JP2005221748A - Image forming apparatus and method for managing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner-counting technology enabling proper accounting, in response to the toner usage by a user. <P>SOLUTION: A gradation value, indicating gradation data generated on the basis of an image signal input from an outside device, is integrated by a dot counter 210. A toner counter 220 multiplies coefficient K1 with the counted value DC to calculate the toner amount used for forming a toner image to add offset values Coff1 and Coff2 corresponding to the toner amount consumed by the other reason so as to find the consumption TC1 of the toner of the apparatus as a whole. CPU 101 manages the residual amount of the toner on the basis of the value TC1, and makes the amount TC2 of the toner supplied to the user as the toner image from among the whole toner consumption TC1 an accounting target. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus that calculates toner consumption accompanying operation of an apparatus and manages the apparatus based on the calculation result, and a management method thereof.

  In an image forming apparatus that forms a toner image using toner stored in the apparatus, such as a printer, a copying machine, and a facsimile apparatus, the user is charged with the usage amount of the apparatus in order to have the user bear the running cost of the apparatus. There are some that charge accordingly. For example, in the image printing apparatus described in Patent Document 1, dot count charging that charges according to an estimated value of the amount of toner used for printing processing, and page count charging that charges according to the number of printed sheets, Any one of the above is selectively applied according to the use state of the user.

  Here, in order to properly charge based on the amount of toner used, it is necessary to accurately determine the amount of toner consumed by printing. Various techniques for calculating toner consumption (hereinafter referred to as “toner counting technique”) have been proposed (see, for example, Patent Document 2).

Japanese Patent Laying-Open No. 2003-296085 (FIG. 5) JP 2002-162800 A (paragraph 0010)

  However, it is not preferable to use the count value by the conventional toner count technique for billing. The reason is as follows. In order to charge properly based on the amount of toner used, it is necessary to obtain only the amount of toner constituting the image that reaches the user's hand out of the toner consumed as the apparatus operates. On the other hand, the conventional toner counting technique is mainly intended to prevent deterioration of image quality due to running out of toner. For this purpose, the count value must be larger than the amount of toner actually used as an image, and if this value is used for charging, it is more for the user than the actual amount of toner used. This causes a disadvantage that the user is charged based on the count value.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a toner counting technique for enabling appropriate charging according to the amount of toner used by a user.

  According to the present invention, in an image forming apparatus that forms a toner image on a recording material according to a user's request using toner stored therein, in order to achieve the above object, the operation of the toner out of the toner is performed. Out of the toner consumption amount calculated by the toner consumption amount calculation means, and the amount of toner adhering to the recording material as the toner image is determined for the user. And a management unit that sets the amount of toner to be charged.

  According to another aspect of the present invention, there is provided an image forming apparatus managing method for forming a toner image on a recording material according to a user's request using toner stored in the toner. A toner consumption amount consumed as the apparatus is operated is calculated, and a toner amount that adheres to the recording material as the toner image in the calculation result is set as a chargeable toner amount for a user. Yes.

  In the invention configured as described above, only the amount of toner constituting the toner image formed on the recording material among the calculation results of the toner consumption amount of the entire apparatus is charged. It is possible to charge appropriately according to the amount of toner used. Further, if the remaining amount of toner stored in the apparatus is managed based on the calculation result of the toner consumption calculated as described above, the image quality may be deteriorated due to running out of toner, and image formation can be performed. It is possible to prevent the inconvenience of being lost.

  Here, the amount of toner used to form the toner image can be calculated based on, for example, an integrated value obtained by integrating dot information values relating to the toner dots constituting the toner image. More specifically, the amount of toner used to form the toner image can be calculated by multiplying the integrated value by a predetermined coefficient. In this way, the toner consumption can be calculated only by calculation based on information used inside the apparatus, so that the configuration of the apparatus can be reduced by omitting a sensor for detecting the remaining amount of toner in the apparatus. Can be simple.

  Further, the toner consumption amount of the entire apparatus may be calculated by adding a first offset value corresponding to the use status of the apparatus to the product of the integrated value and the coefficient. In other words, the amount of toner consumed for reasons other than toner image formation is estimated according to the usage status of the apparatus, and the amount is summed with the amount of toner used for toner image formation, so that the toner consumption can be more accurately determined. It is possible to calculate.

