JP4617729B2 - Powder container and image forming apparatus using the same - Google Patents

Description

  The present invention relates to a powder container for receiving and storing a powdered material such as waste toner in an image forming apparatus such as an electrophotographic copying machine or a laser beam printer, and more particularly to a collection container for receiving powder. The present invention relates to a proposal for accurately detecting a full state.

JP 2002-341710 A

  In an image forming apparatus typified by a printer, a copier, a facsimile, a multifunction peripheral, etc. using an electrophotographic system, an electrostatic recording system, etc., an electrostatic image formed on an image carrier such as a photoconductor according to image information. The latent image is developed with a powder developer (one-component developer composed only of toner or two-component developer composed of toner and carrier) to form a toner image, and the toner image is directly applied to a recording medium such as recording paper. Alternatively, the image is formed by transferring through an intermediate transfer member and fixing by heating and pressing.

  In an image forming apparatus that handles such a developer, for example, an unnecessary developer (mainly toner) that is not transferred to the image carrier or intermediate transfer member and remains attached is generated. The toner is removed and collected by a cleaning device, and the collected unnecessary developer is collected by a powder container.

  The powder storage device includes a recovery container that receives and stores the recovered unnecessary developer immediately or after being transported by the developer transport device, and the inside of the recovery container is filled with the developer. A device provided with detection means for detection is known. When the detection means detects that the recovery container is full of developer (accommodation upper limit amount), the user is notified of the result, and the disposal of the developer stored in the recovery container or a new recovery container is made. It is encouraged to perform necessary processing such as replacement.

  2. Description of the Related Art Conventionally, as the detection means, one configured to directly detect the developer accumulation level in a storage space in a collection container with an optical sensor is known. Specifically, a rectangular detection window is projected from the upper part of the side surface of the collection container, and an optical detection means such as a photosensor detects whether the developer has entered the detection space in the detection window. It has become. When the uppermost level of the developer accumulated in the storage space in the collection container reaches the detection window, the developer in the storage space enters the detection space in the detection window, so that the optical path of the photosensor is blocked, It is possible to grasp whether or not the developer has accumulated to the level of the detection window by changing the output signal of the sensor.

  However, since the storage space in the collection container and the detection space in the detection window are continuous without any partition, it takes place when the powdery developer dropped into the collection container rises and scatters. Since the developer adheres to the wall of the detection window and the amount of light transmitted through the detection window decreases, the output signal of the sensor changes even though the accommodation space is not yet full. May be misdetected. In addition, if the developer is deposited in the recovery container in a state of being offset from the detection window, the developer enters the detection space even though the accumulation level is still low on the opposite side of the accommodation space. The sensor output signal changes and may be falsely detected as full

  On the other hand, in the powder container disclosed in Japanese Patent Application Laid-Open No. 2002-341710, a partition member is provided between the container space and the detection space, and the container space is filled with the collected developer. The developer in the housing space pushes the partition member away and enters the detection space. If comprised in this way, the accumulation amount of the developer in an accommodation space will increase, and the developer in an accommodation space will not penetrate | invade into a detection space, unless a pressure acts from the developer accumulated with respect to the partition member. Therefore, it is possible to prevent the scattered developer from adhering to the detection window as described above, and to prevent the developer from entering the detection space due to uneven deposition, and erroneously detect whether or not the collection container is full. Can be prevented.

  However, with the structure in which the partition wall is provided in this way, if an impact acts on the collection container for any reason, the developer in the storage space pushes the partition member away even though the storage space is not full. In some cases, the detection space may be intruded, and once the developer has entered the detection space, it cannot be restored.

  In particular, in recent miniaturized image forming apparatuses, for the purpose of minimizing the space in the apparatus, the collection container is not configured to be detachable from the image forming apparatus alone, but is a consumable replacement product, for example. In some cases, the transfer roll unit may be attached to and detached from the transfer roll unit. That is, in order to replace the collection container, it is necessary to first remove the transfer roll unit from the image forming apparatus and then remove the collection container from the transfer roll unit. For this reason, when the transfer roll unit is removed from the image forming apparatus for the purpose of removing a paper jam or replacing the transfer roll, the recovery container does not need to be replaced, but the impact when the transfer roll unit is removed and remounted is recovered. As described above, it is assumed that the developer in the accommodation space pushes away the partition member and enters the detection space, and as a result, it is erroneously detected that the collection container is full. .

  The present invention has been made in view of such problems, and the object of the present invention is to erroneously detect the fullness of the collection container until the amount of powder deposited in the storage space reaches a certain level. In addition, even when an impact is applied to the recovery container due to replacement of other units, etc., it is possible to detect the fullness of the recovery container with high reliability without erroneously detecting whether the recovery container is full. An object of the present invention is to provide a powder container that can be used.

  The powder container of the present invention that achieves the above-described object is provided with a recovery container having a storage space in which received powder is deposited, and provided in the recovery container, and is deposited in the storage space continuously with the storage space. A detection window that forms a detection space for the powder to enter, a removal member that periodically scrapes the powder that has entered the detection space into the storage space, and the powder is present in the detection space. And detecting means for detecting through the detection window.

