JP2006251621A - Image forming apparatus and image formation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of preventing the mass generation of defective prints due to discharge irregularity but capable of preceding a present print without making a user consider the cleaning processing of a discharge wire. <P>SOLUTION: The image forming apparatus provided with a cleaning means for cleaning a charging member of a charging means is provided with an information notification means for notifying a user of information concerned with the cleaning of the charging member and a control means for controlling a first judgment part for judging whether a detection value related to the discharge irregularity of the charging member at the time of setting a job exceeds a previously determined detection threshold or not and a second judgment part for judging whether the set number of prints which is set at the time of setting the job exceeds a previously set number-of-prints threshold or not. When the detection value exceeds the detection threshold and the set number of prints exceeds the set number-of-prints threshold, the control means controls the information notification means to notify the information concerned with cleaning. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus and an image forming system such as a copying machine and a laser beam printer, and more particularly to an image forming apparatus and an image forming system provided with a means for informing information relating to cleaning of a charging member in a charging means.

  In image forming apparatuses such as copying machines and laser beam printers, corona chargers are often used as charging members for charging the surface of an image carrier (also referred to as a photosensitive drum), transferring to a recording material, and separating charging. . As a corona charger, a strong electric field is generated between a charging wire, which is an electric-resistant member to which a high voltage is applied, and a shield electrode disposed opposite to the charging wire, and electric charges generated by the corona discharge phenomenon generated by this electric field are It is used to charge or charge a charged object such as an image carrier or recording material.

  The strength of the corona discharge phenomenon is easily affected by the state of the surface of the charging wire, while the surface of the charging wire is likely to adhere to foreign matters due to electrostatic dust collection. Therefore, it is known that when the corona charger is used repeatedly, foreign matter may adhere to the charging wire, thereby causing unevenness in the discharge distribution (hereinafter referred to as “discharge unevenness”).

  This discharge unevenness appears as image density unevenness when it occurs in the uniform charging process on the surface of the image carrier. Further, when it occurs in a transfer charging and separation charging process to a recording material, it appears as a transfer failure or separation failure. In either case, the image quality is degraded.

  In order to clean the discharge unevenness of the corona charger, which causes these density unevenness, transfer failure, and separation failure, there is one provided with a cleaning means for cleaning the surface of the charging wire.

Conventionally, in Patent Document 1, cleaning is performed after a predetermined time has elapsed from the end of the image forming operation, and cleaning is performed only when the predetermined number of prints has been reached after the predetermined time has elapsed. A technique for reducing the waiting time is disclosed. Various image forming apparatuses having a cleaning unit have been proposed. For example, Patent Document 2 discloses a technique that measures a current value flowing from a charging wire into a shield case, issues a warning when the measured value falls below a predetermined value, and knows the cleaning time. .
JP 2003-202734 A JP 2002-132025 A

  However, the prior art described above has the following problems.

  If a certain time has passed since the end of the image forming operation and the number of prints set in advance has been reached, an attempt is made to clean automatically. Is inconvenient because it may be waiting for a long time. In addition, when printing a large amount, if there is uneven discharge, a large amount of defective prints may occur. On the other hand, when printing a small amount, give priority to immediate printing without considering the cleaning process. Sometimes you want to print. However, when a cleaning warning is issued, processing for the cleaning warning tends to be prioritized, and there is a problem that it is difficult to execute printing with priority for the time being.

  Accordingly, the present invention has been made in view of the above-described problems, and an object of the present invention is to prevent the occurrence of a large amount of defective prints related to discharge unevenness, while the user cleans the discharge wires for a small amount of prints. To provide an image forming apparatus capable of giving priority to printing for the time being without considering processing and improving convenience, and an image forming system in which the image forming apparatus and a personal computer are configured on a network. It is in.

