JP2009025610A - Drive switching device and image forming apparatus - Google Patents

Abstract

The present invention provides a drive switching mechanism that has a simple structure, reduces the number of drive sources, is easy to handle, can be selectively switched with a compact, lightweight, and inexpensive structure.
One drive source for generating rotation, drive switching means for transmitting power from the drive source to a plurality of driven means, and switching for the drive switching means. A drive switching device comprising a plurality of the drive switching means and the control elements, the operation signals for the plurality of control elements being provided. The drive switching device 200 is controlled by a control actuator 48 that is smaller than the number of control elements.
[Selection] Figure 5

Description

  The present invention relates to a drive switching device for switching portions of various driving forces in various devices such as an information output device such as a computer, an image forming device such as a copying machine and a facsimile, and an image forming apparatus using the drive switching device.

  Conventionally, what is called a tandem system is known as an image forming apparatus for forming a color image (Patent Document 1).

  This image forming apparatus is provided with a plurality of electrophotographic image forming units, for example, four image forming units for forming toner images of four colors of yellow, magenta, cyan, and black. Each image forming unit is, for example, a developing roller that carries toner, a photosensitive drum that is disposed to face the developing roller, and that forms an electrostatic latent image, and a drum that is disposed to face the drum. It has a charger and an exposure device for forming an electrostatic latent image thereon.

  Since such a tandem image forming apparatus includes a drum for each color, an image developed for each color is sequentially transferred to the transfer belt for each color. As a result, a color image is formed at almost the same speed as that for forming a monochrome image, and thus it is widely used as a method of an image forming apparatus for forming a color image.

  In a tandem image forming apparatus, when a color image is formed, all four drums provided corresponding to four colors of yellow, magenta, cyan, and black are driven. Then, a visible image for each color is sequentially transferred onto a transfer belt to form a color image. Furthermore, when forming a color image, not only the drum corresponding to each color is driven, but also the developing device for each color, the toner replenishing means, and the agitating means of the toner storage unit are respectively driven to match the consumed toner. An amount of toner is supplied from the replenishment toner container to the developing device.

  As described above, in the tandem color image forming apparatus, there are many driven elements as compared with the apparatus (monochrome machine) for forming a monochrome image, and accordingly, the drive source and its switching means Need.

  However, if a motor serving as a drive source and various clutch / solenoid mechanisms serving as drive switching means are provided for each of these requirements, the cost increases. In addition, a power source and a control circuit for driving these motors, clutches and solenoids are required, and the apparatus becomes complicated and large, and the power consumption thereof increases.

  Therefore, for driving the drum, a power transmission path is configured such that power is transmitted from one motor to four drums. Then, switching between driving of four drums when forming a color image and driving of one drum when forming a monochrome image is performed by interposing an electromagnetic clutch in the middle of the power transmission path. It has been proposed to do so by switching. Thus, although the drive switching means by the electromagnetic clutch is increased, it is not necessary to provide four motors corresponding to the four drums, respectively, so that the cost can be reduced and the apparatus configuration can be simplified.

  In addition, a conventional toner replenishment transport mechanism in a tandem image forming apparatus has a configuration as shown in FIGS. 29 to 32 as an example.

  FIG. 29 is an overall view of the toner replenishment transport mechanism. 211, 212, 213, and 214 are four toner containers. The toner container 211 contains K toner for replenishment to a developing device (developing container) of an image forming unit K (not shown) that forms a black (K color) toner image. The toner container 212 stores M toner for supply to the developing device of the image forming unit M that forms a magenta (M) toner image. The toner container 213 contains C toner for supply to the developing device of the image forming unit C that forms a cyan (C color) toner image. The toner container 214 contains Y toner for supply to the developing device of the image forming unit Y that forms a yellow (Y) toner image.

  As shown in FIG. 30, the conveying screw 241 is rotated by a drive mechanism including a toner motor (stepping motor) 242 and a gear train. As a result, the toner in each of the toner containers 211, 212, 213, and 214 is developed by the corresponding developing device from the openings 231, 232, 233, and 234 provided at the ends of the conveying screw cylinders 221, 222, 223, and 224. It is transported to the room. FIG. 31 is an enlarged view of the toner replenishment transport mechanism portion of the Y color image forming unit, representing the toner replenishment transport mechanism of each color image forming unit. FIG. 32 is a cross-sectional view of the toner conveyance path portion of the mechanism, showing the toner conveyance in an easily understandable manner.

  In the toner replenishing and conveying method, an appropriate amount of toner is replenished into the developing chamber and a toner motor (stepping motor) 242 that rotates the conveying screw 241 is used to stabilize the image density (ratio of toner and carrier in the developing chamber). It is driven. The determination value of the toner replenishment amount, that is, the control value of the rotation of the toner motor 242 is calculated such that the consumption amount of each color toner is calculated using the video count value obtained by color analysis of the image during image formation, and the toner is replenished by the consumption amount. To be determined. Further, the difference from the actual density is detected, the change in the density of the patch is detected, the correction amount of toner replenishment is determined, and the toner motor 242 is rotated between one sheet after the end of one job or after a predetermined number of sheets to carry it. The toner is replenished to the developing chamber through an opening at the end of the screw. As described above, since the rotation amount of the toner conveying screw 241 is determined by the recorded image, the toner motor 242 is arranged for each color and controlled individually.

  The toner agitation 243 in the toner container reverses the motor 242 and rotates the agitation 243 separately from the rotation output of the toner replenishing screw 241 via the one-way clutch 244 disposed on the drive gear shaft. I am getting output.

  As a known drive switching technique, there has been proposed an example in which a constantly rotating drive is selectively switched between two outputs by a trigger means including a planetary gear train and an electromagnetic solenoid.

  In recent years, planetary gear mechanisms have been widely used as power switching speed reduction means in image forming apparatuses such as copying machines as well as in the automobile industry (Patent Documents 2 and 3).

