JP4387246B2 - Color image forming apparatus - Google Patents

Description

  The present invention relates to an electrophotographic color image forming apparatus.

  2. Description of the Related Art Today, in electrophotographic image forming apparatuses, there are an increasing number of color image forming apparatuses that output color images, such as color copiers and color printers, in response to market demands.

  As a typical method for forming a color image, a direct transfer method in which toner images of different colors formed on a plurality of photoconductors are transferred while being directly superimposed on transfer paper, and toners of different colors formed on a plurality of photoconductors are used. There is an intermediate transfer method in which an image is transferred while being superimposed on a rotating body, and then transferred onto a transfer sheet at once. These direct transfer type and intermediate transfer type color image forming apparatuses are called a tandem type because a plurality of photoconductors are arranged side by side facing a transfer sheet or rotating body, and magenta (M), An electrophotographic process such as electrostatic latent image formation and development is performed for each color of cyan (C), yellow (Y), and black (K). In the direct transfer method, an intermediate transfer method is performed on a running transfer paper. In, the transfer operation is performed on the rotating body that is running.

  In such a tandem color image forming apparatus, in the direct transfer method, an endless recording material conveyance belt, which is a rotating body that runs while supporting transfer paper, is used in the intermediate transfer method. In general, an endless intermediate transfer belt that is a rotating body that receives and carries an image from the body is employed. In general, an image processing unit including four photoconductors is arranged side by side on one traveling side of an endless belt.

JP 2001-282010 A JP 2000-122431 A

  In such a color image forming apparatus, in order to control the image density, a toner pattern for image density control is formed on each photoconductor, and the formed toner pattern is applied to a rotating body (recording material conveyance belt, intermediate transfer belt). The toner pattern for image density control on the rotator is detected by a sensor, and the image density is controlled based on the detection result. In addition, a toner pattern for registration adjustment for writing of each color is formed on each photoconductor for each color, the formed toner pattern is transferred to a rotating body, and the toner pattern for controlling registration on the rotating body is detected by a sensor. Detection is performed, and writing resist for each color is controlled based on the detection result.

  In a color image forming apparatus, a toner pattern for image density on a rotating body and a toner pattern for resist registration control which are used and become unnecessary are removed by a blade. The blade has a structure that scrapes the toner by abutting on the rotating body, and is called a so-called counter abutting method. Such a counter contact method is inexpensive and has an excellent cleaning performance, but when the coefficient of friction between the blade and the rotating body increases, a phenomenon such as “blade turning” that the blade bends may occur. Here, the toner remaining on the rotating body functions to lower the coefficient of friction between the blade and the rotating body, and has a lubricating function of stabilizing the contact state of the blade with the rotating body. Therefore, in order to obtain a sufficient lubrication function with such toner, a toner pattern for preventing blade curling is formed on the photosensitive member, and the toner pattern for preventing blade curling is transferred onto the rotating member. Control for lowering the coefficient of friction between the blade and the rotating body is performed by the action of the toner pattern for prevention (for example, Patent Documents 1 and 2).

Thus, in the tandem type color image forming apparatus, various toner patterns are formed on the rotating body in the image forming operation. Toner patterns of these various, that in accordance with the toner pattern creation purposes, predetermined forming conditions (the number of recording sheets, creation time, temperature, etc.) in accordance with, is created. That is, the creation intervals of these toner patterns on the rotating body in the sub-scanning direction are individually set. Therefore, depending on the creation timing, these toner patterns must be created at the same position in the sub-scanning direction. If this is the case, the toner patterns will be formed in an overlapping manner. To prevent this, a priority order for creating the toner patterns when the creations overlap at the same position in the sub-scanning direction is set, Control is performed so that toner patterns are created according to the order, and toner patterns with lower priority order are created with the creation timing shifted. As a result, the toner pattern is shifted in the sub-scanning direction. However, there is a problem that such control is complicated.

  An object of the present invention is to prevent complicated control for creating a plurality of types of toner patterns.

According to a first aspect of the present invention, in a color image forming apparatus for transferring a toner image formed on a plurality of photosensitive members by an electrophotographic method onto a rotating member, the toner on the rotating member is removed by contacting the rotating member. A blade, a means for forming a toner pattern for preventing curling of the blade on the rotating body, and at least one type of control toner pattern detected by a sensor for controlling an image forming operation on the rotating body. The toner pattern for control and the toner pattern for preventing curling of the blade are formed side by side in the main scanning direction so as not to overlap at the same position in the main scanning direction, a detection region of the sensor that detects the toner pattern for control, and the toner pattern for preventing curling of the blade, in the same position in the main scanning direction Characterized in that to avoid location.

