JP2006259539A - Method for displaying remaining amount of toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for displaying the remaining amount of toner where an electrophotographic image forming apparatus provides the remaining amount of toner, as accurately as possible using a simple constitution. <P>SOLUTION: A starter cartridge is loaded first and an image formation unit 6 (S1) is set in a primary apparatus body to detect "brand-new" (S2); and an engine control section 64 recognizes a toner charging amount of cartridge ID information (S3). The remaining amount of toner is reported with toner consumption per dot as a default value (S4), and print dots are accumulated (S5); when printing is stopped, because of no toner (S6), toner one-dot actual consumption is calculated (S7) and the default value is rewritten (S8). The toner charging amount of a brand-new option cartridge after replacement and the calculated toner one-dot actual consumption are stored, thereafter (S9 and S11), and a new remaining amount rate of toner is calculated (S12) from a print dot accumulated value, counted by an initialized print dot counter (S10) and the toner one-dot actual consumption and recorded in a memory 68 (S13), so that the new remaining amount rate is displayed and reported (S14). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a toner remaining amount display method that always notifies as much as possible a remaining amount of toner with a simple configuration in an electrophotographic image forming apparatus.

  Conventionally, there is an electrophotographic image forming apparatus that uses toner as an image forming agent. In such an image forming apparatus, if the user can know the remaining amount of toner at an appropriate timing, it is convenient because a countermeasure can be taken without delay, such as preparing a toner cartridge to be replaced next.

In view of this, a proposal has been made to sequentially detect the remaining amount of toner from the change in toner capacitance. (For example, refer to Patent Document 1.)
The toner cartridge is provided with a storage medium for storing at least data relating to the remaining amount of toner or used amount, and the image forming apparatus main body side accesses the above storage medium in a non-contact manner to update data relating to the remaining amount of toner or used amount. An image forming apparatus having a function has been proposed. (For example, see Patent Document 2.)
Japanese Patent Laid-Open No. 2001-312185 ([Summary], FIG. 6) JP 2004-347800 A ([Summary], FIG. 2)

  However, in the method of sequentially detecting the remaining amount of toner from the change in the electrostatic capacity of the toner of Patent Document 1, the electrostatic capacity is other than the remaining amount of toner, for example, remaining toner density, remaining toner movement, ambient temperature and humidity, It is easily affected by factors such as in-machine temperature and humidity.

  Therefore, it can be used for so-called toner-free detection for detecting the presence or absence of toner, but there is a problem that it is not suitable for practical use for so-called remaining amount detection for quantitatively measuring the remaining amount of toner.

  In addition, the method for updating data relating to the remaining amount or amount of toner disclosed in Patent Document 2 requires a communication device that accesses the storage medium in a non-contact manner, which makes the configuration and control complicated and expensive. There is a problem that causes a rise in product prices.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a toner remaining amount display method that always notifies the remaining amount of toner as accurately as possible with a simple configuration in an electrophotographic image forming apparatus in view of the above-described conventional situation.

The configuration of the remaining toner amount display method according to the present invention will be described below.
The toner remaining amount display method of the present invention is the first new product in an image forming unit that includes at least a developing unit and a developer remaining amount detecting unit, has a detachable toner cartridge, and is attached to and detached from the image forming apparatus main body. The remaining amount of toner in the first new toner cartridge is calculated on the basis of a preset toner usage amount per dot of the toner cartridge and notified to the outside, and the first new toner cartridge is detected by the developer remaining amount detecting means. When the first new toner cartridge is detected to be replaced with no toner, the number of print dots from the start of use of the first new toner cartridge to the replacement without toner is accumulated, and the first new toner cartridge is counted. By dividing the amount of toner consumed by the cartridge by the cumulative number of print dots, the amount The actual amount of toner consumed per toner is calculated, and when using a new toner cartridge for the second and subsequent times, the amount of toner per dot calculated from the previous toner cartridge is calculated from the toner filling amount for the second and subsequent new toner cartridges. The remaining amount of toner is calculated by subtracting the product of the toner consumption amount and the actual number of print dots, and the remaining amount of toner is notified to the outside.

  The first new toner cartridge is configured to be a toner cartridge as a service kit with a small toner capacity, for example.

