JP3941752B2 - Image forming apparatus and image forming unit positioning method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus such as a copying machine or a printer, and more particularly to a color image forming apparatus capable of accurately positioning an image forming unit that can be inserted and removed from the apparatus main body in the mounted state.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in an image forming apparatus having an intermediate transfer member, a photosensitive member, and a developing device, the intermediate transfer member, the photosensitive member, the developing device, and the paper transport belt have a unit configuration (hereinafter referred to as an image forming unit). The forming unit can be attached to and detached from the image forming apparatus main body to improve operability and maintainability. In recent years, a belt-like intermediate transfer member, a belt-like photosensitive member (hereinafter referred to as a belt-like image carrier) having a belt suspended on a group of rollers, and a sheet conveying belt have a unit configuration.
[0003]
However, since these image forming units can be attached to and detached from the image forming apparatus main body in consideration of operability, the configuration of the image forming apparatus main body has become complicated, and the position accuracy of each unit deteriorates. There was a problem.
[0004]
In particular, the intermediate transfer body (intermediate transfer belt) of the intermediate transfer body unit is required to have a stable and high positional accuracy in order to achieve high image quality, but is detachable from the image forming apparatus main body. Since it is configured, the number of parts interposed therebetween increases, and accordingly, dimensional errors of the interposed parts tend to accumulate and the position accuracy tends to deteriorate. Further, when the position accuracy of the intermediate transfer belt is deteriorated, not only high image quality cannot be realized, but also an image defect or damage to the intermediate transfer belt may occur due to poor conveyance of the intermediate transfer belt.
[0005]
Further, since the image forming unit is detachable from the image forming apparatus main body, the drive from the drive motor as a driving source is transmitted through a connecting means that can be connected and disconnected when the image forming unit is attached or detached. However, positional accuracy is also required between the connecting means and the image forming unit. That is, when the positional accuracy between the connecting unit and the image forming unit is not sufficient, the connection may be impossible, or the driving roller may be unevenly rotated, and color misregistration may occur due to uneven transfer of the intermediate transfer member. There is. Furthermore, the transferability of the toner image may be deteriorated due to the relative position with respect to the photosensitive drum being shifted.
[0006]
To solve the above problems, when an intermediate transfer body unit having an intermediate transfer body is mounted on the apparatus main body, a drive source provided on the apparatus main body is engaged with the intermediate transfer body unit via a connecting means. The drive of the drive means provided in the drive source is transmitted to the intermediate transfer body unit. Further, a positioning member for positioning the intermediate transfer body unit when the intermediate transfer body unit is mounted on the drive source frame is formed. Then, when the connecting means for mounting the intermediate transfer body unit is engaged, the intermediate transfer body unit is positioned by the positioning member formed on the frame of the drive source, thereby improving the positional accuracy of the intermediate transfer body unit. It is known to increase it (for example, Patent Document 1).
[0007]
FIG. 8 is a diagram schematically showing the positioning of the intermediate transfer body unit of Patent Document 1. In FIG. The positioning pins are fitted into positioning holes provided in the unit frame of the intermediate transfer body unit to position the intermediate transfer body unit with respect to the apparatus main body frame.
[0008]
At the same time, the drive from the drive unit is transmitted to the intermediate transfer body unit 4 through the connecting means.
[0009]
[Patent Document 1]
JP 2003-167411 A
[0010]
[Problems to be solved by the invention]
However, in the image forming apparatus described in Patent Document 1, the first frame to which the coupling means is fastened and the second frame to which the positioning member is fastened are coupled via the rod stay. There were the following problems.
[0011]
That is, since the positioning member also functions as a support member that supports the load of the intermediate transfer body unit, only the end of the positioning member is fastened to the second frame, so that the positioning member is close to the fastening portion of the second frame. Excessive stress is applied and the stress is deformed, and the position of the positioning member relative to the connecting means is displaced. In particular, in an intermediate transfer member unit configured to be freely inserted into and removed from the apparatus main body via a guide rail in order to improve maintainability, a large load is applied to the positioning member. The position also tended to be greatly displaced. Then, such displacement of the position leads to a decrease in positional accuracy between the connecting means and the intermediate transfer body unit as described above, and an image defect occurs.
[0012]
Moreover, in order to ensure sufficient strength to cope with the stress, a thick member must be used for the support member and the second frame, which increases the size and weight of the apparatus, Constraints increase.
