JP2011227354A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus having reduced size and weight, in which a constant amount of toner is supplied to a developing unit by mounting and rotating a toner container detachably mounted to a body of the apparatus, by performing the rotation of the toner container and the toner supply to the developing unit with a common driving source.SOLUTION: In the apparatus, a first coupling part 111 is provided on an end face of a rotating shaft 11 and a tonner bottle 72 is provided on a second coupling part 726. A gear train for transferring a rotary drive by directly or indirectly engaging a first gear 21 in which a third coupling part 211 is formed with a second gear 22 in which a fourth coupling 221 is formed is provided in an internal surface of a front door D that can be opened and closed in an apparatus body 1. When the front door D is closed, the third coupling part 211 engages with the first coupling part 111 and the fourth coupling part 221 engages with the second coupling part 726 so as to transfer a rotary drive of one of the toner bottle 72 and the rotating shaft 11 to the other.

Description

  The present invention relates to an image forming apparatus such as a facsimile, a printer, and a copying machine.

  The developing device is usually provided with a toner concentration detecting means for detecting a toner concentration which is a toner ratio in the developer, and based on the detected toner concentration, the toner is developed from the toner container filled with the replenishing toner. The toner concentration supplied to the apparatus is maintained constant.

  In recent years, a cylindrical toner container which is detachable from the apparatus main body and has a spiral protrusion on the inner peripheral surface is being widely used as a toner container filled with replenishing toner for ease of handling. . By mounting such a toner container in the axial direction with respect to the apparatus main body and rotating it by driving means on the apparatus main body side, the toner container can be operated by a toner conveying action of a spiral protrusion formed on the inner peripheral surface of the container. The toner is discharged from the discharge port formed in the toner and supplied to the developing device.

  However, in the method of discharging the toner by rotating the toner container and supplying it to the developing device, it is difficult to strictly control the amount of toner supplied to the developing device. For this reason, a means is generally used in which the toner discharged from the toner container is temporarily stored in the toner hopper and the toner is quantitatively supplied from the toner hopper to the developing device using a rotary conveying means.

  The rotary conveying means for supplying the toner from the toner hopper to the developing device is preferably arranged on the front side of the apparatus main body in consideration of a countermeasure when trouble such as toner clogging occurs.

  On the other hand, the driving means on the apparatus main body side for rotating the toner container is provided on the back side of the apparatus main body, for example, in Patent Document 1, and the gear on the apparatus main body side and the gear of the toner container are engaged to transmit the rotation drive. ing.

Japanese Patent Laid-Open No. 10-69157

  However, when the toner container is mounted on the apparatus main body, in order to mesh the gears so as not to interfere with each other, a space for moving the gears is required, and the apparatus cannot be reduced in size. In addition, if the rotary conveying means for supplying the toner from the toner hopper to the developing device and the rotation driving means for the toner container are driven by different driving sources, respectively, the apparatus is reduced in size and weight.

  The present invention has been made in view of such a conventional problem, and an object of the present invention is to quantitatively supply toner to a developing device by attaching and rotating a toner container that is detachable from the device body to the device body. In the image forming apparatus supplied to the apparatus, the rotation of the toner container and the toner conveyance to the developing device are performed by a common drive source, thereby reducing the size and weight of the apparatus.

  In the image forming apparatus according to the present invention, a toner container that is detachable from the apparatus main body is attached to the apparatus main body and rotated to replenish the toner from the toner container to the toner hopper, and the toner supply unit is rotated to rotate the toner. An image forming apparatus for quantitatively replenishing toner from a hopper to a developing device, wherein a first coupling portion is provided on an end surface of a rotation shaft of the toner supply means, and a second coupling device is provided on a rear end side of the toner container in the apparatus body mounting direction. A coupling portion is provided, and the first gear having the third coupling portion formed on the end surface and the second gear having the fourth coupling portion formed on the end surface mesh directly or indirectly to transmit the rotational drive. A gear train is provided on the inner surface of the front door that can be opened and closed with respect to the apparatus main body, and when the front door is closed, the third coupling portion, the first coupling portion, and the fourth coupling are provided. And the second coupling part are engaged with each other, and the rotational driving force of one of the toner container and the toner supply means is transmitted to the other, and when the front door is opened, the third coupling part and the first coupling part The engagement state between the first and fourth coupling portions and the second coupling portion is eliminated, and the toner container can be attached to and detached from the apparatus main body.