  According to the present invention, the toner consumption amount per dot set for printing, which is set in advance for use in the calculation of the remaining amount of toner of the first new cartridge, is calculated as the per-print dot actually obtained when the first new cartridge is used. After replacing the amount of toner consumed, the remaining amount of the new toner cartridge replaced after the second time is calculated and the remaining amount of toner is reported, and the printing actually obtained with the previous toner cartridge after the third time is also performed. Since the remaining amount of toner is calculated by calculating the amount of remaining toner per dot, and the amount of remaining toner is notified, rather than continuously informing the remaining amount of toner based on the amount of toner consumed per dot quantified in advance. More accurate toner remaining amount notification can be performed.

  Therefore, the user can know the remaining amount of toner at an appropriate timing, so that it is possible to take a response without delay when preparing a new toner cartridge for replacement next time. It is possible to provide a toner remaining amount display method for realizing the above.

Embodiments of the present invention will be described below with reference to the drawings.
(Embodiment 1)
FIG. 1 is a cross-sectional view illustrating an internal configuration of a color image forming apparatus (hereinafter simply referred to as a printer) including a developing device that uses a non-magnetic one-component toner according to Embodiment 1 of the present invention.

  A printer 1 shown in FIG. 1 is an electrophotographic secondary transfer tandem color image forming apparatus, and includes an image forming unit 2, an intermediate transfer belt unit 3, a paper feeding unit 4, and a duplex printing conveyance unit 5. It consists of

The image forming unit 2 has a configuration in which four image forming units 6 (6M, 6C, 6Y, and 6K) are arranged in a multistage manner from right to left in FIG.
Of the four image forming units 6, three image forming units 6M, 6C, and 6Y on the upstream side (right side in the figure) are magenta (M), cyan (C), yellow (subtractive three primary colors), respectively. A mono-color image is formed with the color toner of Y), and the image forming unit 6K forms a monochrome image with black (K) toner mainly used for dark portions of characters and images.

  Each of the image forming units 6 has the same configuration except for the color of the toner stored in the toner container (toner cartridge). Accordingly, the configuration of the black (K) image forming unit 6K will be described below as an example.

  The image forming unit 6 includes a photosensitive drum 7 at the bottom. The peripheral surface of the photosensitive drum 7 is made of, for example, an organic photoconductive material. A cleaner 8, a charging roller 9, an optical writing head 11, and a developing roller 13 of the developing device 12 are arranged around the periphery of the photosensitive drum 7.

  The developing device 12 puts one of magenta (M), cyan (C), yellow (Y), and black (K) toners in the upper toner container as indicated by M, C, Y, and K in the drawing. An intermediate portion is provided with a toner replenishing mechanism for the lower portion.

  In addition, the developing roller 13 is provided in the lower portion of the developing device 12 at the side opening, and includes a toner stirring member, a toner supply roller for supplying toner to the developing roller 13, and a toner layer on the developing roller 13 as a fixed layer. It has a doctor blade that regulates the thickness.

  The intermediate transfer belt unit 3 has an endless transfer belt 14 extending in a flat loop shape from substantially the left and right sides of the figure at the approximate center of the main unit, and the transfer belt 14 is stretched over the transfer belt 14. A driving roller 15 and a driven roller 16 are provided to circulate and move the belt 14 counterclockwise in the drawing.

  The transfer belt 14 transfers the toner image directly onto the belt surface (primary transfer) and conveys the toner image to the transfer position to the paper for further transfer (secondary transfer). The whole is called an intermediate transfer belt unit.

  The intermediate transfer belt unit 3 includes a belt position control mechanism 17 in the loop of the flat loop-shaped transfer belt 14. The belt position control mechanism 17 includes a primary transfer roller 18 made of a conductive foam sponge that presses against the lower peripheral surface of the photosensitive drum 7 via the transfer belt 14.

  The belt position control mechanism 17 has three primary transfer rollers 18 corresponding to the three image forming units 6M, 6C, and 6Y of magenta (M), cyan (C), and yellow (Y) as vertical support shafts. Rotate to the center with the same period.

  Then, the belt position control mechanism 17 rotates and moves one primary transfer roller 18 corresponding to the black (K) image forming unit 6K at a rotational movement cycle different from the cycle of the three primary transfer rollers 18. The belt 14 is moved away from the photosensitive drum 7.

  That is, the belt position control mechanism 17 moves the position of the transfer belt 14 of the intermediate transfer belt unit 3 to full color mode (all four primary transfer rollers 18 are in contact with the transfer belt 14), monochrome mode (to the image forming unit 6K). Only the corresponding primary transfer roller 18 is in contact with the transfer belt 14) and all non-transfer modes (all four primary transfer rollers 18 are separated from the transfer belt 14).

