JP2011033693A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of simplifying the configuration of the apparatus. <P>SOLUTION: A displacement part 110 periodically moving in a direction crossing an optical path 144C is provided in a detection container 143. The displacement part 110 includes a receiving part 111 in which waste toner W flowing in the detection container 143 is accumulated, and a transmission part 112 adjacent to the receiving part 111. The light of a light emitting part 144A can pass through the receiving part 111. The receiving part 111 does not shield the optical path 144C in movement, when the receiving part 111 does not have the waste toner W inside, but the receiving part 111 periodically shields the optical path 144C in movement by the waste toner W, when the receiving part 111 has the waste toner W inside. The light of the light emitting part 144A can pass through the transmission part 112. The transmission part 112 does not shield the optical path 144C in movement regardless of the presence or absence of the waste toner W in the receiving part 111. Determination means S100 to S109 separately determine the presence or absence of the abnormality of a detection means 144 or the displacement part 110 and the accumulation state of the waste toner in a waste toner container 101 by the detection result of the detection means 144. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image forming apparatus.

  Patent Document 1 discloses an example of a conventional image forming apparatus. The image forming apparatus includes a waste toner container that stores waste toner that has not been transferred to a recording medium, and a transparent detection container provided inside the waste toner container. The lower part of the detection container bulges downward from the bottom part of the waste toner container. The waste toner accumulates in the waste toner container and then gradually flows into the detection container.

  A displacement portion that can be displaced in the vertical direction and a coil spring that biases the displacement portion upward are disposed in the detection container. The displacement part has a dish part on which waste toner that has flowed into the detection container accumulates, and a protrusion part that projects from the lower surface side of the dish part toward the lower part of the detection container.

  Further, this image forming apparatus has a light emitting part and a light receiving part facing each other with the lower part of the detection container interposed therebetween, and supports the shielding or opening of an optical path from the light emitting part through the detection container to the light receiving part. Detecting means for outputting a detection result.

  In this image forming apparatus, when the waste toner flows into the detection container and starts to accumulate on the dish portion, the displacement portion descends against the urging force of the coil spring according to the increase in the weight of the accumulated waste toner. . When a predetermined amount of waste toner accumulates on the dish portion, the projecting portion shields the optical path, and the detection means outputs a detection result corresponding to the shielding of the optical path. Based on the detection result, in the waste toner container It is determined that the waste toner has reached a specific accumulation state (almost full).

JP 2005-331663 A

  However, since the conventional image forming apparatus detects only the accumulation state of the waste toner in the waste toner container, the detection unit or the displacement unit is abnormal (for example, disconnection, breakage, or displacement of the light emitting unit or the light receiving unit). Even if the displacement part cannot be lowered due to entry of foreign matter into the gap between the part and the detection container.), The abnormal state cannot be detected. For this reason, another detection means for detecting an abnormality of the detection means or the displacement portion is necessary, resulting in a complicated apparatus configuration.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus capable of simplifying the configuration of the apparatus.

  An image forming apparatus according to the present invention is an image forming apparatus that forms an image on a recording medium by transferring a toner image to the recording medium, and that contains waste toner that has not been transferred to the recording medium. Light emission facing a toner container and a detection container that is continuously provided in the waste toner container and into which the waste toner flows when the waste toner accumulation state in the waste toner container reaches a specific accumulation state A detection unit that outputs a detection result corresponding to shielding or opening of an optical path that passes through the detection container and reaches the light receiving unit from the light emitting unit, and based on the detection result Determining means for determining whether or not the waste toner has reached a specific accumulation state in the waste toner container, and the detection container has a period in a direction intersecting the optical path. Transition A displacement part that repeats the operation is provided, and the displacement part has a receiving part that receives the waste toner flowing into the detection container and deposits the toner inside thereof, and a transmission part adjacent to the receiving part, The receiving part can transmit light from the light emitting part, and if the waste toner is not accumulated in itself, the receiving part does not shield the optical path during the moving operation, while the waste toner is not inside the self. If accumulated, the accumulated waste toner periodically shields the optical path during the moving operation, and the transmission unit can transmit light from the light emitting unit, and the receiving unit Regardless of whether or not the waste toner is accumulated inside the optical path, the optical path is not shielded during the moving operation, and the determination means is arranged on the detection means or the displacement portion based on the detection result. There is an abnormality And whether the waste toner in the waste toner container is whether the host vehicle has reached the particular storage conditions and characterized by distinguishable determine the city (claim 1).

  According to the image forming apparatus of the present invention, when the displacement portion moves periodically with respect to the optical path, the receiving portion and the transmission portion also periodically pass through the optical path. Here, while the waste toner is not accumulated inside the receiving portion, the receiving portion and the transmitting portion do not shield the optical path when passing through the optical path. For this reason, a detection means outputs the detection result corresponding to the continuous open | release of an optical path, ie, a waveform without a periodic change. In this case, the determination unit can determine that the toner has not reached a specific accumulation state.

  When the waste toner begins to accumulate inside the receiving portion, the transmission portion does not shield the optical path when passing through the optical path, while the receiving portion has a portion of the waste toner accumulated when passing through the optical path that passes through the optical path. Shield periodically. For this reason, a detection means outputs the detection result corresponding to the periodic shielding of an optical path, ie, the waveform which changes periodically. In this case, the determination unit determines that the toner has reached a specific accumulation state. Further, the determination means can determine that the detection means or the displacement unit is operating normally, that is, there is no abnormality, by causing a waveform that periodically changes to appear in the detection result.

  Then, once the determination means determines that there is no abnormality in the detection means or the displacement part, when the periodically changing waveform does not appear in the detection result of the detection means, this means that the optical path remains shielded or opened. Therefore, the determination means can determine that the detection means or the displacement portion is abnormal.

  As described above, since the image forming apparatus of the present invention can determine a plurality of states based on the detection result of one detection unit, the number of parts can be reduced and the apparatus configuration can be simplified.

  In the image forming apparatus of the present invention, the displacement portion has a shielding portion that periodically shields the optical path during the movement operation regardless of whether waste toner is accumulated inside the receiving portion. It is desirable that it is formed adjacent to the receiving part or the transmitting part, or formed in a part of the receiving part (claim 2).

  According to this configuration, while the waste toner is not accumulated inside the receiving part, the receiving part and the transmitting part do not shield the optical path when passing through the optical path, while the shielding part is used when passing through the optical path. Shield the light path periodically. When waste toner begins to accumulate inside the receiving part, the transmission part does not shield the optical path when passing through the optical path, while the toner accumulation part of the shielding part and the receiving part does not shield the optical path when passing through the optical path. Shield periodically.

