JP6984219B2 - Developer replenishment control system, image forming device, and developer replenishment control method - Google Patents

Description

The present invention relates to a developer supply control system, an image forming apparatus, and a developer supply control method.

Conventionally, an electrophotographic image forming apparatus has been widely used not only in a large-scale office environment but also in various fields such as a home office and a general user. In order to provide products that meet these demands, there is a demand for technology that can realize cost reduction, miniaturization, long life, and stable operation. In particular, in the recent situation, it is required to reduce the running cost of the image forming apparatus, and it is strongly required to reduce the cost and extend the life of the consumables to be replaced by the user. Prolonging the service life indicates that the parts replacement cycle can be extended.

Due to such circumstances, in this type of image forming apparatus, the life of the image forming unit (so-called process unit) including the developing apparatus is extended as much as possible to prolong the replacement cycle and reduce the cost. However, in order to extend the service life, the amount of toner as a developer to be retained in the developing apparatus increases accordingly, so that the toner holding capacity must be secured. As a result, the size of the developing device and the image forming device as a whole is increased. In order to solve these problems, recently, the toner storage unit and the image processing unit of the developing device are detachably separated, and while only the storage unit is replaced in a short cycle, the toner is transferred from the storage unit to the image processing unit of the developing device. There is a tendency to adopt a configuration that replenishes the toner.

However, even if such a separation configuration is adopted, for example, after replacing the toner cartridge in the storage unit when the toner runs out is detected, if new toner is replenished all at once while the toner weight in the developing device is low, the developing device is used. Toner may not be fully regulated by the regulating member. In such a case, background stains and vertical band streaks occur due to an excessive amount of toner conveyed.

Therefore, in order to solve these problems, an "image forming device" that suppresses the occurrence of abnormal images such as background stains and toner scattering by always maintaining an appropriate toner concentration even after the toner end recovery (recovering out of toner) operation. (See Patent Document 1).

The above-mentioned technique according to Patent Document 1 includes a toner end detecting means for detecting a state in which toner supplied to a developing unit (developing apparatus) accommodating a two-component developer is exhausted. Further, the toner end detecting means is provided with a time detecting means for detecting a leaving time from detecting a state in which the toner has run out until it is detected that the toner container is taken out and the toner container is installed again. Therefore, the leaving time is detected by the time detecting means, and the timing from when the toner container is installed again to when the image formation is restored is controlled based on the leaving time.

However, according to the technique according to Patent Document 1, although the toner concentration after the toner end recovery operation can be stabilized, new toner is batched in the developing unit (developer) after replacing the new toner cartridge at the time of detecting the toner end. The problem of being replenished has not been addressed. As a result, it is not possible to sufficiently suppress the occurrence of skin stains and vertical band streaks caused by batch toner replenishment.

The present invention has been made to solve such a problem, and a technical problem thereof is to suppress the generation of skin stains and vertical band streaks caused by replacement of a new storage unit.

In order to solve the above technical problems, one embodiment of the present invention comprises a storage unit for storing a developer, a developing device to which the developing agent is replenished from the storage unit, and a residue of the developing agent in the developing device. A remaining amount detecting means for detecting the amount, a control means for controlling the replenishment amount of the developing agent from the storage unit to the developing apparatus based on the remaining amount of the developing agent detected by the remaining amount detecting means, and a control means. A developer replenishment control system comprising a counter for counting the consumption of the developing agent, wherein the control means replenishes the developing apparatus with new developing agent by exchanging the storage unit. The replenishment amount of the new developer is determined based on the consumption amount of the developer counted only by the count value of the counter, and the replenishment of the new developer to the developing apparatus is determined based on the determined replenishment amount. From the first value and the first value, which are predetermined values corresponding to when the remaining amount of the developer in the developing apparatus set in advance of the remaining amount detecting means is exhausted. When the second value is a predetermined value corresponding to the remaining amount of the developer, which is large and less than the full amount of the developer in the developing apparatus, the remaining amount of the developer is the first to the first value. Until the value shifts to the value of 2, the amount of the new developer replenished from the storage unit to the developing device is made larger than the counted consumption of the developer, and the new developer is replenished. the control of and, wherein after the draft surface of the developer in the developing apparatus reaches the second value, said a small supply amount of the new developer, always amount is full to the developer in the developing device It is characterized by controlling so that it becomes. Further, a storage unit for storing the developing agent, a developing device to which the developing agent is replenished from the storage unit, a remaining amount detecting means for detecting the remaining amount of the developing agent in the developing device, and the remaining amount detection. A developer supply control system comprising: a control means for controlling the amount of the developer to be replenished from the storage unit to the developing apparatus based on the remaining amount of the developer detected by the means. The control means includes a counter for counting the consumption of the agent, and when a new developer is replenished to the developing apparatus by exchanging the storage unit, the amount of the developing agent in the apparatus determines the new developing agent. Replenishment is performed in multiple batches until a fixed amount is reached, and the replenishment amount of the developer when replenishing in multiple batches is controlled based on the consumption amount of the developer counted only by the count value of the counter. The first value, which is a predetermined value corresponding to when the remaining amount of the developer in the developing device set in advance of the remaining amount detecting means is exhausted, and the amount of the developing agent larger than the first value and in the developing device. Until the remaining amount of the developer shifts from the first value to the second value when the second value, which is a predetermined value corresponding to the remaining amount of the developer less than the full state, is set. from said reservoir by more than the consumption of the developer to which the counted replenishment of new developer to the developing device and the control of the replenishment of the new developer, the developing device After the water level of the developer reaches the second value, the amount of the new developer replenished is reduced, and the amount of the developer in the developing apparatus is always controlled to be full. There is .

