Recording device, control method, and program

Abstract

In a recording device that fixes an image onto a recording medium by heat treatment, the effect of heating during fixing on the recording medium is suppressed. [Solution] The recording device of the present disclosure includes recording means for recording an image on a recording medium, transport means for transporting the recording medium, fixing means for fixing the image recorded on the recording medium by heating the recording medium, measuring means for measuring the amount of deformation in the thickness direction of the recording medium after the heating treatment by the fixing means, and heating control means for changing the temperature in the heating treatment according to the measurement result by the measuring means.

Description

Technical Field

[0001] The present invention relates to a recording apparatus that fixes an image on a recording medium by performing heat treatment.

Background Art

[0002] In a recording apparatus that records an image by applying ink or the like to a recording medium, there is a type that fixes the image by heating the recording medium after recording the image. In such a heat treatment, the larger the amount of heat applied to the recording medium, the more the evaporation of the solvent contained in the ink, the melting of the resin, and the film formation are promoted, and the image tends to be fixed in a short time and reliably. However, depending on the heating temperature, the molecular structure of the recording medium may change, and the recording medium may be stretched or shrunk. Therefore, it is preferable that the amount of heat is adjusted to such an extent that suitable fixing can be obtained without causing stretching or shrinking. Such a suitable amount of heat depends on the material of the recording medium. Further, even for the same material, the heat capacity also changes depending on the thickness and size of the recording medium.

[0003] Regarding the control of the heat treatment, Patent Document 1 discloses a technique for measuring the amount of expansion and contraction in the width direction of the recording medium before and after heating, and determining the fixing temperature to be lower than the glass transition point at which the molecular structure of the recording medium changes by judging whether it exceeds a predetermined threshold value.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, in relatively large recording devices used in the sign display industry, there are cases where multiple heaters are arranged in the width direction of the recording medium. In recording devices with such a structure, a slight temperature difference occurs between the center and the edges of each heater, and a temperature difference also occurs in the recording medium being heated. This effect causes local differences in the amount of expansion and contraction of the recording medium. If this difference in expansion and contraction becomes large, deformation occurs in the thickness direction of the recording medium, which can lead to a decrease in the commercial value of printed materials, image defects due to misalignment of ink application, and contact between the recording medium and the recording head (head friction).

[0006] The present invention has been made in view of the above problems, and aims to suppress the effect of heating on a recording medium in a recording device that fixes an image on a recording medium by applying heat treatment. [Means for solving the problem]

[0007] The recording device of the present invention comprises: recording means for recording an image on a recording medium; transport means for transporting the recording medium; fixing means for fixing the image recorded on the recording medium by heating the recording medium; measuring means for measuring the amount of deformation in the thickness direction of the recording medium after the heating treatment by the fixing means; and heating control means for changing the temperature in the heating treatment according to the measurement result by the measuring means. [Effects of the Invention]

[0008] According to the present invention, in a recording device that fixes an image onto a recording medium by heat treatment, it is possible to suppress the effect of heating on the recording medium. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view showing the configuration of the recording device. [Figure 2] This is a YZ cross-sectional view showing the configuration of the recording head and carriage. [Figure 3] This is an XY cross-sectional view showing the configuration of the recording head and carriage. [Figure 4] This is a diagram for explaining the lift cam. [Figure 5] This is a diagram showing the configuration of the optical sensor. [Figure 6] This is a diagram showing the configuration of the fixing device. [Figure 7] This is a diagram showing the configuration of the control system of the recording apparatus. [Figure 8] This is a diagram showing the functional configuration of the recording apparatus according to the first embodiment. [Figure 9] This is a diagram showing the positional relationship between the recording head and the optical sensor, and an example of the threshold value. [Figure 10] This is a flowchart showing the flow of the heating control process in the first embodiment. [Figure 11] This is a diagram showing the UI screen for setting the threshold value and an example of the threshold value setting. [Figure 12] This is a diagram showing the UI screen for setting the threshold value and an example of the threshold value setting. [Figure 13] This is a diagram showing an example of the measurement pattern. [Figure 14] This is a diagram showing an example of the pattern length between and the expansion / contraction amount after heating for each fixing temperature. [Figure 15] This is a diagram showing an example of the notification screen. [Figure 16] This is a diagram showing the functional configuration of the recording apparatus according to the second embodiment. [Figure 17] This is a flowchart showing the flow of the heating control process in the second embodiment. [Figure 18] This is a diagram showing the positional relationship between the recording head and the optical sensor, and an example of the threshold value.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the following embodiments do not limit the present invention, and not all combinations of the features described in the present embodiment are essential for the solution means of the present invention.

[0011] <Overall Configuration> FIG. 1 is a perspective view showing the configuration of the recording apparatus 100. FIG. 1(a) shows the appearance of the entire apparatus, and FIG. 1(b) shows a state in which the upper cover 110 of FIG. 1(a) is opened and the internal structure is visible. In the present embodiment, as an example of the recording apparatus 100, an inkjet recording apparatus will be described. The recording apparatus 100 uses ink as a recording material and performs image recording by applying the ink onto the recording medium 105 by an inkjet recording method. The recording medium 105 is conveyed in the Y direction shown in FIG. 1 as the conveyance direction. The carriage 101 mounts the recording head 102 and reciprocates in the X direction intersecting the Y direction. The X direction is the width direction of the recording medium 105. The recording apparatus 100 has a so-called serial type recording head that records an image on the recording medium 105 by discharging ink from the recording head 102 as the carriage 101 moves in the X direction. Note that the present invention is also applicable to an inkjet recording apparatus having a so-called line type recording head in which the ejection port array is configured to extend over the recording width size in the X direction of the recording medium 105. Further, the recording apparatus 100 may be an MFP (Multifunction Peripheral) in which not only a recording function but also a scanning function, a FAX function, a transmission function, etc. are integrated. In the present embodiment, the control unit (such as a CPU) of the recording apparatus 100 executes the following-described processes to realize the functions according to the present invention.

[0012] As shown in FIG. 1, the recording apparatus 100 includes a carriage 101, a recording head 102, a carriage belt 103, a guide shaft 104, a platen 106, a fixing device 108, an input / output unit 109, an upper cover 110, an ink tank 111, a spool member 112, a take-up roll driving device 113, and the like.

[0013] The input / output unit 109 is an operation panel provided with a display and a touch panel integrally, and is provided on the main body of the recording apparatus 100. Information regarding the state and settings of the recording apparatus 100, such as the remaining ink amount and candidates for the type of the recording medium 105, is displayed on the display of the input / output unit 109. The user can select the type of the recording medium 105 or perform various settings regarding image recording and fixing by operating the operation panel.

[0014] The carriage 101 is configured to reciprocate in the X direction along a guide shaft 104, which includes guide rails A131 and B132, via a carriage belt 103, driven by a carriage motor.

[0015] The recording head 102 is positioned so that its nozzle surface, which has multiple nozzles capable of ejecting ink supplied from the ink tank 111, faces the recording medium 105. Each nozzle of the recording head 102 is equipped with a recording element that generates ejection energy for ejecting ink. The recording head 102 moves back and forth in the X direction together with the carriage 101, and during this movement, it ejects ink according to the recording signal and drive pulse output from the CPU 701 and records to the recording medium 105.

[0016] The recording medium 105 is transported on the platen 106 in the Y direction by transport rollers (not shown). The Y direction intersects with the X direction, which is the direction of movement of the carriage 101, and in the example of Figure 1, it is perpendicular to the X direction. In the following explanation, the Y direction will also be referred to as the transport direction of the recording medium 105. In the Y direction, the paper feed side of the platen 106 is considered the upstream side, and the paper discharge side (winding roll drive device 113 side) is considered the downstream side, with transport from upstream to downstream being called forward transport and transport from downstream to upstream being called reverse transport. The recording operation is performed by the carriage 101 scanning the recording medium 105, which has been transported on the platen 106 by the transport rollers, in the X direction, and ejecting ink from the recording head 102. In the following explanation, the position in the Y direction on the recording medium 105 where the recording operation is performed will be referred to as the recording position. When the carriage 101 moves to the edge of the recording area on the recording medium 105, the transport rollers transport the recording medium 105 by a certain amount, moving the area where the next recording operation will be performed to the scanning position (recording position) of the recording head 102. By repeating the above operations, the image is recorded.

[0017] In this embodiment, the ink used for recording is an ink containing resin particles. When heat is applied to the ink, the water evaporates, the resin particles melt and mix with the pigment, forming a film on the surface of the recording medium 105, which then hardens. A recording medium 105 used in an inkjet recording device using a typical water-based ink requires an ink-receiving layer to catch the ink and prevent bleeding. However, the recording device using the above-mentioned ink can record even on a recording medium 105 that does not have an ink-receiving layer.

[0018] After the image is recorded, the recording medium 105 is transported to the fuser 108. The fuser 108 is positioned downstream of the recording position in the transport direction (Y direction) of the recording medium 105. The fuser 108 hardens the ink by applying heat to the recording medium 105 and discharges the recording medium 105 in a state where the ink has been fixed on it (finished state). The recording medium 105 discharged from the fuser 108 is wound onto a winding spool (spool member 112). The winding spool is driven by a winding roll drive device 113, and the recording medium 105 is wound into a roll.

[0019] Here, we will briefly explain the recording medium 105. In the manufacturing process of polymer films that serve as recording media 105 used in industries such as the sign display industry, a process called stretching is generally performed, in which the film is stretched in a certain direction. At this time, the molecules of the film align in a certain direction, causing a characteristic crystallization called orientation crystallization, and a unique structure called a fibrous structure is formed. Such a fibrous structure has a low entropy state at room temperature, but when the temperature exceeds a temperature called the glass transition point, the entropy increases and the amorphous molecules become able to move. As a result, shrinkage due to entropy elasticity (rubber elasticity) occurs, leading to deformation and changes in the rigidity of the film. Therefore, when heat treatment is performed by the fuser 108, expansion and contraction of the recording medium 105 is caused. In this embodiment, a continuous sheet that is continuous in the transport direction is used as the recording medium 105. After the image is recorded and fixed, the continuous sheet is wound into a roll.

[0020] <Configuration of the recording section> Next, the recording head 102 and carriage 101, which constitute the recording unit, will be described.

[0021] Figures 2 and 3 are schematic cross-sectional views showing the configuration of the recording head and carriage. Figure 2 is a schematic cross-sectional view in the ZY plane, and Figure 3 is a schematic cross-sectional view in the XY plane. The carriage 101 holds the recording head 102 and the optical sensor 201, and is configured to reciprocate along guide rails A131 and B132 by receiving the driving force of the carriage motor (CR motor) 715 via the carriage belt 103.

[0022] <Recording head raising and lowering operation> Next, the raising and lowering operation of the recording head 102, which adjusts the distance between the recording head 102 and the platen 106, will be described. In this embodiment, an adjustment unit is provided, which includes a lift cam 117 and a lift motor 121 that drives the lift cam 117. The adjustment unit raises and lowers the recording head 102 via the carriage 101, thereby enabling adjustment of the head position according to predetermined conditions such as the type and thickness of the recording medium 105 and the recording mode. The head position is the position of the recording head 102 in the raising and lowering direction relative to the platen 106 (recording medium 105). In this embodiment, the head position is adjustable in three stages (L, M, H), but it may be two stages or four or more stages.