  When powder accumulates in the storage space of the collection container, the powder enters a detection space continuous with the storage space, and the detection means detects the presence or absence of powder in the detection space through the detection window. Become. However, since there is a removal member that periodically scrapes the powder that has entered the detection space into the storage space, the amount of powder deposited in the storage space is not so large, and the powder that has flowed into the detection space In a slight case, the removal member scrapes the powder in the detection space, so that the detection means can determine that there is no powder in the detection space. Even if the collection container is moved for some reason and the powder temporarily enters the detection space, the detection means detects the powder because the removal means scrapes the powder out of the detection space. If there is powder in the space, there will be no false detection. Furthermore, even when the powder soared in the accommodation space adheres to the inside of the detection window in the detection space, the removal member wipes the inside of the window when scraping the powder in the detection space. The detection means will not make a false detection when powder is present in the detection space.

  When the amount of powder deposited in the storage space increases and becomes equal to or higher than the height of the detection space, even if the removal member scrapes the powder in the detection space, the powder is immediately stored. As a result, the detection means detects powder in the detection space. Thereby, it can be determined that the powder has accumulated to a predetermined level in the accommodation space.

  According to the present invention, the fullness of the collection container is not erroneously detected until the amount of powder deposited in the storage space reaches a certain level, and replacement of other units such as a transfer roll unit is not performed. Even when an impact is applied to the recovery container due to the above, it is possible to detect the fullness of the recovery container with high reliability without erroneously detecting whether the recovery container is full.

Hereinafter, the powder container of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows a schematic configuration of a full-color laser beam printer in which the powder container of the present invention is applied to a waste developer collecting device.

  This full-color printer includes photosensitive drums 11, 12, 13, and 14 for yellow Y, magenta M, cyan C, and black Bk, and charging rolls 21 and 22 for primary charging that are in contact with the photosensitive drums 11 to 14, respectively. , 23, 24, a laser optical unit (not shown) that irradiates laser light 31, 32, 33, 34 of each color of yellow Y, magenta M, cyan C, and black Bk, and developing units 41, 42, 43, 44, Of the four photosensitive drums 11 to 14, the first primary intermediate transfer drum 51 that contacts two photosensitive drums 11 and 12 and the second primary intermediate that contacts the other two photosensitive drums 13 and 14. The transfer drum 52, the secondary intermediate transfer drum 53 that contacts the first and second primary intermediate transfer drums 51, 52, and the final contact that contacts the secondary intermediate transfer drum 53 In the shooting roll 60, a main part is configured.

  Among these configurations, each of the photosensitive drums 11 to 14, the charging rolls 21 to 24, the developing devices 41 to 44, the first and second primary intermediate transfer drums 51 and 52, and the secondary intermediate transfer drum 53 are single. The image forming unit 1 is integrated. For example, when the image quality is deteriorated due to deterioration of the photosensitive drum or the like, the image forming unit 1 is replaced as it is.

  The photosensitive drums 11, 12, 13, and 14 are arranged at a predetermined interval so as to have a common tangential plane M. Further, the first primary intermediate transfer drum 51 and the second primary intermediate transfer drum 52 have a surface target relationship in which each rotation axis is parallel to the photosensitive drums 11 to 14 and a predetermined target surface is a boundary. Arranged to be. Further, the secondary intermediate transfer drum 53 is arranged so that the rotation axis is parallel to the photosensitive drums 11 to 14.

  When forming a full-color image, a signal corresponding to image information for each color is rasterized by an image processing unit (not shown) and input to a laser optical unit (not shown). In this laser optical unit, yellow Y, magenta M, cyan C, and black Bk laser beams 31 to 34 are modulated and irradiated to the corresponding photosensitive drums 11 to 14.

  An image forming process for each color is performed around each of the photosensitive drums 11 to 14 by a known electrophotographic method. First, as the photoconductive drums 11 to 14, photoconductive drums using OPC photoconductors are used. The surfaces of the photoconductive drums 11 to 14 are charged rolls 12, 22, and a DC roll to which a DC voltage of about -800V is applied. For example, the voltage is uniformly charged to about −300 V by 32 and 42.

  Laser beams 31 to 34 modulated in accordance with input image information for each color are irradiated from the laser optical unit onto the surfaces of the photoconductive drums 11 to 14 having a uniform surface potential in this way. An electrostatic latent image corresponding to the color image information is formed at a predetermined timing. When the electrostatic latent image is written by the laser optical unit, the surface potential of the image exposure portion on the photosensitive drums 11 to 14 is discharged to about −60V or less.

  The electrostatic latent images corresponding to the colors of yellow Y, magenta M, cyan C, and black K formed on the surfaces of the photosensitive drums 11 to 14 are developed by the corresponding color developing devices 41 to 44, respectively. The toner images are visualized on the photosensitive drums 11 to 14 as toner images of respective colors of yellow Y, magenta M, cyan C, and black Bk. Each of the developing devices 41 to 44 is filled with a developer composed of yellow Y, magenta M, cyan C, and black Bk toners and carriers of different colors, and the toner is consumed by developing the electrostatic latent image. Then, a developer whose toner mixing ratio is higher than that of the developer in the developing device is replenished from a replenishing device (not shown), while a carrier deteriorated by use over time is discharged into a waste box (not shown). The toner replenishment and the carrier replacement are sequentially performed.

  The developer in the developing unit is magnetically attracted to the developing roll 401 to form a brush-like ear, and this ear comes into contact with the photosensitive drums 11 to 14 as the developing roll rotates. By applying a developing bias voltage of AC + DC between the developing roll 401 and the photosensitive drum, the toner on the developing roll 401 develops the electrostatic latent image formed on the photosensitive drums 11 to 14, and the toner An image is formed.

