KR100667317B1 - A roller and method for manufactuering the roller and image carrier for image forming apparatus - Google Patents

Abstract

A plurality of counseling members arranged sequentially; An intermediate transfer medium in contact with each of the plurality of counseling members; And a plurality of support rollers for driving the intermediate transfer medium, wherein an interval between at least two rotation centers of the plurality of consultation members is an integer multiple of the circumferential length of the support roller. Is initiated.

Consultation delay, driving roller, belt, radial displacement, image error, error overlap

Description

A roller and method for manufactuering the roller and image carrier for image forming apparatus}

1 is a schematic diagram illustrating a general color image forming apparatus.

2 is a schematic structural diagram showing an image forming apparatus according to an embodiment of the present invention;

Figure 3 is a perspective view showing a drive unit shown in FIG.

Figure 4a is an exploded perspective view of the counseling member shown in FIG.

Figure 4b is a perspective view showing an extract of the drive coupler shown in FIG.

Figure 4c is a perspective view for explaining the drive roller shown in FIG.

Figure 5 is a perspective view showing another embodiment of the consultation delay and the drive coupler shown in Figure 4a.

Figure 6 is a schematic configuration diagram for explaining the radial displacement caused by the runout of the consultation delay and the drive roller shown in FIG.

FIG. 7A is a view for explaining contents of monitoring an end portion of the counseling member shown in FIG. 4A; FIG.

FIG. 7B is a schematic perspective view illustrating a method of assembling counseling members as shown in FIG. 4A.

8A is a schematic structural diagram for explaining an image forming apparatus according to a first embodiment of the present invention;

8B and 8C are schematic graphs for explaining image errors caused by the driving roller in the state shown in FIG. 8A.

9A is a block diagram showing an example of a conventional image forming apparatus.

Fig. 9B is a schematic graph for explaining an image error caused by a driving roller in the image forming apparatus as shown in Fig. 9A.

10A is a schematic structural diagram for explaining an image forming apparatus according to a second embodiment of the present invention;

Fig. 10B is a graph for explaining an image error caused by the driving roller in the state of Fig. 10A.

11A is a schematic configuration diagram for explaining another conventional example.

Fig. 11B is a graph for explaining an image error caused by the driving roller in the state shown in Fig. 11A.

12A is a schematic structural diagram showing an image forming apparatus according to a third embodiment of the present invention;

Fig. 12B is a graph for explaining an image error caused by the driving roller in the state shown in Fig. 12A.

Fig. 13 is a block diagram showing the main parts of a general image forming apparatus.

14A to 14D are schematic views for explaining image errors caused by counseling members having radial displacements.

Fig. 14E is a view for explaining an overlapping image of an image error due to the radial displacement of each counseling member.

Fig. 15A is a schematic block diagram showing a general image forming apparatus employing a counseling member having a radial displacement.

FIG. 15B is a graph for explaining image errors caused by counseling members shown in FIG. 15A. FIG.

16A and 16B are schematic diagrams for explaining an image forming apparatus according to a third embodiment of the present invention.

16C and 16D are schematic diagrams for explaining the image forming apparatus according to the fourth and fifth embodiments of the present invention.

Figure 17a is a schematic perspective view showing a jig for counseling delay setting according to an embodiment of the present invention.

17B is a schematic perspective view for explaining another example of a jig for setting a consultation delay according to an embodiment of the present invention.

18A shows an example in which the driving roller is larger than the consultation delay.

18B is a graph for explaining an image error caused by the driving roller and the consultation delay in the state shown in FIG. 18A.

18C is a schematic structural diagram illustrating an image forming apparatus according to a sixth embodiment of the present invention;

18D is a graph showing an image error caused by the driving roller and the consultation delay in the state of FIG. 18C.

19a shows an example in which the radiuses of the driving roller and the consultation delay are the same.

19B is a graph showing an image error caused by the consultation delay and the driving roller in the state shown in FIG. 19A.

19C is a schematic structural diagram illustrating an image forming apparatus according to a seventh embodiment of the present invention;

Fig. 19D is a graph for explaining image errors caused by the consultation delay and the driving roller in the state shown in Fig. 19C.

20A is a schematic configuration diagram showing an example in which the radius of the consultation delay is larger than that of the driving roller.

20B is a graph for explaining an image error caused by the consultation delay and the driving roller in the state shown in FIG. 20A.

20C is a schematic structural diagram illustrating an image forming apparatus according to an eighth embodiment of the present invention;

FIG. 20D is a graph showing an image error caused by the consultation delay and the driving roller in the state of FIG. 20C; FIG.

Fig. 21A is a block diagram showing an image forming apparatus according to a ninth embodiment of the present invention.

FIG. 21B is a schematic view for explaining an image error caused by the driving roller in the state shown in FIG. 21A; FIG.

FIG. 21C is a schematic diagram for explaining image errors caused by counseling agents in the state of FIG. 21A; FIG.

FIG. 21D is a view for explaining a state in which image errors due to the consultation delay and the driving roller are overlapped in the state shown in FIG. 21A;

22A is a block diagram showing an image forming apparatus according to a tenth embodiment of the present invention;

FIG. 22B is a schematic view for explaining an image error caused by the driving roller in the state shown in FIG. 22A; FIG.

FIG. 22C is a schematic diagram for explaining an image error caused by a consultation delay in the state of FIG. 22A; FIG.

FIG. 22D is a schematic view for explaining superposition of image errors caused by the consultation delay and the driving roller in the state of FIG. 22A; FIG.

Fig. 23A is a schematic structural diagram showing an image forming apparatus according to an eleventh embodiment of the present invention.

FIG. 23B is a schematic view for explaining an image error caused by the driving roller in the state shown in FIG. 23A; FIG.

FIG. 23C is a schematic diagram for explaining an image error caused by a consultation delay in the state of FIG. 23A; FIG.

Fig. 23D is a view for explaining the superposition of image errors caused by the driving roller and the consultation delay in the state shown in Fig. 23A.

<Explanation of symbols for the main parts of the drawings>

30,40,50,60,230 .. Counseling delay 33,83 .. First and second driven couplers

70. Intermediate transfer medium 80. Driving roller

91..support roller 93..T1 roller

100 .. Drive unit 101, 103. First and second drive unit

110. Frame 121, 141. First and second drive motors

123,124,125,126 .. 1st drive gear 143..2nd drive gear

133,134,135,136 .. First drive coupler 145..2nd drive coupler

241,242. First and second jig 300 .. Jig device

310 .. Support frame 330∼360 ..

The present invention relates to a roller, a roller manufacturing method, a drive unit and a color image forming apparatus of an image forming apparatus.

In general, an image forming apparatus is roughly divided into a mono image forming apparatus and a color image forming apparatus. A mono image forming apparatus refers to an apparatus for forming an image in black and white using only one color developer, and a color image forming apparatus forms a color image using a developer for each color (usually magenta, cyan, yellow, and black). Says the device.

In the electrophotographic image forming apparatus, as is widely known, an electrostatic latent image is formed by scanning a laser beam by an exposure unit on a counseling member charged to a predetermined potential by a charging unit. This electrostatic latent image is developed with a developer, and then transferred to a printed image as a visible image. In the case of a color image forming apparatus, a color image developer is developed on each color counseling member, and then a superimposed image is transferred to an intermediate transfer medium such as an intermediate transfer belt (ITB). The color image superimposed on the intermediate transfer medium is transferred onto printing paper. Subsequently, the printing paper on which the color image is transferred is discharged to the outside of the image forming apparatus through a series of fixing processes.

1 is a configuration diagram showing a configuration of a general color image forming apparatus which performs a transfer operation in two steps using an intermediate transfer belt. Referring to FIG. 1, the color image forming apparatus includes an intermediate transfer belt 10, a support roller 11, four T1 rollers 12, 13, 14, and 15, and four consultation members 16, 17, 18 and 19, and a T2 roller 20 and a belt drive roller 21.

The counseling members 16, 17, 18, and 19 are attached to the latent electrostatic latent region by the developer corresponding to K (black), C (Cyan), M (Magenta), and Y (Yellow) through the development process, respectively. . T1 rollers 12, 13, 14, and 15 corresponding to the counseling members 16, 17, 18, and 19 are installed with the intermediate transfer belt 10 interposed therebetween. Accordingly, the developer adhering to the surface of each of the consultation members 16, 17, 18, and 19 is primarily applied to the surface of the intermediate transfer belt 10 by the transfer action of each of the T1 rollers 12, 13, 14, and 15. Is moved to In this case, the color at each counseling member 16-19 so that the developer for each color transferred from each counseling member 16, 17, 18, 19 to the intermediate transfer belt 10 can be superimposed at the same position. The star image is transferred to the intermediate transfer belt 10 with a predetermined parallax. Therefore, it is possible to form one complete color image by overlapping the intermediate transfer belt 10 first. Then, the color image on the intermediate transfer belt 10 is transferred to the print medium 23 through the secondary transfer between the T2 transfer roller 20 and the belt drive roller 21. In addition, the belt drive roller 21 serves to move the intermediate transfer belt 10 at an appropriate speed.

On the other hand, the intermediate transfer belt 10 and the counseling members 16, 17, 18, 19 as described above are consumables whose end of life is used after a certain period of time. Therefore, parts that have reached the end of their life should be replaced with new ones.

Therefore, the transfer unit including the intermediate transfer belt 10 and the developing unit including each of the counseling members 16, 17, 18, and 19 are provided in the image forming apparatus by a driving unit and predetermined coupling means to provide power. It is mounted so as to be connectable and detachable.

By the way, when replacing consumables such as the transfer unit and the developing unit, the structure of the coupling means for the relative movement between the drive unit and each unit plays an important function. That is, it is very important to connect the transfer unit and the developing unit to each other so that their rotation centers coincide with each other. In addition, in view of the manufacturing tolerances of the outer circumferential surface of the driving roller of the transfer unit, it is important to implement a high-precision color registration in consideration of the so-called on-shake tolerance between the transfer unit and the developing unit.

Here, the warm shaking tolerance may be understood to include a phenomenon in which the intermediate transfer belt rotates at an appropriate speed and changes in the moving speed at a predetermined cycle by the manufacturing tolerance of the outer circumferential surface of the driving roller of the transfer unit. This warm shaking tolerance affects each developing unit in the same cycle through the intermediate transfer belt. Therefore, it is very important to improve the quality of the color image by making the influence of the generation of the warm-up tolerance constant on the respective developing units.

In addition, the counseling member or the driving roller has a so-called run-out in which the outer circumferential surface does not form a garden and whose radius changes due to manufacturing tolerances. Such a runout has a problem that an image error occurs such that a predetermined portion of the color image superimposed on the intermediate transfer belt is extended or cut off.

The present invention has been made to solve the above problems, the first object is to provide a roller manufactured to control a predetermined phase.

The present invention has been made to solve the above problems, and a second object of the present invention is to provide a method for manufacturing a roller that can control a predetermined phase.

The present invention has been made to solve the above problems, and a third object of the present invention is to provide a driving unit of an image forming apparatus that is improved to control an image error caused by a phase of a roller supporting a belt.

The present invention has been made to solve the above problems, and a fourth object of the present invention is to provide an improved image forming apparatus capable of controlling image errors caused by a plurality of counseling members.

The present invention has been made to solve the above problems, and a fifth object of the present invention is to provide an improved image forming apparatus capable of controlling image errors caused by a plurality of counseling members and a belt support roller.

Roller of the present invention for solving the above object, the roller body having a radial displacement in the circumferential direction; And a driven coupler coupled to one end of the roller body so as to be complementarily coupled to a drive coupler for transmitting power. The roller body is characterized in that a mark is displayed on a predetermined portion so as to check the radial displacement. .

Here, the driven coupler has a positioning portion for determining the engagement position with the drive coupler, it is preferable that the roller body and the driven coupler is coupled so that the positioning portion maintains a predetermined set angle with respect to the mark.

In addition, the mark is preferably provided on a predetermined angle with respect to the maximum radial displacement portion of the roller body.

In addition, the drum body having a radial displacement in the circumferential direction; And a driven coupler coupled to one end of the drum body so as to be complementarily coupled to a drive coupler for transmitting power. The drum body may be marked with a mark on a predetermined portion so as to check the radial displacement.

In addition, the mark is preferably provided at a predetermined position with respect to the maximum radial displacement portion.

In addition, the driven coupler has a positioning portion for determining a coupling position with the drive coupler, the driven coupler is preferably coupled to the drum body so that the positioning portion and the mark maintain a constant angle.

In addition, an end portion of the driven coupler is formed by engraving or embossing a non-circular coupling portion coupled with the driving coupler to receive power, and the positioning portion extends from the coupling portion in a radial direction of the driven coupler.

In addition, the roller manufacturing method of the present invention for achieving the above object, in the manufacturing method of the roller comprising a roller body having a radial displacement in the circumferential direction and a driven coupler coupled to one end of the roller body, Identifying a maximum radial displacement portion of the roller body; Determining the posture of the driven coupler on the basis of the identified portion to a predetermined position and coupling to the roller body.

Here, the checking may include: finding the maximum radial displacement portion by measuring an end of the roller body; It is preferable to include; marking a mark on the roller body so as to identify the maximum portion found.

The coupling of the driven coupler may include: the driven coupler and the roller such that the positioning unit provided in the driven coupler has a predetermined angle with respect to the maximum displacement portion so as to determine a mutual engagement position when the driven coupler and the driving coupler are coupled to each other. It is good to assemble the body.

In addition, the step of coupling, the step of supporting the roller body to the first jig so that the maximum radial displacement portion is located on a constant angle with respect to the reference coordinate axis; Supporting the driven coupler on a second jig such that the driven coupler is positioned at an angle with respect to the reference coordinate axis; And coupling the driven coupler and the roller body by relatively approaching the first jig and the second jig.

In addition, the driving unit of the image forming apparatus of the present invention for achieving the above object is a plurality of first main gear for driving each of the plurality of consultation members arranged sequentially, and the belt passing through the plurality of consultation members. And a second main gear for driving any one of a plurality of support rollers for supporting traveling, wherein a distance between at least two rotation centers of the plurality of first main gears is a positive integer of the circumferential length of the support roller. Characterized in that the ship.

Here, the interval between the centers of rotation of each of the plurality of first main gear is preferably an integer multiple of the circumferential length of any one of the supporting rollers.

In addition, any one of the supporting rollers may be a driving roller connected to the second main gear to receive power.

In addition, any one of the supporting rollers may be a roller having a relatively large maximum value of radial displacement in the circumferential direction among the plurality of supporting rollers.

The first main gear may include first to fourth driving gears sequentially installed based on the driving direction of the belt, and the distance between the centers of the first and second driving gears may be L1, the second and the second driving gears. The distance between the center of the third drive gear L2, The distance between the center of the third and fourth drive gear L3, The distance between the center of the first and third drive gear L4, The center of the first and fourth drive gear When the interval between the L5, the center between the center of the second and fourth drive gear L6, and the circumferential length of any one of the supporting rollers is Sd, the first to fourth drive gear is the following equation 1 It is good to be installed so as to satisfy at least one condition of ① to ⑥.

[Equation 1]

L1 = lSd (1 ± 0.05) (l = 1, 2, 3, ...) -------- ①

L2 = mSd (1 ± 0.05) (m = 1, 2, 3, ...) --------- ②

L3 = nSd (1 ± 0.05) (n = 1, 2, 3, ...) -------- ③

L4 = o Sd (1 ± 0.05) (o = 1, 2, 3, ...) -------- ④

L5 = pSd (1 ± 0.05) (p = 1, 2, 3, ...) -------- ⑤

L6 = qSd (1 ± 0.05) (q = 1, 2, 3, ...) -------- ⑥

In addition, the first to fourth drive gears are preferably installed to satisfy all the conditions of the equation (1).

In addition, the first to fourth drive gears are preferably installed to satisfy L1 = L2 = L3.

In addition, the first to fourth driving gears are preferably installed to satisfy L1 = L2 = L3 = 1Sd.

In addition, the radius of the support roller is preferably the same as the radius of the consultation delay.

The apparatus may further include a plurality of driving couplers provided at the rotation centers of the plurality of first main gears and coupled to each of the plurality of counseling members to transmit power.

In addition, the driving coupler, the coupling portion formed in a non-circular cross-sectional shape corresponding to the driven coupler provided at each end of the consultation member, and is provided on one side of the coupling portion to be coupled to the driven coupler in any one posture. It is preferable to have a positioning unit for determining the position.

In addition, the coupling portion is a coupling groove formed to be introduced into the non-circular cross-sectional shape from one end surface, the positioning portion is preferably a sink formed in a predetermined depth from the inner surface of the coupling groove.

In addition, the driven coupler has a shaft protruding from the end in the direction of the center of rotation, the bottom surface of the coupling groove is preferably formed with a shaft groove to which the shaft is fitted.

In addition, the coupling portion is a coupling protrusion protruding from the one end surface in a non-circular cross-sectional shape, the positioning portion is preferably a protrusion protruding to the outer surface of the coupling protrusion.

In addition, the image forming apparatus of the present invention for achieving the above object comprises: a plurality of counseling members arranged sequentially; An intermediate transfer medium in contact with each of the plurality of counseling members; And a plurality of support rollers for driving the intermediate transfer medium, wherein an interval between at least two rotation centers of the plurality of counseling members is a positive integer multiple of the circumference of one of the support rollers.

The counseling member may include first to fourth counseling members sequentially installed based on the driving direction of the intermediate transfer medium, and the interval between the centers of the first and second counseling carriers may be L1, the second and the second carriers. The distance between the centers of the three carriers L2, The distance between the centers of the third and fourth carriers L3, The distance between the centers of the first and third carriers L4, The center of the first and fourth carriers When the interval between the L5, the center between the center of the second and the fourth supporting member is L6, and the circumferential length of any one of the supporting rollers is Sd, the first to fourth supporting members are It is preferable that at least any one of ① to ⑥ is provided to satisfy the condition.

[Equation 1]

L1 = lSd (1 ± 0.05) (l = 1, 2, 3, ...) -------- ①

L2 = mSd (1 ± 0.05) (m = 1, 2, 3, ...) --------- ②

L3 = nSd (1 ± 0.05) (n = 1, 2, 3, ...) -------- ③

L4 = o Sd (1 ± 0.05) (o = 1, 2, 3, ...) -------- ④

L5 = pSd (1 ± 0.05) (p = 1, 2, 3, ...) -------- ⑤

L6 = qSd (1 ± 0.05) (q = 1, 2, 3, ...) -------- ⑥

In addition, the counseling members are preferably installed to satisfy all the conditions of the equation (1).

