JP4006883B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides a copy mode for reading an image of a document and forming an image based on image data obtained by the reading, and a printer mode for forming an image based on image data transmitted from an image data output device such as a computer. More particularly, the present invention relates to an image forming apparatus that forms an image by electrophotography.
[0002]
[Prior art]
By charging, exposing and developing the photoconductor, a toner image is formed on the photoconductor, and an image is formed on the recording material by an image forming process in which the toner image on the photoconductor is transferred to the recording material. In the image forming apparatus for forming the image forming apparatus, in order to erase the history of the previous image forming process, a precharging process for charging the entire surface of the photoconductor may be performed prior to the start of the next image forming process. Has been done. Further, after the image forming process, post-processing for removing and cleaning the photosensitive member is performed.
[0003]
[Problems to be solved by the invention]
(1) Image formation having a copy mode for reading an image of a document and forming an image based on image data obtained by the reading and a printer mode for forming an image based on image data from an image data output device such as a computer In the apparatus (hereinafter referred to as a multifunction device), the control means for controlling each part in the multifunction device performs image scanning to image formation in the multifunction device in the copying mode. It is known whether there is image data of the current job and when the next job can be started following the previous job, and the pre-charging process, the image forming process, and the post-process are appropriately performed. It is possible to perform sequence control with the highest image formation efficiency at a proper time.
[0004]
However, in the case of a job in a printer mode that forms an image based on image data transmitted from the external image data output device, whether or not there is image data of the next job after the end of the previous job, and Even when there is image data, it is unclear how long it takes to develop the received image data, so that the control means cannot properly perform control, and whether the characteristics of the image data of the next job are In some cases, the image forming efficiency is significantly reduced.
[0005]
Such a decrease in image forming efficiency will be described with reference to FIG.
[0006]
For example, the time required for executing the image forming step b is 1000 ms, the time required for the pre-charging process a is 1200 ms, the time required for the post-processing c is 800 ms, and the time from the end of image formation to the start of post-processing is 100 ms. . FIG. 1 shows a job execution process when the time of each process is assumed as described above, and shows an example in which one image is formed in each of the previous job and the next job following the job.
[0007]
As shown in the time chart (a), when there is image data of the next job at the end of the image forming step b1 of the previous job, the previous job is not involved without the post-processing and the pre-charging. The image forming process b2 of the next job is entered following the image forming process b1. Then, after the image forming step b2, the post-processing c is executed and the process is terminated. On the other hand, as shown in the time chart (b), when there is no image data of the next job at the stage where the image forming process b1 of the previous job is completed, post-processing c is performed after 100 ms. Then, at the stage where the image data of the next job is obtained by reading the original or transmitting image data from the outside, the image forming step b2 of the next job is executed after performing the pre-charging a.
[0008]
In the control as described above, for example, depending on the time required to develop the image data for the image data of the next job started simultaneously with the start of the image forming step b1 of the previous job, the image forming time is Change. Until the time of image development d1 is 1100 ms, the image forming process b2 of the next job is started without interposing the post-processing c and the precharging a in the image forming process b1 of the previous job. The time chart (a) in FIG. 1 shows the image forming time in this case (the time required for image development d1 is 900 ms), and the time for a job to form two images is 4000 ms, that is, 4 seconds. . On the other hand, when the time of image development d2 slightly exceeds 1100 ms, post-processing c and pre-charging a are executed after the image forming step b1 of the previous job, and the image forming step b2 of the next job is It is executed after that. As a result, the job shown in the time chart (b) in which the time required for the image development d2 is 1200 ms requires 6100 ms, that is, 6.1 seconds for all the processes. As described above, if the time required for developing the image data slightly exceeds 1100 ms, the time required for image formation increases from 4000 ms to 6100 ms.
[0009]
The example shown in FIG. 1 is an example in which the execution time of the job changes depending on the time for developing the image data into a printable format, but FIG. 1 also depends on the timing at which the multifunction peripheral acquires the image data from the outside. As shown, the execution is extended and the efficiency of image formation is extremely reduced.
[0010]
In order to solve such a problem, after the image forming process is completed, the post-processing is performed in order to delay the timing for determining the end of the job and extend the time that can be determined to enter the next image forming process. Although it is conceivable to extend the time uniformly, it is not preferable that the time is extended uniformly because post-processing causes deterioration of the photoreceptor or the cleaning blade of the cleaning device.
