KR100631194B1 - Image Forming Apparatus - Google Patents

Abstract

The disclosed image forming apparatus includes an intermediate transfer unit having at least one photosensitive member on which an electrostatic latent image is formed, a developing unit which forms a developer image by developing an electrostatic latent image of the photosensitive member with a developer, and an intermediate transfer belt in which the developer image of the photosensitive member is transferred in between. And a transfer unit for transferring the developer image transferred to the intermediate transfer belt to a print medium, and a cleaning unit provided at an upstream side of the transfer unit to clean the developer remaining on the photosensitive member, and a printing unit flowing into the transfer unit side. And a print media guide unit for guiding the transport of the media, wherein the print media guide unit is installed on one surface of the cleaning unit facing the print media transport path. Through such a configuration, the transfer of the print medium transferred to the transfer unit side can be stabilized to improve the transfer effect and to simplify the guide structure of the print medium.

Image, Formation, Transfer, Print Media, Guide, Photoconductor, Cleaner

Description

Image Forming Apparatus

1 is a vertical sectional view schematically showing the configuration of an image forming apparatus according to the present invention;

Figure 2 is a plan view showing an example in which the imaging unit and the intermediate transfer unit of Figure 1 cartridgeized into a unit,

3 is a perspective view illustrating an example in which the imaging unit and the intermediate transfer unit of FIG. 1 are cartridgeized into one unit;

4 is a perspective view along arrow I of FIG. 3, and

5 is an exploded perspective view illustrating the second waste developer storage container of FIG. 4 separately;

<Description of Main Parts of Drawings>

1: image forming apparatus 101: main body

110: print medium supply unit 130: print medium transfer unit

150: optical scanning unit 170: image forming unit

171a, 171b: first and second photosensitive drum (photosensitive member) 175: developing unit

180: intermediate transfer unit 190: transfer unit

200: cleaning unit 211a, 211b: first and second cleaning blade

213a, 213b: 1st and 2nd waste developer reservoir 220: print media guide unit

221: guide rib

The present invention relates to an image forming apparatus, and more particularly, to an image forming apparatus for guiding a transfer of a print medium entering the transfer unit.

In general, an electrophotographic image forming apparatus such as a laser beam printer forms an electrostatic latent image on a photosensitive medium such as a photosensitive drum or photosensitive belt, develops the electrostatic latent image with a toner of a predetermined color, and transfers the image to a print medium to obtain a desired image. It is a device.

As an example of such an image forming apparatus, Japanese Unexamined Patent Publication (Japanese Patent Application Laid-Open No. 04-204871, title of the invention: color image forming apparatus, inventor: TERADA HIROSHI, KUNISHIGE HIDENORI) has been disclosed.

The schematic configuration includes a plurality of rotating electrostatic support members, developing means developable with a plurality of toners of different colors disposed around at least one electrostatic support member of the electrostatic support member, and toner images of different colors on the electrostatic support member. And an intermediate transfer member which is sequentially transferred by an endless belt to be transferred to form a color image, and transfer means for transferring the color image of the intermediate transfer member onto a transfer material (print medium).

As another conventional example, Japanese Laid-Open Patent Publication No. Hei 10-177286 discloses the name of the invention: an image forming method and apparatus, and inventor: YANAGAWA NOBUYUKI.

In the configuration, an intermediate transfer belt for transferring a toner image on a photosensitive drum and an image forming apparatus for transferring a color image on the intermediate transfer belt to a transfer material (print medium) by a transfer means are provided along the intermediate transfer belt. Has first and second image forming units (I, II) arranged at predetermined intervals, the first image forming unit having developing means for developing an electrostatic latent image on one photosensitive drum with A color toner and C color; And a developing means for developing one electrostatic latent image on one photosensitive drum with a toner of B color, and a developing means for developing with black (D) toner.

 As another conventional example, Japanese Laid-Open Patent Publication (Publication No. 2001-75329, title of the invention: color image recording apparatus, inventor: OTAKI NOBORU) has been disclosed.

Looking at the configuration, in the intermediate transfer type color image recording apparatus, two sets of printing mechanisms A and B for recording color images on a print medium are arranged in parallel at a predetermined distance within the same horizontal plane. The printing mechanism A forms an image with transfer toners of yellow (Y) and magenta (M), and the printing mechanism B forms transfer toner images of cyan (C) and black (K), respectively. Constitutes an electrophotographic LED (light emitting diode) printer mechanism. In addition, an intermediate transfer process is performed through the intermediate transfer belt, and the color image transferred through the intermediate transfer belt is transferred onto the print medium through the transfer means in contact with the intermediate transfer belt.