  Next, the yellow (Y), magenta (M), cyan (C), and black (K) toner images formed on the respective photosensitive drums 11 to 14 are converted into first primary intermediate transfer drums 51. And electrostatically primary-transferred onto the second primary intermediate transfer drum 52. The yellow (Y) and magenta (M) color toner images formed on the photoconductive drums 11 and 12 are formed on the first primary intermediate transfer drum 51 and cyan (on the photoconductive drums 13 and 14). The toner images of C) and black (K) are transferred onto the second primary intermediate transfer drum 52, respectively. By shifting the electrostatic latent image writing start timing on the photosensitive drums 11, 12, 13, and 14 for each color, yellow (Y) and magenta (M) primarily transferred on the first primary intermediate transfer drum 51. A double-color image in which the toner images of the cyan (C) and black (K) are appropriately superimposed on the second primary intermediate transfer drum 52 is formed. A color image is formed. The surface potential necessary for electrostatically transferring the toner images from the photosensitive drums 11 to 14 onto the first and second primary intermediate transfer drums 51 and 52 is about +250 to 500V.

  Thereafter, the double-color toner images formed on the first and second primary intermediate transfer drums 51 and 52 are electrostatically secondary-transferred onto the secondary intermediate transfer drum 53. Therefore, a final toner image in which four colors of yellow (Y), magenta (M), cyan (C), and black (K) are overlapped is formed on the secondary intermediate transfer drum 53. The surface potential necessary for electrostatically transferring the toner image from the first and second primary intermediate transfer drums 51 and 52 onto the secondary intermediate transfer drum 53 is about +600 to 1200V.

  Finally, the quadruple toner image formed on the secondary intermediate transfer drum 53 is tertiary-transferred onto the paper passing through the paper transport path P by the final transfer roll 60. The paper passes through a paper transporting roll 90 through a paper feeding process (not shown), and is fed into the nip portion between the secondary intermediate transfer drum 53 and the final transfer roll 60. After this final transfer step, the final toner image formed on the paper is fixed by the fixing device 70, and a series of image forming processes is completed.

  In the laser beam printer of this embodiment configured as described above, a cleaning device is arranged for each of the photosensitive drums 11 to 14 and the primary intermediate transfer drums 51 and 52.

  First, the cleaning device disposed on the photosensitive drum 11 includes a refresher brush 215 having conductive sliding bristles standing around a metal rotating shaft, and prevents toner from adhering to the charging roll 21. Therefore, it is positioned upstream of the charging roll 21 with respect to the rotation direction of the photosensitive drum 11. Further, a cleaning bias is applied to the refresher brush 215, and the toner whose polarity has been reversed at each transfer portion is temporarily collected from the surface of the photosensitive drum 11 until a cleaning mode described later is started. The toner is held for a while. That is, the toner is charged to (−) polarity in the developing device 41, and in each transfer process, the toner image is transferred toward a higher potential. However, when such a toner image repeatedly passes through the transfer part of each transfer process, a part of the (−) charged toner is inverted to the opposite polarity, that is, charged to the (+) polarity by Paschen discharge or charge injection. In this case, the toner whose polarity is reversed in this way is not transferred to the next process but flows backward to the upstream side. Finally, it is transferred to the photosensitive drum 11 and eventually adhered to the charging roll 21. The refresher brush 215 is provided to catch the toner whose polarity is reversed in front of the charging roll 21 and prevent the toner from adhering to the charging roll 21. Therefore, at the time of forming the toner image, −400 V, which is lower than the surface potential of the photosensitive drum 11 −300 V, is applied to the refresher brush 215. Further, the refresher brush 215 is not provided with any driving means, and the refresher brush 215 is driven by rotation of the photosensitive drum 11 by a frictional force acting between the sliding bristles and the photosensitive drum 11. turning.

  In the above description, the refresher brush 215 provided for the photosensitive drum 11 has been described. However, the refresher brushes 216, 217, and 218 having the same structure are provided for the other photosensitive drums 12 to 14. It has been.

  On the other hand, for the primary intermediate transfer drums 51 and 52, first brush rolls 220 and 221 each having conductive sliding bristles standing around the metal rotary shaft are disposed. These first brush rolls 220 are in positions where toner remaining on the surface of the primary intermediate transfer drum 51 is blocked on the front side of the photosensitive drum 12 after the end of the secondary transfer, and the first brush roll 221 ends the secondary transfer. The toner remaining on the surface of the primary intermediate transfer drum 52 later is disposed at a value for blocking the front side of the photosensitive drum 14.

  A cleaning bias is applied to the first brush rolls 220 and 221, but the polarity is opposite to that applied to the refresher brush 215. In the primary transfer, each photosensitive drum transfers only one color toner image to the primary intermediate transfer drums 51 and 52, so that the transfer efficiency can be set to be somewhat high, and the cleaning device deliberately collects residual toner. Even if the image forming apparatus is not provided, a large support is not generated in image formation, and color mixing does not occur in each of the developing devices 41 to 44. However, in the secondary transfer, the toner images for two colors that overlap each other are transferred to the secondary intermediate transfer drum 53, so that a large amount of toner remains on the primary intermediate transfer drums 51 and 52 without being transferred. This is because if the image is not collected by the apparatus, a ghost is generated in the next transferred toner image. For this reason, the residual toner charged to the (−) polarity is transferred to the first brush rolls 220 and 221 so as to be electrostatically transferred from the primary intermediate transfer drums 51 and 52 to the first brush rolls 220 and 221. A cleaning bias (for example, +600 V) higher than the surface potential of the primary intermediate transfer drums 51 and 52 is applied. Of course, if the atmospheric environment such as temperature and humidity changes and the surface potential of the primary intermediate transfer drums 51 and 52 changes, a potential difference between the first brush rolls 20 and 221 and the primary intermediate transfer drums 51 and 52 is secured. Therefore, it is necessary to change the cleaning bias. Further, these first brush rolls 220 and 221 are not provided with any driving means, and like the refresher brush 215, the first brush rolls 220 and 221 are primarily affected by the frictional force acting between the sliding bristles and the primary intermediate transfer drums 51 and 52. The intermediate transfer drums 51 and 52 are rotated.

