JP2005084131A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which improves graininess even when a dot area ratio in a toner image is high, which recognizes the image quality of a dot form in a toner image and suppresses deterioration in the graininess with time, and which can form a smooth toner image of high quality. <P>SOLUTION: The apparatus comprises: an image carrying body (1) which is rotatably held and carries a toner image; a charging means (2) which uniformly charges on the image holding body (1); a latent image forming means (6) which forms a latent image on the surface (1a) of the image carrying body (1) uniformly charged by the charging means (2), the image formed by repetition of a spacihg dot pattern (5) having a dot (3) composed of a plurality of pixels and having the same length in the longitudinal and lateral sides and having a spacing (4) corresponding to at least one pixel around the dot (3); a developing means (7) to develop the latent image formed by the latent image forming means (6) to obtain a toner image; and a transfer means (9) to transfer the toner image formed by the developing means (7) onto a transfer body (8). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus, and more particularly, to an image forming apparatus such as a copying machine, a facsimile machine, a printer, or a complex machine of these that forms a toner image by an electrophotographic method.

In a conventional image forming apparatus, an electrostatic latent image is formed with a laser beam on a photosensitive member such as an OPC serving as an image carrier, and a toner image developed with toner is directly or directly on a transfer sheet of a transfer object. Images are formed by indirect transfer.
In recent years, high image quality is also required in an electrophotographic image forming method, and attention has been focused on an item of graininess indicating the smoothness of a toner image.
However, as the number of output sheets is increased, the graininess gradually deteriorates and the quality of the formed image is lowered.

Therefore, the image forming apparatus is an image forming apparatus that forms an electrostatic latent image on a photosensitive belt and visualizes the electrostatic latent image with a latent image visualization agent such as toner, and has an output capability of the apparatus. An output capability detection unit to detect, an output capability processing unit that determines an image processing condition based on a detection result by the output capability detection unit, and a process control unit that performs image processing with the image processing condition determined by the output capability processing unit It has been proposed and known to obtain an image forming apparatus that outputs stable high image quality without deterioration of graininess under any environment or condition (see Patent Document 1).
However, the detection of the detection means of the output capability detection unit is an absolute difference between the non-image portion potential (VD) and the image portion potential (VL) on the image carrier, and image quality degradation that occurs in the development and transfer processes. Is not considered.

With the recent progress of high image quality, it is necessary to pay attention to maintaining the image quality. The image quality deteriorates as the number of output sheets increases due to the deterioration of the developer.
Here, when the change in the dot shape with time was observed, as the number of output sheets increased, the toner was scattered mainly at the transfer portion, and the individual dot shapes were also irregular. A toner image with an irregular dot shape gives a rough impression.
It is important to perform correction so that the dot shape is stabilized over time in order to maintain smooth image quality.

14 to 16, the relationship between the dot area ratio (%) and the granularity deterioration degree in the toner image formed in the conventional image forming apparatus is as follows. As shown in the graph of FIG. There is a large difference in the amount of change in the degree of deterioration of granularity between the cases up to and including the dot pattern shown in FIG.
Accordingly, when observing the shape of the dots representing the dot area ratio (%), the dots are separated and the dots are separated and the particle area is less than 41% (dot pattern shown in FIG. 15). However, it was found that when the dot area ratio is 50% (dot pattern shown in FIG. 16) or more, the dots are connected to each other and the granularity deterioration degree is large and bad.

  However, the currently used image quality maintenance method corrects the toner based on the charge amount of the toner, the adhesion amount to the photoreceptor, and the like, and image quality such as the dot shape is not taken into consideration. Therefore, it is difficult to form a smooth, high-quality toner image. In particular, when the dot area ratio is 50% or more, the granularity deterioration degree is large and worse, and it is more difficult.

Therefore, the conventional image forming apparatus prevents the deterioration of graininess and forms a high-quality toner image, so that the absolute values of the non-image portion potential (VD) and the image portion potential (VL) on the image carrier are absolute. Correction is made based on difference detection, toner charge amount and toner adhesion amount on the image carrier, etc., and image quality such as dot shape was not taken into account, so smooth high quality In particular, it is difficult to form a toner image. In particular, when the dot area ratio is 50% or more, the degree of granularity deterioration is large and bad, and there is a problem that it is more difficult.
JP 2002-268290 A

  A conventional image forming apparatus prevents a decrease in graininess and forms a high-quality toner image, so that the absolute difference between the non-image area potential (VD) and the image area potential (VL) on the image carrier is reduced. Corrections are made based on detection, toner charge amount, toner adhesion amount on the image carrier, etc., and image quality such as dot shape is not taken into account, so smooth high-quality toner It is difficult to form an image. In particular, when the dot area ratio is 50% or more, it is difficult to form a smooth high-quality toner image because the degree of granularity deterioration is large and worse. It was.

  Therefore, an object of the present invention is to solve such problems. That is, even if the dot area ratio in the toner image is high, the graininess is improved, the image quality of the dot shape in the toner image is recognized, the deterioration of the graininess over time is suppressed, and a smooth high quality toner image is obtained. An object of the present invention is to provide an image forming apparatus to be formed.

  In order to achieve the above-mentioned object, the present invention according to claim 1 is an image carrier for carrying a toner image formed to be rotatably held in an image forming apparatus for forming a toner image by an electrophotographic method. A charging means for uniformly charging the image bearing member, and a plurality of pixels on the surface of the image bearing member uniformly charged by the charging means around a dot having the same vertical and horizontal length. A latent image forming unit that forms a repeated latent image with an interval dot pattern that is arranged with an interval of at least one pixel, and a latent image formed by the latent image forming unit is developed to form a toner image storage The main feature is that the image forming apparatus includes a developing unit that transfers the toner image formed by the developing unit onto a transfer target.

  Alternatively, the present invention described in claim 2 is the image forming apparatus according to claim 1, wherein the dot area ratio of dots is 40 (%) to 80 (%) in the interval dot pattern. This is the main feature.

  Alternatively, according to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the interval dots arranged in the same shape and at the same interval on the surface of the image carrier or the toner image on the transfer medium. The image forming apparatus mainly comprises an image pickup unit that picks up a pattern and a dot shape recognition unit that recognizes the image quality of the dot shape in the predetermined mesh area in the interval dot pattern picked up by the image pickup unit. Features.

  Alternatively, the present invention described in claim 4 is characterized in that, in the image forming apparatus described in claim 3, the transfer target is an image forming apparatus which is a transfer sheet.

  Alternatively, the present invention described in claim 5 is characterized in that, in the image forming apparatus described in claim 3, the transfer target is an image forming apparatus that is an intermediate transfer belt.

  Alternatively, the present invention described in claim 6 is characterized in that, in the image forming apparatus described in claim 3, 4 or 5, the imaging means is an image forming apparatus comprising a charge transfer element.

