JP2006047778A - Developer replenishing means, image forming apparatus, and process cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developer replenishing means which replenishes a developing unit with toner through a second storage means from a first storage means and in which the toner is sufficiently loosened, the system of a developer detecting means is improved, the detection of the presence or absence of the toner is accurately executed in a short time and the toner replenishment of high accuracy can be performed by preventing the adhesion of the toner to a detection surface of a developer detecting means and the erroneous detection in the toner detection caused by pressing of a detection surface cleaning means, and an image forming apparatus equipped therewith, and a process cartridge. <P>SOLUTION: The second storage means 1 is provided with the developer detecting means 7 and a cleaning member 8 for cleaning the developer detecting means 7. The cleaning member 8 moves back and forth on one plane including the detection surface 7a of the developer detecting means 7 on the same plane and has stopping means 9 and 10 for stopping the forward and backward movement in a fixed position other than the detection surface 7a of the developer detecting means 7. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention employs an electrophotographic system or an electrostatic recording system and develops an electrostatic latent image formed on an image carrier with a developer in an image forming apparatus such as a copying machine, a laser printer, or a facsimile. The present invention relates to a developer replenishing means for replenishing toner to a developing device or a process cartridge that executes an operation.

  Conventionally, an image forming process is performed in which a developer image (toner image) is formed on the surface of an image carrier with a developer by electrophotography or electrostatic recording, and the toner image is transferred and fixed on a transfer material. In an image forming apparatus, particularly in an electrophotographic image forming apparatus, an image carrier that carries a dry developer as a developer on the surface of a developer carrier and carries an electrostatic latent image in the development process. A method for developing and developing an electrostatic latent image by conveying and supplying a developer near the surface of a body and applying an alternating electric field between the image carrier and the developer carrier is widely known. In general, a developing sleeve is used as the developer carrier, and a photosensitive drum is used as the image carrier.

  As a developing method, for example, a developer (two-component developer) having a two-component composition (carrier particles and toner particles) is used, and a magnetic brush is formed on the surface of a developing sleeve in which a magnet is disposed, and a minute brush is formed. The magnetic brush is rubbed or brought close to the opposing photosensitive drum while maintaining the development gap, and an alternating electric field is continuously applied between the developing sleeve and the photosensitive drum (between SD) to develop toner particles. A so-called magnetic brush development method is known in which development is performed by repeatedly performing transition and reverse transition from the sleeve side to the photosensitive drum side.

  Further, in the developing method adopting the two-component developing method, only toner is consumed, so that the consumed toner is replenished in order to maintain a constant toner density (TD ratio) in the developing device that executes the developing operation. For this purpose, a replenishment developer container connected to the developer container containing the developer in the developing device is provided. The replenishment developer container, as a developer cartridge, contains replenishment toner and is normally detachable. When the toner inside is consumed, it is replaced. Then, development that determines the amount of toner to be replenished from the replenishment developer container to the developing device so that the detection value by the developer TD ratio detection in the developer container (hereinafter referred to as “toner density detection”) is always constant. An agent replenishing means has been put into practical use.

  In other words, by supplying toner with the above-described developer replenishing means, a decrease in the toner charge amount during long-term image formation is prevented by appropriately reducing the toner concentration in the two-component developer in the developing container. Thus, the image density during image formation over a long period is kept constant.

  Hereinafter, the construction of the developer replenishing means and the developing unit for developing the two-component magnetic brush as the replenisher will be described. 3A is a schematic cross-sectional view of a general photosensitive drum 101, developing unit 105, and developer supply means 104 in a direction crossing the axial direction of the photosensitive drum 101, and FIG. 3B is a developer. FIG. 3 is a front view of the replenishing unit 104 viewed from the opposite side with respect to the position where the photosensitive drum 101 is disposed.

  The developer replenishing means 104 is roughly divided into a sub-toner container 1 as a second storage means connected to the toner receiving hole 13 at the upper part of the developing device 105, and an upper part of the sub-toner container 1. And a main toner container 2 which is a first storage means for storing supply toner, and two supply developer containers. Then, the replenishment toner stored in the main toner container 2 is stirred in the sub toner container 1, communicated with the sub toner container 1, and the toner as developer conveying means that communicates with the toner receiving hole 13 of the developing device 105. The developer container 11 of the developing device 105 is replenished by the replenishment screw 4.

  As shown in FIG. 3A, the developing sleeve 11 a is disposed in proximity to the photosensitive drum 101 and rotates in the opposite direction or the same direction as the photosensitive drum 101, and the developer (shown by dots) is relative to the photosensitive drum 101. Are set so that they can be developed in contact with each other.

  A developer replenishing unit 104 for replenishing toner from the toner receiving hole 13 is provided above the developing unit 105.

  Here, the developing device 105 and the developer supply means 104 will be described in detail.

  The developing device 105 includes a developing container 11 that stores a two-component developer in which toner particles and a magnetic carrier are mixed, and is provided in an opening provided at a portion facing the photosensitive drum 101 in parallel with the photosensitive drum 101. The cylindrical developing sleeve 11a is provided, and a magnet roller 11b fixedly arranged is built in the developing sleeve 11a.

