JP2018018027A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that a gap for forming an image for supply should be secured as a non-image area, but the formation of the image for supply in the non-image area invites a possibility of reducing productivity of an image formation.SOLUTION: When the formation processing of the second image is completed within the preparation period of the image formation, the second image is formed prior to the first image. When the formation processing of the second image is not completed within the preparation period of the image formation, the second toner image is formed between the first image and the third image. When the formation processing of the second image is completed within the preparation period of the image formation, a first gap which is an image gap between the first image and the third image is shorter than the second gap which is an image gap between the first image and the third image.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an image forming apparatus such as a copying machine or a laser beam printer using an electrophotographic process.

  2. Description of the Related Art Conventionally, in an electrophotographic color image forming apparatus, a system is known in which each color image is sequentially transferred to an intermediate transfer belt, and the image transferred to the intermediate transfer belt is transferred to a recording material. In such a system, a cleaning blade is provided for cleaning residual toner remaining on the intermediate transfer belt after the image on the intermediate transfer belt is transferred to a recording material.

  When cleaning residual toner using a cleaning blade, if the frictional force between the cleaning blade and the surface of the intermediate transfer belt is large, noise may be generated due to vibration of the cleaning blade. In addition, the cleaning blade may turn over, and residual toner may not be cleaned. Therefore, in Patent Document 1, a supply image is formed in a non-image area between images on the intermediate transfer belt, and toner is supplied between the intermediate transfer belt and the cleaning blade. Accordingly, it is disclosed that the frictional force between the intermediate transfer belt and the cleaning blade is reduced.

JP 2007-155750 A

  However, the interval for forming the supply image must be ensured as a non-image region, and forming the supply image between the non-image regions may reduce the productivity of image formation. There was a problem.

  The invention according to the present application has been made in view of the above situation, and an object thereof is to suppress a decrease in productivity of image formation even when a supply image is formed.

  To achieve the above object, an image carrier on which an electrostatic latent image is formed, a developing unit that develops the electrostatic latent image formed on the image carrier as an image with toner, and a cleaning unit that cleans the toner A first image transferred to the recording material, a second image not transferred to the recording material, and a recording material conveyed following the recording material on which the first image is formed. An image forming apparatus for forming the second image, and when the second image forming process is completed within an image formation preparation period, the second image is replaced with the first image. If the second image forming process is completed before the image forming preparation period, the second toner image is formed between the first image and the third image. When the second image formation process is completed within the image formation preparation period The first interval between the first image and the third image is the first interval when the second image formation process is not completed within the image formation preparation period. It is shorter than the 2nd space | interval which is between images and the said 3rd image, It is characterized by the above-mentioned.

  According to the configuration of the present invention, it is possible to suppress a decrease in productivity of image formation even when a supply image is formed.

Schematic configuration diagram of an image forming apparatus Control block diagram The figure which showed the timing which forms the image 200 for supply in the past The figure which showed the timing which forms the image 200 for supply in 1st Embodiment. The flowchart shown about the control which forms the image 200 for supply in 1st Embodiment. The figure which showed the timing which forms the image for supply in 2nd Embodiment. The flowchart shown about the control which forms the image for supply in 2nd Embodiment. The figure which showed the timing which forms the image for supply in 3rd Embodiment. The flowchart shown about the control which forms the image for supply in 3rd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiments do not limit the invention according to the scope of claims, and all combinations of features described in the embodiments are not necessarily essential to the solution means of the invention.

(First embodiment)
[Description of Image Forming Apparatus]
FIG. 1 is a schematic configuration diagram of the image forming apparatus 35. The image forming apparatus 35 includes a main body device 30 that forms an image on a recording material and supply devices 31 to 33 that supply the recording material. The main body device 30 forms a full-color image by superposing four color images of yellow (Y), magenta (M), cyan (C), and black (K). In the following description, the suffixes Y, M, C, and K may be omitted for convenience of description for members that do not particularly need to distinguish yellow, magenta, cyan, and black.

  The photosensitive drum 5 as an image carrier is configured by applying an organic optical transmission layer to the outer periphery of an aluminum cylinder, and is rotated at a predetermined peripheral speed by transmitting a driving force of a driving motor (not shown). When the photosensitive drum 5 rotates at a predetermined peripheral speed, the photosensitive drum 5 is uniformly charged to a predetermined polarity and potential by a charging roller 7 as a charging unit. The charged surface of the photosensitive drum 5 is irradiated with a laser beam from an exposure unit 10 as an exposure unit, and an electrostatic latent image is formed on the surface of the photosensitive drum 5. The formed electrostatic latent image is developed as a toner image by a developing roller 8 as developing means. The photosensitive drum 5, the charging roller 7, and the developing roller 8 are integrated as a cartridge 22 and can be attached to and detached from the main body device 30. Thus, maintenance can be performed by the user himself / herself without depending on the service person. However, the present invention is not limited to such a cartridge type apparatus, and a configuration in which members such as the photosensitive drum 5, the charging roller 7, and the developing roller 8 are installed on the main body apparatus 30 may be used.

  The toner image formed on the photosensitive drum 5 is primarily transferred to an intermediate transfer belt 12 as an intermediate transfer member by applying a primary transfer voltage to a primary transfer roller 4 as a primary transfer unit. The intermediate transfer belt 12 is disposed so as to be sandwiched between the photosensitive drum 5 and the primary transfer roller 4 so as to be in contact with the photosensitive drum 5, and is driven to rotate at substantially the same peripheral speed as that of the photosensitive drum 5. On the intermediate transfer belt 12, the toner images of each color are sequentially transferred sequentially from the yellow toner image, and a color image in which a plurality of color toner images are superimposed on the intermediate transfer belt 12 is formed.

