JP2006208623A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of inspecting abnormality of a waste toner conveyance portion without providing an extra detection sensor by using a fullness detection sensor for a waste toner storage portion where waste toner collected by cleaning is accumulated. <P>SOLUTION: A copying machine 1 is so configured that a CPU 10 decides that the waste toner conveyance portion 61 is abnormal when it is decided that the fullness detection sensor 60, which detects transmitted light transmitted through the waste toner storage portion 59 where the waste toner collected by cleaning is accumulated being cut off by the waste toner, does not detect the transmitted light being cut off. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, and a facsimile, and more particularly, to an inspection technique for a waste toner transport unit.

Conventionally, in an image forming apparatus such as a printer and a copying machine, a waste toner that is a toner removed and collected from a photosensitive drum of an image end member is generally a screw having a plurality of spiral spiral blades. And / or, for example, a transmissive type provided near the entrance of the waste toner storage unit after the waste toner is transported to the waste toner storage unit where the waste toner is stored by the waste toner transport unit having a waste toner transport mechanism such as a transport belt When the photo sensor detects that the transmitted toner is blocked by the waste toner accumulated up to the entrance, it is determined that the waste toner storage unit is full. (For example, refer to Patent Document 1). As a reference example of an image forming apparatus different from the above, an image forming apparatus provided with an inappropriate state detecting unit capable of detecting a non-attached state of a waste toner transport body and the presence or absence of toner in the waste toner transport body is disclosed. -It has been proposed (see, for example, Patent Document 2).
JP 2002-287595 A Japanese Patent No. 3327381

  Certainly, in the case of the image forming apparatus having the above-described configuration, when the waste toner storage unit becomes full of the waste toner, the full detection is detected by the full detection sensor, so that the waste toner storage unit can be replaced immediately. Met.

  However, in the conventional image forming apparatus, when the waste toner transport mechanism of the waste toner transport unit does not operate normally due to breakage of the screw, breakage of the transport belt, abnormality of the drive source of the transport mechanism, or the like immediately. Since there is little possibility that the user will know that the problem is caused by an abnormal condition, printing of several tens to several hundreds of sheets is continuously performed, and the waste toner conveyance path is clogged and the main body of the apparatus is blocked. In some cases, serious damage was done. Further, conventionally, it is difficult to recognize a defect of the waste toner transport unit from the outside other than newly adding a sensor for detecting an abnormality of the waste toner transport unit in addition to the full detection sensor. When a sensor or the like for detecting an abnormality is newly added, there is a problem that the manufacturing cost of the image forming apparatus increases.

  Therefore, it is difficult to find a defect in the waste toner transport unit before the first use of the image forming apparatus (that is, before the shipment of the apparatus), during service maintenance, and when the image forming apparatus is used. Later, a complaint from the user often reveals a defect in the waste toner transport unit, so that disassembling and repairing the image forming apparatus is not possible with respect to the image forming apparatus on the user side (ie, availability). Alternatively, the operating rate (time during which the apparatus can be used normally) is reduced and the service cost on the maintenance side is increased, and the reliability of the image forming apparatus is reduced. In addition, when the waste toner path is clogged, it is necessary to clean the inside of the machine, disassemble and repair the waste toner transport unit, and seriously damage the drive unit of the waste toner transport unit and the drive unit of the photosensitive drum. In such a case, there is a problem that parts and man-hours required for repair become very large.

  In view of the above problems, the present invention inspects the abnormality of the waste toner transport unit by using the full detection sensor of the waste toner accumulation unit that accumulates the waste toner collected by cleaning without adding a new detection sensor. It is an object of the present invention to provide an image forming apparatus capable of doing so.

