JP4475038B2 - Method for detecting fullness of used developer collection container and image forming apparatus using the same - Google Patents

Description

  The present invention relates to an image forming apparatus that forms a recorded image using a developer containing toner, such as an electrophotographic copying machine or a laser beam printer, and more particularly to an image forming apparatus that includes a plurality of image forming engines that form toner images. The present invention relates to a method for accurately detecting the fullness of a collection container containing a used developer that has deteriorated due to use over time.

JP-A-11-65393 JP 62-94883 A JP-A-6-266179

  In an image forming apparatus such as a copying machine, a multifunction machine, or a laser beam printer using an electrophotographic method, an electrostatic latent image corresponding to image information is formed on an image carrier such as a photosensitive member, and then the electrostatic latent image is formed. The toner image is developed with toner, and the visualized toner image is transferred to a recording sheet to form a recorded image. As a method for developing an electrostatic latent image with toner, a two-component development method using a developer in which a non-magnetic toner and a magnetic carrier are mixed is known. In this method, it is not necessary to include magnetic powder in the toner. For this reason, the color toner has excellent color developability and is mainly used in color laser beam printers, color multifunction peripherals and the like.

  In this two-component development method, a developer composed of toner and carrier is stirred in a developing device, and the electrostatic latent image is developed using the frictionally charged toner, and only the toner is consumed by forming the recorded image. . For this reason, the carrier remains in the developing unit and is continuously used by being agitated with newly supplied toner. However, since the carrier deteriorates over time, the carrier is not periodically replaced. There is a problem that a high-quality recorded image cannot be formed stably.

  For this reason, in recent years, a new carrier is added to the developing unit little by little at the same time as replenishing toner to the developing unit, while the deteriorated developer (toner and carrier) in the developing unit overflows corresponding to the replenishing amount. A so-called trickle development method in which this is accommodated in a collection container has been frequently used. Normally, the developer in the developing device is a mixture of toner and carrier in a certain ratio, but in this trickle development method, the amount of toner is larger than the mixing ratio in the developing device, so-called toner-rich developer. Is filled in a replenishing container, and a toner-rich developer (including a carrier) is supplied to the developing device in accordance with the consumption of toner in the developing device. For this reason, when the recording image is repeatedly formed, that is, when the electrostatic latent image is repeatedly developed by the developing unit, the carrier in the developing unit is gradually replaced with a new one as the developing unit replenishes the toner. Spent developer is accumulated in the collection container. Therefore, even when the developing device is used over time, the deterioration of the carrier does not proceed extremely, and the development quality of the recorded image can be stabilized.

  On the other hand, in this trickle development method, it is necessary to replace the collection container when the collection container is full of used developer. In order to replace the collection container in a timely manner, such a collection container is used. It is necessary to detect that the developer is full and notify the user. Conventionally, as a method related to the detection of the fullness of the recovery container, detection means such as a piezoelectric sensor and an optical sensor are provided corresponding to the fullness level in the recovery container, and it is determined whether or not the output from the detection means is full. (Japanese Patent Laid-Open No. 11-65393, Japanese Patent Laid-Open No. 62-94883, etc.).

  However, in the method in which the detection means is provided in the collection container, the detection means is full even though it is not yet full due to variations in detection accuracy in the detection means, uneven developer distribution in the collection container, and the like. It is easy to cause erroneous detection, and the detection unit such as an optical sensor is provided, so that the structure of the recovery container itself is complicated and the cost of the recovery container, which is a consumable item, is increased.

  Another method for detecting the fullness of the collection container is not to use the direct detection means as described above, but to detect the fullness by predicting the accumulation amount in the collection container based on the toner consumption. It has been known. Specifically, the number of times of output of a replenishment request signal to the developer replenishment container is counted, and it is determined that the collection container is full when the request signal reaches a predetermined number (Japanese Patent Laid-Open No. 3-13971). )It has been known. Further, since the developer replenishment request to the developing device is issued based on the toner consumption, the toner consumption amount is calculated from the image information, and the accumulated amount of the used developer in the collection container is predicted based on the calculated toner consumption amount. A thing (JP-A-6-266179) is also proposed.

  However, in reality, there is a variation in the amount of developer supplied from the supply container to the developing device in a single replenishing operation. There is a gap between the amount of spent developer and the amount of spent developer actually deposited in the collection container, and there is a concern that the fullness of the collection container cannot be accurately detected. In particular, in an image forming apparatus equipped with a multi-color image forming engine such as a color copying machine or a color printer, the flowability of the developer is slightly different for each color. The amount of developer supplied to the image forming device is slightly different between the image forming engines. From this, it is determined that the collection container is full even though it is not yet full, prompting the user to replace the collection container wastefully, or conversely notifying the user that the collection container is full. This delays the use of the developer, and the used developer overflows from the collection container.

  The present invention has been made in view of such problems, and the object of the present invention is to provide a recovery container filled with used developer without providing a detection means such as an optical sensor in the recovery container. It is an object of the present invention to provide a recovery container fullness detection method that can accurately detect this and that can be implemented at low cost and can contribute to downsizing of an image forming apparatus.