  Here, the shielding part is formed adjacent to the receiving part or the transmitting part, or is formed at a part of the receiving part. For this reason, the detection result output by the detection means differs in the pattern of one cycle in the waveform that changes periodically depending on whether the waste toner is not deposited in the receiving portion or when it is accumulated. Accordingly, the determination unit can reliably determine whether or not the waste toner has reached a specific accumulation state in the waste toner container based on the difference in the pattern of one cycle.

  In addition, when an abnormality occurs in the detection unit or the displacement unit, a periodically changing waveform does not appear in the detection result of the detection unit regardless of whether waste toner is accumulated in the receiving unit. The means can reliably determine that the detection means or the displacement portion is abnormal.

  In the image forming apparatus of the present invention, the determination unit determines that the waste toner has reached a specific accumulation state in the waste toner container, and then in one cycle of the periodically changing waveform that appears in the detection result, It is desirable that the accumulated state of the waste toner in the waste toner container is judged step by step based on the duration of the waveform corresponding to the shielding of the optical path.

  According to this configuration, the duration of the waveform corresponding to the shielding of the optical path in one cycle of the periodically changing waveform appearing in the detection result according to the accumulation amount of the waste toner accumulated inside the receiving portion. Change. For this reason, even after the determination means determines that the waste toner is almost full (“near full”), the waste toner is almost full (“full”) based on the change in duration. The accumulated state of the waste toner up to can be judged in stages. Then, based on this determination result, the user's usability is improved by notifying the user in detail which stage the waste toner accumulation state is between “near full” and “full”.

  An image forming apparatus according to the present invention includes waste toner transfer means for collecting waste toner in a waste toner container or transferring the collected waste toner in the waste toner container, and drive means for driving the waste toner transfer means. It is preferable that the displacement portion is moved by receiving a driving force from the driving unit and the waste toner transfer unit. According to this configuration, even when an abnormality occurs in the driving unit or the waste toner transfer unit and the displacement unit does not periodically move, the determination unit can determine that the detection unit or the displacement unit is abnormal. As a result, it is possible to prevent a problem that the image forming operation is performed without the drive unit or the waste toner transfer unit operating normally.

  The image forming apparatus of the present invention includes a housing, the waste toner container and the displacement portion constitute a waste toner collecting unit that is detachably attached to the housing, and the detection unit and the determination unit are provided on the housing side. (Claim 5). According to this configuration, even when the waste toner collection unit is removed, the determination unit can determine that the detection unit or the displacement unit is abnormal. As a result, it is possible to prevent a problem that the image forming operation is performed without attaching the waste toner collecting unit.

  In the image forming apparatus of the present invention, the displacement portion has a box shape with an upper surface opened, and reciprocates in the vertical direction within the detection container. The lower portion of the displacement portion in the box shape is a receiving portion, and the displacement portion The upper part of the box shape of the part may be a transmission part (Claim 6). In addition, the displacement part has a box shape with an upper surface opened, and reciprocates horizontally in the detection container. One end side of the displacement part in the box-shaped reciprocation direction is a receiving part, and the displacement part The other end side of the box-shaped reciprocating direction may be a transmission part. Further, the displacement part is formed in a disk shape, and rotates horizontally in the detection container. A recessed part recessed downward from the disk-shaped upper surface of the displacement part is a receiving part, and the recessed part in the displacement part is The adjacent part may be a transmission part (Claim 8). With these specific configurations, the effects of the present invention can be reliably achieved.

1 is a schematic sectional view of an image forming apparatus according to Embodiment 1. FIG. 1 is a perspective view of a waste toner recovery unit according to an image forming apparatus of Embodiment 1. FIG. 1 is a perspective view of a waste toner recovery unit according to an image forming apparatus of Embodiment 1. FIG. FIG. 3 is an exploded perspective view of a waste toner recovery unit according to the image forming apparatus of Embodiment 1. FIG. 5 is a perspective view illustrating the displacement forming unit, the link unit, the conveying screw, and the detection unit in the image forming apparatus according to the first exemplary embodiment (a perspective view in the direction of arrow V illustrated in FIG. 4). FIG. 4 is a partial enlarged cross-sectional view illustrating a relative positional relationship between a vertically moving displacement unit and an optical path in the image forming apparatus of Example 1 (showing a state where waste toner is not accumulated on a receiving unit). FIG. 3 is a partial enlarged cross-sectional view illustrating a relative positional relationship between a vertically moving displacement unit and an optical path in the image forming apparatus of Example 1 (showing a state where waste toner is accumulated in a receiving unit). 1 is a block diagram illustrating an outline of a control system and a sensor control unit according to an image forming apparatus of Example 1. FIG. 5 is a flowchart of a determination program according to the image forming apparatus of Embodiment 1. 6 is a graph illustrating a detection result of a detection unit according to the image forming apparatus of Example 1. 6 is a graph illustrating a detection result of a detection unit according to the image forming apparatus of Example 1. 6 is a graph illustrating a detection result of a detection unit according to the image forming apparatus of Example 1. 6 is a graph illustrating a detection result of a detection unit according to the image forming apparatus of Example 1. FIG. 6 is a perspective view illustrating a displacement unit, a link unit, a conveying screw, and a detection unit extracted from the image forming apparatus of Example 2 (a perspective view in the direction of arrow XIV shown in FIG. 4). FIG. 6 is a partial enlarged cross-sectional view illustrating a relative positional relationship between a displacement part that moves back and forth and an optical path in the image forming apparatus of Example 2 (showing a state where waste toner is accumulated in a receiving part). FIG. 10 is a perspective view illustrating a displacement unit, a gear unit, a conveying screw, and a detection unit extracted from the image forming apparatus according to the third exemplary embodiment. FIG. 10 is a partial enlarged cross-sectional view illustrating a relative positional relationship between a rotating displacement portion and an optical path in the image forming apparatus according to Embodiment 3 (showing a state where waste toner is accumulated in a receiving portion).

  Embodiments 1 to 3 embodying the image forming apparatus of the present invention will be described below with reference to the drawings.

Example 1
As shown in FIG. 1, a printer 1 as an example of an image forming apparatus according to an embodiment is a color laser printer that forms a color image on a sheet (including an OHP sheet) as a recording medium by an electrophotographic method. . In FIG. 1, the right side of the paper is defined as the front side of the apparatus, and the left side of the paper is defined as the rear side of the apparatus. Further, when the apparatus is viewed from the front side, the side that comes to the left hand (the front side of the paper) is defined as the left side, and the opposite side is defined as the right side, and the front, rear, left, and right directions are displayed. 2 to 17 are displayed in correspondence with the respective directions shown in FIG. 1. Hereinafter, each component provided in the printer 1 will be described with reference to FIG.