The above object can be achieved by any of the following means.
(1) In an image forming apparatus provided with a cleaning unit for cleaning a charging member of a charging unit, an information notification unit for reporting information on cleaning of the charging member, and a detection value related to discharge unevenness of the charging member at the time of job setting A first determination unit that determines whether or not a predetermined detection threshold is exceeded, and a second determination unit that determines whether or not the set print number set at the time of job setting exceeds a predetermined set print number threshold Control means for controlling the control means, wherein the control means notifies the cleaning information when the detection value exceeds the detection threshold value and the set print number exceeds the set print number threshold value. An image forming apparatus that controls the image forming apparatus.
(2) In an image forming system in which an image forming apparatus including a cleaning unit for cleaning a charging member of a charging unit and a personal computer are configured on a network, an information notification unit for reporting information on cleaning of the charging member, and a job A first determination unit that determines whether a detection value related to discharge unevenness of the charging member at the time of setting exceeds a predetermined detection threshold value related to the detection value, and a set number of prints set at the time of job setting And a control unit that controls a second determination unit that determines whether or not the determined set print number threshold value is exceeded, wherein the control unit has the detection value that exceeds the detection threshold value and the set print number is When the set print number threshold is exceeded, control is performed so that information related to cleaning is notified by the personal computer. The image forming system according to.

  According to the image forming apparatus of the present invention, it is possible to prevent the occurrence of a large amount of defective prints, but for a small amount of prints, the user can give priority to the current print without considering the discharge wire cleaning process. , Can now improve convenience.

  In addition, according to the image forming system in which the image forming apparatus and the personal computer of the present invention are configured on the network, in the same way as the above-described effect, a large amount of defective prints can be prevented while a small amount of prints are made. As for the user, the user can prioritize printing for the time being without thinking about the cleaning process of the discharge wire, and the convenience can be improved.

(First embodiment)
An image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings. 1 is a schematic configuration diagram of an image forming apparatus according to the present embodiment, FIG. 2 is a configuration diagram of a charging unit and a cleaning unit in FIG. 1, FIG. 3 is a configuration diagram of an operation panel in FIG. 1, and FIG. 2 is a control-related block diagram of a control system in the image forming apparatus according to FIG.

  First, a schematic configuration of the entire image forming apparatus will be described with reference to FIG. The image forming apparatus GH shown in FIG. 1 includes a document conveying device R, a document reading device S, an image forming unit 11, a sheet feeding unit 19, a fixing unit 18, an operation panel 30 and a control-related block 40A.

  A document conveying device R is provided above the image forming apparatus GH, and the document is automatically conveyed. In addition, a document reading device S is provided in the upper part, and a document is read. The image forming unit 11 includes an exposure unit 13, a photosensitive drum 12, a charging unit 20, a developing unit 14, a cleaning unit 17, and the like. The exposure unit 13 irradiates the photosensitive drum 12 with light rays according to image information. After the surface of the photosensitive drum 12 is uniformly charged by the charging unit 20, an electrostatic latent image is formed by the light beam emitted from the exposure unit 13, and this electrostatic latent image is the toner supplied from the developing unit 14. Is developed to form a toner image.

  On the other hand, the recording material P stacked on the feeding tray of the sheet feeding means 19 is separated and fed by the feeding roller and further conveyed to the image recording unit. Here, the recording material P is conveyed between the photosensitive drum 12, the transfer charging unit 15, and the separation charging unit 16. The transfer charging unit 15 charges the recording material P with a polarity opposite to that of the toner on the photoreceptor 12, and transfers the toner image to the recording material P. The separation charging unit 16 performs corona charging on the recording material P, and the recording material P is discharged and separated from the photosensitive drum 12.

  The recording material P onto which the toner image has been transferred is conveyed to the fixing means 18 and is fixed by applying heat and pressure. Thereafter, the paper is discharged and stacked on a discharge tray by a discharge roller.

  The operation panel 30 is configured to set the number of prints, display information on uneven discharge, and the like. The control-related block 40A is a control system block of the image forming apparatus.