  That is, according to the present invention, a plurality of image forming engines that form toner images according to image information, a plurality of replenishing containers that supply replenishment developer to each image forming engine, and these replenishing containers are interchangeably mounted. And a developer supply means for repeatedly supplying a predetermined amount of developer from each supply container to the corresponding image forming means, and a collection container for storing the used developer discharged from each image forming means. A detection method applied to the provided image forming apparatus for determining whether or not the collection container is full, counting the total number of replacement containers, and when the count value reaches a predetermined value, The number of developer replenishment operations using a replenishment container other than the replenishment container involved in the replacement is totaled, and when the total value reaches a predetermined value, it is determined that the collection container is full.

  Usually, a replenishment container for replenishing developer to the developing device is filled with a predetermined amount of developer. Further, when the used developer is discharged from the image forming means to the collection container, the ratio between the deteriorated carrier and the toner adhering thereto is substantially constant. Therefore, if the amount of developer replenished from the replenishing container to the image forming means can be grasped to some extent accurately, it is possible to accurately grasp the amount of used developer discharged from the image forming means to the collection container. is there. On the other hand, when the developer in the supply container is exhausted, it is necessary to replace it with a new supply container. For this reason, the image forming apparatus has a sensor for detecting whether or not the developer in the supply container has been consumed. It is usual to have. For this reason, the fact that the developer for one supply container has been added to the developing device can be easily grasped.

  From this point of view, in the present invention, the total number of replacement containers in each image forming means is counted, and it is determined whether or not the count value has reached a predetermined value. The number of replenishment operations in the remaining replenishing containers other than those that have been performed is totaled to ascertain the availability of the collection containers. After grasping the empty state of the collection container, the number of developer replenishment operations in each image forming unit thereafter is summed, and the collection is checked by checking whether or not the total value has reached a predetermined value. It is determined whether or not the container is full. As described above, when the developer for one supply container is supplied to the image forming means, the amount of the used developer discharged from the image forming means to the recovery container is stable. According to the full detection method, the accumulated amount can be accurately grasped by counting the number of replacement of the replenishing containers until the accumulated amount in the collection container approaches to full. If the number of replacement supply containers reaches a predetermined value, the amount of used developer that can be discharged to the collection container after that is small, and only this small amount can be estimated from the number of developer supply operations. Therefore, even if the actual developer replenishment amount from the custom replenishment container to the image forming means varies, the fullness of the collection container can be detected to some extent accurately.

Hereinafter, the powder container of the present invention will be described in detail with reference to the accompanying drawings.
1 to 5 show an example of a full color laser beam printer to which the present invention is applied. 1 is an external perspective view showing the entire color printer 1 (in a state where the open / close cover is closed), FIG. 2 is an external perspective view showing a state in which the open / close cover is opened, and FIG. 3 is a line of FIG. 4 is a schematic sectional view showing a state in which the opening / closing cover is opened, and FIG. 5 is a schematic sectional view showing a state in which the opening / closing cover is opened and the image carrier unit is attached / detached.

  This color printer 1 is a so-called tandem in which an image forming engine for exclusively forming toner images composed of four colors of yellow (Y), magenta (M), cyan (C) and black (K) is arranged in series. In addition to a single color (mainly black) image, a color (multicolor) image obtained by appropriately combining the four color toner images can be printed.

  As shown in FIG. 3 and the like, the printer 1 includes an image carrier unit 2, an exposure unit 3, a developing unit 4, a final transfer unit 5, and an image forming engine. The paper feeding unit 6, the fixing unit 7 and the like are arranged. Of these, the housing 10 is a three-dimensional structure assembled into a predetermined shape and structure using components such as the support frame 11 and the exterior panel 12. In this case 10, as shown in FIGS. 1 and 2, a user or the like of the printer 1 faces a side surface of a substantially box-shaped external shape constituted by an exterior panel 12 to perform a predetermined operation or the like. It is formed as an operation surface portion 10A for performing, and a part of the upper surface portion is formed as a paper discharge portion 10B having an inclined surface for storing the recording paper P discharged after printing.

  Further, in this printer 1, as shown in FIGS. 2, 4, and 5, a portion (front cover) of the casing 10 that becomes the operation surface portion 10A swings around a support shaft 13A on the lower side. The upper surface portion (top cover) 10C, which is a part of the paper discharge portion 10B, swings around the support shaft 13B on one end side and opens and closes. Yes. The operation surface portion 10A is configured such that the final transfer unit 5 and the fixing unit 6 are attached, and are oscillated and displaced integrally when the operation surface portion A is opened and closed. By adopting such an opening / closing structure, predetermined components (for example, the image carrier unit 2 and the developing unit 4) arranged in the internal space of the housing 10 are exposed, and a necessary work ( Maintenance work, jam removal work, etc.). Further, in the printer 1, in order to handle the image carrier unit 2 in a replaceable manner, the image carrier unit 2 is attached to the housing 10 so as to be detachable as shown in FIG.

