JP2010026156A - Developer storage box and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently recover developer, such as toner, stuck to a transfer belt. <P>SOLUTION: A crankshaft 25A is positioned in an area displaced toward first holding portions 32A and 33A relative to a falling point P. This prevents developer falling while scraped by a scraping blade 23 from being accumulated on the crankshaft 25A. Accordingly, developer which has fallen in a box body 32 is efficiently moved, and degradation in the efficiency of recovering developer is prevented. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a developer storage box for storing developer (waste toner) collected by a cleaning member such as a cleaning roller and a cleaning blade.

For example, in the invention described in Patent Document 1, waste toner recovered by a cleaning device is stored in a developer storage box such as a toner recovery device, and an agitator provided in the developer storage box is stored in a crankshaft. By reciprocating in the horizontal direction, waste toner that has fallen into the developer storage box from the recovery port is conveyed (moved) in the horizontal direction.
JP 2004-77607 A

  By the way, in the invention described in Patent Document 1, since the crankshaft is disposed immediately below the collection port, that is, at a portion corresponding to the drop point of the waste toner, the fallen waste toner is stacked on the crankshaft. There is a high risk of accumulation.

If waste toner accumulates on the crankshaft, the waste toner cannot be efficiently moved, so that waste toner collection efficiency is deteriorated.
In addition, in the developer storage box provided with waste toner collecting means such as a cleaning roller, the size in the height direction is increased if an attempt is made to secure a space for allowing the movement of the crankshaft below the drop point. There's a problem.

  The present invention has been made in view of the above points, and an object of the present invention is to make it possible to reduce the size and to efficiently recover the developer.

  In order to achieve the above object, the present invention is used in an electrophotographic image forming apparatus that forms an image on a recording sheet by transferring a developer image onto the recording sheet. A developer storage box for storing the developer recovered by the developer recovery mechanism, the box body constituting the storage space for storing the recovered developer, and the drop point of the developer falling into the storage space A rotatable crankshaft disposed at a position displaced from the crankshaft, and an agitator attached to the crankshaft and reciprocated by the rotation of the crankshaft to move the developer in a direction perpendicular to the axial direction of the crankshaft. The agitator extends away from the drop point through the crankshaft from the drop point in a direction perpendicular to the axial direction of the crankshaft. And said that you are.

  Thus, in the first aspect of the present invention, the crankshaft is positioned at a position shifted from the drop point, so that the developer can be prevented from being accumulated on the crankshaft. Therefore, since the developer dropped in the box body can be efficiently moved, it is possible to prevent the developer recovery efficiency from deteriorating.

In addition, by disposing the crankshaft at a position shifted from the drop point, the height dimension can be reduced, which is advantageous for downsizing.
In the invention according to claim 2, the holding portion is provided on the side opposite to the position where the crankshaft is provided in the agitator, and the holding portion is provided on the box body by rotating the crankshaft. The agitator is reciprocated while being guided along a horizontal groove.

  Thus, according to the second aspect of the present invention, the developer that has fallen into the box body can be efficiently moved to the holding portion side as the crankshaft swings on the drop point side.

  In the invention according to claim 3, the agitator moves the developer stored in the storage space in the first direction, and causes the developer that has reached a predetermined height or more in the second direction opposite to the first direction. It is made to move.

  As a result, in the invention according to the third aspect, the developer dropped in the box body is not biased and stored in one place, and a larger amount of developer is utilized by using the accommodation space in the box body without waste. Can be accommodated.

  In the invention according to claim 4, the agitator is provided with a plurality of conveying portions extending in the axial direction of the crankshaft with a predetermined interval, and the conveying portion causes the developer to move in the first direction or the reciprocating motion of the agitator. Since the developer is moved in the second direction, the developer dropped in the box body can be moved more effectively by the plurality of transport units.

  Further, in the invention according to claim 5, since the end portion on the drop point side of the agitator is characterized by cranking at least across the drop point, the developer that has fallen into the box body is surely obtained. Moreover, it can be transported promptly.

  According to a sixth aspect of the present invention, the developer recovery mechanism includes a cleaning roller for recovering the developer, and the crankshaft rotates by obtaining power from the recovery mechanism.