  The developing container 105 is partitioned in parallel with the developing sleeve 11a, and is divided into a developing chamber 11c for supplying a developer to the developing sleeve 11a and an agitating chamber 11d provided with a toner receiving hole 13 in the upper portion. The developing chamber 11c is provided with a developing screw 11e, and the stirring chamber 11d is provided with a stirring screw 11f. The developing chamber 11c and the stirring chamber 11d communicate with each other at the ends of the screws 11e and 11f, and the developer circulates between them. While being mixed and stirred. Therefore, the toner replenished from the toner receiving hole 13 in the stirring chamber 11d is mixed with the toner already in the developing container 11 and the developer containing the carrier, and is transported to the developing chamber 11c in a uniform state. It is supplied to the developing sleeve 11a. In the opening of the developing container 11 provided with the developing sleeve 11a, a regulating blade is formed at a position opposite to the developer sleeve 11a on the upstream side in the rotational direction in order to form a thin layer of developer on the surface of the developing sleeve 11a. 11g is arranged.

  The developer carried on the developing sleeve 11a is conveyed to the surface of the photosensitive drum 101 by the rotation of the developing sleeve 11a, and is formed on the photosensitive drum 101 by a developing bias applied to the developing sleeve 11a from a power source (not shown). The electrostatic latent image is developed.

  The developer supply means 104 will be described in detail.

  The main toner container 2 in which the replenishment toner is stored is provided with a stirring blade 12 that is rotatably provided inside and is driven by the driving means 12a. FIG. 3B is a front view seen from the driving means 12a side. The agitating blade 12 acts to loosen the toner in order to prevent the toner from solidifying in the main toner container 2 by rotating, and to the toner supply port 1 a that communicates the toner in the main toner container 2 to the sub toner container 1. An action of conveying the toner in the longitudinal direction (a direction parallel to the paper surface) and an action of pushing out the toner from its supply port 1a and dropping it into the sub-toner container 1 are executed. As the stirring blade 12, for example, a sheet material such as PET is generally used. The main toner container 2 is provided with developer detecting means (toner sensor) 7 for directly detecting the presence or absence of toner electrically or optically. A cleaning member 8 is attached to the rotating shaft of the stirring blade 12 inside the main toner container 2, and rotates with the rotation of the stirring blade 12 to clean the detection surface 7 a of the toner sensor 7.

  A sub toner container 1 is provided as an intermediate container for replenishing the toner contained in the main toner container 2 to the developing device 105. The sub-toner container 1 is formed with a toner supply port 1a capable of receiving supply of toner from the main toner container 2 at the upper part, and the bottom part is formed in a cylindrical shape with side surfaces protruding in a substantially horizontal direction. A toner transport pipe 3 capable of transporting toner from the sub toner container 1 is provided. A toner agitating member 6 that is movably provided is provided at the bottom and the center of the upper portion, and the agitating member 6 is rotated or rotated to loosen the toner. A replenishing screw 4 that is a conveying member having a spiral surface, which is a developer conveying means, is rotatably provided from the bottom of the sub toner container 1 to the inside of the toner conveying pipe 3. A driving means (conveyance driving means) 5 for rotationally driving is provided. Here, the sub toner container 1 and the bottom of the toner transport pipe 3 are continuous, and the replenishing screw 4 is installed from the bottom of the sub toner container 1 to the protruding toner transport pipe 3.

  The developer replenishing means 104 configured as described above replenishes the toner corresponding to the toner consumed by the developing operation in the developing device 105 from the main toner container 2 in which the replenishing toner is stored through the sub toner container 1. The screw 4 is dropped through the receiving hole 13 of the developing container 11 and supplied to the stirring chamber 11d provided with the stirring screw 11f. The developer container 11 contains a developer in which toner particles and a magnetic carrier are mixed, and the mixing ratio of toner particles and magnetic carrier (hereinafter referred to as “T / C ratio”) is within the developer container 11. According to the toner density detection result, the developer is replenished by the developer replenishing means 104 and is kept constant. At this time, various methods for detecting the mixing ratio of the toner particles and the magnetic carrier in the developing container 11, that is, detecting the toner concentration and maintaining the concentration have been put to practical use, and are selected from known methods. .

  The replenishing screw 4 is rotated by the conveyance driving means 5 and is consumed by development in accordance with the toner density detection result in the developing container 11 in order to maintain the T / C ratio between the toner particles in the developing container 11 and the magnetic carrier. The number of rotations or rotation time is set according to the amount of toner corresponding to the amount of toner, and when the set number of rotations or rotation time is reached, the rotation is stopped and the toner required by the developing device 105 is removed. Then, the toner is supplied to the developing container 11.

  At this time, the replenishment screw 4 has a constant toner conveyance amount per rotation or unit time according to its size, and can be controlled to calculate the number of rotations or the rotation time according to the required amount. It has become. Here, since the toner conveyance amount by the screw 4 is proportional to the number of rotations, in order to set the rotation time, it is assumed that the screw 4 is always rotated at a constant speed by the conveyance driving means 5. . Further, if a means for counting the number of rotations is provided, the rotation speed of the screw 4 can be set by the number of rotations regardless of whether it is constant or not.

