JP4001323B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus having a copy function, a DF mechanism, and a plurality of image quality setting functions and capable of adjusting image quality.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, image forming apparatuses such as printers, digital copiers, and facsimile machines may have unstable output image quality due to various factors associated with the use of the apparatus. In particular, in an image forming apparatus having an image reading unit such as a scanner, dust, dust, or the like adheres to the image reading unit, and the image quality of the output image becomes unstable due to this adhesion. Therefore, the instability of image quality is adjusted by adjusting the image quality of the output image corresponding to various factors. Several methods have been proposed for adjusting such instability of image quality. For example, a single color gradation patch for each YMCK such as a copying machine is printed out, read by a reader, and a one-dimensional gradation correction table that has predetermined gradation characteristics is provided for each YMCK. And a method of creating and setting gradation conversion (γ conversion).
[0003]
[Problems to be solved by the invention]
However, conventionally, the adjustment is mainly made by changing the setting data at multiple levels in the image quality selection mode (character mode, photo mode), and it has been difficult to further adjust the selected mode. . When an image abnormality occurs due to dust, dust, or the like adhering to the image reading unit as the image forming operation is repeated over time, it is necessary to reselect setting data in the image quality selection mode and further adjust the image quality. In such a case, it is desirable to finely adjust the image quality mode for dust and dirt in the image reading unit so that the image quality desired by the user can be provided stably. Also, in the multi-level setting data that can be switched by the user operation, even dust and dust that become a problem over time are corrected according to their adaptability and generation amount and the selected setting data (image quality selection mode). It is desirable to update the level and provide stable image quality.
[0004]
Accordingly, a first object of the present invention is to provide a set of image quality setting data adjusted in advance for individual image quality requirements and to enable switching by a user operation, so that a user-desired image quality can be stabilized. An object of the present invention is to provide an image forming apparatus capable of outputting.
The second object of the present invention is to select the setting data (image quality) and the degree of conformity, the amount of generation, and the amount of dust and dust that become a problem over time in setting data of a plurality of levels that can be switched by a user operation. It is an object of the present invention to provide an image forming apparatus that can update a correction level according to a selection mode) and stably output a user-desired image quality. The third object of the present invention is to provide different display / warnings to the user according to the degree of conformity, generation amount, and the number of image forming operations for dust and dirt that are problematic due to image forming operations over time. It is an object of the present invention to provide an image forming apparatus that can prevent the occurrence of abnormal images when correction processing is overcorrected and uncorrected.
[0005]
[Means for Solving the Problems]
  According to the first aspect of the present invention, the image data reading means for reading the image data of the document on the document table, the operation number counting means for counting the number of times of reading the document by the image data reading means, and the image data reading means. Image forming means for forming an image of the read image data on paper in a character mode or a photo mode;A streak determining unit that determines whether or not a streak is generated when the image is formed by the image forming unit; and image data read by the image data reading unit when the streak determining unit determines that a streak is generated A line correction unit that performs line correction on the image, a correction level setting unit that sets a correction level of the line correction performed by the line correction unit from a plurality of levels from weak correction to strong correction, and the correction level setting unit. Correction level changing means for changing the set correction level according to the number of reading operations counted by the operation number counting means;WithThe correction level changing means changes stepwise to a switchable correction level,Said2To achieve the objectives.
[0006]
  In the invention of claim 2, in the invention of claim 1,The image data reading means performs sheet-through type reading.
[0007]
  According to a third aspect of the present invention, in the first or second aspect of the present invention, the operation frequency counting means.InThe third object is achieved by further providing presentation means for presenting the state of the image data reading means.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS.
FIG. 1 is a diagram showing a configuration of an image forming apparatus according to the present embodiment. FIG. 1A is a schematic diagram illustrating the internal configuration of the entire image forming apparatus, and FIG. 1B is a diagram illustrating the configuration of an image forming unit (corresponding to the dotted line portion in FIG. 1A). It is.
In the image forming unit, an OPC (hereinafter referred to as a photoconductor) 3 charged by the charging roller 2 is exposed by exposure (hereinafter referred to as LD (laser diode) writing) 4. The latent image formed by exposure is developed by a developing unit (toner cartridge) 5, toner is transferred onto a transfer sheet by a transfer roller 6, and heat-fixed by a fixing device 7.
[0009]
The developing unit 5 includes a charging roller 2, a toner bottle 8, a photoconductor 3, a toner agitator for agitation, and the like. In addition to the mag roller facing the photoreceptor 3, the developing unit 5 incorporates an agitator and blade for stirring the toner, whereby the toner is frictionally charged.