  Next, the charging unit 20 will be described in detail with reference to FIG. 2. The charging unit 20 is disposed to face the photosensitive drum 12, and has a charging wire 21 that is two charging members. . Each of the charging wires 21 is stretched by connecting one end to an electrode having conductivity and connecting the other end to the electrode through a spring. The electrode is electrically insulated from the installed shield plate 22 by an insulating block. Here, when a high voltage is applied to the electrode, the charging wire 21 causes a corona discharge to charge the surface of the photosensitive drum 12.

  The charging wire 21 is provided with a cleaning means 25. The cleaning means 25 holds the charging wire 21 between a pair of cleaning pads 25a, and is configured to be slidable along the charging wire by a moving member 25b as shown in FIG. 2, and the moving member 25b moves and is cleaned. Done.

  Next, the operation panel 30 will be described in detail with reference to FIG. The operation panel 30 includes a touch panel 31 and hard keys 32. The touch panel 31 has a display necessary for operation, is provided with information notifying means 31a for prompting cleaning, and is provided with buttons 31b and 31c relating to cleaning and is directly input by pressing the display. The hard key 32 is provided with a print button 32a, ten keys 32b of 0, 1 to 9 for setting the number of prints to be set, and the like.

  Next, the control-related block 40A of the image forming apparatus shown in FIG. 1 will be described in detail with reference to FIG.

  The control-related block 40A includes an operation panel 30, a first determination unit 42, a second determination unit 43, a control unit 41, various counters, various memories, and the like.

  Reference numeral 30 denotes the above-described operation panel, which displays information related to setting of the number of prints and cleaning. Reference numeral 42 denotes a first determination unit that determines whether or not the cumulative print number N at the time of job setting exceeds a cumulative print number threshold A related to occurrence of discharge unevenness in advance. The cumulative print number threshold A can be determined in a timely manner. For example, the cumulative print number threshold A can be a value of the cumulative print number at which a large amount of discharge unevenness starts to occur, but is not limited thereto. For example, when it is desired to reduce discharge unevenness as in a photographic image, the cumulative print number threshold value corresponding to the discharge unevenness can be set.

  Reference numeral 48a denotes a non-volatile memory that stores the cumulative print number threshold A, and reference numeral 48b denotes a non-volatile memory (storage means) that stores the total print number N. Reference numeral 43 denotes a second determination unit that determines whether the set print number M for one set exceeds a predetermined set print number threshold value B. 49a is a non-volatile memory (storage means) for storing the set print number threshold B, and 49b is a non-volatile memory for storing the set print number M for one time set at the time of job setting.

  41 is a control means for controlling each block, and the control means 41 once sets the cumulative print number N at the time of job setting exceeding the cumulative print number threshold A related to the occurrence of discharge unevenness. When the set print number M exceeds a preset set print number threshold value B, control is performed so as to notify information related to cleaning.

  Reference numeral 44 denotes a cumulative print number counter that counts the number of prints on which an image has been formed. Reference numeral 45 denotes a cleaning number counter that counts the number of cleanings. The count value of the cleaning number counter 45 is stored in a non-volatile memory (not shown).

  Next, an operation example of the image forming apparatus according to the embodiment will be described with reference to FIGS. In FIG. 5, the set number of prints M has already been set, and the range of the control flowchart is a control flowchart from the print start operation to the start of printing.

