JP2007163670A - Developer conveyance mechanism and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developer conveyance mechanism having such configuration that dirt in an image forming apparatus, damage of a conveyance driving system, etc. due to toner can be prevented by preventing conveyance defects of toner. <P>SOLUTION: The developer conveyance mechanism recovers toner remaining on a latent image carrier by a cleaning means after transfer of a visible image, into which an electrostatic latent image formed on the latent image carrier is developed by a developer including toner, and conveys the recovered toner in order to abandon or recycle the recovered toner, and the developer conveyance mechanism is provided with a control part 100 including; a toner conveyance path P1 connecting with the cleaning means; a rotational transportation means 6 loaded in the path P1; a conveyance abnormality detection means 101 which is provided on the toner conveyance path P1 and is capable of detecting a change from a steady state in the conveyance driving system to the rotational transporting means 6; and a means 102 which gives an alarm in detecting an abnormal conveyance state by the conveyance abnormality detection means 101. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a developer conveying mechanism and an image forming apparatus using the same, and more particularly to a configuration for conveying toner removed from a latent image carrier for disposal or recycling.

  In an image forming apparatus such as a copying machine, a printer, or a facsimile machine, a developer containing toner is used for visible image processing of an electrostatic latent image formed on a latent image carrier. The toner contained in the developer is removed from the latent image carrier by a cleaning device after the transfer process.

  The toner removed by the cleaning device may be returned to the developing device for recycling or discarded.

  As a configuration for conveying the toner collected in the cleaning device toward the developing device or the disposal unit, for example, there is a configuration using a conveying screw that extends between the cleaning device and the developing device (for example, Patent Document 1). .

  In this configuration, the supply pipe is excreted between the cleaning device and the developing device, and a conveying screw that is rotationally driven is disposed inside the cleaning device. The toner accumulated in the cleaning device is developed by the rotation of the conveying screw. It is transferred to the consolidating unit in the apparatus.

  The supply line is configured to be linear so as to suppress heat generation when toner is smoothly transferred and aggregation or accumulation occurs.

In addition, the toner collected in the cleaning device may contain paper dust and additives, and a configuration in which these foreign matters and toner are conveyed separately is proposed (for example, Patent Documents 2 and 3).
JP 2002-229390 A (paragraph “0021” column) Japanese Patent Laid-Open No. 2001-51570 (paragraph “0022” column) Patent No. 3589387 (paragraph "0010" column)

The toner return path constituted by a supply pipe extended between the cleaning device and the developing device is preferably linear in order to facilitate toner movement. However, in recent years, the component parts arranged around the cleaning device and the developing device are also diversified due to the downsizing and high functionality of the device, and the space for installing the return path for toner conveyance may be limited. Many.
For this reason, the return path may be installed near a curved path, near a motor that tends to be hot, or near an electrical board. May agglomerate or melt by heat.

  If toner aggregation or melting occurs, clogging is likely to occur in the pipeline, and as a result, there is a possibility that toner cannot be conveyed. In addition, depending on the degree of aggregation, the pipeline is blocked, so that there is a risk that the toner overflows from the cleaning device located upstream in the toner transfer direction and stains the periphery. In addition, the recovered toner contains paper dust and additives, and paper dust tends to clog between the doctor blade and the latent image carrier surface in the developing device, so that an appropriate developer can be supplied. This is a cause of image defects called fireflies. For this reason, if the amount of collected toner increases, the amount of foreign matter such as paper dust increases, and therefore the amount collected cannot be increased excessively.

  On the other hand, when a phenomenon such as toner clogging occurs in the toner transport path, the load on the toner transport drive system may increase, which may cause damage to the drive system.

  An object of the present invention is to solve the problems in the toner transport mechanism and the image forming apparatus attached to the conventional cleaning device described above, thereby preventing toner transport failure and causing toner internal contamination and transport drive system damage. It is an object of the present invention to provide a toner transport mechanism and an image forming apparatus having a configuration capable of preventing the above.