[0011]
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems in a multi-function machine that performs image formation in various modes.
[0012]
(2) Many multifunction devices switch the pixel density in the copy mode and the pixel density in the printer mode to different values. In such a multi-function device that switches the pixel density, the pixel density is switched by switching the moving speed of the photosensitive member.
[0013]
When the MFP continuously performs image formation in the copy mode and image formation in the printer mode, the next image formation process is performed continuously from the previous image formation process in order not to reduce the image formation efficiency. Although it is desirable to execute this, if the transfer speed of the photosensitive member is switched between the previous image forming process and the subsequent image forming process as described above, the image forming process in the copying mode is changed to the printer mode. When the image forming process is continuous, or when the image forming process in the copying mode is continued with the image forming process in the printer mode, by changing the moving speed of the photosensitive member and various image forming conditions accompanying the change. It becomes difficult to form a satisfactory image in the image forming process after changing the image forming conditions.
[0014]
In order to solve such a problem, it is conceivable to uniformly perform post-processing after the end of the previous image forming process and to perform pre-charging processing before the subsequent image formation. In addition to a significant decrease, pre-charging treatment and post-treatment are not preferable because the photoreceptor is fatigued, ozone is generated due to corona discharge, the discharge wire of the charger is deteriorated, and the cleaning blade of the photoreceptor and the cleaning device is deteriorated.
[0015]
An object of the present invention is to solve the above-described problems in a multifunction machine.
[0016]
[Means for Solving the Problems]
  The object of the present invention is
  (1) By charging, exposing and developing the photosensitive member, a toner image is formed on the photosensitive member, and the toner image formed on the photosensitive member is transferred to a recording material and fixed.Cleaning the toner remaining on the photoconductor after transferAn image forming apparatus for forming an image on a recording material by an image forming process, a pre-charging means for charging the entire surface of the photoconductor before the image forming process, and an entire surface of the photoconductor after the image forming process Post-treatment means for cleaning and eliminating static electricityA print controller for developing image data supplied from outside,In an image forming apparatus having
  A copy mode for reading an original to form an image of the original and a printer mode for forming an image based on image data supplied from the outside are provided.
  If the image forming process in the same mode as the previous image forming process continues after completion of the image forming process in either the copying mode or the printer mode, the post-processing means is activated. If the image forming process is executed without performing the image forming process, and the image forming process in a mode different from the mode of the previous image forming process is continued, the image forming process is performed after the post-processing unit and the pre-charging unit are operated. The control means controls so as to execute the process.An image forming apparatus,
  (2)The recording pixel density in the copying mode and the recording pixel density in the printer mode are different from each other.Image forming apparatus,
  (3) By charging, exposing and developing the photosensitive member, a toner image is formed on the photosensitive member, and the toner image formed on the photosensitive member is transferred to a recording material and fixed.Cleaning the toner remaining on the photoconductor after transferAn image forming apparatus for forming an image on a recording material by an image forming process, a pre-charging means for charging the entire surface of the photoconductor before the image forming process, and an entire surface of the photoconductor after the image forming process Post-treatment means for cleaning and eliminating static electricityA print controller for developing image data supplied from outside,In an image forming apparatus having
  When there are multiple modes for forming images with different pixel densities and the job is executed continuously, if the pixel density of the preceding and succeeding jobs is the same, the image forming process in the previous job is continued. And execute the image forming process in the next job,
  When the pixel densities of the preceding and succeeding jobs are different, the post-processing is executed after the image forming process of the previous job is completed, and the pre-charging process is executed before executing the image forming process of the next job. An image forming apparatus having control means for performing control;
  (4) By charging, exposing and developing the photosensitive member, a toner image is formed on the photosensitive member, and the toner image formed on the photosensitive member is transferred to a recording material and fixed.Cleaning the toner remaining on the photoconductor after transferAn image forming apparatus for forming an image on a recording material by an image forming process.
