JP4403740B2 - Image forming apparatus, supply member used therefor, and developing device - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, or a composite machine using an electrophotographic method, a supply member used for the image forming apparatus, and a developing device.

  2. Description of the Related Art Conventionally, in a developing device used in an image forming apparatus such as a copying machine, a printer, a facsimile, or a composite machine to which this type of electrophotographic method is applied, a developing device filled with a developer (consisting of toner and a magnetic carrier). The developing device is disposed opposite to the photosensitive drum, the toner is ejected onto the surface of the photosensitive drum, and the electrostatic latent image is visualized with the toner, thereby forming an image.

  For example, in the developing device 200 shown in FIG. 21, a magnet roll 203 and two spiral augers 202 and 204 are rotatably supported on the developing device main body 201, and the two spiral augers 202 and 204 are rotated in the opposite directions. (Japanese Patent Application No. 2002-145661 previously proposed by the present applicant).

  A partition wall 206 is formed in the developing device main body 201 along the longitudinal direction of the developing device main body 201, and the inside of the developing device main body 201 is partitioned into a space 208 and a space 210. A spiral auger 202 is disposed in the space 208, and a spiral auger 204 is disposed in the space 210. In addition, circulation ports 212 are provided at both ends of the developing device main body 201 so that the space 208 and the space 210 communicate with each other.

  A developer inlet 214 to which a developer is supplied is provided on the space 210 side, and the developer that has entered the space 210 from the developer inlet 214 is conveyed in the space 210 by the spiral auger 204 and is supplied to the circulation port. After being guided to the space 208 via 212, this time it is conveyed by the spiral auger 202 and the developer is supplied to the magnet roll 203.

  Here, in the case of the spiral auger 202, the developer is efficiently conveyed on the conveying surface 216A side of the spiral blade 216 formed in a spiral shape (conveyed in the direction of the arrow), whereas the developer in the spiral blade 216 of the spiral auger 204 is. Is rotated from the opposite conveying surface 216B side of the spiral blade 216 to the conveying surface 216A side by the rotation of the spiral auger 202, and is conveyed as the developer moves from the conveying surface 216A of the spiral blade 216 to the opposite conveying surface 216B. The amount of will gradually decrease.

  For this reason, in the developer layer formed on the magnet roll 203, a dense portion and a sparse portion of the developer are generated in a spiral shape, and oblique white stripes (density unevenness) are generated on the print. End up. As described above, when density unevenness occurs, erroneous detection occurs when measuring the patch density on the photosensitive drum.

On the other hand, in order to eliminate density unevenness, in Patent Document 1, a spiral-shaped supply member is formed on the axial center portion of a cylindrical body in which spiral protrusions are formed on the outer peripheral surface and openings are intermittently formed on the outer peripheral surface. Is arranged. In Patent Documents 2 and 3, a paddle projects from the outer peripheral surface of the rotating shaft in the radial direction. In Patent Document 4, a supply member configured by multiple spirals is used.
JP 2001-042615 A JP 2001-222154 A Japanese Unexamined Patent Publication No. 07-013420 Japanese Patent Application Laid-Open No. 09-197782

  However, these refer to the difference in the developer amount between the conveying surface side and the non-conveying surface side of the spiral blade, and by reducing the amount of developer between the conveying surface side and the counter-conveying surface side, the developer carrying It does not mean that the developer is uniformly supplied onto the body.

  In consideration of the above-described facts, the present invention reduces the amount of developer on the transport surface side and the counter-transport surface side of the spiral blade, efficiently transports the developer, and reduces density unevenness and It is an object of the present invention to provide a supply member and a developing device used for this.

The invention according to claim 1, 9, bridged parallel to the blade member and the rotary shaft to between anti transport surface facing the conveying surface and the conveying surface of the spiral blade to transport the current image agent, the vane The member is divided at an arbitrary position in the length direction along the axial direction of the rotating shaft to provide a gap . When the blade member is viewed from the side, the tip of the blade member is directed from the outer surface toward the inner surface. It is characterized by being cut at an acute angle .

In the first and ninth aspects of the invention, the outer periphery of the rotating shaft is formed by bridging the blade member in parallel with the rotating shaft between the conveying surface of the spiral blade that conveys the developer and the opposite conveying surface facing the conveying surface. A space is generated between the surface and the inner surface of the blade member.

  Conventionally, the developer conveyed by the conveying surface of the spiral blade is present in a large amount at the position of the conveying surface and present in a small amount at the position of the counter-conveying surface. However, by providing a space between the outer peripheral surface of the rotating shaft and the inner surface of the blade member, the developer is poured into the space, the amount of developer on the conveying surface side is restricted, and the developer is supplied to the blade member. Therefore, the difference in the amount of developer can be reduced between the conveyance surface side and the non-conveyance surface side.

  As a result, the difference in the amount of developer supplied to the developer-carrying member between the spiral blade conveyance surface side and the counter-conveyance surface side can be reduced.

