JP2006163056A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize an apparatus with low cost by suppressing clogging of toner in a duct tube while evading formation of a toner clot in the duct tube or detachment of additives from the toner surface by transporting the toner to a developing apparatus with suction force of suction pumps 78Y, C, M and K and furthermore sharing a driving motor in at least two photoreceptors of the four photoreceptors 2Y, C, M and K. <P>SOLUTION: The image forming apparatus has each suction pump 78Y, C, M and K installed above each corresponding developing apparatus, uses at least one shared driving motor 90 transmitting the driving force in two or more of the four photoreceptors 2Y, C, M and K and at the same time has a motor gear 91 of the shared driving motor 90 positioned below a line segment connecting each rotational center in two driven gears which are in between the two adjacent driven gears 17C and M among a plurality of the driven gears 17Y, C, M and K. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus such as a copying machine, a facsimile machine, or a printer. More specifically, the toner images developed on a plurality of latent image carriers are superimposed on an intermediate transfer member or a recording member. The present invention relates to an image forming apparatus for forming an image.

  As this type of image forming apparatus, for example, the one described in Patent Document 1 is known. This image forming apparatus includes four photosensitive members corresponding to respective colors of yellow, magenta, cyan, and black (hereinafter referred to as Y, M, C, and K) as latent image carriers. A color toner image as a superimposed image can be formed by superimposing and transferring Y, M, C, and K toner images individually formed on these photoreceptors on an intermediate transfer belt as an intermediate transfer member. it can. In the image forming apparatus having such a configuration, it is possible to reduce the cost by using at least two photoconductors as one drive motor instead of driving all the drum-like photoconductors with separate drive motors. It is desirable to plan. In the image forming apparatus described in Patent Document 1, each color toner image developed on each photoconductor is transferred onto the intermediate transfer belt while being superposed on the surface of the paper conveying belt. Each color toner image may be superimposed on the transfer paper. Hereinafter, belts such as a paper conveyance belt and an intermediate transfer belt are collectively referred to as a belt member.

  On the other hand, an image forming apparatus that conveys toner in a toner container to a developing device through a flow pipe provided with a rotating member such as a screw auger has been known. In this type of image forming apparatus, the toner is vigorously rubbed between the rotating member and the inner wall of the flow tube, so that a toner lump is formed in the flow tube or an external additive on the surface is removed from the toner to form an image. It may have an adverse effect. In recent years, there is a tendency to use toner that softens at a lower temperature for the purpose of keeping the fixing temperature of a toner image by a fixing device as low as possible.

  In view of this, an image forming apparatus is known that transports toner fed from a toner container into a flow tube with a suction force of a suction pump without rotation of a rotating member provided in the flow tube. For example, it is a thing of patent document 2. In such a configuration, there is no need to provide a rotating member that rubs violently with the toner in the flow pipe. For this reason, the toner is rubbed between the rotating member and the inner wall of the flow pipe to form a toner lump, or the rubbing causes the external additive to be detached from the toner surface and adversely affect the image. It can be avoided.

JP 2004-205797 A JP 2003-330218 A

  The present inventors are developing a new image forming apparatus that conveys toner by the suction force of the above-described suction pump while using at least two photoconductors as one drive motor. I found that there was a problem. That is, depending on the position of the drive motor and the suction pump, it becomes easy to clog the toner in the flow pipe, and it becomes difficult to reduce the size of the apparatus. Hereinafter, the reason will be described in detail.

  About the suction pump mentioned above, you may connect in the middle of a flow pipe, and may connect to the end of a flow pipe. However, when connecting in the middle of the flow pipe, the toner in the pipe located on the suction side is sucked by the suction pump and discharged to the pipe located on the discharge side and sent to the developing device. Then, depending on the length of the discharge side tube and its scooping form, it becomes easy to pressurize and clog the toner in the discharge side tube. Therefore, it is desirable that the suction pump is connected to one end of the flow pipe in the vicinity of the developing device, and the toner discharged from the discharge port of the suction pump is freely dropped toward the developing device.

  On the other hand, the photoconductors are arranged in such a way that the photoconductors are arranged vertically so that they take a space in the vertical direction rather than in the horizontal direction, and the photoconductors are arranged horizontally so that a space is taken in the horizontal direction rather than the vertical direction. There is a way to arrange. Among these, in the method of arranging them vertically, a belt member such as an intermediate transfer belt is disposed so as to be positioned on the side of each photoconductor. Further, the developing device is disposed above or below the photosensitive member because of the necessity of developing at a location near the upstream side of the belt member on the peripheral surface of the photosensitive member. If the developing device is disposed below the photoreceptor, the suction pump cannot be disposed directly above the developing device, and it is useless if disposed at a position higher than the developing device and avoiding just above the developing device. It will take up space. Further, when the developing device is disposed above the photosensitive member, the developing device and a suction pump disposed so as to overlap the photosensitive member are arranged between the vertically long photosensitive members. Even though it is desired to reduce the space between the photosensitive members as much as possible to save space, it is necessary to increase the interval so as to interpose a suction pump between the developing device and the photosensitive member.

  On the other hand, in the method in which the photoconductors are arranged horizontally, the belt member is disposed so as to be positioned above or below the photoconductors. Further, the developing device is disposed on the side of the photosensitive member, and the suction pump is disposed above the developing device. In such an arrangement, a suction pump is not interposed between the developing device and the photoconductor in the space between the photoconductors arranged horizontally, so that each photoconductor is not provided with a suction pump. It becomes possible to shorten the interval. Therefore, from the viewpoint of space saving, it is desirable to adopt a layout in which the photoconductors are arranged horizontally.

  However, in such a layout, if two or more photoconductors are also used as a drive motor, it is easy to compete between the position where the drive motor is disposed and the position where the suction pump is disposed. Specifically, FIG. 1 shows a main configuration of two photoconductors 2Y and 2C and developing devices 5Y and 5C arranged around the photoconductors 2Y and 2C along with driven gears 17Y and 17C fixed to the shaft of the photoconductor. FIG. In FIG. 2, a Y photoconductor 2Y and a C photoconductor 2C are arranged in a horizontal direction, and each receives a driving force from a driving motor (not shown) on its shaft. The driven gears 17Y and 17C are fixed. Further, a developing device 5Y for Y and a developing device 5C for C are disposed on the left side of each of the two photoconductors 2Y and 2C in the drawing. In the figure, when the two photoconductors 2Y and 2C are driven by a single drive motor, the drive motors are generally arranged at the following positions. That is, as shown in FIG. 2, the driving gear 201 fixed to the motor shaft of the driving motor 200 is engaged with both gears while being positioned between the Y driven gear 17Y and the C driven gear 17C. Position. However, as shown in FIG. 3, this position competes with the position of the C suction pump 78C that discharges toner from above the C developing device 5C. This is because the suction pump 78C is located directly above the two driven gears 17Y and 17C in the same figure. In order to avoid such competition, it is assumed that the suction pump 78C is shifted in a direction perpendicular to the paper surface in FIG. Then, the toner is replenished closer to the center than the end of the developing device 5C in the drawing, and may be transported to the developing region with insufficient mixing with the carrier. It will be high. Further, it is assumed that the drive motor 200 is disposed above the suction pump 78C in order to avoid the above-described competition. Then, as shown in FIG. 4, it becomes necessary to provide the relay gears 202Y and 202C between the driving gear 201 and the two driven gears 17Y and 17C, respectively. These relay gears 202Y and 202C take extra space in the vertical direction in the apparatus, making it difficult to reduce the size of the apparatus.

The present invention has been made in view of the above background, and an object thereof is to provide an image forming apparatus capable of realizing any of the following matters.
(1) The toner is transported to the developing device by the suction force of the suction pump to avoid clogging of the toner in the channel tube while avoiding the formation of a toner lump in the channel tube and the detachment of the external additive from the toner surface. suppress.
(2) Of the plurality of latent image carriers, at least two latent image carriers are also used as a drive motor to reduce the cost while reducing the size of the apparatus.