 The image forming apparatuses configured as described above require a guide structure for uniformly guiding the transfer of the print medium flowing into the transfer unit in order to increase the transfer efficiency.

 SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus which guides a print medium immediately before entering the transfer unit side to improve transfer efficiency, and simplifies the guide structure to obtain a material cost reduction effect.

According to an embodiment of the present invention proposed to achieve the above object, at least one photosensitive member is formed with an electrostatic latent image; A developing unit for developing the electrostatic latent image of the photosensitive member with a developer to form a developer image; An intermediate transfer unit having an intermediate transfer belt to which the developer image of the photosensitive member is transferred in the middle; A transfer unit to transfer the developer image transferred to the intermediate transfer belt onto a print medium; A cleaning unit for cleaning the developer remaining on the photosensitive member; And a print medium guide unit provided in the cleaning unit to guide the transfer of the print medium introduced between the intermediate transfer belt and the transfer unit.

The transfer unit and the photoconductor are installed to face each other with respect to one surface of the transfer belt, and the cleaning unit is preferably installed on one side of the photoconductor close to the paper feed path entering the transfer unit side.

The print medium guide unit is preferably installed on one surface of the cleaning unit facing the print medium transport path.

The printing medium guide unit may be a plurality of guide ribs provided at predetermined intervals in the cleaning unit.

The print medium guide unit may have a shape corresponding to a gap shape between one surface of the cleaning unit and the print medium transport surface.

On the other hand, the photoconductor is composed of first and second photosensitive drums arranged side by side at a predetermined interval on the same vertical surface; The intermediate transfer belt is in contact with the first and second photosensitive drums to perform endless orbital movement, and the transfer unit is rotatably contacted to a lower outer surface thereof; First and second waste developer reservoirs each having first and second cleaning members for removing waste developers on the first and second photosensitive drums are provided at one side of the first and second photosensitive drums; The first and second photosensitive drums and the first and second closed developer reservoirs are installed in one frame to form a single unit; A print media guide unit for guiding the print media entering between the transfer unit and the intermediate transfer belt is preferably provided below the second waste developer storage container.

The printing medium guide unit may be a plurality of guide ribs provided at a predetermined interval in a lower portion of the second waste developer storage container.

Preferably, the print media guide unit has a shape corresponding to a gap shape between one surface of the cleaning unit and the print media transport surface.

According to another embodiment of the present invention, at least one photosensitive member is formed with an electrostatic latent image; A developing unit for developing the electrostatic latent image of the photosensitive member with a developer to form a developer image; An intermediate transfer unit to which the developer image of the photosensitive member is transferred in the middle; A transfer unit to transfer the developer image transferred to the intermediate transfer unit onto a print medium; A cleaning unit for cleaning the developer remaining on the photosensitive member; And a print medium guide unit provided in the cleaning unit to guide the transfer of the print medium flowing into the transfer unit.

The print medium guide unit may be installed on one surface of the cleaning unit facing the print medium transport path.

The print medium guide unit may be a plurality of guide ribs provided at predetermined intervals in the cleaning unit.

Preferably, the print media guide unit has a shape corresponding to a gap shape between one surface of the cleaning unit and the print media transport surface.

Preferably, the photosensitive member is a photosensitive drum, and the intermediate transfer unit is a cylindrical intermediate transfer drum.

According to another embodiment of the present invention, at least one photosensitive member is formed with an electrostatic latent image; A developing unit for developing the electrostatic latent image of the photosensitive member with a developer to form a developer image; A transfer unit for transferring the developer image of the photosensitive member to a print medium; A cleaning unit for cleaning the developer remaining on the photosensitive member; And a print media guide unit installed on one surface of the cleaning unit and guiding the transfer of the print media flowing into the transfer unit side.

Hereinafter, exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings. In the following description, what is described as "upstream side" and "downstream side" is based on the conveying direction of the print medium.

1 is a vertical sectional view schematically showing the configuration of an image forming apparatus according to the present invention.

Referring to FIG. 1, the image forming apparatus 1 is largely comprised of a main body 101, a print medium supply unit 110, a print medium transfer unit 130, a light scanning unit 150, an image display unit 170, and an intermediate portion. It is composed of a transfer unit 180, a transfer unit 190, a fixing unit 210 and the discharge unit 230.

