JP7211074B2 - Gloss control device and gloss control method - Google Patents

Description

The present disclosure relates to controlling the gloss of images formed on recording media.

2. Description of the Related Art In conventional image forming apparatuses such as MFPs (Multi-Functional Peripherals), various proposals have been made for controlling glossiness of images to be formed.

For example, Japanese Patent Application Laid-Open No. 2013-3188 (Patent Document 1) discloses a technique of controlling gloss using a high-gloss toner and a low-gloss toner. Japanese Patent Application Laid-Open No. 2008-151851 (Patent Document 2) discloses a technique of changing the type of toner used for image formation depending on the glossiness of a recording material. Japanese Patent Application Laid-Open No. 2011-180391 (Patent Document 3) discloses a technique of combining cooling peeling and low gloss toner.

Japanese Unexamined Patent Application Publication No. 2013-3188 JP 2008-151851 A JP 2011-180391 A

However, there is a problem that the techniques described in Patent Documents 1 to 3 cannot control the gloss within a sufficient range.

For example, the technology described in Patent Document 1 expresses the contrast between high gloss and low gloss depending on the degree of melting of the toner, so it is difficult to control the temperature, and it is said that the effect cannot be obtained if the temperature changes even a little. I have a problem. In addition, although it is necessary to sufficiently heat the toner in order to secure the fixing strength, if the toner is heated to the required temperature, the toner is sufficiently melted and the image forming surface becomes flat. As a result, there is also the problem that a sufficiently low gloss cannot be obtained.

Even if the type of toner used is changed as described in Patent Document 2, the shape of the image surface has a greater effect on the gloss than the reflectance of the toner itself. There is a problem that the contrast of .

The technology described in Japanese Patent Application Laid-Open No. 2002-200300 requires a plurality of fixing devices, which poses problems in terms of cost, energy consumption, and compactness of the apparatus. Furthermore, the technique described in Patent Document 3 also has a problem that the formed image does not have a natural gloss because a smooth surface remains to some extent in the formed image.

On the other hand, there is a demand to control the glossiness of an image formed on a recording medium arbitrarily and within a sufficient range so as to have natural visibility.

The present disclosure has been conceived in view of such circumstances, and an object thereof is to control the glossiness of an image formed on a recording medium arbitrarily and in a sufficient range so as to have natural visibility. It is to provide the technology to

According to one aspect of the present disclosure, a heating member configured to heat an imaged recording medium; a pressure member configured to sandwich the recording medium with the heating member; and a controller configured to control adhesion of the recording medium to the heating member when the member is released from nipping.

The control unit is configured to control the adhesive force by adjusting the amount of at least one type of toner among a plurality of types of toners each having a different release agent content to be applied to the recording medium. good too.

The plurality of types of toner includes a first toner and a second toner having a release agent content lower than that of the first toner, and the control unit forms the first toner on the recording medium. The toner is applied to the entire area of the image, the second toner is applied on top of the first toner, and the recording medium to which both the first toner and the second toner are applied is sandwiched between a heating member and a pressure member. , may be configured as follows.

The second toner may not contain a release agent.
The control unit adjusts the application amount of the second toner to a value equal to or lower than the value when the glossiness takes a minimum value in the change in the glossiness of the image on the recording medium with respect to the change in the application amount of the second toner. By doing so, the adhesive force may be controlled.

The plurality of types of toner includes a first toner and a second toner having a release agent content lower than that of the first toner, and the controller controls the recording medium of the first toner and the second toner. It may be configured to control the adhesive force by adjusting the ratio applied above.

The multiple types of toners may be colorless toners.
The control unit may be configured to apply toner to the recording medium on which the image is formed, thereby executing a process for controlling adhesion force.

a receiving unit for receiving an input of a recording medium on which an image is formed from an external device; and a reading unit for reading the image formed on the recording medium input via the receiving unit. may be configured to adjust the pattern of applying toner according to the pattern of the image read by the device.

According to another aspect of the present disclosure, when the pressure member and the heating member configured to heat the imaged recording medium release the nipping of the recording medium against the heating member, A gloss control method is provided for controlling the gloss of an image on a recording medium by controlling adhesion.

According to one aspect of the present disclosure, the adhesion of the recording medium to the heating member is controlled when the recording medium is released from the nipping by the heating member and the pressure member, thereby improving the image formed on the recording medium. Gloss is controlled. Thereby, the glossiness of the formed image can be controlled arbitrarily and to have natural visibility within a sufficient range.

FIG. 5 is a diagram schematically showing an example of control of adhesion force of a recording medium to a heating member; FIG. 5 is a diagram schematically showing an example of control of adhesion force of a recording medium to a heating member; FIG. 5 is a diagram schematically showing an example of control of adhesion force of a recording medium to a heating member; FIG. 4 is a diagram for explaining an example of an image gloss control method according to the present embodiment; FIG. 10 is a diagram for explaining another example of the image gloss control method according to the present embodiment; 1 is a hardware block diagram of an image forming apparatus as an example of a gloss control device; FIG. 2 is a diagram showing an example of the configuration of main parts of an image forming section 30 and a fixing section 60 in the image forming apparatus; FIG. 4 is a diagram schematically showing a control block for six types of toner application amounts in the image forming apparatus 1. FIG. 5 is a flow chart of processing executed to control the glossiness of the image forming surface of the paper 130 according to the gloss control method described with reference to FIG. 4. FIG. 5 is a flow chart of processing executed to control the glossiness of the image forming surface of the paper 130 according to the gloss control method described with reference to FIG. 4. FIG. 6 is a flow chart of processing executed to control the glossiness of the image forming surface of the paper 130 according to the gloss control method described with reference to FIG. 5. FIG. It is a figure which shows the structure of the 1st modification of a glossiness control apparatus. It is a figure which shows the structure of the 2nd modification of a glossiness control apparatus. 1 is a diagram schematically showing the configuration of an image forming apparatus used to implement a control example of the gloss control device of the present embodiment; FIG. FIG. 10 is a diagram showing the result of an image formed according to control example (1); FIG. 10 is a diagram showing the result of an image formed according to a reference example; FIG. 10 is a diagram showing the result of an image formed according to control example (2); FIG. 2 is a schematic diagram of a cross section of color toner in an unfixed state; FIG. 2 is a schematic cross-sectional view showing a state in which two types of colorless toner are applied on unfixed color toner; FIG. 19 is a schematic cross-sectional view showing a state in which two kinds of colorless toners are applied on an unfixed color toner by another method.

An embodiment of a gloss control device will be described below with reference to the drawings. In the following description, identical parts and components are given identical reference numerals. Their names and functions are also the same. Therefore, these descriptions will not be repeated.

[1. Gloss Control Mechanism]
According to the present disclosure, the recording medium is sandwiched between the heating member and the pressure member at the nip portion, and the adhesive force of the recording medium to the heating member when the sandwiching is released is controlled, so that the image on the recording medium is displayed. The glossiness of the formed surface (hereinafter also referred to as “image forming surface”) is controlled. 1 to 3 are diagrams schematically showing an example of controlling the adhesive force of the recording medium to the heating member.

