JP4269873B2 - Developer residual state detector for developing device - Google Patents

Description

  The present invention relates to a developer remaining state detection device for a developer used for developing a developer by attaching a developer to an electrostatic latent image in an image forming apparatus such as a copying machine, a printer, or a facsimile machine.

As a method for detecting the remaining amount of developer (toner) in the developing unit, for example, as shown in Patent Document 1, a plurality of transmission type photosensors provided in a lower part of a storage chamber for storing toner in the developing unit It is described that the toner empty is determined based on the sum of the outputs. Further, Patent Document 2 detects the angle of rotation of the feed member from the start of operation of the feed member installed in the developer until the light from the light emitting element is not received by the light receiving element. The point that the total amount of the developer is determined is described.
Japanese Patent Laid-Open No. 6-110332 JP-A-11-143205

  The toner remaining amount detection method described above is basically performed to detect that the toner in the developing device has run out. That is, when the toner near the developing roller runs out, sufficient toner is not supplied to the developing roller, and the electrostatic latent image formed on the photosensitive drum is not sufficiently developed, which may cause image degradation. Because it becomes high. However, factors that cause image degradation include degradation of the toner itself, in addition to insufficient supply of toner. It has been found that the deterioration of the toner itself proceeds as it is agitated by the agitator in the developing device. It is hard to say that those described in the above-mentioned prior art documents sufficiently deal with this point.

  When increasing the amount of toner filled in the developing device, it is necessary to increase the capacity of the replenishing chamber for storing the toner in the developing device, but it is assumed that the overall size of the image forming apparatus is as compact as possible. The shape of the replenishing chamber must be expanded in the horizontal direction, not in the vertical direction. Therefore, the toner is stored so as to spread laterally from the developing roller, and the toner is stored at a position far from the developing roller. Since the toner is sequentially transferred by the agitator from the side closer to the developing roller, the toner is agitated for a long time and transferred to the developing roller for a longer distance, and the deterioration of the toner advances accordingly. Therefore, in the developing device in which the replenishing chamber is expanded in the lateral direction, the deterioration of the toner itself becomes large, and the deterioration toner is supplied to the developing roller only by detecting the absence of the toner in the vicinity of the developing roller. Despite the presence of toner, image deterioration will be caused.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a developer remaining state detecting device for a developing device capable of detecting a remaining state corresponding to the deterioration of the toner itself in a developing device having a replenishment chamber extending in a lateral direction. To do.

Toner remaining state detection apparatus according to the present invention, comprising a supply chamber for supplying the toner to the latent image bearing member on which an electrostatic latent image is formed, a stirring means for stirring the toner together with storing the toner Three or more supply chambers, each of the supply chambers being arranged in parallel in the lateral direction of the supply chamber and communicating with each other, and the supply chamber closest to the supply chamber is in communication with the supply chamber. a developing device of the toner remaining state detection device is, the developing device is the developing device or a developing device or determines the developing device determination means for replenishing, the determined replacement toner remaining necessary for the developing unit in the initial mounting Based on reading means for reading out state data, toner remaining amount detecting means disposed in the replenishing chamber farthest from the supply chamber, and the replenishing chamber farthest from the supply chamber, and detection outputs from the respective toner remaining amount detecting means In the developing unit Residual state determining means for determining a current toner remaining states, by comparing the current toner remaining state data exchange is determined to be necessary toner remaining status data read out when a small current toner remaining state And a notifying means for notifying the replacement time of the developing device .

  Since the remaining amount of developer in the replenishing chamber farthest from the supply chamber and the next furthest supply chamber is detected by having the above-described configuration, the portion where the developer is most deteriorated before being transferred to the supply chamber By determining the remaining state of the developer in the developing device from the remaining amount of the developing device, it becomes possible to replace the developing device before the deteriorated developer is supplied to the latent image carrier, and image deterioration during image formation Can be prevented.

  That is, since three or more supply chambers are arranged in parallel, the developer in the supply chamber close to the supply chamber is sequentially transferred to the supply chamber by the stirring means, but the developer in the furthest supply chamber is transferred to the supply chamber. Since it is agitated by the agitating means in each replenishment chamber until it is done, it is agitated for the longest time and transferred to the supply chamber. Therefore, by detecting the remaining amount of the furthest supply chamber, it is possible to determine how much the developer remaining in the developing device has deteriorated. Furthermore, by detecting the remaining amount of developer in the next furthest replenishment chamber, the remaining amount can be grasped more accurately from the two detection results, and as much developer as possible can be used. It becomes.

  Further, the determination means makes a determination based on the amount of the developer initially filled in the developing device, so that even when a small amount of the developer is filled, the determination can be made accurately according to the deterioration of the developer. become. In the case of a developing device having a large capacity of three or more replenishing chambers, it is conceivable to provide the developer with a small amount of developer to be filled.

  In other words, when the initial filling amount of the developer is large, it is necessary to replace even if there is a large amount of the remaining developer. It is possible to accurately determine the residual state of the developer according to the initial filling amount.

  Hereinafter, embodiments according to the present invention will be described in detail. The embodiments described below are preferable specific examples for carrying out the present invention, and thus various technical limitations are made. However, the present invention is particularly limited in the following description. Unless otherwise specified, the present invention is not limited to these forms.