  In the intermediate transfer belt unit 3, a belt cleaner unit is disposed further upstream of the uppermost image forming unit 6M on the upstream side in the belt movement direction, and is flat and thin so as to be substantially along the entire lower surface. The waste toner collection container 19 is detachably disposed.

  The paper feed unit 4 includes two paper feed cassettes 21 arranged in two upper and lower stages, and in the vicinity of the paper feed opening (right side in the figure) of the two paper feed cassettes 21, respectively, A feeding roller 23, a separating roller 24, and a standby conveying roller pair 25 are disposed.

  In the paper conveyance direction (vertical upward direction in the figure) of the standby conveyance roller pair 25, a secondary transfer roller 26 that is in pressure contact with the driven roller 16 via the transfer belt 14 is disposed, and the secondary transfer portion to the paper is arranged. Forming.

  A belt-type heat fixing device 27 is disposed downstream (upward in the drawing) of the secondary transfer portion, and the sheet after fixing is fixed to the belt-type heat fixing device 27 further downstream of the belt-type heat fixing device 27. A pair of carry-out rollers 28 for carrying out the paper and a pair of paper discharge rollers 31 for discharging the carried paper to a paper discharge tray 29 formed on the upper surface of the apparatus are disposed.

  The duplex printing conveyance unit 5 includes a start return path 32a that branches from the intermediate conveyance path between the carry-out roller pair 28 and the discharge roller pair 31 to the right lateral direction in the drawing, and then an intermediate return path 32b that bends downward. A terminal return path 32c that bends in the left lateral direction opposite to the above and eventually reverses the return sheet, and four return roller pairs 33a, 33b, 33c, and 33d arranged in the middle of these return paths are provided. ing.

The exit of the end return path 32 c communicates with a conveyance path to the pair of standby conveyance rollers 25 corresponding to the sheet feeding cassette 21 below the sheet feeding unit 4.
In this example, a cleaning unit 35 and a take-in roller 36 are disposed on the upper surface of the intermediate transfer belt unit 3.

  The cleaning unit 35 comes into contact with the upper surface of the transfer belt 14 to scrape and remove the waste toner, and the take-in roller 36 takes over the waste toner removed by the cleaning unit 35, and a temporary storage unit of the belt cleaner unit (not shown). The accumulated waste toner is conveyed to the upper part in the dropping cylinder by a conveying screw and sent to the waste toner collecting container 19 through the dropping cylinder.

  Further, in order to bring the cleaning unit 35 into pressure contact with the transfer belt 14 with an appropriate pressure, a pressure roller 37 is provided on the intermediate transfer belt unit 3 side to press the transfer belt 14 toward the cleaning unit 35 from below. ing.

  As shown in FIG. 1, the image forming apparatus 1 does not directly transfer a toner image onto a conventional sheet, but an intermediate transfer belt on a sheet that is vertically conveyed to a secondary transfer unit by a standby conveyance roller pair 25. 14 is a method of transferring a toner image through the image forming apparatus 14.

Therefore, it is possible to cope with a maintenance process for recovering from a problem such as a paper jam occurring in the paper transport path by simply opening the right side of FIG.
In addition, since troubles such as paper jams do not occur in the arrangement section of the kits, the operation for attaching and detaching consumables such as kits concentrated on the left side of FIG. 1 may be a small space that can be replaced in the longitudinal direction. It is configured as follows.

  Thereby, the dimension between kits is reduced as much as possible, and size reduction of the whole apparatus main body is achieved. Further, the optical writing head itself is also miniaturized and is configured closer to the photosensitive drum.

  FIG. 2 is a cross-sectional view showing the image forming unit 6. As shown in FIG. 2, the developing device 12 shown in FIG. 1 includes a toner cartridge 41 including an upper toner hopper A38 and a lower toner hopper B39, and a developing portion 43 including an exterior frame.

  In addition to the developing roller 13 described above, the developing unit 43 includes a supply roller 44 for supplying toner to the developing roller 13 and a layer of toner supplied on the developing roller 13 to a certain thickness. A doctor blade 45, a stirring member 46 for stirring the toner in the developing unit 43, and the like.

  Further, the photosensitive drum 7, the cleaner 8, and the charging roller 9 are integrally incorporated with the developing device 12 inside the exterior frame 42 as a drum unit portion 57. The drum unit 57 and the developing unit 43 of the developing device 12 form a developing drum unit 58.

The photosensitive drum 7 is usually formed by uniformly depositing an organic photoconductor on the surface of a conductive metal roller, and the metal roller portion is grounded.
In addition, the charging roller 9 has a white printing state charging potential (a uniformly applied initializing potential, a method of applying a positive polarity and a method of applying a negative polarity, and a negative polarity in this example. High voltage) is applied to the photosensitive drum 7.