  When a planetary gear mechanism selectively switches a plurality of driven parts while rotating a driving source such as a motor, the planetary gear mechanism transmits power by a gear train having a compact configuration, and there is little loss such as slip. Further, there is little instability due to slip or the like at the time of power switching, and it is possible to switch smoothly and reliably. It is also possible to reduce the rotation of the drive source to a required speed and change the direction of rotation, depending on the configuration of the planetary gear and the gear ratio. Since the drive transmission can be switched by a gear train, it is an effective mechanism for noise reduction, and is also used as a clutch mechanism such as a paper feed clutch of a copying machine (Patent Document 3).

  A clutch mechanism using a planetary gear mechanism as an example of a paper feeding clutch of a copying machine will be described with reference to FIG. The sun gear A, the planet gear B meshed with it, the internal gear C meshed with the planet gear B having the same rotation center axis as the sun gear A, and the planet gear B rotatably supported at the same time as the sun gear A. And a support member (hereinafter referred to as a carrier) D that can rotate around the shaft. The internal gear C is coupled to the drive input shaft G to which the drive from the drive source is transmitted, and rotates integrally. Further, the rotation of the input shaft G, that is, the internal gear C (input side) rotating by the driving force from the driving source, the carrier D connected to the driven part (load side) by a gear train, and the sun gear A is stopped. A solenoid E with a lever F is provided. Since the load is not connected to the sun gear A when the lever F is pulled, the sun gear A is idle. Therefore, the rotation of the internal gear C (input side) rotates the planetary gear B, but the carrier D, which is connected to the driven part and is loaded, has its load resistance, so that the sun meshing with the planetary gear B is engaged. Gear A rotates. That is, the output carrier D is stopped. When the solenoid is operated by the signal and the lever F stops the rotation of the sun gear A, the rotation of the internal gear C (input side) rotates the planetary gear B, but the sun gear A is stopped. The planetary gear B revolves around the sun gear A. Here, since the support shaft of the planetary gear B is formed on the carrier D, the carrier D rotates with the revolving motion of the planetary gear B, and the driving force is transmitted to the load side. In this way, it plays the role of a clutch that interrupts the driving force to the load side.

This is true even if any of the sun gear A, the internal gear B, and the carrier D is used on the input side, output side, and control side.
JP 2002-341621 A JP 61-89851 A JP 2001-227562 A

  However, as means for reducing the number of drive sources, switching of the drive by such an electromagnetic clutch requires an electromagnetic clutch for the required output. Further, the electromagnetic clutch itself and a control circuit for switching the electromagnetic clutch are required, and it is inevitable that the cost is increased and the apparatus configuration is complicated.

  In particular, in the toner replenishing and transporting mechanism, the developing device section needs to supply toner in an amount corresponding to the consumed toner, and the amount of consumed toner depends on the recorded image. Are sequentially controlled and conveyed. For this reason, in the toner transport unit, a transport drive source and a drive switching unit are arranged for each color, which complicates the apparatus configuration and obstructs the downsizing of the apparatus, thereby preventing cost reduction.

  In addition, even in the case of using a planetary gear train and electromagnetic solenoid as an inexpensive drive switching mechanism, in the case of a color image forming apparatus, there are switching mechanisms / electromagnetic solenoids corresponding to the number of types of color toner, and individual control A circuit is required. Therefore, the increase in cost and the complexity of the device configuration are inevitable.

  The present invention has been made to solve such problems, and the object of the present invention is to make the mechanism simple, reduce the driving source, handle easily, and reduce the size, weight, and cost. An object of the present invention is to provide a drive switching mechanism capable of selectively switching the drive.

  Also, by using this drive switching device, each drive is selectively switched with a simple configuration, and a selective image formation of a color image is realized with a simple configuration that is easy to handle, a compact and inexpensive configuration. An object of the present invention is to provide an image forming apparatus capable of performing the above.

  In order to achieve the above object, a typical configuration of a drive switching device according to the present invention includes one drive source that generates rotation, and a drive switching unit that transmits power from the drive source to a plurality of driven units. And a controller for operating the drive switching means to perform a switching operation, and a drive switching device comprising a plurality of the drive switching means and the control elements, the operation for the plurality of control elements The signal is controlled by a control actuator that is smaller than the number of control elements.

  According to the present invention, the number of drive sources and control actuators is reduced, the device configuration is simplified, and there is an effect of reducing the size and weight of the device and saving the drive energy (electric power).

  Hereinafter, the present invention will be described based on illustrated embodiments.

[First embodiment]
(1) Image Forming Unit FIG. 1 is a schematic configuration diagram of an example of an image forming apparatus. FIG. 2 is a partially enlarged view of FIG. This image forming apparatus 300 is a tandem-intermediate transfer type four-color full-color electrophotographic printer (color image forming apparatus: information output apparatus).

  The printer 300 is connected to an external device 400 such as a computer (personal computer), a workstation, or an image reader. Electrical color image information is input from the external device 400 to the control device (control circuit unit, control board) 350 of the printer 300. Then, the printer 300 forms an image, forms a full color image corresponding to the input image information on the recording material P, and outputs it.

  Y, M, C, and K are the first to fourth image forming units (image forming units), and are arranged in a row at a predetermined interval from the right side to the left side in the drawing from left to right with respect to the horizontal. Is arranged. The first image forming unit Y is an image forming unit that forms a yellow (Y) toner image, and the second image forming unit M is an image forming unit that forms a magenta (M) toner image. The third image forming unit C is an image forming unit that forms a cyan (C color) toner image, and the fourth image forming unit K is an image forming unit that forms a black (K color) toner image.

  Each of the image forming units Y, M, C, and K is an electrophotographic process mechanism, and includes a drum type electrophotographic photosensitive member (photosensitive drum: hereinafter referred to as a drum) 301 as an image carrier. Each drum 301 is rotationally driven at a predetermined speed in a counterclockwise direction indicated by an arrow by a driving mechanism (not shown). Around each drum 301, a primary charging roller 302, a developing device 303, a primary transfer roller 304, and a drum cleaner 305 are arranged along the drum rotation direction. The primary charging roller 302 is a charging unit that uniformly charges the surface of the drum 301 to a predetermined polarity and potential. The developing device 303 is a developing unit that visualizes the electrostatic latent image formed on the surface of the drum 301 as a toner image. The primary transfer roller 304 is a transfer unit that primarily transfers a toner image formed on the drum 301 to an intermediate transfer belt 307 described below. The drum cleaner 305 is a cleaning unit that removes the primary transfer residual toner remaining on the drum surface after the primary transfer of the toner image to the intermediate transfer belt 307.

