JP2011043825A - Image forming apparatus and method of the same, and image forming program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which is configured by solving a problem that, if a consumable article is exchanged to the new one when a message to urge a user to exchange the consumable article is displayed, the consumable article that can be used is discarded, to cause a situation that cost is unnecessarily used. <P>SOLUTION: When first information on the numerical quantity of images formed on an image forming medium reaches second information on a period until the exchange of a component is required, an image for correcting image quality is formed on a transfer body by a correction image forming part, and the image quality is detected by an image quality detection part. A screen line number in screen processing in an image processing part is switched based on the detected image quality. After the screen line number is switched, once again, whether or not the image quality of the image is normal is determined by a second determination part based on the image quality detected by the image detection part. If the image quality of the image is not normal, the user is urged to exchange the component. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  Embodiments of the present invention relate to an image forming apparatus and method, and an image forming program for replacing the consumables to maintain the image quality when the lifetime of the consumables such as a photosensitive drum and a developer approaches. .

  Some image forming apparatuses use electrophotography. In the image forming apparatus, a photosensitive drum for forming an electrostatic latent image, and a developer such as toner attached to the electrostatic latent image formed on the photosensitive drum to form a visible image. Development unit. These photosensitive drums and developing materials are consumables, and are parts that require replacement when they can be used, that is, at the end of their service life. When exchanging these consumables, for example, the number of printed sheets or the number of printing pixels (dots) is counted, and when this count value approaches a value corresponding to a predetermined life, for example, replacement of consumables is prompted on the panel. A message is displayed.

JP 2004-354666 A

  The life of consumables has a margin, and even if the number of printed sheets or the number of printed pixels approaches a predetermined count value, it does not affect the quality of images formed on image forming media such as recording paper. In many cases, consumables such as a photosensitive drum or a developer can be used. If a message prompting the replacement of the consumables is displayed, if the consumables are replaced with new ones, the consumables that can be used are discarded, and extra costs are incurred.

  According to the image forming apparatus of the embodiment, the electrostatic latent image corresponding to the image data is formed including the parts that need to be replaced when it can be used, and the coloring material is attached to the electrostatic latent image. A transfer process unit that holds the visible image on a transfer body, and transfers the visible image held on the transfer body to an image forming medium as an image, and screen processing is performed on the image data. An image processing unit capable of controlling the quality of an image to be formed, a measurement unit that measures first information relating to the number of images formed on an image forming medium by the transfer process unit, and replacement of components included in the transfer process unit A storage unit that stores in advance second information relating to a period until it is necessary, and a first unit that determines whether the first information measured by the measurement unit has reached the second information stored in the storage unit By the determination part and the determination part As a result, when the first information reaches the second information, a correction image forming unit that forms an image for image quality correction on the transfer body by the transfer process unit with respect to the image processing unit, and an image quality formed on the transfer body An image quality detection unit that detects the image quality of the correction image, a screen line number switching unit that switches the screen line number of the screen processing in the image processing unit based on the image quality detected by the image quality detection unit, and a screen by the screen line number switching unit After the number of lines is switched, it is determined whether or not the image quality is normal based on the image quality detected by the image quality detection unit. And a determination unit.

1 is a block configuration diagram illustrating an image forming apparatus according to a first embodiment. FIG. 2 is a schematic configuration diagram illustrating a printing unit in the apparatus. FIG. 4 is a diagram showing a density correction image formed by a correction image forming unit in the apparatus. FIG. 4 is a schematic diagram showing screen line number switching by a screen line number switching unit in the apparatus. The figure which shows an example of a message when it determines with the correction | amendment of the density of an image being normal by the 2nd determination part in the apparatus. 6 is an image forming flowchart in the apparatus. FIG. 4 is a block configuration diagram illustrating an image forming apparatus according to a second embodiment. The figure which shows the density | concentration correction execution switching box displayed by the screen switching execution setting part in the same apparatus. 6 is an image forming flowchart in the apparatus.

Hereinafter, a first embodiment will be described with reference to the drawings.
FIG. 1 is a functional block diagram of the image forming apparatus. This apparatus has a function of, for example, a multi-function apparatus that is integrally provided with a copy, a printer, a facsimile, or the like. An operation panel 2, an external device 3, an image reading unit (scanner) 4, and a printing unit (transfer process unit) 5 are connected to the control unit 1. The control unit 1 controls the entire image forming operation of the apparatus. For example, the control unit 1 issues each operation command to the image reading unit 4, the print unit 5, and the like in accordance with an instruction from the operation panel 2 or the like, and forms an image on the image forming medium 52. Take control.