The print medium transport unit 130 transfers a plurality of print media P loaded on the print medium supply unit 110 to the transfer unit 170, and print media loaded on the print medium supply unit 110 ( A pickup roller 131 for picking up P), first and second feed rollers 132 and 133 for feeding paper picked up from the pickup roller 131, and first and second feed idle rollers 134 and 135.

The optical scanning unit 150 irradiates predetermined light necessary for forming the electrostatic latent image on the first and second photosensitive drums 171a and 171b to be described later, and includes the first and second light scanning units 151a and 151b.

The image forming unit 170 forms an image to be transferred to the printing medium P by performing an exposure and development process by light irradiated through the optical scanning unit 150, and the optical scanning unit 151a, A photosensitive member (hereinafter, referred to as the first and second photosensitive drums 171a and 171b) in which an electrostatic latent image is formed through light irradiated through 151b, and the first and second photosensitive drums 171a and 171b. The electrostatic latent images formed on the first and second antistatic rollers 173a and 173b installed to charge the first and second photosensitive drums 171a and 171b and the first and second photosensitive drums 171a and 171b are developed using a predetermined developer. And a developing unit 175 provided around the first and second photosensitive drums 171a and 171b to form a developer image which is a visible image. Here, the photosensitive member is not limited to the photosensitive drum, but may be in the form of a photosensitive belt.

The developing unit 175 forms a visible image by developing the electrostatic latent images of the first and second photosensitive drums 171a and 171b with a color developer, and includes yellow, cyan, magenta, and black. Four pieces for (Black) are provided. Each developing unit 175 includes a developing roller 175a, a developer supplying roller 175b, a developer case 175c, and the like. The two developing units, for example, yellow and cyan, are formed of the first photoconductor ( It is arranged to develop the electrostatic latent image of 171a, and the other two developing units, that is, the magenta and the black, are arranged to develop the electrostatic latent image of the second photosensitive member 171b.

The visible images on the first and second drums 171a, 171b developed for each color by the developing unit 175 as described above are in contact with the first and second photosensitive drums 171a, 171b. By superimposing and transferring the intermediate transfer belt 181 to be described later, the full-color image is implemented on the intermediate transfer belt 221.

Meanwhile, at one side of the first and second photosensitive drums 171a and 171b, a cleaning unit 200 for cleaning the residual developer remaining on the first and second photosensitive drums 171a and 171b is installed. The cleaning unit 200 stores a first cleaning blade 211a that removes the developer remaining on the surface of the first photosensitive drum 171a, and a developer that stores the developer removed through the first cleaning blade 211a. It consists of one waste developer storage container (213a). In addition, the second waste developer for storing the developer removed through the second cleaning blade 211b and the second cleaning blade 211b for removing the developer remaining on the surface of the second photosensitive drum 171b. It consists of a storage container 213b.

The second waste developer reservoir 213b further includes a print medium guide unit 220 to guide the print medium P before entering the transfer unit 190. Detailed description thereof will be described later with reference to FIGS. 4 and 5.

The intermediate transfer unit 180 contacts the first and second photosensitive members 171a and 171b and moves the intermediate transfer belt 181 and the first to third rollers 182 supporting the intermediate transfer belt 181. (183) (184), the first and second intermediate transfer rollers (185, 186) installed inward of the intermediate transfer belt (181) to correspond to the first and second photosensitive drums (171a,) (171b). It is provided. Here, the intermediate transfer unit 180 may take the form of a cylindrical drum without employing the intermediate transfer belt 181 which is infinitely orbitally moved by the rollers 182 to 186 as described above.

The first and second photosensitive drums 171a and 171b and the cleaning unit 200 are integrally installed in the photosensitive frame 230, and each component of the intermediate transfer unit 180 is also integrally formed in the intermediate transfer frame 243. Installed and configured to cartridge into one unit. Detailed description thereof will be described later with reference to FIGS. 2 and 3.

The transfer unit 190 is to transfer the developer image formed on the image forming unit 170 to the print medium P, and is installed to face the third roller 184 and interpose the intermediate transfer belt 181 therebetween. It is composed of a transfer roller 191.

The fixing unit 210 fixes the image transferred onto the print medium P through the transfer unit 190 through a heat pressing operation, and includes a heating roller 211 and a pressing roller 213.

The discharge unit 230 is for discharging the printing medium P on which an image is fixed through the fixing unit 180 to the outside of the main body 101, and the discharge roller 231 and the discharge idle roller 233 corresponding thereto. It consists of.

