JP6933019B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus that expands input print data into image data for printing and prints an image.

Conventionally, there is known an image forming apparatus that outputs a print request when a development process for expanding print data into image data is completed and forms an image based on the print request (see Patent Document 1). Specifically, in this technique, if there is no print request, it is determined whether or not the print data exists, and if it exists, the time required for the expansion process for the print data is longer than the delay allowable time. Determine if it is a long time. If the time required for the unfolding process is longer than the allowable delay time, post-treatment such as cleaning the photoconductor is performed. When the time required for the development process is shorter than the allowable delay time, the image is formed after waiting for a predetermined time and when there is a print request within the predetermined time.

Japanese Unexamined Patent Publication No. 2010-96934

However, in the prior art, the time required for the expansion process is calculated from the input print data, that is, the type and capacity of the print data that has not been expanded, and the printing conditions, so that it may not be calculated appropriately. As a result, there is a possibility that the time actually required for the developing process and the time required for the developing process obtained by calculation are different from each other, the printing completion time may be delayed, or the developer may be unnecessarily driven.

Therefore, an object of the present invention is to suppress a delay in the printing completion time and further suppress unnecessary driving of the developer when the developing process is not completed.

In order to solve the above problems, the image forming apparatus according to the present invention includes a photoconductor, a developer that supplies a developer to the photoconductor, and a control unit.
The control unit can execute an expansion process for expanding the received print data into a raster image and an image formation process for driving the developer to form an image based on the raster image for each page of the sheet. Yes, at the judgment timing set in the period from the start of feeding the sheet of the Nth page during the execution of the image forming process to the default timing of starting the feeding of the sheet of the N + 1th page, the N + 1th page When the unfolding process for the sheet of N + 1 is completed, the sheet of the N + 1 page is fed at the predetermined timing, and the unfolding process for the sheet of the N + 1 page is completed up to a predetermined stage before the completion. In, the developer is driven to execute a standby process of waiting for the sheet to be fed until the unfolding process for the N + 1 page sheet is completed, and the unfolding process for the N + 1 page sheet is up to a predetermined stage. If it is not completed, a stop process for stopping the driving of the developer is executed after the image formation process for the N-page sheet is completed.

According to this configuration, it is determined whether or not the unfolding process for the N + 1th page sheet has been completed up to a predetermined stage before the completion, so that the time calculated based on the print data that has not been unfolded as in the conventional case. Compared with the technique of performing control based on the above, it is possible to suppress the deviation between the actual completion time of the expansion process and the predicted completion time of the expansion process. If the unfolding process for the N + 1 page sheet is completed up to a predetermined stage before the completion, the sheet is fed until the unfolding process for the N + 1 page sheet is completed while the developer is driven. By waiting for, the sheet of the N + 1th page can be printed immediately after the development process is completed, so that the delay in the printing completion time can be suppressed. Further, when the development process for the sheet on the N + 1 page is completed up to a predetermined stage before the completion, the time required for the subsequent expansion process to be completed is short, so this short time can be set appropriately. , It is possible to further suppress driving the developer unnecessarily.

According to the present invention, when the unfolding process is not completed, it is possible to suppress the delay in the printing completion time and further suppress the unnecessary driving of the developer.

It is sectional drawing which shows the color printer which concerns on embodiment of this invention. It is a figure explaining the separation between a photoconductor drum and a developing roller. It is a figure which shows the expansion process which expands the print data into a raster image. It is a flowchart which shows the operation of a control part. It is a flowchart which shows the progress grasp process. It is a flowchart which shows the paper feed adjustment processing.

Next, an embodiment of the present invention will be described in detail with reference to the drawings as appropriate. In the following description, the direction will be described in the direction shown in FIG. That is, in FIG. 1, the left side facing the paper is referred to as the "front side", the right side facing the paper is referred to as the "rear side", the back side facing the paper is referred to as the "left side", and the front side facing the paper is referred to as the "right side". do. In addition, the vertical direction is defined as the "vertical direction" toward the paper surface.

As shown in FIG. 1, a color printer 1 as an example of an image forming apparatus has a paper feeding unit 20 that supplies paper P as an example of a sheet in a main body housing 2, and an image on the paper P that has been fed. The image forming unit 30 for forming the image, the paper discharging unit 90 for discharging the paper P on which the image is formed, and the control unit 100 are provided.

An opening 2A is formed in the upper part of the main body housing 2, and the opening 2A is opened and closed by an upper cover 3 rotatably supported by the main body housing 2. The upper surface of the upper cover 3 is a paper ejection tray 4 for accumulating the paper P ejected from the main body housing 2, and a plurality of LED mounting members 5 for holding the LED unit 40 are provided on the lower surface.

The paper feed unit 20 is provided in the lower part of the main body housing 2, and has a paper feed tray 21 that can be attached to and detached from the main body housing 2, and a paper supply mechanism 22 that conveys the paper P from the paper feed tray 21 to the image forming unit 30. And have. The paper supply mechanism 22 is provided on the front side of the paper feed tray 21, and includes a paper feed roller 23, a separation roller 24, a separation pad 25, a paper dust removing roller 26, a pinch roller 27, and a registration roller 29. I have.