In response to a user operation, the operation panel 2 sets the number of prints or copies, their density, the size of an image forming medium such as recording paper, or displays various messages. This operation panel 2 is operated by the user to set the number of prints or copies, the density thereof, the size of an image forming medium such as recording paper, or the like, or displays various messages. The operation panel 2 is composed of a liquid crystal display including a touch sensor, for example.
The external device 3 is a personal computer, for example, and outputs image data to be printed by the printing unit 5. When the apparatus operates as a copy, the image reading unit 4 reads an image recorded on a document and outputs the image as an image signal.
The print unit 5 receives the image data processed by the control unit 1, and prints the image data on an image forming medium such as a recording sheet.

  FIG. 2 is a schematic configuration diagram of the printing unit 5. The printing unit 5 is a part that needs to be replaced when it can be used, that is, at the end of its life, such as yellow (Y), magenta (M), cyan (C), and black (K) photosensitive drums 53y and 53m. , 53c, 53k, yellow (Y), magenta (M), cyan (C), and black (K) -specific developing devices 54y, 54m, 54c, and 54k. The printing unit 5 is provided with a plurality of rollers 51a to 51d at respective preset positions. An endless transfer belt 52 formed in a belt shape as a transfer member is hung on these rollers 51a to 51d. Among these rollers 51a to 51d, for example, the roller 51a is a driving roller, and the other rollers 51b to 51d are driven rollers. The driving roller 51a is connected to a driving motor. The transfer belt 52 moves, for example, in the direction of arrow A by the rotation of the driving roller 51a.

  On the transfer belt 52, four photosensitive drums 53y, 53m, 53c, and 53k for each color of YMCK are provided at predetermined intervals along the moving direction A of the transfer belt 52 from the downstream side. These photosensitive drums 53y, 53m, 53c, and 53k are in contact with the transfer belt 52, respectively. The arrangement positions of the photosensitive drums 53y, 53m, 53c, and 53k are not particularly determined along the moving direction A of the transfer belt 52, and may be arranged in any arrangement order.

  Corresponding to the photosensitive drums 53y, 53m, 53c, and 53k, developing devices 54y, 54m, 54c, and 54k are provided, respectively. Corresponding to the photosensitive drums 53y, 53m, 53c, and 53k, laser light sources 55y, 55m, 55c, and 55k as exposure units are provided.

The driving roller 51a is provided with a feed roller 56 that is paired with the driving roller 51a. An image forming medium 57 such as a recording sheet is conveyed in the direction of arrow B between the driving roller 51 a and the feed roller 56.
For example, a cleaner 58 is provided on the roller 51c so as to form a pair with the roller 51c. The cleaner 58 cleans the visible image held on the transfer belt 52.
A density detector 59 is provided above the transfer belt 52 and downstream of the photosensitive drum 53y. The density detector 59 detects the density of a density correction image formed on the transfer belt 52, for example.

  In such an image forming process of the printing unit 5, uniform charging is performed on each surface of each of the photosensitive drums 53y, 53m, 53c, and 53k. Next, each laser light output from each laser light source 55y, 55m, 55c, and 55k removes charged charges other than the image portion on each surface of each photosensitive drum 53y, 53m, 53c, and 53k, and creates an image portion. An image (electrostatic latent image) leaving an electrostatic charge is formed. Next, a developer such as yellow, magenta, cyan, and black toner is attached to the electrostatic latent image from each of the developing units 54y, 54m, 54c, and 54k, for example, to create a visible image. Next, the visible images of the photosensitive drums 53y, 53m, 53c, and 53k are held on the transfer belt 52. Since the transfer belt 52 moves in the direction of arrow A and the image forming medium 57 is conveyed in the direction of arrow B, the visible image held on the transfer belt 52 is transferred to the image forming medium 57 as an image. The

The control unit 1 controls the operation of the printing unit 5 according to the number of prints or copies set on the operation panel 2 and the density thereof, the size of an image forming medium such as recording paper, and the like. When functioning as a printer, the control unit 1 performs image processing of image data from the external device 3 into data that can be easily printed on an image forming medium by the printing unit 5 and sends the processed data to the printing unit 5. When functioning as a copy, the control unit 1 processes the image data from the image reading unit 4 into data that can be easily printed on the image forming medium by the printing unit 5 and sends the image data to the printing unit 5.
The control unit 1 includes a computer including, for example, a CPU, a ROM, a RAM, and the like, and executes an image forming program stored in the ROM to obtain image data from the external device 3 or image data from the image reading unit 4. Printing is performed on the image forming medium 57.