By this application, the photosensitive layer on the peripheral surface of the photosensitive drum 7 is uniformly charged to a minus high potential of, for example, “−650 V (volt)”.
The optical writing head 11 shown in FIG. 1 includes a laser light source or an LED light source, and selectively exposes the peripheral surface of the photosensitive drum 7 charged to a minus high potential according to image information.

  By this exposure, a negative low potential portion whose potential is attenuated to about “−70 V” is formed on the surface of the photosensitive drum 7, and the low potential portion of “−70 V” and the high potential of “−650 V” charged in advance are formed. An electrostatic latent image is formed by the portion.

The developing device 12 contains non-magnetic one-component toner. For example, a developing bias of “−350 V” is applied to the developing roller 13 from the high voltage power supply 47.
The supply roller 44 is supplied with a supply bias of “−300 V” to “−600 V” from another high-voltage power supply 48 as will be described in detail later.

Then, a doctor bias of “−300 V” to “−600 V” is applied to the doctor blade 45 from another high-voltage power source 49 as described above.
After the toner adheres to the surface of the developing roller 13 due to the potential difference from the supply roller 44, the toner is regulated to a constant layer pressure by the doctor blade 45 and is weak due to the minus high voltage potential applied from the high voltage power supply 48 via the doctor blade 45. It is charged to a negative potential and adheres to the surface of the developing roller 13 with a certain thickness.

The developing roller 13 conveys the toner to a portion facing the photosensitive drum 7 while rotating.
At the facing portion between the developing roller 13 and the photosensitive drum 7, a potential difference of “−280 V” is formed between the low potential portion of the “−70 V” electrostatic latent image and the developing roller 13. That is, the low potential portion of the electrostatic latent image forms a positive polarity potential relative to the developing roller 13.

  Due to the electric field due to this potential difference, the non-magnetic toner charged to the negative polarity is transferred to the positive potential electrostatic latent image low potential portion of the photosensitive drum 7 to form a toner image. This toner image is conveyed to the facing portion between the photosensitive drum 7 and the primary transfer roller 18 shown in FIG. 1 by the rotation of the photosensitive drum 7.

The primary transfer roller 18 faces the photosensitive drum 7 and presses against the photosensitive drum 7 via the transfer belt 14 to form a transfer portion.
The primary transfer roller 18 is formed of, for example, a conductive sponge and connected to a positive high voltage power source (not shown). The primary transfer roller 18 applies a positive transfer bias to the transfer belt 14.

A negative toner image on the photosensitive drum 7 that is rotated and conveyed to the transfer portion is transferred to the transfer belt 14 that has become a positive potential due to this voltage application.
Similarly, the transfer belt 14 onto which four toner images of magenta (M), cyan (C), yellow (Y), and black (K) are transferred by the four image forming units 6 is transferred to the transfer belt 14. The toner image is conveyed to a secondary transfer portion where the driven roller 16 and the secondary transfer roller 26 are in pressure contact with each other.

  Then, the toner image is transferred to the paper in the secondary transfer unit. The toner image transferred onto the paper is fixed on the paper surface by heat and pressure by the belt-type heat fixing device 27, and is discharged onto the paper discharge tray 29 by the carry-out roller pair 28 and the paper discharge tray 29.

Returning to FIG. 2, the cleaner 8 is provided with a cleaning blade 51 that contacts the peripheral surface of the photosensitive drum 7 and a conveying screw 52.
The cleaning blade 51 removes the waste toner remaining on the peripheral surface of the photosensitive drum 7, and the transport screw 52 passes the removed waste toner through the transport screw 52 b disposed on the upper left exterior frame 42 a of the exterior frame 42. Then, the toner is sent to the waste toner collection bag 54 via the conveying screw 52c in the waste toner storage pipe 53 disposed in the upper toner hopper A38.

  The lower toner hopper B39 is provided with an agitator 55 for agitating the internal toner at the center, and a seal member 56 is interposed between the lower opening and the opening of the developing unit 43. Has been. The internal toner is replenished to the developing unit 43 through the opening of the lower partition wall by the rotation of Agitate 55.

  An outline of the toner supply will be briefly described. The toner cartridge 41 includes an outer case and an inner case, and a toner agitator 55 for sending toner into the developing unit 43 is disposed in the inner case in a rotatable structure.

