JP3596273B2 - Developing device for image forming apparatus - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a developing device for an image forming apparatus, and more particularly, to prevent developer from spilling from the developing device even when the developing device is transported with the image forming device attached to the main body or when the image forming device is operated for a long period of time. The present invention relates to a developing device of an image forming apparatus capable of preventing such a problem.
[0002]
[Prior art]
In an electrophotographic full-color image forming apparatus, three developing units each filled with three primary color developers or four developing units further filled with a black developer are arranged facing the photoconductor. Image formation is performed by visualizing an electrostatic latent image with a developer of a plurality of colors.
[0003]
In addition, for the purpose of reducing the size and cost of the apparatus, a rotating body holding four developing units is arranged near one photosensitive body, and each developing unit is rotated by rotating the rotating body. A full-color image forming apparatus has been proposed in which the developer is sequentially moved to a position opposite to the image forming apparatus and sequentially visualized with each developer.
[0004]
In these image forming apparatuses, one of the three or four developing units stops downward when the apparatus is not operating or operating. For this reason, when the image forming apparatus is transported or operated, there is a problem that the developer is easily spilled from between the developing roll of the developing unit and the housing due to the vibration during transportation and the vibration during operation. In addition, if the spilled developer is left unattended, the spilled developer may be picked up by another developing device and mixed, resulting in a problem that good image quality cannot be maintained.
[0005]
On the other hand, conventionally, with respect to vibration during transportation, measures have been taken such as packing the developing device separately from the main body of the image forming apparatus or increasing the thickness of the packing material. In addition, with regard to the vibration during operation, a serviceman has performed periodic cleaning and requested the user to perform periodic cleaning.
[0006]
[Problems to be solved by the invention]
However, in the above-described conventional apparatus, a large amount of packing material is required, which not only raises costs and wastes resources, but also causes a problem that it takes time to perform a packing operation and an unpacking operation. Further, there is a problem that even if the spilled developer is cleaned, the deterioration of the image quality is unavoidable, and a problem that the cleaning is troublesome.
[0007]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a developing device of an image forming apparatus which eliminates the above-mentioned problems of the prior art and prevents the developer from spilling from a developing device as much as possible.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a stirring chamber for stirring a developer formed by a lid, a housing, and a first partition provided inside the lid, the housing, and the stirred developer. And a supply chamber for supplying the developer to the developing roll. In the developing device of the image forming apparatus that circulates the developer and supplies the developer to the developing roll, the developer can move between the stirring chamber and the supply chamber. As described above, a circulation path formed at both ends of these chambers is formed from the lid toward the housing, and between the housing and the housing, the developer is interposed between the two chambers without being interrupted. And a gap capable of preventing the developer in the stirring chamber from flowing into the supply chamber when the developing device is tilted so that the supply chamber is located below the stirring chamber. the provided Rutotomoni, the stirring chamber And the supply chamber is completely separated by the first partition plate except for the circulation path .
[0009]
In the present invention having this configuration, the developing device can prevent the developer in the stirring chamber from flowing into the supply chamber when the supply chamber is inclined so that the supply chamber is located downward. During transportation or operation, the developer can be minimized from spilling from the developing device.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings. First, a schematic configuration of a full-color printer as an example of an apparatus to which the present invention is applied will be described with reference to FIG.
[0011]
As shown, a charging roll 3, an exposure device 4, a developing assembly 5, a density sensor 6, a transfer roll 7, and a cleaner device 8 are arranged around the photoreceptor 1. The developing assembly 5 includes four developing devices 5Y, 5M, 5C and 5K for full-color development. Each developing device converts a latent image on the photoreceptor 1 into yellow (Y) and magenta (M), respectively. , Cyan (C) and black (K) toners. When developing the toner of each color, the developing assembly 5 is rotated in the direction of arrow R by a motor (not shown), and the developing device of the color is aligned so as to contact the photoconductor 1. The toner images of each color developed on the photoreceptor 1 are sequentially transferred to a belt 9 as an intermediate transfer member by a transfer roll 7, and four color toner images are superimposed. The belt 9 is stretched around rolls 10, 11, 12, and 13. Among these, the roll 10 is connected to a drive source (not shown) and functions as a drive roll for driving the belt 9, and the roll 12 functions as a back roll of the second transfer roll 14. A belt cleaner 15 is provided at a position facing the roll 13 with the belt 9 interposed therebetween, and residual toner on the belt 9 is scraped off by a blade.