  However, it is harsh to let the user bear the cost of consumed toner regardless of the user's intention. Therefore, a value obtained by subtracting a second offset value corresponding to the toner amount consumed without adhering to the recording material from the toner consumption amount calculated by the toner consumption amount calculation means is the chargeable toner amount. Then, it becomes possible to perform more appropriate billing.

  Further, in order to prevent problems such as unexpected toner exhaustion, it is necessary that the calculated value of the toner consumption amount of the entire apparatus does not fall below the actual consumption amount. For this purpose, the toner consumption calculation result may be set to a value larger than the actual consumption. On the other hand, if the user is charged based on the toner consumption thus obtained, the burden on the user is large. Therefore, if the toner consumption amount calculated by the toner consumption amount calculation means is multiplied by a reduction coefficient smaller than 1, the chargeable toner amount does not cause such a disadvantage to the user.

  FIG. 1 is a diagram showing the configuration of an embodiment of an image forming apparatus according to the present invention. FIG. 2 is a block diagram showing an electrical configuration of the image forming apparatus of FIG. This apparatus 1 forms a full color image by superposing four color toners (developers) of yellow (Y), cyan (C), magenta (M), and black (K), or black (K) toner. This is an image forming apparatus that forms a monochrome image using only the image forming apparatus. In the image forming apparatus 1, when an image signal is given to the main controller 11 from an external device such as a host computer, the engine controller 10 controls each part of the engine unit EG in accordance with a command from the main controller 11 to obtain a predetermined image. The forming operation is executed, and an image corresponding to the image signal is formed on the sheet S.

  In the engine unit EG, the photosensitive member 22 is provided to be rotatable in the arrow direction D1 in FIG. A charging unit 23, a rotary developing unit 4 and a cleaning unit 25 are arranged around the photosensitive member 22 along the rotation direction D1. The charging unit 23 is applied with a predetermined charging bias, and uniformly charges the outer peripheral surface of the photoconductor 22 to a predetermined surface potential. The cleaning unit 25 removes the toner remaining on the surface of the photosensitive member 22 after the primary transfer, and collects it in a waste toner tank provided inside. The photosensitive member 22, the charging unit 23, and the cleaning unit 25 integrally constitute the photosensitive member cartridge 2, and this photosensitive member cartridge 2 is detachably attached to the main body of the apparatus 1 as a whole.

  Then, the light beam L is irradiated from the exposure unit 6 toward the outer peripheral surface of the photosensitive member 22 charged by the charging unit 23. The exposure unit 6 exposes the light beam L onto the photosensitive member 22 in accordance with an image signal given from an external device, and forms an electrostatic latent image corresponding to the image signal.

  The electrostatic latent image thus formed is developed with toner by the developing unit 4. That is, in this embodiment, the developing unit 4 is configured as a support frame 40 that is rotatably provided about a rotation axis center orthogonal to the paper surface of FIG. A yellow developing device 4Y, a cyan developing device 4C, a magenta developing device 4M, and a black developing device 4K are provided. The developing unit 4 is controlled by the engine controller 10. Based on the control command from the engine controller 10, the developing unit 4 is driven to rotate, and the developing units 4Y, 4C, 4M, and 4K selectively face the photoconductor 22 with a predetermined gap therebetween. When positioned at a predetermined development position, the toner is applied to the surface of the photosensitive member 22 from a metal developing roller 44 that is provided in the developing unit and carries a charged toner of a selected color and is applied with a predetermined development bias. Is granted. As a result, the electrostatic latent image on the photosensitive member 22 is visualized with the selected toner color. In this embodiment, it is assumed that the toner is negatively charged.

  Each of the developing devices 4Y, 4C, 4M, and 4K is provided with non-volatile memories 91 to 94 for storing information related to the developing devices. One of the connectors 49Y, 49C, 49M, and 49K provided in each developing device is selected as necessary, and the connector 109 provided on the main body side is connected to each other, and the CPU 101 of the engine controller 10 and the memory Communication is performed with 91-94. In this way, information about each developing device is transmitted to the CPU 101, and information in each of the memories 91 to 94 is updated and stored.

  The toner image developed by the developing unit 4 as described above is primarily transferred onto the intermediate transfer belt 71 of the transfer unit 7 in the primary transfer region TR1. The transfer unit 7 includes an intermediate transfer belt 71 stretched between a plurality of rollers 72 to 75, and a drive unit (not shown) that rotates the intermediate transfer belt 71 in a predetermined rotation direction D2 by rotationally driving the roller 73. It has. When a color image is transferred to the sheet S, each color toner image formed on the photosensitive member 22 is superimposed on the intermediate transfer belt 71 to form a color image and taken out from the cassette 8 one by one. The color image is secondarily transferred onto the sheet S conveyed to the secondary transfer region TR2 along the conveyance path F.