  The recording material 70 is supplied from the storage cassette 60 as the storage means onto the conveyance path by the supply roller 50 as the supply means. After being supplied by the supply roller 50, it is conveyed to the registration roller pair 40. After the leading edge of the recording material 70 is detected by the registration sensor 6, it is conveyed to the secondary transfer portion. The supply devices 31 to 33 are optional devices that can be attached to and detached from the main body device 30. As shown in FIG. 1, the supply devices 31 to 33 can be attached to and detached from the main body device 30, and the supply devices can be attached to and detached from each other. The supply devices 31 to 33 are not detachable option devices, and may be configured to be installed between the main body device 30 and the feeding devices. Since the configuration of the supply devices 31 to 33 is the same, the supply device 31 will be described here. The recording material 71 is supplied from the storage cassette 61 by the supply roller 51. After being supplied by the supply roller 51, the recording material 71 is conveyed to the roller pair 41. After the leading edge of the recording material 71 is detected by the sensor 91, the recording material 71 is conveyed to the registration roller pair 40 and conveyed to the secondary transfer unit. Assuming that the recording material is conveyed from each of the supply devices 31 to 33 at the same timing and at the same conveyance speed, the longer the distance to the registration roller pair 40 is, the longer the time required for conveying the recording material to the registration roller pair 40 is. become longer.

  The image primarily transferred onto the intermediate transfer belt 12 is transferred to a recording material 70 at a secondary transfer portion formed by the intermediate transfer belt 12 and a secondary transfer roller 9 as a secondary transfer means. The residual toner that is not secondarily transferred to the recording material 70 and remains on the surface of the intermediate transfer belt 12 is cleaned by the cleaning blade 2 as a cleaning unit, and the residual toner is accumulated in the waste toner container 1. The cleaning blade 2 is in contact with the intermediate transfer belt 12 and is cleaned by scraping the residual toner on the intermediate transfer belt 12 (on the intermediate transfer member) by the cleaning blade 2. The recording material 70 onto which the image has been transferred in the secondary transfer portion is thermally fixed by heat and pressure in a fixing device 13 as a fixing means. The fixed recording material 70 is discharged to the paper discharge tray 14. A full color image is formed by the above operation.

[Explanation of control block diagram]
A control block diagram relating to the image forming apparatus 35 will be described with reference to FIG. The controller 650 connected to the host computer 660 issues an image formation command to the image formation engine 620 via the video interface 640. Further, the controller 650 includes image processing means 651 for developing the image data transmitted from the host computer 660 into image information that can be received by the image forming engine 620. Further, an image memory 652 for accumulating image information processed by the image processing unit 651, a storage unit 653 for storing internal information of the controller 650, a sample image held in advance by the controller 650, and the like are provided. When image formation is performed, image information subjected to image processing by the image processing unit 651 is developed in the image memory 652. Then, image information in the image memory 652 is output to the image forming engine 620 via the video interface 640 in synchronization with an image output timing signal from the image forming engine 620.

  As described with reference to FIG. 1, the image forming unit 630 in the image forming engine 620 includes the cartridge 22, the exposure unit 10, the primary transfer roller 4, the secondary transfer roller 9, the cleaning blade 2, the fixing device 13, and the like. Note that the cartridge 22 includes, for example, a photosensitive drum 5, a charging roller 7, a developing roller 8, and the like.

  The CPU 600 acquires the length of the image forming area in the transport direction (sub-scanning direction) from the controller 650 via the video interface 640. Note that the length in the transport direction is not necessarily limited to the length of the image. For example, the length in the transport direction of the recording material 70 may be used. The image formation start timing is determined according to the acquired length in the transport direction and the length in the transport direction of the supply image 200 to the cleaning blade 2 described later. Then, the CPU 600 transmits an image formation start signal (/ TOP signal) that is a synchronization signal of image output timing to the controller 650 via the video interface 640 based on the determined image formation start timing.

  When the controller 650 receives the / TOP signal from the CPU 600, the controller 650 transmits the video signal developed by the image processing means to the CPU 600 in accordance with the / TOP signal. In accordance with the received video signal, the CPU 600 executes image formation control while controlling each unit of the image forming unit 630 using the RAM 602 as a work area based on various control programs stored in the ROM 601. In the above description, various image formation controls have been described based on the processing of the CPU 600. However, part or all of the control performed by the CPU 600 may be performed by an ASIC that is an integrated circuit.

[Toner supply operation to cleaning blade 2]
Hereinafter, a toner image that is not transferred to the recording material 70 but is supplied to the cleaning blade 2 is referred to as a supply image, and a toner image that is transferred to the recording material 70 is referred to as a normal image. For example, the supply image 200 is formed as a halftone image with a maximum region width in a direction (main scanning direction) orthogonal to the conveyance direction of the supply image 200. The width of the supply image 200 in the main scanning direction can be arbitrarily set according to the amount of toner supplied to the cleaning blade 2. Further, the density of the supply image 200 can be arbitrarily set according to the amount of toner supplied to the cleaning blade 2. The supply image 200 may be formed using all four colors of toner, may be formed of three colors, two colors, or may be formed using only one color.