Here, the blade member is bridged between the conveyance surface side and the non-conveyance surface side of the spiral blade, and the blade member is divided at an arbitrary position in the length direction along the axial direction of the rotation shaft, thereby supplying the supply member Can be prevented from being warped due to thermal shrinkage after molding.
Further, the rotation of the supply member can make it easier to guide the developer into the space provided between the rotation shaft and the blade member, and the transportability of the developer in the axial direction can be improved.
Furthermore, when the blade member is viewed from the side, the tip of the blade member is cut at an acute angle from the outer surface toward the inner surface, so that the development is performed in the space provided between the rotating shaft and the blade member by the rotation of the spiral blade. The developer can be easily guided, and the transportability of the developer in the axial direction can be improved.

Accordingly, the developer can be supplied uniformly onto the developer carrying member, and the developer layer formed on the developer carrying member can be made uniform. As a result, it is possible to prevent the occurrence of oblique white streaks (density unevenness) and obtain a good image.
According to a second aspect of the present invention, a blade member is bridged in parallel with the rotation shaft between a conveying surface of the spiral blade that conveys the developer and an opposite conveying surface that faces the conveying surface, and the blade member However, it is divided at an arbitrary position in the length direction along the axial direction of the rotation shaft, a gap is provided, and the side surface on the rotation direction side of the blade member is moved from the conveyance surface side to the counter conveyance surface side. It is characterized by a downward slope .
According to the second and tenth aspects of the present invention, the developer held on the side surface of the blade member is caused to flow from the conveyance surface side where the developer is densely present to the opposite conveyance surface side by the rotation of the spiral blade, The amount of developer supplied to the developer carrying member can be made more uniform in the axial direction of the rotating shaft.
According to a third aspect of the present invention, a blade member is bridged in parallel with the rotary shaft between a conveying surface of the spiral blade that conveys the developer and an opposite conveying surface that faces the conveying surface. However, the blade member is divided at an arbitrary position in the length direction along the axial direction of the rotary shaft, a gap is provided, and the blade member is cut along a plane orthogonal to the rotary shaft. It is characterized in that the rotation direction side of is thin.
According to the third and eleventh aspects of the present invention, since the area of the side surface of the blade member becomes smaller as going from the counter-conveying surface side to the conveying surface side, the amount of developer on the side surface of the blade member is limited. As a result, the supply amount of the developer to the developer carrier by the blade member can be regulated.
According to a fourth aspect of the present invention, a blade member is bridged between the conveying surface of the spiral blade that conveys the developer and a counter-conveying surface that faces the conveying surface in parallel with the rotation shaft, and the blade member However, it is divided at an arbitrary position in the length direction along the axial direction of the rotation shaft to provide a gap, and the gap is wide on the side toward the rotation direction when the blade member is viewed in plan view. It is characterized by that.
In the invention according to claims 4 and 12, the space provided between the rotating shaft and the blade member by widening the gap toward the rotating direction of the rotating shaft when the blade member is viewed in plan. The developer can be more easily guided into the inside. Accordingly, the developer is further poured into the space, and the transportability of the developer in the axial direction can be further improved.
In the invention described in claims 7 and 15, the blade member that bridges between the conveying surface of the spiral blade that conveys the developer and the opposite conveying surface that faces the conveying surface faces each other with the rotating shaft in between. And a slit is formed on the conveying surface side of one of the blade members, a gap is provided between the blade member and the conveying surface, and a slit is formed on the opposite conveying surface side of the other blade member. A gap is provided between the blade member and the non-conveying surface.
According to the seventh and fifteenth aspects of the present invention, the developer supplied to the developer carrier by the blade member is sparse in the gap portion, but according to this configuration, the facing blade members are mutually connected. Can complement each other. For this reason, in the supply to the developer carrying member by the blade member, the supply amount of the developer can be made substantially constant in the length direction of the blade member, and a better image can be obtained.

The present invention, since the above-described configuration, the conveying surface of the scan Pairaru blades and the counter-conveying surface side, it is possible to reduce the difference in the amount of the developer, it is possible to place the developer blade member The developer can be supplied to the developer carrying member also by the blade member. Further, the developer can be supplied uniformly onto the developer carrying member, and the developer layer formed on the developer carrying member can be made uniform. Therefore, it is possible to prevent the occurrence of oblique white streaks (density unevenness) and obtain a good image.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an outline of an image forming apparatus 10 according to an embodiment of the present invention. The image forming apparatus 10 includes an image forming apparatus main body 12, and a paper feeding unit 14 is provided below the image forming apparatus main body 12.

  The paper feed unit 14 includes a paper tray 22 on which paper is stacked and a paper feed roll 24 that sends out the paper from the paper tray 22, and the paper delivered by the paper feed roll 24 is transported by a transport roll. The paper passes through the paper feed path 30 through the paper 26 and 28, and is conveyed to a transfer roll 74 described later.

  After the toner image is transferred to the paper by the transfer roll 74 and fixed by the fixing roll 32, the toner image is provided on the upper portion of the image forming apparatus main body 12 by the discharge roll 36 or the discharge roll 38 depending on the position of the switching claw 34. The paper is discharged to the first discharge tray 16 or the second discharge tray 18.