  Here, the gear train may be provided in a gear holder, and the gear holder may be provided on the inner surface of the front door.

  Further, a projection or hole is formed in the gear holder, a hole or projection is formed in the apparatus main body, the gear holder is slidably attached to the front door, and when the front door is closed, the projection of the gear holder or The gear holder may be positioned by engaging the hole with the hole or the protrusion of the apparatus main body.

  Further, from the viewpoint that the front door can be closed even when the coupling part is not engaged, and the coupling part is rotated to be in an appropriate engagement state, the first is used. It is preferable to provide urging means for urging the gear toward the first coupling portion and the second gear toward the second coupling portion.

  One of the first coupling part and the third coupling part is a convex part protruding in the axial direction, the other is a concave part engaging with the convex part, and one of the second coupling part and the fourth coupling part May be a convex portion protruding in the axial direction, and the other may be a concave portion engaged with the convex portion.

  In the image forming apparatus according to the present invention, the gear train is provided on the inner surface of the front door that can be opened and closed with respect to the apparatus main body, and the rotational driving force of one of the toner container and the toner supply means is transmitted to the other. The rotation of the toner container and the toner conveyance to the developing device can be performed by a common drive source, and the apparatus can be reduced in size and weight.

1 is a schematic configuration diagram of an image forming apparatus according to the present invention. 3 is a perspective view of a toner hopper equipped with a toner bottle. FIG. FIG. 3 is a perspective view of a toner bottle. FIG. 3 is a partial cross-sectional perspective view of a toner bottle. FIG. 3 is a cross-sectional view of a toner hopper equipped with a toner bottle. 2 is a perspective view of a toner hopper. FIG. FIG. 6 is a cross-sectional view illustrating an operation state of a toner hopper. It is a perspective view of the apparatus main body which made the front door an open state. It is an assembly drawing which shows attachment to the front door of a gear holder. It is a perspective view explaining positioning of a gear holder when a front door is made into a closed state. It is a perspective view which shows the structure of the gear train in a gear holder. It is a perspective view in the state where a coupling part engaged normally. It is a perspective view in the state where the coupling part interfered. It is a perspective view which shows other embodiment of the image forming apparatus which concerns on this invention.

  The image forming apparatus according to the present invention will be described below with reference to the drawings. However, the present invention is not limited to these embodiments.

  FIG. 1 is a schematic diagram showing an example of an image forming apparatus according to the present invention. The apparatus main body 1 of the image forming apparatus mainly includes an image reader unit 10 that reads a document image and a printer unit 20 that prints the read image. The image reader unit 10 is a known unit that reads a document placed on a document glass plate (not shown) by moving a scanner. The original image is color-separated into three colors of red (R), green (G), and blue (B), converted into an electrical signal by a CCD (Charge Coupled Device) image sensor (not shown), and R, G, B Image data is obtained.

  The image data for each color component obtained by the image reader unit 10 is subjected to various processes in the control unit 30 and reproduced in cyan (C), magenta (M), yellow (Y), and black (K). Converted to color image data.

  The image data is stored in the image memory 34 in the control unit 30 for each reproduction color, subjected to correction for positional deviation correction, and then read out for each scanning line in synchronization with the supply of the recording sheet. It becomes a drive signal for the light emitting diode.

  The recording sheets are picked up one by one from the paper feed tray 61 by a paper feed roller 62 and sent in time with an intermediate transfer belt 53 described later.

  The intermediate transfer belt 53 is stretched between the driving roller 51 and the driven roller 52, and the driven roller 52 is urged to the left in FIG. 1 by a spring (not shown), thereby applying tension to the intermediate transfer belt 53. It has been. Then, the drive roller 51 is rotated counterclockwise by the transfer motor 54 controlled by the apparatus main body control unit 31. A resin material such as polycarbonate, polyimide, or polyimide amide is used for the intermediate transfer belt 53.