According to the present invention, according to the above configuration, it is possible to suppress the generation of skin stains and vertical band streaks caused by replacement of a new storage unit. Issues, configurations and effects other than those described above will be clarified by the following description of the embodiments.

It is sectional drawing which shows the schematic structure of the image forming apparatus which includes the developer supply control system which concerns on embodiment of this invention. It is the schematic which showed the state of attachment / detachment of the process unit with respect to the apparatus main body in the image forming apparatus shown in FIG. It is sectional drawing which showed the schematic structure of the developing apparatus provided in the image forming apparatus shown in FIG. 1. It is a schematic view seen from the direction orthogonal to the axis of the developing apparatus shown in FIG. It is sectional drawing which showed the schematic structure of the toner cartridge provided in the image forming apparatus shown in FIG. 1. FIG. 3 is a perspective view showing a schematic configuration of a remaining amount detection sensor provided in the developing apparatus described with reference to FIG. 4 with a partial cross section. FIG. 3 is a characteristic diagram showing an outline of toner replenishment control by a control device provided in the image forming apparatus shown in FIG. 1 in relation to the amount of toner with respect to time in comparison with a well-known technique. It is a flowchart which shows the operation process of the toner supply control by the control device provided in the image forming apparatus shown in FIG. It is a flowchart which shows the detail of the normal replenishment process included in the operation process shown in FIG.

Hereinafter, the developer supply control system, the image forming apparatus, and the developer supply control method of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a cross-sectional view showing a schematic configuration of an image forming apparatus including a developer supply control system according to an embodiment of the present invention.

Referring to FIG. 1, this image forming apparatus is for forming a monochrome image, and a process unit 1 as an image forming unit is detachably attached to the apparatus main body 100. The process unit 1 visualizes a photoconductor 2 as an image carrier that carries an image on the surface, a charging roller 3 as a charging means for charging the surface of the photoconductor 2, and a latent image on the photoconductor 2. A developing device 4 as a developing means is provided. Further, the process unit 1 includes a cleaning blade 5 as a cleaning means for cleaning the surface of the photoconductor 2. Further, the process unit 1 is detachably provided with a toner cartridge 7 in a storage unit for storing toner as a developer.

The toner cartridge 7 has, as its container body 22, a toner accommodating unit 8 for accommodating toner to be replenished to the developing device 4, and also integrally has a toner collecting unit 9 for collecting waste toner removed by the cleaning blade 5. is doing. In the present embodiment, as the developer, a one-component developer composed of only toner containing no carrier is used. Further, it is assumed that a polyester-based toner whose mother body is a polyester-based resin is used as the toner. It is also possible to apply the present invention to a developing apparatus and an image forming apparatus in which a two-component developer composed of toner and a carrier is used. When the present invention is applied to a two-component developing apparatus, the remaining amount of toner as a developing agent is detected by the toner remaining amount detecting means.

Further, the image forming apparatus is provided with a light emitting diode (LED) head array 6 as an exposure means for exposing the surface of the photoconductor 2 at a position facing the photoconductor 2. In addition to the process unit 1, the image forming apparatus includes a transfer device 10 for transferring an image to the paper P of a recording medium, a paper feeding device 11 for supplying the paper P, and a fixing device 12 for fixing the image transferred to the paper P. And a paper ejection device 13 for ejecting the paper P from the apparatus main body 100 to the outside. The paper P also includes thick paper, leaflets, envelopes, plain paper, thin paper, coated paper such as coated paper and art paper, tracing paper, and the like. It is also possible to use an OHP sheet or the like as a recording medium other than the paper P.

The transfer device 10 includes a transfer roller 14 as a transfer member. The transfer roller 14 is in contact with the photoconductor 2 in a state where the process unit 1 is attached to the apparatus main body 100, and a transfer nip (contact) is formed at the contact portion between the two. Further, at least one of a predetermined direct current (DC) voltage and an alternating current (AC) voltage is applied to the transfer roller 14. The paper feed device 11 includes a paper feed cassette 15 containing the paper P and a paper feed roller 16 for feeding the paper P housed in the paper feed cassette 15. Further, on the downstream side of the paper feed roller 16 in the transport direction, a pair of resist rollers 17 as timing rollers for measuring the transport timing and transporting the paper P to the secondary transfer nip are provided.

