JP2014055988A - Developing device and image forming device including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device formed by enclosing developer in advance, without using an enclosing member for enclosing the developer.SOLUTION: A developer conveying member includes a cylindrical member having an opening formed at one end, an outer spiral blade attached on an outer circumferential surface of the cylindrical member, and an inner spiral blade attached on an inner circumferential surface of the cylindrical member. When the developer conveying member is rotated, developer housed in the cylindrical member is discharged.

Description

  The present invention relates to a developing device and an image forming apparatus including the developing device.

  A developing device used in an image forming apparatus such as a copying machine can eliminate the need for a toner cartridge or reduce the number of times the toner cartridge needs to be replaced by pre-filling a developer in its interior during manufacture. It has been known. In such a developing device, in order to prevent developer leakage at the time of transportation or modification of the developer due to contact with the outside air, a method of sealing the developer by attaching a seal member to the developing device is employed. .

  For example, as illustrated in FIG. 7A, the developing device 5Y described in Patent Document 1 includes a first member 75Y including an inner wall of the first chamber 53Y and a second member including an inner wall of the second chamber 54Y. 76Y. The developing device 5Y includes a second sealing member 73Y for closing the communication port 59Y between the first chamber 53Y and the second chamber 54Y, and a first sealing member for closing the toner supply port 58Y. 74Y is provided, and the developer can be preset in the second chamber 54Y.

  FIG. 7B is a diagram in which the communication port 59Y is closed with the second sealing member 73Y. The second sealing member 73Y includes a frame body 73Y-b in which a communication port 59Y is formed, and a sheet 73Y-a bonded to the frame body so as to cover the communication port 59Y. FIG. 7C is a view after the sheet 73Y-a of the second sealing member 73Y is pulled out. This state is a state in which the developing device 5Y is first used, and the toner conveying screw 55Y conveys the developer in the spiral movement direction of the screw, and the developer can move to the developing roller 51Y from the open communication port 59Y. ing.

  By doing so, it is possible to prevent the developer from coming into contact with the developing roller 51Y during transfer and being damaged.

  By the way, among the members that transport the developer in the developing device by the spiral blade attached to the rotation shaft, such as the toner transport screw 55Y of Patent Document 1, the outer spiral blade provided on the outer peripheral surface of the rotation shaft. In addition, there are those having an inner spiral blade provided on the inner peripheral surface of the rotating shaft.

  For example, in the developing device 102 described in Patent Document 2, as shown in FIG. 8A, the developer tank 111 in which the developer is accommodated and the first and second developer transport paths P and Q are arranged. The first and second developer conveying members 112 and 113 are provided. As shown in FIG. 8B, the first developer conveying member 112 is provided with a cylindrical hollow rotating shaft 112a having both end openings 112k and 112m, and a first developer conveying path. P is divided into an external first developer transport path Po and an internal first developer transport path Pi. Further, an outer spiral blade 112b is provided on the outer peripheral surface of the hollow rotary shaft 112a, and an inner spiral blade 112g is provided on the inner peripheral surface. The inner spiral blade 112g transports the developer in the direction opposite to the developer transport direction of the outer spiral blade 112b in the inner first developer transport path Pi, thereby uniformly stirring the toner concentration in the developing device. Play a role.

JP 2006-23619 A JP2012-22192A

  In the developing device of Patent Document 1, since the sheet 73Y-a closes the communication port 59Y between the first chamber 53Y and the second chamber 54Y, the user holds the sheet 73Y-a before starting to use the developing device. I had to pull it out. Therefore, there are problems that the user may forget to pull out the sheet 73Y-a and that his / her hand gets dirty with the toner adhering to the sheet 73Y-a after being pulled out. Further, when the developing device is removed from the image forming apparatus, the communication port 59Y is not blocked, so that the developer remaining in the developing device leaks out of the developing device.

  Therefore, the present invention eliminates the need for an enclosing member for enclosing the developer in the developing device in which the developer is accommodated in advance, and further suppresses leakage of the developer in the developing device during removal. An object of the present invention is to realize a developing device capable of performing the above.

  The developing device of the present invention is a developing device including a developing tank and a developer conveying member provided in the developing tank. The developer conveying member includes a cylindrical member having an opening at one end, and the cylindrical member. An outer spiral blade attached to the outer peripheral surface and an inner spiral blade attached to the inner peripheral surface of the cylindrical member are provided.