  In the developer replenishing means 104, toner is replenished from the main toner container 2 to the sub toner container 1. The presence or absence of toner in the main toner container 2 is always detected by the toner sensor 7 and is replenished to the sub toner container 1 when the toner is present.

  However, the toner sensor 7 cannot detect that the toner is solidified in a part of the main toner container 2 and may make a false detection that it is determined that there is no toner. In order to prevent this, in the main toner container 2, the stirring blade 12 prevents the toner from being loosened and solidified by rotating or rotating. Further, in order to prevent erroneous detection when toner adheres to the sensor detection surface 7a, the detection surface 7a is cleaned by the cleaning member 8. Here, the cleaning member 8 rotates while cleaning the sensor detection surface 7 a while rubbing the sensor detection surface 7 a as the rotary blade 12 rotates as the portion provided radially from the rotating shaft of the stirring blade 12 contacts the sensor detection surface 7 a. It is like that.

  Then, the loosened toner is conveyed to the lower sub-toner container 1 by the stirring blade 12, and is supplied to the lower toner conveyance path 3 by the supply screw 4 in the longitudinal direction of the pipe 3 (direction parallel to the paper surface). The toner is conveyed toward the hole 13 communicating with the toner 11, and the toner is pushed out of the hole 13 and dropped into the developing container 11.

  It is also known that toner supply accuracy is improved by supplying toner by rotating the toner replenishing screw 4 in steps of one rotation as means for carrying the toner by the screw 4 (for example, patents). Reference 2).

  Here, an operation of replenishing toner to the sub toner container 1 when the toner in the main toner container 2 is reduced as the toner is consumed will be described.

  In the main toner container 2, after the toner sensor 7 detects the absence of toner, in consideration of a case where it is a false detection caused by the toner solidifying or adhering to the sensor detection surface 7 a, The stirring blade 12 and the cleaning member 8 operate to clean the toner sensor detection surface 7a. Still, when the toner-free state continues, it is determined that the toner is not completely set in the main toner container 2 but that the toner is really gone.

  Here, the case where the stirring blade 12 rotates after the toner sensor 7 detects the absence of toner has been described. However, since the stirring blade 12 is a sheet material, the toner is not pushed into the sub toner container 1 more than necessary. Even before the absence is detected, there is no problem even if the stirring blade 12 rotates.

  Further, when the stirring member 12 of the main toner container 2 is rotated for a sufficient time and the cleaning member 8 cleans the toner sensor detection surface 7a, the toner sensor 7 does not detect the presence of toner. It can be determined that the toner has run out, and the user is informed of the absence of toner through display means such as an operation panel (not shown).

  The main toner container 2 may be detachable or fixed to the apparatus. When the toner can be removed, the main toner container 2 is generally called a developer cartridge. When the toner runs out, the main toner container 2 is replaced with the main toner container 2 to fill the toner. Further, when fixed to the apparatus, the main toner container 2 is directly filled with toner from another toner container.

  However, the developer replenishing means 104 is a system in which the cleaning member 8 is attached to the rotating shaft of the stirring blade 12 inside the main toner container 2 and rotates simultaneously with the rotation. Usually, the cleaning member 8 is the toner sensor detection surface. The image forming apparatus cannot determine whether it is stopped on the surface 7a or outside the toner sensor detection surface 7a. Therefore, when the amount of toner in the main toner container 2 decreases, the cleaning member is moved when the toner is moved from the main toner container 2 into the sub toner container 1 even though the toner in the main toner container 2 is small. 8 is driven, the detection result of the toner sensor 7 is in a state in which a signal indicating the presence of toner is input by the pressing of the cleaning member 8.

  In order to prevent erroneous detection of the presence / absence of toner in a state where the toner in the main toner container 2 is reduced, the presence / absence detection circuit of the toner sensor 7 detects the absence of toner, and then at a constant speed, When the cleaning member 8 is rotated for a certain time and an instantaneous toner presence signal appears periodically, the toner presence signal determines that the cleaning member 8 has passed the toner sensor detection surface 7a and no toner is present. And Such complicated control is required.

  In addition, the toner sensor 7 is installed not in the main toner container 2 but in the sub toner container 1, and a cleaning member 8 for cleaning the detection surface 7 a of the toner sensor 7 in conjunction with the stirring member 6 of the sub toner container 1. There is also a method of providing. In the sub-toner container 1, since the toner already loosened to some extent in the main toner container 2 is supplied, there is little sticking of the toner to the detection surface 7a, and the pressure on the detection surface 7a of the cleaning member 8 can be lowered. Is unlikely to occur.

  Further, by disposing the toner sensor 7 in the sub-toner container 1 which is the main body of the image forming apparatus, it is possible to eliminate the toner sensor 7 from the main toner container 2 that is normally used for replacement, thereby reducing the cost of the main toner container 2. Thus, the cost (running cost) necessary for toner replacement can be reduced. Since the number of toner replacements increases as the life of the main body is longer, reducing the running cost can reduce the burden on the user.

