Image forming apparatus and image forming method

Abstract

This image forming apparatus provides an image forming apparatus that improves the texture of images transferred to a substrate using a direct-to-film printing method. [Solution] The image forming apparatus is used in an image forming method for forming an image on a transfer object by a Direct To Film printing method, and comprises: a first head for discharging a first liquid for forming a base on a transfer substrate; a second head for discharging a second liquid for forming an image after the base on the transfer substrate has been formed; and a control unit for controlling the discharging of the first liquid by the first head based on information regarding the surface roughness of the transfer object.

Description

Technical Field

[0001] The present invention relates to an image forming apparatus and an image forming method.

Background Art

[0002] As an example of an image forming apparatus, an image forming method of the Direct To Film (DTF) printing method is known. The image forming method of the DTF printing method forms a transfer image by applying coloring ink to a transfer substrate such as a film and performing heating. For example, a heat-soluble adhesive powder or the like is applied to the transfer image, and the coloring ink on the film is transferred to a transfer object such as clothing (see, for example, Patent Document 1).

Summary of the Invention

Problems to be Solved by the Invention

[0003] However, in the technique described in Patent Document 1, there is room for improvement in the texture of the image transferred to the transfer object.

[0004] Therefore, an object of the present invention is to improve the texture of an image transferred to a transfer object by the Direct To Film printing method.

Means for Solving the Problems

[0005] An image forming apparatus according to an aspect of the present disclosure is an image forming apparatus used in an image forming method for forming an image on a transfer object by the Direct To Film printing method, including a first head that discharges a first liquid for forming a base on a transfer substrate, a second head that discharges a second liquid for forming an image after forming the base on the transfer substrate, and a control unit that controls the discharge of the first liquid by the first head based on information regarding the surface roughness of the transfer object.

Effects of the Invention

[0006] According to the present invention, the texture of the image transferred to the object to be transferred by the Direct To Film printing method can be improved. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic diagram illustrating a common Direct-to-Film printing method. [Figure 2] This is a schematic perspective view showing an example of the overall configuration of an image forming apparatus according to an embodiment. [Figure 3] This is a schematic top view showing the overall configuration of an example of an image forming apparatus according to the embodiment. [Figure 4] This is a schematic bottom view showing the liquid discharge head of the image forming apparatus according to the embodiment. [Figure 5] This is a block diagram showing the hardware configuration of an example of an image forming apparatus according to the embodiment. [Figure 6] This figure shows the configuration of a heater in an example of an image forming apparatus according to the embodiment. [Figure 7] This figure shows how an image forming apparatus according to an embodiment acquires information regarding the surface roughness of an object to be transferred using a sensor that measures the surface roughness of the object to be transferred. [Figure 8] This flowchart shows an example of the dot pattern determination operation by the image forming apparatus according to the embodiment. [Figure 9] This figure shows a dot pattern formed by an image forming apparatus according to an embodiment, by discharging a first liquid from a first head. [Modes for carrying out the invention]

[0008] The image forming apparatus and image forming method according to the present invention will be described below with reference to the drawings. It should be noted that the present invention is not limited to the embodiments shown below, and can be modified, added, altered, or deleted to the extent that a person skilled in the art can conceive of it. Any embodiment that achieves the function and effect of the present invention is included within the scope of the present invention.

[0009] The image forming apparatus according to this embodiment is an image forming apparatus used in an image forming method for forming an image on a transfer object by a DTF printing method, and comprises a first head for discharging a first liquid for forming a base on a transfer substrate, and a second head for discharging a second liquid for forming an image on the base formed on the transfer substrate, and is characterized by comprising a control unit that controls the discharging of the first liquid by the first head based on information regarding the surface roughness of the transfer object.