The fixing device 12 includes a fixing roller 18 as a fixing member and a pressure roller 19 as a pressure member. The fixing roller 18 is heated by a heating source such as a heater. The pressure roller 19 is pressurized toward the fixing roller 18 and comes into contact with the fixing roller 18, and a fixing nip is formed at the contact point. The paper ejection device 13 includes a pair of paper ejection rollers 20. The paper P discharged to the outside of the device by the paper ejection roller 20 is loaded on the paper ejection tray 21 formed by denting the upper surface of the apparatus main body 100. Incidentally, the configuration including the toner cartridge 7, the developing device 4, the remaining amount detecting means for detecting the remaining amount of toner in the developing device 4, and the control means for controlling the amount of toner supplied from the storage unit to the developing device 4 is included. It may be called a developer supply control system. The detailed configuration and functions will be explained later.

FIG. 2 is a schematic view showing a state of attachment / detachment of the process unit 1 to / from the apparatus main body 100 in the above-mentioned image forming apparatus.

Referring to FIG. 2, in this image forming apparatus, the cover 101 provided at the rear portion of the apparatus main body 100 can be opened and closed. Further, when the cover 101 is opened, the light emitting diode head array 6 retracts upward via the link mechanism. With such a configuration, the process unit 1 can be removed from the rear (side) while avoiding interference with the light emitting diode head array 6 in the open state of the cover 101. Further, here, with the toner cartridge 7 mounted on the process unit 1, they can be integrally attached to and detached from the rear (side) of the apparatus main body 100. Further, the toner cartridge 7 can be attached to and detached from the process unit 1 in both the state in which the process unit 1 is attached to the apparatus main body 100 and the state in which the process unit 1 is removed.

FIG. 3 is a cross-sectional view showing a schematic configuration of a developing device 4 provided in the above-mentioned image forming device.

Referring to FIG. 3, the developing apparatus 4 includes a developing housing 30 and a developing roller 31 as a developing agent carrier for supporting toner. Further, the developing apparatus 4 includes a supply roller 32 as a developer supplying member for supplying toner to the developing roller 31, and a developing blade 33 as a regulating member for regulating the amount of toner carried on the developing roller 31. .. Further, the developing device 4 includes a first toner transporting member 34 and a second toner transporting member 35 for transporting toner.

The developing roller 31 rotates in the counterclockwise direction in FIG. 3 and conveys the toner held on the surface to the positions facing the developing blade 33 and the photoconductor 2. The supply roller 32 is in contact with the developing roller 31 and rotates counterclockwise with respect to the developing roller 31 to supply the toner in the developing device 4 to the surface layer of the developing roller 31. Incidentally, here, by setting the rotation speed ratio between the developing roller 31 and the supply roller 32 to 1, a good toner supply function is ensured. The tip side of the developing blade 33 is in contact with the surface of the developing roller 31. The toner supplied onto the developing roller 31 by the feeding roller 32 passes through the nip portion between the developing roller 31 and the developing blade 33, so that the thickness is regulated and at the same time, the toner is frictionally charged.

A toner cartridge 7 for accommodating replenishing toner is detachably attached to the upper part of the developing apparatus 4. Therefore, a replenishment port 30a for replenishing the toner in the toner cartridge 7 into the developing device 4 is formed on the upper portion of the developing device 4. Toner replenishment is performed based on the detection result of the remaining amount of toner in the developing device 4 by the remaining amount detecting sensor 60 as the remaining amount detecting means. That is, when the remaining amount detection sensor 60 detects that the toner is consumed in the developing device 4 and the amount of toner is equal to or less than a predetermined value, the toner cartridge 7 is driven for a preset time. As a result, a predetermined amount of toner is supplied to the developing device 4. At this time, the control device as a control means provided in the image forming device of the drive mechanism according to the remaining amount lower limit value and the remaining amount upper limit value set in advance based on the remaining amount of toner detected by the remaining amount detection sensor 60. Adjust the drive amount. As a result, the amount of toner replenished from the toner cartridge 7 in the storage unit into the developing apparatus 4 is controlled.

Inside the developing housing 30, the first accommodating portion A in which the supply port 30a is arranged by the partition wall 36 arranged substantially parallel to the axial direction of the developing roller 31, and the developing means such as the developing roller 31 and the developing blade 33 are provided. It is divided into a second accommodating portion B and a second accommodating portion B in which the above is arranged. Here, the partition wall 36 is erected in the vertical direction, and the first accommodating portion A and the second accommodating portion B are arranged adjacent to each other in the horizontal direction. A first toner transfer member 34 is disposed in the first accommodating portion A, and a second toner transfer member 35 is disposed in the second accommodating portion B. The developing device 4 and the toner cartridge 7 may be integrated with each other.