[0023] The carriage 101 includes a main carriage 114 on which the recording head 102 is mounted, and a rear carriage 115 connected to the carriage belt 103, which are connected via the outer circumference of the lift shaft 116 and the lift cam 117. A lift coupling 118 is provided at one end of the lift shaft 116. The lift coupling 118 is connected to a drive-side coupling 120 provided on the recording device housing 119 when the carriage 101 moves along the guide rail A131 to the right end (X-axis direction - side end). The drive-side coupling 120 is connected to the lift motor 121. When the lift motor 121 rotates with the lift coupling 118 and the drive-side coupling 120 connected, the lift coupling 118 and the lift shaft 116 and lift cam 117 connected to it all rotate together.

[0024] Figure 4 illustrates the lift cam. Figure 4(a) is a schematic diagram showing the shape of the lift cam 117, and Figure 4(b) shows the relationship between the rotation angle of the lift cam 117 and the amount of lift.

[0025] The lift cam 117 has a smooth, arc-shaped outer circumference that is eccentric with respect to the lift shaft 116, and is supported by a cam support surface provided on the rear carriage 115. With this configuration, when the lift cam 117 rotates by the lift motor 121, the cam support surface and the lift shaft 116 move closer together or further apart depending on the amount of eccentricity, so the relative height of the main carriage 114 with respect to the rear carriage 115 changes. As a result, the distance between the recording head 102 and the platen 106 also changes. In this respect, the lift motor 121 is a motor that can adjust the distance between the recording head 102 and the platen 106 via the lift cam 117 and the main carriage 114.

[0026] Furthermore, as shown in Figure 4(b), the shape of the lift cam 117 is configured such that the amount of eccentricity increases when it rotates clockwise from the state shown in Figure 4(a) within the rotation angle range of the lift usage section. Therefore, if the angle of the lift cam 117 can be controlled to stop the lift cam 117 at a predetermined angle and maintain that angle, the height of the recording head 102 can be freely controlled.

[0027] Here, since the outer circumference of the lift cam 117 and the cam support surface are always at an angle, even if the lift cam 117 stops at a predetermined rotation angle, it may not be able to maintain that rotation angle and may rotate if vibrations or other external forces are applied. For this reason, a one-way clutch 148 is attached to the lift shaft 116, so that the lift shaft 116 can only rotate in one direction (clockwise).

[0028] With this configuration, in the lift-operated section, when the lift cam 117 is stopped at a certain rotation angle, rotation in the clockwise direction increases the eccentricity of the lift cam 117. Therefore, in order for the lift cam 117 to rotate from a stopped state, sufficient torque is required to raise the main carriage 114, and it will not be able to rotate without a driving force such as a motor. Furthermore, rotation in the counterclockwise direction is prevented by the one-way clutch 148. With this configuration, even with a lift cam 117 having a smooth outer circumference, rotation of the lift shaft 116 due to external vibrations can be prevented.

[0029] Next, the angle control of the lift cam 117 will be explained. As shown in Figure 3, the lift cam 117 is equipped with a flag 134 that displaces with the rotation of the lift cam 117 so that the phase (rotation angle) during cam rotation can be determined. The starting point of the lift cam 117 is when the flag 134 blocks the light from the light-emitting element of the photosensor 135 located on the rear carriage 115 side (ON), or when it changes from blocking to transmitting light (OFF).

[0030] The angle control of the lift cam 117 is performed by rotating the lift motor 121 by an arbitrary amount, with the ON or OFF timing as the starting point, i.e., 0 degrees. For example, in the example shown in Figure 4(b), there are three head positions, L, M, and H, depending on the angle of the lift cam 117. When the head position is L, the distance between the recording head 102 and the platen 106 is the smallest, and when the head position is H, the distance between the recording head and the platen is the largest. Head position M is a predetermined distance between L and H. The lift motor 121 may be equipped with an optical encoder inside, and its rotation angle may be detected with high resolution. The rotation angle of the lift cam 117 may then be obtained based on the rotation angle of the lift motor 121. Note that known techniques can be appropriately employed to detect the starting point of the lift cam 117 and the rotation angle of the lift motor.

[0031] <Optical sensor configuration> Figure 5 is a schematic YZ cross-sectional view showing the configuration of the optical sensor 201. The optical sensor 201 has multiple measurement functions and may be composed of optical components such as light-emitting elements and light-receiving elements. In this embodiment, the optical sensor 201 optically measures the distance between the optical sensor 201 and the recording medium 105 and detects the measurement pattern described later.

[0032] The optical sensor 201 is a so-called reflective sensor, and its optical elements are arranged to face the recording medium 105 (platen 106). The optical sensor 201 has a first LED 501, a second LED 502, a third LED 503, a first photodiode 504, a second photodiode 505, and a third photodiode 506 as optical elements. In this embodiment, the first LED 501 and the first photodiode 504 are used to measure the measurement pattern described later, so further explanation is omitted. The first LED 501 is a light source having an illumination angle of normal (90°) to the surface (measurement surface) of the recording medium 105. The first photodiode 504 receives the reflected light irradiated from the first LED 501 and reflected on the recording medium 105 at an angle of 45° with respect to the Z direction. In other words, the optical sensor 201 forms an optical system that detects the so-called diffuse reflection component of the reflected light from the recording medium 105. Although the angle of reflected light is not limited to 45°, 45° is preferred considering robustness against height fluctuations of the recording head 102. The optical sensor 201 outputs characteristic values ​​of the received reflected light to the CPU 701. Based on the characteristic values ​​of the reflected light output from the optical sensor 201, the CPU 701 detects the distance to the recording medium 105 and the position of the image recorded on the recording medium 105.

[0033] In this embodiment, the optical sensor 201 is shown to be fixedly held on the recording head 102 by the carriage 101, but other configurations are also possible. For example, the optical sensor 201 may be fixedly installed at a predetermined position on the recording device 100, or it may be installed downstream of the fuser 108. Alternatively, a measuring instrument separate from the recording device 100 may be used, and the characteristic values ​​of the reflected light measured by the measuring instrument may be transmitted to the recording device 100. The measuring instrument measures characteristic values ​​such as diffuse reflection and specular reflection of light irradiated onto the recording medium 105.

[0034] <Fuser Unit Configuration> Figure 6 is a diagram illustrating the configuration of the fuser unit 108. Figure 6(a) is a schematic YZ cross-sectional diagram showing the internal configuration of the fuser unit 108.

[0035] The fuser unit 108 has a blower fan 602, a heater 603, and a temperature sensor 604 inside the chamber 601. The blower fan 602 is an axial-flow type blower fan that takes in outside air and blows it into the chamber 601. The heater 603 heats the air from the blower fan 602 to make warm air. Multiple openings are provided on the surface of the chamber 601 facing the recording medium 105, and warm air is sent to the recording medium 105 from these openings, contributing to ink fixing. The fixing temperature by the heater 603, that is, the heating temperature by the heater 603, can be changed by the control of the CPU 701, and a fixing temperature suitable for the target recording medium 105 is determined by a process described later. The heater 603 has a temperature sensor 604, and stable heater temperature control is possible by temperature feedback from the temperature sensor 604. Note that the change in the above fixing temperature can also be determined by the change in the surface temperature of the recording medium. To measure the surface temperature of the recording medium, a temperature sensor can be provided near the recording medium. In this embodiment, a non-contact type ink fixer is illustrated, which uses a blower fan 602 and a heater 603 to blow dry air onto the recording medium 105. However, the invention is not limited to this example, and contact type heaters or radiant heaters may also be used.

[0036] Figure 6(b) is an XY plan view illustrating the positional relationship between the fuser 108 and the recording medium 105. The figure schematically shows the inside of the fuser 108. As shown in Figure 6(b), the fuser 108 has multiple heater units 610a, 610b, 610c, and 610d arranged in the width direction (X direction) of the recording medium 105. In the following description, if the heater units 610a, 610b, 610c, and 610d are not distinguished, they will be denoted by the reference numeral 610. Each heater unit 610 has a chamber 601, a blower fan 602, a heater 603, and a temperature sensor 604, similar to those in Figure 6(a). The heater 603 is located in the center of each heater unit 610 in the X direction. Although the fuser 108 in Figure 6(b) is configured to have four heater units 610, the number of heater units 610 is not limited to four and can be any number.

[0037] The recording medium 105 is transported in the Y direction, which is perpendicular to the X direction. When the recording medium 105 is subjected to heat treatment using a fuser 108 having multiple heater units 610, the temperature on the recording medium 105 increases the closer it is to the heater 603, which is the heating element. As a result, a temperature difference occurs between the region on the recording medium 105 located directly below the center of each heater unit 610 (heater center) and the region on the recording medium 105 located directly below the end of each heater unit 610. Due to this temperature difference, the amount of expansion and contraction of the recording medium 105 before and after heating differs in each region in the X direction. Specifically, the amount of expansion and contraction in the region directly below the heater center is greater than that in the region directly below the heater end. In other words, there is a difference in the amount of expansion and contraction in the width direction (X direction) of the recording medium 105.

[0038] If this difference in expansion and contraction becomes large, deformation will occur in the thickness direction of the recording medium 105, leading to a decrease in the commercial value of the printed material, image defects due to misalignment of ink application position, and contact between the recording medium 105 and the recording head 102 (head friction). In the first embodiment, the control unit (CPU, etc.) of the recording device 100 performs heating control to suppress the expansion and contraction of the recording medium 105 caused by the heating treatment by the fuser 108, and to suppress deformation in the thickness direction of the recording medium 105.

[0039] <Control configuration of the recording device> Figure 7 is a block diagram showing the configuration of the control system of the recording device 100. The recording device 100 includes a CPU 701, ROM 702, RAM 703, EEPROM 704, input / output control circuit 705, LED control circuit 707, A / D conversion circuit 708, image processing circuit 709, I / F circuit 710, timer 718, and various control circuits. The control circuits include a recording head control circuit 711, an LF (line feed) encoder drive circuit 722, an LF motor drive circuit 712, a CR (carriage) motor drive circuit 714, a fan drive circuit 716, a heater drive circuit 717, a lift motor drive circuit 724, and a winding roll drive circuit 719. In the configuration shown in Figure 7, there is one CPU 701, but multiple CPUs may be provided. In addition to the CPU 701, there may be a dedicated processor for performing specific processing.