  FIG. 1 is a schematic cross-sectional view of the entire image forming apparatus according to the present invention. A document reading unit 2 is arranged at the upper part of the image forming apparatus 1, and a paper feeding unit 3 and a recording unit 4 are arranged at the lower part from the bottom.

  In the document reading unit 2, the document placed on the document tray 11 provided on the document cover 10 is conveyed to the reading position by the document conveying device 12 and is discharged to the document discharge tray 13. At the reading position, a scanning device 16 equipped with a reading device 15 for optically reading a document is arranged so as to face the document. When reading a book or the like, the document cover 10 is rotated upward to place a read portion of the book or the like on the flat bed platen 14, and the scanning device 16 is moved as shown by an arrow to perform a reading operation. Is called. The above-described configuration is the same as that of a conventional document reading apparatus called a so-called ADF or flat bed type.

  In the paper feed unit 3, a paper feed cassette 17 is disposed, and a plurality of sheets of a predetermined size are stacked on the flapper 18. A pickup roller 19 is disposed at the right end of the paper feed cassette 17. The flapper 18 is urged upward by a spring member (not shown) so that the upper surface of the stacked paper comes into pressure contact with the pickup roller 19. When the pickup roller 19 is rotationally driven in this state, the sheets are fed one by one to the sheet conveyance path by the frictional force.

  The fed paper is first conveyed to the recording unit 4 by the feed roller 20 and the press roller 21. The recording unit 4 includes a developing unit 22, a paper dust removing roller 23, a corona charger 24, a photosensitive drum 25, a transfer roller 26, an exposure head 27, and a fixing roller 28 for recording on the conveyed paper. Yes. The paper dust removing roller 23 is composed of a conductive sponge or the like, and supplements toner or paper dust attached to the surface of the photosensitive drum 25 after transfer. The corona charger 24 uniformly charges the surface of the photosensitive drum 25 by the discharge from the corotron. An electrostatic latent image is formed by exposing the photosensitive drum 23 uniformly charged by the paper dust removing roller 23 and the corona charger 24 according to the image recording signal by the exposure head 25. Then, as will be described later, the toner in the developing device 22 is transferred to the electrostatic latent image formed on the photosensitive drum 25 to visualize the electrostatic latent image. The transfer roller 26 is installed at a position facing the photosensitive drum 25 with the paper interposed therebetween, and a toner image formed on the surface of the photosensitive drum 25 is transferred to the paper when a predetermined voltage is applied. The transferred toner image is sandwiched between the fixing roller 28 and the press roller 29 and heated and pressed to be fixed on the paper. The fixed paper is sandwiched between the paper discharge roller 30 and the press roller 31 and is carried out to the paper discharge tray 32.

  In FIG. 1, a sheet conveyance path is indicated by a one-dot chain line from the sheet feeding unit 3 to the sheet discharge tray 32. A conveyance roller and a paper guide arranged along the paper conveyance path constitute a paper conveyance unit.

  A reversal conveyance unit 40 is detachably mounted on a side surface of the apparatus main body, and a paper carry-out port 41 and a paper carry-in port 42 are formed on the mounting side surface. In the transport unit 40, two pairs of transport rollers, a feed roller 43 and a press roller 44, and a feed roller 45 and a press roller 46, are arranged up and down. Then, as shown by a two-dot chain line in FIG. 1, the reverse conveyance path branches off from the sheet conveyance path between the paper discharge roller 30 and the fixing roller 28, and the two pairs of conveyance rollers 43 and 44, 45 and 46 are separated. It is formed so as to pass through and to join the paper conveyance path between the roller pairs 20 and 21 and the pickup roller 19.

  When recording on both sides of the sheet, the sheet is conveyed to the sheet conveyance path indicated by the one-dot chain line in FIG. 1 and recorded on one side, and then the sheet is carried out to the sheet discharge tray 32 by the discharge roller 30. The carry-out operation is temporarily stopped in a state where the rear end portion of the paper is sandwiched between the paper discharge roller 30 and the press roller 31. Then, the paper discharge roller 30 is driven to rotate reversely, the paper is carried into the reverse conveyance path from the rear end, and is nipped by the feed roller 43 and the press roller 44 to be conveyed in the reverse conveyance path. Next, the paper is nipped by the feed roller 45 and the press roller 46 and further conveyed, and the paper is brought into contact between the roller pair 20 and 21. When the sheet is conveyed to the sheet conveyance path in this state, the other surface is recorded to face the photosensitive drum 25, and recording is performed on both sides of the sheet.

  FIG. 2 shows an enlarged cross-sectional view of the recording unit 3 in FIG. 3 shows an enlarged cross-sectional view of the developing device 22, and FIG. 4 shows a perspective view of the developing device 22 as viewed from above.

  As described above, the developing device 22, the paper dust removing roller 23, the corona charger 24, and the transfer roller 26 are disposed around the photosensitive drum 25, and between the corona charger 24 and the developer 22. Laser light is emitted from the exposure head 27 to the surface of the photosensitive drum 25 in accordance with the image recording signal.

