JP2019184642A - Image forming apparatus - Google Patents

Abstract

To obtain an image forming apparatus capable of determining an order in which a second image and a first image are transferred to a body to be transferred on the basis of a type of a special toner without changing a position for arranging a first image section and a second image section.SOLUTION: A first image section and a second image section are arranged side by side in a circulation direction of an object to be transferred, and the second image section forms a second image using one special toner among a plurality of types of special toners. An order in which the second image and a first image are transferred to the object to be transferred is determined on the basis of a type of special toner.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an image forming apparatus.

  An image forming apparatus described in Patent Document 1 includes a metal color developing device that develops a metal color toner image by an electrophotographic method, an intermediate transfer body on which a toner image is formed by the metal color developing device, and an intermediate transfer And a transfer device that transfers the toner image from the body to the recording medium.

JP 2002-229293 A

  A first image portion that forms a first image of a basic color (yellow, magenta, cyan, black) using a basic toner, and a second image that forms a second image of a special color using a special toner different from the basic toner 2. Description of the Related Art There is an image forming apparatus that includes an image portion and a transfer object onto which a first image and a second image are transferred. In this image forming apparatus, a first image portion for forming a first image and a second image portion for forming a second image are formed on the basis of the order in which the first image and the second image are transferred to the transfer target. You have to change the placement position.

  An object of the present invention is to change the order in which the second image and the first image are transferred to the transfer target without changing the positions where the first image portion and the second image portion are arranged, based on the type of special toner. Is to decide.

  The image forming apparatus according to claim 1 of the present invention forms a first image using a basic toner of a basic color and a second image using a special toner different from the basic toner. A second image portion, a transfer object to which the first image and the second image are transferred while rotating, and the first image and the second image transferred to the transfer object are transferred to a recording medium. A transfer member, wherein the first image portion and the second image portion are arranged side by side in a circumferential direction of the transfer target, and the second image portion is a plurality of types of special toners. The second image is formed using one special toner, and the order in which the second image and the first image are transferred to the transfer target is determined based on the type of the special toner. And

  An image forming apparatus according to a second aspect of the present invention is the image forming apparatus according to the first aspect, wherein when the special toner includes a metallic pigment, the first image is transferred to the transfer target. Then, the second image is transferred to the transfer object.

  An image forming apparatus according to a third aspect of the present invention is the image forming apparatus according to the second aspect, wherein the second image is transferred to the transferred body before the first image is transferred to the transferred body. When receiving a transfer instruction, the second image is transferred to the transfer target before the first image is transferred to the transfer target.

  According to a fourth aspect of the present invention, in the image forming apparatus according to the first aspect, when the special toner is a transparent toner, the first image is transferred to the transfer target. In addition, the second image is transferred to the transfer target.

  An image forming apparatus according to a fifth aspect of the present invention is the image forming apparatus according to the fourth aspect, wherein the second image is transferred to the transferred body after the first image is transferred to the transferred body. When receiving an instruction to perform the transfer, the second image is transferred to the transfer target after the first image is transferred to the transfer target.

  An image forming apparatus according to a sixth aspect of the present invention is the image forming apparatus according to the fourth aspect, wherein when receiving an instruction to form the second image on the recording medium under the first image, The second image is transferred to the transfer target after the first image is transferred to the transfer target.

  An image forming apparatus according to a seventh aspect of the present invention is the image forming apparatus according to the first aspect, wherein when the special toner is a white toner, the first image is transferred to the transfer target. The second image is transferred to the transfer object.

  An image forming apparatus according to an eighth aspect of the present invention is the image forming apparatus according to the seventh aspect, wherein the second image is transferred to the transferred object before the first image is transferred to the transferred object. When receiving a transfer instruction, the second image is transferred to the transfer target before the first image is transferred to the transfer target.

  The image forming apparatus according to claim 9 of the present invention is the image forming apparatus according to claim 7, wherein when receiving an instruction to form the second image on the first image on a recording medium, The second image is transferred to the transfer target before the first image is transferred to the transfer target.

  According to the image forming apparatus of the first aspect of the present invention, the order in which the second image and the first image are transferred to the transfer target without changing the positions where the first image portion and the second image portion are arranged is determined. It can be determined based on the type of special toner.

  According to the image forming apparatus of the second aspect of the present invention, the deterioration of the quality of the output image is suppressed as compared with the case where the second image is transferred to the transfer medium prior to the first image.

  According to the image forming apparatus of the third aspect of the present invention, the second image can be transferred to the transfer body before the first image is transferred to the transfer body.

  According to the image forming apparatus of the fourth aspect of the present invention, it is possible to give a stereoscopic effect to the output image as compared with the case where only the first image is transferred to the transfer target.

  According to the image forming apparatus of the fifth aspect of the present invention, the second image can be transferred to the transfer target after the first image is transferred to the transfer target.

  According to the image forming apparatus of the sixth aspect of the present invention, after the first image is transferred to the transfer object, the second image can be transferred to the transfer object.

  According to the image forming apparatus of the seventh aspect of the present invention, the influence of the ground color of the recording medium on the output image can be reduced as compared with the case where only the first image is transferred to the transfer medium.

  According to the image forming apparatus of the eighth aspect of the present invention, the second image can be transferred to the transferred body before the first image is transferred to the transferred body.

  According to the image forming apparatus of the ninth aspect of the present invention, the second image can be transferred to the transfer target before the first image is transferred to the transfer target.

FIG. 2 is a configuration diagram illustrating a toner image forming unit and a transfer unit of the image forming apparatus according to the first embodiment of the present invention. FIG. 2 is a configuration diagram illustrating a toner image forming unit and a transfer unit of the image forming apparatus according to the first embodiment of the present invention. FIG. 2 is a configuration diagram illustrating a toner image forming unit and a transfer unit of the image forming apparatus according to the first embodiment of the present invention. 1 is a configuration diagram illustrating a toner image forming unit of an image forming apparatus according to a first embodiment of the present invention. FIG. 2 is a configuration diagram illustrating a secondary transfer unit of the image forming apparatus according to the first embodiment of the present invention. FIG. 2 is a block diagram illustrating a control system of a control unit of the image forming apparatus according to the first embodiment of the present invention. FIG. 3 is a flowchart showing a control flow by a control unit of the image forming apparatus according to the first embodiment of the present invention. FIG. 3 is a flowchart showing a control flow by a control unit of the image forming apparatus according to the first embodiment of the present invention. FIG. 3 is a flowchart showing a control flow by a control unit of the image forming apparatus according to the first embodiment of the present invention. (A), (B), and (C) are schematic views showing a transfer order when silver toner is used in the image forming apparatus according to the first embodiment of the present invention. (A) and (B) are schematic views showing a transfer order when silver toner is used in the image forming apparatus according to the first embodiment of the present invention. (A) and (B) are schematic views showing a transfer order when transparent toner is used in the image forming apparatus according to the first embodiment of the present invention. (A), (B), and (C) are schematic diagrams illustrating a transfer order when transparent toner is used in the image forming apparatus according to the first embodiment of the present invention. (A), (B), and (C) are schematic views showing a transfer order when white toner is used in the image forming apparatus according to the first embodiment of the present invention. (A) and (B) are schematic views showing a transfer order when white toner is used in the image forming apparatus according to the first embodiment of the present invention. 1 is a schematic configuration diagram illustrating an image forming apparatus according to a first embodiment of the present invention. 2A and 2B are cross-sectional views illustrating silver toner used in the image forming apparatus according to the first embodiment of the present invention. 4A and 4B are plan views showing metallic pigments of silver toner used in the image forming apparatus according to the first embodiment of the present invention. FIG. 6 is a configuration diagram illustrating a toner image forming unit and a transfer unit of an image forming apparatus according to a second embodiment of the present invention. FIG. 6 is a configuration diagram illustrating a toner image forming unit and a transfer unit of an image forming apparatus according to a second embodiment of the present invention. FIG. 6 is a configuration diagram illustrating a toner image forming unit and a transfer unit of an image forming apparatus according to a second embodiment of the present invention. FIG. 6 is a block diagram illustrating a control system of a control unit of an image forming apparatus according to a second embodiment of the present invention. (A), (B), and (C) are schematic views showing a transfer order when silver toner is used in an image forming apparatus according to a second embodiment of the present invention. (A), (B), and (C) are schematic diagrams illustrating a transfer order when transparent toner is used in an image forming apparatus according to a second embodiment of the present invention. (A) and (B) are schematic views showing a transfer order when transparent toner is used in an image forming apparatus according to a second embodiment of the present invention. (A) and (B) are schematic views showing a transfer order when white toner is used in an image forming apparatus according to a second embodiment of the present invention. (A), (B), and (C) are schematic diagrams illustrating a transfer order when white toner is used in an image forming apparatus according to a second embodiment of the present invention.

