KR20030049898A - Development apparatus for electric-photographic printer - Google Patents

Abstract

PURPOSE: A separation type developing device of an electrophotographic image forming apparatus is provided to easily maintain a predetermined nip between a developing roller and an OPC drum, and prevent damage on the developing roller and the OPC drum by removing interference between the developing roller and the OPC drum in mounting a developer unit. CONSTITUTION: An OPC(Organic Photo Conductor) unit(110) is detachably installed at a frame(100) and an OPC drum(111) is assembled with the OPC unit. A developer unit(120) is installed rotatively to the frame and has one side assembled with a developing roller(121) to be exposed. A rotating element rotates the developer unit to the frame, transmits motive power to the developing roller, and is attached in an axial direction of the developing roller. The developing roller presses the OPC drum due to a rotary torque by the developer unit.

Description

Development apparatus for electrophotographic image forming machine {Development apparatus for electric-photographic printer}

The present invention relates to a separate developing device for an electrophotographic image forming machine, and more specifically, to adjust the NIP between a developing roller and an OPC drum by using a rotating torque applied to a developing roller of a separate developer unit. A detachable developing apparatus of an electrophotographic image forming apparatus which can detach a unit in an axial direction of a developing roller.

In general, an electrophotographic image forming machine scans a laser beam onto an OPC drum to form an electrostatic latent image, develops the electrostatic latent image as a visible image with a developer, and then transfers and fixes the image onto paper to print. However, such an electrophotographic image forming machine employs a large number of separate developing apparatuses in which a developing roller for supplying a developer is provided as a separate unit from an OPC drum in order to facilitate replenishment of a developer for developing an electrostatic latent image.

1 illustrates an embodiment of a separate developing apparatus of such a conventional electrophotographic image forming apparatus.

Referring to the drawings, the separate developer includes a frame 1, a developer unit 20, and an OPC unit 10.

The frame 1 is to fix the detachable developing device to the main body (not shown) of the electrophotographic image forming machine, and the first guide rod 3 for guiding the mounting of the OPC unit 10 to the frame 1 is provided. And a second guide rod 5 for guiding mounting of the developer unit 20 to the frame 1.

The OPC unit 10 is assembled so that the OPC drum 11 in which the electrostatic latent image is formed by the laser beam is rotatable, and has a first guide hole 13 inserted into the first guide rod 3.

The developer unit 20 supplies a developer for developing an electrostatic latent image formed on the OPC drum 11, and develops the developer roller 21 and the developer roller 21 for carrying the developer to the OPC drum 11. A developer supply roller 22 for attaching the agent, a stirrer 23 for stirring the developer, and a housing 28 for rotationally supporting the rollers 21, 22, and 23. A developer is contained therein, and a second guide hole 25 inserted into the second guide rod 5 is provided at an upper end thereof. In addition, the developer unit 20 is provided with a guide portion 27 which is guided to the OPC unit 10 when attached to the frame 1 and maintains a distance from the OPC drum 11.

Referring to the operation of the separate developing device of the electrophotographic image forming apparatus having the above configuration is as follows.

When mounting the OPC unit 10 to the frame 1, the first guide hole 13 of the OPC unit 10 is inserted into the first guide rod 3 of the frame 1 to Push in the axial direction to mount.

When the developer unit 20 is mounted, the second guide hole 25 of the developer unit 20 is inserted into the second guide rod 5 of the frame 1 in the axial direction of the development roller 21. When pushed and assembled, the guide part 27 is guided and mounted to the OPC unit 10.

Then, the developer smoothly moves from the developer roller 21 to the OPC drum 11 because the developer roller 21 of the developer unit 20 and the OPC drum 11 of the OPC unit 10 maintain a constant interval. Thus, the latent electrostatic image of the OPC drum 11 is developed.