[0040] The CPU 701 calls various programs stored in the EEPROM 704 or ROM 702 into the work area of ​​the RAM 703 and executes them. The CPU 701 executes processes to control the operation of each part of the recording device 100 based on the various programs. The ROM 702 is a non-volatile memory and stores, for example, a control program for controlling the recording device 100 and a program for realizing the functions of this embodiment. The functions of this embodiment are realized, for example, by the CPU 701 reading a program stored in the ROM 702 or EEPROM 704 into the RAM 703 and executing it. The RAM 703 is also used as the working memory of the CPU 701. The EEPROM 704 stores data that should be retained even when the power to the recording device 100 is turned off. At least the CPU 701 and the ROM 702 or EEPROM 704 realize the function of measuring the expansion and contraction amount of the recording medium 105, which will be described later, and the function related to heating control. Furthermore, the EEPROM 704 stores predetermined types of recording media 105, fixing conditions for each recording mode (heater temperature, heating time, etc.), and thresholds referenced in the processing described later. The fixing conditions, thresholds, and other data may be stored not in the storage medium within the recording device 100, but in ROM or HDD (hard disk drive) of a host computer connected to the recording device 100, or in external storage such as a server.

[0041] The interface circuit (I / F circuit) 710 connects the recording device 100 to an external network such as a LAN. The recording device 100 uses the I / F circuit 710 to send and receive various jobs and data with an external information processing device such as a host computer.

[0042] The input / output unit 109 includes an input unit and an output unit. The input unit includes input devices such as a touch panel, hard keys, and a numeric keypad. The input / output unit 109 receives instructions from the user to power on, to execute recording, and to set various functions, and inputs the received instructions to the CPU 701 via the input / output control circuit 705. The output unit includes an LED display, an LCD display, and a display control circuit. The output unit receives screen data output from the CPU 701 via the input / output control circuit 705 and displays a screen based on the screen data on the display. For example, various device information such as power saving mode, setting screens for various functions that the recording device 100 can execute, UI screens and notification screens described later are displayed. In this embodiment, the input / output unit 109 is an operation panel provided on the recording device 100, and the input / output unit 109 is connected to the system bus 730 via the input / output control circuit 705 so as to be able to send and receive data. In this embodiment, the CPU 701 controls the notification of information to the output unit. The input / output control circuit 705 controls the operation of the input / output unit 109 under the control of the CPU 701.

[0043] The input unit may be an input device of a host computer connected to the recording device 100, and may be capable of receiving user instructions from the host computer. The output unit may be a display connected to the host computer connected to the recording device 100. Furthermore, if the input / output unit 109 has a touch panel, it may be capable of receiving user instructions via software keys. In addition, the input / output unit 109 may include a speaker and a microphone, receive voice input from the user, and output notifications to the user by voice.

[0044] The LED control circuit 707 is connected to the optical sensor 201 and controls the operation of the optical sensor 201 according to instructions from the CPU 701. When measurement is performed using the optical sensor 201, the LED control circuit 707 is driven by the CPU 701 and controlled to light up a predetermined LED in the optical sensor 201. Each photodiode of the optical sensor 201 outputs a signal corresponding to the received light to the A / D conversion circuit 708. The A / D conversion circuit 708 converts the signals acquired from each photodiode of the optical sensor 201 into digital signals, outputs them to the RAM 703, and stores them temporarily. Data that should be saved even when the recording device 100 is powered off is stored in the EEPROM 704.

[0045] The recording head control circuit 711 supplies drive signals corresponding to the recording data to the nozzle drive circuit (recording element), which is mounted on the recording head 102 and includes selectors and switches, and controls the recording operation of the recording head 102, such as the driving order of the nozzles having discharge ports. For example, when data to be recorded is transmitted to the I / F circuit 710 from an external source, the data to be recorded is temporarily stored in the RAM 703. Then, the recording head control circuit 711 drives the recording head 102 based on the recording data, which has been converted from the data to be recorded into data for recording. At that time, the LF motor drive circuit 712 drives the LF motor 713 based on the bandwidth of the recording data, etc., and transports the recording medium 105 in the Y direction by rotating the transport roller connected to the LF motor 713. The LF encoder drive circuit 722 drives the LF encoder 723, which detects the amount of rotation of the LF motor 713, and outputs the amount of rotation of the LF motor 713 detected by the LF encoder 723 to the CPU 701. The CPU 701 obtains the amount of transport of the recording medium 105 based on the amount of rotation of the LF motor 713 detected by the LF encoder 723. The CR motor drive circuit 714 drives the CR motor 715 to scan the carriage 101 in the X direction via the carriage belt 103.

[0046] The data sent from the I / F circuit 710 includes not only the data to be recorded, but also data set by the printer driver. In addition, the data to be recorded may be received from an external host computer via the I / F circuit 710 and stored in a memory unit such as RAM 703 or EEPROM 704, or it may be pre-stored in a memory unit such as a hard disk (not shown). The CPU 701 reads this data from the memory unit and controls the image processing circuit 709 to perform a conversion (binarization) into recording data for driving the recording head 102.

[0047] The image processing circuit 709 performs various image processing operations, including binarization, color space conversion, HV conversion, gamma correction, and image rotation.

[0048] The fan drive circuit 716 controls the amount of air blown from the fan by controlling the rotation speed of the blower fan 602.

[0049] The heater drive circuit 717 acquires fixing temperature setting information output from the CPU 701 and temperature feedback information from the temperature sensor 604 located immediately next to the heater 603, and controls the temperature of the heater 603 based on the acquired information.

[0050] The lift motor drive circuit 724 drives the lift motor 121 connected to the lift cam 117 based on the head position change instruction output from the CPU 701. As a result, the lift shaft 116 connected to the lift cam 117 is raised and lowered, and the height position (head position) of the recording head 102 and optical sensor 201 held by the lift shaft 116 is changed.

[0051] The winding roll drive circuit 719 drives the winding drive motor 720 based on the winding control signal output from the CPU 701 to wind up the recording medium 105. Since the winding diameter of the recording medium 105 changes as it is wound up, the winding roll drive circuit 719 controls the torque of the winding drive to keep it constant according to the winding diameter. The winding drive motor 720 is a motor for driving the roll to rotate the paper tube in the forward and reverse directions via the spool member 112.

[0052] Timer 718 measures the heating time by the fuser unit 108.

[0053] <Functional Configuration> Figure 8 is a block diagram showing the functional configuration related to the heating control of the fuser 108. In order to perform heating control according to the state of thermal deformation of the recording medium 105, the recording device 100 of this embodiment has a measuring unit 801 and a heating control unit 803. These functional units are realized by the CPU 701 of the recording device 100 executing processing according to a program described later. The program is stored in ROM 702 or EEPROM 704.

[0054] The measurement unit 801 measures the amount of deformation in the thickness direction of the recording medium 105 after the recording medium 105 has been heated by the fuser 108. Specifically, the measurement unit 801 measures the distance between the lower surface of the optical sensor 201 (sensor lower surface 201a) and the recording medium 105 at multiple locations in the width direction (X direction) of the recording medium as the amount of deformation. In the following description, the distance between the sensor lower surface 201a and the recording medium 105 is called the GAP value. The measurement unit 801 also measures the amount of expansion and contraction of the recording medium 105 in the transport direction (Y direction) before and after the heating treatment by the fuser 108. As a measurement result, the measurement unit 801 determines the minimum value Dmin among the GAP values ​​measured at multiple locations in the X direction and outputs it to the heating control unit 803. The measurement unit 801 also determines the amount of expansion and contraction of the recording medium 105 in the transport direction (Y direction) and outputs it to the heating control unit 803. If the expansion / contraction amount is measured at one location in the X direction, the measurement unit 801 outputs that amount to the heating control unit 803. If the expansion / contraction amount is measured at multiple locations in the X direction, the measurement unit 801 outputs the expansion / contraction amount that maximizes the absolute value of the expansion / contraction amounts measured at the multiple locations to the heating control unit 803.

[0055] The measuring unit 801 records a pattern for measuring the GAP value and the amount of stretching on the recording medium 105, and measures the GAP value and the amount of stretching by optically detecting the recorded pattern. In the following description, the pattern for measuring the GAP value and the amount of stretching is referred to as the measuring pattern. The measuring pattern in this embodiment has a pair of first and second images spaced a predetermined distance apart in the Y direction. The first and second images are linear images that extend across the entire width of the recording area in the X direction. Based on the positions of the first and second images on the recording medium 105 detected by the optical sensor 201 and the transport amount of the recording medium 105, the measuring unit 801 measures the distance in the Y direction between the pair of first and second images at at least one point in the X direction. The distance in the Y direction between the pair of first and second images is referred to as the pattern length.

[0056] In this embodiment, the measuring unit 801 measures the pattern-interval length using a reflective optical sensor 201. Specifically, the optical sensor 201 detects the positions of the first and second images on the recording medium 105 when measuring the pattern-interval length. The position in the X direction is measured by an encoder that detects the carriage position. The position in the Y direction is measured based on the amount of rotation of an LF encoder 723 provided on the LF motor 713.

[0057] The amount of expansion and contraction is determined based on the difference between the pattern spacing before and after heat treatment. Details regarding the measurement pattern will be described later. The amount of expansion and contraction is determined, for example, by the following equation (1).

[0058] dL = 100 × (Ln - L0) / L0 ... (1)

[0059] Here, dL is the amount of expansion / contraction (%), Ln is the pattern spacing after heating (mm), and L0 is the pattern spacing before heating (mm). In other words, the amount of expansion / contraction is determined as the percentage difference (%) between the pattern spacing before heating and the pattern spacing before heating. If the recording medium 105 shrinks after heating, the amount of expansion / contraction will be a negative value, and if the recording medium 105 expands after heating, the amount of expansion / contraction will be a positive value. Generally, the recording medium 105 shrinks when heated, so the amount of expansion / contraction will be a negative value.

[0060] In measuring the GAP value, the optical sensor 201 irradiates light onto the heated recording medium 105, detects the reflected light, and measures the distance (GAP value) between the sensor's lower surface 201a and the recording medium 105 based on the relationship between the detected light intensity and the distance. The measurement of the GAP value by the optical sensor 201 is performed as the carriage 101 moves and is measured over the entire width of the recording medium 105. For example, the GAP value is measured along a measurement pattern recorded on the recording medium 105. The measurement unit 801 determines the minimum value Dmin of the measured GAP value and outputs it to the heating control unit 803. Note that the detection of the pattern and measurement of the distance by the optical sensor 201 are not limited to the above example and may be done by other methods. For example, the distance between the recording medium 105 and the optical sensor 201 may be determined by measuring the time from when the light-emitting element irradiates light until the light-receiving element receives the reflected light, and deriving the distance corresponding to the time.

[0061] In this embodiment, the measuring unit 801 uses the region where the surface temperature of the recording medium 105 is higher than a predetermined temperature after the heat treatment as the measurement area, and performs the above-mentioned measurement of the inter-pattern length at least after the heat treatment. The measurement of the inter-pattern length may be performed before and after the heat treatment. In this case, the amount of expansion and contraction can be calculated as the difference between the inter-pattern length before the heat treatment and the inter-pattern length after the heat treatment. On the other hand, if the measurement of the inter-pattern length is performed only after the heat treatment, it can be calculated as the difference between the inter-pattern length after the heat treatment and the inter-pattern length (theoretical distance) in the pattern for measuring the amount of expansion and contraction to be recorded. The predetermined temperature is, for example, the average surface temperature of the recording medium 105 in the X direction during the heat treatment. Specifically, the measurement area is the region that includes the position (center of the heater) that is closest in distance to the heater 603 of at least one of the multiple heater units 610 arranged in parallel on the fuser unit 108. More preferably, the measuring unit 801 measures the inter-pattern length described above and measures the amount of expansion and contraction in the region where the surface temperature of the recording medium 105 reaches its highest temperature after the heat treatment.