2 is a plan view illustrating an example in which the imaging unit and the intermediate transfer unit of FIG. 1 are cartridgeized into one unit, and FIG. 3 is a cartridgeized image forming unit and the intermediate transfer unit of FIG. 1 into one unit. It is a perspective view which showed the example.

2 and 3, the photosensitive frame 230, the intermediate transfer frame 240, the hinge unit 250, and the locking unit 260 are configured.

The photosensitive frame 230 includes first and second photosensitive drums 171a and 171b, first and second antistatic rollers 173a and 173b, and first and second cleaning blades 211a and 211b. The waste developer reservoirs 213a and 213b are integrally installed. Here, although the first and second cleaning blades 211a are described as examples, the cleaning member is not limited to the blade shape, and various shapes such as a brush shape may be applied.

The intermediate transfer frame 240 is provided with the intermediate transfer belt 181, the first, second, third rollers (182, 183, 184) and the first and second intermediate transfer rollers (185, 186) integrally.

The hinge unit 250 provides a reference position when the photosensitive frame 230 and the intermediate transfer frame 240 are coupled and separated, and the hinge hole 251 and the intermediate transfer frame formed on both sides of the photosensitive frame 230. The hinge shaft 252 is installed to correspond to the hinge hole 251 in the 240 is configured.

The locking unit 260 is to maintain the coupling state of the photosensitive frame 230 and the intermediate transfer frame 240, so as to correspond to the locker 261 and the locker 261 installed in the intermediate transfer frame 240. The locking protrusion 262 formed on the photosensitive frame 230 is provided.

Referring back to FIG. 1, the photosensitive frame 230 and the intermediate transfer unit 180 are integrally installed with the first and second photosensitive drums 171a and 171b and the cleaning unit 200 as described above. As the photosensitive frame 230 is cartridgeized into one unit, it interferes with the developing unit 400 when the cartridgeized unit is detached or mounted. In order to solve this problem, when the cartridge unit is removed or mounted, the developing unit 400 is installed to be able to move to a side where the first and second light scanning units 151a and 151b are installed. To this end, in conjunction with opening and closing the front door (not shown) of the main body 101 to enable its position movement.

At this time, the developing unit 400 is installed to withdraw and enter between the first and second light scanning units 151a and 151b provided at predetermined intervals so as not to interfere with the first and second light scanning units 151a and 151b. .

4 is a perspective view taken along arrow I of FIG. 3, and FIG. 5 is an exploded perspective view showing the second waste developer storage container of FIG. 4 separately.

4 and 5, it is shown that a plurality of guide ribs 221 is formed as an example of the print medium guide unit 220 on one side of the second waste developer storage container 213b.

The guide rib 221 is provided on one side (shown as a lower side in the drawing) of the second waste developer storage container 213b corresponding to the print medium P transfer path.

Here, the end portion of each guide rib 221 preferably forms a shape corresponding to the gap shape of the lower end of the second waste developer storage container 213b and the print medium P transfer surface. In Figure 1 it is shown as a structure inclined upward along the printing medium (P) transport direction.

Through this configuration, the transfer of the print medium P before entering the intermediate transfer belt 181 and the transfer unit 190 (transfer nip) is stably guided to improve transfer efficiency. That is, the print medium P entering the transfer nip is stably guided by preventing the print medium P from flowing upward. In addition, the configuration of the print medium guide unit 220 is provided in the second waste developer storage container 213b without employing a separate member, thereby simplifying the structure and reducing the number of parts, thereby reducing the material cost.

On the other hand, the print medium guide unit 220 is installed in the second waste developer storage container 213b integrated with the first and second photosensitive drums 171a and 171b in the photosensitive frame 230 and the print medium (P) transfer surface and Maintainability of the gap is improved.

In the above description, the guide rib 221, which is the print medium guide unit 220, has been described as an example formed in the second waste developer storage container 213b. Such guide ribs 221 may be applied to all structures installed in a position close to the transport path.

In addition, the transfer of the image to the printing medium P after the transfer to the transfer unit 190 via the intermediate transfer unit 180 has been described as a structure, but is not limited thereto, and does not intervene in the intermediate transfer unit 180. It is also possible to employ a structure in which an image is directly transferred from the photosensitive member to the transfer unit 190 side.

In addition, the first and second photosensitive drums 171a and 171b and the transfer roller 191 are described as symmetrical with respect to each other with respect to the vertical plane of the intermediate transfer belt 181 as an example, but the intermediate transfer belt 181 is horizontally described. It arranges long and arranges the 1st and 2nd photosensitive drums 171a and 171b on the horizontal surface, and the transfer roller 191 takes the structure which opposes the 1st and 2nd photosensitive drums 171 and 171b with respect to the horizontal surface, etc. The arrangement may take many forms.

