Container holding device, conveying device, image forming apparatus, and method of fixing container

A container holding device includes a container guide member (60) that holds a toner container (50). The toner container (50) can be detachably attached to the container guide member (60). The toner container (50) includes a soft, shrinkable bag (51) for storing contents such as toner. The container guide member (60) can move between a first position at which the toner container (50) is detachably attached and a second position at which the contents of the toner container (50) can be discharged. A moving unit moves the container guide member (60) between the first and second positions. An external pressurizing unit shrinks the bag (51) by applying external pressure, and applies a lower pressure when the container guide member (60) is at the first position than at the second position.

TECHNICAL FIELD

The present invention relates to a technology for holding a container that stores powder, liquid, gas and the like, conveying the contents stored in the container holding device to another device.

BACKGROUND ART

Container holding devices for holding containers, which store powder, liquid, gas and the like, are used in various fields. For example, a container holding device is used in image forming apparatuses for holding a toner container. In case of the image forming apparatuses, a holding part holds the toner container, and a toner conveying device supplies the toner to a developing device of the image forming apparatus.

Toner containers made of hard materials, such as bottles or cartridges, are known. However, the hard toner containers do not shrink when the toner is finished.

Japanese Patent Application Laid-Open Publication Nos. 2001-194907, 2001-324863, and 2002-72649 disclose toner containers that are bag-shaped, made of soft material, and can be reduced in size and volume by a suction pump. These soft toner containers shrink when the toner is finished. The soft containers are better than the hard containers in various respects. For example, because the soft containers shrink, more containers can be accommodated in the same space, so that the transportation costs of returning used toner containers to the manufacturer can be reduced.

However, when the soft toner container shrinks, creases are formed on the container and the toner gets caught in the creases, and cannot be stably supplied to the toner outlet. One approach is to provide fold lines on the container, so that the container shrinks in a fixed shape along the fold lines, and is neatly folded without creases. However, creases are formed even if fold lines are provided. A countermeasure is to provide pressurizing guide members (external pressurizing means) that apply pressure along the fold lines.

However, the pressurizing guide members become obstacles when replacing an empty toner container with a new container. Therefore, the user is required to strongly push the new toner container into its position, against the force of the pressurizing guide members. However, creases are formed on the toner container when it is strongly pushed into its position. In addition, if such creases are created, the container does not fold into a fixed shape along the fold lines, when shrinking. Also, the toner container is apt to tear when being fixed, because of the pressurizing guide members. Therefore, a relatively rigid material has to be used on the container where the fold lines are provided, however, the rigid material is hard to shrink.

These problems are not limited to the container holding device used for the toner conveying device in the image forming apparatus. Such problems also apply to any other container holding device for holding a soft container that shrinks as the contents are ejected.

DISCLOSURE OF THE INVENTION

A container holding device according to an aspect of the present invention includes a container holding member that holds a container, wherein the container can be detachably attached to the container holding member, includes a soft, bag-shaped member that stores contents, and shrinks as external pressure is applied or internal pressure reduces, the container holding member capable of moving between a first position that is a position at which the container is attached to or detached from the container holding member and a second position that is a position at which the contents of the container can be discharged; a moving unit that moves the container holding member between the first position and the second position; and an external pressurizing unit that applies external pressure to the bag-shaped member at least while the container holding member is at the first position and the second position so that the bag-shaped member shrinks when the contents are being discharged, wherein the external pressurizing unit applies a lower pressure to the bag-shaped member when the container holding member is at the first position than when the container holding member is at the second position.

A conveying device according to another aspect of the present invention includes the above container holding device; a discharging unit that causes the contents to be discharged from an outlet of the container by causing the bag-shaped member to shrink by applying external pressure to the bag-shaped member or reducing internal pressure in the bag-shaped member; and a conveying member that conveys the contents discharged from the outlet to another device.

An image forming apparatus according to still another aspect of the present invention includes the above developing device; a discharging unit that causes the contents to be discharged from an outlet of the container by causing the bag-shaped member to shrink by applying external pressure to the bag-shaped member or reducing internal pressure in the bag-shaped member; and a conveying member that conveys the contents discharged from the outlet to another device.

According to still another aspect of the present invention, a method of fixing a container to a container holding device that includes a container holding member, wherein the container has a soft, bag-shaped member that stores contents, shrinks as external pressure is applied or internal pressure reduces, and can be detachably attached to the container holding member, includes moving the container holding member to a first position that is a position at which the container is attached to or detached from the container holding member, from a second position that is a position at which the contents of the container can be discharged; placing the container at the container holding member at the first position; allowing the container to drop by its own weight until an outlet of the container is set where the contents are discharged; moving the container holding member from the first position to the second position; and increasing pressure that is applied to the bag-shaped member as the container holding member moves from the first position to the second position.