[0062] Furthermore, the position and number of measurement areas may differ depending on the width of the recording medium 105.

[0063] The heating control unit 803 executes heating control processing based on the measurement results from the measurement unit 801. As part of the heating control processing, the heating control unit 803 executes a fixing temperature change process 804. In the fixing temperature change process 804, the heating control unit 803 changes the temperature of the heater of the fuser 108 according to the measurement results from the measurement unit 801. The heating control unit 803 may also execute a notification process 805. In the notification process 805, the heating control unit 803 determines the state of thermal deformation of the recording medium 105 according to the measurement results from the measurement unit 801 and notifies the user of the state of thermal deformation.

[0064] The heating control unit 803 determines the state of thermal deformation of the recording medium 105 based on a comparison between at least the minimum GAP value Dmin and a first threshold. In the first embodiment, the first threshold is a threshold (head friction threshold) for determining the possibility that the recording medium 105 may come into contact with the recording head 102 due to thermal deformation. A fixed value for the head friction threshold is predetermined according to the head position and stored in the EEPROM 704. The relationship between the head position and the first threshold (head friction threshold) will be described later (Figure 9). If the minimum GAP value Dmin is less than or equal to the first threshold, it is determined that the amount of deformation in the thickness direction of the recording medium 105 is large and that there is a possibility of contact between the recording medium 105 and the recording head 102. If the minimum GAP value Dmin is less than or equal to the first threshold, the heating control unit 803 changes the temperature in the heating process of the fuser 108 to be lowered. If the minimum GAP value Dmin is greater than the first threshold, it is determined that there is no possibility of head friction.

[0065] <Head position and threshold conditions> Figure 9 shows an example of the positional relationship between the recording head 102 and the optical sensor 201 for each head position, as well as the threshold. The head position is the position of the recording head 102 in the vertical direction (Z direction) relative to the platen 106.

[0066] Figure 9(a) shows the positional relationship between the recording head 102, the optical sensor 201, and the platen 106. D_head is the distance between the surface of the recording head 102 facing the platen 106 (head bottom surface 102a) and the platen 106. D_sen is the distance between the surface of the optical sensor 201 facing the platen 106 (sensor bottom surface 201a) and the platen 106. D_sen_head is the distance from the sensor bottom surface 201a to the head bottom surface 102a.

[0067] Figure 9(b) is an example of a table 900 showing the distance between the recording head 102 and optical sensor 201 and the platen 106 at each head position (L, M, H). In this embodiment, the position of the recording head 102 and optical sensor 201 in the Z direction (up and down direction) is variable in three stages. Table 900 defines the distance D_head, D_sen, and head friction threshold for each head position. In the example in Figure 9, the distance D_sen_head is a fixed value of 1.0 mm. The head friction threshold is a threshold for determining the possibility of head friction and is compared with the minimum value Dmin of the GAP value.

[0068] In the example in Figure 9(b), at the first position (L), D_head is defined as 2.0 mm, D_sen as 3.0 mm, and the head friction threshold as 1.5 mm. At the second position (M), D_head is defined as 2.4 mm, D_sen as 3.4 mm, and the head friction threshold as 1.9 mm. At the third position (H), D_head is defined as 3.0 mm, D_sen as 4.0 mm, and the head friction threshold as 2.5 mm.

[0069] Head friction occurs when Dmin ≤ D_sen_head; therefore, the head friction threshold can be determined by setting a predetermined margin to D_sen_head. In other words, the head friction threshold is a value uniquely determined by the positional relationship between the lower surface 102a of the head and the lower surface 201a of the sensor. Thus, unlike the threshold for expansion and contraction, which can be arbitrarily determined by the user, a fixed value is predetermined and recorded in the EEPROM 704. In this embodiment, the head friction threshold is defined as shown in Figure 9(b).

[0070] The heating control unit 803 compares the minimum GAP value Dmin with the head friction threshold (first threshold), and further compares the amount of expansion / contraction with the second threshold. Based on these comparison results, it determines the state of thermal deformation of the recording medium 105. The second threshold is an expansion / contraction tolerance value, which is a threshold for determining the dimensional accuracy of the recording medium in the Y direction. This value may be arbitrarily set by the user or predetermined depending on the type of recording medium 105. Alternatively, the expansion / contraction tolerance value may be predetermined according to the recording mode. If the amount of expansion / contraction is greater than the second threshold (expansion / contraction tolerance value), it indicates that the expansion / contraction in the Y direction due to heating is large and may not meet the dimensional accuracy of the printed material. If the amount of expansion / contraction is less than or equal to the second threshold (expansion / contraction tolerance value), it indicates that the dimensional accuracy of the printed material is met.

[0071] The heating control unit 803 performs processing according to the comparison result between the minimum value Dmin of the GAP value and the first threshold, and the comparison result between the expansion / contraction amount and the second threshold. Specifically, the heating control unit 803 decides whether or not to change the heating temperature in the fuser 108 according to the state of thermal deformation of the recording medium 105 obtained as a result of the comparison. The heating control unit 803 may also perform notification processing 805 before changing the fixing temperature, and the content of the notification may differ depending on the state of thermal deformation of the recording medium 105.

[0072] In the fixing temperature change process 804, the heating control unit 803 executes a process to lower the heater temperature of the fuser 108 if the minimum value Dmin of the GAP value is less than or equal to the first threshold, or if the expansion / contraction amount is greater than the second threshold. If the minimum value Dmin of the GAP value is greater than the first threshold and the expansion / contraction amount is less than or equal to the second threshold, the heating control unit 803 determines the heater temperature set at that time as the fixing temperature. The process of lowering the heater temperature may be executed forcibly, or it may be executed after the user is asked whether or not to lower the temperature and the user replies that they wish to lower the temperature. The fixing temperature change process 804 will be described later.

[0073] In notification processing 805, the heating control unit 803 determines the notification content according to the state of thermal deformation of the recording medium 105. This results in a notification being sent with content corresponding to the state of thermal deformation of the recording medium 105. For example, a notification may be sent indicating that the amount of deformation in the thickness direction (Z direction) of the recording medium 105 is large and that head friction may occur, or a notification may be sent indicating that the amount of expansion and contraction in the transport direction (Y direction) of the recording medium 105 is large and that dimensional accuracy may not be met. An inquiry about whether or not to lower the heating temperature may also be made along with the notification of the state of thermal deformation of the recording medium 105 in notification processing 805. Notification processing 805 will be described later.

[0074] <Heat control treatment> Figure 10 is a flowchart showing the flow of the heating control process in the first embodiment. The heating control process in the first embodiment will be described below with reference to Figure 10. The program corresponding to the flowchart shown in Figure 10 is recorded in the ROM 702 or EEPROM 704 of the recording device 100, called and executed by the CPU 701.

[0075] As described above, the recording medium 105 expands and contracts due to the heat treatment during fixing after the image is recorded on the recording medium 105. Differences in localized expansion and contraction can cause deformation in the thickness direction, potentially leading to image defects due to misalignment of ink application and printhead rubbing. Furthermore, the recording medium 105 may also expand and contract in the transport direction (Y direction) due to the heat treatment. Therefore, in order to obtain a printed product in good condition, it is necessary to determine the fixing temperature in a way that minimizes deformation to a level that does not cause printhead rubbing while maintaining dimensional accuracy in the transport direction. This flowchart describes a method for deriving the optimal fixing temperature using the method of the present invention.

[0076] When the recording medium 105 is loaded into the recording device 100 by the user, and an instruction to execute the heating control process is input, for example, via the UI screen displayed on the input / output unit 109, the CPU 701 starts the flowchart shown in Figure 10. When this flowchart is started, the fixing temperature (heater setting temperature) is set to the maximum temperature allowed for the type of recording medium 105 and recording mode being used. The head position is also set to an appropriate position according to the type of recording medium 105 and recording mode being used.

[0077] In S1001, the CPU 701 sets thresholds to be used in subsequent processing. In this embodiment, threshold conditions are set to determine the optimal fixing temperature for normal transport and recording that suppresses the expansion and contraction of the recording medium 105 and prevents head friction. The CPU 701 sets a first threshold to determine the possibility of head friction occurring and a second threshold to determine whether the dimensional accuracy is met. The CPU 701 compares the first threshold with the minimum GAP value Dmin to determine whether the distance between the recording head 102 and the recording medium 105 is within the range where head friction does not occur. The CPU 701 also compares the second threshold with the amount of expansion and contraction of the recording medium 105 in the Y direction to determine whether the amount of expansion and contraction meets the dimensional accuracy (is within the acceptable range). The second threshold is set to an expansion and contraction tolerance value. The first threshold is a fixed value predetermined according to the head position. The second threshold may be a value predetermined for each type of recording medium 105, a value predetermined according to the recording mode, or a value arbitrarily set by the user.

[0078] Specifically, the CPU 701 obtains and sets a first threshold value from the EEPROM 704 according to the set head position. If the second threshold value is a predetermined value, the CPU 701 obtains the second threshold value stored in the EEPROM 704. If the user sets the second threshold value arbitrarily, the CPU 701 displays a user interface screen (UI screen) to accept the second threshold value.

[0079] Figure 11 shows an example of a UI screen for setting a threshold (second threshold). The UI screen is displayed on the display of the input / output unit 109 of the recording device 100 based on display instructions from the CPU 701. Alternatively, the UI screen may be displayed on the display of a host computer connected to the recording device 100. The UI screen accepts user operations via the input / output unit 109 or via the input device of the host computer. Signals indicating operations received on the UI screen are input to the CPU 701.

[0080] The UI screen 1100 shown in Figure 11(a) is displayed in the media registration function of the recording device 100 and accepts the registration and editing of the media name (name of the recording medium 105), recording mode, and stretch tolerance value (second threshold). The user can arbitrarily input the media name, recording mode, and stretch tolerance value (second threshold) on the UI screen 1100. In this example, the recording mode is set to "6-pass standard" and the number of passes in multi-pass recording is set, but the recording mode is not limited to this. The user can arbitrarily set the recording mode. Any numerical value can be entered in the stretch tolerance value field 1101.

[0081] The UI screen 1110 shown in Figure 11(b) is an example in which the UI screen 1100 in Figure 11(a) is further configured to allow selection of the stretch tolerance from multiple options displayed in the pull-down menu 1112.