FIG. 1 shows an example in which the glossiness of the image forming surface of the recording medium is relatively low. An enlarged view of the nip portion is shown in the upper right portion of FIG. The enlarged view shows a paper 130 which is an example of a recording medium, a toner layer 120 formed on the paper 130, and a heating member 100 for fixing the toner layer 120 on the paper 130. FIG. Heating member 100 is, for example, a roller or a belt. At the nip portion, the paper 130 is sandwiched between the heating member and the pressure member, but the pressure member is omitted in FIG.

The upper left portion of FIG. 1 shows an enlarged view of the state in which the toner is not melted before the nip. Toner layer 120 includes wax 122 and other ingredients 121 . Another component 121 is, for example, a pigment.

The lower right portion of FIG. 1 shows an enlarged view of the surface of the paper 130 when the sandwiching of the paper 130 between the heating member and the pressure member is released. In the example of FIG. 1, in the toner layer 120, the amount of exudation of the wax 122 on the surface in contact with the heating member 100 is relatively small. When the sandwiching between the heating member and the pressing member is released, the adhesion of the toner layer 120 to the heating member is relatively high. Therefore, when the pinching is released, the toner layer 120 is less likely to separate from the heating member 100, so that the surface state of the toner layer 120 after the pinching is released is relatively uneven. Accordingly, in the example of FIG. 1, the glossiness of the image formed on the paper 130 is relatively low.

FIG. 2 shows an example in which the glossiness of the image forming surface of the recording medium is relatively high. An enlarged view of the nip portion is shown in the upper right portion of FIG. 2, as in the upper right portion of FIG. The upper left portion of FIG. 2 shows an enlarged view of the state where the toner is not melted before the nip. In the example of FIG. 2, the content of wax 122 in the toner layer 120 is higher than in the example of FIG.

The lower right portion of FIG. 2 shows the surface of the paper 130 when the sandwiching of the paper 130 between the heating member and the pressure member is released, as in the lower right portion of FIG. In the example of FIG. 2, since the content of wax 122 in toner layer 120 is high, toner layer 120 is easily peeled off from heating member 100. As a result, the surface of toner layer 120 after the clamping is released is relatively uneven. and the glossiness of the image forming surface of the paper 130 is relatively high.

FIG. 3 shows an example of the relationship between the amount of wax exuding on the recording medium and the glossiness of the image forming surface of the recording medium. The horizontal axis of the graph in FIG. 3 represents the amount of wax exuding on the recording medium. The wax exudation amount is adjusted, for example, by the wax content of the toner applied onto the image forming surface. In another example, the wax content is adjusted by the proportion of different toners applied onto the imaging surface. As indicated by the line Lx, the glossiness of the image forming surface changes according to the amount of wax bleeding.

In the example of FIG. 3, in the region where the wax exudation amount is greater than or equal to the value Vx, the larger the wax exudation amount, the more the recording medium is ejected from the nip portion (when the pinching by the nip portion is released). becomes easier to separate from the heating member, and the glossiness of the image forming surface increases. "Easy to separate" can also be said to be "easy to peel off". In the present embodiment, the amount of exuding wax is controlled to a value V or more to control the glossiness of the image on the recording medium.

[2. Gloss control method (1)]
FIG. 4 is a diagram for explaining an example of an image gloss control method according to the present embodiment. In the example of FIG. 4, the wax-containing toner is applied to the entire "image forming area", which will be described later, and the waxless toner is applied to the portion where the glossiness is desired to be reduced. An example of the gloss control method will be described below together with the four types of conditions A1 to A4 in FIG.

In condition A1, toner layer 120 includes toner 125 with wax. In condition A2, toner layer 120 includes waxless toner 126 in addition to wax-containing toner 125 .

It should be noted that toner layer 120 is intended to be a layer formed on top of the toner applied to form an image on paper 130 when an image is formed on paper 130 with toner.

Compared to Condition A1, under Condition A2, the waxless toner 126 is applied to the surface of the paper 130 in contact with the heating member 100, so that the amount of wax exuding from the surface is small. Accordingly, under condition A2, the glossiness of the image forming surface is lower than under condition A1.

Under condition A3, the toner layer 120 contains more waxless toner 126 than under condition A2. Accordingly, under condition A3, the glossiness of the image forming surface is lower than under condition A2.

In one example, both the wax-containing toner 125 and the wax-less toner 126 are comprised of pigment-free toner. That is, in the present embodiment, in addition to the pigment-containing toner for forming the image, the wax-containing toner 125 and the waxless toner 126 are used to control the glossiness of the image on the paper 130 .

FIG. 4 further shows a graph G01 representing the relationship between the amount of waxless toner applied and the glossiness of the image. In one example, a wax-containing toner 125 is applied to the entire area of the paper 130 where an image is formed (hereinafter also referred to as an “image forming area”), and a waxless toner 125 is applied to the area where glossiness is desired to be reduced. 126 is given. The amount of waxless toner applied per unit area in the image forming area is shown as the horizontal axis in the graph G01 of FIG.

In the graph G01, as indicated by the line L01, the glossiness decreases according to the amount of waxless toner applied until the value on the horizontal axis reaches the value "V0". In the present embodiment, the glossiness of the image is controlled by adjusting the amount of waxless toner applied within a range in which the glossiness decreases according to the amount of waxless toner applied (that is, from "0" to "V0"). be.

Condition A4 corresponds to a region where the amount of waxless toner applied exceeds "V0". Under condition A4, this corresponds to an area in which the glossiness of the formed image increases as the amount of waxless toner applied increases due to the excessive amount of waxless toner applied. Such areas are preferably excluded from image gloss control because too little wax bleeds out and makes it difficult to separate the recording medium from the heating member.

In this specification, "wax-less toner" is an example of toner having a lower wax (release agent) content than "wax-containing toner". Instead of a combination of "waxless toner" and "wax-containing toner", two types of toners having different wax (release agent) contents may be employed. "Wax-containing toner" is an example of the first toner, and "waxless toner" is an example of the second toner.

[3. Gloss control method (2)]
FIG. 5 is a diagram for explaining another example of the image gloss control method according to the present embodiment. In the example of FIG. 5, a toner containing a large amount of wax (toner a) to provide a sufficiently high gloss is used as the first toner, and a toner containing a small amount of wax to provide a sufficiently low gloss (toner b) is used as the first toner. ) is used as the second toner. The ratio of the amounts of toner a and toner b to be applied is adjusted according to the glossiness required for each portion. Another example of the gloss control method will be described below together with the four types of conditions B1 to B4 in FIG.

Under condition B1, the ratio of toner a is the highest. Under condition B4, the percentage of toner b is the highest. The percentage of toner a is highest in condition B1, next highest in condition B2, next highest in condition B3, and lowest in condition B4.

As the ratio of toner a increases, the amount of wax exuding from the portion that contacts the heating member 100 increases. As the amount of wax exuding from the portion in contact with the heating member 100 increases, the paper 130 is more likely to separate from the heating member 100 when the sandwiching of the paper 130 between the heating member and the pressure member is released. , the glossiness of the image formed on the paper 130 is increased.

FIG. 5 also shows a graph G02 showing the relationship between the ratio of the toner b on the surface of the paper 130 and the glossiness of the image on the paper 130. As shown in FIG. As indicated by the line L02 in the graph G02, the glossiness of the image formed on the paper 130 decreases as the proportion of the toner b increases.