[0012]
The recording paper pulled out from the recording paper cassettes 16 and 17 to the transport path by the pull-out rolls 18 and 19 is supplied to a nip portion, that is, a contact portion between the second transfer roll 14 and the belt 9 by roll pairs 20, 21 and 22. Sent. The toner image formed on the belt 9 is transferred onto the recording paper at the nip portion, is thermally fixed by the fixing device 23, and is discharged to the tray 24 or the tray 25.
[0013]
The waste toner scraped off from the photoconductor 1 or the belt 9 by the cleaners 8 and 15 is collected in a waste toner collection box 26. In particular, the waste toner collected from the belt cleaner 15 is conveyed to the waste toner collection box 26 in the pipe 27 by a conveyance means such as an auger and a conveyance screw.
[0014]
FIG. 2 is a sectional view showing a specific example of the developing assembly 5, that is, a rotary developing device. The developing devices 5Y, 5M, 5C and 5K are mounted on the arm 31 of the rotating body 30 by a mounting tool (not shown). Since the developing devices 5Y, 5M, 5C, and 5K have the same configuration, the developing device 5Y will be described as a representative. The developing device 5Y includes a developing device 40 and a developer cartridge 50.
[0015]
In the developing device 40, a long magnet roll 41 in a direction perpendicular to the paper surface, and two spiral augers 42 and 43 extending parallel to the magnet roll 41 are arranged. Here, when the magnet roll 41 rotates, the spiral auger 42 conveys the developer 44 contained in the developing device 40 while stirring the developer 44 in one direction perpendicular to the paper surface. The developer 44 is conveyed while being agitated in a direction opposite to the conveying direction of the developer, and the developer 44 is uniformly supplied to the magnet roll 41.
[0016]
The magnet roll 41 attracts the carrier contained in the developer 44 by magnetic force to form a magnetic brush, and supplies the toner adsorbed to the carrier to the photoconductor 1. Thereby, the electrostatic latent image formed on the photoconductor 1 is visualized.
[0017]
The developer cartridge 50 is composed of a cylindrical container elongated in the direction perpendicular to the plane of the paper, and is divided into a chamber for storing new developer and a chamber for collecting deteriorated developer. A supply port (not shown) is provided in the new developer storage chamber, and communicates with a substantially cylindrical casing 51 for guiding the new developer to the developing device 40 through the supply port. A spiral auger 52 is provided in the casing 51, and the supplied developer is guided to a supply port 53 by the spiral auger 52 and introduced into the developing device 40. A flap 54 is provided at the outlet of the supply port 53, and is open when the developing device is at the position D.
[0018]
In the deteriorated developer collecting chamber 55 of the developer cartridge 50, there is provided a collecting passage 56 that circulates, and the collecting passage 56 is connected to a discharge pipe 57 that is twisted and bent in a rectangular shape. The recovery port 58 at the tip of the discharge pipe 57 is located in the developing device 40. The recovery port 58 faces upstream from the supply port 53, and the developer that has been stirred and conveyed by the spiral augers 42 and 43 and has passed around the inside of the developing device 40 is recovered by the supply port 53. I have.
[0019]
In the rotary developing device having the developing devices 5K, 5C, and 5M having the same configuration as the developing device 5Y, the flap 54 opens the supply port 53 when the developing device is at the D position. The developer is supplied into the developing device 40. When the developing device completes the development of the latent image on the photoconductor 1 and the rotating body rotates to move the developing device from the position D to the position E, the flap 54 is opened halfway as shown in FIG. The developer transported upward and through the discharge pipe 57 flows toward the recovery passage 56 without flowing backward. The deteriorated developer is dropped into the deteriorated developer collection chamber through the collection passage 56 from the position F to the position G of the developing device. As described above, by providing the collecting passage 56 that circulates, the collected developer does not flow backward to the developing device 40. On the other hand, while the developing device is moving from the G position to the D position, the new developer is sent to the casing 51 by the action of an agitator (not shown) provided in the developer cartridge 50, and the spiral auger in the casing 51 is moved. It is guided to the supply port 53 by 52. At this time, the flap 54 is released again, so that the new developer is supplied into the developing device 40.