Initially, the outer case is filled with toner, and no toner enters the inner case.
The toner cartridge 41 is mounted on the developing unit 43 as shown in FIG. 2, and a lock lever (not shown) for fixing the toner cartridge 41 is moved, whereby the claw (not shown) arranged on the toner cartridge 41 also has a claw (not shown). At the same time, the inner case rotates, the toner enters from the outer case, and the toner is replenished from the inner case to the developing unit 43 by the rotation of the agitator 55.

Thus, the toner is sequentially consumed from the image forming unit by a supply flow of outer case → inner case → developing unit → supply porter → developing roller → photosensitive drum.
When the toner is consumed by the image formation and finally the toner is exhausted in the developing unit 43, a toner presence sensor, which will be described later, which is a pressure sensor using a piezoelectric element or the like, confirms that the pressure from the toner has become a predetermined value or less. Detect and notify the control device of “no toner” signal.

In this example, the specification is such that no-toner detection is output when the toner remaining amount is 10 g.
In order to prevent the occurrence of image defects and hardware failures, printing is forcibly prohibited when toner-free detection is activated.

The lifetime of the image forming unit 6 is set at a rotation time of the photosensitive drum 7 of 425,000 seconds, and there is no restriction on how many toner cartridges 41 are used during that time.
The image forming unit 6 is provided with a fuse. When a new image forming unit 6 is mounted on the main body of the printer 1, an electric current is supplied to the fuse to cut the fuse. Thereafter, the fuse breakage is detected. Thus, it is determined whether the image forming unit 6 is new or old.

  Then, the rotation time of the photosensitive drum 7 is measured from the time when a new image forming unit 6 is detected. Accordingly, the remaining life can be displayed by simply subtracting from the set life time of 425,000 seconds.

FIG. 3 is a perspective view showing a state where the toner cartridge 41 and the developing drum unit 58 of the image forming unit 6 of the printer 1 are combined.
FIG. 4 is a diagram showing a configuration in which the toner cartridge 41 can be inserted into and removed from the developing drum unit 58 in the image forming unit 6 in a direction perpendicular to the sheet conveyance direction of the apparatus main body.

FIG. 5 is a diagram for explaining attachment / detachment of the toner cartridge 41. In FIG. 5, the same components as those shown in FIG. 1 are denoted by the same reference numerals as those in FIG.
As shown in FIG. 5, a paper discharge tray 29 is formed on the upper surface of the apparatus main body 1, and an image-formed recording paper (paper) is discharged onto the paper discharge tray 29 above the right hand side of the paper discharge tray 29. A paper discharge roller pair 31 is disposed. An operation panel 59 is disposed in front of the upper surface of the apparatus main body 1. Further, a protective cover 61 is provided on the front side surface of the apparatus main body 1 to cover the entire upper surface of the lower sheet feeding unit 4.

  FIG. 5 shows a state in which the protective cover 61 is opened so as to tilt forward, and the image forming unit 2 inside the apparatus main body 1 is opened. Of the four image forming units 6 (6M, 6C, 6Y, 6K) of the image forming unit 2, the toner cartridge 41 of the developing device 12 of the image forming unit 6K at the left end is pulled out to the front. ing.

  In this way, the toner cartridge 41 of any of the developing devices 12 of the four image forming units 6 can be easily pulled out from the front side of the apparatus main body 1. Thereby, even when the toner in the toner cartridge 41 is used up, it can be easily replaced with a new toner cartridge 41 filled with toner.

  FIG. 6 is a block diagram showing a circuit configuration of a control system related to the toner remaining amount display of the printer 1. As shown in the figure, the control system 62 includes a controller 63 and an engine control unit 64 connected to the controller 63. A host computer PC 65 and a display 66 are connected to the controller 63.

  The display 66 is composed of a liquid crystal display device (not shown in FIG. 5) disposed in the operation panel 59 shown in FIG. 5, and an image display signal is input from the engine control unit 64 via the controller 63. The

Data (printing information) is input from the host computer PC 65 to the engine control unit 64 via the controller 63.
The engine control unit 64 includes a central processing unit (CPU) 67 and a memory 68 connected to the CPU 67. The CPU 67 is connected with a scanner 69 as an external device and a toner-free detection device 71.

  The scanner 69 may be a scanner disposed as an accessory in close contact with the upper surface of the image forming apparatus 1 shown in FIG. 1 where the paper discharge tray 29 is formed, or connected to a connector of the image forming apparatus 1 by a connection cord. It may be an external scanner.