  In order to achieve the above object, an image forming apparatus according to the present invention is a toner formed as a toner image on the surface of an image holding member, or remains on the surface of the image holding member after transfer of the toner image to a sheet. A cleaning unit that collects the toner to be collected, a waste toner transport unit that transports the toner collected by the cleaning unit, and a single or a plurality of waste toner storage units that store the toner transported by the waste toner transport unit And a fullness detection sensor that detects light shielding by the toner of transmitted light that passes through the waste toner accumulation unit, and the fullness detection sensor detects light shielding by the toner accumulated in the waste toner accumulation unit for a predetermined time. A full determination unit that determines that the waste toner storage unit is full, and after the start of the transport of the waste toner transport unit, An error determination unit that determines that the waste toner conveyance unit is abnormal when the full detection sensor does not detect light shielding by the toner conveyed by the waste toner conveyance unit even after the conveyance time has elapsed; It is made up of By adopting such a configuration, it is possible to determine whether or not there is an abnormality in the waste toner conveyance unit by using a full detection sensor that detects the fullness of the waste toner storage unit that stores the waste toner collected by cleaning. Therefore, it is possible to provide a low-cost and highly reliable image forming apparatus without adding a new sensor. In addition, since waste toner can be prevented from being clogged, it is possible to prevent cleaning of the inside of the apparatus due to clogging of waste toner and disassembly and repair of the waste toner transport section, as well as a drive device for the waste toner transport section, a photosensitive drum drive section, etc. Can prevent serious damage to

  The image forming apparatus having the above-described configuration is configured such that the abnormality determination unit determines whether the waste toner transport unit is abnormal in a predetermined inspection mode. By adopting such a configuration, it is possible to inspect abnormalities in the waste toner conveying unit using the full detection sensor in the inspection mode during the manufacturing process of the image forming apparatus or during service maintenance. It can be provided as a highly reliable product without causing an increase in cost.

  The image forming apparatus having the above-described configuration includes: an image forming unit that forms a predetermined toner image on the surface of the image holding member and transfers the image to a sheet; and an operation unit that receives input of predetermined information. And when the predetermined inspection mode is received by the operation unit, the solid toner image formed in a predetermined region on the surface of the image holding member by the image forming unit is displayed on the sheet. The cleaning unit collects the toner image without transferring the toner image, and the abnormality determination unit includes a control unit that determines abnormality of the waste toner conveyance unit. With such a configuration, it is possible to improve the toner detection sensitivity when the abnormality detection of the waste toner transport unit is performed using the full detection sensor.

  Further, the image forming apparatus having the above-described configuration is configured such that the waste toner storage unit includes a movable shutter. With such a configuration, it is possible to improve the toner detection sensitivity when the abnormality detection of the waste toner transport unit is performed using the full detection sensor.

  As described above, the image forming apparatus according to the present invention uses the full detection sensor that detects the fullness of the waste toner accumulation unit that accumulates the waste toner collected by cleaning without adding a new sensor. In addition, it is possible to determine whether or not there is an abnormality in the waste toner conveying portion, and it is possible to provide a low-cost and highly reliable image forming apparatus.

  In the following description, the present invention is applied to a four-color drum full-color tandem copying machine as an example. FIG. 1 is a block diagram showing the configuration of the main part of a copying machine according to the present invention, and FIG. 2 is a longitudinal sectional view schematically showing the structure of the main part of the copying machine according to the present invention. As shown in both figures, the copier 1 of this embodiment includes a central processing unit 10 (hereinafter referred to as a CPU [Central Processing Unit] 10) that controls the operation of the entire apparatus, and a document transport that automatically transports a document. Unit 11, a document take-in unit 12 that takes in a document transported from document transport unit 11 and generates image data, and an operation display unit 13 that includes operation means (such as a numeric keypad or touch panel) and display means (such as a liquid crystal display). An image forming unit 14 that forms (that is, transfers) a toner image that becomes a color or monochrome image on the sheet based on the image data, and fixes the toner image formed on the sheet by the image forming unit 14 on the sheet. A fixing unit 15, a paper feeding unit 16 that feeds paper to the image forming unit 14, a paper discharge unit 17 that is a paper discharge destination, and a ROM [Read Only Memory] in which various control programs are stored. , And it includes a memory unit 18 composed of a hard disk RAM used as a work area [Random Access Memory], and the various data are stored, the. The memory unit 18 stores programs and data necessary for implementing the present invention. Further, an OHP sheet or the like may be used as a transfer destination of the toner image in addition to the sheet as a sheet.