  Further, the developing device of the present invention is a developing device having a first developer transport path and a second developer transport path in a developer tank, wherein the first developer transport path and the second developer transport path are: The central part is separated by a partition parallel to the longitudinal direction of the developing tank, and both end parts communicate with each other. The first developer transport path includes a first developer transport member, and the second developer transport path is A first developer transport member, a first developer transport member and a second developer transport member; a cylindrical member having an opening formed at one end; an outer surface attached to the outer peripheral surface of the cylindrical member; A spiral blade and an inner spiral blade attached to the inner peripheral surface of the cylindrical member, respectively, and the developer transport direction of the outer spiral blade of the first developer transport member and the outer spiral of the second developer transport member The developer transport direction of the blade is reverse.

  According to the present invention, in the developing device in which the developer is sealed in advance, a member for sealing the developer is not necessary, and further, the leakage of the developer in the developing device during the removal is suppressed. It is possible to realize a developing device capable of

1 is a cross-sectional view of an image forming apparatus of the present invention. It is sectional drawing of the longitudinal direction center part of the image development apparatus of this invention. FIG. 3 is a top perspective view of the developing device as viewed from the direction A in FIG. 2. FIG. 3 is a side perspective view of the developing device as viewed from a direction B in FIG. 2. FIG. 3 is a perspective view of a developer conveying member according to the first embodiment of the present invention. FIG. 6 is a perspective view of a developer transport member according to a second embodiment of the present invention. 2 is an explanatory diagram of a developing device described in Patent Document 1. FIG. 10 is an explanatory diagram of a developing device described in Patent Document 2. FIG.

(First embodiment)
<Overall configuration of image forming apparatus>
FIG. 1 is an explanatory diagram showing the overall configuration of an image forming apparatus 200 according to an embodiment of the present invention.

  The image forming apparatus 200 includes members corresponding to black, cyan, magenta, and yellow colors, respectively. Since the structure of these members is the same regardless of the color, k, c, m, and y are respectively added to the end of the reference numerals, and the members common to the four colors are described as k to y.

  The image forming apparatus 200 includes an exposure device 201 that forms an electrostatic latent image on the surface of the photosensitive drum, and developing devices 202k to y. The developing devices 202k to y remove the photosensitive drums 203k to y, charging devices 205k to y for charging the surface of the photosensitive drum, and residual developer remaining on the surface of the photosensitive drum after development and image transfer, respectively. Cleaner units 204k to y are provided.

  The transfer device 208 of the image forming apparatus 200 includes an intermediate transfer belt 207 disposed above the photosensitive drums 203k to 203y, a driving roller 271 for stretching the intermediate transfer belt 207 and rotating it in the direction of arrow C, and The driven roller 272, the intermediate transfer rollers 206k to 206y for transferring the toner images on the surfaces of the photosensitive drums 203k to y to the intermediate transfer belt 207, and the drive roller 271 are disposed in close proximity to each other, and are arranged on the surface of the intermediate transfer belt 207. A transfer roller 211 is provided for transferring the toner image to the recording medium.

  A recording medium such as paper is stored in the paper feed tray 210, and the recording medium on which an image is formed through the sheet conveyance path S and the transfer roller 211 and the fixing device 212 is discharged to the paper discharge tray 215.

Further, the image forming apparatus 200 includes developer replenishing devices 209k to y that individually replenish the developing devices 202k to y with a developer. When the developer replenishing devices 209k-y are mounted on the image forming apparatus 200, a developer discharge member in the developer replenishing devices 209k-y is driven by a drive motor (not shown) and a drive motor control device (not shown). (Not shown) is driven to rotate in reverse for a predetermined time of, for example, 10 seconds, and the developer in the developer replenishing devices 209k to 209y is disengaged.
<Developing device>
FIG. 2 is a cross-sectional view of a substantially central portion in the longitudinal direction of the developing device 202. As shown in FIG. 2, the developing device 202 includes a developing tank 253 that stores a developer. The developing tank 253 has a removable developing tank cover 254 constituting the upper wall. A developer replenishing port 255 for replenishing unused developer is formed on a part of the developer tank cover 254 on the upstream side of the first developer transport path 300a in the developer transport direction. In this embodiment, a two-component developer including toner and a magnetic carrier is used, but the present invention is not limited to this, and a one-component developer may be used.

  The developer tank 253 is roughly divided into two spaces by a partition wall 251 extending in the longitudinal direction of the developer tank 253, and the developer supply port 255 side is separated from the first developer transport path 300a and the developer supply port 255. The other side is a second developer conveyance path 300b. The first developer transport path 300a and the second developer transport path 300b are each configured by a semi-cylindrical inner wall surface.