  As described above, a normal image is formed by transmitting a / TOP signal from the CPU 600 to the controller 650 and receiving a video signal as image information from the controller 650 when the image forming engine 620 is ready for image formation. Is done. Similarly, the supply image 200 is formed by transmitting a / TOP signal from the CPU 600 to the controller 650 and receiving a video signal for the supply image 200 from the controller 650. Note that image information for the supply image 200 is stored in advance in the storage unit 653 in the controller 650. The storage unit 653 stores a plurality of pieces of image information of the supply image 200 having different lengths in the sub-scanning direction. Before transmitting the / TOP signal for the supply image 200 from the CPU 600, the length of the supply image 200 in the sub-scanning direction is transmitted to the controller 650 by transmitting information related to the length of the supply image 200 in the sub-scanning direction. Can be switched.

  The normal image is secondarily transferred onto the recording material by a secondary transfer roller 9 to which a secondary transfer bias having a polarity different from that of the toner is applied in the secondary transfer portion. On the other hand, the supply image 200 is applied by the secondary transfer roller 9 with a secondary transfer bias having the same polarity as the toner in the secondary transfer portion, so that the toner is not transferred to the secondary transfer portion and the cleaning blade 2 is transferred. To be supplied. That is, when the supply image 200 is formed, in order to prevent the toner from adhering to the secondary transfer roller in the secondary transfer unit, the interval (second switching the secondary transfer bias from the same polarity as the toner to a different polarity) Time). Thus, by supplying the supply image 200 to the cleaning blade 2, the frictional force between the cleaning blade 2 and the surface of the intermediate transfer belt 12 is reduced, and abnormal noise and turning of the cleaning blade 2 are prevented. It is possible to maintain a good cleaning performance.

  Further, the CPU 600 can control not to form the supply image 200 between the images by not transmitting the / TOP signal for the supply image 200 to the controller 650 between the normal images. At this time, the image forming engine 620 does not need to switch the polarity of the secondary transfer bias because the supply image 200 does not come to the secondary transfer portion between images. Therefore, it is not necessary to secure the switching time of the secondary transfer bias, and the interval between the images of the normal image, in other words, the interval between the first recording material and the second recording material can be shortened.

[Formation timing of supply image 200]
Next, a conventional timing for forming the supply image 200 will be described with reference to FIG. FIG. 3A shows a timing chart when an image is formed on the recording material 70 accommodated in the accommodation cassette 60. The image forming engine 620 conveys the recording material 70 by the supply roller 50 and the registration roller pair 40, detects that the leading edge of the recording material 70 has reached the registration sensor 6, and moves the recording material 70 to a predetermined position before the secondary transfer unit. Transport. Thus, CPU 600 determines that image formation preparation is completed at timing (1), and transmits a / TOP signal (normal image) for forming a normal image of the first page as the first image. The image forming engine 620 resumes the conveyance of the recording material 70 to the secondary transfer unit by the registration roller pair 40 in synchronization with the output timing of the / TOP signal (normal image).

  After transmitting the / TOP signal (normal image) at timing (1), the CPU 600 forms the supply image 200 as the second image based on the length of the normal image of the first page in the sub-scanning direction. / TOP signal (supply image) is transmitted at timing (2). The / TOP signal (supply image) has a timing such that the supply image 200 is formed at a position away from the rear end of the recording material 70 by a predetermined length so that the supply image 200 is not transferred to the recording material 70. Next, based on the preset formation processing time A of the supply image 200, the CPU 600 sets a timing (3) for the / TOP signal (normal image) for forming the normal image of the second page as the third image. ) The formation processing time A of the supply image 200 is set in advance based on the length of the supply image 200 in the sub-scanning direction and the polarity switching time of the secondary transfer bias. The image forming engine 620 starts feeding the recording material 70 by the supply roller 50 in synchronization with the transmission timing of the / TOP signal (normal image) for the normal image of the second page. The registration roller pair 40 conveys the recording material 70 to the secondary transfer unit without stopping at a predetermined position before the secondary transfer unit.

  FIG. 3B shows a timing chart when an image is formed on the recording material 73 accommodated in the accommodation cassette 63. The image forming engine 620 conveys the recording material 73 by the supply roller 53, the conveyance roller pairs 41 to 43, and the registration roller pair 40, and detects that the leading edge of the recording material 73 has reached by the registration sensor 6, and is in front of the secondary transfer unit. The recording material 73 is conveyed to a predetermined position. As a result, the CPU 600 determines that the image formation preparation is completed at the timing (4), and transmits a / TOP signal (normal image) for forming the normal image of the first page as the first image.

  When a normal image is formed on the recording material 73, the conveyance distance from the storage cassette to the registration sensor 6 is longer than when a normal image is formed on the recording material 70. The time will be longer. The image formation preparation delay time B, which is an additional time until the image formation preparation is completed, can be calculated based on the difference in the transport distance from the storage cassette to the registration sensor 6. The CPU 600 can control the life of the consumable member such as the cartridge 22 not to be unnecessarily advanced by delaying the drive start timing of the consumable member such as the cartridge 22 by the delay time B.

