JP2010085489A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a space-saving image forming apparatus having a scattering developer collection device that has a collected developer conveying means, and fully taking advantage of a space for storing the collected developer. <P>SOLUTION: The image forming apparatus includes: a collection container 17 for storing collected developer; a collection roller member 11 that is rotatably held by the collection container 17 and is used for collecting scattering developer; a scraping member 12 for scraping developer on the collection roller member 11; a collected developer conveying means 40 that reciprocates in a direction perpendicular to the length of the collection roller member 11; and pressing means 11a and 11b for applying a force to the collected developer conveying means 40 in a direction perpendicular to the length of the collection roller member 11. The collected developer conveying means 40 reciprocates in a direction perpendicular to the length of the collection roller member 11 by the pressing means 11a and 11b driven in synchronization with the rotation of the collection roller member 11. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as an electrophotographic copying machine or printer provided with a scattered developer collecting device for collecting scattered developer (toner) in a collecting container.

  In general, an image forming apparatus such as an electrophotographic printer includes a drum-shaped electrophotographic photosensitive member (hereinafter referred to as “photosensitive drum”) as an image carrier. The image forming apparatus includes a charging device that charges the surface of the photosensitive drum with a predetermined level of potential, and a laser scanning unit (exposure device) that scans the charged photosensitive drum surface with laser light. Further, the image forming apparatus includes a phenomenon device that supplies developer (toner) to a region of an electrostatic latent image formed on a photosensitive drum by a scanned laser beam and develops the toner, and toner developed on the photosensitive drum. And a transfer device for transferring the image to the printing paper. Further, the image forming apparatus is provided with a residual toner collecting device that cleans and collects toner remaining on the surface of the photosensitive drum. In addition, in an apparatus that dislikes contamination inside the apparatus, a scattering developer (toner) around the photosensitive drum is provided. Is provided with a scattering developer (toner) collecting device.

  In the above-described configuration, the scattered toner collecting device generally includes a dust collecting roller that adsorbs toner by applying a high-voltage current having a reverse bias to the toner. The scattered toner collecting device includes a scraper that contacts the dust collecting roller and scrapes the collected toner on the dust collecting roller, and a collected toner container that stores the collected toner scraped by the scraper.

  The scraper is provided at the toner inlet of the collected toner container. The collected toner scraped off by such a scraper is accumulated at the toner inlet of the collected toner container, and then gradually pushed out and stored in the collected container. When the collected toner container is filled with the collected toner thus collected, the collected toner container is cleaned or replaced.

  However, in the scattered toner collecting apparatus having the above configuration, the collected toner may be excessively accumulated near the scraper. In this case, there is a problem that not only the function of the scraper is deteriorated due to excessively accumulated collected toner but also the collected toner is not smoothly collected in the collected toner container. There is also a problem that the toner inlet is blocked before the collected toner is evenly filled inside the collected toner container.

  The above-mentioned problem occurs similarly in the residual toner collecting device on the photosensitive drum.

  Therefore, as a countermeasure against such a problem, there is a method shown in FIG. In other words, the collected toner staying near the cleaning blade 220 (corresponding to the scraper) in the collected toner container 210 in contact with the photosensitive drum 200 is scraped by the paddle 233 and pushed into the back (for example, see Patent Document 1). .

In addition, as shown in FIG. 12, a configuration is proposed in which a stirring plate 331 that reciprocates in the longitudinal direction (arrow P direction) of the cleaning blade 322 is provided downstream of the cleaning blade 322 (corresponding to a scraper) in contact with the photosensitive drum 314. Has been. With this configuration, the collected toner is prevented from staying in the cleaning blade 322 (see, for example, Patent Document 2).
Japanese Patent Laid-Open No. 2005-10751 JP 2006-31006 A

  However, the toner collecting / conveying means (paddle 233) shown in Patent Document 1 is configured to have a large mechanism and occupy space.

  Further, in the configuration shown in Patent Document 2, the reciprocating direction of the stirring plate 331 that suppresses the stagnation of the collected toner is perpendicular to the collected toner conveyance direction. For this reason, in order to convey it to the back side in the collection container, it is necessary to push it out with newly supplied collected toner or use its own weight. That is, the configuration is not such that the collected toner is positively conveyed.

  Further, since the stirring plate is arranged at a position higher than the container inlet, there is a possibility that the toner may remain in the vicinity of the scraping portion.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus having a scattered developer collecting device provided with a collected developer conveying means that has a space-saving mechanism and can fully utilize the collected developer storage space. is there.