  Below the intermediate transfer belt 53, yellow (Y), magenta (M), cyan (C), and black (K) image forming portions 41Y, 41M, 41C, and 41K are arranged at predetermined intervals. Transfer rollers 42Y, 42M, 42C, and 42K are arranged at positions that face the photosensitive drums of the respective image forming units with the intermediate transfer belt 53 interposed therebetween. The toner image formed on the surface of the photosensitive drum is primarily transferred onto the intermediate transfer belt 53 when the intermediate transfer belt 53 passes between the photosensitive drum and the transfer roller. When the recording sheet pulled out from the paper feed tray 61 passes through the nip portion between the intermediate transfer belt 53 and the secondary transfer roller 55 through the broken line A, the toner image on the intermediate transfer belt 53 is recorded on the recording sheet. Secondary transferred on top. Thereafter, the recording sheet is conveyed to the fixing unit 80 where it is heated and pressurized to fix the toner image on the recording sheet. Then, the recording sheet on which the toner image is fixed is discharged outside the apparatus. On the other hand, the residual toner on the intermediate transfer belt 53 is collected by the transfer belt cleaner 101 and stored in the waste toner box 102.

  The developing units of the image forming units 41Y, 41M, 41C, and 41K are provided with toner hoppers 70Y, 70M, 70C, and 70K (hereinafter, sometimes collectively referred to as “toner hoppers 70”) that supply a fixed amount of each color toner. From here, it is supplied to each developing unit via joints 71Y, 71M, 71C, 71K. Above the toner hopper 70, toner bottles (toner containers) 72Y, 72M, 72C, 72K (hereinafter may be collectively referred to as “toner bottle 72”) are detachably provided. When the remaining amount of toner in the toner hopper 70 decreases, toner is supplied from the toner bottle 72 to the toner hopper 70. When the toner in the toner bottle 72 runs out, the toner bottle 72 is replaced with a new one.

  2 is a perspective view of the toner hopper 70 and the toner bottle 72, FIG. 3 is a perspective view of the toner bottle 72, and FIG. 4 is a partial sectional view of the toner bottle 72. As shown in FIG. 3, the toner bottle 72 includes a bottle portion 722 that stores toner, a cap portion 723 having a supply port 723a formed on the outer peripheral surface, and a shutter portion 725 that opens and closes the supply port 723a. . The bottle part 722 and the cap part 723 are relatively rotatably attached. On the front side of the cap portion 723, a knob 724 that rotates the toner bottle 72 to open the shutter portion 725 is formed. As shown in FIG. 4, the end of the bottle portion 722 on the supply port side is gradually reduced in diameter to be exposed at the center of the knob 724, and a driving force for rotating the bottle portion 722 is obtained on the end surface. A second coupling portion 726 is formed.

  When the bottle unit 722 is rotated via a rotation transmission mechanism described later, the toner stored in the bottle unit 722 is supplied to the supply port of the cap unit 723 by a spiral groove 727 formed on the inner peripheral surface of the bottle unit 722. 723a. Then, the toner is dropped and supplied to the toner hopper 70 from the supply port 723a.

  FIG. 5 is a schematic configuration diagram of the cap portion 723 and the toner hopper 70 of the toner bottle 72, and FIG. 6 is a perspective view of the toner hopper 70. As shown in FIG. 5, the supply port 723 a of the cap unit 723 is positioned above the toner hopper 70. A float member 704 that detects the upper surface level of toner is provided in the toner hopper 70 so as to be swingable about a shaft 704a. A cam 702 that rotates together with the stirring shaft 12 is provided below the float member 704, and the float member 704 swings up and down by the rotation of the cam 702. A stirring plate 705 is attached to the stirring shaft 12, and the toner in the toner hopper 70 is stirred by the rotation of the stirring plate 705.

  A toner density sensor (not shown) is provided in the developing unit, and when the toner density in the developing unit becomes low, a supply screw (toner supply means) 703 of the toner hopper 70 is set so that a predetermined toner density is obtained. Rotates and toner is supplied to the developing unit.

  As shown in FIG. 6, a gear 81 is attached to the end of the rotating shaft 11 that rotates the supply screw 703 (shown in FIG. 5) protruding from the toner hopper 70, and a first coupling is attached to the end. A portion 111 is provided. A gear 82 is attached to the end of the stirring shaft 12 protruding from the toner hopper 70. The gear 81 and the gear 82 mesh with the intermediate gear 83 that is rotatably attached to the side surface of the toner hopper 70. The rotational driving force is first transmitted from the motor 701 to the rotating shaft 11 by a transmission mechanism (not shown), and the rotating shaft 11 rotates. The rotational driving force is transmitted from the gear 81 to the intermediate gear 83, and from the gear 83 to the gear 82, so that the stirring shaft 12 rotates. A plurality of motors 701a to 701c are provided corresponding to each of the toner hoppers 70 (four in this embodiment). Of course, the number of motors may be reduced by transmitting the rotational driving force only to the necessary toner hopper 70 using a clutch or the like.

