JP2010262101A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus improved in productivity and operability by reducing dead time caused by an image correction operation and material consumption. <P>SOLUTION: The image forming apparatus includes: image correction means; environment detection means; execution status storage means; and control means. The control means interrupts a correction operation being executed when an interruption factor is detected during the image correction operation, and when the interruption factor is eliminated, and the resumption of the correction operation is directed, compares an up-to-date environmental parameter at the interruption stored in the execution status storage means with an environmental parameter detected by the environment detection means when the resumption of the correction operation is directed. When a variation of the environmental parameter is within the allowable range, the control means takes over the correction data from the execution step stored in the execution status storage means, and resumes the image correction from the interrupted execution step. When the variation is beyond the allowable range, it performs control to re-execute the correction from the beginning of the interrupted execution step of the image correction means. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as an electrophotographic copying machine, a facsimile, and a printer. Specifically, the present invention relates to image correction in an image forming apparatus.

  Various methods are known as an image forming apparatus for forming a color image, and one of them is a method called a tandem method. The tandem image forming apparatus includes a photosensitive drum as an image carrier, an optical scanning device that writes image information data on the photosensitive drum, a developing unit that develops an electrostatic latent image formed on the photosensitive drum, and the like. A plurality of image forming apparatuses and a transfer unit for transferring an image, which is a toner image formed on the photosensitive drum in each image forming apparatus, onto one recording material.

  As an image forming apparatus including the transfer unit, an image forming apparatus that transfers an image formed on an image carrier to an intermediate transfer member including an endless belt of the transfer unit and transfers the image on the intermediate transfer member to a recording material is known. It has been. Since the image forming apparatus using the intermediate transfer member can superimpose the image formed on the image carrier on the intermediate transfer member, it is widely applied to a color image forming apparatus for forming a color image on a recording material. ing. In this color image forming apparatus, images of three colors of yellow (Y), magenta (M), cyan (C), or black (Bk) formed on each image carrier are added to the intermediate transfer member. After superimposing and transferring, the superposed image is collectively transferred to a recording material using electrostatic force.

  In general, in the image forming apparatus using the electrophotographic method as described above, in order to ensure a constant image quality, image correction such as charging, exposure, development, and transfer output value adjustment and color image registration correction are performed in a predetermined manner. This is executed when the above conditions are satisfied. Once this image correction operation has been executed, no other operation (especially an image forming operation) can be carried out until the image correction operation is completed. Time), and the productivity of the equipment was reduced.

  On the other hand, a color misregistration correction unit that corrects color misregistration, a detection unit that detects environmental temperature, and a control unit are provided. When the power is turned on, a color misregistration correction operation is performed in parallel with the start-up operation. However, an image forming apparatus is disclosed in which the color misregistration correction operation is re-executed when the activation operation is resumed when the operation is interrupted in the middle (see, for example, Patent Document 1). In Patent Document 1, the color misregistration correction is performed only when the detected temperature when the start-up operation is resumed is equal to or lower than a predetermined value when the color misregistration correction operation has already been completed.

  Also, when performing image correction sequentially with a plurality of image correction means, when the image correction that was interrupted due to external factors is resumed, the temperature or humidity fluctuations at the time when the image correction is interrupted and restarted are compared and within a predetermined range. In this case, an image forming apparatus is disclosed in which an unfinished image correcting unit is operated without re-activating an already completed image correcting unit (see, for example, Patent Document 2).

JP 2004-157413 A JP 2007-316195 A

  In Patent Document 1, when the color misregistration correction operation has already been completed, the color misregistration correction is re-executed only when the detected temperature at the time of restarting the start-up operation is equal to or lower than a predetermined value. By configuring so that the correction is not re-executed, the waiting time of the operator can be reduced by executing the color misregistration correction.

  However, the color misregistration correction operation is not always completed when the activation operation is interrupted, and the correction operation is often in the middle. In Patent Document 1, when the correction operation is in progress, the correction operation is always performed from the beginning regardless of the environmental temperature, and it is difficult to effectively reduce the standby time.

