JP2006098981A - Multi-color developing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multi-color developing device wherein toner accumulated in the vicinity of a toner supply port is uniformly distributed in a short time. <P>SOLUTION: A multi-color developing device 2 arranged in proximity of an electrostatic latent image carrier includes; developing units 4Y, 4M, 4C, and 4K arranged in a circumferential direction for respective toner colors; covers 6Y, 6M, 6C, and 6K extending in a lengthwise direction on outer circumferential surfaces of the developing units; toner supply ports 6Yb, 6Mb, 6Cb, and 6Kb provided in lengthwise-direction positions different by developing units, in the covers; toner vessels 14Y, 14M, 14C, and 14K; toner exits 14Ya, 14Ma, 14Ca, and 14Ka which connect to respective toner vessels and are disposed so as to face the toner supply ports in accordance with turning of the developing units; and opening/closing means added to respective toner supply ports and toner exits. Slopes 6Yg, 6Mg, 6Cg, and 6Kg which are high in vicinities of the toner supply ports and are made lower according as going away from the toner supply ports are formed on rear sides of the covers. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a multicolor developing device mounted on an image forming apparatus.

  In the field of color electrophotography, there is known a developing device that is arranged in the vicinity of an electrostatic latent image carrier and sequentially supplies several types of toner to the electrostatic latent image to perform multicolor development. In this type of developing device, a plurality of developing units having a function of developing with different color toners are sequentially rotated to supply toner of a required color to the electrostatic latent image to form a color image. .

  In the above conventional developing device, it is common to have a mechanism capable of replenishing toner when each developing device runs out of toner. For example, there is known a device that supplies toner by dropping toner into the developing device from a toner replenishing port provided at one place in the longitudinal direction of the outer peripheral surface of the developing device.

  However, in such a developing apparatus, there is a problem that the toner just dropped into the developing device is collected near the toner supply port, and the supplied toner is not uniformly distributed in the developing device.

Therefore, in Patent Document 1, a screw (winged stirring rod) whose winding direction is reversed in the middle from the position of the toner replenishing port is pivotally supported in the longitudinal direction in the developing device, and the screw is placed on the screw from the toner replenishing port. There has been proposed a multi-color developing device in which the toner dropped on the toner is conveyed to both sides in the axial direction by rotation of the screw so that the toner is uniformly distributed in the developing device.
Japanese Patent Publication No. 7-69645

  However, the multi-color developing device proposed in Patent Document 1 has a problem that it takes too much time for the toner to be uniformly distributed only by rotating the screw. To shorten the required time, it is easy to increase the toner conveyance amount by increasing the blade diameter of the screw, or to add a new screw, but this increases the size of the developer and the cost of parts. There was an inevitable problem.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a multi-color developing device capable of uniformly distributing toner accumulated in the vicinity of a toner supply port in a short time while suppressing an increase in the size of a developing device and an increase in parts cost. To do.

  In order to achieve the above object, the present invention provides a multicolor developing device arranged in the vicinity of an electrostatic latent image carrier and sequentially supplying several types of toner to the electrostatic latent image for multicolor development. A plurality of developing devices arranged for each toner color, a toner replenishing port provided with a different longitudinal position for each developing device, a toner container for storing toner for each toner color, and communicating with each toner container A toner outlet disposed so as to face the toner replenishing port according to the rotation of the developing device, developing means for supplying toner to the electrostatic latent image from within each developing device, and each toner replenishing And an opening / closing means attached to each of the toner outlets, and a slope is formed on the inner wall surface of each developer so that the vicinity of the toner supply port is the highest and becomes lower as the distance from the toner supply port increases. And

  Further, the toner replenishing port is provided in a lid that is attached to the outer peripheral surface of each developing device in the longitudinal direction, and the inclined surface is formed on the back surface of each lid.

  According to the present invention, before each developing device is arranged close to the electrostatic latent image carrier, the inclined surface formed on the lid or the casing goes through the arrangement located at the bottom in the developing device, Each toner is uniformly distributed in the sliding developer along the slope. For this reason, it is possible to evenly distribute the toner collected near the toner replenishing port in a short time while suppressing the increase in the size of the developing device and the increase in parts cost, and the toner can be replenished and developed smoothly at the development position. It can be carried out.

