JP2006023448A - Image forming apparatus and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably form a high-quality image by preventing central blanking being an image defect caused in a transfer stage. <P>SOLUTION: The central blanking in an image transferred from an image carrier is detected, and the surface energy of at least either the image carrier or transfer material is controlled based on the result of detection. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, and a multifunction machine having these functions, and relates to an electrophotographic image forming apparatus.

  An image forming process for forming an image by an electrophotographic method generally forms a toner image on a photoreceptor by charging, exposure and development, transfers the formed toner image to a recording material, and fixes the toner image on the recording material. Is a process. As another form of the electrophotographic image forming process, a toner image is formed on a photoreceptor by charging, exposure and development, the formed toner image is transferred to an intermediate transfer member, and the toner image on the intermediate transfer member is transferred. There is a form in which the toner image on the recording material is fixed by transferring to the recording material.

  In the transfer step in the former image forming process, or in the secondary transfer step in which the toner image is transferred from the intermediate transfer member to the recording material in the primary transfer step in which the toner image is transferred from the photosensitive member to the intermediate transfer member in the latter step, It is known that local image omission causes a “middle omission” in which an image is whitened and causes image quality deterioration.

  This “missing” is likely to occur in a fine line or dot image, and is an image defect in which the central part of the fine line or dot is white.

  It has been elucidated that “blank” occurs due to the relationship between the surface energy of the image carrier that carries the toner image and the surface energy of the transfer material that receives the transfer of the toner image. Is set to be lower than the surface energy of the transfer material, thereby preventing the occurrence of “missing”.

  In Patent Documents 1 and 2, the surface energy of the photoconductor is lowered by applying a lubricant to the photoconductor (image carrier).

In Patent Document 2, the amount of toner remaining on the photoconductor after transfer is detected, and the amount of lubricant applied is controlled based on the detection result.
Japanese Unexamined Patent Publication No. 8-21755 JP 2003-263069 A

  By applying a lubricant, “missing” is prevented, but in order to achieve higher prevention of “missing” and stably maintain high image quality, it is disclosed in Patent Documents 1 and 2. Some technologies are not sufficient and need further improvement.

  If the lubricant is simply applied as in Patent Document 1, “collapse” occurs due to changes in the environment, changes in the characteristics of the image carrier such as the photosensitive member, changes in the characteristics of the intermediate transfer member, etc. Probability increases. In addition, due to a change in the amount of the lubricant supply body, etc., the amount of application may change over time, resulting in “missing”.

  In Patent Document 2, it is proposed to control the amount of lubricant applied in accordance with the toner adhesion amount on the photosensitive member or intermediate transfer member. However, since the amount of untransferred toner is detected, "Is not accurately detected, and" missing "cannot be sufficiently prevented.

  In addition, in the conventional technology, the consumption of the lubricant and the maintenance cost are reduced due to an increase in the amount of the lubricant consumed due to the excessive application of the lubricant and the need to replenish the lubricant supplier within a short period of time. There was a problem of becoming higher.

  The present invention solves the above-described problems in the technology for controlling the surface energy of an image carrier or intermediate transfer member, which has been conventionally adopted as a technique for preventing “collapse”, and stabilizes high-quality images. Another object of the present invention is to provide an image forming apparatus that can be formed at a low cost.

The object is achieved by the following invention.
(Claim 1)
An image carrier, an image forming unit that forms a toner image on the image carrier, a transfer unit that uses the toner image on the image carrier as a transfer material, and a surface energy control unit that controls the surface energy of the image carrier. An image forming apparatus having
The image forming unit can form a density detection image on the image carrier,
A density detection means for detecting the density of the density detection image formed on the transfer material by being formed on the image carrier by the image forming means and transferred to the transfer material by the transfer means; and
System control means for controlling the surface energy control means based on the density information detected by the density detection means,
An image forming apparatus comprising:
(Claim 2)
Image carrier, image forming means for forming toner image on image carrier, intermediate transfer member, primary transfer means for transferring toner image on image carrier to intermediate transfer member, toner on intermediate transfer member An image forming apparatus comprising secondary transfer means for transferring an image to a transfer material, and surface energy control means for controlling surface energy of at least one of the image carrier and the intermediate transfer body,
The image forming unit can form a density detection image on the image carrier,
Formed on the image carrier by the image forming means, transferred by the primary transfer means, transferred by the density detection image formed on the intermediate transfer body or the secondary transfer means, and on the transfer material Density detecting means for detecting the density of the formed density detection image; and
System control means for controlling the surface energy control means based on the density information detected by the density detection means,
An image forming apparatus comprising:
(Claim 3)
The image forming apparatus according to claim 1, wherein the surface energy control unit includes a lubricant application unit that applies a lubricant onto the image carrier.
(Claim 4)
The image according to any one of claims 1 to 3, wherein the density detection image is an image in which dots having a diameter of 0.1 mm to 3 mm are arranged at intervals of 0.1 mm to 3 mm. Forming equipment.
(Claim 5)
The lubricant application means includes a lubricant supply body, a brush roller that rotates in contact with the image carrier and the lubricant supply body, and the system control means controls a rotation speed of the brush roller. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.
(Claim 6)
The image forming apparatus according to claim 2, wherein the surface energy control unit includes a polishing unit that polishes a surface of the intermediate transfer member.
(Claim 7)
An image carrier, an image forming unit that forms a toner image on the image carrier, a transfer unit that uses the toner image on the image carrier as a transfer material, and a surface energy control unit that controls the surface energy of the image carrier. An image forming apparatus having
The image forming unit can form a density detection image on the image carrier,
First density detecting means for detecting the density of the density detection image formed on the image carrier by the image forming means, formed on the image carrier by the image forming means, and transferred by the transfer means. Second density detection means for detecting the density of the density detection image formed on the transfer material; and
System control means for controlling the surface energy control means based on the density information detected by the first and second density detection means,
An image forming apparatus comprising:
(Claim 8)
Image carrier, image forming means for forming toner image on image carrier, intermediate transfer member, primary transfer means for transferring toner image on image carrier to intermediate transfer member, toner image on intermediate transfer member An image forming apparatus comprising: a secondary transfer unit that transfers the toner to a transfer material; and a surface energy control unit that controls a surface energy of at least one of the image carrier and the intermediate transfer member,
The image forming unit can form a density detection image on the image carrier,
A first density detecting means for detecting the density of the density detecting image formed on the image carrier by the image forming means; formed on the image carrier by the image forming means; and transferred by the primary transfer means; Second density detection means for detecting the density of the density detection image formed on the transfer material and transferred by the density detection image or the secondary transfer means formed on the intermediate transfer body; and
System control means for controlling the surface energy control means based on the density information detected by the first and second density detection means,
An image forming apparatus comprising:
(Claim 9)
The image forming apparatus according to claim 7, wherein the surface energy control unit includes a lubricant application unit that applies a lubricant onto the image carrier.
(Claim 10)
The image according to any one of claims 7 to 9, wherein the density detection image includes an image in which dots having a diameter of 0.1 mm to 3 mm are arranged at intervals of 0.1 mm to 3 mm. Forming equipment.
(Claim 11)
The lubricant application means includes a lubricant supply body, a brush roller that rotates in contact with the image carrier and the lubricant supply body, and the system control means controls a rotation speed of the brush roller. The image forming apparatus according to claim 7, wherein the image forming apparatus is an image forming apparatus.
(Claim 12)
The image forming apparatus according to claim 7, wherein the surface energy control unit includes a polishing unit that polishes a surface of the intermediate transfer member.
(Claim 13)
Forming a first density detection toner image on the image carrier, transferring the formed first density detection toner image to a transfer material,
A second density detection toner image is formed on the image carrier, and the formed second density detection toner image is transferred onto the transfer material to thereby form the second density detection toner image on the first density detection toner image. Overlaid, and detects the density of the second density detection toner image after transfer,
Controlling at least one of the surface energy of the image carrier and the surface energy of the transfer material based on the detection result;
An image forming method comprising: forming a recording toner image on the image bearing member whose surface energy is controlled; and transferring the formed recording toner image to the transfer material to form an image.
(Claim 14)
Forming a first density detection toner image on the first image carrier, transferring the formed first density detection toner image to a transfer material,
A second density detection toner image is formed on the second image carrier, and the formed second density detection toner image is transferred to the transfer material to thereby transfer the first density detection toner image. Overlaid on top, detects the density of the second density detection toner image after transfer,
Controlling at least one of the surface energy of the first and second image carriers and the surface energy of the transfer material based on a detection result;
Image forming comprising: forming a recording toner image on the first and second image carriers whose surface energy is controlled; and transferring the formed recording toner image to the transfer material to form an image. Method.
(Claim 15)
15. The image forming method according to claim 13, wherein the surface energy of the image carrier is controlled by controlling the amount of lubricant applied to the image carrier.
(Claim 16)
The density detection toner image includes a density detection image in which dots having a dot diameter of 0.1 mm to 3 mm are arranged at intervals of 0.1 mm to 3 mm. The image forming method according to item.
(Claim 17)
The image forming method according to claim 13, wherein the surface energy of the transfer material is controlled by polishing the surface of the transfer material.

