum-shaped rotating roller provided on the rotating shaft 251. 252). As described above, the rotating member 250 is also rotated in the same direction as the rotation direction of the consultation body 121, that is, in a direction opposite to the rotation direction of the developer transfer member 125. At this time, the rotational linear speed of the rotary roller 252 is preferably the same as the rotational linear speed of the consultation body 121 or greater than the rotational linear speed of the consultation body 121.

Meanwhile, the above-described rotating members 150 and 250 are merely exemplary, and in addition to the air flow directions generated by the rotation of the counseling member 121 and the developer conveying member 125 in the developing region A by rotation. Various types of rotating members may be applied to generate air flow in the direction in which the air flows.

An operation of the electrophotographic image forming apparatus having the above structure will be described with reference to FIG. 3.

First, the counseling member 121 is electrically uniformly charged at its surface by the discharge of the charger 122. Subsequently, the digital signal input from the computer or the scanner to the image forming apparatus is converted into an optical signal by the exposure apparatus, and the optical signal forms an electrostatic latent image of a predetermined shape on the consultation body 121.

On the other hand, the developer conveying member 125 is rotated in the direction to mesh with the counseling member 121, as shown in Figure 3 while maintaining a constant interval with the consultation body 121. At this time, the developer carrier 125 rotates about 1.1 to 1.6 times faster than the rotational linear speed of the counseling member 121 so that the developer 128 can sufficiently move to the counseling member 121.

The developer 128 in the developer 124 is supplied to the developer carrier 125 by a supply roller 126. The developer 128 supplied to the developer conveying member 125 is regulated to a constant thickness while passing through the developer layer regulating member 127 to have an appropriate charge amount by frictional charging.

The developer 128 on the regulated developer carrier 125 is transferred to the developing area A between the consultation body 121 and the developer carrier 125. In addition, when a predetermined voltage is applied to the developer carrier 125 from a power supply unit (not shown), the developer 128 reciprocates the developing area A while forming an electrostatic latent image area formed in the counseling member 121. And a visible toner image is formed on the consultation body 121.

When the print medium 123 transferred from the paper feeder (not shown) enters the transfer unit 129, the toner image formed on the counseling body 121 is printed by the voltage applied to the transfer unit 129. Go to (123). Then, the toner image moved to the print medium 123 is fixed to the print medium 123 by the heat and pressure of the fixing unit.

On the other hand, in the developing area A, air flows downward in the developing area A due to the rotation of the consultation body 121 and the developer conveying body 125. Conventionally, the developer 128 particles having insufficient charge amount due to such air flow scattered out of the developing region A by the air flow described above. In addition, when the print medium 123 transferred from the paper feeder (not shown) enters the transfer unit 129, the air flows on the surface of the print medium 123 meet with the above-described air flow, and thus, the inside of the machine. The developer 128, which was scattered and thus scattered, contaminated the inside of the device.

In order to solve this problem, in the present embodiment, in order to generate an air flow that cancels the air flow directed downward by the rotation of the consultation body 121 and the developer transfer member 125 in the developing region A. Rotating the rotating member 150 installed in the lower portion of the conveying body (125). At this time, the rotation member 150 is rotated in the same direction as the rotation direction of the consultation body 121, that is, the opposite direction to the rotation direction of the developer transfer member 125.

When the rotating member 150 is rotated as described above, the air flows upward in the direction of the arrow (c) shown in FIG. 3 by the rotary blades 152 between the counseling member 121 and the rotating member 150. Flow occurs. Accordingly, in the developing region A, the air flow generated by the rotation of the consultation body 121 and the developer carrier 125 and the air flow generated by the rotation of the rotating member 150 cancel each other. As a result, the developer 128 particles having an insufficient charge amount are re-attached to the developer conveyance body 125 without being scattered into the apparatus, thereby circulating inside the developer 124. On the other hand, the amount of air flow generated by the rotation of the rotating member 150 may be controlled by adjusting the shape and number of the rotary blades 152, the rotation speed.

6 is a view schematically showing the main part of an electrophotographic image forming apparatus according to another embodiment of the present invention. 7 is a front view of the developer carrier and the rotating member illustrated in FIG. 6, and FIG. 8 is a perspective view of the rotating member illustrated in FIG. 6.

6 to 8, the developing apparatus 124 ′ according to the present embodiment includes a rotating member 350 that is spaced apart from the counseling member 121 at regular intervals at a lower portion of the developer carrier 125. Equipped. As shown in FIG. 8, the rotating member 350 has a rotating shaft 351 having both ends mounted on a housing of the developing apparatus 124, and at least one rotating blade provided on the rotating shaft 351. 352 and a pair of rotating plates 353 respectively provided at both ends of the rotating shaft 351. Here, the shape or number of the rotary blades 152 may vary depending on the use conditions.