<< First Embodiment >>
An example of the image forming apparatus according to the first embodiment of the present invention will be described with reference to FIGS. In addition, the arrow H shown in each figure is the vertical direction and indicates the apparatus vertical direction, and the arrow W is the horizontal direction and indicates the apparatus width direction.

<Overall configuration of image forming apparatus>
As shown in FIG. 16, the image forming apparatus 10 includes an image forming unit 12 that forms an image by an electrophotographic method, and a sheet member P (an example of a recording medium) on which an image is formed. And a plurality of conveying members (reference numerals omitted).

  The image forming apparatus 10 also includes a cooling unit 20 that cools the sheet member P on which an image is formed, a correction unit 22 that corrects the curvature of the sheet member P, and an image inspection that inspects an image formed on the sheet member P. Part 24.

  Further, in order to form an image on both sides of the sheet member P (double-sided printing), the image forming apparatus 10 reverses the front and back of the sheet member P on which the image is formed and conveys the image again to the image forming unit 12. An inversion path 26 is provided. Further, the image forming apparatus 10 includes a control unit 70 that controls each unit.

  In the image forming apparatus 10 configured as described above, the toner image formed by the image forming unit 12 is formed on the surface of the sheet member P that is transported along the transport path 16. Further, the sheet member P on which the toner image is formed passes through the cooling unit 20, the correction unit 22, and the image inspection unit 24 in this order and is discharged to the outside of the apparatus.

  On the other hand, when an image is formed on the back surface of the sheet member P, the sheet member P having an image formed on the front surface is conveyed along the reverse path 26 and the image forming unit 12 forms an image on the back surface of the sheet member P again. Is done.

<Image forming unit 12>
As shown in FIG. 1, the image forming unit 12 includes a plurality of toner image forming units 30 that respectively form toner images of respective colors, and a transfer that transfers the toner images formed by the toner image forming unit 30 to a sheet member P. Part 32. Further, the image forming unit 12 includes a fixing unit 34 (see FIG. 16) that fixes the toner image transferred to the sheet member P by the transfer unit 32 to the sheet member P.

(Toner image forming unit 30)
A plurality of toner image forming units 30 are provided so as to form a toner image for each color. In this embodiment, a total of five color toner image forming portions 30 of special colors (V), yellow (Y), magenta (M), cyan (C), and black (K) are provided. Yellow (Y), magenta (M), cyan (C), and black (K) are basic colors used to reproduce the requested color. Further, (V), (Y), (M), (C), and (K) shown in FIG. In the following description, when it is not necessary to distinguish the special colors (V), yellow (Y), magenta (M), cyan (C), and black (K), V, Y, M, C, and K are omitted. The toner image forming units 30Y, 30M, 30C, and 30K are examples of the first image unit, and the toner image forming unit 30V is an example of the second image unit. The control of each unit by the control unit 70 when forming an image using the special color (V) and the special color (V) toner will be described later.

  Each color toner image forming unit 30 is basically configured in the same manner except for the toner to be used. As shown in FIG. 4, a rotating cylindrical image holding body 40 and a charging for charging the image holding body 40. Instrument 42. Further, the toner image forming unit 30 forms an electrostatic latent image as a toner image with an exposure device 44 that irradiates the charged image carrier 40 with exposure light to form an electrostatic latent image, and a developer G containing toner. And a developing device 46 for developing.

  Further, as shown in FIG. 1, each color toner image forming unit 30 includes a toner cartridge 78 that stores toner supplied to the developing device 46. Further, as shown in FIG. 1, each color image carrier 40 is in contact with a transfer belt 50 (details will be described later) that circulate. In the circumferential direction of the transfer belt 50 (see the arrow in the figure), toner image forming portions of special colors (V), yellow (Y), magenta (M), cyan (C), and black (K) from the upstream side. 30 are arranged in the horizontal direction in this order. In each color toner image forming section, each color image is formed using each color toner.

(Transfer part 32)
As shown in FIG. 1, the transfer unit 32 is configured to transfer a toner image formed on a transfer belt 50 that is wound around a plurality of rolls (reference numerals omitted) and circulates in an arrow direction in the drawing, and an image holding member 40 of each color. A primary transfer roll 52 for each color to be transferred onto the transfer belt 50 is provided. The transfer belt 50 is an example of a transfer target.

  The primary transfer roll 52 is disposed on the opposite side of the image carrier 40 with the transfer belt 50 interposed therebetween. The primary transfer roll 52 is applied with a transfer bias voltage (positive voltage) having a polarity opposite to the toner polarity (negative polarity in the present embodiment as an example) by a power supply unit (not shown). By applying this transfer bias voltage, a transfer current flows between the primary transfer roll 52 and the image carrier 40, and the toner image formed on the image carrier 40 is transferred onto the transfer belt 50.

  Further, the transfer unit 32 is arranged on the opposite side of the winding roll 56 around which the transfer belt 50 is wound, and the transfer belt 50, and the toner image transferred onto the transfer belt 50 is transferred to the sheet. And a secondary transfer roll 54 to be transferred to the member P. Thus, a transfer nip NT for transferring the toner image to the sheet member P is formed between the secondary transfer roll 54 and the transfer belt 50. The secondary transfer roll 54 is an example of a transfer member.

  The secondary transfer roll 54 is applied with a transfer bias voltage (positive voltage) having a polarity opposite to the toner polarity by a power supply unit (not shown). By applying this transfer bias voltage, a transfer current flows between the secondary transfer roll 54 and the winding roll 56, and the toner image is transferred from the transfer belt 50 to the sheet member P onto the sheet member P passing through the transfer nip NT. (To be formed).

  In this configuration, toner images are superimposed on the transfer belt 50 by the primary transfer roll 52 in the order of special color (V), yellow (Y), magenta (M), cyan (C), and black (K). Primary transcription. The superimposed toner image is secondarily transferred by the secondary transfer roll 54 to the sheet member P passing through the transfer nip NT.

  Details of the primary transfer roll 52 and the winding roll 56 will be described later.

<Main part configuration>
Next, the special toner used as the special color (V), the primary transfer roll 52 and the winding roll 56 of the transfer unit 32, the control unit 70, and the like will be described.