  The surface energy of the image carrier is a characteristic determined by the surface state of the image carrier, that is, the substance that mainly forms the surface of the image carrier and the shape of the surface. The surface energy control means in the present invention is to apply a material that changes the surface characteristics of the image carrier or intermediate transfer member, for example, a lubricant or remove a material adhering to the image carrier. Thus, the surface energy of the image carrier is controlled to be changed. The effect of the surface energy control by the surface energy control means can be evaluated by measuring the contact angle of the image carrier or intermediate transfer body treated by the surface energy control means with water.

  The surface energy control in the present invention will be described with reference to FIG.

  The toner image is transferred from the image carrier A to the transfer material B by pressing the transfer material B against the image carrier A carrying the toner image T by the transfer roller C and applying a transfer voltage V.

  As described above, the transfer is performed mainly by the electrostatic force generated by the transfer electric field formed by the transfer voltage V, but the transferability is influenced by the surface states of the image carrier A and the transfer material B in addition to the electrostatic force. . It has been conventionally performed to ensure good transferability by making the surface energy of the image carrier A lower than the surface energy of the transfer material B.

  In this case, the relationship between the surface energies can be made by a combination of means for reducing the surface energy of the image carrier A and means for increasing the surface energy of the transfer material B.

  The surface energy control in the present invention is control for maintaining good transferability by using at least one of means for lowering the surface energy of the image carrier A and means for increasing the surface energy of the transfer material B.

  As described in the background section, there are electrophotographic image forming processes that do not use an intermediate transfer member and those that use an intermediate transfer member, but the surface energy control in the present invention is an image that does not use an intermediate transfer member. The formation process is performed on the image carrier, and the image formation process using the intermediate transfer member is performed on at least one of the image carrier and the intermediate transfer member shown as the transfer material in FIG. .

  According to the invention of any one of claims 1 to 17, an image forming apparatus capable of satisfactorily preventing an image defect called “void” and stably forming a high-quality image over a long period of time is realized.

  In addition, wasteful consumption of the lubricant used as a means for lowering the surface energy of the image carrier and the transfer material is suppressed. As a result, frequent replenishment of the lubricant is eliminated, and consumables costs and maintenance costs are reduced. .

  An image defect called “void” is likely to occur in a fine line image or a dot image. However, according to the inventions of claims 4, 10, or 16, “void” in a fine line image or a dot image is very good. Is prevented.

  According to any of the thirteenth to seventeenth aspects of the present invention, “missing” in a multicolor toner image formed by superimposing single color toner images can be prevented very well.

[Embodiment 1]
<Image forming apparatus>
FIG. 2 is a diagram showing the image forming apparatus according to Embodiment 1 of the present invention.