However, the above developing apparatus has the first and second guide rods 3 and 5 of the frame 1, the second guide hole 25 of the developer unit 20, and the first guide of the OPC unit 10. Since the distance between the developing roller 21 and the OPC drum 11 is determined by the ball 13 and the degree of assembly of the developing roller 21 and the OPC drum 11, the predetermined interval for smooth development is kept constant. There is a problem that it is difficult to do.

In addition, the above-described method of mounting the developer unit is effective in the non-contact developing method with a predetermined distance between the developing roller 21 and the OPC drum 11, but the developing roller 21 and the OPC drum 11 are in contact with each other. In the contact developing method for forming a constant NIP, the developing roller 21 and the OPC drum 11 are assembled while rubbing each other when the developer unit 20 is mounted, so that the developing roller 21 and the OPC drum 11 are assembled. There is a problem of this being damaged.

The present invention has been made in order to solve the above problems, it is more preferable to keep the gap between the development roller and the OPC drum to be constant by making the pin between the developing roller and the OPC drum is formed by the rotational torque applied to the developing roller. An object of the present invention is to provide a separate developing device for an easy electrophotographic image forming machine.

Further, another object of the present invention is to provide a separate developing apparatus of an electrophotographic image forming apparatus which can prevent damage to the developing roller and the OPC drum by preventing the developing roller from interfering with the OPC drum when the developer unit is mounted. have.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view schematically showing a separate developing apparatus of an electrophotographic image forming apparatus according to the prior art;

2 is a view schematically showing a developing apparatus of an electrophotographic image forming apparatus according to the present invention;

3a is a view showing the turning means of FIG.

3B is a cross-sectional view taken along line A-A of FIG. 3A;

4 is a perspective view illustrating the coupling of FIG. 3A;

5A is a perspective view of the coupling gear of FIG. 3A,

5B is a rear view of FIG. 5A.

* Description of the symbols for the main parts of the drawings *

100; Frame 103; A guide rod

110; OPC unit 111; OPC Drum

113; Guide hole 120; Developer unit

121; Developing roller 123; housing

125; Stopper 130; Means of turning

131; Coupling gear 132; Spline

133; Middle gear 135; Coupling

136; Spline shaft

In order to achieve the above object, a separate developing device of an electrophotographic image forming apparatus according to the present invention includes a frame in which an OPC drum is installed, and a developing roller rotatably installed on the frame and contacting the OPC drum on one side thereof. A developer unit assembled to be exposed and pivoting means for pivoting the developer unit with respect to the frame and transmitting power to the developer roller, wherein the developer roller is operated by the rotational torque by the developer unit. It is characterized by pressing the drum.

In addition, a separate developing device of an electrophotographic image forming apparatus according to the present invention includes a frame, an OPC unit detachably mounted to the frame, and an OPC drum assembled thereon, and rotatably installed on one side of the frame. A developer unit assembled to expose the developing roller in contact with the OPC drum, and turning means for pivoting the developer unit against the frame, transmitting power to the developing roller, and detaching in the axial direction of the developing roller. The developing roller is characterized in that for pressing the OPC drum by the rotational torque by the developer unit.

Here, the pivot means is rotatably installed on the frame, one side of the coupling is formed with a spline shaft for power transmission, and is rotatably installed on the developer unit, and one side is formed with a spline corresponding to the spline shaft and the other The side is characterized in that it comprises a coupling gear formed with an intermediate gear meshing with the gear of the developing roller.

In addition, it is preferable that the groove width of the spline is larger than the thickness of the spline of the spline shaft, and the developer unit is preferably provided with a stopper at the lower end thereof to prevent collision with the OPC unit.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the separate type developing apparatus of the electrophotographic image forming apparatus according to the present invention.

Referring to FIG. 2, a separate developing apparatus of an electrophotographic image forming apparatus according to the present invention includes a frame 100, an OPC unit 110, and a developer unit 120.

The frame 100 fixes the detachable developing device of the electrophotographic image forming machine to an image forming body (not shown), and is equipped with an OPC unit 110 and a developer unit 120.