BEST MODE FOR CARRYING OUT THE INVENTION

Exemplary embodiments of the present invention are explained below with reference to the accompanying drawings. For the sake of explanation, the present invention is applied to an image forming apparatus; moreover, the image forming apparatus is assumed to be a tandem-type color laser printer (hereinafter, “printer”).

FIG. 1is a schematic diagram of a printer according to an embodiment of the present invention. The printer includes four sets of process units,1Y,1M,1C, and1K, that form yellow (Y), magenta (M), cyan (C), and black (K) images, respectively. Hereinafter, a symbol Y, M, C or K denoted after a number represents that the corresponding member is for yellow, magenta, cyan or black. The printer includes an optical writing unit10, an intermediate transfer unit11, a secondary transfer bias roller18, a pair of registration rollers19, a paper feeding cassette20, and a belt-type fixing unit21. The optical writing unit10includes a light source, polygon mirrors, f-θ lenses, reflecting mirrors, and irradiates a laser beam on the surface of a photosensor based on image information.

FIG. 2illustrates an enlarged view of the process unit1Y. The other process units1M,1C, and1K have similar configuration so the descriptions thereof are omitted to avoid redundant explanation. The process unit1Y includes a drum-shaped photosensor2Y, a charging device30Y, a developing device40Y, a drum cleaning device48Y, and a discharging device (not shown).

The charging device30Y includes a charging roller31Y that is applied with alternating voltage. The charging roller31Y rubs against the photosensor2Y, so as to uniformally charge the surface of the photosensor2Y in the dark. A laser beam that is modulated and deflected by the optical writing unit10, scans and irradiates the surface of the charged photosensor2Y. As a result, an electrostatic latent image is formed on the surface of the photosensor2Y. The developing device40Y develops the electrostatic latent image to form a Y toner image.

The developing device40Y includes a developing roller42Y that is housed in a case41Y. The developing roller42Y is arranged such that a part of the surface of the developing roller42Y is exposed from an opening in the case41Y. The developing device40Y also includes a first conveying screw43Y, a second conveying screw44Y, a doctor blade45Y, and a toner density sensor46Y housed in the case41Y.

The case41Y stores two-component developer (not shown) including magnetic carriers and negatively charged Y toner. The first conveying screw43Y and the second conveying screw44Y stir and convey the two-component developer so as to friction charge the two-component developer. The charged two-component developer is then carried on the surface of the developing roller42Y. The doctor blade45Y controls the thickness of the developer before the developer is conveyed to a developing area facing the photosensor2Y, where the Y toner adheres to an electrostatic latent image on the photosensor2Y. As a result, the Y toner image is formed on the photosensor2Y. After the Y toner is used up for development, the two-component developer is returned into the case41Y by the rotation of the developing roller42Y. A partition47Y is provided between the first conveying screw43Y and the second conveying screw44Y. The partition47Y divides the case41Y into a first compartment including the developing roller42Y and the first conveying screw43Y, and a second compartment including the second conveying screw44Y. The first conveying screw43Y is rotated by a driving unit (not shown) to convey the two-component developer in the first compartment to the developing roller42Y. The two-component developer conveyed to the corner of the first compartment by the first conveying screw43Y enters into the second compartment through an opening (not shown) in the partition47Y. The second conveying screw44Y is rotated by a driving unit (not shown) to convey the two-component developer, coming from the first compartment, in a direction opposite to that of the first conveying screw43Y. The two-component developer conveyed to the corner of the second compartment by the second conveying screw44Y returns to the first compartment through another opening (not shown) in the partition47Y.

The toner density sensor46Y, which can be a permeability sensor, is situated near the center of the bottom wall of the second compartment, and outputs a voltage according to the permeability of the two-component developer passing over the toner density sensor46Y. The permeability and the toner density of the two-component developer are substantially correlated, so the voltage output from the toner density sensor46Y is in accordance with the density of the Y toner. A signal of the voltage is transmitted to a control unit (not shown). The control unit includes a RAM that stores a Vtref for Y, that is a reference voltage. The reference voltage is the optimal voltage to be output from the toner density sensor46Y. The RAM also stores the Vtref data for M, C, and K. The Vtref for Y is used to control the operation of a Y toner conveying device (not shown). Specifically, the control unit controls the Y toner conveying device to supply an appropriate amount of Y toner into the second compartment, so that the voltage output from the toner density sensor46Y approaches the Vtref for Y. As a result, the Y toner density of the two-component developer in the developing device40Y is maintained within a predetermined range. The toner supply is controlled in the same manner in the developing devices of the other process units.