  Reference numeral 1 denotes a photoconductor as an image carrier, and an OPC photoconductor, an aSi photoconductor or the like can be used, and a drum-like or belt-like photoconductor can be used. Reference numeral 2 denotes a charging device for uniformly charging the photosensitive member 1, and a corotron, a scorotron or the like is used. Reference numeral 3 denotes an exposure apparatus that performs image exposure of the photosensitive member 1 and scans and exposes the photosensitive member 1 using a laser, an LED array, or the like as a light source. As the exposure apparatus, an apparatus that emits light based on image data and exposes the photosensitive member is preferable. Reference numeral 4 denotes a developing device, and a developing device that develops an electrostatic latent image using a two-component developer having a toner and a carrier or a one-component developer not having a carrier but mainly containing a toner can be used. . In addition, a normal developing type developing device that performs development with toner having a polarity opposite to that of the photosensitive member 1 or a reverse developing type developing device that performs development with toner having the same polarity as that of the photosensitive member 1 can be used. A reversal developing device is preferred. A transfer unit 5 transfers a toner image on the photoreceptor 1 to a recording material P as a transfer material, and includes a semi-conductive transfer roller 5a and a transfer power source 5b. The transfer power source 5b applies a voltage having a polarity opposite to that of toner charging to the transfer roller 5a. The toner image on the photoreceptor 1 is transferred to the recording material P by the transfer means 5. Reference numeral 7 denotes a separation device for separating the recording material P from the photoreceptor 1, and an AC corona discharge device for discharging the recording material P charged by the transfer means 5 is preferably used. Reference numeral 6 denotes a cleaning device that removes untransferred toner and paper dust on the photoreceptor 1, and a cleaning device having a cleaning blade or a cleaning brush is used.

  A fixing device 8 is preferably a heating and fixing device that fixes the toner image by heating and pressurizing the recording material P. Reference numeral 10 denotes a transfer material storage unit for storing a recording material P such as recording paper, and a cassette or a tray is used. Reference numeral 11 denotes a registration roller that supplies the recording material P to the transfer position between the photosensitive member 1 and the transfer unit 5 in synchronization with image formation for forming a toner image on the photosensitive member 1, and 12 is subjected to fixing processing and discharged. A paper discharge tray on which the recording material P is stacked. Reference numeral 9 denotes a lubricant applying means for applying a lubricant to the photosensitive member 1, and DS1 denotes a density detecting means for detecting the density of the toner image on the recording material P. The lubricant applying unit 9 and the concentration detecting unit DS1 will be described later.

The photosensitive member 1 is rotated as indicated by an arrow, and a toner image is formed on the photosensitive member 1 by an image forming unit including a charging device 2, an exposure device 3, and a developing device 4, and the formed toner image is recorded by a transfer unit 5. Transfer to material P. The toner image on the recording material P is fixed by the fixing device P, and the recording material P subjected to the fixing process is discharged onto the paper discharge tray 12.
<Toner>
In the present invention, it is preferable to use a developer having toner and carrier as main components, and the toner preferably used in the present invention is a small particle diameter toner having a volume average particle diameter of 3 to 6 μm.

  The volume average particle diameter is an average particle diameter based on volume, and is a value measured by “Coulter Counter TA-II” or “Coulter Multisizer” (both manufactured by Coulter, Inc.) equipped with a wet disperser.

  With such a small particle size toner, a high-resolution high-quality image can be formed. A toner having a volume average particle diameter larger than 6 μm weakens the characteristics of high image quality.

  When a toner having a volume average particle size of less than 3 μm is used, the image quality is likely to deteriorate due to fogging.

  In the present invention, spherical toner is desirable, and the degree of spheroidization is desirably 0.94 or more and 0.98 or less. The degree of spheroidization is defined by the following equation.

Degree of spheroidization = (perimeter of a circle with the same area as the particle projection image) / (perimeter of the particle projection image)
The degree of spheroidization is obtained by taking a photograph of resin particles enlarged 500 times with a scanning electron microscope or laser microscope for 500 resin particles, and using an image analysis apparatus “SCANNING IMAGE ANALYSER” (manufactured by JEOL Ltd.) Then, the photographic image is analyzed, the circularity is measured, and the arithmetic average value can be obtained. Moreover, as a simple measuring method, it can measure with "FPIA-1000" (made by Toa Medical Electronics Co., Ltd.).

  When the spheroidization degree is less than 0.94, it is pulverized as a result of being subjected to strong stress in the developing means, and fog and toner scattering are likely to occur. If the sphericity is greater than 0.98, it may be difficult to maintain high cleaning performance.

  For the toner having a small particle diameter and a high sphericity as described above, it is desirable to use a polymerized toner.

  The polymerized toner means a toner obtained by forming a binder resin for toner and forming the toner shape by polymerization of a raw material monomer or prepolymer of the binder resin and subsequent chemical treatment. More specifically, it means a toner obtained through a polymerization reaction such as suspension polymerization or emulsion polymerization and, if necessary, a step of fusing particles between them. In a polymerized toner, a raw material monomer or prepolymer is uniformly dispersed in an aqueous system and then polymerized to produce a toner, so that a toner having a uniform toner particle size distribution and shape can be obtained.

Specifically, a polymer is produced by emulsion polymerization of a monomer in a liquid of an aqueous medium to which an emulsion is added or a suspension polymerization method, and then an organic solvent, agglomeration is produced. It can manufacture by the method of adding an agent etc. and making it associate. A method of preparing by mixing with a dispersion liquid of a release agent or a colorant necessary for the constitution of the toner at the time of association, or a toner component such as a release agent or a colorant dispersed in a monomer Examples thereof include emulsion polymerization. Here, the association means that a plurality of resin particles and colorant particles are fused.
<Lubricant>
The lubricant is applied to the surface of the photoreceptor mainly for the purpose of improving transferability and cleaning properties, and generally comprises a fatty acid metal salt. Specific examples of the lubricant include metal stearate such as zinc stearate, aluminum stearate, copper stearate, magnesium stearate, zinc oleate, manganese oleate, iron oleate, copper oleate, magnesium oleate, etc. Metal oleate, metal palmitate such as zinc palmitate, copper palmitate, magnesium palmitate, metal linoleate such as zinc linoleate and zinc linoleate, metal ricinoleate such as zinc ricinoleate and lithium ricinoleate Salts, and the like, metal stearates are preferred, and zinc stearate is particularly preferred.
<Surface energy control>
In the transfer portion, the recording material P is pressed and brought into close contact with the photoreceptor 1 by the transfer roller 5a, and the toner is transferred from the photoreceptor 1 to the recording material P by the electric field formed by the transfer power source 5b, so that the toner image is transferred. Is called.

  In the present embodiment, by applying a lubricant to the surface of the photoreceptor 1, the surface energy of the photoreceptor 1 is maintained at a predetermined low value, and good transferability is maintained.