  Japanese Patent Application Laid-Open No. 2004-26883 discloses an image correction unit that has been interrupted and has not been completed without operating the already-completed image correction unit again when the variation in temperature or humidity at the time of interruption and resumption of image correction is within a predetermined range. It is to be operated. Further, when the fluctuation is outside the predetermined range, the plurality of image correcting means are operated again from the beginning. As a result, the waiting time for the operator is reduced by executing the image correction, and the consumption of materials such as toner is further reduced.

  However, the interrupted image correction means always operates from the first step, and it is difficult to effectively reduce the standby time and the material consumption.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an image forming apparatus in which dead time and material consumption due to an image correction operation are reduced, and productivity and operability are improved. .

  The above object is achieved by the following configuration.

1. When the correction operation is interrupted at an arbitrary execution step of the execution step during the execution of the image correction operation including a plurality of execution steps, there is correction data necessary to restart the correction operation from the arbitrary execution step. A plurality of image correction means capable of resuming and executing the correction operation from the arbitrary execution step;
Environmental detection means for detecting environmental parameters during image correction operation execution;
As the correction operation status during execution of the image correction operation, execution status storage means for storing the execution step, the correction data, and the environmental parameters as needed,
An interruption factor monitoring means for monitoring an interruption factor that makes it impossible to continue the execution step of the correction operation;
Control means for controlling the image correction means,
The control means causes the image correction means to be executed from the beginning of the execution step when starting the correction operation, and when the interruption factor is detected, the correction operation being executed is interrupted and the interruption factor is released. When the restart of the correction operation is instructed, the latest environmental parameters stored at the time of interruption stored in the execution status storage unit and the environment detection unit at the time when the restart of the correction operation is instructed are detected. When the variation amount of the environmental parameter is within an allowable range, the image correction is resumed from the interrupted execution step by taking over the correction data of the interrupted execution step stored in the execution status storage means. When the variation amount is out of the permissible range, the image forming apparatus is controlled so that the correction is re-executed from the beginning of the execution step of the interrupted image correction unit.

  2. 2. The image forming apparatus according to 1, wherein the correction data is measurement data or a calculation result of a correction amount derivation process.

  3. 3. The image forming apparatus according to 1 or 2, wherein the environmental parameter is one or more of temperature, humidity, and time.

  4). The execution step stored in the execution status storage unit includes information that makes it possible to determine an image correction unit being executed from among the plurality of image correction units. The image forming apparatus described in the item.

  5. 5. The image forming apparatus according to any one of claims 1 to 4, wherein the interruption factor is any one of a door opening / closing operation, a power shutdown, and an interrupt operation of a print instruction by an operator.

  6). The interruption factor monitoring means has a function of allowing the operator to select whether to interrupt the correction operation and perform the printing operation when receiving a print instruction from the operator during the correction operation. 6. The image forming apparatus according to any one of 1 to 5, wherein the image forming apparatus is characterized.

  7). 7. The image forming apparatus according to any one of claims 1 to 6, wherein the allowable range of the variation amount can be individually set according to the plurality of image correction units.

  According to the present invention, it is possible to reduce the dead time and material consumption resulting from the interruption of the image correction operation without impairing the reliability of the image correction, and to improve the productivity and operability of the image forming apparatus. Can do.

1 is a diagram illustrating an example of an image forming apparatus according to the present invention. It is a block diagram which shows control of the image correction which concerns on this invention. It is a figure which shows the example of a message displayed with respect to interruption printing. FIG. 10 is a flowchart when an interruption factor is canceled and an image correction operation is restarted.

  Embodiments of an image forming apparatus according to the present invention will be described below with reference to the drawings. The present invention is not limited to the following.

  FIG. 1 is a diagram showing an example of an image forming apparatus according to the present invention.

  The image forming apparatus GH according to the present invention is called a tandem color image forming apparatus, and includes a plurality of image forming units 10Y, 10M, 10C, and 10K, a transfer unit 60 having an endless belt-shaped intermediate transfer body 6, It comprises a sheet feeding / conveying means and a fixing device 9.