In this case, the frame 100 may be integrally formed with the frame 100 and the OPC unit 110, and may be designed in a structure in which only the developer unit 120 is detachable. In FIG. 2, the OPC unit 110 may have a frame. It is in the form which can be attached or detached with respect to (100). Therefore, the guide rod 103 to which the OPC unit 110 is mounted is installed in the frame 100. In addition, the frame 100 is provided with a coupling 135 to which the coupling gear 131 of the developer unit 120 is assembled.

The OPC unit 110 is assembled so that the OPC drum 111, in which the electrostatic latent image is formed by the laser beam, is rotatable, and the guide hole 113 is inserted into the guide rod 103.

The developer unit 120 supplies a developer for developing an electrostatic latent image formed on the OPC drum 111, and includes a developing roller 121, a turning means 130, a housing 123, and a stopper 125.

The developing roller 121 transfers the developer contained in the housing 123 to the OPC drum 111 and forms a constant NIP in contact with the OPC drum 111.

The pivoting means 130 includes a coupling 135 and a coupling gear 131 with reference to FIGS. 3A-5B.

Coupling 135 is rotatably installed in the frame 100, the power transmission spline shaft 136 is formed on one side. On the other side, a power transmission member for transmitting power for driving the developing roller 121 from a driving source of the main body of the electrophotographic image forming apparatus (not shown) is provided.

The coupling gear 131 is rotatably installed in the housing 123 of the developer unit, and a spline 132 corresponding to the spline shaft 136 of the coupling is formed at one side thereof, and the developing roller 121 is formed at the other side thereof. An intermediate gear 133 meshing with the gear is formed.

Here, the width W of the spline groove 132a is formed to be larger than the tooth thickness T of the spline 136a of the spline shaft 136, so that the coupling gear ( 131 may be rotated by a predetermined angle, and the difference may be such that the developing roller 121 of the developer unit can be inserted without interfering with the OPC unit 110 while the developer unit 120 is rotated by a predetermined angle. It is desirable to decide.

The housing 123 rotates and supports the developing roller 121 and the coupling gear 131, and is a container in which a developer is contained.

The stopper 125 is installed at a position corresponding to the OPC unit 110 at the bottom of the housing 123, prevents the developer unit 120 from colliding with the OPC unit 110, and develops the OPC drum 111. The roller 121 is to maintain a constant contact.

In addition, the developer unit 120 may be installed by arranging the above components so that the developing roller 121 has a center of gravity that receives the rotational torque to rotate upward about the axis of the coupling gear 131.

Hereinafter, the operation of the embodiment of the present invention having the above structure will be described with reference to the accompanying drawings.

First, the guide hole 113 of the OPC unit 110 is inserted into the guide rod 103 of the frame 100, and then the OPC unit 110 is pushed in the axial direction of the OPC drum 111.

Subsequently, the spline shaft 136 of the coupling 135 assembled to the frame 100 is inserted into the developer unit 120 by inserting the spline 132 of the coupling gear 131 assembled to the developer unit 120. ) To the frame 100. At this time, the developer unit 120 is mounted at a predetermined angle so as not to interfere with the developing roller 121 and the OPC drum 111 during mounting.

When the spline 132 of the coupling gear 131 is completely inserted into the spline shaft 136 of the coupling 135, the developer roller 121 of the developer unit 120 comes into contact with the OPC drum 111. The angle is turned to complete the mounting of the developer unit 120. Then, since the developer unit 120 tries to rotate the developing roller 121 upward about the coupling gear 131 axis, the developing roller 121 pressurizes the OPC drum 111. At this time, the stopper 125 installed at the lower end of the developer unit 120 contacts the lower end of the OPC unit 110 to prevent excessive force from being applied to the OPC drum 111.

