JP2012078705A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an erroneous toner depletion notification by maintaining a state of a toner use amount of toner supply means or a toner residual amount coinciding with a count value by a toner counter.SOLUTION: A density correction control part 162 detects density of a density correction patch of each color formed by an image formation unit 50 of each color using a density sensor 80 and executes a density correction control to replenish toner of the color having the detected abnormal density from a toner cartridge of the color to the corresponding developing unit. As for a color component in which a density change is not detected between density correction patches when forming the density correction patches and detecting density again after the execution of the density correction control, a toner counting regulation control part 163 performs control not to perform cumulative addition by a count value of a toner amount corresponding to toner replenishing time from the toner cartridge of the color component to the pertinent developing unit in the image density correction control.

Description

  The present invention relates to an image forming apparatus.

  In an image forming apparatus such as a printer or a multifunction peripheral, a toner cartridge that is detachable from the apparatus main body, and a toner replenishing mechanism that replenishes toner from the toner cartridge mounted on the apparatus main body to the developing unit of the image forming unit. A configuration having this is known.

  In addition, some image forming apparatuses of this type do not have a function of detecting that a toner cartridge is mounted from the viewpoint of cost reduction.

  In this type of image forming apparatus, when printing is performed with a toner cartridge not attached, for example, the toner usage amount (or remaining toner amount) corresponding to the toner cartridge is updated, and as a result There may be a situation where the actual toner remaining amount corresponding to the cartridge does not match the count value.

  As an example of the operation control of the image forming apparatus using the remaining amount of toner as an index, Japanese Patent Application Laid-Open No. 2004-26883 discloses an estimated value of the remaining amount of toner in the toner cartridge when the toner concentration in the developing device is lower than a predetermined value. If it is larger than the predetermined value, there is a high possibility that the toner cartridge is not set correctly. Therefore, a technique for stopping the apparatus on the assumption that toner empty has occurred is disclosed.

JP 2010-2649 A

  In the image forming apparatus described above, the toner usage amount or the count value of the remaining amount of toner is referred to, for example, for grasping out of the toner of the corresponding toner cartridge, but printing is executed with the toner cartridge not attached. However, when the count is updated, for example, the remaining amount of toner does not match the count value, and there is a possibility that the toner empty is erroneously notified even though there is toner in the toner cartridge.

  It is an object of the present invention to provide an image forming apparatus capable of maintaining the state where the toner usage amount of the toner supply means or the remaining amount of toner matches the count value of the toner counter, and preventing erroneous operation stop control and toner out notification. Objective.

  In order to achieve the above object, the invention of the image forming apparatus according to claim 1 includes a developing unit that applies toner to an electrostatic latent image formed on an image carrier based on image information and develops the toner image. A toner supply unit that is detachably attached to the apparatus main body and supplies toner to the developing unit, and detects the density of the density correction image formed on the image carrier to which the toner image is transferred based on the density correction image information And density correction control for correcting the image density by supplying toner from the toner supply means to the developing means when the density of the density correction image detected by the density detection means is abnormal. And a density change between the density correction image formed after the image density correction control by the density correction control means and the density correction image formed during the image density correction control. When the density change detection means and the density change detection means detect that there is no density change between the density correction images, the toner count means counts according to the toner replenishment time by the density correction control means. And a restriction control means for restricting the cumulative addition of the toner count value.

  According to a second aspect of the present invention, there is provided the image forming apparatus according to the second aspect, wherein the toner of the color corresponding to the electrostatic latent image formed on the image carrier corresponding to each color component is applied based on the image information of the different color component. A plurality of developing means for developing as a toner image, a plurality of toner supplying means that are detachably attached to the apparatus main body and supply toner of a color corresponding to each of the developing means, and density correction image information of each color component A density detecting unit for detecting the density of the density correction image of each color component formed on the image carrier of the transfer destination on which the toner image of each color component is superimposed and transferred, and each of the colors detected by the density detecting unit Component density correction When the density of an image is abnormal, the toner supply means corresponding to the abnormal color component supplies toner to the corresponding developing means to correct the image density. Density correction control means, the density correction image of the color component having an abnormal density formed after the image density correction control by the density correction control means, and the color component of the color component formed during the image density correction control. A density change detecting unit that detects a density change between density correction images; and the density correction detecting unit detects that there is no density change between the density correction images of the color component having an abnormal density. Regulation control means for regulating cumulative addition of the toner count value counted by the toner counting means corresponding to the toner replenishment time of the color component by the control means.