  An intermediate transfer belt unit 306 is disposed above the image forming units Y, M, C, and K. This unit 306 is a flexible dielectric endless belt (intermediate transfer belt: hereinafter referred to as a belt) as an intermediate transfer member that contacts the upper surface of the drum 301 of each of the image forming units Y, M, C, and K. 307). The belt 307 is suspended and stretched between three parallel rollers: a left driving roller 308, a right driven roller 309, and a lower tension roller 310. The belt 307 is circulated and driven by a driving roller 308 in a clockwise direction indicated by an arrow (a forward direction with respect to the rotation of the drum 301) at a speed corresponding to the rotational speed of the drum 301. The upper surfaces of the drums 301 of the image forming units Y, M, C, and K are in contact with the lower surface of the descending belt portion between the driven roller 309 and the tension roller 310. In addition, four primary transfer rollers 304 are disposed inside the belt 307 so as to face the drum 301 of each image forming unit via a descending belt portion. A contact portion between the drum 301 and the belt 307 in each image forming unit is a primary transfer unit in each image forming unit. Further, a secondary transfer roller 319 is in contact with the driving roller 308 through a belt 307 using the roller 308 as a secondary transfer counter roller. A contact portion between the belt 307 and the secondary transfer roller 319 is a secondary transfer portion. A belt cleaner device 311 is disposed on the belt suspension portion of the driven roller 309.

  Below the first to fourth image forming units Y, M, C, and K, a laser scanner (laser scanning exposure device) 312 is disposed as an image exposure unit for the drum 301 of each image forming unit. . The laser scanner 312 includes laser light emitting means, a polygon mirror, a reflection mirror, and the like that emit light corresponding to time-series electric digital pixel signals of given image information.

  The laser scanner 312 scans and exposes the uniformly charged surface of the drum 301 of each image forming unit Y, M, C, and K with laser light LY, LM, LC, and LK modulated according to image information of each color. Thus, an electrostatic latent image corresponding to the image information of each color is formed. The developing device 303 of each image forming unit stores a developer containing Y toner, a developer containing M toner, a developer containing C toner, and a developer containing K toner. Each developing device 303 develops the electrostatic latent image formed on the drum of each image forming unit as a toner image with the corresponding color toner. In many cases, image exposure and reversal development are used in combination.

  Here, in each of the four image forming units Y, M, C, and K, a process cartridge that can detachably attach a drum 301 and some process means acting on the drum 301 to the printer main body at once. (CRG). In this embodiment, the drum 301, the primary charging roller 302, the developing device 303, and the drum cleaner 305 are integrally assembled in the cartridge frame and detachably attached to the printer body. is there. Each cartridge mounted in a predetermined mounting position (latent image forming position) in the printer main body is held in a state where the cartridge is positioned and fixed by a positioning unit (not shown). In addition, a drive output unit (not shown) on the printer body side is coupled to a drive input unit (not shown) on each cartridge side. Further, a power supply system (not shown) on the printer body side is electrically connected to electrical contacts (not shown) on the cartridge side.

  The printer control device 350 causes each of the image forming units Y, M, C, and K to perform an image forming operation based on the electrical color image information input from the external apparatus 400. Thus, in the first to fourth image forming units Y, M, C, and K, the Y, M, C, and K colors are respectively controlled at predetermined control timings with respect to the surface of the rotating drum 301. A color toner image is formed.

  The color toner image formed on the surface of the drum 301 of each image forming unit is rotationally driven by the primary transfer unit in the rotation direction and forward direction of each drum 301 and at a speed corresponding to the rotation speed of each drum 301. The image is successively superimposed and transferred onto the outer surface of the belt 307. As a result, an unfixed full-color toner image is synthesized and formed on the surface of the belt 307 by superimposing the four color toner images. A predetermined primary transfer bias having a polarity opposite to the charging polarity of the toner is applied to the primary transfer roller 304 of each image forming unit from a power supply unit (not shown) at a predetermined control timing. As a result, the toner image on the drum surface is electrostatically transferred to the outer surface of the belt 307. The drum cleaner 305 of each image forming unit includes a cleaning blade or the like, and scrapes the primary transfer residual toner on the drum 301 from the drum surface to clean the drum surface.

  On the other hand, at a predetermined paper feed timing, the pickup roller 314 of the paper feed cassette 313 in which the recording materials P are stacked and accommodated is driven. As a result, the recording material P is fed out, and one sheet is separated and fed by the sheet feed roller 315 and the retard roller 316. Then, the recording material P is conveyed to the registration roller 318 through the vertical conveyance path 317.

  The registration roller 318 sends the recording material P to the secondary transfer unit in accordance with the image forming timing of the image forming unit. That is, the recording material P is arranged so that the leading end of the recording material P reaches the secondary transfer portion in accordance with the timing when the leading end of the unfixed full-color toner image formed on the rotating belt 307 reaches the secondary transfer portion. The timing is conveyed. As a result, the unfixed full-color toner image on the belt 307 is secondarily transferred sequentially onto the surface of the recording material P at the secondary transfer portion. A predetermined secondary transfer bias having a polarity opposite to the charging polarity of the toner is applied to the secondary transfer roller 319 from a power source (not shown) at a predetermined control timing. As a result, the toner image on the surface of the belt 307 is electrostatically transferred to the recording material P.

  The recording material exiting the secondary transfer portion is separated from the surface of the belt 307 and guided to the fixing nip portion of the image heating fixing device (fixing unit) 321 by the vertical conveyance guide 320. The fixing device 321 melts and mixes the above-described toner images of a plurality of colors and fixes them as fixed images on the surface of the recording material. The recording material P that has exited the fixing device 321 passes through a conveyance path 322 as a full-color image formed product and is sent out onto a paper discharge tray 324 by an external paper discharge roller 323. Thus, a series of image forming operations is completed.