First, in step S1, a print button (32a in FIG. 3) is pressed as a print start operation.
In step S2, the cumulative print number N of the cumulative print number counter (44 in FIG. 4) that counts the number of prints formed with an image exceeds a cumulative print number threshold (also referred to as a threshold) A related to occurrence of discharge unevenness in advance. If it has not exceeded (NO), printing is started. If it has exceeded (YES), the process further proceeds to step S3.
In step S3, it is determined whether or not the set number of prints M to be set exceeds a preset print number threshold B. If it does not exceed (NO), for example, in the case of a small amount of printing, printing is started without displaying a cleaning message in order to prioritize printing for the time being. If it exceeds (YES), for example, in the case of a large amount of printing, the process proceeds to step S4, and a cleaning message is sent by the information notification means (31a in FIG. 3) in order to prevent a large amount of defective printing from occurring. Display and encourage cleaning.
In step S5, it is determined whether or not the charging member is to be cleaned immediately after the cleaning message is displayed. When not cleaning immediately (NO), the button (31b in FIG. 3) is pressed to give priority to printing. When cleaning (NO), the charging member is cleaned, and when cleaning is completed, the button is pressed. (31c in FIG. 3) is pressed to proceed to step S6.
In step S6, the value of the memory (48b in FIG. 4) for the cumulative print number N is reset.
In step S7, the number of cleanings is counted by a cleaning number counter (45 in FIG. 4).
In step S8, the total print count threshold value is changed in advance for each cleaning count. Since the durability of the charging member changes as a result of cleaning, the relationship between the number of cleanings and the cumulative print number threshold related to the occurrence of discharge unevenness is obtained in advance and is changed to the optimum cumulative print number threshold each time cleaning is performed. Like that.
In step S9, printing is started.

  As described above, according to the image forming apparatus of the present invention, it is possible to prevent a large amount of defective prints from occurring. On the other hand, for a small amount of prints, the user does not consider the discharge wire cleaning process for the time being. Can be prioritized, and convenience can be improved.

  Here, a method for changing the predetermined set print number threshold B will be described. In the above embodiment, the set print number threshold value B is initially set. However, if it is better to change the setting according to the application, first, the touch panel 31 of the operation panel 30 shown in FIG. 3 is switched to an application screen (not shown). Then, the value of the set print number threshold B is changed while operating on the application screen.

(Second Embodiment)
Next, an embodiment of an image forming system according to the present invention will be described with reference to the drawings. 6 is a schematic configuration diagram of the image forming system according to the present embodiment, FIG. 7 is a diagram showing an operation screen of a display of a personal computer, and FIG. 8 is a control-related block diagram of a control system in the image forming system according to the embodiment. It is.

  First, the overall schematic configuration of the image forming system will be described with reference to FIG. The image forming system GS is a system in which an image forming apparatus GH and a plurality of personal computers PC are configured on a network (LAN). Since the image forming apparatus GH is mechanically the same as the image forming apparatus described in the first embodiment, description thereof is omitted. The personal computer PC includes a keyboard, a display, a mouse, a main body, and the like.

  Next, the operation screen of the display 51 of the personal computer PC will be described with reference to FIG. The operation screen displays the contents necessary for operation and can be operated with the keyboard and mouse. 51a is an OK display mark for starting printing, 51b is a setting section for setting the number of prints, 51c is information notifying means for prompting cleaning, 51d and 51e are selection button displays, which are input by a click operation or the like.

  Next, control related blocks of the control system of the image forming system will be described with reference to FIG. The control-related block 40B of this image forming system is divided into an image forming apparatus side and a personal computer side. Since the control blocks on the image forming apparatus side are the same as those already described with reference to FIG. 4, the same reference numerals are given and description thereof is omitted, and the personal computer PC side will be described. The control system on the personal computer PC side includes a display 51, a keyboard 52, a mouse 53, and control means 50.

  Reference numeral 50 denotes control means on the personal computer PC side, which controls each block. The display 51 can set a set number of prints, display information on cleaning, and the like. The keyboard 52 and mouse 53 can set the number of prints.

  Next, the operation of the image forming system will be described with reference to FIGS. FIG. 9 is a control flowchart showing an operation example operated from the personal computer side in the image forming system. Note that the set number of prints is set, and the range of the control flowchart indicates from the print start operation to the print start. The method for changing the count of the number of cleanings and the cumulative print number threshold A is the same as in the first embodiment, and the description thereof will be omitted.