In addition, the counseling agents may be installed to satisfy L1 = L2 = L3.

In addition, the counseling agents satisfy the condition that L1 = L2 = L3, and each of L1, L2, and L3 is preferably an integer multiple of Sd.

The plurality of support rollers may include a driving roller for driving the intermediate transfer medium while being driven and rotated with power, and an idle roller driven by supporting the intermediate transfer medium, wherein Sd is a circumference of the driving roller. It is good to define the length.

In addition, it is preferable to further include a driving unit for driving the respective consultation delay and the support roller.

The driving unit may include a first driving unit for simultaneously driving each of the plurality of counseling members; It is preferable to include; a second driving unit for independently driving any one of the plurality of support rollers.

The first driving unit may include a plurality of drive gears that are provided to correspond to each of the plurality of counseling members and are simultaneously linked and rotated; It is preferable to include; a first drive motor for providing power for driving the plurality of drive gears at the same time.

The second driving unit may include a second driving motor; It is preferable to include one driving gear connected to any one of the supporting rollers and driven by the second driving motor.

In addition, it is preferable that the driving gears and the driven couplers coupled to each other at the corresponding ends of the driving gears and the counseling member are complementary to each other.

The driving and driven coupler may further include: a coupling portion having a non-circular shape at each end and complementarily coupled to each other; It is preferable to have a positioning portion extending in a predetermined shape to one side of the coupling portion to determine the coupling posture of the drive and driven coupler.

In addition, each counseling member has a radial displacement in which the radius changes in the circumferential direction, and A1, A2, A3, and A4, in which the radial displacement is a maximum in a predetermined portion, and the first counseling member is transferred to the transfer medium. The angle between the centers of A1 in the reverse rotational direction of the first counseling member when the transfer point is at the transfer start point of? 1, and the reverse of the second consultation member when the second contact point is the transfer start point to the transfer medium. The angle between the centers of the A2 in the rotational direction is α2 and the angle between the centers of the A3s in the reverse rotational direction of the third carriers is α3 when the third carrier is at the transfer start point to the transfer medium; When the fourth counseling member is at the transfer start point to the transfer medium, the angle between the centers of the A4 in the reverse rotation direction of the fourth counseling member is α4, and the radius of the first to fourth supporting members is Ro1. , Ro2, Ro3, Ro4 In this case, the first to fourth counseling member may be installed so as to satisfy any one of ① to ③ of the following equation (2).

[Equation 2]

{2π · l + (α2-α1)} Ro · (1 ± 0.05) = L1, (l = 0, 1, 2, ...), (Ro = Ro1 = Ro2) ------- --- ①

{2π · m + (α3-α1)} Ro · (1 ± 0.05) = L1 + L2, (m = 0, 1, 2, ...), (Ro = Ro1 = Ro3) ----- --- ②

{2π · n + (α4-α1)} Ro · (1 ± 0.05) = L1 + L2 + L3, (n = 0, 1, 2, ...), (Ro = Ro1 = Ro4) --- ③

In addition, the counseling agents may be installed to satisfy L1 = L2 = L3.

In addition, the counseling agents satisfy the condition of L1 = L2 = L3, and each of L1, L2, and L3 is preferably an integer multiple of Sd.

The apparatus may further include a driving unit for driving the counseling members and the support roller, and one end of each of the counseling members is provided with a driven coupler connected to the driving unit to receive power.

In addition, the driven couplers have a positioning unit for determining a coupling position with the drive unit, the sections A1, A2, A3, A4 of each of the counseling members are provided at a predetermined angle from the positioning unit. Coupled couplers are good.

The driving unit may include: a first driving unit for simultaneously driving the first to fourth supporting members; It is preferable to include; a second driving unit for driving the support roller independently.

The first driving unit may include: a plurality of drive gears that are provided to correspond to each of the plurality of counseling members, and rotate at the same time and have a driving coupler coupled at one end to the driven coupler; It is preferable to include; a first drive motor for providing power for driving the plurality of drive gears at the same time.

In addition, the first and the second counseling member may satisfy ① of Equation 2, and may be arranged to satisfy α1 = α2.

In addition, the first and the third counseling member satisfies ③ of Equation 2, and may be arranged to satisfy α1 = α3.

In addition, the first and fourth counseling member may satisfy (3) of Equation 2, and may be arranged to satisfy α1 = α4.

In addition, the first to fourth carriers satisfy all of Equation 2 and may be arranged to satisfy α1 = α2 = α3 = α4.

In addition, each counseling member has a radial displacement in which the radius changes in the circumferential direction, and A1, A2, A3, and A4, which are areas where the radial displacement is maximum in a predetermined portion, and the first counseling member is transferred to the transfer medium. The angle between the centers of A1 in the reverse rotation direction of the counseling members when the transfer point is at the transfer start point, and the angle between the centers of A2 in the reverse rotation direction when the second counseling body is at the transfer start point to the transfer medium. Α2, the angle between the center of the A3 in the reverse direction when the third carrier is at the transfer start point to the transfer medium α3, the transfer point to the transfer medium of the fourth carrier At least two of the first to fourth carriers when the angle between the center of the A4 in the reverse rotation direction is α4 and the radius of the first to fourth carriers is Ro1, Ro2, Ro3, Ro4 More than Is preferably installed so as to satisfy any one of ① to ③ of Equation 3 below.

[Equation 3]

{2π · l + (α2-α1)} Ro · (1 ± 0.05) = L1, (l = 0, 1, 2, ...), (Ro = Ro1 = Ro2) ------- -①

{2π · m + (α3-α2)} Ro · (1 ± 0.05) = L2, (m = 0, 1, 2, ...), (Ro = Ro2 = Ro3) ------- -②

{2π · n + (α4 − α3)} Ro · (1 ± 0.05) = L3, (n = 0, 1, 2, ...), (Ro = Ro3 = Ro4) ------- -③

In addition, the counseling agents may be installed to satisfy L1 = L2 = L3.

In addition, the counseling agents satisfy the condition that L1 = L2 = L3, and L1, L2, and L3 are preferably integer multiples of Sd.

In addition, the counseling members satisfy all of Equation 3 and are arranged to satisfy α1 = α2 = α3 = α4.

In addition, each counseling member has a radial displacement whose radius changes in the circumferential direction, A which is an area where the radial displacement becomes a maximum in a predetermined portion, and the supporting roller has a radial displacement whose radius changes in the circumferential direction, and It has a B section which is the area where the radial displacement is maximum, and when setting a predetermined X, Y coordinate axis based on the rotation center of the support roller and the inlay support body, the support roller from the + X axis of the X, Y coordinate axis The angle between the centers of the section B in the reverse rotation direction is referred to as θd, and in the reverse rotation direction of the consultation support from the + Y axis of the consultation support arranged in a predetermined sequence (x) with respect to the traveling direction of the intermediate transfer medium. When the angle to the middle of the area A is called θox, the radius of the counseling members arranged in the predetermined order (x) is called Rox, and the radius of the supporting rollers is called Rd. It is preferably the following equation (5) in ① to ③ are installed so as to satisfy any of the conditions on the way.

[Equation 5]

Rd θd = (2πl + θox) Rox (1 ± 0.05) (l = 1, 2, 3, ...), (x = 1, 2, 3, ...), Rd = z Rox, (z = 2, 3, 4, 5, ...) ------ ①

Rd θd = Rox θox (1 ± 0.05), Rd = θox, (x = 1, 2, 3, ...) ------ ②

(2π · h + θd) Rd = Rox θox (1 ± 0.05), (h = 1, 2, 3, ...), (x = 1, 2, 3, ...), Rox = k · Rd, (k = 2, 3, 4, 5, ...) ------ ③

In addition, the + X axis may be defined based on a direction parallel to the running direction of the intermediate transfer medium.

In addition, when the center of the section B is located on the + X axis, the change in the traveling speed of the intermediate transfer medium may be maximized.

In addition, when the radius of the support roller is an integer multiple of 2 or more than the radius of the counseling member, the counseling member and the supporting roller may be disposed so as to satisfy ① of Equation 5 above.

In addition, when the radius of the counseling member and the radius of the support roller is the same, it is preferable that the counseling member and the support roller are disposed so as to satisfy the formula (5).

In addition, when the radius of the consultation delay is an integer multiple of 2 or more than the radius of the support roller, the consultation delay and the support roller may be arranged to satisfy the ③ of the equation (5).

The apparatus may further include a driving unit including a first driving unit for simultaneously driving the counseling members and a second driving unit for driving any one of the supporting rollers.

In addition, the counseling member may include a drum body and a driven coupler coupled to one end of the drum body and connected to the first driving unit to receive power.

In addition, the drum body of each counseling member may have a mark for identifying the maximum radial displacement region A.

In addition, the driven coupler of each counseling member has a positioning part for determining a coupling position with the first driving part, and the counseling member and the driven coupler are coupled so that the positioning part is positioned at an angle with respect to the mark. It is good.

The support roller may include a roller body and a driven coupler coupled to one end of the roller body to receive power from the second driving part.

In addition, the driven coupler of the support roller has a positioning portion for determining the engaging position of the second driving portion, the mark on the roller body to determine the position for the section B has a predetermined angle with respect to the positioning portion It is good to be prepared to maintain.

In addition, it is preferable that the counseling members have the same radius as each other.

In addition, the counseling members may be arranged to satisfy L1 = L2 = L3.

In addition, each counseling member has a radial displacement whose radius changes in the circumferential direction, A which is an area where the radial displacement becomes a maximum in a predetermined portion, and the supporting roller has a radial displacement whose radius changes in the circumferential direction, and It has a B section which is the area where the radial displacement is maximum, and when setting a predetermined X, Y coordinate axis based on the rotation center of the support roller and the inlay support body, the support roller from the + X axis of the X, Y coordinate axis The angle between the centers of the section B in the reverse rotation direction is referred to as θd, and in the reverse rotation direction of the consultation support from the + Y axis of the consultation support arranged in a predetermined sequence (x) with respect to the traveling direction of the intermediate transfer medium. When the angle to the middle of the area A is called θox, the radius of the counseling members arranged in the predetermined order (x) is called Rox, and the radius of the supporting rollers is called Rd. It is preferably the following equation (5) in ① to ③ are installed so as to satisfy any of the conditions on the way.

[Equation 5]

Rd θd = (2πl + θox) Rox (1 ± 0.05) (l = 1, 2, 3, ...), (x = 1, 2, 3, ...), Rd = z Rox, (z = 2, 3, 4, 5, ...) ------ ①

Rd θd = Rox θox (1 ± 0.05), Rd = θox, (x = 1, 2, 3, ...) ------ ②

(2π · h + θd) Rd = Rox θox (1 ± 0.05), (h = 1, 2, 3, ...), (x = 1, 2, 3, ...), Rox = k · Rd, (k = 2, 3, 4, 5, ...) ------ ③

In addition, the + X axis may be defined based on a direction parallel to the running direction of the intermediate transfer medium.

In addition, when the center of the section B is located on the + X axis, the change in the traveling speed of the intermediate transfer medium may be maximized.

In addition, when the radius of the support roller is an integer multiple of 2 or more than the radius of the counseling member, the counseling member and the supporting roller may be disposed so as to satisfy ① of Equation 5 above.

In addition, when the radius of the counseling member and the radius of the support roller is the same, it is preferable that the counseling member and the support roller are disposed so as to satisfy the formula (5).

In addition, when the radius of the consultation delay is an integer multiple of 2 or more than the radius of the support roller, the consultation delay and the support roller may be arranged to satisfy the ③ of the equation (5).

In addition, the counseling members may be installed to satisfy the condition that L1 = L2 = L3.

In addition, the counseling agents satisfy the condition that L1 = L2 = L3, and L1, L2, and L3 preferably satisfy a positive integer multiple of Sd.

The apparatus may further include a driving unit for driving the counseling members and the support roller, and one end of each of the counseling members is provided with a driven coupler connected to the driving unit to receive power.

In addition, the driven couplers have a positioning unit for determining a coupling position with the drive unit, the sections A1, A2, A3, A4 of each of the counseling members are provided at a predetermined angle from the positioning unit. Coupled couplers are good.

The driving unit may include: a first driving unit for simultaneously driving the first to fourth supporting members; It is preferable to include; a second driving unit for driving the support roller independently.

The first driving unit may include: a plurality of drive gears that are provided to correspond to each of the plurality of counseling members, and rotate at the same time and have a driving coupler coupled at one end to the driven coupler; It is preferable to include; a first drive motor for providing power for driving the plurality of drive gears at the same time.

In addition, the first and the second counseling member may satisfy ① of Equation 2, and may be arranged to satisfy α1 = α2.

In addition, the first and the third counseling member satisfies ③ of Equation 2, and may be arranged to satisfy α1 = α3.

In addition, the first and fourth counseling member may satisfy (3) of Equation 1, and may be arranged to satisfy α1 = α4.

In addition, the first to fourth carriers satisfy all of Equation 2 and may be arranged to satisfy α1 = α2 = α3 = α4.

In addition, the image forming apparatus according to another aspect of the present invention for achieving the above object is arranged in sequence, each of which has a radial displacement that changes the radius in the circumferential direction, and the area (A) where the radial displacement is maximum A plurality of counseling agents; A transfer medium in contact with each of the plurality of counseling members; And a support roller for guiding driving while supporting the transfer medium, the support roller having a radial displacement of which the radius changes in the circumferential direction, and an area B of which the radial displacement is maximum. When the predetermined X and Y coordinate axes are set based on the rotational center of, the angle between the centers of the B sections in the reverse rotation direction of the support roller from the + X axis of the X and Y coordinate axes is θd, and the The angle from the + Y axis of the counseling member arranged in the predetermined turn (x) to the middle of the area A in the reverse rotation direction of the counseling member in the traveling direction is referred to as θox, and the predetermined turn (x) is arranged. When the radius of the counseling member is called Rox and the radius of the support roller is called Rd, the counseling members and the support roller are installed to satisfy any one of ① to ③ of Equation 5 below. The.

[Equation 5]

Rd θd = (2πl + θox) Rox (1 ± 0.05) (l = 1, 2, 3, ...), (x = 1, 2, 3, ...), Rd = z Rox, (z = 2, 3, 4, 5, ...) ------ ①

Rd θd = Rox θox, Rd = θox (1 ± 0.05), (x = 1, 2, 3, ...) ------ ②

(2π · h + θd) Rd = Rox θox (1 ± 0.05), (h = 1, 2, 3, ...), (x = 1, 2, 3, ...), Rox = k · Rd, (k = 2, 3, 4, 5, ...) ------ ③

Here, the + X axis is preferably defined based on a direction parallel to the running direction of the intermediate transfer medium.

In addition, when the center of the section B is located on the + X axis, the change in the traveling speed of the intermediate transfer medium may be maximized.

In addition, when the radius of the support roller is an integer multiple of 2 or more than the radius of the counseling member, the counseling member and the supporting roller may be disposed so as to satisfy ① of Equation 5 above.

In addition, when the radius of the counseling member and the radius of the support roller is the same, it is preferable that the counseling member and the support roller are disposed so as to satisfy the formula (5).

In addition, when the radius of the consultation delay is an integer multiple of 2 or more than the radius of the support roller, the consultation delay and the support roller may be arranged to satisfy the ③ of the equation (5).

The apparatus may further include a driving unit for driving the counseling members and the support roller, and one end of each of the counseling members is provided with a driven coupler connected to the driving unit to receive power.

In addition, the driven couplers have a positioning unit for determining a coupling position with the drive unit, the sections A1, A2, A3, A4 of each of the counseling members are provided at a predetermined angle from the positioning unit. Coupled couplers are good.

The first driving unit may include: a plurality of drive gears that are provided to correspond to each of the plurality of counseling members, and rotate at the same time and have a driving coupler coupled at one end to the driven coupler; It is preferable to include; a first drive motor for providing power for driving the plurality of drive gears at the same time.

The second driving part may include a drive gear provided to correspond to the support roller and having a driving coupler coupled to a driven coupler provided at one end of the support roller; It is preferable to include a; second drive motor for driving the drive gear.

Hereinafter, an image forming apparatus according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 2, an image forming apparatus according to an embodiment of the present invention includes a belt installed in contact with a plurality of rotating rollers 30, 40, 50, and 60 and the plurality of rotating rollers 30-60. 70 and a plurality of support rollers 80 and 91 and a drive unit 100 for supporting the belt 70.

In the embodiment of the present invention, the plurality of rotary rollers 30-60 will be described as an example of a counseling member provided for each predetermined color so as to sequentially transfer a predetermined color image to the belt 70. And in this embodiment, four kinds Four rollers, i.e., counseling bodies 30-60, can be used to transfer colors of colors K, blac K, Cyan, Magenta, and Y, respectively, to the belt 70 independently. In the following description, the counseling delay is installed.

In addition, each counseling member 30-60 follows K (blacK), C (Cyan), and M along the traveling direction of the belt 70 (in this embodiment, it is shown in the figure as traveling in a counterclockwise direction). (Magenta) and Y (Yellow) will be described with an example provided so as to sequentially transfer the color image to the belt 70 in superimposition.

In addition, unlike the embodiment of the present invention, even if each counseling member 30-60 is provided with four or less, it should be understood that all the features of the present invention described below are applicable. In addition, it should be understood that each counseling member 30-60 may be arranged along the running direction of the belt 70 in a different order from the above-described K, C, M, and Y orders.

Color development units 26, 27, 28, and 29 are provided in the periphery of the counseling members 30-60, preferably on the lower side, to form a color-specific image on the outer periphery of the counseling member. The configuration of the developing units 26-29 does not characterize the present invention, and may be understood as a generally known art.

The belt 70 is supported by the driving roller 80, the support roller 91, and the plurality of T1 rollers 93 and travels in one direction. The belt 70 is driven by the rotational force of the driving roller 80, and sequentially receives the color-specific images formed on the color counseling members 30-60 sequentially. Therefore, the complete color image is superimposed on the surface of the belt 70 past the Y color counseling member 60. The full color image thus formed is transferred to the print medium 97 passing between the belt 70 and the T2 roller 95. The drive roller 80 is connected to the drive unit 100 receives the power to move the belt 70. The support roller 91 may be installed to be elastically biased toward the belt 70 by an elastic body to support the running of the belt 70 and to maintain tension.