  FIG. 3 shows a main part of the image forming apparatus according to Embodiment 1 of the present invention. The lubricant application means 9 is a lubricant supply body 9a made of a rod-like solid lubricant, a brush roller 9b, a spring 9c, and a lubricant supply. It has a support member 9d that supports the body 9a. The brush roller 9b is driven by the motor M to rotate. The spring 9b presses the lubricant supply body 9a against the brush roller 9b, and the brush roller 9b is arranged so as to come into contact with the photosensitive member 1 with a predetermined pressure. The lubricant is scraped off from 9 a and applied to the photoreceptor 1.

  Although any material can be used as the brush constituent material of the brush roll 9b, it is preferable to use a fiber-forming polymer. Examples of such a polymer include rayon, nylon, polycarbonate, polyester, methacrylic acid resin, acrylic resin, polyvinyl chloride, polyvinylidene chloride, polypropylene, polystyrene, polyvinyl acetate, styrene-butadiene copolymer, and vinylidene chloride. -Acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone-alkyd resin, phenol formaldehyde resin, styrene-alkyd resin, polyvinyl acetal (e.g. polyvinyl Butyral). These binder resins can be used alone or as a mixture of two or more. Particularly preferred are rayon, nylon, polyester, acrylic resin and polypropylene.

  DS1 is a density detection means for detecting and detecting the density of the toner image on the recording material P in FIG. 1, and CR is a control of the rotational speed of the motor M based on the density information detected by the density detection means DS1, thereby It is a control part which controls application quantity.

  The lubricant application unit 9 is an example of a surface energy control unit that changes the surface energy of the photosensitive member 1 by applying a lubricant to the surface of the photosensitive member 1, and the control unit CR changes the rotation speed of the brush roller 9b. Thus, system control means for controlling the lubricant application amount is configured.

  FIG. 4 shows a density detection image used in the surface energy control.

  As shown in FIG. 4, the density detection image is a dot image in which a large number of dots are arranged. In the surface energy control, the image data generation unit GS generates the image data of the dot image shown in FIG. 3 under the control of the control unit CR, and the exposure device 3 uses the image data from the image data generation unit GS. Exposure. Therefore, in the surface energy control, the toner image of the dot image shown in FIG. 3 is formed on the photosensitive member 1 and transferred to the recording material P. The dot image is formed in a shape having a high probability of occurrence of “missing”. A preferable form of the dot image is a dot having a dot diameter D1 of 0.1 mm to 3 mm and an interval D2 of 0.1 mm to 3 mm. Note that the dot diameter is the diameter of a converted circle in the case of a dot that is not a circle.

The lower the density ratio, which is the ratio between the reference density and the detected density, that is, the greater the “missing”, the higher the rotational speed of the brush roller (the higher the rotational speed ratio of the photosensitive member 1 to the brush roller 9b). ) By increasing the amount of lubricant applied, it was possible to prevent “missing”.
[Embodiment 2]
FIG. 5 is a view showing a color image forming apparatus according to Embodiment 2 of the present invention.

  The developing unit 4U includes a developing device 4Y that develops with yellow toner, a developing device 4M that develops with magenta toner, a developing device 4C that develops with cyan toner, and a developing device 4K that develops with black toner.

  An image of one color is formed by one rotation of the photosensitive member 1, and a toner image of four colors is formed by four rotations of the photosensitive member 1.

  That is, in the first rotation, the developing device 4Y is set to the illustrated position, in the second rotation, the developing device 4M is set to the position of the developing device 4Y in the drawing, and in the third rotation, the developing device 4C is set. Is set at the position of the illustrated developing device 4Y, and in the fourth rotation, the developing device 4K is set at the position of the illustrated developing device 4Y.

  The toner image formed by the four rotations of the photosensitive member is transferred to the intermediate transfer member 20 by the primary transfer unit 5 including the transfer roller 5a and the transfer power source sb. The transfer is performed by applying a transfer voltage having a polarity opposite to that of the toner to the transfer roller 5. The multicolor toner image formed by superimposing the four color toner images on the intermediate transfer member 20 is transferred to the recording material P by the secondary transfer means 21 comprising a transfer row 21a and a transfer power source 21b.

  Next, surface energy control in the present embodiment will be described.

  In the present embodiment, the density detector DS1 detects the density of the toner image on the recording material P. The configuration of the lubricant bond application unit in the present embodiment is as shown in FIG. 6, and the brush roller 9b is in contact with the lubricant supply body 9a and the photoreceptor 1 as in the lubricant application unit shown in FIG. Rotate, scrape off the lubricant from the lubricant supply 9 a and apply it to the photoreceptor 1. The controller CR controls the surface energy of the photosensitive member 1 by controlling the rotational speed of the brush roller 9a of the lubricant applying means 9 based on the detection result of the density detecting means DS1.

  In the surface energy control, the yellow, magenta, cyan, and black toner images of the dot image shown in FIG. 4 are formed in parallel on the intermediate transfer member 20. Accordingly, the density detection means DS1 detects the density of each single color toner image on the recording material P transferred from the intermediate transfer body 20, and detects the state of “missing” in each single color toner image. Then, the controller CR controls the amount of lubricant applied for each color based on the density information about the single color toner.

  In actual control, lubricant application control is performed so as not to cause “missing” in all single color toner images. Specifically, the rotational speed of the brush roller 9b for each density information is determined from the density information of the four color toner images of the dot image, and the brush roller 9b is driven at the highest rotational speed among the four rotational speeds. Apply lubricant.

  FIG. 7 shows the relationship between the density detected by the density detection means SD1 and the rotational speed of the brush roller 9b that applies the lubricant of an amount that prevents “missing” with respect to the detected density. In the figure, the ratio between the constant reference density and the density detected by the density detection means SD1 is used as the density, and the rotation speed of the photoconductor 1 and the rotation of the brush roller 9b are constant values as the rotation speed of the brush roller 9b. The speed ratio is used. As is apparent from the figure, the lower the detected density, the higher the rotational speed of the brush roller 9b.

  A specific example of the surface energy control is as follows.

  The density detection means DS1 detects the density of a dot image in which 10 dots are arranged vertically and horizontally at a resolution of 600 dpi (600 dots per 25.4 mm), a diameter D1 = 210 μm, and a dot interval D2 = 210 μm. Based on this, control according to the curve shown in FIG. 7 was performed.