  The image forming program causes the computer mounted in the control unit 1 to measure, for example, the number of prints of the image forming medium 57 on which an image is formed or the number of pixels (dots) on which the image is formed on the image forming medium 57 And the measured number of prints of the image forming medium 57 or the number of pixels (dots) on the image forming medium 57 of the consumables such as the photosensitive drums 53y, 53m, 53c, and 53k included in the printing unit 5. The first determination function for determining whether or not the second information regarding the lifetime has been reached and the number of prints of the image forming medium 57 or the number of pixels (dots) on the image forming medium 57 are, for example, the photosensitive drums 53y, When the second information related to the lifetime of consumables such as 53m, 53c, and 53k is reached, an image quality correction image, for example, a density correction image is formed on the transfer belt 52. An image forming function, an image quality detecting function for detecting the density of the density correction image formed on the transfer belt 52 by the density detecting unit 59, and a screen process in the image processing unit 10 based on the density detected by the density detecting unit 59 A screen line number switching function for switching the screen line number, and whether or not the density of an image printed by the print unit 5 is normal based on the density detected by the density detection unit 59 after the screen line number is switched If the density is not normal, for example, a second determination function that prompts replacement of consumables such as the photosensitive drums 53y, 53m, 53c, and 53k is realized.

  Until the image forming program determines that the image density is not normal by the second determining function, the measuring function determines the number of prints of the image forming medium 57 or the number of pixels on which the image is formed on the image forming medium 57 ( The number of dots) is measured, and the first determination function is, for example, each photosensitive drum in which the print unit 5 includes the measured number of prints of the image forming medium 57 or the number of pixels (dots) on the image forming medium 57. It is determined whether or not the second information regarding the life of the consumables such as 53y, 53m, 53c, and 53k has been reached, and the number of prints of the image forming medium 57 or the number of pixels (dot number) on the image forming medium 57 is, for example, When the second information regarding the lifetime of the consumables such as the photosensitive drums 53y, 53m, 53c, and 53k is reached, the image forming function for image quality correction is applied to the transfer belt 52, for example, a density correcting image. The image quality detection function is configured to detect the density of the density correction image formed on the transfer belt 52 by the density detection unit 59, and the screen line number switching function is based on the density detected by the density detection unit 59. The number of screen lines of the screen processing in the processing unit 10 is switched, and thereafter, the image quality correcting image forming function again forms, for example, a density correcting image on the transfer belt 52, and the image quality detecting function is again applied to the transfer belt 52. The density detection unit 59 detects the density of the formed density correction image, and the second determination function again determines whether the density of the image is normal based on the density detected by the density detection unit 59. Make it possible to repeat the determination.

The control unit 1 uses the CPU to perform the following functions, that is, the image processing unit 10, the measurement unit 11, the first first determination unit 12, the corrected image forming unit 13, the screen line number switching unit 14, and the first 2 determination units 15 are realized. The control unit 1 has a storage unit 16 such as a RAM or a ROM.
The storage unit 16 stores in advance information (second information) related to the lifetimes of, for example, the photosensitive drums 53y, 53m, 53c, and 53k and the developing devices 54y, 54m, 54c, and 54k that are consumables. . Information on the lifetimes of the photosensitive drums 53y, 53m, 53c, and 53k and the developing units 54y, 54m, 54c, and 54k is, for example, the photosensitive drums 53y, 53m, 53c, and 53k and the developing units 54y and 54m, respectively. , 54c, and 54k, and converted into the number of prints of the image forming medium 57 on which an image is formed or the number of pixels (dot number) on which the image is formed on the image forming medium 57.

  The image processing unit 10 processes the image data from the external device 3 and the image data from the image reading unit 4 into data that can be easily printed on the image forming medium by the printing unit 5 and sends the processed data to the printing unit 5. The image processing unit 10 performs screen processing when image processing is performed on data that can be easily printed on the image forming medium 57. In this screen process, for example, the density of the image data is changed by changing the number of screen lines. Generally, the higher the number of screen lines, the finer and higher the resolution can be printed, and the lower the number, the more stable the image quality, that is, the gradation.

  The measuring unit 11 includes first information relating to the number of images formed on the image forming medium 57 by the printing unit 5, for example, the number of image forming media 57 on which an image is formed or the number of pixels on which the image is formed on the image forming medium 57 Measure the number of dots. The number and the number of pixels (dots) of the image forming medium 57 can be counted when image data from the external device 3 or image data from the image reading unit 4 is processed. Note that the measurement unit 11 can be set to measure either one or both of the number of images and the number of pixels (number of dots) of the image forming medium 57.

  The first determination unit 12 includes the photosensitive drums 53y, 53m, 53c, 53k, and the number of image forming media 57 measured by the measurement unit 11 or the number of pixels (dots) stored in the storage unit 16. Specifically, whether or not the number of image forming media 57 (for example, 100 sheets) or the number of pixels (the number of dots) corresponding to the lifetime of consumables such as the developing units 54y, 54m, 54c, and 54k has been reached coincides. It is determined whether or not. Here, the lifetime of the consumable item is not a period until the consumable item becomes completely unusable, but a period in which the consumable item can be used without any problem in quality. Therefore, as described above, it is the life of the consumable having a margin.

