Image formation device and image formation method

Abstract

To stabilize the metallic luster of printed matter.SOLUTION: An image formation device 1 previously stores a storage part 81 with a print speed table 96 representing the relation between a value of a dot count d and a print speed VP, and refers to the print speed table 96 in executing print processing to adjust a print speed according to the dot count d at the point of time. The image formation device 1 therefore can increase and decrease the print speed VP properly according to the value of the dot count d, and thereby can suppress variation in mean grain diameter DA to an extremely narrow range even if the remaining amount of silver toner in a toner storage space 21 varies, so that a variation width of an FI value can be suppressed small. Consequently, the image formation device 1 can obtain stable metallic luster in an image printed using silver toner TS without being affected by the remaining amount of silver toner in the toner storage space 21.SELECTED DRAWING: Figure 13

Description

Technical Field

[0001] The present invention relates to an image forming apparatus and an image forming method, and is suitable for application to, for example, an electrophotographic printer.

Background Art

[0002] Conventionally, as an image forming apparatus (also called a printer), based on an image supplied from a computer device or the like, a developer image (also called a toner image) is formed by an image forming unit using a developer (also called toner), transferred to a medium such as paper, and heat and pressure are applied thereto for fixing, whereby a printing process is widely performed.

[0003] In addition, among developers, there are those containing a glittery pigment such as aluminum like a silver developer (also called silver toner) for the purpose of imparting glitter. Also, in an image forming apparatus, in order to obtain a metallic luster, by defining the weight average molecular weight of the silver developer, the size of the glittery pigment, and the content of the glittery pigment in the silver developer, there is one that forms a printed matter having high glitter (FI value) (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in such an image forming apparatus, when printing a printed matter having a glittery developer, it may be difficult to obtain a stable metallic luster.

[0006] The present invention has been made in consideration of the above points, and intends to propose an image forming apparatus and an image forming method capable of stabilizing the metallic luster of printed matter.

Means for Solving the Problems

[0007] In the image forming apparatus of the present invention for solving such problems, it includes a storage unit that stores a luminous developer, an image forming unit capable of forming a luminous developer image with the luminous developer, and a control unit that controls the operation of the image forming unit. When the remaining amount of the luminous developer stored in the storage unit is at a first remaining amount and forming a luminous image on a medium based on predetermined print data, the control unit forms the luminous developer image at a first linear velocity. When the remaining amount of the luminous developer stored in the storage unit is at a second remaining amount less than the first remaining amount and forming a luminous image on a medium based on predetermined print data, the control unit forms the luminous developer image at a second linear velocity lower than the first linear velocity.

[0008] Also, in the image forming method of the present invention, it includes a remaining amount acquisition step of acquiring a remaining amount display value representing the remaining amount of the luminous developer stored in the storage unit of the image forming unit capable of forming a luminous developer image with the luminous developer, a speed setting step of setting the first linear velocity when the remaining amount display value is the first remaining amount and setting the second linear velocity lower than the first linear velocity when the remaining amount display value is a second remaining amount less than the first remaining amount, and a forming step of forming a luminous developer image at the linear velocity set by the speed setting step.

[0009] In the present invention, under the control of the control unit, the rotation speed of the developing roller is changed in the image forming unit to change the linear velocity of the outer peripheral portion, and accordingly, regarding the luminous developer adhering to the surface of the developing roller, the particle size of the luminous developer that can pass between the developing blade is changed. Specifically, in the present invention, when the remaining amount of the luminous developer in the storage unit is at a first remaining amount with a relatively large amount, the average particle size is increased as a relatively high first linear velocity, and when the remaining amount of the luminous developer is at a second remaining amount with a relatively small amount, the average particle size is decreased as a relatively low second linear velocity. Thereby, the present invention can reduce the fluctuation range of the average particle size in the luminous developer. [Effect of the Invention]

[0010] According to the present invention, an image forming apparatus and an image forming method capable of stabilizing the metallic luster of a printed matter can be realized. [Brief Description of the Drawings]

[0011]

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Mode for Carrying Out the Invention

[0012] Hereinafter, the mode for carrying out the invention (hereinafter referred to as the embodiment) will be described with reference to the drawings.

[0013] [1. Configuration of the Image Forming Apparatus] As shown in the schematic side view of FIG. 1, the image forming apparatus 1 according to the present embodiment is an electrophotographic color printer and can form (i.e., print) a color image on a medium MD such as paper. Incidentally, the image forming apparatus 1 does not have an image scanner function for reading a document or a communication function using a telephone line, etc., and is a single - function SFP (Single Function Printer) having only a printer function.

[0014] Various components are arranged inside a housing 2 formed in a substantially box shape in the image forming apparatus 1. Incidentally, hereinafter, with the right - hand end portion in FIG. 1 being defined as the front of the image forming apparatus 1, the vertical direction, the left - right direction, and the front - rear direction when viewed facing this front will be defined and then described.

[0015] The image forming apparatus 1 is overall controlled by a control unit 3. As will be described later, this control unit 3 executes various processes by reading and executing a predetermined program. The control unit 3 is connected wirelessly or wiredly to a host device 100 (Fig. 3) such as a computer device. When image data representing an image to be printed is given from this host device and printing of the image data is instructed, the control unit 3 executes a printing process for forming a printed image on the surface of a medium MD. The display unit 4 is a display device such as a liquid crystal panel, and is disposed on the front side of the upper surface of the housing 2. This display unit 4 displays various information based on the control of the control unit 3.

[0016] Inside the upper side of the housing 2, five image forming units 10K, 10C, 10M, 10Y, and 10S are arranged in order from the front side to the rear side. The image forming units 10K, 10C, 10M, 10Y, and 10S respectively correspond to the colors of black (K), cyan (C), magenta (M), yellow (Y), and special color (S), and only differ in color, and all are configured in the same manner.

[0017] Black (K), cyan (C), magenta (M), and yellow (Y) are all colors used in a general color printer (hereinafter, this is referred to as a normal color or a non-metallic color). On the other hand, the special color (S) is a special color that exhibits metallic luster, that is, has glossiness, such as gold or silver (hereinafter, this is also referred to as a metallic color). This special color may be used alone or may be used overlaid on a normal color. In the present embodiment, the case of using silver as the special color will be described as an example. For convenience of explanation, hereinafter, the image forming units 10K, 10C, 10M, 10Y, and 10S are also collectively referred to as the image forming unit 10. Also hereinafter, the image forming unit 10S is also referred to as a metallic image forming unit.

[0018] As shown in Fig. 2, the image forming unit 10 is roughly composed of an image drum (ID: Image Drum) unit 11, a toner cartridge 12, and an LED (Light Emitting Diode) head 14.

[0019] The toner cartridge 12 houses toner T (also called a developer) inside and is provided with a stirring member or the like for stirring the toner T, and is configured to be detachable from the image drum unit 11. This toner cartridge 12 is attached to the toner supply portion 13 of the image drum unit 11. Incidentally, the toner cartridge 12 may also be called a toner cartridge or a developer container.

[0020] As will be described later, as the silver toner T, a toner containing a bright pigment is used. For convenience of explanation, hereinafter, the silver toner T which is a bright color will be referred to as a silver toner TS, a bright toner, or a bright developer. Further, the toner cartridge 12 containing the silver toner TS is also referred to as a bright developer container.

[0021] On the other hand, as the yellow, magenta, cyan, and black toners T, toners containing organic pigments such as pigment yellow, pigment cyan, pigment magenta, and carbon black are used. For convenience of explanation, hereinafter, the yellow, magenta, cyan, and black (i.e., non-bright color) toners T will also be referred to as color toners, non-bright toners, or non-bright developers.

[0022] The image drum unit 11 (FIG. 2) incorporates a toner supply portion 13, an image forming housing 20, a toner storage space 21, a first supply roller 22, a second supply roller 23, a developing roller 24, a developing blade 25, a photosensitive drum 26, a charging roller 27, and a cleaning blade 28. Among these, the first supply roller 22, the second supply roller 23, the developing roller 24, the photosensitive drum 26, and the charging roller 27 are each configured in a columnar shape with their central axes along the left-right direction, and are each rotatably supported by the image forming housing 20.

[0023] The toner supply unit 13 as a developer supply unit is configured to be switched between an operating state and a stopped state based on the control of the control unit 3. In the operating state, toner is supplied from the toner cartridge 12 to the toner storage space 21.

[0024] The toner storage space 21 as a storage unit stores the toner T supplied from the toner cartridge 12 via the toner supply unit 13. The first supply roller 22 and the second supply roller 23 each have an elastic layer made of conductive urethane rubber foam or the like formed on their circumferential side surfaces. The developing roller 24 has an elastic layer having elasticity, a surface layer having conductivity, or the like formed on its circumferential side surface. The developing blade 25 is made of, for example, a stainless steel plate of a predetermined thickness and has a part thereof in contact with the circumferential side surface of the developing roller 24 in a state of being slightly elastically deformed.

[0025] The photosensitive drum 26 as an image carrier has a thin-film charge generation layer and a charge transport layer sequentially formed on its circumferential side surface and is capable of being charged. The charging roller 27 has a conductive elastic body coated on its circumferential side surface, and this circumferential side surface is in contact with the circumferential side surface of the photosensitive drum 26. The cleaning blade 28 is made of, for example, a thin plate-shaped resin and has a part thereof in contact with the circumferential side surface of the photosensitive drum 26 in a state of being slightly elastically deformed.