1. Schematic Configuration of Printer The housing 3 is a substantially box-shaped body, and a frame member (not shown) is provided inside thereof. The frame member is assembled with a paper feeding unit 20, an image forming unit 10, a transport unit 30, a fixing device 80, a waste toner collecting unit 100, and the like. The image forming unit 10 is located substantially at the center of the housing 3.

  On the upper surface side of the housing 3, a discharge tray 5 for discharging the paper on which image formation has been completed is provided. In addition, a front cover 6 that can be opened and closed with the lower end side as a swing center axis is provided on the front surface of the housing 3. The image forming unit 10 and the transport unit 30 are configured to be detachable from the frame member with the front cover 6 opened. The waste toner collecting unit 100 is also configured to be detachable from the frame member in a state where the image forming unit 10 and the transport unit 30 are detached from the housing 3. Note that a specific configuration in which the image forming unit 10, the conveyance unit 30, and the waste toner collection unit 100 can be attached to and detached from the frame member is well known, and thus description thereof is omitted.

2. Paper Feed Unit The paper feed unit 20 forms an image on a paper feed tray 21 detachably housed below the housing 3 and a sheet placed on the paper feed tray 21 provided above the front end of the paper feed tray 21. A sheet feeding roller 22 that feeds (conveys) the sheet 10 and a separation pad 23 that separates the sheets fed by the sheet feeding roller 22 by giving a predetermined conveyance resistance to the sheets. Yes.

  In addition, the conveyance rollers 24 and 25 that apply a conveyance force to the sheet conveyed to the image forming unit 10 while curving in a substantially U shape at a portion of the sheet conveyance path P that turns to a substantially U shape in front. Is arranged. Further, on the downstream side of the conveyance path P with respect to the conveyance rollers 24 and 25, the skew of the sheet is corrected by contacting the leading edge of the sheet conveyed by the conveyance rollers 24 and 25, and then the sheet is further removed. Registration rollers 26 and 27 for conveying the image forming unit 10 toward the image forming unit 10 are provided.

3. Transport Unit The transport unit 30 is disposed between the paper feed tray 21 and the image forming unit 10 and includes a transport belt 33 and transfer rollers 73K, 73Y, 73M, and 73C.

  The conveyance belt 33 is wound around a driving roller 31 positioned below the rear end side of the image forming unit 10 and a driven roller 32 positioned below the front end side of the image forming unit 10. Then, the driving roller 31 rotates in synchronization with the registration rollers 26 and 27 and the like, so that the conveying belt 33 circulates between the driving roller 31 and the driven roller 32. The upper surface of the conveyance belt 33 is disposed substantially horizontally immediately below the image forming unit 10, and is a sheet conveyance surface 33 </ b> A that contacts the back surface of the sheet and conveys the sheet along the conveyance path P. Yes.

  The transfer rollers 73 </ b> K to 73 </ b> C are provided in the transport unit 30 in a state where the transfer rollers 73 </ b> K to 73 </ b> C are in contact with the transport belt 33 from the back surface side of the sheet transport surface 33 </ b> A. The conveyance belt 33 made of conductive rubber is negatively charged when a transfer voltage is applied to each of the transfer rollers 73K to 73C, and the sheet is adsorbed to the sheet conveyance surface 33A by the electrostatic force, and along the conveyance path P. Transport.

4). Image Forming Unit The image forming unit 10 is of a so-called direct tandem type, and includes a scanner unit 60 disposed at the top inside the housing 3 and toners (developer) of four colors of black, yellow, magenta, and cyan. Have four process cartridges 70K, 70Y, 70M, and 70C.

  The scanner unit 60 includes a laser light source, a polygon mirror, an fθ lens, a reflecting mirror, and the like. The laser beam emitted from the laser light source is deflected by the polygon mirror, passes through the fθ lens, and then the optical path is turned back by the reflecting mirror, and further, the optical path is bent downward by the reflecting mirror, whereby the process is performed. The surface of the photosensitive drum 71 provided in each of the cartridges 70K to 70C is irradiated to form an electrostatic latent image.

  Since the process cartridges 70K to 70C differ only in the color of the toner as the colorant and the others are the same, the structure thereof will be described below using the process cartridge 70C as an example. The process cartridge 70C includes a known photosensitive drum 71, a charger 72, a toner storage chamber 74A in which toner is stored, a supply roller 74B, a development roller 74C, and the like. The toner in the toner storage chamber 74A is supplied to the developing roller 74C side by the rotation of the supply roller 74B, is carried on the surface of the developing roller 74C, and is adjusted to a predetermined thickness by the layer thickness regulating blade 74D. It is supplied to the surface of the photosensitive drum 71.

5). Fixing Device The fixing device 80 is disposed on the downstream side of the image forming unit 10 in the paper transport path P. The fixing device 80 includes a heating roller 81 disposed on the image forming surface side of the sheet, and a pressure roller 82 disposed on the opposite side of the heating roller 81 with the sheet interposed therebetween. The heating roller 81 rotates in synchronization with the conveyance belt 33 and the like, and applies a conveyance force to the sheet while heating the toner transferred to the sheet. On the other hand, the pressure roller 82 is driven and rotated while pressing the sheet toward the heating roller 81. As a result, the fixing device 80 heats and melts the toner transferred onto the paper to fix it on the paper, and conveys the paper downstream of the conveyance path P. The conveyance path P is curved in a substantially U shape toward the upper side on the downstream side of the fixing device 80. The discharge rollers 28 and 29 and the discharge tray 5 are located on the most downstream side of the transport path P.

6). Outline of Image Forming Operation The printer 1 forms an image on a sheet as follows. That is, when the image forming operation is started, the paper feeding unit 20 and the conveyance unit 30 are operated to convey the paper to the image forming unit 10, and the scanner unit 60, the process cartridges 70K to 70C, and the like are operated. Then, the surface of the rotating photosensitive drum 71 is uniformly positively charged by the charger 72 and then exposed to the laser beam emitted from the scanner unit 60. As a result, the surface of the photosensitive drum 71 is used for image formation. An electrostatic latent image corresponding to the data is formed.

  Next, when the developing roller 74C rotates while being in contact with the photosensitive drum 71, the positively charged toner carried on the developing roller 74C is supplied to the electrostatic latent image formed on the surface of the photosensitive drum 71. Is done. As a result, the electrostatic latent image is visualized, and a toner image by reversal development is carried on the surface of the photosensitive drum 71. The toner image is transferred onto the sheet by a transfer voltage applied to the transfer rollers 73K to 73C, and then heated and pressed by the heating roller 81 and the pressing roller 82 to be fixed on the sheet. Finally, the sheet is discharged to the discharge tray 5 and the image forming operation is completed.