The Y toner image formed on the photosensor2Y is transferred onto an intermediate transfer belt (not shown). After the transfer, the drum cleaning device48Y cleans off the residual toner on the surface of the photosensor2Y, and a discharging lamp discharges and the photosensor2Y. Then, the charging device30Y uniformly charges the photosensor2Y to form a next image. The other process units perform the same process.

As illustrated inFIG. 1, the intermediate transfer unit11includes an intermediate transfer belt12, a driving roller13, stretching rollers14and15, a belt cleaning device16, and four intermediate transfer bias rollers17Y,17M,17C, and17K. The intermediate transfer belt12is tensely stretched by the driving roller13, the stretching rollers14and15, and is endlessly revolved in an anti-clockwise direction as viewed in the figure by the driving roller13that is rotated by a driving system (not shown). Intermediate transfer bias is applied to the intermediate transfer bias rollers17Y,17M,17C, and17K from a power source (not shown). Then, the intermediate transfer bias rollers17Y,17M,17C, and17K push the intermediate transfer belt12towards the photosensors2Y,2M,2C, and2K. As a result, a nip is formed between each of the intermediate transfer bias rollers and the corresponding photosensors. In each of the nips, an electric field is formed due to the intermediate transfer bias. The Y toner image formed on the photosensor2Y is transferred onto the intermediate transfer belt12due to the electric field and the pressure of the nip. The M, C, and K toner images formed on the photosensors2M,2C, and2K are sequentially superimposed on the Y toner image. As a result, a four-color toner image is formed on the intermediate transfer belt12. The four-color toner image is then transferred onto a transfer paper P, which is a recording material. The belt cleaning device16is located near the stretching roller15in close contact with the intermediate transfer belt12. The belt cleaning device16cleans off the toner remaining on the surface of the intermediate transfer belt12after the transfer.

The paper feeding cassette20, which stores the transfer paper P in a stack, is located below the optical writing unit10. A paper feeding roller20ais pushed against the top transfer paper P. When the paper feeding roller20arotates at a predetermined timing, the top transfer paper P is led into a paper conveying path.

In the intermediate transfer unit11, the driving roller13contacts the secondary transfer bias roller18, with the intermediate transfer belt12interposed between the two rollers, forming a nip. Secondary transfer bias is applied to the secondary transfer bias roller18from a power source (not shown).

The transfer paper P fed into the paper conveying path is sandwiched between the pair of registration rollers19. As the intermediate transfer belt12rotates, the four-color toner image formed on the intermediate transfer belt12enters the nip. The pair of registration rollers19sends out the transfer paper P at a timing such that the transfer paper P comes into contact with the four-color toner image at the nip. The four-color toner image is then transferred to the transfer paper P at the nip due to the secondary transfer bias and the pressure of the nip, forming a full-color image on the transfer paper P. The transfer paper P with the full-color image is conveyed to the fixing unit21.

The fixing unit21includes a belt unit21b, in which a fixing belt21ais stretched by three rollers and is endlessly revolved, and a heating roller21chaving a heat source inside. The transfer paper P is conveyed in between the belt unit21band the heating roller21c, so that the full-color image is fixed on the surface of the transfer paper P. A pair of paper discharge rollers22leads the transfer paper P outside the printer.

As described above, the printer includes a visible image forming unit that forms a visible image onto a recording material, by using the process units1Y,1M,1C,1K, the intermediate transfer unit11, and so forth.

FIG. 3is a perspective view of the toner container50Y. The toner container50Y includes a bag part51Y that is bag-shaped, made of soft material, a mouth part52Y that is a cap member, and a rod53Y. The bag part51Y is square-shaped, made of a single sheet or layers of sheets, and has a thickness of from 50 micrometers (μm) to 210 μm, and it is shrinkable. The bag part51Y contains Y toner. The sheet can be made of a resin material including polyester, polyethylene, and nylon, or it can be made of paper. In the present embodiment, the bag part51Y has two layers: a polyethylene sheet on the inside, that welds to the mouth part52Y; and a nylon sheet on the outside. The bag part51Y also has reinforcing layers80, made of a material including polyethylene terephthalate and aluminum, provided on two opposing sides.

Fold lines f are provided on the bag part51Y on the sides where the reinforcing layers80are not provided. When the bag part51Y shrinks, the surfaces provided with the reinforcing layers80are maintained in a flat state due to the strength of the reinforcing layers80, without forming any creases. Therefore, the fold lines f do not deform and remain straight. As a result, the bag part51Y gets neatly folded along the fold lines f when shrinking.