First, in step S11, an OK display (51a in FIG. 7) is clicked on the display 51 as a print start operation from the personal computer PC side.
In step S12, data is transmitted to the image forming apparatus GS side.
In step S13, it is determined whether or not the cumulative print number N of the cumulative print number counter (44 in FIG. 8) exceeds a cumulative print number threshold (also referred to as a threshold) A. If not, (NO) printing is started. If it exceeds (YES), the process proceeds to step S14.
In step S14, it is determined whether or not the set number of prints M to be set exceeds a predetermined set number of prints threshold (also referred to as a threshold) B. If it does not exceed (NO), for example, in the case of a small amount of printing, printing is started without displaying a cleaning message in order to prioritize printing for the time being. If it exceeds (YES), for example, in the case of a large amount of printing, the process proceeds to step S15, and data is transmitted to the PC side.
In step S16, in order to prevent a large amount of defective prints from being generated, a message regarding cleaning is displayed on the display 51 to encourage cleaning.
In step S17, whether or not cleaning is performed is selected. If it is selected not to clean immediately (NO), the button (51d in FIG. 7) is pressed to give priority to printing in step S19. If cleaning is selected (YES), the button (51e in FIG. 7) is pressed. Press to advance to step S18.
In step S18, when cleaning is performed immediately after the cleaning message is displayed, cleaning is performed. When the cleaning end button is pressed after the cleaning is completed, the process proceeds to step S19. When cleaning is not performed, the process proceeds to step S20. Give priority to print.
In step S19, the total number of prints in the total number of prints counter (44 in FIG. 8) is reset. In step S20, printing is started.

  As described above, according to the image forming system of the present invention, it is possible to prevent a large amount of defective prints from occurring. On the other hand, for a small amount of prints, the user does not think about the discharge wire cleaning process for the time being. Can be prioritized, and convenience can be improved.

  Here, another first determination unit will be described. In the first determination unit, the detected value is an electrical characteristic value related to the occurrence of uneven discharge of the charging member at the time of job setting, and the detection threshold value is a predetermined characteristic value threshold value related to the characteristic value. It is determined whether the characteristic value exceeds a characteristic value threshold.

  A method for obtaining the characteristic value will be described. FIG. 10 is an explanatory diagram for measuring characteristic values related to the occurrence of discharge unevenness of the charging member. In FIG. 10, an ammeter 27, a connection terminal on the image forming apparatus side connected to the connection terminal 21 a of the charging wire 21, and a connection terminal on the image formation apparatus side connected to the connection terminal 22 a of the shield plate 22, respectively. 26 is connected, so that an applied current value (Icc) to the charging wire 21 and a current value (Is) flowing into the shield plate 22 can be measured. Further, there is a calculation unit 29a connected to the ammeters 27 and 26 for calculating Is / Icc. Furthermore, there is a detecting means 29b for obtaining a characteristic value related to the occurrence of discharge unevenness.

  In the measurement operation, a high voltage + is applied to the charging wire 21 of the charging means and a low voltage + is applied to the shield plate 22 to generate a corona discharge, and the applied current value (Icc) to the charging wire 21 and the charging wire 21 The current value (Is) flowing into the shield plate 22 is measured by the ammeters 27 and 26, and the Is / Icc value is detected by the calculation unit 29a. The relationship between the detected Is / Icc value and the characteristic value related to the discharge unevenness is obtained in advance, and the characteristic value related to the occurrence of discharge unevenness is obtained by the detecting means 29b using the relationship. The characteristic value detected by the detecting unit 29b is stored in a non-volatile storage unit (not shown).

  In the present embodiment, the discharge unevenness of the charging member that charges the surface of the photosensitive drum, which is an image carrier, has been described. However, the present invention is not limited thereto. The same applies to the discharge unevenness of the member that performs the charging means.

  In the present embodiment, the monochrome image forming apparatus has been described. However, the present invention is not limited to this. For example, the same applies to a color image forming apparatus and a printer.