  However, in order to arrange the toner sensor 7 in the sub toner container 1, the area of the toner sensor detection surface 7a and the cleaning member 8 for cleaning the toner sensor detection surface 7a must be arranged, and the volume of the sub toner container 1 increases. This also affects the image forming apparatus main body size. The detection surface 7a of the toner sensor 7 is generally 10 mm to 20 mm in diameter.

  Further, as toner supply means for supplying toner to the developing container 11 using the main toner container 2 and the sub toner container 1, the volume of the toner supply amount can be reduced by making the volume of the sub toner container 1 smaller than that of the main toner container 2. Since it is known that the accuracy is improved, it is functionally disadvantageous to increase the volume of the sub-toner container 1. Therefore, it is difficult to install the toner sensor 7 in the sub toner container 1.

  That is, it is difficult to dispose the toner sensor 7 and the cleaning member 8 having a certain size inside the low-capacity sub-toner container 1, and in particular, the cross-sectional area of the sub-toner container 1 in view of the locus of cleaning of the cleaning member 8. Therefore, it is difficult to achieve consistency between the toner supply accuracy and the volume of the sub-toner container 1 by mounting the toner sensor 7 and the cleaning member 8.

  Further, in Patent Document 1, to prevent erroneous detection of toner in the developing device, the cleaning process of the developer remaining amount detection surface and the developer supplying process to the developing device, which is the movement of the developer in the device, are timed. In some cases, control is performed so that the presence or absence of toner is determined after the cleaning process.

  However, when this is applied to the developer replenishing means 104 and the toner sensor detection surface 7a is cleaned and the toner is supplied to the sub-toner container 1 at different times, the replenishment sequence becomes long and the same problem as described above. A point is generated.

  That is, in the toner presence / absence detecting means for cleaning the toner sensor 7 using the cleaning member 8 as described above, the presence of toner is present although there is no toner because the cleaning member 8 is pressed against the detection surface 7a. Further, there is a possibility of erroneous detection, and since the stop position of the cleaning member 8 is not determined, the cleaning member 8 may stop on the toner sensor detection surface 7a, which adversely affects the detection surface 7a. The reliability of the product may be impaired.

  Therefore, control for preventing erroneous detection is necessary, and it takes time to determine the absence of toner because complicated control is used.

  Further, if the cleaning means 8 is driven excessively to determine the presence / absence of toner, the toner in the sub-toner container 1 is unnecessarily pressured, adversely affecting the toner and degrading the image quality.

  Further, if it takes time to determine the absence of toner, the print job is stopped until the time of determination, and the specifications of the image forming apparatus are also lowered. Although it is possible to increase the operation speed of the cleaning member 8 so as not to affect the specifications, the increase in the speed of the cleaning member 8 adversely affects the toner inside the main toner container 2, and this developer replenishing means 104 can be changed. The installed image forming apparatus has a problem in that the image quality is deteriorated.

In addition, when the control for preventing erroneous detection as described above is included, the number of operations of the cleaning member 8 increases, and there is a concern that the cleaning member 8 may be damaged.
JP-A-7-84445

  It is an object of the present invention to provide a developer replenishing means for replenishing a developer from a first storage means to a developing device through a second storage means, wherein the developer is sufficiently loosened, and the developer is detected on the detection surface of the developer detecting means. Providing developer replenishing means capable of preventing erroneous detection caused by sticking to the detection surface and pressing of the detection surface cleaning means and improving the accuracy of the detection means, and an image forming apparatus and process cartridge provided with the developer supply means It is to be.

The above object is achieved by the developer replenishing means, the image forming apparatus, and the process cartridge according to the present invention. In summary, the first aspect of the present invention is a first storage means capable of storing a developer therein;
A second storage means provided with a supply port through which the developer can be supplied from the first storage means;
Developer conveying means capable of conveying the developer from the second storage means;
A developer for supplying the developer to the replenisher by connecting the developer transporter to the replenisher and driving the developer transporter by the transport driver. In the medicine supply means,
The second storage means includes a developer detecting means for detecting the presence or absence of an internal developer, and a cleaning member for cleaning the developer detecting means, the cleaning member being a detection surface of the developer detecting means. There is provided a developer replenishing means which has a stopping means for performing the cleaning operation by reciprocating and stopping the reciprocating movement at a position other than the detection surface of the developer detecting means.

  According to a second aspect of the present invention, there is provided an image carrier on which an electrostatic latent image is formed on a surface, a developing unit that develops the electrostatic latent image with a developer, and a first unit that replenishes the developer with the developer. And a developer replenishing means of the present invention.

  According to a third aspect of the present invention, there is provided an image carrier on which an electrostatic latent image is formed on a surface, a developing unit that develops the electrostatic latent image with a developer, and a first unit that replenishes the developer with the developer. And a developer replenishing means according to the present invention, wherein the process cartridge is detachable from the image forming apparatus.