FIG. 4 is a schematic view seen from a direction orthogonal to the axis of the developing apparatus 4 shown in FIG.

Referring to FIG. 4, toner can be moved between the first accommodating portion A and the second accommodating portion B in the developing apparatus 4 at least on both ends in the longitudinal direction of the partition wall 36 inside the developing housing 30. The openings 42 and 43 are opened in. The toner replenished in the developing apparatus 4 is conveyed to one side in the axial direction of the developing roller 31 by the first toner conveying member 34 installed in the first accommodating portion A. After that, the toner moves from the openings 42 and 43 on the downstream side in the transport direction to the second accommodating portion B, and is conveyed by the first toner transport member 34 by the second toner transport member 35 provided in the second accommodating portion B. Is transported in the opposite direction of.

On the downstream side of the second toner transport member 35, the toner can be moved to the second accommodating portion B by the openings 42 and 43 of the partition wall 36, and the toner in the developing device 4 can be circulated in the longitudinal direction. The toner transfer speed can be controlled by the configuration of the first toner transfer member 34 and the second toner transfer member 35. When a screw member is used, the toner transfer speed increases in proportion to the screw pitch. This is because the amount of toner transported per rotation of the screw increases, but the toner transport speed can also be controlled by a method such as increasing the screw diameter.

The first toner transfer member 34 and the second toner transfer member 35 have a structure in which drive can be transmitted from a drive source installed in the apparatus main body 100 or the like by a drive transmission member 46 including gears, couplings, or the like. The toner in the developing apparatus 4 can be transferred to the developing roller 31 by a supply roller 32 composed of a sponge or the like capable of supplying the toner to the developing roller 31. The drive transmission member 46 is included in a drive mechanism that is driven and controlled by a control device.

FIG. 5 is a cross-sectional view showing a schematic configuration of a toner cartridge 7 provided in the above-mentioned image forming apparatus.

Referring to FIG. 5, in the toner replenishment container 50 of the toner cartridge 7, the direction of the toner transport unit 51 is ensured by rotating the agitator 52 in which the filled toner is fixed to the rotating shaft 53. It is configured to supply to. The case where the agitator 52 is made of a flexible material such as a PET film can be exemplified. In order to use up the toner in the toner replenishment container 50, it is desirable that the shape of the toner replenishment container 50 is an arc shape according to the rotation start of the agitator 52. The toner transfer unit 51 sends the toner in the toner supply container 50 in the axial direction of the rotation shaft 53 by rotating a member formed of a screw, a coil, or the like by a drive source installed in the apparatus main body 100. This drive source is also included in the drive mechanism that is driven and controlled by the control device.

The toner transfer unit 51 controls the amount of toner transferred by the pitch diameter, size, rotation speed, etc. of the member, and detects the toner shortage by the remaining amount detection sensor 60 installed in the developing device 4. Further, in the toner transport unit 51, when the rotation operation is started and the toner filling is confirmed by the remaining amount detection sensor, the drive is stopped to stabilize the toner amount in the developing device 4, and the control is performed by using a well-known technique. It is preferable to do so.

FIG. 6 is a perspective view showing a schematic configuration of the remaining amount detection sensor 60 provided in the developing apparatus 4 described above with a partial cross section.

Referring to FIG. 6, here, a case where an optical sensor is used as the remaining amount detection sensor 60 for detecting the remaining amount of toner in the developing device 4 is illustrated. The remaining amount detection sensor 60 includes a light emitting sensor, a first light guide 62 made of a highly transparent resin material, a second light guide 63, and a light receiving sensor. In the remaining amount detection sensor 60, the light emitted by the light emitting sensor attached to the side surface portion of the main body of the developing device 4 is incident from the inlet of the first optical guide 62 arranged on the side surface portion of the main body of the developing device 4. The main body of the optical guide 62 of 1 is transmitted and guided to the inside of the developing apparatus 4. The light guided to the inside of the developing apparatus 4 is incident on the entrance of the second optical guide 63 from the exit of the first optical guide 62 through the internal space of the developing apparatus 4, and is the main body of the second optical guide 63. Is transmitted and guided to the outside of the developing apparatus 4. After that, the light guided to the outside of the developing device 4 is received by a light receiving sensor attached to the side surface of the main body of the developing device 4 near the outlet of the second optical guide 63. The light receiving sensor converts the amount of received light into a voltage and detects the presence or absence of light.