1 is a schematic configuration diagram of an image forming apparatus according to an exemplary embodiment. It is a block diagram of the charging means and the cleaning means in FIG. It is a block diagram of the operation panel in FIG. 3 is a control-related block diagram of a control system in the image forming apparatus according to the embodiment. FIG. 4 is a control flowchart illustrating an operation example of the image forming apparatus according to the embodiment. 1 is a schematic configuration diagram of an image forming system according to the present embodiment. It is a figure which shows the operation screen of the display of a personal computer. 3 is a control-related block diagram of a control system in the image forming system according to the embodiment. FIG. 5 is a control flowchart illustrating an operation example operated from the personal computer side in the image forming system. It is explanatory drawing which measures the characteristic value regarding generation | occurrence | production of the discharge nonuniformity of a charging member.

Explanation of symbols

GS image forming system GH image forming apparatus PC personal computer 20 charging means 21 charging wire 25 cleaning means 29b detecting means 30 operation panel 31a, 51c information notifying means 40A, 40B control-related blocks 41, 50 control means 42 first determination unit 43 first 2 Judgment Unit 44 Cumulative Print Counter 45 Cleaning Count Counter A Cumulative Print Threshold (Threshold)
N Cumulative number of prints B Set number of prints threshold (threshold)
M Number of set prints

Claims (11)

In the image forming apparatus including a cleaning unit that cleans the charging member of the charging unit,
Information notifying means for notifying information on cleaning of the charging member;
A first determination unit that determines whether or not a detection value related to discharge unevenness of the charging member at the time of job setting exceeds a predetermined detection threshold; and a set print number that is set in advance when the set print number is set at the time of job setting Control means for controlling a second determination unit for determining whether or not the threshold value is exceeded;
And the control means controls to notify information on cleaning when the detected value exceeds the detection threshold value and the set print number exceeds the set print number threshold value. Image forming apparatus. In the first determination unit, the detected value is a cumulative print number printed by the image forming apparatus at the time of job setting, the detection threshold is a predetermined cumulative print number threshold related to the cumulative print number, and the cumulative print 2. The image forming apparatus according to claim 1, wherein it is determined whether or not a number exceeds the cumulative print number threshold value. Has a cumulative print counter that counts the number of prints that have been imaged,
The image forming apparatus according to claim 2, further comprising a non-volatile storage unit that stores a cumulative print number of the cumulative print number counter. In the first determination unit, the detected value is an electrical characteristic value related to occurrence of uneven discharge of the charging member at the time of setting the job, and the detection threshold value is a predetermined characteristic value threshold value related to the characteristic value. 2. The image forming apparatus according to claim 1, wherein it is determined whether or not the characteristic value exceeds the characteristic value threshold value. Having a detecting means for detecting an electrical characteristic value related to uneven discharge of the charging member;
The image forming apparatus according to claim 4, further comprising a non-volatile storage unit that stores a value detected by the detection unit. The image forming apparatus according to claim 3, wherein the cumulative number of prints of the cumulative number of prints counter is reset after the charging member is cleaned. The image forming apparatus according to claim 2, wherein the cumulative print number threshold is changed according to the number of cleanings of the charging member. 8. The image forming apparatus according to claim 1, wherein at least one of the charging units is for charging the surface of the image carrier. The image forming apparatus according to claim 1, wherein the image forming apparatus is configured to be used on a network. In an image forming system in which an image forming apparatus including a cleaning unit for cleaning a charging member of a charging unit and a personal computer are configured on a network,
Information notifying means for notifying information on cleaning of the charging member;
A first determination unit that determines whether or not a detection value related to discharge unevenness of the charging member at the time of job setting exceeds a predetermined detection threshold value related to the detection value; and a set number of prints set at the time of job setting Control means for controlling a second determination unit for determining whether or not a predetermined set print number threshold value is exceeded;
The control means controls so that the personal computer is notified of cleaning information when the detected value exceeds the detection threshold and the set print count exceeds the set print count threshold. An image forming system. The image forming system according to claim 10, wherein the first determination unit and the second determination unit are provided on an image forming apparatus side.

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