  CPU 600 transmits a / TOP signal (normal image) at timing (4). Thereafter, based on the length in the sub-scanning direction of the normal image of the first page and a length corresponding to a preset margin period, a / TOP signal (supply) for forming the supply image 200 as the second image Image) is transmitted at timing (5). The / TOP signal (supply image) has a timing such that the supply image 200 is formed at a position away from the rear end of the recording material 70 by a predetermined length so that the supply image 200 is not transferred to the recording material 73. Next, based on the preset formation processing time A of the supply image 200, the CPU 600 sets a timing (6) for the / TOP signal (normal image) for forming the normal image of the second page as the third image. ) The formation processing time A of the supply image 200 is set in advance based on the length of the supply image 200 in the sub-scanning direction and the polarity switching time of the secondary transfer bias. The image forming engine 620 starts feeding the recording material 73 by the supply roller 53 in synchronization with the transmission timing of the / TOP signal (normal image) for the normal image of the second page. Then, the recording material 73 is conveyed to the secondary transfer unit by the conveyance roller pairs 41 to 43 and the registration roller pair 40 without stopping at a predetermined position before the secondary transfer unit.

  As described above, the productivity of FIG. 3B is lower than that of FIG. 3A by the amount that the image formation start timing of the normal image of the first page is delayed. Here, as an example, the difference in the length of the image formation preparation period due to the difference in the accommodation cassette has been described, but the present invention is not limited to this. For example, even when the recording material is fed from the same storage cassette, the image formation preparation period may change due to a long start-up time of the exposure unit 10 or the fixing device 13.

  FIG. 4 is a diagram showing the timing for forming the supply image 200 in the present embodiment. FIG. 4 shows a timing chart when an image is formed on the recording material 73 accommodated in the accommodation cassette 63 as an example similar to FIG.

  The CPU 600 performs a delay time B that is a difference between the timing (1) at which image formation preparation is completed in the shortest time and the timing (4) at which image formation is completed in the current situation, and the formation processing of the supply image 200 that is set in advance. Compare time A. Then, the timing for transmitting the / TOP signal (supply image) and the / TOP signal (normal image) is determined. When the delay time B is less than the formation processing time A of the supply image 200 (B <A), the CPU 600 determines that the supply image 200 cannot be formed during the delay time B. Then, similarly to FIGS. 3A and 3B, the supply image 200 is formed between the images between the normal image of the first page and the normal image of the second page.

  When the delay time B is equal to or longer than the formation processing time A of the supply image 200 (B ≧ A), the CPU 600 can form the supply image 200 during the delay time B (within the image formation preparation period). to decide. Then, as shown in FIG. 4, / TOP for forming the supply image 200 at the timing (7) in which the formation processing time A of the supply image 200 is advanced from the completion timing of the image formation preparation at the timing (4). A signal (image for supply) is transmitted. The CPU 600 can control the life of the consumable member such as the cartridge 22 not to be unnecessarily advanced by matching the drive start timing of the consumable member such as the cartridge 22 with the timing (7).

  Next, the CPU 600 transmits a / TOP signal (normal image) for forming the normal image of the first page as the first image at timing (4) when the delay time B has elapsed from timing (1). . Then, the CPU 600 does not form the supply image 200 after the normal image of the first page, and generates a timing (/ TOP signal (normal image) for forming the normal image of the second page as the third image). Send in step 8). At this time, since the supply image 200 is not formed between the normal image of the first page and the normal image of the second page, the CPU 600 does not need to ensure the switching time of the polarity of the secondary transfer bias. Therefore, the interval can be made shorter than that between the images in FIG. As a result, the time required for the total image formation can be shortened in FIG. 4 compared to FIG. 3B. Even if the supply image 200 is not formed between the images, since the supply image 200 is formed before the normal image of the first page is formed, a certain amount of toner is supplied to the cleaning blade 2. Therefore, the cleaning performance can be maintained.

  Here, as an example, when the delay time B is less than the formation processing time A of the supply image 200 (B <A), the supply image 200 is not formed before the normal image of the first page is formed. Although explained, it is not limited to this. For example, even if the timing (4) for starting the formation of the normal image for the first page is slightly delayed, the normal image for the first page is formed if the total image formation time is shorter than that in FIG. It may be controlled to form the supply image 200 before. In the above description, the interval between the normal image on the first page and the normal image on the second page has been described as an example, but the present invention is not limited to this. Any image between the normal image of the Nth page and the normal image of the (N + 1) th page (N is a natural number of 1 or more) can be applied to any image.

  FIG. 5 is a flowchart showing the control for forming the supply image 200 in the present embodiment. In S101, the CPU 600 obtains the delay time B from the difference between the timing (1) when the image formation preparation is completed in the shortest time and the timing (4) when the image formation is completed in the current situation. In S <b> 102, the CPU 600 determines whether the delay time B is less than the formation processing time A of the supply image 200 (B <A).

  If the delay time B is less than the formation processing time A, the CPU 600 forms the normal image of the first page in S103. In step S <b> 104, the CPU 600 sets the interval between the images according to the length in the sub-scanning direction of the supply image 200 in order to form the supply image 200 between the first and second page images. That is, the space between images is wider than when the supply image 200 is not formed. In S <b> 105, the CPU 600 forms the supply image 200 between the images and supplies the toner to the cleaning blade 2. In S106, the CPU 600 forms a normal image for the second page.