In the paper feed unit 20, the paper P sent out from the paper feed tray 21 by the paper feed roller 23 is separated one by one by the separation roller 24 and the separation pad 25 and sent upward, and the paper dust removing roller 26 and the pinch roller are fed. Paper dust is removed in the process of passing between 27. After that, the paper P is turned backward through the transport path 28, skew-corrected by the registration roller 29, and then supplied to the image forming unit 30.

The image forming unit 30 includes four LED units 40, four process cartridges 50, a transfer unit 70, a cleaning device 10, and a fixing device 80.

The LED unit 40 is swingably connected to the LED mounting member 5, and is appropriately positioned and supported by a positioning member provided in the main body housing 2. The LED unit 40 has a plurality of light emitting units arranged in the left-right direction.

The process cartridge 50 is arranged side by side in the front-rear direction between the upper cover 3 and the paper feed unit 20, and includes a drum cartridge 510 and a developing device 530. The drum cartridge 510 includes a photoconductor drum 51 as an example of a photoconductor, a charger 52, and a cleaning roller 55 as an example of a holding roller. The developer 530 is removable from the drum cartridge 510, and includes a developing roller 53 and a toner accommodating chamber 54 for accommodating toner as an example of a developing agent.

The process cartridges 50, which contain toners of various colors for black, yellow, magenta, and cyan, are arranged in this order from the upstream in the transport direction of the paper P, which are indicated by the codes of 50K, 50Y, 50M, and 50C. ing. In the present specification and drawings, when the photoconductor drum 51, the developing roller 53, the cleaning roller 55, etc. corresponding to the toner color are specified, they correspond to each of black, yellow, magenta, and cyan, and K. , Y, M, C symbols will be added.

The photoconductor drums 51 are provided on each of the plurality of drum cartridges 510, and are arranged in a row along the front-rear direction. The photoconductor drum 51 rotates about a rotation axis along the left-right direction.

The developing roller 53 is a roller that supports toner, and comes into contact with the photoconductor drum 51 to supply toner to the electrostatic latent image on the photoconductor drum 51. In the present embodiment, when the toner is supplied from the developing roller 53 to the photoconductor drum 51, the toner is slidably contacted between the developing roller 53 and the supply roller shown by omitting the reference numerals. The toner is positively charged.

As shown in FIG. 2, the developing roller 53 can be brought close to and separated from the photoconductor drum 51 by controlling the known contact / detachment mechanism 110 by the control unit 100. Specifically, in the color mode in which the black, yellow, magenta, and cyan process cartridges 50 are used to form an image, all developing rollers 53K, 53Y, 53M, and 53C correspond to the photoconductor drums 51K, 51Y, respectively. , 51M, 51C are contacted to supply toner to the photoconductor drums 51K, 51Y, 51M, 51C. Further, in the monochrome mode in which an image is formed using only the black process cartridge 50K, only the black (monochrome) developing roller 53K contacts the photoconductor drum 51K, and the other three color developing rollers 53Y, The 53M, 53C are designed to be separated from the corresponding photoconductor drums 51Y, 51M, 51C. Further, in the cleaning control described later, all the developing rollers 53K, 53Y, 53M, 53C are separated from the corresponding photoconductor drums 51K, 51Y, 51M, 51C, respectively.

As shown in FIG. 1, a plurality of cleaning rollers 55 are provided adjacent to each photoconductor drum 51 so as to correspond to each photoconductor drum 51. A holding bias having a polarity opposite to that of the toner is applied to the cleaning roller 55, whereby the cleaning roller 55 can collect the toner on the photoconductor drum 51 and temporarily hold it. It is possible. Further, a discharge bias having the same polarity as the toner is applied to the cleaning roller 55, which makes it possible to move the toner held by the cleaning roller 55 to the photoconductor drum 51. ..

The transfer unit 70 is provided between the paper feed unit 20 and each process cartridge 50, and includes a drive roller 71, a driven roller 72, a transfer belt 73, and a transfer roller 74.

The drive roller 71 and the driven roller 72 are arranged in parallel with each other separated from each other in the front-rear direction, and a transport belt 73 made of an endless belt is stretched between them. Inside the transport belt 73, four transfer rollers 74 that sandwich the transport belt 73 with each photoconductor drum 51 are arranged so as to face each photoconductor drum 51. A transfer bias is applied to the transfer roller 74 during transfer.

The cleaning device 10 is a device that slides into contact with the transport belt 73 and collects toner or the like adhering to the transport belt 73, and is arranged so as to face the lower side of the transport belt 73. Specifically, the cleaning device 10 is configured to collect the toner on the cleaning roller 55 via the photoconductor drum 51 and the transport belt 73. Specifically, the cleaning device 10 includes a sliding contact roller 11, a recovery roller 12, a blade 13, and a waste toner container 14.