In the case of the remaining amount detection sensor 60, light emission is controlled by applying a voltage to the light receiving sensor at the time of performing toner remaining amount detection, and the presence of toner in the internal space in the developing device 4 can be detected by the output of the light receiving sensor. It is possible. However, if toner, foreign matter, or the like adheres between the outlet of the first optical guide 62 and the inlet of the second optical guide 63, the transmitted light is blocked when the remaining amount is detected, which causes erroneous detection. It becomes. Therefore, a cleaning member 61 such as a sheet material can be attached to the rotation shaft of the screw at the remaining amount detection portion of the first toner transport member 34, and deposits in the optical transmission path can be removed by the rotation cycle of the rotation shaft of the screw. It is desirable to provide a cleaning mechanism.

In any case, the detection result of the remaining amount of toner by the remaining amount detection sensor 60 that detects the remaining amount of toner in the developing device 4 is sent to the control device. The image forming apparatus is provided with a counter that counts the remaining amount of toner as a consumption amount in advance. Therefore, the control device adjusts the drive amount of the drive mechanism according to the preset lower limit value and upper limit value of the remaining amount based on the remaining amount of toner, and controls the amount of toner supplied from the toner cartridge 7 to the developing device 4. do. At this time, when the control device detects a new toner cartridge 7 and supplies new toner to the developing device 4, the control device controls the amount of new toner to be replenished stepwise based only on the count value of the counter.

FIG. 7 is a characteristic diagram showing an outline of toner replenishment control by a control device provided in the above-mentioned image forming apparatus in relation to the amount of toner with respect to time t in comparison with a comparative example.

Referring to FIG. 7, in the characteristic C1 of the comparative example, new toner is replenished all at once after the replacement of the new toner cartridge 7. Here, since the toner is replenished in the developing device 4 so that the amount of toner reaches the detection upper limit with a steep slope from the detection lower limit in a short time, there is a possibility that background stains and vertical band streaks may occur due to this. be.

On the other hand, in the characteristic C2 according to the embodiment, the amount of new toner replenishment after replacement of the new toner cartridge 7 is gradually performed with a gentle slope based only on the count value. The "count value" is a dot counter that counts the number of dots corresponding to the number of pixels at the time of image formation, which will be described in detail later, and background stains (a small amount of toner on a blank sheet) that can be calculated from the mileage of the developer. Includes a consumption counter (a phenomenon in which the toner is developed), a toner discharge counter during toner discharge control, and the like. Until the toner detection upper limit is reached, the toner is not replenished all at once, but the toner consumption is calculated only by this count value, and the amount of toner corresponding to the toner consumption is gradually replenished. "Step by step" means that the amount of toner corresponding to the amount of toner consumed is replenished in a plurality of times. Toner is gradually replenished based on the count value, and after the upper limit of the toner amount in the developing device 4 is detected by the remaining amount detection sensor 60, the count value and the remaining amount detection sensor provided in the developing device 4 are detected. By 60, the amount of toner in the developing device is detected, and the amount of toner supplied from the toner cartridge 7 to the developing device 4 is controlled. As a result, new toner is not collectively replenished from the toner cartridge 7 into the developing apparatus 4 after being replaced with a new toner cartridge 7, and the occurrence of background stains and vertical band streaks due to this is sufficiently suppressed. Further, when the lower limit of the remaining amount continues for a predetermined number of times, the control device gives an instruction to warn the replacement of the toner cartridge 7 with a new one by using, for example, the display unit of the image forming apparatus as a warning means. Alternatively, it is also possible to give an announcement warning by voice. As a result, the user of the image forming apparatus can clearly grasp when to replace the toner cartridge 7.

FIG. 8 is a flowchart showing an operation process of toner supply control by the control device provided in the above-mentioned image forming device. However, here, for example, it is assumed that the image forming apparatus is provided with a counter that counts the remaining amount of toner as the consumption amount in advance.

Referring to FIG. 8, in the operation process of the toner replenishment control, first, it is determined (step S1) whether or not the control device has detected a new toner cartridge 7. As a result of this determination, if a new product is not detected, the process proceeds to the normal replenishment process (step S2) described later. On the other hand, if a new product is detected, the toner consumption is estimated by the counter count value Ct (step S3). Incidentally, since it is assumed that the time when a new toner cartridge 7 is detected is after the toner end (after the toner runs out), the amount of toner in the developing apparatus 4 often indicates the lower limit of the remaining amount.

Next, the control device determines whether or not the remaining amount of toner is the upper limit value of the remaining amount based on the detection result of the remaining amount of toner in the developing device 4 by the remaining amount detection sensor (step S4). As a result of this determination, if the remaining amount is the upper limit value, the operation process is terminated after the normal replenishment of new toner (step S5) is performed from the new toner cartridge 7. This normal replenishment (step S5) corresponds to a condition in which the normal value N1 of the toner replenishment amount is equal to or exceeds the count value Ct corresponding to the toner consumption amount. If it is not the remaining amount upper limit value (if it is the remaining amount intermediate value or the intermediate remaining amount intermediate value between it and the remaining amount upper limit value), the new toner cartridge 7 is gradually replenished with new toner (step S6). conduct. After that, the process returns to the process of estimating the toner consumption by the count value Ct of the counter (step S3), and the subsequent operation processes are repeated.