  Further, a second brush roll 230 for removing the toner remaining in the tertiary transfer is also disposed on the secondary intermediate transfer drum 53. Unlike the first brush rolls 220 and 221 and the refresher brushes 215 to 218, the second brush roll 230 is driven to rotate in a direction opposite to the rotation direction of the secondary intermediate transfer drum 53 by a motor (not shown). This is because, in the tertiary transfer in which the toner images of four colors are collectively transferred to the recording sheet P, a large amount of toner remains on the secondary intermediate transfer drum 53, and the brush roll 230 is merely driven and rotated even when a cleaning bias is applied. This is because the residual toner cannot be captured. In particular, when performing a tertiary transfer of a toner image on a high-resistance recording sheet such as an OHP sheet, a transfer current having a predetermined magnitude is obtained between the secondary intermediate transfer drum 53 and the transfer roll 60. Therefore, it is necessary to apply a larger transfer bias to the transfer roll 60, and the charge amount of the toner is weakened even if the polarity is not reversed, so that the toner is not transferred onto the recording sheet but is transferred onto the secondary intermediate transfer drum 53. There is also a large amount of residual toner.

  A cleaning bias is also applied to the second brush roll 230, but for the purpose of removing residual toner generated in the third transfer from the surface of the secondary intermediate transfer drum 53, the polarity thereof is the first brush rolls 220 and 221. Is the same as that applied to. That is, the secondary intermediate transfer drum is disposed on the second brush roll 230 so that the residual toner charged to the (−) polarity is electrostatically transferred from the secondary intermediate transfer drum 53 to the second brush roll 230. A cleaning bias (for example, +1080 V) higher than the surface potential of 53 is applied.

  The refresher brushes 215 to 218, the first brush rolls 220 and 221, and the second brush roll 230 receive toner from the photosensitive drums 11 to 14, the primary intermediate transfer drums 51 and 52, and the secondary intermediate transfer drum 53 that face each other. Although it captures, it does not have any mechanical configuration for discharging the captured toner. Therefore, when the toner image is repeatedly formed, the captured toner overflows from between the rubbing hairs of each brush roll. Therefore, in the printer according to the present embodiment, the following cleaning operation is performed at a predetermined timing, such as before a printing operation, after a printing operation, and every predetermined number of sheets during continuous printing in order to collect the toner captured by each brush roll. The toner temporarily captured by each brush roll is collected by a powder container 80 provided for the transfer roll 60.

  In this cleaning operation, first, for the charging rolls 21 to 24, the refresher brushes 215 to 218, the photosensitive drums 11 to 14, the primary intermediate transfer drums 51 and 52, the secondary intermediate transfer drum 53, and the final transfer roll 60, A voltage having a potential gradient is sequentially applied so that the final transfer roll 60 has the highest negative potential, and thereby, the reverse polarity (+) collected and held by the refresher brushes 215 to 218 during the printing operation. The charged toner is sequentially transferred to the final transfer roll 60 and is collected by a powder container 80 provided in contact with the final transfer roll 60. In the powder container 80, a cleaning blade 801 made of an elastic material such as silicon rubber is in contact with the peripheral surface of the transfer roll 60, and the toner transferred to the transfer roll 60 is scraped off by the cleaning blade 801 and collected in the apparatus. It is supposed to be. Accordingly, when such a cleaning operation is started, the (+) charged toner that has been temporarily held by the refresher brushes 215 to 218 is discharged onto the photosensitive drums 11 to 14, and the refresher brushes 215 to 218 are discharged. Will return to a clean state.

  When the cleaning of the (+) charged toner is completed in this way, the same potential as that at the time of forming the toner image is set to the charging rolls 21 to 24, the photosensitive drums 11 to 14, the primary intermediate transfer drums 51 and 52, and the secondary. While being applied to the intermediate transfer drum 53 and the final transfer roll 60, the first brush roll and the second brush roll are given a potential having a polarity opposite to that at the time of image formation. This time, the first brush rolls 220, 221 and the second brush roll are applied. The (−) charged toner adhering to the brush roll 230 is cleaned. That is, by applying a potential having a polarity opposite to that at the time of image formation to the first brush rolls 220 and 221 and the second brush roll 230, the (−) charged toner held on these brush rolls is the primary intermediate transfer drum 51. , 52 and the secondary intermediate transfer drum 53, and reaches the final transfer roll 60 via the secondary intermediate transfer drum 53 in the same manner as the transfer of a normal toner image. It is scraped off from the surface and collected in the powder container 80.

  By periodically performing such a cleaning operation, the toner trapped in the first and second brush rolls is collected by the powder container 80 with any polarity, and the brush rolls are cleaned. It will be illustrated.

FIG. 2 is a sectional view showing the powder container 80.
The powder storage device 80 is formed in a substantially rectangular shape and includes a recovery container 82 having a storage space 81 for toner, paper powder and the like (hereinafter referred to as “toner etc.”) therein, and the recovery container 82. An agitator 83 for dispersing and leveling the accumulated toner 10 and the like in the accommodation space, and a detection means 84 for detecting that the accumulation level of the toner 10 in the accommodation space 81 has reached a predetermined level. .

