JP2013044939A - Developing device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device capable of improving a stirring performance of a developer, and an image forming apparatus.SOLUTION: A drive shaft 120 of a second stirring/transporting auger 89 that is provided in the developing device, and a rotary shaft 124 having a spiral blade 126 formed around the outer peripheral surface are disposed apart in the radial direction of the drive shaft 120. Thereby, the rotary shaft 124 with the spiral blade 126 rotates about the drive shaft 120. The rotary shaft 124 with the spiral blade 126 rotates in a circular pattern viewed from the rotary shaft direction. Therefore, the spiral blade 126 can apply not only the force in the rotary shaft direction but also force in the peripheral direction about the drive shaft 120, to a developer G so as to improve the stirring performance of the developer G.

Description

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

  The developing device described in Patent Document 1 is provided with a stirring and conveying member that conveys the developer while stirring. The stirring and conveying member includes a first spiral member that serves as a rotation axis of the stirring and conveying member, and a second spiral member that is parallel to the first spiral member.

JP 2006-301348 A

  An object of the present invention is to improve the stirring performance of a developer.

  A developing device according to a first aspect of the present invention is arranged to face a developing member that develops a toner image by rotating a latent image formed on an image carrier with a developer while rotating the latent image. And a first agitating and conveying member that extends along the rotation axis direction of the developing member and conveys the developer to the developing member while stirring the developer, and a driving force from a driving source. A drive shaft portion that is rotated by being transmitted, a rotation shaft portion that extends along an axial direction of the drive shaft portion, and is disposed away from the drive shaft portion in a radial direction of the drive shaft portion, and the drive A connecting portion that connects the shaft portion and the rotating shaft portion, a spiral blade that is formed in a spiral shape on the outer peripheral surface of the rotating shaft portion so as to convey the developer only from one end side to the other end side; And arranged in parallel with the first stirring and conveying member, the rotating shaft Extending countercurrent, characterized in that the developer and a second agitating transporting member for stirring while circulating between the first stirring carrying member.

A developing device according to a second aspect of the present invention is the developing device according to the first aspect, wherein the height of the spiral blade from the outer peripheral surface of the rotary shaft portion is h, the axial radius of the rotary shaft portion is r, When the distance between the center of the drive shaft portion and the center of the rotation shaft portion is 1 when viewed from the rotation shaft direction,
h + r ≧ l
It is characterized by satisfying.

The developing device according to a third aspect of the present invention is the developing device according to the first aspect, wherein the center of the spiral blade and the center of the rotating shaft portion are eccentric, and the rotation of the spiral blade is viewed from the direction of the rotating shaft. The height of the drive shaft portion side from the outer peripheral surface of the shaft portion is hi, the height of the spiral blade on the opposite side of the drive shaft portion side from the outer peripheral surface of the rotation shaft portion is ho, and the rotation shaft portion Where r is the axis radius of the axis and l is the distance between the center of the drive shaft and the center of the rotary shaft.
hi + r ≧ l
0 <ho <hi
It is characterized by satisfying.

  A developing device according to a fourth aspect of the present invention is the developing device according to any one of the first to third aspects, wherein the rotating shaft portion is divided into the rotating shaft direction and is provided in a plurality. As seen, the plurality of rotating shaft portions are arranged so that the center of gravity of the plurality of rotating shaft portions overlaps the rotation center of the drive shaft portion.

  The developing device according to a fifth aspect of the present invention is the developing device according to any one of the first to fourth aspects, wherein the developer is transported around the rotating shaft portion only from one end side to the other end side. Thus, a plurality of spiral blades formed in a spiral shape are formed.

  A developing device according to a sixth aspect of the present invention is the developing device according to any one of the first to fifth aspects, wherein a reciprocating mechanism for reciprocating the second agitating and conveying member in the axial direction of the drive shaft portion is provided. It is characterized by that.

  An image forming apparatus according to a seventh aspect of the present invention visualizes, as a toner image, an image holding body on which an electrostatic latent image is formed, and the electrostatic latent image formed on the image holding body. And a developing device according to any one of 6 above.

  According to the developing device of the first aspect of the present invention, the drive shaft portion that is rotated by the driving force transmitted from the drive source and the rotation shaft portion that is formed with the spiral blades are provided on the same axis. In comparison, the stirring performance of the developer can be improved.

  According to the developing device of the second aspect of the present invention, the developer stirring performance can be improved as compared with the case where the outer peripheral shape of the spiral blade does not reach the rotation center line of the drive shaft portion.

  According to the developing device of the third aspect of the present invention, the developer is stirred without expanding the stirring path as compared with the case where the outer peripheral shape of the eccentric spiral blade does not reach the rotation center line of the drive shaft portion. Performance can be improved.

  According to the developing device of claim 4 of the present invention, the second agitating and conveying is compared with the case where the center of gravity of the plurality of rotating shaft portions does not overlap the rotation center of the driving shaft portion when viewed from the rotating shaft direction. The rotation of the member can be stabilized.

