JP4649875B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  As an image forming method of the image forming apparatus, a method using a known electrophotographic process is known. In a known electrophotographic process, an image is formed on a recording medium such as a recording paper by the following process.

  While rotating the photosensitive drum, the photosensitive drum is uniformly charged to a predetermined potential by a charger. The charged photosensitive drum is exposed to form a latent image. The latent image is developed with a developing device to form a toner image on the photosensitive drum. This toner image is transferred to the recording paper, and the toner image is fixed on the recording paper by a fixing device. Further, residual toner after transfer is removed by a cleaning means and collected in a collection case.

For this reason, it is necessary to detect the amount of collected residual toner and replace the collection case when a predetermined amount or more is collected. Therefore, a detection means for detecting the collected amount of residual toner is provided. (For example, refer to Patent Document 1).
JP 2000-290554 A

  FIG. 9 schematically shows a conventional toner recovery case 300. When the toner collection case 300 is tilted as shown in FIG. 9A, the collected residual toner H4 is largely displaced. Further, as shown in FIG. 9B, even if it becomes horizontal, the deviation is not eliminated so much, and the residual toner H4 becomes non-uniform. Therefore, an accurate recovery amount of the residual toner H4 cannot be detected.

  In particular, the residual toner after transfer has poor fluidity compared to the toner before development. Therefore, the deviation as shown in FIG. 9 is likely to occur.

  Further, in the case of a so-called process cartridge in which the collection case is integrated with an image carrier such as a photosensitive drum, the space for other members disposed around the image carrier together with the collection case, and when the process cartridge is attached / detached Considering user operability, the capacity of the collection case cannot be increased. For this reason, even if the residual toner in the collection case is slightly shifted, the detection unit may erroneously detect the collection amount of the residual toner in the collection case.

  The present invention has been made to solve the above-described problems, and an object thereof is to accurately detect the amount of residual toner that has been removed and recovered.

The image forming apparatus according to claim 1, wherein a toner image is formed and an image carrier that carries the toner image transferred to a transfer medium, and residual toner on the image carrier that is in contact with the image carrier. A cleaning member that removes the residual toner that has been removed from the image carrier by the cleaning member, and a recovery case that is formed inside the recovery case. Two partition walls that are spaced apart in the direction, divide the inside of the collection case, and suppress the movement of the residual toner that falls and accumulates from the opening in the longitudinal direction of the cleaning member, and the collection case It is provided between the bottom definitive the two barrier ribs has a detecting means for detecting the residual amount of toner accumulated between the partition wall and the partition wall, wherein the cleaning Viewed in the longitudinal direction of the timber, said partition wall and said cleaning member, spacing the position opposed to the partition wall is characterized by being configured such that the upper side is narrower than the bottom near.

In the image forming apparatus according to the first aspect, the toner image is formed on the image carrier, and the toner image is transferred to the transfer medium. Residual toner remaining on the image carrier without being transferred is removed by the cleaning member and collected inside the collection case. In the collection case, the two partition walls are formed, the residual toner amount detecting means detects that accumulates between the barrier ribs.

  Now, for some reason (for example, an inclination generated when the image forming apparatus is moved), the collected residual toner may be offset. When the deviation occurs, the distribution of the collected residual toner becomes non-uniform. That is, a portion with a large amount of residual toner and a portion with a small amount of toner are generated. For this reason, the detection means for detecting the residual toner amount cannot be accurately detected.

On the other hand, the space between the partition walls is narrower than the entire collection case. Therefore, even if the residual toner between the partition walls is deviated, the distribution of the residual toner is not so uneven. That is, there is little difference between a portion with a large amount of residual toner and a portion with a small amount of residual toner. Therefore, the detection means detects the amount of residual toner accumulated between the partition walls , so that accurate detection can be performed.

The image forming apparatus according to claim 2, wherein a toner image is formed and an image carrier that carries the toner image transferred to a transfer medium, and residual toner on the image carrier that is in contact with the image carrier. A cleaning member that removes the residual toner that has been removed from the image carrier by the cleaning member, and a recovery case that is formed inside the recovery case. Two partition walls that are spaced apart in the direction, divide the inside of the collection case, and suppress the movement of the residual toner that falls and accumulates from the opening in the longitudinal direction of the cleaning member, and the collection case The residual toner amount provided in the image carrier area of the image carrier at the bottom of the image carrier and provided between the two partition walls and between the partition walls is a predetermined amount. Detecting means for detecting that the cross has the when viewed in the longitudinal direction of the cleaning member, and the partition wall, and the cleaning member at a position facing the partition wall, the distance, the bottom portion and the top than in the vicinity It is characterized in that the side is narrowed .

