JP2010211100A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus, capable of satisfactorily transferring a developer image. <P>SOLUTION: A control unit 84 controls, when the first developer image is transferred to a recording medium by a transfer roll 78 and fixed to the recording medium by a fixing device 28, at least either a transfer condition for transferring the developer image by the transfer roll 78 or a fixing condition for fixing the developer image by the fixing device 28 to be differed from when the second and following developer images are transferred to the recording medium by the transfer roll 78 and fixed to the recording medium by the fixing device 28. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus.

  Patent Document 1 discloses a non-contact development using a two-component developer containing a transparent toner or a white toner, fixing a transfer image to create a glossy sheet, and using a glossy transfer material as copy paper. A glossy image forming apparatus for fixing a toner image is disclosed. Patent Document 2 discloses an image forming apparatus that preheats a recording sheet to a constant temperature and conveys the recording sheet to a transfer unit.

Japanese Patent Laid-Open No. 5-232841 JP 2001-5318 A

  An object of the present invention is to provide an image forming apparatus that can transfer a developer image satisfactorily.

  To achieve the above object, the present invention according to claim 1 is directed to an image carrier, a developing unit that sequentially develops an electrostatic latent image held by the image carrier with a plurality of types of developer, and the developing unit. Is transferred to the recording medium for each type of developer, and the developer image is transferred to the recording medium each time the transfer means transfers the developer image to the recording medium. A fixing unit that fixes the first type of developer image onto a recording medium, and the fixing unit fixes the first type of developer image on the recording medium. At least one of a transfer condition for transferring an image and a fixing condition for fixing the developer image by the fixing unit, the transfer unit transfers the second and subsequent developer images to a recording medium, and the fixing unit has two types. What is the case of fixing the developer image after the eye to the recording medium? And control means for controlling such that an image forming apparatus having a.

  The present invention according to claim 2 further includes information acquisition means for acquiring information relating to the type of the recording medium, and the control means is configured such that the transfer means is a developer image based on the information acquired by the information acquisition means. The image forming apparatus according to claim 1, wherein at least one of a transfer condition for transferring the toner and a fixing condition for fixing the developer image by the fixing unit is controlled.

  According to a third aspect of the present invention, when the fixing unit fixes the first type of developer image on the recording medium, the fixing unit fixes the second and subsequent types of developer images on the recording medium. 3. The image forming apparatus according to claim 1, wherein the image forming apparatus is controlled so as to apply a higher load to the developer image and the recording medium than in the case of forming the image.

  According to a fourth aspect of the present invention, when the transfer unit transfers the first type of developer image to the recording medium, the transfer unit transfers the second or later type of developer image to the recording medium. 4. The image forming apparatus according to claim 1, wherein at least one of a lower load and a smaller current is applied to the developer image and the recording medium.

  According to a fifth aspect of the present invention, the developing means develops the electrostatic latent image held by the image carrier with a transparent developer, and then develops the electrostatic latent image with a colored developer. 5. The image forming apparatus according to claim 1, wherein a developer amount when developing is larger than any developer amount when developing with a colored developer. 6.

  According to a sixth aspect of the present invention, there is provided an image carrier, a developing unit that sequentially develops an electrostatic latent image held by the image carrier with a plurality of types of developer, and the developing unit develops the image carrier. Transfer means for transferring the developer image held by the recording medium to the recording medium for each type of developer, and fixing means for fixing the developer image to the recording medium each time the transfer means transfers the developer image to the recording medium; Information acquisition means for acquiring information on the type of recording medium on which the fixing means fixes the developer image, and the type of recording medium on which the fixing means fixes the developer image based on the information acquired by the information acquisition means When the determination unit determines that the type of the recording medium is a predetermined type, at least the transfer unit displays the first type of developer image. The fixing means is transferred to a recording medium. The determination that the type of the recording medium is not a predetermined type at least one of the transfer condition for transferring the developer image and the fixing condition for fixing the developer image when fixing the type of developer image on the recording medium. And an image forming apparatus having a control unit that performs control differently from the case where the unit determines.

  According to a seventh aspect of the present invention, the information acquisition unit acquires information on the surface roughness of the recording medium, and the determination unit determines the fixing based on the information on the surface roughness acquired by the information acquisition unit. 7. The image forming apparatus according to claim 6, wherein the means determines whether or not the recording medium on which the developer image is fixed has a predetermined surface roughness.

  According to an eighth aspect of the present invention, when the determination unit determines that the control unit has a predetermined surface roughness, the fixing unit fixes the first type developer image on the recording medium. 8. The image forming apparatus according to claim 7, wherein the fixing unit controls to apply a higher load to the developer image and the recording medium than when fixing the second and subsequent types of developer images on the recording medium. .

