Patent Grant
8027618
1. Field of the Invention
The present invention relates to a color electrophotographic image forming apparatus which uses a rotatable rotary supporting member (rotary) which supports a plurality of developing devices.
2. Description of the Related Art
Conventionally, there is known a color electrophotographic image forming apparatus which uses a rotatable rotary supporting member (rotary) which supports a plurality of developing devices. In the color electrophotographic image forming apparatus, there is known a construction in which a pulse motor is independently used as a motor for rotating the rotary supporting member (refer to Japanese Patent Application Laid-Open No. 2005-227719). The pulse motor is engaged with a gear of a large-diameter mounted to the rotary supporting member via multiple gears. By controlling the rotation of the pulse motor, the developing devices supported by the rotary supporting member are positively moved to the development position in which each of the developing devices faces the photosensitive drum.
As described above, in the conventional image forming apparatus, the stop position of the rotary supporting member is controlled by controlling a rotating speed of the pulse motor which can be controlled in its rotating speed. In addition, the pulse motor and the brushless motor which can be controlled in its rotating speed are expensive and large in size, thereby causing increases in cost and space of the apparatus.
An object of the present invention is to provide a color electrophotographic image forming apparatus which can be obtained at lower cost, and which exhibits an improved space efficiency as compared with a case of using a pulse motor or a brushless motor which can be controlled in its rotating speed.
Another object of the present invention is to provide a color electrophotographic image forming apparatus in which each of the developing devices supported by the rotary supporting member can be positively moved to the development position without installing a motor dedicated to rotating the rotary supporting member.
Still another object of the present invention is to provide a color electrophotographic image forming apparatus in which a member to which a rotation force is transmitted (conveyor roller, fixing device, and transfer belt, for example) can be rotated using the rotation force of the motor for rotating the rotary supporting member.
Yet another object of the present invention is to provide a color electrophotographic image forming apparatus which can be downsized and produced at lower cost as compared with the case of using a pulse motor or a brushless motor, which can be controlled in its rotating speed.
In order to achieve the above-mentioned objects, a representative construction of the present invention is a color electrophotographic image forming apparatus for forming an image on a recording medium, including:
an electrophotographic photosensitive member;
a rotatable rotary supporting member which supports a plurality of developing devices for developing an electrostatic latent image formed on the electrophotographic photosensitive member;
a motor;
a rotation force transmission unit which transmits a rotation force from the motor to the rotary supporting member, the rotation force transmission unit assuming a stop state in which reception of transmission of the rotation force from the motor is stopped and an operation state in which transmission of the rotation force from the motor is received, wherein in the operation state, the rotation force transmission unit receives the rotation force from the motor to rotate the rotary supporting member to sequentially move each of the plurality of developing devices to a development position in which the electrostatic latent image is developed.
According to the present invention, there can be provided a color electrophotographic image forming apparatus which is provided at lower cost and exhibits improved space efficiency as compared with the case of using a pulse motor or a brushless motor, which can be controlled in its rotating speed.
Further, according to the present invention, there can be provided a color electrophotographic image forming apparatus in which each of the developing devices supported by the rotary supporting member can be positively moved to the development position even without a motor dedicated to rotating the rotary supporting member.
Still further, according to the present invention, there can be provided a color electrophotographic image forming apparatus in which a member to which a rotation force is transmitted (conveyor roller, fixing device, and transfer belt, for example) can be rotated by the rotation force of the motor for rotating the rotary supporting member.
Yet further, according to the present invention, there can be provided a color electrophotographic image forming apparatus which can be downsized and produced at lower cost as compared with the case of using a pulse motor or a brushless motor.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Hereinafter, with reference to the drawings, preferred embodiments of the present invention are described. Note that, dimensions, materials, configurations, and relative arrangements of the components described in the following embodiments may be appropriately modified in accordance with various conditions and the construction of the apparatus to which the present invention is applied. Therefore, the following embodiments are not construed to limit the scope thereof unless specific descriptions thereof are made.