  A pre-charging unit that charges the entire surface of the photoconductor before the image forming step; and a post-processing unit that cleans the entire surface of the photoconductor and neutralizes the charge after the image forming step;A print controller for developing image data supplied from the outside, the pre-charging means, andControl means for controlling the post-processing means;,With
  A first image recording mode for forming an image based on the image data after the image data for one job has been stored;
  A second image recording mode for forming an image based on the image data at the time when the storage of the image data for one page is completed;
  After the image forming process in either the first image recording mode or the second image recording mode is completed, the control unit performs image recording in the immediately preceding image forming process after the image forming process is completed. If it is determined that the image recording mode is the same as the mode, the subsequent image forming step is performed without operating the post-processing unit,
  An image in which the subsequent image forming process is different from the image recording mode in the immediately preceding image forming process If it is determined that the recording mode is selected, control is performed so that the post-processing unit and the pre-charging unit are operated and then the subsequent image forming process is executed.This is achieved by an image forming apparatus.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 2 is a block diagram of each functional unit of the image forming apparatus according to the embodiment of the present invention.
[0018]
In the figure, thin arrows indicate the transmission direction of control signals, and thick arrows indicate the transmission direction of image data.
[0019]
The image data from the reading unit 3 obtained after being conveyed one by one from a large number of documents is subjected to image processing such as density conversion processing, filter processing, and scaling processing in the image processing unit 5. Image data stored in and read from the storage unit 6, which is a storage unit, is converted into light by a writing unit 7 that performs writing using a laser beam, and is written on a photoconductor in the image forming unit 8. It is.
[0020]
Image data transmitted from an image data output device such as a computer via the print controller 4 is converted into a data format to be processed by the image processing unit 5 in the print controller 4 and then transmitted to the image processing unit 5. The storage unit 6 stores the compressed image data, and has a capacity for storing image data of about 100 pages of an A4 size character document. When the image data output from the image processing unit 5 is stored in the storage unit 6 and then read to form an image, or without being stored, the image data is output directly from the image processing unit 5 to the writing unit 7 to form an image. There is a case to do. The setting unit 2 accepts settings of various functions, modes, and image forming conditions that the image forming apparatus has. The control means 1 exchanges a control signal with each function part shown in the figure, and controls each function part.
[0021]
FIG. 3 shows the configuration of the image forming unit 8 in FIG. The drum-shaped photosensitive member 10 having an organic photoconductive layer as a photosensitive layer is charged with a negative charge by the charger 11 in accordance with the clockwise rotation indicated by the arrow of the motor 19, and the peripheral surface of the photosensitive member 10. A uniform charging potential indicated by V is formed in. Next, the laser beam from the semiconductor laser is exposed with a scanning beam deflected by a polygon mirror, and an electrostatic latent image is formed on the peripheral surface of the photoreceptor 10. The formed electrostatic latent image is reversed and developed with a two-component developer containing a negatively charged toner TN by the developing device 13 to form a toner image on the peripheral surface of the photoreceptor 10. The formed toner image is transferred onto the recording material P by the transfer device 14. The recording material to which the toner image is transferred is separated from the photoreceptor 10 by the separator 15 and fixed by the fixing device 16. Cleaning is performed by removing the toner TR remaining on the photoreceptor 10 after the transfer with the cleaning blade 171 of the cleaning device 17.
[0022]
The image forming unit 8 shown in FIG. 3 performs a photoconductor 10 before starting an image forming process from charging to fixing when a job is executed by operating a copy button or a print command from an image data output device. Is rotated as indicated by an arrow, and a pre-charging process for charging by the charger 11 is performed. This pre-charging process is a process for ensuring a uniform and stable potential during charging for forming an electrostatic latent image in the image forming process on the photoconductor 10, and at least the photoconductor 10 is rotated once. This is performed on the entire surface of the photoreceptor 10. As described above, the charger 11 that performs charging in the image forming process is also used as a pre-charging unit in the pre-charging process.
[0023]
Further, after the job image forming process is completed, post-processing is performed by a post-processing unit including the cleaning device 17 and the charge removal lamp 18. That is, the cleaning by the cleaning device 17 and the charge removal by the exposure of the charge removal lamp 18 are performed on the entire surface of the photoreceptor 10 at least once.
[0024]
At the end of the image forming process, a non-uniform potential may be formed on the surface of the photoconductor 10, and the process may end. When such a non-uniform portion passes through the developing device 13, carrier adhesion or the like occurs. is there. The post-processing is for solving such a problem. The photosensitive member 10 is rotated at least once, and the photosensitive member 10 is cleaned by the cleaning device 17 and uniformly exposed by the charge eliminating lamp 18.