  According to the ninth aspect of the present invention, when the determination unit determines that the recording medium has a predetermined surface roughness, the transfer unit transfers the first type developer image to the recording medium. The transfer means controls to apply at least one of a lower load and a smaller current to the developer image and the recording medium than when transferring the second and subsequent types of developer images to the recording medium. Alternatively, the image forming apparatus according to 8.

  According to the first aspect of the present invention, it is possible to transfer the developer image better than in the case where the present configuration is not provided.

  According to the second aspect of the present invention, in addition to the effect of the present invention according to the first aspect, the developer image is generated according to the information regarding the type of the recording medium as compared with the case where the present configuration is not provided. Can be transferred satisfactorily.

  According to the third aspect of the present invention, in addition to the effect of the first aspect of the present invention according to the first or second aspect, compared with the case where the present configuration is not provided, the recording medium having a surface with unevenness is formed. However, the developer image can be transferred satisfactorily.

  According to the fourth aspect of the present invention, in addition to the effect of the present invention according to any one of the first to third aspects, a recording medium having irregularities formed on the surface as compared with the case where the present configuration is not provided. In contrast, the developer image can be satisfactorily transferred.

  According to the present invention of claim 5, in addition to the effects of the present invention of any one of claims 1 to 4, a recording medium having irregularities formed on the surface thereof as compared with the case without the present configuration In contrast, the developer image can be satisfactorily transferred.

  According to the sixth aspect of the present invention, it is possible to transfer the developer image better than in the case where the present configuration is not provided.

  According to the seventh aspect of the present invention, in addition to the effect of the present invention according to the sixth aspect, the development is performed according to the information on the surface roughness of the recording medium as compared with the case where the present configuration is not provided. The agent image can be transferred satisfactorily.

  According to the present invention of claim 8, in addition to the effect of the present invention of claim 7, the recording medium has a predetermined surface roughness as compared with the case where the present configuration is not provided. However, the developer image can be transferred satisfactorily.

  According to the present invention of claim 9, in addition to the effect of the present invention of claim 7 or 8, the recording medium has a predetermined surface roughness as compared to the case without the present configuration. Even if this is done, the developer image can be transferred satisfactorily.

1 is a side view illustrating an outline of an image forming apparatus according to an embodiment of the present invention. It is a schematic diagram showing a configuration for changing the transfer condition of the transfer roll with respect to the image carrier. FIG. 3 is a schematic diagram illustrating a configuration for changing fixing conditions in a fixing device. It is a block diagram which shows the structure of a control part. 10 is a flowchart illustrating a first processing example (S10) in which a condition for forming an image by the image forming apparatus is set according to information on the type of recording medium. 10 is a flowchart illustrating a second processing example (S20) in which conditions for forming an image by the image forming apparatus are set according to information on the type of recording medium. It is a 1st chart which shows the evaluation result of the transferability with respect to the embossed paper of an image forming apparatus. It is a schematic diagram which shows the state of the developer transcribe | transferred with respect to the recessed part of embossed paper, Comprising: (A) is a schematic diagram which shows an Example, (B) is a schematic diagram which shows a comparative example. It is a 2nd table | surface which shows the evaluation result of the transferability with respect to the embossed paper of an image forming apparatus.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a side view showing an outline of an image forming apparatus 10 according to an embodiment of the present invention.
As shown in FIG. 1, the image forming apparatus 10 includes an image forming apparatus main body 12, and, for example, a one-stage sheet feeding unit 14 is disposed below the image forming apparatus main body 12.

  A take-out roll 16 for taking out a recording medium such as a sheet from the paper feed unit 14 is disposed above the paper feed unit 14. The take-out roll 16 is driven by a drive unit (not shown) and rotates so as to supply the recording medium toward the conveyance path 18.

  The conveyance path 18 is a recording medium path from the take-out roll 16 to the discharge port 24, and this conveyance path 18 is on the back side (left side in FIG. 1) of the image forming apparatus main body 12 and is discharged from the paper supply unit 14. A portion extending substantially vertically to the outlet 24 is provided. An image holding body 62 and a transfer roll 78, which will be described later, are arranged on the upstream side of the fixing device 28 in the conveying path 18, and a registration roll 30 is arranged on the upstream side of the image holding body 62 and the transfer roll 78. For example, a detection device 20 such as a non-contact laser displacement meter that detects irregularities on the surface of the recording medium is disposed on the upstream side of the registration roll 30. The detection device 20 may be a roughness meter that contacts the recording medium to detect the surface roughness of the recording medium, may be disposed on the downstream side of the registration roll 30, or may be disposed in the paper feeding unit 14. It may be arranged. A discharge roll 32 is disposed in the vicinity of the discharge port 24 of the conveyance path 18.

