This application is based on and claims priority under 35 USC 119 from Japanese Patent Application Nos. 2009-056091 filed Mar. 10, 2009 and 2009-092247 filed Apr. 6, 2009.
The present invention relates to an image forming apparatus.
According to an aspect of the invention, there is provided an image forming apparatus including: an image holder that holds an image; a conveying member that conveys an image transferred from the image holder or a recording medium with the image transferred from the image holder thereto; an image holder supporting part that supports the image holder; and a conveying member supporting part that is a separate body from the image holder supporting part and supports the conveying member such that the conveying member is openable and closable.
Exemplary embodiments of the present invention will be described in detail based on the following figures, wherein:
Next, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.
As shown in
The image forming apparatus main body 12 includes a main body frame 300 to be described later (see
The front opening/closing part 18 pivots about a center shaft 24 to open and close with respect to the image forming apparatus main body 12. Also, the front opening/closing part 18 is provided with an operating part 34. The operating part 34 includes, for example, a numeric keypad for inputting the number of recording media to form images thereon, and a start button to be operated at the start of image formation.
Furthermore, on the front opening/closing part 18, a supply opening/closing part 30 is mounted in an openable and closable manner with respect to the front opening/closing part 18. The supply opening/closing part 30 is normally closed with respect to the front opening/closing part 18, as shown in
The main opening/closing part 20 pivots about a center shaft 26 to open and close with respect to the image forming apparatus main body 12. The main opening/closing part 20 is normally closed with respect to the image forming apparatus main body 12. When mounting or removing photoreceptor units 200Y, 200M, 200C, and 200K to be described later in or from the image forming apparatus main body 12, the main opening/closing part 20 is opened. In order to prevent a support roller 70, an intermediate transfer belt 62 and the like, to be described later, mounted on the main opening/closing part 20, from interfering with the front opening/closing part 18, the front opening/closing part 18 is opened before opening the main opening/closing part 20. Also, when closing the front opening/closing part 18 with respect to the image forming apparatus main body 12, the main opening/closing part 20 is closed with respect to the image forming apparatus main body 12 before closing the front opening/closing part 18.
Also, on the main opening/closing part 20, a sub opening/closing part 32 is mounted in an openable and closable manner with respect to the main opening/closing part 20. The sub opening/closing part 32 is openable and closable independently from the main opening/closing part 20, and can be in an open state with respect to the main opening/closing part 20 being in a closed state with respect to the image forming apparatus main body 12. The sub opening/closing part 32 is opened when mounting or removing the whole or part of a cleaning device 96 to be described later in or from the image forming apparatus main body 12. Also, the upper surface of the sub opening/closing part 32 is used as an ejection part for ejecting a recording medium with an image formed thereon.
In the image forming apparatus main body 12, an image forming part 40 for forming an image on a recording medium is provided. The image forming part 40 includes, for example, the four photoreceptor units 200Y, 200M, 200C, and 200K.
The photoreceptor units 200Y, 200M, 200C, and 200K, serving as image forming structures, include photoreceptor drums 210Y, 210M, 210C, and 210K, respectively, and can be removably mounted in the image forming apparatus main body 12. The photoreceptor units 200Y, 200M, 200C, and 200K are disposed in this order from the rear (the right side in
The photoreceptor drums 210Y, 210M, 210C, and 210K are used as image holders for holding images.
Also, the image forming part 40 includes a latent image forming device 41. The latent image forming device 41 emits light on the photoreceptor drums 210Y, 210M, 210C, and 210K to thereby form latent images on respective surfaces of the photoreceptor drums 210Y, 210M, 210C, and 210K.
Furthermore, the image forming part 40 includes development devices 46Y, 46M, 46C, and 46K. The development device 46Y develops, with yellow toner stored therein, the latent image formed on the photoreceptor drum 210Y. The development device 46M develops, with magenta toner stored therein, the latent image formed on the photoreceptor drum 210M. The development device 46C develops, with cyan toner stored therein, the latent image formed on the photoreceptor drum 210C. The development device 46K develops, with black toner stored therein, the latent image formed on the photoreceptor drum 210K.