Accordingly, in the invention described in claim 6, the crankshaft can be disposed close to the recovery mechanism, so that the developer containing box can be made small.
According to the seventh aspect of the present invention, an image carrier that carries a developer image, a charging unit that charges the image carrier, and an image formation that forms an electrostatic latent image on the charged image carrier. Means, developing means for developing the latent image formed on the image carrier with a developer, transfer means for transferring the developer image formed on the image carrier to a recording sheet, and collecting the developer A collection unit, a developer storage box for storing the developer collected by the collection unit, and a developer container provided in the developer storage box and arranged at a position shifted from a drop point of the developer collected by the collection unit A crankshaft and an agitator attached to the crankshaft and swinging up and down and moving the developer in a direction perpendicular to the axial direction of the crankshaft. The agitator drops from the drop point via the crankshaft. Point That extends away from and is characterized in.

  Thus, in the invention described in claim 7, the same effect as that of the invention described in claim 1 can be realized as an image forming apparatus.

  In this embodiment, a developer container according to the present invention is applied to a belt cleaner for a direct tandem type color laser printer (hereinafter referred to as an image forming apparatus), and the embodiment will be described with reference to the drawings. .

1. 1 is a central sectional view showing a schematic configuration of an image forming apparatus 1 according to the present embodiment, FIG. 2 is a top perspective view of a belt cleaner 20, and FIG. 3 is a bottom perspective view of the belt cleaner 20. FIG. 4 is a view of the belt cleaner 20 as viewed from the front side, and FIG. 5 is a cross-sectional perspective view showing the structure of the belt cleaner 20.

  6 to 9 are cross-sectional views taken along the line AA of FIG. 4, FIG. 10 is a perspective view of the box main body 32 and the agitator 25, FIG. 11 is a perspective view of the auger 27, and FIG. 11 is an enlarged view of a portion A in FIG. 11, FIG. 13 is a view taken in the direction of arrow B in FIG. 11, and FIG. 14 is a cross-sectional view taken along line AA in FIG.

  15 is an enlarged view of a portion B in FIG. 13, FIG. 16 is a view showing a mechanism for driving the shielding member 40, and FIG. 17 shows a dimension between the bottom wall portion 32A and the closing member 33. A test for testing whether or not the developer leaks from the mating surface D, using A, the dimension B from the bottom wall portion 32A to the upper end of the transport unit 25B, and the height C of the transport unit 25B as parameters. It is a chart which shows a result.

2. Configuration of image forming apparatus 2.1. Schematic Structure of Image Forming Apparatus In the housing 3 of the image forming apparatus 1, as shown in FIG. 1, a developer image is transferred to a recording sheet (hereinafter referred to as a sheet) such as a recording sheet or an OHP sheet. An electrophotographic image forming unit 5 for forming an image on a sheet is accommodated. As is well known, the image forming unit 5 includes a process cartridge 7, an exposure unit 9, a fixing unit 11, and the like.

  Since the image forming apparatus 1 according to the present embodiment is a direct tandem color laser printer, a plurality (four in the present embodiment) of process cartridges 7 are arranged in series along the sheet conveyance direction. It is installed.

  Specifically, the process cartridge 7K for black, the process cartridge 7Y for yellow, the process cartridge 7M for magenta, and the process cartridge 7C for cyan are sequentially arranged from the upstream side in the sheet conveyance direction.

  In addition, the process cartridges 7K to 7C differ only in the color of the developer stored therein and have substantially the same structure and the like. Specifically, each process cartridge 7K to 7C carries a developer image. And a charger 7B for charging the photosensitive drum 7A. In FIG. 1, for the sake of space, the reference numerals of the photosensitive drum 7A and the charger 7B are attached only to the cyan process cartridge 7C.

  In the configuration described above, when the charged photosensitive drum 7A is exposed by the exposure device 9 to form an electrostatic latent image on the outer peripheral surface of the photosensitive drum 7A, a charged developer is supplied to the photosensitive drum 7A. The developer image is carried (formed) on the outer peripheral surface of the photosensitive drum 7A.

  Further, a transfer roller 15 for transferring the developer carried on the photosensitive drum 7A to the sheet is provided at a position facing the photosensitive drum 7A across the transfer belt 13 for conveying the sheet. A voltage is applied to transfer the developer image carried on the photosensitive drum 7A onto the sheet.

  For this reason, the developer image carried on the photosensitive drum 7 </ b> A is transferred onto the sheet conveyed by the transfer belt 13. Then, the sheet on which the developer image is transferred is conveyed to the fixing device 11 and heated, and the developer image transferred onto the sheet is fused (fixed) to the sheet.

2.2. Belt Cleaner Configuration The belt cleaner 20 is disposed on the opposite side of the process cartridge 7 with the transfer belt 13 interposed therebetween, and removes deposits such as developer and paper dust attached to the surface of the transfer belt 13 that is the object to be cleaned. It is a device to do.