  Here, in the case of double-sided printing, after the printing of the front surface is completed in the above-described order, before the paper is discharged to the first discharge tray 16, the discharge roll 36 is reversed, and the paper is turned to the reverse path 40. Supplied to. The paper is then returned to the paper feed path 30 through the transport rolls 42, 44, 46, and 48, and the back side of the paper is printed. In the case of manual printing, by placing paper on the manual feed tray 20, the paper is transported from the manual feed roll 49 to the paper feed path 30 via the transport roll 48 and printed.

  On the right side of FIG. 1 of the image forming apparatus 10, four developer cartridges 64 filled with a developer (consisting of toner and magnetic carrier) for each color are arranged. The developer cartridge 64 is connected to a later-described developing device 60 through a developer supply path (not shown), and the developer in the developer cartridge 64 is supplied to the developing device 60.

  An exposure unit 62 is disposed on the left side of the developer cartridge 64 in FIG. 1, and four laser beams corresponding to image signals from the exposure unit 62 are disposed on the left side in FIG. 1 of the exposure unit 62. It is emitted toward the photosensitive member 52 constituting the body unit 50 and forms a latent image on the photosensitive member 52.

  The photoconductor unit 50 includes four photoconductors 52 (52Y, 52M, 52K, and 52C) arranged in the vertical direction. From the top, for example, yellow (52Y), magenta (52M), black (52K), and cyan. (52C).

  The photoconductor unit 50 includes a charging roll 56 and a refresh roll 54 corresponding to each photoconductor 52, and is provided so as to rotate in contact with the photoconductor 52. In the charging roll 56, the photosensitive member 52 is uniformly charged, and toner flying from a magnet roll 80 provided in the developing unit 58 described later is attached to the surface of the photosensitive member 52. On the other hand, the refresh roll 54 discharges the photosensitive member 52 to remove residual toner adhering to the surface of the photosensitive member 52, thereby preventing ghosts and the like caused by the toner remaining on the surface of the photosensitive member 52.

  Here, the developing unit 58 is arranged on the lower right side of the photosensitive unit 50 in FIG. 1 and corresponds to the four developing units 60 (60Y, 60Y, 52C) corresponding to the photosensitive units 52 (52Y, 52M, 52K, 52C). 60M, 60K, 60C) are arranged in the vertical direction.

  The developing device 60 is in a trickle developing system (in order to prevent the charging performance of the developer from being lowered and to extend the interval for changing the developer, the developer is gradually replenished in the developing device, but becomes excessive ( This is a developing system in which development is performed while discharging a deteriorated developer (which contains a lot of deteriorated carriers), and the deteriorated developer is collected in a collection container (not shown).

  On the other hand, an intermediate transfer unit 66 is arranged on the left side of the photoconductor unit 50 in FIG. 1, and three drum-shaped intermediate transfer bodies 68, 70, and 72 are provided. The two first intermediate transfer members 68 and 70 are arranged vertically in the vertical direction, and the upper first intermediate transfer member 68 is arranged on the two photoconductors 52Y and 52M arranged at the upper portion of the photoconductor 52. The lower first intermediate transfer member 70 rotates in contact with the two photoconductors 52K and 52C disposed in the lower portion. Further, the second intermediate transfer member 72 is rotated in contact with both the first intermediate transfer members 68 and 70, and the transfer roll 74 described above is rotated in contact with the second intermediate transfer member 72.

  Accordingly, the toner images are transferred from the photoconductors 52Y and 52M to the first intermediate transfer body 68, and the toner images are transferred from the photoconductors 52K and 52C to the first intermediate transfer body 70, respectively. The two color toner images transferred to the first intermediate transfer bodies 68 and 70 are transferred to the second intermediate transfer body 72 to form four colors, and the four color toner images are transferred onto the sheet by the transfer roll 74. Will be.

  A cleaning roll 76 and a cleaning brush 78 are disposed in the vicinity of the intermediate transfer members 68, 70, and 72, respectively, and the residual toner on the surface of the intermediate transfer members 68, 70, and 72 is scraped off.

  Next, details of the developing unit will be described.

  As shown in FIGS. 2 and 3, the developing device unit 58 includes four developing devices 60, and the developing device main body 110 of each developing device 60 includes a magnet roll 80 that supplies toner to the photosensitive member 52, and Two spiral augers 112 and 114 that transport the developer in the developing device 60 and supply the developer to the magnet roll 80 are rotatably supported.

  Each developing device 60 can move between a position where the magnet roll 80 abuts on the photoconductor 52 and a position where the magnet roll 80 is retracted from the photoconductor 52, and the magnet roll 80 contacts the photoconductor 52 during image formation. It comes to touch. As a result, toner adheres to the photoconductor 52 corresponding to the latent image formed on the photoconductor 52. However, when image formation is not performed, the developing unit 58 is retracted from the photoconductor 52. It is supposed to be.

  Specifically, the developing device unit main body 82 constituting the developing device unit 58 is provided with a rail member 84, and a movable piece 86 is supported on the rail member 84 so as to be movable up and down. A cam 88 is in contact with the lower end of the movable piece 86, and the cam 88 is connected to the developing device moving motor 90.

  Further, a drive member 92 is disposed between the movable piece 86 and the developing device 60, and this drive member 92 is rotatably supported with respect to the rail member 84 around the fulcrum pin 94. Yes. One end of the drive member 92 is provided with a pressing pin 96 that can be protruded by the first pressing spring 98, and the pressing pin 96 contacts the developing device 60.