To achieve the above object, a first aspect of the present invention is a latent image carrier that carries a latent image on a rotating peripheral surface thereof, and a rotary shaft member of the latent image carrier that is driven by meshing with a gear on the driving side. A driven gear fixed to the rotation surface, a developing unit that develops the latent image carried on the rotating peripheral surface into a toner image, a flow pipe that circulates toner from the toner container that stores toner toward the developing unit, A plurality of combinations of moving force applying means for applying a moving force to the toner in the flow pipe are provided, and a drive motor having a driving gear meshing with the driven gear and a rotation peripheral surface of each latent image carrier are formed respectively. A belt member that moves the toner image endlessly, or a transfer means that transfers the toner image superimposed on a recording member held on the surface of the belt member. Arranged in In the image forming apparatus, a suction pump that applies a moving force to the toner by sucking the toner in the flow pipe is used as the plurality of moving force applying units, and the suction pump is used for the developing unit corresponding thereto. Each suction pump is disposed so as to be positioned above, and as the drive motor, at least one dual-purpose drive motor that transmits a drive force to all or two or more of the plurality of latent image carriers is used, In addition, among the plurality of driven gears, between the two driven gears adjacent to each other, below the line segment connecting the respective rotation centers of the two driven gears, the driving gear of the dual drive motor It is characterized by having located.
According to a second aspect of the present invention, in the image forming apparatus of the first aspect, the driving force is transmitted to only one of the plurality of latent image carriers in addition to the dual-purpose driving motor as the driving motor. A non-shared drive motor is provided.
According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, at least one of the plurality of latent image carriers to which a driving force is transmitted by the dual-purpose drive motor, The relay gear is engaged with the driven gear fixed to the rotating shaft member and the driven gear fixed to the rotating shaft member of another latent image carrier, and the dual-purpose relay gear relays the driving force between the two driven gears. The driving force by the driving motor is transmitted.
According to a fourth aspect of the present invention, in the image forming apparatus according to the third aspect, the dual-purpose drive motor according to the first aspect and the dual-purpose drive motor according to the second aspect are provided as the drive motor. Four combinations are provided, and the non-shared drive motor drives each of the latent image carriers in each of the four combinations arranged at one end of the row, and the combined drive motor Thus, the respective latent image carriers in the remaining three combinations are driven.

In these image forming apparatuses, by using a suction pump as each of a plurality of moving force applying means for individually applying a moving force to the toner in the plurality of flow path tubes, the toner is provided in each flow path tube. Formation of lumps and separation of external additives from the toner surface can be avoided. Furthermore, by arranging each suction pump so as to be positioned above the corresponding developing device, the toner discharged from the discharge port of the suction pump is supplied to the developing device by free fall, and in the flow path tube Toner clogging can be suppressed. Therefore, the above item (1) can be realized.
In these image forming apparatuses, at least one dual-purpose drive motor that transmits a driving force to all or two or more of the plurality of latent image carriers is used as a drive motor serving as a drive source of the latent image carrier. As a result, at least two latent image carriers can also be used as a drive motor to reduce costs. In addition, by arranging the latent image carriers in a horizontally long arrangement, the developing devices can be arranged on the side of the corresponding latent image carriers. By disposing the suction pump above the developing device, it is possible to avoid a situation in which the suction pump is interposed between the developing device and the photoconductor in the space between the photoconductors. For this reason, as in the case where the suction pump is not used, the interval between the photosensitive members can be shortened to save space. Furthermore, it is possible to explain the following by arranging the driving gear of the dual-purpose drive motor between the two driven gears adjacent to each other and below the line connecting the rotation centers of both driven gears. become. That is, it is necessary to dispose the suction pump (78C) above the line segment as shown in FIG. 3, but the dual drive is performed so that the driving gear is positioned below the line segment. By disposing the motor, it is possible to avoid contention between the suction pump and the combined drive motor. In addition, below the line segment, as in the case above the line segment, the driving gear can be engaged between the two gears without protruding significantly from the vertical ends of the two gears. Therefore, in order to avoid the above-mentioned competition, the driving gear is arranged above the suction pump and two relay gears are provided so that the drive from the driving gear is transmitted to the two driven gears. Unlike the embodiment of FIG. 4 which takes an extra space in the vertical direction, the extra space is not taken up. As a result, the apparatus can be miniaturized. Therefore, the above item (2) can be realized.

Hereinafter, an embodiment of an electrophotographic printer (hereinafter simply referred to as a printer) will be described as an image forming apparatus to which the present invention is applied.
First, the basic configuration of the printer will be described. FIG. 5 is a schematic configuration diagram showing the printer. In this figure, the printer includes four process units 1Y, C, M, and K for generating toner images of yellow, magenta, cyan, and black (hereinafter referred to as Y, C, M, and K). Yes. These use Y, C, M, and K toners of different colors as image forming substances for forming an image. The other configurations are the same, and are replaced when the lifetime is reached. Taking a process unit 1Y for generating a Y toner image as an example, as shown in FIG. 6, a drum-shaped photosensitive member 2Y, a drum cleaning device 3Y, a charge eliminating device (not shown), a charging device 4Y, a developing device 5Y, and the like. It has. The process unit 1Y is detachable from the printer main body, so that consumable parts can be replaced at a time.

  The charging device 4Y uniformly charges the surface of the photoreceptor 2Y that is rotated clockwise in the drawing by a driving unit (not shown). In the figure, a charging bias is applied by a power source (not shown), and a charging roller 6Y that is driven to rotate counterclockwise in the drawing is brought into contact with the photosensitive member 2Y to uniformly charge the photosensitive member 2Y. A charging device 4Y is shown. Instead of the charging roller 6Y, a roller that contacts a charging brush may be used. Moreover, you may use what performs a charging process without contact with respect to the photoreceptor 2Y like a scorotron charger. The surface of the photoreceptor 2Y that is uniformly charged by the charging device 4Y is exposed and scanned by a laser beam emitted from an optical writing unit, which will be described later, and carries an electrostatic latent image for Y.

  The developing device 5Y as developing means has a first agent storage portion 8Y in which a first transport screw 7Y is disposed. Further, it also has a second agent storage portion 13Y in which a toner concentration sensor (hereinafter referred to as a T sensor) 9Y including a magnetic permeability sensor, a second transport screw 10Y, a developing roll 11Y, a doctor blade 12Y, and the like are disposed. In these two agent storage portions, a Y developer (not shown) composed of a magnetic carrier and a negatively chargeable Y toner is included. The first transport screw 7Y is driven to rotate by a driving unit (not shown), thereby transporting the Y developer in the first agent storage portion 8Y from the front side to the back side in the drawing. And it penetrates into the 2nd agent accommodating part 13Y through the communication port which is not shown in the partition wall between the 1st agent accommodating part 8Y and the 2nd agent accommodating part 13Y. The second transport screw 10Y in the second agent storage unit 13Y is driven to rotate by a driving unit (not shown), thereby transporting the Y developer from the back side to the front side in the drawing. The toner density of the Y developer in the middle of conveyance is detected by the T sensor 9Y fixed to the bottom of the first agent storage portion 13Y. In the upper part of the second conveying screw 10Y for conveying the Y developer in this way, a developing roll 11Y containing the magnet roller 15Y in a nonmagnetic pipe 14Y that is driven to rotate counterclockwise in the figure is arranged in parallel. It is installed. The Y developer conveyed by the second conveying screw 10Y is pumped up to the surface of the nonmagnetic pipe 14Y by the magnetic force generated by the magnet roller 15Y. Then, after the layer thickness of the non-magnetic pipe 14Y is regulated by a doctor blade 12Y disposed so as to maintain a predetermined gap, the layer thickness is regulated and conveyed to a developing region facing the photoconductor 2Y. Y toner is adhered to the electrostatic latent image. This adhesion forms a Y toner image on the photoreceptor 2Y. The Y developer that has consumed the Y toner by the development is returned to the second conveying screw 10Y as the nonmagnetic pipe 14Y of the developing roll 11Y rotates. And if it conveys to the front end in a figure, it will return in the 1st agent accommodating part 8Y via the communication port which is not shown in figure.