In the image forming apparatus according to the second aspect, the toner image is formed on the image carrier, and the toner image is transferred to the transfer medium. Residual toner remaining on the image carrier without being transferred is removed by the cleaning member and collected inside the collection case. In the collection case, the two partition walls are formed, the residual toner amount is detected with detection means exceeds a predetermined amount accumulated between the barrier ribs.

  When the residual toner collected for some reason is shifted, the distribution of the collected residual toner becomes non-uniform. That is, a portion with a large amount of residual toner and a portion with a small amount of toner are generated. For this reason, the detection means for detecting the residual toner amount cannot be accurately detected.

In contrast, offset the residual toner between the barrier ribs cause, even if the distribution is not uniform, the sensing means when the residual amount of toner accumulated between the partition and the partition wall exceeds a predetermined amount Since it is detected, it is not affected by the deviation of the residual toner between the partition walls. Therefore, accurate detection can be performed.

  According to a third aspect of the present invention, in the configuration according to the first or second aspect, the two partition walls partition the central portion of the collection case.

  In the image forming apparatus according to the third aspect, the two partition walls partition the central portion of the collection case, and the detection unit detects the residual toner amount in the central portion between the partition walls.

  As described above, since the residual toner in the central portion of the recovery case is detected, the recovery amount of the residual toner in the entire recovery case can be accurately detected.

  The image forming apparatus according to claim 4, wherein the cleaning member is in contact with the image carrier and the residual toner on the image carrier is the structure according to any one of claims 1 to 3. And a fixing plate that fixes the cleaning blade and is attached to the recovery case, and the partition comes into contact with the bending of the fixing plate, and the bending of the fixing plate It also serves as a regulating member that regulates the above.

  The image forming apparatus according to claim 4, wherein a crane blade that contacts the image carrier and scrapes and removes residual toner on the image carrier is fixed to a fixed plate, and the fixed plate is attached to the collection case. .

For example, when the recovery case is distorted due to thermal deformation or the like, the fixing plate bends. When the fixing plate bends, the fixing plate comes into contact with the partition wall and restricts the bending. Therefore, the change in the contact position of the cleaning blade with the image carrier is also restricted. Therefore, it is not affected by the scraping performance of the cleaning blade.

  The image forming apparatus according to claim 5 is the configuration according to any one of claims 1 to 4, wherein at least the image carrier, a cleaning member, and an interior thereof are divided by the partition. And a collection case. The unit is detachable from the main body of the image forming apparatus.

  The image forming apparatus according to claim 5 includes a unit including at least an image carrier, a cleaning member, and a collection case, and the unit is detachable from the image forming apparatus main body. . The unit is inclined when being attached to or detached from the image forming apparatus main body.

  However, the distribution of residual toner between the partition walls does not become very uneven even when tilted. Therefore, accurate detection is possible, which is preferable.

Alternatively, tilted deviation occurs in the residual toner between the barrier ribs, even distribution is not uniform, the sensing means when the residual amount of toner accumulated between the partition and the partition wall exceeds a predetermined amount By detecting, there is no influence of the deviation of the residual toner between the partition walls. Therefore, accurate detection can be performed.

In addition, when the residual toner recovered in the recovery case reaches a predetermined amount and is detected, the unit can be replaced and maintenance is easy.
The image forming apparatus according to claim 6, wherein the cleaning member is in contact with the image carrier, and a cleaning blade that scrapes and removes residual toner on the image carrier and the cleaning blade are fixed. A fixed plate attached to the recovery case, and when viewed in the longitudinal direction of the cleaning member , the interval between the partition and the fixed plate at a position facing the partition is more than the vicinity of the bottom. The upper side is configured to be narrow .
The image forming apparatus according to claim 7 is characterized in that the fixing plate is disposed obliquely when viewed in the longitudinal direction of the cleaning member.
The image forming apparatus according to claim 8 is characterized in that a protruding portion is formed on the inner wall of the box portion so that the upper end portion of the plate portion is caught and does not come out upward.
The image forming apparatus according to claim 9, wherein the measurement member is inserted from the opening at the top of the box portion and pressed downward even when the plate portion hits the protrusion, so that the plate portion is protruded from the protrusion. It gets over the part and is inserted below the protrusion.

According to the present invention described above, as compared with the entire collection case, the residual toner accumulated in the narrow space between the barrier ribs, so much deviation does not occur, the accumulated between the barrier ribs The detection means detects the residual toner amount, so that accurate detection can be performed.

Alternatively, offset the residual toner between the barrier ribs cause, distribution also becomes uneven, the residual amount of toner accumulated between the partition and the partition wall is detected with detection means exceeds a predetermined amount Therefore, it is not affected by the deviation of the residual toner between the partition walls. Therefore, accurate detection can be performed.