The present invention has the following configuration.
(1) After transfer of a visible image obtained by subjecting the electrostatic latent image formed on the latent image carrier to a visible image treatment with a developer containing toner, the toner remaining on the latent image carrier is collected by a cleaning unit. A developer transport mechanism for transporting the collected toner for disposal or recycling,
A toner conveyance path continuous with the cleaning means, and a rotation transfer means loaded therein;
A conveyance abnormality detection means provided in the toner conveyance path;
And a means for alarming when an abnormal conveyance state is detected by the conveyance abnormality detection means.
(2) The developer according to (1), wherein the rotation transfer unit uses a conveyance coil that can be rotated and the toner is transferred in accordance with the rotation of the conveyance coil. Transport mechanism.
(3) The conveyance abnormality detection unit includes a configuration for monitoring a change in driving torque of a rotation transfer unit loaded in the toner conveyance path. (1) or (2) Developer transport mechanism.
(4) The developer according to (1) or (2), wherein the conveyance abnormality detection unit monitors a change in the number of rotations of a rotation transfer unit loaded in the toner conveyance path. Transport mechanism.
(5) The developer transport mechanism (6) according to any one of (1) to (4), wherein the toner transport path is provided with a storage unit for collected toner on the cleaning unit side. The developer conveying mechanism according to (1) or (5), wherein the means for alarming the abnormal conveyance state predicts a full state in the toner storage portion based on the number of image formations.
(7) The means for alarming the abnormal conveyance state predicts a full state in the toner storage unit based on a consumption amount of toner used for the visible image processing (1) or (5) ) Developer transport mechanism.
(8) The means for alarming the abnormal conveyance state predicts a full state of the toner storage portion based on the number of pixels for forming an electrostatic latent image on the latent image carrier. The developer transport mechanism according to 1) or (5).
(9) The developer transport mechanism according to any one of (5) to (8), wherein the toner storage unit is provided with an end detection unit capable of detecting a full state.
(10) The developer conveying mechanism, wherein the cleaning means is provided in a process cartridge in which a developing device used for visible image processing of an electrostatic latent image and the toner conveying path are integrated.
(11) An image forming apparatus using the developer transport mechanism according to any one of (1) to (9).

  According to the present invention, it is possible to warn when the toner collected from the cleaning means becomes abnormal in the toner conveyance path, so that contamination due to overflow on the collection unit side or an increase in load on the drive system due to abnormal conveyance It becomes possible to prevent the damage by the.

  In particular, in the second to fourth aspects of the invention, the toner actually transferred by detecting the conveyance abnormality by monitoring the driving torque of the conveyance coil used in the conveyance drive system or the rotational speed change of the rotation transfer means. Can be judged.

  According to the fifth aspect of the present invention, since the toner storing portion that is collected from the cleaning unit is provided even when the conveyance abnormality occurs in the toner conveyance path, the collected toner is conveyed even when the conveyance abnormality occurs. The toner can be prevented from overflowing to the periphery of the cleaning means by being accommodated at a position different from the path.

  According to the sixth to ninth aspects of the present invention, it is possible to predict a full state in the toner storage portion, so that the amount of toner that can be collected after a conveyance abnormality in the toner conveyance path has occurred can be recognized. Can prevent overflow.

  According to the tenth and eleventh aspects of the present invention, it is possible to prevent the toner from being abnormally conveyed and to prevent contamination of the apparatus due to inadvertent overflow, and to prevent image defects such as fireflies due to foreign matter clogging in the developing means A process cartridge or an image forming apparatus that can be obtained can be obtained.

  The best mode for carrying out the present invention will be described below with reference to the illustrated embodiments.

  FIG. 1 is a schematic diagram of an image forming apparatus to which a developer transport mechanism according to the present embodiment is applied. The image forming apparatus shown in FIG. 1 is a copying machine. It can also be an apparatus or a printing press.

  In FIG. 1, an image forming apparatus 1 includes a drum-shaped photoconductor 2 as a latent image carrier, and a charging device that performs an image forming process in the process of moving the photoconductor 2 around the photoconductor 2. A writing device (none of which is shown), a developing device 3, a transfer device 4 and a cleaning device 5 are arranged, and an electrostatic latent image formed on the photoreceptor 2 by the writing device is supplied by the developing device 3. The visible image is processed with toner contained in the developer.

  The toner image on the photoreceptor 2 that has been subjected to the visible image processing by the developing device 3 is transferred to a transfer paper fed out from a paper feeding device (not shown) via the transfer device 4, and the transfer paper on which the toner image is transferred is shown in the drawing. The transferred image is fixed by a fixing device that does not.

  After the transfer, the untransferred toner is scraped off by the cleaning blade 5A and the cleaning brush 5B provided in the cleaning device 5, and the scraped untransferred toner is moved in the longitudinal direction of the conveying screw 5C in the cleaning device 5. A conveying coil or a conveying screw 6 (in the following description) is provided in a toner conveying path P1 that communicates one end with the toner supply unit 3A in the developing device 3 and is used as a rotational conveying means that can rotate by rotating. The toner is returned to the developing device 3 side via a conveying screw).

  In the developing device 3, new toner is supplied from the supply toner bottle 7 </ b> A attached to the toner supply unit 7 to the toner supply unit 3 </ b> A via the supply screw 7 </ b> B driven by the drive motor M. In the developing device 3, new toner and reused toner, so-called recycled toner, are mixed in a mixed state and used for visible image processing.