The sliding contact roller 11 is arranged so as to come into contact with the outer peripheral surface of the transport belt 73, and a recovery bias is applied between the sliding contact roller 11 and the backup roller 15 arranged on the inner peripheral surface of the transport belt 73, so that the sliding contact roller 11 is placed on the transport belt 73. The deposits are being collected.

The recovery roller 12 is a roller that is in sliding contact with the sliding contact roller 11, and collects deposits adhering to the sliding contact roller 11. Then, the deposits on the recovery roller 12 are scraped off by the blade 13 arranged so as to be in sliding contact with the recovery roller 12 and enter the waste toner container 14.

The fixing device 80 is arranged behind each process cartridge 50 and the transfer unit 70, and includes a heating roller 81 and a pressure roller 82 that is pressed toward the heating roller 81.

In the image forming unit 30 configured as described above, in the color mode, the surface of each photoconductor drum 51 is first uniformly positively charged by the charger 52, and then exposed by each LED unit 40. .. As a result, the potential of the exposed portion is lowered, and an electrostatic latent image based on the image data is formed on each photoconductor drum 51. After that, the toner image positively charged from the developing roller 53 is supplied to the electrostatic latent image, so that the toner image is supported on the photoconductor drum 51.

The toner P formed on each photoconductor drum 51 is formed by passing the paper P supplied on the transport belt 73 between each photoconductor drum 51 and each transfer roller 74 arranged inside the transport belt 73. The image is transferred onto the paper P. Then, the paper P passes between the heating roller 81 and the pressure roller 82, so that the toner image transferred on the paper P is heat-fixed.

The paper ejection unit 90 includes a paper ejection side transport path 91 formed so as to extend upward from the outlet of the fixing device 80 and reverse forward, and a plurality of pairs of transport rollers 92 for transporting the paper P. There is. The paper P to which the toner image is transferred and heat-fixed is conveyed by the transfer roller 92 on the output side transfer path 91, discharged to the outside of the main body housing 2, and accumulated in the output tray 4.

The control unit 100 will be described in detail below.
The control unit 100 includes a CPU, RAM, ROM, non-volatile memory, ASIC, input / output circuit, and the like. The control unit 100 executes control by performing various arithmetic processes based on a print command output from an external computer or the like and a program or data stored in a ROM or the like. Specifically, the control unit 100 can execute the expansion process, the image formation process, the progress status grasp process, the paper feed adjustment process, the standby process, and the stop process.

The expansion process is a process of expanding the received print data into a raster image. As shown in FIG. 3, in the expansion process, the control unit 100 performs a first process of expanding the received print data into object data D1 to D4 composed of vector data or bitmap data, and object data D1 to D4. It is possible to perform a second process of arranging the data in the virtual paper PV and developing it into a raster image RI composed of a plurality of band data BD1 to BD15.

Here, the print data is data created by an external device such as a computer and configured in a page description language or the like, and cannot be handled as exposure data of the color printer 1. Therefore, the control unit 100 performs an expansion process of expanding the print data composed of a page description language or the like into the raster image RI which is the data for exposure.

The object data D1 to D4 are vector data or bitmap data. In the vector data, the vector information that becomes the outline and the fill are defined. Each object data D1 to D4 is associated with position information and a size on a virtual paper PV. In the first process, the received print data is expanded, and the coordinates P located at one vertex of the rectangular frame circumscribing each object data D1 to D4, and the left-right direction (X direction) and the transport direction (Y direction). Get the size. In FIG. 3, the origin coordinates of the virtual paper PV are shown as P0, the starting point coordinates of the object data D1 to D4 on the virtual paper PV, and the starting point coordinates of the object data D1 to D4 on the virtual paper PV are shown as P1 to P4, respectively.

Each band data BD1 to BD15 is composed of a predetermined number, for example, 10 line data. That is, the raster image RI is composed of a plurality of line data. The line data is binary data corresponding to ON / OFF of a plurality of light emitting units of each LED unit 40, and is composed of a plurality of dots arranged in the left-right direction, that is, in the rotation axis direction of the photoconductor drum 51. In the second process, the control unit 100 arranges the object data D1 to D4 on the virtual paper PV based on the position information, and distributes the band data BD1 to BD15, specifically the line data, in the transport direction of the virtual paper PV. It is generated in order from one end of. When generating line data, the control unit 100 refers to all the object data included in the line. The control unit 100 executes the unfolding process for each page of the paper P.

The image forming process is a process of driving the developer 530 to form an image based on the raster image RI on the paper P. Here, the image forming process includes a drive process for driving the process cartridge 50, specifically a developing roller 53, a photoconductor drum 51, and the like, a charging process for charging the photoconductor drum 51, and a charged photoconductor drum 51. The exposure process of exposing the toner image by the LED unit 40, the development process of supplying toner from the developing roller 53 to the electrostatic latent image on the photoconductor drum 51, and the transfer process of transferring the toner image on the photoconductor drum 51 to the paper P. And have. Then, the control unit 100 executes the image forming process for each page of the paper P. In other words, the control unit 100 can execute the exposure process, the developing process, and the transfer process among the image forming processes for each page of the paper P.