  Note that the first determination unit 12 determines that either one or both of the measured number of image forming media 57 and the number of pixels (number of dots) are the photosensitive drums 53y, 53m, 53c, 53k or the developing units 54y. , 54m, 54c, and 54k, it can be set so as to determine whether or not the number of the image forming medium 57 or the number of pixels (the number of dots) corresponding to the respective lifetimes has been reached. In addition, the first determination unit 12 sets the image forming medium 57 corresponding to each life for each consumable such as each photosensitive drum 53y, 53m, 53c, 53k or each developing device 54y, 54m, 54c, 54k. It is determined whether or not the number matches the number of pixels or the number of pixels (number of dots).

  As a result of the determination by the first determination unit 12, the corrected image forming unit 13 determines whether one or both of the number of image forming media 57 and the number of pixels (the number of dots) measured by the measurement unit 11 are the respective photosensitive drums 53y. 53m, 53c, 53k, or the number of image forming media 57 corresponding to the lifetime of each developing device 54y, 54m, 54c, 54k, or the number of pixels (dot number), or both, is shown in FIG. A command for forming a density correction image D on the transfer belt 52 by the printing unit 5 is sent to the image processing unit 10. This density correction image D is for correcting the density of the image formed on the image forming medium 57, and is a solid-colored solid image (FFh) B for each color of patches of a plurality of gradations, for example, YMCK. It consists of a patch with halftone (80h) H. The density correction image D has four colors, YMCK, but is not limited to these four colors and may be at least one of these colors. The density correction image D is composed of patches of a plurality of gradations, for example, patches of solid (FFh) B and halftone (80h) H for each color of YMCK. Only (K) may be used. Accordingly, the present invention can be applied not only to a color image but also to a black (K) monochrome image. Further, the image is not limited to the solid (FFh) B and the halftone (80h) H, but may be a density correction image D using other densities.

  The screen line number switching unit 14 switches the screen line number of the screen processing in the image processing unit 10 based on the density detected by the density detection unit 59. The screen line number switching unit 14 performs halftone color density correction by switching the screen line number. For example, when the density detected by the density detector 59 decreases to a preset density, for example, a density that affects the image quality of an image formed on the image forming medium 57, the screen line number switching unit 14 is shown in FIG. Thus, the normal screen line number (for example, 200 lines) is switched to a screen line number (for example, 100 lines) lower than the screen line number.

  That is, as described above, generally, the higher the number of screen lines, the finer and higher the resolution can be printed, but the photosensitive drums 53y, 53m, 53c, 53k or the developing devices 54y, 54m, 54c which are consumables. , 54k near the end of their lives, there is a high possibility that variations in image density, blurring, etc. will occur in the image formed on the image forming medium 57. Accordingly, the screen line number switching unit 14 determines the density detected in advance by the density detection unit 59 when each of the photosensitive drums 53y, 53m, 53c, and 53k or each of the developing devices 54y, 54m, 54c, and 54k is nearing the end of its life. When the density is lowered to the set density, the image quality, that is, gradation is stabilized by switching the normal screen line number (for example, 200 lines) to the screen line number (low screen line number, for example, 100 lines).

  When the density detected by the density detector 59 decreases to a preset density, the screen line number switching unit 14 is not limited to switching from the normal screen line number to the low screen line number, but the normal screen. A plurality of screen line numbers that decrease for each predetermined line number from the number of lines may be set in advance, and the screen line number may be switched so as to gradually decrease according to the degree of decrease in density detected by the density detection unit 59.

The second determination unit 15 determines whether the image density is normal based on the density detected by the density detection unit 59 after the screen line number switching unit 14 switches the screen line number to a low screen line number. If the image density is not normal, a message prompting the user to replace each of the photosensitive drums 53y, 53m, 53c, and 53k or the developing devices 54y, 54m, 54c, and 54k that is a consumable is displayed on the operation panel 2. To do. For example, if the developing devices 54y, 54m, 54c, and 54k are nearing the end of their life as consumables, this message is displayed as "Developer replacement time is approaching. Request replacement by serviceman" Please do ".
The control unit 1 of the present apparatus includes the measurement unit 11, the first determination unit 12, the corrected image forming unit 13, and the density until the second determination unit 15 determines that the density cannot be corrected. The operations of the detection unit 59 and the second determination unit 15 are repeated.