  Hereinafter, as an example to which the image forming apparatus according to the present invention is applied, a color printer to which a known electrophotographic process is applied will be described with reference to the drawings. The image forming apparatus to which the present invention is applied is not limited to a color printer described below, and may be a monochrome printer. Further, it may be an image forming apparatus such as a copying machine, a facsimile machine, or a multifunction machine. In the following description, detailed descriptions of those not directly related to the essence of the present invention are omitted.

  FIG. 1 shows an outline of a color printer 10 according to an embodiment of the present invention. The color printer 10 includes a color printer main body 12, and an open / close cover 16 that is rotatable about a rotation fulcrum 14 is provided on the upper portion of the color printer main body 12. In addition, a paper feeding unit 18 is disposed below the color printer main body 12.

  The paper supply unit 18 includes a paper supply unit main body 20 and a paper supply cassette 22 in which the recording paper P is stored. A feed roll 24 that feeds recording paper P from the paper feed cassette 22 and a retard roll 26 that scoops the supplied recording paper P one by one are arranged in the upper part near the rear end of the paper feed cassette 22.

  The conveyance path 28 is a path for the recording paper P from the feed roll 24 to the discharge port 30. The conveyance path 28 is in the vicinity of the back side (right side in FIG. 1) of the color printer main body 12 and is formed substantially vertically from the paper feeding unit 18 to the fixing device 90. A secondary transfer roll 80 and a secondary transfer backup roll 72 are arranged on the upstream side of the fixing device 90 in the conveyance path 28, and a resist roll 32 is arranged on the upstream side of the secondary transfer roll 80 and the secondary transfer backup roll 72. Has been. In addition, a discharge roll 34 is disposed in the vicinity of the discharge port 30 of the conveyance path 28.

  Accordingly, the recording paper P sent out from the paper feeding cassette 22 of the paper feeding unit 18 by the feed roll 24 is turned by the retard roll 26 and only the uppermost recording paper P is guided to the transport path 28, and is fed by the registration roll 32. At this time, the toner image is transferred between the secondary transfer roll 80 and the intermediate transfer belt 64 (secondary transfer backup roll 72) at a timing, and the transferred toner image is transferred by the fixing device 90. The toner is fixed and discharged from a discharge port 30 to a discharge portion 36 provided on the upper part of the opening / closing cover 16 by a discharge roll 34. The discharge portion 36 has a low discharge port portion and is inclined so as to gradually increase toward the front direction (left direction in FIG. 1).

  The color printer main body 12 is provided with a rotary developing device 38 at a substantially central portion. Further, on the front side (the left side in FIG. 1) of the rotary developing device 38, a control unit 39 that controls each unit constituting the color printer 10 is disposed.

  The rotary developing device 38 includes developing units 42a to 42d that respectively form toner images of four colors of yellow, yellow, magenta, cyan, and black in the developing unit main body 40. It rotates counterclockwise (counterclockwise in FIG. 1) about the rotary developing device center 44. Each of the developing units 42a to 42d has developing rolls 46a to 46d, and is pressed in the normal direction of the developing unit main body 40 by elastic bodies 48a to 48d such as coil springs.

  The rotary developing device 38 is arranged so that the photosensitive drum 50 rotating about the rotation support shaft 49 is in contact with each other, and the developing rolls 46a to 46d are not in contact with the photosensitive drum 50, respectively. A part of the outer periphery of the developing device protrudes from the outer periphery of the developing device main body 40 in the radial direction by about 2 mm. Further, a tracking roll (not shown) having a diameter slightly larger than the diameter of the developing rolls 46a to 46d is provided at both ends of each of the developing rolls 46a to 46d so as to rotate coaxially with the developing rolls 46a to 46d. Yes. In other words, the developing devices 42 a to 42 d are arranged on the outer periphery of the developing device main body 40 at intervals of 90 ° with the rotary developing device center 44 as the center, and the tracking rolls of the developing rollers 46 a to 46 d are disposed at both ends of the photosensitive drum 50. The latent image on the photosensitive drum 50 is developed with toner of each color while abutting against a provided flange (not shown) and forming a predetermined gap between the developing rolls 46a to 46d and the photosensitive drum 50. To do.

  A charging roll 52 is provided below the photosensitive drum 50, and a charging bias is applied to the charging roll 52 to uniformly charge the photosensitive drum 50. Further, a photosensitive drum cleaner 54 is provided so as to hang from the rotation support shaft 49 of the photosensitive drum 50, and the photosensitive drum 50 and the photosensitive drum cleaner 54 are integrated. The photosensitive drum cleaner 54 includes a cleaning blade 56 that scrapes off residual toner remaining on the photosensitive drum 50 after the primary transfer. The cleaning blade 56 is attached to a sheet metal 57, and the sheet metal 57 is fixed to the toner recovery case 58. In addition, a detection mechanism unit 100 is provided inside the toner recovery case 58. (Details of the detection mechanism unit 100 will be described later).