Below the developing unit 5, toner detecting means (hereinafter referred to as a T sensor) 9 for detecting the presence / absence of toner inside is disposed. The T sensor 9 outputs “H (high)” when it is detected that there is toner inside, and “L (Low)” when it is detected that there is no toner.
The registration sensor 10 is provided at a position where the driving state of a registration roller (not shown) can be detected, and by detecting the leading edge of the image and the leading edge of the transfer paper, Detect paper status.
[0010]
In the sheet-through document feeder (SDF) of the reading unit / operation unit 1, when reading a document, the document is automatically moved to read an image.
The carriage (running body) is initially stopped, and the document fed from the document placement table passes through the curved conveyance unit. On the pressure plate, the carriage moves with the start of reading, and sequentially reads the fixed original. In either case, zooming is performed on the sub-scanning side by slowing the moving speed during enlargement and increasing the moving speed during reduction.
In any case, the shading operation reads a reference white plate over a plurality of lines, and corrects reading unevenness of the original reading data by using the shading data.
[0011]
FIG. 2 is a block diagram showing the control relationship of the image forming apparatus.
The image forming apparatus includes a reading control board 11, a system control board 12, a writing control board 13, an operation / display unit 15, and an I / O (Input / Output) control board 14 as control relationships.
The reading control board 11 is provided with a CCD (photoelectric conversion element) for reading document information, and the read output is transferred to the system control board 12 as a digital signal because the timing generation of this CCD is the main operation.
The system control board 12 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and a nonvolatile RAM, and controls the timing of the entire image forming apparatus. Input / output control of the display unit 15, interface and operation control with other application units (not shown, but functions of FAX, printer, etc.), image processing of image information data (magnification, filter, γ), image memory The image forming apparatus is controlled to store / accumulate image information data using.
[0012]
The writing control board 13 is composed of the LD writing 4 for exposure and its driving unit, and performs writing work based on the image data from the system control board 12.
The I / O control board 14 includes input signals such as various sensors and actuators of the entire image forming apparatus including a scanner unit (corresponding to the reading unit / operation unit 1), a printer unit (corresponding to the image forming unit), a motor, and a solenoid. , A central part of output signals of the clutch, the high-voltage power supply 16 and the like. The output of the T sensor 9 and the output of each thermistor are input to the ADC, and the system control board 12 performs various controls based on this I / O data. Also included are paper presence / absence information on the paper feed tray and manual feed tray, size information, and a registration sensor for transferring the transfer paper.
The operation / display unit 15 is configured by a display unit using key inputs for setting various modes, LED (light emitting diode), LCD (liquid crystal display), 7seg (segment), and the like, and is controlled by the system control board 12. The
[0013]
FIG. 3 is a diagram showing the image processing function of the system control board 12. The functions of image processing in the system control 12 can be roughly divided into configurations as shown in FIG.
In the shading correction, correction related to density unevenness of the light source and the optical system is performed. Before reading the original, the reference white plate is read and the read signal is stored in the memory. Further, correction processing of read data and reference data is performed in dot units.
In the scanner γ conversion, density reverse linear digital data is obtained by inputting a reverse characteristic of the reading characteristic of the scanner. In addition to this, it is possible to intentionally make the low density portion stronger / weaker by setting the conversion table, and the effect of various subsequent corrections can be enhanced.
[0014]
The filter processing has functions such as MFT correction, smoothing processing for removing moire, and edge processing. Filter processing is performed based on setting values (parameters), so that the strength of the processing can be added / subtracted. . Also in the present embodiment, the MTF intensity and the smoothing factor are used as targets of addition / subtraction data.
Further, the addition / subtraction level of the data on the main scanning side and the sub-scanning side is adjusted to allow the data (character, line) to be thickened and thinned, and is the target of the addition / subtraction data like the MTF. Yes.
The scaling process does not directly affect the image quality process, but forms an image with settings according to the operation unit input and operation mode. In γ conversion, gradation processing is performed in consideration of supply and engine characteristics. The image quality processing includes binarization processing of multi-value data after γ conversion processing, dither processing according to a dither matrix, and error diffusion processing.
[0015]
Here, details of the operation specifications in the operation / display unit 15 will be described below. FIG. 4 is a diagram for explaining the image quality adjustment method.
The portions corresponding to the image quality selection mode (character mode, photo mode) are Text (character) and Photo (photo), and each of the operation / display unit 15 is composed of one LED and one key input.