2 and 3, the driving unit 100 includes a frame 110, a first driving unit 101 provided on the frame 110 to drive the counseling members 30-60, and the driving unit. A second driving unit 103 for driving the roller 80 is provided.

The frame 110 includes a front frame 111 and a rear frame 112 coupled side by side.

The first driving unit 101 is a first main motor 121 installed in the frame 110 and a first main gear corresponding to the counseling members 30-60 for each color, that is, first to fourth driving for each color. Gears 123, 124, 125 and 126 and first to fourth drive couplers 133, 134, 135 and 136 are provided to correspond to the rotation centers of the first to fourth drive gears 123, 124, 125 and 126 for each color. The first to fourth driving gears 123 to 126 for each color are disposed at a predetermined magnification interval, and are rotatably installed between the frames 111 and 112. In FIG. 2, reference numeral 122 denotes a shaft gear provided on a driving shaft of the driving motor 121 to drive the respective driving gears 124 and 125. In addition, reference numeral 127 denotes an idle gear for linking the drive gears 123-126. The one driving motor 121 is positioned in the middle of the four first to fourth driving gears 123 to 126 to simultaneously rotate the four driving gears 123 to 126 in the same direction.

The first to fourth driving couplers 133 to 136 rotate together with the respective driving gears 123 to 126. The first to fourth driving couplers 133 to 136 are coupled to each of the driven couplers provided at one end of each counseling member 30 to 60 to have a structure capable of transmitting power. Details of the driving coupler 133-136 and the driven coupler will be described in more detail later.

The second driving unit 103 may be a second main gear installed between the frames 111 and 112 so as to be rotationally driven by the second driving motor 141 installed on the frame 110 and the second driving motor 141. And a fifth driving gear 143 and a fifth driving coupler 145 provided at the center of rotation of the fifth driving gear 143. The fifth driving gear 143 is driven separately from the first to fourth driving gears 123 to 126. The fifth driving coupler 145 is rotated together with the fifth driving gear 143 and has a structure that can be coupled to the driven coupler provided in the driving roller 80 to transfer power. In the exemplary embodiment of the present invention, the first to fifth driving couplers 133 to 136 and 145 have the same coupling structure. Therefore, the configuration of each counseling member 30-60, in particular, the configuration of the driven coupler is also the same As it can be understood that, in the following detailed description of the counseling delay will be described on behalf of the K counseling delay 30 and the first drive coupler 133. The description of the fifth driving coupler 145 corresponding to the driving roller 80 is replaced with the description of the first driving coupler 133.

On the other hand, each of the counseling members 30-60 is a consumable item whose life span expires after forming a predetermined number of images. Therefore, the counseling member 30-60 is a structure that can be attached and detached to the main body 25 independently or as a unit composed of the developing units 26, 27, 28, 29 and replaceable with a new one. Has

These consultation members 30-60 are rotated by receiving power from the drive unit 100. Therefore, when the counseling member 30-60 is mounted in the main body 25, the driven member complementarily coupled to the first to fourth driving couplers 133-136 to receive power from the driving unit 100. It has a coupling structure. Since each of the counseling members 30-60 may be manufactured to have the same configuration, as shown in FIG. 4A, the counseling member 30 will be described in detail with reference to the K-color counseling member 30 forming an image of K color. Let's do it.

Referring to FIG. 4A, the counseling body 30 includes a cylindrical drum body 31 and a driven coupler 33 coupled to one end of the drum body 31. The drum body 31 may be manufactured to have a cylindrical shape with both ends open using a metal material such as stainless steel. Then, it has a structure in which a photosensitive layer on which the image is formed on the outer circumference of the drum body 31 is coated or applied.

 The driven coupler 33 is coupled to one end is pressed into the end of the drum body (31). The driven coupler 33 has a coupling portion 33a having a non-circular cross-sectional shape at the other end and a positioning portion 33b protruding in a predetermined shape from one side end surface of the coupling portion 33a. The coupling portion 33a is a portion coupled to the first driving coupler 133 as shown in FIG. 4B to receive power. The positioning unit 33b is for determining the coupling position of the driven coupler 33, that is, the coupling angle with the first driving coupler 133 of the counseling body 30. Since the driven coupler 33 is applied to the other counseling members 40, 50 and 60 in the same structure, the description of the driven couplers coupled to the other counseling members 40, 50 and 60 will be omitted.

In addition, the driven coupler 33 may further include a shaft 33c protruding from the coupling portion 33a to be provided on a rotation center line. The shaft 33c is coupled to the shaft hole 133c (see FIG. 4B) provided at the center of the first driving coupler 133, so that the rotation centers of the first driving coupler 133 and the driven coupler 33 coincide with each other. Guide to be combined.

Here, in the case of the first driving coupler 133, the coupling portion 133a, which is formed in the end portion in a non-circular shape, and the positioning portion 133b formed in the shape of a sink on the inner surface of the coupling portion 133a. And a shaft hole 133c. The coupling part 133a has a shape corresponding to the coupling part 33a of the driven coupler 33, and the positioning part 133b also has a shape corresponding to the positioning part 33b of the driven coupler 33.

In addition, the driving roller 80 has a roller body 81 and a driven coupler 83 coupled to the end of the roller body 81, as shown in Figure 4c. The driven coupler 83 may have the same configuration as the driven coupler 33 of the counseling member 30 described with reference to FIG. 4A. That is, the driven coupler 83 has a coupling portion 83a having a non-circular cross-sectional shape and a positioning portion 83b extending to one side of the coupling portion 83a. The driven coupler 83 of the driving roller 80 as described above is shown in FIG. Coupling is coupled to the fifth drive coupler 145. Since the driven coupler 83 has the same configuration as the driven coupler 33 described in FIG. 4A, the fifth drive coupler 145 has the same configuration as the first drive coupler 133 to which the driven coupler 33 is coupled. Will have Therefore, the detailed description of the fifth driving coupler 145 will be replaced with the description of the first driving coupler 133 shown in FIG. 4B.

Here, the drive roller 80, that is, the roller body 81 has a predetermined radius (Rd), accordingly has a predetermined circumferential length (Sd = 2π · Rd). In addition, the circumferential length Sd of the driving roller 80 may be designed to be the same as or different from the circumferential length of the counseling member 30-60, and the effect of each case will be described later.

The first to fourth driving couplers 133 to 136 and the driven coupler 33 may be formed in opposite shapes to each other. That is, as shown in FIG. 5, a driven coupler 233 is installed at one end of the roller body 231 of the consultation body 230, and the driven coupler 233 has a non-circularly coupled coupling portion 234. And to the coupling portion 234 It may have a positioning unit 235 formed in a sink shape. In this case, the driving coupler 330 corresponding to the driven coupler 233 of the consultation member 230 is a non-circular coupling portion 331 protruding from the end, and the coupling portion as shown in FIG. 331 has a positioning portion 332 protruding to the side. The positioning unit 332 is complementarily coupled to the positioning unit 235 of the driven coupler 233. In addition, the driven coupler 233 is formed with a shaft hole 236, the drive coupler 330 is provided with a shaft 233 is complementary to the shaft hole 236.

In this way, the driven coupler 233 is provided in an intaglio form at the end of the consultation member 230, and the end of the drive coupler 330 corresponding to the driven coupler 233 can be formed in an embossed form. 5 may be applied to all of the counseling members 30 to 60 and both the first to fourth driving couplers 133 to 136.

In addition, although not shown, it is obvious that the structure of the coupler as shown in FIG. 5 may be equally applicable to each of the driving roller 80 and the fifth driving coupler 145. In addition, although the detailed description is omitted, it is obvious that the coupler structure having the various structures described above may also be applied to the support roller 91.

On the other hand, in general, in manufacturing the rollers of the same type as each of the consultation member 30-60 and the driving roller 80, the roller body can be mass-produced using a mold or the like. By the way, the roller body, that is, the drum body is not easy to implement the garden along the outer circumferential surface due to processing errors generated during production. This will be described in more detail with respect to the consultation delay (30).

As shown somewhat exaggerated in Figure 6, the so-called run-out (run-out) is generated in the outer circumferential surface of the drum body 31 changes the radius in a predetermined section. By this runout, a change in radius, that is, a radial displacement δo, is displayed on the basis of the rotation period of the consultation delay 30. The radial displacement δo due to the runout may be defined as the maximum and minimum values of the continuous radial displacement in the form of a sin curve within one rotation period of the drum body 31, that is, the consultation body 30. have. In this embodiment, the maximum radial displacement of the roller body 31 is set to + δo and the minimum value is set to -δo. As shown in FIG. 6, the section A is a section defined around the maximum radial displacement, that is, + δo, and is largely involved in an image error to be described later, and the range of the section A is the radius of the displacement δo. It may vary depending on size.

As mentioned above, in order to control the influence by the radial displacement (delta) which arises in the roller body 31, it is necessary for an operator to know the position of the said section A. To this end, as shown in FIG. 4A, the roller body 31 may display a mark 31a indicating the position of the section A. FIG. The mark 31a may be provided on the outer circumference or the inner circumference of the roller body 31 to correspond to the center position of the section A. In addition, the mark 31a may be displayed at a position which is out of a predetermined angle from the center of the section A. FIG.

As described above, when the mark 31a showing the center position of the section A is displayed, when the driven coupler 33 is coupled to the drum body 31, the positioning unit 33b of the driven coupler 33 is provided. It can be assembled by controlling the distance between the center and the center of the section A. That is, as shown in Figs. 4A and 6, for each drum body 31 produced, marks 31a can be collectively displayed at a 45 degree angle (+ 45 °) from the center of section A in the rotation direction of the consultation body. Can be. Then, the drum body 31 and the driven coupler 33 can be assembled in a state where the mark 31a and the positioning portion 33b of the driven coupler 33 are aligned with each other. By assembling all of the consultation delays produced in this way, the positioning unit 33b may be arranged at a predetermined position with respect to the section A.

As described above, there may be various methods to match the positioning portion 33b and the mark 31a. For example, as shown in FIG. 7A, an end of each drum body 31 is photographed by a camera (not shown), and the photographed image is viewed through the screen 210 of a predetermined monitor 200. Can be. In this case, the screen 210 may be set as x, y coordinates as a reference, and the garden 211 as a reference may be displayed together. Therefore, when the image 220 of the drum body photographed overlaps with the garden 211, it is possible to find the center of the A section of the photographed image, that is, the center of the maximum radial displacement (+ δ). Then, while the maximum radial displacement (+ δ) is adjusted to be positioned at an angle of 315 ° clockwise from the + x axis, the mark 31a is formed at the outer circumference or end of the drum body 31 corresponding to the + x axis. Can be displayed.

Then, the drum bodies 31 on which the mark 31a is displayed are supported on the predetermined first jig 241 as shown in FIG. 7B, and the marks 31a are formed on the + x axis of the x and y reference coordinates. Align to position. The driven coupler 33 is supported by another second jig 242, and the driven coupler 33 is positioned so that the positioning unit 33b is positioned on the + x 'axis of the predetermined x' and y 'reference coordinates. Align it. In this state, the two jigs 241 and 242 face each other so that the x, y reference coordinates and the x ', y' reference coordinates can be matched. In this state, when the two jigs 241 and 242 approach each other, each driven coupler 33 may be inserted into and coupled to the plurality of drum bodies 31 at the same time, and the center of the A section of each drum body 31 may be combined. To position the positioning unit 33b with respect to It becomes possible. Here, an example of assembling a plurality of counseling members at the same time has been described and described, but is not limited thereto.

In addition, after separately providing a structure capable of rotatably supporting the drum body 31 in the first jig 241, whether or not the mark 31a is located on the + x axis, for example, After rotating the supported drum body 31 while sensing the mark 31a using a sensor or a monitoring device, the drum body 31 is fixed when the mark 31a is positioned on the + x axis. It is also possible to combine with the driven coupler 33.

Any counseling member 30 assembled in the above manner has the center of the section A on the -45 degree angle from the positioning unit 33b. Therefore, considering the fact that there is a section A at a position relative to the positioning unit 33b, it is possible to control the assembly and installation positions of subsequent counseling members, thereby minimizing the occurrence of an image error due to the section A to be described later. You can do it.

Here, for convenience of description, a method of assembling the drum body 31 with the driven coupler 33 based on the section A having the maximum radial displacement (+ δ) has been described, but is not limited thereto. For example, it will be apparent that the initial position of the positioning unit 33b may be determined based on a section having -δo or a section having δo = 0.

In addition, in the same manner as above, it can be seen that the consultation members 40-60 of different colors also have a section A on the -45 degree angle from the positioning unit 33b.

In addition, in the case of the driving roller 80, as in the counseling member 30 described above, it has a runout due to manufacturing process reasons, and as shown in FIG. 6, has a radial displacement δd that changes in the circumferential direction. Such The radial displacement δd caused by the runout of the drive roller 80 also changes in the form of a sin curve on the basis of one rotation period of the drive roller 80, similarly to the consultation delay 30. It can be defined as. Here, the maximum radial displacement of the driving roller 80 is defined as + δd and the minimum radial displacement is defined as −δd. In addition, the predetermined interval at which the maximum radial displacement + δd appears will be described by displaying the interval B. FIG. The section B is driven by the driving roller 80 As a section that affects an image error (to be described in detail later), the range can be defined in various ways. The driving roller 80 is also positioned on a constant rotation angle from the center of section B by assembling the roller body 81 and the driven coupler 83 in the same manner as the assembly method of the consultation body 30. The determination unit 83b may be positioned. Therefore, in the present embodiment, even in the case of the drive roller 80, as shown in Fig. 6, the positioning portion 83a of the driven coupler 83 has a roller (from the center of the section B of the drive roller 80). 80) A description will be made with an example of being positioned at an angle of 45 degrees (-45 °) in the reverse rotation direction.

On the other hand, the maximum and minimum radial displacement ± δd of the drive roller 80 as described above affects the running speed of the belt 70. That is, it can be defined that the tangential velocity at the center of the section B of the driving roller 80 becomes the maximum (Vdmax). Therefore, when the section B and the belt 70 are in close contact with the driving roller 80 and the position receiving the force coincides with each other, that is, the direction of the tangential velocity Vdmax of the driving roller 80 is shown as an imaginary line in FIG. 6. When located side by side with the + y axis, the running speed of the belt 70 becomes maximum. As such, when the traveling speed of the belt 70 is changed, an image error such as an image of each color transferred from the counseling members 30-60 to the belt 70 is stretched, swept or broken. . Since the speed of the belt 70 changes repeatedly by one rotation period by the drive roller 80, such an image error also appears repeatedly on the belt 70 corresponding to one rotation period of the drive roller 80.

As described above, a method of improving the image error caused by the radial displacement δd of the driving roller 80 will be described through the configuration of the present invention. Here, for convenience of explanation, it is assumed that there is no run-out of each counseling member 30-60 and the support roller 91, and therefore, the radial displacement of the counseling member 30-60, δo = 0, , Assuming that it affects the image transferred to the belt 70 only by the radial displacement δd of the drive roller 80, the drive roller 80 is a first step method and effect for minimizing the image error. An example of minimizing the effect of the present invention will be described.

First, as described above with reference to FIG. 6, the driving roller 80 has a maximum radial displacement (+ δ) at + 45 ° when the rotation direction is defined as a positive angle from the positioning unit 83b. Assume that the center of is located. The + 45 ° angle is an arbitrary section set for convenience of description. The drive roller 80 has a radius Rd of a predetermined length and a circumferential length Sd = 2π · Rd. As described above, in the state in which the driving roller 80 having the radial displacement δd is disposed, the counseling members 30-60 may perform at least one of the following conditions ① to ⑥ of Equation 1 below. When disposed satisfactorily, it is possible to reduce an image error occurring in an image superimposed on the belt 70.

L1 = lSd (1 ± 0.05) (l = 1, 2, 3, ...) -------- ①

L2 = mSd (1 ± 0.05) (m = 1, 2, 3, ...) --------- ②

L3 = nSd (1 ± 0.05) (n = 1, 2, 3, ...) -------- ③

L4 = o Sd (1 ± 0.05) (o = 1, 2, 3, ...) -------- ④

L5 = pSd (1 ± 0.05) (p = 1, 2, 3, ...) -------- ⑤

L6 = qSd (1 ± 0.05) (q = 1, 2, 3, ...) -------- ⑥

Referring to FIG. 2, the distance between the centers C1 and C2 of the first driving gear 123 and the second driving gear 124 is represented by L1, the second driving gear 124 and the third driving in Equation 1. The distance between the centers C1 and C3 of the gear 125 is L2, and the distance between the centers C3 and C4 of the third drive gear 125 and the fourth drive gear 126 is L3 and the first drive gear 123. And the distance between the centers C1 and C3 of the third drive gear 125 and L4, and the distance between the centers C1 and C4 of the first drive gear 123 and the fourth drive gear 126 to L5 and the second drive. With gear 124 The interval between the centers C2 and C4 of the fourth drive gear 126 is defined as L6.

In addition, drive couplers 133-136 are provided in the drive gears 123-126, and the counseling members 30-60 are rotatably coupled to the drive couplers 133-136. The centers C1, C2, C3, and C4 also coincide with the center of rotation of each counseling member 30-60. Accordingly, it may be understood that counseling members 30-60 are arranged to satisfy at least one of the equations (1). In this case, of course, L1 is the interval between C1 and C2 centers of K counsel member 30 and C counsel member 40, and L2 is the center (C1) of C counsel member 40 and M counsel member 50. , The interval between C3), L3 is the interval between the centers (C3, C4) of the M counseling member (50) and the Y counseling member (60), and L4 is the center of the K counseling member (30) and the M counseling member (50). The interval between (C1, C3), L5 is K The interval between the counseling member 30 and the center (C1, C4) of the counseling member (60), L6 is the interval between the counseling member (40) and the center (C2, C4) of the counseling member (60), Y. It must be understood.

Therefore, in the end, by setting the system so that the image forming apparatus satisfies at least one of the equations (1) to (6), the number of image errors by the driving roller 80 can be reduced. In the case of FIG. Each counseling member 30-60 is arranged to satisfy all the conditions of Equation 1, and an example of L1 = L2 = L3 is shown as a preferred embodiment.