(Special toner)
As the special toner, silver toner containing a metal pigment, transparent toner (so-called clear toner), and white toner are used. In other words, one special toner among a plurality of types of special toners is used as the special color (V) toner.

-Silver toner-
As shown in FIGS. 17A and 17B, the silver toner is a toner formed by including a metal pigment 110 as an example of a metal pigment and a binder resin 111.

  As for the silver toner image K-2 using the silver toner, in principle, the silver toner image K-2 is formed on the sheet member P so as not to overlap the basic toner image K-1. As a result, a silver metallic glossy image is partially formed (a part of the entire image) (see FIG. 10C).

  However, exceptionally, when the silver toner image K-2 having an image density of 5% is formed on the basic toner image K-1 on the sheet member P, a metallic gloss is imparted to the entire image. An image is formed (see FIG. 11B). The image density need only be such that the silver toner image K-2 gives a metallic gloss to the entire image, and the basic toner image K-1 only needs to be visible through the silver toner image K-2. For this reason, the image density is not limited to 5 [%], and may be, for example, 4 [%] or more and 8 [%] or less. The basic toner image K-1 is an example of a first image, and the silver toner image K-2 is an example of a second image.

  The metal pigment 110 is made of aluminum. When the metal pigment 110 is placed on a plane and viewed from the side, as shown in FIG. 18B, the metal pigment 110 has a dimension in the left-right direction that is longer than the dimension in the vertical direction in the figure. It is made into a shape.

  Further, when the metal pigment 110 shown in FIG. 18B is viewed from above in the drawing, the metal pigment 110 has a shape that is wider than the shape viewed from the side, as shown in FIG. The The pigment 110 has a pair of reflecting surfaces 110A (flat surfaces) facing upward or downward in a state where the pigment 110 is placed on a plane (see FIG. 18B). Then, as shown in FIGS. 17A and 17B, the direction of the reflected light reflected from the image can be controlled by changing the direction in which the reflecting surface 110A of the pigment 110 faces.

-Transparent toner-
The transparent toner is a toner formed by including a dye, a pigment, and a binder resin, and is a transparent toner in which the content of a colorant such as a dye or pigment is 0.01% by mass or less.

  For the transparent toner image K-3 using the transparent toner, in principle, the transparent toner image K-3 having an image density of 100% is formed on the sheet member P so as to overlap the basic toner image K-1. As a result, an image with a stereoscopic effect is formed (see FIG. 12B). The image density need only be such that the transparent toner image K-3 gives a three-dimensional effect to the entire image, and the transparent toner image K-3 is formed on the sheet member P on the basic toner image K-1. What is necessary is just to be formed. For this reason, the image density is not limited to 100 [%], and may be, for example, 70 [%] or more and 100 [%] or less.

  However, as an exception, the transparent toner image K-3 having an image density of 100% is formed on the sheet member P below the basic toner image K-1, so that the surface of the sheet member P is uneven. An image with reduced influence is formed (see FIG. 13C). With respect to this image density, the transparent toner image K-3 only needs to flatten the unevenness of the sheet member, and the transparent toner image K-3 is formed on the sheet member P below the basic toner image K-1. It only has to be. For this reason, the image density is not limited to 100 [%], and may be, for example, 70 [%] or more and 100 [%] or less. The transparent toner image K-3 is an example of a second image.

-White toner-
The white toner is a toner formed by including a dye, a pigment, and a binder resin. The white toner contains a white colorant, and L * a by a spectral color difference meter SE6000 (manufactured by Nippon Denshoku Industries Co., Ltd.). * B * is a toner whose measured value (light source D ₆₅ 2 °) is L *: 90 or more, a *: 5 or less, and b *: 5 or less.

  For the white toner image K-4 using the white toner, in principle, a white toner image K-4 having an image density of 100% is formed on the sheet member P so as to overlap the basic toner image K-1. Thus, an image in which the influence of the background color of the sheet member P is reduced is formed. For this image density, the white toner image K-4 only needs to hide the background color of the sheet member P, and the white toner image K-4 is formed on the sheet member P below the basic toner image K-1. It only has to be done. For this reason, the image density is not limited to 100 [%], and may be, for example, 70 [%] or more and 100 [%] or less.

  However, as an exception, a white toner image K-4 having an image density of 5% is formed on the basic toner image K-1 on the sheet member P, so that an image with a depth added to the color is obtained. It is formed. Regarding the image density, it is sufficient that the white toner image K-4 gives a depth to the color, and it is sufficient that the basic toner image K-1 is visible through the white toner image K-4. For this reason, the image density is not limited to 5 [%], and may be, for example, 4 [%] or more and 8 [%] or less. The white toner image K-4 is an example of a second image.

(Transfer part 32)
As shown in FIG. 4, the transfer unit 32 contacts the primary transfer roll 52 with a rail member 86 that guides the primary transfer roll 52 to a contact position (solid line in the figure) and a separation position (two-dot chain line in the figure). The moving member 88 (refer FIG. 6) moved to a position and a separation position is provided. Specifically, the primary transfer roll 52 moved to the contact position sandwiches the transfer belt 50 between the image holding body 40 and the transfer belt 50 contacts the image holding body 40. Further, the primary transfer roll 52 moved to the separation position is separated from the image carrier 40 and the transfer belt 50 is separated from the image carrier 40 by gravity. The transfer belt 50 is an example of a transfer target.

  Further, as shown in FIG. 5, the transfer unit 32 includes a rail member 96 that guides the winding roll 56 to a contact position (solid line in the drawing) and a separation position (two-dot chain line in the drawing), and the winding roll 56. Is provided with a moving member 98 (see FIG. 6) for moving between the contact position and the separation position. Specifically, the winding roll 56 moved to the contact position sandwiches the transfer belt 50 between the secondary transfer roll 54 and brings the transfer belt 50 into contact with the secondary transfer roll 54. Further, the winding roll 56 moved to the separation position is separated from the secondary transfer roll 54, and the transfer belt 50 is separated from the secondary transfer roll 54 by the tension of the transfer belt 50.

(Other)
As shown in FIG. 6, the image forming apparatus 10 includes a detection unit 80 that detects which toner is used as the special toner. Specifically, the detection unit 80 reads a barcode (not shown) attached to a toner cartridge 78V (see FIG. 1) containing special toner supplied to the developing device 46V. The detection unit 80 detects which toner is used among silver toner, transparent toner, and white toner.

  Further, a switching button 82 (see FIG. 6) for changing the transfer order of the special toner is displayed on the operation screen of the image forming apparatus 10. When the operation button 82 is pressed by the user, the special toner is used for exceptional use.

  Specifically, when transparent toner is used as the special toner, when the switching button 82 is pressed, a transparent toner image K-3 having an image density of 100% is displayed on the sheet member P as a basic toner image K-1. Formed under. That is, on the transfer belt 50, after the basic toner image K-1 is transferred onto the transfer belt 50, the transparent toner image K-3 having an image density of 100% is transferred onto the transfer belt 50.

  Also, when white toner is used as the special toner, the white toner image K-4 having an image density of 5% is placed on the basic toner image K-1 on the sheet member P by pressing the switching button 82. It is formed. That is, on the transfer belt 50, the white toner image K-4 having an image density of 5% is transferred onto the transfer belt 50 before the basic toner image K-1 is transferred onto the transfer belt 50.