In addition to controlling the operation of the entire apparatus, the CPU 10 performs processing related to inspection control of the waste toner conveying unit using a full detection sensor, which will be described in detail later. As will be described later, if the full sensor does not detect a change in transmitted light due to the toner (that is, the waste toner) even after a predetermined transport time has elapsed after the start of the transport of the waste toner transport unit, it is discarded. When the abnormality determination unit that determines that there is an abnormality in the toner transport unit and the full detection sensor continuously detect the toner accumulated in the waste toner storage unit (that is, the waste toner) for a predetermined time, the waste toner storage unit It also plays the role of a fullness determination unit that determines that is full.

  As shown in FIG. 2, the sheet feeding unit 16 includes a plurality of (three in this embodiment) sheet storage units 161 a to 161 c serving as a sheet supply source to the image forming unit 14, and each sheet storage unit 161 a to 161 c. A sheet conveyance unit 162 serving as a common sheet conveyance path from the image forming unit 14 to the image forming unit 14.

  The image forming unit 14 will be described below. FIG. 3 is a longitudinal sectional view schematically showing the image forming unit 14 of the copying machine 1 according to the present embodiment. The image forming unit 14 includes a yellow image forming unit 50a that forms a yellow toner image on a paper, a magenta image forming unit 50b that forms a magenta toner image on a paper, and a cyan toner image on the paper. A cyan image forming unit 50c that performs image formation, a black image forming unit 50d that forms a black toner image on paper, and a waste toner of each color that has been removed and collected by each of the collection blades 56a to 56d described later is conveyed. A waste toner transport unit 61, a waste toner storage unit 59 in which the waste toner transported by the waste toner transport unit 61 is stored, and a light emitting element 60a and a light receiving element 60b at the entrance of the waste toner storage unit 59, emit light. Light transmitted from the waste toner accumulating unit 59 of the light emitted from the element 60a is blocked by the waste toner and is received by the light receiving element 60b. The full detection sensor 60 including a transmission type photo sensor that detects the absence of light reception and inputs the detection signal to the CPU 10 and the sheet conveyed from the sheet feeding unit 16 are conveyed from the image forming unit 14 to the fixing unit 15. A transfer belt 58. In the waste toner accumulation unit 59, at least a detection range portion in which light from the light emitting element 60a of the fullness detection sensor 60 is transmitted toward the light receiving element b is formed of a material that transmits light. A solid line arrow A in FIG. 3 indicates the sheet conveyance direction.

  Further, as shown in FIG. 3, the yellow image forming unit 50a, the magenta image forming unit 50b, the cyan image forming unit 50c, and the black image forming unit 50d are arranged for each color of yellow, magenta, cyan, and black based on the image data. Image end support photosensitive drums 51a to 51d on which toner images are respectively formed on the surfaces of the drums, chargers 53a to 53d for uniformly charging the surfaces of the photosensitive drums 51a to 51d to predetermined potentials, and image data The exposure units 55a to 55d that irradiate the laser beam to form electrostatic latent images on the surfaces of the photosensitive drums 51a to 51d, and yellow, respectively, from the electrostatic latent images on the surfaces of the photosensitive drums 51a to 51d. Developers 52a to 52d for forming magenta, cyan and black toner images on the surfaces of the respective photosensitive drums 51a to 51d. Transfer rollers 57a to 57d for electrostatically transferring toner images formed on the surfaces of the photosensitive drums 51a to 51d onto the conveyed paper, and toner images formed on the surfaces of the photosensitive drums 51a to 51d. After the toner or toner images are transferred to the paper, the recovery blades 56a to 56d serving as a cleaning unit that removes and recovers the toner remaining on the surfaces of the photosensitive drums 51a to 51d, and the toner is removed by the recovery blades 56a to 56d. And neutralizing lamps 54a to 54d for neutralizing the surfaces of the photosensitive drums 51a to 51d.

  Further, as shown in FIG. 3, the waste toner transport unit 61 is disposed in parallel to the photosensitive drums 51a to 51d, and the waste toners of the respective colors collected by the collection blades 56a to 56d are disposed on the front side in the direction perpendicular to the paper surface. The first transport units 62a to 62d that are transported to the inlet portions of the second transport unit 65, which will be described later, and dropped into the second transport unit 65, and the waste transported from the first transport units 62a to 62d And a second transport unit 65 for dropping the toner onto the waste toner storage unit 59.

