JP2014041204A - Image forming device and image forming system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly decide the amount of toner to be supplied to a cleaning device.SOLUTION: An image forming device sets a toner supply amount for deciding a discharge amount of toner to be supplied to a cleaning device with changes (step S1), measures driving torque of a photoreceptor drum 1 at every normal imaging (step S3), supplies the set amount of toner to the cleaning device every time the normal imaging is completed (step S4), and decides an appropriate amount of toner to be discharged, on the basis of the total amount of toner supplied to the cleaning device and the amount of change in driving torque (step S9).

Description

  The present invention relates to an image forming apparatus and an image forming system that remove a residue adhered to an image carrier with a blade.

  2. Description of the Related Art Conventionally, an electrophotographic image forming apparatus forms a latent image corresponding to image information on the surface of a rotatable image carrier such as a photoconductive photoreceptor, and uses the latent image as a toner image (developer image). It is developed, transferred to a recording medium such as paper, fixed and output as an image formed product. The image carrier after the transfer is used for repeated image formation by removing residues such as transfer residual toner and paper powder adhering to the surface by a cleaning device. As a cleaning device, for example, an elastic blade (cleaning blade) is used as a cleaning member, and a blade cleaning system in which the cleaning blade is brought into contact with the rotation direction of the image carrier is generally used. . After the toner image is transferred to the recording medium, the surface of the image carrier is wiped by the edge of the cleaning blade according to the rotation of the image carrier, and the surface residue is scraped off.

  However, in such a cleaning device, when the amount of supplied toner is small, the tip of the cleaning blade may be turned up due to sliding friction between the surface of the image carrier and the edge of the cleaning blade. There is.

  In order to cope with this, there has been proposed an apparatus in which a developer such as toner adheres to the surface of the image carrier as a lubricant and is supplied to the pressure contact portion between the surface of the image carrier and the cleaning blade. Further, there has been proposed a method in which a developer such as toner is supplied when the distortion of the cleaning blade exceeds a certain level (for example, see Patent Document 1).

JP 2010-217766 A

  However, in the conventional image forming apparatus, the amount of developer supplied to the cleaning blade cannot be optimized, and there is a possibility that an unnecessarily large amount of developer is supplied.

  An object of the present invention is to make it possible to appropriately determine the amount of developer supplied to the cleaning means, and to prevent the developer from being consumed more than necessary in order to prevent the blade from turning up.

  In order to achieve the above object, the image forming apparatus according to claim 1 is formed by using a rotating image carrier, a forming unit for forming an electrostatic latent image on the image carrier, and a developer. A developing unit that develops the electrostatic latent image, a transfer unit that transfers the developer image on the image carrier to the transfer material, and after the developer image on the image carrier is transferred to the transfer material by the transfer unit. Cleaning means for removing the residue remaining on the image carrier with a blade in contact with the image carrier, measuring means for measuring the rotational load of the image carrier, and the developer for cleaning the developer And a control means for controlling the forming means and the transfer means, and the control means controls the forming means and the transfer means to supply a plurality of different developer amounts to the cleaning means. Before Based on the result of measurement by the measuring means, and having a determining means for determining the amount of developer supplied to the cleaning unit.

  The image forming system according to claim 5 is an image forming system comprising a plurality of image forming apparatuses and a computer capable of exchanging information with each of the plurality of image forming apparatuses. , Transmitting verification information to at least a part of the plurality of image forming apparatuses, receiving a verification result transmitted by the image forming apparatus according to the verification information, and calculating an image formation related condition based on the received verification result The calculated image formation related conditions are transmitted to the plurality of image forming apparatuses including the image forming apparatus, and each of the plurality of image forming apparatuses performs image formation based on the image formation related conditions received from the computer. It is characterized by performing.

  According to the present invention, it is possible to appropriately determine the amount of developer to be supplied to the cleaning means, and it is possible to prevent an excessive amount of developer from being consumed in order to prevent the blade from turning up.