  A rib or the like is formed on the back side (right side in FIG. 1) of the toner recovery case 58, and is curved to form a part of the conveyance path 28 so that the recording paper P is smoothly conveyed.

  On the lower back side of the rotary developing device 38, an exposure device 60 for writing a latent image on the photosensitive drum 50 charged by the charging roll 52 with a light beam such as a laser beam is disposed. Further, the toner image visualized by the rotary developing device 38 is primarily transferred above the rotary developing device 38 at the primary transfer position, and the secondary transfer position (the nip between the secondary transfer roll 80 and the secondary transfer backup roll 72) is transferred. An intermediate transfer device 62 is provided.

  The intermediate transfer device 62 includes an intermediate transfer belt 64, a primary transfer roll 66, a wrap-in roll 68, a wrap-out roll 70, a secondary transfer backup roll 72, a scraper backup roll 74, a brush backup roll 76, and the like.

  The intermediate transfer belt 64 has elasticity and is stretched substantially flat so as to have a long side and a short side above the rotary developing device 38. The long sides on the upper and lower sides of the intermediate transfer belt 64 are stretched so as to be substantially parallel to the discharge portion 36 provided on the upper portion of the color printer body 12.

  The intermediate transfer belt 64 is positioned between a wrap-in roll 68 disposed upstream of the primary transfer roll 66 below the long side of the intermediate transfer belt 64 and a wrap-out roll 70 disposed downstream of the primary transfer roll 66. Thus, the photosensitive drum 50 has a primary transfer portion (photosensitive drum wrap region) that contacts the photosensitive drum 50 in a wrap shape, is wound around the photosensitive drum 50 by a predetermined range, and is driven by the rotation of the photosensitive drum 50. As described above, the intermediate transfer belt 64 primarily transfers the toner image on the photosensitive drum 50 by the primary transfer roll 66 in the order of yellow, magenta, cyan, and black, and the primary transferred toner image is secondary-transferred. It is conveyed toward the transfer roll 80. Note that the wrap-in roll 68 and the wrap-out roll 70 are separated from the photosensitive drum 50.

  As described above, the intermediate transfer belt 64 is stretched by the five rolls of the wrap-in roll 68, the wrap-out roll 70, the secondary transfer backup roll 72, the scraper backup roll 74, and the brush backup roll 76, and the primary transfer roll 66, the toner image on the photosensitive drum 50 is transferred.

  Further, a flat portion (short side) is formed on the back side (right side surface in FIG. 1) of the intermediate transfer belt 64 by a wrap-out roll 70 and a secondary transfer backup roll 72, and this flat portion is the secondary transfer portion. It faces the transport unit 28.

  In the secondary transfer portion, the wrap-out roll 70 is disposed so that the intermediate transfer belt 64 and the conveyance path 28 are at an angle of about 12 °.

  The scraper backup roll 74 assists the scraper 84 to scrape residual toner remaining on the intermediate transfer belt 64 after the secondary transfer, and the brush backup roll 76 removes residual toner remaining on the intermediate transfer belt 64 after the secondary transfer. Helps the brush roll 86 to scrape.

  A reflective photosensor 78 is provided above the long side of the intermediate transfer belt 64 by being fixed to the back surface (inside) of the open / close cover 16. The reflective photosensor 78 reads a toner patch formed on the intermediate transfer belt 64, detects the position of the intermediate transfer belt 64 in the rotational direction, and detects the density of the toner image.

  A secondary transfer roll 80 is opposed to the secondary transfer backup roll 72 of the intermediate transfer device 62 with the conveyance path 28 interposed therebetween. That is, the secondary transfer position in the secondary transfer portion is between the secondary transfer roll 80 and the secondary transfer backup roll 72, and the secondary transfer roll 80 is intermediate with the assistance of the secondary transfer backup roll 72. The toner image primarily transferred to the transfer belt 64 is secondarily transferred to the recording paper P at the secondary transfer position. Here, the secondary transfer roll 80 is rotated while the intermediate transfer belt 64 rotates three times, that is, while the toner images of three colors of yellow, magenta, and cyan are primarily transferred and conveyed on the intermediate transfer belt. It is separated from the intermediate transfer belt 64, and comes into contact with the intermediate transfer belt 64 when a black toner image is transferred.

  In addition, a predetermined potential difference is generated between the secondary transfer roll 80 and the secondary transfer backup roll 72, and when the secondary transfer roll 80 is set to a high voltage, the secondary transfer backup roll 72 is connected to the ground (GND).