The above object is achieved by an image forming apparatus according to the present invention. In summary, the present invention accommodates an image carrier on which an electrostatic latent image is formed and a developer, and applies the developer to the electrostatic latent image formed on the image carrier to make it visible. In an image forming apparatus having a developing device for an image and a scattered developer collecting device for collecting scattered developer,
The scattering developer recovery device is
A collection container for storing the collected developer;
A collection roller member that is rotatably supported by the collection container and collects the scattered developer;
A scraping member for scraping off the developer on the collecting roller member;
A collected developer conveying means capable of reciprocating in a direction perpendicular to the length of the collected roller member;
A pressure unit that applies a force in a direction perpendicular to the length of the recovery roller member to the recovery developer transport unit;
And the recovered developer conveying means reciprocates in a direction perpendicular to the length of the recovery roller member by the pressing means driven in conjunction with the rotation of the recovery roller member. The image forming apparatus.

  According to the present invention, it is possible to provide an image forming apparatus having a scattered developer collecting device that can save space in the mechanism of the scattered developer collecting device and that can sufficiently utilize the collected developer storage space.

  The image forming apparatus according to the present invention will be described below in more detail with reference to the drawings.

Example 1
FIG. 1 shows a schematic configuration of an embodiment of an image forming apparatus 100 equipped with a scattered developer collecting device 72 configured according to the present invention. In this embodiment, the image forming apparatus 100 is an electrophotographic copying machine. FIG. 2 is a detailed view showing a portion M in FIG. 1, that is, the vicinity of the scattered developer collecting device 72.

  As illustrated in FIG. 1, the image forming apparatus 100 according to the present exemplary embodiment includes a printer (image forming unit) 50 and a scanner (image reading unit) 80.

  The printer (image forming unit) 50 includes an upper cassette 54 and a lower cassette 52 on which recording materials (sheets) S for forming images are stacked. The sheets S in the upper cassette 54 are separated one by one by a separation claw (not shown) and a paper feed roller 51 and fed to the registration roller 56. The sheets S in the lower cassette 52 are separated one by one by a separation claw (not shown) and a paper feed roller 53 and fed to a registration roller 56. The image forming unit 50 forms an image on the surface of the sheet S fed to the registration roller 56.

  Referring to FIGS. 1 and 2, the image forming unit 50 includes a drum-shaped electrophotographic photosensitive member as an image carrier, that is, a photosensitive drum 62 and primary charging for uniformly charging the surface of the photosensitive drum 62. And a container 70.

  An electrostatic latent image is formed on the surface of the photosensitive drum 62 charged by the primary charger 70 by a light image irradiated from a laser modulation 61 such as a laser scanner constituting an exposure apparatus. The electrostatic latent image is developed with the developer contained therein by the developing device 64, and a visible image (toner image) to be transferred to the sheet S is formed on the photosensitive drum 62.

  The image forming unit 50 includes a scattered developer (toner) collecting device 72 for collecting toner scattered from the surface of the photosensitive drum 62, the developing device 64, and the like.

  The image forming unit 50 further includes a post charger 71 that increases the surface charge of the photosensitive drum 62 to improve transfer stability, and a visible image developed on the surface of the photosensitive drum 62, that is, a toner image. A transfer charger 65 for transferring to the sheet S. The image forming unit 50 also includes a separation charger 66 for separating the sheet having the toner image transferred from the photosensitive drum 62, and a cleaner for removing the toner remaining on the photosensitive drum 62 after the toner image is transferred. 73.

  The sheet S on which the toner image is transferred from the photosensitive drum 62 by the image forming unit 50 is conveyed to the fixing device 68 by the conveying belt 67, thermally fixed by the fixing device 68, and then discharged to the sorter 90 by the discharge roller 69. .

  The scanner (image reading unit) 80 includes a scanning optical system light source 81, a platen glass 82, an openable / closable document pressure plate 83, a lens 84, a light receiving element 85 as a photoelectric conversion element, and an image processing unit 86. . The document image read by the scanning optical system light source 81 is processed by the image processing unit 86, converted into an electric signal 87, and transmitted to the laser modulation 61 of the image forming unit.

  Hereinafter, the configuration of the scattering developer (toner) collection device 72 in this embodiment will be described with reference to FIGS.

  As shown in FIG. 2, the scattered toner collecting device 72 of this embodiment is configured integrally with a post charger 71. The post charger 71 is a corona charger in this embodiment, and since its configuration and function are well known to those skilled in the art, further detailed description is omitted.