[0082] Furthermore, the second threshold (stretch tolerance) may be predetermined for each type of recording medium 105 and stored in the EEPROM 704. Figure 11(c) shows a table 1120 that associates the types of recording medium 105 with the second threshold (stretch tolerance). In the table 1120 shown in Figure 11(c), for example, "tarpaulin" is associated with an absolute stretch tolerance of "0.3%". Also, "PVC sheet with release paper" is associated with an absolute stretch tolerance of "0.1%", and "PET film" is associated with an absolute stretch tolerance of "0.2%". In this case, when the type of recording medium 105 is set by the user, the CPU 701 obtains the second threshold associated with the type of recording medium 105 from the EEPROM 704 and sets it.

[0083] Furthermore, a second threshold (stretch tolerance) may be set according to the recording mode. Figure 11(d) shows an example of a UI screen 1130 for setting thresholds according to the recording mode.

[0084] The UI screen 1130 shown in Figure 11(d) is a screen that accepts the setting of the recording mode for heating control. The user can set the media name and recording mode on the UI screen 1130. In this example, the recording mode can be selected from either the productivity priority mode or the dimension priority mode from the pull-down menu 1131. In this case, as shown in the table 1140 in Figure 11(e), the second threshold (expansion tolerance) is predetermined for each recording mode and stored in the EEPROM 704.

[0085] The dimension-priority mode prioritizes dimensional accuracy and performs heat fixing at a relatively low temperature for a long period of time. On the other hand, the productivity-priority mode improves productivity by performing heat fixing at a higher temperature for a shorter period of time than the dimension-priority mode. Therefore, in the dimension-priority mode, a smaller value is set for the expansion / contraction tolerance (absolute value) compared to the productivity-priority mode. In the example in Figure 11(e), the expansion / contraction tolerance (absolute value) is set to "0.1%" in the dimension-priority mode and "0.3%" in the productivity-priority mode. Note that the types of recording modes for heating control are not limited to just two, the productivity-priority mode and the dimension-priority mode, but may be three or more. Furthermore, it may be possible to select a recording mode for each type of recording medium 105, and the expansion / contraction tolerance corresponding to the type of recording medium 105 and the recording mode may be predetermined and stored. The names of each mode are also arbitrary.

[0086] In the UI screen 1130 shown in Figure 11(d), the CPU 701 accepts the user's selection of a recording mode. When a recording mode is selected by the user on the UI screen 1130, the CPU 701 obtains and sets a second threshold associated with the recording mode from the EEPROM 704.

[0087] The CPU 701 may also accept a selection from the user regarding whether to set a threshold based on the type of recording medium 105 (media type), the recording mode, or a user-defined threshold. Figure 12 shows an example of a UI screen that allows the user to select how to set the threshold.

[0088] The UI screen 1200 shown in Figure 12(a) is an example of a screen that accepts the selection of one of the following: "Media Type," "Recording Mode," or "User Settings." Slide buttons 1201 are displayed for each of "Media Type," "Recording Mode," and "User Settings," and the color of the buttons changes when selected. In the example in Figure 12(a), "Media Type" is selected, and "Recording Mode" and "User Settings" are not selected. When "Media Type" is selected, the UI screen 1200 displays the types of selectable recording media 105, which can be selected from a pull-down menu 1202. If any of the types of recording media 105 are selected, the CPU 701 obtains the stretch tolerance value determined in association with the type of recording media 105 from the table 1120 shown in Figure 11(c) and sets it as the second threshold. In this case, the input field 1203 for the stretch tolerance value becomes uneditable.

[0089] The UI screen 1210 shown in Figure 12(b) is a screen that accepts the selection of one of the following: "Media Type," "Recording Mode," or "User Settings," and shows the state where "Recording Mode" is selected. "Media Type" and "User Settings" are not selected. When "Recording Mode" is selected, the selectable recording modes are displayed on the UI screen 1210, selectable from the pull-down menu 1212. When any recording mode is selected, the CPU 701 obtains the stretch tolerance value associated with the recording mode from the table 1140 shown in Figure 11(b) and sets it as the second threshold. In this case, the input field 1203 for the stretch tolerance value becomes uneditable.

[0090] The UI screen 1220 shown in Figure 12(c) is a screen that accepts the selection of one of the following: "Media Type," "Recording Mode," or "User Settings," and shows the state where "User Settings" is selected. "Media Type" and "Recording Mode" are not selected. When "User Settings" is selected, the CPU 701 accepts input to the input field 1103 for the stretch tolerance value. Alternatively, the CPU 701 may display a list of configurable stretch tolerance values ​​in a pull-down menu, as shown in Figure 11(b), and accept a selection. The second threshold value set by the user in this way is stored in the EEPROM 704.

[0091] Returning to the explanation of Figure 10, in S1002, the CPU 701 performs the recording operation of the measurement pattern. During the recording operation, the CPU 701 transmits control signals and data to be recorded to the recording head control circuit 711, LF motor drive circuit 712, CR motor drive circuit 714, and winding roll drive circuit 719, and controls the recording head 102, LF motor 713, CR motor 715, and winding drive motor 720.

[0092] Here, the measurement pattern will be described. Figure 13 shows an example of a measurement pattern. The measurement pattern is an image for measuring the amount of expansion and contraction of the recording medium 105 before and after heating in the Y direction, and the distance (GAP value) between the recording medium 105 and the optical sensor 201 over the entire X direction. The measurement pattern 1300 shown in Figure 13 includes a first image 1301 and a second image 1302 recorded at a predetermined distance from the first image in the Y direction. Both the first image 1301 and the second image 1302 are linear images extending in the X direction and are recorded over the entire recording area in the X direction. The first image 1301 and the second image 1302 form a pair. The first image 1301 is recorded on the upstream side in the Y direction, and the second image 1302 is recorded on the downstream side. The distance (theoretical distance) between the first image 1301 and the second image 1302 is a fixed length, which in this embodiment is, for example, 200 mm.

[0093] Note that the distance between the first image 1301 and the second image 1302 (the length between patterns) is not limited to 200 mm, but can be any length. The longer the length between patterns, the higher the accuracy of calculating the amount of expansion and contraction, but the greater the consumption of the recording medium 105. Therefore, it is preferable to set the length between patterns to an optimal length considering both the accuracy of calculating the amount of expansion and contraction and the consumption of the recording medium 105. In this embodiment, the theoretical length between patterns of the measurement pattern is set with a target calculation accuracy of 0.1% or less and an accuracy of ±0.1 mm for the edge detection function of the optical sensor 201. In this case, if the length between patterns is 200 mm, the amount of expansion and contraction can be calculated with an accuracy of 0.05%. In any case, any measurement method can be used as long as the length of the recording medium 105 in the transport direction can be measured at least at one point in the X direction.

[0094] In the measurement of the inter-pattern length described later, the length in the Y direction between the first image 1301 and the second image 1302 is measured at a predetermined position in the X direction. In other words, the distance in the Y direction between the first image 1301 and the second image 1302 measured at a predetermined position in the X direction is measured as the inter-pattern length. The measurement position is preferably the region passing through the center of the heater unit 610. This is because the position where the heater 603 within the heater unit 610 is located is the center in the X direction of each heater unit 610, and this is where the surface temperature of the recording medium 105 is most likely to be the highest. That is, the temperature of the region on the recording medium 105 passing through the center of the heater unit 610 is higher than the temperature of the region on the recording medium 105 passing through the edge of that heater unit 610.

[0095] Note that the measurement pattern 1300 is not limited to the example shown in Figure 13. For example, multiple pairs of first and second images may be intermittently recorded in each region of the recording medium 105 corresponding to the central and end portions of each of the heater units 610a, 610b, 610c, and 610d included in the fuser unit 108. In this case, when measuring the inter-pattern length, the inter-pattern lengths of each pair of first and second images may be measured to calculate the expansion / contraction amount at multiple positions, and the expansion / contraction amount with the largest absolute value among them may be determined as the expansion / contraction amount of the recording medium 105. Alternatively, pairs of first and second images may also be recorded at the ends of the recording medium 105 and used for measuring the expansion / contraction amount. In any pattern, it is sufficient that the measurement pattern 1300 can be recorded in at least the high-temperature region of the recording medium 105.

[0096] Returning to the explanation of Figure 10, in S1003, the CPU 701 measures the distance between patterns before heating using the optical sensor 201. The measurement point is the distance between the first image 1301 and the second image 1302 of the measurement pattern 1300 recorded in S1001.

[0097] In measuring the length between patterns, the optical sensor 201 emits light from the first LED 501 at a 90° angle in the Z direction, receives the reflected light from the pattern on the recording medium 105 at a 45° angle in the Z direction, and detects the diffuse reflection component. The optical sensor 201 detects the reflected light from the pattern on the recording medium 105 and outputs the detected value to the CPU 701. Based on the detected value output from the optical sensor 201, the CPU 701 detects, for example, the edge position of the image contained in the measurement pattern 1300. The position in the X direction is detected by an encoder that detects the movement position of the carriage. The position in the Y direction is determined based on the amount of rotation of the LF motor 713 detected by the LF encoder 723.

[0098] Measurement by the optical sensor 201 can be performed simultaneously with pattern recording. First, the CPU 701 transports the recording medium 105 to a predetermined starting position, and while recording the second image 1302 at that position (Y-direction position), it detects the second image 1302 using the optical sensor 201. Based on the detection value output from the optical sensor 201, the CPU 701 detects the position of the second image 1302 and stores the detected position in the RAM 703. Subsequently, the CPU 701 transports the recording medium 105 to the recording position of the first image while performing carriage movement operations and recording medium transport operations according to a preset recording mode. When the recording medium 105 is transported to the recording position of the first image 1301, the CPU 701 detects the first image 1301 using the optical sensor 201 while recording the first image 1301. Based on the detection value output from the optical sensor 201, the CPU 701 detects the position of the first image 1301 and stores the detected position in the RAM 703. The CPU 701 calculates the difference in the Y-direction positions of the first image 1301 and the second image 1302 at at least one location in the X-direction and stores it in the RAM 703 as the pattern inter-pattern length L0 before heating. Once the pattern inter-pattern length L0 before heating is measured, the process proceeds to S1004.

[0099] In S1004, the CPU 701 transports the recording medium 105 to the position of the fuser 108 and heats the area on which the measurement pattern 1300 is recorded at a predetermined temperature. After the heat treatment, the process proceeds to S1005.

[0100] In S1005, the CPU 701 measures the distance (GAP value) between the recording medium 105 and the optical sensor 201. The CPU 701 reverses the transport of the recording medium 105 so that the optical sensor 201 is positioned on the measurement pattern 1300 recorded in S1002, and measures the distance between the optical sensor 201 and the recording medium 105 while moving the carriage 101. Since the amount of reflected light from the recording medium 105 differs depending on the distance between the recording medium 105 and the optical sensor 201, the CPU 701 measures the distance between the recording medium 105 and the optical sensor 201 based on the detected value of the reflected light detected by the optical sensor 201, and sets this as the GAP value. The measurement of the GAP value may be performed on both the second image 1302 downstream of the measurement pattern 1300 and the first image 1301 upstream, or on either one of them. It may also be performed at any position in the region between the first image 1301 and the second image 1302. Measurement S1005 measures the GAP value at each position in the width direction of the recording medium 105.

