JP5857631B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus such as an electrophotographic copying machine or printer.

  Conventionally, an image forming apparatus such as an electrophotographic copying machine or a printer visualizes an electrostatic latent image formed on a photoreceptor by supplying toner from a developing device, and the toner image is transferred to an intermediate transfer member. Via or directly onto the paper. In recent years, the overall device has become more compact and faster, and the heat from the fuser, heat from the paper during double-sided printing, heat from various electrical components, sliding heat of rotating bodies such as rollers, etc. Hot air tends to stay in the air. Therefore, it is necessary to pay sufficient attention to the airflow design, and it is desired to construct an air blowing (cooling) system with good performance.

  Conventionally, in order to prevent image abnormalities caused by toner dust, the generated image smoke is sucked into the image forming unit mainly composed of the photoconductor, and discharged to the outside through the filter. An air blowing mechanism is provided. Further, in a model in which the image exposure unit is protruded from the image forming unit, it has been proposed to provide an airflow blocking means so that floating toner does not adhere to the surface of the protruded image exposure unit (see Patent Document 1). .

  With the improvement of the performance of the air blowing (cooling) system described above, diffusion of toner dust and smoke, which had not been a problem in the past, through the opening for routing the electrical harness and the opening for joining electrical components There is a problem that the toner dust generated in the image unit rides on the air current and floats inside the apparatus, and the light irradiation window of the image exposure unit is soiled.

JP 2003-84632 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus capable of effectively suppressing floating of toner powder smoke in a machine by a blowing means.

An image forming apparatus according to a first aspect of the present invention includes:
A plurality of image forming units centered on photoconductors arranged in one direction, an intermediate transfer unit including an intermediate transfer body to which a toner image formed on the photoconductor is transferred, and the image forming units are cooled. An image forming apparatus comprising: a blower unit for:
And the blower unit, the intermediate transfer unit, the image forming order of the gap portion where the image forming unit disposed on the most upstream side in contact of the plurality of image forming units, the intermediate transfer unit and the image forming unit A shielding member that shields air flow from the air into the blower unit is disposed;
It is characterized by.

In the image forming apparatus according to the first embodiment, in the gap portion where the air blowing unit, the intermediate transfer unit, and the image forming unit arranged on the most upstream side in the image forming order among the plurality of image forming units are in contact. Since the shielding member that shields the air flow from the intermediate transfer unit and the image forming unit into the air blowing unit is arranged, the toner dust generated in the image forming unit leaks out of the machine through the air blowing unit, or into the machine Circulation prevents contamination of the image exposure unit and the like.

  According to the present invention, it is possible to effectively suppress floating of the toner powder smoke in the machine by the blowing means.

1 is a schematic configuration diagram of an image forming apparatus. It is explanatory drawing which shows the airflow (before countermeasures) by a ventilation mechanism. It is explanatory drawing which shows 1st Example. It is explanatory drawing which shows the shielding member in 1st Example. 4A and 4B are operation explanatory views of the shielding member in the first embodiment, where FIG. 5A shows when the image forming unit is mounted, and FIG. 5B shows when the image forming unit is detached. It is explanatory drawing which shows 2nd Example.

  Embodiments of an image forming apparatus according to the present invention will be described below with reference to the accompanying drawings. In each figure, the same code | symbol is attached | subjected about the same member and part, and the overlapping description is abbreviate | omitted.

  An image forming apparatus 1 shown in FIG. 1 is a tandem type electrophotographic copying machine, and generally forms toner images of each color of Y (yellow), M (magenta), C (cyan), and K (black). The image forming unit 10 (10y, 10m, 10c, 10k) and the intermediate transfer unit 20 are configured.

  Each of the image forming units 10 is provided with a charging charger (not shown), a developing device 12 and the like around the photosensitive drum 11, and each photosensitive drum is irradiated with a laser beam emitted from the laser scanning optical unit 15. The electrostatic latent image drawn on the image 11 is developed by the developing device 12 to form a toner image of each color. The intermediate transfer unit 20 includes an endless intermediate transfer belt 21 that is rotationally driven in the direction of the arrow X, and each photoconductor drum 11 is subjected to an electric field applied from a primary transfer roller 22 facing each photoconductor drum 11. The toner image formed above is primarily transferred onto the intermediate transfer belt 21 to be synthesized. A secondary transfer roller 25 is in contact with the intermediate transfer belt 21 on the right side of FIG. 1, and a residual toner removing / collecting mechanism 26 is installed on the left side. Note that such an electrophotographic image forming process is well known, and a detailed description thereof will be omitted.