  The scattered toner collecting device 72 of this embodiment is a device that collects the developer (toner) scattered from the surface of the photosensitive drum 62, the developing device 64, and the like as described above.

  The scattered toner collecting device 72 is mounted on the printer 50 so that the downstream (the direction indicated by the arrow A in FIG. 3 is downstream) is lower than the upstream in the collected developer (collected toner) conveyance direction.

  The scattered toner collecting device 72 includes a scattered toner collecting container 17 having a collected toner storage portion 17a. That is, in this embodiment, the bottom surface of the collection container 17 is inclined, and the inclination is lower on the downstream side in the transport direction than on the upstream side in the recovery developer transport direction.

  A collection roller member that collects and collects scattered toner around the photosensitive drum 62 by applying a DC bias to the inlet 17c of the scattered toner collecting container 17, that is, a dust collecting roller 11 is rotatable. Is provided. The toner adsorbed on the dust collecting roller 11 (on the collecting roller member) is scraped off by the scraper sheet 12 which is a scraping member and guided in the direction of arrow A.

  The scattered toner collecting device 72 includes a scraper base 13 that supports the scraper sheet 12, and a collected toner scooping unit that is a collected developer conveying means for forcibly conveying the collected toner accumulated on the scraper base 13 to the collected toner storage portion 17a. 40 (see FIG. 4).

  The dust collecting roller 11 is made of stainless steel as a material, and is applied with a bias voltage of −1 kV, which is a reverse bias, for adsorbing, for example, positively charged scattered toner.

  In FIG. 5, the dust collection arm 20 is disposed so as to contact the drum cam 41 provided on the photosensitive drum 62. When the drum cam 41 rotates with the rotation of the photosensitive drum 62, the cam portion 20 a of the dust collecting arm 20 follows the shape of the drum cam 41, so that the dust collecting arm 20 rotates by a certain angle in the arrow F direction. Further, since the dust collecting arm 20 is urged in the direction of the arrow G by the cam spring 21, the dust collecting arm 20 performs a reciprocating rotation at a certain angle in the direction of the arrow F and the direction of the arrow G in the rotation cycle of the photosensitive drum 62. The rotation angle of the dust collecting arm 20 is determined by the difference between L1 and L2 (maximum outer diameter−minimum outer diameter) of the drum cam 41.

  The dust collecting arm 20 is connected to the dust collecting roller 11 via a one-way clutch CL (see FIG. 4) provided therein. The one-way clutch CL grips the dust collecting roller 11 when the dust collecting arm 20 rotates in the direction of arrow F, and the dust collecting roller 11 and the dust collecting arm 20 operate together. On the other hand, when the dust collecting arm 20 rotates in the direction of the arrow G, the one-way clutch CL is idled inside, and the dust collecting roller 11 is not rotated along with the dust collecting arm 20. That is, the one-way clutch CL acts so that the dust collecting roller 11 rotates only in the arrow F direction.

  FIG. 6B shows that the drum cam 41 rotates in the E direction when the cam shape of the drum cam 41 is divided into three regions (a), (b), and (c) as shown in FIG. The locus | trajectory of the dust collecting arm 20 and the dust collecting roller 11 when it operate | moves is shown. In FIG. 6B, Fmax indicates the position when the dust collecting arm 20 rotates most in the F direction, and Gmax indicates the position when the dust collecting arm 20 rotates most in the G direction.

  The dust collecting arm 20 operates along the shape of the drum cam 41, while the dust collecting roller 11 operates in the direction of the arrow F by the action of the one-way clutch CL as described above, that is, the area indicated by the symbol (b). Only works when

  With the above mechanism, the dust collecting roller 11 rotates in the direction of the arrow F by a certain angle. As shown in FIG. 3, since the scraper sheet 12 is in contact with the surface of the dust collecting roller 11, the toner adsorbed on the dust collecting roller 11 is scraped off.

  In FIG. 4, the collected toner scooping unit 40 includes a sheet member that scoops and conveys the collected toner, that is, the scooping sheet 15, and a block member that holds it, that is, a reciprocating block front 24 and a reciprocating block rear 14. ing. The collected toner scooping unit 40 is arranged so that the scooping sheet 15 is near the downstream side of the scraper sheet 12 in the collected developer transport direction (arrow A direction).