A color electrophotographic image forming apparatus according to Embodiment 1 is described. In this case, a color laser beam printer including four developing devices is exemplified as the color electrophotographic image forming apparatus.
In the beginning, an image forming operation of the color laser beam printer is described. As illustrated in
First, the photosensitive drum 2 is synchronized with the rotation of an intermediate transfer belt (member to which a rotation force is transmitted) 7, and then rotated in the direction indicated by the arrow (counterclockwise) of
Simultaneously with the formation of the yellow electrostatic latent image, a rotary (rotary supporting member) 105 rotatable and capable of supporting the four developing devices 18a to 18d is rotated about a shaft 105b by using a drive transmission mechanism (described later). Accordingly, the rotary 105 is rotated, and the yellow developing device 18a is arranged at a development position 18Y at which the yellow developing device 18a faces the photosensitive drum 2 (
However, the rotary 105 may not support the plurality of developing devices 18a to 18d at equal intervals. For example, in the case where the sizes of the developing devices differ from each other, it is only necessary for the rotary 105 to support each of the developing devices at an interval according to each of the sizes. In this case, the rotary 105 is rotated at an angle according to the size of each of the developing devices.
Further, in order that the yellow developer adheres to the latent image formed on the photosensitive drum 2, a voltage of the same charging polarity and of substantially the same potential as those of the photosensitive drum 2 is applied to a developing roller 182a. Through this process, the yellow developer adheres to the latent image, whereby the latent image is developed. That is, a yellow developer image is formed on the photosensitive drum 2.
After that, a voltage of a reverse polarity to that of the developer is applied to a primary transfer roller 81 arranged inside the intermediate transfer belt 7. The yellow developer image formed on the photosensitive drum 2 is thereby primarily transferred onto the intermediate transfer belt 7.
When the primary transfer of the yellow developer image is ended as described above, the respective developing devices (18b to 18d) of magenta, cyan, and black are sequentially positioned to the development position 18Y by the rotation of the rotary 105. Then, as in the case of yellow, formation of the latent image, development, and primary transfer of each of magenta, cyan, and black are sequentially performed. As a result, the four developer images of the corresponding colors are superimposed on the intermediate transfer belt 7.
During this process, a secondary transfer roller 82 is held in a non-contact state with the transfer belt 7. Simultaneously therewith, a cleaning unit 9 for removing the residual developer on the transfer belt 7 is also held in a non-contact state with the transfer belt 7.
Meanwhile, sheets S serving as recording medium are accommodated in a stacked manner in a feeding cassette 51 provided at the lower portion of the apparatus. By the rotation of a feeding roller 52, each of the sheets S is fed from the cassette 51 while separated from each other. The sheet S is fed to a pair of registration rollers 53 (pair of conveyor rollers, member to which a rotation force is transmitted). The pair of registration rollers 53 sends forth the fed sheet S to the portion between the transfer belt 7 and the transfer roller 82. Meanwhile, the transfer roller 82 is held in pressure contact with the transfer belt 7 (in a state illustrated in
Further, a voltage of a reverse polarity to that of the developer is applied to the transfer roller 82. As described above, the four developer images of the respective colors superimposed on the transfer belt are collectively transferred (secondarily-transferred) onto the surface of the fed sheet S.
The sheet S onto which the developer image is transferred is sent to a fixing device 54 (fixing means, fixing device, member to which a rotation force is transmitted). In the fixing device 54, the sheet S is heated and pressurized. Then, the developer image is fixed to the sheet S, whereby a colored image is formed on the sheet S. After that, the sheet S passes the fixing device 54 to be discharged to a discharge portion formed on an upper cover 55.
Now, with reference to
The drive transmission mechanism illustrated in
Hereinafter, the construction of the drive transmission mechanism is described.