(Control unit 70)
The control unit 70 shown in FIG. 6 controls each unit based on the detection result of the detection unit 80 and the like. In addition, control of each part by the control part 70 is demonstrated with the effect | action mentioned later.

<Operation of main components>
The effect | action of a principal part structure is demonstrated using the flowchart shown in FIGS. In a state before the image forming apparatus 10 is operated, the primary transfer rolls 52 and the winding rolls 56 of the respective colors are arranged at the contact positions.

  When the image forming apparatus 10 receives an image formation instruction, in step S100 illustrated in FIG. 7, the control unit 70 receives a detection signal from the detection unit 80 from the detection unit 80, and whether or not silver toner is used as the special toner. Determine whether. If the toner is silver toner, the process proceeds to step S200. Otherwise, the process proceeds to step S220.

  In step S200, the control unit 70 determines whether an image formation instruction using silver toner has been received. If an image formation instruction using silver toner is received, the process proceeds to step S300. Otherwise, the process proceeds to step S310.

  In step S300, the control unit 70 determines whether or not the silver toner image K-2 is an image formation instruction that is formed on the sheet member P so as not to overlap the basic toner image K-1. If the image forming instruction is such that the silver toner image K-2 is not overlapped with the basic toner image K-1 on the sheet member P, the process proceeds to step S400. Otherwise, the process proceeds to step 410. Transition.

  In step S400, the control unit 70 controls each member to start an image forming operation. Specifically, the control unit 70 controls the moving member 88V and the moving member 98 to move the primary transfer roll 52V and the winding roll 56 from the contact position to the separated position as shown in FIG. . In this state, the control unit 70 forms the basic color basic toner image K-1 by the basic color toner image forming units 30Y, 30M, 30C, and 30K, and circulates the basic toner image K-1. 50 is transferred. As a result, a basic toner image K-1 is formed on the transfer belt 50 as shown in FIG. In addition, the basic toner image K-1 is not formed at a portion where the silver toner image K-2 is formed. In each of the drawings except FIG. 4, the transfer belt 50 is shown in contact with the image carrier 40 with the primary transfer roll 52 disposed at a separated position. It is slightly separated from the holding body 40.

  Further, when the basic toner image K-1 passes between the winding roll 56 and the secondary transfer roll 54, the control unit 70 controls the moving members 88Y, 88M, 88C, 88K, 88V and the moving member 98. To do. 3, the primary transfer roll 52V and the winding roll 56 are moved from the separated position to the contact position, and the primary transfer rolls 52Y, 52M, 52C, and 52K are moved from the contact position to the separated position.

  In this state, the control unit 70 causes the toner image forming unit 30 </ b> V to form a silver toner image K- 2 and transfers the silver toner image K- 2 onto the transfer belt 50. As a result, as shown in FIG. 10B, the silver toner image K-2 is formed on the transfer belt 50 so as not to overlap the basic toner image K-1. As described above, when the special toner includes the metal pigment 110, the silver toner image K-2 is transferred to the transfer belt 50 after the basic toner image K-1 is transferred onto the transfer belt 50.

  That is, the basic toner image K-1 is transferred onto the transfer belt 50 by passing the portion where the basic toner image K-1 is formed on the transfer belt 50 through the transfer nip NT without transferring the image. Later, the silver toner image K-2 is transferred onto the transfer belt 50. In other words, in order to change the order in which the transfer belt 50 is arranged in the circumferential direction and the order in which the transfer belt 50 is transferred to the transfer belt 50, it passes through the position where the toner image transferred to the transfer belt 50 is transferred to the sheet member P. Thereafter, the subsequent toner image is transferred to the transfer belt 50.

  Further, when the basic toner image K-1 and the silver toner image K-2 formed on the transfer belt 50 are transferred onto the sheet member P and fixed on the sheet member P by the secondary transfer roll 54, The control unit 70 discharges the sheet member P to the outside of the apparatus. In this way, as shown in FIG. 10C, the silver toner image K-2 is formed on the sheet member P so as not to overlap the basic toner image K-1.

  When the image forming operation on the sheet member P is completed, the control unit 70 moves the primary transfer roll 52 disposed at the separation position to the contact position, and the series of operations is completed.

  On the other hand, if it is determined in step S300 that the silver toner image K-2 is not an image formation instruction so as not to overlap the basic toner image K-1 on the sheet member P, the process proceeds to step 410. In step S410, the control unit 70 controls each member so that the silver toner image K-2 having an image density of 5% is formed on the basic toner image K-1 on the sheet member P, The image forming operation is started.

  Specifically, the control unit 70 controls the moving member 88 and the moving member 98 so that the primary transfer roll 52 and the winding roll 56 are arranged at the contact positions as shown in FIG. To maintain. In this state, the control unit 70 causes the basic color toner image forming units 30Y, 30M, 30C, and 30K to form the basic color basic toner image K-1, and the silver toner image forming unit 30V to set the image density to 5. [%] Of silvery silver toner image K-2 is formed. Then, the control unit 70 transfers each image onto the rotating transfer belt 50. As a result, as shown in FIG. 11A, on the transfer belt 50, a silver toner image K-2 and a basic toner image K-1 are formed in this order.

  Thus, as can be seen from the above-described operation, the step is performed when the instruction to transfer the silver toner image K-2 to the transfer belt 50 is received before the basic toner image K-1 is transferred to the transfer belt 50. The process proceeds from S300 to step S410.

  Further, when the silver toner image K-2 and the basic toner image K-1 formed on the transfer belt 50 are transferred onto the sheet member P by the secondary transfer roll 54 and fixed on the sheet member P, the control is performed. The unit 70 discharges the sheet member P to the outside of the apparatus. Thus, as shown in FIG. 11B, the basic toner image K-1 and the silver toner image K-2 are formed on the sheet member P in this order.

  When the sheet member P is discharged to the outside of the apparatus, a series of operations ends.

  On the other hand, if it is not an instruction to form an image using silver toner in step S200, the process proceeds to step S310. In step S310, the control unit 70 controls each member to form an image using only the basic toner, and starts an image forming operation.

  Specifically, the control unit 70 controls the moving member 88 and the moving member 98 so that the primary transfer roll 52 and the winding roll 56 are arranged at the contact positions as shown in FIG. To maintain. In this state, the control unit 70 forms the basic color basic toner image K-1 by the basic color toner image forming units 30Y, 30M, 30C, and 30K, and transfers each image onto the rotating transfer belt 50. Let Further, when the basic toner image K-1 formed on the transfer belt 50 is transferred onto the sheet member P by the secondary transfer roll 54 and fixed to the sheet member P, the control unit 70 causes the sheet member P to be transferred. To the outside of the device. In this way, the basic toner image K-1 is formed on the sheet member P.

  When the sheet member P is discharged to the outside of the apparatus, a series of operations ends.

  On the other hand, if silver toner is not used as the special toner in step S100, the process proceeds to step S220.

  In step S220, the control unit 70 determines from the detection signal received from the detection unit 80 whether or not transparent toner is used as the special toner. If it is a transparent toner, the process proceeds to step S320. If it is not a transparent toner, it is determined to be a white toner, and the process proceeds to step S350.

  In step S320, the control unit 70 determines whether an image formation instruction using transparent toner has been received. If the instruction is to form an image using transparent toner, the process proceeds to step S420. Otherwise, the process proceeds to step S430.

  In step S420, the control unit 70 determines whether or not the operation button 82 has been pressed. If the operation button 82 has not been pressed, the process proceeds to step S520, and if it has been pressed, the process proceeds to step S530.