FIG. 8 shows the relationship between the image density and the output of the density detector DS1. The image density on the vertical axis in FIG. 8 is the density of the original image, that is, the density indicated by the image data, and the density detection means output on the horizontal axis is the density detected by the density detection means DS1 for the toner image on the recording material P. Is the output corresponding to. When there is “missing”, the output of the density detection means on the horizontal axis is no longer a linear correspondence as shown in the figure with respect to the image density on the vertical axis, but the linear relationship shown in FIG. As a result of the surface energy control performed, it is shown that “hollow-out” was successfully prevented.
[Embodiment 3]
FIG. 9 is a diagram showing a color image forming apparatus according to Embodiment 3 of the present invention.

  The present embodiment is the same as the color image forming apparatus shown in FIG. 5 except that the density detection means DS2 detects the density of the toner image on the intermediate transfer body 20.

  In the present embodiment, the density of the toner image on the intermediate transfer body 20 is detected by the density detector DS2. The configuration of the lubricant bond applicator in the present embodiment is as shown in FIG. 6, and the controller CR controls the rotation speed of the brush roller 9a of the lubricant applicator 9 based on the detection result of the concentration detector DS2. Thus, the surface energy of the photoreceptor 1 is controlled.

  In the surface energy control, the yellow, magenta, cyan, and black toner images of the dot image shown in FIG. 4 are formed in parallel on the intermediate transfer member 20. Accordingly, the density detection means DS2 detects the density of each single color toner image, and detects the state of “missing” in each single color toner image. Then, the controller CR controls the amount of lubricant applied for each color based on the density information about the single color toner.

The density detection means DS2 detects the density of a dot image in which dots having a resolution of 600 dpi (600 dots per 25.4 mm), a dot of diameter D1 = 210 μm, and a dot interval D2 = 210 μm are arranged 10 dots vertically and horizontally, respectively. Based on this, the rotational speed of the brush roller 9b is controlled.
[Embodiment 4]
FIG. 10 is a diagram showing a color image forming apparatus according to Embodiment 4 of the present invention.

  In the present embodiment, the density detection means DS2 detects the density of the toner image on the intermediate transfer body 20, and also serves as a surface energy control means for the intermediate transfer body 20 as a polishing means for polishing the surface of the intermediate transfer body 20. 5 is the same as the color image forming apparatus shown in FIG.

  As shown in FIG. 10, the controller CR controls the rotational speed of the brush roller 23 based on the density information of the toner image of the dot image detected by the density detector SD2. The lubricant transferred from the photoreceptor 1 is attached to the intermediate transfer member 20, and the surface energy of the intermediate transfer member 20 is reduced by the lubricant.

  The surface energy of the intermediate transfer member 20 is set higher than the surface energy of the photosensitive member 1, and this allows good transfer without “missing”, but the phenomenon described above, that is, the intermediate transfer member. When the lubricant adheres to the surface 20, the surface energy of the intermediate transfer body 20 is lowered, and the “missing” is likely to occur.

  In the present embodiment, the surface of the intermediate transfer member 20 is polished by the brush roller 23 as the surface energy control means. At the same time as polishing, the lubricant transferred from the photosensitive member 1 is wiped off, thereby controlling the surface energy of the intermediate transfer member to be increased, thereby preventing “missing”.

  Any brush roller 23 can be used, but it is preferable to use a fiber-forming polymer. Examples of such a polymer include rayon, nylon, polycarbonate, polyester, methacrylic acid resin, acrylic resin, polyvinyl chloride, polyvinylidene chloride, polypropylene, polystyrene, polyvinyl acetate, styrene-butadiene copolymer, and vinylidene chloride. -Acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone-alkyd resin, phenol formaldehyde resin, styrene-alkyd resin, polyvinyl acetal (e.g. polyvinyl Butyral). These binder resins can be used alone or as a mixture of two or more. Particularly preferred are rayon, nylon, polyester, acrylic resin and polypropylene.

As an example, a brush roller in which 10 denier nylon fibers are planted at a density of 12.4 kF / cm ² is used. However, kF is a kilofilament.

FIG. 11 shows the relationship between the density detected by the density detection means SD2 and the rotation speed of the brush roller 23 that can prevent “missing” with respect to the detected density. In the figure, as the density, the ratio between the constant reference density and the density of the toner image of the dot image detected by the density detection means SD2 is used, and the movement of the intermediate transfer body 20 is a constant value as the rotation speed of the brush roller 23. The ratio between the linear velocity and the linear velocity of movement of the peripheral surface of the brush roller 23 is used. As is apparent from the figure, the lower the detected density, the higher the rotational speed of the brush roller 23.
[Embodiment 5]
FIG. 12 shows a color image forming apparatus according to Embodiment 5 of the present invention.

In the present embodiment, the density of the toner image of the dot image on the recording material P is detected by the second density detector DS1, and the density of the toner image of the dot image on the photoreceptor 1 is detected by the first density detector DS3. Other than the detection, it is the same as the color image forming apparatus shown in FIG. Further, the configuration of the lubricant bond application unit in the present embodiment is as shown in FIG. 6, and the control unit CR controls the rotational speed of the brush roller 9 b of the lubricant application unit 9 to control the surface energy of the photoreceptor 1. To control.
As shown in FIG. 12, the control CR controls the rotation speed of the brush roller 9a based on the density information detected by the second density detector DS1 and the density information detected by the first density detector DS3. Thus, the surface energy of the photoreceptor 1 is controlled.

  Due to the “missing”, the density of the toner image on the recording material P is relatively decreased with respect to the density of the toner image on the photoreceptor 1. By reducing the surface energy of the photoconductor by increasing the amount of lubricant applied when the density of the toner image on the recording material P is reduced with respect to the density of the toner image on the photoconductor 1, This prevents a decrease in the density of the toner image on the recording material P.

  FIG. 13 shows the rotational speed of the brush roller 9b for applying the lubricant without affecting the density of the toner image on the recording material. The resolution is 600 dpi (600 dots per 25.4 mm), the diameter D1 = 210 μm, and the dot interval D2. = In the control for detecting the density of a dot image in which 10 dots are arranged vertically and horizontally by 210 dots by the second density detecting means DS1 and the first density detecting means DS3, the brush roller 9b that does not cause “missing” The rotation speed is shown.