  In the configuration shown in FIG. 1, although not shown, the toner bottle 7A for replenishment has a concave and convex portion whose outer peripheral surface is formed in a spiral shape, and the toner contained therein when rotated by the drive device 7C. Is configured to move in the axial direction and be fed out toward the replenishment conveying screw 7B.

The details of the present embodiment will be described based on the configuration shown in FIG.
FIG. 2 is a view showing a drive mechanism of the conveying screw 6 disposed inside the toner conveying path P1 that is connected to the cleaning device 5 at one end side.
In the figure, the conveying screw 6 is rotationally driven so that the gear 6B provided on the rotating shaft 6A is interlocked with a driving gear 7 driven by a driving motor (not shown). Is provided with a configuration for detecting a conveyance abnormality.
Abnormal conveyance means a state in which toner cannot be transported and clogged when the toner adheres to and accumulates on the inner peripheral surface of the pipeline or the conveyance screw 6 in the toner conveyance path P1.

In the configuration shown in FIG. 2, a torque limiter 8 arranged coaxially with the drive gear 7 is used as a conveyance abnormality detection means.
The torque limiter 8 detects a change in the load on the rotating shaft that occurs when the toner is conveyed abnormally in the toner conveying path P1, and the load change in this case connects the rotating shaft and the shaft on the torque limiter 8 side. When the joint part for this is used, it is set as the detection object that the rotation phase of each axis | shaft connected with a joint part shifts | deviates.

  Further, instead of the torque limiter, a rotation speed sensor that detects a change in the rotation speed of the conveying screw 6 can be used. In this case, the change in the rotation speed is detected by a change with respect to the predetermined rotation speed per predetermined time.

The torque limiter 8 and the rotation speed sensor used as the conveyance abnormality detection means are connected to the input side of the control unit 100 shown in FIG.
In FIG. 3, a control unit 100 is an image forming sequence program execution unit whose main part is constituted by a microcomputer. As a configuration related to the present embodiment, the above-described conveyance abnormality detection means 101 is connected to the input side. Alarm means 102 is connected to the output side.
For example, a display unit such as an operation panel provided in the image forming apparatus is used as the alarm unit 102 located on the output side, and displays an alarm display that a conveyance abnormality has occurred.

  Based on the signal from the conveyance abnormality detection unit 101, the control unit 100 warns when the signal from the detection unit changes from the steady state.

  Next, another embodiment of the present invention will be described.

The embodiment shown in FIG. 4 is characterized in that a toner reservoir is provided at a position on the cleaning device 5 side to which the toner conveyance path P1 is connected, and this reservoir is used as a buffer for temporarily storing toner.
In FIG. 4, a toner storage unit 50 having a toner storage space separately from the cleaning device 5 is continuously arranged in the space of the cleaning device 5 at the connection portion of the toner conveyance path P <b> 1 in the cleaning device 5.

  One end of the toner conveyance path P1 is connected to the toner storage section 50 side. For this reason, the toner collected from the photosensitive member by the cleaning device 5 is stored on the cleaning device 5 side, and is accumulated in the toner storage portion 50 when the cleaning device 5 is filled.

  On the other hand, in this embodiment, when a toner conveyance abnormality occurs, it is predicted that the toner storage unit 50 is full. Thus, the user can recognize in advance the number of times that image formation is possible from the time when the conveyance abnormality occurs.

  That is, the control unit 100 shown in FIG. 3 is used in the configuration for predicting the toner fullness, and the control unit 100 uses the number of copies as input means for the number of times of image formation that affects the amount of collected toner, so-called the number of copies. Instruction means 103, toner consumption detection means 104, pixel counter 105 capable of detecting the number of pixels of the image to be formed as an electrostatic latent image, and toner end detection for detecting that the toner reservoir 50 is filled with toner. Means 106 are connected.

The control unit 100 counts the number of times of image formation from the time when the conveyance abnormality is detected by the conveyance abnormality detection unit 101, and the count value corresponds to the case where the toner stored in the toner storage unit 50 is full. An alarm is given when the value matches.
Further, the toner consumption used as a parameter approximate to the number of image formations is the rotation of the developer supply member on the developing device 4 side, that is, the so-called developing roller capable of carrying the developer, from the time when the conveyance abnormality is detected. Further, the pixels are detected by the ratio of the image area to the background area of the photoreceptor based on the image data.
The toner end detection means 106 detects that the optical sensor provided on the inlet side of the toner storage section 50 is shielded from light when the toner is full.

In the control unit 100, the number of image formations corresponding to the amount of toner collected until the toner storage unit 50 becomes full is registered in advance, and compared with the number of image formations input on the basis of the time when the conveyance abnormality occurs. To alert the number of times image formation is possible.
Such full prediction is performed in the same manner when the number of rotations of the developing roller for determining the toner consumption is used, and when the pixel counter 105 is used, the image area for each image formation is determined. This is done by determining the amount of toner consumption corresponding to.
Further, the toner end detection means 106 is configured to determine a case where the toner cannot be stored any more by detecting the actual toner full state in the toner storage unit 50.

