JP2015001718A - Image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform stable detection of a residual amount of developer without relying on a shape of a developer storage bag in a developer replenishment container using the developer storage bag, which is composed of a flexible bag and the shape of which is deformed.SOLUTION: An image formation device comprises: a developer storage bag that accommodates developer to be used for forming an image, is composed of a flexible material, and has an exhaust part externally exhausting the developer; a pump that controls a volume of the developer storage bag by introduction of air or inhalation thereof; state detection means that, when the volume of the developer storage bag is controlled by the pump and the developer storage bag is filled with air, detects a change in a state of the developer storage bag; and developer residual amount detection means that, when the developer storage bag is filled with the air by the pump until it is determined by the state detection means that the developer storage bag becomes in a prescribed state, detects a residual amount of the developer accommodated in the developer storage bag on the basis of drive information on the pump.

Description

  The present invention relates to an image forming apparatus having a developer replenishing container that is detachably provided in an image forming apparatus such as a laser beam printer, an LED printer, or a copying machine.

  In an electrophotographic image forming apparatus such as a printer, a fine powder developer is used, and it is necessary to replenish the developer from the developer replenishing container every time the developer consumed for image formation is exhausted. .

  As such a developer supply container, a developer supply container having a stirring and conveying member such as a screw for conveying the developer has been widely known. So

  In recent years, in order to reduce the cost of the developer supply container and to make it easier to recycle the developer supply container, it is desired to reduce the number of parts of the developer supply container in order to further simplify the configuration of the developer supply container. It is rare.

  For example, in Patent Document 1, as a developer supply container having a small number of parts, a container main body portion that accommodates the developer is formed of an elastic material that can be expanded and contracted, and the developer is discharged by utilizing the restoring force of the elastic material. A developer supply container is described. According to this configuration, since a stirring and conveying member such as a screw is not necessary, the number of parts can be reduced.

  Further, Patent Document 2 describes a developer supply container in which a container main body for containing a developer is formed of a flexible material and the developer is supplied by a powder pump.

  By the way, in order to supply the developer stably to the image forming apparatus main body, the developer replenishing device has a detecting means for detecting the absence of the developer in the developer replenishing container and the development in the developer replenishing container. There is a need for detection means for detecting the remaining amount of the agent.

  In general, a method is known in which a hopper unit for storing developer is provided between the developer supply device and the developing device, and the presence or absence of the developer is detected by a piezoelectric sensor or an optical sensor provided on the wall surface of the hopper unit. It has been.

  The detection by the piezoelectric sensor utilizes the fact that a piezoelectric sensor that vibrates the detection surface by the piezoelectric element is provided on the wall surface of the hopper unit, and that the vibration characteristics change by the developer adhering to the detection surface. On the other hand, in the detection by the optical sensor, the light emitting element and the light receiving element are arranged to face each other via a hopper, and the light receiving element receives visible light emitted from the light emitting element. With such a configuration, the presence or absence of the remaining amount of developer in the hopper unit is detected.

  Further, even when the hopper unit is not provided, a similar sensor can be provided on the wall surface of the developer supply container to check the presence or absence of the developer. For example, in Patent Document 2, an optical sensor is provided on the side of the developer supply container to detect the presence or absence of the developer.

Sho-60-232578 Japanese Patent Laid-Open No. 2005-17789

  However, as in Patent Document 1, in the case where the container main body portion that stores the developer of the developer supply container is made of an elastic material that can expand and contract, the expansion and contraction of the elastic material is hindered. It is difficult to provide a piezoelectric sensor in the container body.

  Further, the shape of the container main body is greatly deformed by the remaining amount of developer in the developer supply container and the posture of the developer supply container. For this reason, when the detection by the conventional optical sensor is performed, even if the developer remains in the container main body, the developer cannot stay between the light emitting unit and the light receiving unit, and erroneous detection is performed. There is a possibility of being invited.

  In addition, even when the thickness of the material of the container main body changes due to the expansion and contraction of the container main body, and thereby the light transmittance changes, there is a possibility of erroneous detection.

  On the other hand, even in the case of a flexible material that is not an elastic material, depending on the shape of the container main body and the developer supply container, even if the developer remains in the container main body, even on the piezoelectric sensor or optical type In the sensor, the developer cannot stay between the light emitting part and the light receiving part. For this reason, erroneous detection may be caused.

  The present invention solves such problems, and an object of the present invention is to provide a developer supply container made of a flexible material and having a deformed shape, which is stable regardless of the shape of the developer supply container. Another object of the present invention is to provide an image forming apparatus capable of detecting the remaining amount of the developer.

In order to achieve this object, the image forming apparatus of the present invention provides:
An image forming apparatus for forming an image on a recording medium,
A developer containing bag for containing the developer used for forming the image, made of a flexible material, and having a discharge portion for discharging the developer to the outside;
A pump for controlling the volume of the developer containing bag by introducing or sucking air;
A state detecting means for detecting a change in the state of the developer containing bag when the volume of the developer containing bag is controlled by the pump and filled with air;
Based on driving information indicating the driving state of the pump when the pump is filled with air until the state detecting means determines that the developer containing bag is in a predetermined state. And a developer remaining amount detecting means for detecting the remaining amount of developer accommodated in the developer accommodating bag.

  The present invention has a pump that controls the volume of the developer containing bag by introducing or sucking air. Then, when the pump is filled with air until it is determined that the developer containing bag is in a predetermined state by controlling the volume of the developer containing bag with this pump, the developer containing bag is stored in the developer containing bag based on the driving information of the pump. The remaining amount of developer stored is detected.

  Therefore, even in a developer supply container that is made of a flexible material and has a deformed shape, the remaining amount of developer can be detected stably regardless of the shape of the developer supply container.