  That is, in the present embodiment, in the image forming apparatus 1 adopting the direct tandem method, a developer (toner) density adjustment patch or a color misregistration detection registration mark is transferred to the transfer belt at an appropriate timing without carrying the paper. 13 is printed (transferred), and then the patch or registration mark is removed (collected) by the belt cleaner 20 as waste developer (waste toner).

2 and 3, the belt cleaner 20 is a flat box-like one, and can be displaced in the front-rear direction with respect to the image forming apparatus (apparatus main body) 1. As shown in FIGS. 2 and 4, a gripping portion 20 </ b> A for gripping the belt cleaner 20 is provided at one end side in the displacement direction (front end side in the present embodiment). It has been.
As shown in FIG. 6, the belt cleaner 20 includes a cleaning roller 21, a cleaning shaft 22, a peeling blade 23, a scattering prevention blade 24, an agitator 25, a backup roller 26 (see FIG. 1), an auger 27, and a developer. It is comprised from the storage box 30 grade | etc.,.

  The cleaning roller 21 is a cleaning member that is disposed opposite to the transfer belt 13 and collects deposits (mainly developer) attached to the surface of the transfer belt 13 from the transfer belt 13. It is a cleaning member that collects the developer attached to the surface and conveys it to the accommodation space 31.

  As shown in FIG. 1, the backup roller 26 is disposed on the opposite side of the cleaning roller 21 with the transfer belt 13 interposed therebetween, and is a backup member for pressing the transfer belt 13 against the cleaning roller 21.

  The cleaning roller 21 and the cleaning shaft 22 are applied with a potential (in this embodiment, a negative potential) having a polarity opposite to the charge of the developer. That is, the developer adhering to the surface of the transfer belt 13 is electrostatically attracted to the cleaning roller 21 by the electrostatic attraction force generated between the cleaning roller 21 and the developer, and the transfer belt 13 is cleaned.

  Since the cleaning roller 21 is rotationally driven in a direction opposite to the running direction of the transfer belt 13, the developer adhering to the transfer belt 13 is mechanically (physically) scraped off electrostatically. To be recovered.

  At this time, since the absolute value of the potential applied to the cleaning shaft 22 is controlled to be larger than that of the cleaning roller 21, the developer electrostatically attracted to the cleaning roller 21 is cleaned by the electrostatic attraction force. Then, the toner is recovered from the cleaning roller 21 so as to be transferred to the roller 22.

  Then, as shown in FIG. 6, the developer collected on the surface of the cleaning shaft 22 is scraped off by a thin plate-like peeling blade 23, and the developer thus scraped off is cleaned by a scattering prevention blade 24 by a cleaning roller 21. It is prevented from being scattered to the side, and is transferred by the agitator 25 to the storage space 31 formed in the developer storage box 30.

  As shown in FIG. 5, the developer storage box 30 includes a box main body 32 constituting the storage space 31, a closing member 33 that closes the upper side opening of the box main body 32, a blade frame 35, and the like. The closing member 33 and the blade frame 35 are fixed to the box body 32 by mechanical fastening (coupling) means such as screws.

3.2.1. As shown in FIG. 6, the agitator 25 is disposed between the bottom wall portion 32 </ b> A of the box body 32 and the closing member 33 in the housing space 31, and the agitator 25 moves forward in the moving direction ( A gap 31 </ b> A is provided between the left end of FIG. 6 and the side wall of the box body 32.

  Further, the agitator 25 reciprocates in the developer transport direction (in this embodiment, the direction parallel to the paper transport direction) and swings in a direction (vertical direction in this embodiment) perpendicular to the transport direction. By moving, the developer scraped off by the peeling blade 23 is moved in the transfer direction, and the agitator 25 is operated by the crankshaft 25A.

  As shown in FIG. 10, the crankshaft 25 </ b> A is rotated by obtaining a driving force from the gear mechanism 20 </ b> B (see FIG. 2) via a gear 25 </ b> D provided at the longitudinal end thereof, thereby rotating the agitator 25. Swing while reciprocating (see FIGS. 6 to 9).

  Incidentally, as shown in FIG. 6, the gear mechanism 20 </ b> B is a mechanism that rotationally drives the cleaning roller 21 and the like, and obtains a driving force from the apparatus main body to rotationally drive the recovery mechanism such as the cleaning roller 21.