  In step S520, the control unit 70 controls each member to start the image forming operation so that the transparent toner image K-3 is formed on the basic toner image K-1 on the sheet member P. .

  Specifically, the control unit 70 controls the moving member 88 and the moving member 98 so that the primary transfer roll 52 and the winding roll 56 are arranged at the contact positions as shown in FIG. To maintain. In this state, the control unit 70 causes the basic color toner image forming units 30Y, 30M, 30C, and 30K to form the basic color basic toner image K-1. Further, the control unit 70 causes the toner image forming unit 30V to form a transparent transparent toner image K-3, and transfers each image onto the rotating transfer belt 50. As a result, as shown in FIG. 12A, a transparent toner image K-3 and a basic toner image K-1 are formed in this order on the transfer belt 50.

  Further, when the transparent toner image K-3 and the basic toner image K-1 formed on the transfer belt 50 are transferred onto the sheet member P and fixed on the sheet member P by the secondary transfer roll 54, The control unit 70 discharges the sheet member P to the outside of the apparatus. Thus, as shown in FIG. 12B, the basic toner image K-1 and the transparent toner image K-3 are formed on the sheet member P in this order.

  When the sheet member P is discharged to the outside of the apparatus, a series of operations ends.

  On the other hand, when the operation button 82 is pressed in step S420, the process proceeds to step S530. In step S530, the control unit 70 controls each member so that the transparent toner image K-3 having an image density of 100% is formed on the sheet member P below the basic toner image K-1, The image forming operation is started.

  Specifically, the control unit 70 controls the moving member 88V and the moving member 98 to move the primary transfer roll 52V and the winding roll 56 from the contact position to the separated position as shown in FIG. . In this state, the control unit 70 forms the basic color basic toner image K-1 by the basic color toner image forming units 30Y, 30M, 30C, and 30K, and circulates the basic toner image K-1. 50 is transferred. As a result, a basic toner image K-1 is formed on the transfer belt 50 as shown in FIG.

  Further, when the basic toner image K-1 passes between the winding roll 56 and the secondary transfer roll 54, the control unit 70 controls the moving members 88Y, 88M, 88C, 88K, 88V and the moving member 98. To do. Then, as shown in FIG. 3, the primary transfer roll 52V and the winding roll 56 are moved from the separated position to the contact position, and the primary transfer rolls 52Y, 52M, 52C, and 52K are moved from the contact position to the separated position.

  In this state, the control unit 70 causes the toner image forming unit 30V to form a transparent toner image K-3 having an image density of 100% and transfers the transparent toner image K-3 onto the transfer belt 50. As a result, as shown in FIG. 13B, the basic toner image K-1 and the transparent toner image K-3 are formed in this order on the transfer belt 50.

  That is, the basic toner image K-1 is transferred onto the transfer belt 50 by passing the portion where the basic toner image K-1 is formed on the transfer belt 50 through the transfer nip NT without transferring the image. Later, the transparent toner image K-3 is transferred onto the transfer belt 50. In other words, in order to change the order in which the transfer belt 50 is arranged in the circumferential direction and the order in which the transfer belt 50 is transferred to the transfer belt 50, it passes through the position where the toner image transferred to the transfer belt 50 is transferred to the sheet member P. Thereafter, the subsequent toner image is transferred to the transfer belt 50.

  As described above, as can be understood from the above-described operation, when the instruction to transfer the transparent toner image K-3 to the transfer belt 50 is received after the basic toner image K-1 is transferred to the transfer belt 50, step S420. To step S530.

  Further, when the basic toner image K-1 and the transparent toner image K-3 formed on the transfer belt 50 are transferred onto the sheet member P by the secondary transfer roll 54 and fixed on the sheet member P, The control unit 70 discharges the sheet member P to the outside of the apparatus. In this manner, as shown in FIG. 13C, the transparent toner image K-3 and the basic toner image K-1 are formed on the sheet member P in this order.

  When the image forming operation on the sheet member P is completed, the control unit 70 moves the primary transfer roll 52 disposed at the separation position to the contact position, and the series of operations is completed.

  On the other hand, if it is an instruction to form an image without using transparent toner in step S320, the process proceeds to step S430. In step S430, the control unit 70 controls each member to form an image using only the basic toner, and starts an image forming operation.

  Specifically, the control unit 70 controls the moving member 88 and the moving member 98 so that the primary transfer roll 52 and the winding roll 56 are arranged at the contact positions as shown in FIG. To maintain. In this state, the control unit 70 forms the basic color basic toner image K-1 by the basic color toner image forming units 30Y, 30M, 30C, and 30K, and transfers each image onto the rotating transfer belt 50. Let Further, when the basic toner image K-1 formed on the transfer belt 50 is transferred onto the sheet member P by the secondary transfer roll 54 and fixed to the sheet member P, the control unit 70 causes the sheet member P to be transferred. To the outside of the device. In this way, the basic toner image K-1 is formed on the sheet member P.

  When the sheet member P is discharged to the outside of the apparatus, a series of operations ends.

  On the other hand, if it is determined in step S220 that white toner is used as the special toner, the process proceeds to step S350. In step S350, the control unit 70 determines whether an image formation instruction using white toner has been received. If the instruction is to form an image using white toner, the process proceeds to step S450. Otherwise, the process proceeds to step S460.

  In step S450, control unit 70 determines whether or not operation button 82 has been pressed. If the operation button 82 is not pressed, the process proceeds to step S550, and if it is pressed, the process proceeds to step S560.

  In step S560, the control unit 70 controls each member so that a white toner image K-4 having an image density of 100% is formed on the sheet member P below the basic toner image K-1, The image forming operation is started.

  Specifically, the control unit 70 controls the moving member 88V and the moving member 98 to move the primary transfer roll 52V and the winding roll 56 from the contact position to the separated position as shown in FIG. . In this state, the control unit 70 forms the basic color basic toner image K-1 by the basic color toner image forming units 30Y, 30M, 30C, and 30K, and circulates the basic toner image K-1. 50 is transferred. As a result, a basic toner image K-1 is formed on the transfer belt 50 as shown in FIG.

  Further, when the basic toner image K-1 passes between the winding roll 56 and the secondary transfer roll 54, the control unit 70 controls the moving members 88Y, 88M, 88C, 88K, 88V and the moving member 98. To do. Then, as shown in FIG. 3, the primary transfer roll 52V and the winding roll 56 are moved from the separated position to the contact position, and the primary transfer rolls 52Y, 52M, 52C, and 52K are moved from the contact position to the separated position.

  In this state, the control unit 70 causes the toner image forming unit 30V to form a white toner image K-4 having an image density of 100% and transfers the white toner image K-4 onto the transfer belt 50. Accordingly, as shown in FIG. 14B, the basic toner image K-1 and the white toner image K-4 are formed in this order on the transfer belt 50.

  That is, the basic toner image K-1 is transferred onto the transfer belt 50 by passing the portion where the basic toner image K-1 is formed on the transfer belt 50 through the transfer nip NT without transferring the image. Later, the white toner image K-4 is transferred onto the transfer belt 50. In other words, in order to change the order in which the transfer belt 50 is arranged in the circumferential direction and the order in which the transfer belt 50 is transferred to the transfer belt 50, it passes through the position where the previous toner image transferred to the transfer belt 50 is transferred to the sheet member P. Thereafter, the subsequent toner image is transferred to the transfer belt 50.