  According to a second aspect of the present invention, in the color image forming apparatus according to the first aspect, the toner pattern for control is a toner pattern used for controlling image density.

  According to a third aspect of the present invention, in the color image forming apparatus according to the first aspect, the toner pattern for control is a toner pattern used for control for aligning a resist for writing on each of the photoconductors. Features.

The invention of claim 4, wherein, in the color image forming apparatus according to any one of claims 1 to 3, wherein the toner pattern for preventing curling of the blade are distributed in a main scanning direction on said rotating body It is characterized by being formed.

According to a fifth aspect of the present invention, in a color image forming apparatus that transfers toner images formed on a plurality of photoconductors by an electrophotographic method onto a rotating body, two or more types detected by a sensor for controlling an image forming operation. Means for forming a control toner pattern on the rotating body, and the two or more types of control toner patterns are formed side by side in the main scanning direction so as not to overlap at the same position in the main scanning direction, detection areas of the plurality of sensors for detecting the toner pattern for control of the two or more respectively, characterized in that so as not located in the same position in the main scanning direction.

  According to a sixth aspect of the present invention, in the color image forming apparatus according to the first or fifth aspect, the toner pattern for control includes a toner pattern used for image density control and a resist for writing on each of the photoconductors. And a toner pattern used for control for matching.

Invention of claim 7, wherein, in the color image forming apparatus according to one any of claims 1 to 6, wherein the rotary member is an intermediate transfer member, with respect to a plurality of said recording material on said rotating member The toner pattern is formed between a plurality of transfer regions.

Invention of claim 8, in the color image forming apparatus according to one any of claims 1 to 6, wherein the rotary member is a recording material conveying member for conveying the recording material, a plurality of on the rotating body The toner pattern is formed between the recording materials.

  According to the present invention, it is possible to prevent complicated control for creating a plurality of types of toner patterns.

  An embodiment of the present invention will be described with reference to the drawings. This embodiment is an example applied to a color electrophotographic copying machine of an intermediate transfer system (hereinafter simply referred to as “copying machine”) as a color image forming apparatus.

  First, the configuration of the entire copying machine according to the present embodiment will be described. FIG. 1 is a schematic configuration diagram showing the entire copying machine 1 according to the present embodiment. The copying machine 1 includes a copying machine main body 100 that forms an image, a paper feeding device 200 on which the copying machine main body 100 is mounted and that supplies transfer paper 5 as a recording material to the copying machine main body 100, and a copying machine A scanner 300 that is mounted on the main body 100 and reads a document image, an automatic document feeder (ADF) 400 that is mounted on the scanner 300, and an operation unit 500 (see FIG. 3) are provided. The copying machine main body 100 is provided with a manual feed tray 6 for manually feeding the transfer paper 5 and a paper discharge tray 7 for discharging the transfer paper 5 on which an image has been formed.

  FIG. 2 is an enlarged view showing the configuration of the copying machine main body 100. The copying machine main body 100 is provided with an endless belt-like intermediate transfer belt 10 which is an intermediate transfer body as a rotating body. The intermediate transfer belt 10 is rotationally driven in a clockwise direction in FIG. 2 by a drive motor M (see FIG. 3) while being stretched around three support rollers 14, 15, and 16. The width direction of the intermediate transfer belt 10 orthogonal to the rotation direction of the intermediate transfer belt 10 is the main scanning direction, and the rotation direction of the intermediate transfer belt 10 is the sub-scanning direction.

  As shown in FIG. 2, the belt stretched portion between the first support roller 14 and the second support roller 15 among the support rollers 14, 15, 16 has yellow, cyan, magenta, and black (black). Four image forming units 18Y, 18C, 18M, and 18K corresponding to the four colors are arranged side by side. Above these image forming units 18Y, 18C, 18M, and 18K, as shown in FIG. 1, an exposure device 21 that is a laser writing unit is provided. The exposure apparatus 21 emits writing light by driving a semiconductor laser (not shown) by a laser control unit (not shown) based on the image information of the document read by the scanner 300, and each image forming unit. This is for forming an electrostatic latent image on the drum-shaped photoconductors 20Y, 20C, 20M, and 20K as image carriers provided in 18Y, 18C, 18M, and 18K. Here, the emission of the writing light is not limited to the laser, but may be an LED, for example.