There are eight holes80hon each of the reinforcing layers80. A user can hook his fingers into these holes80h, so that it becomes easy when holding the toner container50Y to shake it, or when fixing it into a container holder. These holes80halso function as reference marks that indicate appropriate positions where to place the user's fingers. This prevents the user from holding the bag part51Y in such a way that the fold lines f deform, so that the bag part51Y shrinks in a fixed shape.

The upper half of the bag part51Y is a substantially rectangular solid shape when inflated, and the bottom half is an inverse quadrangular pyramid (in a taper form), forming a hopper that pours the toner downwards to the mouth part52Y. The mouth part52Y is made of a rigid material including resin, and is weld to the tip of the hopper. The toner container50Y is positioned such that the mouth part52Y is at the bottom, and the bag part51Y is connected to the mouth part52Y. A through hole54Y is formed in the mouth part52Y. When the rod53Y is inserted into this through hole54Y, the Y toner (not shown) in the toner container50Y does not ooze out. The other toner containers50M,50C, and50K have a configuration that is similar to that of the toner container50Y, so the descriptions thereof are omitted.

Next, a configuration and operation of the toner conveying device that conveys the toner to the developing device is described below.

FIG. 4is a diagram of the toner conveying device Y and a part of the developing device for the Y toner. The toner conveying device includes a conveying tube70Y, a nozzle71Y that forms a toner conveying path, and a suction pump90Y. The container holder (not shown) holds the toner container50Y. The toner container50Y is fixed into the container holder such that the mouth part52Y is positioned at the bottom. The toner container50Y is replaced with a new toner container when the toner is substantially finished. The nozzle71Y is inserted into the through hole54Y of the mouth part52Y of the new toner container50Y, pushing out the rod53Y from the through hole54Y. As a result, the nozzle71Y is connected to the mouth part52Y and the toner conveying path is formed. The Y toner ejected from the toner container50Y is conveyed to the developing device40Y through the toner conveying path.

The other end of the nozzle71Y is connected to the conveying tube70Y. The conveying tube70Y is made of a flexible material such as rubber or resin that has excellent toner resistance, and has an internal diameter of 4 millimeters (mm) to 10 mm. The other end of the conveying tube70Y is connected to a pump part91Y included in the suction pump90Y. The suction pump90Y is a so-called uniaxial eccentric screw pump, which includes the pump part91Y, a discharge part95Y in connection with the pump part91Y, an axial member96Y, a universal joint97Y, and a suction motor98Y.

The pump part91Y includes a rotor92Y in a shape of an eccentric double-thread screw, made of metal or highly rigid resin, a stator93Y that is hollow inside in the shape of a double-thread screw and made of rubber, and an inhalator94Y. When the suction motor98Y rotates, the rotational drive is transmitted to the rotor92Y via the universal joint97Y and the axial member96Y. As a result, the rotor92Y rotates inside the stator93Y, and then negative pressure is generated at the inhalator94Y. Due to the negative pressure, the Y toner in the bag part51Y is sucked into the suction pump90Y through the mouth part52Y, the nozzle71Y, and the conveying tube70Y, and is then discharged into the discharge part95Y through the stator93Y. The discharge part95Y is connected to the second compartment of the developing device40Y, and the Y toner is supplied to the second compartment to be mixed with the two-component developer (not shown).

The toner container50Y does not require any movable members such as an auger to convey the Y toner, because the suction pump90Y conveys the Y toner. Accordingly, the toner container50Y can be simple in structure and light-weight. In addition, the suction pump90Y shrinks the bag part51Y, reducing the volume of the toner container50Y. As a result, transportation costs can be reduced when returning the used toner containers50Y to the manufacturer for recycling purposes. Also, the conveying tube does not require any screws, etc., to convey the toner, so the conveying tube70Y can bend flexibly. Moreover, the toner container50Y does not necessarily need to be located below the developing device40Y, because the suction pump90Y can pump up and convey the toner, regardless of gravity. As a result, the toner conveying path can be laid out anywhere in the printer, which is advantageous in various respects.

Because the fold lines f are provided on the bag part51Y, the bag part51Y shrinks along the fold lines f due to the suction, and folds into a substantially flat shape as illustrated inFIG. 5. Hence, the transportation costs of the used containers can be further reduced.