  FIG. 7 shows the fluctuation state of the float member 704 corresponding to the toner amount. A floating body 704b is provided on the free end side of the float member 704, and moves up and down according to the upper surface level of the toner. A magnet 704 c is provided on the upper surface of the floating body 704 b, and the position of the magnet 704 c is detected by a reed switch (not shown) disposed on the outer surface of the toner hopper 70. When there is sufficient toner, the float member 704 is positioned above (FIGS. 7A and 7B). On the other hand, when the amount of toner in the toner hopper 70 is reduced, the upper surface of the toner is lowered and the float member 704 is lowered. Then, the reed switch is turned on, the bottle portion 722 of the toner bottle 72 is rotated for a predetermined time (for example, 10 seconds) by the motor 701, and toner is supplied from the toner bottle 72 into the toner hopper 70.

  FIG. 8 is a perspective view of the image forming apparatus when the front door D is opened. The front door D can be opened and closed with the lower side as an axis, and the front door D is maintained in a substantially horizontal state in the open state. When the front door D is in an open state, on the apparatus main body 1 side, the second coupling portion 726 of the toner bottle 72 and the first coupling portion 111 provided at the end of the rotating shaft 11 that rotates the supply screw 703 are exposed. To do. A gear holder GH is attached to the inner side surface of the front door D, and the third coupling portion 211 and the fourth coupling portion 221 are exposed on the surface of the gear holder GH. The internal structure of the gear holder GH will be described later.

  In FIG. 9, the attachment figure to the front door D of the gear holder GH is shown. Since the front door D is usually a resin-molded and relatively large part, it is difficult to obtain high dimensional accuracy. For this reason, if the gear holder GH is fixed to the front door D, there exists a possibility that a coupling part may not engage normally. Therefore, a hole 27 having a larger diameter than the shaft portion of the screw 24 is formed in the gear holder GH, and the shaft portion of the stepped screw 24 is inserted into the hole 27 so that the gear holder GH is slidably attached to the front door D. Then, positioning protrusions 25a and 25b are provided on the gear holder GH, and holes 26a and 26b (shown in FIG. 8) into which the protrusions 25a and 25b are engaged are formed in the apparatus main body 1.

  As shown in FIG. 10, according to such a configuration, when the front door D is closed, the gear holder GH slides so that the protrusions 25a and 25b of the gear holder GH are engaged with the holes 26a and 26b of the apparatus body. Thus, the gear holder GH is positioned at a position where the coupling portion is normally engaged. Of course, a hole may be formed in the gear holder GH, a protrusion may be formed in the apparatus main body 1, and the gear holder GH may be positioned. If one of the holes 26a and 26b formed in the apparatus main body 1 is a long hole, the protrusions 25a and 25b can be smoothly engaged with the holes 26a and 26b.

  FIG. 11 shows the internal structure of the gear holder GH. The gear holder GH incorporates four sets of gear trains according to the toner hopper 70 and the toner bottle 72. Since the four sets of gear trains have the same configuration, one set will be described below. The first gear 21 and the intermediate gear 23, and the intermediate gear 23 and the second gear 22 are rotatably attached to the inner side surface of the gear holder GH. On the end surfaces of the first gear 21 and the second gear 22, a third coupling portion 211 and a fourth coupling portion 221 made of three protrusions are formed at equal intervals in the circumferential direction. Further, the first gear 21 and the second gear 22 are always urged outward by a spring S inserted on the rotation shaft.

  As shown in FIG. 12, when the front door D is closed, the first coupling part 111 of the rotating shaft 11, the third coupling part 211 of the first gear, and the second coupling part 726 of the bottle part 722 The fourth coupling portion 221 of the second gear is engaged. Specifically, the three protrusions of the third coupling portion 211 and the fourth coupling portion 221 engage with the three concave portions of the first coupling portion 111 and the second coupling portion 726. Thereby, when the rotating shaft 11 is rotated by the rotational driving force from the motor 701 (shown in FIG. 6), the first gear 21 is rotated by the engagement between the first coupling portion 111 and the third coupling portion 211. Then, the second gear 22 is rotated via the intermediate gear 23, and the bottle portion 722 is rotated by the fourth coupling portion 221 and the second coupling portion 726. Thus, the rotating shaft 11 of the supply screw 703 and the bottle part 722 are rotated by one motor. The first coupling unit 111 and the third coupling unit 211, and the second coupling unit 726 and the fourth coupling unit 221 are not particularly limited as long as they can be engaged and transmit rotational driving. A conventionally known structure can be used.