[0013]
In the image forming apparatus described in Patent Document 1, in order to ensure the positional accuracy of the connecting means by fitting the positioning member and the fitting hole, the first frame, the first frame and the rod stay, the rod stay, It is necessary to increase the accuracy of the second frame and the second frame, and dimensional errors of these parts still accumulate, and the positional accuracy of both deteriorates. And in order to make positional accuracy high, a great deal of labor is required to reduce the dimensional error of these parts and parts assembly.
[0014]
SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus capable of forming a high-quality color image while being simple and downsized.
[0015]
[Means for Solving the Problems]
The object of the present invention can be achieved by the following constitution.
[0016]
  (Claim 1) A body support member;
A positioning member protruding from the body support member;
An image forming unit having the following (a) and (b), and detachable from the main body support member;
  (A) Image forming support member provided with a fitting hole for fitting with the positioning member
  (B) First connection means supported by the image forming support member and to which driving is transmitted.
A drive unit for driving the image forming unit, having the following (c) and (d), supported by the main body support member;
  (C) Second connecting means that protrudes through the main body support member and is connected to the first connecting means to transmit drive to the image forming unit.
  (D) A drive support member that supports the second connecting means.And a second drive support member disposed opposite to the drive support member at a predetermined interval
In the image forming apparatus in which the first connecting means and the second connecting means are positioned by fitting the positioning member with the fitting hole.
The drive support member is disposed to face the main body support member with a predetermined interval,
The positioning member has an end connected to the drive support member.The middle part is the second drive support memberAnd the other end protrudes through the main body support member.The second connecting means is supported by the drive support member and the second drive support member.An image forming apparatus.
[0017]
(Claim 2) The image forming apparatus according to claim 1, wherein the image forming unit includes a belt-shaped image carrier.
[0018]
(Claim 3) The image forming apparatus according to claim 2, wherein the image forming unit includes a belt-shaped intermediate transfer member.
[0019]
(Claim 4) The image forming apparatus according to any one of claims 1 to 3, wherein the main body support member and the positioning member are fixed via an elastic member.
[0020]
  (Claim 5) The image forming apparatus according to any one of claims 1 to 4, wherein the second drive support member and the main body support member are fastened together.
[0021]
  (Claim 6) The positioning member protruding from the main body support member is fitted in the fitting hole provided in the image forming unit detachable from the main body support member, so that the driving is provided in the image forming unit. In the positioning method of the image forming unit for positioning between the transmitted first connecting means and the second connecting means provided in the drive unit supported by the main body support member and transmitting the drive to the first connecting means.
The drive support member in which the second connecting means and the positioning member are arranged to face the main body support member with a predetermined interval.And second drive support memberAnd projecting through the main body support member.The second connecting means is supported by the drive support member and the second drive support member.A positioning method characterized by the above.
[0022]
  According to invention of Claim 1 and Claim 6, a 2nd connection means and a positioning member are drive support members.And second drive support memberThe connecting position of the second connecting means and the positioning member is high, and the connecting position of the first connecting means supported by the image forming unit is positioned by fitting with the positioning member. The accuracy will be high.In addition, since the positioning member is supported by the drive support member and the second drive support member, it is possible to disperse the stress applied to the positioning member by supporting the load of the image forming unit.As a result, the image forming unit can be driven with high accuracy, and a high-quality color image can be formed.
[0023]
In addition, since the drive support member and the main body support member are arranged to face each other with a predetermined interval, the positioning member can move between the drive support member and the main body support member even when the load of the image forming unit is supported. It is supported at two points, the stress applied to the positioning member is dispersed, deformation of the positioning member is reduced, and high positional accuracy is obtained.
[0024]
According to the second and third aspects of the invention, high positional accuracy can be obtained even in a belt-shaped image forming unit that requires higher positional accuracy.
[0025]
According to the fourth aspect of the present invention, since the positioning member is fixed to the main body support member via the elastic member, even if a displacement occurs in the positional relationship between the positioning member and the main body support member, the elastic member is displaced. Is absorbed, and the relative position between the second connecting member and the positioning member is not displaced. Therefore, high positional accuracy in drive transmission can be obtained.