FIG. 6is a perspective view of an example of a configuration of a mouth part of the toner container50Y, in a disassembled state. The mouth part52Y includes a main part55Y with a large vertical hole and a horizontal through hole54Y, and a welding part56Y that protrudes above the main part. There is also a cap part57Y that fits into the vertical hole of the main part55Y from below. The welding part56Y is welded to the opening of the bag part51Y and fixes the mouth part52Y to the bottom of the bag part. The cap part57Y also has the through hole54Y. Accordingly, when the cap part57Y is fitted into the main part55Y, the through hole54Y penetrates both the main part55Y and the cap part57Y in a horizontal direction. Ring-shaped seals58Y made of an elastic material such as rubber, are provided around the through hole54Y of the cap part57Y. Thus, when the rod53Y or the nozzle71Y is inserted into the through hole54Y, the inside of the cap part57Y is sealed off from outside.

The mouth part52Y is divided into the main part55Y and the cap part57Y so that the Y toner can be easily supplied into the bag part51Y. If the main part55Y and the cap part57Y were combined as one unit, the Y toner has to be supplied from the small through hole54Y, which is positioned at 90 degrees with respect to the toner path from the bag part51Y. On the other hand, if the main part55Y and the cap part57Y are separable, the Y toner can be supplied straightly into the bag part51Y from the large opening of the mouth part52Y. This can prevent the toner from soiling the seals58Y. Meanwhile, the diameter of the rod53Y is to be small enough so that the user's finger does not accidentally push the rod53Y out of the through hole54Y. The cross-sectional area of the rod53Y is to be 8 mm2or less, preferably 6 mm2or less.

FIG. 7is a perspective view of another example of a configuration of the mouth part of the toner container50Y, in a disassembled state. The mouth part52Y includes a welding part156Y and a main part155Y that fits into the welding part156Y. There is also included a cap part157Y that fits into a vertical hole of the main part155Y from above. The welding part156Y is welded to the opening of the bag part51Y. The cap part157fits into the vertical hole of the main part155, and the main part connects to the welding part156Y, so that the mouth part52Y is fixed to the bottom of the bag part. A ring-shaped seal58Y is provided between the cap part157Y and the welding part156Y. In a normal environment, the seal is not required. However, in an environment of reduced pressure (in a high-altitude environment), the air leaks out of the bag part51Y, and packing occurs in the toner when returned to a normal environment. In order to prevent this, the seals58Y are provided.

Also, in the mouth part52Y, a circuit board159Y is provided in the main part155Y. The circuit board159Y includes an electric circuit and a memory to confirm whether the toner container50Y is attached, and the remaining amount of toner. When the toner container50Y is attached to the main part155Y, a contact terminal of the circuit board159Y and a contact terminal of the main part155Y contact each other. The toner container50Y and the main part155Y exchange information by the contact terminals.

FIG. 8is a perspective view of the printer.

There are four container holders75Y,75M,75C, and75K, functioning as container holding devices, located on the front side of the printer. The container holders open and close, by pivoting on a rotational shaft (not shown). Each container holder constitutes part of the toner conveying device, and holds the toner container of the corresponding color. The user unlocks a lock (not shown) when setting the toner container50Y into the container holder75Y, so that the container holder75Y opens towards the front. The user holds the bag part51Y with both hands such that the mouth part52Y is at the bottom in a vertical direction, and inserts the toner container50Y into the container holder75Y.

FIG. 9is a perspective view of the container holder75of the toner conveying device for Y. The toner conveying devices for the other colors have similar configurations. The symbol for representing the color is omitted in the following description, for the sake of simplicity.

The toner conveying device includes a fixing member76that fixes the container holder75to the printer. A container guide member60, functioning as a container holding member, is arranged at the bottom of the container holder75. A rotational shaft75a, located at the bottom of the container guide member60, is fixed in the fixing member76. The container holder75pivots on the rotational shaft75a. A protrusion75bis provided on the upper part of two opposing sides of the container guide member60. The protrusion75bis slidably connected to a slide member72, which is rotatably attached to the printer. Therefore, the angle at which the container holder75opens is restricted by the slide members72. The container holder75is capable of moving between an open position at which a toner container50is attached to or detached from the container guide member60, and a closed position at which the toner container50is fixed into the container holder75.

The container holder75is also provided with a back support part75dthat supports the toner container50on the back side facing the printer. The bottom edge of the back support part75dis rotatably fixed to the container holder75. When the container holder75is open, the back support part75dleans towards the front by its own weight, coming in contact with the container guide member60. However, the back support part75dcan also move towards the printer. Therefore, even if the bottom part of a bag part51is inflated due to the toner, the toner container50can smoothly enter the container holder75. When the container holder75is closed, the back support part75dis sandwiched between the toner container50and the printer.