  At this time, in order to correctly transfer the image on the intermediate transfer belt 71 to a predetermined position on the sheet S, the timing of feeding the sheet S to the secondary transfer region TR2 is managed. Specifically, a gate roller 81 is provided on the transport path F on the front side of the secondary transfer region TR2, and the gate roller 81 rotates in accordance with the timing of the circumferential movement of the intermediate transfer belt 71. S is sent to the secondary transfer region TR2 at a predetermined timing.

  Further, the sheet S on which the color image is thus formed is conveyed to the discharge tray portion 89 provided on the upper surface portion of the apparatus main body via the fixing unit 9, the pre-discharge roller 82 and the discharge roller 83. Further, when images are formed on both sides of the sheet S, when the rear end portion of the sheet S on which the image is formed on one side as described above is conveyed to the reversal position PR behind the pre-discharge roller 82. The rotation direction of the discharge roller 83 is reversed, whereby the sheet S is conveyed in the direction of the arrow D3 along the reverse conveyance path FR. Then, the sheet is again placed on the transport path F before the gate roller 81. At this time, the surface of the sheet S to which the image is transferred by contacting the intermediate transfer belt 71 in the secondary transfer region TR2 is first transferred. It is the opposite surface. In this way, images can be formed on both sides of the sheet S.

  Further, a density sensor 60 and a cleaner 76 are provided in the vicinity of the roller 75. The density sensor 60 optically detects the amount of toner constituting the toner image formed on the intermediate transfer belt 71 as necessary. That is, the density sensor 60 irradiates light toward the toner image, receives reflected light from the toner image, and outputs a signal corresponding to the reflected light amount. The cleaner 76 is configured to be able to come into contact with and separate from the intermediate transfer belt 71, and scrapes the residual toner on the belt 71 by contacting the intermediate transfer belt 71 as necessary.

  In addition, the apparatus 1 includes a display unit 12 controlled by the CPU 111 of the main controller 11 as shown in FIG. The display unit 12 is constituted by, for example, a liquid crystal display, and in accordance with a control command from the CPU 111, the operation guidance to the user, the progress of the image forming operation, the occurrence of an abnormality in the apparatus, the replacement timing of any unit, etc. A predetermined message for notification is displayed.

  In FIG. 2, reference numeral 113 denotes an image memory provided in the main controller 11 for storing an image given from an external device such as a host computer via the interface 112. Reference numeral 106 is a ROM for storing a calculation program executed by the CPU 101, control data for controlling the engine unit EG, and the like. Reference numeral 107 is a RAM for temporarily storing calculation results in the CPU 101 and other data. is there.

  FIG. 3 is a diagram showing signal processing blocks in this apparatus. In this image forming apparatus, when an image signal is input from an external device such as the host computer 100, the main controller 11 performs predetermined signal processing on the image signal. The main controller 11 includes functional blocks such as a color conversion unit 114, a gradation correction unit 115, a halftoning unit 116, a pulse modulation unit 117, a gradation correction table 118, and a correction table calculation unit 119.

  In addition to the CPU 101, ROM 106, and RAM 107 shown in FIG. 2, the engine controller 10 includes a laser driver 121 for driving a laser light source provided in the exposure unit 6 and a detection result of the engine unit EG based on the detection result of the density sensor 60. A gradation characteristic detecting unit 123 that detects a gradation characteristic indicating a gamma characteristic is provided.

  In the main controller 11 and the engine controller 10, these functional blocks may be configured by hardware, or may be realized by software executed by the CPUs 111 and 101.

  In the main controller 11 to which the image signal is given from the host computer 100, the color conversion unit 114 converts the RGB gradation data indicating the gradation level of the RGB component of each pixel in the image corresponding to the image signal into the corresponding CMYK. Conversion into CMYK gradation data indicating the gradation level of the component. In this color conversion unit 114, the input RGB gradation data is, for example, 8 bits per pixel per color component (that is, representing 256 gradations), and the output CMYK gradation data is similarly 8 bits per pixel per color component ( That is, it represents 256 gradations). The CMYK gradation data output from the color conversion unit 114 is input to the gradation correction unit 115.