1 is a schematic cross-sectional view of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a configuration of a process cartridge mounted on the image forming apparatus according to the embodiment of the present invention. 2 is a cross-sectional view illustrating a configuration of the toner cartridge and the apparatus main body when the toner cartridge according to the embodiment of the present invention is mounted on the apparatus main body of the image forming apparatus. FIG. 2 is a perspective view illustrating an appearance of a toner cartridge according to an exemplary embodiment of the present invention. 1 is a perspective view of an image forming apparatus showing a state where a toner cartridge according to an embodiment of the present invention is mounted. 2 is a block diagram illustrating a configuration of a control unit of the image forming apparatus according to the exemplary embodiment of the present invention. FIG. In the embodiment of the present invention, it is a diagram showing a state in which the air in the toner storage bag containing the toner has been naturally deaerated. 6 is a flowchart illustrating a flow of detection of a remaining amount of toner according to an exemplary embodiment of the present invention. FIG. 5 is a cross-sectional view illustrating a toner storage bag and its periphery in a configuration without a container body in the embodiment of the present invention. FIG. 5 is a cross-sectional view of the toner containing bag and its periphery when the toner containing bag is made of a sheet material having no elasticity in the embodiment of the present invention. FIG. 6 is a cross-sectional view illustrating a configuration of a toner cartridge according to another embodiment of the present invention. FIG. 12 is a cross-sectional view illustrating a state where the toner cartridge illustrated in FIG. 11 is attached to the apparatus main body. FIG. 12 is a block diagram illustrating a configuration of a control unit of the image forming apparatus when the toner cartridge illustrated in FIG. 11 is used. 11 is a graph showing the relationship between the pressure in the airtight chamber, the toner containing bag, and the volume when the toner containing bag 41 that does not contain toner is indirectly filled with air when the toner cartridge shown in FIG. 11 is used. It is. 12 is a flowchart showing a flow of detection of the remaining amount of toner when the toner cartridge shown in FIG. 11 is used.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<First Embodiment>
(Schematic configuration of image forming apparatus)
First, the image forming apparatus of this embodiment will be described with reference to FIGS.

  FIG. 1 is a schematic cross-sectional view of the image forming apparatus according to the present embodiment, and FIG. 2 is a diagram illustrating a configuration of a process cartridge mounted on the image forming apparatus.

  The image forming apparatus 100 is a full-color laser printer that employs an inline method and an intermediate transfer method. The image forming apparatus 100 forms a full-color image on the recording medium 12 such as a sheet, a plastic sheet, or a cloth according to the image information.

  The image information is obtained from an image reading apparatus connected to the apparatus main body 101 of the image forming apparatus 100 or a host device such as a personal computer connected to the apparatus main body 101 of the image forming apparatus 100 in a communicable manner. Input to the main body 101.

  The image forming apparatus 100 includes, as a plurality of image forming units, image forming units SY, SM, and SC for forming respective color images of yellow (Y), magenta (M), cyan (C), and black (K). , SK. In the present embodiment, the image forming units SY, SM, SC, and SK are arranged in a line in the horizontal direction.

  The configurations and operations of the image forming units SY, SM, SC, and SK are substantially the same except that the colors of the images to be formed are different. For this reason, in the following, when it is not necessary to distinguish, the subscripts Y, M, C, and K given to the reference numerals to indicate the elements provided for any color are omitted, and image formation is performed. The component parts will be described generally.

  The image forming apparatus 100 includes four photosensitive drums 1 arranged in parallel in a direction intersecting the vertical direction as a plurality of image carriers. The photosensitive drum 1 is rotationally driven in the direction of arrow A in FIG. Around the photosensitive drum 1, a charging roller 2 that uniformly charges the surface of the photosensitive drum 1 and an exposure unit that forms an electrostatic latent image on the photosensitive drum 1 by irradiating a laser based on image information. A scanner unit 3 is arranged.

  Around the photosensitive drum 1, there are arranged a developing unit 4 as developing means for developing an electrostatic image as a toner image, and a cleaning member 6 for removing transfer residual toner remaining on the surface of the photosensitive drum 1 after transfer. ing. Further, an intermediate transfer belt 5 as an intermediate transfer body for transferring the toner image on the photosensitive drum 1 to the recording medium 12 is disposed facing the four photosensitive drums 1. In the rotation direction of the photosensitive drum 1, the charging position by the charging roller 2, the exposure position by the scanner unit 3, the development position by the development unit 4, the transfer position of the toner image to the intermediate transfer belt 5, and the cleaning position by the cleaning member 6 are They are provided in this order.

  The developing unit 4 performs reverse development by bringing a developing roller 17 as a developer carrying member into contact with the photosensitive drum 1. That is, the developing unit 4 attaches the toner charged to the same polarity (negative polarity in this embodiment) as the charging polarity of the photosensitive drum 1 to the portion where the charge is attenuated by exposure on the photosensitive drum 1. Develop the electrostatic image.

  The intermediate transfer belt 5 formed of an endless belt contacts all the photosensitive drums 1 and rotates in the direction of arrow B shown in FIG. The intermediate transfer belt 5 is stretched around a driven roller 51, a secondary transfer counter roller 52, and a driving roller 53 as a plurality of support members.

  On the inner peripheral surface side of the intermediate transfer belt 5, four primary transfer rollers 8 are arranged in parallel so as to face the four photosensitive drums 1, respectively. The primary transfer roller 8 presses the intermediate transfer belt 5 toward the photosensitive drum 1 to form a primary transfer portion N1 where the intermediate transfer belt 5 and the photosensitive drum 1 abut. A bias having a polarity opposite to the normal charging polarity of the toner is applied to the primary transfer roller 8 from a primary transfer bias power source (not shown). As a result, the toner image on the photosensitive drum 1 is primarily transferred onto the intermediate transfer belt 5.

  A secondary transfer roller 9 is disposed at a position facing the secondary transfer counter roller 52 on the outer peripheral surface side of the intermediate transfer belt 5. The secondary transfer roller 9 is in pressure contact with the secondary transfer counter roller 52 via the intermediate transfer belt 5 to form a secondary transfer portion N2 where the intermediate transfer belt 5 and the secondary transfer roller 9 are in contact with each other. A bias having a polarity opposite to the normal charging polarity of the toner is applied to the secondary transfer roller 9 from a secondary transfer bias power source (not shown). As a result, the toner image on the intermediate transfer belt 5 is secondarily transferred to the recording medium 12.