  Hereinafter, the image forming units 10Y, 10M, 10C, and 10K are collectively referred to as the image forming unit 10.

  An image reading device YS including an automatic document feeder 201 and a document image scanning exposure device 202 is installed above the image forming apparatus GH. The document d placed on the document table of the automatic document feeder 201 is transported by a transport unit, and an image on one or both sides of the document is scanned and exposed by the optical system of the document image scanning exposure device 202, and the line image sensor CCD is scanned. Is read.

  The signal formed by photoelectric conversion by the line image sensor CCD is subjected to analog processing, A / D conversion, shading correction, image compression processing, and the like in the image processing unit, and then exposure means 3Y, 3M, 3C, 3K. Sent to.

  In the image forming unit 10Y that forms a yellow (Y) image, a charging unit 2Y, an exposure unit 3Y, a developing device 4Y, and a cleaning unit 8Y are arranged around the photosensitive drum 1Y. In the image forming unit 10M that forms a magenta (M) color image, a charging unit 2M, an exposure unit 3M, a developing device 4M, and a cleaning unit 8M are arranged around the photosensitive drum 1M. In the image forming unit 10C that forms a cyan (C) color image, a charging unit 2C, an exposure unit 3C, a developing device 4C, and a cleaning unit 8C are arranged around the photosensitive drum 1C. In the image forming unit 10K that forms a black (Bk) image, a charging unit 2K, an exposure unit 3K, a developing device 4K, and a cleaning unit 8K are arranged around the photosensitive drum 1K. The charging unit 2Y and the exposure unit 3Y, the charging unit 2M and the exposure unit 3M, the charging unit 2C and the exposure unit 3C, and the charging unit 2K and the exposure unit 3K constitute a latent image forming unit.

  The intermediate transfer body 6 is wound around a plurality of rollers and is rotatably supported.

  The fixing device 9 is stretched between a first pressure roller 93 having an elastic layer on a metal core, a heating roller 92 having a heating means inside, and between the first pressure roller 93 and the heating roller 92. An endless fixing belt 91 and a second pressure roller 94 which is disposed in a position facing the first pressure roller 93 so as to be in pressure contact with the fixing belt 91 and forms a fixing nip portion. The unfixed toner surface of the recording material P carrying the toner passes through the fixing nip portion in a direction in contact with the fixing belt 91 so that the unfixed toner is fixed to the recording material P by heating and pressing.

  Thus, the images of the respective colors formed by the image forming units 10Y, 10M, 10C, and 10K are sequentially superimposed and transferred onto the rotating intermediate transfer body 6 by the transfer means 7Y, 7M, 7C, and 7K (primary). Transfer), an image in which a color image is synthesized is formed.

  The recording material P accommodated in the paper feeding cassette 20 is fed by the paper feeding means 21 and is conveyed to the transfer means 7A through the paper feeding rollers 22A, 22B, 22C, 22D, the registration rollers 23, etc. A color image is transferred onto P (secondary transfer).

  The recording material P to which the color image has been transferred is heated and pressurized in the fixing device 9 and the color image on the recording material P is fixed. Thereafter, the sheet is sandwiched between the sheet discharge rollers 24 and placed on the sheet discharge tray 25 outside the apparatus.

  On the other hand, after the color image is transferred to the recording material P by the transfer means 7A, the residual toner is removed by the cleaning means 8A from the intermediate transfer body 6 from which the recording material P is separated by curvature.

  The image forming apparatus GH is basically configured to perform image formation over a long period of time without maintenance other than toner replenishment. However, the image may be deteriorated due to a change in environmental conditions (temperature / humidity) or a user's usage frequency. Therefore, an image correction unit is provided to keep the image quality constant, and image correction is performed as necessary.

  FIG. 2 is a block diagram showing image correction control according to the present invention.

  The image forming apparatus GH includes a plurality of image correction units, and a plurality of types of image correction are performed by the plurality of image correction units. As a plurality of image correction means, in this embodiment, there are a high density correction means 31a, a medium density correction means 31b, and an image alignment correction means 31c, and three types of image correction are performed. Hereinafter, the high density correction unit 31a, the medium density correction unit 31b, and the image alignment correction unit 31c are collectively referred to as an image correction unit 31.