The image forming process for the predetermined paper P starts when the exposure process corresponding to the predetermined paper P is started, and ends when the transfer process corresponding to the predetermined paper P is completed. Further, the exposure process may be started, for example, by using a paper passing sensor (not shown) provided on the upstream side of the photoconductor drum 51 on the most upstream side in the transport direction as a trigger to detect the passage of the paper P.

The progress status grasping process is a determination set in the period from the start of paper feeding of the Nth page paper P to the default timing of starting the paper feeding of the N + 1th page paper P during the execution of the image formation processing. This is a process for grasping to what extent the unfolding process for the paper P on the N + 1 page is completed at the timing. In other words, in the progress status grasping process, to what extent the unfolding process for the next sheet P is completed before the default timing, which is the timing to start feeding the next sheet P, is reached during the execution of the image forming process. It is a process to grasp whether it is doing.

Here, the default timing is a time after a predetermined time from the start of feeding the paper P on the Nth page, and is appropriately set according to the printing speed. For example, when the printing speed of the color printer 1 is 30 ppm (Page Par Minutes), the default timing is set to a time 2 seconds after the start of feeding the paper P on the Nth page. The time of starting paper feeding of the paper P may be, for example, the time of outputting a drive signal to the paper feeding roller 23, or the paper passing sensor 200 provided on the downstream side of the paper feeding roller 23 in the transport direction (FIG. 1). It may be the time when the passage of the paper P is detected by (see).

The control unit 100 determines the progress status of the expansion process in a plurality of stages in the progress status grasping process, and determines to which stage of the plurality of stages the expansion process is completed at the above-mentioned determination timing. ing. Specifically, the control unit 100 determines whether or not all the deployment processes have been completed in the progress status grasping process, and if not, the progress status of the deployment process is in the first stage and the second stage. And determine which stage of the third stage you have reached.

Here, the first stage, the second stage, and the third stage are the stages before the expansion process is completed, that is, the stages in which all the expansion processes are not completed, and the larger the number, the more the expansion process is progressing. show. The third stage is an example of a predetermined stage.

In the present embodiment, the control unit 100 compares the number of band data generated by the expansion process with the first threshold value TH1, the second threshold value TH2, and the third threshold value TH3 set according to each stage. , Keep track of the progress of the deployment process. Here, the relationship between the threshold values TH1 to TH3 is TH1 <TH2 <TH3.

When the number of band data generated by the expansion process is equal to or greater than the third threshold value TH3, the control unit 100 determines that the expansion process has been completed up to the third stage. That is, the control unit 100 determines that the expansion process has been completed up to the third stage when the raster image RI for one page of the paper is generated up to a predetermined ratio.

When the number of band data generated by the expansion process is less than the third threshold value TH3 and equal to or greater than the second threshold value TH2, the control unit 100 determines that the expansion process has been completed up to the second stage. When the number of band data generated by the expansion process is less than the second threshold value TH2 and equal to or greater than the first threshold value TH1, the control unit 100 determines that the expansion process has been completed up to the first stage.

The paper feed adjustment process is a process for adjusting the paper feed timing of the paper P on the N + 1 page according to the progress of the expansion process. When the control unit 100 determines that the expansion process for the paper P on the N + 1 page is completed in the progress status grasping process, the control unit 100 feeds the paper P on the N + 1 page at the default timing in the paper feed adjustment process. do. Further, when the control unit 100 determines in the progress status grasping process that the expansion process for the paper P on the N + 1 page is not completed, in the paper feed adjustment process, N + 1 is determined according to the progress status of the expansion process. The paper feed timing of the page P is changed to a timing later than the default timing. Specifically, the control unit 100 adjusts the paper feed timing of the paper P on the N + 1 page by executing the standby process and the stop process according to the progress of the expansion process in the paper feed adjustment process.

The standby process is a process of waiting for the paper P to be fed when the expansion process for the paper P on the N + 1 page is not completed. In the present embodiment, the control unit 100 performs the first standby process and the second standby process as the standby process. Specifically, when the unfolding process for the paper P on the N + 1 page is completed up to the third stage, the control unit 100 performs the unfolding process for the paper P on the N + 1 page while driving the developer 530. The first standby process of waiting for the paper P to be fed is executed until it is completed. Further, when the unfolding process for the paper P on the N + 1 page is not completed up to the third stage, the control unit 100 has at least stopped driving the developer 530 by the stop process described later on the N + 1 page. The second standby process of waiting for the paper P to be fed is executed until the unfolding process of the sheet P is completed.

In the stop processing, when the expansion processing for the paper P on the N + 1th page is not completed up to the third stage, at least the drive of the developer 530 is stopped after the image formation processing for the paper P on the Nth page is completed. It is a process. In the present embodiment, the control unit 100 performs a first stop process, a second stop process, and a third stop process as stop processes. The control unit 100 selects and executes the first stop processing, the second stop processing, and the third stop processing according to the progress status grasped in the progress status grasping process. In other words, in the progress status grasping process, the control unit 100 determines to which of the plurality of stages the expansion process is completed, and determines the execution content of the stop process according to the completed stage. change.