[0025]
Now, the image forming apparatus according to the present embodiment has a copying mode for forming an image based on image data obtained by reading by the reading unit 3 and a printer for forming an image based on image data input to the print controller 4. Has a mode. The image forming apparatus further has several modes as described below.
[0026]
(1) Real-time mode
In this mode, image formation based on the obtained image data and storage of the image data are performed in parallel.
[0027]
In the copy mode, reading by the reading unit 3 and image formation by the image forming unit 8 are executed in parallel. When the image data for one page obtained from the reading unit 3 is stored in the storage unit 6, the image data is read from the storage unit 6 to start image formation, and the image data is stored in the storage unit 6. Image data is read from the storage unit 6, written by the writing unit 7, and formed by the image forming unit 8. In the printer mode, the image data from the print controller 4 is developed, and when image data for one page is accumulated in the storage unit 6, the image data is read from the storage unit 6 to form an image, and the print is performed. The image data input to the controller 4 is stored in the storage unit 6.
[0028]
(2) Batch mode
In this mode, the image data is stored in the storage unit 6 and image data is read out from the storage unit 6 after image data for one job has been stored.
[0029]
In the copy mode, the image data obtained by reading by the reading unit 3 is stored in the storage unit 6, and after all the originals in one job have been read, the image data is read from the storage unit 6 to form an image. Start. In the printer mode, the image data input to the print controller 4 is stored in the storage unit 6, and all image data for one job is stored in the storage unit 6, and then read from the storage unit 6 to form an image.
[0030]
(3) Memory mode
Image data obtained by reading by the reading unit 3 is stored in the storage unit 6, and the stored image data is read to form an image. This mode is a generic term for the real-time mode described in (1) and the collective mode described in (2).
[0031]
(4) Through mode
In this mode, the image data is directly input to the image processing unit 5 without storing the image data in the storage unit 6.
[0032]
The copy mode and the printer mode are selectively used according to the operation of the copy button and the image formation start command from the image data output device. The modes (1) to (4) are selected by the setting by the user in the setting unit 2 in the copying mode, and are selected by the setting in the image data output device in the printer mode.
[0033]
  In these modes, pre-charging a and post-processing c executed before and after the image forming step b are:,As described below, the image forming step b is combined with the image forming step b in a different manner.
[0034]
First, in the printer mode, the post-processing time is set to a time T + α longer than the post-processing time T in the copy mode.
[0035]
In the copy mode, post-processing c of the time length T is executed after the end of the last image forming process in the job. In the post-processing step c, as described above, at least one rotation of the photoconductor 10 is performed, and the entire surface of the photoconductor 10 is cleaned by the cleaning device 17 and uniformly exposed by the charge removal lamp 18. As described above, the post-processing c needs to be performed by rotating the photosensitive member 10 at least once to make the surface state of the photosensitive member 10 uniform.
[0036]
In the printer mode, the length of time for which post-processing c is executed is extended to T + α. The added time length α is a time for allowing the image forming process b2 of the next job to be entered without entering the post-processing c of the time length T when the image data is obtained during this time. is there.
[0037]
  In the job execution process when post-processing c is extended to time length T + α,in frontThe post-processing c is executed after the image forming process b1 following the charging a. However, when the image data of the next job is obtained within the time length α, the image forming process b2 of the next job is performed later. It is executed following the process c.
[0038]
  As described above, in copy mode,HandThe stage exchanges control signals with the reading unit 3, and at the end of the image forming process, the control means 1 knows whether there is image data for the next job. Therefore, in the stage before the image forming process b1 of the previous job is completed, the process at the end of the job, that is, the post-processing c is executed, or the image forming process b2 is continuously performed without executing the post-processing c. This can be determined by the control means 1. On the other hand, in the printer mode, when image data is input to the print controller 4 at the end of the image forming step b, and how long it takes to develop the input image data into print format image data. The control means 1 cannot grasp whether it is necessary.
[0039]
  Therefore, in the printer mode, the post-processing time is set longer by α. In the printer mode, the time α added as a post-processing time is preferably a short time in order to avoid deterioration of the photoconductor 10 and the cleaning blade 171. On the other hand, in order not to lower the image forming efficiency, It is desirable to set it long. To eliminate the excessive decrease in image formation efficiency,ReasonThe interval is set as the time required for post-processing c. That is, it is ideal to rotate the photoconductor 10 once.
[0040]
Next, shortening of job execution time, that is, improvement of image forming efficiency in the present embodiment will be described.