  The image correcting unit 31 is configured to output the output values of the charging units 2Y, 2M, 2C, and 2K, the exposure units 3Y, 3M, 3C, and 3K, the developing devices 4Y, 4M, 4C, and 4K, the transfer units 7Y, 7M, 7C, and 7K. A test patch image (hereinafter referred to as a patch) is transferred onto the intermediate transfer body 6 under predetermined conditions. Further, the patch image on the intermediate transfer body 6 is optically measured by the patch sensor 65, and image correction of the image forming unit 10 (10Y, 10M, 10C, 10K) is performed based on the measurement data.

  In this image correction, the charge output value correction is performed by the high density correction unit 31a, the development output value correction is performed by the medium density correction unit 31b, and the registration correction of each color image is performed by the image registration correction unit 31c.

  The correction operation of the image correction unit 31 includes a plurality of execution steps, and each image correction is performed by sequentially executing the execution steps.

  The image correction unit 31 starts the correction operation when the image forming apparatus GH is turned on (on) and the conditions for image correction are satisfied. In addition, if a correction factor is interrupted due to an interruption factor at any execution step during the correction operation, and if there is correction data necessary to restart the correction operation, the correction operation is restarted and executed from any execution step. It is configured to be possible. As the correction data, measurement data obtained by measuring the above-described patch image or a calculation result of a correction amount derivation process for deriving a correction amount based on the measurement data is used.

  The environment detection unit 35 includes an environment sensor 66 and is disposed inside the image forming apparatus GH, and detects temperature and humidity as environment parameters. The environment sensor 66 may be a generally known temperature / humidity sensor.

  The execution status storage unit 33 stores the execution step being executed, the correction data, and the temperature and humidity detected by the environment detection unit as environmental parameters as the correction operation status during execution of the correction operation as needed. In the execution step, any one of the plurality of image correction units 31 is being executed, for example, any one of the high density correction unit 31a, the medium density correction unit 31b, and the image alignment correction unit 31c. Contains information that can be determined. The correction data is the measurement data or the calculation result of the correction amount derivation process as described above, and which is set in advance.

  In addition to the above, the execution status storage means 33 displays the elapsed time from the power-off of the apparatus to the on-state, that is, the apparatus pause time, and the elapsed time from the correction operation interruption to the correction operation restart, ie, the correction operation interruption time. Measure and store as environmental parameters. The apparatus pause time includes a print pause time during which printing is not performed when the apparatus is turned on. In this case, when the power is turned off, it corresponds to the end of the last final printing, and when the power is turned on, it corresponds to the time of printing instruction.

  The interruption factor monitoring unit 34 monitors the occurrence of an interruption factor that makes it impossible to continuously execute the execution step while the correction operation of the image correction unit 31 is being executed. Interrupting factors include the door opening / closing operation of the apparatus by the operator, power supply shut-off (off), and print instruction interruption operation.

  The door opening / closing of the apparatus is detected by an opening / closing detection means (not shown) provided in the apparatus, for example, a switch.

  The control unit 32 controls the image correction unit 31 while referring to the data, signals, and the like of each unit described above. The control means 32 may be configured as a part of a control device (not shown) that controls the entire image forming apparatus GH and the image reading apparatus YS, or may be configured as an independent configuration under the control of the control device. Good. In addition, the control unit 32 includes a restart method determination unit 32a that determines a restart method when the correction operation is interrupted at an arbitrary execution step. The restart method determination unit 32a determines whether to restart from an arbitrary execution step or restart from the initial stage of the interrupted correction operation when restarting the correction operation interrupted at an arbitrary execution step. The restart method determination unit 32 a may be an independent mechanism separately from the control unit 32.

  Next, control of the image correction operation will be described.

  When the power of the image forming apparatus GH is turned on by the operator, the control unit 32 compares the environmental parameter at the previous power-off stored in the execution status storage unit with the environmental parameter at the time of power-on, When the variation amount satisfies the image correction execution condition (image correction execution condition), the image correction operation is started. The image correction is performed on the image correction unit 31 that satisfies the image correction execution condition among the plurality of image correction units (image correction types) 31.