  Therefore, the recording medium taken out from the paper supply unit 14 by the take-out roll 16 is guided to the transport path 18 and temporarily stopped by the registration roll 30, and is timed between an image holding body 62 and a transfer roll 78 described later. For example, a black developer image is transferred, and the transferred black developer image is fixed by the fixing device 28 and discharged from the discharge port 24 by the discharge roll 32.

  However, in the case of color printing, the recording medium is returned to the repetition path, for example, three times. That is, the downstream side of the discharge roll 32 in the conveyance path 18 is divided into two branches, and a switching device 34 is provided at the divided part, and a repetitive path 36 that returns from the divided part to the registration roll 30 is formed. The repeating path 36 is provided with transport rolls 40, 42, 44, and 46. In the case of color printing, the switching device 34 is switched to the side that opens the repeating path 36, and the recording medium is guided to the repeating path 36. In addition, the resist roll 30, the image carrier 62 and the transfer roll 78, and the fixing device 28 pass through the fixing device 28 a total of four times and are discharged from the discharge port 24. Here, the registration roll 30 to the discharge roll 32 in the conveyance path 18 and the repetitive path 36 convey the recording medium that has passed through the fixing device 28 between the image carrier 62 and the transfer roll 78 and to the fixing device 28 again. A retransmission path 50 is formed.

In the image forming apparatus main body 12, for example, a rotary developing device 52 is disposed at a substantially central portion. The rotary developing device 52 includes developing devices 56a to 56d that form developer images of four colors of yellow, yellow, magenta, cyan, and black in the developing device main body 54, respectively. Rotate counterclockwise about the rotary developing device center 58 (counterclockwise in FIG. 1). The developing units 56a to 56d are configured in the same manner except that the colors of the developer to be stored are different, and a predetermined developing voltage (for example, an initial value of the developing voltage: standard setting) between the developing units 56a to 56d is different. Each of the developing rolls 60a to 60d is provided with a value).
The rotary developing device 52 may contain, for example, a transparent developer (clear toner) in any one of the developing devices 56a to 56d, and has five developing devices, which are colored yellow, magenta, cyan, and black. Five types of developers, that is, a developer and a transparent developer may be individually accommodated. The transparent developer is configured in the same manner as the color developer except that it does not contain a colored pigment.

  The rotary developing device 52 is arranged so that an image holding body 62 made of, for example, a photosensitive member comes into contact therewith, and the developing rolls 60 a to 60 d are not in contact with the image holding body 62 and have one outer periphery. The portion protrudes from the outer periphery of the developing device main body 54 in the radial direction, for example, 2 mm. Further, a tracking roll (not shown) having a diameter slightly larger than the diameter of the developing rolls 60a to 60d is provided at both ends of the developing rolls 60a to 60d so as to rotate coaxially with the developing rolls 60a to 60d. Yes. That is, the tracking rolls of the developing rolls 60 a to 60 d abut against flanges (not shown) provided at both ends of the image holding body 62, and a predetermined gap is formed between the developing rolls 60 a to 60 d and the image holding body 62. Then, the latent image on the image carrier 62 is developed with each color developer.

  Above the image holding body 62, a charging device 64 made of, for example, a charging roll for uniformly charging the image holding body 62 is provided. Further, an image carrier cleaner 66 is in contact with the image carrier 62 on the upstream side of the charging device 64 in the rotation direction of the image carrier 62. The image carrier cleaner 66 scrapes off the developer remaining on the image carrier 62 after the primary transfer, for example.

  Above the rotary developing device 52, an optical writing device 76 for writing an electrostatic latent image on the image holding member 62 charged by the charging device 64 by a light beam such as a laser beam is disposed. A transfer roll 78 is provided on the back side of the image carrier 62 to transfer the developer image visualized by the rotary developing device 52 to the recording medium at the transfer position. The transfer roll 78 is provided with a pressure adjusting mechanism 79 so that the pressure contact force with respect to the image holding body 62 can be adjusted (settable).

  As shown in FIG. 2, the pressure adjustment mechanism 79 includes a biasing member 90 such as a spring made of a conductive member such as metal, and a control unit described later with a biasing force (transfer load) by the biasing member 90. And a cam 92 that is adjusted by the control of 84, for example, provided at both ends of the transfer roll 78. For example, the power supply unit 94 is connected to one biasing member 90. The power supply unit 94 is a biasing member so that a predetermined transfer current (for example, an initial value of the transfer current: a standard setting value) flows between the transfer roll 78 and the image holding body 62 under the control of the control unit 84 described later. A predetermined voltage is applied to the transfer roll 78 via 90.

