JP5862208B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an electrophotographic image forming apparatus applied to a copying machine, a facsimile, a printer, and the like.

  The photosensitive member surface is uniformly charged to a predetermined potential by a charging unit, an electrostatic latent image is formed by an exposure unit, and the electrostatic latent image is developed by a developing unit using a two-component developer composed of toner and a carrier. In an electrophotographic image forming apparatus that forms a toner image, toner is consumed from the developer in the developing device when development is performed. Therefore, toner is replenished into the developing device from the toner container. Toner is filled in a toner container (sub hopper) from a toner container such as a toner bottle or a toner cartridge set in the image forming apparatus main body, and is supplied to the developing device. When there is no toner container, the toner container may be used as an alternative to the toner container to directly replenish the toner.

  Conventionally, a method of controlling the toner replenishment amount so as to keep the toner density of the developer constant has been widely used. In general, the toner concentration in the developing device is detected by a magnetic permeability detection sensor or an optical detection sensor, and the toner replenishment amount is calculated from the difference between the reference toner concentration and the detected toner concentration. The amount of toner replenishment is controlled by the operation time of a toner replenishing device (for example, a conveying screw). The replenishment capability of the toner replenishing device is set in advance, and the toner replenishment control is performed by calculating the operation time of the toner replenishing device from the necessary toner replenishment amount.

  In the control method in which the amount of toner to be replenished from the toner containing portion into the developing device is determined by the operation time of the toner replenishing device, an appropriate toner replenishment amount may not be controlled. This is because it is assumed that the operation time and the toner supply amount of the toner supply device are always constant. In reality, however, the relationship varies depending on the apparent density of loose toner.

  A method for deriving the relationship between the toner replenishment time and the toner replenishment amount based on the operation time of the conveying screw in the toner container and the detection result of the toner replenishment amount passing through the toner replenishment path is disclosed in, for example, “Patent Document 1”. ing. Further, there is a method in which the CPU has a table showing a correspondence relationship between the toner replenishment time and the toner replenishment amount for each color toner in advance, and the toner replenishment amount is calculated from the pixel information to determine the operation time of the toner replenishment means. For example, it is disclosed in “Patent Document 2”.

However, the loose density of toner does not change only with the color of the toner, and also varies depending on the production lot in the toner manufacturing process. Therefore, if the replenishment capacity is determined according to the color, there is an error in the replenishment capacity due to the difference in loose apparent density. It will occur.
SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus that solves the above-described problems, corrects fluctuations in replenishment ability caused by differences in the apparent density of toner looseness, and can perform accurate toner replenishment control.

According to the first aspect of the present invention, there is provided a latent image forming means for forming a latent image corresponding to image information on an image carrier, a developing device for developing the latent image formed on the image carrier, and the developing device. Toner replenishment comprising a toner container for containing toner to be supplied therein, a replaceable toner container for containing toner to be filled in the toner container, and a toner filling means for filling toner into the toner container from the toner container And a toner replenishment control means for controlling an operation time of the toner replenishing apparatus, and the toner container has a storage means capable of inputting / outputting data and inputs / outputs data to / from the storage means. and a data processing apparatus to the image forming apparatus main body, is in the storage means and the specific information and the loose apparent density information of the toner is stored, the said toner supply control means and the pixel information Yu The replenishment capability is corrected based on the apparent density information, the operation time of the toner replenishing device is controlled based on the corrected replenishment capability, and the toner before replacement is consumed when the toner container is replaced. The old toner consumption completion pixel count is calculated until the old toner consumption completion pixel count from the time of replacement of the toner container to the old toner consumption completion pixel count by using the replenishment capability based on the loose density density information of the toner before replacement. The replenishment capability based on loose toner apparent density information after replacement is used after the number of pixels has elapsed .

  According to the present invention, when the data in the storage means is updated, the replenishment capability of the toner replenishing device is changed based on this data, and the toner replenishment control device operates the operation time of the toner replenishing device based on the pixel information and the replenishment capability. Therefore, by adopting a toner container in which the toner loose apparent density for each production lot is recorded, it is possible to correct the replenishment ability fluctuation due to the toner loose apparent density and to perform accurate toner replenishment control.

