JP4620885B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus such as a printer, a copying machine, and a facsimile.
[0002]
[Prior art]
In the case of a color image forming apparatus using a plurality of color toners, developing devices having different color toners are arranged around the photoreceptor, and a toner cartridge for supplying toner to these developing devices is provided in the developing device. Built-in requires a lot of space. Although the space problem can be solved by making the toner cartridge small, it is not preferable for the user because the cartridge is frequently replaced.
[0003]
In order to solve these problems, a powder transfer device (toner supply means) such as a pump is provided separately from the developing device, and a toner transport tube (passage member) of the powder transfer device is connected to each developing device. Thus, the toner is supplied to the developing device.
[0004]
[Problems to be solved by the invention]
However, in the above-described technology, a toner transport tube is connected to each developing device. When the toner transport tube is removed from each developing device due to maintenance or the like, one color toner scattered from the toner transport tube is transferred to the other developer device. There is a problem that the color enters a developing device using colors and is mixed.
[0005]
SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus capable of preventing toner color mixture.
[0006]
[Means for Solving the Problems]
According to a first aspect of the present invention, a developing device that develops an electrostatic latent image on an image carrier as a toner image by any one of developing devices having different color toners, and the developing device are provided separately. A replenishing means for replenishing toner of a color corresponding to each developing device, and the replenishing means includes a passage member having a supply port portion connectable to an opening of each developing device, and the toner passes through each passage member and passes through each passage member. In the image forming apparatus supplied to the developing device, the opening of each developing device is arranged on the same straight line, and the supply port of each passage member is connected to the opening of each developing device and separated from the connecting position. It is provided so as to be rotatable at a separation position, and is rotated about an axis parallel to the same straight line connecting the openings of the developing devices.
[0007]
In the first aspect of the present invention, the replenishing means stores toner of a color corresponding to each developing device, and the stored toner is developed through a passage member connected to the corresponding developing device. The vessel is replenished. Connection and release of the supply port portion of each passage member and the opening portion of each developing device are performed by rotating the supply port portion of each passage member around an axis parallel to the same straight line connecting the opening portions of each developing device. By doing.
[0008]
Each supply port portion connectable to each developing device opening rotates about an axis parallel to the same straight line connecting each developing device opening, so that each developing device opening and each passage member The positional relationship with the supply port portion can be prevented from shifting in the arrangement direction, and toner color mixing due to toner scattering can be prevented.
[0009]
According to a second aspect of the present invention, in the first aspect of the present invention, the rotation operation of the supply port portion of the passage member is interlocked with the mounting / demounting operation of the developing device with respect to the developing device.
[0010]
According to the second aspect of the invention, the same effect as that of the first aspect of the invention can be obtained, and the rotation operation of the supply port of the passage member is automatically performed in conjunction with the attaching / detaching operation of the developing device. Since it rotates, maintenance can be easily performed without impairing user operability.
[0011]
The invention according to claim 3 is characterized in that, in the invention according to claim 1 or 2, the passage member bends when the supply port of the passage member is rotated from the connection position to the separation position.
[0012]
The invention according to claim 3 has the same effect as that of the invention according to claim 1 or 2, and when the supply port portion of the passage member is rotated to the separated position, the passage member bends to cause the passage. Therefore, the toner remaining in the passage member can be prevented from leaking from the supply port.
[0013]
According to a fourth aspect of the present invention, in the invention of the third aspect, the return from the separated position of the supply port portion of the passage member to the connection position is performed by a return force that returns the bending of each passage member. And
[0014]
According to the fourth aspect of the invention, the same effect as that of the third aspect of the invention can be achieved, and the return from the separated position of the supply port portion of the passage member to the connection position is a return to return the bending of the passage member. By performing with force, the return operation of the holding member can be easily performed with a simple and low-cost configuration.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a block diagram schematically showing a color printer to which the present invention is applied. As shown in FIG. 1, the color printer 1 generally includes a right image forming unit 3, a left image forming unit 5, an exposure device 7 that performs optical writing on left and right photoconductors 17 and 23, and left and right photoconductors 17. , 23 to which the toner images are primarily transferred, a secondary transfer device 11 for secondary transfer of the toner images on the intermediate transfer belt 9 onto the transfer paper, and a paper feed unit 13 for feeding the transfer paper, And a fixing device 15 for fixing the toner image transferred onto the transfer paper.