[0101] In S1006, CPU701 stores the minimum value of the GAP measured in S1005 as Dmin in RAM703.

[0102] In S1007, CPU701 compares the minimum GAP value Dmin with the head friction threshold (first threshold). As mentioned above, the first threshold is predetermined for each head position. In the judgment of S1007, if the minimum GAP value Dmin is less than or equal to the first threshold, it is determined that head friction may occur, and the process proceeds to S1008.

[0103] In S1008, the CPU 701 executes a process to lower the temperature of the fuser 108. In the process of lowering the heating temperature, the CPU 701 may lower the heater's set temperature by a predetermined temperature range, or, if the heater's output can be changed in multiple stages such as strong, medium, and weak, it may lower the output intensity one stage at a time. After that, the process proceeds to S1002 in Figure 9, and processes S1002 to S1007 are performed.

[0104] If, in S1007, the minimum GAP value Dmin is determined to be greater than the head friction threshold (first threshold), then the amount of paper lift is considered acceptable, and it is determined that there is no possibility of head friction, and the process proceeds to S1009.

[0105] In S1009, the CPU 701 measures the pattern spacing Ln after heating. The CPU 701 reverses the transport of the recording medium 105 and returns it to the starting position described above. Then, while performing the same carriage and transport operations as when the first image 1301 and the second image 1302 were recorded, the optical sensor 201 detects the positions of the first image 1301 and the second image 1302. The measurement position in the X direction is the same as the measurement position for the pattern spacing L0 before heating. The detection position in the Y direction is determined based on the amount of rotation of the LF motor 713 detected by the LF encoder 723. The CPU 701 calculates the difference in the Y-direction positions of the first image 1301 and the second image 1302 at the measurement position and stores it in the RAM 703 as the pattern spacing Ln after heating.

[0106] As a result of the processes in S1003 and S1009, the pattern spacing length L0 before heat treatment and the pattern spacing length Ln after heat treatment are stored in RAM 703.

[0107] In S1010, the CPU 701 calculates the amount of expansion and contraction of the recording medium 105 before and after heating, based on the pattern inter-pattern length L0 before heating. The amount of expansion and contraction is calculated using the above formula (1).

[0108] Figure 14 is Table 1400, which shows examples of inter-pattern length and expansion / contraction after heating for different fixing temperatures. The inter-pattern length is assumed to be set to 200 mm. In the example in Figure 14, when the fixing temperature is 20°C, the inter-pattern length after heat treatment is measured to be 200.0 mm, and the expansion / contraction is 0.00%. When the fixing temperature is 80°C, the inter-pattern length after heat treatment is measured to be 199.8 mm, and the expansion / contraction is -0.10%. When the fixing temperature is 90°C, the inter-pattern length after heat treatment is measured to be 198.9 mm, and the expansion / contraction is -0.55%. The sign "-" for the expansion / contraction indicates that the recording medium 105 has shrunk after heating relative to its pre-heating state. From Table 1400, it can be seen that the higher the fixing temperature, the greater the shrinkage. In other words, by setting a lower fixing temperature, the shrinkage of the recording medium can be suppressed compared to when the fixing temperature is high.

[0109] In S1011, the CPU 701 compares the absolute value of the stretching amount calculated in S1010 with the second threshold (stretching amount threshold). If the absolute value of the stretching amount is greater than the second threshold, it is determined that the stretching amount of the recording medium 105 is large and will have an effect on image degradation, so the process proceeds to S1008. In S1008, the CPU 701 lowers the heating temperature of the fuser 108 and then performs the processing from S1002 to S1010. If the absolute value of the stretching amount is less than or equal to the second threshold, it is determined that the stretching amount is within the acceptable range and will not have an effect on image degradation, so the process proceeds to S1012.

[0110] In S1012, the CPU 701 determines the current heating temperature as the fixing temperature of the fuser 108, stores it in the EEPROM 704, and terminates this flowchart.

[0111] As described above, the recording device 100 of the first embodiment determines threshold conditions for the amount of deformation of the recording medium 105 in the thickness direction and threshold conditions for the amount of expansion and contraction of the recording medium 105 in the transport direction. If either of these threshold conditions is not met, the CPU 701 performs a process to lower the heating temperature of the fuser 108 and then performs the measurement of the inter-pattern length and the GAP value again. If both the threshold conditions for the amount of deformation of the recording medium 105 in the thickness direction and the threshold conditions for the amount of expansion and contraction in the transport direction are met, the CPU 701 determines the temperature set in the fuser 108 as the fixing temperature. In this way, head friction due to thermal deformation of the recording medium 105 can be suppressed and a fixing temperature that satisfies the dimensional accuracy of the recording medium 105 in the transport direction is determined. This is particularly suitable for fixing images to large recording media, such as those used in the sign display industry.

[0112] In the first embodiment, the CPU 701 of the recording device 100 sets the heater temperature at the start of the process shown in the flowchart to the highest temperature within the expected range (maximum temperature), and if the conditions are not met, it gradually lowers the heater temperature. This makes it possible to automatically determine the optimal fixing temperature for the target recording medium 105. On the other hand, for recording mediums 105 that are expected to undergo significant expansion and contraction or deformation, it is preferable to start from a temperature lower than the maximum temperature mentioned above. Therefore, for recording mediums 105 with a high glass transition temperature of the substrate, processing can be started from the maximum temperature mentioned above, and for recording mediums 105 with a low glass transition temperature, processing can be started from a temperature lower than the maximum temperature, thereby reducing the number of trials. The CPU 701 may also accept the heater temperature at the start of processing from the user and start processing from the accepted temperature.

[0113] Furthermore, in the heating control process described above, the CPU 701 may notify the user when changing the heating temperature. In the notification, the CPU 701 may suggest (inquire with) the user to lower the heating temperature and also notify the user of the state of the recording medium after the heating process. Specifically, for example, before the process of changing the temperature in S1008, the notification screen shown in Figure 15 is displayed on the input / output unit 109.

[0114] Figure 15 shows an example of a notification screen. Figure 15(a) shows an example of a notification screen 1510 that is displayed when either S1007 or S1011 is determined to be NO. The notification screen 1510 displays the message, "The current heating temperature may cause deformation of the printed material due to the following reasons," along with the details of the problem 1511, which are "Excessive expansion and contraction of the printed material, print head rubbing." It also displays the message 1512, "Do you want to lower the heating temperature?", and "Yes" buttons 1513 and "No" buttons 1514. The "Yes" button 1513 is selected when the user wishes to lower the heating temperature, and the "No" button 1514 is selected when the user does not wish to lower the heating temperature.

[0115] Figure 15(b) shows an example of the notification screen 1520 that is displayed when the result of S1007 is YES and S1011 is NO. The notification screen 1520 displays the message, "The current heating temperature may cause deformation of the printed material due to the following reasons," along with the description of the problem, "Excessive expansion and contraction of the printed material," 1521. It also displays the message, "Do you want to lower the heating temperature?" 1512, and "Yes" buttons 1513 and "No" buttons 1514.

[0116] Figure 15(c) shows an example of the notification screen 1530 that is displayed when NO is determined in S1007. The notification screen 1530 displays the message, "The current heating temperature may cause deformation of the printed material due to the following reasons," along with the description of the problem, "printer head rubbing" 1531. It also displays the message, "Do you want to lower the heating temperature?" 1512, and "Yes" buttons 1513 and "No" buttons 1514.

[0117] If the user selects to lower the heating temperature on the notification screen, that is, if the user selects the "Yes" button 1513 on the notification screen, the CPU 701 closes the notification screen and proceeds to the process of lowering the heating temperature of S1008. Note that notifications are not limited to displays on the notification screen; they can also be made by outputting an audio message.

[0118] If the user selects the "No" button 1514 on the notification screen, that is, if the user chooses not to lower the heating temperature, the CPU 701 closes the notification screen and proceeds to S1012.

[0119] <Second Embodiment> Next, a second embodiment of the present invention will be described. In the first embodiment, a threshold condition was set to avoid head friction as a threshold condition for the amount of deformation in the thickness direction of the recording medium 105. In the second embodiment, two threshold conditions are set for the amount of deformation in the thickness direction of the recording medium 105, and deformation exceeding an acceptable amount is suppressed by heating control of the fuser 108, while head friction is avoided by changing the head position. Note that the hardware configuration of the recording device 100 and the control system configuration of the second embodiment are the same as those of the first embodiment, so redundant explanations will be omitted.

[0120] <Functional Configuration> Figure 16 is a block diagram showing the functional configuration of the recording device of the second embodiment. The recording device 100 of the second embodiment includes a measuring unit 801, a heating control unit 803, and an adjustment control unit 1601. The adjustment control unit 1601 performs a head position adjustment process 1602 according to the state of thermal deformation of the recording medium 105. These functional units are realized by the CPU 701 of the recording device 100 executing processing according to a program described later. The program is stored in ROM 702 or EEPROM 704.

[0121] The measurement unit 801 measures the GAP value and the amount of expansion and contraction, similar to the first embodiment. As a result of the measurement, the measurement unit 801 determines the minimum value Dmin among the GAP values ​​measured at multiple locations in the X direction and outputs it to the heating control unit 803. Furthermore, in the second embodiment, the measurement unit 801 also outputs the minimum value Dmin of the GAP value to the adjustment control unit 1601. The amount of expansion and contraction is output to the heating control unit 803, similar to the first embodiment. The method for measuring the GAP value and the amount of expansion and contraction in the measurement unit 801 is the same as in the first embodiment.

[0122] In the second embodiment, the heating control unit 803 determines the state of thermal deformation of the recording medium 105 based on a comparison between at least the minimum GAP value Dmin and a first threshold. In the second embodiment, the first threshold is a threshold for determining whether the amount of deformation in the thickness direction of the recording medium 105 is within an acceptable range. In the following description, this first threshold is also referred to as the thermal deformation tolerance value. The thermal deformation tolerance value is, for example, the value at which head friction occurs, and is determined based on the positional relationship between the optical sensor 201 and the recording head 102. In the second embodiment, the value of D_sen_head, which is the distance between the lower surface 201a of the optical sensor 201 and the lower surface 102a of the recording head 102, is set as the thermal deformation tolerance value and as the first threshold. If the minimum GAP value Dmin is less than or equal to the first threshold (thermal deformation tolerance value), head friction occurs, and it is determined that the thermal deformation in the thickness direction of the recording medium 105 exceeds the acceptable range. The heating control unit 803 changes the temperature during the heating process of the fuser 108 to a lower level if the minimum value Dmin of the GAP value is less than or equal to the first threshold. In this case, the heating control unit 803 executes the fixing temperature change process 804 to lower the temperature of the heater of the fuser 108. If the minimum value Dmin of the GAP value is greater than the first threshold, it is determined that the thermal deformation in the thickness direction of the recording medium 105 is within an acceptable range.