FIGS. 10 and 11are cross-sectional views of the toner conveying device for Y, as if cut perpendicularly along the though hole of a mouth part52, when the container holder75is open and closed, respectively.

The toner conveying device includes a movable plate73functioning as a cap holding member. The movable plate73is rotatably attached to the container holder75by a rotational shaft73a, which is fixed to the bottom of the container holder75. The movable plate73moves between a withdrawn position ofFIG. 10and a holding position ofFIG. 11. A cam74is situated at the bottom part of the movable plate73, on the side not facing the toner container50. The cam74includes a cam shaft74athat is rotatably attached to the container holder75. The cam74is rotated by a cam driving gear74b(not shown) provided on the cam shaft74a. The rotation of the cam74causes the movable plate73to move between the withdraws and holding positions on the rotational shaft73a. The cam74, the cam shaft74a, and the cam driving gear74bfunction as a positioning means.

FIGS. 12 and 13illustrate a driving mechanism that rotates the cam74, when the container holder75is open and closed, respectively. The container holder75and the movable plate73are indicated by chain double-dashed lines, and the fixing member76by chain-dashed lines.

The cam driving gear74bis in meshing engagement with a gear part77aof a substantially L-shaped sector gear77. The end of the sector gear77is rotatably attached to a rotational shaft77bthat is fixed to the container holder75. There is an oblong hole in the middle of the sector gear77, through which a fixing shaft76b, fixed to the fixing member76, is inserted.

As the user closes the container holder75, the rotational shaft77bmoves, and the sector gear77rotates in a clockwise direction around the fixing shaft76b. The resulting rotational force is transmitted to the cam driving gear74bvia the gear part77a. The cam driving gear74bthen rotates half a turn in an anti-clock wise direction. A sufficient rotational angle is required to rotate the cam driving gear74bby half a turn, even if the container holder75opens by a small angle. With the above-described link mechanism, the sector gear77rotates by a large angle, and the gear ratio of the gear part77aand the cam driving gear74bis adjusted. The container holder75opens only by 23 degrees at maximum, however, the rotational angle of the cam74is 168 degrees. When the container holder75is closed, the cam74rotates, moving the movable plate73towards the toner container50into the holding position. In the holding position, the movable plate73holds the mouth part52in connection with the nozzle71.

Conversely, when the container holder75is opened, the above mechanism is performed in reverse. The surface of the cam is separated from the movable plate73, and the movable plate73is released from the holding position. As a result, the movable plate73can freely rotate on the rotational shaft73a, and returns to the withdrawn position. A spring or the like can be employed to force the movable plate73to the withdrawn position.

The toner container50can smoothly enter the container holder75when the movable plate73is in the withdrawn position. If the movable plate73is in the holding position, the movable plate73or the inner walls of the container holder75are apt to block the mouth part52. Hence, the mouth part52cannot be inserted into the full depth of the container holder75to connect with the nozzle71. For this reason, the movable plate73is configured to move to the withdrawn position as the mouth part52enters the container holder75and contacts the movable plate73. As a result, a larger space is provided to allow the mouth part52to smoothly reach the deepest part of the container holder75, even if the mouth part52is not inserted straightly.

When the user closes the container holder75after the toner container50is properly set, the movable plate73moves to the holding position, so that the mouth part is connected to the nozzle71.

When the mouth part52is inserted, the bag part51is more apt to fold upwards on the surface without the fold line f, compared to that with the fold line f. For this reason, the movable plate73is arranged so as to face the surface of the bag part51without the fold line f, to facilitate the smooth insertion of the mouth part52.

FIGS. 14 and 15illustrate a nozzle driving mechanism, when the container holder75is open and closed, respectively.

In the toner conveying device, one end of the nozzle71is attached to the bottom of the container holder75, and the other end is connected to the conveying tube70. The nozzle71is fixed to a nozzle holding member78. The nozzle holding member78has two protruding parts78athat protrude in a longitudinal direction parallel to the nozzle71. As the nozzle71is inserted in the mouth part52, the protruding parts78afit into notches of the mouth part52. There are two protrusions78bthat rotatably attach two nozzle driving members79on two opposing sides of the nozzle holding member78. The nozzle driving members79are located on the inside of the sector gear77, and move together with the sector gear77. The nozzle driving members79are connected by the rotational shaft77bthat is rotatably attached to the sector gear77. When the user closes the container holder75, the rotational shaft77bis pushed away from the bag part51. As a result, the nozzle driving members79rotate in a clockwise direction around the fixing shaft76b. The resulting rotational force causes the nozzle holding member78to slide towards the mouth part52on a guide rail84. The protruding parts78afit into the notches of the mouth part52, and the nozzle71enters a through hole54of the mouth part52. On the other hand, when the user opens the container holder75, the above mechanism is performed in reverse. The nozzle holding member78slides away from the mouth part52, pulling the nozzle71out of the through hole54, allowing the toner container50to be removed.