  The configuration of the image forming units 18Y, 18C, 18M, and 18K will be described. In the following description, the image forming unit 18K that forms a black toner image will be described as an example, but the other image forming units 18Y, 18C, and 18M have the same configuration. In the following description, the symbols “M” and “K” indicating the distinction of colors are omitted as appropriate.

  In the image forming unit 18, a charging device 60, a developing device 61, a photoconductor cleaning device 63, and a charge removal device 64 are provided around the photoconductor 20. A primary transfer device 62 is provided at a position facing the photoconductor 20 via the intermediate transfer belt 10. The axial direction of the photoconductor 20 is parallel to the width direction of the intermediate transfer belt 10, that is, the axial direction of the photoconductor 20 is the main scanning direction. In this structure, the surface of the photoconductor 20 is first uniformly charged by the charging device 60 as the photoconductor 20 is rotated by driving of the drive motor M (see FIG. 3). Next, based on the image information read by the scanner 300, the exposure light is irradiated from the exposure device 21 to form an electrostatic latent image on the photoconductor 20. Thereafter, the electrostatic latent image is visualized by the developing device 61 to form a toner image. This toner image is primarily transferred onto the intermediate transfer belt 10 by the primary transfer device 62. The transfer residual toner remaining on the surface of the photoconductor 20 after the primary transfer is removed by the photoconductor cleaning device 63, and then the surface of the photoconductor 20 is discharged by the charge removal device 64 and used for the next image formation. The

  Next, as shown in FIG. 2, a secondary transfer roller 24 as a secondary transfer device is provided at a position facing the third support roller 16 among the support rollers. When the toner image on the intermediate transfer belt 10 is secondarily transferred onto the transfer paper 5, the secondary transfer roller 24 is pressed against the portion of the intermediate transfer belt 10 wound around the third support roller 16. Next transfer is performed. The secondary transfer device may not be configured using the secondary transfer roller 24 but may be configured using, for example, a transfer belt or a non-contact transfer charger. The secondary transfer roller 24 is in contact with a roller cleaning unit 91 that cleans toner adhering to the secondary transfer roller 24.

  Further, on the downstream side of the secondary transfer roller 24 in the transfer paper conveyance direction, an endless belt-like conveyance belt 22 is stretched between the two rollers 23a and 23b. Further, a fixing device 25 for fixing the toner image transferred onto the transfer paper 5 is provided further downstream in the transport direction. The fixing device 25 has a configuration in which a pressure roller 27 is pressed against a heating roller 26.

  Further, a belt cleaning device 17 is provided at a position facing the second support roller 15 among the support rollers of the intermediate transfer belt 10. The belt cleaning device 17 includes a blade 17 a that contacts the surface of the intermediate transfer belt 10. The blade 17 a is disposed to face the second support roller 15 with the intermediate transfer belt 10 interposed therebetween. The belt cleaning device 17 removes residual toner remaining on the intermediate transfer belt 10 by scraping with a blade 17 a after transferring the toner image on the intermediate transfer belt 10 to the transfer paper 5. The toner recovered from the intermediate transfer belt 10 by the blade 17a is transported to the waste toner transport path by the recovery coil 17b.

  Further, a sensor unit 70 is provided opposite to the intermediate transfer belt 10 on the downstream side in the rotational direction of the intermediate transfer belt 10 with respect to all the photoreceptors 20 in the intermediate transfer belt 10. Specifically, the sensor unit 70 is disposed at a position facing the first support roller 14 via the intermediate transfer belt 10. The sensor unit 70 includes a first sensor S1 (see FIG. 5) that detects a toner pattern P1 for image density control, which will be described later, and two second sensors for detecting a toner pattern P2 for registration adjustment, which will be described later. The sensor S2 (see FIG. 5) is installed on the substrate 70a.