  According to a third aspect of the present invention, in the second aspect of the present invention, when there is a color component detected by the density change detecting means that there is no density change between the density corrected images, the toner supply of the color component is performed. It further has an informing means for informing that the means is not correctly attached.

  According to a fourth aspect of the invention, in the invention of the second or third aspect, the count update restriction mode is set in correspondence with the color component detected by the density change detecting means that there is no density change between the density correction images. Setting means for setting is further provided, and the restriction control means forms an image by superimposing and transferring the toner images of the respective color components developed by the respective developing means to a recording medium through the image carrier of the transfer destination. At this time, the cumulative addition of the toner count value counted by the toner counting unit is regulated in correspondence with the toner supply time of each corresponding color from the toner supplying unit to the corresponding developing unit.

  According to a fifth aspect of the present invention, in the invention according to the fourth aspect, when there is no color component detected by the density change detecting means that there is no density change between the density correction images, any of the color components is detected. Correspondingly, when the count update restriction mode is set, the count update restriction mode is canceled.

  According to the image forming apparatus of the first aspect, when the toner cartridge is not attached, the count of the toner counter is not updated, and the state in which the remaining amount of toner matches the count value is maintained, so that the toner shortage is accurately detected. Can be notified.

  According to the invention of the image forming apparatus of the second aspect, in color printing, when the toner cartridge is not mounted for each color component, the count update of the toner counter is prohibited, and the state where the remaining amount of toner and the count value coincide with each other is prohibited. Can be maintained.

  According to the third aspect of the present invention, in the second aspect of the present invention, the installation of the toner cartridge is urged, and the toner density is lowered in the developing device while the toner cartridge is not mounted, and the carrier adheres to the photoconductor. Can be removed.

  According to the invention described in claim 4, in the invention described in claim 2 or 3, it is possible to prohibit the count update of the toner counter of the color component in which the toner cartridge is not mounted even in the normal printing process.

  According to the invention described in claim 5, in the invention described in claim 4, it is possible to return to a state in which a normal toner count can be performed when a toner cartridge is mounted and a change in density is detected during image density correction control. .

1 is a block diagram showing a functional configuration of an image forming apparatus according to an embodiment of the present invention. The figure which shows the structure of an image formation part. 6 is a time chart showing the relationship between image density and toner count value. FIG. 4 is a conceptual diagram illustrating a flow of toner count update restriction control during density correction control. 1 is a diagram illustrating a schematic configuration of a control system of an image forming apparatus. 6 is a flowchart illustrating a density correction / toner count restriction control operation according to the embodiment. The figure which shows the formation form of a density correction patch. The side surface conceptual block diagram which shows the mode of arrangement | positioning of a density sensor and the reading of a density correction patch. The table which shows the information holding | maintenance form of a count update control mode management table. FIG. 6 is a diagram illustrating a display example of a message prompting the user to install a toner cartridge. 6 is a flowchart illustrating an image formation control operation based on a print instruction according to the embodiment.

  FIG. 1 is a block diagram showing a functional configuration of an image forming apparatus 10 according to an embodiment of the present invention.

  The image forming apparatus 10 is premised on a multifunction peripheral, and reads an image of a document and reads and scans the document with the reading unit (scanner unit) 11 that converts the image into an electrical image signal (image data). An image processing unit 12 that performs image processing on the obtained image data and image data input from an external device (in this example, a client terminal 30 realized by a PC) such as a PC (personal computer), An image is formed on a recording medium (recording paper) by executing an electrophotographic process based on an image signal (print data) subjected to image processing by a storage unit 13 for storing various information such as data and operation programs, and an image processing unit 12 ( Image forming unit 14 for printing), display / operation unit 15 including a large-sized bitmap display having a touch panel function, document reading (scanning), copying ( P), printing (printing), facsimile (FAX) communication, etc. The control unit 16 that controls the entire apparatus, such as the operation control of each part, and the external interface (I) that controls the communication interface with the external device / F) portion 17 is provided.

