JP4591066B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus using an electrophotographic system such as a copying machine or a printer that performs development by transferring toner from a developing roll to a photosensitive drum.

  Conventionally, in an image forming apparatus such as a copying machine or a printer using an electrophotographic method, a photosensitive drum is charged by a charging device, and image light is irradiated from an exposure device to form an electrostatic latent image on the surface of the photosensitive drum. Then, toner is transferred from the developing roll disposed in the developing device to the photosensitive drum to form a toner image. This toner image is transferred to the recording medium via the recording medium and the intermediate transfer member by the action of the transfer roll, and the recording image is formed on the recording medium by fixing the toner image.

  In such an image forming apparatus, since the toner is electrostatically held on the photosensitive drum, the toner is transferred from the developing roll to the photosensitive drum, and the toner is transferred from the photosensitive drum to the recording medium or the intermediate transfer member. The toner may drop or scatter at a transfer site to be transferred, a cleaning site for collecting residual toner on the surface of the photosensitive drum, or the like. In recent years, in order to efficiently arrange a charging device, an exposure device, a developing device, a transfer roll, and the like around the photosensitive drum, an exposure device may be arranged below the development site. There is a problem that the toner falls to the vicinity of the protective lens that emits image light.

  As countermeasures against toner falling from the development site, for example, the protective lens of the exposure apparatus is integrated with the charging unit via a guide member, and the toner attached to the protective lens is removed when the charging unit is attached or detached for replacement or cleaning. There has been proposed an image forming apparatus that prevents the camera from falling down (see, for example, Patent Document 1).

  With this configuration, it is possible to prevent the toner from dropping directly onto the exposure apparatus, but the toner adheres to the protective lens. To reduce the amount of toner adhering to the protective lens, it relies solely on airflow from the exhaust fan. However, in image forming devices that have a lot of falling or floating toner, the protective lens must be cleaned frequently. However, it is not sufficient in terms of avoiding exposure obstacles.

  Further, as a countermeasure against the falling toner from the cleaning portion for collecting the residual toner on the photosensitive drum, for example, the toner receiver of the cleaning device for cleaning the photosensitive drum is disposed substantially perpendicular to the circumferential direction of the photosensitive drum, There has been proposed an image forming apparatus in which falling toner is attracted to the outer surface of a toner receiver by the magnetic force of a magnet provided inside the toner receiver (see, for example, Patent Document 2).

However, this configuration is effective for the magnetic toner, but it cannot adsorb the non-magnetic toner for color, and there is a problem that it becomes ineffective for the color toner.
Japanese Patent Laid-Open No. 5-45945 Japanese Patent Laid-Open No. 3-8364

  The present invention has been made in view of the above problems. Toner that has fallen or scattered from a portion where toner is transferred, such as a development portion, a transfer portion, or a cleaning portion, contaminates the inside of the apparatus and causes trouble due to contamination of functional parts ( An object of the present invention is to provide an image forming apparatus capable of preventing the occurrence of an exposure failure or the like.

In order to solve the above-described problems, an image forming apparatus according to an embodiment of the present invention is a waste toner collecting container that is detachably provided to an apparatus main body in which an electrophotographic image forming process is performed. A storage unit for storing waste toner collected in the electrophotographic image forming process; and a capturing unit that captures toner dropped or scattered from a toner transfer site where toner transfer is performed in the electrophotographic image forming process; A storage portion that is provided via a partition plate formed between the storage portion and that stores the toner captured by the capture means, and the capture means is inclined below the toner transfer portion. The slits are formed on the wall surface of the storage unit arranged in this manner, and the toner that has fallen through the slits is guided to the storage unit .

According to the waste toner collecting container according to claim 1, the toner is captured on the wall surface of the housing portion that is arranged to be inclined below the toner transfer portion where the toner is transferred in the electrophotographic image forming process. Since the capturing means is provided, the toner dropped or scattered from the toner transfer site is captured by the capturing means. For this reason, it is possible to suppress toner contamination in the apparatus, in particular, troubles caused by accumulation of toner in the functional components provided in the lower part of the apparatus.