Next, the operation of the apparatus configured as described above will be described with reference to an image forming flowchart shown in FIG.
The control unit 1 controls the operation of the printing unit 5 according to the number of prints or copies set on the operation panel 2 and the density thereof, the size of an image forming medium such as recording paper, and the like. When this apparatus functions as a printer, the control unit 1 performs image processing of image data from the external device 3 into data that can be easily printed on the image forming medium by the printing unit 5 and sends the processed data to the printing unit 5. When this apparatus functions as a copy, the control unit 1 performs image processing on the image data from the image reading unit 4 into data that can be easily printed on the image forming medium by the printing unit 5 and sends the image data to the printing unit 5. The print unit 5 performs the image forming process and transfers the image data from the external device 3 or the image reading unit 4 to the image forming medium 57.

The measuring unit 11 measures one or both of the number of image forming media 57 on which an image is formed by the printing unit 5 and the number of pixels (dots) on which the image is formed on the image forming medium 57 (ACT1). .
The first determination unit 12 includes the photosensitive drums 53y in which either one or both of the number of image forming media 57 and the number of pixels (number of dots) measured by the measurement unit 11 are stored in the storage unit 16. Whether the number of image forming media 57 or the number of pixels (the number of dots) corresponding to the lifetime of one or both of consumables such as 53m, 53c, 53k or developing devices 54y, 54m, 54c, 54k has been reached. Specifically, it is determined whether or not they match (ACT2).

  As a result of this determination, each of the photosensitive drums 53y, 53m, 53c, 53k or each developing device 54y in which either or both of the number of images and the number of pixels (dots) of the image forming medium 57 are stored in the storage unit 16. , 54m, 54c, 54k, etc., the measurement unit 11 returns to ACT1 if it does not match either one or both of the number of images and the number of pixels (dots) of the image forming medium 57 corresponding to each life of the consumables. Then, one or both of the number of image forming media 57 on which an image is formed by the printing unit 5 and the number of pixels (number of dots) are measured.

  Either one or both of the number of image forming media 57 and the number of pixels (number of dots) or both photosensitive drums 53y, 53m, 53c, 53k or developing devices 54y, 54m, 54c, which are stored in the storage unit 16. When the number of image forming media 57 corresponding to the lifetime of either one or both of consumables such as 54k or the number of pixels (the number of dots) coincides with one or both, the corrected image forming unit 13 displays the corrected image forming unit 13 in FIG. A command to form a density correction image D on the transfer belt 52 is sent to the image processing unit 10 by the printing unit 5 as shown in FIG. The image processing unit 10 processes the density correction image D into data that can be easily printed on the image forming medium by the printing unit 5 and sends the processed data to the printing unit 5. The print unit 5 performs the image forming process to form a density correction image D on the transfer belt 52 (ACT3).

The density detection unit 59 detects the density of the density correction image formed on the transfer belt 52 for each solid B and halftone H for each color of YMCK, and outputs these density detection signals. The density detection signal output from the density detection unit 59 is sent to the screen line number switching unit 14 (ACT4).
The screen line number switching unit 14 determines whether or not the density detected by the density detection unit 59 has decreased to a preset density, for example, a density that affects the image quality of the image formed on the image forming medium 57, If it is determined that the number has decreased, the normal screen line number (for example, 200 lines) is switched to a screen line number (for example, 100 lines) lower than the screen line number as shown in FIG. Perform (ACT5). If the screen line number switching unit 14 determines that the screen line number has not decreased, the screen line number switching unit 14 does not change the screen line number while maintaining the normal screen line number (for example, 200 lines).

The correction image forming unit 13 again sends a command to the image processing unit 10 to form the density correction image D on the transfer belt 52 by the printing unit 5 as shown in FIG. The image processing unit 10 processes the density correction image D into data that can be easily printed on the image forming medium by the printing unit 5 and sends the processed data to the printing unit 5. The print unit 5 performs the image forming process to form a density correction image D on the transfer belt 52 (ACT 6).
The density detection unit 59 again detects the density of the density correction image formed on the transfer belt 52 for each solid B and halftone H for each color of YMCK, and outputs these density detection signals. The concentration detection signal output from the concentration detector 59 is sent to the second determination unit 15 (ACT 7).

The second determination unit 15 determines again whether or not the correction of the image density is normal based on the density detected by the density detection unit 59 again (ACT8). This determination is made by, for example, receiving solid B for each color of YMCK and density for each halftone H of the density correction image D on the transfer belt 52 detected by the density detector 59, and these densities are set in advance. The determination may be made based on whether or not the density correction is possible for each of solid B and halftone H.
If the correction of the image density is normal, the measuring unit 11 returns to ACT 1 again, and the number of image forming media 57 on which the image is formed by the printing unit 5 or the number of pixels on which the image is formed on the image forming medium 57. Either one or both of (the number of dots) are measured. Accordingly, the control unit 1 operates by the measurement unit 11, the first determination unit 12, the corrected image forming unit 13, and the image quality correction unit 14 until the density corrected by the image quality correction unit 14 becomes not normal. repeat.