  Further, as shown in FIG. 3, each of the first transport units 62 a to 62 d is arranged in parallel with each of the photosensitive drums 51 a to 51 d, and a plurality of the first conveying units 62 a to 62 d are arranged on the rotation shaft circumferential surface in a cylinder opened on the side of each collection blade 56 a to 56 d. First screws 63a to 63d, which are waste toner transport mechanisms that have spiral spiral blades and that transport waste toner of each color to the near side in the direction perpendicular to the paper surface by being rotated by a driving force (not shown). (That is, the same shape as the second screw 66 described later), and first containers 64a to 64d in which cylinders in which the respective collection blades 56a to 56d are opened and in which the first screws 63a to 63d are disposed are formed, It has.

  Further, as shown in FIG. 3, the second transport unit 65 is disposed in parallel with the transfer belt 58 and has a plurality of spiral spiral blades on the circumferential surface of the rotation shaft in the cylinder, and a driving force (not shown). The second screw 66, which is a waste toner transport mechanism for transporting the waste toner transported by the first transport units 62a to 62d to the waste toner accumulation unit 59, and the first transport units 62a to 62a. 62d and the waste toner storage part 59, and a second container 67 in which a cylinder in which the second screw 66 is disposed is formed.

  As shown in FIG. 3, the waste toner conveyance path, which is a waste toner conveyance path, is a path through which waste toner is conveyed to the waste toner accumulation unit 59 by the first conveyance units 62 a to 62 d and the second conveyance unit 65. is there.

  Next, an example of a document copying operation in the copying machine 1 configured as described above will be described. In the document copying operation in the copying machine 1, first, a document is transported from the document transport unit 11 to the document capture unit 12, and the document capture unit 12 captures the document (generates image data). The generated image data is temporarily stored in the memory unit 18, read again, and sent to the image forming unit 14. An electrostatic latent image is created by each exposure unit 55a-55d based on the image data on the surface of each photosensitive drum 51a-51d uniformly charged to a predetermined potential by the chargers 53a-53d, and the developing device 52a. ˜52d form one color toner images from the electrostatic latent images on the surfaces of the respective photosensitive drums 51a˜51d. The toner images formed on the surfaces of the photosensitive drums 51a to 51d are sequentially transferred onto the paper by the transfer rollers 57a to 57d while the paper conveyed from the paper supply unit 16 is conveyed to the transfer belt 58.

  Thereafter, the sheet carrying the unfixed toner image is sent to the fixing unit 15 and heated and pressed by the fixing unit 15 to fix the toner image on the sheet. It is discharged to the part 17.

  On the other hand, the toner remaining on the photosensitive drums 51a to 51d that has been transferred to the paper or the toner images of the photosensitive drums 51a to 51d that have not been transferred to the paper was removed by the collecting blades 56a to 56d. Thereafter, the surfaces of the photosensitive drums 51a to 51d are neutralized by the neutralizing lamps 54a to 54d.

  The waste toner, which is the toner removed and collected by the collecting blades 56a to 56d, is moved to the front side in the direction perpendicular to the paper surface by the first screws 63a to 63d of the first conveying units 62a to 62d that have started to rotate. After being transported and transported to each inlet portion of the second transport unit 65, it is dropped onto the second transport unit 65.

  Subsequently, the waste toner is conveyed toward the waste toner accumulation unit 59 by the second screw 66 of the second conveyance unit 65 that has started rotating, and is dropped and accumulated in the waste toner accumulation unit 59. The hatched portion in the waste toner accumulation unit 59 in FIG. 3 indicates the accumulated waste toner.

  Further, the waste toner is accumulated up to the vicinity of the entrance of the waste toner accumulation unit 59, and the fullness detection sensor 60 continuously detects light shielding by the waste toner accumulated in the waste toner accumulation unit 59 for a predetermined time. Is continuously input to the CPU 10, the CPU 10 determines that the waste toner storage unit 59 is full. Then, the CPU 10 displays on the operation display unit 13 a request to replace the waste toner storage unit 59.