  The gradation correction unit 115 performs gradation correction on the CMYK gradation data of each pixel input from the color conversion unit 114. That is, the gradation correction unit 115 refers to the gradation correction table 118 registered in advance in the nonvolatile memory, and in accordance with the gradation correction table 118, the input CMYK gradation data of each pixel from the color conversion unit 114. Is converted into corrected CMYK gradation data indicating the corrected gradation level. The purpose of the gradation correction is to compensate for the change in the gamma characteristic of the engine unit EG configured as described above, and to keep the overall gamma characteristic of the image forming apparatus always ideal.

  The corrected CMYK gradation data corrected in this way is input to the halftoning unit 116. The halftoning unit 116 performs halftoning processing such as an error diffusion method, a dither method, and a screen method, and inputs halftone CMYK gradation data of 8 bits per pixel to the pulse modulation unit 117. The content of the halftoning process varies depending on the type of image to be formed. That is, based on a determination criterion such as whether the image is a monochrome image, a color image, a line drawing, or a graphic image, the optimum processing content for the image is selected and executed.

  The CMYK gradation data after halftoning input to the pulse modulation unit 117 is a multilevel signal indicating the size and arrangement of toner dots of CMYK colors to be attached to each pixel. The unit 117 uses the halftone CMYK gradation data to create a video signal for pulse width modulating the exposure laser pulses of the CMYK color images of the engine unit EG, and the engine controller via a video interface (not shown) 10 is output. Upon receiving this video signal, the laser driver 121 controls ON / OFF of the semiconductor laser of the exposure unit 6 to form an electrostatic latent image of each color component on the photosensitive member 22. In this way, image formation corresponding to the image signal is performed.

  Further, in this type of image forming apparatus, the gamma characteristic of the apparatus changes for each apparatus and also in the same apparatus depending on the use situation. Therefore, in order to eliminate the influence of the variation in gamma characteristics on the image quality, a gradation control process is executed to update the contents of the gradation correction table 118 based on the actual measurement result of the image density at a predetermined timing. To do.

  In this gradation control process, for each toner color, a gradation patch gradation image prepared in advance for measuring the gamma characteristic is formed on the intermediate transfer belt 71 by the engine unit EG, and each gradation patch is obtained. The density sensor 60 reads the image density of the image, and the gradation characteristic detecting unit 123 based on the signal from the density sensor 60 determines the gradation characteristic (corresponding to the gradation level of each gradation patch image and the detected image density). The gamma characteristics of the engine unit EG are created and output to the correction table calculation unit 119 of the main controller 11. Then, the correction table calculation unit 119 compensates the actually measured gradation characteristic of the engine unit EG based on the gradation characteristic given from the gradation characteristic detection unit 123 to obtain an ideal gradation characteristic. The tone correction table data is calculated, and the content of the tone correction table 118 is updated to the calculation result. Thus, the gradation correction table 118 is changed and set. By doing so, this image forming apparatus can form an image with stable quality regardless of variations in gamma characteristics of the apparatus and changes over time.

  Next, toner consumption calculation processing in this image forming apparatus will be described. In the actual apparatus, the toner consumption amount is calculated individually for each toner color. However, since the processing content is the same for any toner color, the toner consumption amount for one toner color is obtained below. Specific processing contents of the processing will be described.

  As shown in FIG. 3, the main controller 11 of this embodiment is provided with a dot counter 210 that integrates gradation data for each color of CMYK given from the halftoning unit 116 to the pulse modulation unit 117. On the other hand, the engine controller 10 is provided with a toner counter 220 that calculates the toner consumption amount of the apparatus based on the count value of the dot counter 210.

  The toner counter 220 calculates the toner consumption amount of the entire apparatus, that is, the amount by which the toner stored in each developing device decreases as the apparatus operates. Based on the toner consumption obtained by the toner counter 220, the CPU 101 knows the remaining amount of toner in each developing device, and when the remaining amount becomes a predetermined value or less, for example, prompts replacement of the developing device. A message is displayed on the display unit 12 to notify the user that the toner is low.