Also, the image forming part 40 includes a transfer device 58. The transfer device 58 includes an intermediate transfer belt unit 60 and a second transfer device 84. The intermediate transfer belt unit 60 includes the intermediate transfer belt 62.
The intermediate transfer belt 62 is used as a conveying member for conveying images (toner images) transferred from the photoreceptor drums 210Y, 210M, 210C, and 210K. Also, the intermediate transfer belt 62 is endless, and stretched over support rollers 64, 66, 68, 70, and 72 so as to rotate in the direction shown by the arrow in
Also, the intermediate transfer belt unit 60 includes first transfer rollers 80Y, 80M, 80C, and 80K serving as first transfer devices. The first transfer rollers 80Y, 80M, 80C, and 80K transfer a yellow toner image, a magenta toner image, a cyan toner image, and a black toner image formed on the surfaces of the photoreceptor drums 210Y, 210M, 210C, and 210K, respectively onto the intermediate transfer belt 62.
The intermediate transfer belt unit 60 will be further explained later.
The second transfer device 84 includes a second transfer roller 86. The second transfer roller 86 transfers the yellow, magenta, cyan, and black toner images transferred onto the intermediate transfer belt 62 further onto a recording medium.
The transfer device 58 includes the cleaning device 96. The cleaning device 96 includes a scraping member 98. The scraping member 98 scrapes off the toners of the respective colors remaining on the surface of the intermediate transfer belt 62 after the toner images of the respective colors are transferred onto the recording medium by the second transfer roller 86. The toners scraped off by the scraping member 98 are recovered within a main body of the cleaning device 96. The cleaning device 96 is adapted to be removably mounted in the image forming apparatus main body 12 through an opening to be formed by opening the sub opening/closing part 32.
Among the members constituting the transfer device 58, the intermediate transfer belt unit 60 and the cleaning device 96 are mounted on the main opening/closing part 20, and the second transfer roller 86 is mounted on the image forming apparatus main body 12.
A fixing device 50 for fixing the toner image transferred onto a recording medium by the second transfer roller 86 to the recording medium is provided in the image forming apparatus main body 12.
Also, a recovery container 260 is provided in the image forming apparatus main body 12. The surplus developer discharged from the development devices 46Y, 46M, 46C, and 46K is recovered into the recovery container 260. The recovery container 260 is integral with, for example, the photoreceptor unit 200K.
Also, the recording medium feeding device 510 for feeding recording media to the image forming part 40 is mounted in the image forming apparatus main body 12. The recording medium feeding device 510 can be pulled out on the front side (the left side in
The recording medium feeding device 510 includes a recording medium container 512 for storing recording media such as plain paper in a stacked state. Also, the recording medium feeding device 510 includes a feed roller 514 for extracting the top recording medium stored in the recording medium container 512 to convey the extracted recording medium to the image forming part 40. Further, the recording medium feeding device 510 includes a retard roller 516 that is used for separating recording media to thereby prevent plural recording media from being conveyed to the image forming part 40 in an overlapping state.
Also, a conveyance path 530 for use in conveyance of a recording medium is formed in the image forming apparatus main body 12. The conveyance path 530 includes a main conveyance path 532, a reverse conveyance path 534, and a sub conveyance path 536.
The main conveyance path 532 is used for conveying a recording medium fed from the recording medium feeding device 510 to the image forming part 40 to eject the recording medium with an image formed thereon to the outside of the image forming apparatus main body 12. The above-described feed roller 514 and retard roller 516, a registration roller 542, the above-described second transfer roller 86, the above-described fixing device 50, and a eject roller 544 are disposed along the main conveyance path 532, in this order from the upstream side in a direction to convey a recording medium.
The registration roller 542 temporarily stops the recording medium conveyed from the recording medium feeding device 510, at a leading edge of the recording medium, and thereafter sends the recording medium to the second transfer roller 86 in accordance with the timing at which the toner images of the respective colors are transferred onto the intermediate transfer belt 62.