  The toner absence detection device 71 notifies the engine control unit 64 of a toner absence detection signal output from the toner presence sensor 72. The toner presence / absence sensor 72 is disposed in the developing unit 43 of the image forming unit 6 and is configured by, for example, a piezo element pressure sensor.

  The memory 68 is composed of an EEPROM (electrically erasable programable ROM), and in addition to the processing program executed by the CPU 67, the toner consumption amount per dot of printing as an initial value set as a typical toner consumption amount is used for image formation. It is stored in advance as information on the main body of the apparatus 1.

The toner consumption per dot printed as this initial value is 0.00000000192 g.
Further, the memory 68 stores at least the number of image forming dots at the time of image formation, and when the absence of toner is detected by the toner presence / absence sensor 72, the toner set in advance in the toner cartridge in which no toner is present. The amount of toner used per dot calculated from the amount and the number of image forming dots is stored.

  In this example, the toner cartridge 41 that is removably attached to the image forming unit 6 of the image forming apparatus 1 is a starter as a service kit that is provided to the user in combination with the developing drum unit 58 during assembly at the factory. There are two types of cartridges: an optional cartridge for replacement that is purchased as a commercial product after the toner of the starter cartridge is used up and used sequentially.

These two types of toner cartridges have the same cartridge structure and the same toner material, but only the amount of toner filling is different.
That is, the toner filled inside is 75 g for the starter cartridge and 150 g for the option cartridge. This toner filling amount is, for example, barcode-labeled as ID information of the toner cartridge and attached to the toner cartridge.

  The ID information indicating the toner filling amount is read by the reading device on the main body side of the image forming apparatus when the toner cartridge is combined with the developing drum unit 58 and attached to the image forming apparatus 1, and is stored in the memory 68 of the engine control unit 64. To be recorded.

FIG. 7 is a flowchart for explaining the operation of the remaining toner amount display process for notifying the remaining toner amount as accurately as possible performed by the engine control unit 64.
In this process, an example in which printing is performed on an A4 size sheet at a printing rate of 5% will be described. In this processing, a print dot counter built in the engine control unit 64 is used, and the actual print dot number of the toner cartridge 41 mounted on the developing drum unit 58 of each image forming unit 6 is accumulated.

  First, the starter cartridge is set in the developing drum unit 58. Thereby, the image forming unit 6 including the starter cartridge and the developing drum unit 58 is completed (S1). This process is an assembly process in a factory.

  Hereinafter, on the user side, the image forming unit 6 is set in the main body of the image forming apparatus 1. Accordingly, the engine control unit 64 of the image forming apparatus 1 detects that the image forming unit 6 is new (S2).

Then, the ID information of the starter cartridge is read by a reading device (not shown) and transferred to the engine control unit 64 of the image forming apparatus 1 (S3).
Based on this ID information, together with the toner consumption per print dot set as the default value “print 1 dot = 0.0000000172 g”, the toner filling amount “new toner cartridge (starter cartridge) that has just been inputted” 75g "(however, the effective filling amount is 65g) is recorded in the memory 68 (S4).

  The reason why the effective filling amount is 65 g is that 10 g of toner remains in the developing drum unit 58 in a state where the toner presence sensor 72 detects the absence of toner.

Subsequently, a printing process is executed, and transfer (notification) of the number of printing dots accompanying the execution of the printing process to the engine control unit 64 is started (S5).
During the printing process, the engine control unit 64 sets the toner consumption amounts “printing 1 dot = 0.0000000172 g” and “printing dot number” per printing dot set as the default values. The product is calculated, and a value obtained by subtracting this product from the effective toner filling amount 65 g of the starter cartridge is displayed and notified on the display screen of the display 66 of the operation panel 59 as necessary as the remaining amount of toner.

Then, the engine control unit 64 continues the printing process until the toner runs out, and stops the printing process when “no toner” is notified from the toner absence detection device 71 (S6).
Next, the engine control unit 64 calculates the actual consumption amount of 1 dot of toner (S7).

  That is, when printing is performed using the first starter cartridge, the engine control unit 64 sets the default value “printing 1 dot = 0.0000000172 g” as the toner consumption amount per printing dot until there is no toner. Used to calculate the estimated toner consumption.

  However, when the starter cartridge runs out of toner, it is known in advance that the amount of toner consumed until the starter cartridge runs out of toner is 65 g, and when the toner runs out, the total number of printed dots is found. Therefore, by calculating “65 g ÷ total printing dots”, the actual toner consumption per printing dot in the main body of the image forming apparatus 1 can be calculated.