(Schematic operation of the image forming apparatus)
At the time of image formation, first, the surface of the photosensitive drum 1 is uniformly charged by the charging roller 2. Next, the surface of the charged photosensitive drum 1 is scanned and exposed by laser light corresponding to the image information emitted from the scanner unit 3, and an electrostatic latent image according to the image information is formed on the photosensitive drum 1. . The electrostatic latent image formed on the photosensitive drum 1 is developed as a toner image by the developing unit 4.

  The toner image formed on the photosensitive drum 1 is primarily transferred onto the intermediate transfer belt 5 by the action of the primary transfer roller 8. When forming a full-color image, the above-described processes are sequentially performed in the image forming units SY, SM, SC, and SK, and the toner images of the respective colors are superimposed on the intermediate transfer belt 5 and primarily transferred.

  Thereafter, the recording medium 12 is conveyed to the secondary transfer portion N2 in synchronization with the rotation of the intermediate transfer belt 5, and the four-color toner images on the intermediate transfer belt 5 are batched by the action of the secondary transfer roller 9. Then, it is secondarily transferred onto the recording medium 12.

  The recording medium 12 to which the toner image has been transferred is conveyed to the fixing device 10, and the toner image is fixed to the recording medium 12 by applying heat and pressure to the recording medium 12.

  The primary transfer residual toner remaining on the photosensitive drum 1 after the primary transfer is removed and collected by the cleaning member 6. The secondary transfer residual toner remaining on the intermediate transfer belt 5 after the secondary transfer is cleaned by the intermediate transfer belt cleaning device 11.

(Process cartridge configuration)
Next, the configuration of a process cartridge that can be attached to and detached from the image forming apparatus 100 will be described.

  As shown in FIG. 2, the photosensitive drum 1, the charging roller 2, the developing unit 4, and the cleaning member 6 are integrally formed into a cartridge to form a process cartridge 7. The process cartridge 7 can be attached to and detached from the image forming apparatus 100 via mounting means (not shown) such as a mounting guide and a positioning member provided in the image forming apparatus main body. In this embodiment, the process cartridges 7 for the respective colors all have the same shape, and the process cartridges 7 for the respective colors have yellow (Y), magenta (M), cyan (C), and black (K), respectively. ) Is stored.

  The process cartridge 7 has a configuration in which the photosensitive unit 13 including the photosensitive drum 1 and the developing unit 4 including the developing roller 17 and the like are integrated.

  The photoconductor unit 13 includes a cleaning frame body 14 as a frame body that supports each component in the photoconductor unit 13. In addition to the photosensitive drum 1, the cleaning frame 14 is provided with a charging roller 2, a cleaning member 6, and the like.

  On the other hand, the developing unit 4 has a developing frame 18 as a frame that supports each component in the developing unit 4. The developing unit 4 is provided with a developing roller 17 that contacts the photosensitive drum 1 and rotates in the direction of arrow D in FIG.

  The developing unit 4 is provided with a toner supply roller 20 that supplies toner by rotating in the direction of arrow E in FIG. 2 so as to contact the peripheral surface of the developing roller 17.

  The developing frame 18 is provided with a developing blade 21 that regulates the toner layer thickness. The developing blade 21 is a metal leaf spring and is in contact with the developing roller 17 with a predetermined contact pressure. A thin layer of toner is formed on the developing roller 17 and supplied to the surface of the photosensitive drum 1. .

  The developing frame 18 has a toner storage chamber 18a for temporarily storing toner, and a developing chamber 18b in which a developing roller 17 and a toner supply roller 20 are provided. The toner storage chamber 18a is provided with a toner inlet 22 for receiving toner.

  The toner storage chamber 18a and the developing chamber 18b are partitioned by an opening 18c through which the toner passes, and the toner supplied to the toner storage chamber 18a is stirred by a stirring member 19 provided in the toner storage chamber 18a. It is conveyed to the developing chamber 18b.

  In the above configuration, the toner supplied from the toner inlet 22 is temporarily stored in the toner storage chamber 18a. However, the toner is directly conveyed from the toner inlet 22 to the developing chamber 18b. It is good also as a structure.

(Configuration of toner cartridge)
Next, a toner cartridge (developer supply container) that stores toner to be supplied to the developing unit 4 will be described.

  FIG. 3 is a cross-sectional view illustrating the configuration of the toner cartridge 15 and the apparatus main body 101 when the toner cartridge 15 is mounted on the apparatus main body 101 of the image forming apparatus 100. FIG. 4 is a perspective view showing the external appearance of the toner cartridge 15.

  The toner cartridge 15 has a toner containing bag 41 having elasticity for containing the toner 140. Further, the toner cartridge 15 includes a container body 40 that functions as a frame body that houses (contains) the toner storage bag 41 and supports other components in the toner cartridge 15.

  As the material of the container main body 40, it is preferable to adopt a material having such a rigidity that it does not collapse greatly with respect to changes in internal pressure. In the present embodiment, polystyrene resin is adopted as the material of the container body 40. In addition, regarding the material to be used, as long as the material can withstand pressure, for example, a resin such as ABS, polyester, polyethylene, or polypropylene may be used, or a metal may be used.

  Various materials can be used as the material of the toner containing bag 41. For example, various elastomers such as polyamide, polyurethane, polyamide elastomer, polyester elastomer, polyurethane elastomer, polystyrene elastomer, fluorine-based elastomer, silicone rubber, and latex rubber can be used. Furthermore, what combined 2 or more types of these etc. can also be used conveniently. In particular, in order to increase the toner discharging force by the toner containing bag 41, it is preferable to employ a material having a large elongation and a restoring force. In this embodiment, among the above substances, latex rubber is used as a suitable material for the toner containing bag 41 from the viewpoint of thinning and flexibility.

  The container body 40 is provided with a toner discharge path 42 (discharge section), an air communication path 43 and a mounting guide 48. The toner discharge path 42 is connected to the toner storage bag 41 (developer storage bag) inside the container main body 40, and the toner 140 in the toner storage bag 41 is discharged via the toner discharge path 42. The toner containing bag 41 is supported by the container body 40 by being connected to the toner discharge path 42.