The eject roller 544 ejects the recording medium with the toners of the respective colors fixed thereon by the fixing device 50 to the outside of the image forming apparatus main body 12.
The reverse conveyance path 534 serves as a conveyance path used for reversing a recording medium with a toner image fixed onto one side thereof to convey again the recording medium to the image forming part 40. Along the reverse conveyance path 534, for example, two reverse feed rollers 548 and 548 are disposed. On the reverse conveyance path 534, the eject roller 544 reversely rotates while pinching a rear edge of the recording medium, thereby feeding the recording medium with the rear edge of the recording medium directed forward. The fed recording medium is conveyed to an upstream position of the registration roller 542 through the reverse feed rollers 548 and 548.
The sub conveyance path 536 serves as a conveyance path for feeding a recording medium different from the recording medium stored in the recording medium feeding device 510 to the image forming part 40. The recording medium is fed from the front side of the image forming apparatus main body 12 to the sub conveyance path 536, with the supply opening/closing part 30 opened. A feed roller 552 and a retard roller 554 are provided along the sub conveyance path 536. The feed roller 552 conveys the recording medium fed to the sub conveyance path 536, to the image forming part 40. The retard roller 554 is used for separating recording media fed to the sub conveyance path 536 to thereby prevent plural recording media from being conveyed to the image forming part 40 in an overlapping state.
As shown in
When the main opening/closing part 20, the intermediate transfer belt unit 60, and the cleaning device 96 are integrally opened with respect to the image forming apparatus main body 12, an opening 36 is formed on the image forming apparatus main body 12. Through the opening 36, the photoreceptor units 200Y, 200M, 200C, and 200K are removably mounted in the image forming apparatus main body 12. The recovery container 260 is integral with the photoreceptor unit 200K, as described above. Therefore, the recovery container 260 is removably mounted in the image forming apparatus main body 12, integrally with the photoreceptor unit 200K.
As shown in
In the photoreceptor unit main body 202Y, a charging device 220Y for uniformly charging the surface of the photoreceptor drum 210Y is mounted. The charging device 220Y includes a charging roller 222Y in contact with the photoreceptor drum 210Y. On the surface of the photoreceptor drum 210Y uniformly charged by the charging device 220Y, a latent image is written by the latent image forming device 41 (see
Also, a scraping member 224Y serving as a cleaning device is mounted in the photoreceptor unit main body 202Y. The scraping member 224Y scrapes off yellow toner remaining on the surface of the photoreceptor drum 210Y after the transfer of a yellow toner image onto the intermediate transfer belt 62 by the first transfer roller 80Y (see
In the photoreceptor unit main body 202Y, a recovery chamber 226Y is also provided for recovering the yellow toner scraped off the surface of the photoreceptor drum 210Y by the scraping member 224Y.
Further, a shutter member 230Y is mounted in the photoreceptor unit main body 202Y through, for example, a support member 232Y. The shutter member 230Y is used as a moving member. Also, the shutter member 230Y is connected to a link mechanism 400, and connected to the intermediate transfer belt unit 60 described above through the link mechanism 400.
As shown in
The bearings 206Y and 206Y are each made of a highly heat-conductive material such as metal or heat conductive resin. More specifically, a material having a thermal conductivity of 10 W/m·K or more, and 100 W/m·K or more may be used. Here, brass having a thermal conductivity of 106 W/m·K can be given as an example of the materials for the bearings 206Y and 206Y. For thermal conductivity measurement, the steady-state heat flow meter technique, defined by the American Society for Testing and Materials (ASTM) E1530, can be used.
Furthermore, as shown in
The second position shown in
The shutter member 230Y is in the covering position shown in
The shutter member 230Y is connected to the intermediate transfer belt unit 60 or the main opening/closing part 20 through the link mechanism 400 described above. Also, the shutter member 230Y is adapted to move from the exposure position to the covering position by the action of the link mechanism 400, in association with the operation for opening the intermediate transfer belt unit 60 with respect to the image forming apparatus main body 12. Meanwhile, the shutter member 230Y is adapted to move from the covering position to the exposure position by the action of the link mechanism 400, in association with the operation for closing the intermediate transfer belt unit 60 with respect to the image forming apparatus main body 12.