  3 and 4, the collected toner scooping unit 40 is applied to the length of the dust collecting roller 11 by a pressurizing means constituted by a cam portion of a roller 11, which will be described in detail later, that is, a cam 11a and a cam 11b. And reciprocating in a direction perpendicular to the direction (arrow B direction).

  As a result, the collected toner accumulated on the scraper base 13 after being scraped off by the scraper sheet 12 is rolled up and conveyed to the collected toner storage portion 17a, and sequentially accumulated from the inner side of the scattered toner collecting container 17.

  Next, the drive configuration of the collected toner scooping unit 40 will be described.

  As shown in FIGS. 4 and 8, the dust collecting roller 11 described above is provided with a cam portion constituting a pressurizing unit provided at a plurality of locations (two locations) on the front side and the back side in the longitudinal direction of the roller 11, that is, The cam 11a and the cam 11b are provided. The cam 11a and the cam 11b are arranged so that the front 24 of the reciprocating block and the cam 11a (see FIG. 4) and the rear 14 of the reciprocating block 14 and the cam 11b are in contact with each other. Each of the reciprocating blocks 24 and 14 is disposed outside the longitudinal area (outside the image forming area) of the scraper sheet 12.

  The two scooping mechanism drive configurations of the recovered toner scooping unit 40, that is, the front 24 of the reciprocating block and the cam 11a, and the back 14 of the reciprocating block 14 and the cam 11b, are symmetrical and have the same configuration. Accordingly, only the 14th side after the reciprocating block will be described below with reference to FIG.

  After the reciprocating block 14, two types of long holes 14c and 14d are provided. First, two bosses 22 and 22 protruding from the scattered toner collecting container 17 pass through the first two elongated holes 14c and 14c, and the post-reciprocating block 14 can operate along the bosses 22 and 22. Is provided. Step screws 23, 23 pass through the other elongated hole 14 d to prevent the 14 after the reciprocating block from coming off.

  A tension spring 16 (see also FIG. 3) is provided between the spring hooking portion 17b of the scattered toner collecting container 17 and the spring hooking portion 14a after the reciprocating block 14, and is always downstream in the developer conveyance direction (in the direction of arrow A). The reciprocating block 14 is pulled. As a result, the arm 14b (see FIG. 5) of the reciprocating block 14 contacts the cam 11b that is rotationally driven in conjunction with the rotation of the dust collecting roller 11, and reciprocates along the cam.

  Next, the operation of the collected toner scooping unit 40 will be described in detail with reference to FIGS.

  Similarly to the scooping mechanism drive configuration, the pre-reciprocal block 24 side operates in the same manner as the post-reciprocal block 14, so the post-reciprocal block 14 will be described, and the description of the pre-reciprocal block 24 side will be omitted.

  FIG. 9 is a schematic cross-sectional view showing a series of operations of the collected developer conveying means of the scattered developer collecting device 72 configured according to the present invention.

FIG. 10 is a view showing the locus of the collected toner scooping unit 40 with respect to the dust collecting roller 11 in FIG. 9, and the position of the dust collecting roller 11 in FIG. 9 (i) is shown as 0 °.

  FIG. 9I is a diagram showing a state in which the collected toner scooping unit 40 is at the most upstream side in the collected developer transport direction (a state in which the reciprocating block 14 is at position K). In the rotation cycle of the dust collecting roller 11, the collected toner scooping unit 40 has the longest time in the upstream side. For this reason, a large amount of toner is deposited directly on the scooping sheet 15 and the conveyance efficiency is high.

  When the dust collecting roller 11 further rotates in the H direction from FIG. 9 (i), the arm 14 b of the reciprocating block 14 is completely released from the dust collecting roller 11. Then, the collected toner scooping unit 40 slides in the direction of arrow I by the tension of the tension spring 16 and comes to the position shown in FIG. 9 (ii) (the state where the reciprocating block 14 is in the position L). By vigorously moving by the tension of the spring 16, the collected toner is prevented from adhering to the scooping sheet 15 (see FIG. 10).

  When the dust collecting roller 11 further rotates in the H direction from FIG. 9 (ii), the cam portion 11b of the dust collecting roller 11 contacts the arm 14b of the reciprocating block 14 as shown in FIG. Is gradually pushed back to the arrow J side. By gradually moving the scooping sheet 12 to the arrow J side, the collected toner accumulated on the scraper base 13 is prevented from scattering to the inlet 17c side of the scattered toner collecting container 17 (see FIG. 9 (iii)). .