  Note that, once it is determined that the correction of the image density is normal, the first determination unit 12 determines the number of images or the number of pixels (dots) of the image forming medium 57 measured by the measurement unit 11. Is stored in the photosensitive drums 53y, 53m, 53c, and 53k, or the developing devices 54y, 54m, 54c, and 54k. The number of the image forming medium 57 or the number of pixels (dot number) corresponding to the lifetime at this time is the number of the image forming medium 57 when the first density correction is performed. Alternatively, it is set to the number of the image forming medium 57 or the number of pixels (dot number) which is smaller than the number of pixels (dot number) by a certain value.

  On the other hand, if the image density is not normal, the second determination unit 15 prompts the replacement of the photosensitive drums 53y, 53m, 53c, and 53k or the developing devices 54y, 54m, 54c, and 54k that are consumables. Is displayed on the operation panel 2 (ACT 9). For example, if the developing devices 54y, 54m, 54c, and 54k are nearing the end of their life as consumables, this message is displayed as “Developer replacement time is approaching. Please do ". In this case, the second determination unit 15 determines whether or not density correction is possible for each color of YMCK, so that each photosensitive drum 53y, 53m, 53c, 53k or each development for each color of YMCK. It is possible to display on the operation panel 2 a message urging replacement for each of the devices 54y, 54m, 54c, and 54k.

  On the other hand, if the correction of the image density is not normal based on the density detected again by the density detection unit 59, the image quality correction unit 14 determines that each of the photosensitive drums 53y, 53m, 53c, and 53k or each of the developing devices 54y and 54m. , 54c, 54k, for example, as shown in FIG. 4, a message “Developer replacement time is approaching. Please ask a serviceman for replacement” is displayed on the operation panel 2 (ACT10). ). In this case, the image quality correction unit 14 determines whether or not density correction is possible for each color of YMCK, so that each photosensitive drum 53y, 53m, 53c, 53k or each developing device 54y for each color of YMCK. , 54m, 54c, 54k can be displayed on the operation panel 2 for prompting replacement.

  As described above, according to the first embodiment, the number of prints or the number of pixels (dots) of the image forming medium 57 is the number of prints corresponding to the lifetime of each of the photosensitive drums 53y, 53m, 53c, 53k, or the like. When the number of pixels (the number of dots) matches, the density of the halftone color is corrected by switching from the normal screen line number to the low screen line number based on the density of the density correction image D formed on the transfer belt 52, After this correction, the density correction image D is formed again on the transfer belt 52 and its density is detected. Based on this density, it is determined whether or not the density correction of the image is normal, and the density of the image is determined. If the correction is not normal, a message prompting replacement of consumables such as the photosensitive drums 53y, 53m, 53c, and 53k is displayed on the operation panel 2.

  Thus, even if it is determined that the number of prints or the number of pixels (dots) of the image forming medium 57 has reached the end of the life of consumables such as the photosensitive drums 53y, 53m, 53c, and 53k, the number of screen lines is switched. By stabilizing image quality, that is, gradation, image formation on the image forming medium 57 can be continued without affecting the quality of the image formed on the image forming medium 57 such as recording paper. That is, the life of the consumables such as the photoconductive drums 53y, 53m, 53c, and 53k has a margin, so the consumables such as the photoconductive drums 53y, 53m, 53c, and 53k are determined to be long. Are often usable.

  Accordingly, the consumables such as the photosensitive drums 53y, 53m, 53c, and 53k can be used until they are finally unusable without being replaced with new ones, which are determined to be very long. . Further, the message prompting the replacement of the photosensitive drums 53y, 53m, 53c, 53k and the like is that the consumables such as the photosensitive drums 53y, 53m, 53c, and 53k are finally in an unusable state. It can be replaced with a new one when the product is used up. Consumables such as the photosensitive drums 53y, 53m, 53c, and 53k are not discarded in a usable state, and no extra cost is incurred.

Further, since it is determined whether or not density correction is possible for each color of YMCK, replacement is performed for each photosensitive drum 53y, 53m, 53c, 53k or for each developing device 54y, 54m, 54c, 54k for each color of YMCK. Can be displayed on the operation panel 2.
In particular, after switching the number of screen lines, the density correction image D is formed again on the transfer belt 52 and the density is detected, and it is determined whether or not the density correction of the image is normal based on this density. Therefore, it is possible to increase the accuracy of determining whether or not the density after density correction of the image is normal.

Next, a second embodiment will be described with reference to the drawings. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.
FIG. 7 is a functional block diagram of the image forming apparatus. The control unit 1 includes a screen switching execution setting unit 17. The screen switching execution setting unit 17 sets whether or not to execute density correction by switching the screen line number by the screen line number switching unit 14. The screen switching execution setting unit 17 displays a density correction execution switching box F as shown in FIG. This density correction execution switching box F is used to set whether or not to perform image density correction by switching the screen line number by the screen switching execution setting unit 17. “Do you want to do it?” And “Yes” to select execution of the correction process and “No” not to execute the correction process are displayed.