  Further, a developing roller 256 is provided in the developing tank 253. The developing roller 256 is a magnet roller that is rotationally driven in a direction indicated by an arrow M by a driving unit (not shown). When a developing bias voltage is applied from a power source (not shown), the developer on the surface of the developing roller 256 is shown in FIG. Developer is supplied to the electrostatic latent image on the surface of the photosensitive drum 203. Of the developer supplied to the photosensitive drum 203, the unused developer is peeled off from the surface of the developing roller 256 and then falls into the second developer conveying path 300b. A member that guides the developer may be attached so that the developer peeled from the surface of the developing roller 256 falls into the first developer transport path 300a.

  A doctor blade 257 is provided below the developing roller 256. The doctor blade 257 is a rectangular plate-like member extending in parallel to the axial direction of the developing roller 256, and a lower end thereof is fixed to the developing tank 253, and an upper end thereof is separated from the surface of the developing roller 256 with a predetermined gap. doing. By this doctor blade 257, a uniform developer layer is obtained on the surface of the developing roller 256. Examples of the material of the doctor blade 257 include stainless steel, aluminum, and synthetic resin.

  Further, a developer concentration detection sensor 258 is provided at a lower portion of a substantially central portion in the longitudinal direction of the second developer conveyance path 300b, and the sensor surface is exposed inside the second developer conveyance path 300b. Yes. The developer concentration detection sensor 258 is electrically connected to developer concentration control means (not shown). The developer concentration control means rotates the developer discharge member of the developer supply device 209 in accordance with the measured developer concentration value detected by the developer concentration detection sensor 258, discharges the developer, and discharges the developer. Control is performed so that the toner is supplied into the first developer conveyance path 300a. If the developer concentration control means determines that the measured developer concentration is lower than the developer concentration setting value, a control signal is transmitted to the drive means for driving the developer discharge member to rotate, and the developer discharge member rotates. To do. As the developer concentration detection sensor 258, for example, a general developer concentration detection sensor such as a transmitted light detection sensor, a reflected light detection sensor, or a magnetic permeability detection sensor can be used.

  3 is a top perspective view of the developing device as viewed from the direction A in FIG. As shown in FIG. 3, the first developer transport path 300a and the second developer transport path 300b communicate with each other by the first communication path 264 and the second communication path 265 on both ends in the longitudinal direction of the developing tank 253, An annular developer conveyance path is formed.

In order to convey the developer inside the developing tank 253, the first developer conveying member 311a is provided in the first developer conveying path 300a, and the second developer conveying member 311b is provided in the second developer conveying path 300b. Is rotatably provided.
<First developer conveying member>
FIG. 4 is a side perspective view of the developing device as seen from the direction B in FIG. As shown in FIG. 4, the first developer conveying member 311a includes a cylindrical member 312a and an outer spiral blade 317a fixed to the outer peripheral surface thereof. Further, as shown in the perspective view of FIG. 5, the first developer conveying member 311a includes an inner spiral blade 318a fixed to the inner peripheral surface of the cylindrical member 312a and both ends of the axial center of the cylindrical member 312a. A rotation shaft 313a and a rotation shaft 314a provided, and a gear 316a provided at one end of the rotation shaft 314a are provided. The cylindrical member 312a, the outer spiral blade 317a, and the inner spiral blade 318a are integrally rotated by the gear 316a.

  The cylindrical member 312a is a bottomed cylindrical hollow member that accommodates the developer therein, and an opening 315a is formed at the end of the outer peripheral surface.

  The outer spiral blade 317a includes a normal spiral blade 319a and a reverse spiral blade 320a, and the reverse spiral blade 320a is provided on the opening 315a side. The reverse spiral blade 320a is attached with a spiral in the opposite direction to the normal spiral blade 319a. By the reverse spiral blade 320a, the developer transported by the forward spiral blade 319a can travel toward the second developer transport path 300b through the first communication path 264 without staying on the wall surface at the end in the transport direction. it can.

  The spiral direction of the inner spiral blade 318a is formed in the same direction as that of the regular spiral blade 319a, and the first developer conveying member 311a is driven by a driving unit (not shown) via the gear 316a. 3-5, when the gear 316a rotates in the arrow J direction, the developer in the first developer transport path 300a is transported in the X direction in FIG. 5, and the developer in the cylindrical member 312a is transported in the arrow X direction. Are conveyed in the direction of arrow X ′, which is the same direction as.