The vertical axis in FIG. 13 is the ratio of the rotational speed of the brush roller 9b to the constant rotational speed of the photoconductor 1, and the horizontal axis is on the recording material P with respect to the density of the toner image of the dot image formed on the photoconductor 1. Is the ratio of the density of the toner image of the dot image formed. As is apparent from the figure, the lower the density of the toner image on the recording material P, the higher the rotational speed of the brush roller 9b.
[Embodiment 6]
FIG. 14 shows a color image forming apparatus according to Embodiment 6 of the present invention.

  In the present embodiment, the density of the dot image on the intermediate transfer member 20 is detected by the second density detector DS2, and the toner image of the dot image on the photoreceptor 1 is detected by the first density detector DS3. Other than the detection, it is the same as the color image forming apparatus shown in FIG. Further, the configuration of the lubricant bond application unit in the present embodiment is as shown in FIG. 6, and the control unit CR controls the rotational speed of the brush roller 9 b of the lubricant application unit 9 to control the surface energy of the photoreceptor 1. To control. The control CR controls the rotational speed of the brush roller 9a based on the density information detected by the second density detection means DS2 and the density information detected by the first density detection means DS3, and the surface of the photoreceptor 1 is controlled. Energy is controlled.

  Due to the “missing”, the density of the toner image on the intermediate transfer body 20 is relatively lowered with respect to the density of the toner image on the photoreceptor 1. When the density of the toner image on the intermediate transfer body 20 is reduced with respect to the density of the toner image on the photoreceptor 1, the surface energy of the photoreceptor is reduced by increasing the amount of lubricant applied. Thus, the density of the toner image on the intermediate transfer member 20 is prevented from lowering, and the density of the image formed on the recording material P is prevented from lowering.

  FIG. 15 shows the rotational speed of the brush roller 9b that performs such control, that is, the lubricant application that does not cause a decrease in the density of the toner image on the intermediate transfer member 20 and the recording material P. The resolution is 600 dpi (600 per 25.4 mm). In the control for detecting the density of the dot image in which the dots having the diameter D1 = 210 μm and the dot interval D2 = 210 μm are arranged 10 dots vertically and horizontally by the density detectors DS2 and DS3, no “missing” occurs. The rotational speed of the brush roller 9b is shown.

The vertical axis in FIG. 15 is the ratio of the rotational speed of the brush roller 9 b to the constant rotational speed of the photoconductor 1, and the horizontal axis is the intermediate transfer body 20 with respect to the density of the toner image of the dot image formed on the photoconductor 1. It is the ratio of the density of the toner image of the dot image formed above. As is apparent from the figure, the lower the density of the toner image on the intermediate transfer member 20, the higher the rotational speed of the brush roller 9b.
[Embodiment 7]
FIG. 16 shows a color image forming apparatus according to Embodiment 7 of the present invention.

  In the present embodiment, the density of the toner image on the intermediate transfer body 20 is detected by the second density detection means DS2, and the density of the toner image on the photoconductor 1 is detected by the first density detection means DS3. 4 is the same as the color image forming apparatus shown in FIG. 4 except that a brush roller 23 for polishing the surface of the intermediate transfer body 20 is provided as the surface energy control means of the body 20. The control unit CR controls the rotation speed of the brush roller 23 by performing control based on the density information of the toner image of the dot image detected by the second density detection unit SD2 and the first density detection unit SD3.

  In a specific example, at a resolution of 600 dpi (600 dots per 25.4 mm), dots of 5 pixels (210 μm) × 5 pixels (210 μm), that is, dots having a diameter D1 = 210 μm and a dot interval D2 = 210 μm are arranged vertically and horizontally. The density of the dot image in which 10 dots are arranged is detected by the second density detection means DS2 and the first density detection means DS3, and the rotation speed of the brush 23 is controlled based on the detection result.

FIG. 17 shows the ratio of the density detected by the second density detection means SD2 to the density detected by the first density detection means DS3 in the control using the dot image, and the “missing” for the detected density. The relationship of the rotational speed of the brush roller 23 which can prevent "is shown. In the figure, as the rotation speed of the brush roller 23, a ratio between the rotation speed of the intermediate transfer member 20 and the rotation speed of the brush roller 23, which is a constant value, is used. As apparent from the figure, the lower the density ratio, the higher the rotational speed of the brush roller 23.
[Embodiment 8]
FIG. 18 is a diagram showing a color image forming apparatus according to Embodiment 8 of the present invention.

  In the present embodiment, the structure is the same as that of the color image forming apparatus shown in FIG. 4 except that the color of the toner image on the intermediate transfer body 20 is detected by the density detection means DS2.

  In the present embodiment, the density of the toner image on the intermediate transfer body 20 is detected by the density detector DS2. In the surface energy control, a toner image obtained by superimposing two color single-color toner images of a dot image is formed on the intermediate transfer body 20, and the density detection unit DS2 detects the density of the toner image on the intermediate transfer body. Based on the color information detected by the controller CR, the surface energy of the photoreceptor 1 is controlled by controlling the brush roller 9b and controlling the amount of lubricant applied. In the present embodiment, the density detection unit DS2 detects the density of the toner in the upper layer of the two-color toner image.

  For example, in an example in which an image obtained by superimposing a yellow toner image and a magenta toner image is formed on the intermediate transfer body 20 and the density is detected, the density detection unit DS2 emits green light to detect density. In this case, the output of the density detecting means DS2 changes in accordance with whether or not the transfer of the magenta toner image is good. That is, when the transfer of the magenta toner image is normal, the output of the density detection means DS2 shows a high density, and when “middle” is generated in the transfer of the magenta toner image, the output of the density detection means DS2 is Shows a low concentration.

  It has been found that “missing” is likely to occur in the transfer process in which the second toner image is superimposed on the intermediate transfer member on which the first toner image exists. Therefore, by preventing the “missing” of the upper-layer toner image when two-color toner images are formed on the intermediate transfer member, the “missing” in color image formation and monochrome image formation can be sufficiently prevented. Can do.

  By controlling the surface energy of the superimposed toner image in the present embodiment as described above, it is possible to sufficiently prevent “missing” in monochrome image formation and color image formation.

  FIG. 19 shows the density density of a dot image in which 10 dots are arranged vertically and horizontally with a resolution of 600 dpi (600 dots per 25.4 mm), a diameter D1 = 210 μm, and a dot interval D2 = 210 μm by the density detection means DS2. When the rotation speed of the brush roller 9b is controlled based on the detection result, the relationship between the density that does not cause “missing” and the rotation speed of the brush roller 9a is shown. As shown in the figure, the lower the concentration, the higher the rotational speed and the greater the lubricant application amount.