  A fixing device 28 is disposed downstream of the transfer position of the conveyance path 18 (FIG. 1). The fixing device 28 includes a heating roll 80 and a pressure roll 82, and applies heat and pressure (fixing load) to the developer image transferred to the recording medium by the image carrier 62 and the transfer roll 78 to develop the fixing image. The agent image is transported after being fixed on a recording medium for each transfer. The pressure roll 82 is provided with a pressure adjusting mechanism 83 so that the pressure contact force with respect to the heating roll 80 can be adjusted (settable).

  As shown in FIG. 3, the pressure adjustment mechanism 83 includes an urging member 94 such as a spring, and a cam 96 that adjusts the urging force of the urging member 94 by the control of the control unit 84 described later. For example, it is provided at each end of the pressure roll 82.

The image forming apparatus 10 (FIG. 1) is provided with a control unit 84 that controls each unit constituting the image forming apparatus 10.
For example, as shown in FIG. 4, the control unit 84 includes a CPU 100, a memory 102, a storage device 104 such as a hard disk drive (HDD), a communication interface (IF) 106 that transmits and receives data, and a user interface (UI) such as a touch panel. The devices 108 are configured to be connected to each other via a control bus 110.

  The CPU 100 executes a predetermined process according to a program stored in the memory 102 or the storage device 104 and controls the operation of the control unit 84. Further, instead of providing the program from the memory 102 or the storage device 104, the program can be provided by being stored in a recording medium such as a CD-ROM. This recording medium may be a magnetic disk, a semiconductor memory, or another recording medium. The memory 102 also stores determination criteria for distinguishing the type of recording medium on which the image forming apparatus 10 forms an image. The determination criterion for distinguishing the type of the recording medium may be, for example, a threshold value of the surface roughness, or may be a type name of the recording medium corresponding to the surface roughness.

  The communication IF 106 is a communication interface that connects, for example, a PC (personal computer) and the image forming apparatus 10 via a network or the like. For example, the communication IF 106 receives (acquires) an image forming signal such as a page description language (PDL) transmitted by the PC, and outputs it to the CPU 100.

  The UI device 108 acquires, for example, information related to the type of recording medium, for example, according to the operation of the operator, and outputs it to the CPU 100. The information regarding the type of the recording medium is used to determine, for example, whether or not the recording medium on which the image forming apparatus 10 forms an image is embossed paper, or whether or not the recording medium has a predetermined surface roughness. Information indicating a setting for specifying the type of the recording medium accommodated in the paper supply unit 14, for example, an operator in an embossed paper printing mode or a normal printing (other than embossed paper printing) mode. May be information indicating the setting of the operation mode specified by.

  The control unit 84 is configured such that the CPU 100 and the memory 102 can accept the detection result of the detection device 20 via the control bus 110.

Next, the operation of the image forming apparatus 10 will be described.
For example, the image forming apparatus 10 sets (changes) conditions for forming an image in accordance with an operation mode (information on the type of recording medium) set via the UI apparatus 108, and records in accordance with the set conditions. An image is formed on the medium.
FIG. 5 is a flowchart illustrating a first processing example (S10) in which the conditions for forming an image by the image forming apparatus 10 are set in accordance with information regarding the type of recording medium.
As shown in FIG. 5, in step 100 (S100), the control unit 84 acquires information related to the type of the recording medium, for example, according to an operation mode set via the UI device 108.

  In step 102 (S102), the control unit 84 determines whether or not the embossed paper printing mode is set (whether or not the recording medium accommodated in the paper feeding unit 14 is embossed paper), and the embossed paper printing mode ( Alternatively, if the recording medium accommodated in the paper feeding unit 14 is embossed paper), the process proceeds to S104, and otherwise the setting process is terminated.

  In step 104 (S104), the control unit 84 changes (sets) the development condition of the first type of electrostatic latent image held by the image holding body 62. For example, when the developing unit of the rotary developing device 52 develops the electrostatic latent image initially held by the image carrier 62 in the formation of a color image with the first developer, the control unit 84 performs the image carrier 62. As described above, the amount of developer moving toward the electrostatic latent image is larger than when the developing device of the rotary developing device 52 develops the electrostatic latent image held for the second time with the second type of developer. Change the development voltage setting. However, when the first developer for developing the electrostatic latent image by the rotary developing device 52 is a colored developer, the setting of the development voltage may not be changed from the initial value. The controller 84 may change the amount of the first type of developer by changing the light beam output from the optical writing device 76 instead of changing the development voltage.