 Hereinafter, when each counseling member 30-60 is disposed in a state in which any one of Equations 1 is not satisfied, an image overlapping the belt 70 by the section B of the driving roller 80. Let's look at an example where many image errors occur. Specifically, three cases considering the size of the radius Rd of the driving roller 80 and the radius Ro of the counseling member 30-60 will be described in order.

First, as shown in FIG. 8A, a case in which Rd> Ro will be described. In the case of FIG. 8A, a case where each of the counseling members 30 to 60 does not satisfy any of Equation 1 is illustrated. That is, the case where the distance between two centers selected from the centers C1, C2, C3, and C4 of each counseling member 30-60 is not an integer multiple of the circumference Sd of the driving roller 80 is illustrated.

And, as shown in Fig. 8A, assuming that the K color image starts the transfer for the first time with the center of the section B of the drive roller 80 located on θd (+ 135 °) on the + X axis. Let's see. Then, as shown in Figure 8b, the driving roller 80 has a radial displacement δd in the form of a sinusoidal curve according to the travel distance of the belt 70. It is repeated, and it can be seen that section B appears once every rotation period. In FIG. 8A, if the transfer of the K image starts at the point F0, and the driving roller 80 starts one rotation period from the point where the f0 point is located on the + x axis, an image error that occurs in the K image by the section B is performed. As shown in FIG. 8B, the center of Rke is generated at a position spaced apart from the point F0 by Rd · θd.

Then, when the length of the transfer image by each counseling member is sufficiently short, for example, when the point F1 at which the K-transcription ends and the transfer start point F2 of the C image coincide with each other, the section is in the section where the C image is transferred. Since there is no influence on B, an image error due to the B section does not naturally occur in the C image. Since the transfer of K ends and the C transfer starts before the belt 70 is moved by 1 Sd distance, the point F3 where the C transfer ends is positioned before the belt proceeds from the F0 point by Sd + Rd.θd. An image error does not occur in the C image.

Subsequently, when the M transfer point F4 proceeds at the same position as the time point F3, an image error Rme is generated in the M image by the section B at a distance spaced from the F4 point by a predetermined distance. However, since the distance L4 is not an integer multiple of Sd, the M transfer start time F4 is one rotation period of the driving roller 80, and the belt 80 at the point f1 at which the second rotation period is started. The predetermined distance t1 is further in the traveled position. Therefore, when the M image error Rme sees the image transfer section for each color as the unit image region P1, the K image error Rke and the M image error Rme start the unit image region P1. It occurs at different positions from the line SL. Ie two The image error Rke (Rme) appears in the unit image P1 with a distance difference of Rd.theta.d-t1.

By the same principle as above, the point F5 at which the transfer of the M image is finished and the point at which the Y transfer starts at F6 are performed before the belt 70 is moved by 2Sd, that is, the two rotation cycles of the drive roller 80 are finished. Before. Therefore, an image error (Rye) due to the section B also occurs in the Y image. However, since the start point F6 of the Y image transfer is a predetermined distance t2 before the point f2 at which the second rotation period of the driving roller 80 starts, the center of the Y image error Rye is It occurs at a position spaced apart from the start line SL by t2 + Rd.

As described above, when Rd> Ro, there may be a color image that is not affected by the B section of the driving roller 80, such as a C image. Therefore, in this case, it is not necessary to consider the consultation delay 40 of the corresponding color that does not cause an image error, but at least two of the image errors Rke (Rme) (Rye) that occur apart from each other are matched. Even if the number of image errors occurring in the unit image P1 can be reduced. It can be seen that. Hereinafter, a method of matching the K and M image errors Rke Rme among the three image errors Rke Rme Rye will be described as an example.

In order to make the two image errors Rke (Rme) coincide, a system may be implemented so as to satisfy ④ of Equation 1 above. That is, the distance L4 = o Sd (o = 1, 2, 3, ...) between the centers C1 and C3 of the two counseling members 30 and 50 can be set. For this purpose, as illustrated in FIG. 8A, the counseling member 50 may be installed such that the center C3 is located at a distance of 1 Sd from C1.

In the state where the system is set as described above, assuming that image transfer starts from the K image as described above with reference to FIG. 8B, the center of the K image error Rke is spaced apart from the start line SL by Rd.θd. Will occur at the location. In the C image, as described above with reference to FIG. 8B, an image error does not occur.

Meanwhile, as shown in FIG. 8C, since the center C3 of the M counseling member 50 is 1Sd, that is, at the point f1 at which the second rotation period of the driving roller 80 starts, The transfer start point F4 of the M picture is located before the point F3 where the transfer of the C picture ends. The point F4 is located at the same position as the point f1. Therefore, the center of the M image error Rme by the section B is generated at a position spaced apart from the start line SL of the unit image P1 by Rd · θd. Accordingly, the K and M image errors Rke Rme can be superimposed at the same position. therefore, Since the number of image errors in the final color image to be printed can be reduced, there is an advantage that a high quality image can be obtained. Here, of course, since the Y picture error Rye has not been considered, the Y picture error Rye naturally occurs at a position different from the K and M picture errors Rke Rme as described above with reference to FIG. 8B. .

Here, in the case where all of the Y image errors Rye are to be superimposed at one position, the system is configured to satisfy the condition ④ and ③ in Equation 1 simultaneously, or the condition ④ in Equation 1 above. At the same time You can configure the system to satisfy it. When the above conditions are satisfied, the principle of overlapping the K, M, and Y image errors Rke (Rme) (Rye) is described for the process of matching the two image errors (Rke) (Rme). Since the description can be sufficiently understood from the description, detailed description thereof will be omitted.

In addition, in the present embodiment, since the transfer section of the image for each color by the counseling members 30-60 is arbitrarily defined, each of the start and end points of the transfer of the image is set to be arbitrarily described for convenience of explanation. Without being limited thereto, various examples are possible under the condition that Rd> Ro, Therefore, the number of image errors occurring in the unit image may vary. However, it is a matter of course that at least two or more desired image errors can be superimposed by satisfying at least one of the conditions of Equation 1 irrespective of the number of image errors.

In addition, in the case of FIG. 8A, the case where the variable o = 1 is described as an example in ④ of Equation 1, but this is merely illustrative, and it is obvious that the same effect can be expected when the variable o is an integer of 1 or more. .

A second example of the first step will be described. As shown in FIG. 9A, an image error that occurs when none of the conditions of Equation 1 is satisfied when Rd = Ro is described. Subsequently, any one condition of Equation 1 is satisfied. A method of reducing image errors will be described sequentially.

First, in FIG. 9A, suppose that the K-color image starts to be transferred for the first time when + δ, that is, the center of the B section is at θd (135 °) with respect to the + X axis. In this case, as shown in Fig. 9B, m1 = Rd? Θd in the transfer start line SL of the K image transferred to the unit image region P1. An image error Rke is generated by the section B around the distanced distance. That is, the SL of the K image starts at the point F0, and the point in time at which all the K images are transferred (in this case, the unit image is completed by one rotation of the driving roller 80 for convenience of explanation), that is, the SL When the point F1 is reached, the center of the section B of the driving roller 80 is at the initial position (135 ° from the X axis) as shown in FIG. 9A.

However, since the distance L1 between the centers C1 and C2 of the two counseling members 30 and 40 is longer than the circumferential length Sd of the driving roller 80 by t3 sections, the belt 70 has a t3 section at the F1 point. Move further by, and the C color image starts to be transferred from the F2 point. Here, the rotation angle of the driving roller 80 corresponding to the section of t3 is assumed to be 45 ° will be described. Then, the center of the image error Rce generated in the C image by the section B is spaced apart by Rd.θd from F1. However, since the start line SL of the actual C image is F2, it is m2 from SL of the unit image P1. = Rd.θd-t3 = Rd. (Θd-45 °) = Rd. 90 °. Therefore, the distance between the centers of two image errors Rke (Rce) is generated to be spaced apart by t3 = Rd · 90 ° in the unit image.

In addition, since the distance L2 between the centers C2 and C3 of the C and M counseling members 40 and 50 is also longer by t3 than Sd, the belt 70 is t3 = Rd · 45 from the point F3 where the C transfer ends. Move further by ° to start receiving the M picture from the F4 point. At this time, the F4 is a position moved further by 2t3 distance from the start point f2 of the second rotation period of the drive roller 80. Therefore, considering that the center of the M image error Rme in the B section is generated at a distance in which the belt 70 is advanced by Rd · θd from f2, the center of the M image error Rme is substantially the M unit image area. It occurs at a position spaced apart from the start line SL of (P1) by m3 = Rd.θd-2t3 = m1-2Rd.45 ° = Rd (θd-90 °) = Rd.45 °. As a result, it can be seen that the M image error Rme also occurs at a different position in the unit image region P1 than the other K and C image errors Rke Rce.

9A, the distance L3 = Sd + 2t3 between the centers C3 and C4 of the M counseling member 50 and the Y counseling member 60 is illustrated. In this case, the start point f3 of the third rotation period of the drive roller 80 is 2 t3 sections before the point F5 where the transfer of the M image ends. Then, since the distance between the two counseling members 50 and 60 is further spaced by 2t3 than Sd, the transfer of the Y image starts at the point F6 where the belt 70 is further moved by 2t3 at the point F5. In this case, the point F6 is the point at which the belt 70 is moved by 4t3 from the point f3. Therefore, no image error is caused by section B in the third rotation period of the drive roller 80, but Y image error Rye occurs at a position where m1 = Rd · θd is advanced from the start point f4 of the fifth rotation period. Done. Since f4 is located in the transfer section of the Y image, a Y image error Rye occurs. At this time, the Y image error Rye is from the point F6, that is, from the SL of the unit image region P1, m4 = Sd + m1-4t3 = Rd.2π + Rd.θd-4Rd.45 ° = Rd (2π-45) Occur at positions spaced apart by °). Accordingly, the Y picture error Rye also occurs at positions spaced apart from each other in the other picture errors Rke (Rce) Rme and the unit picture area P1, thereby adversely affecting the quality of the picture. As described above, when Rd = Ro, one or more image errors occur in the color transfer image by each counseling member 30-60. That is, in FIGS. 9A and 9B, when each counseling member 30-60 rotates once, all color unit images are transferred. However, when the counseling members 30-60 rotate two times, One color image may be considered to be completed. Even in this case, it is naturally predicted that one image error may occur in the transfer image for each color. Therefore, when at least two or more of the image errors generated as described above are superimposed on each other, the quality of the image can be improved by that amount.

Therefore, hereinafter, a case in which the system is set to satisfy all the conditions of ①, ②, and ③ of Equation 1 will be described as an example among various embodiments that may correspond to the second of the first step. Referring to FIG. 10A, the system is set so that the interval between the centers C1, C2, C3, C4 of each counseling agent 30-60 satisfies L1 = L2 = L3 = Sd. Under these conditions, when the center of the section B of the driving roller 80 is at an angle rotated by θd = 135 ° on the + x axis, the initial K image starts to be transferred to the belt 70 at the F0 point. Let's see. Then, assuming that one unit image is formed in one rotation of the counseling members 30-60, the interval L1 between the centers C1 and C2 of the two counseling members 30-40 is an integer multiple of Sd, that is, L1 = It corresponds to 1Sd. Accordingly, as shown in FIGS. 10A and 10B, the distance from the transfer start point F0 of the K image to the point F1 at which the K transfer is terminated starts at the second rotation period at f0 where the first rotation period of the drive roller 80 starts. To the distance f1. Therefore, in the K image, the K image error Rke is generated such that the center of the K image error Rke is located at a distance from the SL corresponding to F0 by the distance of the belt 70 by m1 = Rd · θd.

Subsequently, the C transfer start time F2 coincides with F1, and f1 also coincides with F1, so that the center of the C picture error Rce that appears in the C picture by the section B is the point F1, that is, m1 = SL in the C picture. It is in a position spaced apart by Rd 占 θd. Therefore, K and C image errors Rke (Rce) are caused to overlap at the same position.

Further, since L1 = L2 = 1Sd, the M transfer start point F4 is located at the same position as the C transfer end point F3 and the start point f2 of the third rotation period of the drive roller 80. Therefore, the center of the M picture error Rme generated by the section B in the M-transfer image is generated by a difference of m1 = Rd · θd from SL, which is the same position as the F3 point, so that the K and C picture errors ( Rke) (Rce) is generated by overlapping at the same position.

Further, since L1 = L2 = L3 = Sd, the Y transfer start point F6 is at the same position as the transfer end point F5 of the M image and the start point f3 of the fourth rotation period of the driving roller 80. Therefore, the center of the Y image error Rye generated by the section B in the Y-transcribed image is generated at a position equal to the point F6, i.e., m1 = Rd.θd from the start line SL of the unit image region P1. do. Accordingly, the Y picture error Rye is generated by being overlapped at the same position as the K, C, and M picture errors Rke (Rce) Rme, which have already been superimposed above, and thus, the picture error generated in the unit image P1. The number can be significantly reduced, and the quality of the image can be improved.

As a third example of the first step, a case in which Rd <Ro will be described.

11A shows an example of a system in the case where Ro = 2Rd. In this case, each counseling member 30-60 will be described on the assumption that the image for each color is made by one rotation. Therefore, in FIGS. 11A and 11B, when the driving roller 80 is rotated two times, the counseling member 30-60 rotates once and one unit image is formed. Referring to FIG. 11A, the centers C1, C2, C3, and C4 of the counseling members 30-60 are arranged not to satisfy any condition of Equation 1 above. In this state, the K image is first transferred to the belt 70 at a position of the maximum radial displacement + δd of the drive roller 80, that is, the center of the section B spaced apart by θd (+ 135 °) from the + X axis. It can be said that it starts. Here, the position of the section B, ie,? D, is arbitrarily determined for convenience of description.

When the K image is transferred to the belt 70 at the K transfer start time point F0, the start point f0 of one rotation period of the drive roller 80 coincides with the F0 point. Then, the center of the first K picture error Rke1 by the section B is generated at the position where the belt 70 is advanced by the point F0, i.e., m1 = Rd · θd from the transfer start line SL of the unit image. Since the K image transfer is defined by one rotation of the counseling member 30, the driving roller 80 is rotated two times during the K image transfer. Therefore, the second K image error Rke2 occurs at a position where the belt 70 is moved by 1Sd = 2π · Rd from the center of the first K image error Rke1. That is, during K transfer, two K picture errors Rke1 and Rke2 occur in one unit image area P1 by a section B, and the center of the second K picture error Rke2 is Sd + m1 from SL. Occur at a spaced location.

On the other hand, since the distance L1 = 1Sd + t3 between the centers C1 and C2 of the two consultation members 30-40, the transfer of the C image is belted at the starting point f1 of the second rotation period of the driving roller 80 by t3. 70 starts at point F2 where progression is made. Therefore, the center of the first C image error Rce1 generated by the section B in the two rotation periods of the drive roller 80 is generated at the point where the belt 70 is moved by m1 from f1. As a result, the center of the first C image error Rce is generated at a position spaced apart from m2 = m1-t3 in the C-image transfer start line SL. Here, for convenience of description, the distance corresponding to t3 is defined and described as a circumferential path when the driving roller 80 is rotated by 45 °. Then, it can be seen that m2 = Rd.θd-Rd.45 ° = Rd (θd-45 °). Accordingly, the center of the first C picture error Rce1 is generated at a position spaced apart from the centers of the two K picture errors Rke1 and Rke2 in the unit image area P1.

In addition, while the C image is transferred, a second C image error Rce2 caused by the B section occurs during the third rotation of the driving roller 80. The center of the second C picture error Rce2 is generated at the point where the belt 80 is advanced by Sd at the center of the first C picture error Rce1. Accordingly, the center of the second C picture error Rce2 is a position spaced apart from the SL of the C unit image P1 by m2 + Sd = Rd (θd-45 °) + 2πRd = Rd · (2π + 90 °). Will occur in. As described above, two C picture errors Rce1 and Rce2 are generated at different positions in the C unit image P1, and are also generated at positions spaced apart from the K picture errors Rke1 and Rke2.

Subsequently, since the distance L2 = Sd + t3 between the centers C2 and C3 of the C and M counseling members 40 and 50, the transfer start point F4 of the M picture is 2Sd + 2t3 moved from F0, that is, the point f2. The transfer of the M image starts from the point F4 where the belt 70 is moved by 2t3 from. Therefore, the center of the first M image error Rme1 generated in the unit image area P1 during M transfer by the section B is generated at a position spaced apart from the point f2 by m1 = Rd · θd. Therefore, the distance difference m3 between the center of the image error Rme1 and the SL of the unit image region P1 during M transfer is m3 = m1-2t3 = Rd.theta.2Rd.45 ° = Rd. do. The center of the second M image error Rme2 generated by the section B is generated at the point where the belt 70 is moved by Sd from the center of the image error Rme1. Accordingly, the second M picture error Rme2 occurs at a position spaced apart from the SL of the M picture by m3 + Sd = Rd. (Θd-90 °) + 2π.Rd = Rd. (2π + 45 °). . Accordingly, two M picture errors Rme1 and Rme2 occur at different positions from the previous K and C picture errors Rke1, Rke2, and Rme1 and Rme2.

11A, the distance L3 = Sd + 2t3 between the centers C3 and C4 of the M and Y counseling members 50 and 60 is shown. Therefore, the transfer time F6 of the Y image is in the position where the belt 70 is moved as much as 3Sd + 4t3 from the point f0. Then, the center of the first Y image error Rye1 generated by the section B during the fourth rotation of the driving roller 8 is generated at a distance difference of m4 from the F6 point. Here, since the distance difference between F6 and f3 is 4t3, the distance difference between F6 and f4 is Sd-4t3. The distance difference between f4 and the first Y image error Rye1 is m1. Therefore, m4 = Sd-4t3 + m1 = 2π-Rd-4Rd * 45 ° + Rd · θd = Rd · (2π-45 °). Then, the second Y image error Rye1 is issued at the point where the belt 70 is advanced by Sd from the center of the first Y image error Rye1. Therefore, the center of the second Y image error Rye1 is generated at a position spaced apart from m4 + Sd = Rd · (4π−45 °) from the SL of the Y unit image P1. As described above, the Y image errors RYe1 and RYe1 are also generated at different positions from the K, C, and M image errors in the unit image P1, and thus, a large number of images are generated in the unit image P1. An error will occur.

As described above, when at least one pair of image errors generated by two colors are overlapped in the unit image P1, the number of image errors can be reduced by that amount, thereby improving image quality.