  An intermediate transfer belt cleaner 82 is provided at the end of the intermediate transfer belt 64 on the side opposite to the photosensitive drum 50. The intermediate transfer belt cleaner 82 includes a scraper 84, a brush roll 86, a toner collection case 88 and a rotation support shaft 89, and swings about the rotation support shaft 89. The scraper 84 scrapes off and removes residual toner remaining on the intermediate transfer belt 64 after the secondary transfer. The brush roll 86 further scrapes off residual toner remaining after cleaning by the scraper 84. The toner collection case 88 collects residual toner cleaned by the scraper 84 and the brush roll 86. The scraper 84 is made of a thin stainless steel plate, and a voltage having a polarity opposite to that of the toner is applied.

  The brush roll 86 is made of a brush such as acrylic that has been subjected to a conductive treatment. While the intermediate transfer belt 64 conveys the toner image, the scraper 84 and the brush roll 86 are separated from the intermediate transfer belt 64 and come into contact with the intermediate transfer belt 64 at a predetermined timing. Has been.

  A fixing device 90 is disposed above the secondary transfer position. The fixing device 90 includes a heating roll 92 and a pressure roll 94, and fixes the toner image secondarily transferred to the recording paper P by the secondary transfer roll 80 and the secondary transfer backup roll 72 to the recording paper P. It is conveyed toward the discharge roll 34. The discharge roll 34 discharges the recording paper P from the discharge port 30 to a discharge unit 36 provided at the upper part of the opening / closing cover 16.

  An operation panel 106 is provided on the upper side of the color printer main body 12 (the right side in FIG. 1). The operation panel 106 displays various notifications to the user from the control unit 39.

  Further, the intermediate transfer device 62, the photosensitive drum 50, the charging roll 52, the photosensitive drum cleaner 54, and the intermediate transfer belt cleaner 82 are integrated to form an image forming unit 96.

  As shown in FIG. 2, the image forming unit 96 is detachable from the color printer main body 12, and is attached to and detached from the color printer main body 12 by opening the opening / closing cover 16. Therefore, since the respective components of the image forming unit 96 can be exchanged at once, maintenance is easy.

  As shown in FIG. 3, a detection mechanism 100 is attached to the central portion of the toner recovery case 58 of the photosensitive drum cleaner 54. In addition, partition walls 250 and 251 are formed on both ends of the detection mechanism unit 100.

  As shown in FIG. 4, the slopes 250A and 251A of the partition walls 250 and 251 are substantially parallel to the sheet metal 57, and a slight gap (1 mm or less) is opened. (Note that the partition 250 is not visible in FIG. 4, but is the same as the partition 251).

  Further, the detection mechanism unit 100 is located below the tip 56A of the cleaning blade 56 (a position where the cleaning blade 56 is in contact with the photosensitive drum 50).

  As shown in FIGS. 4 and 5, the detection mechanism unit 100 includes a transparent case 102 made of a member through which the sensor light S can be transmitted. The transparent case 102 includes an upper box-shaped box portion 104, a cylindrical first tube portion 106 that is formed at the lower portion of the box portion 104 and is smaller than the box portion 104, and a first tube that is formed at the lower portion of the first tube portion 106. It is comprised from the cylindrical 2nd cylinder part 108 smaller than the part 106. FIG.

  In the transparent case 102, only the upper surface of the box part 104 is opened, and the box part 104, the first cylinder part 106, and the second cylinder part 108 are in communication. Further, the second cylinder portion 108 protrudes from the bottom portion of the toner recovery case 58.

  A T-shaped measuring member 150 is accommodated in the transparent case 102 described above. The measuring member 150 includes a platform portion 151 including a tray portion 152 that fits in the box portion 104 of the transparent case 102, and a support column portion 154 that is formed in the lower portion of the tray unit 152 and inserted into the first tube unit 106. And a protruding portion 156 that can be inserted into the second cylindrical portion 108.

  A spring 180 is housed in the first tube portion 106, and a protruding portion 156 of the measuring member 150 is inserted into the spring 180. Further, the outer diameter of the spring 180 is larger than the inner diameter of the second cylindrical portion 108.

  Therefore, the measuring member 150 is biased upward by the elastic force of the spring 180. In addition, protrusions 110 and 111 are formed on the inner wall of the upper part of the box part 104 so that the dish part 152 does not come out upward. The upper end part of the dish part 152 is caught by the protrusions 110 and 111 and is I can't escape. Therefore, it is maintained in a state of being biased upward. In this state, the protruding portion 156 is not inserted into the second cylinder portion 108.