[0123] In the second embodiment, if the minimum GAP value Dmin is greater than the first threshold (thermal deformation tolerance), the adjustment control unit 1601 compares the minimum GAP value Dmin with the third threshold. The third threshold is, for example, a threshold (head friction threshold) for determining whether the recording medium 105 may come into contact with the recording head 102. The head friction threshold can be the value of D_sen_head plus a margin, as described in the first embodiment. Therefore, the third threshold (head friction threshold) is defined as a value greater than the first threshold (thermal deformation tolerance).

[0124] If the minimum GAP value Dmin is greater than the first threshold and less than or equal to the third threshold, it is determined that the amount of deformation in the thickness direction of the recording medium 105 is within the acceptable range, but there is a possibility of head friction. In this case, without performing heating control, the adjustment control unit 1601 executes the head position adjustment process 1602 to raise the head position by one step. When the head position is raised, the lower surface 102a of the recording head 102 moves away from the recording medium 105. If the minimum GAP value Dmin is greater than the third threshold, it is determined that there is no possibility of head friction, and the adjustment control unit 1601 maintains the current head position.

[0125] The heating control unit 803 may, similar to the first embodiment, compare the amount of expansion / contraction of the recording medium in the Y direction with a second threshold and determine the state of thermal deformation of the recording medium based on the results of this comparison. That is, as described above, the heating control unit 803 changes the temperature of the fuser 108 to a lower level when the minimum value Dmin of the GAP value is less than or equal to the first threshold, or when the amount of expansion / contraction is greater than the second threshold. If the maximum value of the expansion / contraction is less than or equal to the second threshold, it is determined that the amount of expansion / contraction is within the acceptable range. If the minimum value Dmin of the GAP value is greater than the first threshold and the amount of expansion / contraction is less than or equal to the second threshold, the heating control unit 803 sets the temperature of the fuser 108 at that time as the fixing temperature.

[0126] Figure 17 is a flowchart showing the flow of the heating control process in the second embodiment. The heating control process in the second embodiment will be described below with reference to Figure 17. The program corresponding to the flowchart shown in Figure 17 is recorded in the ROM 702 or EEPROM 704 of the recording device 100, called and executed by the CPU 701.

[0127] When the recording medium 105 is loaded into the recording device 100 by the user, and an instruction to execute the fixing temperature change process is input, for example, via the UI screen displayed on the input / output unit 109, the CPU 701 starts the flowchart shown in Figure 17. At the start of the flowchart, the head position is set to the lowest position among the head positions that can be set for the type of recording medium 105 and recording mode. Also, when starting the flowchart, the fixing temperature (heater setting temperature) is set to the maximum temperature allowed for the type of recording medium 105 and recording mode being used.

[0128] In S1701, the CPU 701 sets thresholds used in the processing of this flowchart. In the second embodiment, the thresholds are set to determine the fixing temperature in which the amount of expansion and contraction of the recording medium 105 in the Y direction is kept within an acceptable range and the thermal deformation of the recording medium 105 in the thickness direction is kept within an acceptable range. That is, the CPU 701 sets a first threshold (thermal deformation tolerance) to keep the amount of deformation of the recording medium 105 in the thickness direction within an acceptable range, and a second threshold (expansion tolerance) to determine whether the dimensional accuracy in the Y direction is met. Furthermore, in the second embodiment, the CPU 701 sets a third threshold (head friction threshold) for head position adjustment. Of these thresholds, the first and third thresholds are predetermined as fixed values ​​according to the head position and stored in the EEPROM 704. The second threshold is the expansion tolerance, and as in the first embodiment, a value according to the type of recording medium 105 may be predetermined, or it may be an arbitrary value that can be set by the user, or it may be determined according to the recording mode. The method for setting the second threshold (expansion tolerance) is the same as in the first embodiment, so the explanation is omitted.

[0129] Figure 18(a) is an XZ plan view showing the positional relationship between the recording head 102, the optical sensor 201, and the platen 106. As described in the first embodiment, D_head is the distance between the surface of the recording head 102 facing the platen 106 (head bottom surface 102a) and the platen 106. D_sen is the distance between the surface of the optical sensor 201 facing the recording medium 105 (sensor bottom surface 201a) and the platen 106. D_sen_head is the distance from the sensor bottom surface 201a to the head bottom surface 102a.

[0130] Figure 18(b) is an example of a table 1800 showing the positional relationship between the recording head 102, the optical sensor 201, and the platen 106 at each head position (L, M, H). In this embodiment, the recording head 102 and the optical sensor 201 have a three-stage variable head position. Table 1800 in Figure 18(b) defines D_head, D_sen, thermal deformation tolerance, and head friction threshold corresponding to each head position. Note that the distance D_sen_head is a fixed value, for example, 1.0 mm. The thermal deformation tolerance is set as the first threshold for heating control. The head friction threshold is set as the third threshold for head position adjustment. Both the first and third thresholds are compared with the minimum value Dmin of the GAP value. The relationship between the first and third thresholds is first threshold < third threshold.

[0131] In the example in Figure 18(b), at the first position (L), D_head is defined as 2.0 mm, D_sen as 3.0 mm, the thermal deformation tolerance (first threshold) as 1.0 mm, and the head abrasion threshold (third threshold) as 1.5 mm. At the second position (M), D_head is defined as 2.4 mm, D_sen as 3.4 mm, the thermal deformation tolerance (first threshold) as 1.0 mm, and the head abrasion threshold (third threshold) as 1.9 mm. At the third position (H), D_head is defined as 3.0 mm, D_sen as 4.0 mm, the thermal deformation tolerance (first threshold) as 1.0 mm, and the head abrasion threshold (third threshold) as 2.5 mm.

[0132] Head friction occurs when Dmin ≤ D_sen_head; therefore, the head friction threshold (third threshold) can be determined by adding a predetermined margin to D_sen_head. In addition, the thermal deformation tolerance value (first threshold) set in the second embodiment is the value of D_sen_head. In other words, the first threshold is uniquely determined based on the positional relationship between the recording head 102 and the optical sensor 201. The third threshold is pre-set to be a value that is larger than the first threshold by a margin. The thermal deformation tolerance value (first threshold) and the head friction threshold (third threshold) corresponding to the head position are stored in the EEPROM 704.

[0133] Returning to the explanation of Figure 17, the processes S1702 to S1706 are the same as those in S1002 to S1006 of the first embodiment. That is, the CPU 701 records the measurement pattern 1300 onto the recording medium 105 and measures the pattern interval L0 before heating. Then, the CPU 701 transports the recording medium 105 to the position of the fuser 108 and heats the area on which the measurement pattern 1300 is recorded at a predetermined temperature (the maximum allowable temperature). After that, the CPU 701 measures the GAP value using the optical sensor 201 and stores the minimum value as Dmin in the RAM 703. Then, proceeding to S1707, the minimum value Dmin of the measured GAP value is subjected to threshold determination.

[0134] In S1707, the CPU 701 first compares the minimum GAP value Dmin with the first threshold. As mentioned above, the first threshold is the allowable thermal deformation value. In S1707, if the minimum GAP value Dmin is less than or equal to the first threshold (allowable thermal deformation value), it is determined that the amount of deformation in the thickness direction of the recording medium 105 is an unacceptable amount, and the process proceeds to S1708.

[0135] In S1708, CPU 701 performs a process to lower the heating temperature of the fuser 108. Then, it proceeds to S1702 and executes S1702 to S1707 again.

[0136] In S1707, if the minimum value Dmin of the GAP value is greater than the first threshold (thermal deformation tolerance), it is determined that the amount of deformation in the thickness direction of the recording medium 105 is within the tolerance range, and the process proceeds to S1709.

[0137] In S1709, CPU 701 compares the minimum GAP value Dmin with the third threshold. As mentioned above, the third threshold is a head friction threshold predetermined according to the head position. In S1709, if the minimum GAP value Dmin is less than or equal to the third threshold, it is determined that head friction may occur, and the process proceeds to S1710. If the minimum GAP value Dmin is greater than the third threshold, it is determined that there is no possibility of head friction, and the process proceeds to S1711.

[0138] In S1710, CPU 701 raises the head position by one step and proceeds to S1711. The head position can be changed by rotating the lift cam 117.

[0139] The processing in S1711 to S1714 is the same as the processing in S1009 to S1012 in the heating control processing of the first embodiment. That is, the CPU 701 measures the inter-pattern length Ln after heating and calculates the amount of expansion and contraction of the recording medium 105 before and after heating, using the inter-pattern length L0 before heating as a reference. The CPU 701 compares the absolute value of the expansion and contraction amount calculated in S1712 with a second threshold (expansion and contraction threshold). If the absolute value of the expansion and contraction amount is greater than the second threshold, it is determined that there is an effect of image degradation and the process proceeds to S1708. In S1708, the CPU 701 lowers the heating temperature in the fuser 108. Then S1702 to S1712 are repeated. If the absolute value of the expansion and contraction amount is less than or equal to the second threshold, it is determined that there is no effect of image degradation because it is an acceptable amount of expansion and contraction. In S1714, the CPU 701 determines the current heating temperature as the fixing temperature of the fuser 108 and stores it in the EEPROM 704, and this flowchart ends.

[0140] As described above, the recording device 100 of the second embodiment determines two threshold conditions regarding the amount of deformation in the thickness direction of the recording medium 105 and a threshold condition regarding the amount of expansion and contraction in the transport direction of the recording medium. Regarding the amount of deformation in the thickness direction of the recording medium 105, a stricter condition than the threshold for the possibility of head friction is used to determine whether there is an unacceptable amount of thermal deformation. If it is determined that there is an unacceptable amount of thermal deformation, the heating temperature is reduced. If the amount of thermal deformation is acceptable but there is a possibility of head friction, the heating temperature is not changed, and the head position is raised. In either case, if the amount of expansion and contraction in the Y direction of the recording medium 105 before and after heating exceeds the allowable value of expansion and contraction (second threshold), the heating temperature is reduced. In this way, the fixing temperature can be automatically determined to keep the amount of deformation in the thickness direction of the recording medium 105 within an acceptable range and to satisfy the dimensional accuracy in the transport direction. The head position can also be adjusted to avoid head friction. This is particularly suitable for fixing images to large recording media 105, such as those used in the sign display industry.

[0141] In the second embodiment, as in the first embodiment, the optimal fixing temperature for the target recording medium can be automatically determined by setting the heater temperature at the start of this flowchart to the highest temperature (maximum temperature) within the expected range. On the other hand, for recording media that are expected to undergo significant expansion and contraction or deformation, it is preferable to start from a temperature lower than the maximum temperature mentioned above. Therefore, for recording media with a high glass transition temperature of the substrate, processing can be started from the maximum temperature mentioned above, and for recording media with a low glass transition temperature, processing can be started from a temperature lower than the maximum temperature, thereby reducing the number of trials. The CPU 701 may also accept the heater temperature setting at the start of processing from the user and start processing from the accepted temperature setting.