  In the image forming apparatus 10, for example, as shown in FIG. 2, the toner (Y) of each color of yellow (Y), magenta (M), cyan (C), and black (black: K) is included in the image forming unit 14. , (M), (C), and (K), respectively, image forming units 50Y, 50M, 50C, which form Y (M, C, K) images (toner images). 50K is provided.

  The image forming units 50Y, 50M, 50C, and 50K respectively receive image signals (print data) of color components (Y component, M component, C component, and K component) that are input from the image processing unit 12 and that correspond to the units. ) Based on the exposure unit 51Y, 51M, 51C, 51K that performs image exposure with laser light, and a photosensitive drum 52Y as an image carrier on which an electrostatic latent image corresponding to the image signal of each color component is formed by the image exposure. 52M, 52C, and 52K, and charging portions 53Y, 53M, 53C, and 53K that charge the peripheral surfaces of the photosensitive drums 52Y, 52M, 52C, and 52K before the formation of the electrostatic latent image, and different colors (C, M, Y, and The toner of the color corresponding to the electrostatic latent image formed on the photosensitive drums 52Y, 52M, 52C, and 52K is supplied to form toner images of the respective colors. The developing units 54Y, 54M, 54C, 54K are detachably attached to the apparatus main body, and are loaded with Y color, M color, C color, and K color toners, respectively, and the corresponding color developing units 54Y, 54M, 54C, The toner cartridges 55Y, 55M, 55C, and 55K (toner supply means in the claims) that supply the corresponding color toner to 54K, the corresponding developing units 54Y, 54M, and 55K from the toner cartridges 55Y, 55M, 55C, and 55K There are provided toner supply motors 56Y, 56M, 56C, and 56K that drive a mechanism (not shown) that feeds toner of the corresponding color to 54C and 54K.

  The image forming unit 14 also includes an intermediate transfer belt (hereinafter referred to as transfer belt: transfer in claims) that sequentially multiplex-transfers (primary transfer) toner images of each color developed by the developing units 54Y, 54M, 54C, and 54K. 61), between the photosensitive drum 52Y and the belt conveying roller 63Y, between the photosensitive drum 52M and the belt conveying roller 63M, between the photosensitive drum 52C and the belt conveying roller 63C, and between the photosensitive drum 52K and the belt conveying roller 63K. The transfer belt 61 is passed through the belts, and belt transport rollers 62a and 62b that transport the transfer belt 61 in the direction of the arrow, and each color formed on the transfer belt 61 in density correction control (process control: process control) described later. A density sensor 80 for detecting the density of a toner image (density correction image) for density correction control is provided.

  In the image forming apparatus 10 having the image forming unit 14 having such a configuration, for example, when a print instruction is given from an external client terminal (PC) 30, print data of document information to be printed is generated by the image processing unit 12. Then, image formation is performed by an electrophotographic process based on the print data.

  In this electrophotographic process, in each of the image forming units 50Y, 50M, 50C, 50K, the exposure units 51Y, 51M, 51C, 51K respectively correspond to the corresponding color components (Y component, M component) input from the image processing unit 12. , C component, K component) image exposure by laser light based on image signals (print data) to form electrostatic latent images of the respective color components on the peripheral surfaces of the photosensitive drums 52Y, 52M, 52C, 52K, and then The toners of the colors corresponding to the electrostatic latent images formed on the photosensitive drums 52Y, 52M, 52C, and 52K are supplied by the developing units 54Y, 54M, 54C, and 54K to form toner images of the respective colors. The toner images of the respective colors are superimposed and transferred (primary transfer) onto the transfer belt 61 being conveyed in the illustrated direction.

  The toner images of the respective colors superimposed and transferred on the transfer belt 61 are further transferred (secondly) by a transfer unit (not shown) to a sheet fed and conveyed one by one from a paper feed cassette (not shown). Then, the toner image is fixed on a sheet by a fixing unit (not shown) and discharged.

  FIG. 3 shows the density (toner density) of the image formed by the electrophotographic process and the corresponding color component toner counter (toner counting means in claims: equivalent to the toner counting processing unit 1631 in FIG. 5). 4 is a time chart showing the relationship between toner count values, and particularly shows an example in the case of Y color.