Hereinafter, an embodiment in which image errors Rce1 and Rce2 (Rye1 and Rye2) of C and Y are overlapped with each other among the image errors generated by two colors for each color as shown in FIGS. 11A and 11B will be described. . To this end, in the case of the present invention, the system of the image forming apparatus may be set to satisfy ⑥ in Equation 1 above. That is, the two counseling members 40 and 60 may be arranged as shown in FIG. 12A so as to satisfy L6 = q · Sd. In the case of Figure 12A, L6 = 3Sd. That is, the interval between the centers C2 and C4 of the C and Y counsel members 40 and 60 is arranged to have an integral multiple of the circumferential length Sd of the drive roller 80. And the remaining intervals L1, L2, L3, L4, L5 are not all integer multiples of Sd. That is, when comparing FIG. 11A and FIG. 12A, only the Y counsel member 60 of 12a has changed position. Therefore, the remaining counseling members 30-50 will be understood and described as being disposed in the same position as that of FIG. 11A.

First, in the state as shown in Fig. 12A, when the K image is started from the FO point, the K image is transferred while the driving roller 80 is rotated two times. Therefore, the first and second K picture errors Rke1 and Rke2 caused by the section B occur at the points described above with reference to FIGS. 11A and 11B. That is, the center of the first K picture error Rke1 is generated at the point where the belt 70 is moved by the point m1 = Rd · θd at the point f0 (F0), and the center of the second K picture error Rke2 is the f0 point. From the point where the belt 70 is moved by Sd + m2 will occur.

In addition, the first and second C image errors Rce1 (Rce2) generated during C image transfer also occur at the point described above with reference to FIG. 11B. That is, the center of the first C image error Rce1 is F2. At the point, m2 = m1-t3 = Rd.θd-Rd.45 ° = Rd (θd-45 °). The center of the second C image error Rce2 is m2 + Sd = Rd (? D-45 °) + 2πRd = Rd · (2π) from the point F2, that is, the transfer start line SL of the C unit image P1. + 90 °) at the point where the belt 70 is moved.

In addition, the belt 70 moves from the point F4 to the first M image error Rme1 generated by M image transfer by m3 = m1-2t3 = Rd.θd-2Rd.45 ° = Rd. (Θd-90 °). Occurs at that point. The center of the second M image error Rme2 is the point at which the belt 70 is moved from the point F4 by m3 + Sd = Rd. (Θd-90 °) + 2πRd = Rd. (2π + 45 °). Occurs in the

On the other hand, since the center C4 of the Y counsel member 60 is spaced 3Sd away from C2, the point F6 at which the transfer of the Y image starts is 3Sd also from the point F2 at which the transfer of the C image starts. Is located at the point where it is moved. Then, the point F6 is different from the point f4 by t3, and the center of the first Y image error Rye1 is generated by the section B at the point moved by the distance m1 from the point f4. Therefore, the center of the first Y image error Rye1 is from the point F6, i.e., SL from which the transfer of the Y image starts, m4 = m1-t3 = Rd θd-Rd 45 ° = Rd (θd-45 °) = Since the belt 70 is moved by m2, two image errors Rke1 and Rye1 overlap in the unit image region P1.

In addition, in the case of the second Y image error Rye2, the belt 70 by the point M4 + Sd = m2 + Sd = Rd. (Θd-45 °) + 2πRd = Rd. (2π + 90 °) from the F6 point. Will occur at the point where. Therefore, the second C picture error Rce2 and the second Y picture error Rye2 may overlap at a point spaced apart from the SL in the unit image area P1 by the same distance.

In view of the above, the full-color image region P1 transferred to the belt 70 via all four counseling members 30-60 includes overlapping image errors Rke1, Rye1 (Rke2, Rye2). Since six image errors occur, two fewer than eight image errors occurred in the configuration shown in Fig. 11A. Therefore, the quality of the image is improved as the number of image errors is reduced, thereby ensuring the reliability of the product.

Meanwhile, in FIG. 12A, only the distance L6 between the centers of the C and Y counseling members 40 and 60 is an integer multiple of Sd. For example, at least one of the other distances L1, L2, L3, L4, and L5 may be satisfied. In this case, a larger number of image errors can be superimposed. In addition, when the system is set to satisfy L1 = L2 = L3 = n Sd (n = 1, 2, 3, ...) under the condition of Ro> Rd as described above, eight image errors are detected. The number of superimposed images can be reduced so that the quality of the images can be improved. And this operation and effect will be omitted because it can be fully understood through the description of Figures 12a and 12b described above.

In addition, in describing the embodiment of the present invention according to Equation 1, the description has been focused on minimizing the occurrence of an image error due to the run out of the driving roller 80, but this is merely illustrative. That is, even in the case of an image error caused by the runout of the support roller 91, it is natural that the occurrence of the image error can be minimized by applying the above equation (1).

Therefore, the system is set to satisfy the above Equation 1 on the basis of the roller having a larger radial displacement among the driving roller 80 and the supporting roller 91 to have a greater effect on the image, and the post-process for the remaining rollers. For example, by minimizing runout through precision machining, the occurrence frequency of the image error by the support rollers of the belt 70 may be reduced.

Now, as a second step of reducing image errors occurring in the unit image, the influence of the radial displacement δo on the image quality due to the runout of each counseling member 30, 40, 50, 60, and a method of solving the problem are described. I'll explain.

That is, as described above with reference to FIGS. 4A to 7B, each counseling member 30-60 has an A section in which a maximum radial displacement + δo appears. Image errors such as image scraping, dropping, and sagging may occur in the color-specific image formed in each counseling member 30-60 by the section A and the transferred image transferred to the belt 70. This will be described in detail with reference to FIG. 13. For example, when forming the K image, the counseling member 30 is rotated so that the surface of the counseling member 30 is rotated in contact with the charging roller 35 by the charging roller 35 at a predetermined potential. However, in the section A, the radius increases + δ, and thus increases by + δo from the radius Ro of the counseling member 30, so that the section A has the maximum tangential velocity Vmax. When the section A passes in contact with the charging roller 35 and passes faster, the section A may have a lower electric potential than the other part because the charging amount is insufficient.

In addition, an electrostatic latent image is formed by scanning a laser beam from the laser scanning unit 31 on the surface of the consultation support body 30 to expose a portion corresponding to a desired image. In this case, the tangential velocity in section A is increased. Therefore, the amount of light scanning in the A section is reduced and the scanning area can be increased. In the electrostatic latent image area formed on the surface of the consultation member 30, a developer such as toner supplied from the developing roller 33 is transferred via the developing roller 33 to form a visible image. However, even in this case, the section A passing between the developing roller 33 passes more quickly, and the exposure amount of the electrostatic latent image is also insufficient and slack so that a sufficient amount of the developer cannot be transferred, and the speed is increased. This speeds up the cleaning of the transferred developer. As described above, the visible image formed on the surface of the counseling member 30 through the charging, exposing, and developing stages may cause an image error such as image scuffing, sagging, and breaking in the A section.

As such, before the visible image formed on the surface of the counseling member 30 is transferred to the belt 70, an image error may already occur in the section A. FIG. When the visible image is transferred to the belt 70, an image error occurs in the image transferred to the belt 70 under the influence of the section A. As described above, an image error occurs separately from the runout of the driving roller 80 described above due to the section A by the runout of the counseling member 30-60. As described above, since one or more image errors are generated for each counseling member 30-60 by the runout of the counseling member 30-60, a large number of image errors may occur in the full-color image. For example, when each counseling member 30-60 is configured to rotate two turns to form a unit image, two counseling members 30-60 may cause an image error. In this case, eight image errors may occur in the full color image.

In addition, when each counseling member 30-60 is configured to form a unit image in one rotation, each counseling member 30-60 generates an image error one by one, so a total of four images are included in the full-color image. Is formed.

Meanwhile, as described above with reference to FIGS. 4A to 7B, the center of the section A that generates the image error may be arranged at a predetermined position with respect to the positioning unit 33b of the driven coupler 33. That is, the separate mark 31a is displayed on the predetermined angle of the drum body 31 from the center of the section A, and then assembled by matching the mark 31a with the positioning portion 33b. In addition, the consultation member 30-60 can be assembled using a separate measuring device and a jig without displaying the mark 31a.

In the following, image errors occurring during image formation using the counseling members 30-60 assembled so that the center of the section A is positioned at a predetermined angle with respect to the positioning unit 33b as described above will be described. A method and an operation effect of reducing the number of image errors caused by the embodiment of the present invention will be described.

Herein, the description is made and defined with emphasis on the section A in which + δo of each counseling member 30-60 appears, and of course, the same definition is possible in the region in which -δo appears. However, since the region where + δo appears has a greater influence on the image error than the region where -δo appears, the description will be focused more on the + δo region, and the description of -δo will be replaced with the description regarding + δo.

In addition, for convenience of explanation, it is assumed that the driving roller 80 and the supporting roller 91 are gardens without run-out, and thus the radius of rotation of the belt 70 is set by the rollers 80 and 91. It is assumed that the speed change due to the displacement does not occur and the vehicle is driven at a constant speed.

First, as shown in Figs. 14A to 14D, the counseling members 30-60 for each color are arranged so that the positioning unit 33b of each driven coupler is counterclockwise (defined at + angle) from the + Y axis. It may be arranged to be positioned on another angle. In this state, the transfer start line SL of the unit image P2 transferred for each color is sequentially transferred at the contact positions Po1, Po2, Po3, Po4 of each consultation member 30-60 and the belt 70. To form an overlapping image. Each counseling member 30-60 is configured to have sections A1, A2, A3, A4 having a maximum radial displacement + δo on a certain angle from the positioning unit 33b, as shown in Figs. 14A to 14D. It is assumed that they are installed in different positions at the time of transfer of each counselor. At this time, the case where the SL of each unit image P2 is transferred on the points Po1, Po2, Po3, Po4 on + Y of each counseling member 30-60 will be described. That is, the posture of each counseling member 30-60 means a posture at the start of sequential transcription of each counseling member.

In this case, as shown in FIG. 14A, if the printing starts from the state where the K color counseling member 30 is in contact with the + Y axis, the center of the section A1 is rotated by θ1 angle counterclockwise from the + Y axis. Position it with a difference. In FIGS. 14A to 14D, a description will be made with a difference of 45 gaps between the center of each of the sections A1 to A4 and the positioning unit 33b. Therefore, a K color image error Oke caused by the section A1 occurs at a predetermined position of the unit image region P2 of the belt 70. The image error may include an image bleeding phenomenon, an image sagging phenomenon, an image breaking phenomenon, and the like. That is, in the A section of the surface of the counseling member 30, the tangential velocity Vmax of the counseling member 30 changes faster than the other sections, so that an extended electrostatic latent image is formed on the counseling member (the tangential opposite to the -δo section). Reduced electrostatic latent image may occur as the speed Vmin may be minimal). When the developing roller 33 is developed in contact with the counseling member 30, an image bleeding phenomenon may occur due to the tangential speed difference between the counseling members 30 in the A1 section. When the image formed through this process is transferred to the belt 70, when the A1 section is in contact with the belt 70, a speed difference occurs between the A1 section and the belt 70 contact position, whereby an image blur phenomenon occurs. Can be. The center of the K color image error Oke occurs at a position spaced apart from the start line SL by lok = Ro1 占.

As shown in FIG. 14B, the C-color counseling member 40 will be described as an example where the center of the A2 section is located at θ2 = + 135 ° from the + Y axis. In this case, the C color image error Oce generated by the section A2 is generated in the unit image region P2, but occurs at a position different from the K color image error Oke. That is, C color image error (Oce) is loc = Ro2. Occurs at spaced apart locations.

Referring to FIG. 14C, the center of the section A3 of the M color counseling member 50 is located at θ3 = + 225 ° counterclockwise from the + Y axis. Therefore, the M color image error Ome generated by the section A occurs in the unit image area P2, but occurs at a position different from the K and C color image errors Oke Oce. That is, the M color image error Ome occurs at a position spaced apart from the start line SL by lom = Ro3 占.

14D, the center of the section A4 of the Y color counseling member 60 is located at θ4 = + 315 ° counterclockwise from the + Y axis. Accordingly, the Y color image error Oye generated by the section A4 of the consultation delay 60 is generated in the unit image area P2, but the K, C, and M color image errors Oke (Oce) (Ome). Occurs in a different location than. That is, the Y color image error Oye occurs at a position spaced apart from the start line SL by loy = Ro4 · θ4.

Referring to FIGS. 14A and 14D, when Ro1 = Ro4 = Ro, the distance between each image error Oke and the center of Oce is different by loc-lok = Ro · (θ2-θ1). As a result, the position of the image error for each color in the unit image area P2 is changed so that the image errors Oke (Oce) and Oye (Oye) for each color are present at different positions in the overlapping image. It will adversely affect quality.

An example thereof will be described in detail with reference to FIGS. 15A and 15B.

Fig. 15A shows each of the counseling members 30-60 arranged as shown in Figs. 14A to 14D simultaneously in a single drawing. Therefore, in FIG. 15A, each counseling member 30-60 is shown based on points Po1, Po2, Po3, Po4 starting to transfer each color, and thus the concept of time may be omitted.

FIG. 15B is a diagram illustrating radial displacements (δok, δoc, δom, δoy) for each color in the form of a sin curve according to the rotation period of the counseling members 30-60 for each color. Here, the distance between the centers of the counseling members 30-60 was not taken into account, and the color displacement and color image errors were displayed based on the color transfer points Po1, Po2, Po3, and Po4. . And the same as the radius Ro1-Ro4 = Ro of each consultation member 30-60 is demonstrated to an example.

In FIG. 15B, the first graph from the top shows that the transfer of the K-color counseling member 30 starts in the posture as shown in FIGS. 14A and 15A, and the radial displacement δok according to the rotation period of the counseling member 30. ). Assuming that a K unit image is formed in one rotation of the counseling member 30, the transfer of the K image starts at point Po1, so that the center of the K image error Oke by the A1 section is one rotation period (unit image area; P2) That is, the belt 70 is generated at a distance traveled by lok = Ro · θ1 = Ro · 45 ° from the SL point in order to receive the K image.

In FIG. 15B, the second graph shows the radial displacement δ oc according to the rotation period of the C color counseling member 40 arranged as shown in FIG. 14B. In the case of the C color, the transfer starts from the point Po2, where Po2 represents a point in time at which the point Po1 at which the K image transfer is started coincides with the transfer start line SL of the C image. Accordingly, the distance between the two points Po1 and Po2 on the actual belt 70 is the distance L1 between the rotation centers C1 and C2 of the two counseling members 30 and 40. Therefore, the SL of the K image at which the transfer is started at the point Po1 is met at the point Po2 after the belt 70 runs for the distance L1, and the transfer of the C image is started. Here, in the case of Fig. 14B, since the section A2 is in the phase of θ2 (115 °) from the point Po2, the C image error (Oce) is from SL, i.e., from the point Po2, based on one rotation period (unit image area; P2). The center of the C image error (Oce) is positioned at the distance that the belt 70 is moved by loc = Ro · θ2 (115 °). When both image errors Oke and Oce occur in the unit image region P2, the interval between the centers of the two image errors Oke and Oce is loc-lok = Ro · even on the graph as described above with reference to FIG. 14B. It can be seen that the difference by (θ2-θ1) is increased.

In FIG. 15B, the third graph shows the phase shift δom according to the rotation period of the M counseling member 50 arranged as shown in FIG. 14C. In this case, the center of the section A3 is located at the phase of θ3 (225 °) from the point Po3 at which the transfer of M starts. The M image error Ome in the A3 section is generated in the M image transferred to the belt 70 while the M counseling member 50 is rotated by θ3. Therefore, the center of the M image error (Oce) appears at the distance that the belt 70 is moved by the point lom = Ro? Θ3 from the point Po3. The distance lom = Ro · θ3 is generated when the rotation period of the counseling member 50 is divided by 360 °, and is rotated about 225 ° from the point Po3. Therefore, the distance between the centers of two image errors (Oce, Ome) is different by lom-loc = Ro · (θ3-θ2). Here, the distance between the points Po2 and Po3 represents the distance L2 between the two counseling members 40 and 50 and the center of rotation C2 and C3, and the point Po3 is overlapped by the preceding counseling members 30 and 40. This is the time point at which the SLs of the K and C images coincide with the SLs of the M image.

The fourth graph in FIG. 15B shows the phase shift δoy according to the rotation period of the Y color counseling member 60 arranged as shown in FIG. 14D. In this case, the center of the section A4 is located at the phase of θ4 (315 °) from the point Po4. Therefore, the Y image error Oye caused by the A4 section is generated when the rotation period (unit image area; P2) of the counseling member 60 is divided by 360 °, and is rotated about 315 °. The center of the Y image error (Oye) is located at a distance from the point Po4 where the belt 70 is moved by loy = Ro · θ4 = Ro · 215 °. As a result, the distance between the centers of the two image errors Ome and Oye is different by loy-lom = Ro · (θ4-θ3). According to this result, it can be seen that as each color image is superimposed, image errors may occur at different positions, and thus the quality of the superimposed image may be deteriorated.

That is, as can be seen from the graphs shown in FIG. 15B, a graph showing the radial displacements (δok, δoc, δom, and δoy) for each color shows one rotation period (unit image area; P2) of each counseling member 30-60. ), The radial displacement pattern for the. Therefore, assuming that the unit image area P2 is formed by one rotation period of the counseling agent, image errors Oke (Oce) and Oye (Oye) for each color are all generated at different positions. . Therefore, four image errors occur in the unit image area P2 at different positions.

Meanwhile, in FIGS. 14A to 14D and 15B, the radius of each counseling member 30-60 is the same as Ro, and it is defined that each counseling member 30-60 forms a unit image by one rotation. Explanation was made. In practice, however, depending on the size of the radius of the counseling member 30-60, one unit image may be formed by one rotation, 1.5 rotations, or two rotations. In this case, a unit image transferred in full color Since at least four image errors occur in the area, the quality of the image may be degraded by that amount.

On the other hand, if the position of each radial displacement + δ of each counseling member 30-60 is matched with respect to the initial transfer time of each counseling member 30-60, that is, each image error (Oce, Ome, Oye) If each counseling member 30-50 is adjusted and arranged to be shifted by a predetermined distance, as shown in Fig. 14E, only a single image error Ote in which four color image errors overlap is generated. In this case, as shown in the fifth graph of FIG. 15B, the radial displacements (δok, δoc, δom, δoy) of the counseling members 30-60 for each color have a constant pattern in the unit rotation period (unit image area; P2). Appears to have. Since the radial displacements δok, δoc, δom, and δoy coincide in the unit rotation period (unit image region P2), color-specific image errors Oke (Oce) (Ome) (Oye) coincide in the same phase.