  In this embodiment, when the conveyance abnormality detection unit 101 detects that a conveyance abnormality has occurred, the control unit 100 warns the number of times images can be formed before the toner storage unit 50 becomes full. Even if a conveyance abnormality occurs, it is possible to provide a certain time lag so that the apparatus can be stopped. As a result, it is possible to provide a margin for performing a service man call and improve productivity regarding copying.

  Further, since it can be determined from the signal from the toner end detection means 107 that the toner storage unit 50 is full, this occurs when more toner is introduced by stopping the apparatus at this point. It is possible to prevent a possible overflow.

  In the present embodiment, as shown in FIG. 5, the cleaning device 5 is provided in a process cartridge 200 in which the developing device 4 and the toner conveyance path P1 are integrated, whereby the toner conveyance portion is integrated. It can be removed. Accordingly, it is possible to replace the toner conveying portion at the same time when the apparatus is stopped due to a conveyance abnormality or the like, and it is possible to improve the exchange workability and prevent the toner from spilling at the conveying portion. . Further, since the developing device 4 is also subjected to replacement work at the same time, foreign matters other than toner can be removed at the same time as the replacement. As a result, there is a possibility that the developing device 4 may cause clogging of foreign matter at the doctor unit. Elimination can be facilitated to prevent image loss.

1 is a schematic diagram illustrating an example of an image forming apparatus using a toner conveyance mechanism according to an embodiment of the present invention. FIG. 4 is a schematic diagram illustrating a peripheral portion of a cleaning device for explaining a main configuration of a toner transport mechanism according to a position example of the invention. FIG. 4 is a block diagram for explaining a configuration of a control unit used in the toner conveyance mechanism according to the position example of the invention. FIG. 6 is a schematic diagram illustrating a peripheral portion of a cleaning device for explaining a main configuration of a toner transport mechanism according to another embodiment of the present invention. FIG. 3 is a schematic diagram for explaining a configuration of a process cartridge used in a toner conveyance mechanism according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Copier which is one of image forming apparatuses 2 Photosensitive body which is a latent image carrier 4 Developing device 5 Cleaning device 6 Conveying screw 50 Toner storage unit 100 Control unit 101 Conveyance abnormality detecting unit 102 Alarm unit 103 Copy number command unit 104 Toner consumption detection means 105 Pixel counter 106 Toner end detection means 200 Process cartridge P1 Toner transport path

Claims (11)

After the transfer of the toner image obtained by subjecting the electrostatic latent image formed on the latent image carrier to a visible image treatment with a developer containing toner, the toner remaining on the latent image carrier is collected by a cleaning unit, and the collection is performed. A developer transport mechanism for transporting the used toner for disposal or recycling,
A toner conveyance path continuous with the cleaning means, and a rotation transfer means loaded therein;
A conveyance abnormality detection means provided in the toner conveyance path;
And a means for alarming when an abnormal conveyance state is detected by the conveyance abnormality detection means.   The developer transport mechanism according to claim 1, wherein the rotation transfer unit uses a transportable drive coil, and the toner is transported in accordance with the rotation of the transport coil.   3. The developer conveying mechanism according to claim 1, wherein the conveyance abnormality detecting unit is configured to monitor a change in driving torque of a rotary transfer unit loaded in the toner conveying path.   3. The developer conveying mechanism according to claim 1, wherein the conveyance abnormality detecting unit is configured to monitor a change in the number of rotations of a rotating and conveying unit loaded in the toner conveying path.   5. The developer transport mechanism according to claim 1, wherein the toner transport path is provided with a collected toner storage section on the cleaning unit side.   6. The developer transport mechanism according to claim 1, wherein the means for alarming the abnormal transport state predicts a full state in the toner storage portion based on the number of image formations.   6. The developer according to claim 1, wherein the means for alarming the abnormal conveyance state predicts a full state in the toner storage portion based on a consumption amount of toner used for the visible image processing. Transport mechanism.   2. The means for warning the abnormal conveyance state predicts a full state of the toner storage portion based on the number of pixels for forming an electrostatic latent image on the latent image carrier. 5. The developer conveying mechanism according to 5.   The developer transport mechanism according to claim 5, wherein the toner storage portion is provided with an end detection unit capable of detecting a full state.   The developer conveying mechanism, wherein the cleaning means is provided in a process cartridge in which a developing device used for visible image processing of an electrostatic latent image and the toner conveying path are integrated. An image forming apparatus using the developer transport mechanism according to claim 1.

Images