  The developing device 22 is configured by sealing a lid 51 on the upper portion of the container body 50 by welding or fixing with screws. Three toner chambers 52, 53, and 54 are formed inside the container body 50 as toner replenishing chambers, and a supply chamber 57 having a developing roller 55 and a supply roller 56 at the side end on the photosensitive drum 25 side. Is formed. The first toner chamber 52 and the supply chamber 57 are partitioned by a partition plate 58 extending from the lower surface of the lid 51, and a supply opening 59 is formed in the partition plate 58.

  As shown in FIG. 3, the three toner chambers 52, 53, and 54 are configured to be arranged in parallel in the horizontal direction with the developing unit 22 mounted on the image forming apparatus 1. Paddles 60, 61, and 62 are provided as stirring transfer means in a substantially central portion of the chamber. In FIG. 2, assuming that the vertical direction of the paper surface is the front-rear direction of the developing device 22, the rotation shaft of each paddle is provided so that both ends in the front-rear direction are supported by the front-rear frame of the container body 50 and follow the front-rear direction It has been. A blade 63 made of a flexible resin film is attached to the tip of the paddle 60 so as to follow the rotational direction. Similarly, a blade 64 is attached to the paddle 61, and a blade 65 is attached to the paddle 62. These blades 63 to 65 use a common member. The bottom surface of the container main body 50 is formed with sliding surface portions 66, 67, and 68 that are curved outward in a circular arc shape along the trajectory of the rotational movement of the blade attached to each paddle.

  The toner supplied to each of the toner chambers 52 to 54 is stored in the sliding surface portions 66, 67, and 68. When the paddles 60, 61, 62 rotate, the blades 63, 64, 65 rotate so as to slide on the sliding surface portions 66, 67, 68, respectively. The toner is picked up by the sliding motion of each blade, and the toner is agitated in each toner chamber to prevent deterioration due to toner aggregation. Further, as shown in FIG. 2, the blades 63, 64, 65 rotate counterclockwise, whereby the toner in the third toner chamber 54 is transferred to the second toner chamber 53, and the toner in the second toner chamber 53 Is transferred to the first toner chamber 52. The toner in the first toner chamber 52 is supplied to the supply chamber 57 from the supply opening 59 of the partition plate 58. At that time, the replenished toner is agitated by the paddle 60 in the first toner chamber 52 and preliminarily charged. The supply opening 59 has a slit shape in the front-rear direction, and the amount of toner supplied from the first toner chamber 52 to the supply chamber 57 can be adjusted by adjusting the opening width and the opening position. .

  The toner replenished in the supply chamber 57 is rubbed and charged by slidingly contacting the developing roller 55 while the supply roller 56 rotates, and is carried on the surface of the developing roller 55. On the developing roller 55, a developing blade 69 that regulates the layer thickness of the supplied toner is disposed close to the surface of the developing roller 55. As the developing roller 55 and the photosensitive drum 25 are in sliding contact with each other while rotating, a toner layer regulated to a constant layer thickness by the developing blade 69 adheres to the electrostatic latent image formed on the surface of the photosensitive drum 25. And developed.

  The developing device 22 is detachably attached to the image forming apparatus 1 in the front-rear direction. In FIG. 2, when the front side of the paper surface in the vertical direction is the front surface portion of the developing device 22 and the opposite side is the rear surface portion, the main body frame in the image forming device 1 is inserted when the developing device 22 is inserted into the image forming device 1. It is inserted into the mounting space formed in 70 from the rear surface and mounted. After being inserted, the developing device 22 is set in a state in which the container main body 50 is pushed up from below by a pressing mechanism 71 provided on the main body frame 70 of the image forming apparatus 1 and the developing roller 55 is in contact with the photosensitive drum 25. The Further, the toner remaining amount detecting sensor 72 is raised in conjunction with the pressing operation of the pressing mechanism 71 and is set in the concave groove 73 made of a transparent member provided on the sliding surface portion 67. Similarly, the toner remaining amount detection sensor 74 rises in conjunction with the mounting operation of the developing device 22 and is set in the concave groove 75 made of a transparent member provided on the sliding surface portion 68.

  In the pressing mechanism 71, a bottom surface of a pressing body 79 slidably disposed on a substrate 78 is in contact with a cam member 77 fixed to the rotating shaft 76. When the developing device 22 is mounted, the upper surface of the pressing body 79 faces the pressure contact portion 80 formed in a rib shape on the bottom surface of the developing device 22. When an operator rotates a lever (not shown) fixed to the end of the rotating shaft 76, the cam member 77 rotates clockwise to push up the pressing body 79 in the direction of the arrow. The developing roller 55 comes into contact with the photosensitive drum 25 by pressing. The other end portion of the swing lever 81 having the remaining toner amount detection sensor 72 fixed to one end portion is urged downward by a compression spring (not shown) so as to come into contact with the cam member 77. When the member 77 rotates clockwise, the swing lever 81 rotates clockwise around the shaft 82 and the toner remaining amount detection sensor 72 rises. Similarly, the toner remaining amount detection sensor 74 may be raised in conjunction with the pressing operation of the pressing mechanism 71.