1 is a schematic front view of an image forming apparatus employing an embodiment of the present invention. 1 is a schematic view of a toner replenishing device used in an embodiment of the present invention. It is the schematic explaining the sub hopper used for one Embodiment of this invention. It is the schematic explaining the upper chamber of the sub hopper used for one Embodiment of this invention. It is the schematic explaining the lower chamber of the sub hopper used for one Embodiment of this invention. 1 is a block diagram of a toner supply control device used in an embodiment of the present invention. FIG. 6 is a flowchart illustrating a control operation of a toner supply control device according to an embodiment of the present invention. FIG. 4 is a diagram illustrating a relationship between a toner loose apparent density and a replenishment capability in an embodiment of the present invention. It is a diagram explaining the relationship between the cumulative number of output pixels and the replenishment capability in one embodiment of the present invention.

  FIG. 1 shows a color copying machine 1 which is an example of an image forming apparatus to which an embodiment of the present invention is applied. The color copying machine 1 has a copying machine main body 100 that is an image forming apparatus main body at the center, and a sheet feeding unit 200 configured in a table shape at the lower part thereof, and a scanner 300 and a scanner above the copying machine main body 100. An automatic document feeder (ADF) 400 is disposed above 300.

  The copying machine main body 100 is provided with an intermediate transfer belt 10 as an image carrier constituted by a flexible endless belt wound around a plurality of rollers 14, 15 and 16. In the intermediate transfer belt 10, one of the rollers 14, 15, and 16 is rotationally driven by a driving means (not shown), whereby the intermediate transfer belt 10 is driven to run in the clockwise direction indicated by the arrow, and the other rollers are driven. Followed rotation. An image forming unit 18 which is an image forming unit of black, cyan, magenta, and yellow is arranged in parallel on the upper traveling side of the intermediate transfer belt 10 that travels in this way. That is, four image forming units 18 are arranged on the running side between the roller 14 and the roller 15 to constitute a tandem image forming apparatus 20 as a latent image forming unit.

  The four image forming units 18 include a photosensitive drum 40 as an image carrier in contact with the intermediate transfer belt 10. Around the photosensitive drum 40, a charging device, a developing device, a cleaning device, a static eliminator, and the like are arranged. Further, a transfer is performed on the inner side of the intermediate transfer belt 10 at a contact position between the photosensitive drum 40 and the intermediate transfer belt 10. A device 12 is provided. In this embodiment, the four image forming units 18 have the same structure, but the toner colors in the developing device are divided into four colors of black, cyan, magenta, and yellow. Further, an exposure device 21 for irradiating the surface of each photosensitive drum 40 with light-modulated laser light is disposed above each image forming unit 18, and this laser light is provided between the charging device and the developing device. The drum 40 is irradiated. Although the exposure apparatus 21 may be provided in each image forming unit 18, using the common exposure apparatus 21 is advantageous in terms of cost.

  On the other hand, a secondary transfer device 22 is provided on the side facing the tandem image forming apparatus 20 with the intermediate transfer belt 10 interposed therebetween. The secondary transfer device 22 is arranged so that a secondary transfer belt 24 which is an endless belt is wound around two rollers 23 and the secondary transfer belt 24 is pressed against the roller 16 via the intermediate transfer belt 10. Has been. In FIG. 1, a fixing device 25 for fixing the toner image carried on the sheet is provided on the left side of the secondary transfer device 22. The fixing device 25 includes a pressure roller 27 and a fixing belt 26 pressed against the pressure roller 27. The secondary transfer device 22 is also provided with a sheet transport function for transporting the image-transferred sheet to the fixing device 25. Of course, a non-contact charger may be used as the secondary transfer device 22, and in that case, it is necessary to separately provide a sheet conveying device for conveying the transferred sheet to the fixing device 25. In the illustrated example, a sheet reversing device 28 is provided below the secondary transfer device 22 and the fixing device 25 and disposed in parallel with the tandem image forming device 20 so as to reverse the sheet so as to record images on both sides of the sheet. doing.