When the dust collecting roller 11 further rotates in the H direction from FIG. 9 (iii), the collected toner scooping unit 40 returns to the same position as in FIG. 9 (i) as shown in FIG. 9 (iv), and the collected toner is scooped directly again. Deposit on the sheet 15.

  By repeating the above operation, the collected toner is conveyed to the collected toner storage portion 17a and sequentially accumulated from the inner side of the scattered toner collecting container 17.

  That is, according to the present invention, a space-saving and efficient recovery toner transport mechanism is realized in order to make full use of the recovery capacity. This solves the fact that the scraped toner accumulates in the vicinity of the sheet material for scraping off the developer (toner) on the scattered developer collecting roller member (dust collecting roller 11).

  The material of the dust collecting roller 11 described above is not limited to SUS, and may be manufactured using a conductive member other than SUS. Further, the scattered toner may be adsorbed by using a material that can form a magnetic field such as a magnet without using a bias voltage.

1 is a schematic cross-sectional view of an embodiment of an image forming apparatus according to the present invention in which a scattering developer collecting device configured according to the present invention is incorporated. FIG. 2 is a detailed view of a portion M in FIG. 1 showing the scattered developer recovery device. It is sectional drawing (longitudinal back side) which shows the scattering developer collection | recovery apparatus comprised according to this invention, and a post charger. It is a perspective view of the scattering developer collection apparatus comprised according to this invention. It is a front view which shows the scattering developer collection | recovery apparatus comprised according to this invention, a post charger, and a photosensitive drum. It is a figure explaining operation | movement of the dust collecting arm and dust collecting roller in the position of a drum cam. It is CC sectional view taken on the line of FIG. FIG. 3 is a detailed perspective view of a D part in FIG. 2. It is a schematic structure sectional view explaining a series of operations of the scattering developer recovery device constituted according to the present invention. FIG. 10 is a diagram for explaining the relationship between the operation of the dust collecting roller 11 and the collected toner scooping unit when the position of the dust collecting roller 11 in FIG. It is a schematic diagram which shows an example of the conventional scattering developer collection | recovery apparatus. It is a schematic diagram which shows an example of the conventional scattering developer collection | recovery apparatus.

Explanation of symbols

11 Dust collection roller (collection roller member)
11a, 11b Cam part (pressurizing means)
12 Scraper sheet (scraping member)
13 Scraper base 14 After reciprocating block 15 Scoop sheet (collected developer conveying member)
16 Tension spring 17 Scattered toner collection container 20 Dust collection arm 40 Collected toner scooping unit (collected developer conveying means)
50 Printer (image forming unit)
71 Post charger 72 Spatter toner recovery device (splash developer recovery device)
80 Scanner (image reading unit)

Claims (7)

An image carrier on which an electrostatic latent image is formed, a developing device that contains a developer, and applies the developer to the electrostatic latent image formed on the image carrier to form a visible image; An image forming apparatus having a scattered developer collecting device for collecting the developing developer,
The scattering developer recovery device is
A collection container for storing the collected developer;
A collection roller member that is rotatably supported by the collection container and collects the scattered developer;
A scraping member for scraping off the developer on the collecting roller member;
A collected developer conveying means capable of reciprocating in a direction perpendicular to the length of the collected roller member;
A pressure unit that applies a force in a direction perpendicular to the length of the recovery roller member to the recovery developer transport unit;
And the recovered developer conveying means reciprocates in a direction perpendicular to the length of the recovery roller member by the pressing means driven in conjunction with the rotation of the recovery roller member. Image forming apparatus. The pressurizing means has cam portions provided at a plurality of locations in the longitudinal direction of the collection roller member,
The collected developer conveying means has two block members arranged so as to contact the cam portion, and a sheet member passed to the two block members,
The image forming apparatus according to claim 1, wherein the collected developer conveying unit reciprocates in a direction perpendicular to the length of the collected roller member by the action of the cam portion.   The bottom surface of the recovery container is inclined, and the inclination is lower on the downstream side in the transport direction than on the upstream side in the recovered developer transport direction by the recovered developer transport means. The image forming apparatus described in 1.   The image forming apparatus according to claim 1, wherein the collection roller member is made of a conductive material and is applied with a bias voltage.   The image forming apparatus according to claim 1, wherein the collection roller member is made of a material capable of forming a magnetic field.   The image forming apparatus according to claim 1, wherein the scraping member is a sheet member.   The image forming apparatus according to claim 1, wherein the collected developer conveying unit is disposed in the vicinity of the scraping member and on the downstream side in the developer conveying direction.

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