[0041]
The specific example used in the description of FIG. 1 is applied to this embodiment as follows. As described above, in the present embodiment, the post-processing c and the pre-charging process a are not performed even when the end time of the image development d is after the end time of the image forming step b1 + 100 ms. Assuming that the time is 1200 ms, the image forming start time of the next image forming job in the present embodiment is advanced by 1900 ms ahead of the conventional method shown in FIG. 1 as shown in FIG. Is shortened, and the image forming efficiency is improved.
[0042]
Such a reduction in time is represented by an image forming efficiency expressed by the number of images formed per minute as shown in FIG.
[0043]
In FIG. 5, the vertical axis represents the number of images formed per minute (image formation efficiency), and the horizontal axis represents the development time of image data. A solid polygonal line L1 represents a change in image formation efficiency with respect to the development of image data in the present embodiment, and a broken line L2 represents a change in image formation efficiency with respect to the development of image data in the conventional method. Numerical values in units of milliseconds (ms) are specific examples shown in FIGS.
[0044]
As is apparent from the figure, in the conventional method, the image formation efficiency is uniformly from 54 ppm (the number of images formed per minute is 54) to 20 ppm with respect to the image data development time in which the image development time exceeds 1100 ms. descend. On the other hand, in the present embodiment, from the point m where the image data development time is 1000 ms to the point n where the image data development time is 1900 ms, from 60 ppm to 33 ppm, a decrease corresponding to the increase in the image data development time. From the point n where the image data development time is 1900 ms to the point 3100 ms point o, there is no decrease in image formation efficiency, and when the image data development time is longer than 3100 ms, there is a gradual decrease in image formation efficiency. Yes.
[0045]
In other words, in the present embodiment, the image forming efficiency is improved by the amount indicated by the oblique lines in FIG.
[0046]
In the present embodiment, the uniform post-processing time is not extended, but the post-processing time is extended by a necessary amount in a specific mode. Therefore, the photoconductor 10 and the cleaning blade 171 are post-processed. Degradation is significantly reduced.
[0047]
Second, the post-processing time in the real-time mode is extended to T + β with respect to the post-processing time T in the collective mode.
[0048]
In the collective mode, the image data stored in the storage unit 6 is read and the image forming process b is executed. Therefore, at the end of the previous image forming process b, the control unit 1 determines whether or not the next image data exists. I can grasp it. Accordingly, a steady time T is set as the post-processing time. On the other hand, in the real-time mode, the control unit 1 cannot grasp when image data that can be used for image formation can be generated as in the first case. Therefore, T + β is set as the post-processing time.
[0049]
Third, the post-processing start time in the through mode is extended to T + γ with respect to the post-processing start time T in the memory mode.
[0050]
In the memory mode, the image data stored in the storage unit 6 is read and the image forming step b is executed. Therefore, at the end of the previous image forming step b1, the control unit 1 determines whether or not the next image data exists. I can grasp it. Accordingly, a steady time T is set as the post-processing start time. On the other hand, in the through mode, the control unit 1 cannot grasp when image data that can be used for image formation can be obtained as in the first case. Therefore, T1 + γ is set as the post-processing start time.
[0051]
The addition times β and γ in the second and third cases are the same as the addition time α in the first case, from the viewpoint of preventing deterioration of the photosensitive member 10 and the cleaning blade 171 and from the viewpoint of preventing excessive reduction in image forming efficiency. Therefore, it is set in consideration of characteristics of image data processed in the image forming apparatus, specifications of the image forming apparatus, and the like. In order to avoid complication of control, it is desirable to make these additional times α, β, and γ equal.
[0052]
The job execution process in this embodiment will be described with reference to FIGS.
[0053]
In step F1, a pre-charging process for charging the entire surface of the photoconductor 10 by the charger 11 is performed.
[0054]
As shown in FIG. 7, the pre-charging process is executed for a length of time in which 400 ms is added to the time 800 ms required to rotate the photoreceptor 10 at a steady speed. Note that the numerical values in FIG. 7 are based on the specific example shown in FIG. As described above, the time required for the precharge a to be 400 ms longer than the time required for one revolution of the photoconductor 10 is 400 ms before the precharge step F12, after the motor for driving the photoconductor 10 is turned on (F10). This is because it takes 400 ms for the rotational speed of the photoconductor 10 to reach a certain value.