  Further, the rotation pin 100 provided at the other end of the drive member 92 is fitted in the receiving groove 102 formed in the movable piece 86, and when the movable piece 86 is lowered, the drive member 92 is rotated clockwise. It rotates and moves away from the developing device 60.

  As shown in FIGS. 3 and 4, sliding pins 104 are provided on both sides of the developing device 60, and the sliding pins 104 are formed in sliding grooves 106 provided in the developing device unit main body 82. It is slidably inserted. On the other hand, the developing device unit main body 82 is provided with a second pressing spring 108 that presses the sliding pin 104 in a direction in which the developing device 60 moves away from the photosensitive member 52.

  Therefore, when the developing device moving motor 90 is driven from the state of FIG. 3 and the movable piece 86 is lowered, the driving member 92 rotates clockwise with the fulcrum pin 94 as a fulcrum, and the first pressing spring 98 presses the pressing pin 96. However, the pressing force that presses the developing device 60 is weakened, the pressing force of the second pressing spring 108 overcomes the pressing force of the first pressing spring 98, and the developing device 60 moves away from the photoconductor 52.

  With the above configuration, for example, in the cleaning cycle, toner is prevented from adhering to the photosensitive member 52 and color mixing is prevented. When the developing unit 58 is replaced, the photosensitive member 52 and the magnet roll are replaced. The occurrence of scratches due to contact with 80 can be prevented.

  Next, the main part of the developing device constituting the image forming apparatus according to the first embodiment of the present invention will be described.

  As shown in FIGS. 2 and 5, a magnet roll 80 and two spiral augers 112 and 114 are rotatably supported on the developing device main body 110 of the developing device 60. The spiral auger 114 rotates in opposite directions.

  Further, the developing device main body 110 is provided with a partition wall 113 along the longitudinal direction of the developing device main body 110, and the inside of the developing device main body 110 is divided into spaces 115 and 117. A spiral auger 112 is disposed in the space 115, and a spiral auger 114 is disposed in the space 117, and the developer is conveyed in the direction of the arrow by the spiral augers 112 and 114.

  Further, circulation ports 116 are provided at both ends of the developing device main body 110, and the space 115 and the space 117 are communicated with each other. Further, a developer inlet 118 to which a developer is supplied is provided on the space 117 side of the developing device main body 110, and the developer is supplied from the developer inlet 118. The supplied developer is transported in the space 117 by the spiral auger 112, guided to the space 115 through the circulation port 116, and then transported by the spiral auger 112, and the developer is supplied to the magnet roll 80. Is done.

  On the other hand, a discharge unit 122 is provided on the space 115 side of the developing device main body 110. A developer recovery container (not shown) is connected to the discharge unit 122, and the deteriorated developer is discharged from the discharge unit 122. It collects in the collection container.

Here, the spiral auger 112 according to the implementation embodiments of the present invention will be described in detail. In addition, after demonstrating the reference example relevant to embodiment of this invention, embodiment of this invention is described.

  As shown in FIGS. 5 and 6, the spiral auger 112 includes a rotation shaft 124 and a spiral blade 126 formed around the rotation shaft 124 in a spiral shape. As shown in FIGS. 7A and 7B, on the outer periphery of the spiral blade 126, the blade member 128 is placed between the conveying surface 126A and the counter-conveying surface 126B of the spiral blade 126 in parallel with the rotating shaft 124. Handing over. That is, the outer peripheral part of the spiral blade 126 and the outer surface of the blade member 128 are provided in the same plane in a state in which a plurality of blade members 128 are connected in parallel with the rotation shaft 124.

  As shown in FIG. 8B, the width of the blade member 128 is increased from the counter-transport surface 126B side to the transport surface 126A side, and in the rotation direction of the rotary shaft 124 (arrow A direction). In a state in which the side surface 128A of the blade member 128 located on the opposite side is faced up, a downward slope is formed from the transport surface 126A side to the counter-transport surface 126B side.

  Further, as shown in FIGS. 9A, 9B, and 10, the width of the side surface 128A of the blade member 128 is made narrower from the counter-transport surface 126B side to the transport surface side 126A. The thickness of the member 128 is set so that the rotation direction side of the rotating shaft 124 is thin. Further, the maximum width W of the blade member 128 is an arc of 35 ° or less with the rotation shaft 124 as the center.

  Further, as shown in FIG. 8A, in the relationship between the rotating shaft 124 and the blade member 128, 1 ≦ (distance h from the rotating shaft 124 to the inner surface of the blade member 128) / thickness t ≦ 3. 5 is satisfied.

Next, the operation of the image forming apparatus according to the reference example will be described.

  As shown in FIG. 8A, by providing the spiral auger 112 with a blade member 128 parallel to the rotation shaft 124, a space 120 is created between the outer peripheral surface of the rotation shaft 124 and the inner surface of the blade member 128. It will be.

  Conventionally, the developer conveyed by the conveying surface 126A of the spiral blade 126 is present in a large amount at the position of the conveying surface 126A and is present in a small amount at the position of the anti-conveying surface 126B.