  Next, the air communication passage 43 connects an airtight chamber 44 that is a space between the container main body 40 and the toner containing bag 41 and the outside of the container main body 40, and the airtight chamber 44 and the outside of the container main body 40 are connected to each other. Allow air in and out.

(Toner filling the toner cartridge)
Next, toner filling into the toner cartridge 15 will be described.

  First, the toner containing bag 41 is filled with air from the toner discharge path 42 together with a predetermined amount of toner 140 in a state where the thin film seal member 47 (negative pressure maintenance release means) is not attached. When the toner 140 and air are injected into the toner containing bag 41, the toner containing bag 41 swells inside the container main body 40, and the air present in the airtight chamber 44 passes through the air communication path 43 to the outside of the container main body 40. Is discharged.

  Thereafter, a thin film sealing member 47 for shielding the inflow and outflow of air from the air communication passage 43 is attached. Thereby, the inflow and outflow of air from the air communication passage 43 is shielded, and the negative pressure is maintained. For this reason, even in a state where the air is opened to the atmosphere via the toner discharge path 42, it is possible to prevent the toner 140 and air stored in the toner storage bag 41 from being discharged due to atmospheric pressure.

(Installation of toner cartridge)
Next, attachment of the toner cartridge 15 to the apparatus main body 101 of the image forming apparatus 100 will be described.

  FIG. 5 is a perspective view of the image forming apparatus 100 showing how the toner cartridge 15 is mounted.

  As shown in the figure, when an operator opens the front door 70 of the image forming apparatus 100, an insertion port 71 for mounting the toner cartridge 15 appears. The apparatus main body 101 of the image forming apparatus 100 includes a mounting rib 72, and a mounting guide 48 provided on the container main body 40 is inserted along the mounting rib 72 by sliding the toner cartridge 15.

Then, after the toner cartridge 15 is mounted on the apparatus main body 101, the thin film seal member 47 is peeled off to release the negative pressure, so that air is introduced from the air communication path 43 into the airtight chamber 44 and the airtight chamber 44 is brought to atmospheric pressure. Become. As a result, the toner containing bag 41 contracts, and the toner 140 and air inside the toner containing bag 41 are supplied to the apparatus main body 101 side (configuration on the apparatus main body side).
The apparatus main body 101 of the image forming apparatus 100 is provided with a toner discharge path connection portion 80 that connects to the toner discharge path 42 of the toner cartridge 15 when the toner cartridge 15 is inserted. Further, the toner storage chamber 18a
The toner inlet 22 for supplying the toner 140 from the toner cartridge 15 is provided.

  The toner introduction path 120 between the toner inflow port 22 and the toner discharge path connection portion 80 is provided with a toner discharge path opening / closing member 82 to control the air inflow / outflow of the toner introduction path 120. Is possible.

  The toner discharge path connecting portion 80 is provided with a receiving seal member 81 that engages with the toner discharge path 42 to prevent toner scattering when the toner is supplied. The toner discharge path 42 is connected to the receiving seal member 81. Inserted and engaged.

  Further, the apparatus main body 101 is provided with a pump 73 capable of transporting a constant amount of air per unit time. One end of an air injection path 83 is connected to the pump 73, and the other end of the air injection path 83 is connected between the toner discharge path connecting portion 80 and the toner discharge path opening / closing member 82.

  Then, it is possible to inject air from the toner discharge path 42 to the toner containing bag 41 via the air injection path 83. Further, after the toner cartridge 15 is mounted and the thin film seal member 47 is peeled off, the airtight chamber 44 can allow air to enter and exit from the outside, has no pressure difference from the outside, and does not have airtightness.

(Configuration of control unit that performs toner remaining amount detection)
Next, the configuration of the control unit (developer remaining amount detection means) that performs the remaining toner amount detection will be described.

  FIG. 6 is a block diagram illustrating a configuration of the control unit of the image forming apparatus 100.

  As shown in FIG. 1, the image forming apparatus 100 includes a CPU 300 that is a central processing unit, a pump 73, and a drive circuit 301 that drives the pump 73 based on a command from the CPU 300.

  The CPU 300 includes a timer 303 for measuring time and a toner remaining amount calculation unit 304 that calculates the remaining amount of toner.

  On the other hand, the drive circuit 301 drives the pump 73 by a signal from the CPU 300. Further, the drive circuit 301 is provided with a current measurement circuit 302 that measures a current for driving the pump 73. The current measurement circuit 302 measures the value of the current flowing through the pump 73.

  The current value measured by the current measurement circuit 302 is sequentially fed back to the CPU 300. The CPU 300 measures the time from the drive start instruction of the pump 73 to the drive stop instruction by a timer 303 mounted on the CPU 300.

(Toner remaining amount detection operation)
Next, the operation for detecting the remaining amount of toner in the toner cartridge 15 will be described.

Although the toner storage bag 41 can store air and toner 140, the remaining amount of the toner 140 is detected from a state in which the air in the toner storage bag 41 is naturally deaerated. The term “natural deaeration” as used herein refers to a state in which air is sufficiently removed to the extent that air does not flow out of the toner containing bag 41 even when the opening of the toner containing bag 41 is opened under atmospheric pressure. Say. In this embodiment, this state is the initial state. In the case of this embodiment, it was approximately 0.506 g / cm ³ .

  FIG. 7 is a view showing a state where the air in the toner containing bag 41 containing the toner 140 is naturally deaerated.

  As shown in the figure, the air in the toner storage bag 41 is released and only the toner 140 is stored.

  From the state shown in the figure, first, air is sent to the toner containing bag 41 by the pump 73. When the pump 73 continues to send air to the toner storage bag 41, the expanded toner storage bag 41 starts to hit the inner wall of the container body 40 of the toner cartridge 15.

  When the toner containing bag 41 hits the inner wall of the container main body 40 of the toner cartridge 15, the toner containing bag 41 can no longer expand, and the load on the pump 73 increases rapidly.

  Since the pump 73 is a pump capable of quantitative transport of air, when the load applied to the pump 73 increases, the pump 73 responds by an increase in driving torque, and the amount of current flowing through the pump 73 also increases.