[0026]
  According to the fifth aspect of the present invention, the main unit support member can be easily attached to and detached from the drive unit including the second connecting means, the drive support member, the second drive support member, and the positioning member. Sex is upThe
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. Note that the X, Y, and Z directions illustrated in the drawings are the X direction when the color image forming apparatus of the embodiment is viewed from the front, and the left direction is the reverse X direction. Further, when viewed from the front, the upward direction is the Y direction, and the downward direction is the reverse Y direction. Further, the rear direction when viewed from the front is the Z direction, and the front direction is the reverse Z direction.
[0028]
FIG. 1 is a cross-sectional configuration diagram of a color image forming apparatus showing an example of an embodiment of the present invention. This color image forming apparatus is called a tandem color image forming apparatus, and includes a plurality of sets of image forming units Y, M, C, and K, an intermediate transfer member unit 4 that is an image forming unit, and a paper feeding and conveying unit. 5 and fixing means T. An automatic document feeder 1 and a document image reading device 2 are arranged on the upper part of the apparatus main body GH of the image forming apparatus.
[0029]
A yellow image forming portion Y that forms a yellow image has a charging unit 320, an exposure unit 330, a developing unit D, and a primary transfer unit disposed around a photosensitive drum 310 as a first image carrier. A transfer roller 340 and a cleaning unit 350 are included. A magenta image forming unit M that forms a magenta image, a cyan image forming unit C that forms a cyan image, and a black image forming unit K that forms a black image also have the same configuration.
[0030]
The intermediate transfer body unit 4 that is an image forming unit includes an intermediate transfer belt 401 as a belt-shaped image carrier, a driving roller 405 that rotatably supports the intermediate transfer belt 401, support rollers 406 and 407, and a backup roller 410. And the like, and the backup roller 410 constitutes a secondary transfer means with a transfer roller 510 disposed so as to rotate while pressing against the backup roller with the intermediate transfer belt 401 interposed therebetween. ing.
[0031]
The drive roller 405 drives and rotates the intermediate transfer belt 401 by the drive transmitted from the drive unit 9 provided on the back side (Z side in the drawing) of the intermediate transfer body unit 4. A specific configuration of the drive unit 9 will be described later.
[0032]
Image formation in the image forming apparatus is performed as follows.
The respective color images formed by the image forming units Y, M, C, and K are sequentially transferred onto the rotating intermediate transfer belt 401 by the primary transfer roller 340 to form a combined color image. The paper P as a recording medium stored in the paper feed cassette is fed by one of the paper feed rollers 503, 513, and 523 of the paper feed unit 5, passes through a plurality of intermediate rollers and registration rollers 551, and then is secondary. The color image is transferred onto the sheet P by being conveyed to the transfer unit 510. The paper P on which the color image has been transferred is fixed by the fixing means T, is sandwiched between the paper discharge rollers 603, and is placed on a paper discharge tray outside the apparatus.
[0033]
On the other hand, after the color image is transferred to the paper P by the secondary transfer unit 510, the residual toner is removed by the cleaning unit 415 from the intermediate transfer belt 401 that has separated the curvature of the paper P. Residual toner is collected in the box by an apparatus (not shown).
[0034]
During the image forming process, the primary transfer roller 340 of the black image forming unit K is always in pressure contact with the photosensitive drum 310 via the intermediate transfer belt 401. The primary transfer rollers 340 of the other image forming units Y, M, and C are in pressure contact with the corresponding photosensitive drums 310 only during color image formation. The secondary transfer unit 510 comes into pressure contact with the intermediate transfer belt 401 only when the sheet P passes through the secondary transfer unit 510 and secondary transfer is performed.
[0035]
The photosensitive drum 310, the developing device D, the primary transfer roller 340, the charging device 320, the cleaning unit 350, and the intermediate transfer body unit 4 of each of the color image forming units Y, M, C, and K are used as a process unit 8 as an apparatus. The main body is configured so that it can be inserted and removed integrally (may be removable), and each of the color image forming portions Y, M, C, and K, the photosensitive drum 310, the developing device D, the primary transfer roller 340, and the charging. The apparatus 320, the cleaning unit 350, and the intermediate transfer body unit 4 are configured to be detachable from the process unit 8. The process unit 8 will be described with reference to FIGS.
[0036]
FIG. 2 is a perspective view showing a state in which the process unit 8 is pulled out from the apparatus main body of the image forming apparatus. The process unit 8 includes a photosensitive drum 310, a developing device D, a primary transfer roller 340, a charging device 320, a cleaning unit 350, and an intermediate transfer body unit 4, and is supported by a unit frame 81.