  On the other hand, when the delay time B is equal to or longer than the formation processing time A, in S107, the CPU 600 forms the supply image 200 before forming the normal image of the first page and supplies the toner to the cleaning blade 2. Thereafter, in S108, the CPU 600 forms a normal image for the first page. In S109, since the CPU 600 does not need to form the supply image 200 between the images on the first page and the second page, the CPU 600 sets the length between the images so that the supply image 200 is not formed. That is, as compared with the case where the supply image 200 is formed, it is not necessary to switch the secondary transfer bias, so that the interval between images can be shortened. In S110, the CPU 600 forms a normal image for the second page, and a series of processing ends.

  As described above, when the formation process of the supply image 200 is completed during the image formation preparation, the supply image 200 is not formed between the images on the first page and the second page. Can be shortened. As a result, the time required to form a series of images can be shortened, so that a reduction in productivity due to the formation of the supply image 200 can be suppressed.

  In the present embodiment, the supply image is described as an example, but the present invention is not limited to this. For example, for images that are not secondarily transferred to a recording material formed between the images, such as a density correction image for correcting the density of the image and a color shift correction image for correcting color shift of the image. It is possible to apply form control. Further, as a method for changing the formation start timing of the supply image 200, the method of changing the timing for transmitting the / TOP signal (supply image) has been described, but the present invention is not limited to this. For example, the CPU 600 may notify the controller 650 of information regarding when the supply image 200 is formed, and the controller 650 may control the timing at which the video signal of the supply image 200 is transmitted.

  In this embodiment, the case where an image is formed on the recording material 73 stored in the storage cassette 63 has been described as an example in which the start of image formation is delayed. However, the present invention is not limited to this. For example, the image forming apparatus 35 is installed in a low temperature environment, and the rise of the temperature of the fixing device 13 and the rise of the exposure unit 10 may be delayed. In addition, the controller 650 may receive an image with a large amount of data from the host computer 660, and it may take a long time to convert the image, thereby delaying the start of image formation. For any reason, if the delay time for delaying the start of image formation can be obtained, the delay time is effectively utilized as the time for forming the supply image 200, thereby suppressing a decrease in productivity. be able to.

(Second Embodiment)
In the present embodiment, when there is a time during which the supply image can be formed before the normal image is formed according to the delay time B of the image formation preparation, the subscan of the supply image is performed according to the delay time B. A method for controlling the length in the direction will be described. In addition, description here is abbreviate | omitted about the structure similar to previous 1st Embodiment.

[Formation timing of supply image]
FIG. 6 is a diagram showing the timing for forming the supply image in the present embodiment. FIG. 6A shows a timing chart when an image is formed on the recording material 71 stored in the storage cassette 61. FIG. 6B shows a timing chart when an image is formed on the recording material 72 stored in the storage cassette 62. In this embodiment, in order to form supply images having different lengths in the sub-scanning direction, a plurality of supply image formation processing times C_long, C_medium, and C_short are set in advance as an example. The formation processing time is C_long>C_medium> C_short. In the following, the supply image formed with C_long is also referred to as supply image l, the supply image formed with C_medium is referred to as supply image m, and the supply image formed with C_short is also referred to as supply image s. The length of each supply image in the sub-scanning direction is: supply image l> supply image m> supply image s. The CPU 600 compares the delay time B with the formation processing times C_long, C_medium, and C_short, and determines the timing for transmitting the / TOP signal (supply image) and the / TOP signal (normal image).

  First, the case where the delay time B is less than the formation processing time C_short (B <C_short) will be described. The CPU 600 determines that there is no time for forming the supply image before forming the normal image. Then, as described with reference to FIG. 3, the supply image 1 is formed between the images between the normal images. The CPU 600 forms the supply image 1 based on a preset forming processing time C_long (= forming processing time A).

  Next, a case where the delay time B is equal to or longer than the formation processing time C_short and less than C_medium (C_short ≦ B <C_medium) will be described. In this case, the CPU 600 determines that there is time to form the supply image s before starting the formation of the normal image. Then, as shown in FIG. 6A, the supply image s is formed at the timing (2) in which the formation processing time C_short of the supply image s is advanced from the completion timing of the image formation preparation at the timing (3). The / TOP signal (supply image) is transmitted. The CPU 600 can control the life of the consumable member such as the cartridge 22 not to be unnecessarily advanced by matching the drive start timing of the consumable member such as the cartridge 22 with the timing (2).

  Next, the CPU 600 transmits a / TOP signal (normal image) for forming the normal image of the first page at timing (3) when the delay time B has elapsed from timing (1). Then, the CPU 600 forms a / TOP signal (supply image) for forming the supply image m based on the length of the normal image of the first page in the sub-scanning direction and the length corresponding to a preset margin period. Is transmitted at timing (4).

  Since the supply image s is formed before the normal image of the first page is formed, the supply image m having a shorter length in the sub-scanning direction than the supply image l is formed here. It is possible to shorten the distance between the first page and the second page. Even if the length of the supply image in the sub-scanning direction is changed, the toner can be supplied appropriately for the supply image s and the supply image m, so that a certain amount of toner is supplied to the cleaning blade 2. . Therefore, abnormal noise of the cleaning blade 2 can be suppressed and the cleaning performance can be maintained. Based on the formation processing time C_medium, the CPU 600 transmits a / TOP signal (normal image) for forming the normal image of the second page at timing (5).

  In this way, by forming the supply image s before forming the normal image of the first page, the supply image formed between the normal image of the first page and the normal image of the second page is formed. It can be set as the supply image m. Thus, for example, when the supply image 1 is formed between the normal image on the second page and the normal image on the third page, the image forming the supply image l is formed between the images forming the supply image m. Since it can be made shorter than the interval, a decrease in productivity can be suppressed.