[0055]
After precharging, an image forming process is executed (F2). The image forming process is performed until the set number of images are formed, that is, the set output is completed, and when the set output is completed (F3), it is determined whether the mode of the set image forming process is A or B. (F4).
[0056]
If the mode A is an image forming process, post-processing (F6) for an extended time T + α (T + β or T + γ), that is, after rotating the photoconductor 10 and cleaning the photoconductor 10 with the cleaning device 17 finish. When mode B is set, the post-processing (F5) after the steady post-processing time T is terminated. Such control of the post-processing time, that is, control for extending the post-processing time T to T + α is performed by extending the light emission time of the static elimination lamp 18 by the control means 1 and extending the driving time of the motor.
[0057]
As shown in FIG. 6B, the mode A includes a printer mode, a real time mode, and a through mode, and the mode B includes a copy mode, a batch mode, and a memory mode. Note that the real time mode and the through mode in FIG. 6B are not in the copy mode but in the printer mode.
[0058]
In this embodiment, image formation is performed by setting the pixel density in the copy mode to 400 dpi (dot / inch) and the pixel density in the printer mode to 600 dpi. The pixel density is changed by controlling the motor by the control means 12 and changing the moving speed of the photoconductor 10. In the copying mode, the moving speed of the photoconductor 10 is set to 370 mm / mm. Image formation is performed as s, and in the printer mode, image formation is performed with the moving speed of the photosensitive member 10 being 280 mm / s. The pixel density is changed by controlling the motor by the control unit 1 in the sub-scanning direction and changing the moving speed of the photosensitive member 10 as described above, and by the control unit 1 in the main scanning direction. By controlling the processing unit 5, the frequency of the driving pulse for driving the semiconductor laser (not shown) of the writing unit 7 is changed.
[0059]
Among the printer modes, there are a 400 dpi mode and a 600 dpi mode, and these pixel density conversions are performed by changing the moving speed of the photoconductor 10. When image forming jobs are continuously executed, it is ideal to continuously execute the jobs without intervening time intervals between the jobs in order not to lower the image forming efficiency. Continuous image forming jobs having different pixel densities have a problem in the image forming process. In the present embodiment, discrimination control is performed to determine whether the image forming process is continued or whether post-processing and pre-charging processing are interposed between the image forming processes depending on whether the preceding and following image forming jobs are the same or different. By such discrimination control, reduction in image forming efficiency when jobs are continuously executed in the mixed mode is reduced.
[0060]
FIG. 8 shows control when a plurality of different jobs continue in the present embodiment.
[0061]
After the pre-charging process (F20) for charging the entire surface of the photoconductor 10 by rotating the photoconductor 10 one or more times, an image forming process is executed (F21). When the set number of image formation is completed, that is, when the set output is completed (F22), it is next checked whether there is an image formation mode in the same mode (F23). If there is an image forming job in the same mode, the image forming process of the next image forming job is executed following the image forming process F21 (F24). When the output set for the next image forming job is completed (F25), it is further checked whether there is a next image forming job (F23), and if there is, the process proceeds to step F24 to repeat the image forming process. If it is determined in step F23 that there is no image forming job in the same mode, post-processing is started (F26). During post-processing of step 26, there was third image data to be subjected to an image forming job in the same mode as the previous image forming process, that is, the image forming process in step F21 or the image forming process in step F24. In this case (YES in F27), an image forming process based on the third image data is executed after the post-processing of step F26 (F24). If there is no image data for image formation in the same mode after the execution of the post-processing in step F26 (NO in F27), the post-processing is completed (F28) and the process ends.
[0062]
In steps F23 and F27 in FIG. 8, it is determined whether there is a next job in the same mode to be performed. It is determined whether there is a job that forms an image with the same pixel density as the previous job. Is. In an image forming apparatus having a 400 dpi copying mode and a 600 dpi printer mode, the copying mode or the printer mode is determined in steps F23 and F27. The difference in pixel density is determined in steps F23 and F27.
[0063]
【The invention's effect】
(1) In various modes such as the printer mode, depending on the timing when the control unit of the image forming apparatus acquires the image data, the time required to execute the image forming job becomes long, and the image forming efficiency may be significantly reduced. is there. Such a decrease in image forming efficiency can be reduced by avoiding deterioration of the image forming unit.