Further, since the capturing means is a slit formed on the wall surface of the housing portion, it is possible to capture toner from between the slits to the back side of the wall surface. For this reason, the toner can be guided to the back side of the slit where there is no functional component. In addition, by guiding the toner to the back side of the slit, the floating toner hardly rises and the toner can be prevented from coming out of the slit.

Further, since the toner that has fallen out of the slit is accumulated in the storage portion , it is possible to more reliably prevent the toner from scattering.

According to a second aspect of the present invention, in the configuration according to the first aspect, the wall surface is provided with a louver projecting upward from a lower portion of the slit.

According to the second aspect of the present invention, the toner dropped or scattered from the toner transfer site slides down from the louver to the slit, and is easily captured by the storage portion.

According to a third aspect of the present invention, there is provided an image forming apparatus comprising the waste toner collecting container according to the first or second aspect, wherein the image forming apparatus is disposed below the toner transfer portion and the capturing unit with respect to the image carrier. An exposure apparatus for irradiating image light is provided .

According to the image forming apparatus of the third aspect , the exposure device is provided below the toner transfer site and the capturing unit, and the toner falling or scattered from the toner transfer site is captured by the capture unit, and the toner is exposed. It is possible to prevent accumulation in the apparatus.

According to a fourth aspect of the present invention, in the image forming apparatus according to the third aspect , the toner transfer portion transfers the toner on the developing roll to an electrostatic latent image formed on the surface of the photosensitive drum. A developing nip portion, and the image carrier is the photosensitive drum .

According to the image forming apparatus of the fourth aspect , the toner transfer portion is a developing nip portion that transfers the toner on the developing roll to the electrostatic latent image on the photosensitive drum, and the toner that has fallen or scattered from the developing nip portion. It is possible to prevent the toner from being captured by the capturing means and being accumulated in the exposure apparatus. Such an arrangement in which the exposure device is provided on the lower side of the developing nip is an effective arrangement that can be taken in the recent trend toward miniaturization of image forming apparatuses. Such arrangement has no reliable means other than cleaning by the cleaning member with respect to the toner falling in the vicinity of the exposure apparatus in the prior art, but in the present invention, the falling or scattered toner can be captured more reliably, Toner contamination near the exposure apparatus can be prevented without relying on a cleaning member.

  Since the image forming apparatus according to the present invention is configured as described above, the toner falling or scattering from the toner transfer site can be reliably captured by the capturing unit, and the toner is accumulated in the functional component provided at the lower part of the apparatus. It is possible to suppress the occurrence of trouble due to the operation.

  Embodiments of an image forming apparatus according to the present invention will be described below with reference to the drawings.

  First, the outline of the configuration of the image forming apparatus will be described first, and then the main part of the present invention will be described.

  FIG. 1 is a schematic configuration diagram showing a full-color printer 1 which is an image forming apparatus according to a first embodiment of the present invention.

  Inside the full-color printer 1, a photosensitive drum 2 as an image carrier is rotatably disposed at an upper right part slightly from the center. The surface of the photoconductor drum 2 is covered with a photoconductor layer, and is driven to rotate in the direction of the arrow by a driving unit (not shown). The surface of the photosensitive drum 2 is charged to a predetermined potential by a charging roll 3 disposed almost directly below the photosensitive drum 2, and then an exposure device disposed at a position just below the photosensitive drum 2. 4 (ROS: Raster Output Scanner) exposes the laser beam B to form an electrostatic latent image according to image information.

  The electrostatic latent image formed on the photoconductive drum 2 is fed to the developing units 5Y, 5M, 5C, and 5K of yellow (Y), magenta (M), cyan (C), and black (K) in the circumferential direction. The toner is developed by the rotary developing device 5 disposed along the toner image and becomes a toner image of a predetermined color. At this time, charging, exposure, and development processes are repeated a predetermined number of times on the surface of the photosensitive drum 2 in accordance with the color of the image to be formed. In the rotary developing device 5, the corresponding color developing devices 5 </ b> Y, 5 </ b> M, 5 </ b> C, and 5 </ b> K move to a developing area facing the photosensitive drum 2. For example, when a full-color image is formed, the charging, exposure, and development processes are performed on the surface of the photosensitive drum 2 in yellow (Y), magenta (M), cyan (C), and black (K) colors. The toner image corresponding to each color of yellow (Y), magenta (M), cyan (C), and black (K) is sequentially formed on the surface of the photosensitive drum 2.