  The present invention includes a first storage means capable of storing a developer therein, a second storage means provided with a supply port capable of receiving the supply of the developer from the first storage means, A developer transporting means capable of transporting the developer from the storage means, and a transport driving means for driving the developer transporting means. The developer transporting means communicates with the replenisher and is transported by the transport driving means. In the developer replenishing means for replenishing the developer to the replenisher by driving, in the second storage means, the developer detecting means for detecting the presence or absence of the internal developer, and the cleaning for cleaning the developer detecting means The cleaning member includes a stop unit that performs a cleaning operation by reciprocating the detection surface of the developer detection unit and stops the reciprocation at a position other than the detection surface of the developer detection unit. Complex system Without toner, it is possible to determine the detection of no toner in a short time, and the toner sensor and the cleaning member as the developer detection means can be arranged in the sub-toner container as the second storage means with a small volume. Improvement of toner supply accuracy by the capacity sub-toner container and improvement of toner detection reliability of the toner sensor can be achieved at the same time.

  Further, in the image forming apparatus, it is possible to solve problems such as stoppage of the print job by shortening the toner detection time, or specification reduction of the image forming apparatus due to the prolonged toner replenishment sequence.

  Hereinafter, the developer replenishing means, the image forming apparatus, and the process cartridge according to the present invention will be described in more detail with reference to the drawings.

Example 1
First, an example of an image forming apparatus provided with a developer supply unit and a process cartridge to which the present invention is applied will be described. For example, the present embodiment is applied to the image forming apparatus 100 configured as shown in FIG. In this embodiment, the image forming apparatus 100 is an image forming apparatus such as a tandem electrophotographic copying machine or printer that employs a direct transfer method, and includes a plurality of image forming units UY, UM, UC, UBk is disposed in the horizontal direction, and includes a photosensitive drum 101 as an image carrier that is rotatably disposed. Around the photosensitive drum 101, an image of the charging device 102, a developing device 105 in which a two-component developer of black, cyan, magenta, and yellow color is changed for each image forming unit and a cleaning device 114. Forming means are arranged. In the present invention, the image forming apparatus having another configuration, for example, the color and number of the developer are not limited to this, and only one image forming unit may be used, and image formation using an electrostatic recording method or an intermediate transfer method is possible. A device may be used.

  As the developing device 105, a two-component contact developing device containing a developer containing toner and a carrier is used, and the toner is supplied by the developer replenishing means 104, which will be described in detail later, which is a characteristic part of the present invention. Replenished.

  Further, a transfer belt 107 which is a belt-like transfer material carrier that carries the transfer material P is provided so as to face each photosensitive drum 101. The transfer belt 107 is wound around two rollers 107a and 107b, and a transfer roller 106 as a transfer member is disposed on the inner side at a position on the back side of the surface facing each photosensitive drum 101.

  In each of the image forming units UY, UM, UC, UY, the laser beam L based on the image signal of the document is projected onto the photosensitive drum 101 uniformly charged by the charger 102 via a polygon mirror (not shown). Then, an electrostatic latent image is formed, and this electrostatic latent image is visualized as a developer image (toner image) by the developing device 105. The developing operation of the developing device 105 is performed in the same manner as described in the conventional example.

  When the toner image visualized on the photosensitive drum 101 reaches the transfer portion t facing the transfer roller 106 across the transfer belt 107, the toner image is attracted to the belt 107 by the transfer roller 106 as a transfer member to which a transfer bias is applied. When the transfer material P, which is a transfer medium sent in synchronization with the timing, enters the transfer portion as the transfer belt 107 moves, the color toner images are directly transferred from the respective photosensitive drums 101 in a superimposed manner. The Finally, the transfer material P separated from the transfer belt 107 is fixed by the fixing device 113.

  The adhered toner remaining on the photosensitive drum 101 as it is is cleaned by the cleaning device 114.

  Here, in each of the image forming units UY, UM, UC, and UBk of the image forming apparatus, the photosensitive drum 101, the charger 102, the developing device 105, the developer replenishing unit 104, and the cleaning device 114 are integrated. Thus, when the process cartridge C is configured as shown in FIG. 5 and is detachable from the image forming apparatus, the members of the image forming means for each color can be replaced at a time by replacing the process cartridge C. An image forming apparatus having excellent maintainability can be provided. The process cartridge C includes a photosensitive drum 101, a developing device 105, and a developer supply unit 104, and may not include other image forming units. In some cases, the developer cartridge is not provided with the photosensitive drum 1, but only the developer replenishing means 104 or the developer replenishing means 104 and the developing device 105 are integrated to be detachable from the image forming apparatus. . Further, only the developer replenishing means 104 is used as a developer cartridge, or a part of the developer replenishing means 104, for example, as described in the above-described conventional example, the main toner container 2 is a developer cartridge, and the image forming apparatus 100. In some cases, it may be detachable.