[0142] Furthermore, the head position at the start of this flowchart is set to the lowest possible head position (the closest distance between the recording medium and the bottom surface of the head) among the configurable head positions according to the type of recording medium 105. This makes it possible to prevent head friction simply by adjusting the head position, without changing the heating temperature, as long as the thermal deformation in the thickness direction of the recording medium 105 is within an acceptable range.

[0143] Furthermore, in the heating control process described above, the CPU 701 may notify the user when changing the heating temperature or the head position. In the notification, the CPU 701 may suggest to the user lowering the heating temperature or raising the head position, and may also notify the user of the status of the recording medium 105. Specifically, for example, before the process of changing the temperature in S1708, the notification screen shown in Figure 15 is displayed on the input / output unit 109. Alternatively, in S1710, the CPU 701 may display a notification screen containing a message such as "Head friction may occur. Shall we raise the head position by one step?" and accept a response from the user. In this case, if the CPU 701 receives an instruction from the user to change the head position, it rotates the lift cam 117 to change the head position. Alternatively, in S1710, the CPU 701 may display a message on the notification screen containing an instruction to manually change the head position to the user. Furthermore, notifications are not limited to display on the notification screen, but can also be made by outputting an audio message.

[0144] Although the embodiments described above describe recording devices having a serial recording head, the present invention is not limited thereto. It is also applicable to inkjet recording devices equipped with a so-called line-type recording head, in which the ejection port row is configured to extend across the recording width in the transport direction of the recording medium 105. Furthermore, although an example using a continuous sheet as the recording medium was shown, the present invention is also applicable to cut sheets. In addition, although a recording device having a plurality of heater units 610 as the fuser 108 was described, the present invention is also applicable to recording devices with only one heater unit in the fuser 108. Moreover, it is not limited to recording devices used in the sign display industry, but is also applicable to recording devices used in other industries. Furthermore, it is clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the disclosed technical idea, and these are naturally understood to fall within the technical scope of the present invention.

[0145] <Other Embodiments> The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0146] The above-described embodiments include the following configurations.

[0147] (Composition 1) A recording means for recording images on a recording medium, A transport means for transporting the recording medium, Fixing means for fixing the image recorded on the recording medium by heating the recording medium, A measuring means for measuring the amount of deformation in the thickness direction of the recording medium after the heat treatment by the fixing means, A heating control means that changes the temperature in the heating process according to the measurement results from the measuring means, A recording device characterized by comprising the following features.

[0148] (Configuration 2) The measuring means is a sensor installed facing the recording medium, and the deformation amount is measured by measuring the distance between the sensor and the recording medium. The recording device according to configuration 1, characterized in that the heating control means reduces the temperature in the heating process when the distance measured by the measuring means is less than or equal to a first threshold.

[0149] (Composition 3) The measuring means further measures the amount of expansion and contraction of the recording medium in the transport direction by the transport means before and after the heat treatment by the fixing means, The recording device according to configuration 2, characterized in that the heating control means changes the temperature in the heating process when the distance measured by the measuring means is less than or equal to a first threshold, or when the amount of expansion or contraction measured by the measuring means is greater than a second threshold.

[0150] (Composition 4) The recording apparatus according to configuration 2 or 3, further comprising an adjustment means for raising the vertical position of a recording head provided opposite the recording medium when the distance is greater than the first threshold and less than or equal to a third threshold greater than the first threshold.

[0151] (Composition 5) The recording device according to any one of configurations 1 to 4, wherein the heating control means further inquires with the user whether or not to change the temperature before changing the temperature in the heating process.

[0152] (Composition 6) The recording device according to any one of configurations 1 to 5, further comprising a notification means for notifying the effect of the heat treatment on the recording medium.

[0153] (Composition 7) The recording device according to any one of configurations 1 to 6, characterized in that the recording medium is a continuous sheet that is continuous in the direction of transport by the transport means.

[0154] (Composition 8) The recording apparatus according to configuration 2 or 3, characterized in that the first threshold is a threshold for determining whether the recording medium may come into contact with the recording head.

[0155] (Composition 9) The recording device according to configuration 2 or 3, characterized in that the first threshold is a threshold for determining whether the amount of deformation is within an acceptable range.

[0156] (Composition 10) The recording device according to configuration 3, characterized in that the second threshold is a threshold for determining whether the amount of expansion or contraction is within an acceptable range.

[0157] (Composition 11) The first threshold is a threshold for determining whether the amount of deformation is within an acceptable range. The recording apparatus according to configuration 4, characterized in that the third threshold is a threshold for determining whether the recording medium may come into contact with the recording head.

[0158] (Composition 12) The recording device according to configuration 2, characterized in that the first threshold value is a value predetermined for each position in the vertical direction of the recording head.

[0159] (Composition 13) The recording device according to configuration 3, characterized in that the second threshold is determined according to the type of recording medium.

[0160] (Composition 14) The recording device according to configuration 3, characterized in that the second threshold is determined according to the recording mode.

[0161] (Composition 15) The recording device according to configuration 3, characterized in that the second threshold value is a value set by the user.

[0162] (Composition 16) The recording device according to configuration 3, further comprising display means for displaying a user interface screen for setting the second threshold.

[0163] (Composition 17) The recording device according to configuration 4, characterized in that the third threshold value is a fixed value determined based on the positional relationship between the recording head and the sensor.

[0164] (Composition 18) The measuring means measures the distance between the sensor and the recording medium at multiple locations in the width direction of the recording medium, The recording device according to any one of configurations 2, 3, 4, 8-17, characterized in that the heating control means compares the minimum value among the measured distances with the first threshold.

[0165] (Composition 19) The measuring means measures the distance and the amount of expansion and contraction using the pattern recorded on the recording medium. The recording apparatus according to configuration 3, characterized in that the pattern includes a pair of first and second images spaced a predetermined distance apart in the direction of transport of the recording medium by the transport means.

[0166] (Composition 20) The recording device according to any one of configurations 1 to 19, characterized in that the recording means records the image on the recording medium by moving a recording head, which has a plurality of ejection ports capable of ejecting ink onto the recording medium, in the width direction of the recording medium, and ejecting the ink from the ejection ports.

[0167] (Composition 21) The recording device according to any one of configurations 1 to 20, characterized in that the fixing means comprises a plurality of heaters for performing the heat treatment.

[0168] (Composition 22) A control method for a recording device that fixes an image recorded on a recording medium by performing a heat treatment on the recording medium, A step of measuring the amount of deformation in the thickness direction of the recording medium after the heat treatment, A step of changing the temperature in the heat treatment according to the measurement results, A control method characterized by including

[0169] (Composition 23) A program for causing a computer that controls a recording device to execute a control method, the computer controlling the recording device which fixes an image recorded on a recording medium by performing a heat treatment on the recording medium, The control method described above is A step of measuring the amount of deformation in the thickness direction of the recording medium after the heat treatment, A step of changing the temperature in the heat treatment according to the measurement results, A program characterized by including the following.

Claims

1. A recording means for recording images on a recording medium, A transport means for transporting the recording medium, Fixing means for fixing the image recorded on the recording medium by heating the recording medium, A measuring means for measuring the amount of deformation in the thickness direction of the recording medium after the heat treatment by the fixing means, A heating control means that changes the temperature in the heating process according to the measurement results from the measuring means, A recording device characterized by comprising the following features.

2. The measuring means is a sensor installed facing the recording medium, and the deformation amount is measured by measuring the distance between the sensor and the recording medium. The recording device according to claim 1, characterized in that the heating control means reduces the temperature in the heating process when the distance measured by the measuring means is less than or equal to a first threshold.

3. The measuring means further measures the amount of expansion and contraction of the recording medium in the transport direction by the transport means before and after the heat treatment by the fixing means, The recording device according to claim 2, characterized in that the heating control means changes the temperature in the heating process when the distance measured by the measuring means is less than or equal to a first threshold, and the amount of expansion and contraction measured by the measuring means is greater than a second threshold, in at least one of these cases.

4. The recording apparatus according to claim 2 or 3, further comprising an adjustment means for raising the position of a recording head in the vertical direction, which is provided opposite the recording medium, when the distance is greater than the first threshold and less than or equal to a third threshold greater than the first threshold.

5. The recording device according to claim 1, further characterized in that the heating control means asks the user whether or not to change the temperature before changing the temperature in the heating process.

6. The recording device according to claim 1, further comprising a notification means for notifying the effect of the heat treatment on the recording medium.

7. The recording device according to claim 1, characterized in that the recording medium is a continuous sheet that is continuous in the direction of transport by the transport means.

8. The recording apparatus according to claim 2 or 3, characterized in that the first threshold is a threshold for determining whether the recording medium may come into contact with the recording head.

9. The recording device according to claim 2 or 3, characterized in that the first threshold is a threshold for determining whether the amount of deformation is within an acceptable range.

10. The recording device according to claim 3, characterized in that the second threshold is a threshold for determining whether the amount of expansion or contraction is within an acceptable range.

11. The first threshold is a threshold for determining whether the amount of deformation is within an acceptable range. The recording apparatus according to claim 4, characterized in that the third threshold is a threshold for determining whether the recording medium may come into contact with the recording head.

12. The recording apparatus according to claim 2, characterized in that the first threshold value is a value predetermined for each position of the recording head in the vertical direction.

13. The recording device according to claim 3, characterized in that the second threshold is determined according to the type of recording medium.

14. The recording device according to claim 3, characterized in that the second threshold is determined according to the recording mode.

15. The recording device according to claim 3, characterized in that the second threshold value is a value set by the user.

16. The recording device according to claim 3, further comprising a display means for displaying a user interface screen for setting the second threshold.

17. The recording device according to claim 4, characterized in that the third threshold value is a fixed value determined based on the positional relationship between the recording head and the sensor.

18. The measuring means measures the distance between the sensor and the recording medium at multiple locations in the width direction of the recording medium, The recording device according to claim 2 or 3, characterized in that the heating control means compares the minimum value among the measured distances with the first threshold value.

19. The measuring means measures the distance and the amount of expansion and contraction using the pattern recorded on the recording medium. The recording apparatus according to claim 3, characterized in that the pattern includes a pair of first and second images spaced a predetermined distance apart in the direction of transport of the recording medium by the transport means.

20. The recording device according to claim 1, wherein the recording means records the image on the recording medium by moving a recording head, which has a plurality of ejection ports capable of ejecting ink onto the recording medium, in the width direction of the recording medium, and ejecting the ink from the ejection ports.

21. The recording device according to claim 1, characterized in that the fixing means comprises a plurality of heaters for performing the heat treatment.

22. A control method for a recording device that fixes an image recorded on a recording medium by performing a heat treatment on the recording medium, A step of measuring the amount of deformation in the thickness direction of the recording medium after the heat treatment, A step of changing the temperature in the heat treatment according to the measurement results, A control method characterized by including

23. A program for causing a computer that controls a recording device to execute a control method, the computer controlling the recording device which fixes an image recorded on a recording medium by performing a heat treatment on the recording medium, The control method described above is A step of measuring the amount of deformation in the thickness direction of the recording medium after the heat treatment, A step of changing the temperature in the heat treatment according to the measurement results, A program characterized by including the following.

Images