Next, the operation of the apparatus configured as described above will be described with reference to an image forming flowchart shown in FIG. The operation different from the image forming flowchart shown in FIG. 6 will be described.
It is possible to select whether or not to execute image density correction by the screen switching execution setting unit 17 by the operation of the user or service person. That is, when the user or service person touches a preset density correction execution switching button on the operation panel 2, the screen switching execution setting unit 17 operates a density correction execution switching box F as shown in FIG. Display on panel 2. In the density correction execution switching box F, when the user or service person touches the “Yes” button, the screen switching execution setting unit 17 is set to perform correction processing when the life of the consumable item has reached the end. On the other hand, when the user or service person touches the “No” button, the screen switching execution setting unit 17 is set so as not to perform the correction process when the life of the consumable item comes to an end.

  The first determination unit 12 includes the photosensitive drums 53y in which either one or both of the number of image forming media 57 and the number of pixels (number of dots) measured by the measurement unit 11 are stored in the storage unit 16. 53m, 53c, 53k, or each developing device 54y, 54m, 54c, 54k, etc., whether or not it matches the number or the number of pixels (dot number) of the image forming medium 57 corresponding to the lifetime of either one or both Is determined (ACT2).

The screen switching execution setting unit 17 determines whether or not to perform image density correction by switching the screen line number by the screen line number switching unit 14 (ACT 10). Whether or not to execute the correction of the density of the image is set in advance by the operation of the user or the service person. Therefore, the screen switching execution setting unit 17 determines whether or not to execute the correction of the density of the image from the setting state Determine whether.
If the result of this determination is that the correction process is to be performed when the expendables have reached the end of their life, the process proceeds to ACT 3 and the density correction image D is formed on the transfer belt 52 as described above.

  On the other hand, if the setting is made so that the correction process is not performed when the expendables have reached the end of their life, the second determination unit 15 determines that each of the photosensitive drums 53y, 53m, 53c, and 53k or each of the developing units 54y, 54m, 54c, and 54k For example, as shown in FIG. 5, a message prompting replacement of the consumables is displayed on the operation panel 2 (ACT 9). .

  As described above, according to the second embodiment, it is possible to set whether or not to execute image density correction by switching the screen line number by the screen line number switching unit 14. Thus, for example, in a situation where the user has a contract for a fixed monthly amount, the image density correction function is set to OFF, and the consumable is replaced as soon as the predetermined consumable life is reached. Therefore, this apparatus can always be used in the best condition. Also, in a situation where a contract is incurred incurring costs for each maintenance, if the image density correction function is set to ON, it will continue to be used without replacing the consumable as long as the consumable can be used. It is possible to suppress the cost required for maintenance.

In addition, the said embodiment is not limited as it is, In the implementation stage, a component can be deform | transformed and embodied in the range which does not deviate from the summary. In addition, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.
Messages prompting replacement of consumables such as the photosensitive drums 53y, 53m, 53c, and 53k may be displayed not only on the operation panel 2, but also an alarm sound or a message may be notified by voice.

  1: control unit, 2: operation panel, 3: external device, 4: image reading unit (scanner), 5: printing unit (transfer process unit), 57: image forming medium, 53y, 53m, 53c, 53k: photoconductor Drum, 54y, 54m, 54c, 54k: developing unit, 51a to 51d: roller, 52: transfer belt, 55y, 55m, 55c, 55k: laser light source, 56: feed roller, 58: cleaner, 59: density detector, 10: Image processing unit, 11: Measurement unit, 12: First determination unit, 13: Correction image forming unit, 14: Screen line number switching unit, 15: Second determination unit, 16: Storage unit, 17: Screen Switching execution setting unit.

Claims (9)