In this manner, when the intermediate transfer belt unit 60 is closed with respect to the image forming apparatus main body 12 in a state where the photoreceptor unit 200Y is mounted in the image forming apparatus main body 12, the photoreceptor unit 200Y comes into a state of readiness to form an image.
As shown in
The bearings 48Y and 48Y are each made of a highly heat-conductive material such as metal or heat conductive resin. More specifically, a material having a thermal conductivity of 10 W/m·K or more, and 100 W/m·K or more may be used. Here, brass having a thermal conductivity of 106 W/m·K can be given as an example of the materials for the bearings 48Y and 48Y.
Furthermore, as shown in
The intermediate transfer belt unit 60 includes the intermediate transfer belt 62, and a frame body 100 for supporting the intermediate transfer belt 62. The frame body 100 includes a right side plate 102, a left side plate 104, and a connecting member 106 for connecting the right sideplate 102 and the left side plate 104. The above-described support rollers 64, 66, 68, 70, and 72 (see
Also, the right side plate 102 and the left side plate 104 support the above-described first transfer rollers 80Y, 80M, 80C, and 80K (see
The intermediate transfer belt unit 60 also includes the gear 92 mounted on a shaft of the support roller 70 (see
The intermediate transfer belt unit 60 is connected to the above-described link mechanism 400 (see
Note that, in
The main body frame 300 includes a right side plate 302, a left side plate 304, a rear plate 330, and a base 380.
The right side plate 302 and the left side plate 304 are used as image holder supporting parts for supporting the photoreceptor drums 210Y, 210M, 210C, and 210K. In addition, the right side plate 302 and the left side plate 304 are used as a pair of side plates having the image holder support parts. On each of the right side plate 302 and the left side plate 304, four photoreceptor support grooves 306Y, 306M, 306C, and 306K are formed to be inclined from an upper end toward a lower end thereof. Shafts of the photoreceptor drums 210Y, 210M, 210C, and 210K are respectively inserted, through bearings (not shown), into the photoreceptor support grooves 306Y, 306M, 306C, and 306K formed on each of the right side plate 302 and the left side plate 304. Therefore, the photoreceptor drums 210Y, 210M, 210C, and 210K are rotatably supported by the right side plate 302 and the left side plate 304.
The right side plate 302 and the left side plate 304 are produced by, for example, molding.
Further, for example, the right side plate 302 and the left side plate 304 are made of aluminum alloy and formed by die casting. The aluminum alloy has a thermal conductivity of, for example, 96 W/m·K.
As the materials for the right side plate 302 and the left side plate 304, other materials having a thermal conductivity of 10 W/m·K or more may be used instead of aluminum alloy. Examples of the materials satisfying such conditions include magnesium alloy having a thermal conductivity of 72 W/m·K, zinc alloy having a thermal conductivity of 109 W/m·K, and copper alloy having a thermal conductivity of 207 W/m·K. In addition, the molding method is not limited to the above-described die casting, and the powder metallurgy process may be employed. For example, copper sinter having a thermal conductivity of 180 W/m·K may be employed. The powder metallurgy process includes metal injection molding (MIM).
If the materials to be used for the right side plate 302 and the left side plate 304 can be limited within the above-described conditions, metal is not necessarily required. For example, it is also possible to use heat conductive resin having a thermal conductivity of 10 W/m·K or more, such as heat conductive resin having an improved thermal conductivity in the range of from 14 to 25 W/m·K by mixing low melting point alloy into heat conductive resin having a thermal conductivity of 1.5 W/m·K with a heat conductive filler such as alumina added thereto.
If the right side plate 302 and the left side plate 304 made of those materials are used, it is possible to improve heat dissipation, as compared to the case of the use of normal resin having a thermal conductivity in the range of about 0.1 to 0.5 W/m·K. In other words, the dissipation of heat transferred from the photoreceptor drums 210Y, 210M, 210C, and 210K to the right side plate 302 and the left side plate 304 through the bearings 206Y, 206M, 206C, and 206K may be performed. Also, the dissipation of heat transferred from the developing rollers 49Y, 49M, 49C, and 49K to the right side plate 302 and the left side plate 304 through the bearings 48Y, 48M, 48C, and 48K may be performed. Furthermore, use of the side plates formed by casting or the powder metallurgy process facilitates formation of recesses corresponding to drive transmitting members to thereby facilitate arrangement of gear trains.