[4. Configuration of Gloss Control Device]
In this embodiment, the gloss control device is configured by an image forming apparatus. FIG. 6 is a hardware block diagram of an image forming apparatus, which is an example of a gloss control device. The configuration of an image forming apparatus will be described as an example of the gloss control apparatus with reference to FIG.

The image forming apparatus 1 is an intermediate transfer type color image forming apparatus using an electrophotographic process technology, and is realized by, for example, a color copier or an MFP (Multi-Functional Peripheral). The image forming apparatus 1 includes an image reading section 10, an operation display section 20, an image forming section 30, an image processing section 40, a sheet conveying section 50, a fixing section 60, a communication section 71, a storage section 72, and a control section 1A.

The control unit 1A includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, and the like. The CPU 101 reads out a program corresponding to the processing content from the ROM 102, develops it in the RAM 103, and centrally controls the operation of each block of the image forming apparatus 1 in cooperation with the developed program. At this time, various data stored in the storage unit 72 are referred to. The storage unit 72 is configured by a storage device such as a nonvolatile semiconductor memory (so-called flash memory) or a hard disk drive. In this embodiment, a "gloss level table" is referred to as described later. In FIG. 6, a portion of the storage unit 72 that stores the gloss level table is indicated as a "gloss level table storage unit 720".

The control unit 1A transmits and receives various data to and from an external device (for example, a personal computer) connected to a communication network such as a LAN (Local Area Network) or a WAN (Wide Area Network) via the communication unit 71. conduct. The communication unit 71 is realized by a communication control card such as a network card, for example. The control unit 1A acquires data (image data) of an image to be formed on the paper 130, and forms an image on the paper 130 based on the acquired image data. The control unit 1A acquires input image data by receiving image data transmitted from an external device, for example.

The image reading unit 10 includes elements such as an automatic document feeder called an ADF (Auto Document Feeder) and a document image scanning device (scanner). The automatic document feeder transports the document placed on the document tray by the transport mechanism and sends it to the document image scanning device. The automatic document feeder continuously feeds a large number of documents placed on the document tray to the document image scanning device, and the document image scanning device continuously scans the images of the large number of documents (including both sides). can be read all at once.

The document image scanning device optically scans the document transported onto the contact glass from the automatic document feeder or the document placed on the contact glass, and the reflected light from the document is detected by a CCD (Charge Coupled Device) sensor. to form an image on the light receiving surface of the original, and read the original image. The image reading unit generates input image data based on the result of reading by the document image scanning device. Predetermined image processing is performed on the input image data in the image processing section 40 .

FIG. 7 is a diagram showing an example of the configuration of the main parts of the image forming section 30 and the fixing section 60 in the image forming apparatus. 7, image forming portion 30 includes intermediate transfer belt 301, six types of image forming units 311, 312, 313, 314, 315, and 316 that supply toner to intermediate transfer belt 301, and fixing portion 60. including. The intermediate transfer belt 301 is stretched around rollers 302 and 303 .

The image forming unit 311 supplies clear toner (C(1)), that is, toner containing no pigment. The image forming unit 312 supplies clear toner (C(2)) having a higher wax content than the clear toner (C(1)) of the image forming unit 311 . Clear toner (C(1)) is an example of "toner containing wax" in FIG. 4 and an example of "toner b" in FIG. That is, the clear toner C(1) may be a toner that does not contain wax (release agent). Clear toner (C(2)) is an example of "wax-containing toner" in FIGS.

The image forming unit 313 supplies yellow (Y) toner. The image forming unit 314 supplies magenta (M) toner. The image forming unit 315 supplies cyan (C) toner. The image forming unit 316 supplies black (K) toner.

By rotating the rollers 302 and 303 clockwise in FIG. Units 313-316 apply toner.

In FIG. 7, a transport path 300 represents the path along which the paper 130 is transported. A roller 304 that supports the paper 130 is provided along with the roller 303 on the transport path 300 . Rollers 303 and 304 sandwich intermediate transfer belt 301 and paper 130 . At this time, the toner image formed on the intermediate transfer belt 301 is transferred onto the paper 130 .

Among the toner images transferred onto the paper 130 , the toner images applied by the image forming units 313 to 316 are positioned closest to the paper 130 . Next, clear toner (C(2)) applied by imaging unit 312 is located near paper 130 . The clear toner (C(1)) applied by the image forming unit 311 is positioned farthest from the paper 130 .

The paper 130 to which the toner image has been transferred is sent to the fixing section 60 .
Fixing section 60 includes a fixing belt 601 , a heating roller 602 , an upper pressure roller 603 and a lower pressure roller 604 . The heating roller 602 incorporates a heater. The fixing belt 601 is stretched between a heating roller 602 and an upper pressure roller 603, heated by the heating roller 602, and rotated clockwise by a driving mechanism (not shown). Rotate clockwise. Fixing belt 601 is an example of a heating member.

The lower pressure roller 604 is rotated counterclockwise by a driving mechanism (not shown). Lower pressure roller 604 is an example of a pressure member.

Paper 130 on conveying path 300 is nipped by fixing belt 601 and lower pressure roller 604 at the nip portion formed by fixing belt 601 and lower pressure roller 604, and then rotates as shown in FIG. transported to the left.

Returning to FIG. 6 , the operation display unit 20 is composed of, for example, a liquid crystal display (LCD) with a touch panel, and functions as a display unit 21 and an operation unit 22 . The display unit 21 displays the status of various operation screens/images and the operation status of each function according to the display control signal input from the control unit 1A. The operation unit 22 may be software keys, hardware keys, or a combination thereof. In one example, the operation unit 22 includes various operation keys such as a numeric keypad and a start key, receives various input operations by the user, and outputs operation signals to the control unit 1A.

The image processing unit 40 includes a circuit or the like that performs digital image processing on input image data in accordance with initial settings or user settings. For example, the image processing section 40 performs tone correction based on tone correction data (tone correction table) under the control of the control section 1A. The image processing unit 40 also performs various types of correction processing such as color correction and shading correction, compression processing, and the like on the input image data, in addition to tone correction. The image forming section 30 is controlled based on the input image data subjected to these processes.

The paper transport section 50 includes a paper feed section, a paper discharge section, a transport path section, and the like. Each of the plurality of paper feed tray units constituting the paper feed section accommodates paper 130 (standard paper, special paper) identified based on basis weight, size, etc. for each preset type. The transport path section has a plurality of transport roller pairs such as registration roller pairs.

FIG. 8 is a diagram schematically showing a control block for six types of toner application amounts in the image forming apparatus 1. As shown in FIG. As shown in FIG. 8, the image forming section 30 includes output control sections 321-326 that control the image forming units 311-316, respectively. The output controllers 321-326 are configured by, for example, control boards for controlling the image forming units 311-316, respectively. The controller 1A controls the amount of toner applied by each of the image forming units 311 to 316 via the output controllers 321 to 326, respectively.

The controller 1A refers to the image data and the glossiness table when controlling the amount of toner to be applied. The image data defines the image to be formed on paper 130 . The glossiness table defines the glossiness of the image formed on the paper 130 and the application amount of wax-containing toner and/or waxless toner per unit area. In one example, the control unit 1A refers to the image data to control the manner of toner application by the image forming units 313 to 316, refers to the gloss level table and the target gloss level, and controls the image forming unit 311 , 312 to control the manner in which toner is applied.