  The agitator 25 has a surface substantially orthogonal to the moving direction of the developer, and extends in a direction substantially orthogonal to the moving direction and the swinging direction of the agitator 25 (in this embodiment, the direction orthogonal to the paper surface). A plurality of transport sections 25B formed in a strip shape and a plurality of frames 25C extending in the moving direction and holding the plurality of transport sections 25B are configured in a lattice shape.

  A pair of left and right sliding pins 25E is provided at one end of the agitator 25 in the reciprocating direction and opposite to the crankshaft 25A in order to hold the agitator 25 so as to be able to reciprocate and rotate. Is provided as a holding portion on the agitator 25 side, and these sliding pins 25E are provided with a first holding portion 32A provided on the box body 32 and a first member provided on the closing member 33 as shown in FIG. It is sandwiched between the holding portion 33A. For this reason, the sliding pin 25E is supported so as to be slidable in the horizontal direction along a guide groove (horizontal groove) formed between the first holding part 32A and the first holding part 33A. Incidentally, in FIG. 5, only the right sliding pin 25E is shown.

  That is, as shown in FIG. 6, the first holding portions 32A and 33A (sliding pin 25E side) are opposite to the virtual plane S1 (thick two-dot chain line in FIG. 6) including the drop point P across the crankshaft 25A. The agitator 25 extends from the first holding portions 32A, 33A (sliding pins 25E) side to the imaginary plane S1 including the drop point P over the crankshaft 25A.

  Here, the “fall point P” refers to a set of lines passing through the tip of the peeling blade 23 and orthogonal to the bottom wall portion 32A, and the “virtual plane S1 including the drop point P” is the line of the line. A virtual plane composed of a set. Hereinafter, “virtual plane S1 including the drop point P” is abbreviated as the drop point P.

  A portion of the agitator 25 on the side of the drop point P from the crankshaft 25A, and at least a part thereof (in the present embodiment, the end portion 25F of the agitator 25 on the side of the drop point P from the crankshaft 25A) is shown in FIG. As shown in FIGS. 6 to 9, the reciprocating motion is performed so as to move back and forth between the crankshaft 25A and the crankshaft 25A side across the drop point P.

  In addition, as shown in FIG. 5, both ends of the crankshaft 25A in the longitudinal direction are second holding portions 32B provided on the box body 32 and a second frame provided on the blade frame 35 for holding the peeling blade 23 and the like. Like the crankshaft 25A, the auger 27 is rotatably supported by a holding portion 35A and a third holding portion 32C provided on the box body 32 and a third holding portion 35B provided on the blade frame 35. It is clamped so that it can rotate.

2.2.2. Waste developer detection unit The storage space 31 extends in the width direction on one end side in the width direction (in this embodiment, the left-right direction) of the storage space 31 as shown in FIG. A wall portion 36 that divides a part of the wall portion 36 is provided, and a waste developer detection portion 37 is provided on the opposite side of the drop point P across the wall portion 36.

  The waste developer detection unit 37 receives waste developer 31 from the storage space 31 that is not partitioned by the wall 36, that is, from the storage space 31 on the side where the wall 36 is not provided (left side in FIG. 11). A space 38 (hereinafter, this space is referred to as a detection space 38) in which waste toner that has flowed into the detection unit 37 accumulates is provided, and the detection space 38 is provided in the box body 32 as shown in FIG. It is formed so as to protrude downward from the recessed portion 32D.

  Then, a light sensor 39 (see FIG. 11) for making the beam-shaped light incident on the detection space 38 and receiving the incident light is assembled and fixed to the portion of the apparatus main body corresponding to the detection space 38. ing.

  That is, in the state where the belt cleaner 20 is assembled to the apparatus main body, as shown in FIG. 15, the light emitting portion 39A of the optical sensor 39 is located on one side and the optical sensor 39 on the other side with the detection space 38 in between. The light receiving part 39B is located.

  A signal generated when the light receiving unit 39B receives light is input to a comparator (not shown), and the signal level generated when the light receiving unit 39B receives light exceeds the reference level. When the signal level is low, the Lo signal is output, and when the signal level is lower than the reference level, the Hi signal is output.

  Incidentally, among the members constituting the detection space 38, it is necessary to provide a window portion through which light can pass in a portion corresponding to the optical path L of the light emitted from the light emitting portion 39A. The entire member constituting the detection space 38 is made of a transparent member such as acrylic so that light can pass therethrough.

  The detection space 38 is provided with a shielding member 40 that is displaced between a position that blocks the optical path L and a position that opens the optical path L. The shielding member 40 is shielded as shown in FIG. It is periodically swung in the horizontal direction (in this embodiment, the front-rear direction) by a rocking shaft 40A set on the upper end side of the member 40.