When the expansion process for the paper P on the N + 1 page is less than the third stage and the second stage or more, the control unit 100 executes the first stop process. When the expansion process for the paper P on the N + 1 page is less than the second stage and is the first stage or more, the control unit 100 executes the second stop process. When the expansion process for the paper P on the N + 1 page is less than the first stage, the control unit 100 executes the third stop process.

The control unit 100 stops driving the developer 530 in the first stop process. In the second stop process, the control unit 100 stops the driving of the developing device 530 and separates the developing roller 53 from the photoconductor drum 51. In the third stop process, the control unit 100 stops the driving of the developing device 530, separates the developing roller 53 from the photoconductor drum 51, and further executes cleaning control. In the cleaning control, the control unit 100 applies a discharge bias having the same polarity as the toner to the cleaning roller 55 and a transfer bias having the same polarity as the toner to the transfer roller 74. As a result, the toner held by the cleaning roller 55 moves onto the photoconductor drum 51, then moves onto the transport belt 73, and is collected by the cleaning device 10.

In each stop process, when the drive of the developing device 530 is stopped, the drive of the drum cartridge 510 or the like may also be stopped.

Next, the operation of the control unit 100 will be described in detail. The control unit 100 constantly and repeatedly executes the process shown in FIG.

As shown in FIG. 4, the control unit 100 determines whether or not the print data has been received (S1). When the print data is received in step S1 (Yes), the control unit 100 substitutes 1 for the variable N indicating the number of printed pages of the paper P (S2).

After step S2, the control unit 100 starts the expansion process of expanding the print data into the raster image RI (S3). After step S3, the control unit 100 determines whether or not the expansion process for the Nth page, that is, the first page of the paper P is completed (S4).

If it is determined in step S4 that the expansion process for the Nth page paper P is completed (Yes), the control unit 100 feeds the N + 1th page paper P (S5). After step S5, the control unit 100 determines whether or not there is print data on the N + 1th page (S6).

If it is determined in step S6 that there is print data (Yes), the control unit 100 determines whether or not the first hour T1 has elapsed from the time when the paper P on the Nth page is started to be fed. Then, it is determined whether or not the determination timing described above has been reached (S7). If it is determined in step S7 that the first time T1 has elapsed (Yes), the control unit 100 executes the progress status grasping process (S8), then executes the paper feed adjustment process (S9), and then steps. Return to the process of S5. If No is determined in steps S1 and S6, the control unit 100 ends this control.

As shown in FIG. 5, in the progress status grasping process, the control unit 100 first determines whether or not all the unfolding processes for the paper P on the N + 1 page are completed (S21). When it is determined in step S21 that all the expansion processing is completed (Yes), the control unit 100 sets the progress flag LV indicating the progress status of the expansion processing to LVmax (S22), and ends this control. do.

If it is determined in step S21 that all the expansion processing has not been completed (No), the control unit 100 determines whether or not the expansion processing for the paper P on the N + 1 page has been completed up to the third stage. (S23). If it is determined in step S23 that the expansion process has been completed up to the third stage (Yes), the control unit 100 sets the progress flag LV to LV3 (S24) and ends this control.

If it is determined in step S23 that the unfolding process has not been completed up to the third stage (No), the control unit 100 determines whether or not the unfolding process for the paper P on the N + 1 page has been completed up to the second stage. Is determined (S25). If it is determined in step S25 that the expansion process has been completed up to the second stage (Yes), the control unit 100 sets the progress flag LV to LV2 (S26) and ends this control.

If it is determined in step S25 that the unfolding process has not been completed up to the second stage (No), the control unit 100 determines whether or not the unfolding process for the paper P on the N + 1 page has been completed up to the first stage. Is determined (S27). If it is determined in step S27 that the expansion process has been completed up to the first stage (Yes), the control unit 100 sets the progress flag LV to LV1 (S28) and ends this control. If it is determined in step S27 that the expansion process has not been completed up to the first stage (No), the control unit 100 sets the progress flag LV to LV0 (S29) and ends this control.

As shown in FIG. 6, the control unit 100 determines whether or not the progress flag LV is LVmax in the paper feed adjustment process (S41). If it is determined in step S41 that LV = LVmax (Yes), the control unit 100 determines whether or not the second time T2 has elapsed from the time when the paper P on the Nth page is started to be fed. Therefore, it is determined whether or not the above-mentioned default timing has been reached (S42). When it is determined in step S42 that the second time T2 has elapsed (Yes), the control unit 100 substitutes N + 1 for the variable N, that is, increments the variable N (S58), and ends this control. ..

If it is determined in step S41 that LV = LVmax is not satisfied (No), the control unit 100 determines whether or not the progress flag LV is LV3 (S43). If it is determined in step S43 that LV = LV3 (Yes), the control unit 100 keeps the developer 530 and the like driven, until all the expansion processing for the paper P on the N + 1 page is completed. Wait (S44). When all the expansion processes are completed in step S44, the control unit 100 shifts to the process of step S58.