Therefore, in the present embodiment, the driving torque is increased in the pump 73, when it becomes the predetermined current value I _a current value I flowing to the pump 73 (the driving current) stops the pump 73. In the present embodiment, by filling the air in the toner bag 41, the state of the toner bag 41 when the value of the current flowing through the pump 73 reaches a predetermined current value I _a, the predetermined state S1 Shall be called.

The broken line portion 41a shown in FIG. 7, the current value I flowing through the pump 73 indicates a toner bag 41 when a predetermined current value I _a.

  Here, since the pump 73 is capable of quantitative transport of air, the total amount of air fed into the toner containing bag 41 is (transport amount per unit time of the pump) × (pump operating time) or (pump's operation time). It can be calculated by (transportation amount per revolution) × (pump revolution).

Further, the total amount of air forced in to the toner bag 41, at the time of filling air to the toner bag 41, the current value I flowing through the pump 73 reaches a predetermined current value I _a, the toner bag 41 is the amount of air in the air. Furthermore, when the current value I flowing through the pump 73 reaches a predetermined current value _Ia , the volume of the toner containing bag 41 is such that some toner 140 is contained even when the toner containing bag 41 does not contain air. Even if you do it, it is constant.

Therefore, in a state where the current value I flowing through the pump 73 becomes a predetermined current value _Ia , the smaller the amount of air contained in the toner containing bag 41, the more the toner 140 contained in the toner containing bag 41 becomes. The amount increases.

Thus, the toner bag 41 without accommodating the toner 140, consider the volume of air when the current value I flowing through the pump 73 is filled with air to a predetermined current value I _a. From this volume, the difference obtained by subtracting the volume of air when filled with air until the current value I flowing in the toner containing bag 41 accommodating the toner 140 to the pump 73 becomes a predetermined current value I _a is, the toner storage This is considered to be the volume of the toner 140 contained in the bag 41.

Therefore, the volume of the toner 140 is obtained as follows. That is, the toner bag 41 without accommodating the toner 140, when filled with air until the current value I flowing through the pump 73 becomes a predetermined current value I _a, the total amount of air contained in the toner containing bag 41 (by volume ) Measure _VA .

Then, when the remaining amount detection of toner 140, the toner bag 41 to be detected the amount of residual toner 140, the air current value I flowing through the pump 73 is filled to a predetermined current value I _a total amount (by volume) Measure.

By calculating the difference between the measured volume of air and the volume _VA measured in advance, the remaining amount of the toner 140 stored in the toner storage bag 41 is calculated.

  Next, the flow of detection of the remaining amount of toner will be described using the flowchart shown in FIG.

  First, when the image forming apparatus 100 enters the pump drive mode, preparations for driving the pump 73 are completed. Then, the driving of the pump 73 is started in response to the driving start instruction of the CPU 300, whereby air is sent to the toner containing bag 41, and at the same time, the measurement of the pump driving time by the timer 303 is started as T0 = 0 (step S801).

  Here, the current flowing through the pump 73 is always measured by the current measuring circuit 302, and the measured current value is sent to the CPU 300.

CPU300 compares the current value I and the current value _{I a} that flows through the pump 73 (step S802 (state detection means)). Then, when the current value I is less than the current value I _a continue instructs to send a current to the pump 73, the timer counter counts up one by Tc is one step time of the drive circuit (step S803) . Then, when the current value I of the current flowing through the pump 73 becomes equal to or greater than the current value _Ia ( _a value in _a predetermined range), it is determined that the toner containing bag 41 is in the predetermined state S1. Then, an instruction to stop the pump 73 is sent to the drive circuit 301 (step S804), and the timer 303 is also stopped (step S805).

Then, the operating time T, which is the time from the start to stop of the pump measured by the timer 303, is obtained. Therefore, the total amount (volume) of air sent to the toner storage bag 41 by the pump 73 from the operating time T and the air flow rate V per unit time is obtained as V _a = V × T (step S806).

Further, the difference V _r = V _A −V _a from the air volume V _A when the empty toner containing bag 41 is inflated to the predetermined state S 1, which is known in advance, is calculated. The remaining amount of remaining toner 140 is obtained (step S807).

  That is, the developer remaining amount detecting means obtains the remaining amount of the toner 140 remaining in the toner containing bag 41 based on the operation time T that is drive information indicating the drive state of the pump 73.

(Other configuration examples)
In this embodiment, the remaining amount of toner 140 is calculated after calculating the volume of air. However, the remaining amount of toner 140 is calculated without calculating the volume of air using a data table as follows. It is also possible to do.

That is, until the current value I flowing through the pump 73 reaches a predetermined current value I _a, considered operating time and the rotational speed driving information of the total amount or the pump 73 of the air that is fed by the pump 73. The drive information is configured to have a data table in which the remaining amount (volume) of the toner 140 in the toner storage bag 41 is associated (associated).

  An arithmetic circuit for directly deriving the remaining amount of the toner 140 contained in the toner containing bag 41 from the data table is provided, whereby the remaining amount of the toner 140 can be obtained.

  That is, in this case, the remaining amount of the toner 140 remaining in the toner containing bag 41 is obtained by referring to the data table based on the operation time T that is the driving information of the pump 73 and the rotation speed of the pump 73. .

  In this embodiment, the toner containing bag 41 is provided inside the container main body 40, but the toner cartridge 15 may be configured without the container main body 40.

  FIG. 9 is a cross-sectional view showing the toner containing bag 41 and its periphery in the case of a configuration having no container body.

  As shown in the figure, the toner containing bag 41 can be directly attached to the toner inlet 22 of the apparatus main body 101 of the image forming apparatus 100 without having the container main body 40.

  In this case, even if the toner containing bag 41 is filled with air, it does not hit the inner wall of the container body 40, so that the driving torque of the pump 73 and the current flowing through the pump 73 are not increased by hitting the wall.