The fifth graph of FIG. 15B shows the content of the image errors generated by each of the four counseling members 30-60. In contrast, at least two predetermined counseling members of each counseling member 30-60 are shown. Even if only image errors are superimposed on each other, the total number of image errors can be reduced. Hereinafter, a detailed method and an effect of overlapping image errors caused by two or more counseling members will be described in detail.

On the other hand, in the case of Figure 14a to 14d and 15b, since it was described based on the sequential transfer time of each counseling member, in order to be able to check the coupling relationship between each counseling member and the corresponding driven coupler at the time of system installation It is necessary to explain on the basis of the same time point.

This will be described in detail with reference to FIGS. 16A to 16D.

FIG. 16A is a diagram illustrating a point in time at which the K counsel member 30 is first transferred. Here, the position on the belt 70 at which the K consultation member 30 started the transfer is called D1. At this time, the position of the K consultation member 30 in contact with the belt 70 is called E1. The angle between the center and E1 is called α1. (In this case, it is distinguished from 14a to 14d described on the basis of the sequential transfer time of each counselor. Therefore, the general angle of α1 to α4 is indicated mainly.) The contact point between 40 and the belt 70 is D2, and the position of the C counseling member 40 corresponding thereto is E2, and the angle between the center of the maximum phase region A2 of the C counseling member 40 and the E2. Let be α2. In addition, the position on the belt 70 which starts the transfer of the M counseling member 50 is called D3, and the position of the M counseling member 50 that is in contact at this time is called E3, and between the center of the maximum phase region A3 and E3. The angle is called α3. In this case, the contact point between the Y counsel member 60 and the belt 70 is D4, and the position of the Y counsel member 60 corresponding thereto is E4, and the center of the maximum phase region A4 of the counsel member 60 is The angle between E4 is called α4. When the distance between C1 and C2 is L1, the distance between C2 and C3 is L2, and the distance between C3 and C4 is L3, and the radius of each counselor 30-60 is Ro1, Ro2, Ro3, Ro4. , Counseling delay may be mounted to satisfy at least one of ① to ③ of Equation 2 below.

{2π · l + (α2-α1)} Ro · (1 ± 0.05) = L1, (l = 0, 1, 2, ...), (Ro = Ro1 = Ro2) ------- --- ①

{2π · m + (α3-α1)} Ro · (1 ± 0.05) = L1 + L2, (m = 0, 1, 2, ...), (Ro = Ro1 = Ro3) ----- --- ②

{2π · n + (α4-α1)} Ro · (1 ± 0.05) = L1 + L2 + L3, (n = 0, 1, 2, ...), (Ro = Ro1 = Ro4) --- ③

In the state of FIG. 16A, the K counsel member 30 is first transferred to the K unit image Pk. At this time, the tip SL of the K unit image Pk starts at the position D1 on the belt 70 and is in contact with E1 of the counseling member 30. The center of the section A1 is located on the angle of α1 with respect to the + Y axis from E1. At this time, the consultation body 40 is in contact with the position D2 on the belt 70, the center position of the section A2 from the contact position E2 on the consultation body 40 is rotated by α2. Similarly, the centers of the A3 and A4 sections of the M counseling member 50 and the Y counseling member 60 are located on angles rotated by α3 and α4 from each of E3 and E4.

In the state of FIG. 16A, the K image starts to be transferred to the K unit image Pk, and the center of the K image error Oke due to the section A1 is generated with a difference of b1 = Ro · α1 = Ro1 · α1 from the leading edge SL. Then, the center of the K image error Oke and the belt 70 of the counseling member 40 as shown in Figure 16b When the Po6 position, which is the contact point, is reached, if the center of the C picture error Oce generated in the C unit image Pc coincides with the center position of the Oke by the section A2 of the consultation counselor 40, the two image errors ( Oke, Oce) will be formed overlapping at the same position. At this time, the following equation is established to satisfy the above condition.

Ro-α1 + L1 = Ro-α2, (Ro = Ro1 = Ro2) --------- (1)

The above equation corresponds to a case in which the length of L1 is within 2 pi · Ro of one rotational circumference of the counseling member 30, that is, when L1 <2π · Ro, and when generalized, Equation (1) is as follows.

Ro · α1 + L1 = Ro · (α2 + 2π · l), (l = 0, 1, 2, ...) ------ (2)

Summarizing the above formula (2) and considering the error range ± 5%,

{2π · l + (α2-α1)} Ro (1 ± 0.05) = L1, (l = 0, 1, 2, ...) ------ (3)

Equation (3) corresponds to ① of Equation 2, and when two counseling members 30 and 40 are disposed to satisfy this condition, the K and C counseling members 30 and 40 are arranged in sections A1 and A2. Image errors Oke and Oce are overlapped at the same position. Specifically, when setting the counseling members 30 and 40 in the image forming apparatus, if the S1 and Ro values are determined, the K counseling member 30 is installed first. Then, by substituting the predetermined α1 value of the K counseling member 30 using the conditional expression of Equation 2 above, since the α2 value of the C counseling member 40 can be known, C counseling is performed based on the obtained α2. If the member 40 is properly disposed on the X and Y coordinate axes, the image errors Oke and Oce can be superimposed.

In addition, as seen in the state of FIG. 16A, the center of the K image error Oke is generated with a difference of b1 = Ro · α1 = Ro1 · α1 from the tip SL. As shown in FIG. 16C, when the center of the K image error Oke reaches the contact position Po7 of the belt 70 of the M counseling member 50, by the section A3 of the M counseling member 50. When the center of the M picture error Ome generated in the M unit image Pm coincides with the center of the K picture error Oke, the two picture errors Oke and Ome are overlapped at the same position. As a condition for this, the two counselors 30 and 50 may satisfy the following general formula (4).

Ro · α1 + L1 + L2 = Ro · (α3 + 2π · m), (m = 0, 1, 2, ...), (Ro = Ro1 = Ro3) ---------- ( 4)

When the equation (4) is summarized and the error range is taken into consideration, ② of Equation 2-1 can be derived as follows.

{2π · m + (α3-α1)} Ro · (1 ± 0.05) = L1 + L2, (m = 0, 1, 2, ...), (Ro = Ro1 = Ro3) ----- ----- (5)

Similarly, in order to make Oke coincide with the Y picture error Oye occurring in the unit image Py by the section A4 of the Y counsel member 60, as shown in FIG. 16D, the point D1 of the belt 70 is moved from the point Po8. When b1 = Ro · α1 = Ro1 · α1, the center of the section A4 may be positioned at the point Po8. Such conditions can be represented by the following equation (6).

Ro · α1 + L1 + L2 + L3 = Ro · (α4 + 2π · n), (n = 0, 1, 2, ...), (Ro = Ro1 = Ro4) --------- -(6)

If we sum up the above formula (6) again,

{2π · n + (α4-α1)} Ro · (1 ± 0.05) = L1 + L2 + L3, (n = 0, 1, 2, ...), (Ro = Ro1 = Ro4) --- ------- (7)

That is, Equation (7) in which Equation (6) is summarized in consideration of the error range is the same as (3) in Equation 2.

The conditions of Equation 2-1 described above are images generated by any one of the other counseling members 40-60 based on the K picture error Oke generated by the section A1 of the K counseling member 30. It illustrates the conditions for controlling the installation posture of the counseling agents 40-60 to overlap the error.

In addition, unlike the above Equation 2-1, in order to overlap image errors occurring in at least neighboring counseling members among the counseling members 30-60, Equation 2-2 of Equation 2-2 is given. It is sufficient to set the image forming apparatus so as to satisfy at least one.

{2π · l + (α2-α1)} Ro · (1 ± 0.05) = L1, (l = 0, 1, 2, ...), (Ro = Ro1 = Ro2) ------- -①

{2π · m + (α3-α2)} Ro · (1 ± 0.05) = L2, (m = 0, 1, 2, ...), (Ro = Ro2 = Ro3) ------- -②

{2π · n + (α4-α3)} Ro · (1 ± 0.05) = L3, (n = 0, 1, 2, ...), (Ro = Ro3 = Ro4) ------- -③

Here, 1 in Equation 3 and 1 in Equation 2 are the same Equation. That is, these equations are conditional expressions for superimposing image errors Oke and Oce generated by two counseling members 30 and 40 adjacent to each other.

② of Equation 3 is a conditional expression for matching image errors (Oce, Ome) generated by sections A2 and A3 of C and M counseling members 30 and 40. 30, 40) can be easily understood through the method of superimposing the image errors. That is, when the L2 value and the Ro value are determined, and the α2 value of the C counseling member 40 is determined, the α3 value of the M counseling member 50 can be determined through the condition (2) of Equation (3). Therefore, by setting the M counseling member 50 based on the obtained α3 value, two image errors Oce and Ome can be superimposed.

3 is a conditional expression for superimposing image errors Ome and Oye generated by sections A3 and A4 of the M and Y counseling members 50 and 60. In this case, as described above with reference to FIGS. 16A to 16D, the image error Oke caused by the section A1 of the K counseling member 30 is superimposed on one of the other image errors Oce, Ome, Oye. In the same manner as the method, image errors Ome and Oye of the two counseling members 50 and 60 may be superimposed. That is, when L3 and Ro are given as design values, and the M counseling member 50 is first mounted in a predetermined position, the α3 value of the mounted M counseling member 50 can be known. Then, the value of α4 can be found by substituting α3 into the conditional expression of ③ of Equation 3 above. Therefore, if the Y counsel member 60 is set to correspond to the obtained α4 value, two image errors Ome and Oye can be superimposed.

On the other hand, in the tandem CLBP as in the embodiment of the present invention, the distance between the centers C1, C2, C3, and C4 of each counseling member 30-60 is designed to be the same as L1 = L2 = L3. In general, the above Equation 2 can be summarized as the following Equation 4.

{2π · l + (α2-α1)} Ro · (1 ± 0.05) = L1, (l = 0, 1, 2, ...), (Ro = Ro1 = Ro2) ------- -------------- ①

{2π · m + (α3-α1)} Ro · (1 ± 0.05) = 2L1, (m = 0, 1, 2, ...), (Ro = Ro1 = Ro2 = Ro3) ----- ---------- ②

{2π · n + (α4-α1)} Ro · (1 ± 0.05) = 3L1, (n = 0, 1, 2, ...), (Ro = Ro1 = Ro2 = Ro3 = Ro4) --- ------ ③

Here, in the same manner as described above with reference to FIGS. 4A to 7B, the sections A1, A2, A3, and A4 of each counseling member 30-60 are used to locate the driven coupler of each counseling member 30-60. The counseling members 30-60 may be assembled to be in the same phase with respect to the unit 33b. In this case, L1, Ro, and the maximum delayed position of the counseling delay (which is set in the K counseling delay 30 in this embodiment) (that is, set in the K counseling delay 30 in this embodiment), that is, the position α1 of the section A1, are checked. The maximum radial displacement positions α2, α3, and α4 of the members 40-60 may be obtained to satisfy the above Equation 4, and each counseling member 40-60 may be installed. In order to visually easily check each of the radial displacement positions, as described above with reference to FIG. 4A, the positioning unit 33b of the driven coupler 33 may be positioned at a predetermined range with each phase displacement position (as shown in FIG. 4A). If it is fastened to have a 45 ° as an example), the initial installation position of each consultation member (30-60) will be determined based on the positioning unit (33b).

When the values of α2, α3, and α4 of the other counseling members 40-60 are obtained with respect to α1 of the counseling member 30, which is the reference as described above, the counseling agents ( 30-60) can be set in the image forming apparatus.

As a first setting method, as described above, each consultation member 30-60 is manufactured by assembling the positioning unit 33b of the driven coupler at a predetermined angle with respect to the maximum radial displacement + δ. Subsequently, any counseling member 30 is first coupled to the drive coupler 133 as shown in FIG. 3. In the state where the counseling member 30 is mounted, the α1 value can be measured using a predetermined measuring device. In this state, L1, L2, L3, Ro and α1 are substituted into Equation 2-3 to obtain α2, α3, and α4 of the other upper members 40-60. According to the obtained α2, α3, and α4, the maximum radial displacement + δ of each counseling member 40-60 may be adjusted using the measuring device and then coupled to the driving couplers 134, 135, and 136 in turn. As another example of the first method, the driving coupler 133 to which the K counseling member 30 as a reference is coupled is set to a predetermined posture, and the other driving couplers 134 corresponding to the obtained α2, α3, and α4. With the posture of -136 set, it is possible to couple the consultation delays 30-60 to the set drive coupler 133-136. Here too, of course, each drive coupler 133-136 can adjust the positioning portion of the drive coupler using a predetermined measuring device.

The second setting method is to use a separate jig. As an example, as illustrated in FIG. 17A, a jig device 300 may be used in which a plurality of reference drums 330-360 are adjustable in the jig frame 310. The reference drums 330-360 correspond to portions corresponding to the counseling members 30-60 for each color mounted on the actual image forming apparatus, and the distance between each of the driving units 100 is mounted with the actual counseling members; It is disposed equal to the spacing of the drive couplers (133-136) of FIG. Each of the reference drums 330-360 has a driven coupler 333, 343, 353, 363 corresponding to the driven coupler 33 of the counseling member 30-60 at the tip. Therefore, it is natural that the driven couplers 333, 343, 353, and 363 may be complementarily coupled to each of the driving couplers 133-136. In addition, the positioning portion of the driven couplers 333-363 is the same radial displacement as that of the positioning portion 33b of the driven coupler 33 provided in the corresponding actual counseling members 30-60, that is, the maximum radius of the counseling delay. Naturally, it is provided to be positioned at an angle at the displacement + δ.

On the other hand, each of the reference drums (330-360) is rotatably inserted into the adjustment hole 313 provided in the jig frame 310 at a predetermined interval. The jig frame 310 is provided with a fixing member 320 at a position corresponding to the reference drums 330-360 corresponding to the reference drums 330-360. The plurality of fixing members 320 are screwed to the jig frame 310, and one end of the fixing member 320 is installed to be in contact with the reference drums 330-360 inserted into the adjusting hole 313. Therefore, when the fixing member 320 is rotated in the direction of advancing toward the reference drums 330-360, one end is in close contact with the reference drums 330-360 so that the reference drums 330-360 are fixed to not move. When the fixing member 320 is rotated in a direction away from the reference drum 330-360, the contact between the reference drum 330-360 and the fixing member 320 is separated to rotate the reference drum 330-360. It becomes possible.

When the jig device 300 having the above configuration is used, the posture of each of the reference drums 330-360 instead of the counseling members 30-60 to be mounted on the actual driving unit 100 is expressed by Equation 3. It can be fixed by adjusting to satisfy the condition of 2-3.

Here, the method of adjusting the reference posture of the reference drums 330-360 may use the first setting method described above. That is, after measuring α1 of the predetermined reference drum 330, α2, α3, and α4 of the remaining reference drums 340-360 are obtained. Then, the postures of the respective reference drums 340 to 360 may be adjusted and fixed by using a predetermined measuring device based on the obtained α2, α3, and α4.

As such, when the reference posture of the reference drums 330-360 is determined, the jig apparatus 300 and the driving unit 100 are relatively approached, and the driven couplers 333 of the posture adjusted reference drums 330-360 are relatively close to each other. -363) couples the drive couplers 133-136. Then, the coupler 333-363 is often in a fixed posture, so that the driving couplers 133-136 are rotated to fit the posture of the driven couplers 333-363. As described above, after the driving couplers 133 to 136 are changed in posture and combined with the driven couplers 333 to 363, the jig device 300 and the driving unit 100 are moved in the axial direction of the reference drums 330 to 360. The drive coupler (133-136) and the driven coupler 136 is separated by moving relatively. Here, the driving unit 100 may be moved by a separate moving jig to be combined with the jig device 300, in the state in which the driving unit 100 is mounted on the image forming apparatus, the jig device 30 The driving couplers 133-136 of the driving unit 100 may be adjusted by moving toward the image forming apparatus.

After coupling with the driven couplers 333-363 as described above, the driven couplers 33 of the actual counseling members 30-60 are coupled to the separated drive couplers 133-136. Then, since the driving coupler 133-136 is already in a determined state, the counseling members 30-60 to be assembled may naturally be set to satisfy the condition of Equation 4 above.

Therefore, when using the jig device 300, there is an advantage that can reduce the assembly time during mass production of the product, and can easily control the radial displacement of the consultation delay.

In addition, as a third setting method, the jig device 300 'as shown in FIG. 17B can be used. The jig device 300 ′ shown in FIG. 17B has a similar configuration to the jig device 30 shown in FIG. 17A, and the same reference numerals are assigned to the same components. However, each of the reference drums 330 to 360 has driven couplers 333, 343, 353, and 363 at one end thereof, and gears 371, 372, 373 and 374 are installed at the other end thereof. And, each of the gears (371 ~ 374) Idle gears 375 are disposed therebetween, and the gears 371 to 374 are interlocked with each other. Each of the reference drums 330 to 360 is disposed at a predetermined interval in advance. Therefore, when the posture of one of the reference drums is adjusted, the postures of the other reference drums can be automatically adjusted. And after adjusting the attitude of the reference drums to be fixed so as not to move, for this purpose fixed member 320 is provided. In this case, unlike each of the reference drums 330 to 360 are connected to each other unlike FIG. 17A, one reference member 330 may be fixed using one fixing member 320. Therefore, when fixing the first reference drum 330 by using the fixing member 320, The reference drums 334, 450, and 460 are also fixed. When the jig device 300 ′ as shown in FIG. 17B is used, for example, when one value of one reference drum 330 is obtained, and the attitude of the reference drum 330 is adjusted based on the 1 2, 3 and 4 of the remaining reference drums 340, 350 and 360 are automatically determined and adjusted. Therefore, it is possible to set consultation delays easily and quickly by a simple method.