  The collection container 82 is detachable from the transfer roll unit on which the final transfer roll 60 is mounted. When the transfer roll unit is removed from the printer casing, the collection container 82 is also taken out of the printer casing together with the transfer roll unit. It is configured. Therefore, when the storage space 81 of the collection container 82 is filled with toner 10 or the like, first, the transfer roll unit is removed from the printer housing, and then the full collection container 82 is removed from the transfer roll unit. In exchange for this, after a new collection container 82 is mounted on the transfer roll unit, the transfer roll unit is set in the printer housing.

  As shown in FIG. 2, the cleaning blade 801 is fixed to one side wall of the collection container 82 via a holder 85, and when the collection container 82 is correctly attached to the image forming unit as described above, the cleaning blade 801 is provided. The leading edge of this is abutted against the surface of the final transfer roll 60 at a predetermined angle. Further, a flexible resin sealing film 802 is fixed to the other side wall of the collection container 82 so as to face the tip of the cleaning blade 801, and this sealing film 802 is attached to the surface of the final transfer roll 60. Is in sliding contact. Therefore, the cleaning blade 801 and the seal film 802 function as a lid for the storage space 81 of the collection container 82, and prevent the toner 10 that has fallen into the storage space 81 from leaking outside.

  FIG. 3 is a perspective view showing the structure of the collection container 82. The agitator 83 is formed by bending a metal wire, and its rotation axis is provided in parallel with the axial direction of the final roll 60. A gear 86 is provided at one end of the rotating shaft of the agitator 83. When the collection container 82 is attached to the transfer roll unit, the gear 86 is engaged with the gear provided on the rotating shaft of the final transfer roll 60, and the final transfer roll. The agitator 83 rotates in synchronization with the rotation of 60. The toner 10 and the like 10 scraped off from the surface of the final transfer roll 60 by the cleaning blade 801 accumulates in the storage space 81 of the collection container 82 while forming a mountain immediately below the tip of the cleaning blade 801, but the agitator 83. By rotating the, the formation of this mountain is suppressed, and the toner 10 etc. in the accommodation space 81 can be deposited at a substantially uniform level.

  Further, a transparent detection window portion 87 projects from the side wall of the collection container 82, and a detection space 88 inside the detection window portion 87 is continuous with the accommodation space 81. Accordingly, the toner 10 scraped off from the final transfer roll 60 gradually accumulates in the storage space 81 of the collection container 82, and when the accumulation level rises, the toner 10 in the storage space 81 is detected by the detection window 87. It enters into the detection space 88 inside. The detection window 87 is provided at substantially the same height as the rotation shaft of the agitator 83.

  When the collection container 82 is attached to the transfer roll unit and the transfer roll unit is attached to the printer housing, the optical sensor 89 is positioned with respect to the detection window 87 of the collection container 82 as shown in FIG. It has become. This optical sensor 89 is a photosensor provided with a light emitting element 89a and a light receiving element 89b, and a detection window 87 is inserted between the light emitting element 89a and the light receiving element 89b facing each other. For this reason, when the toner 10 or the like accumulated in the storage space 81 of the recovery container 82 enters the detection space 88, the optical path between the light emitting element 89a and the light receiving element 89b is blocked, and the output signal of the optical sensor 89 is The on / off state changes so that the presence of the toner 10 or the like in the detection space 88 can be grasped.

  On the other hand, a flexible removal member 90 is attached to the agitator 83 at a position facing the detection window 87, and the removal member 90 enters the detection space 88 as the agitator 83 rotates. The toner 10 that has entered the detection space 88 is scraped out to the storage space 81. The removal member 90 is formed of, for example, a sheet-like material such as a resin film. In addition to wiping off toner and the like, the toner and the like 10 in the detection space 88 are scraped out to the accommodation space 81.

  The removal member 90 includes a tip 91 that is pushed into the detection space 88 and deforms as the agitator 83 rotates, and a support 92 that connects the tip 91 and the agitator 83. The portion 91 and the support portion 92 are formed from a single sheet.

  As shown in FIG. 2, the output signal of the optical sensor 89 is input to a detection / determination unit 93 including a microcomputer system. The detection determination unit 93 takes in the output signal of the optical sensor 89 at a predetermined time interval, and counts the number of times the output signal of the optical sensor 89 is turned on while the agitator 83 makes one rotation. For example, the output signal of the optical sensor 89 is fetched 125 times while the agitator 83 makes one rotation, and the number of ON outputs is counted. When the count value exceeds a predetermined number, the detection determination unit 93 determines that the storage space 81 of the collection container 82 is filled with toner 10 or the like, and through a user interface such as a display in the operation panel, The printer user is prompted to replace the collection container 82.

  FIG. 5 schematically shows the accumulation amount of toner or the like in the collection container 82 in three stages, and FIG. 6 shows the output of the optical sensor 89 corresponding to the accumulation amount of toner or the like 10 in the collection container 82. The ratio between the number of signal ON outputs and the number of OFF outputs is schematically shown. When the accumulation level of the toner 10 in the accommodation space 81 is level A shown by a solid line in FIG. 5, the toner 10 accumulated in the accommodation space 81 has not reached the height level in the detection space 88. There is essentially no toner or the like in the detection space 88, and the output signal of the optical sensor 89 does not change from off to on. However, since the removal member 90 wipes the inner surface of the detection window 87 every rotation of the agitator 83 and the optical sensor 89 detects the removal member 90 at that time, as shown in the example of level A in FIG. In addition, the output signal of the optical sensor 89 is periodically switched from OFF to ON, and the number of ON outputs is extremely small compared to the number of OFF outputs.