In the above-mentioned step replenishment (step S6), the range value N2 from the lower limit value to the upper limit value of the toner replenishment amount exceeds the normal value N1 of the toner replenishment amount, and the normal value N1 of the toner replenishment amount is the toner consumption amount. It corresponds to the condition that is equal to or exceeds the count value Ct corresponding to. That is, here, a new toner replenishment amount is replenished more than the counter count value Ct until the remaining amount of toner shifts from the remaining amount lower limit value to the remaining amount upper limit value. Therefore, it is assumed that the range value N2 from the lower limit value to the upper limit value of the toner supply amount is larger than the count value Ct. In this way, the step replenishment (step S6) is repeated until the toner remaining amount detection state reaches the remaining amount upper limit value, and then the operation process is terminated.

Incidentally, if the range value N2 from the lower limit value to the upper limit value of the toner replenishment amount is smaller than the count value Ct, the replenishment amount cannot keep up with the consumption amount, and the toner cartridge 7 is replaced with a new one at an early stage. Toner end detection occurs. Further, if the range value N2 from the lower limit value to the upper limit value of the toner replenishment amount is larger than the count value Ct, the replenishment amount of new toner from the new toner cartridge 7 is excessive and the toner transfer amount becomes excessive. Due to this, vertical band streaks occur during image formation.

FIG. 9 is a flowchart showing the details of the normal replenishment process (step S2) included in the operation process shown in FIG.

Referring to FIG. 9, here, first, the control device estimates the toner consumption by the count value Ct of the counter (step S21), as in the case where a new toner cartridge 7 is detected. After that, the control device determines whether or not the remaining amount of toner is an intermediate value (step S22) based on the detection result of the remaining amount of toner in the developing device 4 by the remaining amount detection sensor. As a result of this determination, if the toner remaining amount is an intermediate value, the toner is replenished according to the count value of the counter corresponding to the toner consumption (step S23), and then the operation process is terminated. This replenishment (step S23) process corresponds to a condition in which the upper limit value N3 of the toner replenishment amount exceeds the normal value N1 of the toner replenishment amount.

Incidentally, if the upper limit value N3 of the toner replenishment amount is smaller than the count value Ct, the replenishment amount cannot keep up with the consumption amount, and toner end detection occurs at an early stage. Further, if the upper limit value N3 of the toner replenishment amount is excessive than the count value Ct, the toner replenishment amount is excessive and the toner transfer amount becomes excessive, which causes vertical band streaks during image formation. It ends up.

Further, as a result of determining whether or not the remaining amount of toner is an intermediate remaining amount (step S22), if it is not an intermediate remaining amount, the control device determines whether or not the number of times of detecting the lower limit of the remaining amount is n or not. (Step S24) is performed. As a result of this determination, if the number of detections of the lower limit of the remaining amount has not reached the predetermined number of times n, the operation process is terminated after shifting to the process of the previous replenishment (step S23). On the other hand, if the number of detections of the lower limit of the remaining amount reaches the predetermined number of times n, the control device displays the toner end on the display unit of the image forming device (step S25) and then ends the operation process. ..

In the image forming apparatus according to the above-described embodiment, a part of the structure is modified so that the process unit 1 and the toner cartridge 7 can be attached to and detached from the apparatus main body 100 as described with reference to FIG. The drive of the process unit 1 was connected to the image-forming drive motor, and the drive of the toner cartridge 7 enabled the drive source of the process unit 1 to be connected to the toner cartridge 7 by a clutch. Further, by connecting the drive source and the drive gear of the toner cartridge 7 as needed, the toner can be replenished from the toner cartridge 7 into the developing apparatus 4. However, the configuration relating to the main part including the toner cartridge 7, the developing device 4, the process unit 1 including the remaining amount detection sensor 60, the counter, and the control device can be regarded as the developer replenishment control system.

To make toner, 55 parts of polyester resin with a softening point of 130 ° C, 35 parts of polyester resin with a softening point of 104 ° C, 6 parts of carbon black, 3 parts of wax (paraffin wax), and CCA (E) are used as toner materials. -84) was used in one copy. CCA is an abbreviation for Charge Control Agent. After sufficiently mixing these toner materials with a Henshell mixer, melt-kneading is performed using a twin-screw extruder with the discharge part removed, and the obtained mixture is rolled to a thickness of 2 mm with a cooling press roller and cooled. After cooling with a belt, it was coarsely ground with a feather mill. After that, it is crushed to an average particle size of 10 to 12 μm with a mechanical crusher, further crushed while classifying coarse powder with a jet crusher, and then fine powder classification is performed using a rotor type classifier to perform volume average particle size. A toner matrix having a diameter of 6 μm and an average circularity of 0.925 was obtained.