  The surface of the belt 307 after separation of the recording material at the secondary transfer portion is cleaned by removing residual deposits such as secondary transfer residual toner by a belt cleaner 311 and repeatedly used for image formation.

  In the mono black print mode, only the fourth image forming unit K that forms the K color toner image is controlled in image forming operation.

  In the printer 300 of this embodiment, the first to fourth image forming units Y, M, C, and K are arranged in the order of yellow, magenta, cyan, and black from the upstream side in the moving direction of the intermediate transfer belt 307. The color order is not limited.

(2) Developing device 303
In the printer 300 of this embodiment, the developing device 303 of each of the image forming units Y, M, C, and K uses a non-magnetic toner and a magnetic carrier as a developer at a predetermined weight ratio (TD ratio = toner weight / (toner weight). This is a two-component development system using a two-component developer mixed at + carrier weight).

  The developing device 303 will be described with reference to FIG. Reference numeral 325 denotes a developing chamber (developing container) of the developing device 303, and a predetermined amount of developer (two-component developer) is accommodated in the developing chamber. In the developing chamber 325, developer agitating and conveying screws 326 and 327, a developing sleeve 328, and a developer regulating blade 329 are disposed.

  The developer in the developing chamber 325 is circulated and conveyed while being stirred in the developing chamber 325 by the rotation of the developer stirring and conveying screws 326 and 327. As a result, the toner and the carrier are uniformly mixed, and the toner is frictionally charged with a predetermined polarity and a predetermined charge amount.

  The developing sleeve 328 is a cylindrical body made of a nonmagnetic material such as aluminum, and is arranged in parallel to the drum 301 with a predetermined clearance (SD gap) from the drum 301. Inside the developing sleeve 328, a magnet roll 330 is disposed in a non-rotating manner. The developing sleeve 328 is driven to rotate around the magnet roll 330 in a clockwise direction indicated by an arrow at a predetermined speed. A part of the developer circulated and conveyed in the developing chamber 325 is magnetically attracted and carried as a developer layer (magnetic brush layer) by the magnetic force of the magnet roll 330 on the outer surface of the developing sleeve 328, and as the developing sleeve 328 rotates. Be transported. Then, the thickness of the developer layer is regulated by a developer regulating blade 329 disposed with a predetermined gap (SB gap) with respect to the developing sleeve 328. The developer layer subjected to the layer thickness regulation is conveyed to the development site which is the opposite portion of the drum 301 and the development sleeve 328 by the subsequent rotation of the development sleeve 328. A predetermined developing bias is applied to the developing sleeve 328 from a power source (not shown) at a predetermined control timing. The electrostatic latent image formed on the drum 301 is developed as a toner image by the developer layer carried on the developing sleeve 328 and the developing bias at the developing portion. The developer layer on the developing sleeve 328 subjected to the development of the electrostatic latent image is conveyed back into the developing chamber by the subsequent rotation of the developing sleeve 328 and detached from the outer surface of the developing sleeve 328 by the action of the repulsive magnetic pole portion of the magnet roller 330. To do. The developer is newly supplied and carried on the outer surface of the developing sleeve.

(3) Toner replenishment transport mechanism 100
In each of the image forming units Y, M, C, and K, the toner of the two-component developer housed in the developing chamber 325 of the developing device 303 is used for developing the electrostatic latent image and is sequentially consumed. The TD ratio of the developer decreases. Therefore, the control device 350 controls the toner density of the toner supply / conveyance mechanism 100 (FIGS. 3 and 4) from the toner container 331 to the developing chamber of the developing device 303 in order to stabilize the image density (TD ratio of the two-component developer in the developing chamber). A toner replenishing operation for replenishing toner in a timely and appropriate amount in 325 is executed. The determination of the toner replenishment amount, that is, the operation control value of the toner replenishment transport mechanism, calculates the consumption amount of each color toner by using the video count value obtained by color analysis of the image during the image forming operation of the printer, and the toner for the consumption amount. To be replenished. Further, a change in the density of the patch is detected from the difference from the actual developed image density, and a correction amount for toner replenishment is determined. Then, a toner replenishing operation for replenishing and mixing an appropriate amount of toner in the developing chamber of the developing device 303 is executed by operating the toner replenishing and conveying mechanism after one job or between a predetermined number of sheets.

  As shown in FIGS. 5 and 6, the toner supply / conveyance mechanism 100 in this embodiment includes first to fourth toner containers (toner hoppers) 331Y, 331M, 331C, and 331K. The toner containers 331Y, 331M, 331C, and 331K are toner storage units that are provided separately from the developing devices 303 of the image forming units Y, M, C, and K of the respective colors. The first toner container 331Y contains Y toner to be replenished to the developing device 303 of the first image forming unit Y. The second toner container 331M contains M toner to be supplied to the developing device 303 of the second image forming unit M. The third toner container 331C contains C-color toner to be supplied to the developing device 303 of the third image forming unit C. The fourth toner container 331K contains K-color toner to be supplied to the developing device 303 of the fourth image forming unit K.

  The first to fourth toner containers 331Y, 331M, 331C, and 331K have the same configuration except that the colors of the contained toner are different. Each toner container 331 has a toner replenishing screw portion 332 at its lower portion, and communicates with the developing chamber 325 of the corresponding developing device 303 via the toner replenishing screw portion 332 as shown in FIGS. ing.

  The toner replenishing screw portion 332 includes a toner conveying cylinder portion 333, a toner conveying screw 104 (FIG. 7) disposed in the cylinder portion, and a communication pipe portion 334 that communicates the toner container 331 and the toner conveying cylinder portion 333. Have The toner in the toner container 331 flows into the toner conveying cylinder portion 333 from the communication pipe portion 334. When the toner conveyance screw 104 is driven to rotate, the toner in the toner conveyance cylinder portion 333 is conveyed to the front end side of the cylinder portion, and the developer in the developing chamber 325 of the developing device 303 is opened from the opening 335 on the front end side of the cylinder portion. Will be replenished. The toner conveying screw 104 is a toner conveying unit that conveys toner from a toner storage unit containing replenishing toner to the developing device.