  Thus, as can be seen from the above-described operation, the step is performed when the instruction to transfer the white toner image K-4 to the transfer belt 50 is received before the basic toner image K-1 is transferred to the transfer belt 50. The process proceeds from S450 to step S560.

  Further, when the basic toner image K-1 and the white toner image K-4 formed on the transfer belt 50 are transferred onto the sheet member P and fixed on the sheet member P by the secondary transfer roll 54, The control unit 70 discharges the sheet member P to the outside of the apparatus. In this way, as shown in FIG. 14C, the white toner image K-4 and the basic toner image K-1 are formed on the sheet member P in this order.

  When the image forming operation on the sheet member P is completed, the control unit 70 moves the primary transfer roll 52 disposed at the separation position to the contact position, and the series of operations is completed.

  On the other hand, if the operation button 82 is pressed in step S450, the process proceeds to step S560. In step S560, the control unit 70 controls each member so that the white toner image K-4 having an image density of 5% is formed on the basic toner image K-1 on the sheet member P. The image forming operation is started.

  Specifically, the control unit 70 controls the moving member 88 and the moving member 98 so that the primary transfer roll 52 and the winding roll 56 are arranged at the contact positions as shown in FIG. To maintain. In this state, the control unit 70 causes the basic color toner image forming units 30Y, 30M, 30C, and 30K to form the basic color basic toner image K-1. Further, the control unit 70 causes the toner image forming unit 30 </ b> V to form a white toner image K- 4 having an image density of 5% and transfers each image onto the rotating transfer belt 50. As a result, as shown in FIG. 15A, on the transfer belt 50, a white toner image K-4 and a basic toner image K-1 are formed in this order.

  Further, when the white toner image K-4 and the basic toner image K-1 formed on the transfer belt 50 are transferred onto the sheet member P and fixed on the sheet member P by the secondary transfer roll 54, The control unit 70 discharges the sheet member P to the outside of the apparatus. Thus, as shown in FIG. 15B, the basic toner image K-1 and the white toner image K-4 are formed on the sheet member P in this order.

  When the sheet member P is discharged to the outside of the apparatus, a series of operations ends.

  On the other hand, if it is an image formation instruction not using white toner in step S350, the process proceeds to step S460. In step S460, the control unit 70 controls each member to form an image using only the basic toner, and starts an image forming operation.

  Specifically, the control unit 70 controls the moving member 88 and the moving member 98 so that the primary transfer roll 52 and the winding roll 56 are arranged at the contact positions as shown in FIG. To maintain. In this state, the control unit 70 forms the basic color basic toner image K-1 by the basic color toner image forming units 30Y, 30M, 30C, and 30K, and transfers each image onto the rotating transfer belt 50. Let Further, when the basic toner image K-1 formed on the transfer belt 50 is transferred onto the sheet member P by the secondary transfer roll 54 and fixed to the sheet member P, the control unit 70 causes the sheet member P to be transferred. To the outside of the device. In this way, the basic toner image K-1 is formed on the sheet member P.

  When the sheet member P is discharged to the outside of the apparatus, a series of operations ends.

(Summary)
As described above, the basic toner image K-1, the silver toner image K-2, the transparent toner image K-3, or the white toner image K-4 can be used without changing the position where the toner image forming unit 30 is disposed. The order in which the toner is transferred onto the transfer belt 50 can be determined based on the type of special toner.

  Further, when the special toner is a silver toner containing a metallic pigment, it is formed so as not to overlap the basic toner image K-1 on the transfer belt 50P in principle. In this case, after the basic toner image K-1 is transferred onto the transfer belt 50, the silver toner image K-2 is transferred onto the transfer belt 50.

  Here, since the silver toner containing a metallic pigment has a lower resistance value than the basic toner, the silver toner image K-2 is transferred onto the transfer belt 50 before the basic toner image K-1. Then, in the downstream primary transfer process, retransfer (a part of silver toner may adhere to the image carrier 40) may be performed on the basic color image carrier 40. However, in the present embodiment, in principle, since the silver toner image K-2 is transferred onto the transfer belt 50 after the basic toner image K-1 is transferred onto the transfer belt 50, the silver toner image K-- As compared with the case where the toner image K-2 is transferred onto the transfer belt 50 before the basic toner image K-1, the silver toner image K-2 is retransferred (so-called retransfer) to the basic color image holding member 40. It is suppressed.

  By suppressing the retransfer of the silver toner image K-2 to the basic color image carrier 40, the silver toner image K-2 is placed on the transfer belt 50 before the basic toner image K-1. Compared with the case where the image is transferred, the deterioration of the quality of the output image is suppressed.

  Further, when a command to transfer the silver toner image K-2 onto the transfer belt 50 is received before the basic toner image K-1 is transferred onto the transfer belt 50, the basic toner image K-1 is transferred to the transfer belt 50. Before being transferred onto the transfer belt 50, the silver toner image K-2 having an image density of 5% is transferred onto the transfer belt 50. Then, a silver toner image K-2 having an image density of 5% is formed on the basic toner image K-1 on the sheet member P. As a result, compared to the case where the silver toner image K-2 having an image density of 5% is not formed, a metallic gloss is imparted to the entire image and the appearance of the image is improved.

  When the special toner is a transparent toner, in principle, the transparent toner image K-3 having an image density of 100% is transferred before the basic toner image K-1 is transferred onto the transfer belt 50. Transferred onto the belt 50. Then, a transparent toner image K-3 having an image density of 100 [%] is formed on the basic toner image K-1 on the sheet member P. Thereby, a stereoscopic effect is given to the whole image, and the appearance of the image is improved.

  Further, after the operation button 82 is pressed and the basic toner image K-1 is transferred onto the transfer belt 50, a command to transfer the transparent toner image K-3 having an image density of 100% to the transfer belt 50 is issued. When received, after the basic toner image K-1 is transferred onto the transfer belt 50, the transparent toner image K-3 is transferred onto the transfer belt 50. Then, a transparent toner image K-3 having an image density of 100 [%] is formed on the sheet member P under the basic toner image K-1. Thereby, the unevenness on the surface of the sheet member P is flattened by the transparent toner image K-3, and the deterioration of the quality of the output image is suppressed as compared with the case where the transparent toner image K-3 is not formed.

  When the special toner is white toner, in principle, after the basic toner image K-1 is transferred onto the transfer belt 50, the white toner image K-4 having an image density of 100% is transferred to the transfer belt. 50 is transferred. A white toner image K-4 having an image density of 100% is formed on the sheet member P under the basic toner image K-1. Thereby, the influence of the ground color of the sheet member P is reduced as compared with the case where the white toner image K-4 is not formed.

  Further, when the operation button 82 is pressed and the instruction to transfer the white toner image K-4 onto the transfer belt 50 is received before the basic toner image K-1 is transferred onto the transfer belt 50, the basic toner image K-1 is transferred to the transfer belt 50. Before the toner image K-1 is transferred onto the transfer belt 50, the white toner image K-4 having an image density of 5% is transferred onto the transfer belt 50. Then, a white toner image K-4 having an image density of 5 [%] is formed on the basic toner image K-1 on the sheet member P. As a result, the color is deeper than when the white toner image K-4 is not formed.

<< Second Embodiment >>
Next, an example of an image forming apparatus according to the second embodiment will be described with reference to FIGS. In addition, about 2nd Embodiment, a different part from 1st Embodiment is mainly demonstrated.