  The toner image of each color of yellow (Y), magenta (M), cyan (C), and black (K) sequentially formed on the photosensitive drum 2 has an intermediate transfer belt 6 wound around the outer periphery of the photosensitive drum 2. At the primary transfer position, the images are transferred onto the intermediate transfer belt 6 while being superimposed on each other by the primary transfer roll 7.

  The yellow (Y), magenta (M), cyan (C), and black (K) toner images transferred onto the intermediate transfer belt 6 in a multiple manner are subjected to secondary transfer by the movement of the intermediate transfer belt 6 in the arrow direction. It is conveyed to a secondary transfer position facing the roll 8. Then, the toner image is secondarily transferred collectively on the recording paper 9 fed at a predetermined timing by the secondary transfer roll 8. The recording paper 9 is fed from a paper feed cassette 10 disposed at the lower part of the full-color printer 1 in a state of being fed one by one by a feed roll 12 and a retard roll 13, conveyed by a conveyance roll 31, and by a registration roll 14. In synchronization with the toner image transferred onto the intermediate transfer belt 6, the toner image is conveyed to the secondary transfer position of the intermediate transfer belt 6.

  The intermediate transfer belt 6 includes a wrap-in roll 15 that specifies the wrap position of the intermediate transfer belt 6 on the upstream side in the rotational direction of the photosensitive drum 2, the primary transfer roll 7 described above, and a downstream side of the wrap position. A wrap-out roll 16 for specifying the wrap position of the intermediate transfer belt 6, a tension roll 17 disposed at a position close to the lower sheet feeding cassette 10 in the apparatus, and the intermediate transfer belt 6 on the secondary transfer roll 8. Between the intermediate transfer belt 6 and the cleaning backup roll 19 facing the cleaning device 23 of the intermediate transfer belt 6 with a predetermined tension. The intermediate transfer belt 6 is driven as the photosensitive drum 2 rotates.

  The cleaning device 23 for the intermediate transfer belt 6 is in contact with the surface of the cleaning roll 24 and the cleaning roll 24 disposed so as to be in pressure contact with the surface of the intermediate transfer belt 6 stretched by the cleaning backup roll 19. The scraper 25 is disposed, and the cleaning brush 26 is disposed so as to come into pressure contact with the surface of the intermediate transfer belt 6 stretched by the wrap-in roll 15, and is removed by the cleaning roll 24, the scraper 25, and the cleaning brush 26. The residual toner and paper dust thus collected are collected inside the cleaning device 23. The cleaning device 23 is supported so as to be retractable from the intermediate transfer belt 6 by a swing member (not shown), and is separated from the surface of the intermediate transfer belt 6 until the secondary transfer of the final color toner image is completed. In addition to being retracted to the position, when the secondary transfer of the final color toner image is completed, it is configured to come into contact with the surface of the intermediate transfer belt 6.

  Further, the recording paper 9 onto which the toner image is transferred from the intermediate transfer belt 6 is conveyed to a fixing device 27, and the toner image is fixed on the recording paper 9 by heat and pressure by the fixing device 27. The paper is discharged as it is onto a discharge tray 29 provided at the top of the full-color printer 1.

  On the other hand, the surface of the photoconductive drum 2 after the primary transfer process of the toner image is finished, the cleaning blade of the cleaning device 30 disposed diagonally to the right of the photoconductive drum 2 every time the photoconductive drum 2 rotates once. 32 removes residual toner and the like, and prepares for the next image forming process. The toner removed by the cleaning blade 32 is stored in a waste toner bottle 34 formed in the lower part of the cleaning device 30.

  The photosensitive drum 2 and the intermediate transfer belt 6 integrally form an image forming unit 21 including the charging roll 3 and the cleaning device 30. The front side of the full-color printer 1 (conveying the recording paper 9). The entire image forming unit 21 is configured to be detachable upward from the full-color printer 1 by opening an opening / closing cover (not shown) provided on the road side.