  Among the above units, the image carrier unit 2 is integrally attached with an image carrier such as a photoconductor and an intermediate transfer member that can carry the toner images of the four colors mainly related to the image forming process. This is a process cartridge that requires replacement depending on the stage when the life of the image carrier has come. As shown in FIG. 3 and FIG. 6 and the like, this image carrier unit 2 has four colors (Y, M, C, K) on a unit frame 20 having an internal space in which the longitudinal sectional shape is substantially trapezoidal. Four photosensitive drums 21Y, 21M, 21C, and 21K on which toner images are formed exclusively, and charging rolls that charge peripheral surfaces of the respective photosensitive drums 21 (Y, M, C, and K) to a predetermined background portion potential. 22, a temporary toner holding brush roll 23 that temporarily holds toner and the like remaining on the peripheral surface of each photosensitive drum 21, and each toner image on the four photosensitive drums 21 is transferred and carried 2. Two first intermediate transfer drums 25, 26, one second intermediate transfer drum 27 that transfers and carries the toner image on the two first transfer drums 25, 26, and each of the intermediate transfer drums 25, 26, Residual on each circumference of 27 Both the toner temporary holding brush roll 28 for holding Chakusuru toner or the like, respectively temporarily in which rotatably mounted.

  The first intermediate transfer drums 25 and 26 have a drum surface potential set to a predetermined potential (for example, about +250 to 500 V) in order to electrostatically transfer the toner images on the photosensitive drums 21 to both transfer drums. The first transfer bias for maintaining the voltage is applied from a bias power source (not shown). The second intermediate transfer drum 27 is electrostatically secondary-transferred with the toner images on the first intermediate transfer drums 25 and 26 to the drum. A second transfer bias for holding at about 1200 V is applied from a bias power supply (not shown).

  Further, as shown in FIG. 5, the image carrier unit 2 is provided with a tilt-accommodating handle 29 on the upper surface portion 20C of the unit frame 20. The handle 29 is raised and held in the hand. Thus, the image carrier unit 2 is attached and detached. As a result, the image carrier unit 2 can be removed from the housing 10 by pulling it up in a substantially vertical direction with the opening / closing cover 10C on the upper surface side of the housing 10 opened as shown in FIG. It can be mounted by being lowered in the vertical direction and housed in a mounting site by the housing 10.

  The exposure unit 3 is for writing an electrostatic latent image by exposing each photosensitive drum 21 of the image carrier unit 2, and as shown in FIG. The carrier unit 2 is installed in a fixed state on the housing 10 on the photosensitive drum arrangement side. As shown in FIG. 3 and the like, the exposure unit 3 includes a light source such as a semiconductor laser (not shown) and a beam light Bm emitted from the light source based on image information in an internal space of a box-shaped unit housing. The optical system components such as a polygon mirror, a reflecting mirror, various lenses, etc. for guiding and scanning on the photosensitive drum 11 to be exposed are appropriately arranged. Further, the exposure unit 3 receives an image signal obtained by subjecting (color) image information input to the printer 1 to predetermined image processing by an image processing unit (not shown).

  Such an exposure unit 3 scans and exposes the light beam Bm (see FIG. 3) onto each photosensitive drum 21 through the exposure gap S (see FIG. 5) of the developing unit 4, thereby each of the photosensitive drums 21. An electrostatic latent image having a predetermined potential is formed on each of the two.

  The developing unit 4 is for developing the electrostatic latent image formed by the exposure from the exposure unit 3 on each photosensitive drum 21 of the image carrying unit 2 with a developer. As shown in FIG. It is installed between the unit 2 and the exposure unit 3. As shown in FIG. 6, the developing unit 4 includes the four colors (Y, M, C, K) in the space of a frame-type unit frame (subframe) 40 in which a rectangular space is formed. The four developing devices 41Y, 41M, 41C, and 41K for developing with the developer (1) are attached in a positional relationship in which they are arranged at intervals in the vertical direction so as to face the photosensitive drums 21. Configured. A penetrating optical path space S for passing the beam light Bm exposed from the exposure unit 3 toward the photosensitive drum 21 of the image carrier unit 2 is secured (formed) on the upper side of each developing device 40.

  Each of the developing devices 41 (Y, M, C, K) is a two-component developing device that performs so-called magnetic brush development using a two-component developer containing (nonmagnetic) toner and (magnetic) carrier. As shown in FIG. 6, the developing device 41 includes a developing roll 42 that rotates in opposition to the photosensitive drum 21 while keeping a predetermined minute distance in the housing, and a two-component developer on the developing roll 42. A paddle 43 that rotates to be supplied, two augers 44 and 45 that rotate so as to circulate and convey the two-component developer accommodated in the developing device to the paddle 42 side, and a developing roll 42 And a layer thickness regulating member 46 that regulates the two-component developer to be a constant layer thickness. Further, a developing bias voltage in which a DC component is superimposed on an AC component is applied to the developing roll 42 from a developing bias power source (not shown).