An example of the glossiness table defines the relationship between the amount of waxless toner applied and the glossiness defined by the line L01 in the graph G01 of FIG. Another example of the glossiness table defines the relationship between the percentage of toner b and the glossiness defined by the line L02 in the graph G01 of FIG.

In this specification, a "table" is an example of information representing a relationship between a plurality of physical quantities. The manner in which the relationship between the amount of toner applied and the glossiness is stored is not limited to the table format.

The fixing belt 601 contacts the paper 130 on which the toner image is formed, and heats and fixes the toner image onto the paper 130 at a fixing temperature (for example, 160 to 200 [° C.]). Here, the fixing temperature is a temperature that can supply the amount of heat required to melt the toner on the paper 130, and varies depending on the type of paper 130 on which an image is formed.

The fixing belt 601 is composed of, for example, a cylindrical substrate having an outer diameter of 110 mm made of PI (polyimide) having a thickness of 50 μm, an elastic layer laminated on the surface (peripheral surface) of the substrate, and an elastic layer. It has a release layer laminated on the surface (peripheral surface) of the. The fixing belt 601 is wound around the heating roller 602 and the upper pressure roller 603 with a predetermined tension to form an oval shape along the horizontal direction. The elastic layer of the fixing belt 601 is made of silicone rubber with a thickness of 200 μm, and the release layer is made of a PFA tube (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer tube) with a thickness of 30 μm. ing. With such a configuration, the heat capacity of the fixing belt is relatively small.

A heating roller 602 heats the fixing belt 601 . The heating roller 602 incorporates a heating source (halogen heater) for heating the fixing belt 601 . The temperature of the heat source is controlled by the controller 1A. The heating roller 602 is heated by the heat source, and as a result, the fixing belt 601 is heated.

The heating roller 602 has, for example, a PTFE (polytetrafluoroethylene) coat laminated on the outer peripheral surface (surface) of a cylindrical core metal, and has an outer diameter of 60 mm. The cored bar is composed of an aluminum plate with a thickness of 1 mm. The heat capacity of the heating roller 602 having such a configuration is relatively small.

A plurality of heater lamps are provided inside the heating roller 602 to heat the heating roller by an electro-thermal conversion method. When heating roller 602 is heated by one or more of the heater lamps, fixing belt 601 running around heating roller 602 is heated, and heated fixing belt 601 forms a fixing nip (nip portion). The paper 130 passing through is heated. The heater lamps are, for example, halogen heater lamps, and are arranged on a circle with a constant radius around the axial center of the heating roller 602 with equal intervals in the circumferential direction. placed along the heart. The rated power of the heater lamp is, for example, 1500W in total.

The heater lamp is turned on (heated) by being supplied with electric power, and heats the heating roller 602 with an amount of heat substantially proportional to the electric power supplied. A plurality of heater lamps have the same length, for example 290 mm. In each of the plurality of heater lamps, in order to ensure fixability at both ends of the fixing belt 601 in the width direction (the direction orthogonal to the paper conveying direction), heat lamps are arranged at both ends in the longitudinal direction. Light (corresponding to light intensity and heating intensity) is greater than light distribution in the central portion in the longitudinal direction. In this embodiment, the light distribution of the 20 mm length portion at each end on each side of the heater lamp is 115%, assuming that the light distribution of the central portion of the 250 mm length other than the ends on both sides is 100%. %It has become.

A temperature sensor (not shown) that detects the surface temperature of the fixing belt 601 is provided near the heating roller 602 . The temperature sensor is arranged facing the upstream portion of the fixing belt 601 in the running direction. A contactless thermistor, for example, is used as the temperature sensor.

The upper pressure roller 603 is pressed against the lower pressure roller 604 driven and rotated by a main drive source (not shown) in the fixing section 60 via the fixing belt 601 . The lower fixing section 60B has, for example, a lower pressure roller 604 that is a back side support member (roller pressure method). The control unit 1A controls the main drive source (driving motor) to rotate the lower pressure roller 604 counterclockwise. Drive control of the drive motor (for example, turning on/off of rotation, peripheral speed, etc.) is performed by the control unit 1A. The lower pressure roller 604 incorporates a heating source (not shown) such as a halogen heater. The lower pressure roller 604 is heated by the heat generated by this heat source. The control unit 1A controls the electric power supplied to the heating source, and controls the lower pressure roller 604 to a predetermined temperature (eg, 80 to 120 [° C.]).

The upper pressure roller 603 has, for example, an aluminum core (30 mm in diameter) and an elastic layer with a thickness of 15 mm laminated on the outer peripheral surface (surface) of the core. The elastic layer is made of, for example, silicone rubber having a JIS A hardness of 10 degrees. Since the upper pressure roller 603 has such a soft elastic layer, it is greatly deformed at the nip portion when pressed against the lower pressure roller 604, and the nip portion can have a sufficient area for fixing.

The lower pressure roller 604 is pressed against the upper pressure roller 603 via the fixing belt 601 with a predetermined fixing load (for example, 2650 [N]). In this manner, a fixing nip is formed between the fixing belt 601 and the lower pressure roller 604 to sandwich and convey the paper 130 . When the lower pressure roller 604 is driven to rotate, the fixing belt 601 is driven to rotate clockwise. Along with this, the upper pressure roller 603 is driven to rotate clockwise.

The lower pressure roller 604 includes, for example, a core made of aluminum (thickness 5 mm), an elastic layer laminated on the outer peripheral surface (surface) of the core, and a layer laminated on the outer peripheral surface (surface) of the elastic layer. and a release layer (not shown). The elastic layer is made of silicone rubber. The release layer is composed of, for example, a PFA tube with a thickness of 30 μm. As described above, the lower pressure roller 604 has a highly rigid structure with an aluminum core with a thickness of 5 mm, and has a larger heat capacity than the fixing belt. The lower pressure roller 604 has a so-called inverted crown shape in which the diameter decreases toward the center in the longitudinal direction. When the outer shape of the end portion is D1 and the outer shape of the central portion is D2, the difference between the two is taken as the reverse crown amount. The reverse crown amount is set to approximately 0.1 to 0.8 mm. Lower pressure roller 604 is rotated at a predetermined surface speed by a drive.

The fixing section 60 has a drive source for rotating the upper pressure roller 603 and a drive source for rotating the lower pressure roller 604 . As these drive sources, for example, general AC motors and DC brushless motors can be used. Structurally, a DC brushless motor has a structure similar to that of a permanent magnet synchronous motor of an AC motor. A permanent magnet is used in the rotor, and the rotational position of the rotor is sensed and referenced by a hall element to rotate. By generating and controlling a magnetic field, torque and speed can be controlled. A drive control device is connected to these drive sources, and the speed and the like can be controlled by the drive control device.

Sheets of paper 130 stored in a paper feed tray unit (not shown) are delivered one by one from the top and transported to image forming section 30 by various rollers on transport path 300 . At this time, the skew of the fed paper 130 is corrected and the conveying timing is adjusted by a registration roller unit having a pair of registration rollers installed immediately before the image forming unit 30 . Then, in the image forming section 30 , the toner images on the intermediate transfer belt 301 are collectively secondary-transferred onto one side of the paper 130 , and the fixing section 60 performs a fixing process. The paper 130 on which the image has been formed is discharged to the outside of the machine by a paper discharge section having a paper discharge roller. Note that the paper ejected outside the machine is ejected onto, for example, a paper ejection tray. Further, during continuous printing in which images are continuously formed on a plurality of printing papers, a plurality of papers are stacked on the discharge tray.