  According to the developing device of claim 5 of the present invention, the stirring performance of the developer can be improved as compared with the case where only one spiral blade formed in a spiral shape is provided around the rotating shaft portion. .

  According to the developing device of the sixth aspect of the present invention, the developer agitating performance can be improved as compared with the case where the second agitating and conveying member does not reciprocate in the axial direction of the drive shaft portion.

  According to the image forming apparatus of the seventh aspect of the present invention, the quality of the output image can be improved as compared with the case where the developing device according to any one of the first to sixth aspects is not provided.

It is the perspective view which showed the 2nd stirring conveyance auger employ | adopted as the developing device which concerns on 1st Embodiment of this invention. FIG. 5 is an enlarged cross-sectional view illustrating a second agitation transport auger employed in the developing device according to the first embodiment of the present invention. It is sectional drawing which looked at the developing device concerning a 1st embodiment of the present invention from the perpendicular direction upper part. It is sectional drawing which looked at the developing device concerning a 1st embodiment of the present invention from the direction of a rotation axis. 1 is a schematic configuration diagram illustrating an image forming apparatus according to a first embodiment of the present invention. It is the perspective view which showed the 2nd stirring conveyance auger employ | adopted as the developing device which concerns on 2nd Embodiment of this invention. It is an expanded sectional view showing the second stirring conveyance auger adopted by the development device concerning a 2nd embodiment of the present invention. It is the perspective view which showed the 2nd stirring conveyance auger employ | adopted as the developing device which concerns on 3rd Embodiment of this invention. It is the perspective view which showed the 2nd stirring conveyance auger employ | adopted as the developing device which concerns on 4th Embodiment of this invention. It is the perspective view which showed the 2nd stirring conveyance auger employ | adopted as the developing device which concerns on 5th Embodiment of this invention. (A) (B) It is the front view which showed the 2nd stirring conveyance auger, the reciprocation mechanism, etc. which were employ | adopted as the developing device which concerns on 6th Embodiment of this invention.

  An example of the developing device and the image forming apparatus according to the first embodiment of the present invention will be described with reference to FIGS. In addition, arrow UP shows the vertical direction upper direction.

(overall structure)
As shown in FIG. 5, the process cartridges 14 of four colors (in this embodiment, yellow, magenta, cyan, and black) are arranged in the vertical direction in the image forming apparatus 10.

  As shown in FIG. 4, the process cartridge 14 includes an image carrier cartridge 62 having the image carrier 16 and a developing device 64 provided below the image carrier cartridge 62.

  The image carrier cartridge 62 includes an image carrier 16 on which an electrostatic latent image is formed, a cleaning device 22 disposed around the image carrier 16, a charging roll 18, an erase lamp 24, and a lateral direction of the cleaning device 22. And a sub-toner replenishing unit 66 disposed in the housing.

  The sub-toner supply unit 66 is provided with a pair of support protrusions 78 that are orthogonal to the rotation axis direction of the image carrier 16 and extend in the horizontal direction. By inserting the support protrusion 78 into a cartridge receiving portion (not shown) of the image forming apparatus 10, the process cartridge 14 is mounted on the image forming apparatus 10 and is detachable from the image forming apparatus 10. .

  Further, the developing device 64 is provided with a developing roller 86 as an example of a developing member that conveys the developer G to the image carrier 16 and visualizes the electrostatic latent image formed on the image carrier 16 into a toner image. ing. Details of the developing device 64 will be described later.

  As shown in FIG. 5, a sheet feeding cassette 26 in which a sheet material P as a recording medium is stored is provided at the lower portion in the vertical direction of the image forming apparatus 10. In the vicinity of the paper feed cassette 26, a feed roll 28 for feeding the sheet material P at a predetermined timing is provided. The sheet material P sent out from the paper feed cassette 26 by the feed roll 28 is sent to the paper transport path 34 via the transport roll 30 and the alignment roll 32 and transported to a transport device 48 described later.

  On the other hand, the process cartridge 14 (see FIG. 4) is arranged in the order of yellow, magenta, cyan, and black from the upstream side of the paper transport path 34. Further, an exposure device 36 for irradiating the process cartridge 14 with scanning light is disposed on the side of the process cartridge 14.

  A semiconductor laser (not shown), a polygon mirror 40, an imaging lens 44, and a mirror 46 are arranged in a housing 38 of the exposure device 36. The light from the semiconductor laser is deflected and scanned by the polygon mirror 40 and irradiated to the image carrier 16 through the imaging lens 44 and the mirror 46. As a result, an electrostatic latent image corresponding to the image information is formed on the image carrier 16.