[0010] Here, Figure 1 is a schematic diagram illustrating a typical DTF printing method. In a typical DTF printing method, an image is formed on the object to be printed by transferring an image formed on a transfer substrate A using an image forming apparatus to the object to be printed E. For example, a color ink layer B, a white ink layer C, and an adhesive layer D are formed on the transfer substrate A, and heat or pressure is applied to the transfer substrate A to transfer to the object to be printed E, such as a T-shirt, thereby forming an image on the object to be printed E.

[0011] For example, the transfer substrate A is a film composed of a substrate layer A1 and a receiving layer A2 on the substrate layer A1. Because the film has a smooth surface, when an image is transferred to the object to be transferred, the color ink layer on the surface of the image may become smoother compared to the surface of the object to which the image has not been transferred. A difference in surface roughness between the areas on the object to which the image has not been transferred and the areas to which the image has been transferred may result in a deterioration of the texture of the image transferred to the object.

[0012] In this embodiment, a base layer is formed on the transfer substrate using a first liquid discharged from a first head, and an image is formed on the base layer of the transfer substrate formed with the first liquid using a second liquid discharged from a second head. By imprinting an image on the base layer, the surface roughness of the image formed on the object to be transferred corresponds to the surface roughness of the base layer. Furthermore, in this embodiment, the discharge of the first liquid by the first head is controlled based on information regarding the surface roughness of the object to be transferred, thereby forming a base layer on the transfer substrate that corresponds to the surface roughness of the object to be transferred. By forming a base layer on the transfer substrate that corresponds to the surface roughness of the object to be transferred, the surface roughness of the image transferred to the object can be made to correspond to the surface roughness of the object to be transferred. As a result, in this embodiment, the texture of the image transferred to the object can be improved using the DTF printing method.

[0013] [Embodiment] <Configuration of the image forming apparatus according to this embodiment> Figure 2 is a schematic perspective view showing the overall configuration of the image forming apparatus 1 according to this embodiment. Figure 3 is a schematic top view showing the overall configuration of the image forming apparatus 1 according to this embodiment. Figure 4 is a schematic bottom view showing the liquid ejection head of the image forming apparatus 1. The image forming apparatus 1 can be used as a recording device, a printing device, an inkjet recording device, a DTF printer, etc.

[0014] As shown in Figures 2 and 3, the image forming apparatus 1 comprises an apparatus body 10 and a support base 11 that supports the apparatus body 10.

[0015] The main body 10 of the apparatus is provided with side plates 10A and 10B on the left and right sides. Guide rods 12 and guide stays 13, which are guide members, are stretched across the side plates 10A and 10B. The image forming apparatus 1 is also provided with a sub-sheet metal guide 14. The guide rods 12 and guide stays 13 slidably hold the carriage 15.

[0016] The main scanning mechanism unit 16 that moves and scans the carriage 15 includes a main scanning motor 17 disposed on one side in the main scanning direction, a driving pulley 18 rotationally driven by the main scanning motor 17, a driven pulley 19 disposed on the other side in the main scanning direction, and a timing belt 20 that is a traction member wound between the driving pulley 18 and the driven pulley 19. The driven pulley 19 is tensioned outward (in a direction away from the driving pulley 18) by a tension spring.

[0017] The carriage 15 moves in the main scanning direction X indicated by the arrow via the timing belt 20 rotationally driven by the main scanning motor 17. The carriage 15 also mounts an optical sensor 21 for detecting the end of the transfer target (paper end).

[0018] The carriage 15 includes a liquid ejection head 23 that ejects droplets of each color ink or functional liquid such as black (K), yellow (Y), magenta (M), cyan (C), white (W), etc. according to the mounted ink cartridge 22.