7). Waste Toner Collection Unit The waste toner collection unit 100 collects the waste toner adhering to the photosensitive drum 71 without being transferred onto the sheet via the transport belt 33. As shown in FIG. 1, the waste toner collecting unit 100 is provided on the lower side of the transport unit 30, and includes a waste toner container 101, a cleaning roller 105, a scraping roller 106, a peeling blade 106A, and an elliptical rotor. 107, 108, a conveying screw 109, a detection container 143, and a displacement part 110.

  As shown in FIGS. 2 to 4, the waste toner container 101 includes a box-shaped container main body 102 whose upper side is opened, and an upper cover 103 that covers the upper portion of the container main body 102. As shown in FIG. 2, an intake port 104 is formed in front of the upper cover 103 and is opened to a width substantially the same as the width of the conveyor belt 33. In the intake port 104, a cleaning roller 105, a scraping roller 106, and a peeling blade 106A are provided side by side in the front-rear direction.

  As shown in FIGS. 1 and 2, the cleaning roller 105 is a solid cylinder having a resin sponge layer formed on the outer surface side, and is rotatable around a rotation axis parallel to the drive roller 31 of the transport unit 30. It is pivotally supported. The cleaning roller 105 contacts the conveyance belt 33 from below with the waste toner collection unit 100 mounted on the frame member.

  The scraping roller 106 is a solid metal cylinder that comes into contact with the cleaning roller 105 from behind, and is rotatably supported around a rotation axis parallel to the cleaning roller 105. The peeling blade 106 </ b> A is obtained by cutting a soft urethane sheet into an elongated shape, and the base side is fixed to the rear edge side of the intake port 104 in a state where the front end side is in contact with the scraping roller 106.

  As shown in FIGS. 2 and 3, a driving force supply mechanism 190 formed by combining a plurality of gears (not shown) is disposed on the left side surface of the waste toner container 101. Although not shown, the left ends of the cleaning roller 105 and the scraping roller 106 are connected to one of the gears constituting the driving force supply mechanism 190 so as to be integrally rotatable.

  In a state where the waste toner collecting unit 100 is mounted on the frame member, as shown in FIG. 3, a driving source 199 such as an electric motor provided on the frame member side and the driving force supply mechanism 190 are engaged. When the driving force of the driving source 199 is transmitted to the driving force supply mechanism 190, a plurality of gears (not shown) constituting the driving force supply mechanism 190 rotate, and the driving force of the driving source 199 is changed. It is supplied to the cleaning roller 105 and the scraping roller 106. Then, as shown in FIG. 1, the cleaning roller 105 is rotationally driven in a rotation direction opposite to the circulation direction of the conveyance belt 33, so that the cleaning roller 105 rubs the waste toner adhering to the surface of the conveyance belt 33. It adheres to the surface and is removed from the conveyor belt 33. The scraping roller 106 is rotated while being in contact with the surface of the cleaning roller 105 in a state where a negative charge opposite to the charge carried by the waste toner is applied, and removes the waste toner adhering to the surface of the cleaning roller 105. Adsorbs electrically. Then, the peeling blade 106A peels off the waste toner adsorbed by the scraping roller 106 and drops it into the waste toner container 101.

  As shown in FIG. 1, the elliptic rotors 107 and 108 are elliptic cylinders, and are rotatably supported around a rotation axis parallel to the cleaning roller 105. The elliptical rotor 107 is located below the peeling blade 106 </ b> A, and the elliptical rotor 108 is located in the middle part of the container main body 102. Although not shown, the elliptical rotors 107 and 108 are also connected to the driving force supply mechanism 190. Then, when the driving force is supplied from the driving force supply mechanism 190 and rotated, the waste toner that has fallen into the waste toner container 101 is pumped backward in the waste toner container 101.

  As shown in FIGS. 1 and 4, at the rear of the waste toner container 101, the container body 102 rises upward from the bottom of the container main body 102 and extends in the left-right direction to the left inner wall and the right inner wall of the container main body 102. A connected partition wall 102B is formed. As shown in FIG. 1, a gap is formed between the upper end edge of the partition wall 102 </ b> B and the upper cover 103. The waste toner pumped to the rear of the waste toner container 101 by the elliptic rotors 107 and 108 accumulates after being blocked by the partition wall 102B, and then passes through the partition wall 102B to the rear end side in the waste toner container 101. Inflow.

  As shown in FIGS. 1 and 4, the conveying screw 109 is disposed behind the partition wall 102 </ b> B in the waste toner container 101. The conveying screw 109 has a rotating shaft 109A that is rotatably supported around a rotating shaft parallel to the cleaning roller 105, and a wing 109B that is formed in a spiral shape around the rotating shaft 109A. Although not shown, the rotating shaft 109A is also connected to the driving force supply mechanism 190. Then, the conveying screw 109 is rotated by being supplied with a driving force from the driving force supply mechanism 190, so that the waste toner flowing into the conveying screw 109 side beyond the partition wall 102B is transferred from the right end side to the left end side of the rotating shaft 109A. Transport toward you.

  As shown in FIGS. 3 to 6, the detection container 143 is a box-shaped body made of a transparent resin that transmits light, and extends downward from a recess 102 </ b> A formed on the rear end side and the left end side of the bottom of the container body 102. It is provided so as to protrude. As shown in FIG. 6, the upper surface side of the detection container 143 is open, and the upper end edge of the opening is coupled to the recess 102A.

  In a state where the waste toner collecting unit 100 is mounted on the frame member, as shown in FIGS. 3 and 5, the detection container 143 protrudes toward the optical sensor 144 as an example of detection means provided on the frame member side. It becomes a state to do. The optical sensor 144 has a light emitting unit 144A and a light receiving unit 144B facing each other with the detection container 143 sandwiched in the left-right direction, and an optical path 144C that passes from the light emitting unit 144A through the detection container 143 to the light receiving unit 144B. It is a well-known one for detecting occlusion or opening.

  As shown in FIGS. 4 and 6, the recess 102A is provided with a communication hole 102C that allows the inside of the detection container 143 to communicate with the rear end side and the left end side of the partition wall 102B in the waste toner container 101. ing. When the accumulation state of the waste toner in the waste toner container 101 is nearly full, the waste toner W conveyed toward the left side of the waste toner container 101 by the conveyance screw 109 is connected to the communication hole 102C as shown in FIG. Into the detection container 143.