  The best mode for carrying out the present invention will be described below with reference to the drawings. In the following embodiments, a rotary multicolor developing device for a color electrophotographic copying apparatus that develops using four-component one-component toner will be described.

  1 and 2, a rotary developing device 2 includes a rotary 3 that is a rotatable cylindrical body, and yellow (Y) and magenta (M) supported on a rotary shaft 3a of the rotary 3. , Cyan (C) and black (K) developing devices 4Y, 4M, 4C, and 4K. Each of these developing devices 4Y, 4M, 4C, 4K is arranged in the circumferential direction of the rotary 3 in the clockwise direction at equal intervals. Each of these developing devices has a spread in the rotary axial direction, and the size thereof corresponds to the longitudinal size of the photosensitive drum 20 facing the rotary 3 in the vicinity thereof.

  The yellow toner developing device 4Y will be described below as an example. As shown in the external perspective view of FIG. 3, the developing device 4 </ b> Y has a lid 6 </ b> Y attached to the casing 5 </ b> Y so as to form the outer peripheral surface of the rotary 3. As shown in FIG. 2, developing means including a developing roller 7Y, a sponge roller 8Y, a sliding contact member 9Y, and the like are provided in the vicinity of the partition wall downstream of the casing 5Y in the rotational direction. A part of the developing roller 7Y is exposed from the outer peripheral surface of the rotary 3, and can be brought close to and opposed to the photosensitive drum 20 at a required rotational position of the rotary 3. Further, a screw 10Y as a stirring means for uniformly distributing the toner in the rotary axis direction is provided in the vicinity of the partition wall on the upstream side in the rotary direction of the casing 5Y.

  As shown in FIG. 4, between the partition walls at both ends in the rotary axis direction of the casing 5Y, beam portions 5Ya forming the rotary outer peripheral edge portion are formed extending in the rotary axis direction. The upper surface of the partition wall 5Yb and the upper surface of the beam portion 5Ya on the upstream side of the casing 5Y in the rotary direction form a flat surface, and the lid 6Y is mounted on the surface (see FIG. 7). A recess 5Yc having a predetermined width is provided at a substantially central portion in the rotary axis direction at the upper end edge of the inner surface of the partition wall 5Yb, and an engagement groove 5Yd is extended along the wall surface of the recess 5Yc. Further, on the inner surface of the partition wall 5Yb, a slope 5Ye is formed so that the vicinity of the toner replenishing port 6Yb protrudes most to the toner storage space side and protrudes to become smaller as the distance from the toner replenishing port 6Yb increases in the longitudinal direction (rotary axis direction). Yes. In other words, when the casing 5Y is placed with the partition wall 5Yb at the bottom and viewed from above, the inclined surface 5Ye is formed so that the vicinity of the toner supply port 6Yb is the highest and becomes lower as the distance from the toner supply port 6Yb increases. Yes.

  As shown in FIG. 5, the lid 6Y has a rectangular recess 6Ya at the right end in the rotary axis direction, and a circular toner supply port 6Yb is formed in the bottom surface of the recess 6Ya. On the downstream side in the rotary direction of the partition wall of the lid 6Y that forms the outer peripheral surface of the lid 6Y, the inclined surface is one step lower. With this shape, a beak portion 6Yc is added to the lid 6Y. As shown in FIG. 6, the outer edge of the lower end of the partition wall 6Yd upstream of the lid 6Y in the rotary rotation direction is provided with a protrusion 6Ye with a predetermined width at a substantially central portion in the rotary rotation axis direction. An engaging projection 6Yf is extended at the tip edge of the. On the rear surface of the partition wall of the lid 6Y that forms the outer peripheral surface of the rotary (in a state where the lid 6Y is attached to the casing 5), the vicinity of the toner replenishing port 6Yb protrudes most to the toner storage space side in the longitudinal direction from the toner replenishing port 6Yb (rotary A slope 6Yg is formed so that the protrusion becomes smaller as the distance in the axial direction increases. In other words, the inclined surface 6Yg is formed such that when the lid 6Y is placed face down and viewed from above, the vicinity of the toner supply port 6Yb is the highest and becomes lower as the distance from the toner supply port 6Yb increases.