In FIG. 18, the surface energy control is performed using the density detection means DS2 for detecting the density of the toner image on the intermediate transfer body 20, but the density detection for detecting the density of the toner image on the recording material P is performed. It is also possible to control the surface energy using means. When the density of the toner image on the recording material is detected, the “missing” caused by the primary transfer is detected. Therefore, the toner image forming the upper layer on the intermediate transfer body 20, that is, on the recording material P To detect the density of the toner image forming the lower layer.
[Embodiment 9]
20 is an overall view of a color image forming apparatus according to Embodiment 10 of the present invention, and FIG. 21 is a view showing an image forming unit.

  Along the endless belt-shaped intermediate transfer body 20, an image forming unit 30Y for forming a yellow toner image, an image forming unit 30M for forming a magenta toner image, an image forming unit 30C for forming a cyan toner image, and a black toner image are formed. In accordance with the movement of the intermediate transfer body 20 indicated by the arrow, the yellow toner image is transferred by the primary transfer unit 35Y, the magenta toner image is transferred by the primary transfer unit 35M, and the cyan toner image is transferred by the primary transfer unit 35C. The black toner image is transferred to the intermediate transfer member 20 by the primary transfer unit 35K, and a multicolor toner image is formed on the intermediate transfer member 20 by superimposing these single color toner images. The formed multicolor toner image is transferred to the recording material P by the secondary transfer means 21 and fixed by the fixing device 37. The intermediate transfer member 20 after the multicolor toner image is transferred is cleaned by the cleaning device 36Z.

  Each of the image forming units 30Y, 30M, 30C, and 30K has a structure shown in FIG. That is, a charging device 32, an exposure device 33, a developing device 34, a primary transfer unit 35, a lubricant application device 38, and a cleaning device 36 are disposed around the drum-shaped photoconductor 31.

  A toner image is formed on the photoconductor 1 by charging, exposure and development in accordance with the rotation of the photoconductor 31 indicated by an arrow, and the formed toner image is transferred to the intermediate transfer body 20 by the transfer means 35.

  The lubricant application device 38 shown in FIG. 6 is the same as that described above, and applies the lubricant to the surface of the photoconductor 31 by the rotation of the brush roller 9b when the photoconductor 31 rotates.

  In the surface energy control, a superimposed image of two color toner images is formed on the intermediate transfer member 30. The density detection means DS2 detects the density of the two-color toner image on the intermediate transfer body 20, and this density detection detects the density of the toner image in the upper layer of the overlapping two-color toner image.

  For example, a yellow toner image of a dot image is formed and transferred to the intermediate transfer member 20 in the image forming unit 30Y, and a magenta toner image of a dot image is formed and transferred onto the intermediate transfer member 20 in the image forming unit 30M. As a result, a two-color toner image in which the yellow toner image and the magenta toner image overlap is formed on the intermediate transfer member 20. The density detector SD2 emits green light and receives the reflected light to detect the density. By using such density detection means SD2, the density of the toner image forming the upper layer on the intermediate transfer member 20 is detected, and the transferability of the upper toner image is detected.

  The controller CR controls the amount of lubricant applied in the image forming unit that forms the upper toner image based on the detection result of the density detector DS2. That is, since the image forming units that form the upper toner image of the multi-layer toner image formed on the intermediate transfer body 20 are 30M, 30C, and 30K, the control unit CR uses the brushes in these image forming units 30M, 30C, and 30K. The amount of lubricant applied is controlled by controlling the rotational speed of the roller 9a. Note that the lubricant application amount in the image forming unit 30Y may be similarly controlled.

  In FIG. 22, the density detection means DS2 detects the density of a dot image in which 10 dots are arranged vertically and horizontally with a resolution of 600 dpi (600 dots per 25.4 mm), a diameter D1 = 210 μm, and a dot interval D2 = 210 μm. Then, based on the detection result, when the rotation speed of the brush roller 9b is controlled, the relationship between the density that does not cause “missing” and the rotation speed of the brush roller 9a is shown. As shown in the figure, the lower the concentration, the higher the rotational speed and the greater the lubricant application amount.

  In FIG. 20, the surface energy control is performed using the DS 2 that detects the density of the toner image on the intermediate transfer member 20, but the density detection unit that detects the density of the toner image on the recording material P is used. It is also possible to perform surface energy control.

It is a figure explaining surface energy control in the present invention. 1 is a diagram illustrating an image forming apparatus according to Embodiment 1 of the present invention. 1 is a schematic view showing a main part of an image forming apparatus according to Embodiment 1 of the present invention. It is a figure which shows the dot image used in surface energy control. It is a figure which shows the color image forming apparatus which concerns on Embodiment 2 of this invention. It is a figure which shows the structure of a lubrication bond application part. It is a figure which shows the relationship between the density | concentration detected by the density | concentration detection means, and the rotational speed of the brush roller which apply | coats the quantity of lubricant which prevents an "indent" to the detected density | concentration. It is a figure which shows the relationship between an image density and the output of a density | concentration detection means. It is a figure which shows the color image forming apparatus which concerns on Embodiment 3 of this invention. It is a figure which shows the color image forming apparatus which concerns on Embodiment 4 of this invention. It is a figure which shows the relationship between the density | concentration detected by the density | concentration detection means SD2, and the rotational speed of the brush roller 23 which can prevent "missing" with respect to the detected density | concentration. FIG. 12 shows a color image forming apparatus according to Embodiment 5 of the present invention. It is a figure which shows the rotational speed of the brush roller 9b which performs the lubricant application quantity which does not raise | generate the density fall of the toner image on a recording material. FIG. 14 shows a color image forming apparatus according to Embodiment 6 of the present invention. FIG. 5 is a diagram showing the rotation speed of a brush roller 9b that performs lubricant application without causing a decrease in density of toner images on the intermediate transfer member 20 and the recording material P. It is a figure which shows the color image forming apparatus which concerns on Embodiment 7 of this invention. The ratio of the density detected by the second density detection means SD2 to the density detected by the first density detection means DS3, and the rotation speed of the brush roller 23 that can prevent “missing” with respect to the detected density. It is a figure which shows the relationship. It is a figure which shows the color image forming apparatus which concerns on Embodiment 8 of this invention. It is a figure which shows the relationship between the density | concentration which does not raise | generate "slow-out", and the rotational speed of the brush roller 9a. FIG. 10 is an overall view of a color image forming apparatus according to Embodiment 10 of the present invention. It is a figure which shows the image formation part of the color image forming apparatus which concerns on Embodiment 10 of this invention. It is a figure which shows the relationship between the density | concentration which does not raise | generate "slow-out", and the rotational speed of the brush roller 9a.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging apparatus 3 Exposure apparatus 4 Developing apparatus 5 Transfer means, primary transfer means 6, 6Z Cleaning apparatus 9 Lubricant application means 9b Brush roller CR control part DS1, DS2 Concentration detection means, Second density detection means DS3 First Density detection means A Image carrier B Transfer material C Transfer roller