  In such a developing unit 4, when the two-component developer is agitated and conveyed by the augers 44 and 45 in each developing device 41 and is supplied to the developing roll 42 via the paddle 43, the layer thickness is increased on the developing roll 42. A magnetic brush regulated to a certain layer thickness is formed by passing the regulating member 46, and then the two-component developer composed of the magnetic brush is rubbed against the surface of the photosensitive drum 21 with a developing bias applied. Let it pass. As a result, the toner in the magnetic brush is electrostatically attached only to the electrostatic latent image portion (image portion) of the photosensitive drum 21, thereby forming a toner image.

  The final transfer unit 5 is used for finally transferring the toner image transferred and formed on the second intermediate transfer drum 27 in the image carrier unit 2 onto the recording paper P. The final transfer unit 5 is attached to the casing 10 serving as the operation surface portion 10A. is set up. The final transfer unit 5 is mainly configured by rotatably mounting a final transfer roll 51 that forms a transfer nip portion in contact with the second intermediate transfer drum 27 on the unit frame. A second transfer bias for electrostatically transferring the toner image on the second intermediate transfer drum 27 to the recording paper P is applied to the final transfer roll 51 from a bias power source (not shown). The final transfer roll 51 is provided with a cleaning device such as a cleaning blade.

  The paper feed unit 6 contains a recording paper P and a paper feed tray 60 that stacks and stores a plurality of recording papers P, and a pickup roll 62a that feeds the recording paper P stacked on the paper feed tray 61 one by one. The feed mechanism 62 is mainly composed of a separating roll 62b. The recording paper P delivered from the paper supply unit 6 passes through the paper supply path 67 including the paper conveyance roll pairs 65a and 66b, the registration roll pair 66, the paper conveyance guide, and the like, and the final intermediate transfer roll 27 and the final transfer roll 27 of the image carrier unit 2. It is conveyed and supplied at a predetermined timing between the final transfer roll 51 of the transfer unit 5.

  The fixing unit 7 mainly includes a unit frame, a heating roll 71 in which a heating lamp is built in the roll space, a pressure roll 72 that rotates in pressure contact with the heating roll 71, and a paper discharge roll 73. ing. In FIG. 4, reference numeral 75 is a paper discharge port for discharging the fixed recording paper P to the paper discharge unit 10B, 76 is for discharging the fixed recording paper P to the paper discharge unit 10B, and 77 is This is a reverse retransmission path at the time of double-sided printing formed by a pair of paper transporting rolls 65c, a paper transporting guide, or the like so as to branch from the paper discharge path and merge with the paper feed path 67 again.

  In this color printer 1, as shown in FIG. 6, a two-component developing device adopting a trickle developing method is used as the four developing devices 41 (Y, M, C, K) in the developing unit 4. A single two-component developer (used developer) 15 that is discharged so as to overflow from each developing device 41 by adopting the trickle developing method is attached to the lower (bottom) side of the image carrier unit 2. The developer is collected in a developer collecting container 8. The used developer 15 discharged from each developing device 41 is conveyed by a tubular developer conveying passage 9 that connects between each developing device 41 and the developer collection container 8.

  First, because of the relationship of adopting the trickle development method, the developing device 41 is replenished with not only toner but also a two-component developer including a carrier. This replenishment is performed by transporting such a two-component developer from a supply container (cartridge type bottle) (not shown) to a predetermined location in the developing device 41 through a developer dispenser. On the other hand, a developer discharge port 49 is formed at one end portion of the developing device 4 so as to allow a part (surplus) of the two-component developer circulated and conveyed by the augers 44 and 45 to overflow. .

  The collection container 8 includes a box body 80 formed in a rectangular shape with an upper surface opened so as to be approximately equal to the size of the bottom surface of the image carrier unit 2. However, the open upper surface is removably attached to the bottom surface of the unit frame 20 of the image carrier unit 2 and integrated.

  As shown in FIG. 7, the box body 80 is formed with a joint port 81 with the developer transport passage 9 on the side wall surface on one end side in the longitudinal direction. An open / close lid 82 is provided that swings around and opens and closes. The opening / closing lid 82 is biased in a direction to close the joint 81 by a helical spring. Further, in the developer accommodating space of the box main body 80, a developer agitating and leveling member 84 in a form in which a wire is spirally wound along the longitudinal direction thereof is provided to rotate. Reference numeral 85 in the figure is a drive gear for rotating the developer agitating and leveling member 84 by receiving the rotational power of the drive system of the developing device 41, for example.

  The developer transport passage 9 includes a collecting cylinder portion 91 for collecting the used developer overflowing from the developer discharge port 49 of each developing device 41 by naturally dropping it, and two components collected by the collecting cylinder portion 91. It is mainly composed of a conveyance cylinder portion 92 that conveys the developer to the collection container 8.

  The collecting cylinder 91 is a hollow that is continuously arranged at the rear of the four developing devices 41 (Y, M, C, K) (the end opposite to the end where the developing roll 42 is installed). A connecting portion 94 having a developer receiving port 93 that is in close contact with the rear portion of each developing device 41 and is connected to the developer discharging port 49 from an obliquely lower side is formed on the cylindrical body of the structure. The inside of the collecting cylinder portion 91 is a linear cavity 95 in which the collected developer naturally falls. On the other hand, the transport cylinder 92 is collected by the collection cylinder 91 and dropped into the internal space of the cylindrical cylinder body connected so that one end communicates with the lower end of the collection cylinder 91. A rotary conveying member (for example, auger) 96 for conveying the component developer toward the collection container 8 is provided so as to rotate. Further, the transfer cylinder 92 is inserted into the joint 81 of the box body 80 of the collection container 8 at the tip end 92a, and the opening / closing lid 82 that is closed at the time of insertion can be expanded (pushed up). It is formed in a dimension and shape that allows it.