[5. Control according to gloss control method (1)]
FIGS. 9 and 10 are flowcharts of processes performed to control the glossiness of the image forming surface of paper 130 according to the gloss control method described with reference to FIG. In the gloss control method of FIG. 4, the wax-containing toner is applied to the entire image forming area, and the wax-less toner is applied to the portion where the glossiness is desired to be reduced. The processing shown in each flow chart is realized, for example, by CPU 101 executing a given program.

(Fig. 9: Controlling the mode of application of waxless toner)
FIG. 9 shows processing for controlling the application mode of waxless toner. At step SA10, CPU 101 reads the target glossiness for each portion of the image formed by image forming units 313-316. In this embodiment, for example, the image data includes a method for specifying target glossiness. More specifically, the image data includes information specifying a target gloss level for each portion of the image to be formed. In one example, the image data includes image information of the background portion, target glossiness of the background portion, image information of the character portion, and target glossiness of the character portion.

At step SA20, CPU 101 generates a pattern (second colorless toner pattern) for applying waxless toner onto paper 130 based on the target glossiness for each portion read at step SA10. In generating the second colorless toner pattern, the CPU 101 uses the relationship shown in the graph G01 in FIG. 4 to determine the amount of waxless toner to be applied to each portion.

At step SA30, CPU 101 controls output control unit 321 to apply waxless toner in the pattern generated at step SA20. Accordingly, the image forming unit 311 applies waxless toner onto the paper 130 in the pattern generated in step SA20. In one example, more waxless toner is applied to portions with lower target glossiness.

(Fig. 10: Controlling the mode of application of wax-containing toner)
FIG. 10 represents the process of controlling the application mode of the wax-containing toner. At step SB10, the CPU 101 reads the pattern of the image formed on the paper 130 with the colored toner from the image data.

At step SB20, CPU 101 generates a pattern (first colorless toner pattern) for applying wax-containing toner onto paper 130 based on the pattern of the image read at step SB10.

At step SB30, CPU 101 controls output control unit 321 to apply wax-containing toner in the pattern generated at step SB20. Accordingly, image forming unit 312 applies wax-containing toner onto paper 130 in the pattern generated in step SB20.

According to the processing described above with reference to FIGS. 9 and 10, wax-containing toner is applied by the image forming unit 312 onto the colored toner image formed by the image forming units 313 to 316 on the paper 130 . is applied, and a waxless toner is applied by the image forming unit 311 to a portion where a low glossiness is required.

[6. Control according to gloss control method (2)]
FIG. 11 is a flow chart of processing executed to control the glossiness of the image forming surface of the paper 130 according to the gloss control method described with reference to FIG. In the gloss control method of FIG. 5, the ratio of the amounts of toner a and toner b to be applied is adjusted for each portion in the image forming area according to the required glossiness. The processing shown in the flowchart of FIG. 11 is realized, for example, by CPU 101 executing a given program.

Referring to FIG. 11, at step SC10, CPU 101 reads the target glossiness for each portion of the image formed by image forming units 313-316.

At step SC20, CPU 101 determines the ratio of toner a and toner b to be applied to each portion of the image based on the target gloss read out at step SC10. The CPU 101 uses the relationship shown in the graph G02 of FIG. 5 to determine the ratio.

At step SC30, CPU 101 generates a pattern (second colorless toner pattern) for applying toner b onto paper 130 based on the ratio of each portion determined at step SC20. In determining the pattern, a predetermined total amount of toner b and toner a per unit area may be used.

At step SC40, CPU 101 controls output control unit 321 to apply toner b in the pattern generated at step SC30. Accordingly, image forming unit 311 applies toner b onto paper 130 in the pattern generated in step SC30. In one example, more toner b is applied to portions with lower target glossiness.

At step SC50, CPU 101 generates a pattern (first colorless toner pattern) for applying toner a onto paper 130 based on the ratio of each portion determined at step SC20. In determining the pattern, a predetermined total amount of toner b and toner a per unit area may be used.

At step SC60, CPU 101 controls output control unit 322 to apply toner a in the pattern generated at step SC50. Accordingly, image forming unit 311 applies toner a onto paper 130 in the pattern generated in step SC50.

[7. Modification of configuration of gloss control device]
In the examples described with reference to FIGS. 6-8, the gloss control device was configured as an image forming device. Note that the gloss control device may not include the image forming means. That is, the glossiness of the image forming surface of the paper 130 may be controlled by applying colorless toner (toner containing no pigment such as cyan) to the paper 130 on which an image has already been formed.

(Modification (1))
FIG. 12 is a diagram showing the configuration of a first modification of the gloss control device. FIG. 12 shows an image forming system including a gloss control device 1200 , an image forming device 1210 and an image data output device 1220 .

Image forming apparatus 1210 is implemented, for example, as a so-called printer. The image data output device 1220 instructs the image forming device 1210 to form a colored image on the paper 130 according to the image data. In response, image forming device 1210 forms a colored image on paper 130 . After that, the image forming apparatus 1210 conveys the paper 130 on which the colored image is formed toward the gloss control apparatus 1200 .

Gloss control apparatus 1200 in FIG. 12 includes control section 1201 and scanner 1202 in addition to image forming units 311 and 312 and fixing section 60 . An insertion port 1209 for receiving the paper 130 conveyed from the image forming apparatus 1210 is formed in the outer shell of the gloss control device 1200 . The paper 130 is introduced into the transport path 300 inside the gloss control device 1200 via the insertion port 1209 .

Control unit 1201 is configured by an information processing device such as a CPU, for example, and controls image forming units 311 and 312 . In the example of FIG. 12, the processing of FIGS. 9 and 10 or the processing of FIG.

The control unit 1201 acquires image data from the image data output device 1220 or the image forming device 1210, and uses the image data to generate a first colorless toner pattern and a second colorless toner pattern (FIGS. 9 to 11). Generate.

A scanner 1202 detects the image pattern of the paper 130 on the transport path 300 . The control unit 1201 controls the positions at which the image forming units 311 and 312 attach toner to the intermediate transfer belt 301 using the position (or timing) information of the image pattern based on the detection output from the scanner 1202 .

In the example shown in FIG. 12, the gloss control device 1200 can apply toner to images formed in any manner. That is, the printing method in the image forming apparatus 1210 may be any method such as offset printing, inkjet printing, and electrophotographic printing. Also, paper on which no image has been formed or no image has been printed by the image forming apparatus 1210 may be input to the gloss control apparatus 1200 .

The image data output device 1220 determines the glossiness of each part of the image based on the image data, and sends the determined glossiness to the gloss control device. Specific examples of how to determine gloss are described, for example, in Examples 1-4 below. The control unit 1201 applies two types of colorless toners to the paper 130 so that the glossiness received from the image data output device 1220 is realized and at a position matching the position of the image read by the scanner.

Example 1: Luminance information (for example, L ^* value) is calculated from image data (RGB data) to obtain a gloss value proportional to the luminance value. The constant of proportionality is, for example, set in the gloss control device 1200 in advance by the user.