  Thus, if the user is informed in advance that the toner is low, the user can prepare a new developing device in preparation for running out of toner. For such applications, the calculated toner consumption is not allowed to be smaller than the actual consumption. When the toner consumption is estimated to be lower than the actual consumption, it is determined that there is actually a sufficient remaining amount of toner, and the image is formed. As a result, the quality of the formed image This is because it may cause a decrease. Further, if the user does not prepare a new developing device when the toner runs out, image formation cannot be performed until it is obtained. On the other hand, if the calculated toner consumption is greater than the actual consumption, it may be determined that the toner has run out even though the toner remains in the developing device. Don't be.

  As described above, the toner counter 220 for appropriately managing the remaining amount of toner in the developing unit is consumed not only by the toner used for forming the toner image but also by the developing unit as the apparatus is operated. It is required that the total amount of toner to be obtained is obtained, and further, the calculation result is required not to be less than the actual consumption amount.

  On the other hand, as another method of using the toner consumption calculation result by the toner counter 220, it may be used for calculating a charge amount when the apparatus administrator collects a charge according to the user's toner usage amount from the user. It is done. However, the user should be charged according to the amount of toner actually consumed by the user. The toner consumed regardless of the user's use, for example, the toner consumed internally for maintaining the performance of the apparatus In addition, it is harsh for the user to ask the user to pay for the toner that has spilled into the apparatus. Therefore, it is necessary to charge the user based not only on the toner consumption amount of the entire apparatus calculated by the toner counter 220 but only on the amount of toner in the user's hand as a toner image.

  Therefore, in this embodiment, the amount of toner consumption calculated by the toner counter 220 excluding the amount of toner consumed for purposes other than the formation of a toner image is set as a charging target for the user, and the charging target toner By allowing the user to pay a fee according to the amount, the user can be charged appropriately.

  FIG. 4 is a diagram showing the configuration of the toner counter. The dot counter 210 integrates gradation values of gradation data that are input as needed within the target period for calculating toner consumption. This integrated value is a value corresponding to the total extension of toner dots of the toner color formed within the period. The toner counter 220 estimates the amount of toner used to form a toner image from the accumulated value DC of the gradation data accumulated by the dot counter 210 and adds the amount of toner consumed for other purposes. Thus, the toner consumption amount of the apparatus is calculated.

  That is, the integrated value DC corresponding to the total extension of the toner dots corresponds to the toner adhesion rate (the density per unit length of the toner that moves from the developing roller 44 to the electrostatic latent image on the photosensitive member 22). By multiplying by the coefficient K1, the amount of toner used for toner image formation is calculated. Here, the toner adhesion rate per unit length of dots is not necessarily constant. That is, the toner adhesion rate varies depending on the size of the toner dots, and the toner adhesion rate may vary for dots of the same size. In the toner counter 220 for managing the remaining amount of toner in the developing unit, it is necessary to estimate the toner adhesion rate to be high in order to reliably prevent image defects due to running out of toner regardless of such variations. . Therefore, for example, if the coefficient K1 corresponding to the maximum variation in the assumed toner adhesion rate is set, it is possible to reliably prevent the calculated toner amount from becoming smaller than the actual consumption amount.

  Further, in this type of image forming apparatus, the toner in the developing device is consumed and reduced for various reasons besides being transferred to the sheet S as a toner image. For example, during the image forming operation, part of the toner carried on the surface of the developing roller 44 may scatter and adhere to the surface of the photosensitive member 22 to cause fogging or adhere to the inside of the apparatus. In addition, this apparatus executes an image quality control operation for maintaining image quality at a predetermined timing such as immediately after power-on or after returning from sleep, but consumes a certain amount of toner when forming a patch image for that purpose. . In addition, there is toner consumed inside the apparatus regardless of the user's intention, such as toner for forming a registration mark for reference when superimposing single color toner images for each toner color.

Even if the toner is consumed for any reason, it causes a reduction in the remaining amount of toner in the developing device. Therefore, in the toner counter 220 for managing the remaining amount of toner in the developing device, it is necessary to include the toner consumption for these reasons. Therefore, in this embodiment, the amount of toner consumed in addition to toner image formation is quantified according to the usage status of the apparatus, and these are added to the calculated values of the counter 220 as offset values Coff1 and Coff2 as necessary. As a result, the toner consumption can be obtained with high accuracy. The details of the offset values Coff1 and Coff2 and the reason why they are divided into two types will be described later. In this way, the toner consumption amount TC1 of the entire apparatus is obtained. That is, the toner consumption amount TC1 is expressed by the following formula:
TC1 = K1 · DC + Coff1 + Coff2 (Formula 1)
It is represented by

  Next, consider a case where the user is charged based on the toner consumption thus calculated. As described above, the user should be charged based on the amount of toner actually used by the user. Therefore, consider how much of the toner consumption amount TC1 calculated by the toner counter 220 should be used by the user.