  As shown in FIGS. 5 and 6, the displacement portion 110 is a transparent resin box-like body that transmits light, and is provided in the detection container 143 below the communication hole 102 </ b> C. The upper surface side of the displacement part 110 opens larger than the communication hole 102C. As a result, the displacement unit 110 receives all the waste toner W flowing into the detection container 143 through the communication hole 102C and deposits it inside. Here, the lower portion of the displacement portion 110 in the box shape and where the waste toner W accumulates is the receiving portion 111, and the upper portion of the displacement portion 110 in the box shape and adjacent to the receiving portion 111 is the portion. It is a transmission part 112.

  As shown in FIG. 5, the displacement part 110 can be displaced only in the vertical direction within the detection container 143 between the outer surface facing the front of the displacement part 110 and the inner wall surface of the detection container 143 facing the outer surface. Guide portions 110G and 143G for guiding are formed.

  As shown in FIGS. 4 and 5, a link portion 120 that is pivotally supported around a swing shaft parallel to the rotation shaft 109A is provided behind the left end side of the rotation shaft 109A. As shown in FIG. 5, the link portion 120 has a fork-shaped first engagement portion 121 that protrudes radially outward on the left end side, and a fork-shaped second engagement that protrudes radially outward on the right end side. Part 122. The first engagement portion 121 is engaged with a columnar eccentric shaft portion 109H that protrudes further leftward while being eccentric from the left end of the rotation shaft 109A. The second engagement portion 122 is engaged with a cylindrical shaft portion 110H that protrudes further leftward from the upper end edge of the outer surface facing the left side of the displacement portion 110. When the eccentric shaft portion 109H rotates eccentrically with the rotation of the conveying screw 109, the first engaging portion 121 swings, and the swing is displaced via the second engaging portion 122 and the shaft portion 110H. Is transmitted to the unit 110. Thereby, the displacement part 110 repeats the periodic reciprocating operation in the vertical direction at the time of the warm-up operation or the image forming operation.

  As shown in FIG. 6, the relative positional relationship between the displacement unit 110 and the optical path 144 </ b> C is periodically moved up and down in the vertical direction, that is, in the direction intersecting the optical path 144 </ b> C. And when the displacement part 110 displaces to the uppermost part, as shown to (a), it displaces to the position above the optical path 144C. On the other hand, when the displacement part 110 is displaced downward, as shown in (b), on the upper end side of the transmission part 112, the light passing from the light emitting part 144A through the optical path 144C to the light receiving part 144B is transmitted. Displace to the position where That is, the displacement part 110 made of a transparent material does not shield the optical path 144C during the up and down operation unless the waste toner W is accumulated inside the receiving part 111.

  On the other hand, as shown in FIGS. 5 and 6, the lower end side of the outer surface facing the left side of the displacement part 110 and the lower end side of the outer surface facing the right side have a rectangular shape elongated in the horizontal direction and transmit light. A pair of shielding parts 113 made of a thin plate material that does not transmit is attached. The shielding part 113 moves up and down integrally with the displacement part 110 to open the optical path 144C (the position shown in FIGS. 6A and 6B) and the position to shield the optical path 144C (FIG. 6A). And a position substantially in the middle of the position shown in FIG. 6A). That is, when the displacement unit 110 moves up and down, the shielding unit 113 periodically shields the optical path 144C.

  Further, as shown in FIGS. 7A and 7B, when the waste toner W flowing into the detection container 143 via the communication hole 102C starts to accumulate inside the receiving portion 111, the receiving portion 111 is The accumulated waste toner W periodically shields the optical path 144C during the up-and-down operation (a position substantially intermediate between the position shown in FIG. 7A and the position shown in FIG. 7A).

8). In the control system of the printer 1 shown in FIG. 8, the exposure control unit 201 controls the operation of the scanner unit 60. The high voltage control unit 202 controls the operation of the toner cartridge 70, that is, a high voltage such as the photosensitive drum 71, toner development and transfer. The panel control unit 203 controls an operation panel (not shown) that is set and operated by the user. The motor control unit 204 controls the electric motor of the drive source 199. The sensor control unit 205 controls the light emitting unit 144A and the light receiving unit 144B of the optical sensor 144. The ROM 206 and the RAM 207 are areas for storing information, and the CPU 208 performs arithmetic processing for controlling the control unit such as the exposure control unit 201 in accordance with a program stored in advance in the ROM 206. The timer 209 counts time and outputs a signal indicating the time.

  The sensor control unit 205 includes a light emission control circuit 205A and a comparator 205B. The light emission control circuit 205A controls the light emission operation of the light emitting unit 144A. The comparator 205B determines whether the signal level emitted when the light receiving unit 144B receives the light from the light emitting unit 144A exceeds the reference level. When the signal level exceeds the reference level, a “Low” signal is output to the CPU 208, and when the signal level is lower than the reference level, a “Hi” signal is output to the CPU 208. As described above, the displacement unit 110 periodically shields the optical path 144C by the waste toner W accumulated in the receiving unit 111 and the shielding unit 113. Therefore, the signal waveform output from the comparator 205B to the CPU 208, that is, The detection result of the optical sensor 144 corresponds to a combination of the shielding part 113 and the amount of waste toner W that accumulates inside the receiving part 111.

9. Operation of Displacement Unit and Optical Sensor When the printer 1 is activated and the warm-up operation is started, or when the printer 1 is switched from the standby state to the operating state, the sensor control unit 205 starts controlling the optical sensor 144. The CPU 208 starts a determination program (steps S100 to S109 shown in FIG. 9) whose details will be described later. Further, the motor control unit 204 starts control of the drive source 199. Then, the driving force of the driving source 199 is transmitted to the conveying belt 33, and the conveying belt 33 starts to circulate and is supplied with the driving force from the driving force supply mechanism 190, so that the cleaning roller 105, the scraping roller 106, the oval The rotors 107 and 108 and the conveying screw 109 also rotate. As a result, the waste toner adhering to the transport belt 33 is accumulated in the waste toner container 101 and then transported toward the detection container 143 by the transport screw 109. The cleaning roller 105, the scraping roller 106, the elliptical rotors 107 and 108, and the conveying screw 109 correspond to waste toner transfer means. The drive source 199 and the drive force supply mechanism 190 correspond to drive means.

  At this time, as shown in FIGS. 5 and 6, the displacement portion 110 also periodically moves up and down via the link portion 120 by the rotation of the conveying screw 109. Here, while the waste toner W is not accumulated inside the receiving portion 111, only the shielding portion 113 periodically shields the optical path 144C. That is, the shielding part 113 shields the optical path 144C twice when the eccentric shaft part 109H makes one rotation. In this case, the signal waveform output from the comparator 205B to the CPU 208 in response to the output signal from the optical sensor 144 is a waveform that periodically switches between “Hi” and “Low” as shown in FIG. Become. One period of the signal waveform, that is, the duration T of “Hi” during one rotation of the eccentric shaft portion 109H is twice the required time T1 for one shielding when the shielding portion 113 shields the optical path 144C. (T = T1 × 2).