In addition, 1 part of hydrophobic silica TS-500 and 2 parts of hydrophobic silica RY50 were added to 100 parts of this toner base, and mixed with a 20 L Henschel mixer at a peripheral speed of 30 m / sec for 5 minutes. Then, it was sieved with a sieve having an opening of 75 μm to obtain pulverized toner. The particle size of the pulverized toner was 6 μm, and the average circularity was 0.926.

Therefore, the toner replenishment control is performed by the above-mentioned control device using the crushed toner and the modified image forming apparatus (printer), and 100,000 blank sheets of paper P are intermittently passed under the conditions of different toner replenishment amounts. Table 1 shows the results of examining the presence or absence of vertical band streaks on image formation.

From Table 1, according to the toner replenishment control by the control device in the image forming apparatus according to the first and second embodiments, vertical band streaks do not occur in the image forming, and a problem-free image is obtained and evaluated. It turns out that it has passed. On the other hand, according to the toner replenishment control by the control device in the image forming apparatus according to Comparative Example 1 and Comparative Example 2, vertical band streaks occur in the image formation, a problematic image is obtained, and the evaluation is disqualified. It turns out. When the toner is crushed toner, the particle size is large and the shape is irregular, so particle size selection is likely to occur, and the difference between the new toner and the deteriorated toner becomes large. It has a great effect of improving the problem that it tends to occur during replenishment. It can be inferred that such a difference is due to how the control device controls the replenishment amount of the pulverized toner in a stepwise manner.

In the toner replenishment control described with reference to FIGS. 8 and 9, a counter that counts the remaining amount of toner as the consumption amount is provided, and the control device controls the replenishment amount of new toner stepwise only by the count value of the counter. The case of performing based on is described. Further, the control device has described the case where the remaining amount of toner is replenished more than the count value of the counter while the remaining amount of toner shifts from the lower limit value of the remaining amount to the upper limit value of the remaining amount. This replenishment control includes a case where the replenishment amount of new toner is replenished more than the count value of the counter between the new detection state of the toner cartridge 7 and the transition of the remaining amount of toner to the upper limit of the remaining amount. Can be regarded as being. In such a case, the toner draft surface in the developing apparatus 4 can be gradually raised to the level of the upper limit of the remaining amount by supplying the toner in an amount larger than the toner consumption in the developing apparatus 4.

By the way, the above-mentioned counter may be a sheet counter that counts the number of sheets of paper P, which is a recording medium used for image formation using toner and new toner. In such a case, by calculating the toner consumption according to the number of sheets of paper P, the control can be simplified and the cost can be suppressed at low cost. Further, the counter may be a mileage counter that counts the mileage in the transport mechanism that transports the paper P. In this case, by calculating the toner consumption according to the mileage in the transport mechanism, the control can be simplified and the cost can be suppressed at a low cost. Further, the counter may be a dot counter that counts the number of dots corresponding to the number of pixels at the time of image formation using toner and new toner. In this case, the toner consumption can be estimated accurately.

In addition, in the developer replenishment control system of the image forming apparatus according to the embodiment, the control device replenishes the amount of new toner replenished less than the count value of the counter when the remaining amount of toner reaches the upper limit of the remaining amount. You may. Here, after the toner draft surface in the developing device 4 reaches the upper limit of the remaining amount, the toner replenishment amount is reduced so that the toner amount in the developing device 4 is always full when there is toner in the toner cartridge 7. To. This makes it possible to reduce the number of times a large amount of toner is replenished at one time.

In addition, the control device may replenish the amount of new toner replenished more than the count value of the counter until the remaining amount of toner shifts from the remaining amount upper limit value to the remaining amount lower limit value. Here, when the amount of toner in the developing apparatus 4 is not full and becomes low, the amount of toner replenished is increased to make it full. This can reduce the chance of replenishing a large amount of toner at one time.

The basic function of the developer replenishment control system described above is a developer replenishment control method in which the control means can control the amount of toner replenished when the toner is replenished to the developing apparatus 4 from the storage unit that stores the toner as the developer. Can be paraphrased as. This developer replenishment control method includes a remaining amount detecting step of detecting the remaining amount of toner in the developing device 4 by the remaining amount detecting means, and a counting step of counting the amount of toner consumed by the counter. Further, this developer replenishment control method has a replenishment amount control step executed by the control means. In the replenishment amount control step, when new toner is replenished to the developing device 4 by exchanging the storage unit, the replenishment amount of the new toner is controlled stepwise based only on the count value of the counter.