[0026] The LED head 14 as an exposure unit is located above the photosensitive drum 26 in the image drum unit 11. The LED head 14 has a plurality of light-emitting element chips arranged linearly along the left-right direction, and each light-emitting element emits light in a light-emitting pattern based on the image data signal supplied from the control unit 3 (FIG. 1).

[0027] The image drum unit 11 is supplied with a driving force from a motor (not shown), and rotates the first supply roller 22, the second supply roller 23, the developing roller 24, and the charging roller 27 in the direction of arrow R1 (clockwise in the figure), and rotates the photosensitive drum 26 in the direction of arrow R2 (counterclockwise in the figure). Further, based on the control of the control unit 3, the image drum unit 11 applies a predetermined bias voltage to the first supply roller 22, the second supply roller 23, the developing roller 24, the developing blade 25, and the charging roller 27, respectively, to charge them.

[0028] Due to charging, the first supply roller 22 and the second supply roller 23 attach the toner T in the toner storage space 21 to the circumferential side surface, and by rotation, attach this toner T to the circumferential side surface of the developing roller 24. Excess toner T is removed from the circumferential side surface of the developing roller 24 by the developing blade 25, and the circumferential side surface is brought into contact with the circumferential side surface of the photosensitive drum 26 in a state where the toner T adheres in a thin film shape.

[0029] On the other hand, the charging roller 27 uniformly charges the circumferential side surface of the photosensitive drum 26 by contacting the photosensitive drum 26 in a charged state. The LED head 14 performs an exposure process of emitting light at predetermined time intervals in a light emission pattern based on the image data signal supplied from the control unit 3 (FIG. 1), thereby sequentially exposing the photosensitive drum 26. As a result, an electrostatic latent image is sequentially formed on the circumferential side surface of the photosensitive drum 26 near its upper end.

[0030] Subsequently, the photosensitive drum 26 rotates in the direction of arrow R2, and the portion where this electrostatic latent image is formed is brought into contact with the developing roller 24. As a result, toner T adheres to the circumferential side surface of the photosensitive drum 26 based on the electrostatic latent image, and a toner image based on the image data is developed. The photosensitive drum 26 further rotates in the direction of arrow R2 to reach the toner image near the lower end of the photosensitive drum 26. For convenience of explanation, hereinafter, the toner image formed by the silver toner TS having a glow property is also referred to as a silver toner image PS, a glow image, or a glow developer image.

[0031] Incidentally, the image drum unit 11 is a consumable that deteriorates slightly with use and is designed to be easily replaceable. Specifically, in the image forming apparatus 1, for example, when the printing process for 30,000 sheets of the medium MD is completed after starting the use of the image drum unit 11, etc., every time a predetermined replacement condition is satisfied, it is replaced with a new image drum unit 11.

[0032] Below each image forming unit 10 in the housing 2 (FIG. 1), an intermediate transfer unit 30 as a transfer unit is arranged. The intermediate transfer unit 30 is provided with a driving roller 31, a driven roller 32, a backup roller 33, an intermediate transfer belt 34, five primary transfer rollers 35, a secondary transfer roller 36, and a reverse bending roller 37. Among these, the driving roller 31, the driven roller 32, the backup roller 33, each primary transfer roller 35, the secondary transfer roller 36, and the reverse bending roller 37 are all formed in a columnar shape with the central axis along the left-right direction and are rotatably supported by the housing 2.

[0033] The driving roller 31 is arranged at the rear lower side of the image forming unit 10S and rotates in the direction of arrow R1 when a driving force is supplied from a belt motor (not shown). The driven roller 32 is arranged at the front lower side of the image forming unit 10K. The upper ends of the driving roller 31 and the driven roller 32 are respectively located at the same level as or slightly below the lower end of the photosensitive drum 26 (FIG. 2) in each image forming unit 10. The backup roller 33 is arranged at the front lower side of the driving roller 31 and the rear lower side of the driven roller 32.

[0034] The intermediate transfer belt 34 as a transfer belt is configured as an endless belt by a high-resistance plastic film and is stretched around the drive roller 31, the driven roller 32, and the backup roller 33. Further, in the intermediate transfer section 30, below the portion of the intermediate transfer belt 34 stretched between the drive roller 31 and the driven roller 32, that is, at a position directly below each of the five image forming units 10, and at positions facing each photosensitive drum 26 across the intermediate transfer belt 34, five primary transfer rollers 35 are respectively arranged. This primary transfer roller 35 is adapted to have a predetermined bias voltage applied thereto based on the control of the control unit 3.

[0035] The secondary transfer roller 36 is located directly below the backup roller 33 and is biased toward the backup roller 33. That is, the intermediate transfer section 30 sandwiches the intermediate transfer belt 34 between the secondary transfer roller 36 and the backup roller 33. Also, the secondary transfer roller 36 is adapted to have a predetermined bias voltage applied thereto. Hereinafter, the secondary transfer roller 36 and the backup roller 33 together are referred to as the secondary transfer section 39.

[0036] The reverse bending roller 37 is located at a position lower forward of the drive roller 31 and upper rearward of the backup roller 33, and biases the intermediate transfer belt 34 in the forward upper direction. Thereby, the intermediate transfer belt 34 is in a state where tension acts between the respective rollers without generating slack. Also, a reverse bending backup roller 38 is provided at a position sandwiching the intermediate transfer belt 34 on the forward upper side of the reverse bending roller 37.

[0037] The intermediate transfer unit 30 rotates the drive roller 31 in the direction of arrow R1 by the driving force supplied from a belt motor (not shown), thereby causing the intermediate transfer belt 34 to travel in the direction along arrow E1. Also, each primary transfer roller 35 rotates in the direction of arrow R1 while a predetermined bias voltage is applied thereto. Thereby, each image forming unit 10 transfers the toner image that has reached the vicinity of the lower end on the circumferential side surface of the photosensitive drum 26 (FIG. 2) to the intermediate transfer belt 34, and can sequentially stack the toner images of respective colors. At this time, on the surface of the intermediate transfer belt 34, the toner images of respective colors are sequentially stacked from the upstream silver (S). The intermediate transfer unit 30 causes the toner image transferred from each image forming unit 10 to reach the vicinity of the backup roller 33 by running the intermediate transfer belt 34.

[0038] Incidentally, inside the housing 2 (FIG. 1), a conveyance path W, which is a path for conveying the medium MD, is formed. This conveyance path W extends from near the lower end inside the housing 2 upward and forward, makes about a half rotation, and then proceeds rearward below the intermediate transfer unit 30. Subsequently, the conveyance path W extends upward, proceeds upward behind the intermediate transfer unit 30 and the image forming unit 10S, and then proceeds forward. That is, the conveyance path W is formed so as to depict a capital letter "S" in FIG. 1. Inside the housing 2, various components are arranged along this conveyance path W.

[0039] Near the lower end inside the housing 2 (FIG. 1), a first paper feeding unit 40 is arranged. The first paper feeding unit 40 is provided with a paper cassette 41, a pickup roller 42, a feed roller 43, a retard roller 44, a conveyance guide 45, and conveyance roller pairs 46, 47, and 48, etc. Incidentally, the pickup roller 42, the feed roller 43, the retard roller 44, and the conveyance roller pairs 46, 47, and 48 are all formed in a columnar shape with the central axis along the left-right direction.

[0040] The paper cassette 41 is configured in the shape of a hollow rectangular parallelepiped and is detachable from the housing 2. This paper cassette 41 stores the media MD with the paper surfaces facing up and down, that is, in a stacked state, i.e., in an integrated state.

[0041] The pickup roller 42 is in contact with the vicinity of the front end at the uppermost surface of the media MD stored in the paper cassette 41. The feed roller 43 is disposed slightly in front of the pickup roller 42. The retard roller 44 is located below the feed roller 43 and forms a gap corresponding to the thickness of one sheet of the media MD between it and the feed roller 43.

[0042] When a driving force is supplied from a paper feed motor (not shown), the first paper feed unit 40 appropriately rotates or stops the pickup roller 42, the feed roller 43, and the retard roller 44. As a result, the pickup roller 42 feeds out one or more sheets at the uppermost surface of the media MD stored in the paper cassette 41 forward. Also, the feed roller 43 and the retard roller 44 feed out the uppermost sheet of the media MD further forward while blocking the second and subsequent sheets. Thus, the first paper feed unit 40 feeds out the media MD forward while separating it sheet by sheet.

[0043] The conveyance guide 45 is disposed at the front lower portion in the conveyance path W and advances the media MD along this conveyance path W in the front upper direction and then in the rear upper direction. The conveyance roller pairs 46 and 47 are respectively disposed near the center and near the upper end of the conveyance guide 45 and rotate in a predetermined direction when a driving force is supplied from a paper feed motor (not shown). Thereby, the conveyance roller pairs 46 and 47 advance the media MD along the conveyance path W.

[0044] Also, a second paper feeding unit 50 is provided on the front side of the conveying roller pair 47 in the housing 2. The second paper feeding unit 50 is provided with a paper tray 51, a pickup roller 52, a feed roller 53, a retard roller 54, and the like. The paper tray 51 is formed in a thin plate shape in the vertical direction, and the medium MD2 is placed on the upper side thereof. Incidentally, on the paper tray 51, a medium MD2 having a different size and paper quality from the medium MD stored in the paper cassette 41, for example, is placed.