 According to the image forming apparatus according to the present invention as described above, there is an advantage to improve the transfer efficiency by adopting a structure for guiding the print medium in the previous step flowing into the transfer unit side.

In addition, the print medium guide structure is integrally formed in the cleaning unit for cleaning the photosensitive member, thereby simplifying the guide structure, thereby reducing the material cost.

As described above, in the detailed description of the present invention, specific embodiments have been described. However, various modifications may be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the claims below and equivalents thereof.

Claims (16)

At least one photosensitive member on which an electrostatic latent image is formed; A developing unit for developing the electrostatic latent image of the photosensitive member with a developer to form a developer image; An intermediate transfer unit having an intermediate transfer belt to which the developer image of the photosensitive member is transferred in the middle; A transfer unit to transfer the developer image transferred to the intermediate transfer belt onto a print medium; A cleaning unit for cleaning the developer remaining on the photosensitive member; And And a print media guide unit provided in the cleaning unit to guide the print media introduced between the intermediate transfer belt and the transfer unit. The method of claim 1, wherein the transfer unit and the photosensitive member is installed to face each other with respect to one surface of the transfer belt, the cleaning unit is installed on one side of the photosensitive member in close proximity to the paper transfer path entering the transfer unit side. An image forming apparatus. The image forming apparatus according to claim 2, wherein the print medium guide unit is installed on one surface of the cleaning unit facing the print medium transport path. The image forming apparatus of claim 2, wherein the print medium guide unit comprises a plurality of guide ribs provided at predetermined intervals in the cleaning unit. The image forming apparatus of claim 3, wherein the print medium guide unit has a shape corresponding to a gap shape between one surface of the cleaning unit and the print medium transporting surface. The image forming apparatus of claim 1, wherein the photosensitive member is a photosensitive drum. 2. The photosensitive display device according to claim 1, wherein the photosensitive member comprises first and second photosensitive drums arranged side by side at a predetermined interval on the same vertical surface; The intermediate transfer belt is in contact with the first and second photosensitive drums to perform endless orbital movement, and the transfer unit is rotatably contacted to a lower outer surface thereof; First and second waste developer reservoirs each having first and second cleaning members for removing waste developers on the first and second photosensitive drums are provided at one side of the first and second photosensitive drums; The first and second photosensitive drums and the first and second closed developer reservoirs are installed in one frame to form a single unit; And a print medium guide unit for guiding the print medium entering between the transfer unit and the intermediate transfer belt below the second waste developer storage container. 8. The image forming apparatus as claimed in claim 7, wherein the print medium guide unit is a plurality of guide ribs provided at a predetermined interval in a lower portion of the second waste developer storage container. The image forming apparatus of claim 7, wherein the print medium guide unit has a shape corresponding to a gap shape between one surface of the cleaning unit and the print medium transport surface. At least one photosensitive member on which an electrostatic latent image is formed; A developing unit for developing the electrostatic latent image of the photosensitive member with a developer to form a developer image; An intermediate transfer unit to which the developer image of the photosensitive member is transferred in the middle; A transfer unit to transfer the developer image transferred to the intermediate transfer unit onto a print medium; A cleaning unit for cleaning the developer remaining on the photosensitive member; And And a print medium guide unit provided in the cleaning unit to guide the transfer of the print medium flowing into the transfer unit. The image forming apparatus according to claim 10, wherein the print medium guide unit is installed on one surface of the cleaning unit facing the print medium transport path. The image forming apparatus of claim 10, wherein the print medium guide unit comprises a plurality of guide ribs provided at predetermined intervals in the cleaning unit. 12. The image forming apparatus as claimed in claim 11, wherein the print medium guide unit has a shape corresponding to a gap shape between one surface of the cleaning unit and the print medium transporting surface. The image forming apparatus according to claim 10, wherein the photosensitive member is a cylindrical photosensitive drum. The image forming apparatus according to claim 10, wherein the intermediate transfer unit is a cylindrical intermediate transfer drum. At least one photosensitive member on which an electrostatic latent image is formed; A developing unit for developing the electrostatic latent image of the photosensitive member with a developer to form a developer image; A transfer unit for transferring the developer image of the photosensitive member to a print medium; A cleaning unit for cleaning the developer remaining on the photosensitive member; And And a print media guide unit installed on one surface of the cleaning unit to guide the transfer of the print media flowing into the transfer unit.

Images