  Note that the copying machine 1 according to the present embodiment controls the abnormality determination of the waste toner conveyance unit 61 that is performed using the full detection sensor 60 that detects the fullness of the waste toner accumulation unit 59 that accumulates the waste toner collected by cleaning. It has the characteristics.

  Therefore, in the following, with reference to the drawings, the waste toner transport unit 61 that uses the full detection sensor 60 that detects the fullness of the waste toner storage unit 59 that stores the waste toner that has been collected by cleaning in the present embodiment. A detailed description of the control related to abnormality determination will be given. FIG. 4 is a flowchart illustrating an example of the abnormality determination inspection mode of the waste toner transport unit 61 in the copying machine 1 according to the present embodiment. FIG. 5 is a flowchart illustrating an example of pre-processing in the abnormality determination inspection mode. FIG. 6 is a flowchart illustrating an example of an abnormality inspection of the waste toner transport unit 61 performed for each color in the abnormality determination inspection mode. In the copying machine 1 of the present embodiment, as shown in FIG. 4, in step S 4-1, a switching button (not shown) for shifting to the abnormality determination inspection mode of the waste toner transport unit 61 displayed on the operation display unit 13 is displayed. When the user presses the key or enters a personal identification number from a numeric keypad (not shown) or the like, the abnormality determination inspection mode of the waste toner conveyance unit 61 is entered.

  Subsequently, in step S4-2, the CPU 10 determines whether the fullness detection sensor 60 is normal. If the CPU 10 repeatedly turns on / off the light emitting element 60a a predetermined number of times and does not recognize that the output from the light receiving element 60b changes (NO in S4-2), the fullness detection sensor 60 has an abnormality. In step S4-3, the operation display unit 13 displays that the fullness detection sensor 60 is abnormal. In step S4-2, the CPU 10 first confirms that the full detection sensor 60 is not blocked by waste toner or the like on a liquid crystal display (not shown) provided with the touch sensor of the operation display unit 13 and the full detection sensor. A confirmation button that is pressed when it is confirmed that 60 is not shielded from light is displayed, and after the confirmation button is pressed by the user, step 4-2 may be performed.

  If it is confirmed in step S4-2 that the CPU 10 repeatedly turns the light emitting element 60a on and off a predetermined number of times and the output from the light receiving element 60b changes (YES in S4-2), step S4 is performed. -4, the waste toner for removing the influence on the abnormality determination of the waste toner transport unit 61 by the toner remaining in the waste toner transport path by printing before the execution of the abnormality determination inspection mode of the waste toner transport unit 61 Preprocessing of the transport path is performed as follows.

  Here, the preprocessing of the waste toner conveyance path in step 4-4 will be described below with reference to the flowchart of FIG. In the copying machine 1 of the present embodiment, in step S5-1, the CPU 10 starts driving the waste toner conveyance unit 61, and in step S5-2, the CPU 10 starts monitoring the full detection sensor 60 as the abnormality determination inspection mode. Is done.

  Subsequently, in step S5-3, the CPU 10 continuously continues the first screws 63a to 63d and the first screw of the waste toner transport unit 61 for a time sufficient to completely discharge the waste toner transport path. When the two screws 66 are driven and the blockage of the transmitted light by the waste toner falling from the second transport unit 65 by the full detection sensor 60 is not detected continuously for 10 seconds in step S5-4 (S5-4 YES). In step S5-5, the CPU 10 stops the driving of the first screws 63a to 63d and the second screw 66 of the waste toner transport unit 61, and this operation is completed.

  In step S5-4, if the CPU 10 determines that the detection of the blocking of transmitted light by the waste toner falling from the second conveyance unit 65 by the full detection sensor 60 is not detected continuously for 10 seconds ( S5-4NO), and in step S5-4, the monitoring is continued until the fullness detection sensor 60 continues to block the transmitted light by the waste toner falling from the second conveyance unit 65 for 10 seconds and no detection is made. The Note that preprocessing of the waste toner conveyance path may be canceled halfway by pressing a stop key (not shown) or the like of the operation display unit 13. Further, the non-detection time for blocking the transmitted light by the waste toner detected by the full detection sensor 60 is not limited to 10 seconds, and may be arbitrarily set. Hereinafter, the description returns to the flowchart of FIG.