  The toner replenished in the developing chamber 325 is circulated and conveyed while being agitated by the developer in the developing chamber 325 by the rotation of the developer agitating / conveying screw 326 and 327, and is uniformly mixed. It is triboelectrically charged with the amount of charge.

  The first to fourth toner containers 331Y, 331M, 331C, and 331K are rotated and driven by toner stirring blades (toner stirring means) 71 and 72 that stir the toner in the toner containers, respectively. 73 and 74 (FIG. 7) are provided.

  In each of the toner containers 331Y, 331M, 331C, and 331K, the toner conveying screw 104 and the toner stirring blades 71, 72, 73, and 74 are operated by the drive switching device 200. In each of the toner containers 331Y, 331M, 331C, and 331K, the toner conveying screw 104 and the toner stirring blades 71, 72, 73, and 74 are a plurality of driven units.

  5 is a perspective view of the entire drive switching device 200 as seen from the front side, and FIG. 6 is a perspective view of the drive switching device 200 as seen from the back side. FIG. 7 is a cutaway view showing the inside of each of the toner containers 331Y, 331M, 331C, and 331K in FIG. 8 is a front view of the drive switching device 200, FIG. 9 is a top view, and FIG. 10 is a rear view. 11 is a cross-sectional view taken along line (11)-(11) in FIG. 12 is a cross-sectional view taken along line (12)-(12) in FIG. 13 is a cross-sectional view taken along line (13)-(13) in FIG. 14 and 15 are perspective views of only the gear train of the toner conveying screw drive system. FIG. 16 is a perspective view of a drive motor and a drive switching portion. FIG. 17 is a plan view of a spring clutch mechanism portion.

  The drive switching device 200 includes one drive source that generates rotation, a drive switching unit that transmits power from the drive source to a plurality of driven units, and a controller that operates the drive switching unit to perform a switching operation. , And a plurality of drive switching means and control elements.

  That is, it has the drive motor 1 as one drive source which generates rotation. A drive gear 2 is fixed to the output shaft of the drive motor 1. The drive gear 2 meshes with a large gear 3 a of a two-stage gear 3 that is fixed to the rotating shaft 4. A gear 5 and a gear 41 are coaxially fixed to the rotary shaft 4. Accordingly, the two-stage gear 3, the gear 5, and the gear 41 are rotated together by the rotation of the drive gear 2.

  The small gear 3b of the two-stage gear 3 is connected to planet gear mechanisms (differential planetary gear mechanisms) 25, 26, 27, and 28 described later of the first to fourth toner containers 331Y, 331M, 331C, and 331K. Meshes with the input gear 51 (FIGS. 10 and 11) to the existing gear train. The planetary gear mechanisms 25, 26, 27, and 28 are a plurality of drive switching means.

  The gear 5 meshes with the drive input gear 6 to the spring clutch mechanism T (a switching control portion that sends a switching signal to the drive switching mechanism).

  The gear 41 is a first gear train connected to toner stirring blades 71, 72, 73, and 74 that stir the toner in the first to fourth toner containers 331Y, 331M, 331C, and 331K. It meshes with the input gear 61a (FIG. 9). The first input gear 61a is fixed to the rotating shaft 61c, and the second input gear 61b is fixed to the rotating shaft 61c coaxially with the first input gear 61a. Accordingly, the rotation of the gear 41 causes the first input gear 61a and the second input gear 61b to rotate together.

  The gear 6 meshes with the input gear 7 of the spring clutch mechanism T, and rotationally drives the input gear 7. Referring mainly to FIGS. 16 and 17, reference numeral 46 denotes a drive input ring of the spring clutch mechanism T, which rotates together with the input gear 7 in a free state. Reference numeral 49 denotes an engagement / disengagement lever for the drive input ring 46, which is sucked and released by the solenoid 48. When the energization to the solenoid 48 is OFF (excitation release), the engagement / disengagement lever 49 moves toward the drive input ring 46 by releasing the attraction to the solenoid 48, and the tip claw portion of the lever 49 is driven. Engage with the locking groove of the input ring 46. As a result, the rotation of the drive input ring 46 is prevented, and the spring clutch mechanism T is turned off. In this clutch-off state, the rotation of the input gear 7 is not transmitted to the bevel gear 11 as the output gear of the spring clutch mechanism T, and the rotation of the bevel gear 11 is stopped. When the energization of the solenoid 48 is ON (excitation), the engagement / disengagement lever 49 is attracted to the solenoid 48 and moves away from the drive input ring 46, and the tip claw portion of the lever 49 is moved. Is disengaged from the locking groove of the drive input ring 46. As a result, the retention of the drive input ring 48 is released, and the spring clutch mechanism T becomes the clutch-ON. In this clutch-ON state, the rotation of the input gear 7 is transmitted to the bevel gear 11 as the output gear of the spring clutch mechanism T. The bevel gear 13 that meshes with the bevel gear 11 is fixed to the camshaft 12 and uses the camshaft 12 as a rotation axis. The camshaft 12 is rotatably held by a stationary bearing member (not shown). Therefore, by controlling excitation / excitation of the solenoid 48, the camshaft 12 can be rotated by a predetermined angle by turning the spring clutch mechanism T ON / OFF. Cams 13, 14, 15, and 17 are arranged on the camshaft 12 corresponding to the toner replenishment conveyance portions for the respective colors, and rotate integrally with the camshaft 12. The cams 13, 14, 15, and 16 control power interruption of the planetary gear mechanisms 25, 26, 27, and 28 that actually transmit power to the toner replenishing and conveying portions for the respective colors.