  In this embodiment, the developing device 105 having the same configuration as that of the conventional example and employing the same image forming method is used, and the toner supply by the developer supply means 104 is similarly received. That is, a toner mounting hole 13 is provided in the upper part of the stirring chamber 11d of the developing device 105, and this is connected to the developer replenishing means 104. The developer replenishing means 104 is a cross-sectional view of FIG. As shown in the front view of (b), the main toner container 2 and the sub toner container 1 are configured, and toner is moved from the main toner container 2 to the sub toner container 1 based on the toner density detection result of the developing device 105. Then, the developer 105 is supplied through the transport pipe 3. Here, the configuration of the developing device 105, the method of toner replenishment control based on the toner detection result of the developing device 105, and the like are the same as those in the conventional example, and thus description thereof is omitted.

  In this embodiment, a conventional toner presence / absence detection system in the main toner container 2 by the toner sensor 7 of the developer supply means 104 is changed. The remaining main toner container 2, sub-toner container 1, and toner transport pipe 3 are the same as in the prior art.

  FIG. 1 is a schematic configuration diagram of the photosensitive drum 101, the developing unit 105, and the developer supply unit 104 in the present embodiment. The basic operation and the role of each internal member are the same as those described in the conventional example. That is, the sub-toner container 1 is supplied with toner from the main toner container 2 from the upper toner supply port 1a, and the bottom part includes a toner conveying pipe 3 that has a side surface protruding in a substantially horizontal direction and formed in a cylindrical shape. . A stirring member 6 is provided at the center of the top and bottom, and acts to loosen the toner. A replenishing screw 4 having a spiral surface, which is a developer conveying means, is rotatably provided from the bottom of the sub-toner container 1 to the inside of the toner conveying pipe 3. Means (conveyance drive means) 5 is provided. Then, the number of rotations of the replenishing screw 4 is determined according to the toner detection result of the developing device 105, and an appropriate amount of toner is replenished to the developing device 105.

  A toner presence / absence detection system in the developer supply means 104 in this embodiment will be described.

  In this embodiment, a toner sensor 7 is provided in the sub-toner container 1 as developer detecting means for directly detecting the presence or absence of toner electrically or optically, and the detection surface 7a of the toner sensor 7 is further cleaned. The cleaning member 8 to be operated is configured to operate in conjunction with the stirring member 6. Further, a position sensor 9 that detects the position of the cleaning member 8 and a sensor flag 10 that is a detected member detected by the position sensor 9 are provided at the lower part of the sub toner container 1.

  Here, the main toner container 2 filled with toner is attached at a predetermined position upstream of the sub toner container 1, the toner is filled in the sub toner container 1, and the toner is supplied to the developing device 105 downstream of the sub toner container 1.

  In this embodiment, as described above, the presence or absence of toner is detected by installing the toner sensor 7 in the sub-toner container 1, and the toner sensor 7 uses a piezo sensor. The piezo sensor is a sensor using a piezoelectric element. When the detection surface 7a is vibrated at a constant frequency, the detection surface 7a receives pressure, and the vibration is reduced, the detection surface 7a is pushed by the toner. It is a sensor that determines that the toner is present and transmits a toner-present signal.

  A toner sensor 7 is disposed on the wall surface of the sub toner container 1 and a cleaning member 8 for cleaning the toner sensor detection surface 7a is disposed. The cleaning member 8 applies a member such as a wire to a certain pressure on the toner sensor detection surface 7a. Is pushing. The pressure of the cleaning member 8 is set to a level that does not adversely affect the toner inside the sub toner container 1. The cleaning member 8 is installed on the stirring member 6, and the stirring member 6 is pivotally supported on the sub toner container 1. The rotating shaft 6a of the stirring member 6 extends to the outside of the sub toner container 1, and the sensor flag 10 is fixed to a part of the rotating shaft 6a. The sensor flag 10 can be integrated with the rotating shaft 6a. As shown in FIG. 1B, when viewed from the front end of the rotation shaft 6a, the sensor flag 10 is not circular, but has a long shape that changes its posture due to the rotation of the rotation shaft 6a.

  A position sensor 9 for detecting the position of the sensor flag 10 is arranged. In this embodiment, a photo sensor is used. By stopping the rotation shaft 6a with the position sensor 9 turned off by the sensor flag 10, the rotation shaft 6a can always be stopped at the same position. The cleaning member 8 and the sensor flag 10 are designed to be in phase so that the cleaning member 8 stops outside the area of the toner sensor detection surface 7a when the rotating shaft 6a is stopped. That is, the sensor flag 10 and the position sensor 9 serve as a stopping unit that stops the cleaning member 8 outside the region of the toner detection surface 7a.

  FIG. 2 shows the cleaning member 8, the agitating member 6, and the stopping means 9 and 10 for the toner sensor 7 in the sub-toner container 1 in this embodiment. The operation of the stirring member 6, the cleaning member 8, and the stopping means 9 and 10 will be described with reference to FIG.