1 is a diagram illustrating a schematic configuration of an image forming apparatus according to a first embodiment. FIG. 2 is a perspective view when the photosensitive drum is viewed from the cleaning device side in FIG. 1. 2 is a flowchart illustrating a procedure of toner supply amount determination processing executed by the image forming apparatus of FIG. FIG. 4 is a diagram illustrating an example of a result when a toner supply amount determination process of FIG. 3 is executed after changing a toner supply amount setting value five times. FIG. 5 is a graph of the amount of change in driving torque per image forming with respect to the amount of toner supply per image forming based on the result of FIG. 2 is a flowchart illustrating a procedure of a printing process after a minimum toner supply amount is determined, which is executed by a main body control device in FIG. 3 is a graph showing fluctuations in the driving torque of the photosensitive drum with respect to the number of images formed. It is a figure which shows an example of the system configuration | structure of the image forming system which concerns on 2nd Embodiment. It is a figure which shows the flow of the control processing which the image forming system of FIG. 8 performs. 9 is a flowchart illustrating a procedure of toner supply amount determination processing executed by each of some of the image forming apparatuses selected by the host computer in FIG. 8. FIG. 9 is a diagram illustrating an example of a verification result provided by the image forming apparatus to the host computer HC for a verification toner supply amount instructed by the host computer in FIG. 8 to the image forming apparatus in FIG. 8; FIG. 12 is a graph of the amount of change in driving torque per image forming with respect to the amount of toner supplied per image forming based on the result of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram illustrating a schematic configuration of an image forming apparatus according to the first embodiment.

  As shown in the figure, this image forming apparatus includes a charging device 2, an exposure device 3, a developing device 4, a transfer device, which are arranged clockwise from above so as to surround a photosensitive drum 1 which is a rotating image carrier. An apparatus 6, a separation apparatus 7, a cleaning apparatus 9, and a pre-image formation exposure apparatus 10 are provided. Further, a torque measuring device 111 for measuring a rotational load (drive torque) is connected to the drive motor M1 that rotates the photosensitive drum 1.

  Image information read by the image reading apparatus 102 is supplied to the main body control apparatus 101. The main body control device 101 includes a central processing unit (CPU), a read only memory (ROM), and a random access memory (RAM). The main body control apparatus 101 outputs the supplied image information to the image processing apparatus 103. The image processing apparatus 103 performs various image processes on the input image information and outputs the processed image information to the laser control apparatus 107. The laser control device 107 controls the laser driving circuit 108 according to the image information after image processing. The laser drive circuit 108 causes the exposure device 3 to irradiate the photosensitive drum 1 with a laser corresponding to image information after image processing. Since the photosensitive drum 1 rotates in the direction of arrow R1 in FIG. 1, the entire surface thereof is negatively charged by the charging device 2. Therefore, an electrostatic latent image corresponding to the laser irradiation from the exposure device 3 is formed on the photosensitive drum 1. Note that a current is supplied to the charging device 2 by the primary current generator 106.

  In the present embodiment, a known reversal development method is adopted as the development method. The developing device 4 contains a negatively charged toner as a developer. The developing device 4 develops the electrostatic latent image into a toner image (developer image). The developing roller (developing sleeve) 4 a is a developer carrying member that carries toner as a developer, and adheres the carried toner to the photosensitive drum 1. The developing roller 4a is rotationally driven at a predetermined speed in the direction of the arrow R2 in the figure by a motor (not shown). A predetermined developing bias is applied to the developing roller 4 a by the developing bias generator 109.

  The transfer material S such as paper is conveyed to the photosensitive drum 1 by the registration roller 5. The transfer device 6 using a corona charger transfers the toner image on the photosensitive drum 1 onto the transfer material S. Further, the transfer material S is separated from the photosensitive drum 1 by the separation charger 7, transported to the fixing device 11 by the transport belt 8, and after the image is fixed by the fixing device 11, it is discharged out of the image forming apparatus. Note that a current is supplied to the transfer device 6 by the transfer current generator 110.

  Residues such as transfer residual toner and paper dust adhere to the surface of the photosensitive drum 1 after the transfer material S is separated, but are removed by the cleaning device 9 for the next image formation. The cleaning device 9 includes a cleaning blade 9 a and a cleaning container 9 b, and the cleaning blade 9 a cleans the surface of the photosensitive drum 1. The cleaning blade 9a is an elastic blade made of an elastic material such as urethane rubber.