  According to FIG. 3, based on the image data of each color component of Y, M, C, and K, the Y image, M image, and timing at the timings of FIGS. 3 (a), (b), (c), and (d), respectively. When printing a C image and a K image, toner supply motors 56Y (DispMot Y), 56M (DispMot M), 56C (DispMot C), and 56K (DispMot K) are respectively shown in FIGS. The toners Y, M, C, and K are supplied from the toner cartridges 55Y, 55M, 55C, and 55K to the developing units 54Y, 54M, 54C, and 54K by being driven at the timings f), (g), and (h). Is done.

  At that time, for the Y color component, as shown in FIG. 3I, the toner counter counts the Y color toner consumption amount by converting the driving time of the Y image toner supply motor 56Y into, for example, the toner consumption amount. The total toner consumption is sequentially updated by cumulatively adding the count values.

  According to this counting operation, when the Y toner cartridge 55Y is mounted in the apparatus main body, the toner is normally supplied to the Y developing unit 54Y. As a result, as shown in FIG. As shown, the image density is maintained within the specified range of the reference value even when printing proceeds.

  On the other hand, when the Y-color toner cartridge 55Y is not mounted in the apparatus main body, the toner supply to the Y-color developing unit 54Y is cut off, so as shown in FIG. The density (below the reference value) gradually decreases.

  Similarly, for the other colors, when the toner cartridges 55M, 55C, and 55K are not mounted in the apparatus main body, the toner supply to the developing units 54M, 54C, and 54K is cut off, and as a result, the printing of each color progresses. The image density gradually decreases.

  As a result, if printing is continued with the toner cartridge 55 not attached, the toner consumption of the toner counter will continue to be counted for the color component without the toner cartridge 55 attached. The amount of toner and the remaining amount of toner remaining in the unmounted toner cartridge 55 are inconsistent, and the replacement timing of the toner cartridge 55 cannot be determined correctly.

  Therefore, in the present exemplary embodiment, it is estimated that the toner cartridge 55 is not installed by using the density correction control function provided in the image forming apparatus 10, and the density of the color estimated that the toner cartridge 55 is not installed is estimated. Control is performed to restrict the cumulative addition of the toner count value corresponding to the toner replenishment time during the correction control.

  FIG. 4 is a conceptual diagram showing the flow of toner count update restriction control during density correction control according to the present embodiment.

  According to FIG. 4, for example, a density correction image (density correction image: hereinafter referred to as a density correction patch) is formed at the density correction control execution timing when the power is turned on (or at the end of printing), and the density is detected (1 If there is a color component with an abnormal density, the toner supply motor 56 for that color component is driven to replenish the toner (step S401).

  At this time, the toner consumption is counted corresponding to the driving time (Disp time) of the toner supply motor 56, and the count value is held (step S402).

  If it is a normal apparatus, then a patch image used for exposure / development control is formed, and the exposure amount and development bias of the corresponding color component are controlled based on the detection result of the density of the patch image (step S422).

  However, in this embodiment, after the toner replenishment based on the density of the density correction patch formed at the first time, a second density correction patch is formed to detect the density (second density detection), and the first time. It is determined whether the density has changed between the formed density correction patch and the density correction patch formed for the second time (step S411).

  If there is a color component having no density change, a process of adding the toner amount (count value) corresponding to the toner replenishment time, which has been held in the density correction control for the first time, to the cumulative value for the color component is performed. Control is performed to restrict (prohibit) (step S412).

  In order to realize such control, in the image forming apparatus 10 (see FIG. 1) of the present embodiment, the control unit 16 includes a print control unit 161 that performs the above-described color image formation (printing) control, and the density of each color toner. In addition to the density correction control unit 162 that performs the correction control, the density change of the density correction patch formed after the density correction control by the density correction control unit 162 is monitored, and the toner count that regulates the toner count update process according to the density change A restriction control unit 163 is provided.

  FIG. 5 shows a schematic configuration of a control system that realizes density correction control and toner count restriction control of the image forming apparatus 10 in FIG.