However, as the elastic limit of the toner containing bag 41 is approached, the driving torque of the pump 73 and the current flowing through the pump 73 rapidly increase. Therefore, when a current value I flowing through the pump 73 to stop the incoming feed air by the pump 73 when it becomes a predetermined current value I _a, the toner bag 41 is provided in the interior of the container body 40 As in the case, the remaining amount of the toner 140 in the toner containing bag 41 can be obtained.

  In this embodiment, the toner containing bag 41 is made of an elastic material. However, even if the toner containing bag 41 is made of a flexible sheet material having no elasticity, the remaining amount of toner can be detected.

  The sheet material is preferably a resin film having a thickness of about 50 to 300 μm. For example, a polyester film, a polyethylene film, or the like can be used.

  FIG. 10 is a cross-sectional view of the toner containing bag 41 and its periphery when the toner containing bag 41 is made of a sheet material having no elasticity.

  As shown in the figure, when the toner cartridge 15 does not have the container main body 40 and the toner containing bag 41 is directly attached to the toner inlet 22 of the apparatus main body 101, the material of the toner containing bag 41 is flexible and elastic. The sheet material does not have Then, the toner containing bag 41 is installed so that the toner discharge path 42 is on the lower side so that the toner 140 is discharged not by the elastic force of the toner containing bag 41 but by its own weight.

  In this case, even if the toner containing bag 41 is filled with air, the toner containing bag 41 does not hit the inner wall of the container main body 40. Therefore, the driving torque of the pump 73 and the current flowing through the pump 73 caused by the hitting the wall are not increased. Absent.

However, since the toner containing bag 41 of this embodiment is not an elastic body, when the volume of the toner containing bag 41 is filled with air, the driving torque of the pump 73 and the current flowing through the pump 73 are abruptly thereafter. To rise. Therefore, when a current value I flowing through the pump 73 to stop the incoming feed air by the pump 73 when it becomes a predetermined current value I _a, the toner bag 41 is provided in the interior of the container body 40 As in the case, the remaining amount of the toner 140 in the toner containing bag 41 can be obtained.

  Further, as a method of discharging the toner 140 from the toner cartridge 15, not only the weight of the toner 140 is relied on, but also air is fed into the toner storage bag 41 by the pump 73 and the reaction of feeding the air is used. The toner 140 may be discharged.

Second Embodiment
Next, another embodiment of the present invention will be described. Parts that are the same as or similar to those in the first embodiment are given the same reference numerals, and redundant descriptions are omitted.

  FIG. 11 is a cross-sectional view showing the configuration of the toner cartridge 15a of the present embodiment.

  The toner cartridge 15a differs from the toner cartridge 15 of the first embodiment in the following configuration.

(Configuration of toner cartridge)
In the toner cartridge 15a of this embodiment, an air communication path 43a is provided on the surface of the container body 40 on the side where the toner discharge path 42 is installed. A thin film seal member 47a is provided in the air communication passage 43a, and the airtight chamber 44 can be kept airtight.

  Further, before the toner cartridge 15a is attached to the apparatus main body, the discharge path sealing member 46 is provided at the outlet of the toner discharge path 42.

(Configuration of the main unit)
FIG. 12 is a cross-sectional view illustrating a state where the toner cartridge 15a of the present embodiment is mounted on the apparatus main body 101a.

  In the present embodiment, an air communication path connection portion 90 is provided in the apparatus main body 101a. When the toner cartridge 15a is attached to the apparatus main body 101a, the thin film seal member 47a is broken and air is introduced from the apparatus main body 101a into the airtight chamber 44 of the toner cartridge 15a.

  The thin film seal member 47a is broken after the toner discharge path 42 is connected to the toner discharge path connecting portion 80 and the toner 140 can be introduced.

  An air communication path opening / closing member 93 for controlling the inflow / outflow of air is provided in the connection path 130 communicating from the air communication path connection portion 90 to the apparatus main body 101a side.

  An air injection path 83a is provided between the air communication path connecting portion 90 and the air communication path opening / closing member 93, and the air injection path 83a is connected to the pump 73a. Unlike the first embodiment, the pump 73a may not be a pump capable of quantitative transport (mass) of air. The pump 73 a can send air into the airtight chamber 44 via the air injection path 83 a or can suck air from the airtight chamber 44.

  Then, the air communication passage opening / closing member 93 is closed to keep the airtight chamber 44 airtight, and the air is supplied to the airtight chamber 44 or the air is sucked from the airtight chamber 44 with the toner discharge passage opening / closing member 82 opened. As a result, the size of the toner containing bag 41 can be indirectly controlled.

  Further, a barometer 305 (barometric pressure detecting means) and a flow meter 306 (flow rate sensor) are provided between the pump 73a and the toner discharge path connecting portion 80. The barometer 305 can measure the atmospheric pressure in a space connected to the pump 73 such as the air injection path 83 and the airtight chamber 44. The flow meter 306 can detect the flow rate of air sucked from the hermetic chamber 44 by the pump 73.

(Configuration of control unit that performs toner remaining amount detection)
Next, the configuration of the control unit that performs toner remaining amount detection will be described.

  FIG. 13 is a block diagram illustrating a configuration of a control unit of the image forming apparatus 100.

  As shown in the figure, the image forming apparatus 100 of this embodiment includes a CPU 300 that is a central processing unit, a pump 73a, and a drive circuit 301 that drives the pump 73a based on a command from the CPU 300. Further, the image forming apparatus 100 includes a barometer 305 and a flow meter 306.

The CPU 300 includes a toner remaining amount calculation unit 304a that calculates the remaining amount of toner, and sequentially receives values measured by the barometer 305 and the flow meter 306,
(Toner remaining amount detection operation)
Next, an operation for detecting the remaining amount of toner in the toner cartridge 15a will be described.

  As in the first embodiment, the toner containing bag 41 is in the initial state when naturally deaerated.

  First, the air communication passage opening / closing member 93 is closed to keep the airtight chamber 44 secret, and the air in the airtight chamber 44 is sucked by the pump 73 in a state where the toner discharge passage opening / closing member 82 is opened.

  Since the toner containing bag 41 is naturally deaerated, the toner 140 is not discharged to the toner inflow port 22 even when the toner discharge path opening / closing member 82 is opened.