[0019] In the example shown in FIG. 4, the liquid ejection head 23 includes heads 23a, 23b, and 23c. When explaining the heads 23a, 23b, and 23c without distinction, it may be referred to as the liquid ejection head 23. The liquid ejection head 23 has a nozzle row, and a plurality of nozzles constituting the nozzle row are arranged in the sub-scanning direction Y indicated by the arrow. Here, the sub-scanning direction is a direction orthogonal to the main scanning direction. The liquid ejection head 23 is mounted with the droplet ejection direction facing downward. For example, the head 23a ejects white ink. The head 23b ejects each of the inks of black (K), yellow (Y), magenta (M), and cyan (C). The head 23c ejects functional liquid. The head 23a and the head 23b correspond to an example of a second head that ejects a second liquid for forming an image on the base formed on the transfer substrate. The white ink and each color ink correspond to an example of the second liquid. The head 23c corresponds to an example of a first head that ejects a first liquid for forming a base on the transfer substrate. The functional liquid corresponds to an example of the first liquid.

[0020] The liquid ejection heads 23 are arranged, for example, shifted in the sub-scanning direction. The carriage 15 is equipped with sub-tanks for supplying ink of each color corresponding to the liquid ejection heads 23. The sub-tanks may supply white ink, clear ink, etc. in addition to ink of each color.

[0021] The image forming apparatus 1 includes a cartridge loading portion 2 for detachably mounting ink cartridges 22a, 22b, and 22c of each color. The ink in the ink cartridges 22 is replenished and supplied to the sub-tanks of the carriage 15 through supply tubes 24 of each color by a supply pump unit. The ink cartridges 22 may include a white ink cartridge, a cartridge for functional liquid, etc.

[0022] The image forming apparatus 1 includes a maintenance and recovery mechanism 3 in a non-printing area on one side in the main scanning direction of the carriage 15. The maintenance and recovery mechanism 3 maintains or recovers the state of the liquid ejection heads 23.

[0023] The maintenance and recovery mechanism 3 includes a cap 31 for capping each nozzle surface of the liquid ejection heads 23 and a wiping unit 32 for wiping the nozzle surface. Also, a replaceable waste liquid tank for storing waste liquid generated by the maintenance and recovery operation is provided below the maintenance and recovery mechanism 3.

[0024] Paper 41 is set in the paper feeding means 40, and paper 41 having different sizes in the width direction can also be set. A transfer substrate may be used as the paper.

[0025] FIG. 5 is a block diagram showing the hardware configuration of the image forming apparatus 1. As shown in FIG. 5, the image forming apparatus 1 includes a control unit 100, an operation panel 120, a sensor 130, a head driver 140, a sub-scanning motor 150, a conveyance belt 160, a printer driver 170, a fan 180, and a heater 190. In the present embodiment, the control unit 100 controls the ejection of the functional liquid by the head 23c based on information regarding the surface roughness of the transfer object.

[0026] The control unit 100 includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, and a RAM (Random Access Memory) 103.

[0027] The CPU 101 controls the entire image forming apparatus 1. The ROM 102 stores fixed data such as programs executed by the CPU 101. The RAM 103 temporarily stores image data and the like.

[0028] The control unit 100 includes an NVRAM (Non-Volatile RAM) 104 and an ASIC (Application Specific Integrated Circuit) 105.

[0029] NVRAM104 is a non-volatile memory that retains data even when the power supply to the image forming apparatus 1 is cut off. ASIC105 processes image data, including various signal processing and sorting, as well as input / output signals for controlling the entire image forming apparatus 1.

[0030] The control unit 100 includes a printing control unit 106. The carriage 15 transfers data for driving the liquid ejection head 23 to the head driver 140. The head driver 140 drives the liquid ejection head 23 provided on the carriage 15 and ejects ink from the liquid ejection head 23.

[0031] The generation of dot pattern data for outputting an image may be performed within the image forming apparatus, for example, by storing font data in ROM 102, or it may be performed by the printer driver 170 on the host device side expanding the image data into bitmap data and transferring it to the control unit 100 of the image forming apparatus.