  FIG. 2 is a perspective view when the photosensitive drum 1 is viewed from the cleaning device 9 side. As shown in the figure, the cleaning blade 9 a is disposed along the rotational axis direction X of the photosensitive drum 1 so that the edge portion of the blade end surface is opposed to the surface of the photosensitive drum 1. A contacting nip portion (cleaning portion) is formed. The surface of the rotating photosensitive drum 1 is wiped by the edge portion of the cleaning blade 9a, and the residue on the surface (on the image carrier) is scraped off. The scraped residue falls to the bottom of the cleaning container 9b and is discharged from the cleaning container 9b to an external recovery toner container (not shown) by a discharge screw (not shown).

  The photosensitive drum 1 is driven via a rotation axis X by a motor M1 (see FIG. 1). Returning to FIG. 1, a torque measuring device 111 is connected to the motor M1. The torque measuring device 111 measures the driving torque based on the driving current flowing through the motor M1.

  When the amount of toner supplied to the photosensitive drum 1 during image formation is small, there is a possibility that the tip of the cleaning blade 9a is turned up due to sliding friction between the surface of the photosensitive drum 1 and the cleaning blade 9a. In order to reduce this sliding friction, in this embodiment, toner as a developer is supplied to the nip portion between the surface of the photosensitive drum 1 and the cleaning blade 9a while being adhered to the surface of the photosensitive drum 1. At this time, a solid image is formed on the photosensitive drum 1. The solid image on the photosensitive drum 1 is exposed to the entire image forming area in the rotational axis direction of the photosensitive drum on the photosensitive drum 1 charged by the charging device 2 by the exposure device 3, and the developed electrostatic latent image is developed into a developing device. 4 is formed by creating a toner image.

  Thereafter, the toner image is conveyed to the nip portion of the cleaning device 9 by rotating the photosensitive drum 1 without conveying the transfer material S and without applying a bias to the transfer device 6 and the separating device 7, and thereby the toner. Supply. The toner amount (developer amount) supplied to the cleaning device 9 is determined by a method described later. Based on the determined amount of toner, the size of the image area of the solid image formed on the photosensitive drum 1, that is, the length in the rotation direction of the photosensitive drum 1 is determined. That is, the exposure of the exposure apparatus 3 is controlled, and the area where the exposure apparatus 3 exposes the photosensitive drum 1 is adjusted in order to form a solid image.

  In the present embodiment, the determined toner amount is defined for each image forming sheet. In the present embodiment, the toner image of the solid image is supplied to the cleaning device 9 during the post-rotation after the normal image forming operation. Therefore, the amount of toner supplied to the cleaning device 9 by this solid image is a shortage of the amount of toner supplied to the cleaning device 9 by the normal image forming operation. Therefore, the amount of toner supplied to the cleaning device 9 during the post-rotation also varies depending on the number of images formed in the normal image forming operation.

  A control process executed by the image forming apparatus configured as described above will be described in detail with reference to FIGS.

  FIG. 3 is a flowchart illustrating a procedure of toner supply amount determination processing executed by the image forming apparatus according to the present embodiment, particularly, the main body control apparatus 101. This toner supply amount determination process determines a toner supply amount to the cleaning device 9 suitable for the state of the cleaning device 9. The toner supply amount determination process is started in response to a user's instruction to start from the operation unit 104.

  When the toner supply amount determination process is started, the main body control device 101 sets a toner amount (hereinafter referred to as “toner supply amount”) gn to be supplied from the developing device 4 to the cleaning device 9 after normal image formation (step S1). ). This toner supply amount gn is an amount corresponding to the nth time and is a predetermined amount. Steps S1 to S7 are repeated a predetermined number of times. Hereinafter, the number of repetitions is expressed by n (1 ≦ n ≦ predetermined number).

  After setting the toner supply amount gn, the main body control apparatus 101 instructs the image processing apparatus 103 to perform normal image formation (step S2).

  During normal image formation, the torque measuring device 111 measures the driving torque based on the driving current flowing through the motor M1, and transmits the measured driving torque value to the main body control apparatus 101 as a measurement result. The main body control apparatus 101 receives the drive torque measurement value and stores it in the RAM, for example (step S3).