  A transport device 48 is disposed on the opposite side of the image carrier 16 with the paper transport path 34 interposed therebetween. The transport device 48 includes a pair of stretching rolls 51 and 52 provided along the side wall 10 </ b> A of the image forming apparatus 10, and a transport belt 53 wound around the stretching rolls 51 and 52. ing. Further, the stretching roll 52 disposed above is rotated by a motor (not shown) so that the conveying belt 53 moves. On the other hand, an adsorption roll 55 is arranged on the opposite side of the tension roll 51 arranged below the conveyance belt 53, and a voltage is applied to the adsorption roll 55, whereby the conveyance belt 53. The sheet material P is electrostatically attracted to the surface.

  In addition, a transfer roll that transfers the toner image on the image carrier 16 to the sheet material P is located on the back surface (the surface that is not in contact with the image carrier 16) of the conveyance belt 53 at a position facing the image carrier 16 of each color. 54 are arranged respectively. Further, on the downstream side of the paper conveyance path 34 with respect to the conveyance device 48, a fixing device 56 that fixes the toner image transferred to the sheet material P to the sheet material P, and a discharge that discharges the sheet material P to the discharge tray 60. A roll 58 is provided.

  In the image forming apparatus 10 configured as described above, an image is formed as follows.

  As shown in FIG. 4, first, the charging roll 18 to which a voltage is applied uniformly charges the surface of the image carrier 16 with a predetermined charging portion potential.

  Exposure is performed by an exposure device 36 (see FIG. 5) so that an image portion on the charged image carrier 16 has a predetermined exposure portion potential, and an electrostatic latent image is formed.

  That is, an electrostatic latent image corresponding to an image is formed on the image carrier 16 by turning on and off a semiconductor laser (not shown) based on image data supplied from a control device (not shown).

  Further, the developer G is conveyed to the electrostatic latent image formed on the image holding member 16 by the developing roller 86 provided in the developing device 64, and the toner of the developer G adheres to the electrostatic latent image, so The electrostatic latent image is visualized as a toner image.

  Therefore, as shown in FIG. 5, the sheet material P stacked on the paper feed cassette 26 is sent out to the paper transport path 34 by the sending roll 28. The fed sheet material P is conveyed at a timing determined by the conveyance roll 30 and the alignment roll 32, passes between the image carrier 16 and the transfer roll 54, and the toner image is transferred to the sheet material P. The The transferred toner image is fixed by the fixing device 56, and the sheet material P on which the toner image is fixed is discharged to the discharge tray 60 by the discharge roll 58.

(Main part configuration)
Next, the developing device 64 will be described.

  As shown in FIG. 4, the developing device 64 is a developer that visualizes the electrostatic latent image on the image carrier 16 facing the image carrier 16 with a two-component developer G composed of a nonmagnetic toner T and a magnetic carrier. A unit 68 and a main toner replenishing unit 70 for replenishing the nonmagnetic toner T to the developing unit 68 are configured.

  The developing unit 68 has a housing 80. The housing 80 is provided on the lower side of the image carrier 16 and has an opening 82 that opens toward the image carrier 16 side. Further, a developer storage chamber 84 is formed in the housing 80, and a developer G composed of a nonmagnetic toner T and a magnetic carrier can be stored in the developer storage chamber 84.

  Further, a developing roll 86 is provided in the housing 80 so as to be partially exposed from the opening 82 of the housing 80 so as to face the image carrier 16, and the developing roll 86 rotates relative to the housing 80. Supported as possible. In addition, a gear (not shown) is fixed to the end of the developing roll 86, and the rotational force from the motor is transmitted to the gear so that the developing roll 86 rotates via the gear.

  Specifically, the developing roll 86 includes a non-magnetic sleeve 86A having a thin cylindrical shape having conductivity that is rotatable, and a fixed columnar magnet roll 86B. It is designed to rotate.

  In addition, a developer regulating member 50 that regulates the layer thickness of the developer G on the developing roll 86 is disposed opposite to the nonmagnetic sleeve 86A with a gap therebetween.

  As a result, the developing roller 86 adsorbs the magnetic carrier contained in the developer G by magnetic force, forms a magnetic brush of the developer G on the surface of the sleeve 86A, and the developer regulating member 50 causes the layer of the developer G to be formed. The thickness is regulated, and the developer G is transported to a position facing the image carrier 16. The electrostatic latent image formed on the image carrier 16 is visualized as a toner image by the developer G on the developing roll 86.

  Below the developing roll 86, a first agitating / conveying auger 88 as an example of a first agitating / conveying member that extends along the rotation axis direction of the developing roll 86 (hereinafter may be simply referred to as the rotation axis direction) and a second agitating member. A second agitating / conveying auger 89 as an example of a conveying member is arranged in parallel.

  As shown in FIG. 3, the first agitating and conveying auger 88 and the second agitating and conveying auger 89 have a driving shaft portion 88 </ b> A and a driving shaft portion 120 that rotate when a driving force is transmitted from a motor (a driving source) (not shown). Each has it. Further, spiral drive blades 88B are wound around the drive shaft 88A of the first agitation transport auger 88 at a predetermined pitch.