  The protrusions 110 and 111 of the box portion 104 are formed with slope portions 110A and 111A. Therefore, when the measuring member 150 is housed in the transparent case 102, the measuring member 150 is inserted from the opening of the box portion 104, and even if the plate portion 152 hits the protrusions 110 and 111, the measuring member 150 is pressed further downward, thereby causing the slope 110 </ b> A. 111A, the plate portion 152 is slightly bent and deformed, and is inserted below the protrusions 110 and 111. In addition, the outer shape of the plate portion 152 is substantially the same size as the inner shape of the box portion 104, and there is almost no gap between the plate portion 152 and the box portion 104.

  As shown in FIG. 5, a U-shaped detection unit 200 is disposed in the color printer main body 12 so as to sandwich the second cylinder portion 108 protruding from the bottom of the toner recovery case 58. In the detection unit 200, a light emitting LED 204 that emits the sensor light S is disposed on one side of the second cylinder portion 108, and a light receiving element 206 that can receive the sensor light S is disposed on the other side.

  Now, as shown in FIG. 6, when the residual toner H2 scraped by the cleaning blade 56 accumulates on the upper part of the plate portion 152, the weight of the residual toner H2 lowers against the elastic force of the spring 180 and protrudes. The part 156 is inserted into the second cylinder part 108.

  As shown in FIG. 5, in a state where the protruding portion 156 of the measuring member 150 is not inserted into the second cylinder portion 108, the sensor light S is transmitted through the second cylinder portion 108, and the light receiving element 206 is the sensor light. S is received.

  However, as shown in FIG. 6, when the residual toner H2 scraped by the cleaning blade 56 accumulates on the upper portion of the plate portion 152, and the protruding portion 156 is inserted into the second cylindrical portion 108 to the lowest point portion. Since the protrusion 156 blocks the sensor light S, the light receiving element 206 does not receive the sensor light S.

  Then, information on whether or not the sensor light S of the light receiving element 206 is received / not received is sent to the control unit 39 (see FIG. 1).

  Next, the operation of the above embodiment will be described.

  When the image forming signal is sent, the photosensitive drum 50 is uniformly charged by the charging roll 52, and a light beam is emitted from the exposure device 60 to the charged photosensitive drum 50 based on the image signal. The light beam from the exposure device 60 exposes the surface of the photosensitive drum 50 to form a latent image. The latent image on the photosensitive drum 50 formed by the exposure device 60 is developed with yellow, magenta, cyan, and black toner images by the rotary developing device 38, and is primarily transferred onto the intermediate transfer belt 64. In the primary transfer, residual toner remaining on the photosensitive drum 50 is scraped off by the cleaning blade 56 and collected in the toner collection case 58.

  On the other hand, the recording paper P stored in the paper feed cassette 22 by a paper feed signal or the like is sent out by the feed roll 24, turned by the retard roll 26, guided to the transport path 28, and temporarily stopped by the registration roll 32, It is conveyed toward the guide member 29 with timing. When the recording sheet P is guided to the secondary transfer position A, the toner image primarily transferred to the intermediate transfer belt 64 is secondarily transferred to the recording sheet P by the secondary transfer roll 80 and the secondary transfer backup roll 72. The The residual toner remaining on the intermediate transfer belt 64 after the secondary transfer is scraped off and collected by the intermediate transfer belt cleaner 82.

  The recording paper P to which the toner image has been transferred is guided to the fixing device 90, and the toner image is fixed by the thermal pressure of the heating roll 92 and the pressure roll 94. The recording paper P on which the toner image is fixed is discharged from the discharge port 30 to the discharge unit 36 by the discharge roll 34.

  As described above, the residual toner remaining on the photosensitive drum 50 is scraped off by the cleaning blade 56 and collected in the toner collection case 58. And it accumulates on the upper part of the plate part 152 of the measurement member 150 of the detection mechanism part 100. FIG.

  When the residual toner accumulation amount is small, as shown in FIG. 5, the measuring member 150 is biased upward by the elastic force of the spring 180, so that the protruding portion 156 is not inserted into the second cylinder portion 108. . Accordingly, the sensor light S emitted from the light emitting LED 204 is transmitted through the second tube portion 108, and the light receiving element 206 receives the sensor light S.

  However, when the residual toner is accumulated, the weight of the residual toner is lowered against the elastic force of the spring 180, and the protruding portion 156 is inserted into the second cylindrical portion 108. As shown in FIG. 6, when the light reaches the lowest point, the sensor light S is blocked by the protrusion 156, and the light receiving element 206 does not receive the sensor light S.

  The control unit 39 (see FIG. 1) to which the light receiving / non-light receiving information of the light receiving element 206 is sent is such that when the light receiving element 206 does not receive light, the toner collection case 58 is almost full of residual toner. And displays a display prompting the user to replace the image forming unit 96 on the operation panel 106 (see FIG. 1). The user views the display and opens the opening / closing cover 16 and replaces the image forming unit 96 as shown in FIG.