  In step 106 (S106), the control unit 84 changes the transfer condition for each developer image. For example, when the transfer roller 78 transfers each developer image in the formation of a color image, the control unit 84 adjusts the pressure so that the transfer load and the transfer current are smaller than the initial values (standard setting values). Settings for the adjustment mechanism 79 and the power supply unit 94 are changed.

  In step 108 (S108), the control unit 84 changes the fixing condition of each developer image. For example, the control unit 84 controls the pressure adjustment mechanism 83 so that the fixing load value becomes larger than the initial value (standard setting value) when the fixing device 28 fixes each developer image in forming a color image. Change the setting.

When the conditions for forming an image are set (changed) in the process of S10, the image forming apparatus 10 forms an image on a recording medium according to the set conditions as described above.
For example, when an image forming signal is sent, the image holding body 62 is uniformly charged by the charging device 64, and the charged image holding body 62 is converted into a yellow image from the optical writing device 76 based on the image signal. Corresponding rays are emitted. The light beam from the optical writing device 76 exposes the surface of the image carrier 62 to form an electrostatic latent image.

  The electrostatic latent image held on the image holding body 62 is developed according to the development conditions set with the yellow developer supplied to the developing roll 60a of the rotary developing device 52. The developed developer image is transferred under the transfer conditions set on the recording medium fed from the paper feeding unit 14. The recording medium to which the yellow developer image has been transferred is guided to the fixing device 28, and heat and a fixing load set by the heating roll 80 and the pressure roll 82 are applied to fix the developer image. The recording medium on which the yellow developer image is fixed is returned to the repetitive path 36 by the switching device 34.

  Then, the developing device main body 54 of the rotary developing device 52 rotates, and the image holding member 62 is uniformly charged by the charging device 64. The charged image holding member 62 has an optical writing device 76 based on the image signal. To emit light rays corresponding to the magenta image. The light beam from the optical writing device 76 exposes the surface of the image carrier 62 to form an electrostatic latent image.

  The electrostatic latent image held on the image holding body 62 is developed according to the developing conditions set with the magenta developer supplied to the developing roll 60b of the rotary developing device 52, and is a record that currently forms an image. Transfer is performed under transfer conditions set on the medium. The recording medium on which the magenta developer image has been transferred is guided to the fixing device 28 and fixed by the heating roll 80 and the pressure roll 82 under the fixing conditions in which the developer image is set. The recording medium on which the magenta developer image is fixed is returned to the repetitive path 36 by the switching device 34.

  The recording medium on which the image is formed is returned to the repeating path 36 a total of three times, so that the developer image developed with the cyan and black developers is fixed by the fixing device 28 in the same manner as the yellow and magenta developer images. The recording medium fixed on the recording medium and having the image fixed thereon is discharged from the discharge port 24 by the discharge roll 32.

FIG. 6 is a flowchart illustrating a second processing example (S20) in which the conditions for forming an image by the image forming apparatus 10 are set in accordance with information on the type of recording medium.
As shown in FIG. 6, in step 200 (S200), the control unit 84 acquires information related to the type of the recording medium, for example, according to the operation mode set via the UI device 108.

  In step 202 (S202), the control unit 84 determines whether or not the embossed paper printing mode is set (whether or not the recording medium accommodated in the paper feed unit 14 is embossed paper), and the embossed paper printing mode ( Alternatively, if the recording medium accommodated in the paper feeding unit 14 is embossed paper), the process proceeds to S204, and otherwise the setting process is terminated.

  In step 204 (S204), the control unit 84 changes (sets) the developing condition of the first type of electrostatic latent image held by the image holding body 62. For example, when the developing unit of the rotary developing device 52 develops the electrostatic latent image initially held by the image carrier 62 in the formation of a color image with the first developer, the control unit 84 performs the image carrier 62. As described above, the amount of developer moving toward the electrostatic latent image is larger than when the developing device of the rotary developing device 52 develops the electrostatic latent image held for the second time with the second type of developer. Change the development voltage setting. However, when the first developer for developing the electrostatic latent image by the rotary developing device 52 is a colored developer, the setting of the development voltage may not be changed from the initial value.

  In step 206 (S206), the control unit 84 changes the transfer condition for the first type of developer image. For example, when the transfer roller 78 transfers the first type of developer image in the formation of a color image, the control unit 84 transfers the transfer load and transfer more than when the transfer roller 78 transfers the second type of developer image. The settings for the pressure adjustment mechanism 79 and the power supply unit 94 are changed so that the current values become smaller.

  In step 208 (S208), the control unit 84 changes the fixing condition for the first type of developer image. For example, when the fixing device 28 fixes the first type of developer image in the formation of a color image, the control unit 84 sets the fixing load value more than when the fixing device 28 fixes the second type of developer image. The setting for the pressure adjustment mechanism 83 is changed so as to increase.