  Further, the image printing rate measuring device 105 measures the image printing rate at the time of the normal image formation, and transmits the measured image printing rate to the image processing device 103. The main body control apparatus 101 reads out the image printing rate from the image processing apparatus 103 and stores it in the RAM (step S4). The image printing rate is a value obtained based on the image-processed image data output from the image processing apparatus 103, and is a value corresponding to an image area where an image is formed using toner.

  Next, the main body control device 101 controls the developing device 4 so as to supply a set amount of toner gn at the time of post-rotation after normal image formation (step S5). As a result, the set amount gn of toner is supplied from the developing device 4 to the cleaning device 9.

  Next, the main body control apparatus 101 determines whether or not the number of images formed with the set toner supply amount gn exceeds a predetermined number X (target number of toner supply amount switching) (step S6). If the result of determination in step S6 is that the number of image formation is equal to or less than the target number X of toner supply amount switching, the main body control apparatus 101 returns the process to step S2 and repeats the processes of steps S2 to S5. On the other hand, when the image forming number exceeds the target number X of the toner supply amount switching, the main body control apparatus 101 advances the process to step S7. That is, after the toner is supplied to the cleaning device 9a at the next post-rotation, the total amount of toner supplied to the cleaning device 9 immediately after the toner supply amount is set in step S1 until the end of the previous normal image formation. Kn and driving torque change amount Tn are calculated. However, “n” indicates the set number of toner supply amounts.

  When the toner supply amount gn is set, the total toner amount Kn supplied to the cleaning device 9 is calculated by the following equation (1).

Kn = {gn + Dn × U × (1-R)} × Nn (1)
Here, Dn is an average printing rate at the time of normal image formation calculated from the image printing rate stored in the RAM of the main body control apparatus 101, and U is a toner consumption amount per unit image printing rate. Further, R is a transfer efficiency at which the toner amount on the photosensitive drum 1 obtained in advance is transferred to the transfer material S, and Nn is from when the toner supply amount g1 is set until the end of the previous normal image formation. This is the number of images created.

  The drive torque change amount Tn is a drive torque measurement value measured by the torque measurement device 111 at the end of the previous normal image formation from a drive torque measurement value measured by the torque measurement device 111 immediately after setting the toner supply amount gn. It is obtained by calculating the amount of change up to. The two drive torque measurement values are both stored in the RAM after measurement.

  Further, the main body control device 101 determines the toner supply amount “Kn / Nn” per image formation and the drive torque change amount “T1 /” per image formation based on the total toner amount Kn and the drive torque change amount Tn. Nn ″ is calculated and stored in the RAM.

  In this embodiment, the value per image formation is obtained as the toner supply amount and the drive torque change amount, but values per predetermined image formation number other than one image may be obtained. Hereinafter, “per image formation” is simply abbreviated as “per image”.

  Next, the main body control apparatus 101 determines whether or not the set number of toner supply amounts exceeds a predetermined number Y (5 times in the present embodiment) (step S8). As a result of this determination, if the set number n of toner supply amounts is equal to or less than the predetermined number Y, the main body control apparatus 101 returns the process to step S1 and repeats the processes of steps S1 to S7.

  In this case, in step S <b> 1, the main body control device 101 sets a new toner supply amount to be supplied from the developing device 4 to the cleaning device 9 in accordance with the set number of toner supply amounts. When the set number n of toner supply amounts is, for example, the third time, “g3” is set as a new toner supply amount. Similarly, for the toner supply amount g3, the main body control device 101 calculates a new total toner supply amount K3 and a new drive torque change amount T3, and the toner supply amount “K3 / N3” per sheet and one sheet. The amount of change in driving torque per hit “T3 / N3” is calculated and stored in the RAM.

  On the other hand, as a result of the determination in step S8, when the set number n of toner supply amounts exceeds the predetermined number Y, the main body control apparatus 101 advances the process to step S9. That is, the minimum toner supply amount is determined from the toner supply amount “Kn / Nn” per sheet and the drive torque change amount “Tn / Nn” per sheet for each set number of times of toner supply amount (step S9). Then, the toner supply amount determination process ends.