FIGS. 16 and 17are a perspective view and a front view of relevant parts of an external pressurizing unit61, respectively, when the container holder75is open. Inner surfaces60aof the container guide member60form a taper that fits around the toner container50near the mouth part52Y. Therefore, the toner container50can be easily accommodated. There are two external pressurizing units61provided on two opposing sides of the container guide member60. The external pressurizing unit61includes a contact member65, a torsion spring64that presses the contact member65against the fold line f of the toner container50(not shown), an arm part76a, and a stud63.

The external pressurizing unit61is positioned near the middle of the side of the container guide member60. The contact member65contacts the fold line f of the bag part51, at least where the upper half and the bottom half of the bag part51meet. The bottom end of the contact member65is rotatably attached to an inner part60cof the container guide member60by a turn down screw62. The contact member65is plate-shaped, made of a resin material. A protruding part65ais located near the middle of the contact member65, protruding outside of the container guide member60. There is an oblong hole65bin the protruding part65a, through which one end64aof the torsion spring64is inserted. The torsion spring64is rotatably attached to the stud63. When the container holder75is closed, the other end64bof the torsion spring64contacts the arm part76athat extends from the fixing member76. As a result, a supporting mechanism that supports the contact member65is formed. The edge of the arm part76abends outside, forming a tapering surface, so that the end64bof the torsion spring64is easily guided to the arm part76a.

When the container holder75is opened (as shown inFIG. 8), the end64bof the torsion spring64is detached from the arm part76a, and the supporting mechanism releases the contact member65. As a result, the contact member65moves to a withdrawn position where it does not block the toner container50, leaning towards the inner surface of the container guide member60by its own weight. This allows the toner container50to smoothly be attached to or detached from the container holder75. The contact member65is configured to lean towards the withdrawn position by its own weight, by making the end64aof the torsion spring64contact the lower part of the oblong hole65b. Also, as illustrated inFIG. 9, a cutout part60dis provided on both sides of the container guide member60, so that a top part65cof the contact member65protrudes outside when the contact member65is at the withdrawn position.

When a user opens the container holder75, the contact members65move to the withdrawn positions, where they do not obstruct the process of replacing a used toner container50with a new one. Hence, the user is not required to strongly push in the toner container50, as the toner container50smoothly enters the container holder75by its own weight. Moreover, the user can insert the toner container50without fear of being torn or damaged by the contact members65. Therefore, the toner container50can be made of a soft material, which folds and shrinks easily.

When the user closes the container holder75after setting the toner container50, the end64bof the torsion spring64attached to the stud63comes into contact with the edge of the arm part76a. With the movement of the container holder75, the end64bis guided along the tapering surface of the arm part76a, and is gradually pushed towards the container guide member60. Therefore, the user can push in the container holder75without feeling a strong resistance. As the end64bof the torsion spring64is gradually pushed, the torsion spring64rotates. With this rotation, the other end64aof the torsion spring64inserted in the oblong hole65bgradually generates a force to push the contact member65towards the toner container50. At this point, the bag part51is filled up with toner and inflated, so the contact member65cannot push further into the bag part51. Therefore, the pressure applied to the contact member65is absorbed by the torsion spring64. As a result, the contact member65strongly pushes against the fold line f.

As the torsion spring64is separable from the contact member65and the arm part76a, the level of pressure can be easily adjusted, simply by exchanging the torsion spring64. This increases the freedom in designing the container holder.

As the toner is consumed and the bag part51shrinks due to suction, the contact members65gradually move toward the toner container50, as shown inFIG. 18. Thus, the bag part51neatly folds along the fold lines f without forming any creases. Because the toner does not get caught in any creases, even toner of low fluidity can be stably discharged, and the toner can be completely consumed. The bag part51is in a taper form, decreasing in diameter towards the mouth part52, so that the toner smoothly moves downwards to the mouth part52. Hence, the amount of the bag part51to be folded inside increases towards the direction opposite to the mouth part52. For this reason, the contact members65are rotatably fixed to the bottom of the container guide member60, where the mouth part52is inserted. As a result, the contact members65move to a greater extent towards the direction opposite to the mouth part52, so that the bag part51is thoroughly folded.