  Subsequently, in step S4-5, the first conveyance unit 62a and the second conveyance unit 65, which are conveyance paths for the yellow waste toner collected from the yellow image forming unit 50a, are inspected as follows.

  Here, with reference to the flowchart of FIG. 6, the abnormality inspection of the first conveyance unit 62 a and the second conveyance unit 65 serving as the conveyance path of the yellow waste toner collected from the yellow image forming unit 50 a in step S <b> 4-5 will be described below. To explain. In the copying machine 1 of the present embodiment, in step S6-1, as shown in FIG. 3, a non-transfer solid toner image is created in a predetermined range of the photosensitive drum 51a by the yellow image forming unit 50a, and the recovery blade 56a. Thus, the non-transfer solid toner image is removed and collected. Then, the waste toner, which is the removed and collected toner, falls to the first conveyance unit 62a and is collected. In addition, in order to be able to inspect the long conveyance path portion in the first conveyance unit 62a, the most upstream portion of the waste toner conveyance path in the first conveyance unit 62a (that is, on the back side in the direction perpendicular to the paper surface of FIG. 3). The toner image is preferably formed on the photosensitive drum 51a by the yellow image forming unit 50a so that the waste toner falls and is recovered. Thus, by creating a non-transfer solid toner image in a predetermined range of the photosensitive drum 51a, it is possible to improve detection sensitivity when waste toner is detected by a full detection sensor 60 described later.

  Subsequently, in step S6-2, rotational driving of the first screw 63a and the second screw 66 of the waste toner transport unit 61 is started, and in step S6-3, the CPU 10 performs a full detection sensor 60 as an abnormality determination inspection mode. Monitoring is started.

  Subsequently, in step S6-4, the CPU 10 continues the first screw 63a and the second screw of the waste toner transport unit 61 continuously for a time sufficient to completely discharge the preset yellow waste toner transport path. The screw 66 is driven, and the CPU 10 causes the waste toner that has fallen from the second transport unit 65 by the full detection sensor 60 even if a predetermined transport time has elapsed after the start of transport of the waste toner transport unit 61 by the CPU 10 in step S6-5. When it is determined that the detection of the blocking of transmitted light is not detected continuously for 10 seconds (that is, when it is determined that it has been detected) (S6-5NO), the CPU 10 performs the first conveyance in step S6-6. It is determined that there is no abnormality in the section 62a and the second transport section 65. Note that the non-detection time during which the transmitted toner is continuously blocked by the waste toner detected by the full detection sensor 60 by the CPU 10 is not limited to 10 seconds, and may be arbitrarily set.

  Subsequently, in step S6-7, the CPU 10 stops monitoring the driving of the waste toner conveying portion 61 and the abnormality detection of the fullness detection sensor 60, and changes to detection of the waste toner fullness in the waste toner accumulation portion by the fullness detection sensor 60. This operation is completed.

  In step S6-5, the CPU 10 blocks the transmitted light by the waste toner falling from the second conveyance unit 65 by the full detection sensor 60 even if a predetermined conveyance time has elapsed after the conveyance of the waste toner conveyance unit 61 is started. In the case where it is determined that no detection continues for 10 seconds (YES in S6-5), it is considered that the first transport unit 62a and the second transport unit 65 are abnormal in step S6-8. In order to improve the certainty of the abnormality determination, the CPU 10 determines that there is an abnormality determination inspection error, counts the number of errors, and stores the number of errors in the memory unit 18.

  Subsequently, in step S6-9, when the CPU 10 recognizes that the number of errors is 2 or less (NO in step S6-9), the process returns to the above-described step S6-1. If the CPU 10 recognizes that the number of errors is 3 in step S6-9 (YES in step S6-9), the CPU 10 causes the first transport unit 62a and the second transport unit in step S6-10. It is determined that there are 65 abnormalities. The number of errors is set in advance, and the number of errors is not particularly limited to three, and the number of errors may be arbitrarily set.