  The minimum value of the toner supply amount is a toner supply amount that needs to be supplied to the cleaning device 9 during image formation so that the cleaning blade of the cleaning device 9 does not turn over. Using the toner supply amount “Kn / Nn” per sheet and the drive torque change amount “Tn / Nn” per sheet obtained by changing the toner supply amount n times, the number of times is set to 1 The relationship between the toner supply amount per sheet and the driving torque change amount per sheet can be obtained. From the relationship between the toner supply amount per sheet and the drive torque change amount per sheet, the toner supply amount that needs to be supplied to the cleaning device 9 at the time of image formation suitable for the state of the cleaning blade can be obtained. .

  FIG. 4 is a diagram illustrating an example of a result when the toner supply amount setting process of FIG. 3 is executed by changing the set value of the toner supply amount five times. In the illustrated example, “U” in the above formula (1), that is, toner consumption per unit image printing rate (1%) is set to “6 mg”, and “R”, that is, transfer efficiency is set to “98%”.

  Then, “N1 to N5”, that is, the number of formed images is “100”. Here, “N1” is set to “100 sheets” (in this embodiment, “N2” to “N5” are also “100 sheets”). This is because the number of sheets for determining the minimum value of the supply amount is 500 sheets. That is, it is considered that about 500 sheets are appropriate as the number of sheets for determining the minimum value of the toner supply amount, compared to 5000 sheets set as the replacement number of the photosensitive drum 1 and the cleaning blade 9a.

  FIG. 5 is a graph showing the amount of change in driving torque per sheet with respect to the amount of toner supplied per sheet based on the result of FIG.

  In the image forming apparatus according to the present embodiment, if the change in driving torque exceeds 300 gf with respect to 5000 sheets set as the replacement number of the photosensitive drum 1 and the cleaning blade 9a, the cleaning blade 9a may be turned up. . This value “300 gf” is a threshold value determined from physical properties such as the elastic modulus of the cleaning blade 9 a and is obtained in advance and stored in the RAM of the main body control device 101. Since “300 gf” is a drive torque change amount for 5000 images, the drive torque change amount per image is “0.06 gf”. In the graph of FIG. 5, the toner supply amount with respect to the drive torque change amount “0.06 gf” per sheet is “2 mg”. Therefore, the main body control apparatus 101 determines this value “2 mg” as the necessary toner supply amount per sheet, that is, the minimum value of the toner supply amount (hereinafter referred to as “minimum toner supply amount”) and stores it in the RAM.

  Normal image formation after the minimum toner supply amount is determined, that is, printing processing is performed while supplying the minimum toner supply amount to the cleaning device 9. This toner supply is performed by post-rotation after normal image formation. At that time, the main body control device 101 causes the image printing rate during normal image formation so that the minimum toner supply amount is always supplied to the cleaning device 9. The toner supply amount is varied according to the number of printed sheets.

  FIG. 6 is a flowchart showing the procedure of the printing process executed by the main body control apparatus 101 after the minimum toner supply amount is determined.

  When the main printing process is started, the main body control apparatus 101 first causes the image processing apparatus 103 to start a normal image forming operation (step S11). In parallel with this image forming operation, the image printing rate measuring device 105 measures the image printing rate for the image being formed and transmits the measured image printing rate to the image processing device 103.

  The main body control apparatus 101 waits until the image formation is completed (step S12), and then reads the image printing rate from the image processing apparatus 103 (step S13). Then, the main body control apparatus 101 calculates a toner supply amount K per image formation based on the read image printing rate (step S14). The toner supply amount K per sheet is calculated by the following equation (2).

K = D × U × (1-R) (2)
Here, D is an average printing rate per sheet during image formation obtained from the stored image printing rate, U is a toner consumption amount per unit image printing rate, and R is a photosensitive drum obtained in advance. 1 is the transfer efficiency at which the toner amount on 1 is transferred to the transfer material S.

  Next, the main body control apparatus 101 determines whether toner supply is necessary based on the calculated toner supply amount K (step S15). Specifically, the toner supply amount K is compared with the minimum toner supply amount. When the toner supply amount K is equal to or less than the minimum toner supply amount (predetermined amount or less), it is determined that toner supply is necessary. When the amount K is larger than the minimum toner supply amount, it is determined that toner supply is not necessary.