[0020]
Next, a schematic configuration of the developing device 40 will be described with reference to a perspective view of FIG. 3, the same reference numerals as those in FIG. 2 denote the same or equivalent components. As shown in FIG. 3, inside the developing device 40, two spiral augers 42 and 43 are arranged in parallel in the longitudinal direction, separated by a partition plate 61. The left and right ends of the partition plate 61 are cut out to form circulation paths 62 and 63 for the developer. The spiral auger 42 (hereinafter referred to as a stirring auger) stirs the developer supplied from the supply port 53 of FIG. 2 and the developer circulating through the circulation path 63 from the left end of the stirring chamber 64 to the right end. While transporting. The stirred developer enters the supply chamber 65 through the circulation path 62. Subsequently, the spiral auger 43 (hereinafter, referred to as a supply auger) transports the developer in the supply chamber 65 from the right end to the left end. In this process, the supply auger 43 supplies the developer to the developing roll 41. The developer transported to the left end of the supply chamber 65 is returned to the stirring chamber 64 through a circulation path 63 formed at the left end.
[0021]
Next, FIG. 4 is a sectional view taken along line AA of FIG. 3, and FIG. 5 is a sectional view taken along line BB of FIG. 4 and 5, the same reference numerals as those in FIGS. 2 and 3 denote the same or equivalent components. As shown in FIG. 4, a partition plate 61 for separating the stirring chamber 64 and the supply chamber 65 is formed integrally with the housing 71 at the center of the developing device 40, and the partition plate 61 is It is formed to penetrate inside. In other words, the stirring chamber 64 and the supply chamber 65 are completely separated.
[0022]
On the other hand, in the circulation path 62, as shown in FIG. 5, a partition plate 73 formed integrally with the lid 72 forms a space between the stirring auger 42 and the supply auger 43 toward the housing 71. Have been. It is preferable that the gap between the end of the partition plate 73 and the housing 71 has a minimum size that allows the developer to smoothly move from the stirring chamber 64 to the supply chamber 65. More specifically, the leading end of the partition plate 73 is positioned below a tangent line contacting the lower part of the developing roll 41, or lower than a line connecting the upper part of the stirring auger 42 and the upper part of the supply auger 43. Is good. Although the internal structure of the circulation path 62 has been described with reference to FIG. 5, the internal structure of the circulation path 63 is the same as that of FIG.
[0023]
In the developing device of the present embodiment, during normal use, as shown in FIG. 6, the developer passes from the stirring chamber 64 through a gap formed between the tip of the partition plate 73 and the housing 71. It smoothly moves from the supply chamber 65 to the supply chamber 65 and vice versa.
[0024]
By the way, in the conventional developing device, the partition plate 73 does not exist inside the circulation path 62 and the circulation path 63, for example, as shown in FIG. For this reason, when the developing device comes to the position of 5K in FIG. 2, for example, the developing roll 41 is positioned below the developing device as shown in FIG. The existing developer 44 falls toward the supply auger 43. Then, when transported or operated in this state, the vibration at that time causes the developer 44 to move further to the upper periphery of the developing roll 41, and finally passes through the gap between the developing roll 41 and the housing 71 to cause the developer to move. Will spill outside.
[0025]
However, according to the present embodiment having the above-described configuration, as shown in FIG. 7, the developer 44 existing around the stirring auger 42 is prevented from dropping toward the supply auger 43 by the partition plate. Blocked by 73. As a result, the developer covering the periphery of the upper portion of the developing roll 41 is completely eliminated or becomes a small amount, and even if the developer vibrates during the transportation or operation, the vibration causes the developer 44 to be removed from the gap between the developing roll 41 and the housing 71. Spilling out of the developing unit through the developing device can be prevented or reduced.
[0026]
In the above embodiment, the partition plate 73 is formed integrally with the lid 72. However, the present invention is not limited to this. A partition plate having the same function as the partition plate 73 is integrated with the housing 71. Alternatively, a partition plate having the same function as the partition plate 73 may be formed with other parts, and the cover 72 or the housing may be formed so that the partition plate comes to the position shown in FIG. 6 or FIG. 71.
[0027]
【The invention's effect】
As is apparent from the above description, according to the present invention, the developer can be moved between the two chambers without being blocked by the developer in the circulation path of the developer, and the developer can be moved so that the supply chamber is located below. Since a partition plate having a gap that can prevent the developer in the stirring chamber from flowing into the supply chamber when the apparatus is tilted is provided, even if the developing apparatus is transported while being incorporated in the image forming apparatus, The spilling of the developer by the medium vibration can be reduced as much as possible. Further, it is possible to minimize the spilling of the developer due to the vibration during the operation of the developing device.