  In FIG. 5, the density correction control unit 162 performs density correction control with a timing determination unit 1621 and a timing determination unit 1621 that determine the timing (for example, when the apparatus is turned on and when printing is finished). If it is determined that the timing is reached, the density correction mode is activated, and the image forming process of each color image forming unit 50 (50Y, 50M, 50C, 50K) is controlled to control the density correction control image (density) for each color. A correction image (hereinafter referred to as a density correction patch) is formed (drawn) and transferred onto the transfer belt 61, whereby density correction patches for each color arranged in the conveying direction on the transfer belt 61 at predetermined intervals. The density correction patch of each color formed on the image forming processing unit 1622 and the transfer belt 61 to be formed is read by the density sensor 80. Each of the colors detected by the image density detection unit 1623 and the image density detection unit 1623 detects the density of the density correction patch of each color from the density detection output. It is determined whether or not the density of the density correction patch is abnormal [out of the specified range with respect to the reference value (density is low)]. If it is determined that the density is abnormal, the image forming unit 50 for each color is determined. In this case, by driving the toner supply motor 56 (56Y, 56M, 56C, 56K) corresponding to the color, the developing unit 54 (54Y) of the color from the toner cartridge 55 (55Y, 55M, 55C, 55K) of the color. , 54M, 54C, 54K) is supplied with toner of the corresponding color, and the density of the toner image of the color is within a specified range. So as constructed by the toner supply control unit 1624 performs density correction control.

  In addition, the toner count restriction control unit 163 performs the toner replenishment time each time the toner of the corresponding color is replenished by determining that the density is low for each color component in the image density correction control by the density correction control unit 162. (Toner drive motor 56 corresponding to the color) is converted into a toner amount and counted, and a toner count processing unit (total toner use amount) is counted by accumulating the count results. Hereinafter, the toner counter) 1631, for each color component, the density correction patch formed first in the image density correction control, and the density formed again after it is determined that the density of the density correction patch is low and toner is supplied. A density change detection unit 1632 that detects whether or not there is a density change between correction patches, and a density correction patch that is first formed by the density change detection unit 1632 and re-formation For the color detected as having a density change between the density correction patches, the toner counter 1631 performs cumulative addition of the toner amount count value corresponding to the toner replenishment time of the color (updating the toner count). For the color detected by the density change detection unit 1632 as having no density change, the toner counter 1631 does not perform cumulative addition of the toner amount count value (toner count update) corresponding to the toner replenishment time of the color. An update restriction control unit 1633 is provided to control as described above.

  Hereinafter, density correction control and toner count regulation control in the image forming apparatus 10 of the present embodiment will be described in detail with reference to examples.

  FIG. 6 is a flowchart illustrating the density correction / toner count restriction control operation of the image forming apparatus 10 according to the embodiment.

  In the image forming apparatus 10 according to the present exemplary embodiment, the control unit 16 performs density correction when the timing determination unit 1621 of the density correction control unit 162 recognizes that the power is turned on (or recognizes that printing is finished). The mode is shifted to and the density correction / toner count restriction control shown in FIG. 6 is started.

  As shown in FIG. 6, when the mode is shifted to the density correction mode, first, a process for forming a density correction patch is performed (step S110: density correction patch forming process).

  In this density correction patch forming process, the image formation processing unit 1622 of the density correction control unit 162 corresponds to each image forming unit 50 for each color image forming unit 50 (50Y, 50M, 50C, 50K). At this timing, a drawing instruction signal for the density correction patch is sequentially transmitted.

  In each color image forming unit 50, based on the density correction patch drawing instruction signal, the exposure unit 51 exposes and scans the photosensitive drum 52 based on the density correction patch data of the corresponding color, thereby generating an electrostatic latent image. Then, the developing unit 54 develops the electrostatic latent image as a toner image (density correction patch) of a corresponding color, and executes control for transferring the density correction patch to the transfer belt 61.

  By this transfer process, for example, as shown in FIG. 7, density correction patches DPk, DPc, DPm, and DPy of respective colors arranged along the transfer belt 61 conveyance direction are formed on the transfer belt 61.

  On the other hand, the density sensor 80 includes, for example, a light emitting element 801 that emits light to the transfer belt 61 and a light receiving element 802 that receives reflected light of the irradiated light from the transfer belt 61 as shown in FIG. .