  In addition, a partition wall 90 is formed between the first stirring / conveying auger 88 and the second stirring / conveying auger 89, and the lower part in the developer storage chamber 84 is separated by the partition wall 90 from the first stirring / conveying auger 88. Is divided into a region (first agitation path) 92 and a region (second agitation path) 93 in which the second agitation transport auger 89 is disposed.

  At both ends in the longitudinal direction of the partition wall 90, communication ports 94 and 95 that connect the first stirring path 92 and the second stirring path 93 are formed.

  Furthermore, gears (not shown) are fixed to the end portions of the drive shaft portion 88A and the drive shaft portion 120, respectively, and the rotational force from the motor is transmitted to the gears, and the first stirring and conveying auger 88 and the The two agitating / conveying augers 89 rotate in opposite directions. As a result, the developer G is transported by the spiral blade 88 </ b> B provided in the first stirring / conveying auger 88 and the spiral blade 126 described later provided in the second stirring / transporting auger 89. As a result, the developer G is agitated while being circulated between the first agitating / conveying auger 88 and the second agitating / conveying auger 89 as shown by arrows in the figure. Details of the second agitating / conveying auger 89 will be described later.

  On the other hand, as shown in FIG. 4, the main toner supply unit 70 adjacent to the developing unit 68 is provided with a toner storage chamber 100 in which the supply toner T is stored. In the toner storage chamber 100, a toner stirring and conveying member 102 that stirs the replenishing toner T while rotating is provided along the axial direction of the developing roller 86. When the driving force is transmitted and the toner stirring and conveying member 102 rotates, the nonmagnetic toner T in the toner storage chamber 100 is conveyed in the direction of the arrow in FIG. 3 while being stirred.

  On the other hand, a wall 104 is provided between the toner storage chamber 100 and the developer storage chamber 84. From the lower part of the wall 104, the curved wall 106 extends toward the toner storage chamber 100, and the partition wall 107 extends toward the developer storage chamber 84, so that a tunnel-shaped toner supply is provided between the bottom plates of the housing 80. A dispensing chamber 108 is provided as a chamber.

  As shown in FIG. 3, in the vicinity of one end of the curved wall 106 in the longitudinal direction, the inlet 112 is arranged so that the toner stored in the toner storage chamber 100 flows into the dispense chamber 108 from the toner storage chamber 100. Is formed. As a result, the nonmagnetic toner T accommodated in the toner accommodating chamber 100 is conveyed through the toner accommodating chamber 100 while being agitated by the toner agitating / conveying member 102, and is fed into the dispensing chamber 108 from the inlet 112. Yes.

  Further, the dispense chamber 108 is provided with a dispense auger 110 that extends along the rotation axis direction of the developing roller 86 and stirs while conveying the nonmagnetic toner T in the dispense chamber 108. The dispense auger 110 includes a columnar shaft portion 110A extending along the rotation axis direction, and a helical spiral blade 110B formed on the outer peripheral surface of the shaft portion 110A and transporting the nonmagnetic toner T while rotating. ing.

  On the other hand, an outlet 114 is formed in the vicinity of the other end in the longitudinal direction of the partition wall 107 so that the toner stirred in the dispensing chamber 108 flows out to the developer storage chamber 84. As a result, the nonmagnetic toner T in the dispense chamber 108 is conveyed through the dispense chamber 108 while being agitated by the dispense auger 110, and is sent from the outlet 114 to the developer storage chamber 84.

<Second stirring auger>
Next, the second stirring / conveying auger 89 will be described.

  As shown in FIG. 1, a columnar drive shaft 120 that rotates when a driving force is transmitted from a motor (not shown) is provided on one end side of the second agitation transport auger 89. On the other hand, on the other end side of the second agitating / conveying auger 89, a cylindrical support shaft portion that rotates about the same axis as the drive shaft portion 120 and is rotatably supported by the housing 80 (see FIG. 4). 122 is provided.

  Further, between the drive shaft portion 120 and the support shaft portion 122, the drive shaft portion 120 extends along the axial direction of the drive shaft portion 120 and is disposed away from the drive shaft portion 120 in the radial direction of the drive shaft portion 120. A cylindrical rotating shaft portion 124 is provided.

  Further, on the outer peripheral surface of the rotating shaft portion 124, a spiral spiral blade 126 formed so as to convey the developer G only from one end side to the other end side by rotation in a predetermined direction is provided. . Further, a plate-like connecting portion 130 that connects one end of the rotating shaft portion 124 and the end portion of the drive shaft portion 120 is provided, and a plate that connects the other end of the rotating shaft portion 124 and the end portion of the support shaft portion 122. A connecting portion 131 is provided.

  Specifically, as shown in FIG. 2, the height of the spiral blade 126 from the outer peripheral surface of the rotating shaft portion 124 is h [mm] (constant), and the shaft radius of the rotating shaft portion 124 is r [mm]. When the distance between the center of the drive shaft portion 120 and the center of the rotation shaft portion 124 is 1 [mm] when viewed from the rotation axis direction, the shape of each portion is determined so as to satisfy the following expression (1).

h + r ≧ l [mm] (1)
(Function)
Next, the operation of the developing device 64 will be described.