  Next, a case where the delay time B is equal to or longer than the formation processing time C_medium and less than C_long (C_medium ≦ B <C_long) will be described. In this case, the CPU 600 determines that there is time to form the supply image m before starting the formation of the normal image. Then, as shown in FIG. 6B, the supply image m is formed at the timing (2) where the formation processing time C_medium of the supply image m is advanced from the completion timing of the image formation preparation at the timing (3). The / TOP signal (supply image) is transmitted. The CPU 600 can control the life of the consumable member such as the cartridge 22 not to be unnecessarily advanced by matching the drive start timing of the consumable member such as the cartridge 22 with the timing (2).

  Next, the CPU 600 transmits a / TOP signal (normal image) for forming the normal image of the first page at timing (3) when the delay time B has elapsed from timing (1). Then, the CPU 600 generates a supply image s based on the length of the normal image of the first page in the sub-scanning direction and a length corresponding to a preset margin period (TOP image (supply image)). Is transmitted at timing (4).

  Since the supply image m is formed before the normal image of the first page is formed, the supply image s having a shorter length in the sub-scanning direction than the supply image l is formed here. It is possible to shorten the distance between the first page and the second page. Even if the length of the supply image in the sub-scanning direction is changed, the toner can be supplied appropriately for both the supply image m and the supply image s, so that a certain amount of toner is supplied to the cleaning blade 2. . Therefore, abnormal noise of the cleaning blade 2 can be suppressed and the cleaning performance can be maintained. Based on the formation processing time C_short, the CPU 600 transmits a / TOP signal (normal image) for forming the normal image of the second page at timing (5).

  In this way, by forming the supply image m before forming the normal image of the first page, the supply image formed between the normal image of the first page and the normal image of the second page is formed. The supply image s can be obtained. Thus, for example, when the supply image 1 is formed between the normal image on the second page and the normal image on the third page, the image forming the supply image l is formed between the images forming the supply image s. Since it can be made shorter than the interval, a decrease in productivity can be suppressed.

  Next, a case where the delay time B is equal to or longer than the formation processing time C_long (B ≧ C_long) will be described. The CPU 600 determines that there is time to form the supply image 1 before starting the formation of the normal image. Then, as described with reference to FIG. 4, the supply image 1 is formed based on the formation processing time C_long (= formation processing time A) before the normal image of the first page. Then, control is performed to shorten the interval between images without forming a supply image between the normal image on the first page and the normal image on the second page.

  FIG. 7 is a flowchart showing control for forming a supply image in the present embodiment. Note that the same steps as those in the flowchart of FIG. 5 are given the same numbers, and description thereof is omitted here. In S201, the CPU 600 determines whether or not the delay time B is less than the formation processing time C_short (B <C_short). When the delay time B is less than the formation processing time C_short, the same processing as S103 to S106 in FIG. 5 is performed.

  If the delay time B is not less than the formation processing time C_short, in S202, the CPU 600 determines whether the delay time B is equal to or greater than the formation processing time C_short and less than C_medium (C_short ≦ B <C_medium). If the delay time B is equal to or longer than the formation processing time C_short and less than C_medium, the CPU 600 forms the supply image s before forming the normal image of the first page and supplies the toner to the cleaning blade 2 in S203. . Thereafter, in S204, the CPU 600 forms a normal image of the first page. In step S <b> 205, the CPU 600 sets a length for forming the supply image m between the images in order to form the supply image m between the first page image and the second page image. That is, compared to the case where the supply image 1 is formed, the length of the supply image in the sub-scanning direction is shortened, so that the interval between the images can be shortened. In S206, the CPU 600 forms the supply image m between the images. In S207, the CPU 600 forms a normal image for the second page.

  If the delay time B is not less than the formation processing time C_short and less than C_medium, in S208, the CPU 600 determines whether the delay time B is not less than the formation processing time C_medium and less than C_long (C_medium ≦ B <C_long). If the delay time B is equal to or longer than the formation processing time C_medium and less than C_long, the CPU 600 forms the supply image m before forming the normal image of the first page and supplies the toner to the cleaning blade 2 in S209. . Thereafter, in S210, the CPU 600 forms a normal image of the first page. In step S211, the CPU 600 sets a length between the images to form the supply image s in order to form the supply image s between the first page image and the second page image. That is, compared to the case where the supply image 1 is formed, the length of the supply image in the sub-scanning direction is shortened, so that the interval between the images can be shortened. In S212, the CPU 600 forms the supply image s between the images. In S213, the CPU 600 forms a normal image for the second page. When the delay time B is not less than the formation processing time C_medium and less than C_long, the same processing as S107 to S110 in FIG. 5 is performed.

  In this way, by changing the length of the supply image in the sub-scanning direction according to the delay time B, the length of the supply image formed between the first and second pages in the sub-scanning direction is changed. The length can be shortened. Thereby, since the interval between images can be shortened, the time required for a series of image formation can be shortened. Therefore, it is possible to suppress a decrease in productivity due to the formation of the supply image. In the present embodiment, the method of setting the length of the supply image in the sub-scanning direction in three stages has been described as an example, but the present invention is not limited to this. Depending on the delay time B, the length of the supply image in the sub-scanning direction can be set in any number of stages.