  However, by providing the space 120 between the outer peripheral surface of the rotating shaft 124 and the inner surface of the blade member 128, the developer is poured into the space 120, the amount of the developer on the conveying surface side 126A is regulated, and the blade Since the developer can be placed on the member 128, the difference in the amount of the developer can be reduced between the transport surface side 126A and the non-transport surface side 126B.

  Thereby, the difference in the amount of developer supplied to the magnet roll 80 at the locations on the transport surface 126A side and the counter-transport surface 126B side of the spiral blade 126 can be reduced.

  Here, the blade member 128 spans the conveying surface 126A side and the counter-conveying surface 126B side of the spiral blade 126, and the blade member 128 is provided on the outer peripheral portion of the spiral blade 126 so that the blade member 128 is transported. It is not divided by 126A or the counter-transport surface 126B, and is provided in a continuous state in the axial direction of the spiral auger 112.

  For this reason, the developer on the blade member 128 moves as a whole along the conveying direction of the spiral auger 112, and the amount of developer on the conveying surface 126A side and the opposite conveying surface 126B side of the spiral blade 126 is increased. There will be no big difference.

  Therefore, the developer can be uniformly supplied onto the magnet roll 80 (see FIG. 5), and the developer layer formed on the magnet roll 80 can be made uniform. Therefore, it is possible to prevent the occurrence of oblique white streaks (density unevenness) and obtain a good image.

  Further, as shown in FIG. 10, the side surface 128A of the blade member 128 positioned on the side of the rotating shaft 124 in the rotational direction is set to have a downward slope from the conveying surface 126A side to the counter-conveying surface 126B side. By the rotation of 112, the developer held on the side surface of the blade member 128 is caused to flow from the conveyance surface 126A side where the developer is densely present to the opposite conveyance surface 126B side, and the developer is applied to the magnet roll 80 by the blade member 128. The supply amount can be made more uniform in the axial direction of the rotating shaft 124.

  Further, as shown in FIGS. 9A, 9B, and 10, the width of the side surface 128A of the blade member 128 is made narrower from the counter-transport surface 126B side to the transport surface side 126A. The thickness of the member 128 is set so that the rotation direction side of the rotating shaft 124 is thin.

  As a result, the area of the side surface 128A of the blade member 128 becomes smaller as going from the counter-transport surface 126B side to the transport surface side 126A. For this reason, the amount of the developer that gets on the side surface 128A of the blade member 128 is limited, and the supply amount of the developer to the magnet roll 80 by the blade member 128 can be regulated.

  Further, by reducing the thickness of the blade member 128 toward the rotation direction of the rotating shaft 124, the blade member 128 can be gently submerged when the blade member 128 sinks into the developer.

  For this reason, the blade member 128 sinks into the developer, so that the developer around the blade member 128 is not affected, and the surface of the magnet roll 80 is affected by the impact when the blade member 128 sinks into the developer. There is no fear that the developer that peels off and returns to the spiral auger 112 side returns to the magnet roll 80 side.

  By the way, since the blade member 128 is located between the rotary shaft 124 and the magnet roll 80, in other words, the blade member 128 covers the periphery of the rotary shaft 124. For this reason, if the maximum width W of the blade member 128 is set to an arc larger than 35 ° centering on the rotation shaft 124, the amount of developer supplied to the magnet roll 80 is reduced, and the amount of the developer onto the print is increased. The effect of preventing density unevenness cannot be obtained.

  Therefore, the amount of developer supplied to the magnet roll 80 is ensured by setting the maximum width W of the blade member 128 to an arc of 35 ° or less centering on the rotation shaft 124.

  Here, as shown in FIG. 8A, the relationship between the rotating shaft 124 and the blade member 128 is 1 ≦ (distance from the rotating shaft 124 to the inner surface of the blade member 128) / the thickness t ≦ 3. 5 is satisfied, the balance between the supply amount of the developer to the magnet roll 80 and the transportability in the axial direction can be achieved, and density unevenness on the print can be prevented. Further, by making the outer peripheral portion of the spiral blade 126 and the outer surface of the blade member 128 the same surface, it is possible to improve the transportability of the developer in the axial direction.

  Here, the plurality of blade members 128 are arranged in a state of being continuous with one in parallel with the rotation shaft 124, but at least the space between the conveying surface 126 </ b> A of the spiral blade 126 and the opposite conveying surface 126 </ b> B is the blade member 128. Since it is sufficient if it can be bridged, one end side of the blade member 128 may be fixed to the spiral blade 126 and the other end side may be brought into contact with the transport surface 126A or the non-transport surface 126B.

  In addition, the blade member 128 is arranged in a state of being continuous with one in parallel with the rotation shaft 124 (hereinafter referred to as “arranged every 360 ° of the spiral blade 126”), but as shown in FIG. 128 may be arranged facing each other with the rotation shaft 124 therebetween (hereinafter referred to as “arrangement every 180 ° of the spiral blade 126”).

  As a result, it is possible to supply more developer to the magnet roll 80 as compared with the case where the blade member 128 is arranged in a state where the spiral blade 126 is continuously connected in parallel with the rotation shaft 124. A better image can be obtained.