  Since the planetary gear mechanisms 25, 26, 27, and 28 have the same configuration, one of them will be described with reference to FIG. (A) is a side view of the planetary gear mechanism 25 (26, 27, 28), (b) is a sectional view taken along line (b)-(b) in (a), (c) is a front view, and (d). These are sectional drawings of (d)-(d) line view in (a). The planetary gear mechanism 25 (26, 27, 28) includes a sun gear 30, a planetary gear 31, and a planetary gear 31 that support a gear (drive input gear) 29, which is a power input unit, and a support member that rotatably supports the planetary gear 31. Hereinafter, there are a carrier 32 and an internal gear 33. An output gear 35 is formed on the outer periphery of the internal gear 33, and has a shaft 34 that rotatably supports the sun gear 30, the carrier 32, and the internal gear 33 on the same axis. The carrier 32 is formed with a protrusion 32a.

  When the camshaft 12 rotates and the cam 13 (14, 15, 16) comes to a position where it engages with the protrusion 32a, the rotation of the carrier 33 is stopped. Then, the rotation of the sun gear 30 that is rotated by transmission of power is transmitted to the planetary gear 31. Since the rotation of the carrier 32 having the support shaft of the planetary gear 31 is restricted, the planetary gear 31 rotates at that position and transmits the power to the internal gear 33. That is, the output-side internal gear 33 that transmits to the toner conveying screw 104 for supplying the toner of the toner conveying portion rotates.

  When the camshaft 12 rotates and the cam 13 deviates from the position where it engages with the protrusion 32a, the rotation of the carrier 33 is not restricted. At this time, the rotation of the sun gear 30 is transmitted to the planetary gear 31, but the idler 110 (FIGS. 8 and 11) that transmits power to the toner conveying screw 104 meshes with the internal gear 33, and the rotational load It is in the state where it took. Therefore, the planetary gear 31 revolves, and the carrier 33 having a rotation shaft formed on the planetary gear 31 is rotated.

  In other words, the rotation of the sun gear 30 that is rotated by transmission of power is transmitted to the carrier 33 that is not restricted in rotation and is not loaded, and the rotation of the internal gear 33 that is subjected to the rotation load is stopped.

  In this way, the camshaft 12 rotates and the cam 13 turns on / off the rotation of the carrier 33, thereby controlling the output to be transmitted to the toner conveying screw 104 side.

  The plurality of planetary gear mechanisms 25, 26, 27, and 28 use the power from one drive motor 1 as a plurality of driven means, and the toner conveying screw 104 and the toner stirring blades 71, 72, and 73 in each toner container. Drive switching means for transmitting to 74.

  Further, power transmission to the planetary gear mechanisms 25, 26, 27, and 28 is transmitted from the step gear 3 through a gear train to another gear train.

  Referring to FIG. 15, for example, the route for transmitting power to the planetary gear mechanism 25 for switching the drive of the Y color toner conveyance unit is as follows. That is, the second gear 3 is connected to the idler gear 34, the input gear 35 of the adjacent planetary gear mechanism 26 for the M-color toner transport unit 26, and the idler gear 36 to the gear 29 of the planetary gear mechanism 25 of the Y-color toner transport unit. .

  Similarly, each of the C-color and K-color toner conveying portions is connected by an input gear of the planetary gear mechanism for the toner conveying portion and an idler gear therebetween, and the drive is transmitted to the conveying screw 104 via each planetary gear mechanism for the toner conveying portion. It is configured to be able to.

  As described above, by controlling the excitation / excitation of the solenoid 48, the spring clutch mechanism T can be turned ON / OFF to rotate the camshaft 12 by a predetermined angle. The cams 13, 14, 15, and 16 are attached to the camshaft 12 by changing the phase by a predetermined angle. Then, by repeating excitation / excitation of the solenoid 48, the planetary gear mechanisms 25, 26, 27, and 28 are arranged so as to come sequentially to positions that engage with the protrusions 32 a of the carrier 32. Also, a sensor plate 45 is attached to the bevel gear 11 so that the sensor 44 can detect when the bevel gear 11 stops in the allocation groove 10 for the home position. This is because when the power is turned off or stopped during the operation, it is not known from which color toner the supply can be started, so that the operation is started once rotated to the home position.

  19, 20, and 21 are a front view, a top view, and a rear view, respectively, of the toner conveyance / stirring / drive switching device in one toner container. 22 is a cross-sectional view taken along line (22)-(22) in FIG. 23 is a cross-sectional view taken along line (23)-(23) in FIG. The configuration of the toner conveying / stirring / drive switching device is the same for each of the first to fourth toner containers 331Y, 331M, 331C, and 331K.

  A toner agitation blade gear 103 rotates integrally with the toner agitation blades 71 (72, 73, 74) for agitating the toner in the toner container. A toner conveying screw gear 105 rotates integrally with the toner conveying screw 104.

  The toner stirring blade gear 103 meshes with the input gear 61b via transmission idler gears 106, 107, 108, and 109 as shown in FIGS. The toner conveying screw gear 105 meshes with a planetary gear mechanism (clutch mechanism using a planetary gear mechanism) 25 (26, 27, 28) as drive switching means via transmission idler gears 109 and 110.

  A description will be given of a plurality of control elements for operating the planetary gear mechanisms 25, 26, 27, and 28, operation signals for the plurality of control elements, and a control actuator.

  The rotation of the drive motor 1 is transmitted from the drive gear 2 fixed to the drive motor 1 to the two-stage gear 3. Then, from the two-stage gear 3 through the shaft 4 to the gear 5 and the gear 6 that meshes with the gear 5, to the switching control portion (drive switching portion) that sends a switching signal to the drive switching mechanism portion including the spring clutch mechanism T. Reportedly.

  The switching control portions are cams (protruding shape portions) 13 as control elements at positions where the projections 32a formed on the carrier 32 portions of the planetary gear mechanisms 25, 26, 27, and 28 as drive switching means are locked. Have a camshaft (control shaft) 12 formed with .about.16. In other words, the plurality of control elements are in the form of control shafts having projecting shapes (cams) 13, 14, 15, 16 having different phases from each other around the same axis. The plurality of cams 13, 14, 15, and 16 are centered on the same axis and have different phases. The solenoid 48 has a spring clutch mechanism T that stops the rotation of the camshaft 12. A solenoid structure for turning on / off the rotation of the camshaft 12 as a control shaft is a control actuator. The operation signals for the four cams 13, 14, 15, and 16 as control elements are controlled by a control actuator that is smaller than the number of cams 13, 14, 15, and 16. In this embodiment, the operation signals for the four cams 13, 14, 15, 16 are controlled by one control actuator, and are individual control values for the respective cams 13, 14, 15, 16.