  Alternatively, according to the seventh aspect of the present invention, in the image forming apparatus according to the third, fourth, fifth, or sixth aspect, the imaging unit is a toner having a color different from that on the surface of the image carrier or the transfer target. Is an image forming apparatus that selects an output of one of the three primary colors of light with high sensitivity based on a difference in color density.

  Alternatively, according to an eighth aspect of the present invention, in the image forming apparatus according to the third, fourth, fifth, sixth, or seventh aspect, the imaging unit includes a developing unit disposed to face the surface of the image carrier. The main feature of the present invention is that the image forming apparatus picks up the same dot shape of the toner image formed on the surface of the image carrier at the position between the transfer unit and the interval dot pattern arranged at the same interval.

  Alternatively, according to a ninth aspect of the present invention, in the image forming apparatus according to the third, fourth, fifth, sixth, seventh, or eighth aspect, the imaging unit is a transfer unit disposed opposite to the transfer target. The main feature is that the image forming apparatus captures the same shape and interval dot patterns arranged at the same intervals of the toner image transferred and formed on the transfer target immediately after the downstream side.

  Alternatively, according to a tenth aspect of the present invention, in the image forming apparatus according to the ninth aspect, the transfer target is an image forming apparatus that is a transfer sheet onto which the toner image on the intermediate transfer belt is transferred. Main features.

  Alternatively, the present invention described in claim 11 is the image forming apparatus according to claim 9, wherein the transfer target includes a yellow image forming unit, a cyan image forming unit, a magenta image forming unit, and a black image forming unit in tandem. The main feature is that the image forming apparatus is an intermediate transfer belt in which the colors of the respective colors formed by these are arranged.

  Alternatively, according to a twelfth aspect of the present invention, in the image forming apparatus according to the eleventh aspect, the imaging unit includes a most downstream yellow image forming unit, cyan image forming unit, magenta image forming unit, or tandem arrangement, or An image that captures a dot pattern of the same shape and the same interval of the toner image formed by transferring onto the intermediate transfer belt of the transfer body at a position immediately downstream of the transfer unit of the black image forming unit. The main feature is the forming device.

  Alternatively, according to a thirteenth aspect of the present invention, in the image forming apparatus according to any one of the third to twelfth aspects, the dots in the predetermined mesh in the interval dot pattern imaged by the imaging unit or the interval The main feature is that the shape of the image forming apparatus is variable by the latent image forming means.

  Alternatively, the present invention described in claim 14 is characterized in that, in the image forming apparatus according to claim 13, the latent image forming means is an image forming apparatus in which the exposure amount or the exposure time is variable. Features.

  Alternatively, according to a fifteenth aspect of the present invention, in the image forming apparatus according to any one of the third to fourteenth aspects, the dot shape recognizing unit is a predetermined one in the interval dot pattern imaged by the imaging unit. The main feature is that the image forming apparatus recognizes the image quality of the shape of the vertical diameter or horizontal diameter of the dots in the mesh.

  Alternatively, according to a sixteenth aspect of the present invention, in the image forming apparatus according to any one of the third to fourteenth aspects, the dot recognizing unit has a predetermined dot pattern in the interval dot pattern captured by the imaging unit. The main feature is that the image forming apparatus recognizes the image quality of the irregular shape of the edge portion of the dot in the mesh.

  Alternatively, according to the seventeenth aspect of the present invention, in the image forming apparatus according to the sixteenth aspect, the disturbance of the edge of the dot is the disturbance of the edge of the dot = the length of the periphery of the dot / the periphery of the unevenness of the dot. The main feature of the image forming apparatus is that the length of the image forming apparatus.

  Alternatively, in the image forming apparatus according to any one of claims 3 to 14, the dot recognizing unit includes a predetermined dot in the interval dot pattern captured by the image capturing unit. The main feature is that the image forming apparatus recognizes the image quality of the shape of the area of the white areas of the dots in the mesh.

  Alternatively, according to a nineteenth aspect of the present invention, in the image forming apparatus according to any one of the third to eighteenth aspects, the dot recognizing unit has a predetermined dot pattern in the interval dot pattern captured by the imaging unit. The charging potential of the image carrier by the charging means is corrected by recognizing the image quality of the vertical or horizontal diameter of the dots in the mesh, the disturbance of the edge of the dot, or the shape of the area of the white portion of the dot. The main feature is that it is an image forming apparatus.

  Alternatively, according to a twentieth aspect of the present invention, in the image forming apparatus according to any one of the third to eighteenth aspects, the dot recognizing unit has a predetermined dot pattern in the interval dot pattern captured by the imaging unit. An image forming apparatus that corrects the developing bias of the developing unit by recognizing the image quality of the vertical or horizontal diameter of the dots in the mesh, the disturbance of the edge portion of the dot, or the shape of the area of the white portion of the dot. It is a major feature.

  Alternatively, according to a twenty-first aspect of the present invention, in the image forming apparatus according to any one of the third to eighteenth aspects, the dot recognizing unit has a predetermined dot pattern in the interval dot pattern captured by the imaging unit. An image forming apparatus that corrects the transfer current of the transfer unit by recognizing the image quality of the vertical or horizontal diameter of the dots in the mesh, the disturbance of the edge of the dot, or the shape of the area of the white portion of the dot. It is a major feature.

  Since the present invention is configured as described below, according to the first aspect of the present invention, even if the dot area ratio in the toner image is high, the graininess is improved and a smooth high-quality toner image is formed. An image forming apparatus can be provided.

  According to the second aspect of the present invention, there is provided an image forming apparatus capable of forming a smooth, high quality toner image with improved graininess even when the dot area ratio in the toner image is as high as 40 (%) to 80 (%). I can do it now.

  According to the invention of claim 3, even if the dot area ratio in the toner image is high, the graininess is improved, and the image quality of the dot shape in the toner image on the surface of the image carrier or the transfer object is recognized. Thus, it has become possible to provide an image forming apparatus that forms a smooth, high-quality toner image while suppressing deterioration of graininess over time.

  According to the invention of claim 4, the graininess is improved even if the dot area ratio in the toner image is high, and the image quality of the shape of the dots in the toner image on the surface of the image carrier or on the transfer sheet of the transfer medium. Thus, it is possible to provide an image forming apparatus that forms a smooth, high-quality toner image while suppressing deterioration of graininess over time.

  According to the invention of claim 5, even if the dot area ratio in the toner image is high, the graininess is improved, and the image of the dot shape in the toner image on the surface of the image carrier or on the intermediate transfer belt of the transfer object. It has become possible to provide an image forming apparatus that recognizes quality, suppresses deterioration of graininess over time, and forms a smooth, high-quality toner image.