[0045] The pickup roller 52, the feed roller 53, and the retard roller 54 are configured in the same manner as the pickup roller 42, the feed roller 43, and the retard roller 44 of the first paper feeding unit 40, respectively. When a driving force is supplied from a paper feeding motor (not shown), the second paper feeding unit 50 appropriately rotates or stops the pickup roller 52, the feed roller 53, and the retard roller 54, thereby feeding out the lowermost one sheet of the medium MD2 on the paper tray 51 backward while blocking the second and subsequent sheets. Thus, the second paper feeding unit 50 feeds out the medium MD2 backward while separating it sheet by sheet. At this time, the fed-out medium MD2 is conveyed along the conveying path W by the conveying roller pair 57 in the same manner as the medium MD. For convenience of explanation, hereinafter, the medium MD2 will be simply referred to as the medium MD without distinguishing it from the medium MD.

[0046] Incidentally, the rotation of the conveying roller pair 47 is appropriately suppressed, and by applying a frictional force to the medium MD, a so-called skew in which the side of the medium MD is inclined with respect to the traveling direction is corrected, and after the leading and trailing edges are aligned along the left and right, it is sent out backward. The conveying roller pair 48 is located at a position a predetermined distance behind the conveying roller pair 47, and by rotating in the same manner as the conveying roller pair 46 and the like, a driving force is supplied to the medium MD conveyed along the conveying path W, and the medium MD is further advanced backward along the conveying path W.

[0047] Behind the conveying roller pair 48, the secondary transfer unit 39 of the intermediate transfer unit 30 described above, that is, the backup roller 33 and the secondary transfer roller 36, are arranged. In this secondary transfer unit 39, the toner image in the state transferred to the intermediate transfer belt 34 formed in the image forming unit 10 is close as the intermediate transfer belt 34 travels, and a predetermined bias voltage is applied to the secondary transfer roller 36. Therefore, the secondary transfer unit 39 transfers the toner image from the intermediate transfer belt 34 to the medium MD conveyed along the conveyance path W, and further advances it rearward.

[0048] Behind the secondary transfer unit 39, a fixing unit 60 is arranged. The fixing unit 60 is composed of a heating unit 61 and a pressing unit 62 arranged to face each other across the conveyance path W. The heating unit 61 has a heater that generates heat, a plurality of rollers, etc. arranged inside a heating belt that is a hollow endless belt. The pressing unit 62 is formed as a columnar pressing roller with its central axis along the left-right direction, and presses the upper surface against the lower surface of the heating unit 61 to form a nip portion.

[0049] Based on the control of the control unit 3, this fixing unit 60 heats the heater of the heating unit 61 to a predetermined temperature, appropriately rotates the roller to run the heating belt in the direction of arrow R1, and rotates the pressing unit 62 in the direction of arrow R2. Moreover, when the fixing unit 60 receives the medium MD onto which the toner image has been transferred by the secondary transfer unit 39, it sandwiches this (that is, nips it) with the heating unit 61 and the pressing unit 62, applies heat and pressure to fix the toner image to the medium MD, and sends it out rearward.

[0050] Behind the fixing unit 60, a conveying roller pair 64 is arranged, and a switching unit 65 is arranged behind it. The switching unit 65 switches the traveling direction of the medium MD upward or downward according to the control of the control unit 3. Above the switching unit 65, a paper discharge unit 70 is provided. The paper discharge unit 70 is composed of a conveyance guide 71 that guides the medium MD upward along the conveyance path W, conveyance roller pairs 72, 73, 74, and 75 that face each other across the conveyance path W, and a discharge port 76.

[0051] Also, a re-conveying unit 66 is disposed below the switching unit 65, the fixing unit 60, the secondary transfer unit 39, etc. The re-conveying unit 66 has a conveying guide, a pair of conveying rollers (not shown) that constitute a re-conveying path Z. The re-conveying path Z extends downward from below the switching unit 65, then proceeds forward, and finally merges into the conveying path W on the downstream side of the pair of conveying rollers 57.

[0052] When the control unit 3 discharges the medium MD, the switching unit 65 switches the traveling direction of the medium MD to the upper paper discharge unit 70 side. The paper discharge unit 70 conveys the medium MD received from the switching unit 65 upward and discharges it from the discharge port 76 to the paper discharge tray 2T. When the control unit 3 turns the medium MD over and returns it, the switching unit 65 switches the traveling direction of the medium MD to the lower re-conveying unit 66 side. The re-conveying unit 66 conveys the medium MD received from the switching unit 65 along the re-conveying path Z, and finally reaches the downstream side of the pair of conveying rollers 57 and conveys the medium MD again along the conveying path W. Thus, in the image forming apparatus 1, the medium MD can be returned to the conveying path W with the front and back sides of the paper surface of the medium MD reversed, and so-called double-sided printing can be performed.

[0053] As described above, in the image forming apparatus 1, a toner image using toner T is formed in the image forming unit 10 and transferred to the intermediate transfer belt 34. In the secondary transfer unit 39, the toner image is transferred from the intermediate transfer belt 34 to the medium MD, and then fixed in the fixing unit 60, whereby an image can be printed on the medium MD, that is, an image can be formed.

[0054] Incidentally, in the image forming apparatus 1, by increasing the absolute value of the bias voltage applied to each unit under the control of the control unit 3, the amount of toner T attached to the toner image transferred to the medium MD can be increased, and by decreasing the absolute value of the bias voltage, the amount of toner attached to the medium can be decreased.

[0055] Next, the circuit configuration of the image forming apparatus 1 will be described with reference to the block diagram of FIG. 3. The control unit 3 of the image forming apparatus 1 is mainly configured around the print control unit 80, and a storage unit 81, an interface unit 82, a display control unit 83, a process control unit 84, a developing voltage control unit 85, a supply voltage control unit 86, an exposure control unit 87, a transfer voltage control unit 88, and a motor control unit 89 are respectively connected to the print control unit 80.

[0056] The print control unit 80 has a CPU (Central Processing Unit) 91, a ROM (Read Only Memory) 92, a RAM (Random Access Memory) 93, etc. inside. While using the RAM 93 as a work area, various programs read from the ROM 92, the storage unit 81, etc. are executed by the CPU 91 to perform various processes.

[0057] The storage unit 81 is a non-volatile storage medium such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive), and stores various programs and various information. The storage unit 81 is provided with a data conversion table 95, a print speed table 96, and a status information table 97.

[0058] The data conversion table 95 stores information for performing a predetermined conversion process on the bitmap data of each color after the bitmap data of each color is generated based on the print data acquired from the host device 100. The print speed table 96 stores information for controlling the print speed (details will be described later). The status information table 97 stores various setting values and various information necessary for executing the print process, such as the currently set print speed and the print density set by the user, and is updated as appropriate.

[0059] The status information table 97 stores various information representing the status and setting values of each part in the image forming apparatus 1, and is updated as appropriate. In this status information table 97, for example, the currently set printing speed, the printing density in each color image forming unit 10, etc. are stored. Also, in the status information table 97, regarding each color toner cartridge 12, for example, the number of dots used (consumed) by printing after the last replacement is counted and totaled and stored. Hereinafter, the counted value thus obtained is also referred to as the dot count d. This dot count d can also be regarded as a value measuring the amount of toner used (consumed) after the start of totaling.

[0060] The interface unit 82 functions as an interface such as a wired LAN (Local Area Network) compliant with standards such as IEEE (Institute of Electrical and Electronics Engineers) 802.3u / ab / an / ae, or a wireless LAN compliant with standards such as IEEE802.11a / b / g / n / ac / ax. This interface unit 82 can transmit and receive various information to and from a host device 100, a predetermined server device (not shown), etc.

[0061] Based on an instruction from the print control unit 80, the display control unit 83 configures display screen data representing various display screens on which characters, graphics, etc. are appropriately arranged, and causes the display unit 4 to display the display screen by sending the display screen data to the display unit 4.

[0062] Based on an instruction from the print control unit 80, the process control unit 84 controls the voltage etc. of each part in each color image forming unit 10. Based on an instruction from the print control unit 80, the developing voltage control unit 85 controls the developing voltage applied to the developing roller 24 and the developing blade 25 (Fig. 2). Based on an instruction from the print control unit 80, the supply voltage control unit 86 controls the supply voltage applied to the first supply roller 22 and the second supply roller 23 (Fig. 2).

[0063] Based on the instructions from the printing control unit 80, the exposure control unit 87 controls the lighting and extinguishing of each light-emitting element chip provided in the LED head 14 respectively. The transfer voltage control unit 88 controls the transfer voltage applied to the primary transfer roller 35, the secondary transfer roller 36 (Fig. 2), etc. based on the instructions from the printing control unit 80. The motor control unit 89 controls the rotation speed of the photosensitive drum 26 (Fig. 2), each roller, etc., or the running speed of the intermediate transfer belt 34, etc. based on the instructions from the printing control unit 80.

[0064] The host device 100 is an information processing device such as a personal computer, etc., and executes various application programs such as document creation, spreadsheet calculation, or image editing, etc. based on the user's operations. Also, a printer driver for printing documents, images, etc. in the image forming apparatus 1 is installed in the host device 100 in advance. When this host device 100 receives a printing instruction for document data, image data, etc. from the user in the application program, it generates printing data based on the said document data, the said image data, etc. by executing the printer driver, and transmits it to the image forming apparatus 1.

[0065] When the control unit 3 of the image forming apparatus 1 receives the printing data from the host device 100, it forms bitmap data for printing based on the printing data, and generates separated bitmap data separated into each color (silver, cyan, etc.). Subsequently, the control unit 3 refers to the data conversion table 95, generates exposure data through a predetermined conversion process, etc. for the bitmap data of each color, and supplies this to the exposure control unit 87.