  The result of detecting the magnetic permeability of the Y developer by the T sensor 9Y is sent as a voltage signal to a control unit (not shown). Since the magnetic permeability of the Y developer has a correlation with the Y toner concentration of the Y developer, the T sensor 9Y outputs a voltage having a value corresponding to the Y toner concentration. The control unit includes a RAM, in which the output voltage from the T sensor 9Y is a target value for the output voltage of Y, Vtref for Y, and the output from the T sensors for C, M, and K mounted in other developing devices. The data of C Vtref, M Vtref, and K Vtref, which are voltage target values, are stored. For the developing device 5Y, the value of the output voltage from the T sensor 9Y is compared with the Y Vtref, and the Y toner supply device described later is driven for a time corresponding to the comparison result. With this driving, an appropriate amount of Y toner is supplied from the first agent storage unit 8Y to the Y developer whose Y toner has been consumed by developing and the Y toner density has been reduced. For this reason, the Y toner concentration of the Y developer in the second agent container 13Y is maintained within a predetermined range. Similar toner supply control is performed for the developers of the process units (1C, M, K) for other colors.

  The Y toner image formed on the photoreceptor 2Y as a latent image carrier is intermediately transferred to an intermediate transfer belt described later. The drum cleaning device 3Y removes the toner remaining on the surface of the photoreceptor 2Y after the intermediate transfer process. Thus, the surface of the photoreceptor 2Y that has been subjected to the cleaning process is neutralized by a neutralization device (not shown). By this charge removal, the surface of the photoreceptor 2Y is initialized and prepared for the next image formation. In FIG. 5 shown above, in the process units 1C, M, and K for other colors, C, M, and K toner images are similarly formed on the photoreceptors 2C, M, and K, and the intermediate transfer belt is formed. Intermediate transfer.

  An optical writing unit 20 is arranged below the process units 1Y, 1C, 1M, and 1K in the drawing. The optical writing unit 20 serving as a latent image forming unit irradiates each photoconductor in each of the process units 1Y, 1C, 1M, and 1K with a laser beam L emitted based on the image information. As a result, electrostatic latent images for Y, C, M, and K are formed on the photoreceptors 2Y, 2C, 2M, and 2K. The optical writing unit 20 deflects the laser light L emitted from the light source by the polygon mirror 21 that is rotationally driven by a motor, and passes through the photosensitive members 2Y, 2C, 2M, and 2K via a plurality of optical lenses and mirrors. Is irradiated.

  A first paper feed cassette 31 and a second paper feed cassette 32 are arranged on the lower side of the optical writing unit 20 in the drawing so as to overlap in the vertical direction. Each of these paper feed cassettes accommodates a plurality of transfer papers P as recording bodies in a stacked state, and the uppermost transfer paper P includes a first paper feed roller 31a, The second paper feed rollers 32a are in contact with each other. When the first paper feed roller 31a is driven to rotate counterclockwise in the figure by driving means (not shown), the uppermost transfer paper P in the first paper feed cassette 31 is vertically oriented on the right side of the cassette in the figure. The paper is discharged toward the paper feed path 33 arranged so as to extend. Further, when the second paper feed roller 32 a is driven to rotate counterclockwise in the figure by a driving means (not shown), the uppermost transfer paper P in the second paper feed cassette 32 is directed toward the paper feed path 33. Discharged. A plurality of transport roller pairs 34 are arranged in the paper feed path 33, and the transfer paper P sent to the paper feed path 33 is sandwiched between the rollers of the transport roller pair 34, while the paper feed path 33. 33 is conveyed from the lower side to the upper side in the figure.

  A registration roller pair 35 is disposed at the end of the paper feed path 33. The registration roller pair 35 temporarily stops the rotation of both rollers as soon as the transfer paper P sent from the transport roller pair 34 is sandwiched between the rollers. Then, the transfer paper P is sent out toward a later-described secondary transfer nip at an appropriate timing.

  Above each of the process units 1Y, 1C, 1M, and 1K, a transfer unit 40 that is endlessly moved counterclockwise in the drawing while an intermediate transfer belt 41 that is an intermediate transfer member is stretched is disposed. In addition to the intermediate transfer belt 40, the transfer unit 40 serving as transfer means includes a belt cleaning device 42, a first bracket 43, a second bracket 44, and the like. Further, four primary transfer rollers 45Y, 45C, 45M, 45K, a secondary transfer backup roller 46, a drive roller 47, an auxiliary roller 48, a tension roller 49, and the like are also provided. The intermediate transfer belt 41 is endlessly moved counterclockwise in the figure by the rotational driving of the driving roller 47 while being stretched by these eight rollers. The four primary transfer rollers 45Y, 45C, 45C, 45M, 45K, and 45K sandwich the intermediate transfer belt 41 that is moved endlessly in this manner from the photoreceptors 2Y, 2C, 2M, and 2K, thereby forming primary transfer nips. ing. Then, a transfer bias having a polarity opposite to that of the toner (for example, plus) is applied to the back surface (loop inner peripheral surface) of the intermediate transfer belt 41. The intermediate transfer belt 41 sequentially passes through the primary transfer nips for Y, C, M, and K along with the endless movement thereof, and on the surface of the photoreceptor 2Y, C, M, K on the front surface. The Y, C, M, and K toner images are superimposed and primarily transferred. As a result, a four-color superimposed toner image (hereinafter referred to as a four-color toner image) is formed on the intermediate transfer belt 41.

  The secondary transfer backup roller 46 sandwiches the intermediate transfer belt 41 with the secondary transfer roller 50 disposed outside the loop of the intermediate transfer belt 41 to form a secondary transfer nip. The registration roller pair 35 described above sends the transfer paper P sandwiched between the rollers toward the secondary transfer nip at a timing at which the transfer paper P can be synchronized with the four-color toner image on the intermediate transfer belt 41. The four-color toner image on the intermediate transfer belt 41 is affected by the secondary transfer electric field formed between the secondary transfer roller 50 to which the secondary transfer bias is applied and the secondary transfer backup roller 46, and the influence of the nip pressure. The secondary transfer is batch-transferred onto the transfer paper P in the secondary transfer nip. Then, combined with the white color of the transfer paper P, a full color toner image is obtained.

  Transfer residual toner that has not been transferred to the transfer paper P adheres to the intermediate transfer belt 41 after passing through the secondary transfer nip. This is cleaned by the belt cleaning device 42.

  A fixing device 60 including a pressure roller 61 and a fixing belt unit 62 is disposed above the secondary transfer nip in the drawing. The fixing belt unit 62 of the fixing device 60 moves the fixing belt 64 endlessly in the counterclockwise direction in the drawing while being stretched by the heating roller 63, the tension roller 65, and the driving roller 66. The heating roller 63 includes a heat source such as a halogen lamp, and heats the fixing belt 64 from the back side. A pressure roller 61 that is driven to rotate clockwise in the figure is in contact with the surface of the fixing belt 64 that is heated in this manner from the front surface side. Thereby, a fixing nip where the pressure roller 61 and the fixing belt 64 abut is formed.

  The transfer paper P that has passed through the secondary transfer nip is separated from the intermediate transfer belt 41 and then fed into the fixing device 60. Then, in the process of being conveyed from the lower side to the upper side in the figure while being sandwiched by the fixing nip, the full-color toner image is fixed by being heated or pressed by the fixing belt 64.

  The transfer sheet P subjected to the fixing process in this manner is discharged outside the apparatus after passing between the rollers of the discharge roller pair 67. A stack unit 68 is formed on the upper surface of the housing of the printer main body, and the transfer sheets P discharged to the outside by the pair of discharge rollers 67 are sequentially stacked on the stack unit 68.