A drive gear (driving member) 173 is rotatably supported with respect to an image forming apparatus main body A. The gear 173 is rotated in one direction (direction indicated by the arrow A of
In this case, the rotation force transmission mechanisms M1 to M4 are not limited to gear trains, but may be members such as belts as long as the members are capable of transmitting a rotation force.
Meanwhile, the member to which a rotation force is transmitted which is rotated while receiving the rotation force from the motor M is not limited to the above-mentioned construction. As the member to which a rotation force is transmitted, there can be employed at least any one of the conveyor rollers (registration rollers) 53 for transferring the sheet S, the fixing device 54 for fixing to the sheet S a developer image transferred thereto, and the photosensitive drum 2.
Further, examples of the rotation force transmission mechanism for transmitting the rotation force to the member to which a rotation force is transmitted from the motor M include the rotation force transmission mechanisms M1, M2, and M3.
Still further, the motor M is not limited to a brush motor, but may be a motor such as a stepping motor, a brush DC motor, and brushless DC motor. In Embodiment 1, although rotating speed of each thereof cannot be controlled, any one of the motors can be used which are less expensive than pulse motors of the same output. In addition, in the case of having the same output as that of the pulse motors, those motors are smaller than the pulse motors. Accordingly, in Embodiment 1, the advantages of those motors are effectively utilized.
The rotary 105 holds the developing devices 18a to 18d, and is rotatably attached to the main-body frames 171 and 172. The developing devices 18a to 18d may be fixed or detachable to the rotary 105. Note that, in Embodiment 1, there are adopted as the developing devices the developing cartridges detachably mounted to the rotary 105. The developing cartridges are detachable to the rotary 105, so maintenance thereof by users is facilitated. Further, a rotary gear 105a is provided on the outer periphery of the rotary 105. The rotary gear 105a is rotated integrally with the rotary 105. The gear 105a is a rotary supporting member gear having a number Y of teeth (where Y is a natural number). A shaft 108, which is rotatably provided with respect to the apparatus main body A, is provided with a rotary drive gear 104 by means of a parallel pin. The gear 104 is a transmission gear (first transmission gear member) which has the X a number X of teeth (where X is a natural number) and transmits the rotation force from the drive gear 173 rotated in one direction. The gear 105a meshes (is engaged) with the gear 104. Therefore, the rotary 105 is rotated in synchronism with the gear 104.
The developing devices 18a to 18d, which are supported by the rotary 105, have the developing rollers 182a to 182d, respectively. Each of the developing rollers 182a to 182d is formed of an elastic member, and has a predetermined elasticity. Each of the developing rollers 182a to 182d develops the latent image while held in pressure contact with the photosensitive drum 2.
The shaft 108 is provided with a trigger cam 101 by means of a parallel pin. Thus, the cam 101 is rotated in synchronism with the shaft 108. The cam 101 has a number M (assuming M to be a natural number, one in this case) of claw portions (engaging portions) 101a engageable with an electric actuator (described later). Notably, the cam (rotary member) 101 is rotated integrally with the gear 104.
There is given an extension spring as an example of a trigger spring 103, one end of which is fixed to the apparatus main body A, and the other end of which is rotatably provided to the cam 101. The spring 103 is a biasing member (elastic member) for biasing the cam 101 in a rotational direction thereof (direction indicated by the arrow B of
Solenoid (engaging member) 102 is fixed to the apparatus main body A. The solenoid 102 locks the claw portion (engaging portion) 101a provided to the cam 101. With this construction, by the elasticity of the spring 103, the cam 101 is prevented from being rotated in a direction indicated by the arrow B (
Further, a voltage can be applied to the solenoid 102 from a control unit C (
Still further, the shaft 108 is provided with a partially-toothless gear 106. The partially-toothless gear 106 is fixed to the side of the cam 101. That is, in Embodiment 1, the partially-toothless gear 106 is integrated with the trigger cam 101. In addition, the partially-toothless gear 106 is not a complete gear. As illustrated in
Accordingly, the cam 101, the drive gear 104, the partially-toothless gear 106, and the shaft 108 are integrated with one another, thereby being rotated about the shaft 108. The drive transmission mechanism is constituted by the above-mentioned members.