  The developer transport passage 9 is attached in a state of being fixed to the unit frame 40 of the developing unit 4. Specifically, as shown in FIG. 6, while the collection cylinder 91 of the developer conveyance path 9 is connected to the rear part of each developing device 41 attached to the unit frame 40, the conveyance cylinder 92 Is attached so that the tip end 92a protrudes to the side facing the collection container 8 through the lower part of the lowermost developing device 41K.

  Further, since the developer transport passage 9 is attached so that the collection container 8 is integrated with the image carrier unit 2, the tip end portion 92 a of the transport cylinder 92 is replaced with the collection container 8 when the image carrier unit 2 is replaced. Thus, the image carrier unit 2 and the collection container 8 are not hindered from being attached or detached.

FIG. 8 is a block diagram showing a configuration for detecting the fullness of the collection container.
Each of the developing devices 41Y, 41M, 41C, and 41K is connected to a developer dispenser 101Y, 101M, 101C, and 101K via a supply tube 105, and is attached to each developer dispenser 101Y, 101M, 101C, and 101K. The developer is supplied from the replenishing containers 100Y, 100M, 100C, and 100K to the corresponding developing devices 41Y, 41M, 41C, and 41K. The replenishing containers 100Y, 100M, 100C, and 100K are configured as cartridges that are detachable from the developer dispensers 101Y, 101M, 101C, and 101K, and the replenishing containers 100Y, 100M, 100C, and 100K are replaced with the developer dispensers 101Y, In the state of being mounted on 101M, 101C, 101K, the developer filled in the supply containers 100Y, 100M, 100C, 100K is dropped into the developer dispensers 101Y, 101M, 101C, 101K, and this developer dispenser 101Y. , 101M, 101C, 101K and a helical conveying means such as an auger provided in the replenishment tube 105, and are conveyed to the corresponding developing devices 41Y, 41M, 41C, 41K connected by the replenishment tube 105. ing.

  The developer dispensers 101Y, 101M, 101C, and 101K are accumulated in the developer dispensers 101Y, 101M, 101C, and 101K and accumulated in the developer dispensers 101Y, 101M, 101C, and 101K. A sensor (not shown) for grasping the above is provided. When the developer in the replenishing containers 100Y, 100M, 100C, and 100K becomes empty and the developer accumulation level in the developer dispensers 101Y, 101M, 101C, and 101K decreases, the output signal of the sensor changes. As a result, it is understood that the developer in the replenishing containers 100Y, 100M, 100C, and 100K has been emptied, and the user can be prompted to replace the replenishing containers 100Y, 100M, 100C, and 100K. Yes.

  The developer dispensers 101Y, 101M, 101C, and 101K are provided with a dispense motor (not shown). By driving the dispense motor in response to a replenishment request signal, the replenishing containers 100Y, 100M, 100C, and 100K The dropped developers dY, dM, dC, and dK are supplied to the developing devices 41Y, 41M, 41C, and 41K through a supply tube. The dispense motor is not driven continuously, but is intermittently driven for a predetermined time, and is driven for a predetermined time even when the amount of developer to be supplied to the developing devices 41Y, 41M, 41C, 41K is large. Is stopped, and this is repeated to supply a required amount of developer to the developing devices 41Y, 41M, 41C, and 41K. Each of the developer dispensers 101Y, 101M, 101C, and 101K is provided with a supply amount counter 102Y, 102M, 102C, and 102K that counts the number of times the dispense motor is driven, and the supply amount counters 102Y, 102M, 102C, and 102K are provided. By checking the counted value, the developer dispensers 101Y, 101M, 101C, and 101K can grasp the amount of developer supplied to the developing devices 41Y, 41M, 41C, and 41K. In this supply amount counter, when the supply containers attached to the developer dispensers 101Y, 101M, 101C, and 101K are replaced, in principle, the count value is reset, and the dispense motor is driven with respect to the newly installed supply containers. It is configured to count up the number of times.

  Each of the developer dispensers 101Y, 101M, 101C, and 101K is also provided with a container detection sensor (not shown) that detects the attachment / detachment of the supply containers 100Y, 100M, 100C, and 100K. By checking this change, it is possible to grasp whether or not the replacement containers 100Y, 100M, 100C, and 100K have been replaced. When it is determined that the replacement containers 100Y, 100M, 100C, and 100K have been replaced, the count value of the replacement number counter 103 is incremented by one, and the replacement number of the supply containers 100Y, 100M, 100C, and 100K is cumulatively counted. It can be counted. This exchange number counter 103 is provided in common for the image forming engines of the respective colors. For example, even if the yellow supply container 100Y is replaced or the magenta supply container 100M is replaced, the count value is incremented by one. It is going to go up. Further, the count value of the replacement number counter 103 is reset when the collection container 8 of the used developer 15 is replaced, and the new collection container 8 is counted again.