  As shown in FIG. 3, the toner agitating / conveying member 102 provided in the toner accommodating chamber 100 rotates, and the nonmagnetic toner T in the toner accommodating chamber 100 is conveyed in the direction of the arrow in the drawing while being agitated. Then, the nonmagnetic toner T conveyed by the toner agitating / conveying member 102 flows from the inlet 112 into the dispensing chamber 108.

  Further, the nonmagnetic toner T flowing into the dispensing chamber 108 from the inlet 112 is conveyed while being stirred toward the outlet 114 by the spiral blade 110B of the rotating dispense auger 110. The nonmagnetic toner T conveyed to the outlet 114 while being stirred by the dispense auger 110 flows out from the outlet 114 to the developer storage chamber 84.

  The nonmagnetic toner T sent from the dispensing chamber 108 to the developer accommodating chamber 84 through the outlet 114 enters the developer G. In the developer storage chamber 84, the developer G is agitated while circulating the developer G in the direction of the arrow between the first agitation conveyance auger 88 and the second agitation conveyance auger 89.

  Further, as shown in FIG. 4, the developer G stirred between the first stirring / transporting auger 88 and the second stirring / transporting auger 89 is adsorbed to the surface of the developing roll 86 by a magnetic force. Specifically, the developing roll 86 adsorbs the magnetic carrier contained in the developer G by magnetic force, and a magnetic brush of the developer G is formed on the surface of the developing roll 86.

  The layer thickness of the developer G adsorbed on the developing roll 86 is regulated by the developer regulating member 50. The developer G whose layer thickness is regulated is conveyed to a position facing the image carrier 16 and the electrostatic latent image formed on the image carrier 16 is visualized as a toner image.

  Here, as shown in FIG. 1, the drive shaft portion 120 of the second agitating / conveying auger 89 provided in the developing device 64 and the rotary shaft portion 124 in which the spiral blades 126 are formed on the outer peripheral surface are the drive shaft. The portions 120 are arranged away from each other in the radial direction.

 Thereby, the rotating shaft part 124 provided with the spiral blade 126 rotates around the drive shaft part 120. That is, when viewed from the direction of the rotation axis, the rotation shaft portion 124 including the spiral blade 126 rotates while drawing a circle. For this reason, since not only the force in the rotation axis direction but also the force in the circumferential direction around the drive shaft portion 120 can be applied to the developer G by the spiral blade 126, the stirring performance of the developer G is improved.

  In recent years, in order to extend the life of the developer G and to reduce the noise of the developing portion, the magnetic force of the trimming pole (the constituent member of the magnet roll 86B) facing the developer regulating member 50 may be lowered (low magnetic force trimming). When low magnetic force trimming is employed, the stress on the developer G can be reduced, but the friction between the developers and the stirring performance due to the magnetic attraction force of the developer G by the trimming pole may be reduced. Can be considered. However, even in such a case, as described above, by disposing the drive shaft portion 120 and the rotary shaft portion 124 apart in the radial direction of the drive shaft portion 120, a decrease in the stirring performance of the developer G is suppressed. The

  Further, the height of the spiral blade 126 from the outer peripheral surface of the rotating shaft portion 124 is h [mm], the shaft radius of the rotating shaft portion 124 is r [mm], and when viewed from the rotating shaft direction, When the distance between the center and the center of the rotation shaft portion is l [mm], the above equation (1) is satisfied. For this reason, since the outer peripheral shape of the spiral blade 126 reaches the rotation center of the drive shaft portion 120, the stirring performance of the developer G is effectively improved.

Second Embodiment
Next, an example of the developing device and the image forming apparatus according to the second embodiment of the present invention will be described with reference to FIGS. In addition, about the same member as 1st Embodiment, the same code | symbol is attached and the description is abbreviate | omitted.

  As shown in FIG. 6, the developer G is transported from the one end side only to the other end side on the outer peripheral surface of the rotary shaft portion 124 provided in the second stirring and transporting auger 140 according to the second embodiment. A spiral eccentric spiral blade 142 formed as described above is provided.

  That is, the center of the spiral blade 142 and the center of the rotation shaft portion 124 are eccentric, and the center of the spiral blade 142 and the center of the rotation shaft portion 124 as viewed from the rotation axis direction are shifted.