Then, the actual toner consumption amount “= 65 g ÷ total printing dots” per dot of printing is recorded in the memory 68 (S8).
Here, since the starter cartridge has run out of toner, the user purchases a replacement option cartridge that is commercially available, and the option cartridge and the starter cartridge are replaced.

  The ID information (toner filling amount 150 g) of the option cartridge newly installed in the developing drum unit 58 is read. The ID information and the actual toner consumption per dot printed and recorded in the memory 68 are read by the engine control unit 64 (S9).

Subsequently, the print dot counter is cleared to “0” and initialized, and preparation for accumulation of the print dot number of the newly installed option cartridge is completed (S10).
Thereafter, in the memory 68, the toner consumption amount per dot of printing is not the default value of “1 dot of printing = 0.0000000172 g”, but “per dot of printing” calculated by exhaustion of the starter cartridge. The actual toner consumption "(actual toner 1-dot consumption) is rewritten. Further, “150 g” is recorded as the toner filling amount of the toner cartridge 41 (S11).

Based on these new numerical values, the engine control unit 64 calculates a remaining toner rate (S12).
The calculated toner remaining rate is expressed as “new toner consumption (g) = actual toner 1-dot consumption” and the expression “new remaining rate (%) = (150 g−“ new toner consumption ”) ÷ 150 g. It is obtained by calculating “× 100” and recorded in the memory 68 (S13).

This new remaining rate is displayed and notified by the engine control unit 64 on the display screen of the display 66 of the operation panel 59 as required (S14).
Here, the follow-up survey based on the above processing method will be described.

  First, the image forming unit 6 on which a new starter cartridge is mounted is mounted on the image forming apparatus 1 and printing of 100 sheets is performed. Printing is executed with a paper size of A4 size and a printing rate of 5%.

In printing with a printing rate of 5% on A4 size paper, writing of 1742860 dots is performed per sheet.
The number of dots is easily determined from the print information sent to the engine control unit 64 via the controller 63.

With 100 sheets of A4 paper, according to calculations, 0.00000000172 g × 1742860 dots × 100 sheets = 3 g of toner is consumed.
The starter cartridge has 75 g of toner, and when it is detected that there is no toner, 10 g of the remaining amount is generated, so that 65 g can actually be used.

  Therefore, in this case, the remaining rate of “(65−3) ÷ 65 × 100 = 95” (%) can be found by calculation. This remaining rate can be displayed on the display screen of the display 66 of the operation panel 59.

When the experiment was continued and printing was continued at a printing rate of 5%, no toner was detected and printing was prohibited on 2000 sheets.
In the calculation, 0.0000000172 g × 1742860 dots × 2000 sheets = 60 g of toner is consumed, and there should be a toner remaining amount of “(65−60) ÷ 65 × 100 = 8%”. Actually, the remaining amount was 0%.

This error is because the preset toner consumption per printed dot is different from the actual one.
The actual toner consumption is an amount that cannot be managed within a certain range due to various variations such as drum sensitivity, individual differences in developing rolls, and average toner particle diameter. The occurrence of discrepancies is reasonable in some respects.

  Here, if the actual toner 1-dot consumption is calculated based on the toner consumption of the starter cartridge, “65 g ÷ (1742860 dots × 2000 sheets) = 0.0000000186 g” is obtained. This is the actual toner consumption per dot printed.

  Therefore, when the absence of toner is detected and the printing process is stopped, the default value of 0.00000000172 g / dot previously recorded in the memory 68 is rewritten to 0.00000000186 g / dot.

  Next, when an image forming unit in which an optional cartridge is replaced and mounted instead of the starter cartridge is mounted in the image forming apparatus 1, the ID information of the optional cartridge is read, the remaining amount of toner is 100% (150 g), and the number of print dots is 0. The record in the memory 68 has been rewritten to the numerical value.

  At this time, the remaining amount of toner in the toner cartridge returned to 100%. Thus, after the replacement with the option cartridge, printing of 2300 sheets with a printing rate of 5% showed a remaining amount of 50%.

  After that, printing at a printing rate of 5% was continued. When 2305 sheets were printed and the remaining amount was displayed at 1%, the no-toner display was turned on, the printing operation was prohibited, and the printing process was stopped.

That is, the remaining amount display with higher accuracy is performed than the remaining amount display using the toner consumption amount information per dot of the default value printing.
As described above, in the toner remaining amount display method of the present invention, first, the toner remaining amount of the first new toner cartridge is calculated based on the preset toner usage amount per dot of the new toner cartridge, and is notified to the outside. To do.