[0032] In this embodiment of the image forming apparatus, according to dot pattern data created in response to image data (input image) input from a host device, a piezoelectric element (drive unit) of a drive nozzle that discharges liquid is selected from among the nozzles on each liquid discharge head of the liquid discharge head 23. When a drive waveform from the print control unit 106 is input to the piezoelectric element of the drive nozzle, the piezoelectric element is driven according to this drive waveform, the pressure in the pressure chamber communicating with the drive nozzle changes, and the liquid in the pressure chamber is discharged from the drive nozzle. As a result, the liquid discharged from the drive nozzle lands on the transfer substrate, and an image according to the dot pattern of the input image is formed (recorded) on the transfer substrate.

[0033] The control unit 100 has a motor drive unit 107. The motor drive unit 107 drives a main scanning motor 17 and a sub-scanning motor 150. The main scanning motor 17 moves and scans the carriage 15 when driven. The sub-scanning motor 150 moves the conveyor belt 160 in a circular motion when driven.

[0034] The control unit 100 has an I / O 108. The I / O 108 acquires information from the sensor 130 and extracts information used for controlling each part of the main body of the image forming apparatus 1. For example, the sensor 130 corresponds to a group of sensors such as a photosensor, temperature sensor, encoder sensor, and optical sensor. The operation panel 120 inputs and outputs various types of information. The detection result from the sensor 130 corresponds to an example of information regarding the surface roughness of the object to be transferred. The I / O 108 corresponds to an example of a unit for acquiring information regarding the surface roughness of the object to be transferred.

[0035] The control unit 100 has a host interface 109. The host interface 109 transmits and receives data and signals with the host. Specifically, it transmits and receives data and signals from the printer driver 170 of the host, such as an information processing device (e.g., client PC), image reading device, or imaging device, via cable or network. The CPU 101 reads and analyzes the print data in the receive buffer included in the host interface 109. Then, the ASIC 105 performs image processing and data rearrangement, and the image data is transferred from the print control unit 106 to the head driver 140.

[0036] The print control unit 106 transfers image data as serial data and outputs the transfer clock, latch signal, control signal, etc. required for transferring the image data to the head driver 140. Based on the image data corresponding to one line of the liquid ejection head 23 input serially, the head driver 140 selectively supplies drive pulses that constitute the drive waveform provided by the print control unit 106 to the pressure generating means of the liquid ejection head 23. As a result, the liquid ejection head 23 is driven and liquid is ejected.

[0037] Furthermore, by selecting some or all of the pulses that make up the drive waveform, or some or all of the waveform elements that form the pulses, it is possible to create dots of different sizes, such as large, medium, and small droplets.

[0038] The control unit 100 includes a fan control unit 110 and a heater control unit 111. The fan control unit 110 controls the output of the fan 180 so that air is blown at a predetermined temperature and volume. The heater control unit 111 controls the heater 190 so that it reaches a set temperature.

[0039] The fan 180 promotes air convection inside the image forming apparatus 1 when driven, preventing the upper part of the image forming apparatus 1 from overheating due to the accumulation of warmed air. The fan 180 is connected to the fan control unit 110 of the control unit 100.

[0040] Figure 6 shows the configuration of the heater 190 of the image forming apparatus 1 according to this embodiment. In the example shown in Figure 6, for simplicity, some of the liquid discharge heads 23 are omitted from the description.

[0041] As shown in Figure 6, the heater 190 includes a preheater 190a, a print heater 190b, a print heater 190c, a postheater 190d, and a drying heater 190e. Each of these heaters 190 is equipped with a temperature sensor, such as a thermistor, for temperature control.

[0042] The preheater 190a is a device that preheats the transfer substrate P to a temperature suitable for forming the liquid-coated surface. For example, the preheater 190a is an aluminum foil cord heater. The preheater 190a is attached to the back surface of the transport guide plate 191. The preheater 190a warms the transfer substrate P by warming the transport guide plate 191 itself.

[0043] Print heaters 190b and 190c are devices that heat the transfer substrate P when forming a liquid coating surface on the transfer substrate P. For example, print heaters 190b and 190c are cord heaters embedded in a platen 192 made of aluminum. Print heaters 190b and 190c heat the transfer substrate P by, for example, heating the platen 192 itself.