[0016]
The right image forming device 3 includes a right photosensitive member 17, and is formed around the right photosensitive member 17 by light writing by a right charging device 19 that uniformly charges the right photosensitive member 17 and an exposure device 7. And a right developing device 21 that supplies toner to the electrostatic latent image on the right photosensitive member 17 to form a toner image. The right developing device 21 includes a black developing device 21B that forms a toner image using black toner and a cyan developing device 21C that forms a toner image using cyan toner.
[0017]
The left image forming device 5 has the same configuration as the right image forming device 3, and includes a left photosensitive member 23, a left charging device 25, and a left developing device 27. The left developing device 27 includes a magenta developing device 27C that forms a toner image with magenta toner, and a yellow developing device 27Y that forms a toner image with yellow toner. The developing devices 21B, 21C, and 27M respectively. 27Y can be attached to and detached from the developing devices 21 and 23.
[0018]
The exposure device 7 drives the LD according to color image information, for example, image data obtained by converting a color image signal from a computer into an optical signal, and irradiates the polygon mirror 29 with the laser light L. When the laser light deflected by the polygon mirror 29 reaches either the photosensitive member 3 or the photosensitive member 5, optical writing corresponding to the image signals of black, cyan, magenta, and yellow is performed, and the left and right photosensitive members are read. An electrostatic latent image is formed on the body drums 17 and 23.
[0019]
With such a configuration, in the image forming process by the color printer 1, first, the right photosensitive member 17 is uniformly charged by the right charging device 19. Next, in the exposure device 7, the LD is driven in accordance with the image data to irradiate the polygon mirror 29 with laser light to form an electrostatic latent image on the right photosensitive member 17, and this electrostatic latent image is transferred from the black developing device 21B. The black toner is developed as a black toner image.
[0020]
This black toner image is primarily transferred to the intermediate transfer belt 9 and then sequentially transferred to the intermediate transfer belt 9 in order to superimpose a cyan toner image, a yellow toner image, and a magenta toner image formed in the same manner. Then, the toner image superimposed on the intermediate transfer belt 9 is secondarily transferred onto the transfer paper fed from the paper feeding unit 13 by the secondary transfer device 11 and fixed by the fixing device 15 to obtain a full color image. .
[0021]
Further, the color printer 1 includes a developing device 21 and a powder transfer device 29 that supplies toner corresponding to each color to the developing devices 21B, 21C, 27M, and 27Y of the left and right developing devices 21 and 27. Prepared separately. Since the powder transfer device 29 is provided separately from the developing devices 21 and 23, compared with the case where the toner cartridge for replenishing toner is directly attached to the developing devices 21 and 23, the area around the photoconductors 17 and 23 is increased. Space can be reduced.
[0022]
The powder transfer device 29 includes a storage unit 31 that stores black, cyan, magenta, and yellow toner, a black tube (passage member) 33 through which black toner passes, a cyan tube 35 through which cyan toner passes, A magenta tube 37 through which magenta toner passes and a yellow tube 39 through which yellow toner passes are provided.
[0023]
As shown in FIG. 2, the nozzle (supply port) 33a of the black tube 33 is connected to the opening 41 of the black developing device 21B, and the nozzle 35a of the cyan tube 35 is connected to the opening 43 of the cyan developing device 21C. The nozzle 37a of the magenta tube 37 is connected to the opening 45 of the magenta developing device 27M, and the nozzle 39a of the yellow tube 39 is connected to the opening 47 of the yellow developing device 27Y. Each nozzle is made of an elastically deformable member.