If it is determined in step S43 that LV = LV3 is not satisfied (No), the control unit 100 determines whether or not the progress flag LV is LV2 (S45). If it is determined in step S45 that LV = LV2 (Yes), the control unit 100 stops driving the developer 530 after the image forming process of the paper P on the Nth page is completed (S46). After step S46, the control unit 100 waits until all the unfolding processes for the paper P on the N + 1 page are completed (S47). When all the unfolding processes are completed in step S47, the control unit 100 resumes driving the developer 530 (S48) and shifts to the process of step S58.

If it is determined in step S45 that LV = LV2 is not satisfied (No), the control unit 100 determines whether or not the progress flag LV is LV1 (S49). When it is determined in step S49 that LV = LV1 (Yes), the control unit 100 stops driving the developing device 530 (S50) and separates the developing roller 53 from the photoconductor drum 51 (S51). ..

After step S51, the control unit 100 waits until all the unfolding processes for the paper P on the N + 1 page are completed (S52). When all the developing processes are completed in step S52, the control unit 100 brings the developing roller 53 into contact with the photoconductor drum 51 (S53) and restarts the driving of the developing device 530 (S54). After step S54, the control unit 100 shifts to the process of step S58.

If it is determined in step S49 that LV = LV1 is not satisfied (No), the control unit 100 stops driving the developing device 530 (S55) and separates the developing roller 53 from the photoconductor drum 51 (S56). After step S56, the control unit 100 executes cleaning control (S57). After step S57, the control unit 100 shifts to the process of step S52.

Next, an example of the operation of the control unit 100 will be described. In the following description, a case where the 10-page paper P is printed, the 1st to 9th pages are print data that does not take a long time for the expansion process, and the 10-page expansion process takes a long time will be described. do.

As shown in FIG. 4, when printing the first page of the paper P, the control unit 100 waits until the unfolding process of the first page of the paper P is completed in step S4. When the unfolding process for the first page paper P is completed, the control unit 100 feeds the first page paper P (S5). After that, in step S6, the control unit 100 determines that there is print data on the second page (Yes), and when a predetermined determination timing comes (S7: Yes), grasps the progress status of the print data on the second page. The process is executed (S8).

In the progress status grasping process shown in FIG. 5, the control unit 100 determines that all the expansion processing for the paper P on the second page is completed (S21: Yes), and sets the progress flag LV to LVmax (S21: Yes). S22). After that, as shown in FIG. 6, the control unit 100 determines Yes in step S41, waits until the predetermined timing is reached (S42: Yes), and then increments the variable N to N = 2 (S58), FIG. In step S5 shown in (1), the paper P on the second page is fed.

After that, the control unit 100 performs the progress status grasping process and the paper feed adjustment process for the print data on the 3rd to 9th pages in the same manner as on the 2nd page described above. In the progress status grasping process for the print data on the 10th page, as shown in FIG. 5, the control unit 100 determines No in step S21. Then, the control unit 100 sets the progress flag LV to any of LV0 to LV3 according to the progress status of the unfolding process for the paper P on the 10th page (S23, S26, S28, S29).

In the paper feed adjustment process for the print data on the 10th page, as shown in FIG. 6, the control unit 100 performs the first standby process (S44) or the first standby process (S44) according to the progress flag LV set in the progress status grasp process. The second standby process (S47, S52) is executed. In the first standby process, the control unit 100 waits for the completion of the unfolding process for the paper P on the 10th page while driving the developer 530. In the second standby process, the control unit 100 stops driving the developer 530 at least (S46, S50, S55) and waits for the completion of the unfolding process for the paper P on the 10th page. Here, if the developing device 530 is left driven, the deterioration of the developing roller 53 and the toner may progress. Therefore, the condition for executing the first standby process is set within the expected remaining development time within the time that allows the developer 530 to remain driven.

When the first standby process is executed, the control unit 100 increments the variable N (S58) after the completion of the first standby process, and feeds the paper P on the 10th page (FIG. 4: S5). ). When the second standby process is executed, the control unit 100 prepares an environment in which the image formation process can be executed after the end of the second standby process (S48, etc.), and increments the variable N (S58), 10 Paper P on the first page is fed (FIG. 4: S5).

After that, in step S6, the control unit 100 determines that there is no print data on the 11th page (No), and ends this control.

Based on the above, the following effects can be obtained in the present embodiment.
When the unfolding process for the paper P on the N + 1 page is completed up to the third stage, the paper P is fed until the unfolding process for the paper P on the N + 1 page is completed while the developer 530 is driven. Is made to wait, so that the delay in the completion time of printing can be suppressed. Further, when the unfolding process for the paper P on the N + 1 page is completed up to the third stage, the time required for the unfolding process to be completed after that is short, so this short time, that is, the state in which the image forming process is not performed. Since the time for driving the developing device 530 can be appropriately set, it is possible to suppress unnecessary driving of the developing device 530.