  When the recording paper P is jammed in the conveyance path 28 and the jammed recording paper P is removed, the user may open the opening / closing cover 16 and take out the image forming unit 96 as shown in FIG. The extracted image forming unit 96 is tilted left and right and back and forth depending on the handling of the user.

  FIG. 9 schematically shows a conventional toner recovery case 300. When the toner collection case 300 is tilted as shown in FIG. 9A, the collected residual toner H4 is largely displaced. Further, as shown in FIG. 9B, even if it becomes horizontal, the deviation is not eliminated so much, and the residual toner H4 becomes non-uniform. Therefore, an accurate recovery amount of the residual toner H4 cannot be detected.

  On the other hand, as shown in FIG. 8, the toner collection case 58 of the present embodiment has partition walls 250 and 251 formed at the center, and measures the residual toner H2 stored between the partition walls 250 and 251.

  Therefore, even if the toner is tilted as shown in FIG. 8A and then horizontal as shown in FIG. 8B, the residual toner H2 stored between the partition walls 250 and 251 is not significantly displaced. (Refer to FIG. 8B for comparison between L1 and L2 in FIG. 9B). Therefore, since the deviation is reduced in this way, an accurate collection amount of the residual toner can be detected.

  The residual toner recovery amount is detected by a mechanism that detects when the residual toner accumulated between the partition walls 250 and 251 exceeds a predetermined amount. Therefore, even if the residual toner H2 stored between the partition walls 250 and 251 is shifted, there is no influence. Therefore, an accurate recovery amount of residual toner can be detected.

  When a large amount of an image pattern in which an image is not formed at the center as shown in FIG. 10 is printed, only residual toners H1 and H3 on both ends of the partition walls 250 and 251 are accumulated, and between the partition walls 250 and 251 at the center. In this case, the residual toner H2 is not collected and cannot be detected accurately. However, it is unthinkable to print such an image pattern in large quantities. Therefore, there is no possibility that the image pattern cannot be accurately detected.

  Rather, normally, since most of the image pattern in which an image is formed in the center portion is detected, it is preferable to detect the residual toner H2 stored between the partition walls 250 and 251 in the center portion.

  Further, when the toner recovery case 58 is distorted due to thermal deformation or the like, the sheet metal 57 is bent. When the sheet metal 57 is bent, the contact position between the tip 56A of the cleaning blade 56 and the photosensitive drum 50 may change, resulting in poor cleaning.

  However, as shown in FIG. 7, when the sheet metal 57 is bent, it strikes the slopes 250A and 251A of the partition walls 250 and 251, and the bending is restricted. Therefore, the contact position between the tip 56A of the cleaning blade 56 and the photosensitive drum 50 hardly changes, so that no cleaning failure occurs. Note that FIG. 7 is shown more extreme than actual so that the bending of the sheet metal 57 can be easily understood.

  The present invention is not limited to the above embodiment.

  For example, in the above embodiment, the recovery amount of the residual toner is detected by the detection mechanism unit 100 and the detection unit 200, but is not limited thereto. For example, an existing toner remaining amount sensor such as a piezoelectric vibration sensor or a magnetic permeability sensor may be used.

  Further, for example, in the above embodiment, the residual toner is removed by scraping with the cleaning blade 56, but the present invention is not limited to this. Other cleaning members may be used. For example, a brush or a roller may be used.

  Further, for example, in the above-described embodiment, the image forming unit 96 in which the intermediate transfer device 62, the photosensitive drum 50, the charging roll 52, the photosensitive drum cleaner 54, and the intermediate transfer belt cleaner 82 are integrated is detachable. However, it is not limited to this. For example, only the photosensitive drum cleaner 54 may be detachable.

  For example, in the above-described embodiment, the present invention is applied to the toner collection case 58 that collects the residual toner remaining on the photosensitive drum 50 after the primary transfer. However, the present invention is not limited to this. For example, the present invention may be applied to a toner recovery case 88 that recovers residual toner remaining on the intermediate transfer belt 64 after the secondary transfer.

Note that both the residual toner remaining on the photosensitive drum 50 and the residual toner remaining on the intermediate transfer belt 64 are poor in fluidity because the particle diameter is smaller than that of the toner before development. Therefore, since the deviation is likely to occur, such as in Figure 9, a housing case for collecting the residual toner and structure of this invention, to reduce the offset is very effective.

Further, for example, not via an intermediate transfer belt, the recording medium material such as a recording paper from the photosensitive drum may be an image forming apparatus configured to transfer a direct toner image.

  Further, for example, a recording medium other than the recording paper P may be used. For example, an OHP sheet may be used, or another recording medium may be used.