Also, the dissipation of heat transferred from the latent image forming device 41 to the right side plate 302 and the left side plate 304 may be performed. In addition, heat transferred from the motor 324 to the right side plate 302 and heat transferred from the motor 322 to the left side plate 304 may be dissipated.
The base 380 is used as a base for mounting the image holder supporting parts and a conveying member supporting part. The right side plate 302, the left side plate 304, and the rear plate 330 are fastened to the upper surface of the base 380 with, for example, screws.
The rear plate 330 is used as a conveying member supporting part for supporting the intermediate transfer belt 62 serving as a conveying member, and is a separate body from the right side plate 302 and the left side plate 304 to support the frame body 100 for supporting the intermediate transfer belt 62 so that the intermediate transfer belt 62 is openable and closable with respect to the exterior cover 14. That is to say, the rear plate 330 supports the intermediate transfer belt 62 through the frame body 100 so that the intermediate transfer belt 62 is opened and closed with respect to the image forming apparatus main body 12 (see
More specifically, the right side plate 102 and the left side plate 104 of the frame body 100 are mounted to the upper surface of the rear plate 330 with hinges 450 and 450, thereby supporting the intermediate transfer belt unit 60 on the rear plate 330. The hinges 450 and 450 to be used herein are the so-called one-way clutch hinges which are adapted to rotate freely in a direction to open the intermediate transfer belt 62 with respect to the image forming apparatus main body 12, and to generate rotating torque in a direction to close the intermediate transfer belt 62 with respect to the image forming apparatus main body 12.
This eliminates the need for excessive force to open the intermediate transfer belt unit 60 with respect to the image forming apparatus main body 12, and allows intermediate transfer belt unit 60 to stop at a halfway open position. Here, the halfway open position of the intermediate transfer belt unit 60 corresponds to a position between the closed position and the open position thereof with respect to the image forming apparatus main body 12 as shown in
Furthermore, the rear plate 330 is fastened to the right side plate 302 and the left side plate 304 with, for example, screws.
The intermediate transfer belt unit 60 provided with the intermediate transfer belt 62 and the like, tends to be increased in weight. Therefore, when the intermediate transfer belt unit 60 is opened or closed with respect to the image forming apparatus main body 12 and the frame body 100 is opened or closed with respect to the rear plate 330, the rear plate 330 is likely to be distorted under the weight of the intermediate transfer belt unit 60 and the like. Also, if the intermediate transfer belt unit 60 and the photoreceptor drums 210Y, 210M, 210C, and 210K are supported by a common member, there is a risk that the support member might be distorted to thereby cause the displacement of the photoreceptor drums 210Y, 210M, 210C, and 210K, resulting in the occurrence of a defect in a formed image.
In view of the foregoing, according to the first exemplary embodiment of the invention, the photoreceptor drums 210Y, 210M, 210C, and 210K are supported by the right side plate 302 and the left side plate 304, and the frame body 100 is supported by the rear plate 330. In this manner, since the photoreceptor drums 210Y, 210M, 210C, and 210K, and the frame body 100 for supporting the intermediate transfer belt 62 are supported by separate members, such image defects due to a distortion of the member for supporting the frame body 100 are less likely to be caused.
As shown in
A surface on the rear side (the near side in
As described above, since the control substrate 344 is disposed within the right box part 340 in the sealed state with the lid member 342, leakage of radio waves emitted from the control substrate 344 is less likely to be caused as compared to the case where the control substrate 344 is disposed in an open space. In addition, by mounting the lid member 342, the strength of the rear plate 330 is increased as compared to the case where the lid member 342 is not mounted.