  If the result of determination in step S15 is that toner supply is necessary, the main body control apparatus 101 calculates the toner supply amount to be supplied (step S16). The toner amount to be supplied is calculated by multiplying the minimum toner supply amount, that is, the difference between the minimum toner supply amount per sheet and the actually supplied toner amount, by the previous image forming number.

  Then, the main body control apparatus 101 supplies the toner of the toner supply amount calculated in step S16 during the subsequent post-rotation (step S17), and then ends the printing process.

  On the other hand, if the result of determination in step S15 is that toner supply is not necessary, the main body control apparatus 101 directly ends this print processing.

  As described above, in this embodiment, it is necessary to suppress the turning of the cleaning blade 9a in advance at a relatively early stage (for example, about 1/10 of the life) of the life of the photosensitive drum 1 and the cleaning blade 9a. A minimum toner supply amount can be determined.

  The determined minimum toner supply amount is optimized according to the type of transfer material S used by the image forming apparatus of the present embodiment and the environment in which the image forming apparatus of the present embodiment is installed. As a result, the supply does not become excessive and the necessary supply amount is obtained. Further, since the supply amount is determined in the initial stage and the toner is supplied from the developing device 4 at a constant rate, it is possible to suppress a change in the image forming state due to a sudden change in the toner supply amount.

  Further, when the cleaning blade 9a or the photosensitive drum 1 is replaced or when there is a significant change in the transfer material S and the installation environment, the minimum toner supply amount to the cleaning device 9 can be determined again. At this time, for example, the user instructs the operation unit 104 to start the toner supply amount determination process of FIG.

  FIG. 7 is a graph showing fluctuations in the driving torque of the photosensitive drum with respect to the number of images formed. In the figure, the drive torque fluctuation for the conventional image forming apparatus is indicated by a broken line, and the drive torque fluctuation for the image forming apparatus of the present embodiment is indicated by a solid line. “T0” represents an initial torque (initial value of the rotational load), “Ts” represents an allowable torque, that is, an upper limit value for preventing the cleaning blade 9a from turning over, and “5000” represents the photosensitive drum 1 and the cleaning. The number of images that the blade 9a reaches the end of its life is shown.

  As shown in FIG. 7, in the conventional image forming apparatus, when the torque increases due to image formation and the torque exceeds the allowable torque “Ts”, the toner is supplied from the developing device 4 to the cleaning device 9 to reduce the torque. Yes. At this time, since the amount of toner consumption differs between the period until the first toner supply and the period after the first toner supply until the next toner supply, the charge amount of the toner changes. However, the stability of the image may be deteriorated.

  In contrast, in the image forming apparatus of the present embodiment, the determined toner supply amount is supplied to the cleaning device 9 after each image forming operation. At this time, the toner consumption amount per image formation is less changed compared to the conventional image forming apparatus, and the density stability is also improved. The transition of torque fluctuation gradually approaches the allowable torque “Ts”, and exceeds the allowable torque “Ts” at the same time as the life of the photosensitive drum 1 and the cleaning blade 9a (5000 sheets). That is, since it can be designed in this way, the total amount of toner supplied from the developing device 4 to the cleaning device 9 can also approach the minimum required amount.

  In the above-described embodiment, the supply of the solid image toner image to the cleaning device 9 is performed at the time of post-rotation. However, the solid image is not limited to the time of post-rotation. It doesn't matter if it exists. For example, the toner image of a solid image may be supplied to the cleaning device at the end of each job.

(Second Embodiment)
FIG. 8 is a diagram showing an example of a system configuration of an image forming system according to the second embodiment of the present invention.

  As shown in the figure, the image forming system according to the present embodiment includes a plurality (30 in the illustrated example) of image forming apparatuses (printers) and a host computer HC. Each image forming apparatus is a host. It is connected to the computer HC. Each of the image forming apparatuses employs the same configuration as that of the image forming apparatus of the first embodiment. Accordingly, the hardware described in FIGS. 1 and 2 is employed as it is as the hardware of each image forming apparatus.

  As such an image forming system, there may be a case where a plurality of the same image forming apparatuses are used in a large-scale office or the like. In this case, the transfer material S is simply used from the viewpoints of cost and image reproducibility. One type is often used.