  Table 1 shows examples of image correction types and image correction execution conditions.

  In the present embodiment, since three types of image correction are performed: high density correction, medium density correction, and image alignment correction, image correction execution conditions corresponding to each correction are set. Note that the image correction execution condition is not limited to this.

  When the image correction operation is started, the above-described patch image is formed, and the execution steps of the high density correction unit 31a, the medium density correction unit 31b, and the image alignment correction unit 31c are executed, and the high density correction and the medium density correction are performed. Density correction and image alignment correction are sequentially performed. The execution order is not limited to this.

  As the image correction operation is executed, the execution status storage unit 33 uses the execution step being executed, the correction data, the temperature and humidity detected by the environment detection unit 35, and the current time as the correction operation status during the correction operation. As you remember. Further, any of the image correction means 31 being executed is stored, for example, any of the high density correction means 31a, the medium density correction means 31b, and the image alignment correction means 31c.

  The interruption factor monitoring unit 34 monitors the occurrence of an interruption factor that makes it impossible to continuously execute the execution step while the correction operation of the image correction unit 31 is being executed. When an interruption factor occurs, a signal is output from the interruption factor monitoring unit 34 to the control unit 32, and the control unit 32 starts processing for interrupting the image correction operation.

  Hereinafter, a case where the interruption factor is an interruption in the print instruction interruption operation by the operator will be described as an example.

  As an interrupt operation of the print instruction by the operator, in order that the operator wants to print quickly without causing a problem with image quality, the manuscript is set on the automatic document feeder 201, and the start button of the operation unit (not shown) is pressed to start the print operation. There are cases where In this case, the image forming apparatus GH displays a message for confirming the interruption of the correction operation on the display device (not shown) to the operator.

  FIG. 3 is a diagram illustrating an example of a message. When the operator sees the message and selects and instructs “Yes”, the interruption factor monitoring unit 34 issues an instruction to interrupt the image correction operation to the control unit 32, and the control unit 32 displays the image of the image correction unit 31. Stop the correction operation. Further, the image forming apparatus GH starts a printing operation.

  When the printing operation is completed, an instruction to resume image correction is issued to the control means 32 from the control device that controls the entire apparatus.

  The control unit 32 determines the type of the interrupted image correction unit 31 and the interrupted execution step from the execution steps stored in the execution status storage unit 33.

  Next, the restart method determination unit 32a of the control unit 32 compares the environmental parameter (temperature, humidity, time) at the time of interruption stored in the execution status storage unit 33 with the current environmental parameter (temperature, humidity, time). Then, it is determined whether or not the fluctuation amount of the environmental parameter is within an allowable range, and it is determined whether or not the correction data can be reused. Whether or not the variation amount of the environmental parameter is within the allowable range is determined based on the variation amount of the environmental parameter and the reusable condition of the correction data corresponding to the preset image correction type.

  The amount of variation can be set individually for each image correction type, that is, for each of the high density correction means 31a, the medium density correction means 31b, and the image alignment correction means 31c.

  Table 2 shows examples of image correction types and reusable conditions.

  Further, the resumption method determination unit 32a determines the resumption method of the image correction operation based on the determination as to whether or not the correction data can be reused. The control unit 32 restarts the image correction operation in the image correction unit 31 based on the determination of the restart method. When the correction data can be reused, the image correction operation is resumed from the execution step of the interrupted image correction unit 31 stored in the execution status storage unit 33. If the correction data cannot be reused, the process is resumed from the first execution step of the interrupted image correction unit 31 stored in the execution status storage unit 33.

  In the image correction, in order to reduce dead time and material consumption due to the image correction operation, when the image correction operation is interrupted, when the operation is resumed, the correction data at the time of interruption is obtained from the interrupted execution step. It is preferable to resume use. However, depending on the amount of change in the environmental parameters at the time of interruption and resumption, if the correction data at the time of interruption is used, it becomes difficult to perform appropriate image correction, and the reliability of image correction is impaired.