In the second stop process and the third stop process, the developing roller 53 was separated from the photoconductor drum 51. Therefore, in the second stop process and the third stop process, for example, the developing device 530 with the photoconductor drum 51 rotated. Even if the drive is stopped, it is possible to prevent the developing roller 53 from being worn.

Since the cleaning control is executed in the third stop process, the time while waiting for the completion of the expansion process can be effectively utilized.

Since the progress status of the expansion process is determined in a plurality of stages and the execution content of the stop process is changed according to the completed stage, appropriate control can be performed according to the progress status of the expansion process.

The present invention is not limited to the above embodiment, and can be used in various forms as illustrated below. In the following description, the same reference numerals will be given to the configurations and steps substantially the same as those in the above embodiment, and the description thereof will be omitted.

In the above embodiment, when the number of band data generated by the expansion process is the third threshold value TH3 or more, it is determined that the expansion process is completed up to the third stage (predetermined stage), but the present invention is limited to this. It is not something that is done. For example, when the first process is completed, the control unit 100 may determine that the expansion process has been completed up to a predetermined stage. Further, the control unit 100 may determine that the expansion process has been completed up to a predetermined stage, for example, when the number of object data that has not been expanded to the line data in the second process is less than or equal to a predetermined number. .. The "predetermined number" may be a fixed value or a value obtained by multiplying the total number of object data expanded in the first process by a predetermined ratio.

Further, the control unit 100 states that, for example, when the total area of one or a plurality of object data that has not been expanded to the line data in the second process is equal to or less than a predetermined area, the expansion process is completed up to a predetermined stage. You may judge. The "predetermined area" may be a fixed value, or may be a value obtained by multiplying the total area of one or a plurality of object data developed in the first process by a predetermined ratio.

In the above-described embodiment, when all the expansion processing for the paper P on the N + 1 page is completed at the determination timing, the paper P on the N + 1 page is fed at the default timing. It is not limited to this. For example, at the judgment timing, when the expansion process for the paper P on the N + 1 page progresses beyond the predetermined stage and is completed up to the stage before the completion (hereinafter, referred to as the “immediately before completion stage”), the N + 1 page Paper feeding of the eye paper P may be started at a predetermined timing. Here, in the stage immediately before completion, the expansion process for the paper P on the N + 1 page is not completed at the determination timing, but when the paper P on the N + 1 page is fed at the specified timing, the paper P on the N + 1 page is fed. This is a stage in which the unfolding process for the paper P on the N + 1 page is completed before the exposure process for the paper P is started.

In order to perform such control, for example, the process of step S21 in the flowchart of FIG. 5 may be changed to a process of determining whether or not the expansion process for the paper P on the N + 1 page has been completed up to the stage immediately before completion. Just do it. According to this, even if all the expansion processing for the paper P on the N + 1th page is not completed, the paper is fed at the default timing, so that it is possible to suppress the slowdown in the printing speed.

In the above-described embodiment, the example of single-sided printing has been described, but the present invention is not limited to this, and the present invention can be applied even when double-sided printing is performed.

In the above-described embodiment, the progress of the expansion process is determined in a plurality of stages, but the present invention is not limited to this, and the progress may be determined in only one stage, that is, in a predetermined stage.

In the above embodiment, a positively charged toner has been exemplified as an example of the developing agent, but the present invention is not limited to this, and the developing agent may be, for example, a negatively charged toner.

In the above embodiment, the photoconductor drum 51 has been exemplified as the photoconductor, but the present invention is not limited to this, and for example, a belt-shaped photoconductor may be used.

In the above embodiment, paper P such as thick paper, postcard, and thin paper is exemplified as an example of the sheet, but the present invention is not limited to this, and may be, for example, an OHP sheet.

In the above embodiment, the present invention is applied to the color printer 1, but the present invention is not limited to this, and the present invention may be applied to other image forming devices such as a monochrome printer, a copying machine, and a multifunction device. ..

In addition, each element described in the above-described embodiment and modification may be arbitrarily combined and implemented.

1 Color printer 51 Photoreceptor drum 53 Developing roller 100 Control unit 530 Developer P Paper

Claims (8)