Example 2: The type of image (photograph, painting, text, etc.) formed on the paper 130 is discriminated. It gives a kind of colorless toner. For example, the glossiness corresponding to each of high glossiness and low glossiness is set in the gloss control device 1200 in advance by the user.

Example 3: The control unit 1201 learns the image pattern and the optimum gloss value for it by machine learning such as AI (Artificial Intelligence), and uses the model generated by the learning to determine each part formed on the paper 130. image type, and determine an appropriate gloss value for each part.

Example 4: Gloss control device 1200 includes a monitor that displays the image formed on paper 130 . While viewing the image displayed on the monitor, the user sets the gloss level of each part in the gloss control device 1200 . The image display may be display of image data transmitted from the image data output device 1220 or display of an image read by the scanner 1202 .

(Modification (2))
FIG. 13 is a diagram showing the configuration of a second modification of the gloss control device. A gloss control device 1300 is shown in FIG.

Gloss control apparatus 1300 in FIG. 13 includes image forming units 311 and 312 and fixing section 60, as well as control section 1301, scanner 1302, input section 1303, determination section 1304, display 1305, and insertion port 1309. FIG. Paper 130 on which an image has already been formed is introduced into conveyance path 300 in gloss control device 1300 via insertion port 1309 .

Control unit 1301 and determination unit 1304 are each configured by an information processing device such as a CPU. A determination unit 1304 determines the glossiness of each portion of the image forming surface of the paper 130 . A control section 1301 controls the image forming units 311 and 312 . In the example of FIG. 13, the processing of FIGS. 9 and 10 or the processing of FIG.

The input unit 1303 is composed of various input devices such as a touch panel, keyboard, and mouse. The input unit 1303 may be configured by a communication device that accepts input of information from the outside. The control unit 1301 uses the image read by the scanner 1302 and the set value of the glossiness of each part input from the input unit 1303 to generate the first colorless toner pattern and the second colorless toner pattern (FIGS. 9 to 11). ).

A scanner 1302 detects the image pattern of the paper 130 on the transport path 300 . The control unit 1301 uses the position (or timing) of the image pattern based on the detection output from the scanner 1302 to control the positions at which the image forming units 311 and 312 attach toner to the intermediate transfer belt 301 .

In the example shown in FIG. 13, the gloss control device 1300 can apply toner to images formed by any method (offset printing, inkjet printing, electrophotographic printing, etc.). Also, paper on which no image is printed may be input to the gloss control device 1300 .

The determination unit 1304 determines the glossiness of each part of the image and sends the glossiness data to the control unit 1301 . Specific examples of how gloss is determined are described, for example, in Examples 1 to 4 above. The control unit 1301 applies two types of colorless toners to the paper 130 so that the glossiness input from the determination unit 1304 is realized and at a position matching the position of the image read by the scanner.

[8. Toner production example]
<Production Example 1 of Resin Dispersion>
85 parts by mass of terephthalic acid, 6 parts by mass of trimellitic acid, and 250 parts by mass of bisphenol A propylene oxide adduct are placed in a reaction vessel equipped with a stirrer, thermometer, cooling tube, and nitrogen gas introduction tube, and the reaction vessel is After purging with dry nitrogen gas, 0.1 part by mass of titanium tetrabutoxide was added, and the mixture was stirred and reacted at about 180° C. for 8 hours under a nitrogen gas stream. Further, 0.2 part by mass of titanium tetrabutoxide was added and the temperature was raised to about 220° C. and the reaction was carried out with stirring for 6 hours. Obtained.

The polyester resin [A1] had a glass transition point (Tg) of 59° C. and a weight average molecular weight (Mw) of 9,000.

200 parts by mass of amorphous polyester resin [A1] is dissolved in 200 parts by mass of ethyl acetate, and while stirring this solution, sodium polyoxyethylene lauryl ether sulfate is added to 800 parts by mass of ion-exchanged water so that the concentration becomes 1% by mass. The aqueous solution in which the solid was dissolved was slowly added dropwise. After removing ethyl acetate from this solution under reduced pressure, the pH was adjusted to 8.5 with ammonia. After that, the solid content concentration was adjusted to 20% by mass. Thus, a dispersion liquid of fine particles of amorphous polyester resin [A1] was prepared in which fine particles of polyester resin [A1] were dispersed in an aqueous medium.

<Production Example 2 of Resin Dispersion>
After putting 315 parts by mass of dodecanedioic acid and 220 parts by mass of 1,6-hexanediol into a reaction vessel equipped with a stirrer, a thermometer, a cooling tube, and a nitrogen gas introduction tube, and replacing the inside of the reaction vessel with dry nitrogen gas, , and 0.1 parts by mass of titanium tetrabutoxide were added, and the mixture was stirred and reacted at about 180° C. for 8 hours under a nitrogen gas stream. Further, 0.2 part by mass of titanium tetrabutoxide was added and the temperature was raised to about 220° C. and the reaction was stirred for 6 hours. Obtained.

The polyester resin [B1] had a melting point (Tm) of 72° C. and a weight average molecular weight (Mw) of 14,000.

The polyester resin [B1] was dissolved in a solvent, aqueous ammonia was added, and then deionized water was added dropwise to obtain a polyester resin solution [B1] by a phase inversion emulsification method. The solid content concentration of the polyester resin solution [B1] was 20%.

<Example of preparation of wax dispersion>
200 parts by mass of an ester wax (melting point: 73°C) was heated to 95°C and melted. This was added to an aqueous surfactant solution prepared by dissolving sodium alkyldiphenyl ether disulfonate in 800 parts by mass of ion-exchanged water to a concentration of 3% by mass, and then subjected to dispersion treatment using an ultrasonic homogenizer. The solid content concentration was adjusted to 20% by mass. Thus, a wax dispersion liquid in which fine particles of wax are dispersed in an aqueous medium was prepared.

<Colorless toner containing wax (toner a)>
300 parts by mass of polyester resin [A1] dispersion, 100 parts by mass of polyester resin [B1] dispersion, 75 parts by mass of wax dispersion, 225 parts by mass of ion-exchanged water and 2.5 parts by mass of sodium polyoxyethylene lauryl ether sulfate, The mixture was put into a reaction vessel equipped with a stirrer, a condenser and a thermometer, and 0.1N hydrochloric acid was added while stirring to adjust the pH to 2.5.

Then, 0.3 parts by mass of an aqueous polyaluminum chloride solution (10% aqueous solution in terms of AlCl3) was added dropwise over 10 minutes, and then the internal temperature was raised to 60°C while stirring. Further, the temperature was gradually raised to 75°C, the internal temperature was maintained at 75°C, and measurement was performed using a Coulter counter. Add 2 parts by mass of sodium aqueous solution (40% aqueous solution) to stop particle size growth, raise the internal temperature to 85° C., and measure the shape factor using "FPIA-2000" when it becomes 0.96. , at a rate of 10° C./min to room temperature. This reaction liquid was repeatedly filtered and washed, and then dried to obtain toner particles.

To the obtained toner particles, 1 mass % of hydrophobic silica (number average primary particle size = 12 nm, degree of hydrophobicity = 68) and 1 mass of hydrophobic titanium oxide (number average primary particle size = 20 nm, degree of hydrophobicity = 63) was added. %, mixed with a "Henschel Mixer" (manufactured by Mitsui Miike Kakoki Co., Ltd.), and then using a sieve with an opening of 45 μm to remove coarse particles to obtain a colorless wax-containing toner (toner a). rice field.