When the image forming apparatus is turned on, when the apparatus is initialized, such as auto-clear or reset, the Text LED is always lit, and if the apparatus is set to the factory default setting, it is called a setting for reproducing a character document. It will be. When Text and Photo are toggled by key input and the Photo LED is lit, halftone (picture) expression is prioritized by dithering.
The operation / display unit 15 is provided with key inputs (initial setting key, system setting key) that enable setting / changing of the state of the image forming apparatus. If reproduction is not possible, it is possible to easily set the image quality setting data group A to G by selecting the image quality mode for the setting / change (see the table of image quality setting data groups in FIG. 4). reference).
[0016]
In general, image quality adjustment is required in cases where special-purpose copies such as normal-use originals, normal copies, and slips (which consist of blue, yellow, and red frames and characters) are used together. It becomes.
In the case of the present embodiment, it is recommended that the image quality setting is “pattern B” in the case of normal copying, and the image quality setting is “pattern E” in the case of special purpose copying. At this time, when the special-purpose copy is used mostly and the normal copy is rarely used, “pattern E” may be registered in the character mode and “pattern B” may be registered in the photo mode. Thus, in the device initialization state, the Text LED is always lit and the special purpose copy setting is performed, so that the user can perform the special purpose copy without setting the key every time.
[0017]
In the case of special applications, the optimum image quality parameters are not always set by default ROM data settings, and fine adjustment of settings according to special documents is required. In the past, adjustment and setting are often required, and since the process of checking the copy sample after changing the setting and adjusting it again is repeated, the difference in the ability and experience of the adjuster (serviceman) becomes the setting amount and setting time. It had a big influence.
Therefore, in the present embodiment, as shown in FIG. 5, the closest setting is selected from preset ROM data A to G patterns, and data to be added / subtracted to the setting state is input. Therefore, the burden on the coordinator can be significantly reduced.
[0018]
FIG. 5 is a diagram showing an image quality pattern using addition / subtraction data.
Because it is addition / subtraction data, it was set from the adjustment mode screen in the selection method such as “weak, normal, strong”, “thin, normal, strong”, which was previously input from “0-7”. You can also do it.
On the other hand, there is a case where after the data value further added / subtracted by the serviceman is changed with respect to the selected ROM data setting, the ROM data is further adjusted to different ROM data by the user by copying another document type or the like. is there. In such a case, since the adjustment value is optimized by changing the old setting, it is necessary to invalidate the added / subtracted data value when the ROM data setting is changed.
Further, when the ROM data is changed by the user and the previous data value to be added / subtracted is reset to the set ROM data setting, the value adjusted with the addition / subtraction data is made valid as before. It has become a structure.
[0019]
Even if the above operation is executed by a user operation or the like many times, the same response is obtained. Such correspondence is possible by having the corresponding ROM data A to G pattern information together with the non-volatile addition / subtraction data, and if the addition / subtraction data is provided in a plurality of sets in the same form. The addition / subtraction data can be adjusted for each ROM data.
It is possible to have more ROM data besides the A to G patterns. The ROM data is doubled by setting only the γ characteristic in the items of the A to G patterns, or the low reproduction / removal part is provided. It is effective to have more than one.
[0020]
The above configuration can be executed by recognizing the input of the operation / display unit 15 on the CPU bus, selecting the ROM data accordingly, and changing the image quality setting.
Similarly, the data input from the operation / display unit 15 in the adjustment mode is stored in the nonvolatile RAM for the addition / subtraction data, and the setting (register setting value) for the image processing device is “ROM area data” ± “ Adjustable addition / subtraction data ”.
For this reason, it is not necessary to store the settings (register setting values) for all devices in the nonvolatile RAM as in the prior art, and it is possible to output an image in which the image quality parameters are changed by setting the combination. Thus, the RAM capacity can be greatly reduced, and the nonvolatile data of the entire image forming apparatus can be transferred to a small capacity chip such as an EEPROM.
[0021]
Next, an image adjustment processing procedure according to the selection mode will be described with reference to FIG. FIG. 6 is a flowchart showing a processing procedure of image adjustment according to the selection mode.
If the image forming operation is not in progress (step 601; N), it is confirmed whether the image quality selection key is ON (step 602). When the image quality selection key is ON (step 602; Y) and the character LED is OFF (step 603; Y), the character LED is switched ON, and the character LED is ON and the photo LED is OFF (step). 604), the character in the ROM data table is searched (step 606).