  According to the invention of claim 6, even when the dot area ratio in the toner image is high, the graininess is improved, and the image quality of the dot shape in the toner image on the surface of the image carrier or on the transfer object is reduced. It has become possible to provide an image forming apparatus that can be easily recognized by the apparatus, suppresses deterioration of graininess over time, and forms a smooth, high-quality toner image.

  According to the invention of claim 7, even when the dot area ratio in the toner image is high, the graininess is improved, and the image quality of the dot shape in the toner image on the surface of the image carrier or the toner image on the transfer body is highly sensitive. Thus, it is possible to provide an image forming apparatus that forms a smooth, high-quality toner image while suppressing deterioration of graininess over time.

  According to the invention of claim 8, even when the dot area ratio in the toner image is high, the graininess is improved, and the image is located at a position between the developing means and the transfer means arranged facing the surface of the image carrier. To provide an image forming apparatus for recognizing the image quality of the shape of dots in a toner image formed on the surface of a carrier, and suppressing the deterioration of graininess over time to form a smooth high quality toner image. Can be done.

  According to the ninth aspect of the present invention, the graininess is improved even if the dot area ratio in the toner image is high, and the toner image is placed on the transfer target at a position immediately downstream of the transfer means disposed opposite the transfer target. It is possible to provide an image forming apparatus that recognizes the image quality of dot shapes in a toner image formed by transfer, suppresses deterioration of graininess over time, and forms a smooth high-quality toner image. Became.

  According to the invention of claim 10, even when the dot area ratio in the toner image is high, the graininess is improved, and the downstream side of the transfer means disposed opposite to the transfer paper on which the toner image on the intermediate transfer belt is transferred. Recognize the image quality of the dot shape in the toner image formed by transferring onto the transfer paper on which the toner image on the intermediate transfer belt is transferred at the position immediately after it, and suppress deterioration in graininess over time Thus, it is possible to provide an image forming apparatus that forms a smooth, high-quality toner image.

  According to the invention of claim 11, the graininess is improved even if the dot area ratio in the toner image is high, and the yellow image forming portion, cyan image forming portion, magenta image forming portion, and black image forming portion are arranged in tandem. An image in the form of a dot in a toner image formed by transferring onto the intermediate transfer belt at a position immediately after the downstream of the transfer means arranged opposite to the intermediate transfer belt where color superposition of each color formed is performed. It has become possible to provide an image forming apparatus that recognizes quality, suppresses deterioration of graininess over time, and forms a smooth, high-quality toner image.

  According to the invention of claim 12, the graininess is improved even if the dot area ratio in the toner image is high, and the yellow image forming unit, the cyan image forming unit, the magenta image forming unit, and the black image forming unit are arranged in tandem. An image in the form of a dot in a toner image formed by transferring onto the intermediate transfer belt at a position immediately after the downstream of the transfer means arranged opposite to the intermediate transfer belt where color superposition of each color formed is performed. It has become possible to provide an image forming apparatus that recognizes quality at a low cost device, suppresses deterioration of graininess over time, and forms a smooth, high-quality toner image.

  According to the invention of claim 13, even when the dot area ratio in the toner image is high, the graininess is improved, and the image quality of the dot shape in the toner image on the surface of the image carrier or on the transfer object is recognized. Thus, it has become possible to provide an image forming apparatus that forms a smooth, high-quality toner image by suppressing deterioration of graininess over time by the latent image forming means.

  According to the invention of claim 14, even when the dot area ratio in the toner image is high, the graininess is improved, and the image quality of the dot shape in the toner image on the surface of the image carrier or on the transfer object is recognized. Thus, it is possible to provide an image forming apparatus that forms a smooth, high-quality toner image by suppressing deterioration of graininess over time by changing the exposure amount or exposure time of the latent image forming means. .

  According to the invention of claim 15, even when the dot area ratio in the toner image is high, the graininess is improved, and the vertical diameter or horizontal diameter of the dot in the surface of the image carrier or in the toner image on the transferred body. It is now possible to provide an image forming apparatus that recognizes the image quality of the shape and suppresses the deterioration of graininess over time and forms a smooth high-quality toner image.

  According to the invention of claim 16, even when the dot area ratio in the toner image is high, the graininess is improved, and the surface of the image carrier or the irregular shape of the edge portion of the dot in the toner image on the transferred body is obtained. It has become possible to provide an image forming apparatus that recognizes image quality, suppresses deterioration of graininess over time, and forms a smooth high-quality toner image.

  According to the invention of claim 17, even when the dot area ratio in the toner image is high, the graininess is improved, and the degree of disturbance of the edge portion of the dot in the surface of the image bearing member or in the toner image on the transferred body is reduced. Image formation that recognizes the image quality of the shape obtained by dividing the perimeter of the dot by the perimeter of the unevenness of the dot, and forms a smooth, high-quality toner image while suppressing deterioration of graininess over time The device can be provided.

  According to the invention of claim 18, even when the dot area ratio in the toner image is high, the graininess is improved, and the shape of the area of the white area of the dot in the surface of the image carrier or the toner image on the transfer object. It is now possible to provide an image forming apparatus that recognizes the image quality and suppresses the deterioration of the graininess over time and forms a smooth high-quality toner image.

  According to the invention of claim 19, even when the dot area ratio in the toner image is high, the graininess is improved, and the image quality of the dot shape in the toner image on the surface of the image carrier or on the transfer object is recognized. Thus, it has become possible to provide an image forming apparatus that forms a smooth, high-quality toner image by correcting deterioration of the graininess over time by correcting the charging potential of the image carrier by the charging means.

  According to the invention of claim 20, even when the dot area ratio in the toner image is high, the graininess is improved, and the image quality of the dot shape in the toner image on the surface of the image carrier or on the transfer object is recognized. Thus, it has become possible to provide an image forming apparatus that forms a smooth high-quality toner image by correcting the development bias of the developing means by suppressing the deterioration of graininess over time.

  According to the invention of claim 21, even when the dot area ratio in the toner image is high, the graininess is improved, and the image quality of the dot shape in the toner image on the surface of the image carrier or on the transfer object is recognized. Thus, it has become possible to provide an image forming apparatus that forms a smooth, high-quality toner image by correcting deterioration of the graininess over time by correcting the transfer current of the transfer means.