Further, in the drive transmission mechanism, the natural numerical values X, M, Y, and V are set such that (X/M) is an aliquot part of (Y/V).
In this case, when the voltage is applied to the solenoid 102, the claw portion 101a of the trigger cam 101 is disengaged from the solenoid 102. Accordingly, the restraining force of the solenoid 102 imparted to the cam 101 is eliminated, and then the cam 101 is rotated in the direction indicated by the arrow B by the tension force (biasing force, elastic force) of the spring 103. As a result, the partially-toothless gear 106 synchronized with the cam 101 is rotated, whereby the gear portion 106a of the partially-toothless gear 106 is engaged with the drive gear 173. That is, the application of the voltage to the solenoid 102 causes the drive transmission mechanism to be rotated in synchronism therewith in the direction indicated by the arrow B of
Meanwhile, the gear 104 is engaged with the gear 105a. Thus, according to the rotation of the gear 106, the rotary 105 also rotates in a direction indicated by the arrow C (
In this case, when the voltage is applied to the solenoid 102 for the time t2 (<t1), the subsequent developing device 18b is moved by the rotary 105 to the development position 18Y to be stopped thereat. Further, when the development by the developing device 18c is performed after the development by the developing device 18b, the voltage is reapplied to the solenoid 102 for the time t2 (<t1). As a result, the subsequent developing device 18c is moved by the rotary 105 to the development position 18Y to be stopped thereat.
Meanwhile, as described above, the assumption is made that the number Y of teeth of the gear 105a is a quadruple of the number X of teeth of the drive gear 104. However, any number is possible as long as the multiple thereof is a natural number multiple of 4. For example, the assumption is made that the number Y of teeth of the gear 105a is 120, and the number X of teeth of the drive gear 104 is 15 (120:15=8:1, 8 times). In this case, the voltage is applied to the solenoid 102 for the time t2 (<t1) twice at sufficient intervals; alternatively, the voltage is applied to the solenoid 102 for the time t2 under the condition that t1<t2<2×t1 is satisfied. As a result, the developing devices 18a to 18d can be sequentially moved to the development position 18Y. Further, the developing devices 18a to 18d can be stopped at the development position 18Y. Notably, the application of the voltage to the solenoid 102 is controlled by the control unit C (
Further, the rotation of the rotary 105 which supports the developing devices 18a to 18d is stopped as follows: First, the application of the voltage to the solenoid 102 is released, whereby the solenoid 102 is engaged with the claw portion 101a. Then, as illustrated in
The drive transmission mechanism where the natural numerical values are set as described above such that (X/M) is an aliquot part of (Y/V) can be structured as follows: That is, whenever the cam 101 makes a 1/M revolution, the rotation force (driving force) is transmitted to the gear 105a from the drive gear 104 which rotates integrally with the cam 101. Then, the rotary 105 can be stopped after rotated by an angle W which is an aliquot part of (360°/V).
That is, in Embodiment 1, the motor may not be independently provided which rotates the rotary 105 so as to accurately determine the position of the rotary 105, which can be controlled in its rotating speed. In Embodiment 1, even in the construction without the motor being independently provided therewith, which can be controlled in its rotating speed, the developing devices mounted to the rotary 105 can be positively moved to the development position, and then can be stopped thereat. That is, downsizing and reduction in cost of the apparatus can be realized. Further, even without the motor being independently provided, which can be controlled in its rotating speed, each of the developing devices mounted to the rotary can be positively moved to the development position, and then can be stopped thereat.
Further, as described above, each of the Y number of teeth of the gear 105a and the X number of teeth of the drive gear 104 is set to 4N (N is a natural number of 2 or larger). As a result, except the position (development position) at which each of the developing rollers 182a to 182d is held in pressure contact with the photosensitive drum 2, the rotary 105 can be stopped at the position in which each of the developing rollers 182a to 182d is out of contact with the photosensitive drum 2.