When the conditions for forming an image are set (changed) in step S20, the image forming apparatus 10 forms an image on a recording medium according to the set conditions as described above.
For example, when an image forming signal is sent, the image holding body 62 is uniformly charged by the charging device 64, and the charged image holding body 62 is supplied with the first type from the optical writing device 76 based on the image signal. A light beam corresponding to a developer image (for example, an image by a clear developer or an image by a yellow developer) is emitted. The light beam from the optical writing device 76 exposes the surface of the image carrier 62 to form an electrostatic latent image.

  The electrostatic latent image held on the image holding body 62 is developed according to the development conditions set by the first type of developer supplied to the developing roll 60a of the rotary developing device 52. The developed developer image is transferred under the transfer conditions set on the recording medium fed from the paper feeding unit 14. The recording medium to which the first type developer image has been transferred is guided to the fixing device 28, and heat and a fixing load set by the heating roll 80 and the pressure roll 82 are applied to fix the developer image. The The recording medium on which the first type developer image is fixed is returned to the repetition path 36 by the switching device 34.

  Then, the developing device main body 54 of the rotary developing device 52 rotates, and the image holding member 62 is uniformly charged by the charging device 64. The charged image holding member 62 has an optical writing device 76 based on the image signal. To emit light corresponding to the image of the second type of developer. The light beam from the optical writing device 76 exposes the surface of the image carrier 62 to form an electrostatic latent image.

  The electrostatic latent image held on the image holding body 62 is developed with the second developer supplied to the developing roll 60b of the rotary developing device 52 according to the initial value (standard setting value) of the developing condition, The image is transferred onto the recording medium on which the image is formed with the initial value (standard setting value) of the transfer condition. The recording medium onto which the second type of developer image has been transferred is guided to the fixing device 28, and the developer image is fixed by the heating roll 80 and the pressure roll 82 at the initial value (standard setting value) of the fixing conditions. . The recording medium on which the second type of developer image is fixed is returned to the repetition path 36 by the switching device 34.

  The recording medium on which the image is formed is returned to the repetitive path 36 a predetermined number of times, so that the necessary third and subsequent developer images are transferred to the recording medium and fixed by the fixing device 28 to fix the image. The recorded recording medium is discharged from the discharge port 24 by the discharge roll 32.

  In the first processing example (S10) and the second processing example (S20) described above, information on the type of the recording medium is acquired according to the operation mode set via the UI device 108, and acquired. The conditions for forming an image are set according to the type of the recording medium. However, the present invention is not limited to this. For example, the image forming apparatus 10 directly receives information on the type of the recording medium via the UI device 108. Conditions for forming an image may be set. In addition, the image forming apparatus 10 may be configured to accept information on the type of recording medium from another computer or the like via the communication IF 106 and set conditions for forming an image. Conditions for determining whether or not the recording medium is a predetermined type of recording medium according to the result (whether or not it has a predetermined surface roughness) and forming an image according to the determination result May be set. Further, instead of disposing the detection device 20 in the paper feeding unit 14, a setting receiving unit that accepts a setting for specifying the type of the recording medium is provided in the paper feeding unit 14, and is specified via the setting receiving unit. The conditions for forming an image may be set according to the type of the recording medium.

Next, transferability of the image forming apparatus 10 to embossed paper will be described based on examples.
FIG. 7 is a first chart showing the evaluation results of the transferability of the image forming apparatus 10 on embossed paper (Rezac 66, 250 gsm).
In each embodiment shown in FIG. 7A, developers of four colors of yellow, yellow, magenta, cyan and black are individually accommodated in the developing devices 56a to 56d. The process speed (image forming speed) is set to 220 mm / s, and blue (Blue) in which cyan (C) of 100% density is superimposed on magenta (M) of 100% density as shown in FIG. 7B. The evaluation results of the embossed paper transferability (image hollow-out grade) obtained by transferring the above image onto the embossed paper are shown.
In addition, the hollow grade is a numerical value obtained by visually observing the degree of occurrence of the void, and the degree of occurrence of the void is G0, and the color of the color image of the concave portion is slightly light, and it is determined that there is no problem with visual observation. G1 is the extent that the recess is slightly white, G2 is the extent that the recess is white, and G3 is the extent that the recess is white.

  In the first example of the normal printing mode, for each color developer image, the transfer load is set to a uniform standard setting value, for example, 11 gf / cm, and the transfer current is set to a uniform standard setting value, for example, 25 μA. Then, the fixing load was set to a uniform standard setting value of, for example, 300 gf / cm, and a blue image only of magenta and cyan was transferred to the embossed paper.