  When image formation is performed using the color copying machine having the above-described configuration, a document is set on the document table 30 of the automatic document feeder 400. Alternatively, the automatic document feeder 400 is opened, a document is set on the contact glass 32 of the scanner 300, and the automatic document feeder 400 is closed to hold the document. Thereafter, when a start switch (not shown) is pressed, when a document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the other contact glass 32. Immediately after the scanner 300 is driven, the first traveling body 33 and the second traveling body 34 travel. Then, the first traveling body 33 emits light from the light source and further reflects the reflected light from the document surface toward the second traveling body 34, and is reflected by the mirror of the second traveling body 34 and passes through the imaging lens 35. The document is placed in the reading sensor 36 and the original content is read.

  Further, when a start switch (not shown) is pressed, the intermediate transfer belt 10 travels and simultaneously, the photosensitive drums 40 start rotating in the respective image forming units 18, and black, yellow, A magenta and cyan monochrome image is formed. Then, as the intermediate transfer belt 10 travels, the transfer device 12 sequentially superimposes and transfers the single color images, and a composite color image is formed on the intermediate transfer belt 10.

  On the other hand, when a start switch (not shown) is pressed, one of the paper feed rollers 42 of the paper feed unit 200 is selectively rotated, and sheets are fed from one of the paper feed cassettes 44 provided in the paper bank 43 in multiple stages. Sent out. The fed sheets are separated one by one by the separation roller 45 and sent to the paper feed path 46, conveyed by the conveyance roller 47 and sent to the paper feed path 48 in the copying machine main body 100, and a registration roller pair 49. Is paused. When manual feeding is selected, the sheet feeding roller 50 rotates to feed the sheets on the manual tray 51, and the separation roller 52 separates the sheets one by one into the sheet feeding path 53. It stops at 49. Then, the registration roller pair 49 is rotated in time with the composite color image on the intermediate transfer belt 10, and the sheet is fed between the intermediate transfer belt 10 and the secondary transfer device 22. A full color image is transferred onto a sheet at once.

  The sheet after the image transfer is conveyed by the secondary transfer device 22 and sent to the fixing device 25, and the transferred image is fixed by heat and pressure in the fixing device 25, and then guided by the switching claw 55 and discharged by the discharge roller 56. The paper is discharged and stacked on the paper discharge tray 57. Alternatively, the sheet is guided by the switching claw 55 and sent to the sheet reversing device 28, where it is reversed and sent again to the transfer position to transfer the image to the back surface, and then discharged by the discharge roller 56 via the fixing device 25. The paper is discharged onto the paper tray 57. On the other hand, after the image transfer, the intermediate transfer belt 10 has the residual toner removed after the image transfer by the intermediate transfer body cleaning device 17, and is prepared for re-image formation by the tandem image forming device 20.

  FIG. 2 is a schematic diagram of a toner replenishing device 150 that replenishes toner to the developing device 60 of the image forming unit 18. In the figure, a toner container 80 containing toner is set in a set unit (not shown) provided in the copying machine main body 100. In this setting portion, a nozzle 90 to be inserted into the toner container 80 is provided in a machine frame (not shown). When the toner container 80 is set in the setting portion, the shutter 81 is pushed out sideways and the nozzle 90 is inserted. The The nozzle 90 has a single tube structure, and a toner transfer tube 59 is connected to the end of the nozzle 90 opposite to the insertion side.

  The toner container 80 is provided with a toner discharge port 83 at the lower center thereof. The toner discharge port 83 is formed of a base member 82 made of a resin such as polyethylene or nylon and fixed to the toner container 80. The toner discharge port 83 is normally closed by the shutter 81, but when the toner container 80 is set in the setting portion, the shutter 81 is pushed out by the nozzle 90 to the side, and the opening of the nozzle 90 and the toner discharge port 83 are discharged. And communicate. In the figure, reference numeral 91 denotes a return spring for the shutter 81, which urges the shutter 81 to return to a position where the toner discharge port 83 is closed when the toner container 80 is removed from the set portion. The toner container may have a bottle shape.