That is, in Embodiment 1, the rotary 105 is rotated by 45 degrees about the shaft 105b from the development position 18Y to be stopped. Accordingly, the developing devices 18a to 18d can be stopped at a standby position 18X at which their respective developing rollers 182a to 182d are out of contact with the photosensitive drum 2.
In this case, the developing rollers 182a to 182d can standby without being in contact with the photosensitive drum 2. Accordingly, the photosensitive drum 2 or the developing rollers 182a to 182d can be prevented from causing deterioration of some kind due to the pressure contact of the developing rollers with the photosensitive drum 2 even outside during the development.
Further, while the four-color developing device is assumed herein, the apparatus may be of three- or two-color type. In this case, the number Y of teeth of the gear 105a is set to 2×P times (where P is a natural number) or 3×Q times (Q is a natural number) of the number X of teeth of the rotary drive gear 104, whereby the same effect can be obtained. The same holds true in the case of a five-color or more type. Incidentally, three developing devices and two developing devices are mounted to the rotary 105 in the cases of the three-color type and the two-color type, respectively.
Further,
In this context, the assumption is made that the number of teeth of the drive gear 104 is X, the number of teeth of the rotary gear 105a is Y, and the number of the claw portions 101a of the cam 101 is M. Thus, the rotary 105 can be rotated at the angle (pitch) W obtained under the condition that 360/(X×M/Y)=W° is satisfied to be stopped. Note that, in order to stop each of the V-color developing devices at the development position, W should be an aliquot part of (360°/V).
As described above, in Embodiment 1, the drive transmission mechanism has a rotation force transmission unit X which may come into a stop state in which transmission of the rotation force from the motor M is stopped, and an operation state in which transmission of the rotation force from the motor M is performed. In the operation state, the rotation force transmission unit X rotates, while receiving the rotation force from the motor M, the rotary 105 by a predetermined amount to sequentially move the developing devices 18a to 18d to the development position 18Y. Herein, the rotation force transmission unit X includes the gear 173, the gear 106, the gear 104, the gear 105a, the cam 101, the solenoid 102, and the spring 103.
Note that, in the developing state as illustrated in
Next, with reference to
In the drive transmission mechanism according to Embodiment 2, unlike Embodiment 1, a torque transmitting means 111 is added, a slipping gear 112 is substituted for the partially-toothless gear 106, and the trigger spring 103 is omitted.
The slipping gear 112 is rotatably provided with respect to the shaft 108, and constantly engaged with the drive gear 173.
Examples of the torque transmitting means 111 include a torque limiter. The torque transmitting means 111 is rotatably provided with respect to the shaft 108, and includes a fixed side (fixed portion) 111a and a slipping side (slipping portion) 111b. The fixed side 111a is engaged with the slipping gear 112 so as to be rotated in synchronism with the slipping gear 112. The slipping side 111b is engaged with the trigger cam 101 so as to be rotated in synchronism with the trigger cam 101. While the fixed side 111a and the slipping side 111b are normally rotated in synchronism with each other, both the fixed side 111a and the slipping side 111b slip when the torque not less than a predetermined torque T is generated therebetween, and are not rotated in synchronism with each other.
As described above, since the slipping gear 112 receives a rotation force from the drive gear 173, the slipping gear 112 is rotated with the fixed side 111a in the direction indicated by the arrow B (of
In this state, when the voltage is applied to the solenoid 102, the claw portion 101a is disengaged from the solenoid 102. Then, the fixed side 111a and the slipping side 111b are rotated in synchronism with each other. Accordingly, the rotation force of the slipping gear 112 is transmitted to the cam 101, whereby the drive transmission mechanism is rotated. That is, the cam 101, the drive gear 104, the shaft 108, the torque transmitting means 111, and the slipping gear 112 are rotated integrally with one another in the direction indicated by the arrow B (
As described above, in Embodiment 2, the drive transmission mechanism has a rotation force transmission unit Y which may come into a stop state in which transmission of a rotation force from the motor M is stopped, and an operation state in which transmission of a rotation force from the motor M is performed. In the operation state, the rotation force transmission unit Y rotates, while receiving the rotation force from the motor M, the rotary 105 by a predetermined amount to sequentially move the developing devices 18a to 18d to the development position 18Y. Herein, the rotation force transmission unit Y includes the gear 173, the gear 112, and the gear 104, the gear 105a, and the solenoid 102.