[0066] [2. Composition of Silver Toner] In the image forming unit 10S (Fig. 2) corresponding to the silver color (silver) which is a brilliant color, the toner cartridge 12 houses the silver toner TS (also called a brilliant developer). Hereinafter, the method of manufacturing the silver toner TS in this embodiment will be described in detail.

[0067] In this embodiment, first, an aqueous medium in which an inorganic dispersant is dispersed is generated. Specifically, 600 parts by weight of industrial trisodium phosphate dodecahydrate is mixed with 18,400 parts by weight of pure water and dissolved at a liquid temperature of 60 [°C], and then dilute nitric acid for pH (hydrogen ion exponent) adjustment is added. To this aqueous solution, an aqueous calcium chloride solution in which 300 parts by weight of industrial anhydrous calcium chloride is dissolved in 2,600 parts by weight of pure water is added, and while maintaining the liquid temperature at 60 [°C], high-speed stirring is performed for 50 minutes at a rotational speed of 3,566 [rpm] using a line mill (Primix Corporation). Thereby, an aqueous phase which is an aqueous medium in which a suspension stabilizer (inorganic dispersant) is dispersed is adjusted.

[0068] Also, in this embodiment, a material-dispersed oily medium is generated. Specifically, 470 parts by weight of a bright pigment (volume median diameter 5.4 [μm]) containing aluminum powder and 23 parts by weight of a charge control agent (BONTRON E-84: manufactured by Orient Chemical Industries Co., Ltd.) are respectively mixed with 7,000 parts by weight of ethyl acetate which is an organic solvent to prepare a pigment dispersion liquid.

[0069] In this embodiment, a bright pigment having a volume average particle diameter (also referred to as volume median diameter) of 5.4 [μm] is used, but it is not limited thereto. Specifically, the volume average particle diameter of the bright pigment is preferably 5 [μm] or more and 20 [μm] or less, and more preferably within the range of 5.3 to 5.7 [μm].

[0070] Among these, the bright pigment contains minute flakes of aluminum (Al), that is, small pieces having planar portions formed in a plate shape, flat shape or scaly shape. Hereinafter, this bright pigment is also referred to as an aluminum pigment or a metal pigment. The volume average particle diameter is also referred to as volume particle size diameter, volume median diameter or average median diameter. In this embodiment, a bright pigment having a volume average particle diameter of 5.4 [μm] is used, but it is not limited thereto, and for example, a bright pigment having a volume average particle diameter within the range of 5.3 to 5.7 [μm] may be used.

[0071] Subsequently, in this embodiment, while maintaining the liquid temperature of the pigment dispersion at 60 [°C], 175 parts by weight of ester wax (WE-4: manufactured by NOF Corporation) and 1670 parts by weight of polyester resin are added, and the mixture is stirred until no solid matter remains. Thereby, an oil phase, which is a pigment-dispersed oily medium, is prepared.

[0072] Next, in this embodiment, the oil phase is added to the aqueous phase whose liquid temperature has been lowered to 55 [°C], and the mixture is stirred at a rotation speed of 1000 [rpm] for 5 minutes to be suspended, forming particles in the suspension. Subsequently, ethyl acetate is removed by vacuum distillation of the suspension to form a slurry containing toner. Further, nitric acid is added to this slurry to adjust the pH to 1.6 or less, and the slurry is stirred to dissolve tricalcium phosphate, which is a suspension stabilizer, and then dehydrated to form toner. Subsequently, the dehydrated toner is redispersed in pure water and stirred, followed by washing with water. Then, in this embodiment, toner mother particles are produced by performing a dehydration step, a drying step, and a classification step.

[0073] In this embodiment, 1.5 [wt%] of small silica (RY200: manufactured by Nippon Aerosil Co., Ltd.), 2.29 [wt%] of colloidal silica (X24-9163A: manufactured by Shin-Etsu Chemical Co., Ltd.), and 0.37 [wt%] of melamine particles (EPOSTAR S: manufactured by Nippon Shokubai Co., Ltd.) are added to the toner mother particles thus produced as an external addition step and mixed. Thus, in this embodiment, a silver toner having brilliance can be obtained.

[0074] By the way, regarding the size of small pieces of aluminum, which is a brilliant pigment, although it is regulated to some extent by the value of the volume average particle diameter as described above, it is considered to exhibit a distribution centered around a certain range, for example, following a Gaussian distribution or the like.

[0075] Therefore, regarding the size of the silver toner manufactured using this fluorescent pigment, it is similarly considered that it exhibits a distribution centered around a certain range. In the present embodiment, when measuring the volume average particle diameter (also referred to as the volume median diameter or average particle diameter) of the created silver toner, it was 15.01 [μm]. Note that the volume median diameter of the silver toner is not limited to 15.01 [μm], and may be, for example, 10 to 20 [μm].

[0076] [3. Evaluation of Fluorescent Image] By the way, in the image forming apparatus 1 (FIG. 1), in the silver image forming unit 10 (that is, the image forming unit 10S), inside the toner cartridge 12 (FIG. 2) in which the silver toner TS is accommodated, inside the toner accommodation space 21, etc., while stirring the toner by a stirring member (not shown), the silver toner is supplied to the first supply roller 22 etc.

[0077] At this time, it was found that in the image forming unit 10, those with relatively small sizes among the silver toner particles tend to be preferentially used (consumed). That is, in the image forming apparatus 1, immediately after replacing the silver image drum unit 11 and the toner cartridge 12, the size of the silver toner TS is relatively small, and as the printing process is performed and the silver toner TS is used (consumed), the size of the silver toner becomes larger.

[0078] This is presumably due to the following reasons. That is, the silver toner TS exhibits a particle size distribution centered around the value of the volume average particle diameter as described above. Also, the silver toner TS has a lower content of the conductive fluorescent pigment and a higher charge amount as the particle size is smaller, so it becomes easier to be developed. As a result, in the image forming unit 10, at the initial stage of printing, which is immediately after replacing the image drum unit 11 and the toner cartridge 12, regarding the fluorescent developer to be developed, the small particle size silver toner TS with less inclusion of the fluorescent pigment and lower conductivity is preferentially used (consumed).

[0079] Accordingly, in the image forming apparatus 1, when printing an image using silver toner, the size of the silver toner TS included in the image varies according to the consumption amount of the silver toner from the time when the silver image drum unit 11 is replaced, and the impression given to the user who visually recognizes this may also vary.

[0080] Also, in the image forming apparatus 1, in the silver image forming unit 10, when the silver toner TS is supplied from the toner cartridge 12 to the image drum unit 11 by the toner supply unit 13, it is considered that the size of the used silver toner TS fluctuates in the same manner as when the image drum unit 11 is replaced.

[0081] By the way, the consumable image drum unit 11 has a certain amount of silver toner TS that is nearly full capacity pre-stored in the toner storage space 21 at the time of factory shipment. Also, in the image forming apparatus 1, the degree of use (consumption) of the silver toner TS after the replacement of the image drum unit 11 becomes a value that is approximately proportional to the dot count d.

[0082] Therefore, in the image forming apparatus 1, the usage amount (consumption amount) and remaining amount of the silver toner TS in the toner storage space 21 are grasped based on the dot count d, and various processes are performed according to this remaining amount. For example, when the dot count d reaches a predetermined value, the image forming apparatus 1 considers that the remaining amount of the silver toner in the toner storage space 21 has sufficiently decreased, and operates the toner supply unit 13 for a predetermined time to supply a predetermined amount of silver toner TS from the toner cartridge 12 to the toner storage space 21. After that, when the dot count d reaches the predetermined value again, the image forming apparatus 1 considers that the remaining amount of the silver toner in the toner storage space 21 has fallen below a predetermined threshold value, and repeats operations such as supplying a predetermined amount of silver toner TS from the toner cartridge 12 to the toner storage space 21 by the toner supply unit 13.

[0083] Therefore, also in this embodiment, this dot count d is treated as a value representing the usage amount (consumption amount) or the remaining amount of the silver toner TS in the toner storage space 21, and an evaluation test of the image forming apparatus 1 was conducted while using the dot count d as an index representing the remaining amount of the silver toner. Hereinafter, this evaluation test will be described. Note that hereinafter, the dot count d is also referred to as a remaining amount display value.

[0084] [3-1. Indicators and Implementation Conditions for Evaluation] In this evaluation test, the amount of toner (mainly silver toner TS) adhered per unit area to the medium MD is represented by the image density [%]. This image density corresponds to the ratio of the area of the printed portion (the portion where the image is formed) on the medium MD to the total area of the printable range (for example, the area corresponding to one sheet of the medium MD) printable by the image forming apparatus 1. Also, this image density is set to 100[%] when printing an image with an area ratio of 100[%], similar to so-called full-area solid printing. For example, when printing an image in an area corresponding to 1[%] of the printable range of the medium MD, the image density is 1[%].

[0085] In addition, when defining a print pattern representing the arrangement of pixels (hereinafter referred to as print pixels) for printing toner after setting a relatively small rectangular unit area, the image density represents the ratio of the number of dots of the print pixels to the total number of dots in the unit area. For example, when the unit area is a rectangle with 8 dots in the vertical direction and 8 dots in the horizontal direction and the total number of dots is 64 dots, if the number of dots of the print pixels is 32 dots, the image density is 50[%], and if the number of dots of the print pixels is 16 dots, the image density is 25[%].