In addition, when developing the electrostatic latent image of the OPC drum 111 by the developing roller 121, the coupling 135 is rotated by the main body driving source (not shown), and when the coupling 135 is rotated, the coupling is performed. Power is transmitted to the spline 132 of the coupling gear 131 by the spline shaft 136 of the coupling gear 131 rotates. When the coupling gear 131 rotates, the developing roller 121 is rotated by the gear of the developing roller 121 engaged with the coupling gear 131 to supply the developer to the OPC drum 111. At this time, when the coupling 135 rotates the coupling gear 131 counterclockwise, the torque of the developer unit 120 itself also rotates counterclockwise about the coupling gear 131 axis by the force. Since it is received, the force that the developing roller 121 presses the OPC drum 111 is increased by that much. That is, the gap between the developing roller 121 and the OPC drum 111 is determined by the sum of the rotational torque due to the center of gravity of the developer unit 120 itself and the driving torque for driving the developing roller 121. .

Accordingly, according to the separate type developing apparatus of the electrophotographic image forming apparatus according to the present invention, the rotational torque between the developing roller 121 and the OPC drum 111 and the driving force of the developing roller 121 by the developer unit 120 are described. Since it is determined by the rotational torque by, it is easy to keep the gap between the developing roller 121 and the OPC drum 11 constant.

In addition, since the developer unit 120 is assembled to the frame 100 in a state where the developer unit 120 is rotated by a predetermined angle, interference does not occur between the developing roller 121 and the OPC drum 111, and thus the developing roller 121 and the OPC drum ( 111) is not damaged by friction during assembly.

As described above, according to the separate developing apparatus of the electrophotographic image forming apparatus according to the present invention, the gap between the developing roller and the OPC drum is applied to the developing roller by the rotational torque caused by the center of gravity of the developer unit and the driving force of the developing roller. Since it is determined by the rotational torque, the gap between the developing roller and the OPC drum can be easily maintained at a predetermined value.

In addition, since the developer unit can be assembled to the frame in a state where the developer unit is rotated at a predetermined angle, interference between the developing roller and the OPC drum does not occur when the developer unit is mounted, thereby preventing damage to the developing roller and the OPC drum. have.

The present invention is not limited to the above-described specific embodiments, and various modifications can be made by those skilled in the art without departing from the gist of the present invention as claimed in the claims. Of course, such changes will fall within the scope of the claims.

Claims (6)

In the separate developing device of the electrophotographic image forming apparatus, the electrostatic latent image formed on the OPC drum by a laser beam is developed by contacting the developing roller with the OPC drum. A frame provided with the OPC drum; A developer unit rotatably installed with respect to the frame and assembled to expose the developing roller on one side; And And turning means for pivoting the developer unit with respect to the frame and transmitting power to the developing roller. And said developing roller pressurizes said OPC drum by a rotating torque by said developer unit. In the separate developing device of the electrophotographic image forming apparatus, the electrostatic latent image formed on the OPC drum by a laser beam is developed by contacting the developing roller with the OPC drum. frame; An OPC unit detachably mounted to the frame and assembled with the OPC drum; A developer unit rotatably installed with respect to the frame and assembled to expose the developing roller on one side; And And rotating means for pivoting the developer unit with respect to the frame and transmitting power to the developing roller and detaching in the axial direction of the developing roller. And said developing roller pressurizes said OPC drum by a rotating torque by said developer unit. The method of claim 2, wherein the pivot means, A coupling rotatably installed on the frame, the coupling having a spline shaft for power transmission formed at one side thereof; A coupling gear rotatably installed on the developer unit, one side of which is formed a spline corresponding to the spline shaft, and the other side of which is formed an intermediate gear meshing with the gear of the developing roller; Separation type developing device of the type image forming machine. 4. The separate developing apparatus of an electrophotographic image forming apparatus according to claim 3, wherein the groove width of the spline is larger than the thickness of the spline of the spline shaft. The method of claim 2, wherein the developer unit, And a stopper for preventing collision with the OPC unit at a lower end thereof. 3. The electrophotographic image forming apparatus as claimed in claim 2, wherein the developing roller pressurizes the OPC drum further includes a rotating torque applied to the developer unit by a driving force for rotating the developing roller. Separate developer.