  In the present invention, it is determined from the count values of the replacement number counter 103 and the supply amount counters 102Y, 102M, 102C, and 102K whether or not the collection container 8 is filled with the used developer 15. The full detection means 104 in the figure is configured as a part of a computer system that constitutes the control unit of the full-color laser beam printer, and outputs signals from the supply amount counters 102Y, 102M, 102C, and 102K and from the exchange number counter 103. And determines whether or not the collection container 8 is full according to the procedure described later.

FIG. 9 is a flowchart showing a processing procedure of the full detection means for detecting whether or not the collection container is full.
This process is initiated when the developer dispenser is driven for any imaging engine. First, referring to the count value of the replacement number counter 103, with respect to the collection container 8 attached to the image carrier unit 2, whether or not the total replacement number of the supply containers 100Y, 100M, 100C, and 100K has reached a predetermined number m. Is checked (ST1). When all of the developer filled in one supply container is supplied to the developing device, the amount of the used developer 15 discharged from the developing device to the collection container 8 is stable. By checking the total number of replacement containers 100Y, 100M, 100C, and 100K with respect to the collection container 8 attached to the image carrier unit 2, the level of the used developer 15 accumulated in the collection container 8 is increased. It can be grasped almost accurately.

  If it is determined that the total number of replacement containers has reached a predetermined number m or more, the number of times that the developer dispensers 101Y, 101M, 101C, and 101K can be driven with the recovery container 8 being supplied, that is, supply The possible number of times is calculated (ST2). Further, when the total number of replacement containers 100Y, 100M, 100C, and 100K has not reached the predetermined number m, it can be determined that the developer 15 accumulated in the collection container 8 is small. The process of detecting fullness of is terminated.

  FIG. 10 shows a flow chart for calculating the replenishable number of times. In order to calculate the number of replenishable times, first, the count values of all supply amount counters 102Y, 102M, 102C, and 102K are read (ST21), and the developers dY and dM are read from the developer dispensers 101Y, 101M, 101C, and 101K. , DC, dK is summed (total number of times of replenishment) (ST22). At this time, if the replacement number of the replenishing containers has just reached the predetermined number m, the count value of the supply counter of the developer dispenser whose replenishing containers have been replaced has been reset. When the sum of the count values is calculated, as a result, the sum of the number of times of replenishment of the developer dispenser whose replacement container has not been replaced is calculated. For example, if the count value of the replacement number counter 103 reaches a predetermined number m by replacing the black supply container 100K, the black supply amount counter 102K has been reset, so that yellow, magenta, and cyan The sum of the count values of the supply amount counters 102Y, 102M, and 102C is calculated.

  Further, if the replenishment operation has been performed after the replacement number of the replenishment containers reaches the predetermined number m, the number of replenishment times of the developer dispenser including the number of times of supplying the developer from the replenishment container after the replacement is included. The sum is calculated. For example, if the black developer dispenser 101K performs a replenishment operation after replacing the black replenishment container 100K, the black supply amount counter 102K counts the number of replenishment operations after the replenishment container 100K is replaced. Therefore, the sum of the count values of the supply amount counters 102Y, 102M, 102C and 102K for all colors including that is calculated. That is, in this ST22, it is grasped how much of the used developer discharged to the collection container is discharged in addition to the amount of m supply containers.

  When the total number of replenishments has been calculated, the difference between the predetermined upper limit replenishment number and the total number of replenishments is obtained, and the replenishable number of times indicating how many replenishment operations can be performed before the collection container 8 is full is calculated ( ST23). That is, the upper limit replenishment count is obtained by converting an amount obtained by subtracting the amount of used developer corresponding to m replenishment containers from the amount stored in the collection container 8 to the replenishment count of the developer dispensers 101Y, 101M, 101C, and 101K. The value obtained by subtracting the total number of times of replenishment from the upper limit number of times of replenishment corresponds to the empty capacity of the collection container 8 at that time converted into the number of times of replenishment of the developer dispenser 101.

  When the flow for calculating the number of replenishable times in ST2 in FIG. 9 is completed in this way, it is checked whether or not the number of replenishable times is 0 (ST3). If it is determined in ST3 that the number of replenishable times is 0, the collection container 8 is considered to be full of the used developer 15, and the collection container 8 is provided to the user through a user interface such as a liquid crystal display panel. (ST4). Thereby, the full detection process of the collection container 8 is complete | finished.

  When the collection container 8 is replaced, the count values of all the supply amount counters 102Y, 102M, 102C, and 102K are reset regardless of whether or not the supply container is replaced. Thereby, the discharge amount of the used developer 15 with respect to the new collection container 8 is newly grasped again.

  As described above, in the present invention, paying attention to the stability of the discharged amount of the used developer generated when the developer for one supply container is supplied to the developing device, first, the replacement number of the supply container is counted, After the replacement number of supply containers reaches a predetermined value, the amount of developer supplied to the developing device other than the replacement number is grasped by referring to the number of developer supply operations. As a result, it is more accurate whether or not the collection container is full of used developer compared to the method of predicting the discharged amount of used developer by referring to the number of developer replenishment operations from the beginning of use of the collection container. It can be judged well.