(Third embodiment)
In the present embodiment, when there is a time during which the supply image can be formed before the normal image is formed according to the delay time B of the image formation preparation, the supply image is sub-scanned according to the delay time B A method for increasing the length in the direction will be described. In addition, description here is abbreviate | omitted about the structure similar to previous 1st Embodiment and 2nd Embodiment.

[Formation timing of supply image]
FIG. 8 is a diagram showing the timing for forming the supply image in the present embodiment. As in the second embodiment, for example, supply image formation processing times D_long, C_medium, and C_short are preset in order to form supply images having different lengths in the sub-scanning direction. . Hereinafter, the supply image formed by D_long is also referred to as a supply image dl. The length of the supply image dl in the sub-scanning direction can be set according to the delay time B. The CPU 600 compares the delay time B with the formation processing time D_long and determines the timing for transmitting the / TOP signal (supply image) and the / TOP signal (normal image).

  A case where the delay time B is equal to or longer than the formation processing time D_long (B ≧ D_long) will be described. As shown in FIG. 8, the CPU 600 forms the supply image dl at the timing (2) where the formation processing time D_long of the supply image dl is advanced from the completion timing of the image formation preparation at the timing (3). A TOP signal (supply image) is transmitted. The CPU 600 can control the life of the consumable member such as the cartridge 22 not to be unnecessarily advanced by matching the drive start timing of the consumable member such as the cartridge 22 with the timing (2).

  Next, the CPU 600 transmits a / TOP signal (normal image) for forming the normal image of the first page at timing (3) when the delay time B has elapsed from timing (1). Then, the CPU 600 transmits a / TOP signal (normal image) for forming a normal image of the second page at timing (4) without transmitting a / TOP signal (supply image) between the images. Since the supply image is not formed between the first and second page images, it is not necessary to secure the switching time of the polarity of the secondary transfer bias, and the interval between the images can be shortened.

  CPU 600 transmits a / TOP signal (normal image) at timing (4). After that, based on the length of the normal image of the second page in the conveyance direction and the length corresponding to a preset margin period, the timing (5) is generated for the / TOP signal (supply image) for forming the supply image ds. ) As shown in FIG. 5, the supply image ds can be changed according to the length of the supply image dl. That is, the longer the supply image dl, the shorter the length of the supply image ds. In this way, by forming the supply image dl before forming the normal image of the first page, it is possible to shorten the supply image ds formed after the normal image of the second page. Thereby, since the time concerning a series of image formation can be shortened, the fall of productivity can be suppressed. Note that, even if the lengths of the supply image dl and the supply image ds in the sub-scanning direction are changed, the toner can be appropriately supplied together with the supply image dl and the supply image ds. A certain amount of toner is supplied. Therefore, abnormal noise of the cleaning blade 2 can be suppressed and the cleaning performance can be maintained.

  FIG. 9 is a flowchart illustrating control for forming a supply image in the present embodiment. Note that the same steps as those in the flowchart of FIG. 5 are given the same numbers, and description thereof is omitted here. In S301, the CPU 600 determines whether or not the delay time B is equal to or longer than the formation processing time D_long (B ≧ D_long). When the delay time B is not equal to or longer than the formation processing time D_long (B ≧ D_long), the same processing as S103 to S106 in FIG. 5 is performed.

  If the delay time B is equal to or longer than the formation processing time D_long (B ≧ D_long), the CPU 600 forms a supply image dl corresponding to the delay time B in S302. In S303, the CPU 600 forms a normal image for the first page. In step S304, the CPU 600 does not need to form a supply image between the images on the first and second pages, and therefore sets the length between images so that the supply image is not formed. That is, as compared with the case of forming the supply image, it is not necessary to switch the secondary transfer bias, so that the interval between images can be shortened. In S305, the CPU 600 forms a normal image for the second page. In S306, the CPU 600 forms the supply image ds according to the length of the supply image dl. That is, the longer the supply image dl, the shorter the length of the supply image ds.

  In this way, the length in the sub-scanning direction of the supply image formed before the first page is changed according to the delay time B. Accordingly, the length in the sub-scanning direction of the supply image formed after the second page can be shortened without forming the supply image between the first and second page images. Therefore, the time required for a series of image formation can be shortened, and a reduction in productivity can be suppressed. In the present embodiment, the method of forming the supply image after the normal image of the second page has been described as an example. However, the present invention is not limited to this. For example, depending on the length of the supply image dl formed before forming the normal image for the first page, the cleaning performance of the cleaning blade 2 can be maintained up to a predetermined page. That is, the formation timing of the supply image ds is not limited to after the second page, and the formation timing of the supply image ds may be controlled according to the length of the supply image dl.

(Modification)
In FIG. 1, an intermediate transfer type image forming apparatus has been described as an example of the image forming apparatus, but the present invention is not limited to this. For example, also in the direct transfer type image forming apparatus that directly transfers the image formed on the photosensitive drum 5 to a recording material, the control of the first to third embodiments can be performed.

  In FIG. 1, an image forming apparatus that forms a color image is described as an example of the image forming apparatus, but the present invention is not limited to this. For example, even in an image forming apparatus that includes one photosensitive drum 5, forms a black image on the photosensitive drum 5, and forms a monochrome image that transfers the formed image onto a recording material, the first to thirteenth embodiments are also described. It is possible to perform the control of the third embodiment.