  Above the transfer unit 40, four toner cartridges 100 Y, C, M, and K that store Y, C, M, and K toners are disposed. The Y, C, M, and K toners in the toner cartridges 100Y, 100C, M, and K are appropriately supplied to the developing devices of the process units 1Y, 1C, 1M, and 1K, respectively. These toner cartridges 100Y, 100C, 100M, and 100K are detachable from the printer main body independently of the process units 1Y, 1C, 1M, and 1K.

  In the printer having the above-described configuration, toner image formation for forming a toner image on the transfer paper P, which is a recording medium, by combining the four process units 1Y, 1C, 1M, 1K, the optical writing unit 20, and the transfer unit 40, etc. Means are configured.

  FIG. 7 is a perspective view showing a toner cartridge 100Y for Y. In the figure, a toner cartridge 100Y as a toner container includes a bottle-shaped bottle portion 101Y that stores Y toner (not shown) and a cylindrical holder portion 102Y. The holder portion 102Y rotatably holds the bottle portion 101Y while engaging the tip portion of the bottle portion 101Y so as to cover an opening (not shown) formed at the tip of the bottle portion 101Y. The bottle portion 101Y is embossed with a screw-like projection that protrudes from the outside toward the inside along the circumferential surface of 103Y. When the bottle portion 101Y is rotated by a drive system (not shown), the Y toner in the bottle portion 101Y moves along the screw-shaped protrusion from the bottle bottom side toward the bottle front end side. Then, the toner flows into the cylindrical holder portion 102Y through an opening (not shown) provided at the tip of the bottle portion 101Y as a toner container.

  A nozzle receiving port 109Y is formed on an end surface of the holder portion 102Y in the bottle axis direction. The nozzle receiving port 109Y is for receiving a later-described suction nozzle fixed to the printer main body side. On both sides of the nozzle receiving port 109Y in the figure, positioning pin receiving ports 110Y each having a slightly smaller diameter than the nozzle receiving port are formed. Each of the positioning pin receiving ports 110Y is formed at a position deviated from the rotation axis of the bottle portion 101Y, and a pin insertion passage (not shown) is provided in a direction parallel to the rotation axis direction of the bottle portion 101Y. It is formed to extend. The bottle portion 101Y is made of a resin material that is so rigid that it is not deformed by an impact when being rotated by the drive transmission gear.

  FIG. 8 is a perspective view showing a cartridge connecting portion 71Y for Y that is a part of a toner replenishing device described later. The Y cartridge connecting portion 71Y is fixed to the upper end of a flow pipe 72Y for flowing Y toner so that a suction nozzle 73Y as a pipe member extends in the horizontal direction. A toner receiving port 74Y for receiving Y toner is formed at the tip of the suction nozzle 73Y. Further, on both sides of the suction nozzle 73Y, rod-like positioning pins 75Y are respectively fixed so as to extend in the horizontal direction (direction parallel to the rotation axis of the bottle portion). A positioning pin 75Y, which is a convex portion of the cartridge connecting portion 71Y as a positioning member, has a tip protruding beyond the tip of the suction nozzle 73Y.

  FIG. 9 is an exploded perspective view showing the toner cartridge 100Y for Y. The holder portion 102Y, which is a rotation engaging member of the Y toner cartridge 100Y, includes an engaging portion that engages with the bottle portion 101Y and a nozzle insertion portion 104Y that is formed separately from the engaging portion. The engaging portion includes a cap portion 105Y that covers the peripheral surface of the tip portion of the bottle portion 101Y while engaging with the bottle portion 101Y, and a toner storage portion 106Y that temporarily stores toner. In the engaging portion, a cylindrical toner storage portion 106Y having a smaller diameter than the inner diameter thereof is fitted in the cylindrical cap portion 105Y. A rubber O-ring 107Y, which is a non-breathable material, is fitted between the two fittings. Thereby, the airtightness between the inner peripheral surface of the cap unit 105Y and the outer peripheral surface of the toner storage unit 106Y is kept high.

  A recess (not shown) is formed in the lower portion of the toner storage portion 106Y formed to have a smaller diameter than the cap portion 105Y, and the nozzle insertion portion 104Y is fitted into the recess. A rubber O-ring 108Y, which is a non-breathable material, is fitted between the two fittings. Thereby, the airtightness between the inner peripheral surface of the concave portion of the toner storage portion 106Y which is a part of the engaging portion and the outer peripheral surface of the convex portion for fitting of the nozzle insertion portion 104Y is kept high.

  A drive receiving gear 111Y that meshes with the rotational driving force of a drive transmission gear (not shown) fixed to the printer main body is formed on the rotational peripheral surface of the front end of the bottle 101Y. When the cap part 105Y of the holder part 102Y is engaged with the tip of the bottle part 101Y, it functions as a peripheral surface covering part that covers the rotational peripheral surface of the tip part of the bottle part 101Y. However, the cap portion 105Y has a gear exposure opening A, and a part of the front end portion of the bottle portion 101Y is exposed from the gear exposure opening A for the drive receiving gear 111Y. Due to this exposure, the drive receiving gear 111Y at the tip of the bottle covered with the cap portion 105Y can be engaged with a drive transmission gear (not shown).

  FIG. 10 is a cross-sectional view showing the front end of the toner cartridge 100Y for Y before being set in the toner replenishing device. The tip of the bottle 101Y has a cylindrical shape with a smaller diameter than the bottle body, and an opening is formed at the tip of the small-diameter cylinder. A hooking portion 112Y that protrudes slightly from the outer peripheral surface of the cylinder is formed on the front end side of the bottle from the peripheral surface of the small-diameter cylinder at the front end and from the drive receiving gear 111Y. The cap portion 105Y of the holder portion 102Y is formed with a cylindrical space for receiving a small-diameter cylinder, which is the tip portion of the bottle portion 101Y, and a projection 113 protruding from the inner periphery of the cylinder is formed at the rear end portion of the cylindrical space. Is formed. The front end portion of the bottle portion 101Y is inserted into the cap portion 105Y so that the hook portion 112Y gets over the protrusion 113Y in the cap portion 105Y, and is rotatably engaged with the cap portion 105Y.

  A plurality of protrusions B are formed on the inner peripheral surface of the rear end portion (end portion on the bottle rear end side) of the cap portion 105Y. The cap portion 105Y as a peripheral surface covering portion that covers the peripheral surface of the front end portion of the bottle portion 111Y by the above-described engagement has these protrusions B more than the locations where the drive receiving gear 111Y is disposed at the front end portion of the bottle portion 101Y. It hits the area on the rear end side. Then, by restricting the movement of the bottle portion 101Y, which is a toner container, in the direction orthogonal to the rotation axis direction from this abutment, the direction orthogonal to the rotation axis direction of the bottle portion 101Y compared to the conventional toner cartridge. Reduce the amount of rattling. Therefore, it is possible to more reliably suppress the load fluctuation of the drive motor due to the backlash of the bottle portion 101Y.

  The nozzle insertion portion 104Y has a fitting convex portion protruding from the upper surface of the tubular nozzle main body portion, and this fitting convex portion is fitted to the bottom of the toner storage portion 106Y inside the cap portion 105Y. Yes. A communication passage 114Y is formed in the fitting convex portion, and the communication passage 114Y communicates with an insertion passage 115Y provided in the nozzle body so as to extend in a direction parallel to the bottle axis direction. . However, a rod-like shutter member 116Y formed in the same diameter as the suction nozzle (74Y) described above is slidably inserted into the insertion passage 115Y, and is located immediately below the communication passage 114Y. Thus, the communication path 114Y and the insertion path 115Y are blocked. Note that the end of the insertion passage 115Y is the nozzle receiving port 109Y previously shown in FIG.

  The toner that has flowed into the toner storage portion 106Y from the small diameter cylinder at the tip of the bottle portion 101Y falls and accumulates in the communication path 114Y of the nozzle insertion portion 104Y by its own weight. The fitting convex portion of the nozzle insertion portion 104Y fitted to the toner storage portion 106Y functions as the bottom portion of the toner storage portion 106Y. The fitting convex communication passage 115Y is formed in a bowl shape as described above, thereby serving as a hopper that collects toner at the bottom in the center of the passage by a taper. In the state shown in the drawing, since the tip of the communication path 114Y is closed by the shutter member 116Y, toner does not flow into the insertion path 115Y from the communication path 114Y.