  When the accumulation level of the toner 10 in the accommodation space 81 rises and reaches a level B indicated by a broken line in FIG. 5, the height level reaches the height of the detection window portion 87. The toner accumulated in 81 enters the detection space. For this reason, the number of ON outputs of the output signal of the optical sensor 89 increases. However, the removing member 90 periodically scrapes the toner 10 in the detection space 88 into the storage space 81, and the accumulation level of the toner 10 in the storage space 81 is completely equal to the height level of the detection window 87. Therefore, after the removal member 90 scrapes out the toner 10 in the detection space 88, the toner 10 in the storage space 81 does not immediately enter the detection space 88 again. For this reason, as shown in the example of level B in FIG. 6, the number of ON outputs of the optical sensor 89 is larger than that of level A, but is smaller than the number of OFF outputs.

  On the other hand, when the accumulation level of the toner 10 or the like in the accommodation space 81 further increases and reaches the level C indicated by the alternate long and short dash line in FIG. 5, the height level reaches a height exceeding the upper limit of the detection window 87. Therefore, even if the removal member 90 scrapes out the toner 10 that has entered the detection space 88, the toner 10 in the storage space 81 immediately flows into the detection space 88 after passing through the removal member 90. For this reason, as shown in the example of level C in FIG. 6, the output signal of the optical sensor 89 is turned off only a few times immediately after the removal member 90 passes through the detection space 88, and the number of on outputs is reduced. It is overwhelmingly larger than the number of off outputs.

  Therefore, as described above, if all the output signals of the optical sensor 89 output a plurality of times during one rotation of the agitator 83 are taken in and the number of times of ON output is counted, the storage space 81 of the recovery container 82 becomes the toner. It can be determined whether or not it has become full. In addition, among the plurality of output signals of the optical sensor 89 that are output while the agitator 83 makes one rotation, the number of times of ON output increases as the accumulation level of the toner 10 in the accommodation space 81 increases. If the number of ON outputs is counted, the toner accumulation level in the storage space 81 can be accurately predicted to some extent, and a warning is issued to the user before the storage space 81 is filled with the toner 10, It is also possible to give a grace time for preparing a new collection container 82. That is, the number of ON outputs of the optical sensor 89 is checked in two stages. If the first number of checks is reached, the user is prompted to prepare a new collection container 82, and if the second number of checks is reached, In order to prevent the toner 10 from overflowing from the collection container 82, the printing operation is prohibited.

  In addition, the detection determination unit 93 that captures the output signal of the optical sensor 89 does not count the number of times of on-output of the optical sensor 89, but calculates the time ratio of the on-output to the capture time of the output signal. May exceed the predetermined ratio, it may be determined that the storage space 81 of the collection container 82 is full of toner 10 or the like. FIG. 7 is a graph showing the relationship between the weight of the toner 10 accumulated in the accommodation space 81 and the ratio of the ON time of the output signal of the optical sensor 89. Here, the capacity of the storage space 81 of the recovery container 82 is set so that the maximum recovery weight of the toner 10 and the like is 120 g. As is apparent from this graph, as the collected weight of the toner 10 or the like increases, the on-output time ratio of the output signal of the optical sensor 89 increases. For example, the on-output time ratio is about 50%. For example, if the ON output time ratio is about 90% up to about 70% of the storage space 81, it can be determined that the toner 10 has accumulated up to about 80% of the storage space 81.

Next, the shape of the detection window portion 87 and the tip shape of the removal member 90 will be described.
FIG. 8 is a schematic view of the removal member 90 observed from above as it passes through the detection space 88. When the detection window portion 87 is formed in a rectangular shape and protrudes from the collection container 82, the side wall surface of the detection window portion 87, that is, the window surface that the optical path of the optical sensor 89 crosses (hereinafter referred to as “detection window surface”). ) Is orthogonal to the rotational axis of the agitator 83. For this reason, in order to remove the toner 10 that has entered the detection space 88 by the removal member 90, it is necessary to form the tip 91 of the removal member 90 in a rectangular shape that matches the shape of the detection space 88. is there. That is, if the cross-sectional shape of the detection space 88 matches the shape of the tip 91 of the removal member 90, the toner 10 in the detection space 88 can be efficiently removed to the storage space 81.

  However, if the distal end portion 91 of the removal member 90 is formed in the same shape as the cross-sectional shape of the detection space 88, the removal member 90 and the removal member 90 can be removed when an error occurs in the attachment position of the removal member 90 in the axial direction of the agitator 83. A gap is generated between the detection window surface and the inconvenience that the toner 10 that has entered the detection space 88 cannot be removed reliably.

  Therefore, as shown in FIG. 9, while the distal end portion 91 of the removal member 90 is formed in a rectangular shape, the detection window portion 87 is formed so that its horizontal cross section has a substantially triangular shape, and the distal end portion of the removal member 90 is formed. It can be considered that both sides (hereinafter referred to as “scraping edge”) 91a of 91 are in contact with the detection window surface with certainty. FIG. 10 is a schematic diagram showing the relationship between the sizes of the detection window portion 87 when the horizontal cross section is formed in a triangular shape while the distal end portion 91 of the removal member 90 is formed in a rectangular shape. It is. Since the detection window surface is inclined with respect to the axial direction of the agitator 83, if the distal end portion 91 of the removal member 90 is sufficiently large with respect to the triangular detection space 88, both corner portions ( The area indicated by the slanted line in the drawing is in contact with the detection window surface while being bent, and it is possible to prevent a gap between the removal member 90 and the detection window surface. As long as the removal member 90 and the detection window surface can be brought into contact with each other without any gaps as described above, even if the removal member 90 is attached in the axial direction of the agitator 83, an error is included in the detection space. Thus, it is possible to reliably remove the toner 10 that has entered 88.