  Cams 13, 14, 15, and 16 of the camshaft 12 are disposed corresponding to the toner conveying / stirring mechanisms of the first to fourth toner containers 331 Y, 331 M, 331 C, and 331 K, respectively. 12 and rotate integrally. When the solenoid 48 is turned ON / OFF, the rotating camshaft 12 is detected by a rotation position detecting means (an apparatus such as a rotary encoder) provided on the camshaft and stopped at a predetermined position for a predetermined time. It is possible to make it.

  Next, the operation of the drive switching device will be described step by step. The flow charts of FIGS. 24A and 24B represent the control of the drive switching device 200, and these are incorporated in the control device 350. Based on the copy start signal, the set number of copies and the recorded image are recognized, and from the video signal of the recorded image to be written to the drum 301 of each of the first to fourth image forming units Y, M, C, and K, The “use amount of toner necessary for recording image” is predicted and calculated in the “image signal-toner amount comparison” table. The number of rotations (time) of the toner replenishing screw 104 for replenishing the amount used is calculated from the “replenished toner amount−screw rotation number” table. Then, the stationary time of each color cam 13, 14, 15, 16 is calculated. Then, under the control of the color discriminating unit in S8, the cam stationary time cam stationary solenoid 48 is sequentially operated and switched in the color order (in order of Y, M, C, and K). That is, the cam is stopped at the Y color position for the Y replenishment time, the drive motor is turned on, the Y color transport screw is rotated, and the Y toner is transported and replenished for the rest time. Similarly, the steps from S9 to S14 are performed in the order of M color, C color, and K color, and after the K color is completed, the process proceeds to step S15 under the control of the color discriminating unit. -Is conveyed. These steps are sequentially performed, and when the predetermined number of sheets is counted in S1, the process proceeds to step S16 and the copying is completed. Here, the driving motor 1 as a driving source for toner replenishment / stirring is rotated together with image formation.

  Therefore, as described above, the agitating blade / planetary gear drive switching sun gear connected to the drive motor 1 through a gear train and the drive input ring 46 of the spring clutch mechanism T of the switching control portion are rotating.

  Here, for example, in the toner conveyance from the first toner container 331Y to the developing device 303 of the first image forming unit Y, the cam shaft 12 is driven by driving the cam stationary solenoid 48 by a signal from the control device 350. Rotate. Then, the cam 13 is stopped for a predetermined time at a position where the protrusion 32a of the carrier 32 of the planetary gear mechanism 25 corresponding to the first toner container 331Y is stopped. During the stationary period of the predetermined time, the output side gear of the planetary gear mechanism 25 rotates on the toner conveying screw 104 of the first toner container 331Y, and the toner conveying screw 104 of the first toner container 331Y rotates via the idler gear. . As a result, a predetermined calculated amount of Y color toner is supplied into the developing chamber 325 of the developing device 303 from the opening 335 of the toner conveying cylinder 333.

  In a similar control procedure, the toner containers 331M, 331C, and 331K corresponding to the developing devices 303 of the second to fourth image forming units M, C, and K are replenished in a timely and appropriate amount, and after a predetermined copy is completed. The drive is turned off and the image copy is completed.

  As described above, a plurality of drive switching means and its control elements are provided, and operation signals for the plurality of control elements are controlled by a control actuator that is smaller than the number of control elements. As a result, the number of drive sources and control actuators is reduced, the device configuration is simplified, and there is an effect of reducing the size and weight of the device and saving the drive energy (electric power).

  Further, the drive source for generating the rotation is one drive source, and the operation signal for the controller is controlled by one control actuator, and it is possible to take individual control values for each controller. Therefore, there is an effect that complicated control switching is possible with a simple device configuration.

  Further, the drive switching means is a clutch mechanism using a planetary gear mechanism, the controller is a control shaft having a protruding shape with the same axis as the center and different phases, and the control actuator turns on the rotation of the control shaft. Solenoid structure to be turned off / off. With this configuration, in addition to the effect of a simple device configuration, there is an effect that the drive can be switched individually by a simple control method.

  Furthermore, a complicated toner replenishment conveyance / stirring mechanism is configured by using the image forming apparatus and its driven means as rotating toner conveying means for each screw of the color image forming apparatus and toner agitating means for each toner storage unit. Simple and easy to handle. Thereby, there is an effect that can be realized with a downsized and inexpensive configuration of the image forming apparatus.

  As described above, the conventional color image forming apparatus requires a large number of drive switching mechanisms and drive sources for the monochrome machine in the image creation process. In particular, in the drive switching of the toner replenishing mechanism portion, a complicated mechanism is present in which a switching mechanism and a driving source exist for each color. The increase in these drive switching mechanisms and drive sources is a factor that obstructs energy saving by complicating the device configuration and deteriorating the reliability of the function, increasing the motive energy. There has been a demand for a drive switching mechanism that has a simple configuration, reduces the number of drive sources, is easy to handle, and is small, light, and inexpensive.

  Therefore, in this embodiment, a mechanism for switching the drive is provided by configuring the power from one drive source (motor) 1 with a plurality of planetary clutches and one actuator (solenoid). With this configuration, the power transmission device selectively transmits power to a plurality of driven parts using one drive source and one actuator. In particular, the color toner replenishment and conveyance mechanism, which is a problem, can be controlled to rotate a plurality (four colors) of color toner (screws) and agitation. A plurality of motors become one. As a result, the power consumption can be reduced, the gear system such as the speed reducer can be shared, the drive unit weight can be reduced and the space can be saved, the power supply can be downsized and the drive source can be reduced. The reliability can be improved, and the entire apparatus can be reduced in size and weight.