Meanwhile, the radius of each counseling member 30-60 is equal to Ro, and the center distance of each counseling member 30-60 is L1 = L2 = L3 = 2π · Rox (x = 1,2,3, .. In the case of a constant system, the angles α1, α2, α3, and α4 have the same value. Therefore, in this case, as shown in FIG. 3, if the positioning portions of the drive couplers 133-136 corresponding to the respective consultation delays 30-60 are constantly aligned in the + X axis direction, the drive couplers 133 The position of the positioning unit of each counseling member 30-60 fastened to -136 may be determined. Therefore, the image errors for each color generated by + δo of each counseling member 30-60 may be superimposed at the same position during sequential transfer. The position of + δo of each counseling member 30-60 is facilitated by controlling the positioning unit 33b of the driven coupler 33 in the same manner as described above with reference to FIGS. 4A to 7B. Can be done.

Summarizing the description so far, i) each of the consultation delay 30-60 and the driving roller 80 has a runout. The positioning units 33b and 83b of the driven coupler 33 and 83 are respectively + δo and + δd so that the number of occurrences of image errors due to + δo and + δd due to this runout can be easily controlled. The method of manufacturing the consultation delay and the driving roller so as to be positioned at a predetermined position with respect to.

Subsequently, in order to overlap at least two or more of the image errors (Rke, Rce, Rme, Rye) due to the runout of one of the rollers of the driving roller 80 or the supporting roller 91, 1) Specific examples and action effects for the case of satisfying the conditions of to ⑥ have been described. In this case, regardless of the number of image errors occurring in the unit image according to the relative magnitude of the radius Rd of the driving roller 80 and the radius Ro of the counseling member, the image errors occurring in the image region of the counseling member desired. Can be nested.

(Iii) at least two of the image errors (Oke, Oce, Ome, Oye) caused by the runout of the counseling members 30-60, regardless of the runout of the drive roller 80 and the support roller 91. The contents of the above formulas (2) to (4) have been described as conditions for overlapping more than one place. That is, when the image error of any one of the remaining counseling members 40-60 is to be superimposed based on the predetermined counseling member 30, the system may be set to satisfy at least one condition of Equation 2. . And, in order to superimpose image errors of at least neighboring counseling members, the system may be set to satisfy any one of the equations (3). In the case of Equations 2 and 3, it is a general formula that can be applied when the relative sizes of the intervals L1, L2, and L3 between the centers of the counseling agents 30-60 are not considered. When the intervals L1 = L2 = L3, the system can be set by setting Equation 2-3 as a general conditional expression. That is, in actual products, manufacturing is made under the condition of L1 = L2 = L3 by considering various angles of assembling, connecting relationship, and size with various other parts. The frequency of errors can be reduced.

As a third step of reducing the number of image errors occurring in the superimposed image, image errors due to the runout of one of the support rollers 91 and the driving rollers 80, and each counseling member 30-60. Let's take a look at how to superimpose the image errors caused by the runout.

As an example, as shown in FIGS. 8A and 8B, an image error Rke is generated in the image region of the K counsel member 30 by the section B of the driving roller 80. In addition, image errors Rme and Rye occur in the image region of another counseling member 50-60 by the section B. In addition, as described above with reference to FIGS. 15A and 15B, an image error Oke is generated by the section A1 of the K counsel member 30. The other counseling members 40-60 also generate image errors Oce, Ome and Oye by the sections A2, A3 and A4, respectively. As described above, when at least two or more of the image errors generated by the sections A1 to A4 and B of the driving roller 80 and the consultation member 30 are respectively overlapped at the same position on the belt 70, the image error occurs. Can reduce the effect on the final full color image.

Referring to FIG. 18A, the angle formed by the position of the center of the section B that defines the radial displacement + δd of the driving roller 80 clockwise from the + X axis is θd, and the predetermined order in the advancing direction of the belt 70. (x) Let θox be the angle at which the radial displacement + δo of the arranged counseling body becomes counterclockwise from the + Y axis. In this case, at least one of the image errors (Rke, Rce, Rme, and Rye) that may be generated by the section B (Rke is described as an example) may be caused by each counseling member 30-60. In order to overlap the corresponding image error Oke among the (Oke, Oce, Ome, Oye) at the same position on the belt 70, there are the following methods. That is, the position where the maximum tangential velocity Vmax of the drive roller 80 according to the section B has the greatest influence on the belt 70, that is, the maximum tangential velocity Vmax direction is shown as an imaginary line in Fig. 18A, + Y When reaching the position parallel to the axis, the consultation member 30 may set the position of the driving roller 80 and the consultation member 30 such that the section A1 is in contact with the belt 70. As described above, in order to superimpose an image error caused by at least one counseling member 30 among the plurality of counseling members 30-60 with respect to the driving roller 80, a condition of ① to ③ of Equation 5 below can be obtained. The system of the image forming apparatus may be set to satisfy at least one of them.

Rd · θd = (2π · l + θox) · Rox · (1 ± 0.05) (l = 1, 2, 3, ...), (x = 1, 2, 3, ...) and Rd = z Rox, (z = 2, 3, 4, 5, ...) ------ ①

Rd θd = Rox θox (1 ± 0.05), Rd = θox, (x = 1, 2, 3, ...) ------ ②

(2π · h + θd) Rd = Rox θox (1 ± 0.05), (h = 1, 2, 3, ...), (x = 1, 2, 3, ...) and Rox = k · Rd, (k = 2, 3, 4, 5, ...) ------ ③

That is, when the system is installed to satisfy the condition of Equation 3, the image errors generated by the radial displacement of the driving roller 80 and the counseling member 30-60 are located at the same position on the belt 70. Overlapping image errors appear only at one position of the overlapping image.

First, assuming that δo = δd, Rox <Rd will be described.

The condition of 1 in Equation 5 is that the support roller, that is, the consultation of the driving roller 80 and the object of interest when the radius Rd of the driving roller 80 is an integer multiple of 2 or more than the radius Rox of the consultation body of interest. Conditional expression that allows to superimpose image errors due to delay.

This will be described in detail with reference to FIGS. 18A and 18B. 18A illustrates an arbitrary state that is not set to satisfy the condition 1 in Equation 5 above. In this case, the counseling member of interest is the first counseling member 30, and Rd = 2Ro1.

As described above, when Rd = 2Ro1, the counseling member 30 rotates twice when the driving roller 80 rotates once. Therefore, for example, if it is assumed that the unit image is formed when the counseling member 30 is rotated by two revolutions, one image error caused by section B of the driving roller 80 and A1 of the counseling member 30 is formed in the unit image area. Two image errors occur due to the section.

Hereinafter, in the state as shown in FIG. 18A, the system is reset to satisfy the condition 1 in Equation 5, and the image error caused by the section B of the driving roller 80 is detected by the section A1 of the counseling member 30. A method of overlapping any one of the dog image errors will be described.

Looking at this in more detail, the center of the A1 section of the counseling member 30 of interest in Figure 18a is set to θox = θo1 = 315 ° phase counterclockwise from the + Y axis, B of the driving roller 80 The center of the interval is located at θd = 315 ° clockwise on the + X axis. In this state, when the K transfer is started, the center of the image error Rke caused by the section B during one rotation of the drive roller 80 is Rd from the transfer start point Po1 of the belt 70, as shown in Fig. 18B. It occurs at the position where the belt 70 is moved by [theta] d. That is, the center of the image error Rke generated in the unit image by the drive roller 80 is generated with a distance difference from SL by Rd · θd.

At this time, the counseling member 30 is rotated two times while the driving roller 80 is rotated one time, so that two first and second images Oke1 and Oke2 are generated in the unit image area by the section A1.

Here, the center of the first image error Oke1 is generated at a position spaced apart from SL by Rox · θox = Ro1 · θo1 = Ro1 · 315 °. Since the second image error Oke2 is spaced apart by 2π · Ro1 from the first image error Oke1, the second image Oke2 is spaced apart by 2π · Ro1 + Ro1 · θo1 = (2π + θo1) · Ro1 from the SL.

Therefore, in order to overlap one of the first and second images Oke1 and Oke2 in the section A1 of the consultation member 30 and the image error Rke in the section B of the driving roller 80 at the same position, The distance Rd · θd from SL to Rke is equal to the distance Rox · θox = Ro1 · θo1 from SL to the first image Oke1, or the distance from SL to Oke2 to the second image (2π + θo1) · Ro1 This is equivalent to

Therefore, when the above conditions are generalized and the error range is considered, the following Equation 5 can be obtained.

Rd · θd = (2π · l + θox) · Rox · (1 ± 0.05) (l = 1, 2, 3, ...), (x = 1, 2, 3, ...) and Rd = z Rox, (z = 2, 3, 4, 5, ...) ------ ①

And since Rd = 2Ro1 and substituting it into ① of the equation (5), the counseling member 30 and the driving roller 80 may be provided so that the condition of θo1 = 2 · θd-2π is satisfied. Since θd = 315 °, θo1 = 630 ° -2π = 270 °. That is, when the initial position of the drive roller 80 is installed by 315 ° clockwise on the + X axis with respect to the section B by ① of Equation 3, as shown in FIG. Section A1 of (30) can be installed at 270 ° with respect to the + Y axis. Here, since the section A1 is predetermined to be positioned at a phase of 45 ° counterclockwise from the positioning unit 33b of the driven coupler, positioning A1 at a position where θo1 = 270 ° can be easily adjusted. .

As such, when the consultation delay 30 and the driving roller 80 are set to satisfy the condition (1) of Equation 5, as shown in FIG. 18D, the Oke2 and the image error Rke are the same distance from the SL, that is, Rd. Θd = Rd.315 ° = (2π + θo1) Ro1 = (2π + 270 °)-and overlapped at a position spaced by Ro1. That is, in the K picture, only one overlap error Te1 in which Oke2 and Rke overlap and the picture error Oke1 which do not overlap are generated.

In addition, as described above, the image error generated by the section A2 of the neighboring consultation member 40 in a state where the first consultation member 30 and the driving roller 80 are arranged to overlap each other. Any of these and the image error by the drive roller 80 may be superimposed. That is, as shown in FIG. 18C, even in the case of the C counseling member 40, since Rd = 2Ro2, it can be seen that θo2 = θo1 = 270 ° according to the conditional expression of ① of Equation 5 above. Accordingly, in the case of the counseling member C 40, when the section A2 is disposed to be 270 ° counterclockwise with respect to + Y, as shown in FIG. 18D, the second image error O2 is caused by the section A2. ) Is generated by being spaced apart from SL by Rd θd, so that it is possible to overlap the overlapping error Te1 superimposed at the same position.

Since the distance between the counseling members 30 and 40 adjacent to each other is not considered here, the image error Rke of the driving roller 80 and the remaining image errors Oke1 and Oce1 do not overlap each other. When the image errors Oke1 and Oce2 caused by the A1 section and the image errors Oce1 and Oce2 caused by the A2 section are overlapped with each other, two counseling delays are satisfied to satisfy the condition of ① of Equation 2 described above. 30, 40 may be disposed. In detail, each of the two counseling members 30 and 40 has already determined its posture to satisfy the condition ① of Equation 5 above. Therefore, it can be seen that θo2 = θo1 = α2 = α1 in FIG. 18C. Therefore, it can be seen that L1 = 2π · l · Ro1 by substituting α2 = α1 into ① in equation (2). Since l = 1, 2, 3, the distance L1 between the centers C1 and C2 of the two counseling members 30 and 40 may be set to be an integer multiple of the circumferential length of the counseling member 30. Then, when l = 1, as shown in FIG. 18D, the C transfer point Po2 of the counseling member 40 is positioned at the position where the belt 70 is advanced by S1 from the K transcription point Po1 of the counseling member 30, and thus, each section. The image errors Oke1 and Oke2 (Oce1 and Oce2) caused by A1 and A2 overlap each other at the same point. In addition, since each of the counseling members 30 and 40 satisfies the condition ① in Equation 5, the image errors Oke2 and Oce2 superimposed on each other are also associated with the image error Rke of the B section of the driving roller 80. Occurs when overlapping.

As described above, when the radius of the driving roller 80 is an even multiple of the radius of the counseling member of interest, when the system is set to satisfy the condition of ① of Equation 5, it is generated by the counseling member of interest. It is possible to superimpose an image error by any one of the plurality of image errors to be the driving roller 80. Also, in the case of a plurality of counseling members independently, if they are arranged so as to satisfy the condition of (1) of Equation 5 independently, any one of the image errors caused by the counseling members is associated with an image error by the driving roller 80, and the like. Can be nested.

In addition, the image errors generated by each of the counseling members 30 and 40 of interest also set the system to additionally satisfy the condition of Equation (2). It is possible to cause the image errors by overlapping at the same position with each other, so that the number of image errors can be greatly reduced.

On the other hand, the above has been described by taking an image error Rke of the driving roller 80 and the image error by the two counseling members 30, 40 by taking two counseling members 30 and 40 as an example, but this is merely illustrative. It is only. That is, if at least one of the plurality of counseling members 30-60 is arbitrarily selected and set to satisfy the condition ① of Equation 5, the same effect can be obtained which can reduce the effect of the image error caused by the counseling member. It is self-evident.

In addition, the case where the condition of ① in Equation 2 is simultaneously satisfied together with ① in Equation 5 has been described as an example, but this is also merely illustrative. That is, in the state where the condition ① of Expression 5 is satisfied, each of the counseling members 30-60 is selected from the conditions of Expressions 1 through 3, Expressions 1 through 3, and Expression 4, respectively. Even if it satisfies at least one, it is obvious that the same effect can be obtained in the counseling member of interest, and thus detailed description thereof will be omitted.

In the second case, it is assumed that δd = δo, and the case where Rd = Rox will be described.

Referring to FIG. 19A, Rd = Rox = Ro1. In this case, when the driving roller 80 rotates once, the counseling member 30 of interest also rotates once. Therefore, assuming that the counseling member 30 rotates two times to form a unit image, as shown in FIG. 19B, two image errors Oke1 and Oke2 caused by section A1 of the counseling member 30 are included in the K unit image. Will occur. Since the section A1 of the consultation delay 30 is located in the phase of? O1 in the counterclockwise direction from + Y, the center of the first image error Oke1 is generated with a difference of Ro1 · θo1 from the transfer start point Po1. The second image error Oke2 is generated at a position spaced apart from Po1 by 2π · Ro1 + Ro1 · θo1. In the K unit image, two image errors Rke1 and Rke2 caused by the section B of the driving roller 80 are generated at a predetermined position. 19A, the center of the section B of the driving roller 80 is in the phase of θd in the clockwise direction on the + X axis. Accordingly, as shown in FIG. 19B, the first image error Rke1 generated by the section B is spaced apart from the Po1 point by Rd · θd, and the center of the second image error Rke2 is 2π · Rd + Rd · from Po1. It occurs at a position separated by θd.

Therefore, the interval between the centers of the first image errors Rke1 and Oke1 is d1 = Ro1 占 01-Rd 占 1d. Of course, the distance between the centers of the second image errors Rke2 and Oke2 also becomes d1 = Ro1 占 θ1-Rd 占 θd.

Here, since Rd = Ro, when the counseling member 30 and the driving roller 80 are set to satisfy the condition of d1 = 0, that is, Ro1 · θo1 = Rd · θd, the image by the counseling member 30 Each of the errors Oke1 and Oke2 can be superimposed at the same position as each of the image errors Rke1 and Rke2 by the drive roller 80. That is, in the case of Fig. 19A, since θd is set at 225 ° and θo1 is set at 315 °, the image error Oke1 caused by the counseling member 30 based on the image errors Rke1 and Rke2 of the driving roller 80 is referred to. In the case of overlapping Oke2, as shown in FIG. 19C, the counseling member 30 may be set such that θd = θo1 = 225 °. Since the section A1 of the consultation delay 30 is predetermined so as to be positioned at a predetermined phase from the positioning portion of the driven coupler, as in the various embodiments described above, A1 of the consultation delay 30 is counterclockwise from + Y. This is done by setting the phase to 225 °. Then, as shown in FIG. 19D, the radial displacements δo and δd of the counseling member 30 and the driving roller 80 may appear in the same pattern period on the belt 70 and may overlap each other. Therefore, only the overlapping images in which the respective image errors Oke1, Oke2, and Rke1, Rke2 are superimposed occur on the unit image, thereby reducing the number of image errors. That is, in the unit image region, only the overlap error Te3 in which Oke1 and Rke1 overlap and the overlap error Te4 in which Oke2 and Rke2 overlap are displayed.

Further, in the state where the counseling member 30 is set for the driving roller 80 so as to satisfy the condition (2) of Equation 5 as described above, any one of the neighboring counseling members 40-60 is represented by the above equation. When setting to satisfy any one of 2-1, (3) and (4), it is possible to superimpose the image error by the consultation delay of interest for the overlap error Te3 and Te4. Since such details have been described in detail with reference to FIGS. 16A to 17, detailed descriptions thereof will be omitted.

In the third case, it is assumed that δd = δo, and the case where Rd <Rox will be described. In this case, since Rd &lt; Rox, the drive roller 80 has a rotation period shorter than that of the consultation member 30-60 in the rotation period per unit time. Therefore, as a result, in the unit image region, more image errors are caused by the driving roller 80 than the number of image errors caused by the consultation delay. Therefore, when one of the plurality of image errors occurring in the unit image area is superimposed with the image error caused by the consultation member of interest, the driving roller 80 can reduce the number of image errors as a whole. To this end, the system may be set to satisfy the condition of Equation (5). In the embodiment of the present invention, the radius Rox of the counseling member of interest is twice as large as the radius Rd of the driving roller 80 (c = 2). ) Will be described as an example. Here, if the unit image of the predetermined color is formed while the driving roller 80 is rotated four times, the counseling member is rotated two times, so that four image errors and consultation by the driving roller 80 are consulted in the unit image region of the predetermined color. A total of six image errors can occur, including two image errors caused by delay.

In the case of FIG. 20A, a case in which Equation 5 is not satisfied is described. The phase with respect to the center of the section B of the driving roller 80 is located at θd = 225 °. In this state, assuming that the transfer of K is first started, as shown in FIG. 20B, the K unit image is transferred to the belt 70 when the driving roller 80 is rotated four times. Four image errors Rke1, Rke2, Rke3, and Rke4 are generated at regular intervals (2? · Rd). The first image error Rke1 occurs at a position spaced apart from the transfer start point Po1 by Rd.θd = Rd.225 °. The remaining image errors Rke2, Rke3, and Rke4 are sequentially generated at positions spaced apart from Po1 by (2π · h + θd) · Rd (h = 1, 2, 3).