  In the first embossed paper printing mode, the process of S10 described above is performed, the transfer load is set to, for example, 5 gf / cm, which is smaller than the uniform standard setting value, and the transfer current is smaller than the uniform standard setting value, for example. As a result of transferring a blue image of only magenta and cyan onto embossed paper, the fixing grade is set to 15 μA, and the fixing load is set to, for example, 360 gf / cm, which is larger than a uniform standard setting value. .

  In the first example of the second embossed paper printing mode, the process of S20 described above is performed, and the transfer load for magenta (first type) is set to, for example, 5 gf / cm, which is smaller than the uniform standard setting value. The transfer current is set to 15 μA, for example, which is smaller than a uniform standard setting value, the fixing load for magenta is set to, for example, 360 gf / cm, which is larger than the uniform standard setting value, and the transfer load for cyan (second and subsequent types) is set. Is set to a uniform standard setting value, for example, 11 gf / cm, and the transfer current for cyan (second and subsequent types) is set to a uniform standard setting value, for example, 25 μA, and the fixing load for cyan (second type and later). Is set to a uniform standard setting value, for example, 300 gf / cm, and the embossed paper is blue with only magenta and cyan. As a result of transferring the image, the hollowed out grade was G0.

FIG. 8 is a schematic diagram illustrating a state of the developer transferred to the concave portion of the embossed paper, in which (A) is a schematic diagram illustrating an example, and (B) is a schematic diagram illustrating a comparative example. is there.
In the concave portion of the embossed paper, the electric field with respect to the developer to be transferred is smaller than other portions. For example, when the transfer condition is changed so that at least one of the transfer load and the transfer current for the first type of developer transferred to the recording medium is smaller than the standard setting value, as shown in FIG. Transfer is performed so that the first developer reaches the concave portion of the paper. When the first type of developer reaches the concave portion of the embossed paper, the second type of developer also easily reaches the concave portion.
Further, after the first type of developer is transferred to the recording medium, if the fixing conditions are changed so that the fixing load is larger than the standard setting value, as shown in FIG. Fixing is performed so that the first type of developer reaches.
When the clear developer is stored in the image forming apparatus 10, the first type of developer transferred to the recording medium is the clear developer.

On the other hand, when both the transfer load and the transfer current for the first type of developer transferred to the recording medium are standard set values, as shown in FIG. Transcription that does not reach the agent. If the first type developer does not reach the recess in the embossed paper, when transferring the second type developer, the transfer electric field (electrostatic force) is bent so that it concentrates on the opening of the recess. It becomes more difficult for the developer of the eye to reach the recess.
Further, when the fixing load for the first type of developer transferred to the recording medium is a standard setting value, it is difficult to press the first type of developer concentrated on the opening of the recess during transfer into the recess.

FIG. 9 is a second chart showing the evaluation result of the transferability of the image forming apparatus 10 to the embossed paper.
In each of the embodiments shown in FIG. 9A, for example, four types of developers of transparent (clear), yellow, magenta, and cyan are individually accommodated in the developing units 56a to 56d, as shown in FIG. 9B. As shown above, the evaluation result of embossed paper transferability (image hollow-out grade) obtained by transferring a blue image of magenta (M) and cyan (C) superimposed on clear developer (CT) onto embossed paper is shown. Has been.

  In the second example of the normal printing mode, for example, an 80% density clear developer, an 80% density magenta developer, and an 80% density cyan developer are used to form a blue image. . In the second example of the normal printing mode, for each color developer image, the transfer load is set to a uniform standard setting value, for example, 11 gf / cm, and the transfer current is a uniform standard setting value, for example, 25 μA. As a result of transferring a blue image in which clear, magenta and cyan developers are superimposed on embossed paper, the fixing load is set to a uniform standard setting value, for example, 300 gf / cm. Became G2.