In Embodiment 2, the same effect can be obtained as that in Embodiment 1.
Further, both the fixed side 111a and the slipping side 111b slip when the torque larger than the predetermined torque T is applied therebetween. Thus, even in the state in which the rotary 105 cannot be rotated due to the foreign body jammed therein, the fixed side 111a and the slipping side 111b slip when the voltage is applied to the solenoid 102 to rotate the rotary 105. For this reason, the drive torque (rotation torque) larger than T is set so as not to be transmitted from the drive source (not shown), whereby the apparatus main body is prevented from being broken down.
Next, with reference to
The drive transmission mechanism illustrated in
The rotary 105 holds the four developing devices 18 (mounted thereto), and is rotatably provided with respect to the main-body frames 171 and 172. As described above, the four developing devices 18 may be fixed or detachable to the rotary 105. Further, a rotary gear 126 is provided on the outer periphery of the rotary 105. The rotary gear 126 rotates integrally with the rotary 105. The gear 126 has a gear portion 126a engageable with a rotary drive gear 127 being rotated in one direction. Further, the gear 126 has the number V of toothless portions 126b facing the drive gear 127 when the solenoid 102 is engaged with any one of claw portions 121a to 121d. In this case, the gear 126 has four toothless portions 126b at equal angles.
A cam 121 serving as a rotary member is engaged (may be integrated) with the rotary 105 so as to be rotatable in synchronism therewith, and has the number V of (four in this case) claw portions (engaged portions) 121a to 121d engageable with the solenoid 102. In this case, the claw portions 121a to 121d of the cam 121 are arranged at equal angles.
Further, the claw portions 121a to 121d of the cam 121 and the four partially-toothless gears 126b of the gear 126 are set to the positions corresponding to the development position.
A biasing cam 122 is engaged (may be integrated) with the cam 121 so as to be rotatable in synchronism therewith. The biasing cam 122 is a guide member having the number V of (four in this case) guide portions 122a.
The trigger lever 123 is a lever member engaged with the guide portions 122a of the biasing cam 122. The lever 123 is provided rotatably about a shaft 125 which is provided to the apparatus main body.
A biasing spring 124 is a biasing member (elastic member) for biasing the lever 123 so as to bias the cam 121 in a rotational direction (direction indicated by the arrow D of
The rotary drive gear (driving member) 127 receives a rotation force from the drive source (not shown), and is constantly rotated in one direction (direction indicated by the arrow F of
The above-mentioned members constitute the drive transmission mechanism. Whenever the claw portions 121a to 121d of the cam 121 are locked and disengaged from the solenoid 102, the gear portion 126a of the gear 126 which is rotated in synchronism with the cam 121 is engaged with the drive gear 127. Then, the drive transmission mechanism rotates the rotary 105 by the angle W which satisfies (360°/V), and then stops the rotary 105.
In the state illustrated in
In this state, when the voltage is applied to the solenoid 102 for a predetermined time, the claw portion 121a of the cam 121 is disengaged from the solenoid 102. Accordingly, the trigger lever 123 biases the biasing cam 122 in the direction indicated by the arrow D (
As described above, in Embodiment 3, the solenoid 102 (engaging member) is engaged with the claw portion (engaging portion) 121a, whereby the rotation of the cam 121 (rotation member) is stopped. With this construction, the drive transmission mechanism may come into a stop state in which transmission of a rotation force from the gear (driving member) 173 to the gear (second transmission gear member) 126 is stopped, and an operation state in which, according to the rotation of the cam 121, the gear 126 is rotated while receiving the transmission of the rotation force from the gear 173. Further, in the operation state, the rotary 105 is rotated by a predetermined amount to sequentially move the developing devices 18a to 18d to the development position 18Y.