The left box part 360 is formed with side parts surrounded by plate-like members, and a surface on the rear side thereof is open. A power supply substrate 362 is mounted in the left box part 360. The power supply substrate 362 is used as an electric substrate to provide electricity to, for example, respective members of the image forming part 40.
As described above, since the power supply substrate 362 is mounted in the left box part 360 with at least one side surface opened, the power supply substrate 362 is easily cooled as compared to the case where the power supply substrate 362 is disposed in a closed space.
The hinge 450 includes a hinge main body 452, a torque limiter mechanism 454, one-way clutch mechanism 456, and a shaft 458. The one-way clutch mechanism 456 is configured so that for rotation of the shaft 458 in one direction, the shaft 458 is opened, while for rotation of the shaft 458 in the other direction, the shaft 458 is prevented from rotating. The torque limiter mechanism 454 is provided for moving a spring thereof in a slackening direction for rotation of the shaft 458 in one direction, to thereby obtain predetermined torque.
Using the hinge 450 constituted as described above, the frame body 100 is supported, and the intermediate transfer belt unit 60 is supported. Therefore, as described above, torque is generated in a direction to close the intermediate transfer belt unit 60 with respect to the image forming apparatus main body 12, thereby causing a damper effect with the torque limiter mechanism 454. Meanwhile, when the intermediate transfer belt unit 60 is opened with respect to the image forming apparatus main body 12, the shaft 458 rotates freely and the intermediate transfer belt unit 60 can be easily opened.
According to the first exemplary embodiment described above, the image forming apparatus 10 includes the intermediate transfer belt 62 for conveying images (toner images) transferred from the photoreceptor drums 210Y, 210M, 210C, and 210K, and the intermediate transfer belt 62 is used as a conveying member. Alternatively, the image forming apparatus 10 may be configured to include, instead of the intermediate transfer belt 62, a conveyor belt for conveying a recording medium (sheet) with images (toner images) transferred from the photoreceptor drums 210Y, 210M, 210C, and 210K thereto. If the image forming apparatus 10 is configured in such a manner, the second transfer device 84 becomes unnecessary and a recording medium with images (toner images) transferred from the photoreceptor drums 210Y, 210M, 210C, and 210K is conveyed to the fixing device 50.
Next, an image forming apparatus 10 according to a second exemplary embodiment of the present invention will be described. With reference to the image forming apparatus 10 according to the second exemplary embodiment, it is noted that common portions with the image forming apparatus 10 according to the first exemplary embodiment previously described will not be described hereinafter, and the description will be limited to the differences between the two exemplary embodiments.
Also, the right side plate 102 and the left side plate 104 support the above-described first transfer rollers 80Y, 80M, 80C, and 80K (see
The intermediate transfer belt unit 60 also includes the gear 92 mounted on a shaft of the support roller 70 (see
The intermediate transfer belt unit 60 is connected to the above-described link mechanism 400 (see
On each of the right side plate 102 and the left side plate 104, a front protrusion 110 and a rear protrusion 112 are provided in an outwardly protruding manner. In
Note that, in
As shown in
The base 380 is used as a base for mounting the image holder supporting parts and a conveying member supporting part. The right side plate 302, the left side plate 304, and the rear plate 330 are fastened to the upper surface of the base 380 with, for example, screws.
The rear plate 330 is used as a supporting part for supporting the intermediate transfer belt unit 60, and is a separate body from the right side plate 302 and the left side plate 304 to support the intermediate transfer belt unit 60 so that the intermediate transfer belt unit 60 is openable and closable with respect to the image forming apparatus main body 12.
More specifically, the right side plate 102 and the left side plate 104 of the frame body 100 are mounted to the upper surface of the rear plate 330 with hinges 450 and 450, thereby supporting the intermediate transfer belt unit 60 on the rear plate 330. The hinges 450 and 450 to be used herein are the so-called one-way clutch hinges which are adapted to rotate freely in a direction to open the intermediate transfer belt 62 with respect to the image forming apparatus main body 12, and to generate rotating torque in a direction to close the intermediate transfer belt 62 with respect to the image forming apparatus main body 12.