The wax-containing colorless toner (toner a) had a volume-based median diameter of 6.10 μm and an average circularity of 0.965.

<Waxless Colorless Toner>
A waxless colorless toner was produced by omitting the use of the wax dispersion in the method for producing the wax-containing colorless toner (toner a).

<Colorless Toner (Toner b)>
In the method for producing a colorless toner containing wax (toner a), the amount of the wax dispersion is changed to 25 parts (1/3 of the amount used in the production of toner a) to produce a colorless toner (toner b). generated. The toner b may be produced by mixing the toner a produced as described above and the waxless colorless toner at a ratio of 1:2.

[9. Control example]
FIG. 14 is a diagram schematically showing the configuration of an image forming apparatus used to implement the control example of the gloss control device of the present embodiment. More specifically, the image forming apparatus 1A of FIG. 14 has a configuration in which two types of image forming units 311 and 312 are omitted from the image forming apparatus 1 shown in FIG.

Three examples (control example (1), reference example, and control example (2)) will be described below. In all three control examples, bizhub PRESS C1070 (manufactured by Konica Minolta) was used as the image forming apparatus 1A. In the bizhub PRESS C1070, toner is applied onto the intermediate transfer belt 301 in the order of yellow toner, magenta toner, cyan toner, and black toner. That is, in the image after being transferred to the paper, black toner is applied on the paper 130, cyan toner is applied on the black toner, magenta toner is applied on the cyan toner, and magenta toner is applied on the magenta toner. Yellow toner will be applied.

In this regard, the three examples to be described apply a second colorless toner instead of a yellow toner, apply a first colorless toner instead of a magenta toner, and additionally use magenta and cyan toners in the image to be formed. The bizhub PRESS C1070 has been modified so that toner is not applied to the areas to be applied.

Espricote C paper (157.0 g/m ² ) manufactured by Nippon Paper Industries Co., Ltd. was used as the paper 130 in Control Example (1), Control Example (2), and Reference Example.

In Control Example (1), Control Example (2), and Reference Example, a bizhub PRESS C1070 fixing device was used as the fixing device, and the surface temperature of the fixing belt 601 was controlled to 190° C. just before the nip portion. This is an example of the case. However, the wax content of the colorless toner, the application amount of the wax-containing toner, and the application amount of the waxless toner vary depending on the type of fixing device and its setting conditions. Therefore, numerical values shown in FIGS. 15 to 17, which will be described later, are merely examples, and the invention derived from the present disclosure is not limited to these numerical values.

Control example (1)
FIG. 15 is a diagram showing the result of an image formed according to control example (1). In control example (1), a wax-containing toner containing 9% wax was used as the first colorless toner, and a wax-free toner containing no wax was used as the second colorless toner. In control example (1), the glossiness of the image forming surface of the paper was controlled according to the glossiness control method described with reference to FIG.

In control example (1), 4.0 g/m ² of the first colorless toner (wax-containing toner) was placed on blank paper, and the second colorless toner (waxless toner) was placed thereon. While adjusting the amount of the second colorless toner to 11 levels in the range of 0 to ² g/m2, 10 sheets of paper were passed at each level (condition), and the surface of the paper after the toner was fixed. 60 degree glossiness was measured. Of the 10 sheets passed through, the sheets that could not be separated from the fixing belt 601 and could not be output from the apparatus were counted as separation NG. FIG. 15 shows four types of items (amount of waxless toner, glossiness, separation, number of separation NG/number of sheets passed) and values of each item. "Waxless toner amount" represents the amount of the second colorless toner applied. "60-degree glossiness" represents the average value of 60-degree glossiness of images on 10 sheets of paper formed under each condition. "Separation" represents whether or not separation NG occurred under each condition. "○" indicates that separation NG did not occur, and "x" indicates that separation NG occurred. The “separation NG number/passed number of sheets” represents the ratio of the number of sheets with separation NG to the number of passed sheets (the number of sheets on which an image is formed) under each condition.

The results shown in FIG. 15 show that the glossiness can be lowered by increasing the amount of waxless toner applied. On the other hand, it is confirmed that when the amount of waxless toner applied increases beyond a certain amount, the glossiness does not decrease, and the amount increases the likelihood of paper feed failure. For this reason, it is desirable to set the maximum amount of the waxless toner to be applied to an amount corresponding to the upper limit value (minimum value of the glossiness) that has the effect of lowering the glossiness. That is, in the example shown in FIG. 15, it is desirable to control the waxless toner within the range enclosed by the thick line.

Therefore, when the glossiness of the image forming surface of the paper is controlled according to the glossiness control method described with reference to FIG. 4, as an example of the "glossiness table", The relationship between the "waxless toner amount" and the "60 degree glossiness" is stored in the glossiness table storage unit 720 (FIG. 6), and can be referred to.

(Reference example)
FIG. 16 is a diagram showing the result of an image formed according to the reference example. The reference example corresponds to an experimental example for confirming an appropriate wax content of the toner b in controlling the glossiness of the image forming surface of the paper according to the glossiness control method described with reference to FIG.

In the reference example, as the first colorless toner, trial colorless toners were used in which the wax content was changed to 11 levels in the range of 1 to 9 g/m ² . 4.0 g/m ² of blank paper was placed on 10 sheets of each level of toner, and the 60-degree glossiness of the paper surface after the toner was fixed was measured. Of the 10 sheets that were passed, those that could not be separated from the fixing belt 601 and could not be output from the apparatus were counted as separation NG. The four items in FIG. 16 (amount of colorless toner, glossiness, separation, number of separation NG/number of sheets passed) have the same meanings as in FIG.

According to the results shown in FIG. 16, it can be seen that the glossiness decreases as the wax content in the toner used as the toner b decreases. On the other hand, it is confirmed that when the wax content is reduced below a certain amount, the glossiness does not decrease even when the wax content is reduced, and the amount of the wax tends to cause paper feed failure. For this reason, in order to achieve both sufficiently low glossiness and paper feeding performance, it is desirable to use a toner with a lower wax content that is effective in lowering the glossiness. That is, in this example, it is desirable to use a toner with a wax content of 3% as the toner b.

Control example (2)
FIG. 17 is a diagram showing the result of an image formed according to control example (2). In control example (2), the glossiness of the image forming surface of the paper was controlled according to the glossiness control method described with reference to FIG. In control example (2), the first colorless toner (toner a) and the second colorless toner (toner b) are adjusted to a total of 4.0 g/m ² and the respective ratios are changed to 6 levels. I put it on the paper of the state. Ten sheets of paper were passed at each level, and the 60 degree glossiness of the surface of the paper after the toner had been fixed was measured. Of the 10 sheets that were passed, those that could not be separated from the heating belt and could not be output from the device were counted as separation NG. The three items in FIG. 17 (60 degree glossiness, separation, number of separation NG/number of sheets passed) have the same meaning as in FIG.

According to the control example (2), by using the toner having the wax content derived from the experimental result of the reference example as the "toner b", "control of the glossiness according to the change in the ratio of the toner a and the toner b" can be achieved. It was confirmed that compatibility with "paper threading performance" is possible.