  The developing device 60 has a sub hopper 61 as a toner container for storing toner to be supplied to the upper portion thereof, and the toner sent from the toner container 80 is temporarily stored in the sub hopper 61. On the sub hopper 61, there is provided a powder pump 70 as a toner filling means for transferring and filling the toner in the toner container 80 into the sub hopper 61. The powder pump 70 is a uniaxial eccentric screw pump, and includes a rotor 71 having an eccentric screw shape made of a material having rigidity such as metal, and a stator 72 having an elastic body such as rubber and having a two-screw shape. And a holder 73 made of a resin material or the like that covers these and forms a powder conveyance path. In the rotor 71, a gear 75 (see FIG. 3) integrally connected to a drive shaft 74 connected by a pin joint is drivingly connected to the first clutch 76 via an idle gear (not shown), and the first clutch 76 is turned on. The operation of the powder pump 70 is controlled by turning off. The first clutch 76 and a second clutch 68 described later are provided on a rotary drive shaft 79 that is driven by a drive device (not shown). A toner suction portion 77 is provided at the tip of the holder 73, that is, the right end in FIG. 2, and a toner transfer tube 59 is connected to the toner suction portion 77. If the powder pump 70 is used, the toner in the toner container 80 is smoothly transported even when the toner discharge port of the toner container 80 is at a lower position in the vertical direction than the toner receiving port of the sub hopper 61. can do.

As shown in FIGS. 2, 3, and 4 , the sub hopper 61 is formed so that its vertical cross-sectional shape is substantially an inverted triangle, and the inside thereof is divided in the direction of gravity by an upper and lower partition member 64, and an upper chamber 62 and a lower chamber 63. And are formed. The upper chamber 62 having a larger floor area than the lower chamber 63 is provided with a pair of upper screws 84 and 85 that rotate in opposite directions, and a partition plate 66 that is disposed between the two screws and is open at both ends. Yes. The partition plate 66 is formed integrally with the upper and lower partition members 64, but both may be configured as separate members.

  In the upper chamber 62 configured as described above, the position indicated by the symbol A as shown in FIG. 4 is the supply position of the toner conveyed by the powder pump 70, and the toner supplied to the position A is the upper screw 84, It is circulated in the direction of arrow P1, that is, counterclockwise by the rotation of 85. Reference numeral B denotes a communication hole between the upper chamber 62 and the lower chamber 63, and the toner circulating in the direction of the arrow P <b> 1 by the upper screws 84 and 85 falls from the communication hole B to the lower chamber 63. Further, as shown in FIG. 5, a lower screw 86 is provided in the lower chamber 63, and the toner supplied from the communication hole B to the position B ′ is moved in the direction of the arrow P <b> 2 by the rotation of the lower screw 86. Reference numeral C denotes a replenishing port that communicates the lower chamber 63 and the developing device 60, and the toner moved in the direction of the arrow P2 falls from the replenishing port C and is replenished into the developing device 60.

  The sub-hopper 61 configured as described above temporarily stores the toner supplied by the powder pump 70, and the stored toner is transferred to the developing device 60 by each screw 84.85.86. The gears 84 a, 85 a, 86 a of the screws 84, 85, 86 are drivingly connected to a second clutch 68 provided on the rotary drive shaft 79 via an idle gear train 87, and are turned on / off by the second clutch 68. Off is controlled. Each of the screws 84, 85, 86 is set so that the toner conveyance amount of the upper screws 84, 85 is larger than that of the lower screw 86 by, for example, making the screw diameter and the rotation speed different. Accordingly, since the upper screws 84 and 85 and the lower screw 86 of the present embodiment are driven at the same time, the toner in the lower chamber 63 is almost full, and the toner in the upper chamber 62 circulates in the direction indicated by the arrow P1. When the toner 63 is replenished, the corresponding toner drops from the communication hole B to the lower chamber 63. The driving of each of the screws 84, 85, 86 can be controlled separately.