  The wall portion 36 provided in the vicinity of the waste developer detection unit 37 is a direct inflow prevention unit that prevents the waste developer stored in the accommodation space 31 from directly flowing into the waste developer detection unit 37. It is. For this reason, an auger 27 for conveying the waste developer stored in the accommodation space 31 to the detection space 38 is provided, and the auger 27 is not provided with a portion other than one end in the width direction, that is, the wall portion 36. The waste developer that has flowed into the waste developer detector 37 from the portion is conveyed to a detection space 38 provided at one end in the width direction.

  Incidentally, as shown in FIG. 12, the auger 27 is a screw-type powder conveyance pump composed of a screw having spiral blades 27A provided around the rotation shaft 27B. The auger 27 does not transport the waste developer to the waste developer detection unit 37 until the waste developer stored in the storage space 31 comes into contact with the blade 27A, and the waste 27A is discarded by the blade 27A. The waste developer that has risen above the height with which the developer contacts is sequentially conveyed toward the waste developer detection unit 37.

  Further, as shown in FIG. 14, in the detection space 38, the waste toner conveyed by the auger 27 is located on the optical path L side, that is, the portion of the detection space 38 sandwiched between the light emitting portion 39A and the light receiving portion 39B. An inclined guide surface 38A is provided that leads to a vertical direction at a portion of the lower end side of the detection space 38 that faces the discharge port 27C of the auger 27. .

  Further, as shown in FIG. 16, the swing shaft 40A of the shielding member 40 is set at a position where the swing center 40B is shifted in the horizontal direction from the rotation center 27D of the auger 27 (rotary shaft 27B). The rotary shaft 27B is connected to the rotary shaft 27B (auger 27) via a link mechanism 41 that converts the rotary motion of the rotary shaft 27B into a swinging motion. For this reason, when the auger 27 (rotating shaft 27B) rotates, the shielding member 40 swings and displaces in the horizontal direction at a cycle proportional to the rotational speed.

  Incidentally, the link mechanism 41 has a crank pin 41A provided at a position eccentric from the rotation center 27D of the rotation shaft 27B, and one end side fixed to the swing shaft 40A, and the other end side slides on the outer peripheral surface of the crank pin 41A. This is a mechanism composed of a link lever 41B and the like provided with a U-shaped cam groove 41C that comes into contact.

3. Actuation of agitator, etc. (See Figs. 6-9)
When the crankshaft 25A rotates and the agitator 25 operates, the agitator 25 reciprocates in the developer transfer direction. Therefore, when the agitator 25 moves toward the gap 31A, It is pressed toward the gap 31A by the transport unit 25B, and sequentially transferred from the drop point to the gap 31A.

  That is, the developer accumulated in a mountain shape at the dropping point P is sequentially transferred to the gap 31A side by the other transport unit 25B while the top part of the mountain is scraped off by the transport unit 25B of the agitator 25. . Therefore, until the pile of developer accumulated exceeds the agitator 25, the pile of developer expands toward the gap 31A (see FIG. 18).

  When the developer piles rise sequentially from the gap 31 </ b> A side in the accommodation space 31, the developer to be transferred gets over the agitator 25 formed in a lattice shape along with the movement of the agitator 25. While accumulating up to the upper part of the space 31, the raised ridge portion of the developer gradually approaches the drop point P side (see FIG. 19).

  When the developer stored in the storage space 31 reaches the auger 27 beyond the drop point P and reaches a height that contacts the blades 27A of the auger 27, the developer is detected by the auger 27 as waste developer. The optical sensor 39 detects that the amount of the developer transferred to the portion 37 and stored in the storage space 31 exceeds a predetermined amount. When it is detected that the amount of developer stored in the storage space 31 exceeds a predetermined amount, the user is notified that the developer storage box 30 should be replaced.

  As is apparent from the above description, the agitator 25 moves the waste developer in the opposite direction when it is moving on the upper side and when it is moving on the lower side. Therefore, the developer stored in the storage space 31 can be reliably sent to the waste developer detection unit 37 before it is collected to the extent that the developer leaks.

  Moreover, the side closer to the crankshaft 25A of the agitator 25 sends the developer to the gap 31A side when moving on the lower side, and sends it from the gap 31A side to the crankshaft 25A side when moving on the upper side. The 31A (sliding pin 25E) side hardly moves up and down. Therefore, on the gap 31A side, the developer hardly moves in any direction, so that the developer hardly leaks.