  In this embodiment, a two-component developer composed of a toner and a carrier is used as the developer, and a non-magnetic toner is used as the color toner stored in the developing devices 5Y, 5M, and 5C. Yes. The developer only needs to contain at least toner, and it is of course possible to use a one-component developer composed of only toner.

  2A and 2B are diagrams showing a cleaning device 30 applied to the full-color printer 1 according to this embodiment, in which FIG. 2A is a cross-sectional view, and FIG. 2B is cut in a direction perpendicular to the longitudinal direction. It is a perspective view.

  As shown in FIGS. 1 and 2A, the cleaning device 30 is disposed at the lower portion of the photosensitive drum 2, and a waste toner bottle 34 is provided at the lower portion. The outer wall surface 36 of the waste toner bottle 34 on the rotary developing device 5 side protrudes below the toner transfer portion A (development nip) where the toner is transferred from the developing roll 22 to the photosensitive drum 2. On the side wall surface 37 located below the toner transfer site A, a plurality of steps 38 are formed that are bent substantially perpendicularly in several steps as it goes downward. As shown in FIG. 2B, the step 38 is formed to have almost the entire width in the longitudinal direction of the cleaning device 30.

  As shown in FIG. 1, the exposure device 4 is disposed below the wall surface 37 of the cleaning device 30 at the toner transfer site A, and the exit 20 for emitting the laser beam B is in the longitudinal direction of the photosensitive drum 2. It is provided at almost the full width. The injection port 20 is located almost directly below the toner transfer site A. A protective lens 20 a is attached to the ejection port 20 so that toner or the like does not enter the exposure apparatus 4.

  Next, the operation of the full color printer 1 of this embodiment will be described.

  As shown in FIG. 1, in the full color printer 1, when the photosensitive drum 2 rotates in the direction of the arrow, the surface of the photosensitive drum 2 is charged to a predetermined potential by the charging roll 3 and is discharged from the ejection port 20 of the exposure device 4. The surface of the photosensitive drum 2 is exposed by the emitted laser beam B, and the potential of the exposed portion of the photosensitive drum 2 is lowered to form an electrostatic latent image. Then, toner charged to a predetermined polarity from the developing roll 22 at the toner transfer portion A facing the rotary developing device 5 is transferred to the electrostatic latent image (potential reduction portion) of the photosensitive drum 2 for development. .

  At that time, the toner may fall or scatter from the developing roll 22 without being transferred to the photosensitive drum 2. In particular, a weakly charged toner or a toner with a reverse polarity falls or scatters without being transferred to the photosensitive drum 2. The dropped or scattered toner is captured by a plurality of steps 38 of the cleaning device 30 located below the toner transfer site A. For this reason, it is possible to reduce the toner dropped or scattered from the toner transfer portion A from adhering to the protective lens 20a of the exposure device 4. For this reason, troubles such as exposure failure due to toner contamination of the protective lens 20a are prevented.

  Further, since the plurality of steps 38 use the wall surface 37 of the waste toner bottle 34, there is an advantage that the captured toner is discharged out of the apparatus every time the user replaces the image forming unit 21.

  The number of steps 38 can be set to an appropriate number in accordance with the layout of the full-color printer 1, the inclination angle of the wall surface, and the amount of dropped toner.

  As a modification of the cleaning device 30 shown in FIG. 2, as shown in FIG. 3, as shown in FIG. 3, a return member 40 that protrudes upward from the step 38 is formed at almost the entire width of the end surfaces of the plurality of steps 38 formed in the cleaning device 30. It may be attached. The toner captured by the plurality of steps 38 by the return member 40 can be prevented from spilling out, and the toner contamination of the protective lens 20a can be further reduced.

  Next, 2nd Embodiment of this invention is described based on drawing.

  In addition, the same code | symbol is attached | subjected to the member same as 1st Embodiment, and the overlapping description is abbreviate | omitted.

  As shown in FIGS. 4A and 4B, in the cleaning device 50, the wall surface 52 of the waste toner bottle 34 positioned below the toner transfer portion A (development nip) is inclined. The wall surface 52 is provided with a plurality of projecting portions 54 that project in a substantially semicircular shape (the lower part is circular). A depression 56 is formed on the upper side of the overhang 54. The overhang portions 54 are arranged in three rows on the wall surface 52 with their positions shifted at substantially equal intervals.