  As shown in FIG. 7, when viewed from the rotation axis direction, the height of the spiral blade 142 on the drive shaft portion 120 side from the outer peripheral surface of the rotation shaft portion 124 is hi [mm] (maximum height), and the spiral blade 142, the height on the opposite side of the drive shaft 120 from the outer peripheral surface of the rotary shaft 124 is set to ho [mm] (minimum height), and the shaft radius of the rotary shaft 124 is set to r [mm]. When the distance between the center of the shaft 120 and the center of the rotating shaft 124 is 1 [mm], the shape of each part is determined so as to satisfy the following expressions (2) and (3).

hi + r ≧ l [mm] (2)
0 <ho <hi [mm] (3)
Thus, by making the height hi [mm] of the spiral blade 142 on the drive shaft portion 120 side higher than the height ho [mm] of the spiral blade 142 on the opposite side to the drive shaft portion 120 side, the height is increased. Compared with the case where it is constant, the rotation radius around the drive shaft portion 120 in the rotation shaft portion 124 is increased without expanding the second stirring path 93.

  Further, since the rotation radius of the rotation shaft portion 124 around the drive shaft portion 120 is increased, the developer G stirring performance is effectively improved. That is, the stirring performance of the developer G is improved without widening the second stirring path 93.

  Other operations are the same as those in the first embodiment.

<Third Embodiment>
Next, an example of a developing device and an image forming apparatus according to the third embodiment of the present invention will be described with reference to FIG. In addition, about the same member as 1st Embodiment, the same code | symbol is attached and the description is abbreviate | omitted.

  As shown in FIG. 8, the rotation shaft portion 150 of the second agitation transport auger 148 according to the third embodiment is divided in the rotation shaft direction, and includes a rotation shaft portion 150A and a rotation shaft portion 150B. Further, when viewed from the rotation axis direction, the rotation shaft portion 150A and the rotation shaft portion 150B are arranged such that the center of gravity of the rotation shaft portion 150 formed by the rotation shaft portion 150A and the rotation shaft portion 150B overlaps the rotation center of the drive shaft portion 120. And are arranged.

  Specifically, the length of the rotation shaft portion 150A and the length of the rotation shaft portion 150B in the rotation axis direction are the same, and when viewed from the rotation axis direction, the rotation shaft portion 150A of the rotation shaft portion 150A is sandwiched across the rotation center of the drive shaft portion 120. A rotating shaft 150B is disposed on the opposite side. That is, the rotation shaft portion 150A and the rotation shaft portion 150B are arranged at a 180-degree pitch with the drive shaft portion 120 as the center. Further, when viewed from the rotation axis direction, the distance from the center of the drive shaft 120 to the center of the rotation shaft 150A is the same as the distance from the center of the drive shaft 120 to the center of the rotation shaft 150B. .

  Further, on the outer peripheral surface of the rotation shaft portion 150A, a spiral helix blade 152A formed so as to convey the developer G only from one end side to the other end side by rotation in a certain direction is provided. Similarly, on the outer peripheral surface of the rotation shaft portion 150B, a spiral helix blade 152B formed so as to convey the developer G only from one end side to the other end side is provided. Furthermore, the end portion of the rotation shaft portion 150A and the end portion of the rotation shaft portion 150B are connected by a plate-like coupling portion 154.

  As described above, the second agitating / conveying auger is provided by arranging the rotation shaft portion 150A and the rotation shaft portion 150B so that the center of gravity of the rotation shaft portion 150 overlaps the rotation center of the drive shaft portion 120 when viewed from the rotation axis direction. The rotation of 148 is stabilized.

  Further, since the rotation of the second agitating / conveying auger 148 is stabilized, the durability of the developing device 64 is improved.

  Further, by stabilizing the rotation of the second agitating / conveying auger 148, vibration of the developing device 64 is suppressed.

  In addition, when vibration occurs in the developing device 64, an uneven image may be output at a pitch (period) corresponding to the vibration. However, as described above, since the vibration of the developing device 64 is suppressed, such unevenness of the output image is suppressed.

  Other operations are the same as those in the first embodiment.

<Fourth embodiment>
Next, an example of a developing device and an image forming apparatus according to the fourth embodiment of the present invention will be described with reference to FIG. In addition, about the same member as 3rd Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 9, the rotation shaft portion 162 of the second agitating / conveying auger 160 according to the fourth embodiment is divided into four in the rotation shaft direction, and the rotation shaft portion 162A, the rotation shaft portion 162B, and the rotation shaft portion. 162C and a rotating shaft part 162D are provided.

  The rotation shaft portion 162A, the rotation shaft portion 162B, the rotation shaft portion 162C, and the rotation shaft portion 162D are arranged in this order from the drive shaft portion 120 toward the support shaft portion 122.

  Further, when viewed from the direction of the rotation axis, the center of gravity of the rotation shaft portion 162 composed of the rotation shaft portion 162A, the rotation shaft portion 162B, the rotation shaft portion 162C, and the rotation shaft portion 162D is overlapped with the rotation center of the drive shaft portion 120. A rotation shaft portion 162A, a rotation shaft portion 162B, a rotation shaft portion 162C, and a rotation shaft portion 162D are arranged.