In the case of the consultation delay 30, the section A1 is located at θo1 = 45 ° in the counterclockwise direction from + Y. Therefore, since the counseling member 30 is rotated two times in order to transfer the K unit image region, as shown in FIG. 20B, two image errors Oke1 and Oke2 caused by the A1 section are 2π each other in the K unit image region. It occurs at a position spaced apart from each other by Ro1. Then, the first image error Oke1 is generated at the position where the belt 70 is moved by Ro1 · θo1 = Ro1 · 45 ° at the transfer start point Po1. Therefore, the interval d2 between the first image errors Oke1 and Rke1 is equal to Rd 占? D-Ro1 占? 1. Since Ro1 = 2Rd, d2 = Ro1 · (0.5θd−θo1) = Ro1 · (112.5 ° -45 °) = Ro1 · 67.5 °.

According to the above result, when two image errors Oke1 and Rke1 are to be superimposed, the distances from Po1 to the image errors Oke1 and Rke1 must match. Therefore, when it is assumed that the driving roller 80 is set first, the condition of Rd.θd = Ro1. (45 ° + 67.5 °) must be satisfied. As a result, the counseling member 30 satisfies Equation 5 above when the phase of the A1 section is set at 112.5 ° counterclockwise from + Y. Then, as shown in FIG. 20D, the centers of the two image errors Oke1 and Rke1 are generated by overlapping at the same positions, that is, spaced apart from Po1 by Rd · θd = Ro1 · θo1 = Ro1 · 112.5 °. . In addition, the second image error Oke2 in the A1 section is overlapped with the third image error Rke3 in the B section. Therefore, the number of six image errors occurring in the K unit image area is reduced to four, thereby reducing the influence of the image error.

Meanwhile, even when Rd <Rox as described above, in the state where the condition of Equation 3 is satisfied, the counseling subject of interest is set to satisfy at least one of the conditions of Equation 2, Equation 3 and Equation 4. You can. Then, at least one of the image errors generated by the driving roller and the image error caused by the consultation delay can be superimposed, and image errors generated in each of the consultation delays can also be superimposed to further reduce the number of image errors. do.

In the following description, a method of overlapping image errors generated by the driving roller 80 when overlapping unit images and at least one or more image errors respectively generated by at least two counseling members at one location will be described. . In this embodiment, the image errors generated in each of the plurality of counseling members 30 to 60 are superimposed and the image errors of the driving rollers are superimposed on the overlapping errors of the counseling members. In this case, the radius of each counselor has the same size.

First, as shown in FIG. 21A, a case in which the radius Rd of the driving roller 80 is larger than the radius Rox of each counseling member 30-60 will be described. Here, the radiuses Rox = Ro of the counseling members 30-60 are the same as each other. In addition, L1, L2, L3, L4, L5, and L6, which define the distances between the centers C1 to C4 of the counseling members 30 to 60, are set to satisfy all the conditions of the equation (1). That is, the positions of the counseling members 30-60 are set to satisfy L1 = L2 = L3 = Sd (2π · Rd). According to this condition, an image error caused by section B of the driving roller 80 is generated at the same position of the superimposed unit image transferred to the belt 70 by each consultation member 30-60. Assuming that the unit image area is formed during one rotation of the driving roller 80, as shown in FIG. 21B, the centers of the image errors Rke-Rye for each color by the section B are from the start line SL in the unit image area. This occurs at a position spaced apart by Rd 占 θd (315 °). In addition, since L1 = L2 = L3 = Sd, one overlapping image error (Rke-Rye) is superimposed on the full color unit image region that has passed through each counseling member 30-60 and is finally superimposed on the belt 70. Only error (Rte) will occur. As a result, as the system is configured to satisfy all of Equation 1, the number of image errors caused by the section B of the driving roller 80 can be reduced to 1/4 to improve the image quality.

On the other hand, each of the counseling members 30-60 also has a radial displacement due to runout. Accordingly, image errors due to sections A1, A2, A3, and A4 of the counseling members 30 to 60 occur. In this way, in order to superimpose the image errors by the sections A1, A2, A3, and A4, the condition of Equations 2 and 3 is set in FIG. 21A. That is, L1 = L2 = L3 is satisfied, and the radius of each counseling member 30-60 is also the same. The maximum radial displacement + δo of each counseling member 30-60 is located at the same phase (270 °) counterclockwise in the + Y axis. According to the above configuration, when the driving roller 80 is rotated once, the counseling members 30 to 60 are each rotated two times to form the unit image area.

Accordingly, two image errors occur in each counseling member 30-60, and as illustrated in FIG. 21C, the first image errors Oke1-Oye1 caused by the counseling members 30-60 are generated. The center is generated by overlapping at a position spaced Ro · 270 ° from the starting line SL. The centers of the second image errors Oke2-Oye2 caused by the counseling members 30-60 overlap each other at positions spaced apart from the SL by Ro · (2π + 270 °). Originally, eight image errors (Oke1-Oye1) (Oke2-Oye2) are generated in the full color overlapping image that has passed through each counseling member (30-60). When the system is set to satisfy the condition of Equation 4, only the overlapping error Ote1 in which the first image errors Oke1-Oye1 overlap and the overlapping error Ote2 in which the second image errors Oke2-Oye2 overlap are generated. In this case, the number of image errors can be reduced to 1/4.

Meanwhile, as described above, the overlapping errors Ote1 and Ote2 by the counseling members 30-60 may occur at different positions from the overlapping error Rte by the driving roller 80 described above. Therefore, when the overlapping error Rte overlaps with any one of the overlapping errors Ote1 and Ote2 caused by the counseling member 30-60, the number of image errors occurring in the unit image area can be further reduced. In the case of Figure 21a, for this purpose is set to satisfy the condition ① of the equation (5). That is, Rd = 2Rox = 2Ro1 = 2Ro2 = 2Ro3 = 2Ro4 here. And θox = θo1 = θo2 = θo3 = θo4 = 270 °. Therefore, the distance Rd · θd from SL to the center of Rte is equal to the distance Ro · (2π + 270 °) from SL to the center of Ote2. That is, since Rd = 2Ro, Rd.θd = 2Ro.315 ° = Ro. (2π + 270 °), so that the two overlapping errors Ote2 and Rte overlap at positions spaced apart from SL by Rd.θd.

In summary, in the case where Rd = 2Ro, the system is set to additionally satisfy ① of Equation 5 while satisfying all of Equation 1 and all of Equation 4, and FIG. As shown in 21d, in the unit image area, the first overlapping error Ote1 generated by the counseling members 30-60, the second overlapping error Ote2 and the driving roller 80 caused by the counseling members, are provided. Only overlap error Te5 with overlapping error (Rte) is generated. As a result, 12 image errors including 4 image errors by the driving roller 8 and 8 image errors by the counseling members 30-60 can be reduced to 2 in total. By reducing the number of errors significantly, it is possible to improve the quality of the image.

Second, when Rd = Rox, a case in which Equations 1, 4 and 5 are satisfied will be described. Also in this case, the radius Rox = Ro of each counseling member 30-60 is the same. Referring to Fig. 22A, the section B of the drive roller 80 is located at the phase of θd (the embodiment θd = 315 ° in this embodiment) in the clockwise direction from the + X axis. Then, the interval L1 = L2 = L3 = 2π · Rd = Sd between the centers C1, C2, C3, C4 of the counseling members 30-60. That is, the counseling members 30-60 are set such that the distance between their centers has an integer multiple of the circumferential length of the drive roller 80. The system set as described above satisfies all of Equation 1 above. For convenience of explanation, assuming that a unit image area is formed during one rotation of the driving roller 80, the influence of the section B is generated in the same phase for each counseling member 30-60. That is, in order to form the final full-color image by superimposing and transferring the image for each color on the belt 70 in each consultation member 30-60, the driving roller 80 must be rotated four times in the state of FIG. At this time, as shown in FIG. 22B, the centers of the image errors Rke-Rye occurring in the overlapping images for each color by the section B overlap at positions spaced apart from the start line SL by Rd.θd = Rd.315 °. Will occur. That is, since the counseling members 30-60 are set to satisfy the equation (1), regardless of the number of rotations of the driving roller 80, the B section at the time of transferring the image by each counseling member 30-60. The image errors Rke-Rye generated by the influence are all generated at the same position, and as a result, only one overlapping image Rte is generated.

In addition, each counseling member 30-60 is arranged to satisfy the condition of Equation 2-3. That is, each of the sections A1, A2, A3, and A4 of the counseling members 30-60 has the same angle counterclockwise at each of the transcription start points Po1, Po2, Po3, and Po4, that is, α1 = α2 = α3 = α4. Each counseling member 30-60 is disposed so as to be positioned in phase. Here, it is assumed that α1 to α4 = 315 °, and for convenience of explanation, it is assumed that a unit image for each color is formed by one rotation of the consultation member 30-60. Then, as illustrated in FIG. 22C, the centers of the image errors Oke-Oye by the sections A1, A2, A3, and A4 of the counseling members 30-60 are Ro from the starting line SL in the unit image area. ? 1 = Ro · 315 ° spaced apart. As a result, only the overlapped image error Ote in which the image errors Oke-Oye are overlapped is generated in the full color unit image region that has passed through each counseling member 30-60 and is superimposed on the belt 70. The overlapping image Ote is generated at a position spaced apart from the SL by Ro 占 315 degrees.

In addition, in the case of the system shown in Fig. 22A, it is installed to satisfy ② of Equation 5, that is, Rd = Rox, and θo1 (= α1) and θo2 (= of each counseling member 30-60. [alpha] 2), [theta] o3 (= [alpha] 3) and [theta] o4 (= [alpha] 4) are all 315 [deg.], which is in phase with [theta] d.

Therefore, the image error caused by the section B of the driving roller 80 overlaps with the image error caused by the sections A1, A2, A3, and A4 of each counseling member 30-60. However, as described above with reference to FIG. 22B, image errors Rke-Rye caused by the driving roller 80 are overlapped and generated as overlapping errors Rte at the same position. The image errors Oke-Oye caused by 60 are also generated by overlapping the overlapping errors Ote at the same position. Accordingly, by implementing a system that satisfies (2) in Equation 5, the two overlapping errors (Rte) (Ote) can also be overlapped at the same position. As a result, as shown in FIG. 22D, only the final overlapping error Te6 in which two overlapping errors Rte and Ote overlap each other is generated in the unit image area. The center of the final overlap error Te6 is generated with a distance difference from SL by Rd · θd = Ro · θo1 = Ro · α1. In this way, when the condition (1), (4) and (5) are satisfied at the same time under the condition of Rd = Ro, since more image errors occurring in the unit image area can be superimposed, the image The number of errors can be reduced. Therefore, it is possible to improve the image quality and to increase the reliability of the product.

Third, as shown in FIG. 23A, a case in which Rox = k · Rd (k = 2, 3, 4, 5, ...) will be described. For convenience of explanation, the case where the radius Rd of the driving roller is twice the radius Rox of the consultation delay will be described as an example. In addition, there are four counseling members of interest, and the radius of each counseling member 30-60 is Rox = Ro1 = Ro2 = Ro3 = Ro4.

First, the interval L1 = L2 = L3 = 2 × 2π · Rd = 2Sd between the centers C1, C2, C3, C4 of each counseling member 30-60. Therefore, when the driving roller 80 rotates two times, each counseling member 30-60 rotates one time. Assuming that a unit image of a predetermined color is formed during two rotations of the drive roller 80, as shown in FIG. 23B, an influence caused by section B of the drive roller 80 occurs in two unit image areas for each color. Done. Here, since the distance between the centers of the counseling members 30-60 is an integer multiple of the circumferential length of the driving roller 80, the centers of the first image errors Rke1 to Rye1 generated for each color are from the start line SL. They are generated by overlapping with a difference of Rd · θd. The centers of the second image errors Rke2 to Rye2 are issued with a difference of 2π · Rd + Rd · θd from the start line SL. Since θd is 180 °, the first image errors Rke1 to Rye1 are represented as one superimposed image Rte1 with a difference of Rd · 180 ° from SL. The second image errors Rke2 to Rye2 are represented as one superimposed image Rte2 with a difference of 2π · Rd + Rd · 180 ° = Rd · (2π + 180 °) from SL.

The intervals between the centers C1, C2, C3, and C4 of the counseling members 30-60 defined in Equations 2 and 3 are L1 = L2 = L3 = 2π · Ro. Since α1 = α2 = α3 = α4 = θo1, the centers of the image errors Oke to Oye by the sections A1, A2, A3, and A4 of the counseling members 30-60 are illustrated in FIG. 23C. As described above, it is generated in the unit image area by a difference of Ro · θo1 from SL. Here, θo1 = α1 = 270 °. Therefore, the image errors Oke to Oye caused by the counseling members 30 to 60 appear as one overlapping error Ote at the point Ro · 270 ° from the SL.

In the case of FIG. 23A, the system is set to satisfy the condition 3 in Expression (5). Since Rox = 2Rd, substituting it into 3 in equation (5) yields (2π + θd) · Rd = Rox · θox = 2Rd · θox. Since θd is 180 °, (2π + 180 °) · Rd = 2Rd · θox. Summarizing the above equation, it can be seen that (2π + 180 °) = 2 · θox, θox = 270 °, that is, θo1 = θo2 = θo3 = θo4 of each counselor 30-60 in FIG. Since it is = 270 °, it can be seen that each of the counseling members 30-60 satisfies e of (5). As such, when Equation 5 is satisfied, as described above with reference to FIGS. 23B and 23C, any one of two overlapping errors Rte1 and Rte2 and another overlapping error Ote are overlapped at the same position. The final overlap error Te7 can be overlapped as shown in FIG. 23D. Here, since the center of the overlapping image error Ote by the counseling members 30-60 is Ro · θo1 = (2π + θd) · Rd from SL, the final overlapping error Te7 is Ro · θo1 = ( The difference is generated twice by 2π + θd) · Rd. As a result, only the overlapping error Rte1 and the final overlapping error Te7 occur in the final full color unit image, as shown in Fig. 23D.

On the other hand, in the case of the present invention, the run-out of each of the counseling members 30-60 which substantially transfers the image to the belt 70 and the drive roller 80 which drives the belt 70 is carried out. Although a large number of image errors occur and the influence on the driven support roller 91 is regarded as having little effect, the description is omitted from the management object, but the relative relationship between the driving roller 80 and the support roller 91 (driven roller) is described. It is obvious that the description can be replaced.

Equations 1 and 3 are applicable to a system in which a plurality of rollers and corresponding at least one corresponding roller are engaged with each other. However, Equation 1 and Equation 3 may be applied to a system error that may occur due to radial displacement as well as image quality improvement. Principles that can be applied to driving load overlapping and conveyance quality improvement are also suggested.

In addition, Equation 2 may be applied to a system in which at least two or more rollers of interest among the plurality of rollers are rotated, and system errors that may occur due to phase change as well as image quality, for example, driving Principles that can be applied to load overlapping and conveyance quality improvement are also suggested.
In addition, in the above equations, the error range has been described in consideration of ± 5%, and within these error ranges, various effects of the aforementioned signatures can be obtained in the same manner.

As described above, the roller and the roller manufacturing method according to the present invention are assembled so that the positioning portion of the driven coupler is positioned at a constant angle with respect to the maximum radial displacement with respect to the roller body (drum body) having a phase. When the roller is employed, it is possible to control the influence on the radial displacement of the roller.

In addition, since the driving unit of the image forming apparatus according to the present invention can control the alignment of the counseling member according to a predetermined criterion, the influence of the radial displacement of the belt support roller and / or the influence of the radial displacement of the counseling members is affected. You have control.

Further, the image forming apparatus according to the present invention can reduce the frequency of image errors in the final superimposed image by controlling the occurrence position of image error occurrence due to the runout of the driving roller. Therefore, the quality of an image can be improved and the reliability of a product can be improved.

In particular, it is possible to reduce the frequency of image errors caused by the runout of the driving roller and / or the consultation delay irrespective of the radius of the consultation delay and the driving roller.

Claims (95)

A roller body having a radial displacement in which the radius changes in the circumferential direction; And a driven coupler coupled to one end of the roller body so as to be complementarily coupled to a drive coupler for transmitting power. The roller body is marked with a mark on a predetermined portion so as to check the radial displacement, And the driven coupler has a positioning portion that determines the engagement position with the drive coupler, wherein the roller body and the driven coupler are coupled so that the positioning portion maintains a predetermined set angle with respect to the mark. delete The roller according to claim 1, wherein the mark is provided at an angle with respect to the maximum radial displacement portion of the roller body. A drum body having a radial displacement in which the radius changes in the circumferential direction; And a driven coupler coupled to one end of the drum body so as to be complementarily coupled to a drive coupler for transmitting power. The drum body is marked with a mark on a predetermined portion to check the radial displacement, The driven coupler has a positioning unit for determining the engagement position with the drive coupler, And the driven coupler is coupled to the drum body such that the positioning unit and the mark maintain a predetermined angle. 5. The counseling post of claim 4, wherein the mark is provided at a predetermined position with respect to the maximum radial displacement portion. delete The method of claim 4, wherein the end of the driven coupler is formed by engraving or embossing the non-circular coupling portion coupled to the drive coupler to receive power, And the positioning unit extends from the coupling unit in a radial direction of the driven coupler. In the manufacturing method of the roller comprising a roller body having a radial displacement of the radius changes in the circumferential direction, and a driven coupler coupled to one end of the roller body, Identifying a portion where the radial displacement of the roller body is changed to the maximum; And determining a posture of the driven coupler on the basis of the identified maximum radial displacement portion and coupling the roller coupler to the roller body. The method of claim 8, wherein the checking step, Measuring the end of the roller body to find the maximum radial displacement portion; And marking a mark on the roller body so as to identify the found maximum portion. The method of claim 8, wherein the coupling of the driven coupler, Roller assembly comprising assembling the driven coupler and the roller body such that the positioning portion provided in the driven coupler has a constant angle with respect to the maximum radial displacement portion so as to determine the mutual coupling position when the driven coupler and the driving coupler are coupled. Way. The method of claim 8, wherein the combining step, Supporting the roller body in a first jig such that the maximum radial displacement portion is positioned at an angle with respect to a reference coordinate axis; Supporting the driven coupler on a second jig such that the driven coupler is positioned at an angle with respect to the reference coordinate axis; And And engaging the driven coupler and the roller body by relatively approaching the first jig and the second jig. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete

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