[0086] Note that the amount of toner (mainly silver toner TS) adhered per unit area to the medium MD may also be referred to as print image density, print duty, or printing rate, in addition to the above-described image density.

[0087] In this evaluation test, the flop index value (hereinafter referred to as the FI value) was used as an index value representing the glossiness of the medium MD. A variable-angle photometer GC-5000L (manufactured by Nippon Denshoku Industries Co., Ltd.) was used to measure this FI value.

[0088] The FI value is a value representing the height of glossiness by the magnitude of a numerical value, and can be calculated by the following formula (1). In this formula (1), when light is irradiated onto the paper surface at an angle of 45°, the intensities of the reflected light received in the directions of 0°, 30°, and -65° with respect to the vertical direction of the paper surface are defined as the reflected light intensities L*0, L*30, and L*-65, respectively.

[0089]

Equation

[0090] In this evaluation test, regarding this FI value, when comparing the value obtained from various images printed on the medium MD with the glossiness visually obtained from the image, when the FI value was 10.0 or more, a sufficiently strong metallic gloss could be felt.

[0091] Furthermore, in this evaluation test, a precision particle size distribution measuring device Multisizer3 (manufactured by Beckman Coulter, Inc.) was used to measure the volume median diameter of the toner T (hereinafter also referred to as the particle size). The measurement conditions and the like are as follows.

[0092] · Aperture diameter: 100 [μm] · Electrolyte: Isoton II (manufactured by Beckman Coulter, Inc.) · Dispersion liquid: Neogen S-20F (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was dissolved in the aforementioned electrolyte and adjusted to a concentration of 5%.

[0093] In this evaluation test, 10 - 20 [mg] of the measurement sample was added to 5 [mL] of the above-mentioned dispersion liquid and dispersed for 1 minute using an ultrasonic disperser. Then, 25 [mL] of the electrolyte solution was added and dispersed for 5 minutes using an ultrasonic disperser. Aggregates were removed through a mesh with an aperture of 75 [μm] to prepare a sample dispersion liquid.

[0094] Furthermore, in this evaluation test, this sample dispersion liquid was added to 100 [mL] of the above-mentioned electrolyte solution, and 30,000 particles were measured using the above-mentioned precision particle size distribution measuring device to obtain the distribution (i.e., volume particle size distribution). Subsequently, in this evaluation test, based on this volume particle size distribution, the volume median diameter (D50) and the fine powder ratio (i.e., the ratio of toner particles with a size of 10 [μm] or less in the volume distribution) were determined respectively.

[0095] The volume median diameter (D50) refers to the particle diameter at which the number or mass of particles larger than a certain particle diameter occupies 50% of the total number or mass of the entire powder in the particle size distribution of the powder. The above-mentioned precision particle size distribution measuring device measures the particle size distribution based on the Coulter principle. This Coulter principle is also called the pore electrical resistance method, in which a constant current is passed through pores (apertures) in an electrolyte solution, and the change in the electrical resistance of the pores when particles pass through the pores is measured to measure the volume of the particles.

[0096] Next, various conditions and the like when printing the silver toner image PS for evaluation on the medium MD by the image forming apparatus 1 in this evaluation test will be described. As shown in FIG. 4, the medium MD has a long side length ML1 of 297 [mm] and a short side length ML2 of 210 [mm]. In this medium MD, the maximum printing area AM, which is the largest area where toner images can be printed, is a rectangular area with a margin length ML3 of 5 [mm] formed as the width of the margin part formed between each side.

[0097] In this evaluation test, in addition to the process of printing the silver toner TS in the maximum printing area AM, as shown in FIG. 5, an evaluation printing area AE is set on the surface of the A4-sized medium MD, and the process of printing the silver toner image PS in this evaluation printing area AE is also performed.

[0098] The evaluation printing area AE is a part within the maximum printing area AM (Figure 4), with the length of the long side ML11 being 77 [mm] and the length of the short side ML12 being 56 [mm]. Also, in the evaluation printing area AE, the short side distance ML13 from each short side of the medium MD is 110 [mm] respectively, and it is arranged at a position where the long side distance ML14 from one long side in the medium MD is 5 [mm].

[0099] Incidentally, in this evaluation test, the resolution of the image by the image forming apparatus 1 is set to 600 [dpi], and the side length of one dot (also called a pixel) is 0.042 [mm].

[0100] [3-2. Measurement Procedure] Next, the detailed procedures and the like in this evaluation test will be described. In this evaluation test, in the image forming apparatus 1, printing processing is performed using the silver toner TS by the silver image forming unit 10S, and at that time, the relationship between the remaining amount of the silver toner TS in the toner storage space 21 (Figure 2) in the image drum unit 11 and the FI value representing the degree of brilliance is evaluated.

[0101] Specifically, in this evaluation test, as the image forming apparatus 1, "C941dn" (manufactured by Oki Electric Industry Co., Ltd.) is used, and as the medium MD, A4-sized OS coated paper W·127 [g / m 2 (manufactured by Fujifilm Business Innovation Co., Ltd., hereinafter referred to as coated paper) and a medium made of a predetermined resin material (hereinafter referred to as a plastic medium) are appropriately used separately.

[0102] In this evaluation test, as described above, for the remaining amount of silver toner TS in the toner storage space 21 within the silver image drum unit 11 (hereinafter referred to as the silver toner remaining amount), the dot count d was used to represent the degree of use (consumption) of the silver toner TS. Specifically, the value of the dot count d at the time of replacing the image drum unit 11 was set to "0", and the increase in the value of the dot count d as the printing process was executed was treated in the same manner as the passage of time. Also, hereinafter, a plurality of dot count d values discretely separated at intervals of approximately 1400 to 2000 counts were appropriately selected and referred to as representative counts RC (RC0, RC1, RC2,...), respectively.

[0103] Furthermore, in this evaluation test, the printing process and various measurement processes were performed according to the following evaluation procedures. <Step 1> In the silver image forming unit 10, replace the image drum unit 11 and set the dot count d to the value "0". That is, the dot count d of the representative count RC0 was set to the value "0". <Step 2> Using the image forming apparatus 1, with coated paper as the medium MD, print a silver toner image PS with an image density of 100 [%] over the entire range of the maximum print area AM (Figure 4) (hereinafter referred to as solid silver printing). <Step 3> Measure the FI value for the medium MD on which solid silver printing has been performed. <Step 4> Using the image forming apparatus 1, with coated paper as the medium MD, repeatedly print a silver toner image PS with an image density of 20 [%] on the maximum print area AM (Figure 4). This advances the value of the dot count d to the next representative count (for example, the second representative count RC1, etc.). <Step 5> Using the image forming apparatus 1, with coated paper as the medium MD, perform solid silver printing. <Step 6> Using the image forming apparatus 1, with a plastic medium as the medium MD, form a silver toner image PS with an image density of 40 [%] on the evaluation print area AE (Figure 5) using the image forming unit 10S, and stop at the stage where the silver toner image PS is transferred to the medium MD. <Step 7> Remove the medium MD from the image forming apparatus 1, and measure the average particle size of the silver toner that is in an unfixed state on the medium MD.

[0104] Also, in this evaluation test, until the silver toner TS in the image drum unit 11 and the toner cartridge 12 runs out, by repeating <Step 4> to <Step 7>, the average particle size of each silver toner TS corresponding to various representative counts RC was determined.

[0105] [3-3. Measurement Regarding Comparative Example] Next, in this evaluation test, as a comparative example, with the printing speed kept constant in the image forming apparatus 1, by performing the above-described evaluation procedure, the relationship between the representative count RC, the particle size distribution of the silver toner TS, and the FI value was examined. As a result, regarding the comparative example, each value as shown as table TL1 in FIG. 6 was obtained, and based on these values, a graph as shown in FIG. 7 was obtained. Incidentally, hereinafter, regarding the value of the dot count d, with 1000 (=1K) counts being regarded as the value "1", that is, it is represented by a numerical value that is 1 / 1000 of the actual value.

[0106] As shown in FIGS. 6 and 7, in this comparative example, the representative counts RC0, RC1, RC2, RC3, and RC4 were set to the values 0, 1769, 3424, 5366, and 7119, respectively. Also, when the average particle size DA corresponding to each was measured, it was 11.9, 12.9, 13.3, 12.6, and 11.9 [μm].

[0107] From FIGS. 6 and 7, it can be seen that in the comparative example with the printing speed kept constant, when the printing process using the silver toner TS is performed and the value of the dot count d increases, the average particle size DA gradually increases and then turns to decrease, showing such fluctuations.

[0108] Next, in this evaluation test, regarding the silver image forming unit 10S in the image forming apparatus 1, while appropriately repeating the printing process using the silver toner TS, the relationship between the value of the dot count d and the weight of the image drum unit 11, and the relationship between the value of the dot count d and the average particle size DA were examined.

[0109] Among these, regarding the weight of the image drum unit 11, the reference weight, which is the reference weight when the dot count d has the value "0", was set to 0 [g], and it was represented by the relative value with respect to the reference weight. Hereinafter, this relative weight is referred to as the ID relative weight. In addition to this, in this evaluation test, the relationship between the value of the dot count d and the average particle diameter DA of the silver toner TS was also separately examined. As a result, each value as shown as table TL2 and TL3 in FIGS. 8(A) and (B) was obtained, and based on these values, a graph as shown in FIG. 9 was obtained.