Next, a description will be given main part of an image forming apparatus according to the implementation embodiments of the present invention. In addition, description is omitted about the content substantially the same as a reference example .

  In the spiral auger 130 shown in FIGS. 12A and 12B, a gap 134 is provided on the side opposite to the conveying surface 126B of the spiral blade 126 of the blade member 132. As shown in FIG. When 132 is viewed from the side (in the case of the spiral auger 130, this corresponds to a plan view), the tip of the blade member 132 is cut at an acute angle from the outer surface toward the inner surface.

Next, the operation of the image forming apparatus according to the implementation embodiments of the present invention.

  As shown in FIGS. 13A and 13B, by providing a gap 134 on the blade member 132 on the side opposite to the conveying surface 126B of the spiral blade 126, the developer on the blade member 132 is allowed to pass through the gap 134. It can flow into the space 138 provided between the member 132 and the rotating shaft 124.

  Thus, since the developer on the blade member 132 is poured into the space 138, the amount of the developer supplied to the magnet roll 80 (see FIG. 5) can be reduced. Transportability can be improved.

  This makes it possible to achieve a balance between the amount of developer supplied to the magnet roll 80 and the amount of developer conveyed in the axial direction, particularly in a model with a small amount of developer in the developing device 60 (see FIG. 5). It is effective.

  Further, by providing the gap 134 in the blade member 132 and dividing the blade member 132, when the spiral auger 140 is integrally formed, it is possible to prevent the rotation shaft 124 from warping due to thermal contraction after the formation.

  Further, when the blade member 132 is viewed from the side, the tip of the blade member 132 is cut at an acute angle from the outer surface toward the inner surface, so that the rotation of the spiral auger 140 causes the rotation between the rotating shaft 124 and the blade member 132. Further, the developer can be easily guided into the space 138, and the transportability of the developer in the axial direction can be improved.

  Here, the blade member 132 is arranged every 360 ° of the spiral blade 126, but the blade member 132 may be arranged every 180 ° of the spiral blade 126 as shown in FIG.

  However, when the blade member 132 is arranged every 180 ° of the spiral blade 126, more developer can be supplied to the magnet roll 80 as compared to the case where the blade member 132 is arranged every 360 ° of the spiral blade 126. However, on the other hand, the transportability of the developer in the axial direction is reduced.

  However, by providing the gap 134 on the side opposite to the conveying surface 126 </ b> B of the spiral blade 126, excess developer can be poured into the space 138 provided between the blade member 132 and the rotating shaft 124 through the gap 134. Therefore, it is possible to improve the transportability of the developer in the axial direction.

  Further, by providing a gap 134 on the side opposite to the conveying surface 126B of the spiral blade 126 and dividing the blade member 132, it is possible to prevent warping of the rotating shaft 124 due to thermal contraction after the formation of the spiral auger 140, and the blade By disposing the member 132 in a face-to-face state, the mold release balance when the spiral auger 140 is released from the mold is improved.

  Further, here, the gap 134 is provided on the side opposite to the conveying surface 126B of the spiral blade 126. For example, for a model having a large amount of developer in the developing device 60 (see FIG. 5), FIG. (B) and FIG. 16 (in FIG. 15A and FIG. 15B, the blade member 142 is arranged every 360 ° of the spiral blade 126, and FIG. 16 shows the blade member 142 every 180 ° of the spiral blade 126. It is more effective to provide a gap 144 on the side of the conveying surface 126A of the spiral blade 126 as shown in FIG.

  Here, the width of the blade member 142 is wider on the conveying surface 126A side of the spiral blade 126 than on the non-conveying surface 126B side. For this reason, compared with the case where the clearance 134 is provided on the side opposite to the conveying surface 126B of the spiral blade 126 (see FIGS. 13A and 13B), the tip end portion of the blade member 142 and the conveying surface 126A of the spiral blade 126 are used. The gap 144 is different in the circumferential direction of the rotating shaft 124. For this reason, here, the minimum value of the gap 144 is set to 1.5 mm or less, and the gap 144 is made wider toward the rotation direction of the rotary shaft 124 (arrow A direction).

  As described above, the gap 144 becomes wider toward the rotation direction of the rotation shaft 124, so that the developer can be more easily guided into the space 146 provided between the rotation shaft 124 and the blade member 132. be able to. Thereby, the developer is further poured into the space 146, and the transportability of the developer in the axial direction can be further improved.

  Further, by setting the minimum value of the gap 144 to 1.5 mm or less, the amount of the developer flowing into the gap 144 is regulated, and the effect of preventing density unevenness on the print is surely obtained.

  In addition, since it is only necessary to provide a gap in a part of the blade member, FIGS. 17 (A), (B) and FIG. 18 (note that FIGS. 17 (A), (B) are shown every 360 ° of the spiral blade 126. The blade member 148 is arranged, and as shown in FIG. 18, the blade member 148 is arranged every 180 ° of the spiral blade 126), the blade member 148 is divided at a substantially central portion in the length direction. Also good.

  In this way, by dividing the blade member 148 at the substantially central portion in the length direction of the blade member 148, the magnet roll 80 (see FIG. 5) regardless of the amount of developer in the developing device 60 (see FIG. 5). ) And the amount of developer conveyed in the axial direction can be balanced.