  When the Y toner cartridge 100Y is set on a cartridge mounting table of a toner replenishing device to be described later, first, an opening / closing door (not shown) provided on the side plate of the printer housing is opened. Then, the cartridge mounting table of the toner supply device in the housing is exposed. The cartridge mounting table is provided with four semi-cylindrical recesses in parallel for mounting four toner cartridges for Y, C, M, and K in parallel. The operator holds the toner cartridge 100Y in such a posture that the holder portion 102Y is positioned at the head. Then, after placing the holder part 102Y on the end of the Y depression among the four depressions on the half cylinder provided on the cartridge mounting table, slide along the bottle axis of rotation so that the entire cartridge is inserted. Move. By this sliding movement, the toner cartridge 100Y is pushed to a predetermined position and set on the cartridge mounting table.

  In FIG. 8 described above, the two positioning pins 73Y of the Y cartridge connecting portion 71Y in the toner replenishing device are fixed so that the tip ends protrude beyond the tip of the suction nozzle 73Y. And the front-end | tip part is taper rather than the rear-end side. While the toner cartridge is being inserted onto the cartridge mounting table at the time of setting, the tapered tip ends of the two positioning pins 73Y respectively enter the two positioning pin receiving ports 110Y of the toner cartridge 100Y shown in FIG. When the toner cartridge 100Y is further inserted, the rear end side that is thicker than the front end portion of the positioning pin 73Y also enters the pin receiving port 110Y. When the rear end side, which is thicker than the front end portion, enters the pin receiving port 110Y, the toner cartridge 100Y is positioned on the cartridge mounting table in the direction perpendicular to the rotational axis direction.

  When the toner cartridge 100Y is further inserted after such positioning, the suction nozzle 73Y in the cartridge connecting portion 109Y of the toner replenishing device shown in FIG. 8 is placed in the nozzle receiving port 109Y of the holder portion 102Y shown in FIG. Enter. When the inside of the suction nozzle 73Y is pushed to a certain extent into the insertion passage (115Y) extending inside the nozzle receiving port 109Y, the setting of the toner cartridge 100Y is completed.

  FIG. 11 is a vertical cross-sectional view showing the front end portion of the Y toner cartridge 100Y set in the toner replenishing device. When the toner cartridge 100Y is set on a cartridge mounting table of a toner supply device (not shown), the suction nozzle 73Y fixed to the toner supply device is inserted into the insertion passage 115Y of the nozzle insertion portion 104Y in the holder portion 102Y. At this time, in the insertion path 115Y, the shutter member 116Y located immediately below the communication path 114Y is pushed by the tip of the suction nozzle 73Y inserted in the insertion path 115Y and slides from the right side to the left side in the drawing. To do. Then, while retracting from directly below the communication path 114Y, a toner receiving port (74Y in FIG. 6) provided at the tip of the suction nozzle 73Y is positioned directly below the communication path 114Y. As a result, the inside of the toner storage unit 106Y and the inside of the suction nozzle 73Y communicate with each other via the communication path 114Y of the nozzle insertion unit 104Y.

  Two O-rings 117Y made of rubber, which is a non-breathable material, are fixed to the inner peripheral surface of the insertion passage 115Y in which the suction nozzle 73Y and the shutter member 116Y can slide. The suction nozzle 73Y and the shutter member 116Y slide in the insertion passage 115Y so as to penetrate the inside of the O-ring 117Y. One of the two O-rings 117Y is fixed at a position closer to the inlet side (nozzle inlet side) than the communication path 114Y on the inner wall of the insertion path 115Y, and at this position, the insertion path 115Y and the suction nozzle as a tube member Sealing with 73Y. This prevents air from flowing into the insertion passage 115Y from the gap between the inlet (toner receiving port) of the insertion passage 115Y and the suction nozzle 73Y. The other O-ring 117Y is fixed to a location on the outlet side of the communication passage 114Y on the inner wall of the insertion passage 115Y, and the insertion passage 115Y and the suction nozzle 73Y are sealed at this location. Thereby, the inflow of air into the insertion passage 115Y is prevented from the gap between the outlet of the insertion passage 115Y and the suction nozzle 73Y.

  A toner cartridge 100Y set in a toner supply device (not shown) meshes a gear portion 117Y formed at the tip of the bottle portion 101Y with a drive transmission gear 76Y fixed to the toner supply device. When the drive transmission gear 76Y is rotationally driven by a drive source (not shown), the bottle portion 101Y rotates while being held by the holder portion 102Y by meshing with the drive transmission gear 76Y. By this rotation, the Y toner in the bottle portion 101Y is conveyed from the bottle rear end side toward the front end side, and flows into the toner storage portion 106Y of the holder portion 102. Then, it accumulates on the communication path 114Y which is the bottom of the toner storage portion 106Y.

  Assume that the holder 102Y that rotatably holds the bottle 101Y tries to rotate on the cartridge mounting table due to the reaction of the rotational movement of the bottle 101Y. In this case, the inner wall of the pin insertion passage as the concave engaging portion that is engaged with the positioning pin (75Y) as the convex portion fixed to the toner replenishing device at a position shifted from the rotation axis of the bottle portion 101Y is caught. . And by this catching, by preventing rotation of the holder part 102, the position shift of the holder part 102Y accompanying rotation of the bottle part 101Y can be avoided.

  In addition, although the example which provided the positioning pin 75Y as a convex part engaged with the pin insertion channel | path which is a concave engagement part of the holder part 102Y as the cartridge connection part 71Y which is a positioning member was demonstrated, the relationship of an unevenness | corrugation is reversed. May be. Specifically, a concave portion extending in a direction parallel to the bottle rotation axis direction is provided in the cartridge connecting portion 71Y, and a convex engaging portion extending in the same direction is formed in the holder portion 102Y of the toner cartridge 100Y.

  A suction pump is connected to a region (not shown) of the flow pipe 72Y connected to the suction nozzle 73Y, and air and toner in the flow pipe 72Y are sucked by this operation. Then, the suction force is transmitted to the inside of the communication path 114Y and the toner storage part 106Y through the inside of the flow pipe 72Y and the inside of the suction nozzle 73Y. Then, the Y toner in the toner reservoir 106Y and the communication path 114Y is sucked into the suction nozzle 73Y.

  As described above, the insertion passage 115Y and the suction nozzle 73Y inserted into the insertion passage 115Y are sealed by the O-ring 117Y which is a non-breathable sealing member. On the other hand, the cap portion 105Y of the holder portion 102Y and the bottle portion 101Y engaged with the cap portion 105Y are sealed by a ring seal 118Y which is a breathable seal member. In such a configuration, the airtightness between the insertion passage 115Y and the suction nozzle 73Y is higher than the airtightness between the bottle portion 101Y and the cap portion 105Y engaged therewith. When the suction nozzle 73Y, the communication path 114Y, and the toner storage unit 106Y have negative pressure accompanying suction by the suction pump, the air inflow from the outside is inferior in airtightness as indicated by arrows in the figure. Occurs between the portion 101Y and the cap portion 105Y. Specifically, air is interposed between the bottle part 101Y and the toner storage part 106Y via the inside of the cap part 105Y and the outside of the bottle part 101Y inserted therein. Reaching the ring seal 118Y. Then, the toner flows into the toner storage unit 106Y through the inside of the ring seal 118Y. Since the airtightness between the insertion passage 115Y and the suction nozzle 73Y is kept high by the O-ring 117Y, there does not occur a situation in which air is introduced from here and sucked into the suction nozzle 73Y. For this reason, it is possible to satisfactorily exert the suction force from the toner reservoir 106Y toward the suction nozzle 73Y. Accordingly, a stable amount of Y toner can be discharged from the toner storage unit 106Y toward the developing device on the printer main body side.