  When the waste toner W starts to accumulate inside the receiving portion 111, as shown in FIG. 11, the shielding portion 113 periodically shields the optical path 144C, and the receiving portion 111 also accumulates within itself. The toner W periodically shields the optical path 144C. That is, the shielding part 113 and the receiving part 111 on which the waste toner W is accumulated shields the optical path 144C twice when the eccentric shaft part 109H rotates once. In this case, the signal waveform output from the comparator 205B to the CPU 208 in response to the output signal from the optical sensor 144 is periodically switched between “Hi” and “Low” as shown in FIG. Compared with the signal waveform of FIG. 10, the waveform has a longer duration of “Hi”. The period of the signal waveform, that is, the duration T of “Hi” during one rotation of the eccentric shaft portion 109H, is when the shielding portion 113 and the receiving portion 111 on which the waste toner W is accumulated shields the optical path 144C. This is twice the required time T1 + TW for one shielding (T = (T1 + TW) × 2).

  In this embodiment, the shielding part 113 overlaps a part of the receiving part 111. For this reason, while the waste toner W in the receiving portion 111 is deposited lower than the shielding portion 113, TW = 0, and when the waste toner W in the receiving portion 111 starts to accumulate higher than the shielding portion 113, the TW Increases from zero. Since the TW increases in proportion to the increase in the amount of waste toner W accumulated in the receiving portion 111, the duration T also increases in proportion.

  In addition, when a malfunction occurs in the transport screw 109, the driving force supply mechanism 190 upstream of the transport screw 109, the drive source 199, or the like during the operation of the optical sensor 144, the transport screw 109 is not rotated and the eccentric shaft The portion 109H also does not rotate eccentrically. Then, the displacement part 110 also does not move up and down, and the receiving part 111 or the shielding part 113 on which the waste toner W is accumulated also keeps the position where the optical path 144C is shielded or opened.

  Thus, in a state where the displacement unit 110 is stopped, the signal waveform output from the comparator 205B to the CPU 208 in response to the output signal from the optical sensor 144 is “Hi” or as shown in FIG. The waveform remains unchanged at “Low”.

  Further, when the printer 1 is started up with the waste toner collecting unit 100 removed from the housing 3, the optical path 144C is left open, so that the comparator 205B receives the output signal from the optical sensor 144 and the CPU 205 As shown in FIG. 12, the signal waveform output toward is a waveform that remains “Low” and does not change.

  Further, when an abnormality occurs in the optical sensor 144 (for example, disconnection or damage of the light emitting unit 144A or 144B), the output signal from the optical sensor 144 is interrupted or does not change, so the comparator 205B is directed to the CPU 208. As shown in FIG. 12 or FIG. 13, the output signal waveform is a waveform that remains “Hi” or “Low” and does not change.

10. Details of Determination Program As shown in FIG. 9, the CPU 208 starts a determination program (steps S100 to S109) as an example of a determination unit. Note that the determination program is repeatedly executed by the CPU 208 while the drive source 199 is activated and the drive force is supplied by the drive force supply mechanism 190, such as during the image forming operation of the printer 1. First, in step S100, a signal waveform output from the comparator 205B in response to an output signal from the optical sensor 144 is acquired. Here, if the waveform as described above is generated, signals for a period sufficient to confirm the waveform are acquired.

  Next, the process proceeds to step S101, and it is determined whether or not the acquired signal waveform is a waveform that periodically changes. As shown in FIG. 12 or FIG. 13, when the acquired signal waveform is a waveform that remains “Hi” or “Low” and does not change, “No” is determined in step S101, and the process proceeds to step S102. Then, in step S102, it is determined that “the optical sensor 144 or the displacement unit 110 or the like is abnormal”, the CPU 208 is notified of this, and the process is terminated. As a result, in the CPU 208, the optical sensor 144 is damaged, the displacement unit 110, the conveying screw 109, the driving force supply mechanism 190 on the upstream side of the conveying screw 109, the driving power supply failure, or the waste toner collecting unit 100 is damaged. It is possible to perform troubleshooting assuming various troubles such as non-installation and to warn the user. In this case, the printer 1 stops the image forming operation until a predetermined countermeasure is taken for the warning. As a result, it is possible to prevent a problem that the image forming operation is performed while the optical sensor 144, the displacement unit 110, the conveying screw 109, and the like are not normally operated or the waste toner collecting unit 100 is not attached.

  On the other hand, when the acquired signal waveform is a waveform that periodically switches between “Hi” and “Low” as shown in FIG. 10 or FIG. 11, “Yes” in step S101, and the process proceeds to step S103. . Then, “Hi” duration T in one cycle is extracted from the output signal waveform.

  Next, the process proceeds to step S104, and it is determined whether or not the CPU has been notified that “waste toner is“ near full ”. In the execution of the past determination program, if the CPU has been notified of “waste toner is“ near full ”” by the processing of steps S105 to S106, which will be described later, “Yes” is determined in step S104. The process proceeds to S107.

  On the other hand, if “No” in step S104, the process proceeds to step S105, and it is determined whether or not the “Hi” duration T in one cycle is greater than the threshold value G1. Here, in this embodiment, the threshold value G1 is set to a value slightly larger than “T1 × 2”. When the signal waveform acquired in step S100 is the waveform shown in FIG. 10 and the duration of “Hi” in one cycle is T = T1 × 2 ≦ threshold G1, “No” in step S105, “ It is determined that the waste toner W in the receiving unit 111 is not deposited higher than the shielding unit 113, and the processing is terminated. In the present embodiment, “the state in which the waste toner W in the receiving unit 111 is accumulated higher than the shielding unit 113” means “the near full (printing) state that the waste toner accumulation state is almost full. Can be continued). Thereafter, the above processing is repeated from step S100.

  On the other hand, when the signal waveform acquired in step S100 is the duration T = (T1 + TW) × 2> threshold G1 of “Hi” in one cycle as shown in FIG. 11, “Yes” in step S105, The process proceeds to step S106. Then, in step S106, it is determined that “the waste toner W in the receiving unit 111 is accumulated higher than the shielding unit 113”, that is, the accumulation state of the waste toner W is “near full”. Notify In response to this, for example, the CPU 208 notifies the user that “the replacement timing of the waste toner collection unit 100 is approaching”. And this process is once complete | finished and the said process is repeated from step S100.