  However, since the removal member 90 passes through the detection space 88 such that the hatched area in the drawing is dragged with respect to the detection window surface, the scraping edge 91a of the removal member 90 is removed as shown in FIG. Although it is possible to surely scrape the toner 10 that has fallen asleep against the detection window surface and has entered the detection space 88, the force to scrape off the toner 10 adhered to the detection window surface tends to be insufficient.

  For this reason, as shown in FIG. 12, the distal end portion 91 of the removal member 90 is also formed in a shape substantially the same as the detection space 88 and slightly larger than the detection space 88, and is in contact with the detection window surface. It is preferable that a slightly bent area (shaded area in the figure) is generated. For example, the leading end width W1 of the removing member 90 is set slightly larger than the width W0 of the protruding end of the detection window 87. If the distal end portion 91 of the removal member 90 is formed in such a size, the distal end portion 91 of the removal member 90 pushed into the detection space 88 is bent, but as shown in FIG. The scraping edge 91a in contact comes to stand up with respect to the detection window surface, and the ability to scrape off the toner 10 attached to the detection window surface can be sufficiently exhibited.

  Further, at this time, from the viewpoint of facilitating the bending deformation of the distal end portion 91 of the removing member 90, the distal end portion is connected to the agitator 83 with respect to the width D1 of the distal end portion 91 pushed into the detection space 88. It is preferable that the width D2 of the connecting support portions is narrowed.

  From the viewpoint of preventing the scraping edge 91a of the removing member 90 from falling on the detection window surface, as shown in FIG. 13, a slit is formed from the front end side of the removing member 90 toward the support portion. 93 is preferably formed. When the slit 93 is formed in this way, the distal end portion 91 of the removal member 90 can be easily deformed, and the scraping edges 91a located on both sides of the distal end portion 91 are brought into contact with the opposing detection window portion 87 without any gaps. The scraping edge 91a can be raised with respect to the detection window surface, and the toner 10 and the like adhering to the detection window 87 can be wiped off reliably.

  As the removal member 90, a resin film made of polyethylene terephthalate (PET), polyphenylene sulfide (PPS), or the like can be used. As a result of investigations by the inventors, the thickness of the film is 50 to 150 μm. Is preferred. If the removal member 90 becomes excessively thin, the tip 91 will bend too easily, and the scraping edge 91a cannot be pressed by exerting a sufficient pressure contact force against the detection window surface, so that the toner 10 or the like is scraped off. The effect is not fully exhibited. On the other hand, if the removal member 90 is excessively thick, it is difficult to push the tip 91 into the detection space 88, and the toner in the detection space 88 cannot be sufficiently removed, and the rotational torque of the agitator 83 is increased. Noise when the removal member 90 enters and exits the detection space 88 is increased.

  On the other hand, the removal member 90 is fixed to the rotation shaft of the agitator 83, and the distal end portion 91 of the removal member 90 is pushed into the detection space 88 as the agitator 83 rotates. If it bends easily, the tip 91 will not be sufficiently pushed into the detection space 88 and will pass through the detection space 88, and the toner 10 in the detection space 88 may not be sufficiently removed. is there. In addition, permanent deformation occurs at the base of the removal member 90, that is, the connection portion between the support portion 92 and the agitator 83 due to use over time, and the distal end portion 91 is not sufficiently pushed into the detection space 88, and the detection space There is a risk of passing through 88.

  For this reason, the support portion 92 of the removal member 90 needs to be less bent than the tip portion 91. For example, as shown in FIGS. 14 and 15, the support portion 92 is bonded with a reinforcing member 94 or the like. It is better to increase the flexural modulus. The reinforcing member 94 to be bonded may be a resin film or other material. Further, it may be a resin film made of the same material as the removing member 90 or a different material. The thickness of the reinforcing member 94 may be the same as that of the removing member 90, but from the viewpoint of increasing the rigidity of the support portion 92, if a member thicker than the film forming the removing member 90 itself is used. Good. Further, the reinforcing member 94 should not hinder the bending deformation of the distal end portion 91 of the removing member 90, and the scraping edges 91a located on both sides of the distal end portion 91 are bent while being pressed against the detection window surface. In view of this, it is preferable that the reinforcing member 94 increases the bending elastic modulus of the supporting portion 92 only in the center in the width direction in the vicinity where the supporting portion 92 and the leading end portion 91 are continuous, and the leading end of the reinforcing member 94 is in the width direction. It is preferable to form a protruding chevron at the center of the center (see FIG. 14).

  Further, according to the inventors' confirmation, it is preferable that the removing member 90 is configured to rotate so as to be dragged by the rotation of the agitator 83 and to push the tip end portion 91 into the detection space 88. That is, as shown in FIG. 16A, the removal member 90 is attached to the agitator 83 with a negative retraction angle θ with respect to the radial direction of the rotation axis of the agitator 83. On the contrary, when the removal member 90 is attached with a positive advancing angle ω with respect to the radial direction of the rotating shaft of the agitator 83, as shown in FIG. Since the distal end portion 91 enters so as to pierce the detection space 88, troubles such as cracks occurring in the distal end portion 91 due to use over time occurred. As shown in FIG. 16A, when the removal member 90 enters the detection space 88 so as to be dragged by the rotation of the agitator 83, the leading end 91 of the removal member 90 enters the detection space 88. It was carried out relatively gently, and no cracks were generated at the tip portion with use over time.