On the other hand, if the image quality selection key is ON (step 602; Y) and the character LED is not OFF (step 603; N), the character LED is OFF and the photo LED is ON (step 605), and the ROM data A photograph of the table is searched (step 607).
[0022]
Then, ROM data (image quality patterns A to G) selected in the character mode and the photo mode is selected by the image quality selection key on the operation / display unit 15 (step 606). Corresponding ROM data stored in the non-volatile RAM together with the addition / subtraction data is searched (step 608), and a comparison is made as to whether it is equal to the addition / subtraction data table (step 609).
When one of the ROM data (image quality patterns A to G) corresponding to the mode selected by the image quality selection and the corresponding ROM data are equal (step 609; Y), the adjustment data is validated and added / subtracted. The device is set as above (steps 610 to 612).
[0023]
If the ROM data (image quality patterns A to G) corresponding to the mode selected by the image quality selection does not match (step 609; N), it is regarded as another ROM data adjustment value, and addition / subtraction by the adjustment data is performed. Without adjustment, all adjustment data is set to 0 and set to the device (steps 611 to 612). The adjustment data itself remains on the non-volatile RAM. When the ROM data setting is changed again by the user or the like, the above processing is always repeated.
Since only maintenance personnel such as service personnel can input adjustment data, corresponding ROM data, etc., the input can be changed through special operation from the operation / display unit 15 or maintenance I / F tool. Generally it is.
[0024]
FIG. 7 is a flowchart showing a processing procedure in the case where the LED blinks according to the factory default setting.
If the character LED is OFF (step 701; Y), it is confirmed whether or not the ROM data selected and set is the image quality pattern G (step 702). If it is not the image quality pattern G (step 702; N), it is different from the default (factory shipment) ROM data, so the photographic LED is displayed blinking (step 704).
On the other hand, if the character LED is not OFF (step 701; N), it is confirmed whether or not the ROM data selected and set is the image quality pattern B (step 703). If it is not the image quality pattern B (step 703; N), since it is different from the default ROM data, the character LED is displayed blinking (step 705).
As described above, when the character mode and photo mode settings (ROM data) are set to be different from the defaults that are assumed to be compatible with general manuscripts, the LED is blinked by changing the display means from the conventional one. , Can prompt warning / attention.
[0025]
Next, correction processing other than acquisition of shading data in the shading device portion will be described. In the shading correction shown in FIG. 3, the following correction processing is also performed.
For example, there is a concern that the image quality may change due to dust and dust entering over time.
If dust, dust, or the like adheres to a reference white plate when acquiring shading data (white reference data), the white level may decrease, and a white streak image may be generated due to the incorrect data. In such a case, since the signal level shifts to the black level side only in the foreign matter adhering portion compared to the surrounding pixels, the amount of data change (threshold, inclination, etc.) with the adjacent pixels on the left and right is greater than or equal to a predetermined value. In this case, it will be subject to correction.
For such a correction target, a separate main scanning line memory required for shading data is required. After the shading data is acquired, the above correction algorithm processing is performed, and the corrected data is stored in another main scanning line memory. Store and use as corrected shading data.
[0026]
The detection threshold level of the amount of change shifted to the black level and the correction level for the target pixel can be set in a plurality of settings from weak correction to strong correction, respectively, by register setting. Further, a data difference between the line memories before and after correction can be calculated, and a CPU-accessible counting memory that can store the result is provided.
In general, the possibility of entering and adhering foreign matter such as dust and dirt increases with repeated reading operations over time. For this purpose, log data such as an image forming operation and the number of scans (first reading and second reading) are held in a nonvolatile memory on the system control board 12 of the image forming apparatus. Then, by changing the correction level of the streak correction means stepwise (from weak to strong) according to the predetermined number of first reading operations, the side effects of image detection due to false detection and uncorrection can be reduced. / The correction level change is held until repair / maintenance / cleaning is performed by the repair person. The input level to the device by the service / repair person and the arrival level are corrected by the reset operation.
[0027]
FIG. 8 is a flowchart showing the processing procedure for streak correction. In the processing procedure of FIG. 8, the streak correction is described with respect to the black streak correction of the feeder, but the processing in the white streak correction is also the same. For shading data correction, both the first and second reading operations are targeted.