  In the image forming system of the present embodiment, the host computer HC and each image forming apparatus are connected by, for example, a LAN (Local Area Network). Information is exchanged between the host computer HC and each image forming apparatus (the main body control apparatus 101) via the LAN.

  FIG. 9 is a diagram illustrating a flow of control processing executed by the image forming system according to the present embodiment.

  In the figure, the host computer HC needs to determine the toner supply amount from all the connected image forming apparatuses (printers), that is, the “minimum toner supply amount” in the first embodiment. Image forming apparatus is selected. Then, the host computer HC instructs each of the selected image forming apparatuses about a verification toner supply amount (verification information) (block B1). In FIG. 8, 15 printers Pa to Po are selected as some of the image forming apparatuses (in FIG. 8, the selected printer is given a “★” mark). Similarly, it is assumed that the printers Pa to Po are selected.

  Each of the image forming apparatuses Pa to Po in which the verification toner supply amount is instructed from the host computer HC calculates the toner supply amount and the drive torque change amount by executing a toner supply amount determination process described later with reference to FIG. To do. Then, each of the image forming apparatuses Pa to Po provides the calculation result, that is, the verification result to the host computer HC (block B2). The host computer HC calculates the optimum condition (image formation related condition) of the toner supply amount based on the verification results provided from the image forming apparatuses Pa to Po (block B3). The host computer HC determines the toner supply amount (minimum toner supply amount) based on the calculated optimum condition, and includes the determined toner supply amount for all image forming apparatuses (not participating in the toner supply amount determination). ) (Block B4).

  FIG. 10 is a flowchart illustrating a procedure of toner supply amount determination processing executed by each of the partial image forming apparatuses selected by the host computer HC. The toner supply amount determination process in FIG. 9 is configured by changing a part of the toner supply amount determination process in FIG. 3 described above. Therefore, in FIG. 10, steps that perform the same processes as those in FIG. 3 are given the same numbers, and descriptions thereof are omitted.

  This toner supply amount determination processing is performed when the host computer HC selects a part of image forming apparatuses necessary for determining the toner supply amount and transmits a verification toner supply amount to each of the selected image forming apparatuses. Be started. The selection of some of the image forming apparatuses may be arbitrarily performed, or data such as usage frequency is transferred from all the image forming apparatuses to the host computer HC and statistically processed in the host computer HC. You may choose. The selection of the image forming apparatus is not limited to a part but may be all.

  The toner supply amount verified for determining the toner supply amount in the image forming system of the present embodiment is the same number and the same content as the five patterns set by the image forming apparatus of the first embodiment. Adopted. Therefore, the host computer HC assigns at least one image forming apparatus to the verification toner supply amount of each pattern. In order to ensure higher reliability, it is desirable to select and verify a plurality of image forming apparatuses for each verification toner supply amount. In the system configuration of FIG. 8, three image forming apparatuses are selected for each of the five patterns (supply amounts # 1 to # 5) of the verification toner supply amount. That is, 15 units are selected as the image forming apparatuses used for determining the toner supply amount, and 15 units are selected as the unused image forming apparatuses. At this time, an image forming apparatus that is not used for determining the toner supply amount can be used as usual.

  Returning to FIG. 10, when the toner supply amount determination process is started, the main body control apparatus 101 first receives the verification toner supply amount from the host computer HC (step S21).

  Next, the main body control apparatus 101 executes the processes of steps S2 to S7 based on the received verification toner supply amount, and the toner amount and drive torque change amount supplied to the cleaning device 9 immediately after the toner supply amount is set. Is calculated. However, in the present embodiment, both the toner amount and the drive torque change amount are amounts per image formation. Then, the main body control device 101 transmits the calculated toner amount and driving torque change amount to the host computer HC (step S22).

  FIG. 11 is a diagram illustrating an example of a verification result provided by the image forming apparatuses Pa to Po to the host computer HC with respect to the verification toner supply amount designated by the host computer HC to the image forming apparatuses Pa to Po. FIG. 12 is a graph showing the amount of change in driving torque per sheet with respect to the amount of toner supplied per sheet based on the result of FIG. FIGS. 11 and 12 correspond to FIGS. 4 and 5 in the first embodiment, respectively.