  The sub hopper 61 is provided with a toner end sensor 69 as a toner amount detecting means for detecting the presence or absence of toner on the side wall in the vicinity of the upstream side in the toner circulation direction of the position A to which the toner transferred by the powder pump 70 is supplied. ing. The toner end sensor 69 shown in this embodiment is a vibration type sensor, and detects the presence or absence of toner on a detection surface 69a that contacts the toner in the upper chamber 62.

  In the toner replenishing device 150 configured as described above, when a toner replenishing command is issued to the developing device 60, the second clutch 68 is turned on and the screws 84, 85, 86 are operated to rotate the lower screw 86. The developing device 60 is replenished with an amount of toner corresponding to the above. Toner replenishment from the toner container 80 to the sub hopper 61, the toner end sensor 69 monitors the toner in the upper chamber 62, and when the toner decreases below the detection position of the sensor 69, the powder pump 70 is activated to operate the toner container. The toner in 80 is supplied into the sub hopper 61. At this time, the amount of toner transferred by the powder pump 70 is set to be larger than the amount replenished to the developing device 60 by the lower screw 86. The sub hopper 61 may have a structure that is not divided into upper and lower chambers.

  If the toner detection amount of the toner end sensor 69 remains below the specified amount even after the powder pump 70 is operated several times, it is determined that the toner near the end of the toner container 80 is almost out, and a predetermined operation, for example, illustrated in FIG. The operation panel is informed that it is time to replace the cartridge, and the operation is stopped after a predetermined number of times of image formation. When the toner near end is detected, the sub hopper 61 does not have any toner, so the toner density of the developing device 60 does not decrease, and the image density does not become unstable when the toner near end is detected.

  In order to reliably obtain the above-described effect, it is preferable to dispose the toner end sensor 69 in the vicinity of the position A where the toner is replenished by the powder pump 70. Even if the toner amount is insufficient at this position, the sub hopper 61 is provided. Forms a toner circulation path so that the maximum amount of toner can be stored using the internal space. Accordingly, the upper chambers 62 are spaced from the position A where the toner is replenished by the powder pump 70 to the communication hole B where the toner is supplied to the lower chamber 63 by an upper screw 84, 85 with an interval of more than a half circumference of the path through which the toner circulates. When the amount of toner is low, the toner from the toner container 80 does not immediately fall into the lower chamber 63, and toner supply to the developing device 60 can be continued to some extent even if it is determined that the toner is near the end. As a result, it is possible to reliably suppress the deterioration of the image quality of the recorded matter due to the fluctuation of the image density, which often occurs at the time of toner near-end.

  The color copying apparatus 1 shown in this embodiment has a toner supply control device 401 as a toner supply control means for the developing device 60, and this block diagram is shown in FIG. In FIG. 6, the color copying apparatus 1 includes a two-component developing type developing device 60, a toner supplying device 150 for supplying toner to the developing device 60, and a pixel information acquiring unit 151 for acquiring pixel information. The developing device 60 has a magnetic permeability. A toner density sensor 152 that detects the toner density of the two-component developer by a detection method is provided.

In this embodiment, a storage unit 145 that records toner information in the toner container 80 is provided, and toner replenishment control based on information stored for each toner container 80 is performed. The toner container 80 has storage means 145 capable of writing and reading out the characteristic information of the toner stored in the toner container 80, and the storage means 145 is stored by the toner replenishment control device 401 provided in the copying machine main body 100. It reads the data, when the data held in the toner container 80 is updated, based on the pixel information from the loose apparent density information and pixel information obtaining unit 151 from the storage unit 145 to supply capability of the toner supply device 150 to correct.

  The storage unit 145 stores unique ID information of the toner container 80. This unique information stores information unique to the toner contained in the toner container, such as the production date of the toner and the production lot. The storage unit 145 is preferably capable of automatic reading in cooperation with a reading device (not shown) such as an ID chip or a barcode on the main body side. When the toner is replaced, the storage unit 145 for acquiring the characteristic value information of the set toner is used as an ID chip so that the image forming apparatus main body side can read the information in a non-contact manner. It becomes possible to prevent.