[0037]
The process unit 8 can be pulled out from the apparatus main body. That is, the front door 101 of the apparatus main body is opened, and the unit handle members 830 and 831 formed in the process unit 8 are gripped and pulled out to the front side. The process unit 8 is guided and slid by the left and right support rails 82L and 82R, and is drawn forward (in the reverse Z direction). When the process unit 8 is inserted, the process unit 8 is accurately fixed to the frame body 970 which is a main body support member on the back side of the main body, and an image can be formed.
[0038]
A support rail 82 </ b> L on the left side of the process unit 8 is disposed on the left side of the intermediate transfer belt 401 in the upper space of the fixing unit T. The support rail 82 </ b> R on the right side of the process unit 8 is disposed near the lower portion of the developing means D of the lowermost black image forming unit K. The support rail 82R is disposed at a position that does not hinder the operation of attaching and detaching the developing unit D of the image forming unit of each color to the process unit 8.
[0039]
The intermediate transfer body unit 4 is fixed to the front panel 800 of the process unit 8 by a fixing member 817. The fixing member 817 can be attached to and detached from the front panel 800, and can be firmly coupled to the front panel 800 when attached.
[0040]
A frame body 970 that is a main body support member is a frame body that supports various members related to color image formation such as the process unit 8, the exposure unit 330, the fixing unit T in FIG. It consists of
[0041]
3 is a perspective view of the unit frame 81 of the process unit 8 as viewed from the direction A in FIG.
[0042]
In the figure, a front panel 800 and a rear panel 801 are side plates arranged to face each other at a predetermined interval, and guide when a cover 803 provided above the developing device D, the developing device D, and the charging means 320 are attached and detached. The pedestal 805 or the like that functions as an integral structure.
[0043]
807 is an opening for attaching / detaching the developing device D, 809 is an opening for attaching / detaching the charging unit 320, 811 is a holding portion for holding the support shaft of the photosensitive drum 310, and 812 is implanted in a side plate of each developing device D. It is a support member that supports the developing device when the process unit 8 is pulled out from the apparatus main body through a groove into which the pin is dropped.
[0044]
Reference numeral 813 denotes a holding member that supports the intermediate transfer body unit through a groove into which a pin provided in the frame of the intermediate transfer body unit 4 is dropped, and a fixing member 817 is provided in the vicinity of the holding member 815. It protrudes inward through the hole provided above. The fixing member 817 is fitted into a hole provided in the frame of the intermediate transfer body unit 4, and the intermediate transfer body unit 4 is detachably supported on the process unit 8.
[0045]
In the above description, various members that are mainly visible on the front panel 800 have been described. However, a similar member or a member that performs a similar function is provided on the rear panel 801 or, depending on the device, on the apparatus main body side, and has a predetermined function. It has come to fulfill. For example, the holding member 813 is provided on the inner side of the rear panel 801 similarly to the front panel 800.
[0046]
By rotating the unit handle members 830 and 831 in the direction of the arrow, the lock member 835 is driven and engaged with a lock member such as a rod (not shown) provided on the apparatus main body side so that the process unit 8 is moved into the apparatus main body. Are securely positioned at the predetermined positions, and when they are pivoted inward from each other, the locked state is released and the process unit 8 can be pulled out from the apparatus main body.
[0047]
Reference numeral 850 denotes a positioning pin for the process unit 8 provided at an upper portion of the front panel 800, and when the insertion is completed, the positioning pin 850 is fitted into a positioning hole (not shown) provided on the apparatus main body side.
[0048]
An intermediate transfer body unit which is an image transfer unit according to the present invention will be described with reference to FIG. FIG. 4 is a front view of the intermediate transfer body unit as seen from the direction A in FIG. 2, and is a view of the frame 400 as seen from the outside.
[0049]
The same reference numerals are assigned to the same members as those already described. The description will be made with reference to FIGS. 1 to 3 as necessary.
[0050]
The intermediate transfer belt 401, which is a semiconductive endless belt-shaped image carrier, includes a drive roller 405, support rollers 406, 407, a backup roller 410, and the like that are rotatably supported by a frame 400 that is a unit support member. The roller group is rotatably suspended.
[0051]
A primary transfer roller 340 as a primary transfer unit is disposed in a loop of the intermediate transfer belt 401 facing the photosensitive drum 310, and an auxiliary roller 450 is provided at an upper position adjacent to each of the primary transfer rollers 340. ing.