Claims (17)

An image carrier, an image forming unit that forms a toner image on the image carrier, a transfer unit that uses the toner image on the image carrier as a transfer material, and a surface energy control unit that controls the surface energy of the image carrier. An image forming apparatus having
The image forming unit can form a density detection image on the image carrier,
A density detection means for detecting the density of the density detection image formed on the transfer material by being formed on the image carrier by the image forming means and transferred to the transfer material by the transfer means; and
System control means for controlling the surface energy control means based on the density information detected by the density detection means,
An image forming apparatus comprising: Image carrier, image forming means for forming toner image on image carrier, intermediate transfer member, primary transfer means for transferring toner image on image carrier to intermediate transfer member, toner on intermediate transfer member An image forming apparatus comprising secondary transfer means for transferring an image to a transfer material, and surface energy control means for controlling surface energy of at least one of the image carrier and the intermediate transfer body,
The image forming unit can form a density detection image on the image carrier,
Formed on the image carrier by the image forming means, transferred by the primary transfer means, transferred by the density detection image formed on the intermediate transfer body or the secondary transfer means, and on the transfer material Density detecting means for detecting the density of the formed density detection image; and
System control means for controlling the surface energy control means based on the density information detected by the density detection means,
An image forming apparatus comprising: The image forming apparatus according to claim 1, wherein the surface energy control unit includes a lubricant application unit that applies a lubricant onto the image carrier. The image according to any one of claims 1 to 3, wherein the density detection image is an image in which dots having a diameter of 0.1 mm to 3 mm are arranged at intervals of 0.1 mm to 3 mm. Forming equipment. The lubricant application means includes a lubricant supply body, a brush roller that rotates in contact with the image carrier and the lubricant supply body, and the system control means controls a rotation speed of the brush roller. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. The image forming apparatus according to claim 2, wherein the surface energy control unit includes a polishing unit that polishes a surface of the intermediate transfer member. An image carrier, an image forming unit that forms a toner image on the image carrier, a transfer unit that uses the toner image on the image carrier as a transfer material, and a surface energy control unit that controls the surface energy of the image carrier. An image forming apparatus having
The image forming unit can form a density detection image on the image carrier,
First density detecting means for detecting the density of the density detection image formed on the image carrier by the image forming means, formed on the image carrier by the image forming means, and transferred by the transfer means. Second density detection means for detecting the density of the density detection image formed on the transfer material; and
System control means for controlling the surface energy control means based on the density information detected by the first and second density detection means,
An image forming apparatus comprising: Image carrier, image forming means for forming toner image on image carrier, intermediate transfer member, primary transfer means for transferring toner image on image carrier to intermediate transfer member, toner image on intermediate transfer member An image forming apparatus comprising: a secondary transfer unit that transfers the toner to a transfer material; and a surface energy control unit that controls a surface energy of at least one of the image carrier and the intermediate transfer member,
The image forming unit can form a density detection image on the image carrier,
A first density detecting means for detecting the density of the density detecting image formed on the image carrier by the image forming means; formed on the image carrier by the image forming means; and transferred by the primary transfer means; Second density detection means for detecting the density of the density detection image formed on the transfer material and transferred by the density detection image or the secondary transfer means formed on the intermediate transfer body; and
System control means for controlling the surface energy control means based on the density information detected by the first and second density detection means,
An image forming apparatus comprising: The image forming apparatus according to claim 7, wherein the surface energy control unit includes a lubricant application unit that applies a lubricant onto the image carrier. The image according to any one of claims 7 to 9, wherein the density detection image includes an image in which dots having a diameter of 0.1 mm to 3 mm are arranged at intervals of 0.1 mm to 3 mm. Forming equipment. The lubricant application means includes a lubricant supply body, a brush roller that rotates in contact with the image carrier and the lubricant supply body, and the system control means controls a rotation speed of the brush roller. The image forming apparatus according to claim 7, wherein the image forming apparatus is an image forming apparatus. The image forming apparatus according to claim 7, wherein the surface energy control unit includes a polishing unit that polishes a surface of the intermediate transfer member. Forming a first density detection toner image on the image carrier, transferring the formed first density detection toner image to a transfer material,
A second density detection toner image is formed on the image carrier, and the formed second density detection toner image is transferred onto the transfer material to thereby form the second density detection toner image on the first density detection toner image. Overlaid, and detects the density of the second density detection toner image after transfer,
Controlling at least one of the surface energy of the image carrier and the surface energy of the transfer material based on the detection result;
An image forming method comprising: forming a recording toner image on the image bearing member whose surface energy is controlled; and transferring the formed recording toner image to the transfer material to form an image. Forming a first density detection toner image on the first image carrier, transferring the formed first density detection toner image to a transfer material,
A second density detection toner image is formed on the second image carrier, and the formed second density detection toner image is transferred to the transfer material to thereby transfer the first density detection toner image. Overlaid on top, detects the density of the second density detection toner image after transfer,
Controlling at least one of the surface energy of the first and second image carriers and the surface energy of the transfer material based on a detection result;
Image forming comprising: forming a recording toner image on the first and second image carriers whose surface energy is controlled; and transferring the formed recording toner image to the transfer material to form an image. Method. 15. The image forming method according to claim 13, wherein the surface energy of the image carrier is controlled by controlling the amount of lubricant applied to the image carrier. The density detection toner image includes a density detection image in which dots having a dot diameter of 0.1 mm to 3 mm are arranged at intervals of 0.1 mm to 3 mm. The image forming method according to item. The image forming method according to claim 13, wherein the surface energy of the transfer material is controlled by polishing the surface of the transfer material.

Images