  Next, the control operation of the toner supply control device 401 will be described with reference to the flowchart shown in FIG. The toner replenishment control by the toner replenishment control device 401 is executed for every sheet passing or at intervals of a predetermined time. First, pixel information of each color is obtained from the input image using the pixel information acquisition unit 151, and the toner supply amount is calculated by calculating the toner consumption amount for each sheet passing or every predetermined time from the pixel information. Then, by supplying the same amount of toner as the toner consumption at a predetermined control interval, fluctuations in toner density are suppressed. The toner replenishment amount is controlled by the operating time of the lower screw 86 provided in the sub hopper 61. However, since the replenishment capability of the toner replenishing device 150 fluctuates due to the difference in the apparent density of toner loosening, the replenishment capability is corrected. Do.

FIG. 8 shows the relationship (cyan) between the apparent density of loose toner and the replenishment capability of the toner replenishing device 150. As shown in the figure, the replenishment ability tends to increase as the loose apparent density increases. The yellow, magenta, cyan, and black toners used in the color copying apparatus 1 shown in the present embodiment are all loose depending on the production lot, and the apparent density varies within a range of 0.38 ± 0.02 (g / cm ³ ). There is.

  Here, a method for measuring the loose apparent density will be described. First, 10 g of toner is placed in a 50 ml graduated cylinder, and then covered and shaken 50 times. The scale is read after opening the lid and allowed to stand for 10 minutes, and the ratio to the measured toner amount is calculated to obtain the loose apparent density.

  The loose apparent density is measured for each toner production lot by the above-described method, and stored in the storage means 145 unique to the toner container 80. The slack apparent density information stored in the storage unit 145 is read by the toner replenishment control device 401 when the toner container 80 is replaced, and is used for toner replenishment control. Here, if the toner replenishment capability is changed based on the information stored in the storage unit 145 immediately after the toner container 80 is replaced, the toner before the toner container 80 is replaced remains in the developing device 60 and the sub hopper 61. Therefore, an error occurs in the replenishment amount. In order to prevent the occurrence of this problem, the number of old toner consumption completed pixels from when the toner container 80 is replaced until the toner before replacement is consumed is obtained in advance. The replenishment capability based on the loose apparent density of the toner before replacement is used from the time of replacement of the toner container 80 to the number of completed pixels of the old toner consumption, and the replenishment based on the apparent density of loose toner after the replacement of the old toner consumption pixels Change to ability.

The cumulative number of output pixels from toner near-end detection is calculated by adding the input pixel information for each color, and the replenishment capability is based on the apparent density of loose toner after replacement based on the old toner consumption completion pixel count. As shown by a broken line in FIG. 9, the relationship between the cumulative output pixel number and the loose apparent density may be linear, and the replenishment ability based on the loose apparent density is calculated based on the cumulative output pixel number from the toner near end detection. This is indicated by a broken line in FIG. From the toner near-end detection to the replacement of the toner container 80, the replenishment ability based on the loose apparent density of the toner before replacement is used for the replenishment control. From the time of replacement of the toner container 80, the replenishment capability (shown by a solid line in FIG. 9) used for replenishment control is changed based on the calculated replenishment capability. Thereafter, the replenishment capability based on the loose apparent density is gradually updated by 0.05 mg / ms, and when the old toner consumption complete pixel count is reached, the replenishment capability based on the loose apparent density of the replaced toner is set.

  The toner supply control device 401 calculates toner supply time (operation time of the lower screw 86) from the toner supply amount and supply capability, and performs toner supply control. In addition, the toner density of the developer in the developing device 60 is detected by a toner density sensor 152 as density measuring means. The toner density in the developing device 60 needs to be controlled within an appropriate range. When the toner density is too high, the toner scatters, and when the toner density becomes too low, the carrier adheres. Each will occur. For this reason, upper and lower limits are set for the toner density. When the toner density reaches the upper limit value, replenishment is stopped, and when the toner density reaches the lower limit value, the toner density falls within the upper and lower limit ranges. Control to keep.