  Subsequently, in step S6-11, the CPU 10 stops the driving of the waste toner transport unit 61 and the monitoring as the abnormality determination inspection mode by the fullness detection sensor 60, and the waste toner storage unit 59 is full of waste toner by the fullness detection sensor 60. The operation is changed to the detection operation, and this operation is completed. Hereinafter, the description returns to the flowchart of FIG.

  Subsequently, abnormality inspection of the first conveyance unit 62b and the second conveyance unit 65, which are conveyance paths of magenta waste toner collected from the magenta image forming unit 50b, which is performed in steps S4-6 to S4-8, respectively, cyan In the abnormality inspection of the first conveyance unit 62c and the second conveyance unit 65, which are conveyance paths of cyan waste toner collected from the image forming unit 50c, and in the conveyance path of black waste toner collected from the black image formation unit 50d The first conveyance unit 62a and the second conveyance unit 62a and the second conveyance unit 65a are transport paths for the yellow waste toner collected from the yellow image forming unit 50a in step S4-5 described above. The inspection is performed in the same manner as the abnormality inspection of the transport unit 65 (that is, steps S6-1 to S6-11 in FIG. 6).

  Subsequently, in step S4-9, among the first transport units 62a to 62d and the second transport unit 65 of the waste toner transport unit 61, the transport unit that is determined to be abnormal is displayed on the operation display unit 13 by the CPU 10 as follows. Is displayed. If an abnormality is detected in the waste toner conveyance unit for three or less colors among the first conveyance units 62a to 62b and the second conveyance unit 65, the abnormality in the first conveyance unit corresponding to the color of the toner is determined. Is displayed, and it is determined that there is an abnormality in the transport section of the waste toner for four colors, all the first transport sections 62a to 62d are abnormal, or the second transport section 65 is abnormal. Is displayed and this operation is completed.

  The copying machine 1 of the present embodiment has a configuration including one waste toner storage unit 59. However, the present invention is similarly applied to a copying machine including a plurality of waste toner storage units. You may apply.

  If the abnormality inspection of the waste toner conveyance unit 61 described above is performed during the manufacturing process of the copying machine 1, the abnormality inspection is performed using the full detection sensor 60, which causes an increase in the cost of the copying machine 1. Therefore, a highly reliable product can be provided.

  A shutter (not shown) is provided near the downstream side of the full detection sensor 60 position for blocking and accumulating the fall of waste toner, and the CPU 10 in step 6-3 monitors the full detection sensor 60 as an abnormality determination inspection mode. Is started, the shutter (not shown) is closed, and the detection of blocking of the transmitted light by the waste toner accumulated is performed by the full detection sensor 60, and the CPU 10 determines whether the waste toner transport unit 61 is abnormal or not. The configuration may be such that the shutter (not shown) is opened again after the determination. By adopting such a configuration, it is possible to improve the detection sensitivity of the full detection sensor 60 for shielding light from waste toner.

  As described above, the configuration shifts to the abnormality determination / inspection mode of the waste toner conveyance unit 61 by a predetermined input. However, when the copying machine 1 forms an image on a sheet, the CPU 10 is full. From the processing operation in which the waste toner detection signal of the detection sensor 60 is used to determine whether the waste toner storage unit 59 is full of waste toner, the waste toner detection signal of the full detection sensor 60 is automatically used to discard waste toner. The processing operation that is determined to be abnormal in the transport unit 61 is changed, and the light transmitted through the waste toner storage unit 59 is blocked by the waste toner falling on the waste toner storage unit 59 after the start of transport of the waste toner transport unit 61. If the full detection sensor 60 does not continue to detect for a predetermined time even after the elapse of time, the operation table indicates that the waste toner transport unit 61 is abnormal. It may be displayed on the section 13.

  It should be noted that the abnormality inspection of the waste toner conveyance unit 61 described above may be automatically performed by the CPU 10 when a preset time has elapsed or when printing is performed for a set number of sheets or more.

  As described above, in the present embodiment, the description has been given by taking the four-color drum full-color tandem type copying machine 1 as an example. However, the present invention is applicable to a monochrome image machine or a color image forming apparatus other than the tandem system. May be applied.