  Next, a procedure for attaching the lid 6Y to the casing 5Y will be described with reference to FIG. A pressing member 11Y made of a letter-shaped sheet metal that forms the outer peripheral surface of the rotary is attached to the partition wall edge portions at both ends in the rotary axial direction of the casing 5Y. The pressing member 11Y has a notch 11Ya formed in a portion corresponding to the recess 6Ya of the lid 6Y. The beak portion 6Yc of the lid body 6Y is inserted into the space on the back side of the pressing member 11Y thus attached, the engagement protrusion 6Yf and the engagement groove 5Yd are engaged, and the lid body on the upper surface of the partition wall 5Yb and the beam portion 5Ya of the casing 5Y. Wear 6Y. Then, the guide member 12Y is mounted in the recess 6Ya and the notch 7Ya. A shutter 13Y is slidably fitted to the guide member 12Y, and the toner supply port 6Yb is opened and closed by sliding the shutter 13Y in the rotary rotation direction. The shutter 13Y is driven to open and close by a rack and pinion mechanism driven by a motor or a mechanism using a solenoid. Thus, the shutter 13Y and the driving mechanism are collectively referred to as an opening / closing means for the toner replenishing port 6Yb.

  The above is the main configuration regarding the developing device 4Y. The various members in the developing device 4Y are exactly the same in other developing devices. Therefore, the reference numerals indicating the constituent members of the other developing devices are indicated by the reference symbols in which the letter Y is replaced with M, C, and K without changing the numerals in the reference numerals for the developing device 4Y. Here, the toner replenishing port is shifted at a constant interval in the rotary axis direction. That is, the toner replenishing port 6Mb is located closer to the center than the toner replenishing port 6Yb when viewed from the direction of the arrow A in FIG. 1, the toner replenishing port 6Cb is located on the left end side, and the toner replenishing port 6Kb is located on the leftmost end side. This deviation of the toner replenishing ports is to correspond to each of the toner containers 14Y, 14M, 14C, and 14K described later.

  Four toner containers 14Y, 14M, 14C, and 14K containing yellow, magenta, cyan, and black toners are fixed on the color electrophotographic apparatus main body obliquely above the rotary 3. The toner containers 14Y, 14M, 14C, and 14K are arranged in this order in the rotary axial direction, and have toner outlets that communicate with the toner containers.

  For example, as shown in FIG. 2, the developing roller 7 </ b> Y is closest to the photosensitive drum 20 at the rotational position of the rotary 3 when the toner supply port 6 </ b> Yb matches the toner outlet 14 </ b> Ya by the rotation of the rotary 3. The electrostatic latent image is developed with yellow toner. At the same time, the shutter 13Y is opened and the valve 14Yb serving as a means for opening and closing the toner outlet 14Ya is opened, so that the yellow toner stored in the toner container 14Y is supplied to the developing device 4Y. The replenished yellow toner falls on the partition wall of the casing 5Y and the screw 10Y, and is transported in the axial direction and uniformly distributed according to the rotation of the screw 10Y.

  At this time, in the cyan toner developing device 4C, the surface having the inclined surface 6Cg of the lid 6C is positioned at the bottom in the developing device, and the cyan toner slides along the inclined surface 6Cg and moves to both sides in the rotary axis direction. The toner is evenly distributed. On the other hand, in the black toner developing device 4K, the inner surface of the partition wall upstream in the rotation direction of the casing 5K is located at the bottom in the developing device, and the inclined surface 5Ke (the inclined surface does not exist at the sectional position in FIG. The black toner slides along the rotary axis and moves to both sides of the rotary axis, and the black toner is uniformly distributed.

  Thus, when the yellow toner is replenished, the valve 14Yb is closed and the shutter 13Y is also closed. When the development with yellow toner is completed, the rotary 3 rotates in the direction of the arrow α, and stops at a position where the toner supply port 6Kb matches the toner outlet 14Ka communicating with the toner container 14K. This stop position is also a position where the developing roller 7K is closest to the photosensitive drum 20.