  The density correction patches DPk, DPc, DPm, and DPy of each color formed on the transfer belt 61 in the density correction patch forming process in step S110 are thereafter density sensors shown in FIG. 8 in accordance with the conveyance of the transfer belt 61. The 80 reading positions are sequentially passed.

  At this time, from the density sensor 80 (light receiving element 802), the density correction patches DPk, DPc, DPm, and DPy formed on the transfer belt 61 sequentially pass through the reading position of the density sensor 80, and The density detection output of each color patch image is obtained.

  The image density detector 1623 detects the density of each color toner of K, C, M, and Y from the detection output of the density sensor 80 (step S120: toner density detection process).

  Next, the image density detection unit 1623 temporarily holds the toner density information (density detection data) of each color detected in step S120, for example, in a predetermined area of the storage unit 13 (step S130).

  Next, the toner replenishment control unit 1624 checks whether or not the density detection is the first time (step S131).

  If it is determined that the first density detection is made (YES in step S131), the image density detection unit 1623 determines whether the detected image density is normal for each color based on the density detection data held in step S130. Alternatively, it is checked whether it is abnormal, that is, whether the reference density is maintained or thinner (step S132).

  If it is determined that the density is normal (step S132 NO), the process proceeds to the exposure / development control process (step S150).

  On the other hand, when it is determined that the image density of any color is abnormal (light) (YES in step S132), the toner replenishment control unit 1624 develops the color of which the toner density is determined to be abnormal (light). Control is performed so that the toner of the corresponding color is replenished from the corresponding toner cartridge 55 (step S133).

  In this toner replenishment control, the toner supply motor 56 corresponding to the color in which the toner density is determined to be abnormal (light) is driven, so that the toner cartridge 55 of the color corresponds to the corresponding developing unit 54 of the image forming unit 50. Replenish toner of that color.

  In the toner supply control, the toner counter 1631 counts the toner amount (toner consumption amount) corresponding to the toner supply time (driving time of the toner supply motor 56) at this time, and holds the count value (step S134). .

  Thereafter, the process proceeds to step S110, where the image formation processing unit 1622 again forms the density correction patch on the transfer belt 61 through the above process based on the density correction patch data, and the image density detection unit 1623 outputs the detection output of the density sensor 80. The image density of each color is detected (step S120), and the density detection data is held (step S130).

  Subsequently, the toner replenishment control unit 1624 checks whether or not the density detection is the first time (step S131). If it is determined that the density detection is not the first time (NO in step S131), the toner counting restriction control is performed. The density change detection unit 1632 of the unit 163 stores the density detection data of the density correction patch formed at the beginning (during the first density detection) held in step S130 and the density correction control by the density correction patch ( The density is compared between the density detection data of the density correction patches formed at the time of the second density detection), and for each color, there is a color in which the second detected density does not change with respect to the first detected density It is checked whether or not to perform (step S141).

  If it is determined that there is a color having no density change between the first density correction patch and the second density correction patch (YES in step S141), the update restriction control unit 1633 stores the color held in step S134. Control is performed to restrict (prohibit) the cumulative addition of the count value of the toner amount (toner consumption amount) corresponding to the color toner replenishment time (step S142).

  At this time, for the color in which the density between the density correction patches is changed, the cumulative addition of the count value of the toner amount (toner consumption amount) corresponding to the toner replenishment time of the color held in step S134. Is executed.

  In step S134, after the cumulative addition regulation control of the toner count value of the color having no density change between the density correction patches (and the cumulative addition regulation processing of the toner count value of the color having the density change), the update regulation control unit 1633 sets the count update restriction mode corresponding to the color whose density has not changed (step S143).

  The setting of the count update restriction mode corresponds to, for example, a color whose density has not changed in the count update restriction mode management table 135 (for example, provided in the storage unit 13) having a configuration as shown in FIG. This is done by setting (writing) a flag ["1"] indicating the count update restriction mode.

  In FIG. 9, C color is determined as a color having no density change between the density correction patch formed first time and the density detection formed second time, and the count update restriction mode is set for the C color. An example was given.

  Subsequently, the update restriction control unit 1633 notifies that the toner cartridge 55 of the color set in the count update restriction mode (the color in which the detected density does not change between the first time and the second time) is urged to be attached (step S144). Then, the process proceeds to step S150.