  Specifically, the lengths of the respective rotation shaft portions 162 in the rotation shaft direction are the same, and the rotation shaft portion on the opposite side of the rotation shaft portion 162A across the rotation center of the drive shaft portion 120 as viewed from the rotation shaft direction. 162C is arranged. In addition, a rotation shaft portion 162D is disposed on the opposite side of the rotation shaft portion 162B across the rotation center of the drive shaft portion 120.

  Further, when the drive shaft portion 120 is rotated 90 degrees clockwise as viewed from the rotation axis direction, the rotation shaft portion 162A moves to the position where the rotation shaft portion 162B is disposed, and the rotation shaft portion 162B becomes the rotation shaft portion. 162C is moved to the position where the rotation shaft portion 162C is disposed, the rotation shaft portion 162C is moved to the position where the rotation shaft portion 162D is disposed, and the rotation shaft portion 162D is moved to the position where the rotation shaft portion 162A is disposed. It has become. That is, the rotating shaft portions 162 are arranged at a 90-degree pitch with the drive shaft portion 120 as the center.

  Further, on the outer peripheral surface of the rotating shaft portion 162A, a spiral helix blade 164A formed so as to convey the developer G only from one end side toward the other end side is provided. Similarly, on the outer peripheral surfaces of the rotary shaft portion 162B, the rotary shaft portion 162C, and the rotary shaft portion 162D, a spiral spiral formed so as to convey the developer G from only one end side toward the other end side. A blade 164B, a spiral blade 164C, and a spiral blade 164D are provided.

  Further, the end portion of the rotating shaft portion 162A and the end portion of the rotating shaft portion 162B are connected by an L-shaped coupling portion 166. Further, the end portion of the rotating shaft portion 162B and the end portion of the rotating shaft portion 162C are connected by an L-shaped coupling portion 168. Furthermore, the end portion of the rotating shaft portion 162C and the end portion of the rotating shaft portion 162D are connected by an L-shaped coupling portion 170.

  The operation is the same as in the fourth embodiment.

<Fifth Embodiment>
Next, an example of a developing device and an image forming apparatus according to the fifth embodiment of the present invention will be described with reference to FIG. In addition, about the same member as 1st Embodiment, the same code | symbol is attached and the description is abbreviate | omitted.

  As shown in FIG. 10, the developer G is transported from the one end side only to the other end side on the outer peripheral surface of the rotating shaft portion 182 of the second stirring and transporting auger 180 according to the fifth embodiment. Two formed spiral spiral blades 184 and spiral blades 186 are provided.

  Thus, by providing the two spiral blades 184 and the spiral blade 186, the area where the two spiral blades 184 and the spiral blade 186 are not in contact with the developer G is reduced, and the developer stirring performance is improved.

  Other operations are the same as those in the first embodiment.

<Sixth Embodiment>
Next, an example of a developing device and an image forming apparatus according to the sixth embodiment of the present invention will be described with reference to FIG. In addition, about the same member as 1st Embodiment, the same code | symbol is attached and the description is abbreviate | omitted.

  11A and 11B, the developing device 190 according to the sixth embodiment includes a reciprocating mechanism 194 that reciprocates the second agitating / conveying auger 192 in the direction of the rotation axis of the drive shaft 120. Is provided.

  A gear 196 is provided on the end side of the drive shaft portion 120, and a gear 198 that meshes with the gear 196 is fixed to the output shaft of the motor 200. The gear 198 is provided so as to extend in the rotation axis direction so that the meshing between the gear 196 and the gear 198 is not released even when the gear 196 moves as the second stirring / conveying auger 192 reciprocates.

  On the other hand, the reciprocating mechanism 194 includes a reciprocating guide member 202 disposed on the support shaft portion 122 side and a coil-shaped biasing spring 204 disposed on the drive shaft portion 120 side.

  Specifically, the urging spring 204 is provided on the outside of the housing 80, and is between a plate-shaped bracket 208 that is bent with its end fixed to the housing 80 and the ring 210 that is fixed to the drive shaft 120. Arranged in a compressed state. Thereby, the urging spring 204 urges the second agitating / conveying auger 192 toward the support shaft 122.

  On the other hand, the reciprocating guide member 202 disposed on the support shaft portion 122 side includes an end surface 202 </ b> A that faces the end surface 122 </ b> A of the support shaft portion 122. The end surface 122A of the support shaft portion 122 is inclined with respect to the rotation axis direction, and the end surface 202A of the reciprocating guide member 202 is also inclined with respect to the rotation axis direction.

  As shown in FIG. 11A, when the end surface 122A and the end surface 202A are in surface contact, the second agitating / conveying auger 192 is disposed on the right side of the sheet by the urging force of the urging spring 204.

  On the other hand, as shown in FIG. 11B, when the second agitating / conveying auger 192 is rotated 180 degrees, the apex of the end surface 122A and the apex of the end surface 202A come into contact, and the second agitating / conveying auger 192 is attached. It moves to the left side of the drawing against the urging force of the urging spring 204.