[0044] The post-heater 190d and drying heater 190e are devices that heat the transfer substrate P on which the liquid-coated surface is formed in order to dry and fix the liquid such as ink. For example, the post-heater 190d is an aluminum foil cord heater. The post-heater 190d is attached to the back surface of the transport guide plate 191. The post-heater 190d heats the transfer substrate P by heating the transport guide plate 191 itself. Alternatively, for example, the drying heater 190e is an IR heater. The drying heater 190e radiates IR radiation onto the liquid-coated surface of the transfer substrate P to dry it. The drying heater 190e may also be equipped with a fan to blow hot air onto the liquid-coated surface of the transfer substrate P.

[0045] <Operation of Image Forming Apparatus 1> Next, an example of the operation of the image forming apparatus 1 according to this embodiment will be described.

[0046] The CPU 101 reads and analyzes the print data in the receive buffer of the host I / F 109, performs necessary image processing and data rearrangement processing using the ASIC 105, and then transfers the data to the print control unit 106.

[0047] The print control unit 106 outputs image data and drive waveforms to the head driver 140 at the required timing. Specifically, the print control unit 106 generates a drive waveform consisting of one or more drive pulses by D / A conversion and amplification of the drive pulse pattern data stored in the ROM 102 and read by the CPU 101.

[0048] Furthermore, the generation of image data for image output can be performed, for example, by storing font data in ROM 102, or by having the host-side printer driver expand the image data into a bitmap and transfer it to the image forming apparatus 1.

[0049] The head driver 140 drives the liquid ejection head 23 by selectively applying drive pulses, which constitute a drive waveform provided by the print control unit 106 based on the input image data, to the pressure generating means of the liquid ejection head 23.

[0050] The heater 190 lights up when it wakes from sleep mode and is controlled to a set temperature according to the transfer substrate P and the mode. When the heater 190 starts up, the image forming apparatus 1 becomes ready to form a liquid-coated surface and starts the initial operation for forming the liquid-coated surface. The drying heater 190e starts to light up when the formation of the liquid-coated surface begins.

[0051] The transfer substrate P is set on the preheater 190a side. The transfer substrate P is transported in the sub-scanning direction Y by a conveyor belt 160 driven by a sub-scanning motor 150, and a liquid-coated surface is formed by the discharge of liquid from the liquid discharge head 23. For example, in addition to roll-type transfer substrates, flexible packaging media such as PET, PVC, OPP, and sheet-shaped media can be used as P.

[0052] The transfer substrate P, which has been sent from the preheater 190a side, is first preheated by the preheater 190a to a temperature suitable for forming a liquid-coated surface. The preheated transfer substrate P is then sent by the conveyor belt 160 to the image forming unit 193 where the liquid discharge head 23 is located.

[0053] In the image forming unit 193, the transfer substrate P is kept warm by the print heaters 190b and 190c, and a liquid such as ink is discharged from the liquid discharge head 23 to form a liquid-coated surface. The heated air rises along with the steam, but to prevent the upper part of the image forming apparatus 1 from overheating due to its stagnation, the fan 180 promotes air convection.

[0054] The transfer substrate P is transported in the sub-scanning direction, and the carriage 15 scans in a direction perpendicular to the movement direction of the transfer substrate P, thereby forming an image. When forming an image, the number of scans can be changed according to the resolution of the image to be formed, thereby forming a high-resolution image.

[0055] The transfer substrate P, on which the liquid-coated surface has been formed in the image forming unit 193, is further sent downstream.

[0056] The drying heater 190e preheats the filament to the desired temperature before the transfer substrate P, which has the liquid-coated surface formed on it, arrives. Then, when the transfer substrate P with the liquid-coated surface formed on it arrives, the drying heater 190e lights up in synchronization with the stop timing of the sub-scan. The lighting timing can be changed depending on the type and mode of the transfer substrate P.