Next, embodiments of the present invention will be described in detail with reference to the drawings.
1 to 3, an image forming apparatus 0 that forms a toner image by an electrophotographic method includes a drum-shaped photosensitive drum of an image carrier 1 that carries a toner image that is rotatably held, and A charging unit 2 that uniformly charges the drum-shaped photosensitive drum of the image carrier 1 and a plurality of drums on the surface 1a of the drum-shaped photosensitive drum of the image carrier 1 that are uniformly charged by the charging unit 2. The dots 3 have a dot area ratio of 40 (%) to 80 (%) arranged with a gap 4 of at least one pixel around the dots 3 having the same vertical and horizontal lengths. The latent image forming means 6 for forming a latent image repeated with the interval dot pattern 5, the developing means 7 for developing the latent image formed by the latent image forming means 6 to form a toner image, and the developing means 7 The toner image formed is transferred A transfer means 9 for transferring the toner image onto the transfer paper 8a, and the surface 1a of the drum-shaped photosensitive drum of the image carrier 1, or the same shape of the toner image on the transfer paper 8a of the transfer body 8; A charge transfer element (CCD) 10a of the image pickup means 10 for picking up the interval dot patterns 5 arranged at the same interval, and a predetermined dot in the interval dot pattern 5 picked up by the charge transfer element (CCD) 10a of the image pickup means 10 It comprises dot shape recognition means 11 for recognizing the image quality of the shape of the dot 3 in the mesh region, and the graininess is improved even when the dot area ratio in the toner image is high, and the image quality of the shape of the dot 3 in the toner image. Is recognized, and deterioration of graininess over time is suppressed, and a smooth high-quality toner image is formed.

In the copying machine for forming a toner image by the electrophotographic method of the image forming apparatus 0, a document image reading device 12 for reading an image of the document (O) is disposed at the top.
On the other hand, a paper feeding device 14 for placing the image forming means 13 and supplying the transfer paper 8a of the transfer target 8 is disposed in the lower part.

The charging unit 2 emits light by causing the laser diode of the latent image forming unit 6 to emit light by an electrophotographic method in which the original image reading device 12 forms a toner image with image data of the original image of the original (0) to be read. A latent image is formed on the surface 1a of the drum-shaped photosensitive drum of the image carrier 1 that is uniformly charged.
The electrostatic latent image formed by causing the laser diode of the latent image forming means 6 to emit light is visualized by the developing means 7 to form a toner image.

The toner image visualized by the developing means 7 is transferred by the transfer means 9 to the transfer paper 8 a of the transfer body 8 conveyed from the paper feeding device 14.
The toner image transferred to the transfer sheet 8 a of the transfer body 8 by the transfer unit 9 is heated and pressed by the fixing unit 15, and then the transfer sheet 8 a of the transfer body 8 is discharged by a paper discharge roller 16. The paper is discharged onto the paper discharge tray 17 and stored.

  On the other hand, the surface 1a of the drum-shaped photosensitive drum of the image carrier 1 transfers the toner image onto the transfer paper 8a of the transfer body 8, and then the drum-shaped photosensitive drum of the image carrier 1. The residual toner adhering to the surface 1a is scraped off and cleaned by the cleaning means 18 to prepare for image formation in the next process.

  The charge transfer element (CCD) 10a of the imaging means 10 can easily select any one of the three primary colors (RBG) of light with a small device, and the drum-shaped photoconductor of the image carrier 1 The toner image formed on the surface 1a of the drum-shaped photosensitive drum of the image carrier 1 at a position between the developing unit 7 and the transfer unit 9 disposed to face the surface 1a of the drum. The interval dot pattern 5 arranged in the same shape and at the same interval, or the position immediately after the transfer means 9 arranged on the transfer body 8 facing the transfer sheet 8a of the transfer object 8 The interval dot pattern 5 arranged in the same shape and interval of the toner image transferred and formed on the transfer sheet 8a is imaged with high sensitivity.

  The dot recognition means 11 is a vertical diameter (A) described with reference to FIG. 7 of the dots 3 in a predetermined mesh area in the interval dot pattern 5 imaged by the charge transfer element (CCD) 10a of the imaging means 10. Or image quality of the shape of the horizontal diameter (B), the disturbance of the edge portion of the dot 3 described in FIG. 9 (C), or the area (F) of the white portion of the dot 3 described in FIG. As a result, the charging means 2 corrects the charging potential of the image carrier 1, the developing bias of the developing means 7, or the transfer current of the transferring means 9 to correct the graininess over time. Deterioration is suppressed.

The interval dot pattern 5 shown in FIG. 2 in the image forming apparatus 0 has a dot area ratio of 50% (see the dot pattern shown in FIG. 16) in the conventional image forming apparatus, and 2 around the dots 3. By providing the interval 4 for the number of pixels 3a to reduce the amount of scattering, a shape having an equivalent dot area ratio of 51% was used.
The shape of the dots 3 in the predetermined mesh in the interval dot pattern 5 captured by the charge transfer element (CCD) 10 a of the imaging unit 10 or the interval 4 is the exposure of the latent image forming unit 6. The amount or the exposure time can be varied.
The charge transfer element (CCD) 10a of the image pickup means 10 includes the surface 1a of the drum-shaped photosensitive drum of the image carrier 1, the transfer sheet 8a of the transfer body 8, or an intermediate (not shown). Using the toner (T) of a different color from that on the transfer belt 8b, the output of one of the three primary colors of light with high sensitivity is selected according to the difference in color density.
Here, as shown in the graph of FIG. 3, when the change in graininess with respect to the number of output sheets is seen, the graininess of the image forming apparatus 0 of the present invention is improved as compared with the conventional image forming apparatus. .
Note that the graininess of the image forming apparatus 0 of the present invention is improved even for image brightness of 40 to 80, which is visually sensitive to the change in graininess.

  Therefore, even if the dot area ratio of the dots 3 in the toner image is high, the graininess is improved, and the surface 1a of the drum-shaped photosensitive drum of the image carrier 1 or the transfer sheet of the transfer target 8 is used. To provide the image forming apparatus 0 for recognizing the image quality of the shape of the dot 3 in the toner image formed on 8a and suppressing the deterioration of the graininess over time and forming a smooth high quality toner image. Can be done.

  In FIG. 4, the color printer of the color image forming apparatus 00 that forms a toner image by the electrophotographic method of the image forming apparatus 0 has a drum-shaped photosensitive drum of the image carrier 1 having a photoconductive layer in a tandem manner. Four drum-shaped photosensitive drums of the image carrier 1 are arranged in the yellow (Y) of the yellow image forming unit 00a, the cyan image forming unit 00b, the magenta image forming unit 00c, and the black image forming unit 00d. ), Cyan (C), magenta (M), and black (Bk) are assigned to four color image formations, and a color toner image is formed by superimposing these colors.