  In the second example of the second embossed paper printing mode, for example, a 100% density clear developer, a 70% density magenta developer, and a 70% density cyan developer are used to form a blue image. Used, the developer amount of the clear developer is made larger than any developer amount of the colored developer, and the total developer amount is adjusted to be the same as the total developer amount in the second example of the normal printing mode. Has been. In the second example of the second embossed paper printing mode, the process of S20 described above is performed, and the transfer load for clear (first type) is set to, for example, 5 gf / cm, which is smaller than the uniform standard setting value. The transfer current for clear is set to, for example, 15 μA, which is smaller than the uniform standard setting value, and the fixing load for clear is set to, for example, 360 gf / cm, which is larger than the uniform standard setting value. ) Is set to a uniform standard setting value, for example, 11 gf / cm, the transfer current for magenta and cyan is set to a uniform standard setting value, for example, 25 μA, and the fixing load for magenta and cyan is a uniform standard. The set value is set to, for example, 300 gf / cm, and clear, magenta, and cyan are displayed on the embossed paper. As a result of transferring the blue image on which the image agent was superimposed, the hollow-out grade was G0.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 28 Fixing device 52 Rotary developing device 56a-56d Developing device 60a-60d Developing roll 62 Image holding body 64 Charging device 76 Optical writing device 78 Transfer roll 79 Pressure adjusting mechanism 80 Heating roll 82 Pressure roll 83 Pressure adjusting mechanism 84 Control unit 94 Power supply unit 100 CPU
106 Communication IF
108 UI device

Claims (9)

An image carrier,
Developing means for sequentially developing the electrostatic latent image held by the image carrier with a plurality of types of developer;
Transfer means for transferring the developer image developed by the developing means and held by the image carrier to a recording medium for each type of developer;
Fixing means for fixing the developer image to the recording medium each time the transfer means transfers the developer image to the recording medium;
When the transfer unit transfers the first type of developer image to the recording medium and the fixing unit fixes the first type of developer image on the recording medium, the transfer unit transfers the developer image and At least one of the fixing conditions for fixing the developer image by the fixing unit is that the transfer unit transfers the second and subsequent developer images to the recording medium, and the fixing unit transfers the second and subsequent developer images. Control means for controlling differently from the case of fixing to a recording medium;
An image forming apparatus. It further has an information acquisition means for acquiring information related to the type of recording medium,
The control means includes
The image according to claim 1, wherein at least one of a transfer condition for transferring the developer image by the transfer unit and a fixing condition for fixing the developer image by the fixing unit is controlled based on the information acquired by the information acquisition unit. Forming equipment. The control means includes
When the fixing unit fixes the first type developer image on the recording medium, a higher load is applied to the developer image and the recording medium than when the fixing unit fixes the second and subsequent types of developer image on the recording medium. The image forming apparatus according to claim 1, wherein the image forming apparatus is controlled to be applied. The control means includes
When the transfer unit transfers the first type of developer image to the recording medium, the transfer unit applies at least one of a lower load and a smaller current than when the transfer unit transfers the second type of developer image to the recording medium. The image forming apparatus according to claim 1, wherein the image forming apparatus is controlled to be applied to a developer image and a recording medium. The developing means includes
After the electrostatic latent image held by the image carrier is developed with a transparent developer, the electrostatic latent image is developed with a color developer, and the amount of developer is developed with a color developer. 5. The image forming apparatus according to claim 1, wherein the amount of the developer is larger than any amount of the developer in the case of performing the processing. An image carrier,
Developing means for sequentially developing the electrostatic latent image held by the image carrier with a plurality of types of developer;
Transfer means for transferring the developer image developed by the developing means and held by the image carrier to a recording medium for each type of developer;
Fixing means for fixing the developer image to the recording medium each time the transfer means transfers the developer image to the recording medium;
Information acquisition means for acquiring information relating to the type of recording medium on which the fixing means fixes the developer image;
A determination unit that determines whether or not the type of the recording medium on which the fixing unit fixes the developer image is a predetermined type based on the information acquired by the information acquisition unit;
When the determination unit determines that the type of the recording medium is a predetermined type, at least the transfer unit transfers the first type developer image to the recording medium, and the fixing unit sets the first type developer image. When the determination unit determines that at least one of the transfer condition for transferring the developer image and the fixing condition for fixing the developer image when fixing the image on the recording medium is not a predetermined type Control means to control differently,
An image forming apparatus. The information acquisition means includes
Obtain information about the surface roughness of the recording medium,
The determination means includes
The image formation according to claim 6, wherein the fixing unit determines whether or not a recording medium on which the developer image is fixed has a predetermined surface roughness based on information on the surface roughness acquired by the information acquisition unit. apparatus. The control means includes
When the determination unit determines that the recording medium has a predetermined surface roughness, when the fixing unit fixes the first type of developer image on the recording medium, the fixing unit develops the second and subsequent types. The image forming apparatus according to claim 7, wherein control is performed so that a higher load is applied to the developer image and the recording medium than when the agent image is fixed to the recording medium. The control means includes
When the determination unit determines that the recording medium has a predetermined surface roughness, when the transfer unit transfers the first type developer image to the recording medium, the transfer unit develops the second and subsequent types. The image forming apparatus according to claim 7 or 8, wherein at least one of a lower load and a smaller current than when transferring the agent image to the recording medium is controlled to be applied to the developer image and the recording medium.

Images