  With this configuration, when the second stirring / conveying auger 192 is rotated, the second stirring / conveying auger 192 reciprocates in the direction of the rotation axis of the drive shaft 120. Thus, by reciprocating the second agitating / conveying auger 192, the area where the spiral blade 126 does not contact the developer G is reduced, and the developer agitating performance is improved.

  Other operations are the same as those in the first embodiment.

  Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments are possible within the scope of the present invention. It is clear to the contractor. For example, in the second and third embodiments, the configuration in which the rotation shaft portion is divided into two or four has been described. However, the center of gravity of the plurality of rotation shaft portions as viewed from the rotation shaft direction is the drive shaft portion. If it overlaps with the rotation center, it may be divided into three or may be divided into five or more. Further, the arrangement of the divided rotation shaft portions is not limited to the 90-degree pitch or the 180-degree pitch around the drive shaft portion, and the rotation shaft portions may be provided at other angles.

  In the fifth embodiment, the two spiral blades 184 and 186 are formed on the outer peripheral surface of the rotating shaft portion 182, but the number is not particularly limited to two and may be three or more.

  Further, although not specifically described in the above embodiment, the embodiments may be combined within a range not departing from the gist of the invention.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 16 Image holding body 64 Developing apparatus 86 Developing roll (an example of developing member)
88 1st stirring conveyance auger (an example of the 1st stirring conveyance member)
89 Second agitating and conveying auger (an example of a second agitating and conveying member)
120 Drive shaft portion 124 Rotating shaft portion 126 Spiral blade 130 Connecting portion 140 Second agitating and conveying auger (an example of a second agitating and conveying member)
142 Spiral blade 148 Second agitating and conveying auger (an example of second agitating and conveying member)
150 Rotating shaft portion 150A Rotating shaft portion 150B Rotating shaft portion 152A Spiral blade 152B Spiral blade 160 Second agitating and conveying auger (an example of a second agitating and conveying member)
162 Rotating shaft portion 162A Rotating shaft portion 162B Rotating shaft portion 162C Rotating shaft portion 162D Rotating shaft portion 164A Spiral blade 164B Spiral blade 164C Spiral blade 164D Spiral blade 180 Second stirring auger (an example of a second stirring and conveying member)
182 Rotating shaft 184 Spiral blade 186 Spiral blade 190 Developing device 192 Second agitating and conveying auger (an example of second agitating and conveying member)
194 Reciprocating mechanism

Claims (7)

A developing member that develops the latent image formed on the image carrier with a developer while rotating the latent image, and forms a toner image;
The developer member is disposed opposite to the developing member, extends along the rotation axis direction of the developing member, conveys the developer in the rotation axis direction while stirring the developer, and delivers the developer to the developing member. A stirring and conveying member;
A drive shaft that rotates when a driving force is transmitted from a drive source, and a rotation shaft that extends along the axial direction of the drive shaft and is spaced apart from the drive shaft in the radial direction of the drive shaft And a connecting portion that connects the drive shaft portion and the rotating shaft portion, and a spiral shape so that the developer is conveyed only from one end side to the other end side on the outer peripheral surface of the rotating shaft portion. And a second agitator that is disposed in parallel with the first agitating and conveying member, extends in the direction of the rotation axis, and agitates while circulating the developer between the first agitating and conveying member. A conveying member;
A developing device comprising: The height of the spiral blade from the outer peripheral surface of the rotating shaft portion is h, the shaft radius of the rotating shaft portion is r, and the center of the drive shaft portion and the rotating shaft portion are viewed from the rotating shaft direction. If the distance from the center is l,
h + r ≧ l
The developing device according to claim 1, wherein: The center of the spiral blade and the center of the rotating shaft are eccentric,
The height on the drive shaft side from the outer peripheral surface of the rotation shaft portion in the spiral blade as viewed from the rotation shaft direction is hi, and the drive shaft portion side from the outer peripheral surface of the rotation shaft portion in the spiral blade. Is the height of the opposite side is ho, the shaft radius of the rotating shaft is r, and the distance between the center of the drive shaft and the center of the rotating shaft is l,
hi + r ≧ l
0 <ho <hi
The developing device according to claim 1, wherein: A plurality of the rotation shaft portions are provided by being divided in the rotation axis direction,
The plurality of rotation shaft portions are arranged such that the center of gravity of the plurality of rotation shaft portions provided overlaps the rotation center of the drive shaft portion when viewed from the rotation shaft direction. The developing device according to claim 1.   5. A plurality of spiral blades formed in a spiral shape so as to convey the developer only from one end side to the other end side are formed around the rotating shaft portion. The developing device according to 1.   The developing device according to claim 1, further comprising a reciprocating mechanism that reciprocates the second agitating and conveying member in an axial direction of the drive shaft portion. An image carrier on which an electrostatic latent image is formed on the surface;
The developing device according to claim 1, wherein an electrostatic latent image formed on the image carrier is visualized as a toner image;
An image forming apparatus comprising:

Images