  If the airtightness between the inside and the outside of the toner cartridge 100Y is too high, the outside air does not flow into the cartridge due to the toner suction by the suction pump, and the bottle portion 101Y is deformed by an excessive negative pressure. . However, in the toner cartridge 100Y of the printer, a ring seal 118Y made of a sponge that is a breathable material is used. For this reason, when the toner reservoir 106Y becomes slightly negative pressure as the toner is sucked, an appropriate amount of outside air flows into the toner reservoir 106Y through the ring seal 118Y. Therefore, deformation of the bottle part 101Y due to excessive negative pressure can be avoided.

  Further, although the Y toner cartridge 100Y containing Y toner has been described in detail, the toner cartridges for other colors (100C, M, K) have the same configuration.

  FIG. 12 is a perspective view showing a suction pump 78Y for Y among the four suction pumps for Y, C, M, and K. The suction pump 78Y is of a type called a uniaxial eccentric screw pump (commonly known as a Mono pump). The pump portion 80Y includes a rotor 81Y processed into an eccentric double screw shape using a metal or a highly rigid resin, a stator 82Y in which a double screw cavity is formed in a material such as rubber, and a resin containing these. It is made up of a made holder and the like. The suction pump 78Y includes, in addition to the pump unit 80Y, a discharge unit 83Y, a motor 84Y that rotates the rotor 81Y, and the like. When the double screw-shaped rotor 81Y rotates in the stator 82Y, a negative pressure is generated on the suction side (right side in the drawing) of the pump unit 80Y. With this negative pressure, the Y toner in the Y toner cartridge 100Y is sucked through the flow pipe 72Y and the like. Then, it reaches the pump portion 80Y of the suction pump 78Y, and is discharged from the discharge portion 83Y through the stator 82Y. The suction pumps for other colors have the same configuration.

Next, a characteristic configuration of the printer will be described.
FIG. 12 is a perspective view showing the toner replenishing device and the surrounding configuration. The toner replenishing device 70 includes a cartridge mounting table 77, four cartridge connecting portions 71Y, C, M, and K, four suction pumps 78Y, C, M, and K, and the like. The cartridge mounting table 77 has four semi-cylindrical recesses for mounting the four toner cartridges 100Y, 100C, 100M, and 100K in parallel. A transfer unit (not shown) is disposed below the cartridge mounting table 77, and four developing devices are disposed below the transfer unit. In the drawing, for convenience, only the developing device 5K for Y among the four developing devices is shown.

  An opening / closing door for exchanging cartridges is provided on the side surface of the printer casing (not shown). When the opening / closing door is opened, the toner replenishing device 70 in the casing is exposed at the back side in the drawing. The operator sets the toner cartridges 100Y, 100C, 100M, and 100K in the toner replenishing device 70 by sliding them on the cartridge mounting table 77 so as to push the toner cartridges 100Y, 100C, 100M, and 100K in the bottle longitudinal direction from the open / close door.

  A connecting portion support plate 79 for supporting the four cartridge connecting portions 71Y, 71C, 71M, and 71K is erected on one end portion of the cartridge mounting table 77. The suction nozzles of the cartridge connecting portions 71Y, 71Y, 71C, 71M, and 71K are inserted into the nozzle insertion passages (not shown) of the toner cartridges 100Y, 100C, 100M, and 100K mounted on the cartridge mounting table 77, respectively. Suction pumps 78Y, C, M, and K are connected to the ends of the flow pipes 72Y, C, M, and K of the cartridge connecting portions 71Y, 71C, 71M, and 71K. Immediately below each suction pump 78Y, C, M, K, the toner replenishing port E of each developing device is located. The Y, C, M, and K toners discharged from the discharge portions of the suction pumps 78Y, 78C, 78M, and 78K are replenished into the developing device through the toner replenishing ports of the corresponding developing devices. In the drawing, only the developing device 5K for K is shown, but the developing devices for Y, M, and C are also provided directly under the suction pumps 78Y, 78M, and 78C for Y, M, and C, respectively. positioned.

  As shown in FIG. 5, the printer includes a Y photoconductor 2Y, a driven gear fixed to the rotation shaft member, a Y developing device 5Y, a Y flow pipe (not shown), and a Y (not shown). A first combination of suction pumps is provided. Also, second, third, and fourth combinations for C, M, and K, which are similar device combinations, are provided.

  The driven gears (not shown) fixed to the rotating shaft members of the respective photoconductors are positioned on the back side of the photoconductors in the drawing. This printer has an opening / closing door (not shown) on the front side of the housing. Each process unit 1Y, C, M, K, each toner cartridge 101Y, 101C, M, K, and transfer unit 40 are supported in a housing so as to be slidable in the depth direction in the figure. The operator opens the above-described opening / closing door to expose the end face on the near side in the figure of each device located above the paper feed cassette in the housing. Then, by gripping a handle (not shown) provided on the end face of the device to be attached / detached (process unit, toner cartridge, transfer unit) and pushing it, the device can be attached and detached by sliding. . That is, the device to be attached / detached is slid while being pushed from the near side to the far side in the drawing, and is set on the printer housing. In such a configuration, if the drive transmission system of each device is provided at the end on the front side in the figure in the housing, gears and the like will obstruct the movement of the device. Provided. For this reason, in the same drawing, each driven gear is located on the back side of each photoconductor in the drawing.

  FIG. 14 is a side view showing a gear configuration of each photoconductor in the printer. In the drawing, four driven gears 17Y, 17C, 17M, and 17K are arranged in a straight line in the horizontal direction so as to be arranged at equal intervals of length L1 (110 mm). Since the driven gears 17Y, 17C, 17M, and 17K are arranged at equal intervals, of course, the photosensitive members 2Y, 2C, 2M, and 2K positioned on the front side in the drawing with respect to the driven gear are also equally spaced (length). L1).

  The driven gears 17Y, 17C, 17M, and 17K are fixed to the rotating shaft members 2aY, 2C, 2M, and 2K of the photoreceptors 2Y, 2C, 2M, and 2K, respectively. The outer diameters (tooth tip circle diameters) of the driven gears 17Y, 17C, 17M, and 17K are 107.96 [mm], and 352 teeth (not shown) are formed on each gear outer edge. The photoreceptors 2Y, 2C, 2M, and 2K that receive the rotational driving force by the driven gears 17Y, 17C, 17M, and 17K each have an outer diameter of 40.06 [mm]. It is rotationally driven at a linear speed of 138 [mm / sec]. In the low-speed print mode, it is rotationally driven at a linear speed of 77 [mm / sec].

  A Y suction pump 78Y is disposed on the left side of the Y driven gear 17Y in the drawing, and is located near the upper portion of a Y developing device (not shown). Further, between the Y driven gear 17Y and the C driven gear 17C adjacent to each other, and above the line segment connecting the respective rotation centers of the two driven gears (indicated by a one-dot chain line in the figure), C A suction pump 78C is disposed in non-contact with both gears. The suction pump 78C is located in the vicinity of the upper portion of a C developing device (not shown). Further, an M suction pump 78M is provided between the C driven gear 17C and the M driven gear 17M adjacent to each other and above the line segment connecting the respective rotation centers of the two driven gears. The two gears are arranged in a non-contact manner. The suction pump 78M is positioned in the vicinity of the upper portion of an M developing device (not shown). Further, a suction pump 78K for K is provided between the M driven gear 17M and the K driven gear 17K adjacent to each other and above the line segment connecting the respective rotation centers of the two driven gears. The two gears are arranged in a non-contact manner. The suction pump 78K is located in the vicinity of the upper side of a developing device for K (not shown). Each suction pump 78Y, C, M, K extends in the depth direction in the figure so as to straddle the area on the near side from the area on the near side of each driven gear in the depth direction in the figure. When these suction pumps 78Y, 78M, 78C, and 78K are arranged so as to be located only in the region on the front side of the driven gear, the toner is supplied to the end portions in the depth direction in the drawing with respect to the developing devices. Can not do.