  In the lower part of the apparatus main body, automatic paper feeding units 30 for feeding a material to be transferred (hereinafter referred to as paper) one by one are arranged in three stages, and the paper is sent from the paper feeding rollers 31 to the vertical conveyance path. Then, the toner image (synthetic color image) is transferred to the nip portion between the intermediate transfer belt 21 and the secondary transfer roller 25 through the timing roller pair 32 and the toner image (synthesized color image) is applied by the electric field applied from the secondary transfer roller 25 Transcribed. Thereafter, the sheet is conveyed to the fixing unit 35 where the toner is heated and fixed, and is discharged to the tray portion 2 disposed on the upper surface of the apparatus main body. In the case of duplex copying, the sheet on which the image is formed on the first side is returned to the timing roller pair 32 via the refeed conveyance path 33 and is conveyed again to the secondary transfer nip portion.

  In the image forming apparatus 1, a blower unit 40 is provided to dissipate heat generated from the image forming unit 10, the optical unit 15, the intermediate transfer unit 20, and the like. As shown in FIGS. 2 and 3, the blower unit 40 includes an introduction fan 41 for introducing outside air and an exhaust fan 43 that discharges the air inside the machine to the outside. The introduction fan 41 is opposite to the other image forming units 10m, 10c, and 10k with respect to the image forming unit 10y arranged on the most upstream side in the image forming order in the image forming unit 10, and is connected to the optical unit 15. Closely arranged. The exhaust fan 43 is disposed immediately above the introduction fan 41 and adjacent to the image forming unit 10y.

  The introduction fan 41 and the exhaust fan 43 are partitioned by a partition plate 45. The partition plate 45 extends to the right in FIG. 2 from the blower unit 40 and reaches from the image forming units 10y, 10m, and 10c to the image forming unit 10k. The partition plate 45 has a laser beam emitted from an opening 45a for routing a cable for supplying power to the intermediate transfer unit 20, the image forming unit 10 and the optical unit 15 and a harness for transmitting a control signal and the optical unit 15. An exposure slit for passing through is formed.

  The introduction fan 41 sucks outside air from the introduction port 42 into the apparatus and first blows air around the optical unit 15 (see arrow a). The airflow flows around the image forming unit 10 through the exposure slit of the partition plate 45 arranged immediately above the optical unit 15 (see arrow b). The exhaust fan 43 exhausts the air flow that has recirculated from the periphery of the image forming unit 10 to the outside through the exhaust port 44. The optical unit 15 and the image forming unit 10 are cooled by the circulation of the air flow. Further, a filter (not shown) is installed at the exhaust port 44 so that floating toner and the like are not discharged outside the apparatus.

  At this time, if no special measures are taken, as shown in FIG. 2, between the casing 13 of the image forming unit 10y and the casing of the intermediate transfer unit 20 (specifically, the housing 27 of the removal / recovery mechanism 26). Since there is a gap C, an air flow from the gap C (see arrow c) is generated, and the toner dust generated in the developing area of each image forming unit 10 rides on the air flow indicated by the arrow c and is an exhaust fan. It floats around 43. Further, the floating toner flows around the introduction fan 41 through the opening 45a of the partition plate 45 (see arrow d). The optical unit 15 is contaminated.

  Therefore, as a first embodiment, as shown in FIG. 3, a portion where the blower unit 40, the intermediate transfer unit 20, and the image forming unit 10y arranged on the most upstream side in the image formation order intersect (that is, the above-described portion). In the gap C), a shielding member 50 for shielding the air flow is provided. The shielding member 50 abuts a part of the casing 27 of the intermediate transfer unit 20 and a part of the casing 13 of the image forming unit 10 y to shield the developing area of each image forming unit 10 and the air blowing unit 40. Yes.

  As described above, the toner dust generated in the image forming unit 10 by the shielding member 50 is prevented from leaking out of the apparatus through the blower unit 40 or circulating inside the apparatus to contaminate the optical unit 15 and the like.

  The shielding member 50 is a long member or a sheet-like member made of an elastic material such as rubber, sponge, or urethane, and extending in the axial direction of the image forming unit 10 or the intermediate transfer unit 20. The length of the shielding member 50 is preferably equal to or longer than the image forming width W shown in FIG.

  FIG. 4 also shows the positional relationship of the introduction fan 41 and the exhaust fan 43 as viewed from the side of the apparatus main body. That is, the introduction fan 41 is disposed on the front side of the apparatus, and the exhaust fan 43 is disposed on the back side of the apparatus.