  As shown in FIG. 4, the lid 51 of the developing device 22 is formed in a plate shape so as to seal the upper opening of the container body 50, and protrudes upward from the center toward the developing roller 55 side. Is provided with a step portion 83, and an inclined portion 84 that is inclined downward from the step portion 83 toward the developing roller 55 is formed. The step portion 83 is formed from the front end to the rear end of the lid 51 along the insertion direction of the developing device 22. As shown in FIG. 3, a gap 85 is formed on the inner surface of the lid 51 so as to expand upward from the stepped portion 83 to the inclined portion 84. Guide protrusions 86a and 86b projecting upward are formed at the end of the inclined portion 84 on the developing roller 55 side. The guide projections 86a and 86b are arranged along the insertion direction of the developing device 22 on the developing roller 55 side of the lid 51, and the guide projection 86a is arranged on the rear end side in the insertion direction. Are arranged on the distal end side in the insertion direction. The distance between the guide protrusion 86a and the developing roller 55 is set to be slightly larger than the distance between the guide protrusion 86b. The guide protrusions 86a and 86b have a gap formed therein, and a rib is formed along the insertion direction at the center of the gap. Also, a plurality of streak-like ribs are formed between the two along the insertion direction. The side surfaces 87a and 87b of the guide projections 86a and 86b that face each other are inclined so as to spread toward the developing roller 55 in accordance with the irradiation range of the laser beam irradiated by the exposure head 27 shown in FIG.

  As shown in FIG. 4, a flat plate portion 88 extends in the horizontal direction on the front surface portion of the container main body 50, and a grip portion 89 is formed on the lower surface thereof downward. The grip portion 89 has a rectangular parallelepiped shape opened upward, and a plurality of reinforcing ribs 90 are provided in the front and rear direction in the space inside. On the upper surface of the flat plate portion 88, rectangular frame-shaped attachment portions 91a to 91e are arranged in a direction substantially orthogonal to the insertion direction of the developing device 22, and the developing portions 22 are provided on the attachment portions 91a to 91e. And an identification protrusion 92 for identifying compatibility with the apparatus main body. Since the identification protrusion 92 is fixed to the mounting portion 91 selected for each type of developing device, the developing device cannot be inserted when the mounting position of the identification protrusion 92 is not compatible with the apparatus main body. .

  FIG. 5 is a perspective view showing a state in which the developing device 22 is inserted into the main body frame 70 and attached. A space for mounting the developing device 22 is set between the bottom surface portion 93 and the top surface portion 94 of the main body frame 70. The heights of the guide projections 86a and 86b are set such that a slight gap is formed between the lower surface of the upper surface portion 94 when the developing device 22 is mounted. This prevents the developing unit 22 from moving up and down.

  On the lower surface of the upper surface portion 94, a regulating member 95 and an identification engagement portion 96 are provided so as to protrude downward along the front opening end on the front side of the sheet of FIG. The restricting member 95 is formed with a guide surface 97 inclined in the insertion direction on the front opening side, and the restricting surface 98 opposite to the photosensitive drum 25 is inserted with the developing device 22 away from the photosensitive drum 25. So that it is positioned. When the guide protrusion 86a or 86b comes to a position regulated by the regulating surface 98, there is only a slight gap between the side surface of the developing device 22 and the side surface portion 99 of the main body frame 70. Is put in and out without shaking from side to side. The identification engagement portion 96 can be fixed to five attachment positions corresponding to the attachment portions 91a to 91e, and the arrangement positions of the identification engagement portions 96 are compatible developing units 22 that can be attached to the apparatus main body. The identification projection 92 is arranged so as to be aligned with the arrangement position of the identification projection 92, so that the identification projection 92 and the identification engagement portion 96 do not collide when the developing device 22 is inserted. . When a developing device that is not compatible with the apparatus main body is inserted, the identification protrusion 92 and the identification engaging portion 96 collide with each other, but the side surface of the developing device 22 is in contact with the side surface portion 99 of the main body frame 70 as described above. Since there is only a slight gap between them, the developing device 22 cannot be shifted to the left and right to avoid a collision between them, and an incompatible developing device cannot be installed after all.

  In the above-described example, the case where the step portion 83 is provided on the lid 50 of the developing device 22 is described. However, the compatibility of the developing device 22 can be provided by the presence or absence of the step portion 83. That is, in FIG. 5, a gap 100 for allowing the stepped portion 83 to pass is formed between the attachment location of the identification engagement portion 96 and the position where the restricting member is disposed. In the developing device having the step portion 83, the step portion 83 collides and cannot be inserted. Then, when the stepped portion 83 is cut and forced to be inserted, for example, when the stepped portion 83 is cut along the cutting line AA as shown in FIG. 6A, a gap 85 is formed as shown in FIG. 6B. Communicates with the outside, and a hole is opened, so that the toner is released and the toner becomes unusable.

As described above, in order to ensure compatibility between the developing device and the apparatus main body,
(1) A combination of identification protrusions 92 fixed to the mounting portions 91a to 91e of the developing device (2) Physical means such as the presence or absence of a step portion 83 of the developing device is used.

  Next, in order to identify the compatibility between the developing device and the apparatus main body, an electric means can be used. First, an electrical connection mechanism between the developing device 22 and the apparatus main body at the time of mounting will be described.