The yellow image forming unit 00a, the cyan image forming unit 00b, and the magenta image forming arranged in tandem in the color printer of the color image forming device 00 that forms a toner image by the electrophotographic method of the image forming device 0 The portion 00c and the black image forming portion 00d use a small-diameter drum having a diameter of 40 mm, which is a drum-shaped photosensitive member having the photoconductive layer of the image carrier 1.
A drum-shaped photosensitive member having a photoconductive layer of the image carrier 1 of each of the yellow image forming unit 00a, the cyan image forming unit 00b, the magenta image forming unit 00c, and the black image forming unit 00d arranged in tandem. Around the body drum, the charging unit 2, the latent image forming unit 6, the developing unit 7, the image carrier cleaning unit 18a of the cleaning unit 18, and the like are arranged.
The drum-shaped photosensitive drum having the photoconductive layer of the image carrier 1 is provided between the developing means 7 and the image carrier cleaning means 18 a of the cleaning means 18, and the intermediate transfer belt 8 b of the transfer object 8. Abut.

  When forming a color toner image in the color printer of the color image forming apparatus 00 that forms a toner image by the electrophotographic method of the image forming apparatus 0, first, the yellow image forming section 00a is rotatably held and rotated. The surface 1a of the drum-shaped photosensitive drum having the photoconductive layer of the image carrier 1 is uniformly charged by the charging roller of the charging means 2 and is uniformly charged to about -450V.

Thereafter, image exposure is performed by a laser optical system which is an exposure device of the latent image forming means 6, and a static image is formed on the photoconductive layer on the surface 1 a of the drum-shaped photosensitive drum having the photoconductive layer of the image carrier 1. An electrostatic latent image is formed.
Then, an electrostatic latent image on the photoconductive layer on the surface 1a of the drum-shaped photosensitive drum having the photoconductive layer of the image carrier 1 is transferred from the developing sleeve 7a provided in the developing means 7 to yellow ( Y) Development is performed using toner (T) as a developer, and the latent image is visualized as a yellow (Y) toner image.

The developing means 7 includes a developing container 7b containing a two-component developer and a developing sleeve 7a, a stirring screw 7c, and a doctor blade 7d that forms a toner thin layer on the surface of the developing sleeve 7a. Has been.
The developing sleeve 7a is disposed close to the surface 1a of the drum-shaped photosensitive drum having the photoconductive layer of the image carrier 1 at least during development, and a developer is disposed on the image carrier 1. It is set so that development can be performed in contact with the surface 1a of the drum-shaped photosensitive drum having the photoconductive layer.

The two-component developer used in the color printer of the color image forming apparatus 00 for forming a toner image by the electrophotographic method of the image forming apparatus 0 is a negatively charged toner (T) having an average particle diameter of 5 to 6 μm manufactured by a polymerization method. ) And a magnetic carrier having an average particle diameter of 35 μm.
The mixing ratio of the toner and the carrier is set by toner density control as a weight ratio of 8:92.
Further, at the time of development, -300 V is applied as a developing bias to the developing sleeve 7a and development is performed.

The toner image visualized on the surface 1 a of the drum-shaped photosensitive drum having the photoconductive layer of the image carrier 1 is transferred to the primary transfer unit 9 a of the transfer unit 9 and the toner image of the transfer target 8. It is transferred to the intermediate transfer belt 8b.
Thereafter, the cyan image forming unit 00b, the magenta image forming unit 00c, and the black image forming unit 00d in this order on the surface 1a of the drum-shaped photosensitive drum having the photoconductive layer of the image carrier 1 respectively. The toner image is transferred to the intermediate transfer belt 8b of the transfer body 8, and a color toner image is formed by superimposing colors on the intermediate transfer belt 8b of the transfer body 8.

  The toner image formed by superimposing colors on the intermediate transfer belt 8 b of the transfer body 8 is transferred to the transfer paper 8 a of the transfer body 8 by the secondary transfer device 9 b of the transfer means 9. Thereafter, the color toner image is thermally fixed on the transfer sheet 8 a of the transfer target 8 by the fixing unit 15, and is discharged and stored on the discharge tray 17 by the discharge roller 16.

  The toner image formed by superimposing colors is transferred to the transfer paper 8a of the transfer body 8, and the residual toner remaining on the transfer belt 8b of the transfer body 8 remains on the intermediate transfer belt. It is cleaned by the cleaning means 18b to prepare for the formation of a color toner image in the next process.

  The charge transfer element (CCD) 10a of the image pickup means 10 includes a yellow image forming unit 00a, a cyan image forming unit 00b, a magenta image forming unit 00c, and a black image forming unit 00d arranged in tandem. The image carrier 1 is positioned at a position between the developing means 7 and the primary transfer device 9a of the transfer means 9 which are arranged to face the surface 1a of the drum-shaped photosensitive drum of the image carrier 1. The color toner image formed on the surface 1a of the drum-shaped photosensitive drum has the same shape, the interval dot pattern 5 arranged at the same interval, or the intermediate transfer belt 8b of the transfer body 8 facing the intermediate transfer belt 8b. The most downstream yellow image forming unit 00a, cyan image forming unit 00b, magenta image forming unit 00c, or black image arranged in tandem. The same shape and shape of the color toner image formed by primary transfer on the intermediate transfer belt 8b of the transfer target 8 at a position immediately downstream of the primary transfer unit 9a of the transfer means 9 of the forming unit 00d. On the transfer sheet 8a of the transfer object 8 at a position immediately downstream of the secondary transfer unit 9b of the transfer means 9 at one location of the interval dot pattern 5 which is an inexpensive device arranged at intervals. The interval dot pattern 5 arranged in the same shape and at the same interval of the color toner image formed by the next transfer is picked up.

  The dot recognition means 11 is a vertical diameter (A) described with reference to FIG. 7 of the dots 3 in a predetermined mesh area in the interval dot pattern 5 imaged by the charge transfer element (CCD) 10a of the imaging means 10. Or image quality of the shape of the horizontal diameter (B), the disturbance of the edge portion of the dot 3 described in FIG. 9 (C), or the area (F) of the white portion of the dot 3 described in FIG. The image carrier 1 is charged by the charging means 2 of the yellow image forming section 00a, cyan image forming section 00b, magenta image forming section 00c, and black image forming section 00d arranged in tandem. Correction of the developing bias of the developing unit 7, or correction of the transfer current of the primary transfer unit 9a and the secondary transfer unit 9b of the transfer unit 9 to reduce the graininess over time. It is adapted to suppress.

  Therefore, even if the dot area ratio of the dots 3 in the color toner image is high, the graininess is improved, and the yellow image forming unit 00a, the cyan image forming unit 00b, the magenta image forming unit 00c, arranged in tandem, A color toner image formed on the surface 1a of the drum-shaped photosensitive drum of the image carrier 1 of the black image forming unit 00d, or on the intermediate transfer belt 8b or the transfer paper 8a of the transfer body 8. The toner image is formed by the electrophotographic method of the image forming apparatus 0 that recognizes the image quality of the shape of the dot 3 in the image, suppresses the deterioration of the graininess with time, and forms a smooth, high-quality color toner image. Thus, an inexpensive color printer for the color image forming apparatus 00 can be provided.