4). Determination of attachment of belt cleaner and determination of developer amount in accommodation space Since the shielding member 40 is periodically oscillated by the oscillation shaft 40A, the belt cleaner 20 is attached to the apparatus main body and the detection space When the developer is not accumulated in 38, the optical path L is periodically blocked.

  Therefore, when the belt cleaner 20 is attached to the apparatus main body and the developer is not accumulated in the detection space 38, the Hi signal and the Lo signal are periodically and alternately output from the comparator. On the other hand, when the belt cleaner 20 is mounted on the apparatus main body and the developer is accumulated in the detection space 38, the optical path L remains blocked by the developer. Is output from.

  Further, since the optical sensor 39 is mounted on the apparatus main body, when the belt cleaner 20 is not mounted on the apparatus main body, there is nothing blocking the optical path L, and the Lo signal is continuously output from the comparator. The

  Therefore, in the present embodiment, when light is periodically detected, it is determined that the belt cleaner 20 is attached to the apparatus main body and that the developer can be further accumulated in the accommodation space 31. Is not periodically detected, it is determined that the developer cannot be further accumulated in the storage space 31, and when light is continuously detected, the belt cleaner 20 is not assembled to the apparatus main body. It is determined that it is in a state.

5). Features of Developer Storage Box According to this Embodiment In this embodiment, as shown in FIG. 6, the crankshaft 25A is displaced toward the first holding portions 32A, 33A (sliding pins 25E) with respect to the drop point P. Therefore, the developer scraped and dropped by the peeling blade 23 can be prevented from accumulating on the crankshaft 25A. Therefore, since the developer dropped in the box body 32 can be efficiently moved, it is possible to prevent the developer recovery efficiency from deteriorating.

  By the way, in this embodiment, when the agitator 25 is displaced toward the first holding portions 32A and 33A, the developer is pushed toward the first holding portions 32A and 33A, thereby causing the developer to move toward the first holding portions 32A and 33A. Therefore, it is necessary to push the developer toward the first holding portions 32A and 33A at least on the drop point P side which is the starting point side in the movement direction.

  On the other hand, the amount of developer that can be moved (conveyed) when the agitator 25 reciprocates once (conveyed amount) is the amount of movement of the agitator 25 due to the rocking displacement, that is, the amount of movement in the direction orthogonal to the moving direction ( The larger the (swing amount), the larger.

In this embodiment, since the crankshaft 25A is provided on the drop point P side, the swing amount is the largest on the drop point P side.
Therefore, in this embodiment, since the conveyance amount on the drop point P side, which is the starting point side in the movement direction, can be increased, the developer dropped into the box body 32 can be moved more efficiently, and the developer It is possible to prevent the recovery efficiency of the fuel from being improved.

  As described above, in this embodiment, it is possible to increase the conveyance amount on the falling point P side that is the moving direction start point side while preventing the developer from being accumulated on the crankshaft 25A. The developer dropped in the box body 32 can be moved more efficiently.

  In the present embodiment, the end 25F of the agitator 25 on the side of the drop point P from the crankshaft 25A has a crankshaft opposite to the crankshaft 25A across the drop point P, as shown in FIGS. Since the reciprocating motion moves back and forth between the 25A side, the dropped developer can be reliably conveyed.

  In the present embodiment, the crankshaft 25A is rotated by obtaining power from the gear mechanism 20B that rotationally drives the cleaning roller 21 and the like, so that the crankshaft 25A can be disposed close to the gear mechanism 20B. Therefore, the developer storage box 30 can be reduced in size.

  By the way, if the height C (see FIG. 6) of the transport portion 25B provided in the agitator 25 is increased, the developer transport capability (moving capability) can be increased, but if the transport capability is increased, the box body The possibility that the developer leaks out from the mating surface (D portion in FIG. 6) of the sealing member 32 and the closing member 33 is increased.

  On the other hand, in this embodiment, the ratio (= C /) of the height dimension C (see FIG. 6) of the transport section 25B to the dimension A (see FIG. 6) between the bottom wall portion 32A and the closing member 33. By setting A) to 0.1 or less, the developer is prevented from leaking out from the mating surface D without particularly improving the sealing performance at the mating surface D.

  Further, the ratio (= B / A) of the dimension B (see FIG. 6) from the bottom wall part 32A to the upper end of the transport part 25B with respect to the dimension A between the bottom wall part 32A and the closing member 33 is set to 0. If it is 35 or less, it is possible to more effectively prevent the developer from leaking from the mating surface D to the outside.