  On the other hand, when the cross-sectional shape of the detection window 87 is substantially triangular as described above, the light emitted from the light emitting element 89a of the optical sensor 89 crosses the detection space 88 as shown in FIG. Instead of entering the light receiving element 89b, it may pass through the inside of the plastic material constituting the detection window 87 and enter the light receiving element 89b. When the light enters the light receiving element 89b through such a path, the output signal of the optical sensor 89 does not switch from OFF to ON even when toner or the like is present in the detection space 88. For this reason, from the viewpoint of preventing erroneous detection by the optical sensor 89, an optical path between the light emitting element 89a and the light receiving element 89b is avoided at the tip of the detection window 87 formed in a substantially triangular shape. A light shielding cover 95 may be attached so that the light emitted from the light emitting element 89a of the optical sensor 89 always reaches the light receiving element 89b across the detection space 88. If such a light shielding cover 95 is attached to the detection window portion 87, the output signal of the optical sensor 89 accurately corresponds to the presence or absence of the toner 10 in the detection space 88. By counting the number of ON outputs and the ON output time of the output signal, it is possible to accurately grasp the accumulation amount of the toner or the like 10 in the collection container 82.

  As described above, according to the powder recovery apparatus of the present invention, it is possible to accurately determine whether or not the recovery container 82 is full by monitoring the output signal of the optical sensor 89 attached to the detection window 87. Further, by optimizing the shape and rigidity of the removal member 90, the removal member 90 can stably remove the toner and the like in the detection space 88. Also in this respect, recovery is possible. It is possible to accurately determine whether or not the container 82 is full.

It is a schematic block diagram which shows an example of a full color printer provided with the powder recovery apparatus of this invention. It is a schematic block diagram of the powder container to which this invention is applied. It is a perspective view which shows the structure of a collection container. It is a plane sectional view showing the positional relationship between a detection window part and an optical sensor. FIG. 6 is a schematic diagram illustrating the accumulation level of toner or the like in a collection container in three stages. 6 is a timing chart illustrating an example of an output signal of an optical sensor corresponding to the accumulation level of toner or the like illustrated in FIG. 5. 6 is a graph showing a relationship between a time ratio of output signals of an optical sensor and a toner accumulation amount in a collection container. It is a model which shows the example which formed the shape of the detection window part and the front-end | tip part of a removal member in the substantially same rectangular shape. It is a schematic diagram which shows the example which formed the detection window in the substantially triangular shape, and formed the front-end | tip part of the removal member in the rectangular shape. It is a figure which shows 1st Example of the shape of the front-end | tip part of a removal member. It is a figure which shows the example of the contact state of the scraping edge of the front-end | tip part of a removal member, and a detection window surface. It is a figure which shows 2nd Example of the front-end | tip part of a removal member. It is a figure which shows 3rd Example of the front-end | tip part of a removal member. It is a top view which shows the example which bonded the reinforcement member to the support part of the removal member. It is a side view which shows the bending state of this removal member when a reinforcement member is bonded together to the support part of a removal member. It is a figure explaining the attachment angle of the removal member with respect to an agitator. It is a plane sectional view showing the example which attached the shading cover to the detection window part.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 81 ... Storage space, 82 ... Recovery container, 83 ... Stirring member (agitator), 84 ... Detection means, 87 ... Detection window part, 88 ... Detection space, 89 ... Optical sensor, 90 ... Removal member, 93 ... Detection judgment part

Claims (7)

A collection container with a storage space in which the received powder is deposited;
A detection window provided in the recovery container and forming a detection space into which the powder deposited in the storage space enters continuously with the storage space;
A stirring member that is provided in the storage space of the recovery container and rotates to level the powder accumulation surface in the storage space;
A flexible sheet-like material provided in the stirring member, and a removal member that periodically scrapes the powder that has entered the detection space into the storage space;
Detection means for detecting the presence of powder in the detection space through the detection window;
Have
The detection window portion protrudes in a substantially triangular shape so as to form a detection space having a substantially triangular cross section from the side surface of the collection container,
The detection means is arranged so that the light emitting portion and the light receiving portion face each other with the detection window portion interposed therebetween,
The removal member is formed in a substantially triangular shape that is slightly larger than the cross section of the detection space, and has a distal end portion that is pushed into the detection space while being bent as the stirring member rotates, and has a narrower width than the distal end portion. A powder container , comprising: a support portion that is formed and that connects the tip portion to the stirring member .   The detection means includes an optical sensor that outputs an on / off binary signal according to whether powder is present in the detection space, and an on / off time ratio of the output signal of the optical sensor. The powder container according to claim 1, further comprising a detection determination unit configured to determine the amount of powder deposited in the storage space. The powder container according to claim 1 , wherein a slit for facilitating bending deformation is formed at a distal end portion of the removing member . 2. The powder container according to claim 1, wherein the support portion of the removing member has a bending elastic modulus larger than that of the tip portion . 2. The powder container according to claim 1, wherein the support portion of the removing member is attached with a negative retraction angle with respect to the radial direction of the rotating shaft of the stirring member . 3. The powder container according to claim 2, wherein a light shielding cover is attached to the tip of the detection window so as to avoid an optical path between the light emitting part and the light receiving part of the optical sensor . Images forming apparatus powder container device you characterized by using as the recovery device of the waste toner according to any one of claims 1 to 6.

Images