[0052]
The auxiliary roller 450 is always urged toward the intermediate transfer belt 401 by an elastic member such as a spring, and is driven and controlled to be displaced toward the intermediate transfer belt 401 during image formation to maintain the mechanical position. After completion of image formation, the image is returned to the initial position. Thereby, by increasing the winding angle of the intermediate transfer belt 401 with respect to the peripheral surface of the photosensitive drum 310, the transferability by the transfer unit 340 can be improved.
[0053]
The pin 460 protrudes outside the frame 400 and is dropped into a groove (housing portion) of the holding member 813 provided on the rear panel 801 in FIG. 3. As a result, the intermediate transfer body unit 4 is replaced with the process unit. 8 has a function of being held in a suspended state.
[0054]
Reference numerals 470 and 471 denote positioning fitting holes provided on the upper side and the lower side of the frame 400. When the process unit 8 is mounted on the apparatus main body, it is fitted with positioning pins provided on the apparatus main body side. As a result, the position of the intermediate transfer body unit is determined. The fitting hole 470 is slightly elongated from the viewpoint of operability.
[0055]
Reference numeral 472 denotes a box-shaped reinforcing member, which is provided between the frame 400 and a side plate provided facing the frame 400.
[0056]
Reference numeral 480 denotes a first connecting means which is fixed to the shaft end portion of the driving roller 405. By connecting to the first connecting means 480 with the second connecting means provided in the drive unit 9 of FIG. 1, the drive from the drive motor provided in the drive unit 9 is transmitted via the gear train.
[0057]
Next, the structure of the drive unit according to the present invention will be described with reference to the plan view of FIG. The drive unit 9 is a gear train formed by meshing of a drive support member 900 and a second drive support member 901 which are drive support members opposed to each other with a predetermined interval, and a plurality of helical gears provided on both drive support members. 903, a drive motor 905 that is a drive source provided outside the drive support member 900, a positioning pin 910 that is a positioning member that regulates the position of the intermediate transfer body unit 4 in the apparatus main body, The first connection means 480 and the second connection means 930 connected to each other are provided as main components.
[0058]
The drive support member 900 and the second drive support member 901 are maintained at intervals and parallelism by rod stays 930 and 931, and the drive unit 9 itself is connected via the second drive support member 901. Finally, it is attached and fixed on the frame body 97 of FIG.
[0059]
One end portion of the positioning pin 910 which is the positioning member of the present invention is coupled (fastened) to the drive support member 900 with a screw 911, and also passes through the fitting hole provided in the second drive support member 901. It is supported.
[0060]
More specifically, the positioning pin 910 includes a base portion 913 having a small diameter, an intermediate portion 915 having a larger diameter than that of the base portion, a tapered portion having a diameter smaller than that of the intermediate portion 915 and gradually decreasing in diameter from the middle toward the tip. And a tip portion 919 including 917.
[0061]
The positioning pin 910 is related to the second drive support member 901 in a step portion (not shown) formed by the small diameter of the base portion 913 and the large diameter of the intermediate portion 915 of the second drive support member 901. It has a relationship such that the outer side faces each other. A thin groove (not shown) is provided on the base portion 913 adjacent to the step portion, and the disc spring 950 that is an elastic member is fixed by the C-type retaining ring 951.
[0062]
In this way, by firmly screwing the rear end portion of the positioning pin 910 to the drive support member 900, the positioning pin 910 and the drive support member 900 can be firmly coupled. Further, the second driving support member 901 is pressed and fixed to the step portion formed on the outer peripheral portion of the positioning pin 910 in the intermediate portion 915, so that the positioning pin 910 and the second driving support member 901 are elastically coupled. be able to.
[0063]
The pressing force obtained by the disc spring 950 can be appropriately changed by selecting the type. In addition, as long as the initial purpose can be achieved, another elastic member, for example, an O-ring may be used instead of the disc spring.
[0064]
The second connecting means 920 is supported by the drive support member 900 and the second drive support member 901, and has a configuration in which a pin 921 is fixed to the tip of the rod.
[0065]
The pin 921 engages with the first connecting means 480 of the intermediate transfer body unit as the process unit 8 is attached to the apparatus main body, and the power of the drive motor 905 after being decelerated by the gear train portion 903. Is established to the drive roller 405.
[0066]
The configuration of the coupling between the drive support member 900 and the second drive support member 901 and the second connecting means is the same as the configuration of the coupling between the positioning pin 910 and the drive support member 900 and the second drive support member 901, for example. be able to.