  However, when attention is paid to the total number of replacement containers 100Y, 100M, 100C, and 100K, for example, when there is an error in the amount of developer filled in the supply container, or before the supply container is empty. If the medium is replaced in the middle, the amount of the used developer 15 discharged into the collection container 8 cannot be accurately grasped.

  Further, even when the toner amount corresponding to the same number of recording sheets with the same image area ratio is filled in the supply containers 100Y, 100M, 100C, and 100K for the four colors, the toner filling amount and the carrier filling amount. The ratio of the developer is slightly different for each color, and due to the difference in developer fluidity, even if the developer dispenser is operated for a predetermined time, the amount of developer supplied to the developer in one replenishment operation Will be different for each color.

  Therefore, when the total number of replacement containers 100Y, 100M, 100C, and 100K is counted by the replacement counter 103, it is preferable to perform a correction process as shown in FIG. This process is performed when one of the supply containers 100Y, 100M, 100C, and 100K attached to the developer dispensers 101Y, 101M, 101C, and 101K is replaced, and first corresponds to the replaced supply container. The count value of the supply amount counter is read before being reset, and the ratio between the read count value and the life predicted value in the supply container before replacement is obtained (ST50). This life prediction value is the standard number of replenishment operations that can be performed before the refill container is emptied based on the amount of developer that is normally filled in the replaced refill container. Regardless of the toner color being used, it is determined purely by the amount of developer filled at the time of supply of the supply container. On the other hand, if the collection container 8 for the used developer 15 is replaced or the supply containers 100Y, 100M, 100C, and 100K are replaced, the supply amount counters 102Y, 102M, 102C, and 102K are reset. The count value of the supply amount counter read at the time of replacement indicates the number of developer supply operations performed using the replaced supply container. For example, when the black supply container 100K is replaced, the count value of the supply amount counter 102K read immediately before being reset represents the number of replenishment operations using the supply container 100K removed from the developer dispenser 101K. .

  Therefore, when the ratio of the count value read from the supply amount counter 102K to the life predicted value inherent to the removed supply container 100K (hereinafter referred to as “use ratio”) is extremely smaller than 1, the supply container 100K It can be determined that the replenishing container has been replaced before consuming all of the filled developer. On the contrary, when the usage ratio is extremely larger than 1, it may be determined that the developer container 100K is filled with a larger amount of developer than the standard developer filling amount at the time of shipment. it can. For this reason, it is checked whether or not the calculated usage ratio is 0.8 or more (ST51). If it is determined that the usage ratio is 0.8 or more, whether or not the usage ratio is 1.2 or less. (ST52) and if it is determined that it is 0.2 or less, that is, if 0.8 ≦ (use ratio) ≦ 1.2, it is determined that one supply container has been replaced, and replenishment The container exchange count is determined as 1 (ST53). On the other hand, when the check result in ST51 or ST52 is No, the amount of the developer dK supplied from the replaced supply container 100K to the developing device 41K does not reach one supply container or is supplied. Since it can be determined that it is larger than one container, the calculated use ratio is determined as it is as the replacement count (ST54). For example, if the usage ratio calculated in ST50 is 0.5, the exchange count = 0.5.

  Next, the supply container replacement count determined in this manner is multiplied by a correction coefficient β inherent to the supply container removed from the developer dispenser, and the replacement container counter added to be added by the replacement counter is finalized. (ST55). This is because, even in the replenishing containers 100Y, 100M, 100C, and 100K filled with the same amount of developer, the filling ratio of the toner and the carrier differs depending on the toner color, and the developer dispenser 101Y depends on the toner color. , 101M, 101C, 101K, the amount of developer supplied to the developing devices 41Y, 41M, 41C, 41K is slightly different in one replenishment operation, and the amount of used developer 15 discharged to the collection container 8 This is because of the influence. This correction coefficient β can be stored in each of the replenishing containers 100Y, 100M, 100C, and 100K and stored in the developer dispensers 101Y, 101M, 101C, and 101K. It is possible to easily read out the correction coefficient β inherent to the refill container that has been used. The value of β differs for each toner color.

  If the final number of exchanges is determined in ST55, it is counted up by the exchange number counter 103. For example, when a black supply container 100K that has already consumed half of the initial filling amount is newly installed in the developer dispenser 101K, and it is determined that the supply container 100K has been emptied and replaced, The use ratio in ST50 is about 0.5, and in ST54, the replacement count of the supply container 100K is replaced with 0.5 instead of 1. If the correction coefficient β stored in the memory of the black supply container 100K is 1, the final replacement number determined in ST55 is 0.5 × 1 = 0.5. As a result, when the black supply container 100K is replaced, the replacement number counter newly counts up 0.5.