[0110] Among these, in FIGS. 8(A) and 9, the ID relative weight initially decreases as the value of the dot count d increases, but at the point when the value of the dot count d reaches 3908, it turns to increase, and at the point when the value of the dot count d reaches 5219, it turns to decrease again. From this, in the silver image forming unit 10S, during the period when the value of the dot count d is from 3908 to 5219 or before and after that, the silver toner TS is supplied from the toner cartridge 12 to the toner storage space 21 of the image drum unit 11 by the toner supply unit 13 (FIG. 2).

[0111] Also, in FIGS. 8(B) and 9, although the average particle diameter DA increases as the ID relative weight decreases, when the ID relative weight turns to increase, the average particle diameter DA turns to decrease. From this, in the silver image forming unit 10S, while the silver toner TS is decreasing from the toner storage space 21 of the image drum unit 11, the average particle diameter DA tends to increase, but when new silver toner TS is supplied to the toner storage space 21, the average particle diameter DA tends to turn to decrease, and such a relationship is seen.

[0112] Incidentally, it is believed that the larger the average particle diameter DA of silver toner TS, the better it reflects light, and therefore the more lustrous it becomes. In other words, it is believed that there is a certain degree of correlation between the average particle diameter DA and the FI value of silver toner TS. Therefore, when the average particle diameter DA and the FI value of each of the four types of silver toner TS were measured, the values ​​shown in Table TL4 in Figure 10 were obtained, and based on these values, the graph shown in Figure 11 was obtained.

[0113] 10 and 11, it is presumed that there is a proportional correlation between the average particle diameter DA of the silver toner TS and the FI value. When the relationship between the average particle diameter DA [μm] of the silver toner TS and the FI value (represented by the symbol FI) was calculated by linear approximation, the following relationship was obtained:

[0114]

number

[0115] This formula (2) represents a straight line as shown by the dashed line in Figure 11. The coefficient of determination R 2 The value was 0.8177.

[0116] Referring again to Figure 6, the values ​​of average particle diameter DA in the representative counts RC0, RC2, and RC3 are the values ​​also shown in the table of Figure 10. Therefore, the FI values ​​in the representative counts RC0, RC2, and RC3 are 10.2, 13.1, and 12.3, respectively, according to the table of Figure 10. On the other hand, the FI values ​​in the representative counts RC1 and RC4 can be calculated using the value of the average particle diameter DA according to formula (2), and are 12.5 and 10.8, respectively.

[0117] Therefore, in the table of Figure 6, the FI values ​​calculated by formula (2) based on the average particle diameter DA for the representative counts RC1 and RC4 are shown. In Figure 6, the calculated FI values ​​are marked with the symbol "*" to indicate that they are calculated values. The same applies to the subsequent FI values.

[0118] [3-4. Changes in Printing Speed and FI Values in the Embodiment] Next, in this evaluation test, as an example, while changing the printing speed VP in the image forming apparatus 1, by performing the above-described evaluation procedure, the relationship between the representative count RC and the particle size distribution and average particle size DA of the silver toner TS was examined. In this example, as shown as Table TL5 in FIG. 12, the printing speed VP [mm / s] was changed according to the value of the dot count d.

[0119] This printing speed VP is the speed at which the medium MD is conveyed by the first paper feeding unit 40 or the like in the image forming apparatus 1 (FIG. 1), and is also the speed at which the toner image is formed on the circumferential side surface of the photosensitive drum 26 by each image forming unit 10. Therefore, changing the printing speed VP in the image forming apparatus 1 means changing the rotational speed of each roller in the first paper feeding unit 40 or the like, or changing the rotational speed of the photosensitive drum 26, the developing roller 24, etc. in each image forming unit 10.

[0120] In this example, the values as shown as Table TL6 in FIG. 13 corresponding to FIG. 6 were obtained. Also in this example, based on the obtained average particle size DA, by performing the arithmetic processing using the above-described formula (2), as shown in Table TL6 (FIG. 13), the FI values were calculated respectively. Furthermore, in Table TL6, the values obtained by calculating the standard deviation of the FI value in each of the example and the comparative example were described. In addition to this, based on the value of the dot count d and the calculated FI value, a graph as shown in FIG. 14 corresponding to FIG. 7 was obtained.

[0121] From the graph of FIG. 14, it can be seen that the fluctuation range of the FI value when the dot count d changes is smaller in the example than in the comparative example. In particular, in terms of the value of the standard deviation shown in Table 6, the comparative example has a value of 1.22, while the example has a value of 0.31. That is, it can be seen that in the example, when compared with the comparative example, the fluctuation range of the FI value with respect to the dot count d is extremely small, that is, the fluctuation range of the FI value is relatively small and a substantially constant glossiness can be maintained.

[0122] Here, the reason for changing the printing speed VP in the image forming apparatus 1 will be described. First, pay attention to the range from the representative count RC0 to RC2 in Table TL5 (Fig. 12). In this range from the representative count RC0 to RC2, as shown in Figs. 8(A) and 9, the silver toner TS is not supplied from the toner cartridge 12, and since the silver toner TS is used from the toner storage space 21, the remaining amount of the silver toner will monotonically decrease.

[0123] In this range from the representative count RC0 to RC2, in the comparative example, the printing speed VP remains constant at the value "105.1", whereas in the example, the printing speed VP changes stepwise so as to decrease from the value "214.9" to "191.1" and "86.0".

[0124] The average particle size DA in this range increased from the value "11.9" to "12.9" and then to "13.3" in the comparative example, whereas in the example, it changed to the values "12.5", "12.9", and "12.8", and the change range was 0.9, remaining as slight fluctuations within a relatively narrow range. Also, as described with reference to Figs. 10 and 11, a correlation similar to a proportional relationship is seen between the average particle size DA and the FI value, as shown by equation (2). When calculated using this equation (2), the FI values in the example in this range became the values "11.8", "12.6", and "12.4" respectively, as shown in Table TL6 (Fig. 13). As can be seen from Fig. 14, each FI value in this example has a much smaller fluctuation range compared to the corresponding FI values "10.2", "12.5", and "13.1" in the comparative example, and is a stable value.

[0125] Furthermore, for example, taking the remaining amount of silver toner at the representative count RC1 (value "1597") as the first remaining amount and the printing speed "191.1" at this time as the first speed (first linear speed), and taking the remaining amount of silver toner at the representative count RC2 (value "3195") as the second remaining amount and the printing speed "86.0" at this time as the second speed (second linear speed). That is, the second remaining amount is less than the first remaining amount, and the second speed is lower (slower) than the first speed. Then, in the embodiment, in the second remaining amount which is less than the first remaining amount, a silver toner image PS (that is, a bright developer image) is formed at the second speed which is lower than the first speed. Note that the linear speed in the present embodiment represents, for example, the moving speed of the outer peripheral portion of a rotating member such as the photosensitive drum 26 and various rollers, and the unit is [mm / s].

[0126] Next, pay attention to the range from the representative count RC2 to RC4 in the table TL5 (FIG. 12). Among them, in the range from the representative count RC2 to RC3, as shown in FIGS. 8(A) and 9, the silver toner TS is being used while the silver toner TS is being supplied from the toner cartridge 12 to the toner storage space 21, and the remaining amount of silver toner will increase. After that, in the range from the representative count RC3 to RC4, since the silver toner TS is used again from the toner storage space 21, the remaining amount of silver toner will monotonically decrease.

[0127] In the range from this representative count RC2 to RC4, in the comparative example, the printing speed VP remains constant at the value "105.1", while in the embodiment, the printing speed VP increases from the value "86.0" to "152.8" and then decreases again to return to "86.0". The average particle diameter DA in this range decreased from the value "13.3" to "12.6" and then to "11.93" in the comparative example (FIG. 6), while in the embodiment (FIG. 13), although the value fluctuated slightly, it remained unchanged at the approximate value of "12.8" up to the first decimal place.

[0128] When calculated using the above-described formula (2), the FI values in the examples within this range were the values "12.4", "12.3", and "12.5" as shown in Table TL6 (Figure 13). As can be seen from Figure 14, each FI value in this example has a significantly smaller fluctuation range compared to the corresponding FI values "13.1", "12.3", and "10.8" in the comparative examples, and is a stable value.

[0129] Furthermore, in the same manner as described above, when the remaining amount of silver toner at the representative count RC2 (value "3195") is taken as the second remaining amount and the printing speed at this time, "86.0", is taken as the second speed, and further, the remaining amount of silver toner at the representative count RC3 (value "5235") is taken as the third remaining amount and the printing speed at this time, "152.8", is taken as the third speed (third linear speed). That is, the third remaining amount is larger than the second remaining amount, and the third speed is higher (faster) than the second speed. Then, in the example, a silver toner image PS (i.e., a brilliant developer image) is formed at the third speed, which is higher than the second speed, with the third remaining amount, which is larger than the second remaining amount. Also, "152.8" of the third speed is a smaller (slower) value than "191.1" of the first speed.

[0130] Here, as shown in Table TL7 in Figure 15, when the standard deviation of the FI values of the examples was calculated, the value was "0.31". Similarly, when the standard deviation of the FI values of the comparative examples was calculated, the value was "1.22". Thus, in the examples, the value of the standard deviation has significantly decreased compared to the comparative examples. From this, it can also be seen that the FI values of the examples have a smaller fluctuation range compared to the examples.

[0131] In this evaluation test, as such, in the comparative examples (Figure 6), as the dot count d changes, the average particle size DA increases and decreases relatively greatly, and the FI value also increases and decreases. On the other hand, in the examples (Figure 13), even when the dot count d changes, the fluctuation range of the average particle size DA remains relatively small, and the FI value also remains stable.