  The agitating member 6 and the cleaning member 8 are driven by a conveyance driving means 5 that drives the replenishing screw 4. The conveyance drive unit 5 also drives the replenishment screw 4. When the drive unit 5 rotates once, the replenishment screw 4 rotates once, conveys a certain amount of toner, and supplies the toner to the downstream developing container 11. As shown in FIG. 2, the protrusion of the transport driving means 5 and the elongated hole of the sensor flag 10 mesh with each other, and when the transport driving means 5 makes one rotation, the sensor flag 10 reciprocates at a constant angle with the rotation shaft 6a as an axis. Designed to rotate. In accordance with this movement, the cleaning member 8 is also driven to reciprocate at a constant angle about the rotation shaft 6a, clean the toner sensor detection surface 7a, and stop at the same position every time. It is the position sensor 9 that detects one rotation of the transport driving means 5.

  As described above, when the cleaning member 8 is reciprocally rotated at a constant angle, the wall surface of the sub-toner container 1 provided with the cleaning member 8 does not require an area for the cleaning member 8 to rotate 360 °. Since only an area corresponding to the angle is required, the toner sensor 7 and the cleaning member 8 can be arranged also in the sub-toner container 1 having a small volume. The movement of the cleaning member 8 is not necessarily limited to rotation, and may be a parallel movement as long as it reciprocates on a single plane including the toner sensor detection surface 7a on the same surface. .

  In the present invention, the position sensor 9 uses a photo sensor, and detects one rotation by the sensor flag 10 shielding the optical axis. Of course, one rotation may be detected at a position that is not shielded.

  Even if the combination of the sensor flag 10 and the photo sensor is not used, the cleaning member 8 can be used as a toner sensor by using a stepping motor or the like that has high rotational accuracy and little time delay at the time of start and stop. It is possible to stop at the same position outside the detection surface 7a every time.

  As described above, since the toner sensor 7 and the cleaning member 8 can be disposed also in the sub-toner container 1 by reciprocatingly rotating the cleaning member 8 at a constant angle, the conveyance driving means for the stirring member 6 and the cleaning member 8 is provided. 5 can be the same as the conveyance driving means 5 of the replenishing screw 4.

  In addition, it is known that the accuracy of the toner supply amount to the developing container is improved by rotating the replenishment screw 4 in units of one rotation and supplying the toner (see, for example, Patent Document 2). Therefore, by synchronizing the rotation of the agitating member 6 with the rotation of the replenishing screw 4, the toner can be supplied to the developing device 11 and the sub-toner container 1 can be agitated at the same time, and the bulk density inside the sub-toner container 1 can be reduced. It can be stabilized. That is, it is possible to simultaneously improve the accuracy of toner supply by the small-capacity sub-toner container 1 and the reliability of toner detection by the toner sensor 7.

  In other words, by cleaning the cleaning member 8 in synchronism with the stirring member 6, the toner sensor 7 is cleaned at the same time as the toner is consumed, as well as the advantage of not providing a new drive source. Accordingly, it is possible to prevent erroneous detection of toner detection due to the powder surface of the toner becoming unstable when the toner in the sub toner container 1 decreases. In addition, the merit of improving the toner supply accuracy in Patent Document 2 is not impaired.

  Hereinafter, in the present exemplary embodiment, an operation of replenishing toner to the sub toner container 1 when the toner in the sub toner container 1 is reduced as the toner is consumed will be described.

  Again, as in the conventional example, the stirring member 6 has a function of loosening the toner in order to prevent the toner from solidifying in the sub-toner container 1 by rotating. The replenishing screw 4 transports the toner in the sub toner container 1 toward the hole 13 communicating with the developing container 11 in the longitudinal direction (direction parallel to the paper surface) and pushes the toner out of the hole 13 to the developing container 11. It is provided to make it fall.

  After the toner sensor 7 detects the absence of toner, if the toner-free state continues even if the stirring blade 12 inside the main toner container 2 is operated, the toner is partially in the sub-toner container 1 and the main toner container 2. In other words, it is determined that the entire toner supply means 104 has run out of toner. Note that after the presence of toner is detected, toner supply is continued from the sub-toner container 1 via the supply screw 4. The configuration of the stirring blade 12 inside the main toner container 2 is the same as that of the conventional example.

  Even if the stirring blade 12 of the main toner container 2 is rotated for a sufficient time, if the toner sensor 7 does not detect the presence of toner, it is determined that the toner is not replenished to the sub toner container 1, that is, the main toner container 2 has run out of toner. The user can be notified of the absence of toner through display means such as an operation panel (not shown).

  The timing for detecting the presence or absence of toner by a detection circuit (not shown) is only when the cleaning member 8 is stopped. Since the stop position of the cleaning member 8 is detected by the position sensor 9, it can be made other than the toner sensor detection surface 7a. Therefore, the toner sensor detection surface 7a is not pressed by the cleaning member 8 when the cleaning member 8 is stopped. When the sensor 7 detects the absence of toner, it is possible to determine the absence of toner as it is. Therefore, it is possible to determine the absence of toner in a short time without using complicated control as in the conventional embodiment.