  Further, as shown in FIG. 1, the copying machine main body 100 is provided with a conveyance path 48 that guides the transfer paper 5 fed from the paper feeding device 200 to the paper discharge tray 7 via the secondary transfer roller 24. Along the conveyance path 48, a conveyance roller 49a, a registration roller 49b, a discharge roller 56, and the like are provided. A switching claw 55 is provided on the downstream side of the transport path 48 to switch the transport direction of the transfer paper 5 after transfer to the paper discharge tray 7 or the paper reversing device 93. The paper reversing device 93 reverses the transfer paper 5 and sends it again toward the secondary transfer roller 24. Further, the copying machine main body 100 is provided with a manual feed path 53 that joins from the manual feed tray 6 to the transport path 48, and the transfer paper 5 set in the manual feed tray 6 is located upstream of the manual feed path 53. A sheet feeding roller 50 and a separation roller 51 are provided for feeding sheets one by one.

  The paper feeding device 200 includes a plurality of paper feeding cassettes 44 that store the transfer paper 5, a paper feeding roller 42 and a separation roller 45 that feed the transfer papers stored in these paper feeding cassettes 44 one by one, and the fed transfer paper Is composed of a transport roller 47 that transports the paper along the paper feed path 46. The paper feed path 46 is connected to the conveyance path 48 of the copying machine main body 100.

  The scanner 300 will be briefly described with reference to FIG. In the scanner 300, first and second traveling bodies 33 and 34 mounted with a document illumination light source and a mirror reciprocate in order to read and scan a document (not shown) placed on the contact glass 31. To do. The image information scanned by the traveling bodies 33 and 34 is collected by the imaging lens 35 on the imaging surface of the reading sensor 36 installed behind the imaging lens 35 and read by the reading sensor 36 as an image signal.

  FIG. 3 is a block diagram showing an electrical connection of each part provided in the copying machine 1 of the present embodiment. As shown in FIG. 3, the copier 1 of the present embodiment is provided with a main controller 600, and the main controller 600 drives and controls each part. The main controller 600 includes an image forming unit 18 and a driving motor M of the copying machine main body 100, each unit such as the first and second sensors S1 and S2, the sheet feeding device 200, the I / O device control unit 601, and the like. A scanner 300, an automatic document feeder 400, and an operation unit 500 are connected.

  Next, the operation of the copying machine 1 according to the present embodiment will be described. When copying a document using the copying machine 1 having the above configuration, first, the document is set on the document table 30 of the automatic document feeder 400. Alternatively, the automatic document feeder 400 is opened, a document is set on the contact glass 31 of the scanner 300, and the automatic document feeder 400 is closed and pressed by it. Thereafter, when the user presses a start switch (not shown) of the operation unit 500, when the document is set on the automatic document feeder 400, the document is transported onto the contact glass 31. Then, the scanner 300 is driven and the first traveling body 33 and the second traveling body 34 start traveling. Thereby, the light from the first traveling body 33 is reflected by the document on the contact glass 31, and the reflected light is reflected by the mirror of the second traveling body 34 and guided to the reading sensor 36 through the imaging lens 35. . In this way, the image information of the original is read.

  Further, when the start switch is pressed by the user, the drive motor M is driven, and one of the support rollers 14, 15, 16 is rotationally driven, and the intermediate transfer belt 10 is rotationally driven. At the same time, the photosensitive members 20Y, 20C, 20M, and 20K of the image forming units 18Y, 18C, 18M, and 18K are also rotationally driven. Thereafter, based on the image information read by the reading sensor 36 of the scanner 300, writing light is respectively applied from the exposure device 21 onto the photoreceptors 20Y, 20C, 20M, and 20K of the image forming units 18Y, 18C, 18M, and 18K. Irradiated. As a result, electrostatic latent images are formed on the respective photoreceptors 20Y, 20C, 20M, and 20K, and are visualized by the developing devices 61Y, 61C, 61M, and 61K. Then, yellow, cyan, magenta, and black toner images are formed on the photoreceptors 20Y, 20C, 20M, and 20K, respectively.

  Each color toner image formed in this way is primarily transferred by the primary transfer devices 62Y, 62C, 62M, and 62K so as to sequentially overlap each other on the intermediate transfer belt 10. As a result, a composite toner image in which the toner images of the respective colors overlap is formed on the intermediate transfer belt 10. The transfer residual toner remaining on the intermediate transfer belt 10 after the secondary transfer is removed by the blade 17a of the belt cleaning device 17.