  In the notification process in step S144, for example, a message that prompts the user to attach the toner cartridge 55 is displayed on the display panel of the display / operation unit 15.

  As a specific example, when the C color is set to the count update restriction mode as shown in FIG. 9, the density of C color (cyan) is abnormal as shown in FIG. The notification screen 155 including a message such as “Please set.” Is displayed.

  On the other hand, if it is determined in step S141 that there is no color having no density change between the density correction patches (NO in step S141), the update restriction control unit 1633 displays the count update restriction mode management table 135 (see FIG. 9). When there is a color [flag is “1”] that is set in the count update restriction mode, the count update restriction mode for that color is canceled (flag “1” is deleted), and then step S150. Migrate to

  When the process proceeds to the exposure / development control process in step S150, the print control unit 161 forms an exposure / development control patch on the transfer belt 61, and the exposure amount, development bias, and the like are determined according to the density detection result of the patch. Adjustment control is performed, and then the process proceeds to a normal image forming process based on a print instruction or the like.

  As can be seen from the series of control operations shown in FIG. 6, in the image forming apparatus 10, the toner cartridge 55 for a certain color is replenished when the toner cartridge 55 for a certain color is not mounted and the density correction patch for that color is light. If the density does not change even after the toner is added, control is performed to prohibit the cumulative addition based on the toner count value in the toner counter 1633 corresponding to the toner replenishment time of the color. It is a mechanism that allows printing to continue with being mounted (no control for stopping printing when no toner cartridge is mounted).

  The image forming control operation of the image forming apparatus 10 in this case will be described with reference to the flowchart shown in FIG.

  In FIG. 11, for example, when the image forming apparatus 10 receives a print instruction from the PC 30 (YES in step S <b> 201), the image forming apparatus 10 performs an electrophotographic process based on the print data of the document information instructed to print under the control of the print control unit 161. Then, an image is formed (printed) on the paper and output (step S202).

  During execution of the electrophotographic process, the toner counter 1631 adjusts toner supply from the toner cartridge 55 to the corresponding developing unit 54 when forming an image for each color (FIGS. 3E to 3I). The toner amount corresponding to the toner replenishment time is counted, and the count value is held (step S203).

  It is checked whether or not the printing of the page has been completed while performing the processes of steps S202 and S203 (step S204), and if it is determined that the printing of the page has been completed (YES in step S204), the update restriction control unit 1633 counts. The update restriction mode management table 135 (see FIG. 9) is searched to check whether there is a color set in the count update restriction mode (flag “1” is written) (step S205).

  Here, if there is a color set in the count update restriction mode, the cumulative addition of the toner count value corresponding to the toner replenishment time of the color held in step S203 is prohibited for the color (step S203). S206a) On the other hand, for other colors that are not set in the count update restriction mode, the cumulative addition of the toner count value corresponding to the toner replenishment time of the corresponding color held in step S203 is executed (step S206b). .

  Subsequently, it is checked whether or not there is a next page (step S207). While there is a next page (step S207 YES), printing of the corresponding page is continued (steps S202 to S206), and there is no next page during this period. Is determined (NO in step S207), the series of image formation control ends.

  In the image forming apparatus 10 according to the present exemplary embodiment, only when the image density correction control (procedure control) is performed, the toner counter is updated for a color in which there is no density change between the first and second density correction patches (a toner cartridge is not mounted). When the process is to be restricted, the process of step S106a shown in FIG. 11 is not necessary, and the processes of steps S143 and S145 in FIG. 6 are also unnecessary.

  In the above embodiment, the case where the toner counter 1631 counts the amount of toner used (consumed amount) has been described as an example. However, the toner counter 1631 counts the toner consumed amount, and further responds based on the count value. This can also be applied to the case where the remaining amount of toner in the toner cartridge 55 to be counted is counted (the toner consumption amount is subtracted from the toner accommodation amount of the toner cartridge 55).

  In addition, the present invention is not limited to the embodiment described above and shown in the drawings, and can be implemented by being appropriately modified within a range not changing the gist thereof.

  For example, in the above-described embodiment, an example of toner counter update restriction control for a color that does not change in density at the time of pro-conversion for all colors in the color image forming apparatus has been described, but K that is performed when printing in monochrome mode is performed. The present invention can also be applied to K color toner counter update restriction control at the time of a process control for only color.