[Second Embodiment]
A second embodiment will be described with reference to FIGS. In the present embodiment, a toner supply screw gear 201 and a drive input gear 202 to the toner agitating member are further arranged in the output side gear train of the planetary gear mechanism 25 (26, 27, 28). Then, a swing arm switching mechanism 203 that switches the driving force between the forward rotation and the reverse rotation of the drive motor 1 of the drive source is arranged. In FIG. 25, the swing arm is switched to the toner supply screw gear 201 side, and the toner supply screw 104 rotates. In FIG. 26, the swing arm is switched to the drive input gear 202 side to the toner stirring member, and the toner stirring blade 71 (72, 73, 74) rotates through the idler gear train 206.

  In this embodiment, in a device in which toner for replenishment is contained in a box or a cylindrical container, the toner in the container aggregates, the stirring torque at the initial time increases, and even when a large stirring drive source is required, each color An example of handling by driving is shown. Thereby, the power of the drive motor 1 of the drive source can be reduced, and the power consumption and the power supply circuit can be saved.

[Third embodiment]
A third embodiment will be described with reference to FIGS. In the embodiment, belts 210 and 211 connect the driving motor 1 as a driving source and the input side pulleys of the planetary gear mechanisms 25, 26, 27, and 28. The drive transmission means is changed from a gear to a belt. In particular, in the belt drive transmission means, a mechanism that absorbs the slack of the belt to the impact at the time of ON / OFF of the belt bending drive source rotation is essential, but in the drive switching device of the present invention, the drive is continuously switched. Therefore, it is more advantageous, and a combination of the belts 210 and 211 and the planetary gear mechanisms 25, 26, 27, and 28 provides a simpler switching mechanism.

  In the drawing, the driving on the toner stirring gear side is omitted for the sake of clarity, but the same effect as that of the drive switching device of the first embodiment or the second embodiment can be obtained.

  Each of the above embodiments is an example in which the drive switching device according to the present invention is used for the toner replenishment conveyance portion of the image forming apparatus. It can also be applied to individual drive switching of a plurality of cassettes in the paper portion. Further, the present invention can also be applied to paper path drive switching when the conveyance unit is single-sided or double-sided and paper conveyance speed switching in the conveyance path. In any case, the drive switching mechanism can be simplified, the number of drive sources, switching clutches, and solenoids can be reduced, and the device can be realized with a small size, energy saving, and an inexpensive apparatus configuration.

  The present invention relates to a drive switching device, a feed roller drive, a transport roller drive, and a duplex transport drive of a toner replenishment transport portion in an information output device such as a computer, an image forming apparatus such as a copying machine, and a facsimile. It can also be applied to the switching part. The present invention can also be applied to speed switching, ON / OFF switching, and forward / reverse switching portions of a driving mechanism such as development driving, drum and intermediate transfer member driving.

  According to the present invention, a complicated drive switching device is realized with a simple mechanism configuration, and in particular, a color image forming apparatus is realized with a simple, easy-to-handle, compact, energy-saving and inexpensive device configuration. be able to.

1 is a schematic configuration diagram of an image forming apparatus according to a first embodiment. Partial enlarged view of FIG. Explanatory drawing of developing device A perspective view showing a connecting portion between the developing device and the toner container Perspective view of the entire drive switching device as seen from the front A perspective view seen from the back side Partial cutaway view of FIG. Front view of the entire drive switching device Top view of the entire drive switching device Rear view of the entire drive switching device Sectional view taken along line (11)-(11) in FIG. Sectional view taken along line (12)-(12) in FIG. Sectional view taken along line (13)-(13) of FIG. A perspective view of only the gear train of the toner conveying screw drive system as seen from the front A perspective view seen from the back side Perspective view of drive motor and drive switching part Plan view of the spring clutch mechanism Illustration of planetary gear mechanism Front view of one toner transport / stirring / drive switching device Same top view Similarly back view 20 is a sectional view taken along line (22)-(22) in FIG. Sectional view taken along line (23)-(23) in FIG. Toner replenishment control flowchart (Part 1) Toner replenishment control flowchart (Part 2) Explanatory drawing of 2nd Example (the 1) Explanatory drawing of 2nd Example (the 2) Explanatory drawing of 3rd Example (the 1) Explanatory drawing of 3rd Example (the 2) Explanatory drawing of the conventional toner replenishment transport mechanism (part 1) Explanatory drawing of the conventional toner replenishment transport mechanism (part 2) Explanatory drawing of the conventional toner replenishment transport mechanism (part 3) Explanatory drawing of the conventional toner replenishment transport mechanism (part 4) Illustration of planetary gear mechanism

Explanation of symbols

  1: drive motor, 12: camshaft, 13-16: actuator drive unit, 25-28: drive switching mechanism, 71-74: toner stirring blade, 104: toner conveying screw

Claims (5)

One drive source for generating rotation, drive switching means for transmitting power from the drive source to a plurality of driven means, and a controller for operating the drive switching means for switching operation , A drive switching device comprising a plurality of the drive switching means and the controller,
The drive switching device, wherein operation signals for the plurality of control elements are controlled by a control actuator smaller than the number of control elements.   2. The drive switching device according to claim 1, wherein the operation signals for the plurality of control elements are controlled by one control actuator, and are individual control values for the respective control elements.   The plurality of drive switching means is a clutch mechanism using a planetary gear mechanism, and the plurality of control elements are in the form of control shafts each having a protruding shape with a phase different from each other around the same axis, and the control actuator The drive switching device according to claim 1 or 2, wherein the motor has a solenoid structure for turning on and off the rotation of the control shaft. In an image forming apparatus that has a plurality of driven units that are switched by a drive switching device and forms an image on a recording material,
An image forming apparatus, wherein the drive switching device is the drive switching device according to claim 1, 2, or 3.   The plurality of driven means are a toner transporting means for transporting toner from a toner storage unit storing replenishment toner to a developing device, and a toner stirring unit for stirring the toner in the toner storage unit. The image forming apparatus according to claim 4.