[0057] The post-heater 190d and the drying heater 190e, which blows hot air, dry and fix the liquid such as ink on the transfer substrate P. The dried and fixed transfer substrate P is then wound into a roll downstream.

[0058] Next, the details of the image forming apparatus 1 will be described. The image forming apparatus 1 includes a liquid dispensing unit that dispenses liquid onto a transfer substrate, an imaging unit that performs imaging on the transfer substrate, a heating unit that applies energy to heat the transfer substrate from which the liquid has been dispensed, and a control unit.

[0059] The liquid discharge unit is, for example, a liquid discharge head 23. The imaging unit is, for example, a sensor 130. The heating unit is, for example, a print heater 190b and a print heater 190c. The control unit is, for example, a control unit 100.

[0060] The image forming apparatus 1 has a carriage 15 that mounts a liquid ejection unit (heads 23a to 23c) and an imaging unit (sensor 130). By using a carriage 15 that mounts the liquid ejection unit and the imaging unit, the apparatus layout can be improved.

[0061] For the heating section, for example, print heaters 190b and 190c shown in Figure 6 are used. As can be seen from Figure 6, in this example, the heating section (print heaters 190b and 190c) is located opposite the carriage 15 via the transport section for the transfer substrate P. This allows for a good apparatus layout and makes it easier to adjust the heating temperature for each location on the transfer substrate by controlling the print heaters 190b and 190c.

[0062] As shown in Figure 6, the transfer substrate is transported on the platen 192, so the transport location for the transfer substrate is, for example, on the platen 192. The print heaters 190b and 190c apply energy (infrared rays in this example) to the transfer substrate P via the platen 192, heating the transfer substrate P.

[0063] For example, a film is used as the transfer substrate. The film is composed of, for example, a substrate layer and a receiving layer on the substrate layer.

[0064] The method by which the image forming apparatus of the present invention acquires information regarding the surface roughness of the object to be transferred can be appropriately selected.

[0065] Figure 7 shows an example of a method by which an image forming apparatus acquires information regarding the surface roughness of a material to be transferred, using a sensor 130 that measures the surface roughness of the material to be transferred. The measuring unit (sensor 130) may be mounted on the carriage 15 together with the liquid discharge head 23. In this case, the apparatus layout can be improved.

[0066] The placement of the sensor 130 is not limited to the example shown in Figure 7 and can be changed as appropriate. For example, the sensor 130 may not be mounted on the carriage 15 and may be placed upstream of the liquid discharge section. For example, in the example shown in Figure 6, it may be placed upstream of the conveyor belt 160. The sensor 130 may also be placed opposite the preheater 190a. The sensor 130 measures the surface roughness of the image transfer object by irradiating the surface of the transfer object with spot light and measuring the scattered light, and the image forming apparatus 1 acquires information regarding the surface roughness of the transfer object. Although an optical sensor is used here, it is not limited to this method, and other types of optical sensors, stylus-type sensors, estimated surface roughness predicted from image information and adhesion amount, or other means may also be used. Furthermore, the sensor 130 does not have to be mounted on the image forming apparatus. For example, the surface roughness information of the transfer object measured by the sensor 130 may be transmitted to and received from the image forming apparatus 1 via cable or network.

[0067] The method for obtaining information on the surface roughness of the object to be transferred is not limited to the example using the sensor 130. Alternatively, the information on the surface roughness of the object to be transferred, after measuring its surface roughness, may be stored in the control unit 100, and the type of object to be transferred can be selected on the operation panel 120 to retrieve the stored surface roughness information of the object to be transferred.