  The electrostatic latent image is developed with black toner by the developing roller 7K. The developing device 4K is replenished with black toner in the toner container 14K. Further, before the developing unit 4K is arranged at the developing position, the black toner is uniformly distributed in the developing unit 4K by passing through the arrangement in which the inclined surfaces 6Kg and 5Ke are located at the bottom in the developing unit. Therefore, the black toner can be replenished and developed smoothly.

  At this time, in the magenta toner developing device 4M, the surface having the inclined surface 6Mg of the lid 6M is positioned at the bottom in the developing device, and the magenta toner slides along the inclined surface 6Mg and moves to both sides in the rotary axis direction. The toner is evenly distributed. On the other hand, in the cyan toner developing device 4C, the inner surface of the partition wall upstream in the rotation direction of the casing 5C is located at the bottom in the developing device, and the cyan toner slides along the inclined surface 5Ce and moves to both sides in the rotary axis direction. The toner is evenly distributed.

  In accordance with the above-described steps, replenishment and development are sequentially performed for other toners.

  The toner replenishing ports 6Yb, 6Mb, 6Cb, 6Kb are closed tightly by the shutters 13Y, 13M, 13C, 13K, etc., except when toner is replenished, so that toner does not scatter or flow out to the outside. Has been. The same applies to the valves provided at the toner outlets of the toner containers 14Y, 14M, 14C, and 14K. The sliding members 9Y, 9M, 9C, and 9K that are in sliding contact with the developing roller have a sealing function at the same time as charging the toner by friction. The sponge rollers 8Y, 8M, 8C, and 8K have an auxiliary function of attaching toner to each developing roller.

  Note that the shape of the screws 10Y, 10M, 10C, and 10K is such that the direction of winding is reversed at the portion corresponding to the toner replenishing port, and the pitch and outer diameter of the wings are made non-uniform so In combination, the toner can be more uniformly distributed in the developing device.

  The present invention can be used in an image forming apparatus.

FIG. 2 is a perspective view of a main part of a rotary multicolor developing device according to the present invention. These are sectional views of the developing device. FIG. 3 is an external perspective view of a developing device for yellow toner. These are perspective views of the casing of the developing device. These are perspective views of the upper surface side of the lid of the developing device. FIG. 2 is a perspective view of the lower surface side of the lid of the developing device. FIG. 3 is an exploded perspective view of an external portion of the developing device.

Explanation of symbols

2 Rotary developing device 3 Rotary 3a Rotating shaft 4Y Yellow toner developing device
5Y casing
5Ye slope
6Y lid
6Yb Toner supply port
6Yg Slope 4M Magenta toner developer
5M casing
5Me slope
6M lid
6Mb toner supply port
6Mg slope 4C cyan toner developer
5C casing
5Ce slope
6C lid
6Cb Toner Supply Port 6Cg Slope
4K black toner developer
5K casing
5 Ke slope
6K lid
6Kb toner supply port
6Kg Slope 14Y Yellow toner toner container 14M Magenta toner toner container 14C Cyan toner toner container 14K Black toner toner container 20 Photosensitive drum

Claims (2)

In a multi-color developing device that is arranged in proximity to an electrostatic latent image carrier and sequentially supplies several types of toner to the electrostatic latent image to perform multi-color development,
A plurality of developing devices arranged for each toner color in the circumferential direction, a toner replenishing port provided with a different longitudinal position for each developing device, a toner container for storing toner for each toner color, and each toner A toner outlet disposed in communication with the container so as to face the toner replenishing port according to the rotation of the developing device; a developing means for supplying toner to the electrostatic latent image from within each developing device; Opening means attached to each toner supply port and each toner outlet, and a slope is formed on the inner wall surface of each developer so that the vicinity of the toner supply port is the highest and becomes lower as the distance from the toner supply port increases. A multi-color developing device characterized by that.   2. The multicolor developing device according to claim 1, wherein the toner replenishing port is provided in a lid that is attached to the outer peripheral surface of each developing device in the longitudinal direction, and the inclined surface is formed on the back surface of each lid. apparatus.

Images