[0067]
As described above, the positioning pin 910 and the second connecting means 920 are fixed to the same drive support member 900, and the intermediate portion is supported by the second drive support member 901. The positional accuracy of the positioning pin 910 is extremely high, and even if a load is applied to the positioning pin 910, the relative position between the positioning pin 910 and the second connecting means is difficult to be displaced.
[0068]
Next, positioning of the drive unit 9 and the intermediate transfer body unit 8 will be described with reference to FIGS. FIG. 6 is a schematic diagram showing a state of the process unit 8 and positioning pins provided on the frame body 970 which is a main body support member immediately before the process unit 8 is inserted into a predetermined position in the apparatus main body. FIG. FIG. 6 is a partial schematic view showing a state where the unit 8 is completely attached.
[0069]
In the figure, reference numeral 970 denotes a frame body which is a main body support member, and reference numeral 971 denotes a positioning pin provided on the frame body 970.
[0070]
The drive unit 9 is fixed by fastening the second drive support member 901 and the frame body 970 with screws. And the positioning pin 910 and the 2nd connection means 920 penetrate the through-hole provided in the frame 970, and protrude in the process unit 8 side (illustration reverse Z side).
[0071]
On the other hand, in the intermediate transfer unit 4, the pin 460 is dropped into the groove of the holding member 813 provided on the rear panel 801 of the process unit 8 and is held in the process unit 8 in a suspended state.
[0072]
When the process unit 8 is pushed in the Z direction in the figure from the state of FIG. 6, the process unit 8 moves while being supported by the rails 82L and 82R of FIG. 2, and eventually the positioning pins 910 and 971 are moved to the intermediate transfer body. The fitting is started with the fitting hole 470 and the hole 471 for positioning provided in the frame 400 of the unit 4. The frame 400 is guided by a tapered portion 917 provided at the tip of the positioning pin 910. After that, when the outer surface of the frame 400 comes to a position close to the stepped portion of the positioning pins 910 and 971, the mounting is completed, and the intermediate transfer body The unit 4 is positioned.
[0073]
At this time, the connection between the first connecting means 480 and the second connecting means 920 is also completed, and the power transmission path to the driving roller 405 is completed. In addition, the specific structure of the 1st connection means 480 is the aspect which formed the processus | protrusion in two places of the front-end | tip of a cylindrical roller, and axial symmetry.
[0074]
Further, the positioning pin 850 for the process unit 8 is fitted to a fitting hole (not shown) on the apparatus main body side, and finally the handles 830 and 831 in FIG. 3 are opened outward from the closed state. The locking operation of the process unit 8 is completed by engaging the locking member 835 with the locking member on the apparatus main body side and closing the front door 101 in FIG.
[0075]
Thereafter, when the auxiliary roller 450 is displaced and the relationship between the photosensitive drum 310, the intermediate transfer belt 401, the rollers constituting the transfer unit 340, and the like is determined, the image formation preparation is completed.
[0076]
At this time, the intermediate transfer body unit 4 receives a reaction force (load) from the photosensitive drum 310 in accordance with the displacement of the auxiliary roller 450, and the intermediate transfer body unit 4 near the positioning pin 910 in particular is on the near side (illustrated). However, the positioning pin 910 and the second connecting means 920 are firmly supported by the drive support member 900 arranged to face the frame body 970 with a predetermined interval by screws, and the positioning pin 910. Is supported by a frame body 970 that is a main body support member via a disc spring 950 that is an elastic member and a second drive support member 901, and the drive unit 9 is further supported by the second drive support member 901. Therefore, the positioning pin 910 is not displaced by the reaction force, and therefore the positioning pin 910 and the second link are not displaced. Never displaced to a position relation between the device 920 occurs. That is, the positional relationship between the first connecting means 480 and the second connecting means 920 of the intermediate transfer body unit 4 positioned by the positioning pins 910 is not distorted.
[0077]
In other words, for example, the driving support member 900 and the positioning pin 910 based on the urging force of the disc spring 950 are coupled to the positioning pin 910 in the conventional driving unit, and a weight of about 50 to 60 grams is applied to the distal end portion 919 of the positioning pin. Compared to moving only by applying to, it is possible to obtain an extremely large binding force.
[0078]
As described above, the drive unit 9 and the intermediate transfer body unit 4 according to the present invention can sufficiently exhibit their functions even when a large rigidity cannot be obtained. The locking position of the fourth frame 400 can be suitably used even under harsh conditions where it must be installed at a position several tens of millimeters away from the supporting panel surface.