  FIG. 7 shows an external view of the rear surface portion of the developing device 22. A rotating shaft 102 of the developing roller 55, a rotating shaft 103 of the supply roller 56, and a rotating shaft 104 of the paddles 60 to 62 are rotatably supported on the rear frame 101 of the container body 50, respectively. The end of each rotating shaft protrudes outward from the rear frame 01, and a drive transmission gear 105 is attached to the protruding portion. When the developing device 22 is mounted, the driving shaft 106 is connected to the driving mechanism on the apparatus main body side. Is transmitted to each rotary shaft by a transmission gear. A cover member 107 that covers a portion near the developing roller including the rotating shafts 102 and 103 is attached to the rear frame 101.

  FIG. 8 shows an enlarged view of the cover member 107 attached to the rear surface portion of the developing device 22. Mounting holes 108 a and 108 b for screwing the rear frame 101 are formed in the cover member 107, and at positions corresponding to the rotating shaft 102 of the developing roller 55, the rotating shaft 103 of the supply roller, and the driving shaft 106. Are provided with circular openings 109, 110 and 111, respectively. On the back surface side of the cover member 107, there are a first contact member 112 that contacts the rotating shaft 102 of the developing roller 55, a second contact member 113 that contacts the rotating shaft 103 of the supply roller, and a blade that contacts the surface of the developing roller 55. A third contact member 115 that is in contact with the pressing plate 114 is attached.

  The 1st contact member 112 consists of metal wires, and has the shape of the character bent at the center part. One end is inserted and held in the holding portion 116 of the cover member 107. The holding portion 116 is formed so as to protrude stepwise toward the back surface side of the cover member 107, and a window for inserting the first contact member 112 is opened. The other end is bent in a U-shape to form a contact portion 117, which is engaged and fixed in a narrow insertion hole 118 and a circular engagement hole 119 formed in the cover member 107. ing. When attaching the contact portion 117 to the cover member 107, the contact portion 117 is first inserted into the insertion hole 118 from the back surface side, the contact portion 117 is brought out to the front surface side, and the bent tip portion is inserted into the engagement hole 119. By attaching the contact portion 117 in this manner, the contact portion 117 is set in a state of protruding from the front surface side of the cover member 107, and can reliably contact and be electrically connected to the electrode of the image forming apparatus 1. Since the diameter of the engagement hole 119 is formed to be substantially the same as the diameter of the first contact member 112, the other end is firmly fixed, and one end is held by the holding portion 116. Thus, the first contact member 112 does not come out of the cover member 107. The first contact member 112 is in pressure contact with the rotating shaft 102 by the elastic force biased upward, and the first contact member 112 and the rotating shaft 102 can maintain a stable contact state, and are electrically The connection state can be secured reliably.

  Similarly to the first contact member 112, the second contact member 113 is made of a metal wire formed in a dogleg shape, and the other end portion is bent to form a U-shaped contact portion 120. Then, one end portion of the second contact member 113 is inserted and held in the holding portion 121 provided in the same manner as the holding portion 116, and the contact portion 120 is provided in the cover member 107 in the same manner as the contact portion 117. Are engaged and fixed in a circular insertion hole 122 and a circular engagement hole 123. Therefore, the second contact member 113 is securely held without coming out of the cover member 107, and the contact portion 120 is set in a state of projecting to the surface side of the cover member 107 so as to reliably contact the electrode of the image forming apparatus 1. Can be electrically connected. In addition, the second contact member 113 is in pressure contact with the rotating shaft 103 by the elastic force biased upward, and the second contact member 113 is also in stable contact with the rotating shaft 103 like the first contact member 112. The state can be maintained, and the electrical connection state can be reliably ensured.

  The third contact member 115 is made of a thin metal wire, and one end is formed in a coil spring shape, and the other end is bent in an L shape at a right angle to form a contact portion 124 with a tip end. Furthermore, it is bent into a bowl shape. When the third contact member 115 is attached to the cover member 107, the other end portion is inserted into the circular insertion hole 125 provided in the cover member 107 from the back surface side so that the contact portion 124 is on the front surface side of the cover member 107. The bent portion at the tip is inserted into the circular engagement hole 126 and fixed. Since the diameter of the engagement hole 126 is formed substantially the same as the diameter of the third contact member 115, the other end is firmly fixed. Therefore, the third contact member 115 is securely held without coming out of the cover member 80, and the contact portion 124 is set in a state of projecting to the front surface side of the cover member 107 and reliably contacts the electrode of the image forming apparatus 1. Can be electrically connected. In addition, a portion formed in the shape of a coil spring at one end is held in a compressed state in contact with the end of the pressing plate 114 of the blade when the cover member 107 is attached to the rear frame 101. . Therefore, a stable contact state with the pressing plate 114 can be maintained, and the electrical connection state can be ensured.