First, when the first reading operation is performed (step 801; Y), the number of scans is counted using nonvolatile data (step 802). If the count value of the number of scans is greater than 2000 (step 803; Y), the streak correction setting is set to “+1” (step 804). Furthermore, when the count value of the number of scans is larger than 5000 (step 805; Y), the line correction setting is set to “+1” (step 806). Then, the subsequent first reading setting is updated (step 807). By adding “+1” as the streak correction setting, the register data is changed from 2 → 3 → 4 according to the change with time.
[0028]
The image quality patterns A, B, and D of the image quality setting data (ROM data table) are intended to set the character mode, and therefore often include edge enhancement processing such as stripes and lines. For this reason, “the image quality patterns A, B, and D of the ROM data table are set to 2 to 3 by default”, “the image quality patterns C, E, F, and R of the ROM data table are set to 0 to 1 by default. “G” is set so that the character setting is stronger in the correction process.
As described above, streak correction data can be set from 0 (no correction) to 7 (maximum correction) in the same manner as other parameters (MTF, thinning). In FIG. 8, as an example, when the first reading operation is a predetermined number of times (here, 2000 times, 5000 times) or more, the correction register data is set to “+1”.
In addition, if the CPU has a count memory that can calculate the data difference between the line memories before and after correction and can store the result, correction processing is performed from the count memory data for each reading operation. Read the level for the number of times. Then, if the number of times correction processing is performed and the level exceeds a predetermined threshold value, it is determined that there is a large amount of foreign matter such as dust and dust entering and adhering, and the correction level is changed (weak → strong). It has become. If the number of reading operations is also added to this threshold value, the number of sudden correction processes will be reduced, and the effect of large correction level fluctuations on level changes will be less likely to occur. Can be reduced.
[0029]
FIG. 9 is a flowchart showing a processing procedure of line correction according to the number of operations. Note that the streak correction in the processing procedure shown in FIG. 9 is described with respect to the black streak correction of the feeder.
First, after the first reading operation is started (step 901; Y), the number of operations is counted (step 902). The reading / accumulation count of the correction processing frequency data is checked (step 903). When the operation count reaches 500 or more (step 904; Y), the operation count is cleared (step 905). If the integrated count is less than 5000 and greater than 100 (step 906; N, step 907; Y), the line correction setting is set to “−1” (step 909). On the other hand, when the integrated count is greater than 5000 (step 906; Y), the streak correction setting is set to “+1” (step 908). Then, after changing the streak correction setting (steps 908 and 909), the accumulated count is cleared (step 910).
[0030]
FIG. 10 is a diagram showing white stripe correction processing. A difference of a predetermined value or more from an adjacent pixel is abruptly generated (black level transition), and is further corrected when a sudden difference of the same level occurs in the reverse direction (black to white) within a predetermined period. A value at the same level as the pixel level before and after the difference is assigned to the pixels within a predetermined period. The correction parameter change includes a data change amount threshold value and a data period width threshold value.
FIG. 11 is a diagram showing the relationship between the number of operations and the correction level. At a normal streak correction level, a transition such as “◎ 2” in FIG. 11 is performed according to the operation count log data. When the number of times of streak correction processing (integration count) is small, the correction level is weakened, and when the number of times of streak correction processing is large, the correction is set to be larger. In the processing procedure of FIG. 9, the cumulative count value serving as the threshold has been described as being 5000 times and 100 times, but is not limited thereto.
[0031]
In the first reading mode using a sheet-through document feeder (hereinafter referred to as ADF), in addition to dust adhering to the reference white plate, dust adhering to the original reading portion (glass portion of the original conveying surface) is also abnormal. It is often the cause of. Since the carriage stops and only the original fed from the original placing table moves, the dust adhering portion is always read, and the dust is reproduced in a streak shape. This streak correction can also be performed at the adjacent pixel level using the same algorithm as in the case of dust adhesion on the reference white plate. Complement processing according to image data that is constantly updated at the time of document reading. Similar to the above description, it is effective to update the correction only in the first reading mode according to the count memory data and the number of reading operations.
[0032]
In addition to correction, a display that prompts the user to clean the document reading unit (the glass part of the document transfer surface) according to the counting memory data and the number of reading operations is also effective for providing stable image quality. When the correction processing by the count memory data is small, when it is increasing, when it is stably reduced from the increase, the case division is judged at a predetermined cycle so as to perform the optimum display that can prompt the user to clean. It may be.
As described with reference to FIG. 9, the number of corrections (integrated count) is checked for each operation number (here, as an example, the predetermined interval is every 50 sheets), and in any of regions A, B, C, and D in FIG. Determine if it applies. In FIG. 12, area A is a correction target for large fluctuations and has a small number of corrections, area B is a correction target for only large fluctuations and has a large number of corrections (a large amount of dust), and area C is a small fluctuation. In addition, it is assumed that the correction target has a small number of corrections, and the region D includes a small fluctuation and a correction target that has a large number of corrections.