  Therefore, as described above, the copying machine 1 according to the present embodiment uses the full detection sensor 60 that detects the fullness of the waste toner accumulation unit 59 that accumulates the waste toner that has been collected by cleaning. Since it is possible to determine whether there is an abnormality in 61, it is possible to provide a low-cost and highly reliable copying machine without adding a new sensor. Further, since waste toner can be prevented from being clogged, it is possible to prevent cleaning of the inside of the apparatus due to clogging of waste toner and disassembly and repair of the waste toner transport unit 61, and driving of the waste toner transport unit 61 and driving of the photosensitive drum. Serious damage to parts and the like can be prevented.

  The present invention can be widely applied to image forming apparatuses such as printers and facsimiles in addition to copying machines, and is a technique useful for determining an abnormality in a waste toner transport unit.

FIG. 2 is a block diagram showing a main configuration of a copier according to the present invention. These are the longitudinal cross-sectional views which show typically the principal part structure of the copying machine which concerns on this invention. These are longitudinal sectional views schematically showing the image forming unit 14 of the copying machine 1 of the present embodiment. These are flowcharts showing an example of an abnormality determination inspection mode of the waste toner conveying section 61 in the copying machine 1 of the present embodiment. These are the flowcharts which show an example of the pre-process in abnormality determination test | inspection mode. These are flowcharts showing an example of an abnormality inspection of the waste toner conveying unit 61 performed for each color in the abnormality determination inspection mode.

Explanation of symbols

1 Copier 10 Central processing unit (CPU)
DESCRIPTION OF SYMBOLS 11 Document conveyance part 12 Document take-in part 13 Operation display part 14 Image formation part 15 Fixing part 16 Paper feed part 161a-161c Paper storage part 162 Paper conveyance part 17 Paper discharge part 18 Memory part 50a Yellow image formation part 50b Magenta image formation Section 50c Cyan image forming section 50d Black image forming section 51a to 51d Photosensitive drums 52a to 52d Developers 53a to 53d Chargers 54a to 54d Charge eliminating lamps 55a to 55d Exposure units 56a to 56d Recovery blades 57a to 57d Transfer rollers 58 Transfer belt 59 Waste toner accumulation part 60 Full detection sensor 60a Light emitting element 60b Light receiving element 61 Waste toner conveying part 62a to 62d First conveying part 63a to 63d First screw 64a to 64d First container 65 Second conveying part 66 Second screw 67 Second container

Claims (4)

A cleaning unit that collects toner formed as a toner image on the surface of the image holding member, or toner that remains on the surface of the image holding member after transfer of the toner image to a sheet, and the cleaning unit that collects the toner. A waste toner transport unit that transports toner, one or more waste toner storage units in which the toner transported by the waste toner transport unit is stored, and shielding of transmitted light that passes through the waste toner storage unit by the toner When the fullness detection sensor continuously detects light blocking by the toner accumulated in the waste toner accumulation unit for a predetermined time, it is determined that the waste toner accumulation unit is full. An image forming apparatus comprising: a full determination unit;
If the fullness detection sensor does not detect light blocking by the toner transported by the waste toner transport unit even after a predetermined transport time has elapsed after the start of transport of the waste toner transport unit, the waste toner transport unit An image forming apparatus comprising: an abnormality determination unit that determines that the abnormality is normal.   The image forming apparatus according to claim 1, wherein the abnormality determination unit determines whether the waste toner conveyance unit is abnormal in a predetermined inspection mode. An image forming unit that forms a predetermined toner image on the surface of the image end-carrying member and transfers the image to a sheet; and an operation unit that receives input of predetermined information.
When the predetermined inspection mode is received by the operation unit, the solid toner image formed in a predetermined region on the surface of the image end member by the image forming unit is transferred to the sheet. The control unit according to claim 2, further comprising: a control unit that causes the cleaning unit to collect the toner image without causing the abnormality determination unit to perform an abnormality determination of the waste toner transport unit. Image forming apparatus.   The image forming apparatus according to claim 1, wherein the waste toner accumulation unit includes a movable shutter.

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