  The cover member 107 is provided with a fourth contact member 127 and a fifth contact member 128 for identifying the developing device 22. The fourth contact member 127 is made of a thin metal wire, and one end thereof is bent into a bowl shape and is inserted on the back side of a lid member 129 that is detachably provided on the cover member 107. The central portion is exposed on the front surface side of the cover member 107, and the other end is bent into a narrow insertion hole 130 provided in the cover member 107 and inserted on the back surface side of the cover member 107. . An insertion hole 131 similar to the insertion hole 130 is provided in the cover member 107, and when the length of the fourth contact member 127 is short, the other end is inserted into the insertion hole 131.

  The fifth contact member 128 is made of a thin metal wire, and, like the fourth contact member 127, one end is bent in a hook shape and inserted into the back surface side of the lid member 129. The other end is bent into a narrow insertion hole 132 provided in the cover member 107 and inserted into the back side of the cover member 107.

  The end portion inserted into the back surface side of the lid member 129 of the fourth contact member 127 and bent into a bowl shape is disposed to face the bent end portion of the fifth contact member 128, and any end portion is arranged. In addition, a metal coil spring 133 is mounted. A fuse member 134 is held between the two coil springs 133.

  When the developing device 22 is attached to the apparatus main body, as shown in FIG. 9, the two connection terminals 135 a and 135 b on the apparatus main body abut against the fourth contact member 127. The connection terminal 135a is disposed in the vicinity of the insertion hole 131 and the connection terminal 135b is disposed in the vicinity of the insertion hole 130. When the fourth contact member 127 has a length to the insertion hole 130, both are provided. The connection terminal contacts the fourth contact member 127. However, when the connection terminal 131 has a short length to the insertion hole 131, only the connection terminal 135a contacts the fourth contact member 127. Further, the connection terminal 135 c on the apparatus main body side is in contact with the fifth contact member 128 in the vicinity of the insertion hole 132.

  Accordingly, a state in which the developing device 22 is mounted and the connection terminal on the apparatus main body abuts is shown in a circuit diagram as shown in FIG. If the connection terminal 135a is set to the ground potential and the presence / absence of conduction between the connection terminals 135a and 135b is detected, the fourth contact member 127 is inserted when the conduction is detected. It is identified that the case is long up to the hole 130, and if it is not conductive, it is identified that the fourth contact member 127 is short to the insertion hole 131. Therefore, the type of the developing device 22 can be identified by changing the length of the fourth contact member 127 attached according to the type of the developing device 22. In addition, if a current sufficient to blow the fuse member 134 is supplied between the connection terminals 135a and 135c, the fuse member 134 is cut when the developing device 22 is mounted. Therefore, the developing device attached to the apparatus main body is not electrically connected between the connection terminals 135a and 135c, and if the presence or absence of the conduction between the connection terminals 135a and 135c is detected, the developing device 22 is new or used. Can be identified.

As described above, as an electrical means for identifying the developing device on the apparatus main body side,
(3) Detection of presence / absence of conduction between connection terminals 135a and 135b (4) Detection of presence / absence of conduction between connection terminals 135a and 135c.

  Next, the detection mechanism of the toner remaining amount detection sensors 72 and 74 will be described. As shown in FIG. 2, the remaining toner amount detection sensors 72 and 74 are set in concave grooves 73 and 75 provided on the bottom surface of the replenishing chamber of the developing device 22 when the developing device 22 is mounted. Become. Since the detection mechanisms of the remaining toner detection sensors 72 and 74 are the same mechanism, the case of the remaining toner detection sensor 72 will be described, and the description of the remaining toner detection sensor 74 will be omitted.

  FIG. 11 shows a cross-sectional view of the central portion of the concave groove 73 of FIG. 2 when cut in the vertical direction perpendicular to the paper surface. Two concave grooves 73 are provided on both sides of the remaining amount detection unit 136, and the concave groove 73 and the remaining amount detection unit 136 are integrally formed of a synthetic resin transparent member. As shown in FIG. 2, the remaining amount detection unit 136 is formed with a predetermined groove width along the rotation locus of the cleaning member 137 attached to the paddle 61, and the toner in the remaining amount detection unit 136 is Every time the cleaning member 137 slides inside the remaining amount detection unit 136, the cleaning member 137 is once discharged out of the remaining amount detection unit 136. The cleaning member 137 is configured by stacking a plurality of rectangular sheet bodies made of rubber. The width of one sheet body is slightly larger than the groove width of the remaining amount detection unit 205 and is orthogonal to the traveling direction. It is attached to the surface to be Accordingly, the both side portions 138 of the remaining amount detection unit 136 always slide in contact with the sheet member of the cleaning member 137, and the toner is once removed. On the other hand, in the toner remaining amount detection sensor 72, the light emitting device 140 is fixed to the protruding portion 139 set in one concave groove 73, and the protruding portion 141 set in the other concave groove 73 receives light. The container 142 is fixed. The light receiver 142 outputs a detection signal depending on whether or not the light transmitted from the light emitter 141 through the remaining amount detector 136 is received.

  Each time the cleaning member 137 slides in the remaining amount detection unit 136 in synchronization with the rotation of the paddle 61, the light from the light emitter 140 passes through the remaining amount detection unit 136 and the light receiver 142 outputs a detection signal. When a sufficient amount of toner is stored in the replenishing chamber, the remaining amount detection unit 136 after sliding of the cleaning member 137 is again filled with toner, so that the light receiver 142 does not detect the light of the light emitter 140. However, when the remaining amount of toner in the replenishing chamber decreases, the amount of toner filling the remaining amount detection unit 136 decreases, and the light receiver 142 continues to detect light. Based on such a change in the detection signal, the toner remaining amount detection sensor 72 transmits a detection signal indicating the remaining amount of toner to the control unit of the apparatus main body.