1 is a cross-sectional view schematically showing the inside of a color printer according to an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing how an image forming unit is attached to and detached from a color printer main body. It is a fragmentary sectional perspective view which shows the cleaner for photoreceptor drums. It is sectional drawing seen from the side which shows the inside of the cleaner for photoconductor drums. FIG. 5 is a cross-sectional view showing a state where the residual toner is not accumulated on the dish portion, as seen from the front, showing the detection mechanism portion and the detection portion. FIG. 5 is a cross-sectional view showing a state where residual toner is accumulated on a dish portion, as viewed from the front, showing a detection mechanism portion and a detection portion. In FIG. 4, it is sectional drawing which shows the state which the sheet metal bent and contact | abutted to the partition. FIG. 5 is a diagram for explaining the residual toner in a toner recovery case of the color printer according to the embodiment of the present invention. FIG. 10 is a diagram for explaining a residual toner in a conventional toner recovery case. It is a figure which shows the example of the image pattern in which an image is not formed only in the center part.

Explanation of symbols

10 Color printer (image forming device)
12 Color printer body (image forming device body)
50 Photosensitive drum (image carrier)
56 Cleaning blade 57 Sheet metal (fixed plate)
58 Toner Collection Case (Collection Case)
64 Intermediate transfer belt (transfer medium)
96 Image forming unit (unit)
100 Detection mechanism (detection means)
200 Detection unit (detection means)
250 Bulkhead 251 Bulkhead

Claims (9)

An image carrier that carries the toner image on which a toner image is formed and transferred to a transfer medium;
A cleaning member that contacts the image carrier and removes residual toner on the image carrier;
A collection case for collecting the residual toner removed from the image carrier by the cleaning member from an opening;
A longitudinal direction of the cleaning member for the residual toner that is formed inside the recovery case and arranged at intervals in the longitudinal direction of the cleaning member, divides the interior of the recovery case, and drops and accumulates from the opening. Two partition walls that suppress the movement of
Detecting means provided between the two partition walls at the bottom of the recovery case and detecting the amount of residual toner accumulated between the partition walls;
Have
When viewed in the longitudinal direction of the cleaning member, an interval between the partition and the cleaning member at a position facing the partition is configured such that the upper side is narrower than the vicinity of the bottom. Image forming apparatus. An image carrier that carries the toner image on which a toner image is formed and transferred to a transfer medium;
A cleaning member that contacts the image carrier and removes residual toner on the image carrier;
A collection case for collecting the residual toner removed from the image carrier by the cleaning member from an opening;
A longitudinal direction of the cleaning member for the residual toner that is formed inside the recovery case and arranged at intervals in the longitudinal direction of the cleaning member, divides the interior of the recovery case, and drops and accumulates from the opening. Two partition walls that suppress the movement of
The residual toner amount that is provided between the two partition walls and in the image bearing region of the image carrier at the bottom of the collection case and is stored between the partition walls is a predetermined amount. Detection means for detecting that the
Have
When viewed in the longitudinal direction of the cleaning member, an interval between the partition and the cleaning member at a position facing the partition is configured such that the upper side is narrower than the vicinity of the bottom. Image forming apparatus.   The image forming apparatus according to claim 1, wherein the two partition walls partition a central portion of the collection case. The cleaning member is
A crane blade that abuts the image carrier and scrapes and removes residual toner on the image carrier;
A fixing plate that fixes the cleaning blade and is attached to the collection case;
Consists of
The image forming apparatus according to claim 1, wherein the partition wall abuts when the fixing plate is bent, and also serves as a regulating member that regulates the bending of the fixing plate. At least a unit comprising the image carrier, a cleaning member, and the recovery case divided inside by the partition;
The image forming apparatus according to claim 1, wherein the unit is detachable from the main body of the image forming apparatus. The cleaning member is
A crane blade that abuts the image carrier and scrapes and removes residual toner on the image carrier;
A fixing plate that fixes the cleaning blade and is attached to the collection case;
Consists of
When viewed in the longitudinal direction of the cleaning member , an interval between the partition and the fixing plate at a position facing the partition is configured such that the upper side is narrower than the vicinity of the bottom. The image forming apparatus according to any one of claims 1 to 5.   The image forming apparatus according to claim 6, wherein the fixing plate is disposed obliquely when viewed in the longitudinal direction of the cleaning member.   The projecting part which protruded so that the upper end part of the said dish part might be caught on the inner wall of the said box part, and it may not fall upwards is formed in any one of Claims 1-7 characterized by the above-mentioned. The image forming apparatus described.   The measuring member is inserted from the opening at the top of the box part and pressed downward even when the dish part hits the protrusion, so that the dish part gets over the protrusion and below the protrusion. The image forming apparatus according to claim 8, wherein the image forming apparatus is inserted.

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