  When the user presses the start switch, the paper feed roller 42 of the paper feed device 200 corresponding to the transfer paper 5 selected by the user rotates, and the transfer paper 5 is sent out from one of the paper feed cassettes 44. The transferred transfer paper 5 is separated into one sheet by the separation roller 45 and enters the paper feed path 46, and is conveyed by the conveyance roller 47 to the conveyance path 48 in the copying machine main body 100. The transfer sheet 5 thus transported is stopped when it abuts against the registration roller 49b. When the transfer paper 5 not set in the paper feed cassette 44 is used, the transfer paper 5 set on the manual feed tray 6 is fed out by the paper feed roller 50 and separated into one sheet by the separation roller 52, and then manually fed. It is conveyed through the paper path 53. Then, it stops when it hits the registration roller 49b.

  The registration roller 49 b starts to rotate in accordance with the timing at which the composite toner image formed on the intermediate transfer belt 10 as described above is conveyed to the secondary transfer unit facing the secondary transfer roller 24. Here, the registration roller 49b is generally used while being grounded, but a bias may be applied to remove the paper dust of the transfer paper 5. The transfer paper 5 sent out by the registration roller 49b is sent between the intermediate transfer belt 10 and the secondary transfer roller 24, and the secondary transfer roller 24 causes the composite toner image on the intermediate transfer belt 10 to be transferred onto the transfer paper 5. Secondary transfer is performed. Thereafter, the transfer paper 5 is conveyed to the fixing device 25 while being attracted to the secondary transfer roller 24, and heat and pressure are applied by the fixing device 25 to perform a toner image fixing process. The transfer paper 5 that has passed through the fixing device 25 is discharged to the paper discharge tray 7 by the discharge roller 56 and stacked. When image formation is performed also on the back surface of the surface on which the toner image is fixed, the transfer paper 5 that has passed through the fixing device 25 is switched by the switching claw 55 and sent to the paper reversing device 93. The transfer paper 5 is then reversed and guided to the secondary transfer roller 24 again.

  Under such a configuration, the characteristic part of the present embodiment will be described with reference to FIGS. FIG. 4 is an explanatory diagram for explaining each toner pattern, and FIG. 5 is a plan view showing each toner pattern on the intermediate transfer belt 10 and the sensor unit 70. FIG. 6 is a plan view showing the relationship between the transfer area 10a on the intermediate transfer belt 10 and the toner pattern.

  In the present embodiment, various toner patterns P (P1, P2, P3) are created on the intermediate transfer belt 10. As the toner pattern P, a toner pattern P1 for image density control which is a control toner pattern P used for controlling an image forming operation, a toner pattern P2 for resist registration control for writing of each color, and turning of the blade 17a And a toner pattern P3 for prevention. These toner patterns are formed on the photoreceptor 20 and then transferred to the intermediate transfer belt 10. Here, means for forming the toner pattern P3 for preventing the curling of the blade 17a on the intermediate transfer belt 10 which is a rotating body, and one or more types of control detected by the sensors S1 and S2 for controlling the image forming operation. The toner patterns P1 and P2 are formed on the intermediate transfer belt 10, and two or more types of control toner patterns P1 and P2 detected by the sensors S1 and S2 for controlling the image forming operation are intermediate transferred. The function of the means forming on the belt 10 is performed.

Here, the usage method and function of these toner patterns will be described. First, image density control processing using the toner pattern P1 for image density control will be described. In this process, the toner pattern P1 for image density control formed on the intermediate transfer belt 10 is read by the first sensor S1 of the sensor unit 70, and a portion on the intermediate transfer belt 10 where no image is formed and the image density. Based on the density ratio with the control toner pattern P1, the current image forming conditions are determined, and proper charging conditions, developing conditions, and writing conditions are corrected, and control is performed so as to obtain a predetermined image density. In the present embodiment, the toner pattern P1 for image density control is created, for example, every 30 sheets, and the image forming conditions are corrected each time.

  Next, each color writing registration control using the toner pattern P2 for color registration registration control will be described. In this process, the registration adjustment control toner pattern P2 formed on the intermediate transfer belt 10 is read by the second sensor S2 of the sensor unit 70, the writing position of each color on the photoconductor 20 is synchronized, and a color image is displayed. Is controlled to minimize color misregistration. In the present embodiment, each time a temperature change of the exposure apparatus 21 occurs by 5 degrees, a toner pattern P2 for resist alignment control is created, and color misregistration correction is performed each time.