In addition, the magnitude | size of the spiral of the outer spiral blade | wing 317a and the inner spiral blade | wing 318a, a width | variety, a pitch, etc. are not specifically limited.
<Second developer conveying member>
Since the structure of the second developer conveying member 311b is the same as that of the first developer conveying member 311a, the part corresponding to the first developer conveying member 311a will be described with “a” at the end of the symbol as “b”.

As shown in FIG. 3, the second developer conveying member 311b is attached so that the opening 315b is in the opposite position with respect to the first developer conveying member 311a. When the inner spiral blade 318b of the second developer conveying member 311b is driven by a driving means (not shown) via the gear 316b and rotates in the direction of arrow K, as shown in FIG. 3, the inner spiral blade 318b in the second developer conveying path 300b. The developer is conveyed in the arrow Y direction.
<Developer discharge / accommodation operation>
Here, an operation when starting to use the new developing device 202 will be described.

  In the developing device 202, the developer is sealed in advance inside the cylindrical member 312a and the cylindrical member 312b.

  In order to prevent the developer from leaking from the opening 315a and the opening 315b when the developing device is transported, the opening 315a and the opening 315b may be oriented upward in the vertical direction. Furthermore, in order to reliably prevent the developer from leaking, if the encapsulated developer is a one-component developer composed of a magnetic toner or a two-component developer composed of a toner and a magnetic carrier, Magnets (not shown) may be detachably provided on the outer peripheral surface of the developing tank 253 in the vicinity of the portion 315b and the opening 315b. By doing so, the developer in the vicinity of the opening 315a and the opening 315b can be hardened by the magnetic field of the magnet, so that this acts as a lid, and leakage of the developer can be prevented. Then, when the use of the developing device 202 is started, the magnet may be removed. These magnets are members attached to the developing device before the use of the image forming apparatus is started. However, these magnets may be installed in the image forming apparatus before the use of the image forming apparatus is started. You may affix on the packing material which packs an apparatus.

  When starting to use the new developing device 202, as shown in FIG. 3, the first developer conveying member 311a is rotated in the arrow J direction and the second developer conveying member 311b in the arrow K direction for a predetermined time. . As a result, the developer enclosed in the cylindrical member 312a moves in the direction of the arrow X 'and is sequentially discharged from the opening 315a to the first developer conveyance path 300a. Similarly, the developer enclosed in the cylindrical member 312b moves in the direction of arrow Y, and is sequentially discharged from the opening 315b to the first developer conveyance path 300a.

  By doing in this way, even in a form in which the developer is sealed in the developing device 202 in advance, an encapsulating member such as a sealing material becomes unnecessary, so there is no need to remove the sealing material, forgetting to remove the sealing material, It is possible to prevent dirt on the hands when removing.

  While the developing device 202 is in use, the developer replenishing device 209 sequentially replenishes the developing device 202 with developer, and the developer is supplied to the outer spiral blade 317a of the first developer conveying member 311a and the second developer conveying member 311b. The developer is supplied to the developing roller 256 while being circulated through the first developer conveying path 300a and the second developer conveying path 300b by the outer spiral blade 317b.

  Next, an operation when removing the developing device 202 will be described.

Before the developing device 202 is removed, the developing device 202 is rotated in the direction opposite to that when the first developer conveying member 311a and the second developer conveying member 311b are attached. That is, in FIG. 3, the first developer conveying member 311a is rotated in the direction of arrow J ′ and the second developer conveying member 311b is rotated in the direction of arrow K ′ for a predetermined time. By doing so, the developer present in the first developer transport path 300a is collected inside the cylindrical member 312a by the inner spiral blade 318a. Similarly, the developer present in the second developer conveyance path 300b is collected inside the cylindrical member 312b by the inner spiral blade 318b. Therefore, most of the developer present in the developing tank 253 can be collected in the cylindrical member 312a and the cylindrical member 312b, so that the developing device 202 develops when the developing device 202 is detached from the image forming apparatus 200. The leakage of the agent can be suppressed.
(Second Embodiment)
FIG. 6 is a side perspective view of the first developer conveying member 411a according to the second embodiment. Since the difference from the first developer conveying member 311a in the first embodiment is only the difference in the direction of the inner spiral blade 418a and the position of the opening 415a, the description of the common parts is omitted.