  Further, as shown in FIG. 19, the blade members 150 and 152 are arranged every 180 ° of the spiral blade 126, and the blade member 150 is provided with a gap 154 on the conveying surface 126 </ b> A side, and the blade member 152 is the anti-conveying surface 126 </ b> B. A gap 156 may be provided on the side.

  The developer supplied to the magnet roll 80 by the blade members 150 and 152 becomes sparse in the gaps 154 and 156, respectively, but the blade members 150 and 152 facing each other can complement each other. For this reason, in the supply to the magnet roll 80 by the blade members 150 and 152, the supply amount of the developer can be made substantially constant in the length direction of the blade members 150 and 152, and a better image can be obtained.

  Here, as shown in FIG. 20, the length may be changed between the facing blade member 158 and the blade member 160. Thereby, it is possible to achieve a balance between the amount of developer supplied to the magnet roll 80 and the amount conveyed in the axial direction.

  Here, although the length is changed between the blade member 158 and the blade member 160, the balance between the amount of developer supplied to the magnet roll 80 (see FIG. 5) and the amount of developer conveyed in the axial direction is achieved. Therefore, the shape of the blade members 158 and 160 themselves may be changed.

  Further, in this embodiment, the outer peripheral portion of the spiral blade and the outer surface of the blade member are flush with each other. However, since the blade member may be provided on the spiral blade, the outer peripheral portion of the spiral blade and the inner surface of the blade member May be on the same plane, and a blade member may be arranged inside the outer periphery of the spiral blade.

  Furthermore, in this embodiment, the spiral auger has a single spiral blade, but the present invention is not limited to this, and multiple spiral blades may be used. By using multiple spiral blades, the transportability of the developer in the axial direction can be improved. Furthermore, it can also be applied to a suede auger as a spiral blade. In addition, the use of a spherical toner as the toner can improve the fluidity of the developer, which is more effective in the present invention.

1 is a side view showing an image forming apparatus according to an embodiment of the present invention. FIG. 3 is a perspective view showing a developing unit used in the image forming apparatus according to the embodiment of the invention. FIG. 3 is a side view showing a part of a developing unit used in the image forming apparatus according to the embodiment of the present invention. FIG. 3 is a cross-sectional view illustrating a part of a developing unit used in the image forming apparatus according to the embodiment of the present invention. It is sectional drawing which shows the developing device used for the image forming apparatus which concerns on a reference example . It is a perspective view which shows the spiral auger which concerns on a reference example . (A) which shows the spiral auger which concerns on a reference example is a top view, (B) is a front view. (A), (B) is an enlarged view of FIG. 7 (A), (B). (A), (B) is sectional drawing which shows the shape of the blade member of the spiral auger which concerns on a reference example . It is a perspective view which shows the blade member of the spiral auger which concerns on a reference example . It is an enlarged plan view which shows the modification of the spiral auger which concerns on a reference example . Shows a spiral auger according to implementation embodiments of the present invention (A) is a plan view, (B) is a front view. (A), (B) is an enlarged view of FIG. 12 (A), (B). It is an enlarged plan view showing a first modification of the spiral auger according to implementation embodiments of the present invention. (A) of the spiral auger showing a second modification of the implementation form of the present invention is an enlarged plan view, (B) is an enlarged front view. It is an enlarged plan view of a spiral auger showing a third modification of the implementation of the invention. (A) the spiral auger showing a fourth modification of the implementation form of the present invention is an enlarged plan view, (B) is an enlarged front view. It is an enlarged plan view of a spiral auger showing a fifth modification of the implementation of the invention. It is an enlarged plan view of a spiral auger showing a sixth modification of the implementation of the invention. A seventh modification of the implementation form of the present invention is an enlarged plan view of a spiral auger shown. It is sectional drawing which shows the developing device used for the conventional image forming apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 60 Developing device 112 Spiral auger (supply member)
114 Spiral auger (supply member)
124 Rotating shaft 126 Spiral blade 126B Non-transport surface 126A Transport surface 128 Blade member 128A Side surface 130 Spiral auger (supply member)
132 Blade member 134 Clearance 140 Spiral auger (supply member)
142 blade member 144 gap 148 blade member 150 blade member 152 blade member 154 gap 156 gap 158 blade member 160 blade member W width h distance t thickness

Claims (17)