  As a method for detecting the remaining amount of toner, a timing signal indicating the rotation of the paddle 61 can be added to the detection signal in which the light receiver 142 detects light. For example, the time from when the cleaning member 137 passes the remaining amount detection unit 136 until the light receiver 142 stops detecting light is detected, and a correlation with the remaining amount of toner is tested in advance to obtain the correlation. The remaining amount of toner may be detected from the relationship. Further, the number of times the light of the light emitter 140 is blocked by the toner may be counted based on the presence / absence of a signal detecting the light of the light receiver 142, and used as an index indicating the degree of toner deterioration as the number of toner agitation.

  The toner remaining amount detection sensor 74 detects the remaining amount of the toner chamber 54 farthest from the supply chamber 57, and the toner remaining amount detection sensor 72 detects the remaining amount of the toner chamber 53 that is next farthest, so that toner remains to some extent. It becomes possible to detect even if it is in the state. That is, since the toner is sequentially transferred to the supply chamber by the paddle, the remaining amount increases from the toner chamber 54 farthest from the supply chamber 57 to the toner chamber 52. Therefore, if the change in the remaining amount of the toner chambers 54 and 53 that are likely to change in the toner amount is detected, the remaining state of the toner in the developing device 22 can be accurately determined.

  Therefore, it is possible to notify the replacement timing of the developing device 22 according to the remaining state of the toner in the developing device 22. FIG. 12 shows an example of the circuit configuration. Detection signals from the remaining toner detection sensors 72 and 74 are input from the detection circuits 143 and 144 to the control circuit 145. The storage circuit 146 stores in advance data indicating the correlation between the toner presence / absence detection patterns from the toner remaining amount detection sensors 72 and 74 and the remaining state in the developing device 22, and the control circuit 145 stores the data. Then, the correlation data is read out and compared with the input data from the detection circuits 143 and 144, and the remaining state in the developing unit 22 is monitored. On the other hand, from the detection circuit 147, detection signals regarding the presence / absence of the connection terminals 135 a and 135 b and the presence / absence of the connection terminals 135 a and 135 c are input to the control circuit 145.

  When detecting whether or not the connection terminals 135a and 135c are in a conductive state, the control circuit 145 detects whether or not the connection terminals 135a and 135c are conductive, and if they are conductive, a new developing device is mounted. The process proceeds to the subsequent processing. Then, current is supplied to such an extent that the fuse member 134 is blown, and the terminals are brought out of conduction. If the two terminals are not conductive, the control circuit 145 determines that a used developer is installed, and does not proceed to the subsequent processing. For example, the control circuit 145 controls the display circuit 148 to display an error. Process.

  Next, even in a new developing device, the amount of toner charged in the developing device is set to be larger in the developing device initially mounted in the image forming apparatus and the developing device mounted for replenishment thereafter. . Therefore, as shown in (3) above, when the fourth contact member 127 is long in advance by utilizing the fact that the presence or absence of the conductive state of the connection terminals 135a and 135b is determined by the length of the fourth contact member 127 ( It is preset that the developing device is initially mounted (when continuity is present), and the developing device for replenishment when short (when continuity is absent), and when the developing device is mounted, the control circuit 145 sets the connection terminal 135a. And the detection data relating to the presence / absence of the conductive state 135b, it is determined whether the developing device is initially mounted or the replenishing developing device.

  The storage circuit 146 stores in advance data on the residual toner state that must be exchanged between the initially mounted developer and the replenishment developer, and the control circuit 145 determines whether the connection terminals 135a and 135b are in a conductive state. The data on the remaining toner state of the corresponding developing device is read out from the detection data relating to the above. If the current residual state is small compared to the data regarding the current residual state in the developing device described above, data is transmitted to display the replacement time on the display circuit 148.

  In the case of a replenishing developer, since the toner filling amount is large, even if the residual state of the toner is large, the deterioration of the toner by agitation is progressing, and the replacement timing is notified when the residual state is large. On the contrary, since the initially installed developing device has a small amount of toner filling, the replacement timing is notified when the remaining state is small.

  FIG. 13 shows an example in which the compatibility between the apparatus main body and the developing device is ensured by using the above (1) and (2). In this example, a group of M1 to M3 and a group of P1 to P3 are set as the model of the apparatus main body. First, between each group, the setting of the toner of the developing device and the recording unit such as the photosensitive drum of the apparatus main body is adjusted. For example, when a high-resolution image is formed, the characteristics such as the toner particle size and the recording unit are adjusted to the optimum state. It will not be obtained. Therefore, compatibility is ensured by using the presence or absence of the stepped portion 83 to discriminate between the two groups. The presence or absence of the stepped portion 83 can be recognized when attempting to insert the developing device into the apparatus main body, and therefore cannot be inserted without compatibility. In the P1 to P3 group, only a type of developing device without the stepped portion 83 can be mounted, and a developing device having the stepped portion 83 compatible with the M1 to M3 group cannot be mounted. Even if the stepped portion 83 is cut off and forcibly mounted, as described with reference to FIG. 6, a hole is opened and the toner leaks, causing trouble in the apparatus main body. In addition, since the developing devices of the type having no stepped portion can be attached to the apparatus main bodies of the M1 to M3 groups, two types of developing devices can be used.