[0024]
In the present embodiment, the openings 41, 43, 45, 47 of the developing devices are arranged on the same straight line (see FIG. 5), and similarly, the nozzles 33a, 35a, 37a, 39a are also on the same straight line. Are held in the holding member 49 in this state. The holding member 49 is arranged on the upper side of the left and right developing devices 21 and 27 so as to intersect with the replacement direction (vertical direction in FIG. 1) of the developing devices 21B, 21C, 27M, and 27Y, so that the toner can be freely passed. It is easy to fall.
[0025]
As shown in FIGS. 3 and 4, the holding member 49 is provided with a support portion 53 through which the rotation shaft 51 is inserted and a projection portion 57 held by a hook 55 provided in the image forming apparatus main body. ing. The holding member 49 includes a connecting position where each nozzle 33a, 35a, 37a, 39a is connected to each opening 41, 43, 45, 47 (a position indicated by a solid line in FIG. 4) and a separating position where the nozzle 33a, 35a, 37a, 39a is separated from the connecting position (see FIG. 4 (the position of the two-dot chain line) and the rotation shaft 51 as a center.
[0026]
In addition, the support portion 53 of the holding member 49 is provided with an abutting portion 53a at a position corresponding to each of the developing devices 21B, 21C, 27M, and 27Y. When the developing device is replaced, the developing device is moved in the direction of arrow C. When lifted, the abutting portion 53a abuts against the developing device, whereby the holding member 49 is rotated from the connecting position indicated by the solid line toward the separated position indicated by the two-dot chain line. When the holding member 49 rotates to the separated position, the protrusion 57 is engaged with the hook, so that the holding member 49 is held at the separated position. As described above, since the rotation of the holding member 49 is automatically rotated in conjunction with the attaching / detaching operation of the developing device, the maintenance can be easily performed without impairing the operability for the user. Further, since the plurality of nozzles 33a, 35a, 37a and 39a are held by the holding member 49 to form a single unit, the developer can be replaced more easily.
[0027]
In the present embodiment, as shown in FIG. 5, the axis R of the rotation shaft 51 of the holding member 49 is the arrangement direction of the openings 41, 43, 45, 47 of each developing device, that is, the same connecting the openings. It is parallel to the straight line M. Therefore, when the holding member 49 is rotated, in other words, when the nozzles 33a, 35a, 37a, 39a are rotated, the openings 41, 43, 45, 47 of the developing devices and the nozzles 33a of the passage members. , 35a, 37a, 39a are not displaced in the arrangement direction (straight line M direction). For this reason, it is possible to prevent toner of other colors from entering the opening of the developing device (for example, black toner scattered from the nozzle 33a of the black tube 35 enters the opening 43 of the cyan developing device 21C, etc.). Toner color mixing due to scattering can be prevented.
[0028]
On the other hand, as shown in FIG. 7, when the holding member 100 is configured to rotate around a shaft 103 provided in a direction perpendicular to the line M connecting the openings, the nozzle 101 of the black tube The scattered toner does not enter the opening 104 of the black developing device but enters the opening 105 of the cyan developing device, which may cause toner mixing and the toner scattered from other nozzles 106, 107, etc. May contaminate the cabin.
[0029]
In the present embodiment, when the developing devices 21B, 21C, 27M, and 27Y are set in the developing devices 21 and 27, the holding member 49 is set as indicated by the solid lines in FIGS. However, when the developing device is removed in the direction of arrow C due to replacement of the developing device or the like, the holding member 49 rotates toward the separating position indicated by the two-dot chain line in FIG. Held in. At this time, as shown in FIG. 6, the tubes 33, 35, 37, and 39 are twisted (bent) due to the rotation of the holding member 49, thereby preventing the toner from moving in each tube and preventing toner scattering. At the same time, the return power is stored.
[0030]
In this state, when the developing device is set, the developing device pushes the abutting portion 53a of the holding member 49 in the direction of the arrow D, so that the locked state between the hook 55 and the protruding portion 57 is released, and the tube It returns to the position of the solid line of FIG.3 and FIG.4 by the restoring force of torsion. At this time, the bending of the tube returns to the original, and the toner can be supplied again.