  5 to 8, the image forming apparatus 0 for forming a toner image by an electrophotographic method or the color image forming apparatus 00 for forming a toner image by an electrophotographic method is an aggregate of the pixels 3a having the same shape. When the dot 3 (see FIGS. 5 and 6) is formed with the interval dot pattern 5 aligned at the same interval in the horizontal and vertical directions, the drum-shaped photosensitive member of the image carrier 1 is formed. When the toner image is developed or transferred by the developing means 7 or the transfer means 9 on the surface 1a of the drum, the transfer paper 8a of the transfer body 8 or the intermediate transfer belt 8b. The irregularity of the image quality of the dot 3 is measured, and the irregularity of the image quality of the dot 3 is corrected.

First, extraction of the shape of each dot 3 will be described (see FIG. 7). The distance formed by the distance 3 and the distance 3 on the surface 1a of the drum-shaped photosensitive drum of the image carrier 1, the transfer sheet 8a of the transfer target 8, or the intermediate transfer belt 8b. The dot pattern 5 is imaged by the charge transfer element (CCD) 10a of the imaging means 10 to obtain a toner image in which the dots 3 having the same shape are arranged at the same interval, and then the presence portion of the toner (T) is specified. Further, due to the difference in density between the surface 1a of the drum-shaped photosensitive drum of the image carrier 1 or the transfer paper 8a of the transfer target 8 or the intermediate transfer belt 8b and the toner (T). Then, binarization is performed using a central value between the maximum density value and the minimum density value as a threshold value.
In order to divide the individual dots 3, a mesh region that is parallel to the arrangement of the dots 5 a of the input image and is formed by a straight line passing through the center between the dots 3 is created, and the dots 3 existing in the individual meshes are created. The shape of a square or a rhombus is extracted as shown in FIG. 5 (see FIGS. 5, 6, and 7).

Next, the vertical diameter (A) or the horizontal diameter (B) of the dots 3 in a predetermined mesh in the interval dot pattern 5 imaged by the charge transfer element (CCD) 10a of the imaging means 10 is disturbed. Will be described.
The dot shape recognition means 11 measures the diameter of each dot 3 obtained by binarization and recognizes the image quality of the shape of the dot 3. The diameter includes a vertical diameter (A) and a horizontal diameter (B).
That is, when there are the dots 3 as shown in FIG. 7, the diameters of the dots 3 are projected onto the X axis and the Y axis.

By measuring the diameter of the dot 3 existing in each mesh, the degree of disorder of the shape of the dot 3 can be known.
Therefore, if this value is equal for each dot 3 (see FIG. 7a), the uniformity of the shape is maintained for each dot 3.

  If the vertical diameter (A) or the horizontal diameter (B) of each diameter is uniform, a high-quality toner image with good graininess can be obtained. Therefore, the dots 5a (FIG. Reference) and the dot 3 of the deteriorated dot (see FIG. 7b) are changed, the charging means 2 corrects the charging potential of the image carrier 1 and the developing bias of the developing means 7 changes. Or the transfer current of the primary transfer device 9a and the secondary transfer device 9b of the transfer means 9 is suppressed to suppress deterioration of graininess over time (FIGS. 1 and 4). See).

  Here, as shown in the graph of FIG. 8, when the change in graininess with respect to the number of output sheets is observed, the charging means is detected when the image forming apparatus 0 of the present invention detects the irregular shape of the dots 3. 2 for correcting the charging potential of the image carrier 1 by the image carrier 1, correcting the developing bias of the developing means 7, or transferring the primary transfer device 9 a and the secondary transfer device 9 b of the transfer means 9. By correcting the current, it was confirmed that the shape of the dot 3 was made uniform and the graininess was maintained.

  Therefore, even if the dot area ratio in the toner image is high, the graininess is improved, and the image quality of the shape of the vertical diameter (A) or horizontal diameter (B) of the dot 3 in the toner image is recognized, It has become possible to provide an upper image forming apparatus 0 that forms a smooth, high-quality toner image while suppressing deterioration in graininess.

  9 and 10, the image forming apparatus 0 for forming a toner image by an electrophotographic method or the color image forming apparatus 00 for forming a toner image by an electrophotographic method has the same shape of the dots 3 respectively. When the interval dot pattern 5 arranged at the same interval in the horizontal and vertical directions is formed, the surface 1a of the drum-shaped photosensitive drum of the image carrier 1 or the transfer of the transfer target 8 is transferred. Disturbance (C) of the edge portion of the dot 3 when the toner image is developed or transferred by the developing means 7 or the transfer means 9 on the paper 8a or the intermediate transfer belt 8b is measured. The shape irregularity of the image quality of the shape of the disturbance (C) of the edge portion of the dot 3 is corrected.

First, extraction of the shape of each individual dot 3 will be described (see FIG. 9). The distance formed by the distance 3 and the distance 3 on the surface 1a of the drum-shaped photosensitive drum of the image carrier 1, the transfer sheet 8a of the transfer target 8, or the intermediate transfer belt 8b. The dot pattern 5 is imaged by the charge transfer element (CCD) 10a of the imaging means 10 to obtain a toner image in which the dots 3 having the same shape are arranged at the same interval, and then the presence portion of the toner (T) is specified. Further, due to the difference in density between the surface 1a of the drum-shaped photosensitive drum of the image carrier 1 or the transfer paper 8a of the transfer target 8 or the intermediate transfer belt 8b and the toner (T). Then, binarization is performed using a central value between the maximum density value and the minimum density value as a threshold value.
In order to divide the individual dots 3, a mesh region that is parallel to the arrangement of the dots 5 a of the input image and is formed by a straight line passing through the center between the dots 3 is created, and the dots existing in the individual meshes The shape of 3 is extracted.

Next, the disturbance (C) of the edge portion of the dot 3 in a predetermined mesh in the interval dot pattern 5 imaged by the charge transfer element (CCD) 10a of the imaging means 10 will be described.
The dot shape recognition means 11 measures the disturbance (C) of the edge portion of the dot 3 in each dot 3 obtained by binarization, and recognizes the image quality of the shape of the dot 3.
The disturbance (C) of the edge part of the dot 3 is the disturbance (C) of the edge part of the dot 3 = the peripheral length (D) of the dot (3) / the length of the outer contour line of the dot 3 It is the length (E) around the unevenness of a certain dot (3).

By measuring the disturbance (C) of the edge portion of the dot 3 existing in each mesh, the degree of the disturbance (C) of the shape of the dot 3 can be known.
Therefore, if this value is equal for each dot 3 (see FIG. 9a), the uniformity of the shape is maintained for each dot 3.