  In the host computer HC, as in the image forming apparatus of the first embodiment, an allowable value of the amount of change in drive torque (“0.06 gf” in FIG. 12) is determined in advance, for example, a storage device (not shown). )). The host computer HC executes a process similar to the process executed by the image forming apparatus according to the first embodiment using FIG. 5 in step S9 of FIG. (Minimum toner supply amount) is determined to be “2 mg”. Then, the host computer HC instructs all the image forming apparatuses with the determined minimum toner supply amount (see block B4 in FIG. 9). When receiving an instruction for the minimum toner supply amount from the host computer HC, each image forming apparatus stores the instructed minimum toner supply amount in its own storage device, for example, a RAM. When the printing process is executed after the minimum toner supply amount is stored, each image forming apparatus executes the printing process after the minimum toner supply amount is determined as in the image forming apparatus of the first embodiment. . Since this printing process has been described in detail with reference to FIG.

  As described above, in this exemplary embodiment, the verification toner supply amount is allocated and provided to a plurality of image forming apparatuses, and the toner supply amount is optimized based on the supply from each image forming apparatus. Accordingly, it is possible to optimize the toner supply amount in a shorter time than the optimization of the toner supply amount with one image forming apparatus. In addition, since verification is performed by a plurality of image forming apparatuses, it is possible to more stably cope with accidental disturbance factors such as measurement errors during verification by statistical processing such as averaging.

DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Charging apparatus 3 Exposure apparatus 4 Developing apparatus 6 Transfer apparatus 9 Cleaning apparatus 9a Cleaning blade 101 Main body control apparatus 102 Image reading apparatus 103 Image processing apparatus 104 Operation part 105 Image printing rate measuring apparatus 106 Primary current generator 107 Laser control Device 108 Laser drive circuit 109 Development bias generator 110 Transfer current generator 111 Torque measuring device

Claims (5)

A rotating image carrier;
Forming means for forming an electrostatic latent image on the image carrier;
Developing means for developing the formed electrostatic latent image using a developer;
Transfer means for transferring the developer image on the image carrier to a transfer material;
Cleaning means for removing a residue remaining on the image carrier after the developer image on the image carrier is transferred to a transfer material by the transfer unit, using a blade in contact with the image carrier;
Measuring means for measuring the rotational load of the image carrier;
Control means for controlling the forming means and the transfer means to supply the developer to the cleaning means;
The control unit controls the forming unit and the transfer unit to supply a developer amount to be supplied to the cleaning unit based on the measurement result of the measurement unit after supplying a plurality of different developer amounts to the cleaning unit. A decision means to decide;
An image forming apparatus comprising:   The determination unit obtains a relationship between the amount of developer supplied to the cleaning unit and the amount of change in the measurement result based on the measurement result of the measurement unit, and changes the amount of developer supplied to the cleaning unit and the measurement result. 2. The image forming apparatus according to claim 1, wherein a developer amount corresponding to a change amount of a predetermined value is obtained from a relationship with the amount. Measuring means for measuring the image printing rate based on the image information;
A calculation unit that calculates a developer amount supplied to the cleaning unit in image formation based on the image information based on the image printing rate;
The control means includes
3. The developer amount supplied to the cleaning unit is controlled based on the developer amount determined by the determining unit and the developer amount calculated by the calculating unit. Image forming apparatus.   The control unit controls the forming unit and the transfer unit to control the forming unit and the transfer unit and control the developer to the cleaning unit when it is not a normal image forming time for controlling the forming unit and the transfer unit based on the input image information. The image forming apparatus according to claim 1, wherein the image forming apparatus is supplied. An image forming system comprising a plurality of image forming apparatuses and a computer capable of exchanging information with each of the plurality of image forming apparatuses,
The computer transmits verification information to at least a part of the plurality of image forming apparatuses, receives a verification result transmitted by the image forming apparatus in response to the verification information, and performs image formation related based on the received verification result Calculating the conditions, and transmitting the calculated image formation-related conditions to the plurality of image forming apparatuses including the image forming apparatus,
Each of the plurality of image forming apparatuses forms an image based on an image formation related condition received from the computer.

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