[0132] Next, the reason why the variation range of the average particle size DA could be suppressed to be smaller than that in the comparative example by changing the printing speed VP in the examples will be described.

[0133] As described above, in the image drum unit 11 (FIG. 2) of the image forming unit 10, a developing blade 25 is provided, and the developing blade 25 is brought into contact with the circumferential side surface of the developing roller 24 while being elastically deformed slightly. When performing printing processing, the image drum unit 11 scrapes off excess toner with the developing blade 25 on the circumferential side surface of the rotating developing roller 24 and attaches it in a thin film shape, and forms (develops) a toner image on the circumferential side surface of the photosensitive drum 26 with this thin film-shaped toner.

[0134] Here, in an environment where silver toner TS, which is a powder, exists as in the image drum unit 11, in a configuration where a regulating member such as the developing blade 25 is brought into contact with the circumferential side surface of a cylindrical member such as the developing roller 24, there are two possible explanations for the change in the average particle size DA.

[0135] The first explanation is that since the distance between the developing blade 25 and the circumferential side surface of the developing roller 24 is regulated, among the silver toner TS which is a powder, those with large particle sizes are blocked from passing through and those with small particle sizes preferentially pass through.

[0136] In this explanation, when the rotation speed of the developing roller 24 increases, the area receiving force from the developing blade 25 per unit time increases on the circumferential side surface of the developing roller 24. Then, the force acting from the developing blade 25 per unit area becomes smaller on the circumferential side surface of the developing roller 24, and the force regulating the silver toner TS, which is a powder, becomes weaker, so that powders with large particle sizes are more likely to pass through.

[0137] The second explanation is that among the silver toner TS in powder form, those with a small particle size are highly charged, and the adhesion force to the developing roller 24 becomes strong. Therefore, at the locations where the first supply roller 22 and the second supply roller 23 are in contact with or close to the developing roller 24, the relatively large particle size powder is more likely to be peeled off.

[0138] Here, regarding the charge amount - mass ratio (hereinafter also denoted as Q / m) [μC / mg], which is the ratio of the charge amount to the mass of the silver toner TS, when measured for each printing speed shown in Table TL6 (Figure 14), the values shown as Table TL8 in Figure 16 were obtained, and a graph as shown in Figure 17 was obtained. From the graph in Figure 17, even when the printing speed was changed, no significant change was observed in the charge amount - mass ratio (Q / m). Based on such a relationship, regarding this evaluation test, the second explanation was negated, and the first explanation was considered to be more plausible.

[0139] Based on such results, the image forming apparatus 1 stores the content of Table TL5 (Figure 12) in advance in the printing speed table 96 of the storage unit 81 (Figure 3), and when executing the printing process, refers to the printing speed table 96 and changes the printing speed according to the dot count d.

[0140] [3 - 5. Printing process procedure] Next, the printing process procedure when the image forming apparatus 1 executes the printing process will be described with reference to the flowchart of Figure 18. When the control unit 3 of the image forming apparatus 1 acquires printing data from the host device 100 in the image forming apparatus 1, it starts the printing process procedure RT1 (Figure 18) and moves to the first step SP1.

[0141] In step SP1, the control unit 3 acquires the current printing speed from the status information table 97 (Figure 3) of the storage unit 81 and moves to the next step SP2. In step SP2, the control unit 3 reads the value of the silver dot count d from the status information table 97 and moves to the next step SP3.

[0142] In step SP3, the control unit 3 reads out the printing speed corresponding to the value of the silver dot count d from the printing speed table 96 (Figs. 3 and 12) in the storage unit 81 (hereinafter referred to as the adaptive printing speed), and moves to the next step SP4. In step SP4, the control unit 3 determines whether the current printing speed matches the adaptive printing speed. If a negative result is obtained here, this indicates that it is necessary to change the current printing speed. At this time, the control unit 3 moves to the next step SP5, changes the printing speed to the adaptive printing speed, and moves to the next step SP6.

[0143] On the other hand, if an affirmative result is obtained in step SP4, this indicates that the current printing speed matches the adaptive printing speed, so there is no need to change it. At this time, the control unit 3 moves to the next step SP6.

[0144] In step SP6, the control unit 3 controls the motor control unit 89 (Fig. 3), etc. based on the set printing speed, and performs printing processing by adjusting the speed at which the toner image is formed in each image forming unit 10 and the conveyance speed of the medium MD to match this printing speed. Thereafter, the control unit 3 moves to the next step SP7 and ends the printing processing procedure RT1.

[0145] [4. Effects, etc.] In the above configuration, the image forming apparatus 1 according to the present embodiment stores in advance in the storage unit 81 a printing speed table 96 (Figs. 3 and 12) representing the relationship between the value of the dot count d and the printing speed VP, and refers to the printing speed table 96 during the execution of the printing process, and adjusts the printing speed according to the dot count d at that time.

[0146] As a result, when the image forming apparatus 1 starts using the silver toner TS in the toner storage space 21 (Fig. 2) in the silver image drum unit 11 such as the representative count RC0, by setting the printing speed VP to a relatively high speed, the average particle size DA is increased to raise the FI value. Also, when the remaining amount of silver toner in the toner storage space 21 decreases as in the representative counts RC1 and RC2, the image forming apparatus 1 sets the printing speed VP to a relatively low speed to decrease the average particle size DA and lower the FI value.

[0147] Furthermore, when the silver toner TS is supplied from the toner cartridge 12 and the remaining amount of silver toner in the toner storage space 21 increases again as in the representative count RC3, the image forming apparatus 1 again sets the printing speed VP to a relatively high speed to increase the average particle size DA and raise the FI value. Also, when the remaining amount of silver toner in the toner storage space 21 decreases again as in the representative count RC4, the image forming apparatus 1 sets the printing speed VP to a relatively low speed with respect to the toner cartridge 12 to decrease the average particle size DA and lower the FI value.

[0148] In this way, although the remaining amount of silver toner in the toner storage space 21 varies according to the value of the dot count d, the image forming apparatus 1 can suppress the variation of the average particle size DA within an extremely narrow range by appropriately increasing and decreasing the printing speed VP, and accordingly can sufficiently reduce the variation width of the FI value (Figs. 13 and 14).

[0149] As a result, the image forming apparatus 1 can obtain a stable metallic luster in the image formed (i.e., printed) using the silver toner TS without being affected by the value of the dot count d, that is, without being affected by the remaining amount of silver toner in the toner storage space 21.

[0150] In particular, in view of the fact that in the toner storage space 21, the average particle size DA changes according to the remaining amount of silver toner, and accordingly the FI value fluctuates, the image forming apparatus 1 utilizes the relationship between the printing speed VP and the average particle size DA. As a result, the image forming apparatus 1 does not need to change various setting values such as the applied voltage and the printing density, etc., so that the color tone of the image is not unnecessarily changed, and stable brilliance can be obtained.

[0151] Also, in the image drum unit 11, at the time of factory shipment, the amount of silver toner TS (i.e., the initial value) stored in the toner storage space 21 is substantially constant. Further, the image forming apparatus 1 supplies the silver toner TS from the toner cartridge 12 to the toner storage space 21 based on the dot count d that is reset to the value "0" when the image drum unit 11 is replaced. For this reason, in the image forming apparatus 1, the amount of silver toner TS stored in the toner storage space 21, that is, the remaining amount of silver toner, can be grasped by the dot count d without using a sensor or the like.

[0152] Therefore, the image forming apparatus 1 can set an appropriate printing speed VP for the dot count d in advance, and by simply adjusting the printing speed VP according to the value of the dot count d, it can be adjusted to the printing speed VP suitable for the remaining amount of silver toner in the toner storage space 21, and as a result, the brilliance can be stabilized. That is, the image forming apparatus 1 does not need to perform complex arithmetic processing or the like, nor does it need to perform processing according to the detection result of the sensor or the like. It only needs to set the printing speed VP associated with each dot count d in the printing speed table 96 as it is.

[0153] Also, in the image forming apparatus 1, for example, when the printing speed needs to be changed according to various conditions such as the thickness of the paper used and the ambient temperature, etc., it inherently has a mechanism for adjusting the printing speed VP. For this reason, in the image forming apparatus 1, there is no need to add a mechanism for changing the printing speed VP to the conventional configuration, and only the value of the printing speed VP to be changed needs to be determined.

[0154] According to the above configuration, the image forming apparatus 1 stores in advance in the storage unit 81 a printing speed table 96 representing the relationship between the value of the dot count d and the printing speed VP. When executing the printing process, the image forming apparatus 1 refers to the printing speed table 96 and adjusts the printing speed according to the dot count d at that time. Thereby, the image forming apparatus 1 can appropriately increase or decrease the printing speed VP according to the value of the dot count d. Therefore, regardless of the variation in the remaining amount of silver toner in the toner storage space 21, the variation in the average particle size DA can be suppressed within an extremely narrow range, and accordingly, the variation width of the FI value can be sufficiently reduced. As a result, the image forming apparatus 1 can obtain a stable metallic luster in the image printed using the silver toner TS without being affected by the remaining amount of silver toner in the toner storage space 21.

[0155] [5. Other Embodiments] In the above-described embodiment, the form in which the values of a plurality of discrete dot counts d and the printing speed VP in the silver image forming unit 10 are respectively associated and stored in the tabular printing speed table 96 has been described (FIGS. 3 and 12). However, the present invention is not limited to this. For example, the printing speed VP may be represented as a function of the dot count d, and the value of the printing speed VP may be obtained from the value of the dot count d by various methods such as calculating the printing speed VP from the dot count d using the function.