  That is, FIG. 17 is a combination of the dimension A between the bottom wall part 32A and the closing member 33, the dimension B from the bottom wall part 32A to the upper end of the conveying part 25B, and the height dimension C of the conveying part 25B as parameters. 10 is a chart showing test results when testing whether or not the developer leaks from the surface D to the outside.

  As shown in FIG. 6, the mating surface D of the box body 32 and the closing member 33 has a maze structure in which the gap between the box body 32 and the closing member 33 (about 0.4 mm in this embodiment) is meandered. This prevents the developer from leaking out. The dimensions A and B are dimensions when the agitator 25 is farthest from the bottom wall portion 32A. Incidentally, in this embodiment, as shown in FIG. 6, in the most separated state, the agitator 25 is substantially parallel to the bottom wall portion 32A so as to be substantially horizontal.

  In FIG. 17, “waste toner leakage” is a result of visual determination of whether or not the developer has leaked from the mating surface D, and “◯” indicates that no leakage has occurred. , “×” indicates that a leak occurred.

  The “waste toner amount at full tank detection” indicates the amount of developer stored in the storage space 31 when the developer is detected by the waste developer detection unit 37, and “waste toner amount”. The “determination” means a waste toner amount at the time of full tank detection that becomes a minimum value in the developer storage box 30 that is determined as “x” in “waste toner leakage” (hereinafter, this value is referred to as a minimum detection amount). This is the result of determining pass / fail based on.

  That is, in the waste toner amount determination, when the amount of developer stored in the storage space 31 exceeds a predetermined amount based on the minimum detection amount (in this embodiment, about 90% of the minimum detection amount). The amount of the developer stored in the storage space 31 when the developer is detected by the waste developer detection unit 37 is regarded as the minimum detection amount. Is equal to or less than a predetermined amount, it is regarded that the developer does not leak from the mating surface D (“◯”), and the quality of the developer storage box 30 is determined. In this embodiment, the quality of the developer storage box 30 is determined by setting the minimum detection amount to about 500 g and the predetermined amount based on the minimum detection amount to 450 g.

  Incidentally, in the result shown in FIG. 17, the amount of waste toner at the time of full tank detection when the determination is “x” due to waste toner leakage is 506.7 g to 558.6 g, and the variation width is an average. Is about ± 25 g with respect to the amount of waste toner when full tank is detected.

  Therefore, when the threshold for determining the amount of waste toner is 450 g, even if a variation of about ± 25 g occurs, the maximum value of 475 g is less than the minimum detection amount of 500 g. The possibility that the developer leaks out of the printer appears to be sufficiently small.

As described above, when C / A is set to 0.1 or less, and more desirably, B / A is set to 0.35 or less, it is possible to effectively prevent the developer from leaking from the mating surface D to the outside.
(Other embodiments)
In the above-described embodiment, a seal structure in which the mating surface D is a maze structure is employed. However, the present invention is not limited to this, and may be a seal structure in which a packing is interposed, for example.

Further, the pressure feeding means for transporting the developer in the accommodation space 31 is not limited to the one composed of the agitator 25, the crankshaft 25A, and the like.
The application target of the present invention is not limited to a direct tandem color laser printer.

  That is, in the present embodiment, in the image forming apparatus 1 adopting the direct tandem method, a developer (toner) density adjustment patch or a color misregistration detection registration mark is transferred to the transfer belt at an appropriate timing without carrying the paper. 13, the patch or registration mark is removed (collected) by the belt cleaner 20 as waste developer (waste toner), but the present invention is not limited to this. For example, for a transfer belt of an intermediate transfer system to which a developer image is transferred, in addition to a density patch or a registration mark for color misregistration detection, a so-called transfer residual developer is collected. There may be.

Further, the present invention can be applied to a belt cleaner or the like that collects a transfer residual developer such as a photosensitive belt.
Further, the present invention is not limited to the above-described embodiment as long as it matches the gist of the invention described in the claims.