  In such a cleaning device 50, the toner dropped or scattered from the toner transfer site A is captured in the plurality of depressions 56. For this reason, it is possible to suppress the dropped or scattered toner from adhering to the protective lens 20a of the exposure device 4 (see FIG. 1), and it is possible to prevent an exposure failure due to toner contamination of the protective lens 20a.

  The number of the recessed portions 56 can be set to an appropriate number according to the layout of the full-color printer 1, the inclination angle of the wall surface 52, and the amount of falling toner.

  Next, 3rd Embodiment of this invention is described based on drawing.

  In addition, the same code | symbol is attached | subjected to the member same as 1st Embodiment, and the overlapping description is abbreviate | omitted.

  As shown in FIG. 5, in the cleaning device 60, the wall surface 64 of the waste toner bottle 34 positioned below the toner transfer site A (development nip) is inclined, and slits 66 are arranged at substantially equal intervals on the wall surface 64. It is formed with. The slit 66 is provided in almost the entire width in the longitudinal direction of the photosensitive drum 2 (see FIG. 1). A partition plate 62 is formed between the rear side of the slit 66 and the waste toner bottle 34 to form a two-part structure, and a collection unit 68 for collecting toner that has fallen through the slit 66 is provided.

  In such a cleaning device 60, the toner that has fallen or scattered from the toner transfer site A falls out of the slit 66 and is captured by the collection unit 68. For this reason, it is possible to suppress the dropped or scattered toner from adhering to the protective lens 20a of the exposure device 4 (see FIG. 1), and it is possible to prevent an exposure failure due to toner contamination of the protective lens 20a. Further, since the partition plate 62 is provided between the collection unit 68 and the waste toner bottle 34, the toner stored in the waste toner bottle 34 does not leak out from the slit 66 to the outside.

  The number of slits 66 can be set to an appropriate number according to the layout of the full-color printer 1, the inclination angle of the wall surface 64, and the amount of falling toner.

  As a modification of the cleaning device 60 shown in FIG. 5, a slit 76 formed in a wall surface 74 on the lower side of the toner transfer portion A (development nip) as in the cleaning device 70 shown in FIG. A louver 78 protruding upward from the lower portion of the louver may be provided. As a result, the toner dropped or scattered from the toner transfer site A slides down from the louver 78 to the slit 76 and is easily captured by the collection unit 68.

  Next, 4th Embodiment of this invention is described based on drawing.

  In addition, the same code | symbol is attached | subjected to the member same as 1st Embodiment, and the overlapping description is abbreviate | omitted.

  As shown in FIG. 7, in the cleaning device 70, the wall surface 82 (outer wall surface) of the waste toner bottle 34 located below the toner transfer site A (development nip) is inclined, and foamed rubber is formed on the wall surface 82. A material 84 is attached. For the foamed rubber material 84, for example, foamed urethane rubber or the like is used.

  In such a cleaning device 70, the toner that has fallen or scattered from the toner transfer site A is captured by a large number of bubbles in the foamed rubber material 84. For this reason, it is possible to suppress the dropped or scattered toner from adhering to the protective lens 20a of the exposure device 4 (see FIG. 1), and it is possible to prevent an exposure failure due to toner contamination of the protective lens 20a.

  The specifications of the foam rubber material 84, such as the cell diameter and the foam density, can be set to appropriate numbers according to the layout of the full-color printer 1, the inclination angle of the wall surface 82, and the amount of falling toner.

  Further, the member provided on the wall surface 82 may be other than the foamed rubber material 84 as long as it easily captures the toner. For example, a member having another cell structure, a member having a fiber structure, a waste, etc. It may be a non-woven fabric or adhesive tape. A member having a fiber structure or a non-woven fabric can capture the toner between the fibers, and the adhesive tape can adhere the toner with an adhesive.

  Next, a fifth embodiment of the present invention will be described with reference to the drawings.

  In addition, the same code | symbol is attached | subjected to the member same as 1st Embodiment, and the overlapping description is abbreviate | omitted.