[0068] <Operation of Image Forming Apparatus 1> The operation of the image forming apparatus 1 will be described with reference to Figures 8 and 9. Figure 8 is a flowchart showing an example of the dot pattern determination operation by the image forming apparatus 1. Figure 9 shows a dot pattern formed by the image forming apparatus 1 discharging a functional liquid from the liquid discharge head 23. The dot pattern corresponds to an example of a base formed on the transfer substrate by the head 23c. The image forming apparatus 1 starts the operation shown in Figure 8, for example, when an operator of the image forming apparatus 1 inputs an operation to start the dot pattern determination operation via the control panel in Figure 5.

[0069] First, in step S11, the image forming apparatus 1 acquires information regarding the surface roughness of the object to be transferred via the I / O 108 using the sensor 130.

[0070] Next, in step S12, the image forming apparatus 1, using the control unit 100, determines whether the surface roughness of the object to be transferred is greater than or equal to threshold a, based on information regarding the surface roughness of the object to be transferred. Surface roughness is represented, for example, by surface roughness Ra. Threshold a is preset by the value of surface roughness Ra.

[0071] In step S12, if it is determined that the surface roughness of the object to be transferred is greater than or equal to a predetermined threshold a (step S12, YES), the image forming apparatus 1, in step S13, uses the control unit 100 to determine the dot pattern to be formed by ejecting the functional liquid from the head 23c to be the dot pattern DA shown in Figure 9. In the dot pattern DA shown in Figure 9, the black areas indicate regions to which the functional liquid is applied, and the white areas indicate regions to which the functional liquid is not applied. This is also true for the dot pattern DB and dot pattern DC shown in Figure 9. The dot pattern DA is a dot pattern in which regions to which the functional liquid is applied and regions to which the functional liquid is not applied are arranged alternately in both the vertical and horizontal directions. After determining the dot pattern to be formed by the functional liquid to be the dot pattern DA, the image forming apparatus 1 terminates its operation.

[0072] On the other hand, if in step S12 it is determined that the surface roughness of the object to be transferred is not equal to or greater than a predetermined threshold a (step S12, NO), the image forming apparatus 1, in step S14, uses the control unit 100 to determine whether the surface roughness of the object to be transferred is equal to or greater than a threshold b, based on information regarding the surface roughness of the object to be transferred. Threshold b is preset as the value of the surface roughness Ra. The surface roughness Ra of threshold b is smaller than the surface roughness Ra of threshold a.

[0073] In step S14, if it is determined that the surface roughness of the object to be transferred is greater than or equal to a predetermined threshold b (step S14, YES), the image forming apparatus 1, in step S15, uses the control unit 100 to determine the dot pattern to be formed by ejecting the functional liquid from the head 23c to be the dot pattern DB shown in Figure 9. The dot pattern DB is a dot pattern in which areas to which the functional liquid has been applied and areas to which the functional liquid has not been applied are arranged randomly compared to the dot pattern DB. After determining the dot pattern to be formed by the functional liquid to be the dot pattern DB, the image forming apparatus 1 terminates its operation.

[0074] On the other hand, if in step S14 it is determined that the surface roughness of the object to be transferred is not greater than or equal to a predetermined threshold b (step S14, NO), the image forming apparatus 1, in step S16, uses the control unit 100 to determine the dot pattern to be formed by ejecting the functional liquid from the head 23c to be the dot pattern DC shown in Figure 9. The dot pattern DC is a dot pattern in which the dot diameter formed by the functional liquid is larger than the dot diameter formed by the functional liquid in the dot pattern DA, and the areas to which the functional liquid is applied are aligned vertically and horizontally. After determining the dot pattern to be formed by the functional liquid to be the dot pattern DC, the image forming apparatus 1 terminates its operation.

[0075] As described above, the image forming apparatus 1 can determine the dot pattern to be formed by the functional liquid.

[0076] The image forming apparatus 1 can increase the surface roughness Ra of the image transferred to the object to be transferred in accordance with the surface roughness Ra of the object to be transferred by forming a dot pattern DA on the transfer substrate when the surface roughness Ra of the object to be transferred is greater than or equal to threshold a.