[0156] Also, in the above-described embodiments, the value of the dot count d in the silver image forming unit 10 is regarded as a value corresponding to the remaining amount of the silver toner TS stored in the toner storage space 21 in the image drum unit 11, and the value of the dot count d and the printing speed are associated and stored in the printing speed table 96 (FIGS. 3 and 12). However, the present invention is not limited to this. For example, a remaining amount sensor for detecting the remaining amount of the silver toner TS in the toner storage space 21 may be provided in the image drum unit 11, and the detected value of the remaining amount sensor and the value of the printing speed may be associated and stored in the printing speed table 96. That is, various values corresponding to the remaining amount of the silver toner TS stored in the toner storage space 21 and the printing speed may be associated and stored in the printing speed table 96.

[0157] Furthermore, in the above-described embodiments, a form in which the printing speed VP is increased at the stage when the silver toner TS is supplied from the toner cartridge 12 to the toner storage space 21, such as the representative count RC3 (FIG. 13), has been described. However, the present invention is not limited to this. For example, when it is known in advance that the amount of the silver toner TS supplied from the toner cartridge 12 to the toner storage space 21 is relatively small and the degree of change in the average particle diameter DA is relatively small, the printing speed VP may be maintained without increasing when the silver toner TS is supplied to the toner storage space 21.

[0158] Furthermore, in the above-described embodiments, a form in which aluminum (Al) contained in the fluorescent pigment used when generating the silver toner TS is formed into minute flakes having a planar portion has been described. However, the present invention is not limited to this. The aluminum (Al) contained in the fluorescent pigment may be formed into small pieces having various shapes, such as spherical or rod-shaped.

[0159] Furthermore, in the above-described embodiments, the form in which the metal contained in the phosphorescent pigment used for generating the developer is aluminum (Al) has been described. However, the present invention is not limited to this, and the metal contained in the phosphorescent pigment may be various metals such as brass or iron oxide. In this case, the color exhibited by the developer when fixed to the medium MD is the color corresponding to this metal.

[0160] Furthermore, in the above-described embodiments, the form in which the silver toner T (silver toner TS) is used as the toner T having phosphorescence has been described. However, the present invention is not limited to this, and various colored toners T having phosphorescence such as gold or copper may be used. For example, the gold toner T can be manufactured by partially changing the manufacturing process of the silver toner TS described in the embodiments. Specifically, when adding aluminum powder as the phosphorescent pigment, a yellow pigment (for example, C.I.Pigment Yellow 180 which is an organic pigment), a magenta pigment (for example, C.I.Pigment Red 122 which is an organic pigment), an orange-red fluorescent dye (for example, FM-34N_Orange (manufactured by Shinroi Chemical Co., Ltd.)), and a yellow fluorescent dye (FM-35N_Yellow (manufactured by Shinroi Chemical Co., Ltd.)) are added respectively, whereby the gold toner T can be manufactured. Also, as the phosphorescent pigment, not limited to aluminum (Al), various other phosphorescent pigments such as pearl pigments (natural mica) and inorganic pigments made of titanium oxide may be used.

[0161] Furthermore, in the above-described embodiments, the case where five image forming units 10 are provided in the image forming apparatus 1 (FIG. 1) has been described. However, the present invention is not limited to this, and four or less or six or more image forming units 10 may be provided in the image forming apparatus 1.

[0162] Furthermore, in the above-described embodiments, the image forming apparatus (FIG. 1) is of a so-called intermediate transfer type, and the toner image formed in each image forming unit 10 is primarily transferred to the intermediate transfer belt 34, and the toner image is secondarily transferred from the intermediate transfer belt 34 to the medium MD. However, the present invention is not limited to this. For example, the image forming apparatus may be of a so-called direct transfer type, and the toner image formed in each image forming unit 10 may be directly transferred to the medium MD.

[0163] Furthermore, in the above-described embodiments, the case where the present invention is applied to the image forming apparatus 1 that forms an image using a developer used in a one-component development system has been described. However, the present invention is not limited to this, and the present invention may be applied to an image forming apparatus that forms an image using a developer used in a two-component development system, which is a system in which a carrier and toner are mixed and an appropriate charge amount is imparted to the toner by utilizing the friction between the carrier and the toner. In addition, when explaining in terms of the two-component development system, particles containing a bright pigment, a binder resin, and an external additive or a powder formed by aggregation of these particles are defined as a bright toner or a bright developer.

[0164] Furthermore, in the above-described embodiments, the form in which the printing speed table 96 and various programs are stored in advance in the storage unit 81 of the image forming apparatus 1 has been described. However, the present invention is not limited to this. For example, the content of the printing speed table 96 and various programs may be downloaded from a predetermined server device (not shown) connected via the interface unit 82 and used or executed.

[0165] Furthermore, in the above-described first embodiment, the case where the present invention is applied to the image forming apparatus 1 which is a single-function printer has been described. However, the present invention is not limited to this, and the present invention may be applied to an image forming apparatus having various other functions, such as an MFP (Multi Function Peripheral) having functions of a copier or a facsimile machine.

[0166] Furthermore, the present invention is not limited to each of the above-described embodiments and other embodiments. That is, the present invention applies to embodiments in which any combination of some or all of the above-described embodiments and the above-described other embodiments is arbitrarily combined, or embodiments in which a part is extracted.

[0167] Furthermore, in the above-described embodiments, the form in which the image forming apparatus 1 as an image forming apparatus is configured by the image forming unit 10 as an image forming unit and the control unit 3 as a control unit has been described. However, the present invention is not limited to this, and the image forming apparatus may be configured by an image forming unit having various other configurations and a control unit.

Industrial Applicability

[0168] The present invention can be used when forming an image on a medium using a fluorescent developer by an electrophotographic method.

Explanation of Reference Numerals

[0169] 1... Image forming apparatus, 3... Control unit, 10... Image forming unit, 11... Image drum unit, 12... Toner cartridge, 13... Toner supply unit, 21... Toner storage space, 24... Developing roller, 25... Developing blade, 26... Photoconductor drum, 60... Fixing unit, 80... Printing control unit, 81... Storage unit, 89... Motor control unit, 96... Printing speed table, 97... Status information table, DA... Average particle size, MD... Medium, PS... Silver toner image, T... Toner, TS... Silver toner, VP... Printing speed, d... Dot count.

Claims

1. An image forming unit including a storage unit that stores a phosphorescent developer, and capable of forming a phosphorescent developer image with the phosphorescent developer, A control unit that controls the operation of the image forming unit provided, The control unit When forming a phosphorescent image on a medium based on predetermined print data when the remaining amount of the phosphorescent developer stored in the storage unit is a first remaining amount, the phosphorescent developer image is formed at a first linear velocity, When forming the phosphorescent image on the medium based on the predetermined print data when the remaining amount of the phosphorescent developer stored in the storage unit is a second remaining amount less than the first remaining amount, the phosphorescent developer image is formed at a second linear velocity lower than the first linear velocity An image forming apparatus characterized by the above.

2. When the control unit forms the phosphorescent image on the medium based on the predetermined print data when the phosphorescent developer is supplied to the storage unit and the remaining amount becomes a third remaining amount greater than the second remaining amount, the phosphorescent developer image is formed at a third linear velocity higher than the second linear velocity The image forming apparatus according to claim 1, characterized by the above.

3. The third linear velocity is lower than the first linear velocity The image forming apparatus according to claim 2, characterized by the above.

4. A developer supply unit that supplies the phosphorescent developer to the storage unit based on the control of the control unit further provided, When the remaining amount of the phosphorescent developer stored in the storage unit falls below a predetermined threshold value, the control unit causes the developer supply unit to supply the phosphorescent developer to the storage unit The image forming apparatus according to claim 1, characterized by the above.

5. The control unit counts a count value representing the amount of the phosphorescent developer used, and recognizes the remaining amount based on the count value The image forming apparatus according to claim 1, characterized in that...

6. A remaining amount sensor that detects the remaining amount of the phosphorescent developer stored in the storage unit and further includes: The control unit recognizes the remaining amount based on the detection result by the remaining amount sensor The image forming apparatus according to claim 1, characterized in that...

7. The image forming unit includes: A developing roller to which the phosphorescent developer stored in the storage unit adheres; A developing blade that regulates the amount of the phosphorescent developer adhering to the developing roller; An image carrier on which a phosphorescent developer image is formed by developing the phosphorescent developer with the developing roller for an electrostatic latent image that has been exposed; and further includes: The control unit forms the phosphorescent developer image at a second linear velocity lower than the first linear velocity by changing at least the linear velocity of the image carrier. The image forming apparatus according to claim 1, characterized in that...

8. A transfer unit that transfers the phosphorescent developer image formed on the transfer belt by the image forming unit and further includes: The control unit forms the phosphorescent developer image at a second linear velocity lower than the first linear velocity by changing the linear velocity of the transfer belt. The image forming apparatus according to claim 1, characterized in that...

9. A remaining amount acquisition step of acquiring a remaining amount display value representing the remaining amount of the phosphorescent developer stored in the storage unit of an image forming unit capable of forming a phosphorescent developer image with a phosphorescent developer; A speed setting step of setting a first linear velocity when the remaining amount display value is a first remaining amount, and setting a second linear velocity lower than the first linear velocity when the remaining amount display value is a second remaining amount less than the first remaining amount; A forming step of forming the fluorescent developer image at the linear velocity set by the velocity setting step An image forming method characterized by including the above

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