[0031]
The present invention is not limited to the embodiment described above, and various modifications can be made without departing from the scope of the invention. For example, in the present embodiment, the present invention is applied to a copying machine that forms a color image with four color toners. For example, the copying machine forms an image with two, three, or five or more toners. There is no particular limitation as long as it uses toners of a plurality of colors.
[0032]
In the present embodiment, the tubes 33a, 35a, 37a, 39a are rotated together while being held by the holding member. However, the present invention is not limited to this. Also good.
[0033]
Although the present invention is applied to the color printer 1, the present invention is not limited to this. For example, the present invention can be applied to an image forming apparatus such as a copying machine, a facsimile, or a complex machine in addition to the color printer 1. Get the effect.
[0034]
【The invention's effect】
In the first aspect of the present invention, each supply port that can be connected to the opening of each developing device rotates about an axis parallel to the same straight line that connects the opening of each developing device. The positional relationship between the opening of the developing device and the supply port of each passage member can be prevented from shifting in the arrangement direction, and toner color mixing due to toner scattering can be prevented.
[0035]
According to the second aspect of the invention, the same effect as that of the first aspect of the invention can be obtained, and the rotation operation of the supply port portion of the passage member is automatically rotated in conjunction with the attaching / detaching operation of the developing device. Therefore, maintenance can be easily performed without impairing user operability.
[0036]
The invention described in claim 3 has the same effect as that of the invention described in claim 1 or 2, and when the supply port of the passage member is rotated to the separated position, the passage member bends to seal the passage. Therefore, the toner remaining in the passage member can be prevented from leaking from the supply port.
[0037]
The invention described in claim 4 has the same effect as that of the invention described in claim 3, and the return from the separated position of the supply port portion of the passage member to the connection position is performed by a return force that returns the bend of the passage member. By being performed, the return operation of the holding member can be easily performed with a simple and low-cost configuration.
[Brief description of the drawings]
FIG. 1 is a configuration diagram schematically illustrating a color printer to which the present invention is applied.
FIG. 2 is a cross-sectional view illustrating a state where a tube nozzle is connected to an opening of a developing device.
FIG. 3 is a perspective view showing a holding member when in a connection position.
4 is a view of the holding member of FIG. 2 as viewed from the direction of arrow A, and is a view for explaining the rotation operation of the holding member. FIG.
5 is a plan view of the holding member of FIG. 2 as viewed from the direction of arrow B. FIG.
FIG. 6 is a perspective view showing a holding member when in a separated position.
FIG. 7 is a front view showing a state in which a holding member according to a comparative example is in a separated position.
[Explanation of symbols]
1 Color printer (image forming device)
17, 19 Photoconductor (image carrier)
21, 23 Developing devices 21B, 21C, 27M, 27Y Developing device 29 Powder transfer device (replenishment means)
33, 35, 37, 39 Tube (passage member)
33a, 35a, 37a, 39a Nozzle (passage member supply port)
41, 43, 45, 47 Opening of developer unit

Claims (4)

A developing device that develops the electrostatic latent image of the image carrier as a toner image by any of the developing devices having different color toners, and a color toner that is provided separately from the developing device and corresponds to each developing device A replenishing means for replenishing the toner, and the replenishing means comprises a passage member having a supply port portion connectable to the opening of each developing device, and the toner is replenished to each developing device through each passage member. In
The opening of each developing device is arranged on the same straight line, and the supply port of each passage member is provided so as to be rotatable between a connecting position connected to the opening of each developing device and a separated position separated from the connecting position. And an image forming apparatus that rotates about an axis parallel to the same straight line connecting the openings of the developing devices. The image forming apparatus according to claim 1, wherein the rotation operation of the supply port portion of the passage member is interlocked with the attaching / detaching operation of the developing device with respect to the developing device. The image forming apparatus according to claim 1, wherein the passage member is bent when the supply port portion of the passage member is rotated from the coupling position to the separation position. The image forming apparatus according to claim 3, wherein the return of the supply port portion of the passage member from the separated position to the connection position is performed by a return force that returns the bending of each passage member.

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