(Constitution)
In the image forming apparatus 310 of the second embodiment, as shown in FIG. 19, in the circumferential direction of the transfer belt 50, yellow (Y), magenta (M), cyan (C), black (K), The special color (V) toner image forming units 30 are arranged in this order. Further, as shown in FIG. 22, the image forming apparatus 310 includes a control unit 370 that controls each unit.

(Function)
-When the special toner is silver toner-
When the silver toner image K-2 is formed on the sheet member P so as not to overlap the basic toner image K-1, the control unit 370 controls each member to start an image forming operation (FIG. 7). Step S400).

  Specifically, the control unit 370 controls the moving member 88 and the moving member 98 so that the primary transfer roll 52 and the winding roll 56 are disposed at the contact positions as shown in FIG. To maintain. In this state, the control unit 370 causes the basic color toner image forming units 30Y, 30M, 30C, and 30K to form the basic color basic toner image K-1, and the silver toner image forming unit 30V to form the silver silver color. A toner image K-2 is formed, and each image is transferred onto the rotating transfer belt 50. Thus, the silver toner image K-2 is formed on the transfer belt 50 so as not to overlap with the basic toner image K-1 (see FIG. 10B). That is, after the basic toner image K-1 is transferred to the transfer belt 50, the silver toner image K-2 is transferred to the transfer belt 50.

  Further, when the silver toner image K-2 and the basic toner image K-1 formed on the transfer belt 50 are transferred onto the sheet member P and fixed on the sheet member P by the secondary transfer roll 54, The control unit 370 discharges the sheet member P to the outside of the apparatus. In this way, the silver toner image K-2 is formed on the sheet member P so as not to overlap the basic toner image K-1 (see FIG. 10C).

  On the other hand, when the silver toner image K-2 having an image density of 5% is formed on the basic toner image K-1 on the sheet member P, the control unit 370 controls each member. Thus, the image forming operation is started (step S410 in FIG. 7).

  Specifically, the control unit 370 controls the moving members 88Y, 88M, 88C, 88K and the moving member 98, and as shown in FIG. 20, the primary transfer rolls 52Y, 52M, 52C, 52K, and the windings The hanging roll 56 is moved from the contact position to the separated position. In this state, the control unit 370 forms a silver toner image K-2 having an image density of 5% by the toner image forming unit 30V of silver toner, and on the transfer belt 50 that circulates the silver toner image K-2. Let them transcribe. As a result, a silver toner image K-2 is formed on the transfer belt 50 as shown in FIG.

  Further, when the silver toner image K-2 passes between the winding roll 56 and the secondary transfer roll 54, the control unit 370 controls the moving members 88Y, 88M, 88C, 88K, 88V and the moving member 98. To do. Then, as shown in FIG. 21, the primary transfer rolls 52Y, 52M, 52C, 52K and the winding roll 56 are moved from the separated position to the contact position, and the primary transfer roll 52V is moved from the contact position to the separated position.

  In this state, the basic toner image K-1 is formed by the toner image forming units 30Y, 30M, 30C, and 30K, and the basic toner image K-1 is transferred onto the transfer belt 50. Thus, as shown in FIG. 23B, a silver toner image K-2 is formed on the transfer belt 50 below the basic toner image K-1.

  That is, the silver toner image K-2 is transferred onto the transfer belt 50 by passing the portion where the silver toner image K-2 is formed on the transfer belt 50 through the transfer nip NT without transferring the image. Later, the basic toner image K-1 is transferred onto the transfer belt 50. In other words, in order to change the order in which the transfer belt 50 is arranged in the circumferential direction and the order in which the transfer belt 50 is transferred to the transfer belt 50, it passes through the position where the previous toner image transferred to the transfer belt 50 is transferred to the sheet member P. Thereafter, the subsequent toner image is transferred to the transfer belt 50.

  Further, when the silver toner image K-2 and the basic toner image K-1 formed on the transfer belt 50 are transferred onto the sheet member P and fixed on the sheet member P by the secondary transfer roll 54, The control unit 370 discharges the sheet member P to the outside of the apparatus. Thus, as shown in FIG. 23C, the basic toner image K-1 and the silver toner image K-2 are formed on the sheet member P in this order.

-When special toner is transparent toner-
When the transparent toner image K-3 having an image density of 100% is formed on the basic toner image K-1 on the sheet member P, the control unit 370 controls each member to perform the image forming operation. Start (step S520 in FIG. 8).

  Specifically, the control unit 370 controls the moving members 88Y, 88M, 88C, 88K and the moving member 98, and as shown in FIG. 20, the primary transfer rolls 52Y, 52M, 52C, 52K, and the windings The hanging roll 56 is moved from the contact position to the separated position. In this state, the control unit 370 forms the transparent toner image K-3 with an image density of 100% by the toner image forming unit 30V of the transparent toner, and the transfer belt 50 that circulates the transparent toner image K-3. Let them transcribe. As a result, a transparent toner image K-3 is formed on the transfer belt 50 as shown in FIG.

  Further, when the transparent toner image K-3 passes between the winding roll 56 and the secondary transfer roll 54, the control unit 370 controls the moving members 88Y, 88M, 88C, 88K, 88V and the moving member 98. To do. Then, as shown in FIG. 21, the primary transfer rolls 52Y, 52M, 52C, and 52K and the winding roll 56 are moved from the separated position to the contact position, and the primary transfer roll 52V is moved from the contact position to the separated position.

  In this state, the basic toner image K-1 is formed by the toner image forming units 30Y, 30M, 30C, and 30K, and the basic toner image K-1 is transferred onto the transfer belt 50. Accordingly, as shown in FIG. 24B, a transparent toner image K-3 and a basic toner image K-1 are formed in this order on the transfer belt 50.

  That is, the transparent toner image K-3 is transferred onto the transfer belt 50 by passing the portion where the transparent toner image K-3 is formed on the transfer belt 50 through the transfer nip NT without transferring the image. Later, the basic toner image K-1 is transferred onto the transfer belt 50. In other words, in order to change the order in which the transfer belt 50 is arranged in the circumferential direction and the order in which the transfer belt 50 is transferred to the transfer belt 50, it passes through the position where the previous toner image transferred to the transfer belt 50 is transferred to the sheet member P. Thereafter, the subsequent toner image is transferred to the transfer belt 50.

  Further, when the transparent toner image K-3 and the basic toner image K-1 formed on the transfer belt 50 are transferred onto the sheet member P and fixed on the sheet member P by the secondary transfer roll 54, The control unit 370 discharges the sheet member P to the outside of the apparatus. Thus, as shown in FIG. 24C, the basic toner image K-1 and the transparent toner image K-3 are formed on the sheet member P in this order.

  In contrast, when the transparent toner image K-3 having an image density of 100% is formed on the sheet member P below the basic toner image K-1, the control unit 370 controls each member. Then, the image forming operation is started (step S530 in FIG. 8).

  Specifically, the control unit 370 controls the moving member 88 and the moving member 98 so that the primary transfer roll 52 and the winding roll 56 are disposed at the contact positions as shown in FIG. To maintain. In this state, the control unit 370 causes the basic color toner image forming units 30Y, 30M, 30C, and 30K to form the basic color basic toner image K-1, and the toner image forming unit 30V to form the transparent toner image K--. 3 is formed, and each image is transferred onto the circulating transfer belt 50. Thus, as shown in FIG. 25A, the basic toner image K-1 and the transparent toner image K-3 are formed in this order on the transfer belt 50.