  Arranged between the driven gear 17C for C and the driven gear 17M for M and below the line connecting the respective rotation centers of the driven gears, the driven gear 91 is arranged to mesh with the driven gears. It is installed. This driving gear 91 having the number of teeth of 16 and the outer diameter of 5.05 [mm] is fixed to the motor shaft of the dual-purpose drive motor 90 existing on the near side in the drawing, The motor rotates counterclockwise in the figure. By this rotation, the driven gear 17C for C and the driven gear 17M for M are each driven to rotate clockwise in the drawing. Then, the photoreceptors 2C, M are driven to rotate clockwise in the drawing via the rotation shaft members 2aC, M, respectively. A line segment connecting the respective rotation centers of the Y driven gear 17C and the M driven gear 17M, and a line segment extending from the rotation center of the C driven gear 17C to the rotation center of the driving gear 91. The formed angle θ1 is 13.25 [°]. Similarly, a line segment connecting the rotation centers of the Y driven gear 17C and the M driven gear 17M, and a line segment extending from the rotation center of the M driven gear 17M to the rotation center of the driving gear 91, Is also 13.25 [°]. Further, the horizontal distance L3 between the rotation center of the driving gear and the rotation center of the driven gear 17C for C is half of the above-described interval, that is, 55 [mm].

  Between the Y driven gear 17Y and the C driven gear 17C, the idle gear 92, which is a relay gear, is located in the region below the line segment connecting the respective rotation centers of the two driven gears. It arrange | positions so that it may each mesh with a driven gear. The idle gear 92 has an outer diameter of 22.22 [mm], and 72 teeth (not shown) are formed on the outer edge. When the C driven gear 17C meshes with the driving gear 91 of the dual-purpose drive motor 90 and is driven to rotate clockwise in the figure, the idle gear 92 meshed with the driven gear 91 is rotationally driven counterclockwise in the figure. Then, the Y driven gear 17Y meshing with this and the Y photoconductor 2Y having both the rotating shaft member and the Y driven gear 17Y are driven to rotate clockwise in the drawing. An angle formed by a line segment connecting the rotation centers of the Y driven gear 17Y and the C driven gear 17C and a line segment extending from the rotation center of the Y driven gear 17Y to the rotation center of the idle gear 92. θ2 is 32.33 [°]. Similarly, a line segment connecting the respective rotation centers of the Y driven gear 17Y and the C driven gear 17C, and a line segment extending from the rotation center of the M driven gear 17M to the rotation center of the idle gear 92, The angle formed by is also 32.33 [°]. Further, the horizontal distance L2 between the rotation center of the idle gear 92 and the rotation center of the Y driven gear 17Y is half of the above-described interval, that is, 55 [mm].

  A non-cumulative drive motor 93 is disposed below the K photoconductor 2K disposed at one end of each of the photoconductors 2Y, 2C, 2M, and 2K. A driving gear 94 is fixed to the motor. In the depth direction of the figure, the non-use drive motor 93 is located on the front side of the driving gear 94. The drive gear 94 of the non-use drive motor 93 is meshed with the K driven gear 17K fixed to the rotary shaft member 2aK of the K photoconductor 2K. When the driving gear 94 is rotated counterclockwise in the figure by driving the non-use driving motor 93, the K driven gear 17K and the K photoconductor 2K are rotated clockwise in the figure. Thus, in this printer, the dual-purpose drive motor 90 drives the three Y, C, and M photoconductors 2Y, 2C, and 2M, while the K photoconductor 2K is driven by the non-shared drive motor 93. It is supposed to be. Note that θ3 in the figure is 5 [°], but the driving gear 94 of the non-combined drive motor 93 may also be disposed at the same position as the driving gear 91 of the combined drive motor 90. Specifically, the position is between the driven gear 17M for M and the driven gear 17K for K and below the line segment connecting the respective rotation centers of the driven gears. However, unlike the driving gear 91 of the dual-purpose drive motor 90, it is necessary to dispose it so as to mesh only with the K driven gear 17k, rather than meshing with both driven gears.

  From the viewpoint of cost reduction by sharing the drive motor, it is best to drive all of the four photoconductors 2Y, 2C, 2M, and 2K with one drive motor. However, in this printer, only the K photoconductor 2K is driven not by the dual-purpose drive motor 93 but by the non-double-purpose drive motor 93 that is not shared with the other photoconductors for the following reason. That is, in the case of forming a color image by a plurality of process units (1Y, C, M, K) as in this printer, not all originals to be printed are in color. Rather, there are more cases where a K single-color document consisting only of K toner images is output. Even in the case of K single color output, which is more demanding than other colors, it is not preferable to operate the photoconductors and developing devices of other colors because they are wasted. Therefore, in this printer, the three primary transfer rollers 45 Y, C, and M for Y, C, and M in FIG. 5 described above are supported by the first bracket 43 while the primary for K is used. The transfer roller 45K is supported by the second bracket 44. In the case of K monochromatic output, the first bracket 43 that can be moved up and down is moved from the lower side to the upper side in the drawing. Then, the stretched portions of the intermediate transfer belt 41 by the three primary transfer rollers 45Y, 45C, 45M move from the lower side to the upper side in the figure following the movement of the first bracket 43, and the photosensitive members 2Y, M, Leave C. In this way, by separating the intermediate transfer belt 41 from the photoreceptors 2Y, 2M, 2C, it is possible to perform K monochrome output while stopping the rotation of the photoreceptors 2Y, 2M, 2C. However, in such K single color output, it is necessary to drive only the K photoconductor 2K while stopping the rotation of the photoconductors 2Y, 2C, and 2M. Therefore, only the K photoconductor 2 </ b> K is driven by the non-shared drive motor 93.

  Heretofore, a printer has been described in which each color toner image individually formed on each photoconductor is transferred onto an intermediate transfer belt (41) as a belt member. However, a paper transport belt is used as the belt member. May be. In this case, in the process of transporting the transfer paper as a recording medium on the surface of the paper transport belt while transporting it along with the endless movement of the belt, each color toner image on each photoconductor may be superimposed on the transfer paper. .

  As described above, in this printer, the photosensitive member (2), which is a latent image carrier that carries a latent image on the rotation peripheral surface, is fixed to the rotating shaft member of the latent image carrier so as to be engaged with and driven by the gear on the driving side. A driven gear (17), a developing device (5) as developing means for developing the latent image carried on the rotating peripheral surface into a toner image, and a developing device from a toner cartridge (100) as a toner container for storing toner. A plurality of combinations including a distribution pipe (72) that distributes the toner toward the center and a suction pump (78) that is a moving force applying unit that applies a moving force to the toner in the distribution pipe are provided. Further, a driving motor (90, 93) in which a driving gear meshing with a driven gear is fixed to a motor shaft, or an intermediate transfer belt (41) which is a belt member for endlessly moving a toner image formed on the rotating peripheral surface of each photoconductor. And a transfer unit (40) which is a transfer means for transferring the image in a superimposed manner. In addition, the respective photoconductors are arranged in a horizontally long arrangement having a space in the horizontal direction rather than the vertical direction. Further, as a plurality of moving force applying means for applying a moving force to the toner in the flow pipe, a suction pump (78) for sucking the toner in the flow pipe is used, and these suction pumps are respectively located above the corresponding developing devices (5). Each suction pump is arranged so as to be positioned in the vicinity. Further, as the drive motor, a dual-purpose drive motor 90 that transmits a driving force to two or more of the plurality of photosensitive members is used. Furthermore, among the plurality of driven gears, between the C driven gear 17C and the M driven gear 17M adjacent to each other, below the line segment connecting the respective rotation centers of the two driven gears, The driving gear 91 of the dual-purpose drive motor 90 is positioned. In such a configuration, the suction pumps 78Y, C, M, and K are used as the plurality of moving force applying units, respectively, so that the toner masses are formed and the toner surface is formed in each of the flow path pipes 72Y, 72C, 72M, and 72K. The detachment of the external additive can be avoided. Further, the suction pumps 78Y, C, M, and K are arranged so as to be positioned in the vicinity of the upper portions of the developing devices 5Y, C, M, and K, so that the toner discharged from the discharge port of the suction pump can be freely dropped. By supplying the toner into the developing device, toner clogging in the flow path tube can be suppressed. Further, as a drive motor serving as a drive source for the photoconductor, at least one dual-purpose drive motor 90 that transmits a drive force to two or more of the four photoconductors 2Y, 2C, 2M, and 2K is used. The cost can be reduced by using one photoconductor as a drive motor. Further, by arranging the photoconductors 2Y, 2C, 2M, and 2K in a horizontally long arrangement, the developing devices 5Y, MC, M, and K can be arranged on the side of the corresponding photoconductors. Become. Then, suction pumps 78Y, C, M, and K are disposed above the developing devices 5Y, 5C, 5M, and 5K, so that suction is performed between the developing device and the photoconductor in the space between the photoconductors. Avoid situations such as interposing a pump. For this reason, as in the case where the suction pump is not used, the space between the photoconductors can be shortened to save space. Further, the drive gear 91 of the dual-purpose drive motor 90 is arranged between the C driven gear 17C and the M driven gear 17M adjacent to each other below the line connecting the rotation centers of the two driven gears. By installing, it becomes possible to explain next. That is, as shown in FIG. 14, the suction pump 78M for M is disposed above the line segment, while the dual drive motor 90 is disposed below the line segment. The competition of the arrangement positions in the suction pump 78M and the dual-purpose drive motor 90 is avoided. Moreover, below the line segment, similarly to above the line segment, the driving gear 91 can be engaged between the two gears without protruding greatly from the vertical ends of the two gears. . For this reason, in order to avoid competition, the driving gear 91 is disposed above the suction pump 78M and two relay gears are provided to transmit the driving from the driving gear to the two driven gears. Unlike the form of taking an extra space in the vertical direction, the extra space is not taken up. As a result, the apparatus can be miniaturized.