Photoreceptor and
A developer that supplies a developer to the photoconductor and
With a control unit
The control unit
The expansion process that expands the received print data into a raster image, and
The image forming process of driving the developer to form an image based on the raster image can be executed for each page of the sheet.
At the judgment timing set in the period from the start of feeding the Nth page sheet during the execution of the image forming process to the default timing of starting the feeding of the N + 1th page sheet.
When the expansion process for the N + 1 page sheet is completed, the N + 1 page sheet is fed at the predetermined timing, and the N + 1 page sheet is fed.
If the unfolding process for the N + 1 page sheet is completed up to a predetermined stage before the completion, the sheet is fed until the unfolding process for the N + 1 page sheet is completed while the developer is driven. Execute the wait process to make it wait,
If the unfolding process for the N + 1 page sheet is not completed up to a predetermined stage, a stop process for stopping the driving of the developer is executed after the image forming process for the N page sheet is completed .
In the expansion process, the first process of expanding the received print data into object data composed of vector data or bitmap data, and the raster of the object data arranged in a virtual sheet and composed of a plurality of line data. It is possible to execute the second process of expanding to the image,
An image forming apparatus, characterized in that, when the first process is completed, it is determined that the unfolding process has been completed up to a predetermined stage. Photoreceptor and
A developer that supplies a developer to the photoconductor and
With a control unit
The control unit
The expansion process that expands the received print data into a raster image, and
The image forming process of driving the developer to form an image based on the raster image can be executed for each page of the sheet.
At the judgment timing set in the period from the start of feeding the Nth page sheet during the execution of the image forming process to the default timing of starting the feeding of the N + 1th page sheet.
When the expansion process for the N + 1 page sheet is completed, the N + 1 page sheet is fed at the predetermined timing, and the N + 1 page sheet is fed.
If the unfolding process for the N + 1 page sheet is completed up to a predetermined stage before the completion, the sheet is fed until the unfolding process for the N + 1 page sheet is completed while the developer is driven. Execute the wait process to make it wait,
If the unfolding process for the N + 1 page sheet is not completed up to a predetermined stage, a stop process for stopping the driving of the developer is executed after the image forming process for the N page sheet is completed.
In the expansion process, the first process of expanding the received print data into object data consisting of vector data or bitmap data, and the raster of the object data arranged in a virtual sheet and composed of a plurality of line data. When the number of object data that can be expanded to the image and the expansion to the line data is not completed in the second processing is less than or equal to a predetermined number, the expansion process is completed up to a predetermined stage. images forming device you wherein the determining. Photoreceptor and
A developer that supplies a developer to the photoconductor and
With a control unit
The control unit
The expansion process that expands the received print data into a raster image, and
The image forming process of driving the developer to form an image based on the raster image can be executed for each page of the sheet.
At the judgment timing set in the period from the start of feeding the Nth page sheet during the execution of the image forming process to the default timing of starting the feeding of the N + 1th page sheet.
When the expansion process for the N + 1 page sheet is completed, the N + 1 page sheet is fed at the predetermined timing, and the N + 1 page sheet is fed.
If the unfolding process for the N + 1 page sheet is completed up to a predetermined stage before the completion, the sheet is fed until the unfolding process for the N + 1 page sheet is completed while the developer is driven. Execute the wait process to make it wait,
If the unfolding process for the N + 1 page sheet is not completed up to a predetermined stage, a stop process for stopping the driving of the developer is executed after the image forming process for the N page sheet is completed.
In the expansion process, the first process of expanding the received print data into object data consisting of vector data or bitmap data, and the raster of the object data arranged in a virtual sheet and composed of a plurality of line data. When the total area of the object data that can be expanded to the image and the expansion to the line data is not completed in the second processing is less than or equal to the predetermined area, the expansion process is completed up to the predetermined stage. images forming apparatus you and determines that. Photoreceptor and
A developer that supplies a developer to the photoconductor and
With a control unit
The control unit
The expansion process that expands the received print data into a raster image, and
The image forming process of driving the developer to form an image based on the raster image can be executed for each page of the sheet.
At the judgment timing set in the period from the start of feeding the Nth page sheet during the execution of the image forming process to the default timing of starting the feeding of the N + 1th page sheet.
When the expansion process for the N + 1 page sheet is completed, the N + 1 page sheet is fed at the predetermined timing, and the N + 1 page sheet is fed.
If the unfolding process for the N + 1 page sheet is completed up to a predetermined stage before the completion, the sheet is fed until the unfolding process for the N + 1 page sheet is completed while the developer is driven. Execute the wait process to make it wait,
If the unfolding process for the N + 1 page sheet is not completed up to a predetermined stage, a stop process for stopping the driving of the developer is executed after the image forming process for the N page sheet is completed.
In the expansion process, the first process of expanding the received print data into object data composed of vector data or bitmap data, and the raster of the object data arranged in a virtual sheet and composed of a plurality of line data. It is possible to execute the second process of expanding to the image,
Wherein when the number of band data of a predetermined number of line data is generated above the threshold in the second processing, development processing images forming apparatus you and determines that complete up to a predetermined stage. The developer includes a developing roller that carries a developer.
The image forming apparatus according to any one of claims 1 to 4 , wherein the control unit separates the developing roller from the photoconductor in the stopping process. A holding roller for collecting and holding the developer on the photoconductor is provided.
The image forming apparatus according to any one of claims 1 to 5 , wherein the control unit moves the developer held by the holding roller onto the photoconductor in the stopping process. .. At the determination timing, the control unit advances the expansion process for the sheet on the N + 1 page from the predetermined stage, and if the expansion process is completed up to the stage before the completion, the sheet on the N + 1 page at the predetermined timing. The image forming apparatus according to any one of claims 1 to 6 , wherein the paper feeding is started. The control unit determines the progress of the expansion process at a plurality of stages including the predetermined stage, and at the determination timing, determines to which stage of the plurality of stages the expansion process is completed. The image forming apparatus according to any one of claims 1 to 7 , wherein the execution content of the stop processing is changed according to the completed stage.

Images