1 is a central sectional view showing a schematic configuration of an image forming apparatus 1 according to the present embodiment. 3 is a top perspective view of the belt cleaner 20. FIG. 3 is a perspective view of the lower surface side of the belt cleaner 20. FIG. It is the figure which looked at the belt cleaner 20 from the front side. 2 is a cross-sectional perspective view showing a structure of a belt cleaner 20. FIG. It is AA sectional drawing of FIG. It is AA sectional drawing of FIG. It is AA sectional drawing of FIG. It is AA sectional drawing of FIG. It is a perspective view of the box body 32, the agitator 25, and the like. It is a perspective view of auger 27 grade. It is the A section enlarged view of FIG. It is a B arrow line view of FIG. It is AA sectional drawing of FIG. It is the B section enlarged view of FIG. It is a figure which shows the mechanism for driving the shielding member. It is a chart which shows a test result. It is a figure explaining the effect | action of the agitator 25. FIG. It is a figure explaining the effect | action of the agitator 25. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 5 ... Image forming part, 7 ... Process cartridge,
7A ... photosensitive drum, 7C ... process cartridge, 7K ... process cartridge,
7M: Process cartridge, 7Y: Process cartridge, 9: Exposure unit,
DESCRIPTION OF SYMBOLS 11 ... Fixing device, 13 ... Transfer belt, 15 ... Transfer roller, 20 ... Belt cleaner,
20A ... gripping part, 20B ... gear mechanism, 21 ... cleaning roller,
22 ... cleaning shaft, 23 ... peeling blade, 24 ... scattering prevention blade,
25 ... Agitator, 25A ... Crankshaft, 25B ... Conveying section,
25C ... Frame, 25D ... Gear, 25E ... Sliding pin, 25F ... End,
26 ... backup roller, 27 ... auger, 27A ... blade, 27B ... rotating shaft,
27C ... Discharge port, 27D ... Center of rotation, 30 ... Developer storage box, 31 ... Storage space,
31A ... Gap, 32 ... Box body, 32A ... First holding part, 32A ... Bottom wall part,
32B ... 2nd holding part, 32C ... 3rd holding part, 32D ... Recessed part, 33 ... Closure member,
33A ... 1st holding part, 35 ... Blade frame, 35A ... 2nd holding part,
35B ... Third holding portion, 36 ... Wall portion, 37 ... Waste developer detection portion, 38 ... Detection space,
38A ... Inclination guide surface, 39 ... Optical sensor, 39A ... Light emitting part, 39B ... Light receiving part,
40 ... shielding member, 40A ... swing shaft, 40B ... swing center, 41 ... link mechanism,
41A ... crank pin, 41C ... cam groove, P ... drop point.

Claims (7)

This is a developer storage box that is used in an electrophotographic image forming apparatus that forms an image on a recording sheet by transferring the developer image to the recording sheet and that stores the developer recovered by the developer recovery mechanism. And
A box body constituting a storage space for storing the collected developer;
A rotatable crankshaft disposed at a position deviated from the drop point of the developer falling into the storage space;
An agitator that is attached to the crankshaft, reciprocates by rotation of the crankshaft, and moves the developer in a direction orthogonal to the axial direction of the crankshaft;
The developer storage box, wherein the agitator extends from the drop point through the crankshaft so as to be separated from the drop point in a direction orthogonal to the axial direction of the crankshaft. A holding portion is provided on the side of the agitator opposite to the position where the crankshaft is provided,
2. The developer storage box according to claim 1, wherein the agitator is reciprocated by rotating the crankshaft and guiding the holding portion along a horizontal groove provided in the box body. 3. .   The agitator moves the developer stored in the storage space in a first direction, and moves the developer that has reached a predetermined height or more in a second direction opposite to the first direction. Item 3. The developer storage box according to Item 1 or 2. The agitator is provided with a plurality of conveying portions extending in the axial direction of the crankshaft via a predetermined interval,
4. The developer storage box according to claim 1, wherein the transport unit moves the developer in the first direction or the second direction by a reciprocating motion of the agitator. 5.   5. The developer storage box according to claim 1, wherein an end of the agitator on the drop point side performs a crank motion with at least the drop point interposed therebetween. The developer recovery mechanism includes a cleaning roller for recovering the developer,
The developer storage box according to claim 1, wherein the crankshaft rotates by obtaining power from the developer recovery mechanism. An image carrier for carrying a developer image;
Charging means for charging the image carrier;
Image forming means for forming an electrostatic latent image on the charged image carrier;
Developing means for developing the latent image formed on the image carrier with a developer;
Transfer means for transferring the developer image formed on the image carrier to a recording sheet;
A collecting means for collecting the developer;
A developer storage box for storing the developer recovered by the recovery means;
A crankshaft provided in the developer storage box and disposed at a position deviated from a drop point of the developer recovered by the recovery means;
An agitator attached to the crankshaft and swinging up and down to move the developer in a direction orthogonal to the axial direction of the crankshaft;
The image forming apparatus, wherein the agitator extends from the drop point through a crankshaft in a direction away from the drop point.