Further, in Embodiment 3, the drive transmission mechanism has a rotation force transmission unit Z which may come into the stop state in which transmission of a rotation force from the motor M is stopped, and the operation state in which transmission of a rotation force from the motor M is performed. In the operation state, the rotation force transmission unit Z rotates, while receiving the rotation force from the motor M, the rotary 105 by a predetermined amount to sequentially move the developing devices 18a to 18d to the development position 18Y. Herein, the rotation force transmission unit Z includes the gear 127, the gear 126, the cam 121, the cam 122, and the solenoid 102.
Even with the above-mentioned construction, the same effects can be obtained as those of Embodiments 1 and 2. That is, even without the driving motor which can be controlled in its rotating speed being independently provided therewith, the rotation of the rotary can be controlled.
Note that, in Embodiment 3, in order to sequentially move the four developing devices having respective colors, the four claw portions 121a to 121d and the four toothless portions 126a to 126d are provided at equal angles, respectively. However, it is only necessary for those members to be provided at 4×N portions (N is a natural number). Further, as described in Embodiments 1 and 2, it is only necessary for those members to be provided at 3×N portions (N is a natural number) in the case of three colors, and at 2×N portions (N is a natural number) in the case of two colors. The same holds true in the cases of five colors or more.
In Embodiments 1 to 3 described above, the solenoid 102 is controlled by the unit C.
Further, in Embodiments 1 to 3, the member for transmitting the rotation force is not limited to the gear. Examples of the gear member which can be appropriately used include a gear, a toothed belt, and a transmission belt which transmit the rotation force.
Still further, in Embodiments 1 to 3, the motor M continues to be rotated even in the stop state, whereby the control of the motor is simplified.
Yet further, in Embodiments 1 to 3, the rotation force from the motor M rotates not only the rotary 105, but also the member to which a rotation force is transmitted after transmission thereto. In this case, examples of the member to which a rotation force is transmitted include at least one of the conveyor rollers (registration rollers) 53 for conveying the sheets S, the fixing device 54 for fixing the developer image transferred onto the sheet S, and the transfer belt 7 for conveying the sheets S to the photosensitive drum 2 so as to transfer the developer image formed on the photosensitive drum 2 onto the sheet S.
Yet further, in the Embodiments, a printer is exemplified as an electrophotographic image forming apparatus. However, the present invention is not limited thereto. The present invention may be applicable to other electrophotographic image forming apparatus such as a copying machine and a facsimile machine, or a complex machine having the combined functions of those machines. Further, an image forming apparatus is exemplified, in which with the use of the intermediate transfer member (belt), the developer image of each color is sequentially superimposed on one another to be transferred onto the intermediate transfer member, and then the developer images held on the intermediate transfer member are collectively transferred onto the recording medium. However, the present invention is not limited thereto. The present invention may be applicable to an electrophotographic image forming apparatus in which, with the use of the recording medium carrying member, the developer image of each color is sequentially superimposed on one another to be transferred onto the recording medium carried on the recording medium carrying member. The same effects can be obtained by the application of the present invention to the image forming apparatus.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Applications No. 2007-128983, filed May 15, 2007, and No. 2008-112000, filed Apr. 23, 2008, which are hereby incorporated by reference herein in their entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2007-128983 | May 2007 | JP | national |
| 2008-112000 | Apr 2008 | JP | national |
This application is a divisional of U.S. patent application Ser. No. 12/114,311, filed May 2, 2008.
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| Number | Date | Country | |
|---|---|---|---|
| 20110076060 A1 | Mar 2011 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12114311 | May 2008 | US |
| Child | 12957673 | US |