  Further, when the recovery container 8 is not full, when it is pulled out of the housing 10 together with the image carrier unit 2, the image carrier unit 2 is mounted on the housing 10 again without replacing the recovery container 8. May be used. Even when the image carrier unit 2 is remounted as described above, in order to continuously detect the fullness of the collection container 8, a memory is provided in the image carrier unit 2, and the image carrier unit 2 is installed in the image carrier unit 2. Before removing from the housing 10, it is preferable to write the count value of the replacement number counter 103 to the memory and write the sum of the count values of the supply amount counters 102Y, 102M, 102C, and 102K for all colors.

  With this configuration, when the image carrier unit 2 is remounted on the housing 10, the number of replacement containers 100Y, 100M, 100C, and 100K written in the memory of the image carrier unit 2 and the total number of replenishments By reading the number of times, the amount of the used developer 15 already accumulated in the collection container 8 can be grasped, and even when the image carrier unit 2 is remounted, the collection shown in FIGS. It is possible to normally execute the procedure for detecting the fullness of the container 80.

1 is a perspective view illustrating an example of a color printer to which the present invention is applied. FIG. 2 is a perspective view showing a state in which an opening / closing cover or the like of the color printer of FIG. 1 is opened. It is a schematic sectional drawing in alignment with the III-III line of the color printer of FIG. It is a schematic diagram which shows the state which opened the one part opening-and-closing cover of FIG. FIG. 4 is a schematic diagram showing a state in which an opening / closing cover necessary for taking out the image carrying unit and the like of FIG. 3 is opened. FIG. 2 is a schematic cross-sectional view showing an image carrier unit and a used developer recovery container in an integrated state. It is a perspective view which shows a collection container and developer conveyance parts. It is a block diagram which shows the structure for full detection of a collection container. It is explanatory drawing which shows the relationship between a developing device and a collection box. It is a flowchart which shows the procedure of a full detection process of a collection container. It is a flowchart which shows the calculation process of the frequency | count of replenishment in a full detection process. It is a flowchart which shows the correction process procedure of the replacement | exchange number of a replenishment container.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 2 ... Image holding unit, 8 ... Collection container, 10 ... Housing, 15 ... Used developer, 41Y, 41M, 41C, 41K ... Developer, 100Y, 100M, 100C, 100K ... Supply container, 101Y, 101M, 101C , 101K ... Developer dispenser, 102Y, 102M, 102C, 102K ... Supply amount counter, 103 ... Replacement number counter, 104 ... Full detection means

Claims (9)

A plurality of image forming means for forming a toner image according to image information; a plurality of supply containers for supplying supply developer to each image forming means; In an image forming apparatus comprising: a developer replenishing unit that repeatedly replenishes a predetermined amount of developer from a container to a corresponding image forming unit; and a collection container that stores a used developer discharged from each image forming unit A detection method for determining whether such a collection container is full,
When the total number of replacement containers is counted, and the count value reaches a predetermined value, the number of developer replenishment operations in all the image forming units thereafter is summed, and the total value reaches the predetermined value. A method for detecting the fullness of a collection container that determines that the collection container is full. A plurality of image forming means for forming a toner image according to image information; a plurality of supply containers for supplying supply developer to each image forming means; A developer replenishing means for repeatedly replenishing a predetermined amount of developer from the container to the corresponding image forming means; a recovery container for storing used developer discharged from each image forming means; and each developer replenishing means. A supply amount grasping means that counts the number of times the developer replenishment operation is performed from the supply container to the corresponding image forming means for each supply container, and cumulatively calculates the replacement number of developer supply containers in all image forming means, and Replenishment container counting means whose cumulative value is reset when the collection container is replaced, and when the total number of exchanges counted by the replenishing container counting means reaches a predetermined value, the number of replenishment operations in all supply amount grasping means is integrated. And the total cost There the image forming apparatus characterized by comprising a full detection means for determining the full the collection container upon reaching the predetermined value. The replenishing container counting means obtains a ratio between the life predicted value when the replenishing container is used and the actual number of times of replenishing operation with respect to the replenishing container removed from the developer replenishing means when the replenishing container is replaced. 3. The image forming apparatus according to claim 2, wherein the ratio is counted as the number of replacement of the replenishing container. The replenishing container counting means reads a correction coefficient corresponding to the developer replenishing container removed from the developer replenishing means when replacing the developer replenishing container, and corrects the replacement number to be added to the replenishing container coefficient means. The image forming apparatus according to claim 3. The image forming apparatus according to claim 4, wherein the correction coefficient is determined for each supply container. 6. The image forming apparatus according to claim 4, wherein the correction container is provided with a storage unit for storing the correction coefficient. A container detection sensor for detecting attachment / detachment of a supply container with respect to the developer supply means is provided, and the supply container counting means calculates a replacement number of supply containers based on a signal change of the container detection sensor. Item 4. The image forming apparatus according to Item 2 or 3. 3. The storage container is provided with a storage means, and the storage means stores the total number of times of replenishment calculated by the fullness detection means for each replenishment operation by the developer replenishment means. Image forming apparatus. 9. The plurality of image forming means are included in a single process cartridge that is detachable from the image forming apparatus main body, and the collection container is provided integrally with the process cartridge. The image forming apparatus described.

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