  That is, in the direct transfer type image forming apparatus and the image forming apparatus that forms a monochrome image, for example, the control in the first embodiment is as follows. When the delay time B is equal to or longer than the formation processing time A (B ≧ A), the CPU 600 determines that the supply image 200 can be formed during the delay time B. Then, as shown in FIG. 4, / TOP for forming the supply image 200 at the timing (7) in which the formation processing time A of the supply image 200 is advanced from the completion timing of the image formation preparation at the timing (4). A signal (image for supply) is transmitted. Next, the CPU 600 transmits a / TOP signal (normal image) for forming the normal image of the first page at timing (4) when the delay time B has elapsed from timing (1). Then, the CPU 600 transmits the / TOP signal (normal image) for forming the normal image of the second page at timing (8) without forming the supply image 200 after the normal image of the first page.

  As described above, in the direct transfer type image forming apparatus, the toner can be supplied to the cleaning blade in contact with the recording material conveyance body by forming the supply image on the recording material conveyance belt as the recording material conveyance body. In an image forming apparatus that forms a monochrome image, toner can be supplied to a cleaning blade in contact with the image carrier by forming a supply image on a photosensitive drum as an image carrier. As in the case of the intermediate transfer type image forming apparatus, if the above-described control is performed, and the supply image forming process is completed during image formation preparation, the image between the first page and the second page is displayed. Since no supply image is formed between them, the interval between images can be shortened. As a result, the time required to form a series of images can be shortened, so that a reduction in productivity due to the formation of the supply image 200 can be suppressed. Although a detailed description of the second embodiment and the third embodiment is omitted here, in the image forming apparatus for forming a monochrome image in the direct transfer type image forming apparatus as in the first embodiment. The same control can be performed.

2 Cleaning blade 5 Photosensitive drum 8 Developing roller 600 CPU

Claims (13)

An image carrier on which an electrostatic latent image is formed;
Developing means for developing the electrostatic latent image formed on the image carrier as an image with toner;
Cleaning means for cleaning toner,
A first image transferred to the recording material, a second image not transferred to the recording material, and a third image transferred to the recording material conveyed following the recording material on which the first image is formed An image forming apparatus for forming
If the second image formation process is completed within the image formation preparation period, the second image is formed before the first image;
When the second image forming process is not completed within the image formation preparation period, the second toner image is formed between the first image and the third image,
When the second image forming process is completed within the image formation preparation period, the first interval between the first image and the third image is within the image formation preparation period. An image forming apparatus characterized in that the second interval is shorter than the second interval between the first image and the third image when the second image forming process is not completed. An image carrier on which an electrostatic latent image is formed;
Developing means for developing the electrostatic latent image formed on the image carrier as an image with toner;
Cleaning means for cleaning toner,
A first image transferred to the recording material, a second image not transferred to the recording material, and a third image transferred to the recording material conveyed following the recording material on which the first image is formed And a fourth image that is not transferred to the recording material,
The length of the second image formed before the first image in the sub-scanning direction is determined in accordance with a preparation period for image formation, and the length of the second image in the sub-scanning direction is determined. And determining a length in a sub-scanning direction of a fourth image formed between the first image and the third image. An image carrier on which an electrostatic latent image is formed;
Developing means for developing the electrostatic latent image formed on the image carrier as an image with toner;
Cleaning means for cleaning toner,
A first image transferred to the recording material, a second image not transferred to the recording material, and a third image transferred to the recording material conveyed following the recording material on which the first image is formed And a fourth image that is not transferred to the recording material,
The length of the second image formed before the first image in the sub-scanning direction is determined in accordance with a preparation period for image formation, and the length of the second image in the sub-scanning direction is determined. An image forming apparatus that determines a length of the fourth image formed after the third image in the sub-scanning direction.   The image forming apparatus according to claim 3, wherein no image is formed between images between the first image and the third image.   The image forming apparatus according to claim 4, wherein a first interval between the images is shorter than a second interval in the case of forming an image between the images.   The second image is a supply image for supplying toner to the cleaning unit, a density correction image for correcting the density of the image, or a color shift correction for correcting a color shift of the image. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image for use.   The second image and the fourth image are correction images for supplying toner to the cleaning unit, density correction images for correcting image density, or image color misregistration. The image forming apparatus according to claim 2, wherein the image forming apparatus is a color misregistration correction image. Primary transfer means for primary transfer of an image formed on the image carrier to an intermediate transfer member;
Secondary transfer means for secondary transfer of the image primarily transferred to the intermediate transfer member to a recording material,
The image forming apparatus according to claim 1, wherein the cleaning unit contacts the intermediate transfer member to clean toner on the intermediate transfer member. A transfer means for transferring the image formed on the image carrier to a recording material carrier;
The image forming apparatus according to claim 1, wherein the cleaning unit contacts the recording material conveyance body to clean toner on the recording material conveyance body.   The image forming apparatus according to claim 1, wherein the cleaning unit contacts the image carrier and cleans toner on the image carrier. A feeding means for feeding the recording material,
The image forming apparatus according to claim 1, wherein the image formation preparation period is a period determined based on a period during which the recording material is conveyed from the feeding unit to the image forming unit. . Fixing means for fixing a toner image on a recording material,
11. The image formation according to claim 1, wherein an image formation preparation period is determined based on a period until the temperature of the fixing unit reaches a predetermined temperature for image formation. apparatus. Development means for performing image data development processing,
11. The image forming apparatus according to claim 1, wherein a preparation period for image formation is determined based on a period required for the development processing of the image data by the development unit.

Images