  In the present embodiment, since the airtight chamber 44 has an airtight configuration and the toner containing bag 41 is an elastic body and has a contraction force when inflated, the airtight chamber 44 can maintain a negative pressure state.

  In this embodiment, the volume of the container main body 40 is 250 cc, and the air pressure in the airtight chamber 44 when the toner containing bag 41 is inflated to 200 cc in the state containing the toner 140 and air in the container main body 40 with respect to the atmospheric pressure. It was a sufficiently small state of about −10 kPa. Therefore, even when the toner discharge path opening / closing member 82 is opened, the toner containing bag 41 is not contracted by the negative pressure, and the toner 140 is not discharged.

  When the air in the hermetic chamber 44 is sucked by the pump 73a, the amount of air in the hermetic chamber 44 decreases, and the toner containing bag 41 expands as air flows from the toner containing chamber 18a. The flow rate of air sucked from the hermetic chamber 44 by the pump 73a is sequentially detected by the flow meter 306, and the air pressure in the hermetic chamber 44 at that time is sequentially detected by the barometer 305.

  When the air in the airtight chamber 44 is continuously sucked by the pump 73a, the swelled toner containing bag 41 starts to hit the inner wall of the toner cartridge 15a. Furthermore, if the suction is continued, the air pressure in the hermetic chamber 44 drops rapidly. Here, if the air in the hermetic chamber 44 is further sucked by the pump 73, the inside of the hermetic chamber 44 is finally in a vacuum state, and the pump 73 cannot suck the air. In the present embodiment, suction is not performed until the inside of the hermetic chamber 44 is in a vacuum state, and when the value detected by the barometer 305 decreases and reaches a predetermined value, the suction of air by the pump 73a is stopped. .

  FIG. 14 shows the pressure in the airtight chamber 44 and the toner containing bag when the toner containing bag 41 that does not contain the toner 140 is indirectly filled with air by sucking the air in the airtight chamber 44 by the pump 73. It is a graph which shows the relationship between 41 and a volume.

In the figure, the vertical axis represents the air pressure in the airtight chamber 44, and the horizontal axis represents the amount of air sucked from the airtight chamber 44 by the pump 73a, which is substantially equal to the amount of air filled in the toner containing bag 41. Although a peak value P _a corresponding to the volume V _a of the toner bag 41 at the beginning bulge balloon, which is an inherent peak value in accordance with aspects of the balloon.

A volume _Vb shown in FIG. 14 is a point where the toner containing bag 41 starts to hit the inner wall of the airtight chamber 44. It can be seen from FIG. 14 that the pressure value suddenly drops after exceeding the volume _Vb of the toner containing bag 41.

For this reason, in this embodiment, it sets so that the pump 73a may be stopped when the pressure value P of the barometer 305 becomes the predetermined pressure value _Pc . In the present embodiment, the state of the toner containing bag 41 when the pressure value P of the barometer 305 becomes the predetermined pressure value _Pc is referred to as a predetermined state S2.

  Here, the amount (volume) of air sucked by the pump 73a between the initial state and the predetermined state S2 of the toner containing bag 41 is the case where the pump 73a is not capable of quantitative transport of air. The amount (volume) of air sucked from the hermetic chamber 44 per unit time is different. Further, the volume of the air changes depending on the atmospheric pressure.

For this reason, in this embodiment, the barometer 305 and the flow meter 306 always detect the air pressure in the hermetic chamber 44 and the flow rate per unit time, that is, the volume of air sucked per unit time. Then, using that value, the pressure value P of the barometer 305 is sequentially converted into the amount (volume) of air sucked per unit time under a predetermined state S2 where the pressure value P becomes a predetermined pressure value _Pc .

By sequentially storing and accumulating these values in the image forming apparatus 100, the total amount of air sucked from the airtight chamber 44 by the pump 73a can be obtained. That is, the volume V of air in the storage bag in the predetermined state S2 that is the amount (volume) of air filled in the toner storage bag 41 from the initial state to the predetermined state S2. _c can be obtained.

Therefore, as in the first embodiment, the toner containing bag 41 that does not contain the toner 140 is filled with air until the pressure value P of the barometer 305 reaches the predetermined pressure value _Pc . The air volume _Vc is measured in advance. When the remaining amount of toner 140 is detected, the volume V _c and the toner containing bag 41 for which the remaining amount of toner 140 is to be detected are filled with air until the pressure value P of the barometer 305 reaches a predetermined pressure value P _c . The difference from the air volume _Vcc in the toner containing bag 41 in the state is taken. Then, by accumulating the differences, the volume of the toner 140 stored in the toner storage bag 41 is calculated.

  Next, the operation of detecting the remaining amount of toner will be described in detail using the flowchart shown in FIG.

  First, when the image forming apparatus 100 enters the pump drive mode, preparations for driving the pump 73a are completed.

  By starting the driving of the pump 73a according to the driving start instruction of the CPU 300, air is sucked from the hermetic chamber 44 (step S1501). The flow rate V of air sucked by the pump 73a and the pressure value P of the airtight chamber 44 at that time are always sent from the flow meter 306 and the barometer 305 to the CPU 300.

Here, the pressure value P of the barometer 305 is compared with the predetermined pressure value _Pc (step S1502). When the pressure value P of the barometer 305 is larger than the predetermined pressure value _Pc , the received flow rate V of the flow meter 306 is calculated using the pressure value P measured by the barometer 305. That is, the total amount V _n = V _n−1 + (P / P _c ) × V of air sucked by the pump 73a from the start of driving to the present time is calculated, and the pump 73a continues to drive (step S1503).

On the other hand, when the pressure value P of the barometer 305 becomes equal to or less than the predetermined pressure value _Pc (predetermined range), the CPU 300 sends a stop signal to the drive circuit 301 and stops the pump 73a (step S1504). Then, the remaining toner amount calculation unit 304a calculates the remaining toner amount (step S1505).