  FIG. 5 is a diagram for explaining the breakdown of toner consumption. As described above, the toner consumption amount TC1 calculated by the toner counter 220 includes the toner used for forming the toner image, the toner consumed by the fog, and the execution of the image quality control operation (including the gradation control process). The toner consumed for forming the patch image and other toners are included. Of these, the toner used for forming the toner image based on the user's request should naturally be borne by the user. On the other hand, since the toner consumed by fogging is a part of the toner transferred onto the sheet S and reaching the user's hand, the cost of this toner may be borne by the user. On the other hand, since fog is irrelevant to the user's desire, it can be considered that the cost should not be passed on to the user. Here, the former concept is adopted.

  On the other hand, the toner used for image quality control operation and other purposes is consumed regardless of the user's intention, and should be excluded from the charge target. Therefore, in this embodiment, among the toner consumed by the entire apparatus, the toner used for forming the toner image and the toner consumed by the fog are charged for the user.

  Here, in the calculation process by the toner counter 220, in order to prevent image defects due to running out of toner, the toner counter 220 was used for forming a toner image regardless of variations in the toner adhesion rate from the developing roller 44 to the photosensitive member 22. The calculated value of the amount of toner was not reduced below the actual consumption. That is, the coefficient K1 in (Equation 1) is set on the assumption that the toner adhesion rate becomes the maximum in the range of the variation and the toner usage amount is the largest. However, the amount of toner actually consumed by the user is often considered to be less than the estimated amount of toner.

  The toner image visualized on the photosensitive member 22 is sequentially transferred to the intermediate transfer belt 71 and the sheet S as a recording material, but the toner constituting the toner image is not completely transferred. The transfer efficiency is 100% or less. For example, if the transfer efficiency in the primary transfer from the photosensitive member 22 to the intermediate transfer belt 71 and the secondary transfer from the intermediate transfer belt 71 to the sheet S are both 95%, the toner that actually adheres on the sheet S is reduced. The amount is limited to about 90% of the amount of toner constituting the toner image formed on the photosensitive member 22.

  Therefore, the actual chargeable toner amount is preferably set to a value slightly smaller than the amount estimated by the toner counter 220 as the toner amount used for toner image formation and fogging. Therefore, in this embodiment, a value obtained by multiplying a toner amount consumed for toner image formation and fogging estimated by the toner counter 220 by a predetermined reduction coefficient K2 smaller than 1 is charged to the user. The amount is TC2.

Specifically, such arithmetic processing is realized by configuring the toner counter 220 and the CPU 101 as shown in FIG. That is, the toner counter 220 estimates the amount of toner used for forming a toner image by multiplying the dot count value DC output from the dot counter 210 by a coefficient K1 corresponding to the toner adhesion rate. Then, among the toners consumed for other reasons, the offset value Coff1 corresponding to the amount that should be borne by the user and the offset value Coff2 corresponding to the amount that should not be borne by the user are added. Thus, the toner consumption amount TC1 of the entire apparatus is calculated and output to the CPU 101. Separately from this, the CPU 101 sets the value obtained by multiplying the value before adding the latter offset value Coff2 in the toner counter 220 by the coefficient K2 (0 <K2 <1) as the chargeable toner amount. That is,
TC2 = K2 · (K1 · DC + Coff1) (Formula 2)
Or
TC2 = K2 (TC1-Coff2) (Formula 3)
It is. Although (Expression 2) and (Expression 3) are expressed differently, the contents are the same.

  The coefficient K1 is a coefficient corresponding to the maximum value of the toner adhesion rate within the range of the variation, but the product of the coefficients K1 and K2 (K1 · K2) represents the average toner adhesion rate and the transfer efficiency. It takes into account the value. These coefficients can be obtained experimentally by forming various types of images in advance and measuring the toner consumption amount and the toner adhesion amount on the sheet S at that time.

  The CPU 101 performs life management of each developing device based on these values TC1 and TC2, and if necessary, for example, the amount of toner to be charged to the user according to the operation of the apparatus administrator or serviceman, Alternatively, the charge amount calculated according to the toner amount is notified.