Therefore, when the glossiness of the image forming surface of the paper is controlled according to the glossiness control method described with reference to FIG. 5, the "toner a: toner b The relationship between (ratio of toner a and toner b)” and “60 degree glossiness” is stored in the glossiness table storage unit 720 (FIG. 6), and can be referred to.

[10. Example of Toner Application Mode]
A specific example of a preferable toner application mode corresponding to the gloss control method will be described with reference to FIGS. 18 to 20. FIG. This description is merely an example, and the manner of applying toner corresponding to the gloss control method shown in this specification is not limited to the example in this description.

FIG. 18 is a schematic cross-sectional view of color toner in an unfixed state. FIG. 19 is a schematic cross-sectional view showing a state in which two kinds of colorless toners are applied on unfixed color toner. FIG. 20 is a schematic cross-sectional view showing a state in which two kinds of colorless toners are applied on the unfixed color toner by a method different from that of FIG. That is, the state of the paper surface changes from the state shown in FIG. 18 to the state shown in FIG. 19 in one example, and from the state shown in FIG. 18 to the state shown in FIG. state.

FIG. 18 shows paper 131 and color toner 120-CL. 19 and 20 further show two types of colorless toner (wax toner 120-WI and waxless toner 120-WL).

In FIG. 19, the height of the layer of the color toner 120-CL and the wax-containing toner 120-WI is increased by supplementing the portion other than the portion where the color toner 120-CL is most applied with the wax-containing toner 120-WI. becomes uniform. That is, the area and amount to which wax toner 120-WI is applied is adjusted by the area and amount to which color toner 120-CL is applied. On top of this, waxless toner 120-WL is applied so as to give desired gloss to the portion where gloss is desired to be controlled.

According to the control shown in FIG. 19, the output image has fewer steps, and the image looks better.

On the other hand, in FIG. 20, the wax-containing toner 120-WI is uniformly applied regardless of the area and amount to which the color toner 120-CL is applied. On top of that, waxless toner 120-WL is applied so as to give desired gloss to the portion where gloss is desired to be controlled.

The image produced by the control shown in FIG. 20 may have a slight level difference on the surface, so the appearance may be slightly inferior to the image produced by the control shown in FIG. It is not necessary to control the application mode of 120-WI in accordance with the application mode of color toner 120-CL. Therefore, it is possible to adjust the glossiness while simplifying the control for image formation.

Note that the method shown in FIG. 19 is preferable to the method shown in FIG. 20 if the following conditions are satisfied.

Condition 1: When the glossiness control method described with reference to FIG. 4 is adopted for glossiness control Condition 2: As shown in FIG. 7, the glossiness of an image formed by electrophotographic printing is controlled. In the case where the color toner and the colorless toner are simultaneously applied to the paper in an unfixed state and fixed at the same time (the glossiness of the image already formed by another image forming apparatus shown in FIG. 12 or 13) control)
Condition 3: Color toner and wax-containing colorless toner have substantially the same wax content The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims. In addition, the inventions described in the embodiments and modifications are intended to be implemented either singly or in combination as much as possible.

1, 1210 image forming apparatus 1A 1201 1301 control unit 10 image reading unit 20 operation display unit 21 display unit 22 operation unit 30 image forming unit 40 image processing unit 50 paper conveying unit 60 fixing Section 71 Communication Section 72 Storage Section 100 Heating Member 101 CPU 120 Toner Layer 125 Toner Containing Wax 126 Waxless Toner 130 Paper 300 Conveyance Path 301 Intermediate Transfer Belt 302, 303, 304 Roller 311, 312, 313, 314, 315, 316 image forming unit 321, 322, 326 output control unit 601 fixing belt 602 pressure roller 603 upper pressure roller 604 lower pressure roller 720 glossiness table storage Sections 1200, 1300 Gloss Control Device 1202, 1302 Scanner 1209, 1309 Insertion Port 1220 Image Data Output Device 1303 Input Section 1304 Decision Section 1305 Display.

Claims (8)

a heating member configured to heat an imaged recording medium;
a pressing member configured to sandwich a recording medium together with the heating member;
a controller configured to control adhesion force of the recording medium to the heating member when the holding by the heating member and the pressure member is released;
The control unit is configured to control the adhesion force by adjusting the amount of at least one type of toner among a plurality of types of toners each having a different release agent content to be applied to the recording medium. and
the plurality of types of toners include a first toner and a second toner having a release agent content lower than that of the first toner;
The control unit
applying the first toner to the entire area of the image formed on the recording medium;
applying the second toner onto the first toner;
sandwiching a recording medium to which both the first toner and the second toner are applied by the heating member and the pressure member;
A gloss control device configured to : 2. The gloss control device of claim 1 , wherein the second toner does not contain a release agent. The control unit sets the application amount of the second toner to a value equal to or lower than the value when the glossiness of the image on the recording medium takes a minimum value in changes in the glossiness of the image on the recording medium with respect to the change in the application amount of the second toner. 3. A gloss control device according to claim 1 or claim 2 , configured to control the adhesion force by adjusting. a heating member configured to heat an imaged recording medium;
a pressing member configured to sandwich a recording medium together with the heating member;
a controller configured to control adhesion force of the recording medium to the heating member when the holding by the heating member and the pressure member is released;
The control unit is configured to control the adhesive force by adjusting the ratio of applying a plurality of types of toner having different contents of release agents onto the recording medium,
The gloss control device , wherein the plurality of types of toner includes a first toner that is a colorless toner and a second toner that is a colorless toner containing a release agent less than that of the first toner . 5. The controller according to any one of claims 1 to 4 , wherein the controller is configured to apply toner to a recording medium on which an image is formed, thereby executing the process for controlling the adhesive force. 2. A gloss control device according to claim 1. a reception unit that receives an input of a recording medium on which an image is formed from an external device;
a reading unit for reading an image formed on a recording medium input via the reception unit;
6. The gloss control device according to claim 5 , wherein said control section is configured to adjust the pattern of applying toner according to the pattern of the image read by said reading section. By controlling the adhesive force of the recording medium to the heating member when the recording medium is released from the pressing member and the heating member configured to heat the recording medium on which an image is formed, Controls the glossiness of images on recording media ,
The control of the glossiness of the image on the recording medium is performed by adjusting the amount of at least one kind of toner among a plurality of kinds of toners having different release agent contents to be applied to the recording medium. including controlling adhesion,
the plurality of types of toners include a first toner and a second toner having a release agent content lower than that of the first toner;
Controlling the gloss of the image on the recording medium comprises:
applying the first toner to the entire area of the image formed on the recording medium;
applying the second toner onto the first toner;
sandwiching a recording medium to which both the first toner and the second toner are applied by the heating member and the pressure member;
A method of controlling gloss , including: By controlling the adhesive force of the recording medium to the heating member when the recording medium is released from the pressing member and the heating member configured to heat the recording medium on which an image is formed, Controls the glossiness of images on recording media ,
Controlling the glossiness of the image on the recording medium includes controlling the adhesive force by adjusting the ratio of applying to the recording medium a plurality of types of toners each having a different release agent content. ,
The method of controlling glossiness , wherein the plurality of types of toner includes a first toner that is colorless toner and a second toner that is colorless toner containing a release agent less than that of the first toner .

Images