[0033]
FIG. 13 is a diagram showing display / notification according to the region determination result. For example, when the current determination result is the C region and the previous determination result is the C region based on the determination result of which region A to D corresponds to and the previous region determination result, it is described in FIG. The contents corresponding to the corresponding part of “weak correction” are displayed. Thereby, an appropriate operation setting can be notified to the user.
If the “abnormal image” in FIG. 13 is applicable, “abnormal image may occur. Clean the reading glass.” Is displayed. When “Display_None” is applicable, no warning is displayed, and when “Correction is weakened”, “Reading glass dust is reduced.” Is displayed and “Cleaning instruction” is displayed. If this is the case, a message such as “Please clean the dust on the reading glass.” Is displayed. By displaying such display guidance alternately on the normal operation / setting screen at a certain cycle, the user can be alerted, and overcorrection of correction processing such as cleaning operation, before the occurrence of abnormal images due to uncorrected Can be prevented in advance.
[0034]
【The invention's effect】
  In invention of Claim 1,When streaks occur at the time of image formation, the scanned image data is corrected, the correction level is changed according to the number of reading operations, and further, switching is possible when changing the correction level. Since the level is changed step by step to the correction level, it is less likely to be affected by large fluctuations in the correction level when foreign matter such as dust or dust attached due to repeated scanning operations enters. Can be reduced.
[0035]
  In invention of Claim 2,Since the image data reading means performs a sheet-through type reading, it is possible to correct reading unevenness.
[0036]
  In the invention according to claim 3, the operation number counting meansInBased on the above, it is further provided with a presenting means for presenting the state of the image data reading means, so that the degree of conformity, generation amount and number of image forming operations with respect to dust and dirt of the image reading unit which are problematic due to the image forming operation over time It is possible to prevent occurrence of abnormal images due to overcorrection of correction processing such as attention and cleaning operation by performing different display / warning to the user step by step and uncorrected.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration of an image forming apparatus according to an exemplary embodiment.
FIG. 2 is a block diagram illustrating a control relationship of the image forming apparatus.
FIG. 3 is a diagram illustrating an image processing function of a system control board.
FIG. 4 is a diagram illustrating a method for adjusting image quality.
FIG. 5 is a diagram showing an image quality pattern using addition / subtraction data.
FIG. 6 is a flowchart illustrating an image adjustment processing procedure according to a selection mode.
FIG. 7 is a flowchart showing a processing procedure when an LED blinks in accordance with factory default settings.
FIG. 8 is a flowchart showing a processing procedure for streak correction.
FIG. 9 is a flowchart showing a process procedure of line correction according to the number of operations.
FIG. 10 is a diagram showing white stripe correction processing;
FIG. 11 is a diagram showing the relationship between the number of operations and the correction level.
FIG. 12 is a diagram showing a region corresponding to the relationship between the correction level and the number of corrections.
FIG. 13 is a diagram showing display / notification according to a region determination result.
[Explanation of symbols]
1 Reading unit / Operation unit
2 Charging roller
3 OPC (photoconductor)
4 Exposure (LD writing)
5 Development unit
6 Transfer roller
7 Fixing device
8 Toner bottle
9 Toner detection means (T sensor)
10 Registration sensor

Claims (3)

Image data reading means for reading image data of a document on a document table;
An operation number counting means for counting the number of times of reading operation of the document by the image data reading means;
Image forming means for forming an image of the image data read by the image data reading means on a paper in a character mode or a photo mode;
Streak determining means for determining whether or not streaks are generated during image formation by the image forming means;
A line correction unit that performs line correction on the image data read by the image data reading unit when the line determination unit determines that a line is generated;
Correction level setting means for setting the correction level of the line correction performed by the line correction means from a plurality of levels from weak correction to strong correction;
Correction level changing means for changing the correction level set by the correction level setting means according to the number of reading operations counted by the operation number counting means ,
The image forming apparatus, wherein the correction level changing unit changes the correction level step by step to a switchable correction level. The image forming apparatus according to claim 1 , wherein the image data reading unit performs a sheet-through type reading . Wherein based on the operation number counting means, the image data reading unit according to claim 1 or the image forming apparatus according to claim 2, characterized in that further comprising presenting means for presenting the state of.

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