[0079]
Further, the image forming apparatus provided with the drive unit can maintain the position of the process unit 8 with respect to the apparatus main body or the position of the intermediate transfer body unit 4 in relation to the both with high accuracy, so that a high-quality image can be stabilized. Can be formed.
[0080]
The drive unit 9 and the frame body 970 which is the main body support member are fixed by fastening the second drive support member 901 to the frame body 970. However, the drive unit 9 is the second drive support member. The rod stays 930 and 931 may be fastened to the frame body 970 with screws. At this time, the relationship between the positioning pin 910 and the frame body 970 is the same as the relationship between the positioning pin 910 and the second drive support member 901 in FIG. The disc spring 950 is fixed with a C-type retaining ring 951.
[0081]
【The invention's effect】
As described above, according to the present invention, the positional accuracy between the drive unit in the image forming apparatus and the image forming unit to which the drive is transmitted by being connected to the drive unit is high, which is simple and downsized. However, it has become possible to form high-quality color images.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a configuration of an image forming apparatus of the present invention.
FIG. 2 is a perspective view illustrating a state in which a process unit is pulled out from the apparatus main body of the image forming apparatus.
FIG. 3 is a perspective view of a unit frame of a process unit.
FIG. 4 is a front view illustrating a configuration of an intermediate transfer body unit.
FIG. 5 is a plan view showing a configuration of a drive unit according to the present invention.
FIG. 6 is a schematic diagram illustrating a state of the intermediate transfer body unit and the positioning pins immediately before the intermediate transfer body unit is inserted into a predetermined position in the apparatus main body.
FIG. 7 is a partial schematic diagram illustrating a state where the intermediate transfer member unit is completely mounted.
FIG. 8 is a partial schematic diagram illustrating a state where the conventional intermediate transfer body unit is completely mounted.
[Explanation of symbols]
1 Automatic document feeder
2 Document reading section
3 Image forming unit
310 Photosensitive drum
320 Charging means
330 Exposure means
340 Primary transfer roller
350 Cleaning means
D Development means
4 Intermediate transfer unit
400 frame 400
401 Intermediate transfer belt
470,471 Mating hole
480 1st connection means
8 process units
9 Drive unit
905 Drive motor
900 Drive support member
902 Second drive support member
910 Positioning pin
920 second connection means
970 frame

Claims (6)

A body support member;
A positioning member protruding from the body support member;
An image forming unit having the following (a) and (b), and detachable from the main body support member;
(A) An image forming support member provided with a fitting hole for fitting with the positioning member. (B) First connecting means supported by the image forming support member and to which driving is transmitted. A drive unit for driving the image forming unit, which is supported by the main body support member;
(C) Second connecting means that protrudes through the main body support member and is connected to the first connecting means and transmits drive to the image forming unit. (D) Drive support that supports the second connecting means. A second drive support member disposed opposite to the member and the drive support member at a predetermined interval , and the positioning member is fitted into the fitting hole, whereby the first connection means and In the image forming apparatus positioned with the second connecting means,
The drive support member is disposed to face the main body support member with a predetermined interval,
The positioning member has an end portion supported by the drive support member, an intermediate portion supported by the second drive support member , and the other end protruding through the body support member, and the second connection The image forming apparatus is characterized in that the means is supported by the drive support member and the second drive support member .   The image forming apparatus according to claim 1, wherein the image forming unit includes a belt-shaped image carrier.   The image forming apparatus according to claim 2, wherein the image forming unit includes a belt-shaped intermediate transfer member.   The image forming apparatus according to claim 1, wherein the main body support member and the positioning member are fixed via an elastic member.   The image forming apparatus according to claim 1, wherein the second drive support member and the main body support member are fastened together. The positioning member protruding from the main body support member is fitted into a fitting hole provided in the image forming unit detachable from the main body support member, whereby the first member provided in the image forming unit and transmitted to the drive is transmitted. In the positioning method of the image forming unit for positioning the connecting means and the second connecting means provided in the drive unit supported by the main body support member and transmitting the drive to the first connecting means.
The second connecting means and the positioning member are supported by a drive support member and a second drive support member that are arranged to face the main body support member with a predetermined interval, and project through the main body support member. And the second connecting means is supported by the drive support member and the second drive support member .

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