Furthermore, the rear plate 330 is fastened to the right side plate 302 and the left side plate 304 with, for example, screws.
The right side plate 302 and the left side plate 304 are used as a pair of side plates on which at least one of the photoreceptor drum 210, the development device 46, and the latent image forming device 41 is mounted. On each of the right side plate 302 and the left side plate 304, photoreceptor support grooves 306Y, 306M, 306C, and 306K are formed from an upper end toward a lower end thereof (see
That is, the bearings 206Y, 206M, 206C, and 206K protruding from the right side surfaces of the photoreceptor units 200Y (see
Development device support holes 308Y, 308M, 308C, and 308K are formed in the right side plate 302 and the left side plate 304. The development device support holes 308Y, 308M, 308C, and 308K are used for supporting the development devices 46Y, 46M, 46C, and 46K, respectively.
That is to say, the bearings 48Y, 48M, 48C, and 48K protruding from the right side surfaces of the development device main bodies 47Y (see
A drive transmitting mechanism 312 including the motor 324 described above is mounted on the right side plate 302. The drive transmitting mechanism 312 includes, for example, a gear train, to transmit drive of the motor 324 to the intermediate transfer belt 62 with the gear train (see
As described above, according to the second exemplary embodiment, the photoreceptor drums 210Y, 210M, 210C, and 210K and the developing rollers 49Y, 49M, 49C, and 49K are mounted on both the right side plate 302 and the left side plate 304. With this structure, it is possible to precisely regulate the positions between the photoreceptor drums 210Y, 210M, 210C, and 210K, and the developing rollers 49Y, 49M, 49C, and 49K, as compared to the case where the photoreceptor drums 210Y, 210M, 210C, and 210K and the developing rollers 49Y, 49M, 49C, and 49K are supported by members different from each other.
Furthermore, when vibrations occur, the photoreceptor drums 210Y, 210M, 210C, and 210K, the developing rollers 49Y, 49M, 49C, and 49K, the right side plate 302, and the left side plate 304 vibrate in the same cycle, and therefore image deterioration due to vibration is less likely to be caused.
Also, according to the second exemplary embodiment, the photoreceptor drums 210Y, 210M, 210C, and 210K, and the developing rollers 49Y, 49M, 49C, and 49K are different in length in the longitudinal direction thereof from each other. This allows higher-density mounting of the photoreceptor drums 210Y, 210M, 210C, and 210K, and the developing rollers 49Y, 49M, 49C, and 49K, as compared to the case where the lengths in the longitudinal direction of the photoreceptor drums 210Y, 210M, 210C, and 210K are the same as those of the developing rollers 49Y, 49M, 49C, and 49K.
A drive transmitting mechanism 310 including the motor 322 described above is mounted on the left side plate 304. The drive transmitting mechanism 310 includes, for example, a gear train, to transmit drive of the motor 322 to the photoreceptor drums 210Y, 210M, 210C, and 210K with the gear train. Since the drive transmitting mechanism 310 is mounted on the left side plate 304 supporting the photoreceptor drums 210 and the developing rollers 49 in such a manner, it is unnecessary to provide another member for supporting the drive transmitting mechanism 310 in addition to the left side plate 304.
In the second exemplary embodiment, the drive transmitting mechanism 312 is mounted on the right side plate 302, and the drive transmitting mechanism 310 is mounted on the left side plate 304. In short, the pair of side plates is provided with the respective drive transmitting mechanisms. However, only one of the side plates may be provided with a drive transmitting mechanism, namely, a drive transmitting mechanism may be provided on only one of the right side plate 302 and the left side plate 304.