  In the above embodiment, an example of application to a color image forming apparatus is given. However, any apparatus having a process control function can be applied to a monochrome image forming apparatus.

  The present invention can be applied to an image forming apparatus such as a printer or a multifunction peripheral having an image density correction function without having a toner cartridge mounting detection function.

  DESCRIPTION OF SYMBOLS 10 ... Image forming apparatus, 11 ... Reading part, 12 ... Image processing part, 13 ... Memory | storage part, 14 ... Image forming part, 50Y, 50M, 50C, 50K ... Image forming unit, 54Y, 54M, 54C, 54K ... Developing part 55Y, 55M, 55C, 55K ... toner cartridge, 56Y, 56M, 56C, 56K ... toner supply motor, 60 ... transfer belt, 15 ... display / operation unit, 16 ... control unit, 161 ... print control unit, 162 ... density Correction control unit, 1621 ... Timing determination unit, 1622 ... Image formation processing unit, 1623 ... Image density detection unit, 1624 ... Toner replenishment control unit, 163 ... Toner counting restriction control unit, 1631 ... Toner counting processing unit (toner counter), 1632 ... Density change detection unit, 1633 ... Update restriction control unit, 17 ... External interface (I / F) unit, 30 ... Client end (PC: Personal Computer), 80 ... concentration sensor

Claims (5)

Developing means for applying toner to the electrostatic latent image formed on the image carrier based on the image information and developing it as a toner image;
A toner supply means that is detachably attached to the apparatus main body and supplies toner to the developing means;
Density detecting means for detecting the density of a density-corrected image formed on an image carrier to which the toner image is transferred based on density-corrected image information;
Density correction control means for correcting image density by supplying toner from the toner supply means to the developing means when the density of the density correction image detected by the density detection means is abnormal;
Density change detection means for detecting a density change between the density correction image formed after the image density correction control by the density correction control means and the density correction image formed during the image density correction control;
When the density change detecting means detects that there is no density change between the density correction images, the cumulative addition of the toner count value counted by the toner counting means corresponding to the toner replenishment time by the density correction control means An image forming apparatus comprising: restriction control means for restricting A plurality of developing means for applying toner of a color corresponding to an electrostatic latent image formed on an image carrier corresponding to each color component based on image information of different color components and developing as a toner image of each color;
A plurality of toner supply means that are detachably attached to the apparatus main body and supply toner of a color corresponding to each of the developing means;
Density detecting means for detecting the density of the density-corrected image of each color component formed on the image carrier of the transfer destination that superimposes and transfers the toner image of each color component based on the density-corrected image information of each color component;
When the density of the density correction image of each color component detected by the density detection unit is abnormal, toner is supplied from the toner supply unit corresponding to the color component with the abnormal density to the corresponding developing unit. Density correction control means for correcting the image density,
Density change between the density correction image of the color component having an abnormal density formed after the image density correction control by the density correction control unit and the density correction image of the color component formed at the time of the image density correction control Concentration change detecting means for detecting
When it is detected by the density change detection means that there is no density change between the density correction images of the color component having an abnormal density, the toner corresponding to the toner replenishment time of the color component by the density correction control means An image forming apparatus comprising: restriction control means for restricting cumulative addition of toner count values counted by the counting means. In the case where there is a color component detected by the density change detection means that there is no density change between the density correction images, there is further provided an informing means for informing that the toner supply means for the color component is not correctly attached. The image forming apparatus according to claim 2. A setting means for setting a count update restriction mode corresponding to the color component detected by the density change detection means that there is no density change between the density correction images;
The regulation control means is
When the toner images of the respective color components developed by the developing means are superimposed and transferred onto a recording medium through the image carrier as the transfer destination, an image is formed from the toner supplying means to the corresponding developing means. The image forming apparatus according to claim 2, wherein the cumulative addition of the toner count value counted by the toner counting unit is regulated in correspondence with the toner supply time of each corresponding color. When there is no color component detected by the density change detection means that there is no density change between the density correction images, the count update restriction mode is set corresponding to any of the color components. The image forming apparatus according to claim 4, wherein the update restriction mode is canceled.

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