  FIG. 6 is a diagram for explaining the breakdown of offset values. As described above, in this embodiment, since the cost of toner consumed by fogging is borne by the user, the corresponding toner amount is included in the offset value Coff1. In addition, the amount of toner consumed by fogging is substantially determined by the execution time (operation time) of the image forming operation during the period, so the toner amount corresponding to this is determined by the user using the apparatus. It shall be calculated according to the number of sheets.

  Further, since the image quality control operation is executed regardless of the user's intention, the toner amount consumed thereby is included in the offset value Coff2 so as not to be charged. The pattern of the patch image formed in the image quality control operation is known, and the amount of toner consumed in one image quality control operation can also be predicted. Therefore, a value corresponding to the number of executions of the image quality control operation in the period may be added to the offset value Coff2. For toner consumed for other reasons, the toner consumption is calculated in an appropriate unit according to the principle and the usage status of the apparatus, and added to the offset value Coff2. Of these, if it is considered appropriate to bear the cost, the offset value Coff1 may be included in the offset value Coff2.

  FIG. 7 is a diagram showing a difference between two types of remaining amount management toner amounts and chargeable toner amounts. The calculated value of the toner consumption amount TC1 obtained for managing the remaining amount of toner increases as the dot count value DC increases. In the developing device, the maximum toner amount Tmax that can be used is set in advance in consideration of the toner capacity and the minimum toner amount required in the developing device. When the toner consumption amount TC1 for managing the remaining amount of toner reaches the maximum value Tmax, the CPU 101 causes the display unit 12 to display a message prompting the user to replace the developing device. In this way, the user can know that the toner is low before the toner runs out and an image defect occurs.

  At this time, the toner consumption amount TC1 calculated by the toner counter 220 includes the amount of toner ΔT consumed inside the apparatus regardless of the user's intention. Therefore, by charging the user based on the value TC2 calculated by the CPU 101 as a value T2 obtained by subtracting the toner amount, it is possible to charge appropriately according to the actual toner usage amount of the user.

  Note that the cost of the sheet S in the user's hand should also be borne by the user. Therefore, the charge amount may be calculated from both the number of sheets S consumed by the user and the user's toner usage amount TC2 calculated by the toner counter 220.

  As described above, in this embodiment, the toner consumption amount of the entire apparatus is calculated by the toner counter 220 in order to manage the remaining amount of toner in the developing device. The toner counter 220 calculates the amount of toner used for forming the toner image by multiplying the integrated value DC of the gradation data by a coefficient K1 corresponding to the toner adhesion rate, and the amount of toner consumed for other reasons. The offset values Coff1 and Coff2 corresponding to are added to calculate the toner consumption amount TC1 of the entire apparatus. In such a calculation method, the toner consumption can be obtained by a simple calculation based on a signal given from an external device or generated inside the device or a preset numerical value. In addition, by managing the remaining amount of toner in each developing device based on the calculation result thus obtained, inconveniences such as an image defect due to unexpected toner exhaustion are eliminated.

  In addition, the user is charged according to the amount of toner consumed. In view of the fact that the toner consumed for a reason not directly related to the user is included in the calculation result of the toner counter 220, Only the amount of toner used by the user is charged. Specifically, the amount of toner consumed inside the apparatus is excluded from the calculation result of the toner counter 220, and the toner adhesion rate is set to be high in order to prevent image defects due to running out of toner. This is corrected by multiplying by a smaller coefficient K2, and the amount of toner used by the user is calculated based on the average toner adhesion rate. By doing so, the user is charged based on a value closer to the actual toner usage by the user. As a result, in this embodiment, the user is charged appropriately according to the toner usage.

  As described above, in this embodiment, the toner counter 220 functions as the “toner consumption calculation means” of the present invention. Further, the CPU 101 that manages the remaining amount of toner and the amount of toner used by the user based on the calculation result functions as the “management unit” of the present invention. The total of the offset values Coff1 and Coff2 used in the toner counter 220 corresponds to the “first offset value” of the present invention, and the offset value Coff2 subtracted from the charge object is the “second offset” Corresponds to “offset value of”. Further, in this embodiment, the sheet S corresponds to the “recording material” of the present invention.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in the above embodiment, the toner consumption is calculated using the gradation data given from the halftoning unit 116 of the main controller 11 to the pulse modulation unit 117, but in addition to such gradation data, Any signal including information indicating the size of a dot to be formed can be used. In addition to such numerically expressed signals, for example, the width of a pulse output from the pulse modulation unit 117 and the continuous irradiation time of the exposure beam L are measured, and the toner consumption can be obtained using the measured values. It is possible to determine the quantity.