As described later, the latent image forming device 41, in addition to the photoreceptor drums 210Y, 210M, 210C, and 210K, and the developing rollers 49Y, 49M, 49C, and 49K, is also mounted on the right side plate 302 and the left side plate 304. In
As shown in
As described above, the photoreceptor drums 210Y, 210M, 210C, and 210K, and the developing rollers 49Y, 49M, 49C, and 49K are mounted on both the right side plate 302 and the left side plate 304. In
As shown in
The right side plate 302 supports, from the lower side in the direction of gravitational force, the front protrusion 110 and the rear protrusion 112 provided on the intermediate transfer belt unit 60 being in the closed state with respect to the image forming apparatus main body 12. In the same manner as the right side plate 302, the left side plate 304 supports, from the lower side in the direction of gravitational force, the front protrusion 110 and the rear protrusion 112 provided on the intermediate transfer belt unit 60. Thus, a distortion of the intermediate transfer belt unit 60 can be less likely to occur as compared to the case where the intermediate transfer belt unit 60 is not supported by the right side plate 302 and the left side plate 304. Also, a recess having a shape corresponding to a gear train serving as a drive transmitting member (not shown) is formed on the right side plate 302, and the gear train is inserted into and disposed in the recess.
As shown in
As described above, according to the second exemplary embodiment, the photoreceptor drums 210Y, 210M, 210C, and 210K, and the latent image forming device 41 are mounted on both the right side plate 302 and the left side plate 304. With this structure, it is possible to precisely regulate the positions between the photoreceptor drums 210Y, 210M, 210C, and 210K and the latent image forming device 41, as compared to the case where the photoreceptor drums 210Y, 210M, 210C, and 210K and the latent image forming device 41 are supported by members different from each other.
Furthermore, when vibrations occur, the photoreceptor drums 210Y, 210M, 210C, and 210K, the latent image forming device 41 vibrate in the same cycle, and therefore image deterioration due to vibration is less likely to be caused.
The right side plate 302 and the left side plate 304 are made of aluminum alloy and formed by die casting. The aluminum alloy has a thermal conductivity of, for example, 96 W/m·K.
As the materials for the right side plate 302 and the left side plate 304, other materials having a thermal conductivity of 10 W/m·K or more may be used instead of aluminum alloy. Examples of the materials satisfying such conditions include magnesium alloy having a thermal conductivity of 72 W/m·K, zinc alloy having a thermal conductivity of 109 W/m·K, and copper alloy having a thermal conductivity of 207 W/m·K. In addition, the molding method is not limited to the above-described die casting and the powder metallurgy process may be employed. For example, copper sinter having a thermal conductivity of 180 W/m·K may be employed. The powder metallurgy process includes metal injection molding (MIM).
If the materials to be used for the right side plate 302 and the left side plate 304 can be limited within the above-described conditions, metal is not necessarily required. For example, it is also possible to use heat conductive resin having a thermal conductivity of 10 W/m·K or more, such as heat conductive resin having an improved thermal conductivity in the range of from 14 to 25 W/m·K by mixing low melting point alloy into heat conductive resin having a thermal conductivity of 1.5 W/m·K with a heat conductive filler such as alumina added thereto.
If the right side plate 302 and the left side plate 304 made of those materials are used, it is possible to improve heat dissipation, as compared to the case of the use of normal resin having a thermal conductivity in the range of about 0.1 to 0.5 W/m·K. In other words, the dissipation of heat transferred from the photoreceptor drums 210Y, 210M, 210C, and 210K to the right side plate 302 and the left side plate 304 through the bearings 206Y, 206M, 206C, and 206K may be performed. Also, the dissipation of heat transferred from the developing rollers 49Y, 49M, 49C, and 49K to the right side plate 302 and the left side plate 304 through the bearings 48Y, 48M, 48C, and 48K may be performed. Furthermore, use of the side plates formed by casting or the powder metallurgy process facilitates formation of recesses corresponding to drive transmitting members to thereby facilitate arrangement of gear trains.
Also, the dissipation of heat transferred from the latent image forming device 41 to the right side plate 302 and the left side plate 304 may be performed. In addition, heat transferred from the motor 324 to the right side plate 302 and heat transferred from the motor 322 to the left side plate 304 may be dissipated.
As described above, the present invention can be applied to image forming apparatuses such as copying machines, printers, and facsimile machines.
The foregoing description of the exemplary embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The exemplary embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.
Number | Date | Country | Kind |
---|---|---|---|
2009-056091 | Mar 2009 | JP | national |
2009-092247 | Apr 2009 | JP | national |