[0077] The image forming apparatus 1 can increase the surface roughness Ra of the image transferred to the object by forming a dot pattern DB on the transfer substrate when the surface roughness Ra of the object to be transferred is less than threshold a and greater than or equal to threshold b, compared to when a dot pattern DA is formed.

[0078] The image forming apparatus 1 can increase the surface roughness Ra of the image transferred to the object by forming a dot pattern DC on the transfer substrate when the surface roughness Ra of the object to be transferred is less than the threshold b, compared to when a dot pattern DB is formed.

[0079] The image forming apparatus 1 controls the discharge of the functional liquid by the head 23c based on information regarding the surface roughness of the object to be transferred, thereby forming a dot pattern on the transfer substrate that corresponds to the surface roughness of the object to be transferred. By forming a dot pattern on the transfer substrate that corresponds to the surface roughness of the object to be transferred, the surface roughness of the image transferred to the object can be made to correspond to the surface roughness of the object to be transferred. In this embodiment, this makes it possible to improve the texture of the image formed on the object to be transferred.

[0080] A liquid dispensing head is used as the liquid dispensing unit, and liquid dispensing head 23 is shown in the illustration. In this example, three liquid dispensing heads are used, and heads 23a to 23c are shown. There are no particular restrictions on the number or color of the liquid dispensing heads. [Explanation of Symbols]

[0081] 1. Image forming apparatus 10 Main unit of the device 10A, 10B side plate 11 Support stand 12 Guide Rods 13 Guidestay 14 Sub-Sheet Metal Repair Guide 15 Carriage 16 Main scanning mechanism 17 Main scanning motor 18 Drive pulley 19 Driven pulley 20 Timing belt 21 Optical Sensors 22 Ink Cartridges 23 Liquid dispensing head 23a, 23b, 23c head 40 Paper feeding means 41 sheets 100 Control Unit 101 CPU 102 ROM 103 RAM 104 NVRAM 105 ASIC 106 Printing Control Unit 107 Motor drive unit 108 I / O 109 Host I / F 120 Control Panel 130 sensors 140 Head Driver 150 Sub-scanning motor 160 conveyor belts 170 Printer Drivers 180 fans 190 Heater 190a Preheater 190b Print Heater 190°C Print Heater 191 Conveyor guide plate 193 Image forming unit X Main scanning direction Y sub-scanning direction DA, DB, DC dot pattern [Prior art documents] [Patent Documents]

[0082] [Patent Document 1] Patent No. 5773120

Claims

1. An image forming apparatus used in an image forming method that forms an image on a transfer object by a Direct To Film printing method, A first head that dispenses a first liquid to form a base on a transfer substrate, A second head for dispensing a second liquid to form an image after the base layer has been formed on the transfer substrate, An image forming apparatus comprising: a control unit that controls the discharge of the first liquid by the first head based on information regarding the surface roughness of the object to be transferred.

2. It has a unit for acquiring information regarding the surface roughness of the object to be transferred, The image forming apparatus according to claim 1, characterized in that the control unit controls the discharge of the first liquid by the first head based on the surface roughness information received by the acquisition unit.

3. The image forming apparatus according to claim 1 or 2, characterized in that the first head forms the substrate with a dot pattern determined according to the information regarding the surface roughness.

4. The image forming apparatus according to claim 3, characterized in that the dot diameter of the dot pattern is determined according to the information regarding the surface roughness.

5. The image forming apparatus according to claim 3, characterized in that the arrangement of dots in the dot pattern is determined according to the information regarding the surface roughness.

6. An image forming method using an image forming apparatus used in an image forming method for forming an image on a transfer object by a Direct To Film printing method, wherein the image forming apparatus is The first head dispenses a first liquid that forms a base layer on the transfer substrate. The second head dispenses a second liquid that forms an image after the base layer has been formed on the transfer substrate. An image forming method comprising a control unit that controls the discharge of the first liquid by the first head based on information regarding the surface roughness of the object to be transferred.

Images