  Each image forming unit 10 is installed so as to be able to be taken in and out in one direction (perpendicular to the paper surface of FIG. 3) with respect to the image forming apparatus main body. As shown in FIG. 5, the shielding member 50 is fixed to the tip of a lever 51 that is rotatable about a support shaft 52 provided on a frame (not shown) of the apparatus main body. The lever 51 is provided with a protrusion 51 a that is in contact with the casing 13 of the image forming unit 10 y at the lower portion thereof, and is elastically biased in the direction of arrow e by a coil spring 53.

  In the configuration shown in FIG. 5, the shielding member 50 is interlocked with the taking in / out operation of the image forming unit 10 y, moves to the contact position with respect to the casing 13 when inserted, and moves to the release position with respect to the casing 13 when detached. . That is, when the image forming unit 10y is inserted into the apparatus main body, as shown in FIG. 5A, the projection 51a is urged to the left by the casing 13, and the lever 51 is supported against the coil spring 53. The shielding member 50 shields the gap C by rotating clockwise about 52 as a fulcrum. On the other hand, when the image forming unit 10y is pulled out from the apparatus main body, as shown in FIG. 5B, the lever 51 is biased by the coil spring 53 and rotates counterclockwise around the support shaft 52 as a fulcrum. The contact of the shielding member 50 with the casings 13 and 27 is released. Thus, the image forming unit 10y can be attached to and detached from the apparatus main body without being interfered by the shielding member 50.

  Next, a second embodiment will be described with reference to FIG. In the second embodiment, the opening 45 a formed in the partition plate 45 disposed between the introduction fan 41 and the exhaust fan 43 is closed by the second shielding member 46. A resin sheet is preferably used as the second shielding member 46.

  The opening 45 a formed in the partition plate 45 is for routing an electrical harness or the like as described above, and the harness is inserted into a slit formed in the second shielding member (resin sheet) 46. Since the opening 45a is blocked by the second shielding member 46, the toner dust generated in the developing area of the image forming unit 10 is prevented from circulating in the apparatus. Therefore, the optical unit 15 and the like are not contaminated with the floating toner.

  Note that the image forming apparatus according to the present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the gist thereof.

  In particular, the material, detailed configuration, and shape of the shielding member are arbitrary.

  As described above, the present invention is useful for an electrophotographic image forming apparatus, and is particularly excellent in that the floating of toner powder smoke by a blowing unit in a machine can be effectively suppressed.

DESCRIPTION OF SYMBOLS 10 ... Image forming unit 11 ... Photosensitive drum 20 ... Intermediate transfer unit 21 ... Intermediate transfer belt 40 ... Blower unit 41 ... Introducing fan 43 ... Exhaust fan 45 ... Partition plate 45a ... Opening 46 ... Second shielding member (resin sheet) )
50 ... Shielding member

Claims (8)

A plurality of image forming units centered on photoconductors arranged in one direction, an intermediate transfer unit including an intermediate transfer body to which a toner image formed on the photoconductor is transferred, and the image forming units are cooled. An image forming apparatus comprising: a blower unit for:
And the blower unit, the intermediate transfer unit, the image forming order of the gap portion where the image forming unit disposed on the most upstream side in contact of the plurality of image forming units, the intermediate transfer unit and the image forming unit A shielding member that shields air flow from the air into the blower unit is disposed;
An image forming apparatus.   The image forming apparatus according to claim 1, wherein the shielding member is in contact with a part of the intermediate transfer unit and a part of the image forming unit disposed on the most upstream side. The image forming unit is installed so that it can be taken in and out in one direction with respect to the image forming apparatus main body,
The shielding member is attached to the image forming apparatus main body, and that extends in the drawing direction of the imaging unit,
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   The shielding member is interlocked with the taking in / out operation of the image forming unit arranged on the most upstream side, and moves to a contact position with the image forming unit when inserted, and moves to a release position when detached. The image forming apparatus according to claim 2, wherein the image forming apparatus is an image forming apparatus.   The image forming apparatus according to claim 1, wherein the shielding member is a long member or a sheet member made of an elastic material.   The image forming apparatus according to claim 5, wherein a length of the shielding member is equal to or longer than an image forming width.   The blower unit includes a fan for introducing outside air, and the fan is installed on the opposite side to the other image forming unit with respect to the image forming unit arranged on the most upstream side. The image forming apparatus according to claim 1.   The image forming apparatus according to claim 1, wherein the blower unit blows air to the image exposure unit.

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