  Here, when the coupling portion is engaged, the convex portion of one coupling portion may not engage the other concave portion depending on the rotational phase relationship between the two. That is, as shown in FIG. 13, the coupling portion may interfere in the axial direction, and the front door D may not be completely closed. In the present embodiment, the first gear 21 and the second gear 22 are always urged outward in the axial direction by the spring S, the tooth width of the intermediate gear 23 is increased, and the first gear 21 and the second gear 22 are formed as spur teeth. Since the engagement with the intermediate gear 23 is possible even if the gear 22 moves, the first gear 21 and the second gear 22 retract against the urging force of the spring S when the coupling portion interferes. The front door D can be completely closed. Thereafter, when the coupling portion rotates, the phase difference of the coupling portion disappears, and the retracted first gear 21 and second gear 22 move outward in the axial direction by the biasing force of the spring S. Thereby, a coupling part will be in an appropriate engagement state, and rotation drive transmission is attained.

  FIG. 14 is a perspective view showing another embodiment of the image forming apparatus according to the present invention. The image forming apparatus shown in this figure is different from the image forming apparatus shown in FIG. 8 in that the image forming apparatus can be opened and closed with one side of the front door D as an axis. With this configuration, the space for opening and closing the front door D is wider than that of the apparatus of the above embodiment, but a member that supports the weight of the front door D when it is in an open state is not particularly required.

  In the image forming apparatus according to the present invention, the rotation of the toner container and the toner supply to the developing device can be performed by a common drive source, which is useful because the device can be reduced in size and weight.

1 Device body D Front door S Spring (biasing means)
DESCRIPTION OF SYMBOLS 11 Rotating shaft 21 1st gear 22 2nd gear 25a, 25b Convex part 26a, 26b Concave part 70 Toner hopper 72 Toner bottle (toner container)
GH gear holder 111 first coupling part 211 third coupling part 221 fourth coupling part 703 supply screw (toner supply means)
726 Second coupling part

Claims (5)

A toner container that is detachable from the apparatus main body is attached to the apparatus main body and rotated to replenish toner from the toner container to the toner hopper, and the toner supply means is rotated to quantitatively supply the toner from the toner hopper to the developing device In an image forming apparatus for replenishing
A first coupling portion is provided on an end surface of the rotation shaft of the toner supply means;
A second coupling portion is provided on the rear end side of the toner container in the apparatus body mounting direction,
A gear train in which a first gear having a third coupling portion formed on an end surface and a second gear having a fourth coupling portion formed on an end surface mesh with each other directly or indirectly to transmit rotational drive. Provided on the inner surface of the front door that can be opened and closed with respect to the main body,
When the front door is closed, the third coupling portion, the first coupling portion, the fourth coupling portion, and the second coupling portion are engaged with each other, and one of the toner container and the toner supply means is driven to rotate. When the force is transmitted to the other and the front door is opened, the engagement state between the third coupling portion and the first coupling portion and the fourth coupling portion and the second coupling portion is canceled respectively. An image forming apparatus, wherein a toner container can be attached to and detached from an apparatus main body.   The image forming apparatus according to claim 1, wherein the gear train is provided in a gear holder, and the gear holder is provided on an inner surface of the front door.   A protrusion or hole is formed in the gear holder, a hole or protrusion is formed in the apparatus main body, the gear holder is slidably attached to the front door, and when the front door is closed, the protrusion or hole of the gear holder is formed in the apparatus. The image forming apparatus according to claim 2, wherein the gear holder is positioned by engaging with a hole or a protrusion of the main body.   4. The image forming apparatus according to claim 1, further comprising urging means for urging the first gear toward the first coupling portion and the second gear toward the second coupling portion.   One of the first coupling part and the third coupling part is a convex part protruding in the axial direction, and the other is a concave part engaging with the convex part, and one of the second coupling part and the fourth coupling part The image forming apparatus according to claim 1, wherein a convex portion protruding in the axial direction and the other is a concave portion engaged with the convex portion.