  However, when it is detected that the first new toner cartridge is out of toner and this first new toner cartridge is replaced without toner, the number of print dots from the start of use of the first new toner cartridge to the replacement without toner is accumulated. The actual amount of toner consumed per dot is calculated by dividing the amount of toner consumed by the first new toner cartridge by the total number of printed dots.

  Then, when using a new toner cartridge for the second and subsequent times, the actual toner consumption and the actual print dots per dot calculated from the previous toner cartridge are calculated from the toner filling amount of the second and subsequent new toner cartridges. The remaining amount of toner obtained by subtracting the product of the number is calculated and displayed.

  Accordingly, the remaining amount display with improved accuracy can be performed in the second and subsequent use of a new toner cartridge.

FIG. 3 is a cross-sectional view illustrating an internal configuration of a printer including a developing device that uses a non-magnetic one-component toner according to the first exemplary embodiment. FIG. 2 is a cross-sectional view illustrating an image forming unit of the printer according to the first embodiment. FIG. 3 is a perspective view illustrating a state in which the toner cartridge and the developing drum unit of the image forming unit of the printer in Embodiment 1 are united. FIG. 2 is a diagram illustrating a configuration in which a toner cartridge can be inserted into and removed from a developing drum unit in a direction orthogonal to a paper transport direction of the apparatus main body in the image forming unit of the printer according to the first embodiment. FIG. 3 is a diagram for explaining attachment / detachment of a toner cartridge of an image forming unit of a printer according to Embodiment 1. FIG. 3 is a block diagram illustrating a circuit configuration of a control system related to a toner remaining amount display of the printer according to the first exemplary embodiment. 6 is a flowchart illustrating an operation of a remaining toner amount display process performed by an engine control unit of the printer according to the first embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printer 2 Image formation part 3 Intermediate transfer belt unit 4 Paper feed part 5 Duplex printing conveyance unit 6 (6M, 6C, 6Y, 6K) Image formation unit 7 (7m, 7c, 7y, 7k) Photosensitive drum 8 Cleaner 9 Charging roller 11 Optical writing head 12 Developer 13 Developing roller 14 Transfer belt 15 Drive roller 16 Driven roller 17 Belt position control mechanism 18 Primary transfer roller 19 Waste toner collection container 21 Paper feed cassette 22 Paper take-out roller 23 Feed roller 24 Roller 25 Standby transport roller pair 26 Secondary transfer roller 27 Belt type heat fixing device 28 Unloading roller pair 29 Paper discharge tray 31 Paper discharge roller pair 32a Start return path 32b Intermediate return path 32c End return path 33a, 33b, 33c, 33d Return Roller pair 35 Cleaning unit 36 Capture roller 7 the pressing roller 38 the toner hopper A
39 Toner Hopper B
41 toner cartridge 42 exterior frame 42a upper left exterior frame 43 developing unit 44 supply roller 45 doctor blade 46 stirring member 47, 48, 49 high voltage power supply 51 cleaning blade 52, 52b, 52c conveying screw 53 waste toner containing pipe 54 waste toner collecting bag 55 Agitator 56 Seal member 57 Drum unit portion 58 Developing drum unit 59 Operation panel 61 Protective cover 62 Control system 63 I / F (interface) controller 64 Engine control portion 65 Host computer PC
66 Display 67 CPU
68 Memory 69 Scanner 71 No-toner detection device 72 Toner presence sensor

Claims (2)

In an image forming unit that includes at least a developing unit and a developer remaining amount detecting unit, has a detachable toner cartridge, and is detachable from an image forming apparatus main body.
Calculate the remaining toner amount of the first new toner cartridge based on the preset toner usage per dot of the first new toner cartridge, and notify the outside.
When the absence of toner in the first new toner cartridge is detected by the developer remaining amount detection means, and the first new toner cartridge is replaced without toner,
By accumulating the number of print dots from the start of use of the first new toner cartridge to the replacement without toner, and dividing the amount of toner consumed by the first new toner cartridge by the accumulated number of print dots. Calculate the actual toner consumption per dot,
When using a new toner cartridge for the second and subsequent times, the product of the toner consumption per dot calculated from the previous toner cartridge and the actual number of printed dots from the toner filling amount for the second and subsequent new toner cartridges. Calculate the remaining amount of toner by subtracting
Informing the outside of the toner remaining amount,
A method for displaying the remaining amount of toner.   2. The toner remaining amount display method according to claim 1, wherein the first new toner cartridge is a toner cartridge as a service kit with a small toner capacity.