  With the above configuration, when the data in the storage unit 145 is updated, the replenishment capability of the toner replenishment device 150 is changed based on this data, and the toner replenishment control device 401 uses the pixel information and the replenishment capability to change the toner replenishment device 150. Therefore, by adopting the toner container 80 in which the toner loose apparent density for each production lot is recorded, the supply capacity fluctuation due to the toner loose apparent density is corrected, and accurate toner replenishment control is performed. be able to.

  In addition, by using the storage unit 145 as an ID chip, the image forming apparatus main body can read information in a non-contact manner, and the complexity of manual input and input errors can be prevented. Further, when the data stored in the storage unit 145 is updated, the toner in the developing device 60 is replaced immediately after the toner container 80 is replaced by changing the replenishment capability according to the cumulative number of output pixels. In other words, the replenishment capability can be corrected according to the toner replacement condition, and accurate toner replenishment control can be performed. Further, the toner replenishment control device 401 controls the operation of the toner replenishment device 150 so as to maintain the toner concentration within the upper and lower toner density ranges based on the measurement result of the toner density sensor 152, so that the toner density is out of the upper and lower limits. It is possible to prevent the occurrence of abnormality. Further, the sub hopper 61 has a toner end sensor 69, and when the toner amount detected by the toner end sensor 69 falls below the threshold, the sub hopper 61 is filled with toner by the powder pump 70, so the toner in the sub hopper 61 Variations in the amount of replenishment due to shortage can be minimized.

  In the above-described embodiment, an example in which a color copying machine having a plurality of photosensitive drums 40 is used as the image forming apparatus 1, but the image forming apparatus to which the present invention is applicable is not limited to this, and may be a printer, a plotter, a facsimile machine. The present invention can also be applied to other image forming apparatuses such as these multifunction peripherals and monochrome copying machines having only one photosensitive drum 40.

1 Image forming device (color copier)
20 Latent image forming means (tandem image forming apparatus)
40 Image carrier (photosensitive drum)
60 Developing Device 61 Toner Container (Sub Hopper)
69 Toner amount detection means (toner end sensor)
70 Toner filling means (powder pump)
80 Toner container 100 Image forming apparatus main body (copier main body)
150 toner replenishing device 152 density measuring means (toner density sensor)
145 Storage unit 401 Toner supply control unit (toner supply control device)

JP 2003-5503 A JP-A-5-27528

Claims (4)

A latent image forming unit that forms a latent image according to image information on an image carrier, a developing device that develops the latent image formed on the image carrier, and toner to be supplied into the developing device are accommodated. A toner replenishing device comprising: a toner container; a replaceable toner container that contains toner to be filled in the toner container; and a toner filling device that fills the toner container from the toner container; A toner replenishment control means for controlling an operation time, and the toner container has a storage means capable of inputting / outputting data, and a data processing apparatus for inputting / outputting data to / from the storage means to have, in the storage means and the loose apparent density information and unique information of the toner is stored, the toner supply control means to said loose apparent density information and the pixel information Then, the replenishment capability is corrected, the operation time of the toner replenishing device is controlled based on the corrected replenishment capability, and the old toner consumption until the pre-replacement toner is consumed when the toner container is replaced. Calculate the number of completed pixels, and use the replenishment capability based on the information on the apparent density of loose toner before the replacement from the time of replacement of the toner container to the number of completed pixels of the old toner. An image forming apparatus using the replenishment capability based on the information on the apparent density of loose toner later . The image forming apparatus according to claim 1.
The image forming apparatus, wherein the storage means is an ID chip . The image forming apparatus according to claim 1 or 2,
The toner supply control means controls the operation of the toner supply device so as to maintain the toner density within the upper and lower limits of the toner density based on the measurement result of the density measurement means. An image forming apparatus. The image forming apparatus according to any one of claims 1 to 3,
The toner container has toner amount detection means for detecting the amount of toner inside, and when the toner amount detected by the toner amount detection means falls below a threshold value, the toner is filled from the toner filling means to the toner container. An image forming apparatus which is filled .

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