  On the other hand, in the present invention, as described above, it is determined whether or not the variation amount of the environmental parameter is within the prescribed allowable range. Then, the correction data at the time of interruption is continued and the image correction operation is restarted. If it is out of the allowable range, the image correction operation is resumed from the first execution step of the interrupted image correction means 31 of the plurality of image correction means 31 instead of from the beginning of all of the plurality of image correction means 31. . In this case, correction data at the time of interruption is not used.

  As a result, it is possible to reduce the dead time and material consumption resulting from the image correction operation without impairing the reliability of the image correction.

  FIG. 4 is a flowchart when the interruption factor is canceled and the image correction operation is resumed after the image correction operation is interrupted.

  In step S101, after the interruption factor is cancelled, it is determined whether or not the environmental parameter variation is within an allowable range. If it is within the allowable range (S101; Yes), the process proceeds to step S102. If it is outside the allowable range (S101; No), the process proceeds to step S104, and the image correction operation is restarted from the first execution step of the interrupted image correction means 31.

  In step S102, the execution step and the correction data when the image correction operation is interrupted are referred to.

  In step S103, the image correction operation is restarted from the execution step at the time of interruption.

  When the above-described image correction operation is completed, the print mode is entered and printing is possible.

  As a result, the dead time and material consumption due to the interruption of the image correction operation can be reduced without impairing the reliability of the image correction, and the productivity and operability of the image forming apparatus can be improved. it can.

GH Image forming device YS Image reading device P Recording material 10, 10Y, 10M, 10C, 10K Image forming unit 60 Transfer unit 6 Intermediate transfer member 9 Fixing device 31 Image correcting means 31a High density correcting means 31b Medium density correcting means 31c Image position Matching correction means 32 Control means 32a Resumption method determination section 33 Execution status storage means 34 Interruption factor monitoring means 35 Environment detection means 65 Patch sensor 66 Environment sensor

Claims (7)

When the correction operation is interrupted at an arbitrary execution step of the execution step during the execution of the image correction operation including a plurality of execution steps, there is correction data necessary to restart the correction operation from the arbitrary execution step. A plurality of image correction means capable of resuming and executing the correction operation from the arbitrary execution step;
Environmental detection means for detecting environmental parameters during image correction operation execution;
As the correction operation status during execution of the image correction operation, execution status storage means for storing the execution step, the correction data, and the environmental parameters as needed,
An interruption factor monitoring means for monitoring an interruption factor that makes it impossible to continue the execution step of the correction operation;
Control means for controlling the image correction means,
The control means causes the image correction means to be executed from the beginning of the execution step when starting the correction operation, and when the interruption factor is detected, interrupts the correction operation being executed and cancels the interruption factor. When the restart of the correction operation is instructed, the latest environmental parameters stored at the time of interruption stored in the execution status storage unit and the environment detection unit at the time when the restart of the correction operation is instructed are detected. When the variation amount of the environmental parameter is within an allowable range, the image correction is resumed from the interrupted execution step by taking over the correction data of the interrupted execution step stored in the execution status storage means. When the variation amount is out of the permissible range, the image forming apparatus is controlled so that the correction is re-executed from the beginning of the execution step of the interrupted image correction unit.   The image forming apparatus according to claim 1, wherein the correction data is measurement data or a calculation result of a correction amount derivation process.   The image forming apparatus according to claim 1, wherein the environmental parameter is one or more of temperature, humidity, and time.   4. The execution step stored in the execution status storage unit includes information that makes it possible to determine an image correction unit being executed among the plurality of image correction units. 2. The image forming apparatus according to item 1.   5. The image forming apparatus according to claim 1, wherein the interruption factor is any one of a door opening / closing operation, a power shutdown, and an interrupt operation of a print instruction by an operator.   The interruption factor monitoring means has a function of allowing the operator to select whether to interrupt the correction operation and perform the printing operation when receiving a print instruction from the operator during the correction operation. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   The image forming apparatus according to claim 1, wherein the allowable range of the variation amount can be individually set according to the plurality of image correction units.

Images