  In this printer, in addition to the dual-purpose drive motor 90, a non-double-purpose drive motor 93 that transmits a driving force only to the K photoconductor 2K of the plurality of photoconductors is provided as a drive motor. In such a configuration, as described above, in the case of K single color output with a high degree of demand, the rotational driving of the photoconductors 2Y, 2C, and 2M of colors other than K can be stopped to avoid unnecessary consumption. it can.

  In this printer, of the three photoconductors 2Y, 2C, and 2M to which the driving force is transmitted by the dual-purpose drive motor 90, the Y photoconductor 2Y is fixed to the rotary shaft member 2aY. Dual drive via an idle gear 92 which is a relay gear that meshes with the driven gear 17Y and the driven gear 17C fixed to the rotating shaft member 2aC of the C photoconductor 2C, and relays the driving force between the driven gears. The driving force by the motor 90 is transmitted. In such a configuration, the three photoconductors 2Y, 2C, and 2M can be driven by one single drive motor 90.

  Further, in this printer, four combinations including a photoconductor, a driven gear, a developing device, a flow pipe, and a suction pump are provided, and the non-shared drive motor 93 provides each photoconductor 2Y, C, M in the four combinations. , K, the photoconductor 2K for K, which is disposed at one end of the line, is driven. Further, the dual-purpose drive motor 93 drives the respective photoreceptors 2Y, 2C, and 2M in the remaining three combinations. In such a configuration, the three photoconductors 2Y, 2C, and 2M driven by the dual-purpose drive motor 93 are successively positioned in the arrangement of all the photoconductors, and the K photoconductor is positioned therebetween. There is no. Therefore, two of the three photoreceptors 2Y, 2C, 2M, and 2M that are not continuous with each other because they are not continuous with each other even though it is desired to transmit the driving force by the dual-purpose drive motor 93 to each of the three photoreceptors 2Y, 2C, 2M There is no need to take measures such as using a timing belt that enables relaying of driving force over a relatively long distance. As a result, the driving force is relayed not by the timing belt but by the idle gear 92 having a simple configuration, so that the complexity of the configuration and the increase in size of the apparatus can be suppressed.

FIG. 3 is a side view showing an example of a configuration in which a plurality of units including a photoconductor, a driven gear, a developing device, and the like are arranged. The side view for demonstrating an example of the arrangement position of the drive motor in the same structure. The side view for demonstrating an example of the arrangement | positioning position of the suction pump in the same structure. The side view for demonstrating another example of the arrangement | positioning position of the drive motor and suction pump in the same structure. 1 is a schematic configuration diagram illustrating a printer according to an embodiment. FIG. 3 is an enlarged configuration diagram illustrating a process unit for Y of the printer. FIG. 3 is a perspective view showing a toner cartridge for Y of the printer. FIG. 3 is a perspective view showing a cartridge connecting portion for Y in the toner supply device of the printer. FIG. 3 is an exploded perspective view showing the toner cartridge. FIG. 3 is a cross-sectional view showing a front end portion of the toner cartridge before being set in the toner supply device. FIG. 3 is a cross-sectional view showing a front end portion of the toner cartridge set in the toner supply device. FIG. 3 is a perspective view showing a suction pump for Y in the toner replenishing device. FIG. 3 is a perspective view showing the toner replenishing device and its peripheral configuration. The side view which shows the gear structure of each photoconductor.

Explanation of symbols

1Y, C, M, K Process unit 2Y, C, M, K Photosensitive member (latent image carrier)
2aY, C, M, K Rotating shaft member (Rotating shaft member)
5Y, C, M, K Development device (development means)
17Y, C, M, K Driven gear 40 Transfer unit (transfer means)
41 Intermediate transfer belt (belt member)
72Y, C, M, K Flow pipes 78Y, C, M, K Suction pump 90 Combined drive motor 91 Driving gear 92 Idle gear (relay gear)
93 Non-used drive motor 94 Driving gear 100Y, C, M, K Toner cartridge (toner container)
P Transfer paper (recording medium)

Claims (4)

A latent image carrier that carries a latent image on a rotating peripheral surface, a driven gear that is fixed to a rotating shaft member of the latent image carrier so as to be engaged with and driven by a gear on the driving side, and the rotating peripheral surface. Developing means for developing the latent image into a toner image, a distribution pipe for distributing the toner from the toner container storing the toner toward the developing means, and a moving force applying means for applying a moving force to the toner in the distribution pipe And a drive motor having a driving gear meshing with the driven gear, and a toner image formed on the rotating peripheral surface of each latent image carrier, and a belt member that moves endlessly or the surface thereof. An image forming apparatus in which each latent image carrier is arranged in a horizontally long arrangement with a space in the horizontal direction rather than the vertical direction.
As the plurality of moving force applying means, a suction pump that applies a moving force to the toner by sucking the toner in the flow pipe is used, and the suction pump is positioned above the corresponding developing means. And at least one dual-purpose drive motor that transmits a driving force to all or two or more of the plurality of latent image carriers, and a plurality of the above-described suction pumps. Among the driven gears, the driving gear of the dual drive motor is positioned between two driven gears adjacent to each other and below a line segment connecting the respective rotation centers of the two driven gears. An image forming apparatus. The image forming apparatus according to claim 1.
In addition to the dual-purpose drive motor, an image forming apparatus comprising a non-common-purpose drive motor that transmits a drive force to only one of the plurality of latent image carriers. The image forming apparatus according to claim 1 or 2,
Of at least one of the plurality of latent image carriers to which the driving force is transmitted by the dual-purpose drive motor, a driven gear fixed to the rotation shaft member and a rotation shaft of another latent image carrier An image forming apparatus, wherein a driving force transmitted by the dual-purpose driving motor is transmitted through a relay gear that meshes with a driven gear fixed to a member and relays the driving force between the driven gears. The image forming apparatus according to claim 3.
As the drive motor, the dual-purpose drive motor according to claim 1 and the non-shared drive motor according to claim 2 are provided, and the four combinations are provided, and each of the four combinations is provided by the non-shared drive motor. Of the above-mentioned latent image carriers are driven at one end thereof, and the latent image carriers in the remaining three combinations are driven by the dual drive motor. An image forming apparatus characterized by that.

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