  On the other hand, when “Yes” is set in step S104 and the process proceeds to step S107, it is determined whether or not the duration “T” of “Hi” in one cycle is larger than the threshold value G2. Here, in the present embodiment, the threshold value G2 is set to the same value as “(T1 + TW) × 2” in a state where about 80% of the waste toner W is accumulated in the receiving unit 111. In the present embodiment, “a state where about 80% of the waste toner W has accumulated in the receiving portion 111” means that the state where the waste toner W is accumulated is almost full. ". In step S107, since “near full” has already been notified, the signal waveform acquired in step S100 is the waveform shown in FIG. 11, and the duration of “Hi” in one cycle is T = (T1 + TW) × 2. is there.

  In step S107, if the duration time T = (T1 + TW) × 2> threshold value G2, the process proceeds to step S108, where it is determined that the accumulated state of the waste toner W is “full”. Then, the CPU 208 is notified to that effect, and this process ends. In response to this, for example, the CPU 208 notifies the user that “please replace the waste toner collecting unit 100 immediately”. Also in this case, the printer 1 stops the image forming operation until a predetermined countermeasure is taken for the notification.

  On the other hand, if “No” in step S107, the process proceeds to step S109. Then, (continuation time T−threshold G1) / (threshold G2−threshold G1) is calculated, and the calculation result is notified to the CPU 208. And this process is once complete | finished and the said process is repeated from step S100. Here, the calculation result of (duration time T−threshold G1) / (threshold G2−threshold G1) indicates what percentage of the waste toner W accumulation state is between “near full” and “full”. It is an indicator to show. The CPU 208 that has received the above calculation result can, for example, notify the user in a step-by-step manner that “there is about **% remaining until“ full ””. Thereby, the user's usability improves.

<Effect>
According to the printer 1 of the first embodiment, a plurality of states, that is, whether or not there is an abnormality in the optical sensor 144 or the displacement unit 110 based on the detection result of one optical sensor 144, and in the waste toner container 101. Since it can be determined whether or not the waste toner has reached “near full”, the number of parts can be reduced and the apparatus configuration can be simplified.

(Example 2)
The printer of the second embodiment employs a displacement section 210 and a link section 220 as shown in FIGS. 14 and 15 instead of the displacement section 110 and the link section 120 in the printer 1 of the first embodiment. Other configurations are the same as those of the printer 1 of the embodiment. For this reason, about the same structure as Example 1, the same code | symbol is attached | subjected and description is abbreviate | omitted or simplified.

  As shown in FIGS. 14 and 15, the displacement portion 210 is a transparent resin box-like body that transmits light, and is provided in the detection container 143 below the communication hole 102 </ b> C. The upper surface side of the displacement part 210 is larger than the communication hole 102C, and is elongated in the front-rear direction. As a result, as shown in FIG. 15, the displacement unit 210 reciprocates in the front-rear direction, receives all waste toner W flowing into the detection container 143 through the communication hole 102 </ b> C, and deposits it inside itself. Here, the box-shaped internal space of the displacement portion 210, where the waste toner W accumulates is the receiving portion 211, the side wall facing the rear of the displacement portion 210, and the portion adjacent to the receiving portion 211 is. A transmission unit 212 is provided.

  As shown in FIG. 14, a cylindrical shaft portion 210 </ b> H protrudes further leftward from the upper end edge of the outer surface facing the left side of the displacement portion 210. On the rear side of the left end side of the rotation shaft 109A, there is provided a link portion 220 that is pivotally supported so as to be swingable around a swing shaft parallel to the rotation shaft 109A. The first engaging part 221 and the second engaging part 222 of the link part 220 differ from the first engaging part 121 and the second engaging part 122 of the first embodiment only in the protruding direction, and the other The configuration of is the same. When the eccentric shaft portion 109H rotates eccentrically with the rotation of the conveying screw 109, the first engagement portion 221 swings, and the swing is displaced via the second engagement portion 222 and the shaft portion 210H. Is transmitted to the unit 210. Thereby, the displacement part 210 repeats the cyclic | annular reciprocation operation | movement of the front-back direction.

  As shown in FIG. 15, the relative positional relationship between the displacement unit 210 and the optical path 144 </ b> C is periodically reciprocated in the front-rear direction, that is, the direction intersecting the optical path 144 </ b> C. And when the displacement part 210 displaces most forward, as shown to (a), it displaces to the position ahead rather than 144 C of optical paths. On the other hand, when the displacement unit 210 is displaced most rearward, as shown in FIG. 5B, the receiving unit 211 passes the light from the light emitting unit 144A to the light receiving unit 144B through the light path 144C. Displace. That is, the displacement portion 210 made of a transparent material does not shield the optical path 144C during the front-rear operation unless the waste toner W is accumulated inside the receiving portion 211.

  As shown in FIGS. 14 and 15, the rear end side of the outer surface facing the left side of the displacement portion 110 and the rear end side of the outer surface facing the right side have a rectangular shape elongated in the vertical direction, and light is transmitted through the rear end side. A pair of shielding portions 213 made of a thin plate material that does not transmit is attached. The shielding part 213 moves back and forth integrally with the displacement part 210 to open the optical path 144C (the position shown in FIGS. 15A and 15B) and the position to shield the optical path 144C (FIG. 15A). And a position substantially in the middle of the position shown in FIG. 15A). That is, when the displacement unit 210 moves back and forth, the shielding unit 213 periodically shields the optical path 144C.

  Then, as shown in FIGS. 15A and 15B, when the waste toner W that flows into the detection container 143 through the communication hole 102C is accumulated to the same height as the optical path 144C in the receiving portion 211, The receiving unit 211 periodically shields the optical path 144 </ b> C by the accumulated waste toner W during the front-rear operation.

  The printer according to the second embodiment having such a configuration can achieve the same effect as the printer 1 according to the first embodiment, and can reduce the thickness of the apparatus by the displacement unit 210 that moves back and forth.

(Example 3)
The printer of the third embodiment employs a displacement portion 310 and gear portions 109G and 310G as shown in FIGS. 16 and 17 instead of the displacement portion 110 and the link portion 120 in the printer 1 of the first embodiment. Other configurations are the same as those of the printer 1 of the embodiment. For this reason, about the same structure as Example 1, the same code | symbol is attached | subjected and description is abbreviate | omitted or simplified.

  As shown in FIGS. 16 and 17, the displacement part 310 is a transparent resin disk that transmits light, and is provided below the communication hole 102 </ b> C so as to be rotatable in a horizontal plane. The upper surface side of the displacement part 310 is divided into four fan parts. One fan part is recessed downward and serves as a receiving part 311 for accumulating waste toner W flowing into the detection container 143. In addition, two fan parts adjacent to both sides of the receiving part 311 are transmissive parts 312 that transmit light. Further, the fan portion facing the receiving portion 311 is a shielding portion 313 formed by attaching a thin plate material that does not transmit light.