[0028]
In addition, there is no need to separately pack the developing device when transporting the image forming apparatus, so that there is an effect that packing materials can be saved and resources are not wasted. In addition, since it is possible to reduce the spilling of the developer during the operation of the apparatus, it is possible to improve the image quality and to save the trouble of cleaning the spilled developer.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an example of an image forming apparatus to which the present invention is applied.
FIG. 2 is a detailed sectional view of the developing device of FIG.
FIG. 3 is a perspective view illustrating an internal configuration of the developing device.
FIG. 4 is a sectional view taken along line AA of FIG. 3;
FIG. 5 is a sectional view taken along line BB of FIG. 3;
FIG. 6 is a cross-sectional view illustrating a flow of a developer during operation of the developing device.
FIG. 7 is a cross-sectional view illustrating the movement of the developer when the developing device is inclined.
FIG. 8 is a cross-sectional view illustrating a flow of a developer when a conventional developing device is operated.
FIG. 9 is a cross-sectional view illustrating movement of a developer when a conventional developing device is tilted.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Photoreceptor, 3 ... Charging roll, 4 ... Exposure device, 5 ... Development assembly, 5Y, 5M, 5C, 5K ... Developing device, 6 ... Density sensor, 7 ... Transfer roll, 8 ... Cleaner device, 7 ... Transfer roll , 9 ... belt, 10, 11, 12, 13 ... roll, 14 ... second transfer roll, 30 ... rotating body, 31 ... arm, 40 ... developing unit, 41 ... magnet roll, 42 ... stirring auger, 43 ... supply auger , 44: developer, 50: developer cartridge, 51: casing, 52: spiral auger, 53: supply port, 54: flap, 55: deteriorated developer collection chamber, 56: collection passage, 57: discharge pipe, 58 ... Collection port, 61: partition plate, 62, 63: circulation path, 64: stirring chamber, 65: supply chamber, 71: housing, 72: lid, 73: partition plate.

Claims (7)

A stirring chamber for stirring the developer formed by the lid, the housing, and the first partition plate provided therein, and a supply chamber for supplying the stirred developer to the developing roll. In the developing device of the image forming apparatus having the developer circulating and supplying the developer to the developing roll,
A circulation path is formed at both ends of the stirring chamber and the supply chamber so that the developer can flow between the stirring chamber and the supply chamber. The circulation path is formed from the lid toward the housing. When the developing device is tilted such that the developer can move between the two chambers without being interrupted, and the supply chamber comes below the stirring chamber, the developer in the stirring chamber is supplied to the supply chamber. a second partition plate having a gap can be prevented from Nadarekomu the provided Rutotomoni,
The developing device of the image forming apparatus, wherein the stirring chamber and the supply chamber are completely separated by the first partition plate except for the circulation path . The developing device of the image forming apparatus according to claim 1,
The gap formed between the second partition plate and the housing is a minimum gap required for the developer to move between the stirring chamber and the supply chamber. Developing device. The developing device for an image forming apparatus according to claim 1, wherein the second partition plate is formed integrally with the lid. The developing device of the image forming apparatus according to claim 1,
A free end of the second partition plate facing the housing is positioned closer to the housing than a line on the lid side that connects a contour of the stirring auger and a supply auger provided in each of the stirring chamber and the supply chamber. A developing device for an image forming apparatus, comprising: The developing device of the image forming apparatus according to claim 1,
A free end of the second partition plate facing the housing is parallel to and close to a line on the lid side that connects a contour of the stirring auger and a supply auger provided in each of the stirring chamber and the supply chamber. Wherein the developing roller is located closer to the housing than a tangent to the developing roll. The developing device of the image forming apparatus according to claim 1,
A developing device for an image forming apparatus, wherein the gap formed by the second partition plate has the same size at both ends of the stirring chamber and the supply chamber. The developing device of the image forming apparatus according to claim 1,
The developing device according to claim 2, wherein the developing device is of a two-component developing type that rotates with respect to the main body of the image forming device, and faces at a direction other than the developing position in a direction different from the developing position. .

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