It should be noted that the present invention is not limited to the above-described embodiments and the gist disclosed in each embodiment, and various modifications can be made without departing from the technical gist thereof, and the technical idea described in the claims. All of the technical matters contained in the present invention are the subject of the present invention. Although the above embodiments and examples show suitable examples, those skilled in the art can realize various modifications from the disclosed contents, but these are described in the attached claims. Included in the technical scope.

1 Process unit 2 Photoreceptor 3 Charging roller 4 Developing device 5 Cleaning blade 6 Light emitting diode (LED) head array 7 Toner cartridge 8 Toner storage unit 9 Toner collection unit 10 Transfer device 11 Paper feed device 12 Fixing device 13 Paper ejection device 14 Transfer Roller 15 Paper cassette 16 Paper feed roller 17 Resist roller 18 Fixing roller 19 Pressurized roller 20 Paper discharge roller 21 Paper discharge tray 22 Container body 30 Development housing 30a Replenishment port 31 Development roller 32 Supply roller 33 Development blade 34 First toner transfer Member 35 Second toner transfer member 36 Partition wall 42, 43 Opening 46 Drive transmission member 50 Toner replenishment container 51 Toner transfer unit 52 Agitator 53 Rotating shaft 60 Remaining amount detection sensor 61 Cleaning member 62 First optical guide 63 Second optical guide 100 Device body 101 Cover A 1st storage B 2nd storage P Paper

Japanese Patent No. 4623496

Claims (5)

With a storage unit for storing the developing agent, a developing device to which the developing agent is replenished from the storage unit, a remaining amount detecting means for detecting the remaining amount of the developing agent in the developing device, and the remaining amount detecting means. A developer supply control system comprising: a control means for controlling the amount of the developer to be replenished from the storage unit to the developing apparatus based on the detected remaining amount of the developer.
A counter for counting the consumption of the developer is provided.
When the new developer is replenished to the developing apparatus by exchanging the storage unit, the control means measures the replenishment amount of the new developer by the consumption amount of the developer counted only by the count value of the counter. The new developer is gradually replenished to the developing apparatus based on the determined replenishment amount.
The first value, which is a predetermined value corresponding to when the remaining amount of the developer in the developing device set in advance of the remaining amount detecting means is exhausted, and the amount of the developing agent in the developing device, which is larger than the first value. When the second value, which is a predetermined value corresponding to the remaining amount of the developer less than the full state, is set ,
The amount of the new developer supplied from the storage unit to the developing device is counted while the remaining amount of the developing agent shifts from the first value to the second value. Controlling to replenish the new developer more than the amount consumed ,
After the draft level of the developer in the developing device reaches the second value, the amount of the new developing agent replenished is reduced, and the amount of the developing agent in the developing device is always controlled to be full. A developer supply control system characterized by this. With a storage unit for storing the developing agent, a developing device to which the developing agent is replenished from the storage unit, a remaining amount detecting means for detecting the remaining amount of the developing agent in the developing device, and the remaining amount detecting means. A developer supply control system comprising: a control means for controlling the amount of the developer to be replenished from the storage unit to the developing apparatus based on the detected remaining amount of the developer.
A counter for counting the consumption of the developer is provided.
When a new developer is replenished to the developing apparatus by exchanging the storage unit, the control means replenishes the new developing agent in a plurality of times until the amount of the developing agent in the apparatus reaches a predetermined amount. ,
The replenishment amount of the developer when replenishing in a plurality of times is controlled based on the consumption amount of the developer counted only by the count value of the counter.
The first value, which is a predetermined value corresponding to when the remaining amount of the developer in the developing device set in advance of the remaining amount detecting means is exhausted, and the amount of the developing agent in the developing device, which is larger than the first value. When the second value, which is a predetermined value corresponding to the remaining amount of the developer less than the full state, is set ,
The amount of the new developer supplied from the storage unit to the developing device is counted while the remaining amount of the developing agent shifts from the first value to the second value. Controlling to replenish the new developer more than the amount consumed ,
After the draft level of the developer in the developing device reaches the second value, the amount of the new developing agent replenished is reduced, and the amount of the developing agent in the developing device is always controlled to be full. A developer supply control system characterized by this. In the developer supply control system according to claim 1 or 2.
Provided with a warning means to warn the replacement of the storage unit with a new one.
The developer supply control system is characterized in that the control means instructs the warning means to warn the replacement of a new storage unit when the first value continues a predetermined number of times. In the developer supply control system according to claim 1 or 2.
The counter is
A sheet counter that counts the number of recording media used for image formation using the developer and the new developer, or
A mileage counter that counts the mileage in a transport mechanism that transports a recording medium used for image formation using the developer and the new developer, or a mileage counter.
A developer supply control system comprising a dot counter that counts the number of dots corresponding to the number of pixels at the time of image formation using the developer and the new developer. An image forming apparatus comprising the developer supply control system according to any one of claims 1 to 4.

Images