  Further, when the transparent toner image K-3 and the basic toner image K-1 formed on the transfer belt 50 are transferred onto the sheet member P and fixed on the sheet member P by the secondary transfer roll 54, The control unit 370 discharges the sheet member P to the outside of the apparatus. Thus, as shown in FIG. 25B, the transparent toner image K-3 and the basic toner image K-1 are formed on the sheet member P in this order.

-When special toner is white toner-
When the white toner image K-4 having an image density of 100% is formed below the basic toner image K-1 on the sheet member P, the control unit 370 controls each member to perform the image forming operation. Start (step S550 in FIG. 9).

  Specifically, the control unit 370 controls the moving member 88 and the moving member 98 so that the primary transfer roll 52 and the winding roll 56 are disposed at the contact positions as shown in FIG. To maintain. In this state, the control unit 370 causes the basic color toner image forming units 30Y, 30M, 30C, and 30K to form the basic color basic toner image K-1, and the toner image forming unit 30V to form the white toner image K--. 4 is formed, and each image is transferred onto the rotating transfer belt 50. As a result, as shown in FIG. 26A, the basic toner image K-1 and the white toner image K-4 are formed in this order on the transfer belt 50.

  Further, when the white toner image K-4 and the basic toner image K-1 formed on the transfer belt 50 are transferred onto the sheet member P and fixed on the sheet member P by the secondary transfer roll 54, The control unit 370 discharges the sheet member P to the outside of the apparatus. In this way, as shown in FIG. 26B, the white toner image K-4 and the basic toner image K-1 are formed on the sheet member P in this order.

  On the other hand, when the white toner image K-4 having an image density of 5% is formed on the basic toner image K-1 on the sheet member P, the control unit 370 controls each member. Then, the image forming operation is started (step S560 in FIG. 9).

  Specifically, the control unit 370 controls the moving members 88Y, 88M, 88C, 88K and the moving member 98, and as shown in FIG. 20, the primary transfer rolls 52Y, 52M, 52C, 52K, and the windings The hanging roll 56 is moved from the contact position to the separated position. In this state, the control unit 370 forms a white toner image K-4 having an image density of 5% by the white toner image forming unit 30V, and the white toner image K-4 is circulated on the transfer belt 50. Let them transcribe. As a result, a white toner image K-4 is formed on the transfer belt 50 as shown in FIG.

  Further, when the white toner image K-4 passes between the winding roll 56 and the secondary transfer roll 54, the control unit 370 controls the moving members 88Y, 88M, 88C, 88K, 88V, and the moving member 98. To do. Then, as shown in FIG. 21, the primary transfer rolls 52Y, 52M, 52C, 52K and the winding roll 56 are moved from the separated position to the contact position, and the primary transfer roll 52V is moved from the contact position to the separated position.

  In this state, the basic toner image K-1 is formed by the toner image forming units 30Y, 30M, 30C, and 30K, and the basic toner image K-1 is transferred onto the transfer belt 50. As a result, as shown in FIG. 27B, a white toner image K-4 and a basic toner image K-1 are formed in this order on the transfer belt 50.

  That is, the white toner image K-4 is transferred onto the transfer belt 50 by passing the portion where the white toner image K-4 is formed on the transfer belt 50 through the transfer nip NT without transferring the image. Later, the basic toner image K-1 is transferred onto the transfer belt 50. In other words, in order to change the order in which the transfer belt 50 is arranged in the circumferential direction and the order in which the transfer belt 50 is transferred to the transfer belt 50, it passes through the position where the previous toner image transferred to the transfer belt 50 is transferred to the sheet member P. Thereafter, the subsequent toner image is transferred to the transfer belt 50.

  Further, when the white toner image K-4 and the basic toner image K-1 formed on the transfer belt 50 are transferred onto the sheet member P and fixed on the sheet member P by the secondary transfer roll 54, The control unit 370 discharges the sheet member P to the outside of the apparatus. In this way, as shown in FIG. 27C, the basic toner image K-1 and the white toner image K-4 are formed on the sheet member P in this order.

  In addition, the other effect | action of 2nd Embodiment is the same as that of 1st Embodiment.

  Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments can be taken within the scope of the present invention. This will be apparent to those skilled in the art. For example, in the above-described embodiment, the silver toner is used as the special toner including the metal pigment. However, any special toner including the metal pigment may be used. For example, a gold toner may be used.

  In the above-described embodiment, the operation button 82 is pressed to use the transparent toner and the white toner exceptionally. However, in the image forming instruction received by the control units 70 and 370, an instruction to use the exception is used. May be included.

  Although not specifically described in the above embodiment, when the special toner cartridge 78V is replaced with another type of special toner cartridge 78V, the developing device 46 may also be replaced.

  Although not specifically described in the above embodiment, an instruction button for instructing the order of transferring the toner image of the special toner and the basic toner image K-1 of the basic toner to the transfer belt 50 in all cases. May be included in the image forming apparatus.

10 Image forming apparatus 30 Toner image forming unit (an example of a first image unit)
30Y toner image forming unit (an example of a first image unit)
30M toner image forming unit (an example of a first image unit)
30C toner image forming unit (an example of a first image unit)
30K toner image forming unit (an example of a first image unit)
30V toner image forming unit (an example of a second image unit)
50 Transfer belt (an example of a transfer target)
54 Secondary transfer roll (an example of a transfer member)
110 Metal pigment (an example of a metal pigment)
K-1 Basic toner image (example of first image)
K-2 Silver toner image (example of second image)
K-3 Transparent toner image (example of third image)
K-4 White toner image (example of fourth image)

Claims (9)

A first image portion that forms a first image using a basic toner of a basic color;
A second image portion for forming a second image using a special toner different from the basic toner;
A transfer object onto which the first image and the second image are transferred while circling;
A transfer member that transfers the first image and the second image transferred to the transfer object to a recording medium,
The first image portion and the second image portion are arranged side by side in the circumferential direction of the transfer object,
The second image portion forms the second image using one special toner among a plurality of types of special toners,
An image forming apparatus that determines the order in which the second image and the first image are transferred to the transfer target based on the type of the special toner.   2. The image formation according to claim 1, wherein, when the special toner includes a metallic pigment, the second image is transferred to the transfer target after the first image is transferred to the transfer target. apparatus.   Before receiving the instruction to transfer the second image to the transfer object before the first image is transferred to the transfer object, the first image is transferred to the transfer object. The image forming apparatus according to claim 2, wherein the second image is transferred to the transfer target.   2. The image forming apparatus according to claim 1, wherein when the special toner is a transparent toner, the second image is transferred to the transfer target before the first image is transferred to the transfer target. .   After receiving the instruction to transfer the second image to the transferred body after the first image is transferred to the transferred body, after the first image is transferred to the transferred body, The image forming apparatus according to claim 4, wherein the second image is transferred to the transfer body.   When receiving a command to form the second image on the recording medium under the first image, the second image is transferred to the transferred body after the first image is transferred to the transferred body. The image forming apparatus according to claim 4, which is transferred.   2. The image forming apparatus according to claim 1, wherein when the special toner is white toner, the second image is transferred to the transfer target after the first image is transferred to the transfer target.   Before receiving the instruction to transfer the second image to the transfer object before the first image is transferred to the transfer object, the first image is transferred to the transfer object. The image forming apparatus according to claim 7, wherein the second image is transferred to the transfer target.   When receiving a command to form the second image on the recording medium on the first image, the second image is transferred to the transferred body before the first image is transferred to the transferred body. 8. The image forming apparatus according to claim 7, wherein the image forming apparatus is transferred to the image forming apparatus.