  The inner spiral blade 418a in the second embodiment is provided in the direction opposite to the normal spiral blade 319a. Therefore, when the first developer conveying member 411a is rotated in the direction of arrow J, the regular spiral blade 319a conveys the developer outside the cylindrical member 312a in the X direction. On the other hand, the inner spiral blade 418a conveys the developer inside the cylindrical member 312a in the X ′ direction opposite to the X direction in FIG. 6 and discharges the developer from the opening 415a.

  Similarly, when the first developer conveying member 411a is rotated in the direction of arrow J ′, the normal spiral blade 319a conveys the developer outside the cylindrical member 312a in the X ′ direction of FIG. 6, and the inner spiral blade 418a is opened. The developer near the portion 415a is conveyed in the X direction in FIG. 6 toward the inside of the cylindrical member 312a. That is, since the developer conveyance direction is opposed to the inside and the outside of the cylindrical member 312a, the developer conveyed by the regular spiral blade 319a can be quickly accommodated inside the cylindrical member 312a. Therefore, the developer can be prevented from leaking from the developing device when the developing device is detached. In addition, as in the first embodiment, since an encapsulating member such as a sealing material is unnecessary, there is no need to remove the sealing material at the start of use, and it is possible to prevent contamination of the hand when removing the sealing material. Can do.

  As described above, in the first and second embodiments, the developing device having two developer transport paths and two developer transport members has been described. However, the present invention is not limited thereto, and the developer transport path and the developer transport are not limited thereto. A developing device having one member at a time may be used.

200 Image forming apparatus 201 Exposure apparatus 202 (202 k to y) Developing apparatus 203 (203 k to y) Photosensitive drum 204 (204 k to y) Cleaner unit 205 (205 k to y) Charging apparatus 206 (206 k to y) Intermediate transfer roller 207 Intermediate transfer belt 208 Transfer device 209 (209 k to y) Developer supply device 210 Paper feed tray 211 Transfer roller 212 Fixing device 215 Paper discharge tray 251 Partition 253 Developer tank 254 Developer tank cover 255 Developer supply port 256 Developer roller 257 Doctor blade 258 Developer concentration detection sensor 264 First communication path 265 Second communication path 271 Drive roller 272 Driven roller 300a First developer transport path 300b Second developer transport path 311a First developer transport member 311b Second developer transport member 312a, 312b Cylindrical member 313a, 313b, 314a, 314b Rotating shaft 315a, 315b Opening 316a, 316b Gear 317a, 317b Outer spiral blade 318a, 318b Inner spiral blade 319a, 319b Normal spiral blade 320a, 320b Reverse spiral blade 411a First developer Conveying member 415a Opening 418a Inner spiral blade

Claims (7)

In a developing device including a developing tank and a developer conveying member provided in the developing tank,
The developer conveying member includes a cylindrical member having an opening formed at one end, an outer spiral blade attached to the outer peripheral surface of the cylindrical member, and an inner spiral blade attached to the inner peripheral surface of the cylindrical member. A developing device. The developer housed inside the cylindrical member is
The developing device according to claim 1, wherein the developer conveying member is discharged from the opening by the inner spiral blade by rotating the developer conveying member in a predetermined direction. The developer inside the developing tank is
The developing device according to claim 2, wherein the developer conveying member is accommodated in the cylindrical member by the inner spiral blade by rotating the developer conveying member in a direction opposite to the predetermined direction. The outer spiral blade is
A regular spiral blade attached to a portion excluding one end of the cylindrical member; and
The developing device according to claim 1, comprising a reverse spiral blade attached to one end of the cylindrical member and having a spiral opposite to the normal spiral blade. In the developing device having the first developer transport path and the second developer transport path in the developing tank,
The first developer transport path and the second developer transport path are separated from each other by a partition parallel to the longitudinal direction of the developing tank, and both ends are in communication with each other.
The first developer transport path includes a first developer transport member,
The second developer transport path includes a second developer transport member,
The first developer conveying member and the second developer conveying member include a cylindrical member having an opening at one end, an outer spiral blade attached to an outer peripheral surface of the cylindrical member, and an inner portion of the cylindrical member. Each has an inner spiral blade attached to the peripheral surface,
The developing device, wherein the developer conveying direction of the outer spiral blade of the first developer conveying member and the developer conveying direction of the outer spiral blade of the second developer conveying member are opposite to each other. . The developer is a one-component magnetic developer or a two-component developer,
The developing device according to claim 1, wherein a magnet is detachably provided near the opening of the developing device.   An image forming apparatus comprising the developing device according to claim 1.