  As shown in FIG. 8, this full-color printer 100 is provided with the same cleaning device 30 as that in FIG. 2 below the photosensitive drum 2, and a plurality of steps 38 are provided below the toner transfer portion A (development nip). Is formed. A fan 102 that forms an air flow is provided above the exposure device 4 and behind the rotary developing device 5. The fan 102 gently blows air in the full-color printer 100 in the direction of a plurality of steps 38 of the cleaning device 30 as indicated by arrows.

  In such a full-color printer 100, the air in the full-color printer 100 is gently blown onto the plurality of steps 38 by the fan 102, so that the toner dropped or scattered from the toner transfer site A can be more reliably captured by the plurality of steps 38. Can do.

  The full-color printer 100 is provided with the cleaning device 30 shown in FIG. 2, but is not limited to this configuration. The present invention can be similarly applied to the cleaning apparatus shown in FIGS.

  In the above-described embodiment, the toner falling or scattered from the developing nip is captured. However, the present invention is not limited to such a configuration. For example, it may be used as a countermeasure against toner falling or scattered from a transfer nip or a cleaning nip (nip between a seal and a photosensitive drum or an intermediate transfer belt).

  In the above-described embodiment, the function of causing a failure when the toner is attached is described below using the exposure apparatus as an example. However, the present invention is not limited to such a configuration. For example, the present invention can also be applied to a case where toner is dropped directly onto a recording sheet from a gap between frames in a different layout.

1 is a schematic configuration diagram illustrating a full-color printer according to a first embodiment of the present invention. It is sectional drawing and perspective view which show the cleaning apparatus used with the full-color printer which concerns on 1st Embodiment of this invention. It is a block diagram which shows the modification of the cleaning apparatus shown in FIG. It is sectional drawing and perspective view which show the cleaning apparatus used with the full-color printer which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows the cleaning apparatus used with the full-color printer which concerns on 3rd Embodiment of this invention. It is sectional drawing which shows the modification of the cleaning apparatus shown in FIG. It is sectional drawing which shows the cleaning apparatus used with the full-color printer which concerns on 4th Embodiment of this invention. It is a schematic block diagram which shows the full-color printer which concerns on 5th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Full color printer 2 Photosensitive drum 4 Exposure apparatus 5 Rotating developing device 6 Intermediate transfer belt 7 Primary transfer roll 8 Secondary transfer roll 9 Recording paper 20 Outlet 20a Protection lens 21 Image forming unit 22 Developing roll 30 Cleaning device 31 Conveying roll 32 Cleaning blade 34 Waste toner bottle 36 Outer wall surface 37 Wall surface 38 Step 40 Returning member 50 Cleaning device 52 Wall surface 54 Overhanging portion 56 Recessed portion 60 Cleaning device 62 Partition plate 64 Wall surface 66 Slit 68 Collection unit 70 Cleaning device 74 Wall surface 76 Slit 78 Louver 82 Wall surface 84 Foam rubber material 100 Full color printer 102 Fan

Claims (4)

A waste toner collecting container detachably provided to an apparatus main body where an electrophotographic image forming process is performed,
A storage unit for storing waste toner collected in the electrophotographic image forming process;
A trapping means for trapping the toner dropped or scattered from the toner metastatic sites metastasis of toner is carried out in the electrophotographic image forming process,
A storage unit that is provided through a partition plate formed between the storage unit and stores the toner captured by the capturing unit;
The capturing means is a slit formed on the wall surface of the housing portion arranged to be inclined below the toner transfer site, and guides the toner that has fallen through the slit to the housing portion. Waste toner collection container. The waste toner collecting container according to claim 1 , wherein a louver projecting upward from a lower portion of the slit is provided on the wall surface . A waste toner collecting container according to claim 1 or 2,
An image forming apparatus, wherein an exposure device for irradiating image light onto an image carrier is provided below the toner transfer portion and the capturing means . The toner transfer portion is a developing nip portion that transfers toner on the developing roll to an electrostatic latent image formed on the surface of the photosensitive drum,
The image forming apparatus according to claim 3, wherein the image carrier is the photosensitive drum .

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