  In addition to the method of counting the image signal or a signal generated based on the image signal as in the above-described embodiment, the toner consumption amount of the entire apparatus is calculated using, for example, a sensor for measuring the toner amount in each developing device. You may take the method of calculating | requiring by providing.

  The toner counter 220 may be realized by any of a hardware configuration using, for example, a gate array or a discrete element, a software configuration executed by the CPU 101 or a dedicated processor, or a configuration in which these are mixed. Good. Further, the dot counter 210 may be provided in the engine controller 10 or the toner counter 220 may be provided in the main controller 10.

  The image forming apparatus according to the above-described embodiment is a so-called “non-contact developing type” image forming apparatus in which the photosensitive member 22 and the developing roller 44 are disposed to face each other with a gap therebetween. However, the present invention can also be applied to a “contact development type” apparatus in which the photosensitive member 22 and the developing roller 44 are disposed in contact with each other.

  Further, the present invention is not limited to the configuration of the above-described embodiment. For example, an apparatus that includes only a developing device corresponding to black toner and forms a monochrome image, and an apparatus that includes a transfer medium (transfer drum, transfer sheet, etc.) other than the intermediate transfer belt. In addition, the present invention can be applied to other image forming apparatuses such as copying machines and facsimile machines.

1 is a diagram illustrating an embodiment of an image forming apparatus according to the present invention. FIG. 2 is a block diagram illustrating an electrical configuration of the image forming apparatus in FIG. 1. It is a figure which shows the signal processing block in this apparatus. It is a figure which shows the structure of a toner counter. It is a figure which shows the breakdown of a toner consumption. It is a figure explaining the breakdown of an offset value. FIG. 7 is a diagram illustrating a difference between a remaining amount management toner amount and a charge target toner amount.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Engine controller, 11 ... Main controller, 101 ... CPU (management means), 210 ... Dot counter, 220 ... Toner counter (toner consumption calculation means), EG ... Engine part, Coff1, Coff2 ... Offset value, DC ... Dot Count value, K1, K2 ... coefficient

Claims (10)

In an image forming apparatus that forms a toner image on a recording material according to a user's request using toner stored therein,
A toner consumption amount calculating means for calculating a toner consumption amount of the toner that is consumed as the apparatus is operated;
The image processing apparatus includes: a managing unit that sets a toner amount that adheres to the recording material as the toner image out of the toner consumption amount calculated by the toner consumption amount calculating unit as a chargeable toner amount for a user. Forming equipment.   The image forming apparatus according to claim 1, wherein the management unit manages a remaining amount of toner stored in the apparatus based on a calculation result of the toner consumption.   3. The toner consumption calculating unit calculates an amount of toner used to form the toner image based on an integrated value obtained by integrating dot information values relating to toner dots constituting the toner image. The image forming apparatus described in 1.   The image forming apparatus according to claim 3, wherein the toner consumption amount calculating unit calculates an amount of toner used to form the toner image by multiplying the integrated value by a predetermined coefficient.   5. The toner consumption amount calculating unit calculates a toner consumption amount of the entire apparatus by adding a first offset value corresponding to a use state of the apparatus to a product of the integrated value and the coefficient. Image forming apparatus.   The management means subtracts a value obtained by subtracting a second offset value corresponding to the amount of toner consumed without adhering to the recording material from the toner consumption calculated by the toner consumption calculation means. 6. The image forming apparatus according to claim 1, wherein a target toner amount is set.   7. The image formation according to claim 1, wherein the management unit sets a value obtained by multiplying the toner consumption calculated by the toner consumption calculation unit by a reduction coefficient smaller than 1 as the chargeable toner amount. apparatus. In a management method of an image forming apparatus that forms a toner image on a recording material according to a user's request using toner stored therein,
A toner consumption amount that is consumed with the operation of the apparatus is calculated among the toners, and a toner amount that adheres to the recording material as the toner image in the calculation result is set as a chargeable toner amount for the user. An image forming apparatus management method.   The image forming apparatus management method according to claim 8, wherein the remaining amount of toner stored in the apparatus is managed based on a calculation result of the toner consumption.   10. The method of managing an image forming apparatus according to claim 8, wherein the user is charged for an amount corresponding to the charge target toner amount.

Images