[0064]
(2) When jobs in image forming modes having different pixel densities are continuously executed, image formation can be performed without reducing image forming efficiency and avoiding deterioration of the image forming unit.
[Brief description of the drawings]
FIG. 1 is a time chart of a job in a conventional image forming apparatus.
FIG. 2 is a block diagram illustrating functions of the image forming apparatus according to the embodiment of the present invention.
FIG. 3 is a diagram illustrating a configuration of an image forming unit of the image forming apparatus according to the embodiment of the present invention.
FIG. 4 is a job time chart according to the embodiment of the present invention.
FIG. 5 is a diagram showing image formation efficiency in comparison between an embodiment of the present invention and a conventional image forming apparatus.
FIG. 6 is a flowchart of control in a job in various modes according to the embodiment of the present invention.
FIG. 7 is a flowchart of pre-charging processing.
FIG. 8 is a flowchart of control in a job in a mode in which the pixel density is different according to the embodiment of the present invention.
[Explanation of symbols]
1 Control means
2 Setting section
3 Reading unit
4 Print controller
5 Image processing section
6 storage unit
7 Writing section
8 Image forming part
10 photoconductor
11 Charger
17 Cleaning device
18 Static elimination lamp

Claims (4)

By charging, exposing and developing the photoconductor, a toner image is formed on the photoconductor, and the toner image formed on the photoconductor is transferred and fixed on a recording material. An image forming apparatus for forming an image on a recording material by an image forming process for cleaning toner remaining thereon, a pre-charging unit for charging the entire surface of the photoconductor before the image forming process, and an image forming process After, in an image forming apparatus having post-processing means for cleaning and neutralizing the entire surface of the photoconductor, and a print controller for developing image data supplied from the outside,
A copy mode for reading an original to form an image of the original and a printer mode for forming an image based on image data supplied from the outside are provided.
When the image forming process in the same mode as the previous image forming process is continued after the image forming process in either the copying mode or the printer mode is completed, the post-processing unit is activated. If the image forming process is executed without performing the image forming process, and the image forming process in a mode different from the mode of the previous image forming process is continued, the image forming process is performed after operating the post-processing unit and the pre-charging unit. An image forming apparatus, wherein the control unit performs control so as to execute a process. The image forming apparatus according to claim 1, wherein a recording pixel density in the copying mode is different from a recording pixel density in the printer mode. By charging, exposing and developing the photoconductor, a toner image is formed on the photoconductor, and the toner image formed on the photoconductor is transferred and fixed on a recording material. An image forming apparatus for forming an image on a recording material by an image forming process for cleaning toner remaining thereon, a pre-charging unit for charging the entire surface of the photoconductor before the image forming process, and an image forming process After, in an image forming apparatus having post-processing means for cleaning and neutralizing the entire surface of the photoconductor, and a print controller for developing image data supplied from the outside,
When there are a plurality of modes for forming images with different pixel densities and the jobs are executed continuously, if the pixel density of the preceding and succeeding jobs is the same, the image forming process in the previous job is continued. And execute the image forming process in the next job,
When the pixel densities of the preceding and succeeding jobs are different, the post-processing is executed after the image forming process of the previous job is completed, and the pre-charging process is executed before executing the image forming process of the next job. An image forming apparatus having control means for performing control. By charging, exposing and developing the photoconductor, a toner image is formed on the photoconductor, and the toner image formed on the photoconductor is transferred and fixed on a recording material. An image forming apparatus for forming an image on a recording material by an image forming process for cleaning toner remaining on the top,
A pre-charging unit that charges the entire surface of the photoconductor before the image forming step, a post-processing unit that cleans and discharges the entire surface of the photoconductor after the image forming step, and image data supplied from the outside And a controller for controlling the pre-charging means and the post-processing means,
A first image recording mode for forming an image based on the image data after the image data for one job has been stored;
A second image recording mode for forming an image based on the image data at the time when the storage of the image data for one page is completed;
After the image forming process in either the first image recording mode or the second image recording mode is completed, the control unit performs image recording in the immediately preceding image forming process after the image forming process is completed. If it is determined that the image recording mode is the same as the mode, the subsequent image forming process is executed without operating the post-processing means,
When it is determined that the subsequent image forming process is an image recording mode different from the image recording mode in the immediately preceding image forming process, the subsequent image is operated after the post-processing unit and the pre-charging unit are operated. Image forming apparatus controlled to execute a forming process .

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