  In addition, since the cleaning member 8 and the replenishing screw 4 are simultaneously driven by the same driving unit 5, the cleaning process and the toner supplying process to the developing device 3 can be performed simultaneously, so that a print job in the image forming apparatus can be performed. Problems such as interruptions and down specifications can be easily avoided.

  Further, since it is not necessary to control the cleaning member 8 to confirm the absence of toner after detecting the absence of toner, the number of operations of the cleaning member 8 is reduced, and the adverse effect on the toner sensor detection surface 7a is reduced. It is possible to reduce problems such as breakage.

  In this embodiment, a piezo sensor is used as the toner sensor 7, but an optical sensor can also be used. The toner detection by the optical sensor is arranged outside the sub-toner container 1, and the sub-toner container 1 is provided with a window serving as a light guide member of the optical sensor, and the cleaning member 8 cleans the window. Generally, a flexible material such as a PET sheet is used for cleaning the window of the optical sensor.

  In this embodiment, the position sensor 9 is installed in the main body of the developer supply means 104. However, the toner sensor 7 is installed in a consumable item such as a process cartridge or a developer cartridge, and the position of the cleaning member 8 is set. The position sensor 9 for detection can be installed in the image forming apparatus main body.

  In the process cartridge and image forming apparatus provided with the developer replenishing means 104 of this embodiment, the presence / absence of toner detection is high, so that the number of times of developer replacement such as toner bottle replacement from the outside is reduced and maintenance is performed. Improved. In addition, the stoppage of the print job is reduced due to the shortening of the toner detection time.

  1 and 3, for the sake of clarity, the longitudinal directions of the photosensitive drum 101 and the developing container 10 are perpendicular to the paper surface, and the longitudinal directions of the sub-toner container 1, the replenishing screw 4 and the main toner container 2 are the same. Although it is drawn in a direction parallel to the paper surface, in practice, these longitudinal directions are generally the same direction.

  The configuration in which the developing device for developing the two-component magnetic brush is used as the supply device has been described above. However, various other methods such as a one-component contact developing method have been put to practical use.

  Further, the configuration of the developing unit and the developer replenishing means do not necessarily have the shape as shown in FIG. 1, and if the toner agitating member and the conveying member such as screws can convey the toner, as shown in FIG. It does not have to be a shape.

FIG. 2 is a schematic configuration diagram illustrating an example of a developer supply unit according to the present invention and a periphery thereof. It is a perspective view which shows an example of the operation mechanism of the cleaning member in the 2nd storage means which concerns on this invention. It is a schematic block diagram which shows an example of the conventional developer supply means, and its periphery. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus. It is a schematic block diagram which shows an example of a process cartridge.

Explanation of symbols

1 Sub-toner container (second storage means)
1a Sub-toner container toner supply port 2 Main toner container (first storage means)
3 Toner transport pipe 4 Toner supply screw (developer transport means)
5 Conveyance drive means 6 Toner stirring member 7 Toner sensor (developer detection means)
8 Cleaning member 9 Position sensor (stopping means)
10 Sensor flag (stopping means)
DESCRIPTION OF SYMBOLS 11 Developing container 12 Stirring blade 13 Developer toner receiving hole 100 Image forming apparatus 101 Photosensitive drum (image carrier)
104 Developer supply means 105 Developer (replenisher)

Claims (10)

A first storage means capable of storing the developer therein;
A second storage means provided with a supply port through which the developer can be supplied from the first storage means;
Developer transport means capable of transporting developer from the second storage means;
A developer for supplying the developer to the replenisher by connecting the developer transporter to the replenisher and being driven by the transport driver. In the medicine supply means,
The second storage means includes a developer detecting means for detecting the presence or absence of an internal developer, and a cleaning member for cleaning the developer detecting means, and the cleaning member is a detection surface of the developer detecting means. A developer replenishing means, comprising: a stopping means for performing the cleaning operation by reciprocating and stopping the reciprocating movement at a position other than the detection surface of the developer detecting means.   The developer replenishing means according to claim 1, wherein the stopping means stops the reciprocating operation at a fixed position.   3. The developer replenishing means according to claim 1, wherein the second storage means further includes a stirring member inside, and the cleaning member performs a cleaning operation in conjunction with the stirring member.   The developer replenishing means according to claim 1, 2 or 3, wherein the driving means for driving the cleaning member is the same as the transport driving means.   The developer replenishing means according to claim 1, wherein all or part of the developer cartridge is detachable from the image forming apparatus.   6. The developer replenishing means according to claim 5, wherein at least the first storage means is configured to be detachable as the developer cartridge.   The image bearing member on which an electrostatic latent image is formed on the surface, a developing device for developing the electrostatic latent image with a developer, and supplying the developer to the developing device. An image forming apparatus comprising the developer replenishing means described in the item.   The image forming apparatus according to claim 7, wherein the developing unit contains a developer including toner and a carrier.   The image bearing member on which an electrostatic latent image is formed on the surface, a developing device for developing the electrostatic latent image with a developer, and supplying the developer to the developing device. And a developer replenishing means, and is detachable from the image forming apparatus.   The process cartridge according to claim 9, wherein the developer contains a developer including toner and a carrier.

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