  In the case where the compatibility is set by further finely dividing within each group, it can be set by a combination of identification protrusions 92 fixed to the mounting portions 91a to 91e of the developing device. If the compatibility of the stepped portion 83 matches, the developing device can be inserted. However, if the identification protrusion 92 does not match the main body of the apparatus, the developing device cannot be inserted to the end, so there is no compatibility at that time. It is recognized. In this example, two identification protrusions 92 are used to identify three models in the group. M1 and P1 have an attaching projection 91 fixed to the mounting portions 91c and 91d, M2 and P2 have an identifying projection 92 fixed to the attaching portions 91a and 91c, and M3 and P3 have an attaching portion 91c. And the identification protrusion 92 is being fixed to 91e. Therefore, if the identification engagement portion 96 is fixed to the apparatus main body at a position corresponding to the position where the identification protrusion 92 is not fixed as shown in FIG. It becomes possible to be able to attach only. Further, if the number of identification engaging portions 96 to be fixed is reduced, the number of compatible developing devices can be increased correspondingly, and the compatibility pattern can be variously changed as necessary.

  As described in (3) above, the identification of the developing device by the presence / absence detection of the connection between the connection terminals 135a and 135b has been described as being used for initial mounting and identification for replenishment. There is a compatibility match due to the combination of the identification protrusions 92, the developing device is set at a predetermined mounting position, and the fourth contact member 127 comes into contact with the connection terminals 135a and 135b. Therefore, the compatibility of the developing device is ensured by triple identification.

  In the case of a model that does not use a replenishment developing unit and has only an initial developing unit, the presence / absence detection in (3) above need not be used for identification for initial mounting and replenishment. In this case, the storage circuit 146 shown in FIG. 12 stores a flag for identifying the model that uses only the initially installed developing device as the initial setting value and data indicating compatibility between the apparatus main body and the developing device. deep. Then, when this identification flag is stored, the control circuit 145 compares the detection signal of the presence / absence of continuity (3) with the data indicating compatibility, and if they match, the control circuit 145 considers that they are compatible. Subsequent processing is performed. If they do not match, the subsequent processing is stopped and control processing is performed so that an error is displayed on the display circuit 148. Therefore, in addition to ensuring mechanical compatibility as in (1) and (2) above, compatibility is ensured by electrical means. For example, the toner type is set to the conduction in (3) above. If it is identified by the presence / absence detection, the compatibility of the toner type between the mechanical means and the electric means is ensured twice, and the safety can be further improved.

1 is a schematic sectional view of an entire image forming apparatus according to an embodiment of the present invention. It is an expanded sectional view regarding a recording part. It is an expanded sectional view regarding a developing device. FIG. 2 is an external perspective view of the entire developing device. It is the perspective view which looked at the state which inserted the developing device in the main body frame from the front side. It is explanatory drawing when the level | step-difference part of a developing device is excised. It is an external view regarding the rear surface part of a developing device. It is an enlarged view regarding the electrical connection structure of a developing device. It is an enlarged view of the part which performs identification detection electrically. FIG. 10 is a circuit diagram of FIG. 9. 6 is an explanatory diagram regarding a detection operation of a toner remaining amount detection sensor. FIG. 3 is a circuit configuration diagram for performing electrical detection of a developing device. It is explanatory drawing regarding the example of a setting of the level | step-difference part of a developing device, and an identification protrusion.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Document reading part 3 Paper feed part 4 Recording part
22 Developer
25 Photosensitive drum
50 Container body
51 lid
55 Developing roller
70 Body frame
71 Pressing mechanism
72 Toner level detection sensor
74 Toner level detection sensor
83 Step
91 Mounting part
92 Identification protrusion
96 Identification engagement part

Claims (1)

Comprising a supply chamber for supplying the toner to the latent image bearing member on which an electrostatic latent image is formed, and three or more supply chambers provided with a stirring means for stirring the toner together with storing the toner, wherein The replenishing chambers are arranged in parallel in the lateral direction of the supply chamber and communicate with each other, and the replenishing chamber closest to the supply chamber communicates with the supply chamber, and is a toner remaining state detection device for a developer. A developing unit determining unit for determining whether the developing unit is an initially mounted developing unit or a replenishing developing unit; a reading unit for reading out data on a residual toner state that needs to be replaced with respect to the determined developing unit; A toner remaining amount detecting unit disposed in the replenishing chamber farthest from the chamber and the next furthest chamber, and a current toner remaining state in the developing device based on detection outputs from the toner remaining amount detecting units. determining residual shape And determining means, notification for notifying the exchange timing of the developing device when the read replacement compared the current is determined to be necessary toner remaining status data and a toner remaining status data of the current toner remaining state is small toner remaining state detection apparatus characterized by comprising a means.

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