  If the irregularity (C) of the edge portion of each dot 3 is uniform, a high-quality toner image with good graininess can be obtained. Therefore, the dot 5a (see FIG. 9a) of the input image having a normal shape is deteriorated. Correction of the charging potential of the image carrier 1 by the charging means 2 when the value of the disturbance (C) of the edge portions of the two dots 3 of the dots 3 (see FIG. 9b) of the dots changes, Correction of the developing bias of the developing unit 7 or correction of the transfer current of the primary transfer unit 9a and the secondary transfer unit 9b of the transfer unit 9 is performed to suppress deterioration of graininess over time. (See FIGS. 1 and 4).

  Here, as shown in the graph of FIG. 10, when the change in the graininess with respect to the number of output sheets is seen, when the disturbance (C) of the edge portion of the dot 3 is detected by the image forming apparatus 0 of the present invention. Correction of the charging potential of the image carrier 1 by the image carrier 1 by the charging means 2, correction of the developing bias of the developing means 7, or the primary transfer device 9 a and the secondary transfer of the transfer means 9. By correcting the transfer current of the container 9b, it was confirmed that the shape of the dot 3 was made uniform and the graininess was maintained.

  Therefore, even if the dot area ratio in the toner image is high, the graininess is improved, and the image quality of the shape (C) of the edge 3 of the dot 3 in the toner image is recognized to suppress the deterioration of the graininess over time. Thus, it is possible to provide the upper image forming apparatus 0 that forms a smooth high-quality toner image.

  11 to 13, in the image forming apparatus 0 for forming a toner image by an electrophotographic method or the color image forming apparatus 00 for forming a toner image by an electrophotographic method, the dots 3 having the same shape are respectively provided. When the interval dot pattern 5 arranged at the same interval in the horizontal and vertical directions is formed, the surface 1a of the drum-shaped photosensitive drum of the image carrier 1 or the transfer of the transfer target 8 is transferred. The area (F) of the void portion of the dot 3 when the toner image is developed or transferred by the developing means 7 or the transfer means 9 on the paper 8a or the intermediate transfer belt 8b is measured. Thus, the disturbance of the shape of the image quality of the shape of the area (F) of the white portion of the dot 3 is corrected.

First, extraction of the shape of each individual dot 3 will be described (see FIG. 11). The distance formed by the distance 3 and the distance 3 on the surface 1a of the drum-shaped photosensitive drum of the image carrier 1, the transfer sheet 8a of the transfer target 8, or the intermediate transfer belt 8b. The dot pattern 5 is imaged by the charge transfer element (CCD) 10a of the imaging means 10 to obtain a toner image in which the dots 3 having the same shape are arranged at the same interval, and then the presence portion of the toner (T) is specified. Further, due to the difference in density between the surface 1a of the drum-shaped photosensitive drum of the image carrier 1 or the transfer paper 8a of the transfer target 8 or the intermediate transfer belt 8b and the toner (T). Then, binarization is performed using a central value between the maximum density value and the minimum density value as a threshold value.
In order to divide the individual dots 3, a mesh region that is parallel to the arrangement of the dots 5 a of the input image and is formed by a straight line passing through the center between the dots 3 is created, and the dots existing in the individual meshes The shape of 3 is extracted.

Next, the area (F) of the white portion of the dot 3 in the predetermined mesh in the interval dot pattern 5 imaged by the charge transfer element (CCD) 10a of the imaging means 10 will be described.
The dot shape recognizing means 11 measures the area (F) of the white portion of the dot 3 in each dot 3 obtained by binarization, and recognizes the image quality of the shape of the dot 3.

  As shown in the graph of FIG. 12, the relationship between the area (F) of the white portion of the white area of the dot 3 and the toner adhesion amount, the area (F) of the white area of the dot 3 when the toner adhesion amount is small. ) And the area (F) of the white portion of the dot 3 is increased due to a further decrease in the toner adhesion amount.

By measuring the area (F) of the white portion of the dot 3 existing in each mesh, the extent of the area (F) of the white portion of the dot 3 can be known.
Therefore, if this value is equal for each dot 3 (see FIG. 11a), the uniformity of the shape is maintained for each dot 3.

  If the area (F) of the white portion of each dot 3 is uniform, a high-quality toner image with good graininess can be obtained. Therefore, the dot 5a (see FIG. 11a) of the input image having a normal shape can be obtained. Correction of the charging potential of the image carrier 1 by the charging means 2 when the value of the area (F) of the white portion of the two dots 3 of the dots 3 (see FIG. 11b) of the deteriorated dots changes. The development bias of the developing unit 7 or the transfer current of the primary transfer unit 9a and the secondary transfer unit 9b of the transfer unit 9 is corrected to suppress deterioration of graininess over time. (See FIGS. 1 and 4).

  Here, as shown in the graph of FIG. 13, when the change in graininess with respect to the number of output sheets is seen, when the area (F) of the white portion of the dot 3 is detected by the image forming apparatus 0 of the present invention. Further, the charging means 2 corrects the charging potential of the image carrier 1 by the image carrier 1, corrects the developing bias of the developing means 7, or the primary transfer device 9 a and the secondary of the transfer means 9. It was confirmed that by correcting the transfer current of the transfer unit 9b, the shape of the dots 3 was made uniform and the graininess was maintained.

  Accordingly, even if the dot area ratio in the toner image is high, the graininess is improved, and the image quality of the shape of the area (F) of the white portion of the dot 3 in the toner image is recognized, and the graininess over time is reduced. It is possible to provide the image forming apparatus 0 that forms a smooth, high-quality toner image.

1 is an explanatory diagram illustrating an image forming apparatus according to an exemplary embodiment of the present invention. 1 is an enlarged view for explaining a main part of an image forming apparatus showing an embodiment of the present invention. 6 is a graph illustrating the number of output sheets and graininess characteristics of another main part of the image forming apparatus according to the exemplary embodiment of the present invention. It is explanatory drawing explaining the image forming apparatus which shows the other embodiment of this invention. It is an enlarged view explaining the other main part of the image forming apparatus which shows the embodiment of this invention. It is an enlarged view explaining the principal part of the image forming apparatus which shows the other embodiment of this invention. FIG. 6 is an enlarged view for explaining a state of another main part of the image forming apparatus showing the embodiment of the present invention. 6 is a graph illustrating the number of output sheets and graininess characteristics of another main part of the image forming apparatus according to the exemplary embodiment of the present invention. It is an enlarged view explaining the state of the principal part of the image forming apparatus which shows the other embodiment of this invention. 6 is a graph illustrating the number of output sheets and graininess characteristics of another main part of an image forming apparatus showing another embodiment of the present invention. It is an enlarged view explaining the state of the principal part of the image forming apparatus which shows the other embodiment of this invention. 6 is a graph for explaining the characteristics of the toner adhesion amount and the area (F) of a white spot in another main part of the image forming apparatus showing another embodiment of the present invention. 6 is a graph illustrating the number of output sheets and graininess characteristics of another main part of an image forming apparatus showing another embodiment of the present invention. It is a graph explaining the characteristics of the dot area ratio (%) and granularity deterioration degree of the main part of the conventional image forming apparatus. It is an enlarged view explaining the state of the other main part of the conventional image forming apparatus. It is an enlarged view for explaining another state of another main part of the conventional image forming apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 0 Image forming apparatus 00 Color image forming apparatus 00a Yellow image forming part 00b Cyan image forming part 00c Magenta image forming part 00d Black image forming part 1 Image carrier 1a Surface 2 Charging means 3 Dot 3a Pixel 4 Interval 5 Interval dot pattern 5a Input Image dots 6 Latent image forming means 7 Developing means 7a Developing sleeve 7b Developing container,
7c Stirring screw 7d Doctor blade 8 Transfer object 8a Transfer paper 8b Intermediate transfer belt 9 Transfer means 9a Primary transfer device 9b Secondary transfer device 10 Imaging means 10a Charge transfer element (CCD)
DESCRIPTION OF SYMBOLS 11 Dot shape recognition means 12 Document image reading apparatus 13 Image forming means 14 Paper feed apparatus 15 Fixing means 16 Paper discharge roller 17 Paper discharge tray 18 Cleaning means 18a Image carrier cleaning means 18b Intermediate transfer belt cleaning means