A supply member that conveys the developer and supplies the developer to the developer carrying member includes a rotating shaft and a spiral blade formed in a spiral shape around the rotating shaft,
A blade member is bridged in parallel with the rotation axis between the conveying surface of the spiral blade that conveys the developer and the opposite conveying surface facing the conveying surface,
When the blade member is divided at an arbitrary position in the length direction along the axial direction of the rotation shaft, a gap is provided, and when the blade member is viewed from the side, the tip of the blade member extends from the outer surface to the inner surface. An image forming apparatus characterized by being cut at an acute angle toward. A supply member that conveys the developer and supplies the developer to the developer carrying member includes a rotating shaft and a spiral blade formed in a spiral shape around the rotating shaft,
A blade member is bridged in parallel with the rotation axis between the conveying surface of the spiral blade that conveys the developer and the opposite conveying surface facing the conveying surface,
The blade member is divided at an arbitrary position in the length direction along the axial direction of the rotation shaft, a gap is provided, and the side surface on the rotation direction side of the blade member is moved from the transport surface side to the anti-transport. An image forming apparatus having a downward slope toward the surface side. A supply member that conveys the developer and supplies the developer to the developer carrying member includes a rotating shaft and a spiral blade formed in a spiral shape around the rotating shaft,
A blade member is bridged in parallel with the rotation axis between the conveying surface of the spiral blade that conveys the developer and the opposite conveying surface facing the conveying surface,
The blade member is divided at an arbitrary position in the length direction along the axial direction of the rotating shaft, a gap is provided, and a cross section when the blade member is cut at a plane orthogonal to the rotating shaft is as follows: An image forming apparatus, wherein the blade member is thin on a rotational direction side. A supply member that conveys the developer and supplies the developer to the developer carrying member includes a rotating shaft and a spiral blade formed in a spiral shape around the rotating shaft,
A blade member is bridged in parallel with the rotation axis between the conveying surface of the spiral blade that conveys the developer and the opposite conveying surface facing the conveying surface,
The blade member is divided at an arbitrary position in the length direction along the axial direction of the rotation shaft to provide a gap, and the gap has a wide side toward the rotation direction when the blade member is viewed in plan. An image forming apparatus.   The image forming apparatus according to claim 1, wherein the blade member is provided on an outer peripheral portion of the spiral blade.   The image forming apparatus according to claim 1, wherein the blade member is disposed so as to face each other with the rotation shaft interposed therebetween. A supply member that conveys the developer and supplies the developer to the developer carrying member includes a rotating shaft and a spiral blade formed in a spiral shape around the rotating shaft,
A blade member that bridges between the conveyance surface of the spiral blade that conveys the developer and the opposite conveyance surface that faces the conveyance surface is disposed to face the rotation shaft, and one of the blades A slit is formed on the conveying surface side of the member to provide a gap between the blade member and the conveying surface, and a slit is formed on the opposite conveying surface side of the other blade member to provide a gap between the blade member and the anti-conveying surface. An image forming apparatus provided.   The image forming apparatus according to claim 7, wherein shapes of the blade members facing each other are different. A rotation axis;
Spiral blades that are formed in a spiral shape around the rotation axis and convey the developer;
A blade member spanned in parallel with the rotation shaft between a conveying surface of the spiral blade that conveys the developer and an opposite conveying surface facing the conveying surface;
Consists of
When the blade member is divided at an arbitrary position in the length direction along the axial direction of the rotation shaft, a gap is provided, and when the blade member is viewed from the side, the tip of the blade member extends from the outer surface to the inner surface. A supply member that is cut at an acute angle toward the front. A rotation axis;
Spiral blades that are formed in a spiral shape around the rotation axis and convey the developer;
A blade member spanned in parallel with the rotation shaft between a conveying surface of the spiral blade that conveys the developer and an opposite conveying surface facing the conveying surface;
Consists of
The blade member is divided at an arbitrary position in the length direction along the axial direction of the rotation shaft, a gap is provided, and the side surface on the rotation direction side of the blade member is moved from the transport surface side to the anti-transport. A supply member having a downward slope toward the surface. A rotation axis;
Spiral blades that are formed in a spiral shape around the rotation axis and convey the developer;
A blade member spanned in parallel with the rotation shaft between a conveying surface of the spiral blade that conveys the developer and an opposite conveying surface facing the conveying surface;
Consists of
The blade member is divided at an arbitrary position in the length direction along the axial direction of the rotating shaft, a gap is provided, and a cross section when the blade member is cut at a plane orthogonal to the rotating shaft is as follows: The supply member according to claim 1, wherein a rotation direction side of the blade member is thin. A rotation axis;
Spiral blades that are formed in a spiral shape around the rotation axis and convey the developer;
A blade member spanned in parallel with the rotation shaft between a conveying surface of the spiral blade that conveys the developer and an opposite conveying surface facing the conveying surface;
Consists of
The blade member is divided at an arbitrary position in the length direction along the axial direction of the rotation shaft to provide a gap, and the gap has a wide side toward the rotation direction when the blade member is viewed in plan. A supply member, characterized in that The supply member according to any one of claims 9 to 12, wherein the blade member is provided on an outer peripheral portion of the spiral blade.   The supply member according to any one of claims 9 to 13, wherein the blade member is disposed so as to face each other with the rotation shaft interposed therebetween. A rotation axis;
Spiral blades that are formed in a spiral shape around the rotation axis and convey the developer;
A blade member disposed so as to face between the conveying surface of the spiral blade conveying the developer and the opposite conveying surface facing the conveying surface, and facing the rotation shaft;
Consists of
A slit is formed on the conveying surface side of one of the blade members and a gap is provided between the blade member and the conveying surface, and a slit is formed on the opposite conveying surface side of the other blade member so that the blade member and the anti-conveying surface A supply member provided with a gap therebetween.   The supply member according to claim 15, wherein the shapes of the blade members facing each other are different.   A developing device comprising the supply member according to any one of claims 9 to 16.

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