It includes parts that need to be replaced when it can be used, forms an electrostatic latent image according to the image data, and holds a visible image with a coloring material attached to the electrostatic latent image on the transfer body, A transfer process unit that transfers the visible image held on the transfer body to an image forming medium as an image;
Screen processing the image data, and an image processing unit capable of controlling the quality of the image formed by the transfer process unit;
A measuring unit that measures first information related to the number of images formed on the image forming medium by the transfer process unit;
A storage unit that stores in advance second information related to the period until the replacement of the component included in the transfer process unit is required;
A first determination unit that determines whether or not the first information measured by the measurement unit has reached the second information stored in the storage unit;
As a result of determination by the determination unit, when the first information reaches the second information, a correction image forming unit that forms an image quality correction image on the transfer body by the transfer process unit with respect to the image processing unit When,
An image quality detection unit for detecting an image quality of the image for image quality correction formed on the transfer body;
A screen line number switching unit that switches the screen line number of the screen processing in the image processing unit based on the image quality detected by the image quality detection unit;
After the screen line number is switched by the screen line number switching unit, it is determined whether the image quality of the image is normal based on the image quality detected by the image quality detection unit, and the image quality of the image is If not normal, a second determination unit that prompts replacement of the part;
An image forming apparatus comprising: The correction image forming unit forms the image for image quality correction on the transfer body again after switching the screen line number by the screen line number switching unit,
The image quality detection unit detects the image quality of the image for image quality correction formed on the transfer body again after switching the number of screen lines,
The second determination unit determines again whether the image quality is normal based on the image quality detected by the image quality detection unit. If the image quality is not normal, the second determination unit determines whether the image quality is normal. Encourage exchange,
The image forming apparatus according to claim 1. The transfer process unit includes a photoreceptor for forming the electrostatic latent image;
A developing device for attaching a coloring material to the electrostatic latent image formed on the photoconductor to form a visible image;
Holding the visible image formed on the photoreceptor, and transferring the visible image to an image forming medium to form the image,
The parts that require replacement include at least the photoconductor and the developing unit.
The image forming apparatus according to claim 1. The image quality detection unit is a density detection unit that detects the density of the density correction image,
The second determination unit determines whether the density of the image is normal based on the density detected by the density detection unit after the screen line number is switched by the screen line number switching unit. If the density of the image is not normal, prompt replacement of the part,
The image forming apparatus according to claim 1. It contains parts that need to be replaced when it can be used, forms an electrostatic latent image on the photoconductor, and holds a visible image on the transfer body with a color material attached to the electrostatic latent image by a developing device. In the image forming method of forming an image by transferring the visible image held on the transfer body to an image forming medium as an image,
The measurement unit measures first information regarding the number of images formed on the image forming medium,
Determining whether the measured first information has reached second information relating to the period until the replacement of the component included in the transfer process unit is required;
As a result of this determination, when the first information reaches the second information, an image for image quality correction is formed on the transfer body,
The image quality detection unit detects the image quality of the image quality correction image formed on the transfer body,
Based on the image quality detected by the image quality detection unit, the number of screen lines in the screen processing of the image processing unit is switched,
After the number of screen lines is switched, it is determined whether the image quality is normal based on the image quality detected by the image quality detection unit. Urge you to replace
An image forming method. After switching the number of screen lines, again form the image for image quality correction on the transfer body,
Again detecting the image quality of the image for image quality correction formed on the transfer body,
Re-determining whether the image quality is normal based on the detected image quality, and if the image quality is not normal, prompting replacement of the component;
The image forming method according to claim 5. An electrostatic latent image corresponding to the image data is formed on the photosensitive member, a visible image obtained by attaching a coloring material to the electrostatic latent image with a developing device is held on the transfer member, and the above-described holding member held on the transfer member To a computer of an image forming apparatus that performs image formation by transferring a visible image to an image forming medium as an image,
A measurement function for measuring, by a measurement unit, first information related to the number of images formed on the image forming medium;
A first determination function for determining whether or not the measured first information has reached second information regarding the period until the replacement of the component included in the transfer process unit is necessary;
As a result of the determination, when the first information reaches the second information, an image quality correcting image forming function for forming an image quality correcting image on the transfer body;
An image quality detection function for detecting an image quality of the image quality correction image formed on the transfer body by an image quality detection unit;
A screen line number switching function for switching the screen line number of the screen processing in the image processing of the image data based on the image quality detected by the image quality detection unit;
After the number of screen lines is switched, it is determined whether or not the image quality of the image is normal based on the image quality detected by the image quality detection unit. A second determination function that prompts replacement of
An image forming program that realizes The image quality correction image forming function forms a density correction image as the image quality correction image,
The image quality detection function detects a density of the density correction image formed on the transfer body by a density detection unit,
The second determination function determines whether the density of the image is normal based on the density detected by the density detection unit after the screen line number is switched, and the density of the image The image forming program according to claim 7, wherein if it is not normal, prompting replacement of the component is realized. Until it is determined that the density of the image is not normal,
The measurement function measures first information related to the number of images formed on the image forming medium,
The first determination function determines whether or not the measured first information has reached second information regarding the period;
When the first information reaches the second information, the image quality correction image forming function forms the density correction image on the transfer body,
The image quality detection function detects the density of the density correction image,
The screen line number switching function switches the screen line number based on the density of the density correction image,
Thereafter, the image quality correction image forming function again forms a density correction image on the transfer body,
The image quality detection function detects the density of the density correction image formed on the transfer body again by the density detection unit,
The second determination function determines whether the density of the image is normal based on the density detected again by the density detection unit.
8. The image forming program according to claim 7, wherein the image forming program is repeated.

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