To calculate the remaining amount of toner, first, the amount of air sucked by the pump 73a until the toner containing bag 41 reaches the predetermined state S2, that is, the amount of air filled in the toner containing bag 41, is calculated based on V _n accumulated in step S1503. The volume is _Vcc which is the total amount. Then, the difference between the volume V _c of air and the volume V _cc when the empty toner containing bag 41 is inflated to the predetermined state S2 is calculated. The calculated difference is a value indicating the remaining amount of toner 140 remaining in the toner containing bag 41.

  In the present embodiment, the volume of the toner 140 in the toner containing bag 41 is calculated by measuring the total amount of air sucked by the pump 73a from the initial state until the toner containing bag 41 reaches the predetermined state S2. . However, it can also be measured as follows.

  That is, first, the toner containing bag 41 is filled with air so that the toner containing bag 41 is in a predetermined state S2. Next, air is fed into the airtight chamber 44 by the pump 73a until the initial state is restored. At this time, using the total amount of air sent by the pump 73a, the remaining amount of the toner 140 in the toner containing bag 41 can be obtained in the same manner.

DESCRIPTION OF SYMBOLS 15, 15a ... Toner cartridge 18a ... Toner storage chamber 22 ... Toner inlet 40 ... Container main body 41 ... Toner storage bag 42 ... Toner discharge path 43, 43a ... Air communication path 44 ... Airtight chamber 45 ... One-way valve 46 ... Discharge path Sealing member 47, 47a ... Thin film sealing member 48 ... Mounting guide 70 ... Front door 71 ... Insertion port 72 ... Mounting rib 73, 73a ... Pump 80 ... Toner discharge path connection part 81 ... Receiving seal member 82 ... Toner discharge path opening / closing member DESCRIPTION OF SYMBOLS 83, 83a ... Air injection path 90 ... Air communication path connection part 91 ... Seal breaking member 92 ... Air seal member 93 ... Air communication path opening / closing member 100 ... Image forming apparatus 101, 101a ... Apparatus main body 120 ... Toner introduction path 130 ... Connection Path 140 ... Toner 300 ... CPU
DESCRIPTION OF SYMBOLS 301 ... Drive circuit 303 ... Timer 304, 304a ... Toner remaining amount calculation part 305 ... Barometer 306 ... Flow meter

Claims (13)

An image forming apparatus for forming an image on a recording medium,
A developer containing bag for containing the developer used for forming the image, made of a flexible material, and having a discharge portion for discharging the developer to the outside;
A pump for controlling the volume of the developer containing bag by introducing or sucking air;
A state detecting means for detecting a change in the state of the developer containing bag when the volume of the developer containing bag is controlled by the pump and filled with air;
Based on driving information indicating the driving state of the pump when the pump is filled with air until the state detecting means determines that the developer containing bag is in a predetermined state. An image forming apparatus comprising: a developer remaining amount detecting unit that detects a remaining amount of the developer stored in the developer storage bag.   The image forming apparatus according to claim 1, wherein the predetermined state is a state in which a value of a driving torque or a driving current of the pump is in a predetermined range. The state detection means includes atmospheric pressure detection means for measuring the atmospheric pressure of a space into which air is introduced or sucked by the pump,
The image forming apparatus according to claim 1, wherein the predetermined state is a state in which a value detected by the atmospheric pressure detection unit is in a predetermined range.   The drive information is any one of a total amount of air introduced or sucked by the pump, an operation time of the pump, and a rotation speed of the pump. The image forming apparatus described in the item. The pump is capable of transporting a certain amount of air per unit time,
The developer remaining amount detecting means is
The air transported by the pump by determining the value obtained by multiplying the transport amount per unit time of the pump by the operating time of the pump or the value obtained by multiplying the transport amount per unit number of the pump by the number of rotations of the pump. The total amount of
5. The image forming apparatus according to claim 1, wherein the remaining amount of the developer stored in the developer storage bag is detected using the total amount as the driving information. 6. The developer remaining amount detecting means comprises a flow rate sensor for measuring a flow rate of air introduced or sucked by the pump,
By integrating the flow rate measured by the flow sensor, the total amount of air introduced or sucked by the pump is obtained, and the remaining amount of developer stored in the developer storage bag is detected using the total amount as the drive information. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. The developer remaining amount detecting means is
The predetermined state in the developer containing bag when detecting the amount of air contained in the developer containing bag in the predetermined state and the remaining amount of the developer in the predetermined state without containing the developer The remaining amount of the developer accommodated in the developer accommodating bag is detected from a difference from the amount of air contained in the developer accommodating bag at the time when the air is filled up to the point. The image forming apparatus according to claim 5 or 6. The developer remaining amount detecting means is
The image forming apparatus according to claim 7, wherein the smaller the amount of air contained in the developer containing bag is detected, the more the amount of developer contained in the developer containing bag is detected. The developer remaining amount detecting means is
A data table associating the driving information of the pump with the remaining amount of the developer;
When the developer containing bag is filled with air by the pump until it is determined by the state detecting means that the developer containing bag is in a predetermined state, the remaining amount of developer is referred to by referring to the data table. The image forming apparatus according to claim 1, wherein the image forming apparatus is detected.   10. The image forming apparatus according to claim 1, further comprising a developer supply container including the developer containing bag. 11.   11. The pump according to any one of claims 1 to 10, wherein the pump is configured to send air into the developer containing bag so as to bring the developer containing bag into the predetermined state. The image forming apparatus according to one item. An airtight chamber which is a space between the developer supply container and the developer containing bag,
12. The image forming apparatus according to claim 10, wherein the pump is configured to suck air in the hermetic chamber. The developer containing bag is an elastic body,
The developer supply container is detachable from the apparatus main body of the image forming apparatus, and has negative pressure maintenance releasing means for maintaining and releasing the negative pressure state of the hermetic chamber,
Before the developer supply container is mounted on the apparatus main body, the negative pressure in the hermetic chamber is maintained by the negative pressure maintenance release means so that the developer stored in the developer storage bag is externally attached. And the developer supply container is accommodated in the developer containing bag by releasing the negative pressure in the airtight chamber by the negative pressure maintenance releasing means after the developer supply container is mounted on the apparatus main body. The image forming apparatus according to claim 12, wherein the developer is supplied to the apparatus main body.

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