  The toner pattern P3 for preventing curling of the blade 17a lowers the coefficient of friction between the blade 17a and the intermediate transfer belt 10 and stabilizes the frictional resistance in this state. This prevents the “blade turning” phenomenon that the blade 17a bends when the friction coefficient between the blade 17a and the intermediate transfer belt 10 is high. The blade turning prevention toner pattern P3 is created once, for example, every 50 sheets.

  Next, the positional relationship between these toner patterns P will be described. These toner patterns P are formed on the intermediate transfer belt 10 at positions that are not the same position in the main scanning direction. Specifically, the toner pattern P1 for image density control and the toner pattern P2 for registration adjustment control have detection areas by the first sensor S1 and the second sensor S2, respectively. Each other, the detection region, and the blade 17a toner pattern P3 for preventing turning are not formed at the same position in the main scanning direction. In the present embodiment, the toner pattern P1 for image density control is formed at the center of the intermediate transfer belt 10 in the main scanning direction. Two toner patterns P2 for resist registration control are formed, and in the main scanning direction on the intermediate transfer belt 10, the toner pattern P1 for image density control is positioned between them, and the pattern for image control is set. It is formed at a position excluding the region. The toner pattern P3 for preventing the blade 17a from turning up is a belt-like shape, and a plurality of toner patterns P3 are formed. The toner patterns P3 for preventing the blades 17a from being turned over are formed distributed over the entire width in the main scanning direction (substantially the same as the width of the blades 17a) on the intermediate transfer belt 10. Each of the blades 17a is prevented from being turned over in the intermediate transfer belt 10 in a range excluding the image density control toner pattern P1 and the resist alignment control toner pattern P2 in the main scanning direction.

  As shown in FIG. 6, these toner patterns are formed between a plurality of transfer areas 10 a that are areas where the toner image is transferred onto the transfer paper 5 in the intermediate transfer belt 10.

  With this configuration, even when the toner patterns P1, P2, and P2 are formed at the same position in the sub-scanning direction, the toner pattern for controlling the image density, which is the toner pattern P for controlling the image forming operation. Other toner patterns P are not located at the same position in the main scanning direction in the detection areas of the first sensor S1 and the second sensor S2 in the registration pattern control toner pattern P2 for P1 and writing of each color, and they overlap. Therefore, it is not necessary to perform complicated control so that the toner patterns do not overlap in the sub-scanning direction as in the prior art. Therefore, control for creating a plurality of types of toner patterns P1, P2, and P3 is complicated. Is prevented.

  In addition, other toner patterns P are the same in the main scanning direction in the detection areas of the first sensor S1 and the second sensor S2 in the toner pattern P1 for image density control and the toner pattern P2 for registration adjustment for writing of each color. Since the toner patterns P are not formed at the positions and do not overlap with each other, the toner patterns P can be arranged in the main scanning direction at the same time. Therefore, compared to the case where the toner pattern P is not created at the same time, the operation time of the image-related parts accompanying the creation of the toner pattern P is shortened, and this also reduces the travel distance of the image-related parts. Therefore, the life of the imaging-related parts can be extended.

  In addition, since the toner patterns P can be formed in the main scanning direction at the same time as described above, the area necessary for forming all the toner patterns P in the sub scanning direction is, for example, the toner pattern P. Is shorter than the case of forming by shifting in the sub-scanning direction. Therefore, when the toner pattern P is formed between the plurality of transfer areas 10a on the intermediate transfer belt 10, the distance between the transfer areas 10a can be shortened. That the transfer areas 10a are shortened means that the distance between sheets, which is the distance between the transfer sheets 5 to be conveyed, is shortened. Here, the print speed is substantially determined by the paper feed speed and the inter-paper distance, which is the distance between the transfer papers 5 being conveyed, so that the print speed is improved by shortening the distance between the transfer regions 10a. Can do.

  Further, the toner pattern P3 for preventing the blade 17a from turning over is formed distributed over the entire width in the main scanning direction (substantially the same as the width of the blade 17a) in the intermediate transfer belt 10, so that the toner pattern is wide in the blade 17a. The effect | action which reduces the friction coefficient by the pattern P3 can be show | played.