The rotating plates 353 are power transmission means for receiving power from the developer transporter 125, and engaged with the outer circumferential surface of the developer transporter 125 in which the outer circumferential surfaces thereof rotate as shown in FIGS. 6 and 7, respectively. It is supposed to rotate. Therefore, when the developer carrier 125 rotates, the rotating plates 353 rotate in a direction opposite to the rotation direction of the developer carrier 125, and thus are provided between the rotary plates 353. Rotating blades 352 are also rotated. As described above, when the rotating member 350 rotates in accordance with the rotation of the developer conveying member 125, the counseling member 121 and the developer conveying member 125 may be disposed between the counseling member 121 and the rotating member 350. Air flow is generated in a direction opposite to the air flow direction generated by the rotation, thereby preventing the developer 128 from scattering into the device.

Although the preferred embodiment according to the present invention has been described above, this is merely exemplary, and various modifications and equivalent other embodiments are possible to those skilled in the art. Therefore, the true technical protection scope of the present invention will be defined by the appended claims.

As described above, the developing apparatus and the electrophotographic image forming apparatus employing the same according to the present invention have the following effects.

First, it is possible to prevent the developer from being scattered into the image forming apparatus by generating the air flow in a direction opposite to the air flow direction generated by the rotation of the counseling member and the developer conveying member in the developing region. Accordingly, the inside of the image forming apparatus can be prevented from being contaminated with the developer.

Second, image quality can be improved by preventing unwanted developer from adhering to the non-image area of the print medium.

Third, since the structure for preventing developer from scattering is simpler than before, it is possible to realize miniaturization and low cost of the developing apparatus.

1 is a view schematically showing the main part of a conventional electrophotographic image forming apparatus.

2 is a view showing a developing apparatus of a conventional electrophotographic image forming apparatus.

3 is a view schematically showing the main part of an electrophotographic image forming apparatus according to an embodiment of the present invention.

4 is a perspective view of the rotating member shown in FIG.

5 is a perspective view of another rotating member that may be applied to the electrophotographic image forming apparatus shown in FIG. 3.

6 is a view schematically showing the main part of an electrophotographic image forming apparatus according to another embodiment of the present invention.

FIG. 7 is a front view of the developer carrier and the rotating member illustrated in FIG. 6.

8 is a perspective view of the rotating member shown in FIG.

<Description of the symbols for the main parts of the drawings>

120 ... Cleaning Blade 121 ... Consultation Delay

122 ... Charger 123 ... Print Media

124 ... developer 125 ... developer carrier

126 ... supply roller 127 ... developer layer control member

128 ... developer 128 '... waste developer

129 ... Transfer Unit 131 ... Stirrer

150,250,350 ... rotating member A ... developing area

Claims (14)

A developer carrier for developing an electrostatic latent image formed on the counseling member while rotating and spaced apart from the counseling member at regular intervals; It is installed so as to be spaced apart from the counseling member so as to be rotatable, and opposite to the air flow direction generated by rotation of the counseling member and the developer transporter in the developing region between the counseling member and the developer transporter by the rotation. Rotating member for generating an air flow in the direction; And a developing apparatus for an electrophotographic image forming apparatus. The method of claim 1, And the rotating member is installed under the developer conveying member. The method of claim 1, And the rotating member is rotated in the same direction as the rotation direction of the consultation member. The method of claim 1, And the rotational linear speed of the rotating member is equal to or higher than the rotational linear speed of the counseling member. The method of claim 1, And the rotating member includes a rotating shaft and at least one rotating blade provided on the rotating shaft. The method of claim 1, And the rotating member includes a rotating shaft and a rotating roller provided on the rotating shaft. The method according to claim 5 or 6, The rotating member further includes a power transmission means for receiving power from the developer conveying member. The method of claim 7, wherein And the power transmission means are provided at both ends of the rotating shaft, and include a pair of rotating plates that rotate in engagement with an outer circumferential surface of the developer conveying member that rotates. Consultation delay; A developer conveying body for developing an electrostatic latent image formed on the counseling member while rotating and spaced apart from the counseling member at a predetermined interval, and installed to be rotatable while being spaced apart from the counseling member. A developing device including a rotating member for generating air flow in a direction opposite to an air flow direction generated by the rotation of the consultation member and the developer conveying body in a developing region between the conveying bodies; Electrophotographic image forming apparatus comprising a. The method of claim 9, And the rotating member is installed under the developer conveying body. The method of claim 9, And the rotating member rotates in the same direction as the rotation direction of the photosensitive drum. The method of claim 9, The rotational linear speed of the rotating member is equal to the rotational linear speed of the counseling member or greater than the rotational linear speed of the counseling member. The method of claim 9, And the rotating member includes a rotating shaft and at least one rotating blade provided on the rotating shaft. The method of claim 9, And the rotating member includes a rotating shaft and a rotating roller provided on the rotating shaft.