Claims (21)

  In an image forming apparatus for forming a toner image by an electrophotographic method, an image carrier that carries a toner image that is rotatably held, a charging unit that uniformly charges the image carrier, and the charging Repeated in an interval dot pattern in which a plurality of pixels are arranged on the surface of the image carrier uniformly charged by the means and arranged at intervals of at least one pixel around a dot having the same vertical and horizontal length. A latent image forming means for forming the latent image, a developing means for developing the latent image formed by the latent image forming means to form a toner image storage, and a toner image formed by the developing means for transferring the toner image An image forming apparatus comprising transfer means for transferring the image on the image forming apparatus.   The image forming apparatus according to claim 1, wherein the dot area ratio of dots is 40 (%) to 80 (%) in the interval dot pattern.   The image forming apparatus according to claim 1, wherein an imaging unit that images the surface of the image carrier or a toner dot image on the transfer target body having the same shape and spacing interval pattern, and the imaging unit. An image forming apparatus comprising dot shape recognition means for recognizing an image quality of a dot shape in a predetermined mesh area in the captured interval dot pattern.   4. The image forming apparatus according to claim 3, wherein the transfer target is transfer paper.   4. The image forming apparatus according to claim 3, wherein the transfer target is an intermediate transfer belt.   6. The image forming apparatus according to claim 3, wherein the image pickup unit includes a charge transfer element.   7. The image forming apparatus according to claim 3, wherein the imaging unit uses a toner having a color different from that of the surface of the image carrier or the transfer target, and has a sensitivity due to a difference in color density. An image forming apparatus that selects one of the three primary colors of high light.   8. The image forming apparatus according to claim 3, wherein the imaging unit is located at a position between a developing unit and a transfer unit that are disposed to face the surface of the image carrier. An image forming apparatus for picking up imaged dot patterns of the same shape and the same interval of the toner image formed on the surface.   9. The image forming apparatus according to claim 3, 4, 5, 6, 7, or 8, wherein the image pickup unit is placed on the transfer target at a position immediately downstream of the transfer unit disposed to face the transfer target. An image forming apparatus that images interval dot patterns arranged in the same shape and at the same interval of a toner image formed by transfer.   The image forming apparatus according to claim 9, wherein the transfer target is transfer paper onto which the toner image on the intermediate transfer belt is transferred.   The image forming apparatus according to claim 9, wherein the transfer target has a yellow image forming unit, a cyan image forming unit, a magenta image forming unit, and a black image forming unit arranged in tandem so that the color overlap of each color formed by these is formed. An image forming apparatus, wherein the image forming apparatus is an intermediate transfer belt.   12. The image forming apparatus according to claim 11, wherein the imaging unit is immediately downstream of the transfer unit of the most downstream yellow image forming unit, cyan image forming unit, magenta image forming unit, or black image forming unit arranged in tandem. An image forming apparatus characterized in that, at the position, an image of a dot pattern having the same shape and the same interval of a toner image transferred and formed on the intermediate transfer belt of the transfer target is imaged.   13. The image forming apparatus according to claim 3, wherein the dots in the predetermined mesh in the interval dot pattern imaged by the imaging unit or the shape of the interval can be changed by the latent image forming unit. An image forming apparatus, comprising:   14. The image forming apparatus according to claim 13, wherein the latent image forming unit is capable of varying an exposure amount or an exposure time.   15. The image forming apparatus according to claim 3, wherein the dot shape recognition unit includes a vertical diameter of a dot in a predetermined mesh in the interval dot pattern captured by the imaging unit, or a horizontal direction. An image forming apparatus that recognizes the image quality of a diameter shape.   15. The image forming apparatus according to claim 3, wherein the dot recognizing unit has a disordered shape of an edge portion of a dot in a predetermined mesh in the interval dot pattern imaged by the imaging unit. An image forming apparatus that recognizes image quality.   17. The image forming apparatus according to claim 16, wherein the disturbance of the edge portion of the dot is the disturbance of the edge portion of the dot = the length of the periphery of the dot / the length of the periphery of the unevenness of the dot. Forming equipment.   15. The image forming apparatus according to claim 3, wherein the dot recognizing unit has a shape of an area of a white portion of a dot in a predetermined mesh in the interval dot pattern captured by the image capturing unit. An image forming apparatus characterized by recognizing the image quality.   The image forming apparatus according to any one of claims 3 to 18, wherein the dot recognizing unit includes a vertical diameter or a horizontal diameter of dots in a predetermined mesh in the interval dot pattern imaged by the imaging unit, An image forming apparatus, wherein the charging potential of the image carrier by the charging means is corrected by recognizing the image quality of the shape of the dot edge portion disorder or the area of the white area of the dot.   19. The image forming apparatus according to claim 3, wherein the dot recognition unit includes a vertical diameter or a horizontal diameter of dots in a predetermined mesh in the interval dot pattern captured by the imaging unit, An image forming apparatus, wherein the developing bias of the developing unit is corrected by recognizing the image quality of the shape of the dot edge portion disorder or the area of the white portion of the dot.   The image forming apparatus according to any one of claims 3 to 18, wherein the dot recognizing unit includes a vertical diameter or a horizontal diameter of dots in a predetermined mesh in the interval dot pattern imaged by the imaging unit, An image forming apparatus, wherein the transfer current of the transfer unit is corrected by recognizing the image quality of the shape of the dot edge portion disorder or the area of the white portion of the dot.

Images