  In the third embodiment, the detection container 143 is changed to a shape that encloses the displacement portion 310. The light emitting unit 144A and the light receiving unit 144B of the optical sensor 144 are opposed to each other with the detection container 143 and the displacement unit 310 interposed therebetween in the vertical direction, and the optical path 144C extends in the vertical direction to extend from the detection container 143 and the displacement unit. 310.

  As shown in FIG. 16, gear portions 109 </ b> G and 310 </ b> G that mesh with each other are formed at the left end of the rotation shaft 109 </ b> A and the outer peripheral edge of the displacement portion 310. When the rotation shaft 109A rotates, the rotation is transmitted to the displacement portion 310 via the gear portions 109G and 310G, and the displacement portion 310 rotates in the horizontal plane. And it repeats that the receiving part 311, the permeation | transmission part 312, the shielding part 313, and the permeation | transmission part 312 pass below 102 C of communicating holes in this order, and also pass the optical path 144C.

  As shown in FIG. 17, a scraper 102D is disposed below the communication hole 102C. The lower end edge of the scraper 102D is in contact with the upper surface of the displacement portion 310 so that the waste toner W flowing into the detection container 143 falls only into the receiving portion 311 through the communication hole 102C.

  While the waste toner W is not accumulated in the receiving part 311, only the shielding part 313 periodically shields the optical path 144C. When the waste toner W is accumulated in the receiving portion 311, the receiving portion 311 on which the waste toner W is accumulated and the shielding portion 313 periodically shield the optical path 144 </ b> C.

  The printer according to the third embodiment having such a configuration can achieve the same effect as the printer 1 according to the first embodiment, and can reduce the thickness of the apparatus by the horizontally rotating displacement portion 310.

  In the above, the present invention has been described with reference to the first to third embodiments. However, the present invention is not limited to the first to third embodiments, and can be appropriately modified and applied without departing from the spirit of the present invention.

  For example, the light emitting unit 144A and the light receiving unit 144B of the first embodiment may be disposed so as to face each other with the displacement unit 110 interposed therebetween in the detection container 143.

  The present invention is applicable to an image forming apparatus.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus (printer), 3 ... Housing, 100 ... Waste toner collection unit,
101 ... Waste toner container, 143 ... Detection container, 144 ... Detection means (optical sensor),
144A ... light emitting portion, 144B ... light receiving portion, 144C ... light path, W ... waste toner,
110, 210, 310 ... displacement part, 111, 211, 311 ... receiving part,
112, 212, 312 ... transmission part, 113, 213, 313 ... shielding part,
S100 to S109 ... judgment means, T ... duration of the waveform corresponding to shielding of the optical path in one cycle of the periodically changing waveform appearing in the detection result,
105-109 ... waste toner transfer means (105 ... cleaning roller, 106 ... scraping roller, 107, 108 ... elliptical rotor, 109 ... conveying screw),
199, 190 ... driving means (199 ... driving source, 190 ... driving force supply mechanism)

Claims (8)

An image forming apparatus for forming an image on a recording medium by transferring a toner image to the recording medium,
A waste toner container for storing waste toner that has not been transferred to the recording medium;
A detection container that is continuously provided in the waste toner container and into which the waste toner flows when the accumulation state of the waste toner in the waste toner container reaches a specific accumulation state;
A detecting unit that has a light emitting unit and a light receiving unit facing each other, and outputs a detection result corresponding to shielding or opening of an optical path that passes through the detection container and reaches the light receiving unit from the light emitting unit;
Determination means for determining whether or not the waste toner has reached a specific accumulation state in the waste toner container based on the detection result;
Further, in the detection container, a displacement portion that repeats a periodic movement operation in a direction intersecting the optical path is provided,
The displacement portion includes a receiving portion that receives the waste toner flowing into the detection container and deposits the waste toner therein, and a transmission portion adjacent to the receiving portion,
The receiving part can transmit light from the light emitting part, and if the waste toner is not accumulated in itself, the receiving part does not shield the optical path during the moving operation, while the waste toner is not inside the self. If accumulated, the accumulated waste toner periodically shields the optical path during the moving operation,
The transmission unit is capable of transmitting light from the light emitting unit, and does not block the optical path during the moving operation, regardless of whether the waste toner is accumulated inside the receiving unit,
The determination means determines whether the detection means or the displacement portion is abnormal based on the detection result, and whether the waste toner has reached a specific accumulation state in the waste toner container. An image forming apparatus characterized in that the determination is made in a distinguishable manner. The displacement portion has a shielding portion that periodically shields the optical path during the moving operation regardless of whether the waste toner is accumulated inside the receiving portion, or not.
The image forming apparatus according to claim 1, wherein the shielding portion is formed adjacent to the receiving portion or the transmitting portion, or is formed at a part of the receiving portion.   The determination means shields the optical path within one period of a periodically changing waveform appearing in the detection result after determining that the waste toner has reached a specific accumulation state in the waste toner container. 3. The image forming apparatus according to claim 1, wherein an accumulation state of the waste toner in the waste toner container is determined in a stepwise manner based on a duration of a waveform corresponding to. Waste toner transfer means for recovering the waste toner in the waste toner container or transferring the recovered waste toner in the waste toner container;
Drive means for driving the waste toner transfer means,
The image forming apparatus according to claim 2, wherein the displacement unit performs the moving operation in response to a driving force from the driving unit and the waste toner transfer unit. A housing,
The waste toner container and the displacement portion constitute a waste toner collection unit that is detachably attached to the housing.
The image forming apparatus according to claim 1, wherein the detection unit and the determination unit are provided on the housing side. The displacement portion has a box shape with an upper surface opened, and reciprocates in the vertical direction in the detection container.
The image forming apparatus according to claim 1, wherein a lower side of the box shape of the displacement portion is the receiving portion, and an upper side of the box shape of the displacement portion is the transmission portion. The displacement portion has a box shape with an upper surface opened, and reciprocates in the horizontal direction in the detection container.
The one end side in the reciprocating direction of the box shape of the displacement portion is the receiving portion, and the other end side of the reciprocating direction of the displacement portion in the box shape is the transmission portion. The image forming apparatus described. The displacement part is a disk shape, and rotates horizontally within the detection container,
6. The recess portion recessed downward from the disk-shaped upper surface of the displacement portion is the receiving portion, and a portion adjacent to the recess portion in the displacement portion is the transmission portion. 6. Image forming apparatus.

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