Although the present embodiment has been described as an example applied to the intermediate transfer type copying machine 1 using the intermediate transfer belt 10 as a rotating body, an endless recording material conveyance belt 700 as shown in FIG. 7 is rotated. The present invention can be similarly applied to a direct transfer type copying machine 701 as a body. In FIG. 7 , parts that perform the same functions as those shown in FIG. 1 or 2 are denoted by the same reference numerals.

  That is, in the copying machine 701, a recording material conveyance belt 700 is provided instead of the intermediate transfer belt 10 shown in FIG. 1, and the toner images formed on the photoreceptors 20Y, 20C, 20M, and 20K are transferred to the recording material conveyance belt 700. The transfer sheet 5 is transferred while being directly superimposed on the transfer sheet 5 conveyed by.

  In this case, the toner patterns P1, P2, and P3 formed on the photoconductors 20Y, 20C, 20M, and 20K are transferred between the transfer sheet 5 and the transfer sheet on the recording material transport belt 700 in the recording material transport belt 700 (see FIG. What is necessary is just to control so that it may transfer between paper.

1 is a schematic configuration diagram illustrating an entire copying machine according to an embodiment of the present invention. FIG. 2 is an enlarged view showing a configuration of a copying machine main body. FIG. 2 is a block diagram showing electrical connections of respective units provided in the copying machine. FIG. 6 is an explanatory diagram for explaining each toner pattern. FIG. 4 is a plan view showing toner patterns and a sensor unit on an intermediate transfer belt. FIG. 6 is a plan view showing a relationship between a transfer area on an intermediate transfer belt and a toner pattern. 1 is a schematic configuration diagram showing a direct transfer type copying machine.

Explanation of symbols

1 Copying machine (color image forming device)
5 Transfer paper (transfer material)
10 Intermediate transfer belt (intermediate transfer belt, rotating body)
10a transfer region 17a blade 20 photoconductor (image carrier)
700 Recording material conveyance belt (recording material conveyance body)
701 Copier (color image forming apparatus)
P1 Control toner pattern P2 Control toner pattern P3 Blade turnover toner pattern S1 First sensor (sensor)
S2 Second sensor (sensor)

Claims (8)

In a color image forming apparatus for transferring toner images formed on a plurality of photoconductors by electrophotography onto a rotating body,
A blade that contacts the rotating body and removes toner on the rotating body;
Means for forming on the rotating body a toner pattern for preventing the blade from turning over;
Means for forming on the rotating body one or more types of control toner patterns detected by a sensor for controlling an image forming operation;
With
The toner pattern for control and the toner pattern for preventing turning of the blade are formed side by side in the main scanning direction so as not to overlap at the same position in the main scanning direction,
A detection region of the sensor that detects the toner pattern for the control, a color image and the toner pattern for preventing curling of the blade, characterized in that so as not located in the same position in the main scanning direction Forming equipment.   2. The color image forming apparatus according to claim 1, wherein the toner pattern for control is a toner pattern used for image density control.   2. The color image forming apparatus according to claim 1, wherein the toner pattern for control is a toner pattern used for control for aligning a resist for writing on each of the photoconductors. The toner pattern for preventing curling of the blade, the color image forming apparatus according to any one of claims 1 to 3, characterized in that it is formed and distributed in a main scanning direction on said rotating body. In a color image forming apparatus for transferring toner images formed on a plurality of photoconductors by electrophotography onto a rotating body,
Means for forming two or more types of control toner patterns detected by a sensor for controlling an image forming operation on the rotating body;
The two or more types of control toner patterns are formed side by side in the main scanning direction so as not to overlap at the same position in the main scanning direction,
Detection areas of the plurality of sensors for detecting the toner pattern for control of the two or more respectively, the color image forming apparatus is characterized in that so as not located in the same position in the main scanning direction.   The toner pattern for control is a toner pattern used for image density control and a toner pattern used for control for aligning a resist for writing on each of the photoconductors. 5. A color image forming apparatus according to 5. The rotating body is an intermediate transfer body,
The color image forming apparatus according to to one one any of 6 to claim 1, characterized in that the toner pattern is formed between the plurality of transfer areas to a plurality of said recording material on said rotating member. The rotating body is a recording material transport body that transports a recording material,
The color image forming apparatus according to one any of claims 1 to 6, wherein said that the toner pattern is formed between a plurality of recording material on the rotating body.

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