The contact members65do not have to contact the fold lines f entirely. If the contact members65contact the fold lines f at least where the upper half and the bottom half of the bag part51meet, the bag part51can fold smoothly.

In the present embodiment, the contact members65are configured to lean to the withdrawn positions by their own weight, but another mechanism can be employed.FIG. 19illustrates an example in which the edge of the arm part76abends inward toward the container guide member60, so that the end64bof the torsion spring64is pushed toward the fixing member76, when the container holder75is opened. The torsion spring64rotates in an anti-clockwise direction, moving down the other end64aof the torsion spring64that is inserted through the oblong hole65b. As a result, the contact member65moves to the withdrawn position. When the container holder75is closed, the above mechanism is performed in reverse, moving the contact member65to the holding position. This mechanism ensures that the contact members65move out of the way when the toner container50is being attached or detached.

FIGS. 20 and 21are perspective views of relevant parts of another example of the external pressurizing unit, when the container holder75is open and closed, respectively. The external pressurizing unit includes an external pressurizing member161made by bending a rigid material, and the arm part76athat presses the external pressurizing member161toward the toner container50. The external pressurizing member161includes a bag contact part161cthat contacts the fold line f of the bag part51, a pressing part161athat presses the bag contact part161cagainst the bag part51, and an arm contact part161dthat contacts the arm part76aof the fixing member76. The bottom part of the external pressurizing member161is rotatably attached to the inner-front part of the container guide member60(not shown) by a turn down screw162. The external pressurizing member161is bent outwards at the middle, forming the pressing part161a. The outer edge of the pressing part161abends towards the fixing member76, forming the arm contact part161d. The bag contact part161cis located at the upper part of the external pressurizing member161.

When the container holder75is open, the arm contact part161dis detached from the arm part76a, so that the external pressurizing member161is not supported by the arm part76a. As a result, the bag contact part161cleans towards the side of the container guide member60to a withdrawn position, by the weight of the pressing part161aand the arm contact part161d. Therefore, a used toner container50can be smoothly replaced with a new one without being obstructed by the bag contact part161c. When the new toner container50is fixed, and the user closes the container holder75, the arm contact part161dcomes in contact with the arm part76a. As the arm part76ais a tapering surface, the arm contact part161dis gradually pushed towards the container guide member60, as the user pushes the container holder75. Then, the bag contact part161cgradually pushes against the fold line f of the bag part51. At this point, the bag part51is filled up with toner and inflated, so the bag contact part161ccannot push further into the bag part51. Therefore, the pressure applied to the bag contact part161cis absorbed by the pressing part161a. As a result, a gap a in the pressing part161aopens wider to the gap a′, as illustrated inFIGS. 22 and 23.

When the container holder75is closed, the contact the bag contact parts161cpush against the fold lines f, so that the bag part51folds along the fold lines f. As the toner is consumed and the bag part51shrinks, the bag contact parts161ccause the bag part51to neatly fold along the fold lines f without forming any creases. The bag contact parts161care rotatably fixed to the bottom of the container guide member60. Hence, the bag contact parts161cmove to a greater extent towards the direction opposite to the mouth part52, in proportion to the amount of the bag part51to be folded inside, so that the bag part51is thoroughly folded.

The conveying device in the present embodiment conveys toner, however, the same effects can be achieved with any other powder, liquid, or gas.

According to the present invention, the external pressurizing unit61applies a lower pressure to both sides of the bag part51when the container guide member60is at the open position (a first position) than when the container guide member60is at the closed position (a second position). Thus, the user can attach the toner container50into the container guide member60without strongly pushing the toner container50, so that the toner container50is not crushed.

Moreover, as the pressure is automatically released from the bag part51as the user opens the container holder75, an additional operation to release the pressure is not required. Because the pressure is released, the toner container50is not obstructed or torn when being replaced. Therefore, the bag part51can be made of a soft material that gets neatly folded without forming creases. This allows the toner, or any other content, to be stably discharged and conveyed to another device, without getting caught in creases.

Furthermore, the toner container50shrinks into a small, fixed shape along the fold lines f, reducing transportation costs when the used toner containers50are returned to the manufacturer for recycling purposes.

The contact members65that apply the pressure are configured to move aside to the withdrawn positions by their own weight. Therefore, the external pressurizing unit61has a simple structure without requiring additional pressurizing or driving devices, which reduces production costs and the incidence of failure.

INDUSTRIAL APPLICABILITY

The container holding device, the conveying device, the image forming apparatus, and the method of fixing the container according to the present invention provide a useful technology when replacing a used container with a new container. One example of the container is a toner container of the image forming apparatus.